Localhost working - is this the best way to do it?

Fix Github CICD Action and add Improvements

.env.example

@@ -0,0 +1,5 @@
+# Copy this file to .env and fill in your values
+# Required for connecting to Pangolin service
+PANGOLIN_ENDPOINT=https://example.com
+NEWT_ID=changeme-id
+NEWT_SECRET=changeme-secret

.github/workflows/cicd.yml

@@ -1,64 +1,601 @@
 name: CI/CD Pipeline
 
 permissions:
-  contents: read
+  contents: write          # gh-release
+  packages: write          # GHCR push
+  id-token: write          # Keyless-Signatures & Attestations
+  attestations: write      # actions/attest-build-provenance
+  security-events: write   # upload-sarif
+  actions: read
 
 on:
-    push:
-        tags:
-            - "*"
+  push:
+    tags:
+      - "*"
+  workflow_dispatch:
+    inputs:
+      version:
+        description: "SemVer version to release (e.g., 1.2.3, no leading 'v')"
+        required: true
+        type: string
+      publish_latest:
+        description: "Also publish the 'latest' image tag"
+        required: true
+        type: boolean
+        default: false
+      publish_minor:
+        description: "Also publish the 'major.minor' image tag (e.g., 1.2)"
+        required: true
+        type: boolean
+        default: false
+      target_branch:
+        description: "Branch to tag"
+        required: false
+        default: "main"
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event_name == 'workflow_dispatch' && github.event.inputs.version || github.ref_name }}
+  cancel-in-progress: true
 
 jobs:
-    release:
-        name: Build and Release
-        runs-on: ubuntu-latest
+  prepare:
+    if: github.event_name == 'workflow_dispatch'
+    name: Prepare release (create tag)
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: write
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          fetch-depth: 0
 
-        steps:
-            - name: Checkout code
-              uses: actions/checkout@v5
+      - name: Validate version input
+        shell: bash
+        env:
+          INPUT_VERSION: ${{ inputs.version }}
+        run: |
+          set -euo pipefail
+          if ! [[ "$INPUT_VERSION" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-rc\.[0-9]+)?$ ]]; then
+            echo "Invalid version: $INPUT_VERSION (expected X.Y.Z or X.Y.Z-rc.N)" >&2
+            exit 1
+          fi
+      - name: Create and push tag
+        shell: bash
+        env:
+          TARGET_BRANCH: ${{ inputs.target_branch }}
+          VERSION: ${{ inputs.version }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          git config user.name  "github-actions[bot]"
+          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
+          git fetch --prune origin
+          git checkout "$TARGET_BRANCH"
+          git pull --ff-only origin "$TARGET_BRANCH"
+          if git rev-parse -q --verify "refs/tags/$VERSION" >/dev/null; then
+            echo "Tag $VERSION already exists" >&2
+            exit 1
+          fi
+          git tag -a "$VERSION" -m "Release $VERSION"
+          git push origin "refs/tags/$VERSION"
+  release:
+    if: ${{ github.event_name == 'workflow_dispatch' || (github.event_name == 'push' && github.actor != 'github-actions[bot]') }}
+    name: Build and Release
+    runs-on: ubuntu-24.04
+    timeout-minutes: 120
+    env:
+      DOCKERHUB_IMAGE: docker.io/${{ vars.DOCKER_HUB_USERNAME }}/${{ github.event.repository.name }}
+      GHCR_IMAGE: ghcr.io/${{ github.repository_owner }}/${{ github.event.repository.name }}
 
-            - name: Set up QEMU
-              uses: docker/setup-qemu-action@v3
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          fetch-depth: 0
 
-            - name: Set up Docker Buildx
-              uses: docker/setup-buildx-action@v3
+      - name: Capture created timestamp
+        run: echo "IMAGE_CREATED=$(date -u +%Y-%m-%dT%H:%M:%SZ)" >> $GITHUB_ENV
+        shell: bash
 
-            - name: Log in to Docker Hub
-              uses: docker/login-action@v3
-              with:
-                  username: ${{ secrets.DOCKER_HUB_USERNAME }}
-                  password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@29109295f81e9208d7d86ff1c6c12d2833863392 # v3.6.0
 
-            - name: Extract tag name
-              id: get-tag
-              run: echo "TAG=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1
 
-            - name: Install Go
-              uses: actions/setup-go@v6
-              with:
-                  go-version: 1.25
+      - name: Log in to Docker Hub
+        uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef # v3.6.0
+        with:
+          registry: docker.io
+          username: ${{ vars.DOCKER_HUB_USERNAME }}
+          password: ${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}
 
-            - name: Update version in main.go
-              run: |
-                  TAG=${{ env.TAG }}
-                  if [ -f main.go ]; then
-                    sed -i 's/version_replaceme/'"$TAG"'/' main.go
-                    echo "Updated main.go with version $TAG"
-                  else
-                    echo "main.go not found"
-                  fi
+      - name: Log in to GHCR
+        uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef # v3.6.0
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
 
-            - name: Build and push Docker images
-              run: |
-                  TAG=${{ env.TAG }}
-                  make docker-build-release tag=$TAG
+      - name: Normalize image names to lowercase
+        run: |
+          set -euo pipefail
+          echo "GHCR_IMAGE=${GHCR_IMAGE,,}" >> "$GITHUB_ENV"
+          echo "DOCKERHUB_IMAGE=${DOCKERHUB_IMAGE,,}" >> "$GITHUB_ENV"
+        shell: bash
 
-            - name: Build binaries
-              run: |
-                  make go-build-release
+      - name: Extract tag name
+        env:
+          EVENT_NAME: ${{ github.event_name }}
+          INPUT_VERSION: ${{ inputs.version }}
+        run: |
+          if [ "$EVENT_NAME" = "workflow_dispatch" ]; then
+            echo "TAG=${INPUT_VERSION}" >> $GITHUB_ENV
+          else
+            echo "TAG=${{ github.ref_name }}" >> $GITHUB_ENV
+          fi
+        shell: bash
 
-            - name: Upload artifacts from /bin
-              uses: actions/upload-artifact@v4
-              with:
-                  name: binaries
-                  path: bin/
+      - name: Validate pushed tag format (no leading 'v')
+        if: ${{ github.event_name == 'push' }}
+        shell: bash
+        env:
+          TAG_GOT: ${{ env.TAG }}
+        run: |
+          set -euo pipefail
+          if [[ "$TAG_GOT" =~ ^[0-9]+\.[0-9]+\.[0-9]+(-rc\.[0-9]+)?$ ]]; then
+            echo "Tag OK: $TAG_GOT"
+            exit 0
+          fi
+          echo "ERROR: Tag '$TAG_GOT' is not allowed. Use 'X.Y.Z' or 'X.Y.Z-rc.N' (no leading 'v')." >&2
+          exit 1
+      - name: Wait for tag to be visible (dispatch only)
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        run: |
+          set -euo pipefail
+          for i in {1..90}; do
+            if git ls-remote --tags origin "refs/tags/${TAG}" | grep -qE "refs/tags/${TAG}$"; then
+              echo "Tag ${TAG} is visible on origin"; exit 0
+            fi
+            echo "Tag not yet visible, retrying... ($i/90)"
+            sleep 2
+          done
+          echo "Tag ${TAG} not visible after waiting"; exit 1
+        shell: bash
+
+      - name: Ensure repository is at the tagged commit (dispatch only)
+        if: ${{ github.event_name == 'workflow_dispatch' }}
+        run: |
+          set -euo pipefail
+          git fetch --tags --force
+          git checkout "refs/tags/${TAG}"
+          echo "Checked out $(git rev-parse --short HEAD) for tag ${TAG}"
+        shell: bash
+
+      - name: Detect release candidate (rc)
+        run: |
+          set -euo pipefail
+          if [[ "${TAG}" =~ ^[0-9]+\.[0-9]+\.[0-9]+-rc\.[0-9]+$ ]]; then
+            echo "IS_RC=true" >> $GITHUB_ENV
+          else
+            echo "IS_RC=false" >> $GITHUB_ENV
+          fi
+        shell: bash
+
+      - name: Install Go
+        uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
+        with:
+          go-version-file: go.mod
+
+      - name: Resolve publish-latest flag
+        env:
+          EVENT_NAME: ${{ github.event_name }}
+          PL_INPUT: ${{ inputs.publish_latest }}
+          PL_VAR: ${{ vars.PUBLISH_LATEST }}
+        run: |
+          set -euo pipefail
+          val="false"
+          if [ "$EVENT_NAME" = "workflow_dispatch" ]; then
+            if [ "${PL_INPUT}" = "true" ]; then val="true"; fi
+          else
+            if [ "${PL_VAR}" = "true" ]; then val="true"; fi
+          fi
+          echo "PUBLISH_LATEST=$val" >> $GITHUB_ENV
+        shell: bash
+
+      - name: Resolve publish-minor flag
+        env:
+          EVENT_NAME: ${{ github.event_name }}
+          PM_INPUT: ${{ inputs.publish_minor }}
+          PM_VAR: ${{ vars.PUBLISH_MINOR }}
+        run: |
+          set -euo pipefail
+          val="false"
+          if [ "$EVENT_NAME" = "workflow_dispatch" ]; then
+            if [ "${PM_INPUT}" = "true" ]; then val="true"; fi
+          else
+            if [ "${PM_VAR}" = "true" ]; then val="true"; fi
+          fi
+          echo "PUBLISH_MINOR=$val" >> $GITHUB_ENV
+        shell: bash
+
+      - name: Cache Go modules
+        if: ${{ hashFiles('**/go.sum') != '' }}
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        with:
+          path: |
+            ~/.cache/go-build
+            ~/go/pkg/mod
+          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
+          restore-keys: |
+            ${{ runner.os }}-go-
+      - name: Go vet & test
+        if: ${{ hashFiles('**/go.mod') != '' }}
+        run: |
+          go version
+          go vet ./...
+          go test ./... -race -covermode=atomic
+        shell: bash
+
+      - name: Resolve license fallback
+        run: echo "IMAGE_LICENSE=${{ github.event.repository.license.spdx_id || 'NOASSERTION' }}" >> $GITHUB_ENV
+        shell: bash
+
+      - name: Resolve registries list (GHCR always, Docker Hub only if creds)
+        shell: bash
+        run: |
+          set -euo pipefail
+          images="${GHCR_IMAGE}"
+          if [ -n "${{ secrets.DOCKER_HUB_ACCESS_TOKEN }}" ] && [ -n "${{ vars.DOCKER_HUB_USERNAME }}" ]; then
+            images="${images}\n${DOCKERHUB_IMAGE}"
+          fi
+          {
+            echo 'IMAGE_LIST<<EOF'
+            echo -e "$images"
+            echo 'EOF'
+          } >> "$GITHUB_ENV"
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@c1e51972afc2121e065aed6d45c65596fe445f3f # v5.8.0
+        with:
+          images: ${{ env.IMAGE_LIST }}
+          tags: |
+            type=semver,pattern={{version}},value=${{ env.TAG }}
+            type=semver,pattern={{major}}.{{minor}},value=${{ env.TAG }},enable=${{ env.PUBLISH_MINOR == 'true' && env.IS_RC != 'true' }}
+            type=raw,value=latest,enable=${{ env.PUBLISH_LATEST == 'true' && env.IS_RC != 'true' }}
+          flavor: |
+            latest=false
+          labels: |
+            org.opencontainers.image.title=${{ github.event.repository.name }}
+            org.opencontainers.image.version=${{ env.TAG }}
+            org.opencontainers.image.revision=${{ github.sha }}
+            org.opencontainers.image.source=${{ github.event.repository.html_url }}
+            org.opencontainers.image.url=${{ github.event.repository.html_url }}
+            org.opencontainers.image.documentation=${{ github.event.repository.html_url }}
+            org.opencontainers.image.description=${{ github.event.repository.description }}
+            org.opencontainers.image.licenses=${{ env.IMAGE_LICENSE }}
+            org.opencontainers.image.created=${{ env.IMAGE_CREATED }}
+            org.opencontainers.image.ref.name=${{ env.TAG }}
+            org.opencontainers.image.authors=${{ github.repository_owner }}
+      - name: Echo build config (non-secret)
+        shell: bash
+        env:
+          IMAGE_TITLE:        ${{ github.event.repository.name }}
+          IMAGE_VERSION:      ${{ env.TAG }}
+          IMAGE_REVISION:     ${{ github.sha }}
+          IMAGE_SOURCE_URL:   ${{ github.event.repository.html_url }}
+          IMAGE_URL:          ${{ github.event.repository.html_url }}
+          IMAGE_DESCRIPTION:  ${{ github.event.repository.description }}
+          IMAGE_LICENSE:      ${{ env.IMAGE_LICENSE }}
+          DOCKERHUB_IMAGE:    ${{ env.DOCKERHUB_IMAGE }}
+          GHCR_IMAGE:         ${{ env.GHCR_IMAGE }}
+          DOCKER_HUB_USER:    ${{ vars.DOCKER_HUB_USERNAME }}
+          REPO:               ${{ github.repository }}
+          OWNER:              ${{ github.repository_owner }}
+          WORKFLOW_REF:       ${{ github.workflow_ref }}
+          REF:                ${{ github.ref }}
+          REF_NAME:           ${{ github.ref_name }}
+          RUN_URL:            https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}
+        run: |
+          set -euo pipefail
+          echo "=== OCI Label Values ==="
+          echo "org.opencontainers.image.title=${IMAGE_TITLE}"
+          echo "org.opencontainers.image.version=${IMAGE_VERSION}"
+          echo "org.opencontainers.image.revision=${IMAGE_REVISION}"
+          echo "org.opencontainers.image.source=${IMAGE_SOURCE_URL}"
+          echo "org.opencontainers.image.url=${IMAGE_URL}"
+          echo "org.opencontainers.image.description=${IMAGE_DESCRIPTION}"
+          echo "org.opencontainers.image.licenses=${IMAGE_LICENSE}"
+          echo
+          echo "=== Images ==="
+          echo "DOCKERHUB_IMAGE=${DOCKERHUB_IMAGE}"
+          echo "GHCR_IMAGE=${GHCR_IMAGE}"
+          echo "DOCKER_HUB_USERNAME=${DOCKER_HUB_USER}"
+          echo
+          echo "=== GitHub Kontext ==="
+          echo "repository=${REPO}"
+          echo "owner=${OWNER}"
+          echo "workflow_ref=${WORKFLOW_REF}"
+          echo "ref=${REF}"
+          echo "ref_name=${REF_NAME}"
+          echo "run_url=${RUN_URL}"
+          echo
+          echo "=== docker/metadata-action outputs (Tags/Labels), raw ==="
+          echo "::group::tags"
+          echo "${{ steps.meta.outputs.tags }}"
+          echo "::endgroup::"
+          echo "::group::labels"
+          echo "${{ steps.meta.outputs.labels }}"
+          echo "::endgroup::"
+      - name: Build and push (Docker Hub + GHCR)
+        id: build
+        uses: docker/build-push-action@263435318d21b8e681c14492fe198d362a7d2c83 # v6.18.0
+        with:
+          context: .
+          push: true
+          platforms: linux/amd64,linux/arm64
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+          cache-from: type=gha,scope=${{ github.repository }}
+          cache-to: type=gha,mode=max,scope=${{ github.repository }}
+          provenance: mode=max
+          sbom: true
+
+      - name: Compute image digest refs
+        run: |
+          echo "DIGEST=${{ steps.build.outputs.digest }}" >> $GITHUB_ENV
+          echo "GHCR_REF=$GHCR_IMAGE@${{ steps.build.outputs.digest }}" >> $GITHUB_ENV
+          echo "DH_REF=$DOCKERHUB_IMAGE@${{ steps.build.outputs.digest }}" >> $GITHUB_ENV
+          echo "Built digest: ${{ steps.build.outputs.digest }}"
+        shell: bash
+
+      - name: Attest build provenance (GHCR)
+        id: attest-ghcr
+        uses: actions/attest-build-provenance@977bb373ede98d70efdf65b84cb5f73e068dcc2a # v3.0.0
+        with:
+          subject-name: ${{ env.GHCR_IMAGE }}
+          subject-digest: ${{ steps.build.outputs.digest }}
+          push-to-registry: true
+          show-summary: true
+
+      - name: Attest build provenance (Docker Hub)
+        continue-on-error: true
+        id: attest-dh
+        uses: actions/attest-build-provenance@977bb373ede98d70efdf65b84cb5f73e068dcc2a # v3.0.0
+        with:
+          subject-name: index.docker.io/${{ vars.DOCKER_HUB_USERNAME }}/${{ github.event.repository.name }}
+          subject-digest: ${{ steps.build.outputs.digest }}
+          push-to-registry: true
+          show-summary: true
+
+      - name: Install cosign
+        uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad # v4.0.0
+        with:
+          cosign-release: 'v3.0.2'
+
+      - name: Sanity check cosign private key
+        env:
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD:    ${{ secrets.COSIGN_PASSWORD }}
+        run: |
+          set -euo pipefail
+          cosign public-key --key env://COSIGN_PRIVATE_KEY >/dev/null
+        shell: bash
+
+      - name: Sign GHCR image (digest) with key (recursive)
+        env:
+          COSIGN_YES: "true"
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD:    ${{ secrets.COSIGN_PASSWORD }}
+        run: |
+          set -euo pipefail
+          echo "Signing ${GHCR_REF} (digest) recursively with provided key"
+          cosign sign --key env://COSIGN_PRIVATE_KEY --recursive "${GHCR_REF}"
+        shell: bash
+
+      - name: Generate SBOM (SPDX JSON)
+        uses: aquasecurity/trivy-action@b6643a29fecd7f34b3597bc6acb0a98b03d33ff8 # v0.33.1
+        with:
+          image-ref: ${{ env.GHCR_IMAGE }}@${{ steps.build.outputs.digest }}
+          format: spdx-json
+          output: sbom.spdx.json
+
+      - name: Validate SBOM JSON
+        run: jq -e . sbom.spdx.json >/dev/null
+        shell: bash
+
+      - name: Minify SBOM JSON (optional hardening)
+        run: jq -c . sbom.spdx.json > sbom.min.json && mv sbom.min.json sbom.spdx.json
+        shell: bash
+
+      - name: Create SBOM attestation (GHCR, private key)
+        env:
+          COSIGN_YES: "true"
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD:    ${{ secrets.COSIGN_PASSWORD }}
+        run: |
+          set -euo pipefail
+          cosign attest \
+            --key env://COSIGN_PRIVATE_KEY \
+            --type spdxjson \
+            --predicate sbom.spdx.json \
+            "${GHCR_REF}"
+        shell: bash
+
+      - name: Create SBOM attestation (Docker Hub, private key)
+        continue-on-error: true
+        env:
+          COSIGN_YES: "true"
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD:    ${{ secrets.COSIGN_PASSWORD }}
+          COSIGN_DOCKER_MEDIA_TYPES: "1"
+        run: |
+          set -euo pipefail
+          cosign attest \
+            --key env://COSIGN_PRIVATE_KEY \
+            --type spdxjson \
+            --predicate sbom.spdx.json \
+            "${DH_REF}"
+        shell: bash
+
+      - name: Keyless sign & verify GHCR digest (OIDC)
+        env:
+          COSIGN_YES: "true"
+          WORKFLOW_REF: ${{ github.workflow_ref }}  # owner/repo/.github/workflows/<file>@refs/tags/<tag>
+          ISSUER: https://token.actions.githubusercontent.com
+        run: |
+          set -euo pipefail
+          echo "Keyless signing ${GHCR_REF}"
+          cosign sign --rekor-url https://rekor.sigstore.dev --recursive "${GHCR_REF}"
+          echo "Verify keyless (OIDC) signature policy on ${GHCR_REF}"
+          cosign verify \
+            --certificate-oidc-issuer "${ISSUER}" \
+            --certificate-identity "https://github.com/${WORKFLOW_REF}" \
+            "${GHCR_REF}" -o text
+        shell: bash
+
+      - name: Sign Docker Hub image (digest) with key (recursive)
+        continue-on-error: true
+        env:
+          COSIGN_YES: "true"
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD:    ${{ secrets.COSIGN_PASSWORD }}
+          COSIGN_DOCKER_MEDIA_TYPES: "1"
+        run: |
+          set -euo pipefail
+          echo "Signing ${DH_REF} (digest) recursively with provided key (Docker media types fallback)"
+          cosign sign --key env://COSIGN_PRIVATE_KEY --recursive "${DH_REF}"
+        shell: bash
+
+      - name: Keyless sign & verify Docker Hub digest (OIDC)
+        continue-on-error: true
+        env:
+          COSIGN_YES: "true"
+          ISSUER: https://token.actions.githubusercontent.com
+          COSIGN_DOCKER_MEDIA_TYPES: "1"
+        run: |
+          set -euo pipefail
+          echo "Keyless signing ${DH_REF} (force public-good Rekor)"
+          cosign sign --rekor-url https://rekor.sigstore.dev --recursive "${DH_REF}"
+          echo "Keyless verify via Rekor (strict identity)"
+          if ! cosign verify \
+            --rekor-url https://rekor.sigstore.dev \
+            --certificate-oidc-issuer "${ISSUER}" \
+            --certificate-identity "https://github.com/${{ github.workflow_ref }}" \
+            "${DH_REF}" -o text; then
+            echo "Rekor verify failed — retry offline bundle verify (no Rekor)"
+            if ! cosign verify \
+              --offline \
+              --certificate-oidc-issuer "${ISSUER}" \
+              --certificate-identity "https://github.com/${{ github.workflow_ref }}" \
+              "${DH_REF}" -o text; then
+              echo "Offline bundle verify failed — ignore tlog (TEMP for debugging)"
+              cosign verify \
+                --insecure-ignore-tlog=true \
+                --certificate-oidc-issuer "${ISSUER}" \
+                --certificate-identity "https://github.com/${{ github.workflow_ref }}" \
+                "${DH_REF}" -o text || true
+            fi
+          fi
+      - name: Verify signature (public key) GHCR digest + tag
+        env:
+          COSIGN_PUBLIC_KEY: ${{ secrets.COSIGN_PUBLIC_KEY }}
+        run: |
+          set -euo pipefail
+          TAG_VAR="${TAG}"
+          echo "Verifying (digest) ${GHCR_REF}"
+          cosign verify --key env://COSIGN_PUBLIC_KEY "$GHCR_REF" -o text
+          echo "Verifying (tag) $GHCR_IMAGE:$TAG_VAR"
+          cosign verify --key env://COSIGN_PUBLIC_KEY "$GHCR_IMAGE:$TAG_VAR" -o text
+        shell: bash
+
+      - name: Verify SBOM attestation (GHCR)
+        env:
+          COSIGN_PUBLIC_KEY: ${{ secrets.COSIGN_PUBLIC_KEY }}
+        run: cosign verify-attestation --key env://COSIGN_PUBLIC_KEY --type spdxjson "$GHCR_REF" -o text
+        shell: bash
+
+      - name: Verify SLSA provenance (GHCR)
+        env:
+          ISSUER: https://token.actions.githubusercontent.com
+          WFREF: ${{ github.workflow_ref }}
+        run: |
+          set -euo pipefail
+          # (optional) show which predicate types are present to aid debugging
+          cosign download attestation "$GHCR_REF" \
+            | jq -r '.payload | @base64d | fromjson | .predicateType' | sort -u || true
+          # Verify the SLSA v1 provenance attestation (predicate URL)
+          cosign verify-attestation \
+            --type 'https://slsa.dev/provenance/v1' \
+            --certificate-oidc-issuer "$ISSUER" \
+            --certificate-identity "https://github.com/${WFREF}" \
+            --rekor-url https://rekor.sigstore.dev \
+            "$GHCR_REF" -o text
+        shell: bash
+
+      - name: Verify signature (public key) Docker Hub digest
+        continue-on-error: true
+        env:
+          COSIGN_PUBLIC_KEY: ${{ secrets.COSIGN_PUBLIC_KEY }}
+          COSIGN_DOCKER_MEDIA_TYPES: "1"
+        run: |
+          set -euo pipefail
+          echo "Verifying (digest) ${DH_REF} with Docker media types"
+          cosign verify --key env://COSIGN_PUBLIC_KEY "${DH_REF}" -o text
+        shell: bash
+
+      - name: Verify signature (public key) Docker Hub tag
+        continue-on-error: true
+        env:
+          COSIGN_PUBLIC_KEY: ${{ secrets.COSIGN_PUBLIC_KEY }}
+          COSIGN_DOCKER_MEDIA_TYPES: "1"
+        run: |
+          set -euo pipefail
+          echo "Verifying (tag) $DOCKERHUB_IMAGE:$TAG with Docker media types"
+          cosign verify --key env://COSIGN_PUBLIC_KEY "$DOCKERHUB_IMAGE:$TAG" -o text
+        shell: bash
+
+      - name: Trivy scan (GHCR image)
+        id: trivy
+        uses: aquasecurity/trivy-action@b6643a29fecd7f34b3597bc6acb0a98b03d33ff8 # v0.33.1
+        with:
+          image-ref: ${{ env.GHCR_IMAGE }}@${{ steps.build.outputs.digest }}
+          format: sarif
+          output: trivy-ghcr.sarif
+          ignore-unfixed: true
+          vuln-type: os,library
+          severity: CRITICAL,HIGH
+          exit-code: ${{ (vars.TRIVY_FAIL || '0') }}
+
+      - name: Upload SARIF
+        if: ${{ always() && hashFiles('trivy-ghcr.sarif') != '' }}
+        uses: github/codeql-action/upload-sarif@4e94bd11f71e507f7f87df81788dff88d1dacbfb # v4.31.0
+        with:
+          sarif_file: trivy-ghcr.sarif
+          category: Image Vulnerability Scan
+
+      - name: Build binaries
+        env:
+          CGO_ENABLED: "0"
+          GOFLAGS: "-trimpath"
+        run: |
+          set -euo pipefail
+          TAG_VAR="${TAG}"
+          make go-build-release tag=$TAG_VAR
+        shell: bash
+
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@6da8fa9354ddfdc4aeace5fc48d7f679b5214090 # v2.4.1
+        with:
+          tag_name: ${{ env.TAG }}
+          generate_release_notes: true
+          prerelease: ${{ env.IS_RC == 'true' }}
+          files: |
+            bin/*
+          fail_on_unmatched_files: true
+          body: |
+            ## Container Images
+            - GHCR: `${{ env.GHCR_REF }}`
+            - Docker Hub: `${{ env.DH_REF || 'N/A' }}`
+            **Digest:** `${{ steps.build.outputs.digest }}`

.github/workflows/mirror.yaml

@@ -0,0 +1,132 @@
+name: Mirror & Sign (Docker Hub to GHCR)
+
+on:
+  workflow_dispatch: {}
+
+permissions:
+  contents: read
+  packages: write
+  id-token: write   # for keyless OIDC
+
+env:
+  SOURCE_IMAGE: docker.io/fosrl/newt
+  DEST_IMAGE: ghcr.io/${{ github.repository_owner }}/${{ github.event.repository.name }}
+
+jobs:
+  mirror-and-dual-sign:
+    runs-on: amd64-runner
+    steps:
+      - name: Install skopeo + jq
+        run: |
+          sudo apt-get update -y
+          sudo apt-get install -y skopeo jq
+          skopeo --version
+
+      - name: Install cosign
+        uses: sigstore/cosign-installer@faadad0cce49287aee09b3a48701e75088a2c6ad # v4.0.0
+
+      - name: Input check
+        run: |
+          test -n "${SOURCE_IMAGE}" || (echo "SOURCE_IMAGE is empty" && exit 1)
+          echo "Source : ${SOURCE_IMAGE}"
+          echo "Target : ${DEST_IMAGE}"
+
+      # Auth for skopeo (containers-auth)
+      - name: Skopeo login to GHCR
+        run: |
+          skopeo login ghcr.io -u "${{ github.actor }}" -p "${{ secrets.GITHUB_TOKEN }}"
+
+      # Auth for cosign (docker-config)
+      - name: Docker login to GHCR (for cosign)
+        run: |
+          echo "${{ secrets.GITHUB_TOKEN }}" | docker login ghcr.io -u "${{ github.actor }}" --password-stdin
+
+      - name: List source tags
+        run: |
+          set -euo pipefail
+          skopeo list-tags --retry-times 3 docker://"${SOURCE_IMAGE}" \
+            | jq -r '.Tags[]' | sort -u > src-tags.txt
+          echo "Found source tags: $(wc -l < src-tags.txt)"
+          head -n 20 src-tags.txt || true
+
+      - name: List destination tags (skip existing)
+        run: |
+          set -euo pipefail
+          if skopeo list-tags --retry-times 3 docker://"${DEST_IMAGE}" >/tmp/dst.json 2>/dev/null; then
+            jq -r '.Tags[]' /tmp/dst.json | sort -u > dst-tags.txt
+          else
+            : > dst-tags.txt
+          fi
+          echo "Existing destination tags: $(wc -l < dst-tags.txt)"
+
+      - name: Mirror, dual-sign, and verify
+        env:
+          # keyless
+          COSIGN_YES: "true"
+          # key-based
+          COSIGN_PRIVATE_KEY: ${{ secrets.COSIGN_PRIVATE_KEY }}
+          COSIGN_PASSWORD:    ${{ secrets.COSIGN_PASSWORD }}
+          # verify
+          COSIGN_PUBLIC_KEY:  ${{ secrets.COSIGN_PUBLIC_KEY }}
+        run: |
+          set -euo pipefail
+          copied=0; skipped=0; v_ok=0; errs=0
+
+          issuer="https://token.actions.githubusercontent.com"
+          id_regex="^https://github.com/${{ github.repository }}/.+"
+
+          while read -r tag; do
+            [ -z "$tag" ] && continue
+
+            if grep -Fxq "$tag" dst-tags.txt; then
+              echo "::notice ::Skip (exists) ${DEST_IMAGE}:${tag}"
+              skipped=$((skipped+1))
+              continue
+            fi
+
+            echo "==> Copy ${SOURCE_IMAGE}:${tag} → ${DEST_IMAGE}:${tag}"
+            if ! skopeo copy --all --retry-times 3 \
+                 docker://"${SOURCE_IMAGE}:${tag}" docker://"${DEST_IMAGE}:${tag}"; then
+              echo "::warning title=Copy failed::${SOURCE_IMAGE}:${tag}"
+              errs=$((errs+1)); continue
+            fi
+            copied=$((copied+1))
+
+            digest="$(skopeo inspect --retry-times 3 docker://"${DEST_IMAGE}:${tag}" | jq -r '.Digest')"
+            ref="${DEST_IMAGE}@${digest}"
+
+            echo "==> cosign sign (keyless) --recursive ${ref}"
+            if ! cosign sign --recursive "${ref}"; then
+              echo "::warning title=Keyless sign failed::${ref}"
+              errs=$((errs+1))
+            fi
+
+            echo "==> cosign sign (key) --recursive ${ref}"
+            if ! cosign sign --key env://COSIGN_PRIVATE_KEY --recursive "${ref}"; then
+              echo "::warning title=Key sign failed::${ref}"
+              errs=$((errs+1))
+            fi
+
+            echo "==> cosign verify (public key) ${ref}"
+            if ! cosign verify --key env://COSIGN_PUBLIC_KEY "${ref}" -o text; then
+              echo "::warning title=Verify(pubkey) failed::${ref}"
+              errs=$((errs+1))
+            fi
+
+            echo "==> cosign verify (keyless policy) ${ref}"
+            if ! cosign verify \
+                 --certificate-oidc-issuer "${issuer}" \
+                 --certificate-identity-regexp "${id_regex}" \
+                 "${ref}" -o text; then
+              echo "::warning title=Verify(keyless) failed::${ref}"
+              errs=$((errs+1))
+            else
+              v_ok=$((v_ok+1))
+            fi
+          done < src-tags.txt
+
+          echo "---- Summary ----"
+          echo "Copied        : $copied"
+          echo "Skipped       : $skipped"
+          echo "Verified OK   : $v_ok"
+          echo "Errors        : $errs"

.github/workflows/test.yml

@@ -11,13 +11,13 @@ on:
 
 jobs:
   test:
-    runs-on: ubuntu-latest
+    runs-on: amd64-runner
 
     steps:
-      - uses: actions/checkout@v5
+      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
         with:
           go-version: 1.25
 

.gitignore

@@ -6,3 +6,4 @@ nohup.out
 *.iml
 certs/
 newt_arm64
+key

CONTRIBUTING.md

@@ -4,11 +4,7 @@ Contributions are welcome!
 
 Please see the contribution and local development guide on the docs page before getting started:
 
-https://docs.fossorial.io/development
-
-For ideas about what features to work on and our future plans, please see the roadmap:
-
-https://docs.fossorial.io/roadmap
+https://docs.pangolin.net/development/contributing
 
 ### Licensing Considerations
 
@@ -21,4 +17,4 @@ By creating this pull request, I grant the project maintainers an unlimited,
 perpetual license to use, modify, and redistribute these contributions under any terms they
 choose, including both the AGPLv3 and the Fossorial Commercial license terms. I
 represent that I have the right to grant this license for all contributed content.
-```
+```

Dockerfile

@@ -1,5 +1,8 @@
 FROM golang:1.25-alpine AS builder
 
+# Install git and ca-certificates
+RUN apk --no-cache add ca-certificates git tzdata
+
 # Set the working directory inside the container
 WORKDIR /app
 
@@ -13,7 +16,7 @@ RUN go mod download
 COPY . .
 
 # Build the application
-RUN CGO_ENABLED=0 GOOS=linux go build -o /newt
+RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /newt
 
 FROM alpine:3.22 AS runner
 
@@ -22,6 +25,9 @@ RUN apk --no-cache add ca-certificates tzdata
 COPY --from=builder /newt /usr/local/bin/
 COPY entrypoint.sh /
 
+# Admin/metrics endpoint (Prometheus scrape)
+EXPOSE 2112
+
 RUN chmod +x /entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]
-CMD ["newt"]
+CMD ["newt"]

README.md

@@ -9,7 +9,7 @@ Newt is a fully user space [WireGuard](https://www.wireguard.com/) tunnel client
 
 Newt is used with Pangolin and Gerbil as part of the larger system. See documentation below:
 
--   [Full Documentation](https://docs.fossorial.io)
+-   [Full Documentation](https://docs.pangolin.net)
 
 ## Preview
 
@@ -33,61 +33,109 @@ When Newt receives WireGuard control messages, it will use the information encod
 
 ## CLI Args
 
+### Core Configuration
+
 -   `id`: Newt ID generated by Pangolin to identify the client.
 -   `secret`: A unique secret (not shared and kept private) used to authenticate the client ID with the websocket in order to receive commands.
 -   `endpoint`: The endpoint where both Gerbil and Pangolin reside in order to connect to the websocket.
-
--   `mtu` (optional): MTU for the internal WG interface. Default: 1280
--   `dns` (optional): DNS server to use to resolve the endpoint. Default: 9.9.9.9
+-   `blueprint-file` (optional): Path to blueprint file to define Pangolin resources and configurations.
+-   `no-cloud` (optional): Don't fail over to the cloud when using managed nodes in Pangolin Cloud. Default: false
 -   `log-level` (optional): The log level to use (DEBUG, INFO, WARN, ERROR, FATAL). Default: INFO
--   `enforce-hc-cert` (optional): Enforce certificate validation for health checks. Default: false (accepts any cert)
+
+### Docker Integration
+
 -   `docker-socket` (optional): Set the Docker socket to use the container discovery integration
--   `ping-interval` (optional): Interval for pinging the server. Default: 3s
--   `ping-timeout` (optional): Timeout for each ping. Default: 5s
--   `updown` (optional): A script to be called when targets are added or removed.
--   `tls-client-cert` (optional): Client certificate (p12 or pfx) for mTLS. See [mTLS](#mtls)
--   `tls-client-cert` (optional): Path to client certificate (PEM format, optional if using PKCS12). See [mTLS](#mtls)
--   `tls-client-key` (optional): Path to private key for mTLS (PEM format, optional if using PKCS12)
--   `tls-ca-cert` (optional): Path to CA certificate to verify server (PEM format, optional if using PKCS12)
 -   `docker-enforce-network-validation` (optional): Validate the container target is on the same network as the newt process. Default: false
--   `health-file` (optional): Check if connection to WG server (pangolin) is ok. creates a file if ok, removes it if not ok. Can be used with docker healtcheck to restart newt
+
+### Accpet Client Connection 
+
 -   `accept-clients` (optional): Enable WireGuard server mode to accept incoming newt client connections. Default: false
     -   `generateAndSaveKeyTo` (optional): Path to save generated private key
     -   `native` (optional): Use native WireGuard interface when accepting clients (requires WireGuard kernel module and Linux, must run as root). Default: false (uses userspace netstack)
         -   `interface` (optional): Name of the WireGuard interface. Default: newt
         -   `keep-interface` (optional): Keep the WireGuard interface. Default: false
--   `blueprint-file` (optional): Path to blueprint file to define Pangolin resources and configurations.
--   `no-cloud` (optional): Don't fail over to the cloud when using managed nodes in Pangolin Cloud. Default: false 
+
+### Metrics & Observability
+
+-   `metrics` (optional): Enable Prometheus /metrics exporter. Default: true
+-   `otlp` (optional): Enable OTLP exporters (metrics/traces) to OTEL_EXPORTER_OTLP_ENDPOINT. Default: false
+-   `metrics-admin-addr` (optional): Admin/metrics bind address. Default: 127.0.0.1:2112
+-   `metrics-async-bytes` (optional): Enable async bytes counting (background flush; lower hot path overhead). Default: false 
+-   `region` (optional): Optional region resource attribute for telemetry and metrics.
+
+### Network Configuration
+
+-   `mtu` (optional): MTU for the internal WG interface. Default: 1280
+-   `dns` (optional): DNS server to use to resolve the endpoint. Default: 9.9.9.9
+-   `ping-interval` (optional): Interval for pinging the server. Default: 3s
+-   `ping-timeout` (optional): Timeout for each ping. Default: 5s
+
+### Security & TLS
+
+-   `enforce-hc-cert` (optional): Enforce certificate validation for health checks. Default: false (accepts any cert)
+-   `tls-client-cert` (optional): Client certificate (p12 or pfx) for mTLS or path to client certificate (PEM format). See [mTLS](#mtls)
+-   `tls-client-key` (optional): Path to private key for mTLS (PEM format, optional if using PKCS12)
+-   `tls-ca-cert` (optional): Path to CA certificate to verify server (PEM format, optional if using PKCS12)
+
+### Monitoring & Health
+
+-   `health-file` (optional): Check if connection to WG server (pangolin) is ok. creates a file if ok, removes it if not ok. Can be used with docker healtcheck to restart newt
+-   `updown` (optional): A script to be called when targets are added or removed.
 
 ## Environment Variables
 
 All CLI arguments can be set using environment variables as an alternative to command line flags. Environment variables are particularly useful when running Newt in containerized environments.
 
+### Core Configuration
+
 -   `PANGOLIN_ENDPOINT`: Endpoint of your pangolin server (equivalent to `--endpoint`)
 -   `NEWT_ID`: Newt ID generated by Pangolin (equivalent to `--id`)
 -   `NEWT_SECRET`: Newt secret for authentication (equivalent to `--secret`)
--   `MTU`: MTU for the internal WG interface. Default: 1280 (equivalent to `--mtu`)
--   `DNS`: DNS server to use to resolve the endpoint. Default: 9.9.9.9 (equivalent to `--dns`)
+-   `CONFIG_FILE`: Load the config json from this file instead of in the home folder.
+-   `BLUEPRINT_FILE`: Path to blueprint file to define Pangolin resources and configurations. (equivalent to `--blueprint-file`)
+-   `NO_CLOUD`: Don't fail over to the cloud when using managed nodes in Pangolin Cloud. Default: false (equivalent to `--no-cloud`)
 -   `LOG_LEVEL`: Log level (DEBUG, INFO, WARN, ERROR, FATAL). Default: INFO (equivalent to `--log-level`)
+
+### Docker Integration
+
 -   `DOCKER_SOCKET`: Path to Docker socket for container discovery (equivalent to `--docker-socket`)
--   `PING_INTERVAL`: Interval for pinging the server. Default: 3s (equivalent to `--ping-interval`)
--   `PING_TIMEOUT`: Timeout for each ping. Default: 5s (equivalent to `--ping-timeout`)
--   `UPDOWN_SCRIPT`: Path to updown script for target add/remove events (equivalent to `--updown`)
--   `TLS_CLIENT_CERT`: Path to client certificate for mTLS (equivalent to `--tls-client-cert`)
--   `TLS_CLIENT_CERT`: Path to client certificate for mTLS (equivalent to `--tls-client-cert`)
--   `TLS_CLIENT_KEY`: Path to private key for mTLS (equivalent to `--tls-client-key`)
--   `TLS_CA_CERT`: Path to CA certificate to verify server (equivalent to `--tls-ca-cert`)
 -   `DOCKER_ENFORCE_NETWORK_VALIDATION`: Validate container targets are on same network. Default: false (equivalent to `--docker-enforce-network-validation`)
--   `ENFORCE_HC_CERT`: Enforce certificate validation for health checks. Default: false (equivalent to `--enforce-hc-cert`)
--   `HEALTH_FILE`: Path to health file for connection monitoring (equivalent to `--health-file`)
+
+### Accept Client Connections
+
 -   `ACCEPT_CLIENTS`: Enable WireGuard server mode. Default: false (equivalent to `--accept-clients`)
 -   `GENERATE_AND_SAVE_KEY_TO`: Path to save generated private key (equivalent to `--generateAndSaveKeyTo`)
 -   `USE_NATIVE_INTERFACE`: Use native WireGuard interface (Linux only). Default: false (equivalent to `--native`)
 -   `INTERFACE`: Name of the WireGuard interface. Default: newt (equivalent to `--interface`)
 -   `KEEP_INTERFACE`: Keep the WireGuard interface after shutdown. Default: false (equivalent to `--keep-interface`)
--   `CONFIG_FILE`: Load the config json from this file instead of in the home folder.
--   `BLUEPRINT_FILE`: Path to blueprint file to define Pangolin resources and configurations. (equivalent to `--blueprint-file`)
--   `NO_CLOUD`: Don't fail over to the cloud when using managed nodes in Pangolin Cloud. Default: false (equivalent to `--no-cloud`)
+
+### Monitoring & Health
+
+-   `HEALTH_FILE`: Path to health file for connection monitoring (equivalent to `--health-file`)
+-   `UPDOWN_SCRIPT`: Path to updown script for target add/remove events (equivalent to `--updown`)
+
+### Metrics & Observability
+
+-   `NEWT_METRICS_PROMETHEUS_ENABLED`: Enable Prometheus /metrics exporter. Default: true (equivalent to `--metrics`)
+-   `NEWT_METRICS_OTLP_ENABLED`: Enable OTLP exporters (metrics/traces) to OTEL_EXPORTER_OTLP_ENDPOINT. Default: false (equivalent to `--otlp`)
+-   `NEWT_ADMIN_ADDR`: Admin/metrics bind address. Default: 127.0.0.1:2112 (equivalent to `--metrics-admin-addr`)
+-   `NEWT_METRICS_ASYNC_BYTES`: Enable async bytes counting (background flush; lower hot path overhead). Default: false (equivalent to `--metrics-async-bytes`)
+-   `NEWT_REGION`: Optional region resource attribute for telemetry and metrics (equivalent to `--region`)
+
+### Network Configuration
+
+-   `MTU`: MTU for the internal WG interface. Default: 1280 (equivalent to `--mtu`)
+-   `DNS`: DNS server to use to resolve the endpoint. Default: 9.9.9.9 (equivalent to `--dns`)
+-   `PING_INTERVAL`: Interval for pinging the server. Default: 3s (equivalent to `--ping-interval`)
+-   `PING_TIMEOUT`: Timeout for each ping. Default: 5s (equivalent to `--ping-timeout`)
+
+### Security & TLS
+
+-   `ENFORCE_HC_CERT`: Enforce certificate validation for health checks. Default: false (equivalent to `--enforce-hc-cert`)
+-   `TLS_CLIENT_CERT`: Path to client certificate for mTLS (equivalent to `--tls-client-cert`)
+-   `TLS_CLIENT_KEY`: Path to private key for mTLS (equivalent to `--tls-client-key`)
+-   `TLS_CA_CERT`: Path to CA certificate to verify server (equivalent to `--tls-ca-cert`)
+-   `SKIP_TLS_VERIFY`: Skip TLS verification for server connections. Default: false
 
 ## Loading secrets from files
 
@@ -98,7 +146,7 @@ $ cat ~/.config/newt-client/config.json
 {
   "id": "spmzu8rbpzj1qq6",
   "secret": "f6v61mjutwme2kkydbw3fjo227zl60a2tsf5psw9r25hgae3",
-  "endpoint": "https://pangolin.fossorial.io",
+  "endpoint": "https://app.pangolin.net",
   "tlsClientCert": ""
 }
 ```

SECURITY.md

@@ -3,7 +3,7 @@
 If you discover a security vulnerability, please follow the steps below to responsibly disclose it to us:
 
 1. **Do not create a public GitHub issue or discussion post.** This could put the security of other users at risk.
-2. Send a detailed report to [security@fossorial.io](mailto:security@fossorial.io) or send a **private** message to a maintainer on [Discord](https://discord.gg/HCJR8Xhme4). Include:
+2. Send a detailed report to [security@pangolin.net](mailto:security@pangolin.net) or send a **private** message to a maintainer on [Discord](https://discord.gg/HCJR8Xhme4). Include:
 
 - Description and location of the vulnerability.
 - Potential impact of the vulnerability.

bind/shared_bind.go

@@ -0,0 +1,675 @@
+//go:build !js
+
+package bind
+
+import (
+	"bytes"
+	"fmt"
+	"net"
+	"net/netip"
+	"runtime"
+	"sync"
+	"sync/atomic"
+
+	"github.com/fosrl/newt/logger"
+	"golang.org/x/net/ipv4"
+	"golang.org/x/net/ipv6"
+	wgConn "golang.zx2c4.com/wireguard/conn"
+)
+
+// Magic packet constants for connection testing
+// These packets are intercepted by SharedBind and responded to directly,
+// without being passed to the WireGuard device.
+var (
+	// MagicTestRequest is the prefix for a test request packet
+	// Format: PANGOLIN_TEST_REQ + 8 bytes of random data (for echo)
+	MagicTestRequest = []byte("PANGOLIN_TEST_REQ")
+
+	// MagicTestResponse is the prefix for a test response packet
+	// Format: PANGOLIN_TEST_RSP + 8 bytes echoed from request
+	MagicTestResponse = []byte("PANGOLIN_TEST_RSP")
+)
+
+const (
+	// MagicPacketDataLen is the length of random data included in test packets
+	MagicPacketDataLen = 8
+
+	// MagicTestRequestLen is the total length of a test request packet
+	MagicTestRequestLen = 17 + MagicPacketDataLen // len("PANGOLIN_TEST_REQ") + 8
+
+	// MagicTestResponseLen is the total length of a test response packet
+	MagicTestResponseLen = 17 + MagicPacketDataLen // len("PANGOLIN_TEST_RSP") + 8
+)
+
+// PacketSource identifies where a packet came from
+type PacketSource uint8
+
+const (
+	SourceSocket   PacketSource = iota // From physical UDP socket (hole-punched clients)
+	SourceNetstack                     // From netstack (relay through main tunnel)
+)
+
+// SourceAwareEndpoint wraps an endpoint with source information
+type SourceAwareEndpoint struct {
+	wgConn.Endpoint
+	source PacketSource
+}
+
+// GetSource returns the source of this endpoint
+func (e *SourceAwareEndpoint) GetSource() PacketSource {
+	return e.source
+}
+
+// injectedPacket represents a packet injected into the SharedBind from an internal source
+type injectedPacket struct {
+	data     []byte
+	endpoint wgConn.Endpoint
+}
+
+// Endpoint represents a network endpoint for the SharedBind
+type Endpoint struct {
+	AddrPort netip.AddrPort
+}
+
+// ClearSrc implements the wgConn.Endpoint interface
+func (e *Endpoint) ClearSrc() {}
+
+// DstIP implements the wgConn.Endpoint interface
+func (e *Endpoint) DstIP() netip.Addr {
+	return e.AddrPort.Addr()
+}
+
+// SrcIP implements the wgConn.Endpoint interface
+func (e *Endpoint) SrcIP() netip.Addr {
+	return netip.Addr{}
+}
+
+// DstToBytes implements the wgConn.Endpoint interface
+func (e *Endpoint) DstToBytes() []byte {
+	b, _ := e.AddrPort.MarshalBinary()
+	return b
+}
+
+// DstToString implements the wgConn.Endpoint interface
+func (e *Endpoint) DstToString() string {
+	return e.AddrPort.String()
+}
+
+// SrcToString implements the wgConn.Endpoint interface
+func (e *Endpoint) SrcToString() string {
+	return ""
+}
+
+// SharedBind is a thread-safe UDP bind that can be shared between WireGuard
+// and hole punch senders. It wraps a single UDP connection and implements
+// reference counting to prevent premature closure.
+// It also supports receiving packets from a netstack and routing responses
+// back through the appropriate source.
+type SharedBind struct {
+	mu sync.RWMutex
+
+	// The underlying UDP connection (for hole-punched clients)
+	udpConn *net.UDPConn
+
+	// IPv4 and IPv6 packet connections for advanced features
+	ipv4PC *ipv4.PacketConn
+	ipv6PC *ipv6.PacketConn
+
+	// Reference counting to prevent closing while in use
+	refCount atomic.Int32
+	closed   atomic.Bool
+
+	// Channels for receiving data
+	recvFuncs []wgConn.ReceiveFunc
+
+	// Port binding information
+	port uint16
+
+	// Channel for packets from netstack (from direct relay) - larger buffer for throughput
+	netstackPackets chan injectedPacket
+
+	// Netstack connection for sending responses back through the tunnel
+	// Using atomic.Pointer for lock-free access in hot path
+	netstackConn atomic.Pointer[net.PacketConn]
+
+	// Track which endpoints came from netstack (key: netip.AddrPort, value: struct{})
+	// Using netip.AddrPort directly as key is more efficient than string
+	netstackEndpoints sync.Map
+
+	// Pre-allocated message buffers for batch operations (Linux only)
+	ipv4Msgs []ipv4.Message
+
+	// Shutdown signal for receive goroutines
+	closeChan chan struct{}
+
+	// Callback for magic test responses (used for holepunch testing)
+	magicResponseCallback atomic.Pointer[func(addr netip.AddrPort, echoData []byte)]
+}
+
+// MagicResponseCallback is the function signature for magic packet response callbacks
+type MagicResponseCallback func(addr netip.AddrPort, echoData []byte)
+
+// New creates a new SharedBind from an existing UDP connection.
+// The SharedBind takes ownership of the connection and will close it
+// when all references are released.
+func New(udpConn *net.UDPConn) (*SharedBind, error) {
+	if udpConn == nil {
+		return nil, fmt.Errorf("udpConn cannot be nil")
+	}
+
+	bind := &SharedBind{
+		udpConn:         udpConn,
+		netstackPackets: make(chan injectedPacket, 1024), // Larger buffer for better throughput
+		closeChan:       make(chan struct{}),
+	}
+
+	// Initialize reference count to 1 (the creator holds the first reference)
+	bind.refCount.Store(1)
+
+	// Get the local port
+	if addr, ok := udpConn.LocalAddr().(*net.UDPAddr); ok {
+		bind.port = uint16(addr.Port)
+	}
+
+	return bind, nil
+}
+
+// SetNetstackConn sets the netstack connection for receiving/sending packets through the tunnel.
+// This connection is used for relay traffic that should go back through the main tunnel.
+func (b *SharedBind) SetNetstackConn(conn net.PacketConn) {
+	b.netstackConn.Store(&conn)
+}
+
+// GetNetstackConn returns the netstack connection if set
+func (b *SharedBind) GetNetstackConn() net.PacketConn {
+	ptr := b.netstackConn.Load()
+	if ptr == nil {
+		return nil
+	}
+	return *ptr
+}
+
+// InjectPacket allows injecting a packet directly into the SharedBind's receive path.
+// This is used for direct relay from netstack without going through the host network.
+// The fromAddr should be the address the packet appears to come from.
+func (b *SharedBind) InjectPacket(data []byte, fromAddr netip.AddrPort) error {
+	if b.closed.Load() {
+		return net.ErrClosed
+	}
+
+	// Unmap IPv4-in-IPv6 addresses to ensure consistency with parsed endpoints
+	if fromAddr.Addr().Is4In6() {
+		fromAddr = netip.AddrPortFrom(fromAddr.Addr().Unmap(), fromAddr.Port())
+	}
+
+	// Track this endpoint as coming from netstack so responses go back the same way
+	// Use AddrPort directly as key (more efficient than string)
+	b.netstackEndpoints.Store(fromAddr, struct{}{})
+
+	// Make a copy of the data to avoid issues with buffer reuse
+	dataCopy := make([]byte, len(data))
+	copy(dataCopy, data)
+
+	select {
+	case b.netstackPackets <- injectedPacket{
+		data:     dataCopy,
+		endpoint: &wgConn.StdNetEndpoint{AddrPort: fromAddr},
+	}:
+		return nil
+	case <-b.closeChan:
+		return net.ErrClosed
+	default:
+		// Channel full, drop the packet
+		return fmt.Errorf("netstack packet buffer full")
+	}
+}
+
+// AddRef increments the reference count. Call this when sharing
+// the bind with another component.
+func (b *SharedBind) AddRef() {
+	newCount := b.refCount.Add(1)
+	// Optional: Add logging for debugging
+	_ = newCount // Placeholder for potential logging
+}
+
+// Release decrements the reference count. When it reaches zero,
+// the underlying UDP connection is closed.
+func (b *SharedBind) Release() error {
+	newCount := b.refCount.Add(-1)
+	// Optional: Add logging for debugging
+	_ = newCount // Placeholder for potential logging
+
+	if newCount < 0 {
+		// This should never happen with proper usage
+		b.refCount.Store(0)
+		return fmt.Errorf("SharedBind reference count went negative")
+	}
+
+	if newCount == 0 {
+		return b.closeConnection()
+	}
+
+	return nil
+}
+
+// closeConnection actually closes the UDP connection
+func (b *SharedBind) closeConnection() error {
+	if !b.closed.CompareAndSwap(false, true) {
+		// Already closed
+		return nil
+	}
+
+	// Signal all goroutines to stop
+	close(b.closeChan)
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	var err error
+	if b.udpConn != nil {
+		err = b.udpConn.Close()
+		b.udpConn = nil
+	}
+
+	b.ipv4PC = nil
+	b.ipv6PC = nil
+
+	// Clear netstack connection (but don't close it - it's managed externally)
+	b.netstackConn.Store(nil)
+
+	// Clear tracked netstack endpoints
+	b.netstackEndpoints = sync.Map{}
+
+	return err
+}
+
+// ClearNetstackConn clears the netstack connection and tracked endpoints.
+// Call this when stopping the relay.
+func (b *SharedBind) ClearNetstackConn() {
+	b.netstackConn.Store(nil)
+
+	// Clear tracked netstack endpoints
+	b.netstackEndpoints = sync.Map{}
+}
+
+// GetUDPConn returns the underlying UDP connection.
+// The caller must not close this connection directly.
+func (b *SharedBind) GetUDPConn() *net.UDPConn {
+	b.mu.RLock()
+	defer b.mu.RUnlock()
+	return b.udpConn
+}
+
+// GetRefCount returns the current reference count (for debugging)
+func (b *SharedBind) GetRefCount() int32 {
+	return b.refCount.Load()
+}
+
+// IsClosed returns whether the bind is closed
+func (b *SharedBind) IsClosed() bool {
+	return b.closed.Load()
+}
+
+// SetMagicResponseCallback sets a callback function that will be called when
+// a magic test response packet is received. This is used for holepunch testing.
+// Pass nil to clear the callback.
+func (b *SharedBind) SetMagicResponseCallback(callback MagicResponseCallback) {
+	if callback == nil {
+		b.magicResponseCallback.Store(nil)
+	} else {
+		// Convert to the function type the atomic.Pointer expects
+		fn := func(addr netip.AddrPort, echoData []byte) {
+			callback(addr, echoData)
+		}
+		b.magicResponseCallback.Store(&fn)
+	}
+}
+
+// WriteToUDP writes data to a specific UDP address.
+// This is thread-safe and can be used by hole punch senders.
+func (b *SharedBind) WriteToUDP(data []byte, addr *net.UDPAddr) (int, error) {
+	if b.closed.Load() {
+		return 0, net.ErrClosed
+	}
+
+	b.mu.RLock()
+	conn := b.udpConn
+	b.mu.RUnlock()
+
+	if conn == nil {
+		return 0, net.ErrClosed
+	}
+
+	return conn.WriteToUDP(data, addr)
+}
+
+// Close implements the WireGuard Bind interface.
+// It decrements the reference count and closes the connection if no references remain.
+func (b *SharedBind) Close() error {
+	return b.Release()
+}
+
+// Open implements the WireGuard Bind interface.
+// Since the connection is already open, this just sets up the receive functions.
+func (b *SharedBind) Open(uport uint16) ([]wgConn.ReceiveFunc, uint16, error) {
+	if b.closed.Load() {
+		return nil, 0, net.ErrClosed
+	}
+
+	b.mu.Lock()
+	defer b.mu.Unlock()
+
+	if b.udpConn == nil {
+		return nil, 0, net.ErrClosed
+	}
+
+	// Set up IPv4 and IPv6 packet connections for advanced features
+	if runtime.GOOS == "linux" || runtime.GOOS == "android" {
+		b.ipv4PC = ipv4.NewPacketConn(b.udpConn)
+		b.ipv6PC = ipv6.NewPacketConn(b.udpConn)
+
+		// Pre-allocate message buffers for batch operations
+		batchSize := wgConn.IdealBatchSize
+		b.ipv4Msgs = make([]ipv4.Message, batchSize)
+		for i := range b.ipv4Msgs {
+			b.ipv4Msgs[i].OOB = make([]byte, 0)
+		}
+	}
+
+	// Create receive functions - one for socket, one for netstack
+	recvFuncs := make([]wgConn.ReceiveFunc, 0, 2)
+
+	// Add socket receive function (reads from physical UDP socket)
+	recvFuncs = append(recvFuncs, b.makeReceiveSocket())
+
+	// Add netstack receive function (reads from injected packets channel)
+	recvFuncs = append(recvFuncs, b.makeReceiveNetstack())
+
+	b.recvFuncs = recvFuncs
+	return recvFuncs, b.port, nil
+}
+
+// makeReceiveSocket creates a receive function for physical UDP socket packets
+func (b *SharedBind) makeReceiveSocket() wgConn.ReceiveFunc {
+	return func(bufs [][]byte, sizes []int, eps []wgConn.Endpoint) (n int, err error) {
+		if b.closed.Load() {
+			return 0, net.ErrClosed
+		}
+
+		b.mu.RLock()
+		conn := b.udpConn
+		pc := b.ipv4PC
+		b.mu.RUnlock()
+
+		if conn == nil {
+			return 0, net.ErrClosed
+		}
+
+		// Use batch reading on Linux for performance
+		if pc != nil && (runtime.GOOS == "linux" || runtime.GOOS == "android") {
+			return b.receiveIPv4Batch(pc, bufs, sizes, eps)
+		}
+		return b.receiveIPv4Simple(conn, bufs, sizes, eps)
+	}
+}
+
+// makeReceiveNetstack creates a receive function for netstack-injected packets
+func (b *SharedBind) makeReceiveNetstack() wgConn.ReceiveFunc {
+	return func(bufs [][]byte, sizes []int, eps []wgConn.Endpoint) (n int, err error) {
+		select {
+		case <-b.closeChan:
+			return 0, net.ErrClosed
+		case pkt := <-b.netstackPackets:
+			if len(pkt.data) <= len(bufs[0]) {
+				copy(bufs[0], pkt.data)
+				sizes[0] = len(pkt.data)
+				eps[0] = pkt.endpoint
+				return 1, nil
+			}
+			// Packet too large for buffer, skip it
+			return 0, nil
+		}
+	}
+}
+
+// receiveIPv4Batch uses batch reading for better performance on Linux
+func (b *SharedBind) receiveIPv4Batch(pc *ipv4.PacketConn, bufs [][]byte, sizes []int, eps []wgConn.Endpoint) (int, error) {
+	// Use pre-allocated messages, just update buffer pointers
+	numBufs := len(bufs)
+	if numBufs > len(b.ipv4Msgs) {
+		numBufs = len(b.ipv4Msgs)
+	}
+
+	for i := 0; i < numBufs; i++ {
+		b.ipv4Msgs[i].Buffers = [][]byte{bufs[i]}
+	}
+
+	numMsgs, err := pc.ReadBatch(b.ipv4Msgs[:numBufs], 0)
+	if err != nil {
+		return 0, err
+	}
+
+	// Process messages and filter out magic packets
+	writeIdx := 0
+	for i := 0; i < numMsgs; i++ {
+		if b.ipv4Msgs[i].N == 0 {
+			continue
+		}
+
+		// Check for magic packet
+		if b.ipv4Msgs[i].Addr != nil {
+			if udpAddr, ok := b.ipv4Msgs[i].Addr.(*net.UDPAddr); ok {
+				data := bufs[i][:b.ipv4Msgs[i].N]
+				if b.handleMagicPacket(data, udpAddr) {
+					// Magic packet handled, skip this message
+					continue
+				}
+			}
+		}
+
+		// Not a magic packet, include in output
+		if writeIdx != i {
+			// Need to copy data to the correct position
+			copy(bufs[writeIdx], bufs[i][:b.ipv4Msgs[i].N])
+		}
+		sizes[writeIdx] = b.ipv4Msgs[i].N
+
+		if b.ipv4Msgs[i].Addr != nil {
+			if udpAddr, ok := b.ipv4Msgs[i].Addr.(*net.UDPAddr); ok {
+				addrPort := udpAddr.AddrPort()
+				// Unmap IPv4-in-IPv6 addresses to ensure consistency with parsed endpoints
+				if addrPort.Addr().Is4In6() {
+					addrPort = netip.AddrPortFrom(addrPort.Addr().Unmap(), addrPort.Port())
+				}
+				eps[writeIdx] = &wgConn.StdNetEndpoint{AddrPort: addrPort}
+			}
+		}
+		writeIdx++
+	}
+
+	return writeIdx, nil
+}
+
+// receiveIPv4Simple uses simple ReadFromUDP for non-Linux platforms
+func (b *SharedBind) receiveIPv4Simple(conn *net.UDPConn, bufs [][]byte, sizes []int, eps []wgConn.Endpoint) (int, error) {
+	for {
+		n, addr, err := conn.ReadFromUDP(bufs[0])
+		if err != nil {
+			return 0, err
+		}
+
+		// Check for magic test packet and handle it directly
+		if b.handleMagicPacket(bufs[0][:n], addr) {
+			// Magic packet was handled, read another packet
+			continue
+		}
+
+		sizes[0] = n
+		if addr != nil {
+			addrPort := addr.AddrPort()
+			// Unmap IPv4-in-IPv6 addresses to ensure consistency with parsed endpoints
+			if addrPort.Addr().Is4In6() {
+				addrPort = netip.AddrPortFrom(addrPort.Addr().Unmap(), addrPort.Port())
+			}
+			eps[0] = &wgConn.StdNetEndpoint{AddrPort: addrPort}
+		}
+
+		return 1, nil
+	}
+}
+
+// handleMagicPacket checks if the packet is a magic test packet and responds if so.
+// Returns true if the packet was a magic packet and was handled (should not be passed to WireGuard).
+func (b *SharedBind) handleMagicPacket(data []byte, addr *net.UDPAddr) bool {
+	// Check if this is a test request packet
+	if len(data) >= MagicTestRequestLen && bytes.HasPrefix(data, MagicTestRequest) {
+		logger.Debug("Received magic test REQUEST from %s, sending response", addr.String())
+		// Extract the random data portion to echo back
+		echoData := data[len(MagicTestRequest) : len(MagicTestRequest)+MagicPacketDataLen]
+
+		// Build response packet
+		response := make([]byte, MagicTestResponseLen)
+		copy(response, MagicTestResponse)
+		copy(response[len(MagicTestResponse):], echoData)
+
+		// Send response back to sender
+		b.mu.RLock()
+		conn := b.udpConn
+		b.mu.RUnlock()
+
+		if conn != nil {
+			_, _ = conn.WriteToUDP(response, addr)
+		}
+
+		return true
+	}
+
+	// Check if this is a test response packet
+	if len(data) >= MagicTestResponseLen && bytes.HasPrefix(data, MagicTestResponse) {
+		logger.Debug("Received magic test RESPONSE from %s", addr.String())
+		// Extract the echoed data
+		echoData := data[len(MagicTestResponse) : len(MagicTestResponse)+MagicPacketDataLen]
+
+		// Call the callback if set
+		callbackPtr := b.magicResponseCallback.Load()
+		if callbackPtr != nil {
+			callback := *callbackPtr
+			addrPort := addr.AddrPort()
+			// Unmap IPv4-in-IPv6 addresses to ensure consistency
+			if addrPort.Addr().Is4In6() {
+				addrPort = netip.AddrPortFrom(addrPort.Addr().Unmap(), addrPort.Port())
+			}
+			callback(addrPort, echoData)
+		} else {
+			logger.Debug("Magic response received but no callback registered")
+		}
+
+		return true
+	}
+
+	return false
+}
+
+// Send implements the WireGuard Bind interface.
+// It sends packets to the specified endpoint, routing through the appropriate
+// source (netstack or physical socket) based on where the endpoint's packets came from.
+func (b *SharedBind) Send(bufs [][]byte, ep wgConn.Endpoint) error {
+	if b.closed.Load() {
+		return net.ErrClosed
+	}
+
+	// Extract the destination address from the endpoint
+	var destAddrPort netip.AddrPort
+
+	// Try to cast to StdNetEndpoint first (most common case, avoid allocations)
+	if stdEp, ok := ep.(*wgConn.StdNetEndpoint); ok {
+		destAddrPort = stdEp.AddrPort
+	} else {
+		// Fallback: construct from DstIP and DstToBytes
+		dstBytes := ep.DstToBytes()
+		if len(dstBytes) >= 6 { // Minimum for IPv4 (4 bytes) + port (2 bytes)
+			var addr netip.Addr
+			var port uint16
+
+			if len(dstBytes) >= 18 { // IPv6 (16 bytes) + port (2 bytes)
+				addr, _ = netip.AddrFromSlice(dstBytes[:16])
+				port = uint16(dstBytes[16]) | uint16(dstBytes[17])<<8
+			} else { // IPv4
+				addr, _ = netip.AddrFromSlice(dstBytes[:4])
+				port = uint16(dstBytes[4]) | uint16(dstBytes[5])<<8
+			}
+
+			if addr.IsValid() {
+				destAddrPort = netip.AddrPortFrom(addr, port)
+			}
+		}
+	}
+
+	if !destAddrPort.IsValid() {
+		return fmt.Errorf("could not extract destination address from endpoint")
+	}
+
+	// Check if this endpoint came from netstack - if so, send through netstack
+	// Use AddrPort directly as key (more efficient than string conversion)
+	if _, isNetstackEndpoint := b.netstackEndpoints.Load(destAddrPort); isNetstackEndpoint {
+		connPtr := b.netstackConn.Load()
+		if connPtr != nil && *connPtr != nil {
+			netstackConn := *connPtr
+			destAddr := net.UDPAddrFromAddrPort(destAddrPort)
+			// Send all buffers through netstack
+			for _, buf := range bufs {
+				_, err := netstackConn.WriteTo(buf, destAddr)
+				if err != nil {
+					return err
+				}
+			}
+			return nil
+		}
+		// Fall through to socket if netstack conn not available
+	}
+
+	// Send through the physical UDP socket (for hole-punched clients)
+	b.mu.RLock()
+	conn := b.udpConn
+	b.mu.RUnlock()
+
+	if conn == nil {
+		return net.ErrClosed
+	}
+
+	destAddr := net.UDPAddrFromAddrPort(destAddrPort)
+
+	// Send all buffers to the destination
+	for _, buf := range bufs {
+		_, err := conn.WriteToUDP(buf, destAddr)
+		if err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+// SetMark implements the WireGuard Bind interface.
+// It's a no-op for this implementation.
+func (b *SharedBind) SetMark(mark uint32) error {
+	// Not implemented for this use case
+	return nil
+}
+
+// BatchSize returns the preferred batch size for sending packets.
+func (b *SharedBind) BatchSize() int {
+	if runtime.GOOS == "linux" || runtime.GOOS == "android" {
+		return wgConn.IdealBatchSize
+	}
+	return 1
+}
+
+// ParseEndpoint creates a new endpoint from a string address.
+func (b *SharedBind) ParseEndpoint(s string) (wgConn.Endpoint, error) {
+	addrPort, err := netip.ParseAddrPort(s)
+	if err != nil {
+		return nil, err
+	}
+	return &wgConn.StdNetEndpoint{AddrPort: addrPort}, nil
+}

bind/shared_bind_test.go

@@ -0,0 +1,605 @@
+//go:build !js
+
+package bind
+
+import (
+	"net"
+	"net/netip"
+	"sync"
+	"testing"
+	"time"
+
+	wgConn "golang.zx2c4.com/wireguard/conn"
+)
+
+// TestSharedBindCreation tests basic creation and initialization
+func TestSharedBindCreation(t *testing.T) {
+	// Create a UDP connection
+	udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create UDP connection: %v", err)
+	}
+	defer udpConn.Close()
+
+	// Create SharedBind
+	bind, err := New(udpConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+
+	if bind == nil {
+		t.Fatal("SharedBind is nil")
+	}
+
+	// Verify initial reference count
+	if bind.refCount.Load() != 1 {
+		t.Errorf("Expected initial refCount to be 1, got %d", bind.refCount.Load())
+	}
+
+	// Clean up
+	if err := bind.Close(); err != nil {
+		t.Errorf("Failed to close SharedBind: %v", err)
+	}
+}
+
+// TestSharedBindReferenceCount tests reference counting
+func TestSharedBindReferenceCount(t *testing.T) {
+	udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create UDP connection: %v", err)
+	}
+
+	bind, err := New(udpConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+
+	// Add references
+	bind.AddRef()
+	if bind.refCount.Load() != 2 {
+		t.Errorf("Expected refCount to be 2, got %d", bind.refCount.Load())
+	}
+
+	bind.AddRef()
+	if bind.refCount.Load() != 3 {
+		t.Errorf("Expected refCount to be 3, got %d", bind.refCount.Load())
+	}
+
+	// Release references
+	bind.Release()
+	if bind.refCount.Load() != 2 {
+		t.Errorf("Expected refCount to be 2 after release, got %d", bind.refCount.Load())
+	}
+
+	bind.Release()
+	bind.Release() // This should close the connection
+
+	if !bind.closed.Load() {
+		t.Error("Expected bind to be closed after all references released")
+	}
+}
+
+// TestSharedBindWriteToUDP tests the WriteToUDP functionality
+func TestSharedBindWriteToUDP(t *testing.T) {
+	// Create sender
+	senderConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create sender UDP connection: %v", err)
+	}
+
+	senderBind, err := New(senderConn)
+	if err != nil {
+		t.Fatalf("Failed to create sender SharedBind: %v", err)
+	}
+	defer senderBind.Close()
+
+	// Create receiver
+	receiverConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create receiver UDP connection: %v", err)
+	}
+	defer receiverConn.Close()
+
+	receiverAddr := receiverConn.LocalAddr().(*net.UDPAddr)
+
+	// Send data
+	testData := []byte("Hello, SharedBind!")
+	n, err := senderBind.WriteToUDP(testData, receiverAddr)
+	if err != nil {
+		t.Fatalf("WriteToUDP failed: %v", err)
+	}
+
+	if n != len(testData) {
+		t.Errorf("Expected to send %d bytes, sent %d", len(testData), n)
+	}
+
+	// Receive data
+	buf := make([]byte, 1024)
+	receiverConn.SetReadDeadline(time.Now().Add(2 * time.Second))
+	n, _, err = receiverConn.ReadFromUDP(buf)
+	if err != nil {
+		t.Fatalf("Failed to receive data: %v", err)
+	}
+
+	if string(buf[:n]) != string(testData) {
+		t.Errorf("Expected to receive %q, got %q", testData, buf[:n])
+	}
+}
+
+// TestSharedBindConcurrentWrites tests thread-safety
+func TestSharedBindConcurrentWrites(t *testing.T) {
+	// Create sender
+	senderConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create sender UDP connection: %v", err)
+	}
+
+	senderBind, err := New(senderConn)
+	if err != nil {
+		t.Fatalf("Failed to create sender SharedBind: %v", err)
+	}
+	defer senderBind.Close()
+
+	// Create receiver
+	receiverConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create receiver UDP connection: %v", err)
+	}
+	defer receiverConn.Close()
+
+	receiverAddr := receiverConn.LocalAddr().(*net.UDPAddr)
+
+	// Launch concurrent writes
+	numGoroutines := 100
+	var wg sync.WaitGroup
+	wg.Add(numGoroutines)
+
+	for i := 0; i < numGoroutines; i++ {
+		go func(id int) {
+			defer wg.Done()
+			data := []byte{byte(id)}
+			_, err := senderBind.WriteToUDP(data, receiverAddr)
+			if err != nil {
+				t.Errorf("WriteToUDP failed in goroutine %d: %v", id, err)
+			}
+		}(i)
+	}
+
+	wg.Wait()
+}
+
+// TestSharedBindWireGuardInterface tests WireGuard Bind interface implementation
+func TestSharedBindWireGuardInterface(t *testing.T) {
+	udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create UDP connection: %v", err)
+	}
+
+	bind, err := New(udpConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+	defer bind.Close()
+
+	// Test Open
+	recvFuncs, port, err := bind.Open(0)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+
+	if len(recvFuncs) == 0 {
+		t.Error("Expected at least one receive function")
+	}
+
+	if port == 0 {
+		t.Error("Expected non-zero port")
+	}
+
+	// Test SetMark (should be a no-op)
+	if err := bind.SetMark(0); err != nil {
+		t.Errorf("SetMark failed: %v", err)
+	}
+
+	// Test BatchSize
+	batchSize := bind.BatchSize()
+	if batchSize <= 0 {
+		t.Error("Expected positive batch size")
+	}
+}
+
+// TestSharedBindSend tests the Send method with WireGuard endpoints
+func TestSharedBindSend(t *testing.T) {
+	// Create sender
+	senderConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create sender UDP connection: %v", err)
+	}
+
+	senderBind, err := New(senderConn)
+	if err != nil {
+		t.Fatalf("Failed to create sender SharedBind: %v", err)
+	}
+	defer senderBind.Close()
+
+	// Create receiver
+	receiverConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create receiver UDP connection: %v", err)
+	}
+	defer receiverConn.Close()
+
+	receiverAddr := receiverConn.LocalAddr().(*net.UDPAddr)
+
+	// Create an endpoint
+	addrPort := receiverAddr.AddrPort()
+	endpoint := &wgConn.StdNetEndpoint{AddrPort: addrPort}
+
+	// Send data
+	testData := []byte("WireGuard packet")
+	bufs := [][]byte{testData}
+	err = senderBind.Send(bufs, endpoint)
+	if err != nil {
+		t.Fatalf("Send failed: %v", err)
+	}
+
+	// Receive data
+	buf := make([]byte, 1024)
+	receiverConn.SetReadDeadline(time.Now().Add(2 * time.Second))
+	n, _, err := receiverConn.ReadFromUDP(buf)
+	if err != nil {
+		t.Fatalf("Failed to receive data: %v", err)
+	}
+
+	if string(buf[:n]) != string(testData) {
+		t.Errorf("Expected to receive %q, got %q", testData, buf[:n])
+	}
+}
+
+// TestSharedBindMultipleUsers simulates WireGuard and hole punch using the same bind
+func TestSharedBindMultipleUsers(t *testing.T) {
+	// Create shared bind
+	udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create UDP connection: %v", err)
+	}
+
+	sharedBind, err := New(udpConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+
+	// Add reference for hole punch sender
+	sharedBind.AddRef()
+
+	// Create receiver
+	receiverConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create receiver UDP connection: %v", err)
+	}
+	defer receiverConn.Close()
+
+	receiverAddr := receiverConn.LocalAddr().(*net.UDPAddr)
+
+	var wg sync.WaitGroup
+
+	// Simulate WireGuard using the bind
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		addrPort := receiverAddr.AddrPort()
+		endpoint := &wgConn.StdNetEndpoint{AddrPort: addrPort}
+
+		for i := 0; i < 10; i++ {
+			data := []byte("WireGuard packet")
+			bufs := [][]byte{data}
+			if err := sharedBind.Send(bufs, endpoint); err != nil {
+				t.Errorf("WireGuard Send failed: %v", err)
+			}
+			time.Sleep(10 * time.Millisecond)
+		}
+	}()
+
+	// Simulate hole punch sender using the bind
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		for i := 0; i < 10; i++ {
+			data := []byte("Hole punch packet")
+			if _, err := sharedBind.WriteToUDP(data, receiverAddr); err != nil {
+				t.Errorf("Hole punch WriteToUDP failed: %v", err)
+			}
+			time.Sleep(10 * time.Millisecond)
+		}
+	}()
+
+	wg.Wait()
+
+	// Release the hole punch reference
+	sharedBind.Release()
+
+	// Close WireGuard's reference (should close the connection)
+	sharedBind.Close()
+
+	if !sharedBind.closed.Load() {
+		t.Error("Expected bind to be closed after all users released it")
+	}
+}
+
+// TestEndpoint tests the Endpoint implementation
+func TestEndpoint(t *testing.T) {
+	addr := netip.MustParseAddr("192.168.1.1")
+	addrPort := netip.AddrPortFrom(addr, 51820)
+
+	ep := &Endpoint{AddrPort: addrPort}
+
+	// Test DstIP
+	if ep.DstIP() != addr {
+		t.Errorf("Expected DstIP to be %v, got %v", addr, ep.DstIP())
+	}
+
+	// Test DstToString
+	expected := "192.168.1.1:51820"
+	if ep.DstToString() != expected {
+		t.Errorf("Expected DstToString to be %q, got %q", expected, ep.DstToString())
+	}
+
+	// Test DstToBytes
+	bytes := ep.DstToBytes()
+	if len(bytes) == 0 {
+		t.Error("Expected DstToBytes to return non-empty slice")
+	}
+
+	// Test SrcIP (should be zero)
+	if ep.SrcIP().IsValid() {
+		t.Error("Expected SrcIP to be invalid")
+	}
+
+	// Test ClearSrc (should not panic)
+	ep.ClearSrc()
+}
+
+// TestParseEndpoint tests the ParseEndpoint method
+func TestParseEndpoint(t *testing.T) {
+	udpConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create UDP connection: %v", err)
+	}
+
+	bind, err := New(udpConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+	defer bind.Close()
+
+	tests := []struct {
+		name      string
+		input     string
+		wantErr   bool
+		checkAddr func(*testing.T, wgConn.Endpoint)
+	}{
+		{
+			name:    "valid IPv4",
+			input:   "192.168.1.1:51820",
+			wantErr: false,
+			checkAddr: func(t *testing.T, ep wgConn.Endpoint) {
+				if ep.DstToString() != "192.168.1.1:51820" {
+					t.Errorf("Expected 192.168.1.1:51820, got %s", ep.DstToString())
+				}
+			},
+		},
+		{
+			name:    "valid IPv6",
+			input:   "[::1]:51820",
+			wantErr: false,
+			checkAddr: func(t *testing.T, ep wgConn.Endpoint) {
+				if ep.DstToString() != "[::1]:51820" {
+					t.Errorf("Expected [::1]:51820, got %s", ep.DstToString())
+				}
+			},
+		},
+		{
+			name:    "invalid - missing port",
+			input:   "192.168.1.1",
+			wantErr: true,
+		},
+		{
+			name:    "invalid - bad format",
+			input:   "not-an-address",
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ep, err := bind.ParseEndpoint(tt.input)
+			if (err != nil) != tt.wantErr {
+				t.Errorf("ParseEndpoint() error = %v, wantErr %v", err, tt.wantErr)
+				return
+			}
+			if !tt.wantErr && tt.checkAddr != nil {
+				tt.checkAddr(t, ep)
+			}
+		})
+	}
+}
+
+// TestNetstackRouting tests that packets from netstack endpoints are routed back through netstack
+func TestNetstackRouting(t *testing.T) {
+	// Create the SharedBind with a physical UDP socket
+	physicalConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create physical UDP connection: %v", err)
+	}
+
+	sharedBind, err := New(physicalConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+	defer sharedBind.Close()
+
+	// Create a mock "netstack" connection (just another UDP socket for testing)
+	netstackConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create netstack UDP connection: %v", err)
+	}
+	defer netstackConn.Close()
+
+	// Set the netstack connection
+	sharedBind.SetNetstackConn(netstackConn)
+
+	// Create a "client" that would receive packets
+	clientConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create client UDP connection: %v", err)
+	}
+	defer clientConn.Close()
+
+	clientAddr := clientConn.LocalAddr().(*net.UDPAddr)
+	clientAddrPort := clientAddr.AddrPort()
+
+	// Inject a packet from the "netstack" source - this should track the endpoint
+	testData := []byte("test packet from netstack")
+	err = sharedBind.InjectPacket(testData, clientAddrPort)
+	if err != nil {
+		t.Fatalf("InjectPacket failed: %v", err)
+	}
+
+	// Now when we send a response to this endpoint, it should go through netstack
+	endpoint := &wgConn.StdNetEndpoint{AddrPort: clientAddrPort}
+	responseData := []byte("response packet")
+	err = sharedBind.Send([][]byte{responseData}, endpoint)
+	if err != nil {
+		t.Fatalf("Send failed: %v", err)
+	}
+
+	// The packet should be received by the client from the netstack connection
+	buf := make([]byte, 1024)
+	clientConn.SetReadDeadline(time.Now().Add(2 * time.Second))
+	n, fromAddr, err := clientConn.ReadFromUDP(buf)
+	if err != nil {
+		t.Fatalf("Failed to receive response: %v", err)
+	}
+
+	if string(buf[:n]) != string(responseData) {
+		t.Errorf("Expected to receive %q, got %q", responseData, buf[:n])
+	}
+
+	// Verify the response came from the netstack connection, not the physical one
+	netstackAddr := netstackConn.LocalAddr().(*net.UDPAddr)
+	if fromAddr.Port != netstackAddr.Port {
+		t.Errorf("Expected response from netstack port %d, got %d", netstackAddr.Port, fromAddr.Port)
+	}
+}
+
+// TestSocketRouting tests that packets from socket endpoints are routed through socket
+func TestSocketRouting(t *testing.T) {
+	// Create the SharedBind with a physical UDP socket
+	physicalConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create physical UDP connection: %v", err)
+	}
+
+	sharedBind, err := New(physicalConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+	defer sharedBind.Close()
+
+	// Create a mock "netstack" connection
+	netstackConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create netstack UDP connection: %v", err)
+	}
+	defer netstackConn.Close()
+
+	// Set the netstack connection
+	sharedBind.SetNetstackConn(netstackConn)
+
+	// Create a "client" that would receive packets (this simulates a hole-punched client)
+	clientConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create client UDP connection: %v", err)
+	}
+	defer clientConn.Close()
+
+	clientAddr := clientConn.LocalAddr().(*net.UDPAddr)
+	clientAddrPort := clientAddr.AddrPort()
+
+	// Don't inject from netstack - this endpoint is NOT tracked as netstack-sourced
+	// So Send should use the physical socket
+
+	endpoint := &wgConn.StdNetEndpoint{AddrPort: clientAddrPort}
+	responseData := []byte("response packet via socket")
+	err = sharedBind.Send([][]byte{responseData}, endpoint)
+	if err != nil {
+		t.Fatalf("Send failed: %v", err)
+	}
+
+	// The packet should be received by the client from the physical connection
+	buf := make([]byte, 1024)
+	clientConn.SetReadDeadline(time.Now().Add(2 * time.Second))
+	n, fromAddr, err := clientConn.ReadFromUDP(buf)
+	if err != nil {
+		t.Fatalf("Failed to receive response: %v", err)
+	}
+
+	if string(buf[:n]) != string(responseData) {
+		t.Errorf("Expected to receive %q, got %q", responseData, buf[:n])
+	}
+
+	// Verify the response came from the physical connection, not the netstack one
+	physicalAddr := physicalConn.LocalAddr().(*net.UDPAddr)
+	if fromAddr.Port != physicalAddr.Port {
+		t.Errorf("Expected response from physical port %d, got %d", physicalAddr.Port, fromAddr.Port)
+	}
+}
+
+// TestClearNetstackConn tests that clearing the netstack connection works correctly
+func TestClearNetstackConn(t *testing.T) {
+	physicalConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create physical UDP connection: %v", err)
+	}
+
+	sharedBind, err := New(physicalConn)
+	if err != nil {
+		t.Fatalf("Failed to create SharedBind: %v", err)
+	}
+	defer sharedBind.Close()
+
+	// Set a netstack connection
+	netstackConn, err := net.ListenUDP("udp", &net.UDPAddr{IP: net.IPv4zero, Port: 0})
+	if err != nil {
+		t.Fatalf("Failed to create netstack UDP connection: %v", err)
+	}
+	defer netstackConn.Close()
+
+	sharedBind.SetNetstackConn(netstackConn)
+
+	// Inject a packet to track an endpoint
+	testAddrPort := netip.MustParseAddrPort("192.168.1.100:51820")
+	err = sharedBind.InjectPacket([]byte("test"), testAddrPort)
+	if err != nil {
+		t.Fatalf("InjectPacket failed: %v", err)
+	}
+
+	// Verify the endpoint is tracked
+	_, tracked := sharedBind.netstackEndpoints.Load(testAddrPort.String())
+	if !tracked {
+		t.Error("Expected endpoint to be tracked as netstack-sourced")
+	}
+
+	// Clear the netstack connection
+	sharedBind.ClearNetstackConn()
+
+	// Verify the netstack connection is cleared
+	if sharedBind.GetNetstackConn() != nil {
+		t.Error("Expected netstack connection to be nil after clear")
+	}
+
+	// Verify the tracked endpoints are cleared
+	_, stillTracked := sharedBind.netstackEndpoints.Load(testAddrPort.String())
+	if stillTracked {
+		t.Error("Expected endpoint tracking to be cleared")
+	}
+}

blueprint.yaml

@@ -12,9 +12,9 @@ resources:
       sso-roles:
       - Member
       sso-users:
-      - owen@fossorial.io
+      - owen@pangolin.net
       whitelist-users:
-      - owen@fossorial.io
+      - owen@pangolin.net
     targets:
     # - site: glossy-plains-viscacha-rat
     - hostname: localhost

clients.go

@@ -1,20 +1,17 @@
 package main
 
 import (
-	"fmt"
 	"strings"
 
+	"github.com/fosrl/newt/clients"
+	wgnetstack "github.com/fosrl/newt/clients"
+	"github.com/fosrl/newt/clients/permissions"
 	"github.com/fosrl/newt/logger"
-	"github.com/fosrl/newt/proxy"
 	"github.com/fosrl/newt/websocket"
 	"golang.zx2c4.com/wireguard/tun/netstack"
-
-	"github.com/fosrl/newt/wgnetstack"
-	"github.com/fosrl/newt/wgtester"
 )
 
-var wgService *wgnetstack.WireGuardService
-var wgTesterServer *wgtester.Server
+var wgService *clients.WireGuardService
 var ready bool
 
 func setupClients(client *websocket.Client) {
@@ -27,43 +24,29 @@ func setupClients(client *websocket.Client) {
 
 	host = strings.TrimSuffix(host, "/")
 
+	logger.Info("Setting up clients with netstack2...")
+
+	// if useNativeInterface is true make sure we have permission to use native interface
 	if useNativeInterface {
-		setupClientsNative(client, host)
-	} else {
-		setupClientsNetstack(client, host)
+		logger.Debug("Checking permissions for native interface")
+		err := permissions.CheckNativeInterfacePermissions()
+		if err != nil {
+			logger.Fatal("Insufficient permissions to create native TUN interface: %v", err)
+			return
+		}
 	}
 
-	ready = true
-}
-
-func setupClientsNetstack(client *websocket.Client, host string) {
-	logger.Info("Setting up clients with netstack...")
 	// Create WireGuard service
-	wgService, err = wgnetstack.NewWireGuardService(interfaceName, mtuInt, generateAndSaveKeyTo, host, id, client, "9.9.9.9")
+	wgService, err = wgnetstack.NewWireGuardService(interfaceName, mtuInt, host, id, client, dns, useNativeInterface)
 	if err != nil {
 		logger.Fatal("Failed to create WireGuard service: %v", err)
 	}
 
-	// // Set up callback to restart wgtester with netstack when WireGuard is ready
-	wgService.SetOnNetstackReady(func(tnet *netstack.Net) {
-
-		wgTesterServer = wgtester.NewServerWithNetstack("0.0.0.0", wgService.Port, id, tnet) // TODO: maybe make this the same ip of the wg server?
-		err := wgTesterServer.Start()
-		if err != nil {
-			logger.Error("Failed to start WireGuard tester server: %v", err)
-		}
-	})
-
-	wgService.SetOnNetstackClose(func() {
-		if wgTesterServer != nil {
-			wgTesterServer.Stop()
-			wgTesterServer = nil
-		}
-	})
-
 	client.OnTokenUpdate(func(token string) {
 		wgService.SetToken(token)
 	})
+
+	ready = true
 }
 
 func setDownstreamTNetstack(tnet *netstack.Net) {
@@ -75,16 +58,9 @@ func setDownstreamTNetstack(tnet *netstack.Net) {
 func closeClients() {
 	logger.Info("Closing clients...")
 	if wgService != nil {
-		wgService.Close(!keepInterface)
+		wgService.Close()
 		wgService = nil
 	}
-
-	closeWgServiceNative()
-
-	if wgTesterServer != nil {
-		wgTesterServer.Stop()
-		wgTesterServer = nil
-	}
 }
 
 func clientsHandleNewtConnection(publicKey string, endpoint string) {
@@ -103,8 +79,6 @@ func clientsHandleNewtConnection(publicKey string, endpoint string) {
 	if wgService != nil {
 		wgService.StartHolepunch(publicKey, endpoint)
 	}
-
-	clientsHandleNewtConnectionNative(publicKey, endpoint)
 }
 
 func clientsOnConnect() {
@@ -114,19 +88,17 @@ func clientsOnConnect() {
 	if wgService != nil {
 		wgService.LoadRemoteConfig()
 	}
-
-	clientsOnConnectNative()
 }
 
-func clientsAddProxyTarget(pm *proxy.ProxyManager, tunnelIp string) {
+// clientsStartDirectRelay starts a direct UDP relay from the main tunnel netstack
+// to the clients' WireGuard, bypassing the proxy for better performance.
+func clientsStartDirectRelay(tunnelIP string) {
 	if !ready {
 		return
 	}
-	// add a udp proxy for localost and the wgService port
-	// TODO: make sure this port is not used in a target
 	if wgService != nil {
-		pm.AddTarget("udp", tunnelIp, int(wgService.Port), fmt.Sprintf("127.0.0.1:%d", wgService.Port))
+		if err := wgService.StartDirectUDPRelay(tunnelIP); err != nil {
+			logger.Error("Failed to start direct UDP relay: %v", err)
+		}
 	}
-
-	clientsAddProxyTargetNative(pm, tunnelIp)
 }

clients/permissions/permissions_darwin.go

@@ -0,0 +1,18 @@
+//go:build darwin
+
+package permissions
+
+import (
+	"fmt"
+	"os"
+)
+
+// CheckNativeInterfacePermissions checks if the process has sufficient
+// permissions to create a native TUN interface on macOS.
+// This typically requires root privileges.
+func CheckNativeInterfacePermissions() error {
+	if os.Geteuid() == 0 {
+		return nil
+	}
+	return fmt.Errorf("insufficient permissions: need root to create TUN interface on macOS")
+}

clients/permissions/permissions_linux.go

@@ -0,0 +1,96 @@
+//go:build linux
+
+package permissions
+
+import (
+	"fmt"
+	"os"
+	"unsafe"
+
+	"github.com/fosrl/newt/logger"
+	"golang.org/x/sys/unix"
+)
+
+const (
+	// TUN device constants
+	tunDevice = "/dev/net/tun"
+	ifnamsiz  = 16
+	iffTun    = 0x0001
+	iffNoPi   = 0x1000
+	tunSetIff = 0x400454ca
+)
+
+// ifReq is the structure for TUNSETIFF ioctl
+type ifReq struct {
+	Name  [ifnamsiz]byte
+	Flags uint16
+	_     [22]byte // padding to match kernel structure
+}
+
+// CheckNativeInterfacePermissions checks if the process has sufficient
+// permissions to create a native TUN interface on Linux.
+// This requires either root privileges (UID 0) or CAP_NET_ADMIN capability.
+func CheckNativeInterfacePermissions() error {
+	logger.Debug("Checking native interface permissions on Linux")
+
+	// Check if running as root
+	if os.Geteuid() == 0 {
+		logger.Debug("Running as root, sufficient permissions for native TUN interface")
+		return nil
+	}
+
+	// Check for CAP_NET_ADMIN capability
+	caps := unix.CapUserHeader{
+		Version: unix.LINUX_CAPABILITY_VERSION_3,
+		Pid:     0, // 0 means current process
+	}
+
+	var data [2]unix.CapUserData
+	if err := unix.Capget(&caps, &data[0]); err != nil {
+		logger.Debug("Failed to get capabilities: %v, will try creating test TUN", err)
+	} else {
+		// CAP_NET_ADMIN is capability bit 12
+		const CAP_NET_ADMIN = 12
+		if data[0].Effective&(1<<CAP_NET_ADMIN) != 0 {
+			logger.Debug("Process has CAP_NET_ADMIN capability, sufficient permissions for native TUN interface")
+			return nil
+		}
+		logger.Debug("Process does not have CAP_NET_ADMIN capability in effective set")
+	}
+
+	// Actually try to create a TUN interface to verify permissions
+	// This is the most reliable check as it tests the actual operation
+	return tryCreateTestTun()
+}
+
+// tryCreateTestTun attempts to create a temporary TUN interface to verify
+// we have the necessary permissions. This tests the actual ioctl call that
+// will be used when creating the real interface.
+func tryCreateTestTun() error {
+	f, err := os.OpenFile(tunDevice, os.O_RDWR, 0)
+	if err != nil {
+		return fmt.Errorf("cannot open %s: %v (need root or CAP_NET_ADMIN capability)", tunDevice, err)
+	}
+	defer f.Close()
+
+	// Try to create a TUN interface with a test name
+	// Using a random-ish name to avoid conflicts
+	var req ifReq
+	copy(req.Name[:], "tuntest0")
+	req.Flags = iffTun | iffNoPi
+
+	_, _, errno := unix.Syscall(
+		unix.SYS_IOCTL,
+		f.Fd(),
+		uintptr(tunSetIff),
+		uintptr(unsafe.Pointer(&req)),
+	)
+
+	if errno != 0 {
+		return fmt.Errorf("cannot create TUN interface (ioctl TUNSETIFF failed): %v (need root or CAP_NET_ADMIN capability)", errno)
+	}
+
+	// Success - the interface will be automatically destroyed when we close the fd
+	logger.Debug("Successfully created test TUN interface, sufficient permissions for native TUN interface")
+	return nil
+}

clients/permissions/permissions_windows.go

@@ -0,0 +1,38 @@
+//go:build windows
+
+package permissions
+
+import (
+	"fmt"
+
+	"golang.org/x/sys/windows"
+)
+
+// CheckNativeInterfacePermissions checks if the process has sufficient
+// permissions to create a native TUN interface on Windows.
+// This requires Administrator privileges.
+func CheckNativeInterfacePermissions() error {
+	var sid *windows.SID
+	err := windows.AllocateAndInitializeSid(
+		&windows.SECURITY_NT_AUTHORITY,
+		2,
+		windows.SECURITY_BUILTIN_DOMAIN_RID,
+		windows.DOMAIN_ALIAS_RID_ADMINS,
+		0, 0, 0, 0, 0, 0,
+		&sid)
+	if err != nil {
+		return fmt.Errorf("failed to initialize SID: %v", err)
+	}
+	defer windows.FreeSid(sid)
+
+	token := windows.Token(0)
+	member, err := token.IsMember(sid)
+	if err != nil {
+		return fmt.Errorf("failed to check admin group membership: %v", err)
+	}
+
+	if !member {
+		return fmt.Errorf("insufficient permissions: need Administrator to create TUN interface on Windows")
+	}
+	return nil
+}

common.go

@@ -2,11 +2,9 @@ package main
 
 import (
 	"bytes"
-	"encoding/base64"
-	"encoding/hex"
+	"context"
 	"encoding/json"
 	"fmt"
-	"net"
 	"os"
 	"os/exec"
 	"strings"
@@ -14,32 +12,20 @@ import (
 
 	"math/rand"
 
+	"github.com/fosrl/newt/internal/telemetry"
 	"github.com/fosrl/newt/logger"
 	"github.com/fosrl/newt/proxy"
 	"github.com/fosrl/newt/websocket"
 	"golang.org/x/net/icmp"
 	"golang.org/x/net/ipv4"
-	"golang.zx2c4.com/wireguard/device"
 	"golang.zx2c4.com/wireguard/tun/netstack"
 	"gopkg.in/yaml.v3"
 )
 
-func fixKey(key string) string {
-	// Remove any whitespace
-	key = strings.TrimSpace(key)
-
-	// Decode from base64
-	decoded, err := base64.StdEncoding.DecodeString(key)
-	if err != nil {
-		logger.Fatal("Error decoding base64: %v", err)
-	}
-
-	// Convert to hex
-	return hex.EncodeToString(decoded)
-}
+const msgHealthFileWriteFailed = "Failed to write health file: %v"
 
 func ping(tnet *netstack.Net, dst string, timeout time.Duration) (time.Duration, error) {
-	logger.Debug("Pinging %s", dst)
+	// logger.Debug("Pinging %s", dst)
 	socket, err := tnet.Dial("ping4", dst)
 	if err != nil {
 		return 0, fmt.Errorf("failed to create ICMP socket: %w", err)
@@ -98,7 +84,7 @@ func ping(tnet *netstack.Net, dst string, timeout time.Duration) (time.Duration,
 
 	latency := time.Since(start)
 
-	logger.Debug("Ping to %s successful, latency: %v", dst, latency)
+	// logger.Debug("Ping to %s successful, latency: %v", dst, latency)
 
 	return latency, nil
 }
@@ -136,7 +122,7 @@ func reliablePing(tnet *netstack.Net, dst string, baseTimeout time.Duration, max
 		// If we get at least one success, we can return early for health checks
 		if successCount > 0 {
 			avgLatency := totalLatency / time.Duration(successCount)
-			logger.Debug("Reliable ping succeeded after %d attempts, avg latency: %v", attempt, avgLatency)
+			// logger.Debug("Reliable ping succeeded after %d attempts, avg latency: %v", attempt, avgLatency)
 			return avgLatency, nil
 		}
 	}
@@ -176,7 +162,7 @@ func pingWithRetry(tnet *netstack.Net, dst string, timeout time.Duration) (stopC
 		if healthFile != "" {
 			err := os.WriteFile(healthFile, []byte("ok"), 0644)
 			if err != nil {
-				logger.Warn("Failed to write health file: %v", err)
+				logger.Warn(msgHealthFileWriteFailed, err)
 			}
 		}
 		return stopChan, nil
@@ -217,11 +203,13 @@ func pingWithRetry(tnet *netstack.Net, dst string, timeout time.Duration) (stopC
 					if healthFile != "" {
 						err := os.WriteFile(healthFile, []byte("ok"), 0644)
 						if err != nil {
-							logger.Warn("Failed to write health file: %v", err)
+							logger.Warn(msgHealthFileWriteFailed, err)
 						}
 					}
-					return
 				}
+			case <-pingStopChan:
+				// Stop the goroutine when signaled
+				return
 			}
 		}
 	}()
@@ -230,7 +218,7 @@ func pingWithRetry(tnet *netstack.Net, dst string, timeout time.Duration) (stopC
 	return stopChan, fmt.Errorf("initial ping attempts failed, continuing in background")
 }
 
-func startPingCheck(tnet *netstack.Net, serverIP string, client *websocket.Client) chan struct{} {
+func startPingCheck(tnet *netstack.Net, serverIP string, client *websocket.Client, tunnelID string) chan struct{} {
 	maxInterval := 6 * time.Second
 	currentInterval := pingInterval
 	consecutiveFailures := 0
@@ -293,6 +281,9 @@ func startPingCheck(tnet *netstack.Net, serverIP string, client *websocket.Clien
 						if !connectionLost {
 							connectionLost = true
 							logger.Warn("Connection to server lost after %d failures. Continuous reconnection attempts will be made.", consecutiveFailures)
+							if tunnelID != "" {
+								telemetry.IncReconnect(context.Background(), tunnelID, "client", telemetry.ReasonTimeout)
+							}
 							stopFunc = client.SendMessageInterval("newt/ping/request", map[string]interface{}{}, 3*time.Second)
 							// Send registration message to the server for backward compatibility
 							err := client.SendMessage("newt/wg/register", map[string]interface{}{
@@ -319,6 +310,10 @@ func startPingCheck(tnet *netstack.Net, serverIP string, client *websocket.Clien
 				} else {
 					// Track recent latencies
 					recentLatencies = append(recentLatencies, latency)
+					// Record tunnel latency (limit sampling to this periodic check)
+					if tunnelID != "" {
+						telemetry.ObserveTunnelLatency(context.Background(), tunnelID, "wireguard", latency.Seconds())
+					}
 					if len(recentLatencies) > 10 {
 						recentLatencies = recentLatencies[1:]
 					}
@@ -353,89 +348,6 @@ func startPingCheck(tnet *netstack.Net, serverIP string, client *websocket.Clien
 	return pingStopChan
 }
 
-func parseLogLevel(level string) logger.LogLevel {
-	switch strings.ToUpper(level) {
-	case "DEBUG":
-		return logger.DEBUG
-	case "INFO":
-		return logger.INFO
-	case "WARN":
-		return logger.WARN
-	case "ERROR":
-		return logger.ERROR
-	case "FATAL":
-		return logger.FATAL
-	default:
-		return logger.INFO // default to INFO if invalid level provided
-	}
-}
-
-func mapToWireGuardLogLevel(level logger.LogLevel) int {
-	switch level {
-	case logger.DEBUG:
-		return device.LogLevelVerbose
-	// case logger.INFO:
-	// return device.LogLevel
-	case logger.WARN:
-		return device.LogLevelError
-	case logger.ERROR, logger.FATAL:
-		return device.LogLevelSilent
-	default:
-		return device.LogLevelSilent
-	}
-}
-
-func resolveDomain(domain string) (string, error) {
-	// Check if there's a port in the domain
-	host, port, err := net.SplitHostPort(domain)
-	if err != nil {
-		// No port found, use the domain as is
-		host = domain
-		port = ""
-	}
-
-	// Remove any protocol prefix if present
-	if strings.HasPrefix(host, "http://") {
-		host = strings.TrimPrefix(host, "http://")
-	} else if strings.HasPrefix(host, "https://") {
-		host = strings.TrimPrefix(host, "https://")
-	}
-
-	// if there are any trailing slashes, remove them
-	host = strings.TrimSuffix(host, "/")
-
-	// Lookup IP addresses
-	ips, err := net.LookupIP(host)
-	if err != nil {
-		return "", fmt.Errorf("DNS lookup failed: %v", err)
-	}
-
-	if len(ips) == 0 {
-		return "", fmt.Errorf("no IP addresses found for domain %s", host)
-	}
-
-	// Get the first IPv4 address if available
-	var ipAddr string
-	for _, ip := range ips {
-		if ipv4 := ip.To4(); ipv4 != nil {
-			ipAddr = ipv4.String()
-			break
-		}
-	}
-
-	// If no IPv4 found, use the first IP (might be IPv6)
-	if ipAddr == "" {
-		ipAddr = ips[0].String()
-	}
-
-	// Add port back if it existed
-	if port != "" {
-		ipAddr = net.JoinHostPort(ipAddr, port)
-	}
-
-	return ipAddr, nil
-}
-
 func parseTargetData(data interface{}) (TargetData, error) {
 	var targetData TargetData
 	jsonData, err := json.Marshal(data)
@@ -468,7 +380,8 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 			continue
 		}
 
-		if action == "add" {
+		switch action {
+		case "add":
 			target := parts[1] + ":" + parts[2]
 
 			// Call updown script if provided
@@ -494,7 +407,7 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 			// Add the new target
 			pm.AddTarget(proto, tunnelIP, port, processedTarget)
 
-		} else if action == "remove" {
+		case "remove":
 			logger.Info("Removing target with port %d", port)
 
 			target := parts[1] + ":" + parts[2]
@@ -512,6 +425,8 @@ func updateTargets(pm *proxy.ProxyManager, action string, tunnelIP string, proto
 				logger.Error("Failed to remove target: %v", err)
 				return err
 			}
+		default:
+			logger.Info("Unknown action: %s", action)
 		}
 	}
 

docker-compose.metrics.collector.yml

@@ -0,0 +1,41 @@
+services:
+  newt:
+    build: .
+    image: newt:dev
+    env_file:
+      - .env
+    environment:
+      - NEWT_METRICS_PROMETHEUS_ENABLED=false   # important: disable direct /metrics scraping
+      - NEWT_METRICS_OTLP_ENABLED=true          # OTLP to the Collector
+      # optional:
+      # - NEWT_METRICS_INCLUDE_TUNNEL_ID=false
+  # When using the Collector pattern, do NOT map the Newt admin/metrics port
+  # (2112) on the application service. Mapping 2112 here can cause port
+  # conflicts and may result in duplicated Prometheus scraping (app AND
+  # collector being scraped for the same metrics). Instead either:
+  #  - leave ports unset on the app service (recommended), or
+  #  - map 2112 only on a dedicated metrics/collector service that is
+  #    responsible for exposing metrics to Prometheus.
+  # Example: do NOT map here
+  # ports: []
+  # Example: map 2112 only on a collector service
+  # collector:
+  #   ports:
+  #     - "2112:2112"  # collector's prometheus exporter (scraped by Prometheus)
+
+  otel-collector:
+    image: otel/opentelemetry-collector-contrib:latest
+    command: ["--config=/etc/otelcol/config.yaml"]
+    volumes:
+      - ./examples/otel-collector.yaml:/etc/otelcol/config.yaml:ro
+    ports:
+      - "4317:4317"   # OTLP gRPC
+      - "8889:8889"   # Prometheus Exporter (scraped by Prometheus)
+
+  prometheus:
+    image: prom/prometheus:latest
+    volumes:
+      - ./examples/prometheus.with-collector.yml:/etc/prometheus/prometheus.yml:ro
+    ports:
+      - "9090:9090"
+

docker-compose.metrics.yml

@@ -0,0 +1,56 @@
+name: Newt-Metrics
+services:
+  # Recommended Variant A: Direct Prometheus scrape of Newt (/metrics)
+  # Optional: You may add the Collector service and enable OTLP export, but do NOT
+  # scrape both Newt and the Collector for the same process.
+
+  newt:
+    build: .
+    image: newt:dev
+    env_file:
+      - .env
+    environment:
+      OTEL_SERVICE_NAME: newt
+      NEWT_METRICS_PROMETHEUS_ENABLED: "true"
+      NEWT_METRICS_OTLP_ENABLED: "false"   # avoid double-scrape by default
+      NEWT_ADMIN_ADDR: ":2112"
+      # Base NEWT configuration
+      PANGOLIN_ENDPOINT: ${PANGOLIN_ENDPOINT}
+      NEWT_ID: ${NEWT_ID}
+      NEWT_SECRET: ${NEWT_SECRET}
+      LOG_LEVEL: "DEBUG"
+    ports:
+      - "2112:2112"
+
+  # Optional Variant B: Enable the Collector and switch Prometheus scrape to it.
+  # collector:
+  #   image: otel/opentelemetry-collector-contrib:0.136.0
+  #   command: ["--config=/etc/otelcol/config.yaml"]
+  #   volumes:
+  #     - ./examples/otel-collector.yaml:/etc/otelcol/config.yaml:ro
+  #   ports:
+  #     - "4317:4317"   # OTLP gRPC in
+  #     - "8889:8889"   # Prometheus scrape out
+
+  prometheus:
+    image: prom/prometheus:v3.6.0
+    volumes:
+      - ./examples/prometheus.yml:/etc/prometheus/prometheus.yml:ro
+    ports:
+      - "9090:9090"
+
+  grafana:
+    image: grafana/grafana:12.2.0
+    container_name: newt-metrics-grafana
+    restart: unless-stopped
+    environment:
+      - GF_SECURITY_ADMIN_USER=admin
+      - GF_SECURITY_ADMIN_PASSWORD=admin
+    ports:
+      - "3005:3000"
+    depends_on:
+      - prometheus
+    volumes:
+      - ./examples/grafana/provisioning/datasources:/etc/grafana/provisioning/datasources:ro
+      - ./examples/grafana/provisioning/dashboards:/etc/grafana/provisioning/dashboards:ro
+      - ./examples/grafana/dashboards:/var/lib/grafana/dashboards:ro

examples/README.md

@@ -0,0 +1,167 @@
+# Extensible Logger
+
+This logger package provides a flexible logging system that can be extended with custom log writers.
+
+## Basic Usage (Current Behavior)
+
+The logger works exactly as before with no changes required:
+
+```go
+package main
+
+import "your-project/logger"
+
+func main() {
+    // Use default logger
+    logger.Info("This works as before")
+    logger.Debug("Debug message")
+    logger.Error("Error message")
+    
+    // Or create a custom instance
+    log := logger.NewLogger()
+    log.SetLevel(logger.INFO)
+    log.Info("Custom logger instance")
+}
+```
+
+## Custom Log Writers
+
+To use a custom log backend, implement the `LogWriter` interface:
+
+```go
+type LogWriter interface {
+    Write(level LogLevel, timestamp time.Time, message string)
+}
+```
+
+### Example: OS Log Writer (macOS/iOS)
+
+```go
+package main
+
+import "your-project/logger"
+
+func main() {
+    // Create an OS log writer
+    osWriter := logger.NewOSLogWriter(
+        "net.pangolin.Pangolin.PacketTunnel",
+        "PangolinGo",
+        "MyApp",
+    )
+    
+    // Create a logger with the OS log writer
+    log := logger.NewLoggerWithWriter(osWriter)
+    log.SetLevel(logger.DEBUG)
+    
+    // Use it just like the standard logger
+    log.Info("This message goes to os_log")
+    log.Error("Error logged to os_log")
+}
+```
+
+### Example: Custom Writer
+
+```go
+package main
+
+import (
+    "fmt"
+    "time"
+    "your-project/logger"
+)
+
+// CustomWriter writes logs to a custom destination
+type CustomWriter struct {
+    // your custom fields
+}
+
+func (w *CustomWriter) Write(level logger.LogLevel, timestamp time.Time, message string) {
+    // Your custom logging logic
+    fmt.Printf("[CUSTOM] %s [%s] %s\n", timestamp.Format(time.RFC3339), level.String(), message)
+}
+
+func main() {
+    customWriter := &CustomWriter{}
+    log := logger.NewLoggerWithWriter(customWriter)
+    log.Info("Custom logging!")
+}
+```
+
+### Example: Multi-Writer (Log to Multiple Destinations)
+
+```go
+package main
+
+import (
+    "time"
+    "your-project/logger"
+)
+
+// MultiWriter writes to multiple log writers
+type MultiWriter struct {
+    writers []logger.LogWriter
+}
+
+func NewMultiWriter(writers ...logger.LogWriter) *MultiWriter {
+    return &MultiWriter{writers: writers}
+}
+
+func (w *MultiWriter) Write(level logger.LogLevel, timestamp time.Time, message string) {
+    for _, writer := range w.writers {
+        writer.Write(level, timestamp, message)
+    }
+}
+
+func main() {
+    // Log to both standard output and OS log
+    standardWriter := logger.NewStandardWriter()
+    osWriter := logger.NewOSLogWriter("com.example.app", "Main", "App")
+    
+    multiWriter := NewMultiWriter(standardWriter, osWriter)
+    log := logger.NewLoggerWithWriter(multiWriter)
+    
+    log.Info("This goes to both stdout and os_log!")
+}
+```
+
+## API Reference
+
+### Creating Loggers
+
+- `NewLogger()` - Creates a logger with the default StandardWriter
+- `NewLoggerWithWriter(writer LogWriter)` - Creates a logger with a custom writer
+
+### Built-in Writers
+
+- `NewStandardWriter()` - Standard writer that outputs to stdout (default)
+- `NewOSLogWriter(subsystem, category, prefix string)` - OS log writer for macOS/iOS (example)
+
+### Logger Methods
+
+- `SetLevel(level LogLevel)` - Set minimum log level
+- `SetOutput(output *os.File)` - Set output file (StandardWriter only)
+- `Debug(format string, args ...interface{})` - Log debug message
+- `Info(format string, args ...interface{})` - Log info message
+- `Warn(format string, args ...interface{})` - Log warning message
+- `Error(format string, args ...interface{})` - Log error message
+- `Fatal(format string, args ...interface{})` - Log fatal message and exit
+
+### Global Functions
+
+For convenience, you can use global functions that use the default logger:
+
+- `logger.Debug(format, args...)`
+- `logger.Info(format, args...)`
+- `logger.Warn(format, args...)`
+- `logger.Error(format, args...)`
+- `logger.Fatal(format, args...)`
+- `logger.SetOutput(output *os.File)`
+
+## Migration Guide
+
+No changes needed! The logger maintains 100% backward compatibility. Your existing code will continue to work without modifications.
+
+If you want to switch to a custom writer:
+1. Create your writer implementing `LogWriter`
+2. Use `NewLoggerWithWriter()` instead of `NewLogger()`
+3. That's it!

examples/grafana/dashboards/newt-overview.json

@@ -0,0 +1,898 @@
+{
+  "annotations": {
+    "list": [
+      {
+        "builtIn": 1,
+        "datasource": {
+          "type": "grafana",
+          "uid": "-- Grafana --"
+        },
+        "enable": true,
+        "hide": true,
+        "iconColor": "rgba(0, 211, 255, 1)",
+        "name": "Annotations & Alerts",
+        "type": "dashboard"
+      }
+    ]
+  },
+  "editable": true,
+  "fiscalYearStartMonth": 0,
+  "graphTooltip": 0,
+  "id": null,
+  "links": [],
+  "liveNow": false,
+  "panels": [
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "decimals": 0,
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "red",
+                "value": 500
+              }
+            ]
+          }
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 7,
+        "w": 6,
+        "x": 0,
+        "y": 0
+      },
+      "id": 1,
+      "options": {
+        "colorMode": "value",
+        "graphMode": "area",
+        "justifyMode": "auto",
+        "orientation": "horizontal",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "textMode": "value_and_name"
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "go_goroutine_count",
+          "instant": true,
+          "legendFormat": "",
+          "refId": "A"
+        }
+      ],
+      "title": "Goroutines",
+      "transformations": [],
+      "type": "stat"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "decimals": 1,
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "orange",
+                "value": 256
+              },
+              {
+                "color": "red",
+                "value": 512
+              }
+            ]
+          },
+          "unit": "bytes"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 7,
+        "w": 6,
+        "x": 6,
+        "y": 0
+      },
+      "id": 2,
+      "options": {
+        "colorMode": "background",
+        "graphMode": "area",
+        "justifyMode": "auto",
+        "orientation": "horizontal",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "textMode": "value_and_name"
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "go_memory_gc_goal_bytes / 1024 / 1024",
+          "format": "time_series",
+          "instant": true,
+          "legendFormat": "",
+          "refId": "A"
+        }
+      ],
+      "title": "GC Target Heap (MiB)",
+      "transformations": [],
+      "type": "stat"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "decimals": 2,
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "orange",
+                "value": 10
+              },
+              {
+                "color": "red",
+                "value": 25
+              }
+            ]
+          },
+          "unit": "ops"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 7,
+        "w": 6,
+        "x": 12,
+        "y": 0
+      },
+      "id": 3,
+      "options": {
+        "colorMode": "value",
+        "graphMode": "area",
+        "justifyMode": "auto",
+        "orientation": "horizontal",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "textMode": "value_and_name"
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(rate(http_server_request_duration_seconds_count[$__rate_interval]))",
+          "instant": false,
+          "legendFormat": "req/s",
+          "refId": "A"
+        }
+      ],
+      "title": "HTTP Requests / s",
+      "transformations": [],
+      "type": "stat"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "decimals": 3,
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              },
+              {
+                "color": "orange",
+                "value": 0.1
+              },
+              {
+                "color": "red",
+                "value": 0.5
+              }
+            ]
+          },
+          "unit": "ops"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 7,
+        "w": 6,
+        "x": 18,
+        "y": 0
+      },
+      "id": 4,
+      "options": {
+        "colorMode": "value",
+        "graphMode": "area",
+        "justifyMode": "auto",
+        "orientation": "horizontal",
+        "reduceOptions": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "fields": "",
+          "values": false
+        },
+        "textMode": "value_and_name"
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(rate(newt_connection_errors_total{site_id=~\"$site_id\"}[$__rate_interval]))",
+          "instant": false,
+          "legendFormat": "errors/s",
+          "refId": "A"
+        }
+      ],
+      "title": "Connection Errors / s",
+      "transformations": [],
+      "type": "stat"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "mappings": [],
+          "unit": "bytes"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 0,
+        "y": 7
+      },
+      "id": 5,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(go_memory_used_bytes)",
+          "legendFormat": "Used",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "go_memory_gc_goal_bytes",
+          "legendFormat": "GC Goal",
+          "refId": "B"
+        }
+      ],
+      "title": "Go Heap Usage vs GC Goal",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "decimals": 0,
+          "mappings": [],
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 12,
+        "y": 7
+      },
+      "id": 6,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "rate(go_memory_allocations_total[$__rate_interval])",
+          "legendFormat": "Allocations/s",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "rate(go_memory_allocated_bytes_total[$__rate_interval])",
+          "legendFormat": "Allocated bytes/s",
+          "refId": "B"
+        }
+      ],
+      "title": "Allocation Activity",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "mappings": [],
+          "unit": "s"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 0,
+        "y": 16
+      },
+      "id": 7,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "histogram_quantile(0.5, sum(rate(http_server_request_duration_seconds_bucket[$__rate_interval])) by (le))",
+          "legendFormat": "p50",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "histogram_quantile(0.95, sum(rate(http_server_request_duration_seconds_bucket[$__rate_interval])) by (le))",
+          "legendFormat": "p95",
+          "refId": "B"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "histogram_quantile(0.99, sum(rate(http_server_request_duration_seconds_bucket[$__rate_interval])) by (le))",
+          "legendFormat": "p99",
+          "refId": "C"
+        }
+      ],
+      "title": "HTTP Request Duration Quantiles",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "mappings": [],
+          "unit": "ops"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 12,
+        "y": 16
+      },
+      "id": 8,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(rate(http_server_request_duration_seconds_count[$__rate_interval])) by (http_response_status_code)",
+          "legendFormat": "{{http_response_status_code}}",
+          "refId": "A"
+        }
+      ],
+      "title": "HTTP Requests by Status",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "mappings": [],
+          "unit": "ops"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 0,
+        "y": 25
+      },
+      "id": 9,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(rate(newt_connection_attempts_total{site_id=~\"$site_id\"}[$__rate_interval])) by (transport, result)",
+          "legendFormat": "{{transport}} • {{result}}",
+          "refId": "A"
+        }
+      ],
+      "title": "Connection Attempts by Transport/Result",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "mappings": [],
+          "unit": "ops"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 12,
+        "y": 25
+      },
+      "id": 10,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(rate(newt_connection_errors_total{site_id=~\"$site_id\"}[$__rate_interval])) by (transport, error_type)",
+          "legendFormat": "{{transport}} • {{error_type}}",
+          "refId": "A"
+        }
+      ],
+      "title": "Connection Errors by Type",
+      "type": "timeseries"
+    },
+    {
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "decimals": 3,
+          "mappings": [],
+          "unit": "s"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 0,
+        "y": 34
+      },
+      "id": 11,
+      "options": {
+        "legend": {
+          "calcs": [],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "multi",
+          "sort": "desc"
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "histogram_quantile(0.5, sum(rate(newt_tunnel_latency_seconds_bucket{site_id=~\"$site_id\", tunnel_id=~\"$tunnel_id\"}[$__rate_interval])) by (le))",
+          "legendFormat": "p50",
+          "refId": "A"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "histogram_quantile(0.95, sum(rate(newt_tunnel_latency_seconds_bucket{site_id=~\"$site_id\", tunnel_id=~\"$tunnel_id\"}[$__rate_interval])) by (le))",
+          "legendFormat": "p95",
+          "refId": "B"
+        },
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "histogram_quantile(0.99, sum(rate(newt_tunnel_latency_seconds_bucket{site_id=~\"$site_id\", tunnel_id=~\"$tunnel_id\"}[$__rate_interval])) by (le))",
+          "legendFormat": "p99",
+          "refId": "C"
+        }
+      ],
+      "title": "Tunnel Latency Quantiles",
+      "type": "timeseries"
+    },
+    {
+      "cards": {},
+      "color": {
+        "cardColor": "#b4ff00",
+        "colorScale": "sqrt",
+        "colorScheme": "interpolateTurbo"
+      },
+      "dataFormat": "tsbuckets",
+      "datasource": {
+        "type": "prometheus",
+        "uid": "prometheus"
+      },
+      "fieldConfig": {
+        "defaults": {
+          "custom": {},
+          "mappings": [],
+          "unit": "s"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 9,
+        "w": 12,
+        "x": 12,
+        "y": 34
+      },
+      "heatmap": {},
+      "hideZeroBuckets": true,
+      "id": 12,
+      "legend": {
+        "show": false
+      },
+      "options": {
+        "calculate": true,
+        "cellGap": 2,
+        "cellSize": "auto",
+        "color": {
+          "exponent": 0.5
+        },
+        "exemplars": {
+          "color": "rgba(255,255,255,0.7)"
+        },
+        "filterValues": {
+          "le": 1e-9
+        },
+        "legend": {
+          "show": false
+        },
+        "tooltip": {
+          "mode": "single",
+          "show": true
+        },
+        "xAxis": {
+          "show": true
+        },
+        "yAxis": {
+          "decimals": 3,
+          "show": true
+        }
+      },
+      "pluginVersion": "11.1.0",
+      "targets": [
+        {
+          "datasource": {
+            "type": "prometheus",
+            "uid": "prometheus"
+          },
+          "editorMode": "code",
+          "expr": "sum(rate(newt_tunnel_latency_seconds_bucket{site_id=~\"$site_id\", tunnel_id=~\"$tunnel_id\"}[$__rate_interval])) by (le)",
+          "format": "heatmap",
+          "legendFormat": "{{le}}",
+          "refId": "A"
+        }
+      ],
+      "title": "Tunnel Latency Bucket Rate",
+      "type": "heatmap"
+    }
+  ],
+  "refresh": "30s",
+  "schemaVersion": 39,
+  "style": "dark",
+  "tags": [
+    "newt",
+    "otel"
+  ],
+  "templating": {
+    "list": [
+      {
+        "current": {
+          "selected": false,
+          "text": "Prometheus",
+          "value": "prometheus"
+        },
+        "hide": 0,
+        "label": "Datasource",
+        "name": "DS_PROMETHEUS",
+        "options": [],
+        "query": "prometheus",
+        "refresh": 1,
+        "type": "datasource"
+      },
+      {
+        "current": {
+          "selected": false,
+          "text": "All",
+          "value": "$__all"
+        },
+        "datasource": {
+          "type": "prometheus",
+          "uid": "prometheus"
+        },
+        "definition": "label_values(target_info, site_id)",
+        "hide": 0,
+        "includeAll": true,
+        "label": "Site",
+        "multi": true,
+        "name": "site_id",
+        "options": [],
+        "query": {
+          "query": "label_values(target_info, site_id)",
+          "refId": "SiteIdVar"
+        },
+        "refresh": 2,
+        "regex": "",
+        "skipUrlSync": false,
+        "sort": 1,
+        "tagValuesQuery": "",
+        "tags": [],
+      "tagsQuery": "",
+        "type": "query",
+        "useTags": false
+      },
+      {
+        "current": {
+          "selected": false,
+          "text": "All",
+          "value": "$__all"
+        },
+        "datasource": {
+          "type": "prometheus",
+          "uid": "prometheus"
+        },
+        "definition": "label_values(newt_tunnel_latency_seconds_bucket{site_id=~\"$site_id\"}, tunnel_id)",
+        "hide": 0,
+        "includeAll": true,
+        "label": "Tunnel",
+        "multi": true,
+        "name": "tunnel_id",
+        "options": [],
+        "query": {
+          "query": "label_values(newt_tunnel_latency_seconds_bucket{site_id=~\"$site_id\"}, tunnel_id)",
+          "refId": "TunnelVar"
+        },
+        "refresh": 2,
+        "regex": "",
+        "skipUrlSync": false,
+        "sort": 1,
+        "tagValuesQuery": "",
+        "tags": [],
+        "tagsQuery": "",
+        "type": "query",
+        "useTags": false
+      }
+    ]
+  },
+  "time": {
+    "from": "now-6h",
+    "to": "now"
+  },
+  "timepicker": {
+    "refresh_intervals": [
+      "10s",
+      "30s",
+      "1m",
+      "5m",
+      "15m",
+      "30m",
+      "1h",
+      "2h",
+      "1d"
+    ],
+    "time_options": [
+      "5m",
+      "15m",
+      "1h",
+      "6h",
+      "12h",
+      "24h",
+      "2d",
+      "7d",
+      "30d"
+    ]
+  },
+  "timezone": "browser",
+  "title": "Newt Overview",
+  "uid": "newt-overview",
+  "version": 1,
+  "weekStart": ""
+}

examples/grafana/provisioning/dashboards/dashboard.yaml

@@ -0,0 +1,9 @@
+apiVersion: 1
+providers:
+  - name: "newt"
+    folder: "Newt"
+    type: file
+    disableDeletion: false
+    allowUiUpdates: true
+    options:
+      path: /var/lib/grafana/dashboards

examples/grafana/provisioning/datasources/prometheus.yaml

@@ -0,0 +1,9 @@
+apiVersion: 1
+datasources:
+  - name: Prometheus
+    type: prometheus
+    access: proxy
+    url: http://prometheus:9090
+    uid: prometheus
+    isDefault: true
+    editable: true

examples/logger_examples.go

@@ -0,0 +1,161 @@
+// Example usage patterns for the extensible logger
+package main
+
+import (
+	"fmt"
+	"os"
+	"time"
+
+	"github.com/fosrl/newt/logger"
+)
+
+// Example 1: Using the default logger (works exactly as before)
+func exampleDefaultLogger() {
+	logger.Info("Starting application")
+	logger.Debug("Debug information")
+	logger.Warn("Warning message")
+	logger.Error("Error occurred")
+}
+
+// Example 2: Using a custom logger instance with standard writer
+func exampleCustomInstance() {
+	log := logger.NewLogger()
+	log.SetLevel(logger.INFO)
+	log.Info("This is from a custom instance")
+}
+
+// Example 3: Custom writer that adds JSON formatting
+type JSONWriter struct{}
+
+func (w *JSONWriter) Write(level logger.LogLevel, timestamp time.Time, message string) {
+	fmt.Printf("{\"time\":\"%s\",\"level\":\"%s\",\"message\":\"%s\"}\n",
+		timestamp.Format(time.RFC3339),
+		level.String(),
+		message)
+}
+
+func exampleJSONLogger() {
+	jsonWriter := &JSONWriter{}
+	log := logger.NewLoggerWithWriter(jsonWriter)
+	log.Info("This will be logged as JSON")
+}
+
+// Example 4: File writer
+type FileWriter struct {
+	file *os.File
+}
+
+func NewFileWriter(filename string) (*FileWriter, error) {
+	file, err := os.OpenFile(filename, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0644)
+	if err != nil {
+		return nil, err
+	}
+	return &FileWriter{file: file}, nil
+}
+
+func (w *FileWriter) Write(level logger.LogLevel, timestamp time.Time, message string) {
+	fmt.Fprintf(w.file, "[%s] %s: %s\n",
+		timestamp.Format("2006-01-02 15:04:05"),
+		level.String(),
+		message)
+}
+
+func (w *FileWriter) Close() error {
+	return w.file.Close()
+}
+
+func exampleFileLogger() {
+	fileWriter, err := NewFileWriter("/tmp/app.log")
+	if err != nil {
+		panic(err)
+	}
+	defer fileWriter.Close()
+
+	log := logger.NewLoggerWithWriter(fileWriter)
+	log.Info("This goes to a file")
+}
+
+// Example 5: Multi-writer to log to multiple destinations
+type MultiWriter struct {
+	writers []logger.LogWriter
+}
+
+func NewMultiWriter(writers ...logger.LogWriter) *MultiWriter {
+	return &MultiWriter{writers: writers}
+}
+
+func (w *MultiWriter) Write(level logger.LogLevel, timestamp time.Time, message string) {
+	for _, writer := range w.writers {
+		writer.Write(level, timestamp, message)
+	}
+}
+
+func exampleMultiWriter() {
+	// Log to both stdout and a file
+	standardWriter := logger.NewStandardWriter()
+	fileWriter, _ := NewFileWriter("/tmp/app.log")
+
+	multiWriter := NewMultiWriter(standardWriter, fileWriter)
+	log := logger.NewLoggerWithWriter(multiWriter)
+
+	log.Info("This goes to both stdout and file!")
+}
+
+// Example 6: Conditional writer (only log errors to a specific destination)
+type ErrorOnlyWriter struct {
+	writer logger.LogWriter
+}
+
+func NewErrorOnlyWriter(writer logger.LogWriter) *ErrorOnlyWriter {
+	return &ErrorOnlyWriter{writer: writer}
+}
+
+func (w *ErrorOnlyWriter) Write(level logger.LogLevel, timestamp time.Time, message string) {
+	if level >= logger.ERROR {
+		w.writer.Write(level, timestamp, message)
+	}
+}
+
+func exampleConditionalWriter() {
+	errorWriter, _ := NewFileWriter("/tmp/errors.log")
+	errorOnlyWriter := NewErrorOnlyWriter(errorWriter)
+
+	log := logger.NewLoggerWithWriter(errorOnlyWriter)
+	log.Info("This won't be logged")
+	log.Error("This will be logged to errors.log")
+}
+
+/* Example 7: OS Log Writer (macOS/iOS only)
+// Uncomment on Darwin platforms
+
+func exampleOSLogWriter() {
+	osWriter := logger.NewOSLogWriter(
+		"net.pangolin.Pangolin.PacketTunnel",
+		"PangolinGo",
+		"MyApp",
+	)
+
+	log := logger.NewLoggerWithWriter(osWriter)
+	log.Info("This goes to os_log and can be viewed with Console.app")
+}
+*/
+
+func main() {
+	fmt.Println("=== Example 1: Default Logger ===")
+	exampleDefaultLogger()
+
+	fmt.Println("\n=== Example 2: Custom Instance ===")
+	exampleCustomInstance()
+
+	fmt.Println("\n=== Example 3: JSON Logger ===")
+	exampleJSONLogger()
+
+	fmt.Println("\n=== Example 4: File Logger ===")
+	exampleFileLogger()
+
+	fmt.Println("\n=== Example 5: Multi-Writer ===")
+	exampleMultiWriter()
+
+	fmt.Println("\n=== Example 6: Conditional Writer ===")
+	exampleConditionalWriter()
+}

examples/oslog_writer_example.go

@@ -0,0 +1,86 @@
+//go:build darwin
+// +build darwin
+
+package main
+
+/*
+#cgo CFLAGS: -I../PacketTunnel
+#include "../PacketTunnel/OSLogBridge.h"
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"fmt"
+	"runtime"
+	"time"
+	"unsafe"
+)
+
+// OSLogWriter is a LogWriter implementation that writes to Apple's os_log
+type OSLogWriter struct {
+	subsystem string
+	category  string
+	prefix    string
+}
+
+// NewOSLogWriter creates a new OSLogWriter
+func NewOSLogWriter(subsystem, category, prefix string) *OSLogWriter {
+	writer := &OSLogWriter{
+		subsystem: subsystem,
+		category:  category,
+		prefix:    prefix,
+	}
+
+	// Initialize the OS log bridge
+	cSubsystem := C.CString(subsystem)
+	cCategory := C.CString(category)
+	defer C.free(unsafe.Pointer(cSubsystem))
+	defer C.free(unsafe.Pointer(cCategory))
+
+	C.initOSLogBridge(cSubsystem, cCategory)
+
+	return writer
+}
+
+// Write implements the LogWriter interface
+func (w *OSLogWriter) Write(level LogLevel, timestamp time.Time, message string) {
+	// Get caller information (skip 3 frames to get to the actual caller)
+	_, file, line, ok := runtime.Caller(3)
+	if !ok {
+		file = "unknown"
+		line = 0
+	} else {
+		// Get just the filename, not the full path
+		for i := len(file) - 1; i > 0; i-- {
+			if file[i] == '/' {
+				file = file[i+1:]
+				break
+			}
+		}
+	}
+
+	formattedTime := timestamp.Format("2006-01-02 15:04:05.000")
+	fullMessage := fmt.Sprintf("[%s] [%s] [%s] %s:%d - %s",
+		formattedTime, level.String(), w.prefix, file, line, message)
+
+	cMessage := C.CString(fullMessage)
+	defer C.free(unsafe.Pointer(cMessage))
+
+	// Map Go log levels to os_log levels:
+	// 0=DEBUG, 1=INFO, 2=DEFAULT (WARN), 3=ERROR
+	var osLogLevel C.int
+	switch level {
+	case DEBUG:
+		osLogLevel = 0 // DEBUG
+	case INFO:
+		osLogLevel = 1 // INFO
+	case WARN:
+		osLogLevel = 2 // DEFAULT
+	case ERROR, FATAL:
+		osLogLevel = 3 // ERROR
+	default:
+		osLogLevel = 2 // DEFAULT
+	}
+
+	C.logToOSLog(osLogLevel, cMessage)
+}

examples/otel-collector.yaml

@@ -0,0 +1,61 @@
+# Variant A: Direct scrape of Newt (/metrics) via Prometheus (no Collector needed)
+# Note: Newt already exposes labels like site_id, protocol, direction. Do not promote
+# resource attributes into labels when scraping Newt directly.
+#
+# Example Prometheus scrape config:
+# global:
+#   scrape_interval: 15s
+# scrape_configs:
+#   - job_name: newt
+#     static_configs:
+#       - targets: ["newt:2112"]
+#
+# Variant B: Use OTEL Collector (Newt -> OTLP -> Collector -> Prometheus)
+# This pipeline scrapes metrics from the Collector's Prometheus exporter.
+# Labels are already on datapoints; promotion from resource is OPTIONAL and typically NOT required.
+# If you enable transform/promote below, ensure you do not duplicate labels.
+
+receivers:
+  otlp:
+    protocols:
+      grpc:
+        endpoint: ":4317"
+
+processors:
+  memory_limiter:
+    check_interval: 5s
+    limit_percentage: 80
+    spike_limit_percentage: 25
+  resourcedetection:
+    detectors: [env, system]
+    timeout: 5s
+  batch: {}
+  # OPTIONAL: Only enable if you need to promote resource attributes to labels.
+  # WARNING: Newt already provides site_id as a label; avoid double-promotion.
+  # transform/promote:
+  #   error_mode: ignore
+  #   metric_statements:
+  #     - context: datapoint
+  #       statements:
+  #         - set(attributes["service_instance_id"], resource.attributes["service.instance.id"]) where resource.attributes["service.instance.id"] != nil
+  #         - set(attributes["site_id"], resource.attributes["site_id"]) where resource.attributes["site_id"] != nil
+
+exporters:
+  prometheus:
+    endpoint: ":8889"
+    send_timestamps: true
+  # prometheusremotewrite:
+  #   endpoint: http://mimir:9009/api/v1/push
+  debug:
+    verbosity: basic
+
+service:
+  pipelines:
+    metrics:
+      receivers: [otlp]
+      processors: [memory_limiter, resourcedetection, batch] # add transform/promote if you really need it
+      exporters: [prometheus]
+    traces:
+      receivers: [otlp]
+      processors: [memory_limiter, resourcedetection, batch]
+      exporters: [debug]

examples/prometheus.with-collector.yml

@@ -0,0 +1,16 @@
+global:
+  scrape_interval: 15s
+
+scrape_configs:
+  # IMPORTANT: Do not scrape Newt directly; scrape only the Collector!
+  - job_name: 'otel-collector'
+    static_configs:
+      - targets: ['otel-collector:8889']
+
+    # optional: limit metric cardinality
+    relabel_configs:
+      - action: labeldrop
+        regex: 'tunnel_id'
+      # - action: keep
+      #   source_labels: [site_id]
+      #   regex: '(site-a|site-b)'

examples/prometheus.yml

@@ -0,0 +1,21 @@
+global:
+  scrape_interval: 15s
+
+scrape_configs:
+  - job_name: 'newt'
+    scrape_interval: 15s
+    static_configs:
+      - targets: ['newt:2112']  # /metrics
+    relabel_configs:
+    # optional: drop tunnel_id
+      - action: labeldrop
+        regex: 'tunnel_id'
+    # optional: allow only specific sites
+      - action: keep
+        source_labels: [site_id]
+        regex: '(site-a|site-b)'
+
+  # WARNING: Do not enable this together with the 'newt' job above or you will double-count.
+  # - job_name: 'otel-collector'
+  #   static_configs:
+  #     - targets: ['otel-collector:8889']

go.mod

@@ -3,32 +3,49 @@ module github.com/fosrl/newt
 go 1.25
 
 require (
-	github.com/docker/docker v28.5.0+incompatible
+	github.com/docker/docker v28.5.1+incompatible
 	github.com/google/gopacket v1.1.19
 	github.com/gorilla/websocket v1.5.3
+	github.com/prometheus/client_golang v1.23.2
 	github.com/vishvananda/netlink v1.3.1
-	golang.org/x/crypto v0.42.0
-	golang.org/x/exp v0.0.0-20250718183923-645b1fa84792
-	golang.org/x/net v0.45.0
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.63.0
+	go.opentelemetry.io/contrib/instrumentation/runtime v0.63.0
+	go.opentelemetry.io/otel v1.38.0
+	go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc v1.38.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.38.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.60.0
+	go.opentelemetry.io/otel/metric v1.38.0
+	go.opentelemetry.io/otel/sdk v1.38.0
+	go.opentelemetry.io/otel/sdk/metric v1.38.0
+	golang.org/x/crypto v0.44.0
+	golang.org/x/exp v0.0.0-20251113190631-e25ba8c21ef6
+	golang.org/x/net v0.47.0
 	golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20241231184526-a9ab2273dd10
+	google.golang.org/grpc v1.76.0
 	gopkg.in/yaml.v3 v3.0.1
 	gvisor.dev/gvisor v0.0.0-20250503011706-39ed1f5ac29c
 	software.sslmate.com/src/go-pkcs12 v0.6.0
 )
 
 require (
-	github.com/Microsoft/go-winio v0.6.2 // indirect
-	github.com/containerd/errdefs v1.0.0 // indirect
+	github.com/Microsoft/go-winio v0.6.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
+	github.com/cenkalti/backoff/v5 v5.0.3 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
+	github.com/containerd/errdefs v0.3.0 // indirect
 	github.com/containerd/errdefs/pkg v0.3.0 // indirect
 	github.com/distribution/reference v0.6.0 // indirect
-	github.com/docker/go-connections v0.5.0 // indirect
-	github.com/docker/go-units v0.5.0 // indirect
+	github.com/docker/go-connections v0.6.0 // indirect
+	github.com/docker/go-units v0.4.0 // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/go-logr/logr v1.4.3 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/google/btree v1.1.3 // indirect
 	github.com/google/go-cmp v0.7.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/grafana/regexp v0.0.0-20240518133315-a468a5bfb3bc // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.2 // indirect
 	github.com/josharian/native v1.1.0 // indirect
 	github.com/mdlayher/genetlink v1.3.2 // indirect
 	github.com/mdlayher/netlink v1.7.2 // indirect
@@ -37,18 +54,29 @@ require (
 	github.com/moby/sys/atomicwriter v0.1.0 // indirect
 	github.com/moby/term v0.5.2 // indirect
 	github.com/morikuni/aec v1.0.0 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/opencontainers/go-digest v1.0.0 // indirect
-	github.com/opencontainers/image-spec v1.1.1 // indirect
+	github.com/opencontainers/image-spec v1.1.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.66.1 // indirect
+	github.com/prometheus/otlptranslator v0.0.2 // indirect
+	github.com/prometheus/procfs v0.17.0 // indirect
 	github.com/vishvananda/netns v0.0.5 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
-	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.62.0 // indirect
-	go.opentelemetry.io/otel v1.37.0 // indirect
-	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.36.0 // indirect
-	go.opentelemetry.io/otel/metric v1.37.0 // indirect
-	go.opentelemetry.io/otel/trace v1.37.0 // indirect
-	golang.org/x/sync v0.16.0 // indirect
-	golang.org/x/sys v0.36.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.38.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.38.0 // indirect
+	go.opentelemetry.io/otel/trace v1.38.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.7.1 // indirect
+	go.yaml.in/yaml/v2 v2.4.2 // indirect
+	golang.org/x/mod v0.30.0 // indirect
+	golang.org/x/sync v0.18.0 // indirect
+	golang.org/x/sys v0.38.0 // indirect
+	golang.org/x/text v0.31.0 // indirect
 	golang.org/x/time v0.12.0 // indirect
+	golang.org/x/tools v0.39.0 // indirect
 	golang.zx2c4.com/wintun v0.0.0-20230126152724-0fa3db229ce2 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20250825161204-c5933d9347a5 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20250825161204-c5933d9347a5 // indirect
+	google.golang.org/protobuf v1.36.8 // indirect
 )

go.sum

@@ -1,12 +1,15 @@
 github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c h1:udKWzYgxTojEKWjV8V+WSxDXJ4NFATAsZjh8iIbsQIg=
 github.com/Azure/go-ansiterm v0.0.0-20250102033503-faa5f7b0171c/go.mod h1:xomTg63KZ2rFqZQzSB4Vz2SUXa1BpHTVz9L5PTmPC4E=
-github.com/Microsoft/go-winio v0.6.2 h1:F2VQgta7ecxGYO8k3ZZz3RS8fVIXVxONVUPlNERoyfY=
-github.com/Microsoft/go-winio v0.6.2/go.mod h1:yd8OoFMLzJbo9gZq8j5qaps8bJ9aShtEA8Ipt1oGCvU=
-github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
-github.com/cenkalti/backoff/v5 v5.0.2 h1:rIfFVxEf1QsI7E1ZHfp/B4DF/6QBAUhmgkxc0H7Zss8=
-github.com/cenkalti/backoff/v5 v5.0.2/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
-github.com/containerd/errdefs v1.0.0 h1:tg5yIfIlQIrxYtu9ajqY42W3lpS19XqdxRQeEwYG8PI=
-github.com/containerd/errdefs v1.0.0/go.mod h1:+YBYIdtsnF4Iw6nWZhJcqGSg/dwvV7tyJ/kCkyJ2k+M=
+github.com/Microsoft/go-winio v0.6.0 h1:slsWYD/zyx7lCXoZVlvQrj0hPTM1HI4+v1sIda2yDvg=
+github.com/Microsoft/go-winio v0.6.0/go.mod h1:cTAf44im0RAYeL23bpB+fzCyDH2MJiz2BO69KH/soAE=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
+github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
+github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
+github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
+github.com/containerd/errdefs v0.3.0 h1:FSZgGOeK4yuT/+DnF07/Olde/q4KBoMsaamhXxIMDp4=
+github.com/containerd/errdefs v0.3.0/go.mod h1:+YBYIdtsnF4Iw6nWZhJcqGSg/dwvV7tyJ/kCkyJ2k+M=
 github.com/containerd/errdefs/pkg v0.3.0 h1:9IKJ06FvyNlexW690DXuQNx2KA2cUJXx151Xdx3ZPPE=
 github.com/containerd/errdefs/pkg v0.3.0/go.mod h1:NJw6s9HwNuRhnjJhM7pylWwMyAkmCQvQ4GpJHEqRLVk=
 github.com/containerd/log v0.1.0 h1:TCJt7ioM2cr/tfR8GPbGf9/VRAX8D2B4PjzCpfX540I=
@@ -15,12 +18,12 @@ github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/distribution/reference v0.6.0 h1:0IXCQ5g4/QMHHkarYzh5l+u8T3t73zM5QvfrDyIgxBk=
 github.com/distribution/reference v0.6.0/go.mod h1:BbU0aIcezP1/5jX/8MP0YiH4SdvB5Y4f/wlDRiLyi3E=
-github.com/docker/docker v28.5.0+incompatible h1:ZdSQoRUE9XxhFI/B8YLvhnEFMmYN9Pp8Egd2qcaFk1E=
-github.com/docker/docker v28.5.0+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
-github.com/docker/go-connections v0.5.0 h1:USnMq7hx7gwdVZq1L49hLXaFtUdTADjXGp+uj1Br63c=
-github.com/docker/go-connections v0.5.0/go.mod h1:ov60Kzw0kKElRwhNs9UlUHAE/F9Fe6GLaXnqyDdmEXc=
-github.com/docker/go-units v0.5.0 h1:69rxXcBk27SvSaaxTtLh/8llcHD8vYHT7WSdRZ/jvr4=
-github.com/docker/go-units v0.5.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
+github.com/docker/docker v28.5.1+incompatible h1:Bm8DchhSD2J6PsFzxC35TZo4TLGR2PdW/E69rU45NhM=
+github.com/docker/docker v28.5.1+incompatible/go.mod h1:eEKB0N0r5NX/I1kEveEz05bcu8tLC/8azJZsviup8Sk=
+github.com/docker/go-connections v0.6.0 h1:LlMG9azAe1TqfR7sO+NJttz1gy6KO7VJBh+pMmjSD94=
+github.com/docker/go-connections v0.6.0/go.mod h1:AahvXYshr6JgfUJGdDCs2b5EZG/vmaMAntpSFH5BFKE=
+github.com/docker/go-units v0.4.0 h1:3uh0PgVws3nIA0Q+MwDC8yjEPf9zjRfZZWXZYDct3Tw=
+github.com/docker/go-units v0.4.0/go.mod h1:fgPhTUdO+D/Jk86RDLlptpiXQzgHJF7gydDDbaIK4Dk=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
 github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
@@ -28,6 +31,8 @@ github.com/go-logr/logr v1.4.3 h1:CjnDlHq8ikf6E492q6eKboGOC0T8CDaOvkHCIg8idEI=
 github.com/go-logr/logr v1.4.3/go.mod h1:9T104GzyrTigFIr8wt5mBrctHMim0Nb2HLGrmQ40KvY=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
 github.com/go-logr/stdr v1.2.2/go.mod h1:mMo/vtBO5dYbehREoey6XUKy/eSumjCCveDpRre4VKE=
+github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
+github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/google/btree v1.1.3 h1:CVpQJjYgC4VbzxeGVHfvZrv1ctoYCAI8vbl07Fcxlyg=
 github.com/google/btree v1.1.3/go.mod h1:qOPhT0dTNdNzV6Z/lhRX0YXUafgPLFUh+gZMl761Gm4=
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+golang.org/x/tools v0.39.0/go.mod h1:JnefbkDPyD8UU2kI5fuf8ZX4/yUeh9W877ZeBONxUqQ=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
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@@ -136,15 +175,16 @@ golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb h1:whnFRlWMcXI9d+Z
 golang.zx2c4.com/wireguard v0.0.0-20250521234502-f333402bd9cb/go.mod h1:rpwXGsirqLqN2L0JDJQlwOboGHmptD5ZD6T2VmcqhTw=
 golang.zx2c4.com/wireguard/wgctrl v0.0.0-20241231184526-a9ab2273dd10 h1:3GDAcqdIg1ozBNLgPy4SLT84nfcBjr6rhGtXYtrkWLU=
 golang.zx2c4.com/wireguard/wgctrl v0.0.0-20241231184526-a9ab2273dd10/go.mod h1:T97yPqesLiNrOYxkwmhMI0ZIlJDm+p0PMR8eRVeR5tQ=
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+gonum.org/v1/gonum v0.16.0 h1:5+ul4Swaf3ESvrOnidPp4GZbzf0mxVQpDCYUQE7OJfk=
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holepunch/holepunch.go

@@ -0,0 +1,521 @@
+package holepunch
+
+import (
+	"encoding/json"
+	"fmt"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/fosrl/newt/bind"
+	"github.com/fosrl/newt/logger"
+	"github.com/fosrl/newt/util"
+	"golang.org/x/crypto/chacha20poly1305"
+	"golang.org/x/crypto/curve25519"
+	mrand "golang.org/x/exp/rand"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+// ExitNode represents a WireGuard exit node for hole punching
+type ExitNode struct {
+	Endpoint  string `json:"endpoint"`
+	PublicKey string `json:"publicKey"`
+}
+
+// Manager handles UDP hole punching operations
+type Manager struct {
+	mu         sync.Mutex
+	running    bool
+	stopChan   chan struct{}
+	sharedBind *bind.SharedBind
+	ID         string
+	token      string
+	publicKey  string
+	clientType string
+	exitNodes  map[string]ExitNode // key is endpoint
+	updateChan chan struct{}       // signals the goroutine to refresh exit nodes
+
+	sendHolepunchInterval time.Duration
+}
+
+const sendHolepunchIntervalMax = 60 * time.Second
+const sendHolepunchIntervalMin = 1 * time.Second
+
+// NewManager creates a new hole punch manager
+func NewManager(sharedBind *bind.SharedBind, ID string, clientType string, publicKey string) *Manager {
+	return &Manager{
+		sharedBind:            sharedBind,
+		ID:                    ID,
+		clientType:            clientType,
+		publicKey:             publicKey,
+		exitNodes:             make(map[string]ExitNode),
+		sendHolepunchInterval: sendHolepunchIntervalMin,
+	}
+}
+
+// SetToken updates the authentication token used for hole punching
+func (m *Manager) SetToken(token string) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	m.token = token
+}
+
+// IsRunning returns whether hole punching is currently active
+func (m *Manager) IsRunning() bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+	return m.running
+}
+
+// Stop stops any ongoing hole punch operations
+func (m *Manager) Stop() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if !m.running {
+		return
+	}
+
+	if m.stopChan != nil {
+		close(m.stopChan)
+		m.stopChan = nil
+	}
+
+	if m.updateChan != nil {
+		close(m.updateChan)
+		m.updateChan = nil
+	}
+
+	m.running = false
+	logger.Info("Hole punch manager stopped")
+}
+
+// AddExitNode adds a new exit node to the rotation if it doesn't already exist
+func (m *Manager) AddExitNode(exitNode ExitNode) bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if _, exists := m.exitNodes[exitNode.Endpoint]; exists {
+		logger.Debug("Exit node %s already exists in rotation", exitNode.Endpoint)
+		return false
+	}
+
+	m.exitNodes[exitNode.Endpoint] = exitNode
+	logger.Info("Added exit node %s to hole punch rotation", exitNode.Endpoint)
+
+	// Signal the goroutine to refresh if running
+	if m.running && m.updateChan != nil {
+		select {
+		case m.updateChan <- struct{}{}:
+		default:
+			// Channel full or closed, skip
+		}
+	}
+
+	return true
+}
+
+// RemoveExitNode removes an exit node from the rotation
+func (m *Manager) RemoveExitNode(endpoint string) bool {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if _, exists := m.exitNodes[endpoint]; !exists {
+		logger.Debug("Exit node %s not found in rotation", endpoint)
+		return false
+	}
+
+	delete(m.exitNodes, endpoint)
+	logger.Info("Removed exit node %s from hole punch rotation", endpoint)
+
+	// Signal the goroutine to refresh if running
+	if m.running && m.updateChan != nil {
+		select {
+		case m.updateChan <- struct{}{}:
+		default:
+			// Channel full or closed, skip
+		}
+	}
+
+	return true
+}
+
+// GetExitNodes returns a copy of the current exit nodes
+func (m *Manager) GetExitNodes() []ExitNode {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	nodes := make([]ExitNode, 0, len(m.exitNodes))
+	for _, node := range m.exitNodes {
+		nodes = append(nodes, node)
+	}
+	return nodes
+}
+
+// ResetInterval resets the hole punch interval back to the minimum value,
+// allowing it to climb back up through exponential backoff.
+// This is useful when network conditions change or connectivity is restored.
+func (m *Manager) ResetInterval() {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if m.sendHolepunchInterval != sendHolepunchIntervalMin {
+		m.sendHolepunchInterval = sendHolepunchIntervalMin
+		logger.Info("Reset hole punch interval to minimum (%v)", sendHolepunchIntervalMin)
+	}
+
+	// Signal the goroutine to apply the new interval if running
+	if m.running && m.updateChan != nil {
+		select {
+		case m.updateChan <- struct{}{}:
+		default:
+			// Channel full or closed, skip
+		}
+	}
+}
+
+// TriggerHolePunch sends an immediate hole punch packet to all configured exit nodes
+// This is useful for triggering hole punching on demand without waiting for the interval
+func (m *Manager) TriggerHolePunch() error {
+	m.mu.Lock()
+
+	if len(m.exitNodes) == 0 {
+		m.mu.Unlock()
+		return fmt.Errorf("no exit nodes configured")
+	}
+
+	// Get a copy of exit nodes to work with
+	currentExitNodes := make([]ExitNode, 0, len(m.exitNodes))
+	for _, node := range m.exitNodes {
+		currentExitNodes = append(currentExitNodes, node)
+	}
+	m.mu.Unlock()
+
+	logger.Info("Triggering on-demand hole punch to %d exit nodes", len(currentExitNodes))
+
+	// Send hole punch to all exit nodes
+	successCount := 0
+	for _, exitNode := range currentExitNodes {
+		host, err := util.ResolveDomain(exitNode.Endpoint)
+		if err != nil {
+			logger.Warn("Failed to resolve endpoint %s: %v", exitNode.Endpoint, err)
+			continue
+		}
+
+		serverAddr := net.JoinHostPort(host, "21820")
+		remoteAddr, err := net.ResolveUDPAddr("udp", serverAddr)
+		if err != nil {
+			logger.Error("Failed to resolve UDP address %s: %v", serverAddr, err)
+			continue
+		}
+
+		if err := m.sendHolePunch(remoteAddr, exitNode.PublicKey); err != nil {
+			logger.Warn("Failed to send on-demand hole punch to %s: %v", exitNode.Endpoint, err)
+			continue
+		}
+
+		logger.Debug("Sent on-demand hole punch to %s", exitNode.Endpoint)
+		successCount++
+	}
+
+	if successCount == 0 {
+		return fmt.Errorf("failed to send hole punch to any exit node")
+	}
+
+	logger.Info("Successfully sent on-demand hole punch to %d/%d exit nodes", successCount, len(currentExitNodes))
+	return nil
+}
+
+// StartMultipleExitNodes starts hole punching to multiple exit nodes
+func (m *Manager) StartMultipleExitNodes(exitNodes []ExitNode) error {
+	m.mu.Lock()
+
+	if m.running {
+		m.mu.Unlock()
+		logger.Debug("UDP hole punch already running, skipping new request")
+		return fmt.Errorf("hole punch already running")
+	}
+
+	if len(exitNodes) == 0 {
+		m.mu.Unlock()
+		logger.Warn("No exit nodes provided for hole punching")
+		return fmt.Errorf("no exit nodes provided")
+	}
+
+	// Populate exit nodes map
+	m.exitNodes = make(map[string]ExitNode)
+	for _, node := range exitNodes {
+		m.exitNodes[node.Endpoint] = node
+	}
+
+	m.running = true
+	m.stopChan = make(chan struct{})
+	m.updateChan = make(chan struct{}, 1)
+	m.mu.Unlock()
+
+	logger.Info("Starting UDP hole punch to %d exit nodes with shared bind", len(exitNodes))
+
+	go m.runMultipleExitNodes()
+
+	return nil
+}
+
+// Start starts hole punching with the current set of exit nodes
+func (m *Manager) Start() error {
+	m.mu.Lock()
+
+	if m.running {
+		m.mu.Unlock()
+		logger.Debug("UDP hole punch already running")
+		return fmt.Errorf("hole punch already running")
+	}
+
+	if len(m.exitNodes) == 0 {
+		m.mu.Unlock()
+		logger.Warn("No exit nodes configured for hole punching")
+		return fmt.Errorf("no exit nodes configured")
+	}
+
+	m.running = true
+	m.stopChan = make(chan struct{})
+	m.updateChan = make(chan struct{}, 1)
+	m.mu.Unlock()
+
+	logger.Info("Starting UDP hole punch with %d exit nodes", len(m.exitNodes))
+
+	go m.runMultipleExitNodes()
+
+	return nil
+}
+
+// runMultipleExitNodes performs hole punching to multiple exit nodes
+func (m *Manager) runMultipleExitNodes() {
+	defer func() {
+		m.mu.Lock()
+		m.running = false
+		m.mu.Unlock()
+		logger.Info("UDP hole punch goroutine ended for all exit nodes")
+	}()
+
+	// Resolve all endpoints upfront
+	type resolvedExitNode struct {
+		remoteAddr   *net.UDPAddr
+		publicKey    string
+		endpointName string
+	}
+
+	resolveNodes := func() []resolvedExitNode {
+		m.mu.Lock()
+		currentExitNodes := make([]ExitNode, 0, len(m.exitNodes))
+		for _, node := range m.exitNodes {
+			currentExitNodes = append(currentExitNodes, node)
+		}
+		m.mu.Unlock()
+
+		var resolvedNodes []resolvedExitNode
+		for _, exitNode := range currentExitNodes {
+			host, err := util.ResolveDomain(exitNode.Endpoint)
+			if err != nil {
+				logger.Warn("Failed to resolve endpoint %s: %v", exitNode.Endpoint, err)
+				continue
+			}
+
+			serverAddr := net.JoinHostPort(host, "21820")
+			remoteAddr, err := net.ResolveUDPAddr("udp", serverAddr)
+			if err != nil {
+				logger.Error("Failed to resolve UDP address %s: %v", serverAddr, err)
+				continue
+			}
+
+			resolvedNodes = append(resolvedNodes, resolvedExitNode{
+				remoteAddr:   remoteAddr,
+				publicKey:    exitNode.PublicKey,
+				endpointName: exitNode.Endpoint,
+			})
+			logger.Info("Resolved exit node: %s -> %s", exitNode.Endpoint, remoteAddr.String())
+		}
+		return resolvedNodes
+	}
+
+	resolvedNodes := resolveNodes()
+
+	if len(resolvedNodes) == 0 {
+		logger.Error("No exit nodes could be resolved")
+		return
+	}
+
+	// Send initial hole punch to all exit nodes
+	for _, node := range resolvedNodes {
+		if err := m.sendHolePunch(node.remoteAddr, node.publicKey); err != nil {
+			logger.Warn("Failed to send initial hole punch to %s: %v", node.endpointName, err)
+		}
+	}
+
+	// Start with minimum interval
+	m.mu.Lock()
+	m.sendHolepunchInterval = sendHolepunchIntervalMin
+	m.mu.Unlock()
+
+	ticker := time.NewTicker(m.sendHolepunchInterval)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-m.stopChan:
+			logger.Debug("Hole punch stopped by signal")
+			return
+		case <-m.updateChan:
+			// Re-resolve exit nodes when update is signaled
+			logger.Info("Refreshing exit nodes for hole punching")
+			resolvedNodes = resolveNodes()
+			if len(resolvedNodes) == 0 {
+				logger.Warn("No exit nodes available after refresh")
+			}
+			// Reset interval to minimum on update
+			m.mu.Lock()
+			m.sendHolepunchInterval = sendHolepunchIntervalMin
+			m.mu.Unlock()
+			ticker.Reset(m.sendHolepunchInterval)
+			// Send immediate hole punch to newly resolved nodes
+			for _, node := range resolvedNodes {
+				if err := m.sendHolePunch(node.remoteAddr, node.publicKey); err != nil {
+					logger.Debug("Failed to send hole punch to %s: %v", node.endpointName, err)
+				}
+			}
+		case <-ticker.C:
+			// Send hole punch to all exit nodes
+			for _, node := range resolvedNodes {
+				if err := m.sendHolePunch(node.remoteAddr, node.publicKey); err != nil {
+					logger.Debug("Failed to send hole punch to %s: %v", node.endpointName, err)
+				}
+			}
+			// Exponential backoff: double the interval up to max
+			m.mu.Lock()
+			newInterval := m.sendHolepunchInterval * 2
+			if newInterval > sendHolepunchIntervalMax {
+				newInterval = sendHolepunchIntervalMax
+			}
+			if newInterval != m.sendHolepunchInterval {
+				m.sendHolepunchInterval = newInterval
+				ticker.Reset(m.sendHolepunchInterval)
+				logger.Debug("Increased hole punch interval to %v", m.sendHolepunchInterval)
+			}
+			m.mu.Unlock()
+		}
+	}
+}
+
+// sendHolePunch sends an encrypted hole punch packet using the shared bind
+func (m *Manager) sendHolePunch(remoteAddr *net.UDPAddr, serverPubKey string) error {
+	m.mu.Lock()
+	token := m.token
+	ID := m.ID
+	m.mu.Unlock()
+
+	if serverPubKey == "" || token == "" {
+		return fmt.Errorf("server public key or OLM token is empty")
+	}
+
+	var payload interface{}
+	if m.clientType == "newt" {
+		payload = struct {
+			ID        string `json:"newtId"`
+			Token     string `json:"token"`
+			PublicKey string `json:"publicKey"`
+		}{
+			ID:        ID,
+			Token:     token,
+			PublicKey: m.publicKey,
+		}
+	} else {
+		payload = struct {
+			ID        string `json:"olmId"`
+			Token     string `json:"token"`
+			PublicKey string `json:"publicKey"`
+		}{
+			ID:        ID,
+			Token:     token,
+			PublicKey: m.publicKey,
+		}
+	}
+
+	// Convert payload to JSON
+	payloadBytes, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("failed to marshal payload: %w", err)
+	}
+
+	// Encrypt the payload using the server's WireGuard public key
+	encryptedPayload, err := encryptPayload(payloadBytes, serverPubKey)
+	if err != nil {
+		return fmt.Errorf("failed to encrypt payload: %w", err)
+	}
+
+	jsonData, err := json.Marshal(encryptedPayload)
+	if err != nil {
+		return fmt.Errorf("failed to marshal encrypted payload: %w", err)
+	}
+
+	_, err = m.sharedBind.WriteToUDP(jsonData, remoteAddr)
+	if err != nil {
+		return fmt.Errorf("failed to write to UDP: %w", err)
+	}
+
+	logger.Debug("Sent UDP hole punch to %s: %s", remoteAddr.String(), string(jsonData))
+
+	return nil
+}
+
+// encryptPayload encrypts the payload using ChaCha20-Poly1305 AEAD with X25519 key exchange
+func encryptPayload(payload []byte, serverPublicKey string) (interface{}, error) {
+	// Generate an ephemeral keypair for this message
+	ephemeralPrivateKey, err := wgtypes.GeneratePrivateKey()
+	if err != nil {
+		return nil, fmt.Errorf("failed to generate ephemeral private key: %v", err)
+	}
+	ephemeralPublicKey := ephemeralPrivateKey.PublicKey()
+
+	// Parse the server's public key
+	serverPubKey, err := wgtypes.ParseKey(serverPublicKey)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse server public key: %v", err)
+	}
+
+	// Use X25519 for key exchange
+	var ephPrivKeyFixed [32]byte
+	copy(ephPrivKeyFixed[:], ephemeralPrivateKey[:])
+
+	// Perform X25519 key exchange
+	sharedSecret, err := curve25519.X25519(ephPrivKeyFixed[:], serverPubKey[:])
+	if err != nil {
+		return nil, fmt.Errorf("failed to perform X25519 key exchange: %v", err)
+	}
+
+	// Create an AEAD cipher using the shared secret
+	aead, err := chacha20poly1305.New(sharedSecret)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create AEAD cipher: %v", err)
+	}
+
+	// Generate a random nonce
+	nonce := make([]byte, aead.NonceSize())
+	if _, err := mrand.Read(nonce); err != nil {
+		return nil, fmt.Errorf("failed to generate nonce: %v", err)
+	}
+
+	// Encrypt the payload
+	ciphertext := aead.Seal(nil, nonce, payload, nil)
+
+	// Prepare the final encrypted message
+	encryptedMsg := struct {
+		EphemeralPublicKey string `json:"ephemeralPublicKey"`
+		Nonce              []byte `json:"nonce"`
+		Ciphertext         []byte `json:"ciphertext"`
+	}{
+		EphemeralPublicKey: ephemeralPublicKey.String(),
+		Nonce:              nonce,
+		Ciphertext:         ciphertext,
+	}
+
+	return encryptedMsg, nil
+}

holepunch/tester.go

@@ -0,0 +1,343 @@
+package holepunch
+
+import (
+	"crypto/rand"
+	"fmt"
+	"net"
+	"net/netip"
+	"sync"
+	"time"
+
+	"github.com/fosrl/newt/bind"
+	"github.com/fosrl/newt/logger"
+	"github.com/fosrl/newt/util"
+)
+
+// TestResult represents the result of a connection test
+type TestResult struct {
+	// Success indicates whether the test was successful
+	Success bool
+	// RTT is the round-trip time of the test packet
+	RTT time.Duration
+	// Endpoint is the endpoint that was tested
+	Endpoint string
+	// Error contains any error that occurred during the test
+	Error error
+}
+
+// TestConnectionOptions configures the connection test
+type TestConnectionOptions struct {
+	// Timeout is how long to wait for a response (default: 5 seconds)
+	Timeout time.Duration
+	// Retries is the number of times to retry on failure (default: 0)
+	Retries int
+}
+
+// DefaultTestOptions returns the default test options
+func DefaultTestOptions() TestConnectionOptions {
+	return TestConnectionOptions{
+		Timeout: 5 * time.Second,
+		Retries: 0,
+	}
+}
+
+// HolepunchTester monitors holepunch connectivity using magic packets
+type HolepunchTester struct {
+	sharedBind *bind.SharedBind
+	mu         sync.RWMutex
+	running    bool
+	stopChan   chan struct{}
+
+	// Pending requests waiting for responses (key: echo data as string)
+	pendingRequests sync.Map // map[string]*pendingRequest
+
+	// Callback when connection status changes
+	callback HolepunchStatusCallback
+}
+
+// HolepunchStatus represents the status of a holepunch connection
+type HolepunchStatus struct {
+	Endpoint  string
+	Connected bool
+	RTT       time.Duration
+}
+
+// HolepunchStatusCallback is called when holepunch status changes
+type HolepunchStatusCallback func(status HolepunchStatus)
+
+// pendingRequest tracks a pending test request
+type pendingRequest struct {
+	endpoint  string
+	sentAt    time.Time
+	replyChan chan time.Duration
+}
+
+// NewHolepunchTester creates a new holepunch tester using the given SharedBind
+func NewHolepunchTester(sharedBind *bind.SharedBind) *HolepunchTester {
+	return &HolepunchTester{
+		sharedBind: sharedBind,
+	}
+}
+
+// SetCallback sets the callback for connection status changes
+func (t *HolepunchTester) SetCallback(callback HolepunchStatusCallback) {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+	t.callback = callback
+}
+
+// Start begins listening for magic packet responses
+func (t *HolepunchTester) Start() error {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if t.running {
+		return fmt.Errorf("tester already running")
+	}
+
+	if t.sharedBind == nil {
+		return fmt.Errorf("sharedBind is nil")
+	}
+
+	t.running = true
+	t.stopChan = make(chan struct{})
+
+	// Register our callback with the SharedBind to receive magic responses
+	t.sharedBind.SetMagicResponseCallback(t.handleResponse)
+
+	logger.Debug("HolepunchTester started")
+	return nil
+}
+
+// Stop stops the tester
+func (t *HolepunchTester) Stop() {
+	t.mu.Lock()
+	defer t.mu.Unlock()
+
+	if !t.running {
+		return
+	}
+
+	t.running = false
+	close(t.stopChan)
+
+	// Clear the callback
+	if t.sharedBind != nil {
+		t.sharedBind.SetMagicResponseCallback(nil)
+	}
+
+	// Cancel all pending requests
+	t.pendingRequests.Range(func(key, value interface{}) bool {
+		if req, ok := value.(*pendingRequest); ok {
+			close(req.replyChan)
+		}
+		t.pendingRequests.Delete(key)
+		return true
+	})
+
+	logger.Debug("HolepunchTester stopped")
+}
+
+// handleResponse is called by SharedBind when a magic response is received
+func (t *HolepunchTester) handleResponse(addr netip.AddrPort, echoData []byte) {
+	logger.Debug("Received magic response from %s", addr.String())
+	key := string(echoData)
+
+	value, ok := t.pendingRequests.LoadAndDelete(key)
+	if !ok {
+		// No matching request found
+		logger.Debug("No pending request found for magic response from %s", addr.String())
+		return
+	}
+
+	req := value.(*pendingRequest)
+	rtt := time.Since(req.sentAt)
+	logger.Debug("Magic response matched pending request for %s (RTT: %v)", req.endpoint, rtt)
+
+	// Send RTT to the waiting goroutine (non-blocking)
+	select {
+	case req.replyChan <- rtt:
+	default:
+	}
+}
+
+// TestEndpoint sends a magic test packet to the endpoint and waits for a response.
+// This uses the SharedBind so packets come from the same source port as WireGuard.
+func (t *HolepunchTester) TestEndpoint(endpoint string, timeout time.Duration) TestResult {
+	result := TestResult{
+		Endpoint: endpoint,
+	}
+
+	t.mu.RLock()
+	running := t.running
+	sharedBind := t.sharedBind
+	t.mu.RUnlock()
+
+	if !running {
+		result.Error = fmt.Errorf("tester not running")
+		return result
+	}
+
+	if sharedBind == nil || sharedBind.IsClosed() {
+		result.Error = fmt.Errorf("sharedBind is nil or closed")
+		return result
+	}
+
+	// Resolve the endpoint
+	host, err := util.ResolveDomain(endpoint)
+	if err != nil {
+		host = endpoint
+	}
+
+	_, _, err = net.SplitHostPort(host)
+	if err != nil {
+		host = net.JoinHostPort(host, "21820")
+	}
+
+	remoteAddr, err := net.ResolveUDPAddr("udp", host)
+	if err != nil {
+		result.Error = fmt.Errorf("failed to resolve UDP address %s: %w", host, err)
+		return result
+	}
+
+	// Generate random data for the test packet
+	randomData := make([]byte, bind.MagicPacketDataLen)
+	if _, err := rand.Read(randomData); err != nil {
+		result.Error = fmt.Errorf("failed to generate random data: %w", err)
+		return result
+	}
+
+	// Create a pending request
+	req := &pendingRequest{
+		endpoint:  endpoint,
+		sentAt:    time.Now(),
+		replyChan: make(chan time.Duration, 1),
+	}
+
+	key := string(randomData)
+	t.pendingRequests.Store(key, req)
+
+	// Build the test request packet
+	request := make([]byte, bind.MagicTestRequestLen)
+	copy(request, bind.MagicTestRequest)
+	copy(request[len(bind.MagicTestRequest):], randomData)
+
+	// Send the test packet
+	_, err = sharedBind.WriteToUDP(request, remoteAddr)
+	if err != nil {
+		t.pendingRequests.Delete(key)
+		result.Error = fmt.Errorf("failed to send test packet: %w", err)
+		return result
+	}
+
+	// Wait for response with timeout
+	select {
+	case rtt, ok := <-req.replyChan:
+		if ok {
+			result.Success = true
+			result.RTT = rtt
+		} else {
+			result.Error = fmt.Errorf("request cancelled")
+		}
+	case <-time.After(timeout):
+		t.pendingRequests.Delete(key)
+		result.Error = fmt.Errorf("timeout waiting for response")
+	}
+
+	return result
+}
+
+// TestConnectionWithBind sends a magic test packet using an existing SharedBind.
+// This is useful when you want to test the connection through the same socket
+// that WireGuard is using, which tests the actual hole-punched path.
+func TestConnectionWithBind(sharedBind *bind.SharedBind, endpoint string, opts *TestConnectionOptions) TestResult {
+	if opts == nil {
+		defaultOpts := DefaultTestOptions()
+		opts = &defaultOpts
+	}
+
+	result := TestResult{
+		Endpoint: endpoint,
+	}
+
+	if sharedBind == nil {
+		result.Error = fmt.Errorf("sharedBind is nil")
+		return result
+	}
+
+	if sharedBind.IsClosed() {
+		result.Error = fmt.Errorf("sharedBind is closed")
+		return result
+	}
+
+	// Resolve the endpoint
+	host, err := util.ResolveDomain(endpoint)
+	if err != nil {
+		host = endpoint
+	}
+
+	_, _, err = net.SplitHostPort(host)
+	if err != nil {
+		host = net.JoinHostPort(host, "21820")
+	}
+
+	remoteAddr, err := net.ResolveUDPAddr("udp", host)
+	if err != nil {
+		result.Error = fmt.Errorf("failed to resolve UDP address %s: %w", host, err)
+		return result
+	}
+
+	// Generate random data for the test packet
+	randomData := make([]byte, bind.MagicPacketDataLen)
+	if _, err := rand.Read(randomData); err != nil {
+		result.Error = fmt.Errorf("failed to generate random data: %w", err)
+		return result
+	}
+
+	// Build the test request packet
+	request := make([]byte, bind.MagicTestRequestLen)
+	copy(request, bind.MagicTestRequest)
+	copy(request[len(bind.MagicTestRequest):], randomData)
+
+	// Get the underlying UDP connection to set read deadline and read response
+	udpConn := sharedBind.GetUDPConn()
+	if udpConn == nil {
+		result.Error = fmt.Errorf("could not get UDP connection from SharedBind")
+		return result
+	}
+
+	attempts := opts.Retries + 1
+	for attempt := 0; attempt < attempts; attempt++ {
+		if attempt > 0 {
+			logger.Debug("Retrying connection test to %s (attempt %d/%d)", endpoint, attempt+1, attempts)
+		}
+
+		// Note: We can't easily set a read deadline on the shared connection
+		// without affecting WireGuard, so we use a goroutine with timeout instead
+		startTime := time.Now()
+
+		// Send the test packet through the shared bind
+		_, err = sharedBind.WriteToUDP(request, remoteAddr)
+		if err != nil {
+			result.Error = fmt.Errorf("failed to send test packet: %w", err)
+			if attempt < attempts-1 {
+				continue
+			}
+			return result
+		}
+
+		// For shared bind test, we send the packet but can't easily wait for
+		// response without interfering with WireGuard's receive loop.
+		// The response will be handled by SharedBind automatically.
+		// We consider the test successful if the send succeeded.
+		// For a full round-trip test, use TestConnection() with a separate socket.
+
+		result.RTT = time.Since(startTime)
+		result.Success = true
+		result.Error = nil
+		logger.Debug("Test packet sent to %s via SharedBind", endpoint)
+		return result
+	}
+
+	return result
+}

internal/state/telemetry_view.go

@@ -0,0 +1,80 @@
+package state
+
+import (
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/fosrl/newt/internal/telemetry"
+)
+
+// TelemetryView is a minimal, thread-safe implementation to feed observables.
+// Since one Newt process represents one site, we expose a single logical site.
+// site_id is a resource attribute, so we do not emit per-site labels here.
+type TelemetryView struct {
+	online     atomic.Bool
+	lastHBUnix atomic.Int64 // unix seconds
+	// per-tunnel sessions
+	sessMu   sync.RWMutex
+	sessions map[string]*atomic.Int64
+}
+
+var (
+	globalView atomic.Pointer[TelemetryView]
+)
+
+// Global returns a singleton TelemetryView.
+func Global() *TelemetryView {
+	if v := globalView.Load(); v != nil { return v }
+	v := &TelemetryView{ sessions: make(map[string]*atomic.Int64) }
+	globalView.Store(v)
+	telemetry.RegisterStateView(v)
+	return v
+}
+
+// Instrumentation helpers
+func (v *TelemetryView) IncSessions(tunnelID string) {
+	v.sessMu.Lock(); defer v.sessMu.Unlock()
+	c := v.sessions[tunnelID]
+	if c == nil { c = &atomic.Int64{}; v.sessions[tunnelID] = c }
+	c.Add(1)
+}
+func (v *TelemetryView) DecSessions(tunnelID string) {
+	v.sessMu.Lock(); defer v.sessMu.Unlock()
+	if c := v.sessions[tunnelID]; c != nil {
+		c.Add(-1)
+		if c.Load() <= 0 { delete(v.sessions, tunnelID) }
+	}
+}
+func (v *TelemetryView) ClearTunnel(tunnelID string) {
+	v.sessMu.Lock(); defer v.sessMu.Unlock()
+	delete(v.sessions, tunnelID)
+}
+func (v *TelemetryView) SetOnline(b bool) { v.online.Store(b) }
+func (v *TelemetryView) TouchHeartbeat() { v.lastHBUnix.Store(time.Now().Unix()) }
+
+// --- telemetry.StateView interface ---
+
+func (v *TelemetryView) ListSites() []string { return []string{"self"} }
+func (v *TelemetryView) Online(_ string) (bool, bool) { return v.online.Load(), true }
+func (v *TelemetryView) LastHeartbeat(_ string) (time.Time, bool) {
+	sec := v.lastHBUnix.Load()
+	if sec == 0 { return time.Time{}, false }
+	return time.Unix(sec, 0), true
+}
+func (v *TelemetryView) ActiveSessions(_ string) (int64, bool) {
+	// aggregated sessions (not used for per-tunnel gauge)
+	v.sessMu.RLock(); defer v.sessMu.RUnlock()
+	var sum int64
+	for _, c := range v.sessions { if c != nil { sum += c.Load() } }
+	return sum, true
+}
+
+// Extended accessor used by telemetry callback to publish per-tunnel samples.
+func (v *TelemetryView) SessionsByTunnel() map[string]int64 {
+	v.sessMu.RLock(); defer v.sessMu.RUnlock()
+	out := make(map[string]int64, len(v.sessions))
+	for id, c := range v.sessions { if c != nil && c.Load() > 0 { out[id] = c.Load() } }
+	return out
+}
+

internal/telemetry/constants.go

@@ -0,0 +1,19 @@
+package telemetry
+
+// Protocol labels (low-cardinality)
+const (
+	ProtocolTCP = "tcp"
+	ProtocolUDP = "udp"
+)
+
+// Reconnect reason bins (fixed, low-cardinality)
+const (
+	ReasonServerRequest  = "server_request"
+	ReasonTimeout        = "timeout"
+	ReasonPeerClose      = "peer_close"
+	ReasonNetworkChange  = "network_change"
+	ReasonAuthError      = "auth_error"
+	ReasonHandshakeError = "handshake_error"
+	ReasonConfigChange   = "config_change"
+	ReasonError          = "error"
+)

internal/telemetry/constants_test.go

@@ -0,0 +1,32 @@
+package telemetry
+
+import "testing"
+
+func TestAllowedConstants(t *testing.T) {
+	allowedReasons := map[string]struct{}{
+		ReasonServerRequest:  {},
+		ReasonTimeout:        {},
+		ReasonPeerClose:      {},
+		ReasonNetworkChange:  {},
+		ReasonAuthError:      {},
+		ReasonHandshakeError: {},
+		ReasonConfigChange:   {},
+		ReasonError:          {},
+	}
+	for k := range allowedReasons {
+		if k == "" {
+			t.Fatalf("empty reason constant")
+		}
+	}
+
+	allowedProtocols := map[string]struct{}{
+		ProtocolTCP: {},
+		ProtocolUDP: {},
+	}
+	for k := range allowedProtocols {
+		if k == "" {
+			t.Fatalf("empty protocol constant")
+		}
+	}
+}
+

internal/telemetry/metrics.go

@@ -0,0 +1,542 @@
+package telemetry
+
+import (
+	"context"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// Instruments and helpers for Newt metrics following the naming, units, and
+// low-cardinality label guidance from the issue description.
+//
+// Counters end with _total, durations are in seconds, sizes in bytes.
+// Only low-cardinality stable labels are supported: tunnel_id,
+// transport, direction, result, reason, error_type.
+var (
+	initOnce sync.Once
+
+	meter metric.Meter
+
+	// Site / Registration
+	mSiteRegistrations metric.Int64Counter
+	mSiteOnline        metric.Int64ObservableGauge
+	mSiteLastHeartbeat metric.Float64ObservableGauge
+
+	// Tunnel / Sessions
+	mTunnelSessions metric.Int64ObservableGauge
+	mTunnelBytes    metric.Int64Counter
+	mTunnelLatency  metric.Float64Histogram
+	mReconnects     metric.Int64Counter
+
+	// Connection / NAT
+	mConnAttempts metric.Int64Counter
+	mConnErrors   metric.Int64Counter
+
+	// Config/Restart
+	mConfigReloads     metric.Int64Counter
+	mConfigApply       metric.Float64Histogram
+	mCertRotationTotal metric.Int64Counter
+	mProcessStartTime  metric.Float64ObservableGauge
+
+	// Build info
+	mBuildInfo metric.Int64ObservableGauge
+
+	// WebSocket
+	mWSConnectLatency   metric.Float64Histogram
+	mWSMessages         metric.Int64Counter
+	mWSDisconnects      metric.Int64Counter
+	mWSKeepaliveFailure metric.Int64Counter
+	mWSSessionDuration  metric.Float64Histogram
+	mWSConnected        metric.Int64ObservableGauge
+	mWSReconnects       metric.Int64Counter
+
+	// Proxy
+	mProxyActiveConns      metric.Int64ObservableGauge
+	mProxyBufferBytes      metric.Int64ObservableGauge
+	mProxyAsyncBacklogByte metric.Int64ObservableGauge
+	mProxyDropsTotal       metric.Int64Counter
+	mProxyAcceptsTotal     metric.Int64Counter
+	mProxyConnDuration     metric.Float64Histogram
+	mProxyConnectionsTotal metric.Int64Counter
+
+	buildVersion     string
+	buildCommit      string
+	processStartUnix = float64(time.Now().UnixNano()) / 1e9
+	wsConnectedState atomic.Int64
+)
+
+// Proxy connection lifecycle events.
+const (
+	ProxyConnectionOpened = "opened"
+	ProxyConnectionClosed = "closed"
+)
+
+// attrsWithSite appends site/region labels only when explicitly enabled to keep
+// label cardinality low by default.
+func attrsWithSite(extra ...attribute.KeyValue) []attribute.KeyValue {
+	attrs := make([]attribute.KeyValue, len(extra))
+	copy(attrs, extra)
+	if ShouldIncludeSiteLabels() {
+		attrs = append(attrs, siteAttrs()...)
+	}
+	return attrs
+}
+
+func registerInstruments() error {
+	var err error
+	initOnce.Do(func() {
+		meter = otel.Meter("newt")
+		if e := registerSiteInstruments(); e != nil {
+			err = e
+			return
+		}
+		if e := registerTunnelInstruments(); e != nil {
+			err = e
+			return
+		}
+		if e := registerConnInstruments(); e != nil {
+			err = e
+			return
+		}
+		if e := registerConfigInstruments(); e != nil {
+			err = e
+			return
+		}
+		if e := registerBuildWSProxyInstruments(); e != nil {
+			err = e
+			return
+		}
+	})
+	return err
+}
+
+func registerSiteInstruments() error {
+	var err error
+	mSiteRegistrations, err = meter.Int64Counter("newt_site_registrations_total",
+		metric.WithDescription("Total site registration attempts"))
+	if err != nil {
+		return err
+	}
+	mSiteOnline, err = meter.Int64ObservableGauge("newt_site_online",
+		metric.WithDescription("Site online (0/1)"))
+	if err != nil {
+		return err
+	}
+	mSiteLastHeartbeat, err = meter.Float64ObservableGauge("newt_site_last_heartbeat_timestamp_seconds",
+		metric.WithDescription("Unix timestamp of the last site heartbeat"),
+		metric.WithUnit("s"))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func registerTunnelInstruments() error {
+	var err error
+	mTunnelSessions, err = meter.Int64ObservableGauge("newt_tunnel_sessions",
+		metric.WithDescription("Active tunnel sessions"))
+	if err != nil {
+		return err
+	}
+	mTunnelBytes, err = meter.Int64Counter("newt_tunnel_bytes_total",
+		metric.WithDescription("Tunnel bytes ingress/egress"),
+		metric.WithUnit("By"))
+	if err != nil {
+		return err
+	}
+	mTunnelLatency, err = meter.Float64Histogram("newt_tunnel_latency_seconds",
+		metric.WithDescription("Per-tunnel latency in seconds"),
+		metric.WithUnit("s"))
+	if err != nil {
+		return err
+	}
+	mReconnects, err = meter.Int64Counter("newt_tunnel_reconnects_total",
+		metric.WithDescription("Tunnel reconnect events"))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func registerConnInstruments() error {
+	var err error
+	mConnAttempts, err = meter.Int64Counter("newt_connection_attempts_total",
+		metric.WithDescription("Connection attempts"))
+	if err != nil {
+		return err
+	}
+	mConnErrors, err = meter.Int64Counter("newt_connection_errors_total",
+		metric.WithDescription("Connection errors by type"))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func registerConfigInstruments() error {
+	mConfigReloads, _ = meter.Int64Counter("newt_config_reloads_total",
+		metric.WithDescription("Configuration reloads"))
+	mConfigApply, _ = meter.Float64Histogram("newt_config_apply_seconds",
+		metric.WithDescription("Configuration apply duration in seconds"),
+		metric.WithUnit("s"))
+	mCertRotationTotal, _ = meter.Int64Counter("newt_cert_rotation_total",
+		metric.WithDescription("Certificate rotation events (success/failure)"))
+	mProcessStartTime, _ = meter.Float64ObservableGauge("process_start_time_seconds",
+		metric.WithDescription("Unix timestamp of the process start time"),
+		metric.WithUnit("s"))
+	if mProcessStartTime != nil {
+		if _, err := meter.RegisterCallback(func(ctx context.Context, o metric.Observer) error {
+			o.ObserveFloat64(mProcessStartTime, processStartUnix)
+			return nil
+		}, mProcessStartTime); err != nil {
+			otel.Handle(err)
+		}
+	}
+	return nil
+}
+
+func registerBuildWSProxyInstruments() error {
+	// Build info gauge (value 1 with version/commit attributes)
+	mBuildInfo, _ = meter.Int64ObservableGauge("newt_build_info",
+		metric.WithDescription("Newt build information (value is always 1)"))
+	// WebSocket
+	mWSConnectLatency, _ = meter.Float64Histogram("newt_websocket_connect_latency_seconds",
+		metric.WithDescription("WebSocket connect latency in seconds"),
+		metric.WithUnit("s"))
+	mWSMessages, _ = meter.Int64Counter("newt_websocket_messages_total",
+		metric.WithDescription("WebSocket messages by direction and type"))
+	mWSDisconnects, _ = meter.Int64Counter("newt_websocket_disconnects_total",
+		metric.WithDescription("WebSocket disconnects by reason/result"))
+	mWSKeepaliveFailure, _ = meter.Int64Counter("newt_websocket_keepalive_failures_total",
+		metric.WithDescription("WebSocket keepalive (ping/pong) failures"))
+	mWSSessionDuration, _ = meter.Float64Histogram("newt_websocket_session_duration_seconds",
+		metric.WithDescription("Duration of established WebSocket sessions"),
+		metric.WithUnit("s"))
+	mWSConnected, _ = meter.Int64ObservableGauge("newt_websocket_connected",
+		metric.WithDescription("WebSocket connection state (1=connected, 0=disconnected)"))
+	mWSReconnects, _ = meter.Int64Counter("newt_websocket_reconnects_total",
+		metric.WithDescription("WebSocket reconnect attempts by reason"))
+	// Proxy
+	mProxyActiveConns, _ = meter.Int64ObservableGauge("newt_proxy_active_connections",
+		metric.WithDescription("Proxy active connections per tunnel and protocol"))
+	mProxyBufferBytes, _ = meter.Int64ObservableGauge("newt_proxy_buffer_bytes",
+		metric.WithDescription("Proxy buffer bytes (may approximate async backlog)"),
+		metric.WithUnit("By"))
+	mProxyAsyncBacklogByte, _ = meter.Int64ObservableGauge("newt_proxy_async_backlog_bytes",
+		metric.WithDescription("Unflushed async byte backlog per tunnel and protocol"),
+		metric.WithUnit("By"))
+	mProxyDropsTotal, _ = meter.Int64Counter("newt_proxy_drops_total",
+		metric.WithDescription("Proxy drops due to write errors"))
+	mProxyAcceptsTotal, _ = meter.Int64Counter("newt_proxy_accept_total",
+		metric.WithDescription("Proxy connection accepts by protocol and result"))
+	mProxyConnDuration, _ = meter.Float64Histogram("newt_proxy_connection_duration_seconds",
+		metric.WithDescription("Duration of completed proxy connections"),
+		metric.WithUnit("s"))
+	mProxyConnectionsTotal, _ = meter.Int64Counter("newt_proxy_connections_total",
+		metric.WithDescription("Proxy connection lifecycle events by protocol"))
+	// Register a default callback for build info if version/commit set
+	reg, e := meter.RegisterCallback(func(ctx context.Context, o metric.Observer) error {
+		if buildVersion == "" && buildCommit == "" {
+			return nil
+		}
+		attrs := []attribute.KeyValue{}
+		if buildVersion != "" {
+			attrs = append(attrs, attribute.String("version", buildVersion))
+		}
+		if buildCommit != "" {
+			attrs = append(attrs, attribute.String("commit", buildCommit))
+		}
+		if ShouldIncludeSiteLabels() {
+			attrs = append(attrs, siteAttrs()...)
+		}
+		o.ObserveInt64(mBuildInfo, 1, metric.WithAttributes(attrs...))
+		return nil
+	}, mBuildInfo)
+	if e != nil {
+		otel.Handle(e)
+	} else {
+		// Provide a functional stopper that unregisters the callback
+		obsStopper = func() { _ = reg.Unregister() }
+	}
+	if mWSConnected != nil {
+		if regConn, err := meter.RegisterCallback(func(ctx context.Context, o metric.Observer) error {
+			val := wsConnectedState.Load()
+			o.ObserveInt64(mWSConnected, val, metric.WithAttributes(attrsWithSite()...))
+			return nil
+		}, mWSConnected); err != nil {
+			otel.Handle(err)
+		} else {
+			wsConnStopper = func() { _ = regConn.Unregister() }
+		}
+	}
+	return nil
+}
+
+// Observable registration: Newt can register a callback to report gauges.
+// Call SetObservableCallback once to start observing online status, last
+// heartbeat seconds, and active sessions.
+
+var (
+	obsOnce       sync.Once
+	obsStopper    func()
+	proxyObsOnce  sync.Once
+	proxyStopper  func()
+	wsConnStopper func()
+)
+
+// SetObservableCallback registers a single callback that will be invoked
+// on collection. Use the provided observer to emit values for the observable
+// gauges defined here.
+//
+// Example inside your code (where you have access to current state):
+//
+//	telemetry.SetObservableCallback(func(ctx context.Context, o metric.Observer) error {
+//	    o.ObserveInt64(mSiteOnline, 1)
+//	    o.ObserveFloat64(mSiteLastHeartbeat, float64(lastHB.Unix()))
+//	    o.ObserveInt64(mTunnelSessions, int64(len(activeSessions)))
+//	    return nil
+//	})
+func SetObservableCallback(cb func(context.Context, metric.Observer) error) {
+	obsOnce.Do(func() {
+		reg, e := meter.RegisterCallback(cb, mSiteOnline, mSiteLastHeartbeat, mTunnelSessions)
+		if e != nil {
+			otel.Handle(e)
+			obsStopper = func() {
+				// no-op: registration failed; keep stopper callable
+			}
+			return
+		}
+		// Provide a functional stopper mirroring proxy/build-info behavior
+		obsStopper = func() { _ = reg.Unregister() }
+	})
+}
+
+// SetProxyObservableCallback registers a callback to observe proxy gauges.
+func SetProxyObservableCallback(cb func(context.Context, metric.Observer) error) {
+	proxyObsOnce.Do(func() {
+		reg, e := meter.RegisterCallback(cb, mProxyActiveConns, mProxyBufferBytes, mProxyAsyncBacklogByte)
+		if e != nil {
+			otel.Handle(e)
+			proxyStopper = func() {
+				// no-op: registration failed; keep stopper callable
+			}
+			return
+		}
+		// Provide a functional stopper to unregister later if needed
+		proxyStopper = func() { _ = reg.Unregister() }
+	})
+}
+
+// Build info registration
+func RegisterBuildInfo(version, commit string) {
+	buildVersion = version
+	buildCommit = commit
+}
+
+// Config reloads
+func IncConfigReload(ctx context.Context, result string) {
+	mConfigReloads.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("result", result),
+	)...))
+}
+
+// Helpers for counters/histograms
+
+func IncSiteRegistration(ctx context.Context, result string) {
+	attrs := []attribute.KeyValue{
+		attribute.String("result", result),
+	}
+	mSiteRegistrations.Add(ctx, 1, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+func AddTunnelBytes(ctx context.Context, tunnelID, direction string, n int64) {
+	attrs := []attribute.KeyValue{
+		attribute.String("direction", direction),
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mTunnelBytes.Add(ctx, n, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+// AddTunnelBytesSet adds bytes using a pre-built attribute.Set to avoid per-call allocations.
+func AddTunnelBytesSet(ctx context.Context, n int64, attrs attribute.Set) {
+	mTunnelBytes.Add(ctx, n, metric.WithAttributeSet(attrs))
+}
+
+// --- WebSocket helpers ---
+
+func ObserveWSConnectLatency(ctx context.Context, seconds float64, result, errorType string) {
+	attrs := []attribute.KeyValue{
+		attribute.String("transport", "websocket"),
+		attribute.String("result", result),
+	}
+	if errorType != "" {
+		attrs = append(attrs, attribute.String("error_type", errorType))
+	}
+	mWSConnectLatency.Record(ctx, seconds, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+func IncWSMessage(ctx context.Context, direction, msgType string) {
+	mWSMessages.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("direction", direction),
+		attribute.String("msg_type", msgType),
+	)...))
+}
+
+func IncWSDisconnect(ctx context.Context, reason, result string) {
+	mWSDisconnects.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("reason", reason),
+		attribute.String("result", result),
+	)...))
+}
+
+func IncWSKeepaliveFailure(ctx context.Context, reason string) {
+	mWSKeepaliveFailure.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("reason", reason),
+	)...))
+}
+
+// SetWSConnectionState updates the backing gauge for the WebSocket connected state.
+func SetWSConnectionState(connected bool) {
+	if connected {
+		wsConnectedState.Store(1)
+	} else {
+		wsConnectedState.Store(0)
+	}
+}
+
+// IncWSReconnect increments the WebSocket reconnect counter with a bounded reason label.
+func IncWSReconnect(ctx context.Context, reason string) {
+	if reason == "" {
+		reason = "unknown"
+	}
+	mWSReconnects.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("reason", reason),
+	)...))
+}
+
+func ObserveWSSessionDuration(ctx context.Context, seconds float64, result string) {
+	mWSSessionDuration.Record(ctx, seconds, metric.WithAttributes(attrsWithSite(
+		attribute.String("result", result),
+	)...))
+}
+
+// --- Proxy helpers ---
+
+func ObserveProxyActiveConnsObs(o metric.Observer, value int64, attrs []attribute.KeyValue) {
+	o.ObserveInt64(mProxyActiveConns, value, metric.WithAttributes(attrs...))
+}
+
+func ObserveProxyBufferBytesObs(o metric.Observer, value int64, attrs []attribute.KeyValue) {
+	o.ObserveInt64(mProxyBufferBytes, value, metric.WithAttributes(attrs...))
+}
+
+func ObserveProxyAsyncBacklogObs(o metric.Observer, value int64, attrs []attribute.KeyValue) {
+	o.ObserveInt64(mProxyAsyncBacklogByte, value, metric.WithAttributes(attrs...))
+}
+
+func IncProxyDrops(ctx context.Context, tunnelID, protocol string) {
+	attrs := []attribute.KeyValue{
+		attribute.String("protocol", protocol),
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mProxyDropsTotal.Add(ctx, 1, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+func IncProxyAccept(ctx context.Context, tunnelID, protocol, result, reason string) {
+	attrs := []attribute.KeyValue{
+		attribute.String("protocol", protocol),
+		attribute.String("result", result),
+	}
+	if reason != "" {
+		attrs = append(attrs, attribute.String("reason", reason))
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mProxyAcceptsTotal.Add(ctx, 1, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+func ObserveProxyConnectionDuration(ctx context.Context, tunnelID, protocol, result string, seconds float64) {
+	attrs := []attribute.KeyValue{
+		attribute.String("protocol", protocol),
+		attribute.String("result", result),
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mProxyConnDuration.Record(ctx, seconds, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+// IncProxyConnectionEvent records proxy connection lifecycle events (opened/closed).
+func IncProxyConnectionEvent(ctx context.Context, tunnelID, protocol, event string) {
+	if event == "" {
+		event = "unknown"
+	}
+	attrs := []attribute.KeyValue{
+		attribute.String("protocol", protocol),
+		attribute.String("event", event),
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mProxyConnectionsTotal.Add(ctx, 1, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+// --- Config/PKI helpers ---
+
+func ObserveConfigApply(ctx context.Context, phase, result string, seconds float64) {
+	mConfigApply.Record(ctx, seconds, metric.WithAttributes(attrsWithSite(
+		attribute.String("phase", phase),
+		attribute.String("result", result),
+	)...))
+}
+
+func IncCertRotation(ctx context.Context, result string) {
+	mCertRotationTotal.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("result", result),
+	)...))
+}
+
+func ObserveTunnelLatency(ctx context.Context, tunnelID, transport string, seconds float64) {
+	attrs := []attribute.KeyValue{
+		attribute.String("transport", transport),
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mTunnelLatency.Record(ctx, seconds, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+func IncReconnect(ctx context.Context, tunnelID, initiator, reason string) {
+	attrs := []attribute.KeyValue{
+		attribute.String("initiator", initiator),
+		attribute.String("reason", reason),
+	}
+	if ShouldIncludeTunnelID() && tunnelID != "" {
+		attrs = append(attrs, attribute.String("tunnel_id", tunnelID))
+	}
+	mReconnects.Add(ctx, 1, metric.WithAttributes(attrsWithSite(attrs...)...))
+}
+
+func IncConnAttempt(ctx context.Context, transport, result string) {
+	mConnAttempts.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("transport", transport),
+		attribute.String("result", result),
+	)...))
+}
+
+func IncConnError(ctx context.Context, transport, typ string) {
+	mConnErrors.Add(ctx, 1, metric.WithAttributes(attrsWithSite(
+		attribute.String("transport", transport),
+		attribute.String("error_type", typ),
+	)...))
+}

internal/telemetry/metrics_test_helper.go

@@ -0,0 +1,59 @@
+package telemetry
+
+import (
+	"sync"
+	"time"
+)
+
+func resetMetricsForTest() {
+	initOnce = sync.Once{}
+	obsOnce = sync.Once{}
+	proxyObsOnce = sync.Once{}
+	obsStopper = nil
+	proxyStopper = nil
+	if wsConnStopper != nil {
+		wsConnStopper()
+	}
+	wsConnStopper = nil
+	meter = nil
+
+	mSiteRegistrations = nil
+	mSiteOnline = nil
+	mSiteLastHeartbeat = nil
+
+	mTunnelSessions = nil
+	mTunnelBytes = nil
+	mTunnelLatency = nil
+	mReconnects = nil
+
+	mConnAttempts = nil
+	mConnErrors = nil
+
+	mConfigReloads = nil
+	mConfigApply = nil
+	mCertRotationTotal = nil
+	mProcessStartTime = nil
+
+	mBuildInfo = nil
+
+	mWSConnectLatency = nil
+	mWSMessages = nil
+	mWSDisconnects = nil
+	mWSKeepaliveFailure = nil
+	mWSSessionDuration = nil
+	mWSConnected = nil
+	mWSReconnects = nil
+
+	mProxyActiveConns = nil
+	mProxyBufferBytes = nil
+	mProxyAsyncBacklogByte = nil
+	mProxyDropsTotal = nil
+	mProxyAcceptsTotal = nil
+	mProxyConnDuration = nil
+	mProxyConnectionsTotal = nil
+
+	processStartUnix = float64(time.Now().UnixNano()) / 1e9
+	wsConnectedState.Store(0)
+	includeTunnelIDVal.Store(false)
+	includeSiteLabelVal.Store(false)
+}

internal/telemetry/state_view.go

@@ -0,0 +1,106 @@
+package telemetry
+
+import (
+	"context"
+	"sync/atomic"
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// StateView provides a read-only view for observable gauges.
+// Implementations must be concurrency-safe and avoid blocking operations.
+// All methods should be fast and use RLocks where applicable.
+type StateView interface {
+	// ListSites returns a stable, low-cardinality list of site IDs to expose.
+	ListSites() []string
+	// Online returns whether the site is online.
+	Online(siteID string) (online bool, ok bool)
+	// LastHeartbeat returns the last heartbeat time for a site.
+	LastHeartbeat(siteID string) (t time.Time, ok bool)
+	// ActiveSessions returns the current number of active sessions for a site (across tunnels),
+	// or scoped to site if your model is site-scoped.
+	ActiveSessions(siteID string) (n int64, ok bool)
+}
+
+var (
+	stateView atomic.Value // of type StateView
+)
+
+// RegisterStateView sets the global StateView used by the default observable callback.
+func RegisterStateView(v StateView) {
+	stateView.Store(v)
+	// If instruments are registered, ensure a callback exists.
+	if v != nil {
+		SetObservableCallback(func(ctx context.Context, o metric.Observer) error {
+			if any := stateView.Load(); any != nil {
+				if sv, ok := any.(StateView); ok {
+					for _, siteID := range sv.ListSites() {
+						observeSiteOnlineFor(o, sv, siteID)
+						observeLastHeartbeatFor(o, sv, siteID)
+						observeSessionsFor(o, siteID, sv)
+					}
+				}
+			}
+			return nil
+		})
+	}
+}
+
+func observeSiteOnlineFor(o metric.Observer, sv StateView, siteID string) {
+	if online, ok := sv.Online(siteID); ok {
+		val := int64(0)
+		if online {
+			val = 1
+		}
+		o.ObserveInt64(mSiteOnline, val, metric.WithAttributes(
+			attribute.String("site_id", siteID),
+		))
+	}
+}
+
+func observeLastHeartbeatFor(o metric.Observer, sv StateView, siteID string) {
+	if t, ok := sv.LastHeartbeat(siteID); ok {
+		ts := float64(t.UnixNano()) / 1e9
+		o.ObserveFloat64(mSiteLastHeartbeat, ts, metric.WithAttributes(
+			attribute.String("site_id", siteID),
+		))
+	}
+}
+
+func observeSessionsFor(o metric.Observer, siteID string, any interface{}) {
+	if tm, ok := any.(interface{ SessionsByTunnel() map[string]int64 }); ok {
+		sessions := tm.SessionsByTunnel()
+		// If tunnel_id labels are enabled, preserve existing per-tunnel observations
+		if ShouldIncludeTunnelID() {
+			for tid, n := range sessions {
+				attrs := []attribute.KeyValue{
+					attribute.String("site_id", siteID),
+				}
+				if tid != "" {
+					attrs = append(attrs, attribute.String("tunnel_id", tid))
+				}
+				o.ObserveInt64(mTunnelSessions, n, metric.WithAttributes(attrs...))
+			}
+			return
+		}
+		// When tunnel_id is disabled, collapse per-tunnel counts into a single site-level value
+		var total int64
+		for _, n := range sessions {
+			total += n
+		}
+		// If there are no per-tunnel entries, fall back to ActiveSessions() if available
+		if total == 0 {
+			if svAny := stateView.Load(); svAny != nil {
+				if sv, ok := svAny.(StateView); ok {
+					if n, ok2 := sv.ActiveSessions(siteID); ok2 {
+						total = n
+					}
+				}
+			}
+		}
+		o.ObserveInt64(mTunnelSessions, total, metric.WithAttributes(attribute.String("site_id", siteID)))
+		return
+	}
+}

internal/telemetry/telemetry.go

@@ -0,0 +1,384 @@
+package telemetry
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"os"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	promclient "github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"go.opentelemetry.io/contrib/instrumentation/runtime"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc"
+	"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/sdk/metric"
+	"go.opentelemetry.io/otel/sdk/resource"
+	"go.opentelemetry.io/otel/sdk/trace"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
+	"google.golang.org/grpc/credentials"
+)
+
+// Config controls telemetry initialization via env flags.
+//
+// Defaults align with the issue requirements:
+//   - Prometheus exporter enabled by default (/metrics)
+//   - OTLP exporter disabled by default
+//   - Durations in seconds, bytes in raw bytes
+//   - Admin HTTP server address configurable (for mounting /metrics)
+type Config struct {
+	ServiceName    string
+	ServiceVersion string
+
+	// Optional resource attributes
+	SiteID string
+	Region string
+
+	PromEnabled bool
+	OTLPEnabled bool
+
+	OTLPEndpoint string // host:port
+	OTLPInsecure bool
+
+	MetricExportInterval time.Duration
+	AdminAddr            string // e.g.: ":2112"
+
+	// Optional build info for newt_build_info metric
+	BuildVersion string
+	BuildCommit  string
+}
+
+// FromEnv reads configuration from environment variables.
+//
+//	NEWT_METRICS_PROMETHEUS_ENABLED (default: true)
+//	NEWT_METRICS_OTLP_ENABLED       (default: false)
+//	OTEL_EXPORTER_OTLP_ENDPOINT     (default: "localhost:4317")
+//	OTEL_EXPORTER_OTLP_INSECURE     (default: true)
+//	OTEL_METRIC_EXPORT_INTERVAL     (default: 15s)
+//	OTEL_SERVICE_NAME               (default: "newt")
+//	OTEL_SERVICE_VERSION            (default: "")
+//	NEWT_ADMIN_ADDR                 (default: ":2112")
+func FromEnv() Config {
+	// Prefer explicit NEWT_* env vars, then fall back to OTEL_RESOURCE_ATTRIBUTES
+	site := getenv("NEWT_SITE_ID", "")
+	if site == "" {
+		site = getenv("NEWT_ID", "")
+	}
+	region := os.Getenv("NEWT_REGION")
+	if site == "" || region == "" {
+		if ra := os.Getenv("OTEL_RESOURCE_ATTRIBUTES"); ra != "" {
+			m := parseResourceAttributes(ra)
+			if site == "" {
+				site = m["site_id"]
+			}
+			if region == "" {
+				region = m["region"]
+			}
+		}
+	}
+	return Config{
+		ServiceName:          getenv("OTEL_SERVICE_NAME", "newt"),
+		ServiceVersion:       os.Getenv("OTEL_SERVICE_VERSION"),
+		SiteID:               site,
+		Region:               region,
+		PromEnabled:          getenv("NEWT_METRICS_PROMETHEUS_ENABLED", "true") == "true",
+		OTLPEnabled:          getenv("NEWT_METRICS_OTLP_ENABLED", "false") == "true",
+		OTLPEndpoint:         getenv("OTEL_EXPORTER_OTLP_ENDPOINT", "localhost:4317"),
+		OTLPInsecure:         getenv("OTEL_EXPORTER_OTLP_INSECURE", "true") == "true",
+		MetricExportInterval: getdur("OTEL_METRIC_EXPORT_INTERVAL", 15*time.Second),
+		AdminAddr:            getenv("NEWT_ADMIN_ADDR", ":2112"),
+	}
+}
+
+// Setup holds initialized telemetry providers and (optionally) a /metrics handler.
+// Call Shutdown when the process terminates to flush exporters.
+type Setup struct {
+	MeterProvider  *metric.MeterProvider
+	TracerProvider *trace.TracerProvider
+
+	PrometheusHandler http.Handler // nil if Prometheus exporter disabled
+
+	shutdowns []func(context.Context) error
+}
+
+// Init configures OpenTelemetry metrics and (optionally) tracing.
+//
+// It sets a global MeterProvider and TracerProvider, registers runtime instrumentation,
+// installs recommended histogram views for *_latency_seconds, and returns a Setup with
+// a Shutdown method to flush exporters.
+func Init(ctx context.Context, cfg Config) (*Setup, error) {
+	// Configure tunnel_id label inclusion from env (default true)
+	if getenv("NEWT_METRICS_INCLUDE_TUNNEL_ID", "true") == "true" {
+		includeTunnelIDVal.Store(true)
+	} else {
+		includeTunnelIDVal.Store(false)
+	}
+        if getenv("NEWT_METRICS_INCLUDE_SITE_LABELS", "true") == "true" {
+                includeSiteLabelVal.Store(true)
+        } else {
+                includeSiteLabelVal.Store(false)
+        }
+	res := buildResource(ctx, cfg)
+	UpdateSiteInfo(cfg.SiteID, cfg.Region)
+
+	s := &Setup{}
+	readers, promHandler, shutdowns, err := setupMetricExport(ctx, cfg, res)
+	if err != nil {
+		return nil, err
+	}
+	s.PrometheusHandler = promHandler
+	// Build provider
+	mp := buildMeterProvider(res, readers)
+	otel.SetMeterProvider(mp)
+	s.MeterProvider = mp
+	s.shutdowns = append(s.shutdowns, mp.Shutdown)
+	// Optional tracing
+	if cfg.OTLPEnabled {
+		if tp, shutdown := setupTracing(ctx, cfg, res); tp != nil {
+			otel.SetTracerProvider(tp)
+			s.TracerProvider = tp
+			s.shutdowns = append(s.shutdowns, func(c context.Context) error {
+				return errors.Join(shutdown(c), tp.Shutdown(c))
+			})
+		}
+	}
+	// Add metric exporter shutdowns
+	s.shutdowns = append(s.shutdowns, shutdowns...)
+	// Runtime metrics
+	_ = runtime.Start(runtime.WithMeterProvider(mp))
+	// Instruments
+	if err := registerInstruments(); err != nil {
+		return nil, err
+	}
+	if cfg.BuildVersion != "" || cfg.BuildCommit != "" {
+		RegisterBuildInfo(cfg.BuildVersion, cfg.BuildCommit)
+	}
+	return s, nil
+}
+
+func buildResource(ctx context.Context, cfg Config) *resource.Resource {
+	attrs := []attribute.KeyValue{
+		semconv.ServiceName(cfg.ServiceName),
+		semconv.ServiceVersion(cfg.ServiceVersion),
+	}
+	if cfg.SiteID != "" {
+		attrs = append(attrs, attribute.String("site_id", cfg.SiteID))
+	}
+	if cfg.Region != "" {
+		attrs = append(attrs, attribute.String("region", cfg.Region))
+	}
+	res, _ := resource.New(ctx, resource.WithFromEnv(), resource.WithHost(), resource.WithAttributes(attrs...))
+	return res
+}
+
+func setupMetricExport(ctx context.Context, cfg Config, _ *resource.Resource) ([]metric.Reader, http.Handler, []func(context.Context) error, error) {
+	var readers []metric.Reader
+	var shutdowns []func(context.Context) error
+	var promHandler http.Handler
+	if cfg.PromEnabled {
+		reg := promclient.NewRegistry()
+		exp, err := prometheus.New(prometheus.WithRegisterer(reg))
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		readers = append(readers, exp)
+		promHandler = promhttp.HandlerFor(reg, promhttp.HandlerOpts{})
+	}
+	if cfg.OTLPEnabled {
+		mopts := []otlpmetricgrpc.Option{otlpmetricgrpc.WithEndpoint(cfg.OTLPEndpoint)}
+		if hdrs := parseOTLPHeaders(os.Getenv("OTEL_EXPORTER_OTLP_HEADERS")); len(hdrs) > 0 {
+			mopts = append(mopts, otlpmetricgrpc.WithHeaders(hdrs))
+		}
+		if cfg.OTLPInsecure {
+			mopts = append(mopts, otlpmetricgrpc.WithInsecure())
+		} else if certFile := os.Getenv("OTEL_EXPORTER_OTLP_CERTIFICATE"); certFile != "" {
+			if creds, cerr := credentials.NewClientTLSFromFile(certFile, ""); cerr == nil {
+				mopts = append(mopts, otlpmetricgrpc.WithTLSCredentials(creds))
+			}
+		}
+		mexp, err := otlpmetricgrpc.New(ctx, mopts...)
+		if err != nil {
+			return nil, nil, nil, err
+		}
+		readers = append(readers, metric.NewPeriodicReader(mexp, metric.WithInterval(cfg.MetricExportInterval)))
+		shutdowns = append(shutdowns, mexp.Shutdown)
+	}
+	return readers, promHandler, shutdowns, nil
+}
+
+func buildMeterProvider(res *resource.Resource, readers []metric.Reader) *metric.MeterProvider {
+	var mpOpts []metric.Option
+	mpOpts = append(mpOpts, metric.WithResource(res))
+	for _, r := range readers {
+		mpOpts = append(mpOpts, metric.WithReader(r))
+	}
+	mpOpts = append(mpOpts, metric.WithView(metric.NewView(
+		metric.Instrument{Name: "newt_*_latency_seconds"},
+		metric.Stream{Aggregation: metric.AggregationExplicitBucketHistogram{Boundaries: []float64{0.005, 0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2.5, 5, 10, 30}}},
+	)))
+	mpOpts = append(mpOpts, metric.WithView(metric.NewView(
+		metric.Instrument{Name: "newt_*"},
+		metric.Stream{AttributeFilter: func(kv attribute.KeyValue) bool {
+			k := string(kv.Key)
+			switch k {
+			case "tunnel_id", "transport", "direction", "protocol", "result", "reason", "initiator", "error_type", "msg_type", "phase", "version", "commit", "site_id", "region":
+				return true
+			default:
+				return false
+			}
+		}},
+	)))
+	return metric.NewMeterProvider(mpOpts...)
+}
+
+func setupTracing(ctx context.Context, cfg Config, res *resource.Resource) (*trace.TracerProvider, func(context.Context) error) {
+	topts := []otlptracegrpc.Option{otlptracegrpc.WithEndpoint(cfg.OTLPEndpoint)}
+	if hdrs := parseOTLPHeaders(os.Getenv("OTEL_EXPORTER_OTLP_HEADERS")); len(hdrs) > 0 {
+		topts = append(topts, otlptracegrpc.WithHeaders(hdrs))
+	}
+	if cfg.OTLPInsecure {
+		topts = append(topts, otlptracegrpc.WithInsecure())
+	} else if certFile := os.Getenv("OTEL_EXPORTER_OTLP_CERTIFICATE"); certFile != "" {
+		if creds, cerr := credentials.NewClientTLSFromFile(certFile, ""); cerr == nil {
+			topts = append(topts, otlptracegrpc.WithTLSCredentials(creds))
+		}
+	}
+	exp, err := otlptracegrpc.New(ctx, topts...)
+	if err != nil {
+		return nil, nil
+	}
+	tp := trace.NewTracerProvider(trace.WithBatcher(exp), trace.WithResource(res))
+	return tp, exp.Shutdown
+}
+
+// Shutdown flushes exporters and providers in reverse init order.
+func (s *Setup) Shutdown(ctx context.Context) error {
+	var err error
+	for i := len(s.shutdowns) - 1; i >= 0; i-- {
+		err = errors.Join(err, s.shutdowns[i](ctx))
+	}
+	return err
+}
+
+func parseOTLPHeaders(h string) map[string]string {
+	m := map[string]string{}
+	if h == "" {
+		return m
+	}
+	pairs := strings.Split(h, ",")
+	for _, p := range pairs {
+		kv := strings.SplitN(strings.TrimSpace(p), "=", 2)
+		if len(kv) == 2 {
+			m[strings.TrimSpace(kv[0])] = strings.TrimSpace(kv[1])
+		}
+	}
+	return m
+}
+
+// parseResourceAttributes parses OTEL_RESOURCE_ATTRIBUTES formatted as k=v,k2=v2
+func parseResourceAttributes(s string) map[string]string {
+	m := map[string]string{}
+	if s == "" {
+		return m
+	}
+	parts := strings.Split(s, ",")
+	for _, p := range parts {
+		kv := strings.SplitN(strings.TrimSpace(p), "=", 2)
+		if len(kv) == 2 {
+			m[strings.TrimSpace(kv[0])] = strings.TrimSpace(kv[1])
+		}
+	}
+	return m
+}
+
+// Global site/region used to enrich metric labels.
+var siteIDVal atomic.Value
+var regionVal atomic.Value
+var (
+	includeTunnelIDVal  atomic.Value // bool; default true
+	includeSiteLabelVal atomic.Value // bool; default false
+)
+
+// UpdateSiteInfo updates the global site_id and region used for metric labels.
+// Thread-safe via atomic.Value: subsequent metric emissions will include
+// the new labels, prior emissions remain unchanged.
+func UpdateSiteInfo(siteID, region string) {
+	if siteID != "" {
+		siteIDVal.Store(siteID)
+	}
+	if region != "" {
+		regionVal.Store(region)
+	}
+}
+
+func getSiteID() string {
+	if v, ok := siteIDVal.Load().(string); ok {
+		return v
+	}
+	return ""
+}
+
+func getRegion() string {
+	if v, ok := regionVal.Load().(string); ok {
+		return v
+	}
+	return ""
+}
+
+// siteAttrs returns label KVs for site_id and region (if set).
+func siteAttrs() []attribute.KeyValue {
+	var out []attribute.KeyValue
+	if s := getSiteID(); s != "" {
+		out = append(out, attribute.String("site_id", s))
+	}
+	if r := getRegion(); r != "" {
+		out = append(out, attribute.String("region", r))
+	}
+	return out
+}
+
+// SiteLabelKVs exposes site label KVs for other packages (e.g., proxy manager).
+func SiteLabelKVs() []attribute.KeyValue {
+	if !ShouldIncludeSiteLabels() {
+		return nil
+	}
+	return siteAttrs()
+}
+
+// ShouldIncludeTunnelID returns whether tunnel_id labels should be emitted.
+func ShouldIncludeTunnelID() bool {
+	if v, ok := includeTunnelIDVal.Load().(bool); ok {
+		return v
+	}
+	return true
+}
+
+// ShouldIncludeSiteLabels returns whether site_id/region should be emitted as
+// metric labels in addition to resource attributes.
+func ShouldIncludeSiteLabels() bool {
+	if v, ok := includeSiteLabelVal.Load().(bool); ok {
+		return v
+	}
+	return false
+}
+
+func getenv(k, d string) string {
+	if v := os.Getenv(k); v != "" {
+		return v
+	}
+	return d
+}
+
+func getdur(k string, d time.Duration) time.Duration {
+	if v := os.Getenv(k); v != "" {
+		if p, e := time.ParseDuration(v); e == nil {
+			return p
+		}
+	}
+	return d
+}

internal/telemetry/telemetry_attrfilter_test.go

@@ -0,0 +1,53 @@
+package telemetry
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// Test that disallowed attributes are filtered from the exposition.
+func TestAttributeFilterDropsUnknownKeys(t *testing.T) {
+        ctx := context.Background()
+        resetMetricsForTest()
+        t.Setenv("NEWT_METRICS_INCLUDE_SITE_LABELS", "true")
+        cfg := Config{ServiceName: "newt", PromEnabled: true, AdminAddr: "127.0.0.1:0"}
+	tel, err := Init(ctx, cfg)
+	if err != nil {
+		t.Fatalf("init: %v", err)
+	}
+	defer func() { _ = tel.Shutdown(context.Background()) }()
+
+	if tel.PrometheusHandler == nil {
+		t.Fatalf("prom handler nil")
+	}
+	ts := httptest.NewServer(tel.PrometheusHandler)
+	defer ts.Close()
+
+	// Add samples with disallowed attribute keys
+	for _, k := range []string{"forbidden", "site_id", "host"} {
+		set := attribute.NewSet(attribute.String(k, "x"))
+		AddTunnelBytesSet(ctx, 123, set)
+	}
+	time.Sleep(50 * time.Millisecond)
+
+	resp, err := http.Get(ts.URL)
+	if err != nil {
+		t.Fatalf("GET: %v", err)
+	}
+	defer resp.Body.Close()
+	b, _ := io.ReadAll(resp.Body)
+	body := string(b)
+	if strings.Contains(body, "forbidden=") {
+		t.Fatalf("unexpected forbidden attribute leaked into metrics: %s", body)
+	}
+	if !strings.Contains(body, "site_id=\"x\"") {
+		t.Fatalf("expected allowed attribute site_id to be present in metrics, got: %s", body)
+	}
+}

internal/telemetry/telemetry_golden_test.go

@@ -0,0 +1,76 @@
+package telemetry
+
+import (
+	"bufio"
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Golden test that /metrics contains expected metric names.
+func TestMetricsGoldenContains(t *testing.T) {
+	ctx := context.Background()
+	resetMetricsForTest()
+	t.Setenv("NEWT_METRICS_INCLUDE_SITE_LABELS", "true")
+	cfg := Config{ServiceName: "newt", PromEnabled: true, AdminAddr: "127.0.0.1:0", BuildVersion: "test"}
+	tel, err := Init(ctx, cfg)
+	if err != nil {
+		t.Fatalf("telemetry init error: %v", err)
+	}
+	defer func() { _ = tel.Shutdown(context.Background()) }()
+
+	if tel.PrometheusHandler == nil {
+		t.Fatalf("prom handler nil")
+	}
+	ts := httptest.NewServer(tel.PrometheusHandler)
+	defer ts.Close()
+
+	// Trigger counters to ensure they appear in the scrape
+	IncConnAttempt(ctx, "websocket", "success")
+	IncWSReconnect(ctx, "io_error")
+	IncProxyConnectionEvent(ctx, "", "tcp", ProxyConnectionOpened)
+	if tel.MeterProvider != nil {
+		_ = tel.MeterProvider.ForceFlush(ctx)
+	}
+	time.Sleep(100 * time.Millisecond)
+
+	var body string
+	for i := 0; i < 5; i++ {
+		resp, err := http.Get(ts.URL)
+		if err != nil {
+			t.Fatalf("GET metrics failed: %v", err)
+		}
+		b, _ := io.ReadAll(resp.Body)
+		_ = resp.Body.Close()
+		body = string(b)
+		if strings.Contains(body, "newt_connection_attempts_total") {
+			break
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+
+	f, err := os.Open(filepath.Join("testdata", "expected_contains.golden"))
+	if err != nil {
+		t.Fatalf("read golden: %v", err)
+	}
+	defer f.Close()
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		needle := strings.TrimSpace(s.Text())
+		if needle == "" {
+			continue
+		}
+		if !strings.Contains(body, needle) {
+			t.Fatalf("expected metrics body to contain %q. body=\n%s", needle, body)
+		}
+	}
+	if err := s.Err(); err != nil {
+		t.Fatalf("scan golden: %v", err)
+	}
+}

internal/telemetry/telemetry_smoke_test.go

@@ -0,0 +1,65 @@
+package telemetry
+
+import (
+	"context"
+	"io"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+)
+
+// Smoke test that /metrics contains at least one newt_* metric when Prom exporter is enabled.
+func TestMetricsSmoke(t *testing.T) {
+	ctx := context.Background()
+	resetMetricsForTest()
+	t.Setenv("NEWT_METRICS_INCLUDE_SITE_LABELS", "true")
+	cfg := Config{
+		ServiceName:          "newt",
+		PromEnabled:          true,
+		OTLPEnabled:          false,
+		AdminAddr:            "127.0.0.1:0",
+		BuildVersion:         "test",
+		BuildCommit:          "deadbeef",
+		MetricExportInterval: 5 * time.Second,
+	}
+	tel, err := Init(ctx, cfg)
+	if err != nil {
+		t.Fatalf("telemetry init error: %v", err)
+	}
+	defer func() { _ = tel.Shutdown(context.Background()) }()
+
+	// Serve the Prom handler on a test server
+	if tel.PrometheusHandler == nil {
+		t.Fatalf("Prometheus handler nil; PromEnabled should enable it")
+	}
+	ts := httptest.NewServer(tel.PrometheusHandler)
+	defer ts.Close()
+
+	// Record a simple metric and then fetch /metrics
+	IncConnAttempt(ctx, "websocket", "success")
+	if tel.MeterProvider != nil {
+		_ = tel.MeterProvider.ForceFlush(ctx)
+	}
+	// Give the exporter a tick to collect
+	time.Sleep(100 * time.Millisecond)
+
+	var body string
+	for i := 0; i < 5; i++ {
+		resp, err := http.Get(ts.URL)
+		if err != nil {
+			t.Fatalf("GET /metrics failed: %v", err)
+		}
+		b, _ := io.ReadAll(resp.Body)
+		_ = resp.Body.Close()
+		body = string(b)
+		if strings.Contains(body, "newt_connection_attempts_total") {
+			break
+		}
+		time.Sleep(100 * time.Millisecond)
+	}
+	if !strings.Contains(body, "newt_connection_attempts_total") {
+		t.Fatalf("expected newt_connection_attempts_total in metrics, got:\n%s", body)
+	}
+}

internal/telemetry/testdata/expected_contains.golden

@@ -0,0 +1,3 @@
+newt_connection_attempts_total
+newt_websocket_reconnects_total
+newt_proxy_connections_total

key

@@ -1 +0,0 @@
-oBvcoMJZXGzTZ4X+aNSCCQIjroREFBeRCs+a328xWGA=

linux.go

@@ -1,74 +0,0 @@
-//go:build linux
-
-package main
-
-import (
-	"fmt"
-	"os"
-	"runtime"
-
-	"github.com/fosrl/newt/logger"
-	"github.com/fosrl/newt/proxy"
-	"github.com/fosrl/newt/websocket"
-	"github.com/fosrl/newt/wg"
-	"github.com/fosrl/newt/wgtester"
-)
-
-var wgServiceNative *wg.WireGuardService
-
-func setupClientsNative(client *websocket.Client, host string) {
-
-	if runtime.GOOS != "linux" {
-		logger.Fatal("Tunnel management is only supported on Linux right now!")
-		os.Exit(1)
-	}
-
-	// make sure we are sudo
-	if os.Geteuid() != 0 {
-		logger.Fatal("You must run this program as root to manage tunnels on Linux.")
-		os.Exit(1)
-	}
-
-	// Create WireGuard service
-	wgServiceNative, err = wg.NewWireGuardService(interfaceName, mtuInt, generateAndSaveKeyTo, host, id, client)
-	if err != nil {
-		logger.Fatal("Failed to create WireGuard service: %v", err)
-	}
-
-	wgTesterServer = wgtester.NewServer("0.0.0.0", wgServiceNative.Port, id) // TODO: maybe make this the same ip of the wg server?
-	err := wgTesterServer.Start()
-	if err != nil {
-		logger.Error("Failed to start WireGuard tester server: %v", err)
-	}
-
-	client.OnTokenUpdate(func(token string) {
-		wgServiceNative.SetToken(token)
-	})
-}
-
-func closeWgServiceNative() {
-	if wgServiceNative != nil {
-		wgServiceNative.Close(!keepInterface)
-		wgServiceNative = nil
-	}
-}
-
-func clientsOnConnectNative() {
-	if wgServiceNative != nil {
-		wgServiceNative.LoadRemoteConfig()
-	}
-}
-
-func clientsHandleNewtConnectionNative(publicKey, endpoint string) {
-	if wgServiceNative != nil {
-		wgServiceNative.StartHolepunch(publicKey, endpoint)
-	}
-}
-
-func clientsAddProxyTargetNative(pm *proxy.ProxyManager, tunnelIp string) {
-	// add a udp proxy for localost and the wgService port
-	// TODO: make sure this port is not used in a target
-	if wgServiceNative != nil {
-		pm.AddTarget("udp", tunnelIp, int(wgServiceNative.Port), fmt.Sprintf("127.0.0.1:%d", wgServiceNative.Port))
-	}
-}

logger/logger.go

@@ -2,16 +2,15 @@ package logger
 
 import (
 	"fmt"
-	"io"
-	"log"
 	"os"
+	"strings"
 	"sync"
 	"time"
 )
 
 // Logger struct holds the logger instance
 type Logger struct {
-	logger *log.Logger
+	writer LogWriter
 	level  LogLevel
 }
 
@@ -20,17 +19,29 @@ var (
 	once          sync.Once
 )
 
-// NewLogger creates a new logger instance
+// NewLogger creates a new logger instance with the default StandardWriter
 func NewLogger() *Logger {
 	return &Logger{
-		logger: log.New(os.Stdout, "", 0),
+		writer: NewStandardWriter(),
+		level:  DEBUG,
+	}
+}
+
+// NewLoggerWithWriter creates a new logger instance with a custom LogWriter
+func NewLoggerWithWriter(writer LogWriter) *Logger {
+	return &Logger{
+		writer: writer,
 		level:  DEBUG,
 	}
 }
 
 // Init initializes the default logger
-func Init() *Logger {
+func Init(logger *Logger) *Logger {
 	once.Do(func() {
+		if logger != nil {
+			defaultLogger = logger
+			return
+		}
 		defaultLogger = NewLogger()
 	})
 	return defaultLogger
@@ -39,7 +50,7 @@ func Init() *Logger {
 // GetLogger returns the default logger instance
 func GetLogger() *Logger {
 	if defaultLogger == nil {
-		Init()
+		Init(nil)
 	}
 	return defaultLogger
 }
@@ -49,9 +60,11 @@ func (l *Logger) SetLevel(level LogLevel) {
 	l.level = level
 }
 
-// SetOutput sets the output destination for the logger
-func (l *Logger) SetOutput(w io.Writer) {
-	l.logger.SetOutput(w)
+// SetOutput sets the output destination for the logger (only works with StandardWriter)
+func (l *Logger) SetOutput(output *os.File) {
+	if sw, ok := l.writer.(*StandardWriter); ok {
+		sw.SetOutput(output)
+	}
 }
 
 // log handles the actual logging
@@ -60,24 +73,8 @@ func (l *Logger) log(level LogLevel, format string, args ...interface{}) {
 		return
 	}
 
-	// Get timezone from environment variable or use local timezone
-	timezone := os.Getenv("LOGGER_TIMEZONE")
-	var location *time.Location
-	var err error
-
-	if timezone != "" {
-		location, err = time.LoadLocation(timezone)
-		if err != nil {
-			// If invalid timezone, fall back to local
-			location = time.Local
-		}
-	} else {
-		location = time.Local
-	}
-
-	timestamp := time.Now().In(location).Format("2006/01/02 15:04:05")
 	message := fmt.Sprintf(format, args...)
-	l.logger.Printf("%s: %s %s", level.String(), timestamp, message)
+	l.writer.Write(level, time.Now(), message)
 }
 
 // Debug logs debug level messages
@@ -128,6 +125,29 @@ func Fatal(format string, args ...interface{}) {
 }
 
 // SetOutput sets the output destination for the default logger
-func SetOutput(w io.Writer) {
-	GetLogger().SetOutput(w)
+func SetOutput(output *os.File) {
+	GetLogger().SetOutput(output)
+}
+
+// WireGuardLogger is a wrapper type that matches WireGuard's Logger interface
+type WireGuardLogger struct {
+	Verbosef func(format string, args ...any)
+	Errorf   func(format string, args ...any)
+}
+
+// GetWireGuardLogger returns a WireGuard-compatible logger that writes to the newt logger
+// The prepend string is added as a prefix to all log messages
+func (l *Logger) GetWireGuardLogger(prepend string) *WireGuardLogger {
+	return &WireGuardLogger{
+		Verbosef: func(format string, args ...any) {
+			// if the format string contains "Sending keepalive packet", skip debug logging to reduce noise
+			if strings.Contains(format, "Sending keepalive packet") {
+				return
+			}
+			l.Debug(prepend+format, args...)
+		},
+		Errorf: func(format string, args ...any) {
+			l.Error(prepend+format, args...)
+		},
+	}
 }

logger/writer.go

@@ -0,0 +1,54 @@
+package logger
+
+import (
+	"fmt"
+	"os"
+	"time"
+)
+
+// LogWriter is an interface for writing log messages
+// Implement this interface to create custom log backends (OS log, syslog, etc.)
+type LogWriter interface {
+	// Write writes a log message with the given level, timestamp, and formatted message
+	Write(level LogLevel, timestamp time.Time, message string)
+}
+
+// StandardWriter is the default log writer that writes to an io.Writer
+type StandardWriter struct {
+	output   *os.File
+	timezone *time.Location
+}
+
+// NewStandardWriter creates a new standard writer with the default configuration
+func NewStandardWriter() *StandardWriter {
+	// Get timezone from environment variable or use local timezone
+	timezone := os.Getenv("LOGGER_TIMEZONE")
+	var location *time.Location
+	var err error
+
+	if timezone != "" {
+		location, err = time.LoadLocation(timezone)
+		if err != nil {
+			// If invalid timezone, fall back to local
+			location = time.Local
+		}
+	} else {
+		location = time.Local
+	}
+
+	return &StandardWriter{
+		output:   os.Stdout,
+		timezone: location,
+	}
+}
+
+// SetOutput sets the output destination
+func (w *StandardWriter) SetOutput(output *os.File) {
+	w.output = output
+}
+
+// Write implements the LogWriter interface
+func (w *StandardWriter) Write(level LogLevel, timestamp time.Time, message string) {
+	formattedTime := timestamp.In(w.timezone).Format("2006/01/02 15:04:05")
+	fmt.Fprintf(w.output, "%s: %s %s\n", level.String(), formattedTime, message)
+}

main.go

@@ -1,7 +1,9 @@
 package main
 
 import (
+	"context"
 	"encoding/json"
+	"errors"
 	"flag"
 	"fmt"
 	"net"
@@ -20,8 +22,12 @@ import (
 	"github.com/fosrl/newt/logger"
 	"github.com/fosrl/newt/proxy"
 	"github.com/fosrl/newt/updates"
+	"github.com/fosrl/newt/util"
 	"github.com/fosrl/newt/websocket"
 
+	"github.com/fosrl/newt/internal/state"
+	"github.com/fosrl/newt/internal/telemetry"
+	"go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp"
 	"golang.zx2c4.com/wireguard/conn"
 	"golang.zx2c4.com/wireguard/device"
 	"golang.zx2c4.com/wireguard/tun"
@@ -91,6 +97,14 @@ func (s *stringSlice) Set(value string) error {
 	return nil
 }
 
+const (
+	fmtErrMarshaling        = "Error marshaling data: %v"
+	fmtReceivedMsg          = "Received: %+v"
+	topicWGRegister         = "newt/wg/register"
+	msgNoTunnelOrProxy      = "No tunnel IP or proxy manager available"
+	fmtErrParsingTargetData = "Error parsing target data: %v"
+)
+
 var (
 	endpoint                           string
 	id                                 string
@@ -102,9 +116,7 @@ var (
 	err                                error
 	logLevel                           string
 	interfaceName                      string
-	generateAndSaveKeyTo               string
-	keepInterface                      bool
-	acceptClients                      bool
+	disableClients                     bool
 	updownScript                       string
 	dockerSocket                       string
 	dockerEnforceNetworkValidation     string
@@ -120,8 +132,17 @@ var (
 	preferEndpoint                     string
 	healthMonitor                      *healthcheck.Monitor
 	enforceHealthcheckCert             bool
-	blueprintFile                      string
-	noCloud                            bool
+	// Build/version (can be overridden via -ldflags "-X main.newtVersion=...")
+	newtVersion = "version_replaceme"
+
+	// Observability/metrics flags
+	metricsEnabled    bool
+	otlpEnabled       bool
+	adminAddr         string
+	region            string
+	metricsAsyncBytes bool
+	blueprintFile     string
+	noCloud           bool
 
 	// New mTLS configuration variables
 	tlsClientCert string
@@ -133,6 +154,10 @@ var (
 )
 
 func main() {
+	// Prepare context for graceful shutdown and signal handling
+	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
+	defer stop()
+
 	// if PANGOLIN_ENDPOINT, NEWT_ID, and NEWT_SECRET are set as environment variables, they will be used as default values
 	endpoint = os.Getenv("PANGOLIN_ENDPOINT")
 	id = os.Getenv("NEWT_ID")
@@ -142,11 +167,16 @@ func main() {
 	logLevel = os.Getenv("LOG_LEVEL")
 	updownScript = os.Getenv("UPDOWN_SCRIPT")
 	interfaceName = os.Getenv("INTERFACE")
-	generateAndSaveKeyTo = os.Getenv("GENERATE_AND_SAVE_KEY_TO")
-	keepInterfaceEnv := os.Getenv("KEEP_INTERFACE")
-	keepInterface = keepInterfaceEnv == "true"
-	acceptClientsEnv := os.Getenv("ACCEPT_CLIENTS")
-	acceptClients = acceptClientsEnv == "true"
+
+	// Metrics/observability env mirrors
+	metricsEnabledEnv := os.Getenv("NEWT_METRICS_PROMETHEUS_ENABLED")
+	otlpEnabledEnv := os.Getenv("NEWT_METRICS_OTLP_ENABLED")
+	adminAddrEnv := os.Getenv("NEWT_ADMIN_ADDR")
+	regionEnv := os.Getenv("NEWT_REGION")
+	asyncBytesEnv := os.Getenv("NEWT_METRICS_ASYNC_BYTES")
+
+	disableClientsEnv := os.Getenv("DISABLE_CLIENTS")
+	disableClients = disableClientsEnv == "true"
 	useNativeInterfaceEnv := os.Getenv("USE_NATIVE_INTERFACE")
 	useNativeInterface = useNativeInterfaceEnv == "true"
 	enforceHealthcheckCertEnv := os.Getenv("ENFORCE_HC_CERT")
@@ -205,17 +235,11 @@ func main() {
 	if interfaceName == "" {
 		flag.StringVar(&interfaceName, "interface", "newt", "Name of the WireGuard interface")
 	}
-	if generateAndSaveKeyTo == "" {
-		flag.StringVar(&generateAndSaveKeyTo, "generateAndSaveKeyTo", "", "Path to save generated private key")
-	}
-	if keepInterfaceEnv == "" {
-		flag.BoolVar(&keepInterface, "keep-interface", false, "Keep the WireGuard interface")
-	}
 	if useNativeInterfaceEnv == "" {
-		flag.BoolVar(&useNativeInterface, "native", false, "Use native WireGuard interface (requires WireGuard kernel module) and linux")
+		flag.BoolVar(&useNativeInterface, "native", false, "Use native WireGuard interface")
 	}
-	if acceptClientsEnv == "" {
-		flag.BoolVar(&acceptClients, "accept-clients", false, "Accept clients on the WireGuard interface")
+	if disableClientsEnv == "" {
+		flag.BoolVar(&disableClients, "disable-clients", false, "Disable clients on the WireGuard interface")
 	}
 	if enforceHealthcheckCertEnv == "" {
 		flag.BoolVar(&enforceHealthcheckCert, "enforce-hc-cert", false, "Enforce certificate validation for health checks (default: false, accepts any cert)")
@@ -286,6 +310,43 @@ func main() {
 		flag.BoolVar(&noCloud, "no-cloud", false, "Disable cloud failover")
 	}
 
+	// Metrics/observability flags (mirror ENV if unset)
+	if metricsEnabledEnv == "" {
+		flag.BoolVar(&metricsEnabled, "metrics", true, "Enable Prometheus /metrics exporter")
+	} else {
+		if v, err := strconv.ParseBool(metricsEnabledEnv); err == nil {
+			metricsEnabled = v
+		} else {
+			metricsEnabled = true
+		}
+	}
+	if otlpEnabledEnv == "" {
+		flag.BoolVar(&otlpEnabled, "otlp", false, "Enable OTLP exporters (metrics/traces) to OTEL_EXPORTER_OTLP_ENDPOINT")
+	} else {
+		if v, err := strconv.ParseBool(otlpEnabledEnv); err == nil {
+			otlpEnabled = v
+		}
+	}
+	if adminAddrEnv == "" {
+		flag.StringVar(&adminAddr, "metrics-admin-addr", "127.0.0.1:2112", "Admin/metrics bind address")
+	} else {
+		adminAddr = adminAddrEnv
+	}
+	// Async bytes toggle
+	if asyncBytesEnv == "" {
+		flag.BoolVar(&metricsAsyncBytes, "metrics-async-bytes", false, "Enable async bytes counting (background flush; lower hot path overhead)")
+	} else {
+		if v, err := strconv.ParseBool(asyncBytesEnv); err == nil {
+			metricsAsyncBytes = v
+		}
+	}
+	// Optional region flag (resource attribute)
+	if regionEnv == "" {
+		flag.StringVar(&region, "region", "", "Optional region resource attribute (also NEWT_REGION)")
+	} else {
+		region = regionEnv
+	}
+
 	// do a --version check
 	version := flag.Bool("version", false, "Print the version")
 
@@ -296,16 +357,62 @@ func main() {
 		tlsClientCAs = append(tlsClientCAs, tlsClientCAsFlag...)
 	}
 
-	logger.Init()
-	loggerLevel := parseLogLevel(logLevel)
-	logger.GetLogger().SetLevel(parseLogLevel(logLevel))
+	logger.Init(nil)
+	loggerLevel := util.ParseLogLevel(logLevel)
+	logger.GetLogger().SetLevel(loggerLevel)
+
+	// Initialize telemetry after flags are parsed (so flags override env)
+	tcfg := telemetry.FromEnv()
+	tcfg.PromEnabled = metricsEnabled
+	tcfg.OTLPEnabled = otlpEnabled
+	if adminAddr != "" {
+		tcfg.AdminAddr = adminAddr
+	}
+	// Resource attributes (if available)
+	tcfg.SiteID = id
+	tcfg.Region = region
+	// Build info
+	tcfg.BuildVersion = newtVersion
+	tcfg.BuildCommit = os.Getenv("NEWT_COMMIT")
+
+	tel, telErr := telemetry.Init(ctx, tcfg)
+	if telErr != nil {
+		logger.Warn("Telemetry init failed: %v", telErr)
+	}
+	if tel != nil {
+		// Admin HTTP server (exposes /metrics when Prometheus exporter is enabled)
+		logger.Info("Starting metrics server on %s", tcfg.AdminAddr)
+		mux := http.NewServeMux()
+		mux.HandleFunc("/healthz", func(w http.ResponseWriter, r *http.Request) { w.WriteHeader(200) })
+		if tel.PrometheusHandler != nil {
+			mux.Handle("/metrics", tel.PrometheusHandler)
+		}
+		admin := &http.Server{
+			Addr:              tcfg.AdminAddr,
+			Handler:           otelhttp.NewHandler(mux, "newt-admin"),
+			ReadTimeout:       5 * time.Second,
+			WriteTimeout:      10 * time.Second,
+			ReadHeaderTimeout: 5 * time.Second,
+			IdleTimeout:       30 * time.Second,
+		}
+		go func() {
+			if err := admin.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
+				logger.Warn("admin http error: %v", err)
+			}
+		}()
+		defer func() {
+			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			_ = admin.Shutdown(ctx)
+		}()
+		defer func() { _ = tel.Shutdown(context.Background()) }()
+	}
 
-	newtVersion := "version_replaceme"
 	if *version {
 		fmt.Println("Newt version " + newtVersion)
 		os.Exit(0)
 	} else {
-		logger.Info("Newt version " + newtVersion)
+		logger.Info("Newt version %s", newtVersion)
 	}
 
 	if err := updates.CheckForUpdate("fosrl", "newt", newtVersion); err != nil {
@@ -376,6 +483,8 @@ func main() {
 	}
 	endpoint = client.GetConfig().Endpoint // Update endpoint from config
 	id = client.GetConfig().ID             // Update ID from config
+	// Update site labels for metrics with the resolved ID
+	telemetry.UpdateSiteInfo(id, region)
 
 	// output env var values if set
 	logger.Debug("Endpoint: %v", endpoint)
@@ -419,7 +528,7 @@ func main() {
 	var wgData WgData
 	var dockerEventMonitor *docker.EventMonitor
 
-	if acceptClients {
+	if !disableClients {
 		setupClients(client)
 	}
 
@@ -484,6 +593,10 @@ func main() {
 	// Register handlers for different message types
 	client.RegisterHandler("newt/wg/connect", func(msg websocket.WSMessage) {
 		logger.Debug("Received registration message")
+		regResult := "success"
+		defer func() {
+			telemetry.IncSiteRegistration(ctx, regResult)
+		}()
 		if stopFunc != nil {
 			stopFunc()     // stop the ws from sending more requests
 			stopFunc = nil // reset stopFunc to nil to avoid double stopping
@@ -502,43 +615,48 @@ func main() {
 
 		jsonData, err := json.Marshal(msg.Data)
 		if err != nil {
-			logger.Info("Error marshaling data: %v", err)
+			logger.Info(fmtErrMarshaling, err)
+			regResult = "failure"
 			return
 		}
 
 		if err := json.Unmarshal(jsonData, &wgData); err != nil {
 			logger.Info("Error unmarshaling target data: %v", err)
+			regResult = "failure"
 			return
 		}
 
-		logger.Debug("Received: %+v", msg)
+		logger.Debug(fmtReceivedMsg, msg)
 		tun, tnet, err = netstack.CreateNetTUN(
 			[]netip.Addr{netip.MustParseAddr(wgData.TunnelIP)},
 			[]netip.Addr{netip.MustParseAddr(dns)},
 			mtuInt)
 		if err != nil {
 			logger.Error("Failed to create TUN device: %v", err)
+			regResult = "failure"
 		}
 
 		setDownstreamTNetstack(tnet)
 
 		// Create WireGuard device
 		dev = device.NewDevice(tun, conn.NewDefaultBind(), device.NewLogger(
-			mapToWireGuardLogLevel(loggerLevel),
+			util.MapToWireGuardLogLevel(loggerLevel),
 			"wireguard: ",
 		))
 
 		host, _, err := net.SplitHostPort(wgData.Endpoint)
 		if err != nil {
 			logger.Error("Failed to split endpoint: %v", err)
+			regResult = "failure"
 			return
 		}
 
 		logger.Info("Connecting to endpoint: %s", host)
 
-		endpoint, err := resolveDomain(wgData.Endpoint)
+		endpoint, err := util.ResolveDomain(wgData.Endpoint)
 		if err != nil {
 			logger.Error("Failed to resolve endpoint: %v", err)
+			regResult = "failure"
 			return
 		}
 
@@ -549,17 +667,19 @@ func main() {
 public_key=%s
 allowed_ip=%s/32
 endpoint=%s
-persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.PublicKey), wgData.ServerIP, endpoint)
+persistent_keepalive_interval=5`, util.FixKey(privateKey.String()), util.FixKey(wgData.PublicKey), wgData.ServerIP, endpoint)
 
 		err = dev.IpcSet(config)
 		if err != nil {
 			logger.Error("Failed to configure WireGuard device: %v", err)
+			regResult = "failure"
 		}
 
 		// Bring up the device
 		err = dev.Up()
 		if err != nil {
 			logger.Error("Failed to bring up WireGuard device: %v", err)
+			regResult = "failure"
 		}
 
 		logger.Debug("WireGuard device created. Lets ping the server now...")
@@ -572,9 +692,13 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 		}
 		// Use reliable ping for initial connection test
 		logger.Debug("Testing initial connection with reliable ping...")
-		_, err = reliablePing(tnet, wgData.ServerIP, pingTimeout, 5)
+		lat, err := reliablePing(tnet, wgData.ServerIP, pingTimeout, 5)
+		if err == nil && wgData.PublicKey != "" {
+			telemetry.ObserveTunnelLatency(ctx, wgData.PublicKey, "wireguard", lat.Seconds())
+		}
 		if err != nil {
 			logger.Warn("Initial reliable ping failed, but continuing: %v", err)
+			regResult = "failure"
 		} else {
 			logger.Debug("Initial connection test successful")
 		}
@@ -585,11 +709,14 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 		// as the pings will continue in the background
 		if !connected {
 			logger.Debug("Starting ping check")
-			pingStopChan = startPingCheck(tnet, wgData.ServerIP, client)
+			pingStopChan = startPingCheck(tnet, wgData.ServerIP, client, wgData.PublicKey)
 		}
 
 		// Create proxy manager
 		pm = proxy.NewProxyManager(tnet)
+		pm.SetAsyncBytes(metricsAsyncBytes)
+		// Set tunnel_id for metrics (WireGuard peer public key)
+		pm.SetTunnelID(wgData.PublicKey)
 
 		connected = true
 
@@ -610,7 +737,8 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 			// }
 		}
 
-		clientsAddProxyTarget(pm, wgData.TunnelIP)
+		// Start direct UDP relay from main tunnel to clients' WireGuard (bypasses proxy)
+		clientsStartDirectRelay(wgData.TunnelIP)
 
 		if err := healthMonitor.AddTargets(wgData.HealthCheckTargets); err != nil {
 			logger.Error("Failed to bulk add health check targets: %v", err)
@@ -626,10 +754,19 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 
 	client.RegisterHandler("newt/wg/reconnect", func(msg websocket.WSMessage) {
 		logger.Info("Received reconnect message")
+		if wgData.PublicKey != "" {
+			telemetry.IncReconnect(ctx, wgData.PublicKey, "server", telemetry.ReasonServerRequest)
+		}
 
 		// Close the WireGuard device and TUN
 		closeWgTunnel()
 
+		// Clear metrics attrs and sessions for the tunnel
+		if pm != nil {
+			pm.ClearTunnelID()
+			state.Global().ClearTunnel(wgData.PublicKey)
+		}
+
 		// Mark as disconnected
 		connected = false
 
@@ -648,9 +785,13 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 
 	client.RegisterHandler("newt/wg/terminate", func(msg websocket.WSMessage) {
 		logger.Info("Received termination message")
+		if wgData.PublicKey != "" {
+			telemetry.IncReconnect(ctx, wgData.PublicKey, "server", telemetry.ReasonServerRequest)
+		}
 
 		// Close the WireGuard device and TUN
 		closeWgTunnel()
+		closeClients()
 
 		if stopFunc != nil {
 			stopFunc()     // stop the ws from sending more requests
@@ -675,7 +816,7 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 
 		jsonData, err := json.Marshal(msg.Data)
 		if err != nil {
-			logger.Info("Error marshaling data: %v", err)
+			logger.Info(fmtErrMarshaling, err)
 			return
 		}
 		if err := json.Unmarshal(jsonData, &exitNodeData); err != nil {
@@ -716,7 +857,7 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 				},
 			}
 
-			stopFunc = client.SendMessageInterval("newt/wg/register", map[string]interface{}{
+			stopFunc = client.SendMessageInterval(topicWGRegister, map[string]interface{}{
 				"publicKey":   publicKey.String(),
 				"pingResults": pingResults,
 				"newtVersion": newtVersion,
@@ -819,7 +960,7 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 		}
 
 		// Send the ping results to the cloud for selection
-		stopFunc = client.SendMessageInterval("newt/wg/register", map[string]interface{}{
+		stopFunc = client.SendMessageInterval(topicWGRegister, map[string]interface{}{
 			"publicKey":   publicKey.String(),
 			"pingResults": pingResults,
 			"newtVersion": newtVersion,
@@ -829,17 +970,17 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 	})
 
 	client.RegisterHandler("newt/tcp/add", func(msg websocket.WSMessage) {
-		logger.Debug("Received: %+v", msg)
+		logger.Debug(fmtReceivedMsg, msg)
 
 		// if there is no wgData or pm, we can't add targets
 		if wgData.TunnelIP == "" || pm == nil {
-			logger.Info("No tunnel IP or proxy manager available")
+			logger.Info(msgNoTunnelOrProxy)
 			return
 		}
 
 		targetData, err := parseTargetData(msg.Data)
 		if err != nil {
-			logger.Info("Error parsing target data: %v", err)
+			logger.Info(fmtErrParsingTargetData, err)
 			return
 		}
 
@@ -854,17 +995,17 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 	})
 
 	client.RegisterHandler("newt/udp/add", func(msg websocket.WSMessage) {
-		logger.Info("Received: %+v", msg)
+		logger.Info(fmtReceivedMsg, msg)
 
 		// if there is no wgData or pm, we can't add targets
 		if wgData.TunnelIP == "" || pm == nil {
-			logger.Info("No tunnel IP or proxy manager available")
+			logger.Info(msgNoTunnelOrProxy)
 			return
 		}
 
 		targetData, err := parseTargetData(msg.Data)
 		if err != nil {
-			logger.Info("Error parsing target data: %v", err)
+			logger.Info(fmtErrParsingTargetData, err)
 			return
 		}
 
@@ -879,17 +1020,17 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 	})
 
 	client.RegisterHandler("newt/udp/remove", func(msg websocket.WSMessage) {
-		logger.Info("Received: %+v", msg)
+		logger.Info(fmtReceivedMsg, msg)
 
 		// if there is no wgData or pm, we can't add targets
 		if wgData.TunnelIP == "" || pm == nil {
-			logger.Info("No tunnel IP or proxy manager available")
+			logger.Info(msgNoTunnelOrProxy)
 			return
 		}
 
 		targetData, err := parseTargetData(msg.Data)
 		if err != nil {
-			logger.Info("Error parsing target data: %v", err)
+			logger.Info(fmtErrParsingTargetData, err)
 			return
 		}
 
@@ -904,17 +1045,17 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 	})
 
 	client.RegisterHandler("newt/tcp/remove", func(msg websocket.WSMessage) {
-		logger.Info("Received: %+v", msg)
+		logger.Info(fmtReceivedMsg, msg)
 
 		// if there is no wgData or pm, we can't add targets
 		if wgData.TunnelIP == "" || pm == nil {
-			logger.Info("No tunnel IP or proxy manager available")
+			logger.Info(msgNoTunnelOrProxy)
 			return
 		}
 
 		targetData, err := parseTargetData(msg.Data)
 		if err != nil {
-			logger.Info("Error parsing target data: %v", err)
+			logger.Info(fmtErrParsingTargetData, err)
 			return
 		}
 
@@ -998,7 +1139,7 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 
 		jsonData, err := json.Marshal(msg.Data)
 		if err != nil {
-			logger.Info("Error marshaling data: %v", err)
+			logger.Info(fmtErrMarshaling, err)
 			return
 		}
 		if err := json.Unmarshal(jsonData, &sshPublicKeyData); err != nil {
@@ -1155,9 +1296,9 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 		}
 
 		if err := healthMonitor.EnableTarget(requestData.ID); err != nil {
-			logger.Error("Failed to enable health check target %s: %v", requestData.ID, err)
+			logger.Error("Failed to enable health check target %d: %v", requestData.ID, err)
 		} else {
-			logger.Info("Enabled health check target: %s", requestData.ID)
+			logger.Info("Enabled health check target: %d", requestData.ID)
 		}
 	})
 
@@ -1180,9 +1321,9 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 		}
 
 		if err := healthMonitor.DisableTarget(requestData.ID); err != nil {
-			logger.Error("Failed to disable health check target %s: %v", requestData.ID, err)
+			logger.Error("Failed to disable health check target %d: %v", requestData.ID, err)
 		} else {
-			logger.Info("Disabled health check target: %s", requestData.ID)
+			logger.Info("Disabled health check target: %d", requestData.ID)
 		}
 	})
 
@@ -1252,7 +1393,7 @@ persistent_keepalive_interval=5`, fixKey(privateKey.String()), fixKey(wgData.Pub
 		}
 
 		// Send registration message to the server for backward compatibility
-		err := client.SendMessage("newt/wg/register", map[string]interface{}{
+		err := client.SendMessage(topicWGRegister, map[string]interface{}{
 			"publicKey":           publicKey.String(),
 			"newtVersion":         newtVersion,
 			"backwardsCompatible": true,

netstack2/handlers.go

@@ -0,0 +1,350 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2017-2025 WireGuard LLC. All Rights Reserved.
+ */
+
+package netstack2
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"sync"
+	"time"
+
+	"github.com/fosrl/newt/logger"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+	"gvisor.dev/gvisor/pkg/waiter"
+)
+
+const (
+	// defaultWndSize if set to zero, the default
+	// receive window buffer size is used instead.
+	defaultWndSize = 0
+
+	// maxConnAttempts specifies the maximum number
+	// of in-flight tcp connection attempts.
+	maxConnAttempts = 2 << 10
+
+	// tcpKeepaliveCount is the maximum number of
+	// TCP keep-alive probes to send before giving up
+	// and killing the connection if no response is
+	// obtained from the other end.
+	tcpKeepaliveCount = 9
+
+	// tcpKeepaliveIdle specifies the time a connection
+	// must remain idle before the first TCP keepalive
+	// packet is sent. Once this time is reached,
+	// tcpKeepaliveInterval option is used instead.
+	tcpKeepaliveIdle = 60 * time.Second
+
+	// tcpKeepaliveInterval specifies the interval
+	// time between sending TCP keepalive packets.
+	tcpKeepaliveInterval = 30 * time.Second
+
+	// tcpConnectTimeout is the default timeout for TCP handshakes.
+	tcpConnectTimeout = 5 * time.Second
+
+	// tcpWaitTimeout implements a TCP half-close timeout.
+	tcpWaitTimeout = 60 * time.Second
+
+	// udpSessionTimeout is the default timeout for UDP sessions.
+	udpSessionTimeout = 60 * time.Second
+
+	// Buffer size for copying data
+	bufferSize = 32 * 1024
+)
+
+// TCPHandler handles TCP connections from netstack
+type TCPHandler struct {
+	stack        *stack.Stack
+	proxyHandler *ProxyHandler
+}
+
+// UDPHandler handles UDP connections from netstack
+type UDPHandler struct {
+	stack        *stack.Stack
+	proxyHandler *ProxyHandler
+}
+
+// NewTCPHandler creates a new TCP handler
+func NewTCPHandler(s *stack.Stack, ph *ProxyHandler) *TCPHandler {
+	return &TCPHandler{stack: s, proxyHandler: ph}
+}
+
+// NewUDPHandler creates a new UDP handler
+func NewUDPHandler(s *stack.Stack, ph *ProxyHandler) *UDPHandler {
+	return &UDPHandler{stack: s, proxyHandler: ph}
+}
+
+// InstallTCPHandler installs the TCP forwarder on the stack
+func (h *TCPHandler) InstallTCPHandler() error {
+	tcpForwarder := tcp.NewForwarder(h.stack, defaultWndSize, maxConnAttempts, func(r *tcp.ForwarderRequest) {
+		var (
+			wq  waiter.Queue
+			ep  tcpip.Endpoint
+			err tcpip.Error
+			id  = r.ID()
+		)
+
+		// Perform a TCP three-way handshake
+		ep, err = r.CreateEndpoint(&wq)
+		if err != nil {
+			// RST: prevent potential half-open TCP connection leak
+			r.Complete(true)
+			return
+		}
+		defer r.Complete(false)
+
+		// Set socket options
+		setTCPSocketOptions(h.stack, ep)
+
+		// Create TCP connection from netstack endpoint
+		netstackConn := gonet.NewTCPConn(&wq, ep)
+
+		// Handle the connection in a goroutine
+		go h.handleTCPConn(netstackConn, id)
+	})
+
+	h.stack.SetTransportProtocolHandler(tcp.ProtocolNumber, tcpForwarder.HandlePacket)
+	return nil
+}
+
+// handleTCPConn handles a TCP connection by proxying it to the actual target
+func (h *TCPHandler) handleTCPConn(netstackConn *gonet.TCPConn, id stack.TransportEndpointID) {
+	defer netstackConn.Close()
+
+	// Extract source and target address from the connection ID
+	srcIP := id.RemoteAddress.String()
+	srcPort := id.RemotePort
+	dstIP := id.LocalAddress.String()
+	dstPort := id.LocalPort
+
+	logger.Info("TCP Forwarder: Handling connection %s:%d -> %s:%d", srcIP, srcPort, dstIP, dstPort)
+
+	// Check if there's a destination rewrite for this connection (e.g., localhost targets)
+	actualDstIP := dstIP
+	if h.proxyHandler != nil {
+		if rewrittenAddr, ok := h.proxyHandler.LookupDestinationRewrite(srcIP, dstIP, dstPort, uint8(tcp.ProtocolNumber)); ok {
+			actualDstIP = rewrittenAddr.String()
+			logger.Info("TCP Forwarder: Using rewritten destination %s (original: %s)", actualDstIP, dstIP)
+		}
+	}
+
+	targetAddr := fmt.Sprintf("%s:%d", actualDstIP, dstPort)
+
+	// Create context with timeout for connection establishment
+	ctx, cancel := context.WithTimeout(context.Background(), tcpConnectTimeout)
+	defer cancel()
+
+	// Dial the actual target using standard net package
+	var d net.Dialer
+	targetConn, err := d.DialContext(ctx, "tcp", targetAddr)
+	if err != nil {
+		logger.Info("TCP Forwarder: Failed to connect to %s: %v", targetAddr, err)
+		// Connection failed, netstack will handle RST
+		return
+	}
+	defer targetConn.Close()
+
+	logger.Info("TCP Forwarder: Successfully connected to %s, starting bidirectional copy", targetAddr)
+
+	// Bidirectional copy between netstack and target
+	pipeTCP(netstackConn, targetConn)
+}
+
+// pipeTCP copies data bidirectionally between two connections
+func pipeTCP(origin, remote net.Conn) {
+	wg := sync.WaitGroup{}
+	wg.Add(2)
+
+	go unidirectionalStreamTCP(remote, origin, "origin->remote", &wg)
+	go unidirectionalStreamTCP(origin, remote, "remote->origin", &wg)
+
+	wg.Wait()
+}
+
+// unidirectionalStreamTCP copies data in one direction
+func unidirectionalStreamTCP(dst, src net.Conn, dir string, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	buf := make([]byte, bufferSize)
+	_, _ = io.CopyBuffer(dst, src, buf)
+
+	// Do the upload/download side TCP half-close
+	if cr, ok := src.(interface{ CloseRead() error }); ok {
+		cr.CloseRead()
+	}
+	if cw, ok := dst.(interface{ CloseWrite() error }); ok {
+		cw.CloseWrite()
+	}
+
+	// Set TCP half-close timeout
+	dst.SetReadDeadline(time.Now().Add(tcpWaitTimeout))
+}
+
+// setTCPSocketOptions sets TCP socket options for better performance
+func setTCPSocketOptions(s *stack.Stack, ep tcpip.Endpoint) {
+	// TCP keepalive options
+	ep.SocketOptions().SetKeepAlive(true)
+
+	idle := tcpip.KeepaliveIdleOption(tcpKeepaliveIdle)
+	ep.SetSockOpt(&idle)
+
+	interval := tcpip.KeepaliveIntervalOption(tcpKeepaliveInterval)
+	ep.SetSockOpt(&interval)
+
+	ep.SetSockOptInt(tcpip.KeepaliveCountOption, tcpKeepaliveCount)
+
+	// TCP send/recv buffer size
+	var ss tcpip.TCPSendBufferSizeRangeOption
+	if err := s.TransportProtocolOption(tcp.ProtocolNumber, &ss); err == nil {
+		ep.SocketOptions().SetSendBufferSize(int64(ss.Default), false)
+	}
+
+	var rs tcpip.TCPReceiveBufferSizeRangeOption
+	if err := s.TransportProtocolOption(tcp.ProtocolNumber, &rs); err == nil {
+		ep.SocketOptions().SetReceiveBufferSize(int64(rs.Default), false)
+	}
+}
+
+// InstallUDPHandler installs the UDP forwarder on the stack
+func (h *UDPHandler) InstallUDPHandler() error {
+	udpForwarder := udp.NewForwarder(h.stack, func(r *udp.ForwarderRequest) {
+		var (
+			wq waiter.Queue
+			id = r.ID()
+		)
+
+		ep, err := r.CreateEndpoint(&wq)
+		if err != nil {
+			return
+		}
+
+		// Create UDP connection from netstack endpoint
+		netstackConn := gonet.NewUDPConn(&wq, ep)
+
+		// Handle the connection in a goroutine
+		go h.handleUDPConn(netstackConn, id)
+	})
+
+	h.stack.SetTransportProtocolHandler(udp.ProtocolNumber, udpForwarder.HandlePacket)
+	return nil
+}
+
+// handleUDPConn handles a UDP connection by proxying it to the actual target
+func (h *UDPHandler) handleUDPConn(netstackConn *gonet.UDPConn, id stack.TransportEndpointID) {
+	defer netstackConn.Close()
+
+	// Extract source and target address from the connection ID
+	srcIP := id.RemoteAddress.String()
+	srcPort := id.RemotePort
+	dstIP := id.LocalAddress.String()
+	dstPort := id.LocalPort
+
+	logger.Info("UDP Forwarder: Handling connection %s:%d -> %s:%d", srcIP, srcPort, dstIP, dstPort)
+
+	// Check if there's a destination rewrite for this connection (e.g., localhost targets)
+	actualDstIP := dstIP
+	if h.proxyHandler != nil {
+		if rewrittenAddr, ok := h.proxyHandler.LookupDestinationRewrite(srcIP, dstIP, dstPort, uint8(udp.ProtocolNumber)); ok {
+			actualDstIP = rewrittenAddr.String()
+			logger.Info("UDP Forwarder: Using rewritten destination %s (original: %s)", actualDstIP, dstIP)
+		}
+	}
+
+	targetAddr := fmt.Sprintf("%s:%d", actualDstIP, dstPort)
+
+	// Resolve target address
+	remoteUDPAddr, err := net.ResolveUDPAddr("udp", targetAddr)
+	if err != nil {
+		logger.Info("UDP Forwarder: Failed to resolve %s: %v", targetAddr, err)
+		return
+	}
+
+	// Resolve client address (for sending responses back)
+	clientAddr, err := net.ResolveUDPAddr("udp", fmt.Sprintf("%s:%d", srcIP, srcPort))
+	if err != nil {
+		logger.Info("UDP Forwarder: Failed to resolve client %s:%d: %v", srcIP, srcPort, err)
+		return
+	}
+
+	// Create unconnected UDP socket (so we can use WriteTo)
+	targetConn, err := net.ListenUDP("udp", nil)
+	if err != nil {
+		logger.Info("UDP Forwarder: Failed to create UDP socket: %v", err)
+		return
+	}
+	defer targetConn.Close()
+
+	logger.Info("UDP Forwarder: Successfully created UDP socket for %s, starting bidirectional copy", targetAddr)
+
+	// Bidirectional copy between netstack and target
+	pipeUDP(netstackConn, targetConn, remoteUDPAddr, clientAddr, udpSessionTimeout)
+}
+
+// pipeUDP copies UDP packets bidirectionally
+func pipeUDP(origin, remote net.PacketConn, serverAddr, clientAddr net.Addr, timeout time.Duration) {
+	wg := sync.WaitGroup{}
+	wg.Add(2)
+
+	// Read from origin (netstack), write to remote (target server)
+	go unidirectionalPacketStream(remote, origin, serverAddr, "origin->remote", &wg, timeout)
+	// Read from remote (target server), write to origin (netstack) with client address
+	go unidirectionalPacketStream(origin, remote, clientAddr, "remote->origin", &wg, timeout)
+
+	wg.Wait()
+}
+
+// unidirectionalPacketStream copies packets in one direction
+func unidirectionalPacketStream(dst, src net.PacketConn, to net.Addr, dir string, wg *sync.WaitGroup, timeout time.Duration) {
+	defer wg.Done()
+
+	logger.Info("UDP %s: Starting packet stream (to=%v)", dir, to)
+	err := copyPacketData(dst, src, to, timeout)
+	if err != nil {
+		logger.Info("UDP %s: Stream ended with error: %v", dir, err)
+	} else {
+		logger.Info("UDP %s: Stream ended (timeout)", dir)
+	}
+}
+
+// copyPacketData copies UDP packet data with timeout
+func copyPacketData(dst, src net.PacketConn, to net.Addr, timeout time.Duration) error {
+	buf := make([]byte, 65535) // Max UDP packet size
+
+	for {
+		src.SetReadDeadline(time.Now().Add(timeout))
+		n, srcAddr, err := src.ReadFrom(buf)
+		if ne, ok := err.(net.Error); ok && ne.Timeout() {
+			return nil // ignore I/O timeout
+		} else if err == io.EOF {
+			return nil // ignore EOF
+		} else if err != nil {
+			return err
+		}
+
+		logger.Info("UDP copyPacketData: Read %d bytes from %v", n, srcAddr)
+
+		// Determine write destination
+		writeAddr := to
+		if writeAddr == nil {
+			// If no destination specified, use the source address from the packet
+			writeAddr = srcAddr
+		}
+
+		written, err := dst.WriteTo(buf[:n], writeAddr)
+		if err != nil {
+			logger.Info("UDP copyPacketData: Write error to %v: %v", writeAddr, err)
+			return err
+		}
+		logger.Info("UDP copyPacketData: Wrote %d bytes to %v", written, writeAddr)
+
+		dst.SetReadDeadline(time.Now().Add(timeout))
+	}
+}

netstack2/proxy.go

@@ -0,0 +1,710 @@
+package netstack2
+
+import (
+	"context"
+	"fmt"
+	"net"
+	"net/netip"
+	"sync"
+	"time"
+
+	"github.com/fosrl/newt/logger"
+	"gvisor.dev/gvisor/pkg/buffer"
+	"gvisor.dev/gvisor/pkg/tcpip"
+	"gvisor.dev/gvisor/pkg/tcpip/checksum"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
+	"gvisor.dev/gvisor/pkg/tcpip/link/channel"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv4"
+	"gvisor.dev/gvisor/pkg/tcpip/network/ipv6"
+	"gvisor.dev/gvisor/pkg/tcpip/stack"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/icmp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
+	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
+)
+
+// PortRange represents an allowed range of ports (inclusive)
+type PortRange struct {
+	Min uint16
+	Max uint16
+}
+
+// SubnetRule represents a subnet with optional port restrictions and source address
+// When RewriteTo is set, DNAT (Destination Network Address Translation) is performed:
+//   - Incoming packets: destination IP is rewritten to the resolved RewriteTo address
+//   - Outgoing packets: source IP is rewritten back to the original destination
+//
+// RewriteTo can be either:
+//   - An IP address with CIDR notation (e.g., "192.168.1.1/32")
+//   - A domain name (e.g., "example.com") which will be resolved at request time
+//
+// This allows transparent proxying where traffic appears to come from the rewritten address
+type SubnetRule struct {
+	SourcePrefix netip.Prefix // Source IP prefix (who is sending)
+	DestPrefix   netip.Prefix // Destination IP prefix (where it's going)
+	RewriteTo    string       // Optional rewrite address for DNAT - can be IP/CIDR or domain name
+	PortRanges   []PortRange  // empty slice means all ports allowed
+}
+
+// ruleKey is used as a map key for fast O(1) lookups
+type ruleKey struct {
+	sourcePrefix string
+	destPrefix   string
+}
+
+// SubnetLookup provides fast IP subnet and port matching with O(1) lookup performance
+type SubnetLookup struct {
+	mu    sync.RWMutex
+	rules map[ruleKey]*SubnetRule // Map for O(1) lookups by prefix combination
+}
+
+// NewSubnetLookup creates a new subnet lookup table
+func NewSubnetLookup() *SubnetLookup {
+	return &SubnetLookup{
+		rules: make(map[ruleKey]*SubnetRule),
+	}
+}
+
+// AddSubnet adds a subnet rule with source and destination prefixes and optional port restrictions
+// If portRanges is nil or empty, all ports are allowed for this subnet
+// rewriteTo can be either an IP/CIDR (e.g., "192.168.1.1/32") or a domain name (e.g., "example.com")
+func (sl *SubnetLookup) AddSubnet(sourcePrefix, destPrefix netip.Prefix, rewriteTo string, portRanges []PortRange) {
+	sl.mu.Lock()
+	defer sl.mu.Unlock()
+
+	key := ruleKey{
+		sourcePrefix: sourcePrefix.String(),
+		destPrefix:   destPrefix.String(),
+	}
+
+	sl.rules[key] = &SubnetRule{
+		SourcePrefix: sourcePrefix,
+		DestPrefix:   destPrefix,
+		RewriteTo:    rewriteTo,
+		PortRanges:   portRanges,
+	}
+}
+
+// RemoveSubnet removes a subnet rule from the lookup table
+func (sl *SubnetLookup) RemoveSubnet(sourcePrefix, destPrefix netip.Prefix) {
+	sl.mu.Lock()
+	defer sl.mu.Unlock()
+
+	key := ruleKey{
+		sourcePrefix: sourcePrefix.String(),
+		destPrefix:   destPrefix.String(),
+	}
+
+	delete(sl.rules, key)
+}
+
+// Match checks if a source IP, destination IP, and port match any subnet rule
+// Returns the matched rule if BOTH:
+//   - The source IP is in the rule's source prefix
+//   - The destination IP is in the rule's destination prefix
+//   - The port is in an allowed range (or no port restrictions exist)
+//
+// Returns nil if no rule matches
+func (sl *SubnetLookup) Match(srcIP, dstIP netip.Addr, port uint16) *SubnetRule {
+	sl.mu.RLock()
+	defer sl.mu.RUnlock()
+
+	// Iterate through all rules to find matching source and destination prefixes
+	// This is O(n) but necessary since we need to check prefix containment, not exact match
+	for _, rule := range sl.rules {
+		// Check if source and destination IPs match their respective prefixes
+		if !rule.SourcePrefix.Contains(srcIP) {
+			continue
+		}
+		if !rule.DestPrefix.Contains(dstIP) {
+			continue
+		}
+
+		// Both IPs match - now check port restrictions
+		// If no port ranges specified, all ports are allowed
+		if len(rule.PortRanges) == 0 {
+			return rule
+		}
+
+		// Check if port is in any of the allowed ranges
+		for _, pr := range rule.PortRanges {
+			if port >= pr.Min && port <= pr.Max {
+				return rule
+			}
+		}
+	}
+
+	return nil
+}
+
+// connKey uniquely identifies a connection for NAT tracking
+type connKey struct {
+	srcIP   string
+	srcPort uint16
+	dstIP   string
+	dstPort uint16
+	proto   uint8
+}
+
+// destKey identifies a destination for handler lookups (without source port since it may change)
+type destKey struct {
+	srcIP   string
+	dstIP   string
+	dstPort uint16
+	proto   uint8
+}
+
+// natState tracks NAT translation state for reverse translation
+type natState struct {
+	originalDst netip.Addr // Original destination before DNAT
+	rewrittenTo netip.Addr // The address we rewrote to
+}
+
+// ProxyHandler handles packet injection and extraction for promiscuous mode
+type ProxyHandler struct {
+	proxyStack        *stack.Stack
+	proxyEp           *channel.Endpoint
+	proxyNotifyHandle *channel.NotificationHandle
+	tcpHandler        *TCPHandler
+	udpHandler        *UDPHandler
+	subnetLookup      *SubnetLookup
+	natTable          map[connKey]*natState
+	destRewriteTable  map[destKey]netip.Addr // Maps original dest to rewritten dest for handler lookups
+	natMu             sync.RWMutex
+	enabled           bool
+}
+
+// ProxyHandlerOptions configures the proxy handler
+type ProxyHandlerOptions struct {
+	EnableTCP bool
+	EnableUDP bool
+	MTU       int
+}
+
+// NewProxyHandler creates a new proxy handler for promiscuous mode
+func NewProxyHandler(options ProxyHandlerOptions) (*ProxyHandler, error) {
+	if !options.EnableTCP && !options.EnableUDP {
+		return nil, nil // No proxy needed
+	}
+
+	handler := &ProxyHandler{
+		enabled:          true,
+		subnetLookup:     NewSubnetLookup(),
+		natTable:         make(map[connKey]*natState),
+		destRewriteTable: make(map[destKey]netip.Addr),
+		proxyEp:          channel.New(1024, uint32(options.MTU), ""),
+		proxyStack: stack.New(stack.Options{
+			NetworkProtocols: []stack.NetworkProtocolFactory{
+				ipv4.NewProtocol,
+				ipv6.NewProtocol,
+			},
+			TransportProtocols: []stack.TransportProtocolFactory{
+				tcp.NewProtocol,
+				udp.NewProtocol,
+				icmp.NewProtocol4,
+				icmp.NewProtocol6,
+			},
+		}),
+	}
+
+	// Initialize TCP handler if enabled
+	if options.EnableTCP {
+		handler.tcpHandler = NewTCPHandler(handler.proxyStack, handler)
+		if err := handler.tcpHandler.InstallTCPHandler(); err != nil {
+			return nil, fmt.Errorf("failed to install TCP handler: %v", err)
+		}
+	}
+
+	// Initialize UDP handler if enabled
+	if options.EnableUDP {
+		handler.udpHandler = NewUDPHandler(handler.proxyStack, handler)
+		if err := handler.udpHandler.InstallUDPHandler(); err != nil {
+			return nil, fmt.Errorf("failed to install UDP handler: %v", err)
+		}
+	}
+
+	// // Example 1: Add a rule with no port restrictions (all ports allowed)
+	// // This accepts all traffic FROM 10.0.0.0/24 TO 10.20.20.0/24
+	// sourceSubnet := netip.MustParsePrefix("10.0.0.0/24")
+	// destSubnet := netip.MustParsePrefix("10.20.20.0/24")
+	// handler.AddSubnetRule(sourceSubnet, destSubnet, nil)
+
+	// // Example 2: Add a rule with specific port ranges
+	// // This accepts traffic FROM 10.0.0.5/32 TO 10.20.21.21/32 only on ports 80, 443, and 8000-9000
+	// sourceIP := netip.MustParsePrefix("10.0.0.5/32")
+	// destIP := netip.MustParsePrefix("10.20.21.21/32")
+	// handler.AddSubnetRule(sourceIP, destIP, []PortRange{
+	// 	{Min: 80, Max: 80},
+	// 	{Min: 443, Max: 443},
+	// 	{Min: 8000, Max: 9000},
+	// })
+
+	return handler, nil
+}
+
+// AddSubnetRule adds a subnet with optional port restrictions to the proxy handler
+// sourcePrefix: The IP prefix of the peer sending the data
+// destPrefix: The IP prefix of the destination
+// rewriteTo: Optional address to rewrite destination to - can be IP/CIDR or domain name
+// If portRanges is nil or empty, all ports are allowed for this subnet
+func (p *ProxyHandler) AddSubnetRule(sourcePrefix, destPrefix netip.Prefix, rewriteTo string, portRanges []PortRange) {
+	if p == nil || !p.enabled {
+		return
+	}
+	p.subnetLookup.AddSubnet(sourcePrefix, destPrefix, rewriteTo, portRanges)
+}
+
+// RemoveSubnetRule removes a subnet from the proxy handler
+func (p *ProxyHandler) RemoveSubnetRule(sourcePrefix, destPrefix netip.Prefix) {
+	if p == nil || !p.enabled {
+		return
+	}
+	p.subnetLookup.RemoveSubnet(sourcePrefix, destPrefix)
+}
+
+// LookupDestinationRewrite looks up the rewritten destination for a connection
+// This is used by TCP/UDP handlers to find the actual target address
+func (p *ProxyHandler) LookupDestinationRewrite(srcIP, dstIP string, dstPort uint16, proto uint8) (netip.Addr, bool) {
+	if p == nil || !p.enabled {
+		return netip.Addr{}, false
+	}
+
+	key := destKey{
+		srcIP:   srcIP,
+		dstIP:   dstIP,
+		dstPort: dstPort,
+		proto:   proto,
+	}
+
+	p.natMu.RLock()
+	defer p.natMu.RUnlock()
+
+	addr, ok := p.destRewriteTable[key]
+	return addr, ok
+}
+
+// resolveRewriteAddress resolves a rewrite address which can be either:
+// - An IP address with CIDR notation (e.g., "192.168.1.1/32") - returns the IP directly
+// - A plain IP address (e.g., "192.168.1.1") - returns the IP directly
+// - A domain name (e.g., "example.com") - performs DNS lookup
+func (p *ProxyHandler) resolveRewriteAddress(rewriteTo string) (netip.Addr, error) {
+	logger.Debug("Resolving rewrite address: %s", rewriteTo)
+
+	// First, try to parse as a CIDR prefix (e.g., "192.168.1.1/32")
+	if prefix, err := netip.ParsePrefix(rewriteTo); err == nil {
+		return prefix.Addr(), nil
+	}
+
+	// Try to parse as a plain IP address (e.g., "192.168.1.1")
+	if addr, err := netip.ParseAddr(rewriteTo); err == nil {
+		return addr, nil
+	}
+
+	// Not an IP address, treat as domain name - perform DNS lookup
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	ips, err := net.DefaultResolver.LookupIP(ctx, "ip4", rewriteTo)
+	if err != nil {
+		return netip.Addr{}, fmt.Errorf("failed to resolve domain %s: %w", rewriteTo, err)
+	}
+
+	if len(ips) == 0 {
+		return netip.Addr{}, fmt.Errorf("no IP addresses found for domain %s", rewriteTo)
+	}
+
+	// Use the first resolved IP address
+	ip := ips[0]
+	if ip4 := ip.To4(); ip4 != nil {
+		addr := netip.AddrFrom4([4]byte{ip4[0], ip4[1], ip4[2], ip4[3]})
+		logger.Debug("Resolved %s to %s", rewriteTo, addr)
+		return addr, nil
+	}
+
+	return netip.Addr{}, fmt.Errorf("no IPv4 address found for domain %s", rewriteTo)
+}
+
+// Initialize sets up the promiscuous NIC with the netTun's notification system
+func (p *ProxyHandler) Initialize(notifiable channel.Notification) error {
+	if p == nil || !p.enabled {
+		return nil
+	}
+
+	// Add notification handler
+	p.proxyNotifyHandle = p.proxyEp.AddNotify(notifiable)
+
+	// Create NIC with promiscuous mode
+	tcpipErr := p.proxyStack.CreateNICWithOptions(1, p.proxyEp, stack.NICOptions{
+		Disabled: false,
+		QDisc:    nil,
+	})
+	if tcpipErr != nil {
+		return fmt.Errorf("CreateNIC (proxy): %v", tcpipErr)
+	}
+
+	// Enable promiscuous mode - accepts packets for any destination IP
+	if tcpipErr := p.proxyStack.SetPromiscuousMode(1, true); tcpipErr != nil {
+		return fmt.Errorf("SetPromiscuousMode: %v", tcpipErr)
+	}
+
+	// Enable spoofing - allows sending packets from any source IP
+	if tcpipErr := p.proxyStack.SetSpoofing(1, true); tcpipErr != nil {
+		return fmt.Errorf("SetSpoofing: %v", tcpipErr)
+	}
+
+	// Add default route
+	p.proxyStack.AddRoute(tcpip.Route{
+		Destination: header.IPv4EmptySubnet,
+		NIC:         1,
+	})
+
+	return nil
+}
+
+// HandleIncomingPacket processes incoming packets and determines if they should
+// be injected into the proxy stack
+func (p *ProxyHandler) HandleIncomingPacket(packet []byte) bool {
+	if p == nil || !p.enabled {
+		return false
+	}
+
+	// Check minimum packet size
+	if len(packet) < header.IPv4MinimumSize {
+		return false
+	}
+
+	// Only handle IPv4 for now
+	if packet[0]>>4 != 4 {
+		return false
+	}
+
+	// Parse IPv4 header
+	ipv4Header := header.IPv4(packet)
+	srcIP := ipv4Header.SourceAddress()
+	dstIP := ipv4Header.DestinationAddress()
+
+	// Convert gvisor tcpip.Address to netip.Addr
+	srcBytes := srcIP.As4()
+	srcAddr := netip.AddrFrom4(srcBytes)
+	dstBytes := dstIP.As4()
+	dstAddr := netip.AddrFrom4(dstBytes)
+
+	// Parse transport layer to get destination port
+	var dstPort uint16
+	protocol := ipv4Header.TransportProtocol()
+	headerLen := int(ipv4Header.HeaderLength())
+
+	// Extract port based on protocol
+	switch protocol {
+	case header.TCPProtocolNumber:
+		if len(packet) < headerLen+header.TCPMinimumSize {
+			return false
+		}
+		tcpHeader := header.TCP(packet[headerLen:])
+		dstPort = tcpHeader.DestinationPort()
+	case header.UDPProtocolNumber:
+		if len(packet) < headerLen+header.UDPMinimumSize {
+			return false
+		}
+		udpHeader := header.UDP(packet[headerLen:])
+		dstPort = udpHeader.DestinationPort()
+	default:
+		// For other protocols (ICMP, etc.), use port 0 (must match rules with no port restrictions)
+		dstPort = 0
+	}
+
+	// Check if the source IP, destination IP, and port match any subnet rule
+	matchedRule := p.subnetLookup.Match(srcAddr, dstAddr, dstPort)
+	if matchedRule != nil {
+		// Check if we need to perform DNAT
+		if matchedRule.RewriteTo != "" {
+			// Create connection tracking key using original destination
+			// This allows us to check if we've already resolved for this connection
+			var srcPort uint16
+			switch protocol {
+			case header.TCPProtocolNumber:
+				tcpHeader := header.TCP(packet[headerLen:])
+				srcPort = tcpHeader.SourcePort()
+			case header.UDPProtocolNumber:
+				udpHeader := header.UDP(packet[headerLen:])
+				srcPort = udpHeader.SourcePort()
+			}
+
+			// Key using original destination to track the connection
+			key := connKey{
+				srcIP:   srcAddr.String(),
+				srcPort: srcPort,
+				dstIP:   dstAddr.String(),
+				dstPort: dstPort,
+				proto:   uint8(protocol),
+			}
+
+			// Key for handler lookups (doesn't include srcPort for flexibility)
+			dKey := destKey{
+				srcIP:   srcAddr.String(),
+				dstIP:   dstAddr.String(),
+				dstPort: dstPort,
+				proto:   uint8(protocol),
+			}
+
+			// Check if we already have a NAT entry for this connection
+			p.natMu.RLock()
+			existingEntry, exists := p.natTable[key]
+			p.natMu.RUnlock()
+
+			var newDst netip.Addr
+			if exists {
+				// Use the previously resolved address for this connection
+				newDst = existingEntry.rewrittenTo
+				logger.Debug("Using existing NAT entry for connection: %s -> %s", dstAddr, newDst)
+			} else {
+				// New connection - resolve the rewrite address
+				var err error
+				newDst, err = p.resolveRewriteAddress(matchedRule.RewriteTo)
+				if err != nil {
+					// Failed to resolve, skip DNAT but still proxy the packet
+					logger.Debug("Failed to resolve rewrite address: %v", err)
+					pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{
+						Payload: buffer.MakeWithData(packet),
+					})
+					p.proxyEp.InjectInbound(header.IPv4ProtocolNumber, pkb)
+					return true
+				}
+
+				// Store NAT state for this connection
+				p.natMu.Lock()
+				p.natTable[key] = &natState{
+					originalDst: dstAddr,
+					rewrittenTo: newDst,
+				}
+				// Store destination rewrite for handler lookups
+				p.destRewriteTable[dKey] = newDst
+				p.natMu.Unlock()
+				logger.Debug("New NAT entry for connection: %s -> %s", dstAddr, newDst)
+			}
+
+			// Check if target is loopback - if so, don't rewrite packet destination
+			// as gVisor will drop martian packets. Instead, the handlers will use
+			// destRewriteTable to find the actual target address.
+			if !newDst.IsLoopback() {
+				// Rewrite the packet only for non-loopback destinations
+				packet = p.rewritePacketDestination(packet, newDst)
+				if packet == nil {
+					return false
+				}
+			} else {
+				logger.Debug("Target is loopback, not rewriting packet - handlers will use rewrite table")
+			}
+		}
+
+		// Inject into proxy stack
+		pkb := stack.NewPacketBuffer(stack.PacketBufferOptions{
+			Payload: buffer.MakeWithData(packet),
+		})
+		p.proxyEp.InjectInbound(header.IPv4ProtocolNumber, pkb)
+		return true
+	}
+
+	return false
+}
+
+// rewritePacketDestination rewrites the destination IP in a packet and recalculates checksums
+func (p *ProxyHandler) rewritePacketDestination(packet []byte, newDst netip.Addr) []byte {
+	if len(packet) < header.IPv4MinimumSize {
+		return nil
+	}
+
+	// Make a copy to avoid modifying the original
+	pkt := make([]byte, len(packet))
+	copy(pkt, packet)
+
+	ipv4Header := header.IPv4(pkt)
+	headerLen := int(ipv4Header.HeaderLength())
+
+	// Rewrite destination IP
+	newDstBytes := newDst.As4()
+	newDstAddr := tcpip.AddrFrom4(newDstBytes)
+	ipv4Header.SetDestinationAddress(newDstAddr)
+
+	// Recalculate IP checksum
+	ipv4Header.SetChecksum(0)
+	ipv4Header.SetChecksum(^ipv4Header.CalculateChecksum())
+
+	// Update transport layer checksum if needed
+	protocol := ipv4Header.TransportProtocol()
+	switch protocol {
+	case header.TCPProtocolNumber:
+		if len(pkt) >= headerLen+header.TCPMinimumSize {
+			tcpHeader := header.TCP(pkt[headerLen:])
+			tcpHeader.SetChecksum(0)
+			xsum := header.PseudoHeaderChecksum(
+				header.TCPProtocolNumber,
+				ipv4Header.SourceAddress(),
+				ipv4Header.DestinationAddress(),
+				uint16(len(pkt)-headerLen),
+			)
+			xsum = checksum.Checksum(pkt[headerLen:], xsum)
+			tcpHeader.SetChecksum(^xsum)
+		}
+	case header.UDPProtocolNumber:
+		if len(pkt) >= headerLen+header.UDPMinimumSize {
+			udpHeader := header.UDP(pkt[headerLen:])
+			udpHeader.SetChecksum(0)
+			xsum := header.PseudoHeaderChecksum(
+				header.UDPProtocolNumber,
+				ipv4Header.SourceAddress(),
+				ipv4Header.DestinationAddress(),
+				uint16(len(pkt)-headerLen),
+			)
+			xsum = checksum.Checksum(pkt[headerLen:], xsum)
+			udpHeader.SetChecksum(^xsum)
+		}
+	}
+
+	return pkt
+}
+
+// rewritePacketSource rewrites the source IP in a packet and recalculates checksums (for reverse NAT)
+func (p *ProxyHandler) rewritePacketSource(packet []byte, newSrc netip.Addr) []byte {
+	if len(packet) < header.IPv4MinimumSize {
+		return nil
+	}
+
+	// Make a copy to avoid modifying the original
+	pkt := make([]byte, len(packet))
+	copy(pkt, packet)
+
+	ipv4Header := header.IPv4(pkt)
+	headerLen := int(ipv4Header.HeaderLength())
+
+	// Rewrite source IP
+	newSrcBytes := newSrc.As4()
+	newSrcAddr := tcpip.AddrFrom4(newSrcBytes)
+	ipv4Header.SetSourceAddress(newSrcAddr)
+
+	// Recalculate IP checksum
+	ipv4Header.SetChecksum(0)
+	ipv4Header.SetChecksum(^ipv4Header.CalculateChecksum())
+
+	// Update transport layer checksum if needed
+	protocol := ipv4Header.TransportProtocol()
+	switch protocol {
+	case header.TCPProtocolNumber:
+		if len(pkt) >= headerLen+header.TCPMinimumSize {
+			tcpHeader := header.TCP(pkt[headerLen:])
+			tcpHeader.SetChecksum(0)
+			xsum := header.PseudoHeaderChecksum(
+				header.TCPProtocolNumber,
+				ipv4Header.SourceAddress(),
+				ipv4Header.DestinationAddress(),
+				uint16(len(pkt)-headerLen),
+			)
+			xsum = checksum.Checksum(pkt[headerLen:], xsum)
+			tcpHeader.SetChecksum(^xsum)
+		}
+	case header.UDPProtocolNumber:
+		if len(pkt) >= headerLen+header.UDPMinimumSize {
+			udpHeader := header.UDP(pkt[headerLen:])
+			udpHeader.SetChecksum(0)
+			xsum := header.PseudoHeaderChecksum(
+				header.UDPProtocolNumber,
+				ipv4Header.SourceAddress(),
+				ipv4Header.DestinationAddress(),
+				uint16(len(pkt)-headerLen),
+			)
+			xsum = checksum.Checksum(pkt[headerLen:], xsum)
+			udpHeader.SetChecksum(^xsum)
+		}
+	}
+
+	return pkt
+}
+
+// ReadOutgoingPacket reads packets from the proxy stack that need to be
+// sent back through the tunnel
+func (p *ProxyHandler) ReadOutgoingPacket() *buffer.View {
+	if p == nil || !p.enabled {
+		return nil
+	}
+
+	pkt := p.proxyEp.Read()
+	if pkt != nil {
+		view := pkt.ToView()
+		pkt.DecRef()
+
+		// Check if we need to perform reverse NAT
+		packet := view.AsSlice()
+		if len(packet) >= header.IPv4MinimumSize && packet[0]>>4 == 4 {
+			ipv4Header := header.IPv4(packet)
+			srcIP := ipv4Header.SourceAddress()
+			dstIP := ipv4Header.DestinationAddress()
+			protocol := ipv4Header.TransportProtocol()
+			headerLen := int(ipv4Header.HeaderLength())
+
+			// Extract ports
+			var srcPort, dstPort uint16
+			switch protocol {
+			case header.TCPProtocolNumber:
+				if len(packet) >= headerLen+header.TCPMinimumSize {
+					tcpHeader := header.TCP(packet[headerLen:])
+					srcPort = tcpHeader.SourcePort()
+					dstPort = tcpHeader.DestinationPort()
+				}
+			case header.UDPProtocolNumber:
+				if len(packet) >= headerLen+header.UDPMinimumSize {
+					udpHeader := header.UDP(packet[headerLen:])
+					srcPort = udpHeader.SourcePort()
+					dstPort = udpHeader.DestinationPort()
+				}
+			}
+
+			// Look up NAT state for reverse translation
+			// The key uses the original dst (before rewrite), so for replies we need to
+			// find the entry where the rewritten address matches the current source
+			p.natMu.RLock()
+			var natEntry *natState
+			for k, entry := range p.natTable {
+				// Match: reply's dst should be original src, reply's src should be rewritten dst
+				if k.srcIP == dstIP.String() && k.srcPort == dstPort &&
+					entry.rewrittenTo.String() == srcIP.String() && k.dstPort == srcPort &&
+					k.proto == uint8(protocol) {
+					natEntry = entry
+					break
+				}
+			}
+			p.natMu.RUnlock()
+
+			if natEntry != nil {
+				// Perform reverse NAT - rewrite source to original destination
+				packet = p.rewritePacketSource(packet, natEntry.originalDst)
+				if packet != nil {
+					return buffer.NewViewWithData(packet)
+				}
+			}
+		}
+
+		return view
+	}
+
+	return nil
+}
+
+// Close cleans up the proxy handler resources
+func (p *ProxyHandler) Close() error {
+	if p == nil || !p.enabled {
+		return nil
+	}
+
+	if p.proxyStack != nil {
+		p.proxyStack.RemoveNIC(1)
+		p.proxyStack.Close()
+	}
+
+	if p.proxyEp != nil {
+		if p.proxyNotifyHandle != nil {
+			p.proxyEp.RemoveNotify(p.proxyNotifyHandle)
+		}
+		p.proxyEp.Close()
+	}
+
+	return nil
+}

network/interface.go

@@ -0,0 +1,165 @@
+package network
+
+import (
+	"fmt"
+	"net"
+	"os/exec"
+	"regexp"
+	"runtime"
+	"strconv"
+	"time"
+
+	"github.com/fosrl/newt/logger"
+	"github.com/vishvananda/netlink"
+)
+
+// ConfigureInterface configures a network interface with an IP address and brings it up
+func ConfigureInterface(interfaceName string, tunnelIp string, mtu int) error {
+	logger.Info("The tunnel IP is: %s", tunnelIp)
+
+	// Parse the IP address and network
+	ip, ipNet, err := net.ParseCIDR(tunnelIp)
+	if err != nil {
+		return fmt.Errorf("invalid IP address: %v", err)
+	}
+
+	// Convert CIDR mask to dotted decimal format (e.g., 255.255.255.0)
+	mask := net.IP(ipNet.Mask).String()
+	destinationAddress := ip.String()
+
+	logger.Debug("The destination address is: %s", destinationAddress)
+
+	// network.SetTunnelRemoteAddress() // what does this do?
+	SetIPv4Settings([]string{destinationAddress}, []string{mask})
+	SetMTU(mtu)
+
+	if interfaceName == "" {
+		return nil
+	}
+
+	switch runtime.GOOS {
+	case "linux":
+		return configureLinux(interfaceName, ip, ipNet)
+	case "darwin":
+		return configureDarwin(interfaceName, ip, ipNet)
+	case "windows":
+		return configureWindows(interfaceName, ip, ipNet)
+	default:
+		return fmt.Errorf("unsupported operating system: %s", runtime.GOOS)
+	}
+}
+
+// waitForInterfaceUp polls the network interface until it's up or times out
+func waitForInterfaceUp(interfaceName string, expectedIP net.IP, timeout time.Duration) error {
+	logger.Info("Waiting for interface %s to be up with IP %s", interfaceName, expectedIP)
+	deadline := time.Now().Add(timeout)
+	pollInterval := 500 * time.Millisecond
+
+	for time.Now().Before(deadline) {
+		// Check if interface exists and is up
+		iface, err := net.InterfaceByName(interfaceName)
+		if err == nil {
+			// Check if interface is up
+			if iface.Flags&net.FlagUp != 0 {
+				// Check if it has the expected IP
+				addrs, err := iface.Addrs()
+				if err == nil {
+					for _, addr := range addrs {
+						ipNet, ok := addr.(*net.IPNet)
+						if ok && ipNet.IP.Equal(expectedIP) {
+							logger.Info("Interface %s is up with correct IP", interfaceName)
+							return nil // Interface is up with correct IP
+						}
+					}
+					logger.Info("Interface %s is up but doesn't have expected IP yet", interfaceName)
+				}
+			} else {
+				logger.Info("Interface %s exists but is not up yet", interfaceName)
+			}
+		} else {
+			logger.Info("Interface %s not found yet: %v", interfaceName, err)
+		}
+
+		// Wait before next check
+		time.Sleep(pollInterval)
+	}
+
+	return fmt.Errorf("timed out waiting for interface %s to be up with IP %s", interfaceName, expectedIP)
+}
+
+func FindUnusedUTUN() (string, error) {
+	ifaces, err := net.Interfaces()
+	if err != nil {
+		return "", fmt.Errorf("failed to list interfaces: %v", err)
+	}
+	used := make(map[int]bool)
+	re := regexp.MustCompile(`^utun(\d+)$`)
+	for _, iface := range ifaces {
+		if matches := re.FindStringSubmatch(iface.Name); len(matches) == 2 {
+			if num, err := strconv.Atoi(matches[1]); err == nil {
+				used[num] = true
+			}
+		}
+	}
+	// Try utun0 up to utun255.
+	for i := 0; i < 256; i++ {
+		if !used[i] {
+			return fmt.Sprintf("utun%d", i), nil
+		}
+	}
+	return "", fmt.Errorf("no unused utun interface found")
+}
+
+func configureDarwin(interfaceName string, ip net.IP, ipNet *net.IPNet) error {
+	logger.Info("Configuring darwin interface: %s", interfaceName)
+
+	prefix, _ := ipNet.Mask.Size()
+	ipStr := fmt.Sprintf("%s/%d", ip.String(), prefix)
+
+	cmd := exec.Command("ifconfig", interfaceName, "inet", ipStr, ip.String(), "alias")
+	logger.Info("Running command: %v", cmd)
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("ifconfig command failed: %v, output: %s", err, out)
+	}
+
+	// Bring up the interface
+	cmd = exec.Command("ifconfig", interfaceName, "up")
+	logger.Info("Running command: %v", cmd)
+
+	out, err = cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("ifconfig up command failed: %v, output: %s", err, out)
+	}
+
+	return nil
+}
+
+func configureLinux(interfaceName string, ip net.IP, ipNet *net.IPNet) error {
+	// Get the interface
+	link, err := netlink.LinkByName(interfaceName)
+	if err != nil {
+		return fmt.Errorf("failed to get interface %s: %v", interfaceName, err)
+	}
+
+	// Create the IP address attributes
+	addr := &netlink.Addr{
+		IPNet: &net.IPNet{
+			IP:   ip,
+			Mask: ipNet.Mask,
+		},
+	}
+
+	// Add the IP address to the interface
+	if err := netlink.AddrAdd(link, addr); err != nil {
+		return fmt.Errorf("failed to add IP address: %v", err)
+	}
+
+	// Bring up the interface
+	if err := netlink.LinkSetUp(link); err != nil {
+		return fmt.Errorf("failed to bring up interface: %v", err)
+	}
+
+	return nil
+}

network/interface_notwindows.go

@@ -0,0 +1,12 @@
+//go:build !windows
+
+package network
+
+import (
+	"fmt"
+	"net"
+)
+
+func configureWindows(interfaceName string, ip net.IP, ipNet *net.IPNet) error {
+	return fmt.Errorf("configureWindows called on non-Windows platform")
+}

network/interface_windows.go

@@ -0,0 +1,63 @@
+//go:build windows
+
+package network
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+
+	"github.com/fosrl/newt/logger"
+	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
+)
+
+func configureWindows(interfaceName string, ip net.IP, ipNet *net.IPNet) error {
+	logger.Info("Configuring Windows interface: %s", interfaceName)
+
+	// Get the LUID for the interface
+	iface, err := net.InterfaceByName(interfaceName)
+	if err != nil {
+		return fmt.Errorf("failed to get interface %s: %v", interfaceName, err)
+	}
+
+	luid, err := winipcfg.LUIDFromIndex(uint32(iface.Index))
+	if err != nil {
+		return fmt.Errorf("failed to get LUID for interface %s: %v", interfaceName, err)
+	}
+
+	// Create the IP address prefix
+	maskBits, _ := ipNet.Mask.Size()
+
+	// Ensure we convert to the correct IP version (IPv4 vs IPv6)
+	var addr netip.Addr
+	if ip4 := ip.To4(); ip4 != nil {
+		// IPv4 address
+		addr, _ = netip.AddrFromSlice(ip4)
+	} else {
+		// IPv6 address
+		addr, _ = netip.AddrFromSlice(ip)
+	}
+	if !addr.IsValid() {
+		return fmt.Errorf("failed to convert IP address")
+	}
+	prefix := netip.PrefixFrom(addr, maskBits)
+
+	// Add the IP address to the interface
+	logger.Info("Adding IP address %s to interface %s", prefix.String(), interfaceName)
+	err = luid.AddIPAddress(prefix)
+	if err != nil {
+		return fmt.Errorf("failed to add IP address: %v", err)
+	}
+
+	// This was required when we were using the subprocess "netsh" command to bring up the interface.
+	// With the winipcfg library, the interface should already be up after adding the IP so we dont
+	// need this step anymore as far as I can tell.
+
+	// // Wait for the interface to be up and have the correct IP
+	// err = waitForInterfaceUp(interfaceName, ip, 30*time.Second)
+	// if err != nil {
+	// 	return fmt.Errorf("interface did not come up within timeout: %v", err)
+	// }
+
+	return nil
+}

network/network.go

@@ -1,195 +0,0 @@
-package network
-
-import (
-	"encoding/binary"
-	"encoding/json"
-	"fmt"
-	"log"
-	"net"
-	"time"
-
-	"github.com/google/gopacket"
-	"github.com/google/gopacket/layers"
-	"github.com/vishvananda/netlink"
-	"golang.org/x/net/bpf"
-	"golang.org/x/net/ipv4"
-)
-
-const (
-	udpProtocol = 17
-	// EmptyUDPSize is the size of an empty UDP packet
-	EmptyUDPSize = 28
-	timeout      = time.Second * 10
-)
-
-// Server stores data relating to the server
-type Server struct {
-	Hostname string
-	Addr     *net.IPAddr
-	Port     uint16
-}
-
-// PeerNet stores data about a peer's endpoint
-type PeerNet struct {
-	Resolved bool
-	IP       net.IP
-	Port     uint16
-	NewtID   string
-}
-
-// GetClientIP gets source ip address that will be used when sending data to dstIP
-func GetClientIP(dstIP net.IP) net.IP {
-	routes, err := netlink.RouteGet(dstIP)
-	if err != nil {
-		log.Fatalln("Error getting route:", err)
-	}
-	return routes[0].Src
-}
-
-// HostToAddr resolves a hostname, whether DNS or IP to a valid net.IPAddr
-func HostToAddr(hostStr string) *net.IPAddr {
-	remoteAddrs, err := net.LookupHost(hostStr)
-	if err != nil {
-		log.Fatalln("Error parsing remote address:", err)
-	}
-
-	for _, addrStr := range remoteAddrs {
-		if remoteAddr, err := net.ResolveIPAddr("ip4", addrStr); err == nil {
-			return remoteAddr
-		}
-	}
-	return nil
-}
-
-// SetupRawConn creates an ipv4 and udp only RawConn and applies packet filtering
-func SetupRawConn(server *Server, client *PeerNet) *ipv4.RawConn {
-	packetConn, err := net.ListenPacket("ip4:udp", client.IP.String())
-	if err != nil {
-		log.Fatalln("Error creating packetConn:", err)
-	}
-
-	rawConn, err := ipv4.NewRawConn(packetConn)
-	if err != nil {
-		log.Fatalln("Error creating rawConn:", err)
-	}
-
-	ApplyBPF(rawConn, server, client)
-
-	return rawConn
-}
-
-// ApplyBPF constructs a BPF program and applies it to the RawConn
-func ApplyBPF(rawConn *ipv4.RawConn, server *Server, client *PeerNet) {
-	const ipv4HeaderLen = 20
-	const srcIPOffset = 12
-	const srcPortOffset = ipv4HeaderLen + 0
-	const dstPortOffset = ipv4HeaderLen + 2
-
-	ipArr := []byte(server.Addr.IP.To4())
-	ipInt := uint32(ipArr[0])<<(3*8) + uint32(ipArr[1])<<(2*8) + uint32(ipArr[2])<<8 + uint32(ipArr[3])
-
-	bpfRaw, err := bpf.Assemble([]bpf.Instruction{
-		bpf.LoadAbsolute{Off: srcIPOffset, Size: 4},
-		bpf.JumpIf{Cond: bpf.JumpEqual, Val: ipInt, SkipFalse: 5, SkipTrue: 0},
-
-		bpf.LoadAbsolute{Off: srcPortOffset, Size: 2},
-		bpf.JumpIf{Cond: bpf.JumpEqual, Val: uint32(server.Port), SkipFalse: 3, SkipTrue: 0},
-
-		bpf.LoadAbsolute{Off: dstPortOffset, Size: 2},
-		bpf.JumpIf{Cond: bpf.JumpEqual, Val: uint32(client.Port), SkipFalse: 1, SkipTrue: 0},
-
-		bpf.RetConstant{Val: 1<<(8*4) - 1},
-		bpf.RetConstant{Val: 0},
-	})
-
-	if err != nil {
-		log.Fatalln("Error assembling BPF:", err)
-	}
-
-	err = rawConn.SetBPF(bpfRaw)
-	if err != nil {
-		log.Fatalln("Error setting BPF:", err)
-	}
-}
-
-// MakePacket constructs a request packet to send to the server
-func MakePacket(payload []byte, server *Server, client *PeerNet) []byte {
-	buf := gopacket.NewSerializeBuffer()
-
-	opts := gopacket.SerializeOptions{
-		FixLengths:       true,
-		ComputeChecksums: true,
-	}
-
-	ipHeader := layers.IPv4{
-		SrcIP:    client.IP,
-		DstIP:    server.Addr.IP,
-		Version:  4,
-		TTL:      64,
-		Protocol: layers.IPProtocolUDP,
-	}
-
-	udpHeader := layers.UDP{
-		SrcPort: layers.UDPPort(client.Port),
-		DstPort: layers.UDPPort(server.Port),
-	}
-
-	payloadLayer := gopacket.Payload(payload)
-
-	udpHeader.SetNetworkLayerForChecksum(&ipHeader)
-
-	gopacket.SerializeLayers(buf, opts, &ipHeader, &udpHeader, &payloadLayer)
-
-	return buf.Bytes()
-}
-
-// SendPacket sends packet to the Server
-func SendPacket(packet []byte, conn *ipv4.RawConn, server *Server, client *PeerNet) error {
-	fullPacket := MakePacket(packet, server, client)
-	_, err := conn.WriteToIP(fullPacket, server.Addr)
-	return err
-}
-
-// SendDataPacket sends a JSON payload to the Server
-func SendDataPacket(data interface{}, conn *ipv4.RawConn, server *Server, client *PeerNet) error {
-	jsonData, err := json.Marshal(data)
-	if err != nil {
-		return fmt.Errorf("failed to marshal payload: %v", err)
-	}
-
-	return SendPacket(jsonData, conn, server, client)
-}
-
-// RecvPacket receives a UDP packet from server
-func RecvPacket(conn *ipv4.RawConn, server *Server, client *PeerNet) ([]byte, int, error) {
-	err := conn.SetReadDeadline(time.Now().Add(timeout))
-	if err != nil {
-		return nil, 0, err
-	}
-
-	response := make([]byte, 4096)
-	n, err := conn.Read(response)
-	if err != nil {
-		return nil, n, err
-	}
-	return response, n, nil
-}
-
-// RecvDataPacket receives and unmarshals a JSON packet from server
-func RecvDataPacket(conn *ipv4.RawConn, server *Server, client *PeerNet) ([]byte, error) {
-	response, n, err := RecvPacket(conn, server, client)
-	if err != nil {
-		return nil, err
-	}
-
-	// Extract payload from UDP packet
-	payload := response[EmptyUDPSize:n]
-	return payload, nil
-}
-
-// ParseResponse takes a response packet and parses it into an IP and port
-func ParseResponse(response []byte) (net.IP, uint16) {
-	ip := net.IP(response[:4])
-	port := binary.BigEndian.Uint16(response[4:6])
-	return ip, port
-}

network/route.go

@@ -0,0 +1,282 @@
+package network
+
+import (
+	"fmt"
+	"net"
+	"os/exec"
+	"runtime"
+	"strings"
+
+	"github.com/fosrl/newt/logger"
+	"github.com/vishvananda/netlink"
+)
+
+func DarwinAddRoute(destination string, gateway string, interfaceName string) error {
+	if runtime.GOOS != "darwin" {
+		return nil
+	}
+
+	var cmd *exec.Cmd
+
+	if gateway != "" {
+		// Route with specific gateway
+		cmd = exec.Command("route", "-q", "-n", "add", "-inet", destination, "-gateway", gateway)
+	} else if interfaceName != "" {
+		// Route via interface
+		cmd = exec.Command("route", "-q", "-n", "add", "-inet", destination, "-interface", interfaceName)
+	} else {
+		return fmt.Errorf("either gateway or interface must be specified")
+	}
+
+	logger.Info("Running command: %v", cmd)
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("route command failed: %v, output: %s", err, out)
+	}
+
+	return nil
+}
+
+func DarwinRemoveRoute(destination string) error {
+	if runtime.GOOS != "darwin" {
+		return nil
+	}
+
+	cmd := exec.Command("route", "-q", "-n", "delete", "-inet", destination)
+	logger.Info("Running command: %v", cmd)
+
+	out, err := cmd.CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("route delete command failed: %v, output: %s", err, out)
+	}
+
+	return nil
+}
+
+func LinuxAddRoute(destination string, gateway string, interfaceName string) error {
+	if runtime.GOOS != "linux" {
+		return nil
+	}
+
+	// Parse destination CIDR
+	_, ipNet, err := net.ParseCIDR(destination)
+	if err != nil {
+		return fmt.Errorf("invalid destination address: %v", err)
+	}
+
+	// Create route
+	route := &netlink.Route{
+		Dst: ipNet,
+	}
+
+	if gateway != "" {
+		// Route with specific gateway
+		gw := net.ParseIP(gateway)
+		if gw == nil {
+			return fmt.Errorf("invalid gateway address: %s", gateway)
+		}
+		route.Gw = gw
+		logger.Info("Adding route to %s via gateway %s", destination, gateway)
+	} else if interfaceName != "" {
+		// Route via interface
+		link, err := netlink.LinkByName(interfaceName)
+		if err != nil {
+			return fmt.Errorf("failed to get interface %s: %v", interfaceName, err)
+		}
+		route.LinkIndex = link.Attrs().Index
+		logger.Info("Adding route to %s via interface %s", destination, interfaceName)
+	} else {
+		return fmt.Errorf("either gateway or interface must be specified")
+	}
+
+	// Add the route
+	if err := netlink.RouteAdd(route); err != nil {
+		return fmt.Errorf("failed to add route: %v", err)
+	}
+
+	return nil
+}
+
+func LinuxRemoveRoute(destination string) error {
+	if runtime.GOOS != "linux" {
+		return nil
+	}
+
+	// Parse destination CIDR
+	_, ipNet, err := net.ParseCIDR(destination)
+	if err != nil {
+		return fmt.Errorf("invalid destination address: %v", err)
+	}
+
+	// Create route to delete
+	route := &netlink.Route{
+		Dst: ipNet,
+	}
+
+	logger.Info("Removing route to %s", destination)
+
+	// Delete the route
+	if err := netlink.RouteDel(route); err != nil {
+		return fmt.Errorf("failed to delete route: %v", err)
+	}
+
+	return nil
+}
+
+// addRouteForServerIP adds an OS-specific route for the server IP
+func AddRouteForServerIP(serverIP, interfaceName string) error {
+	if err := AddRouteForNetworkConfig(serverIP); err != nil {
+		return err
+	}
+	if interfaceName == "" {
+		return nil
+	}
+	if runtime.GOOS == "darwin" {
+		return DarwinAddRoute(serverIP, "", interfaceName)
+	}
+	// else if runtime.GOOS == "windows" {
+	//	return WindowsAddRoute(serverIP, "", interfaceName)
+	// } else if runtime.GOOS == "linux" {
+	//	return LinuxAddRoute(serverIP, "", interfaceName)
+	// }
+	return nil
+}
+
+// removeRouteForServerIP removes an OS-specific route for the server IP
+func RemoveRouteForServerIP(serverIP string, interfaceName string) error {
+	if err := RemoveRouteForNetworkConfig(serverIP); err != nil {
+		return err
+	}
+	if interfaceName == "" {
+		return nil
+	}
+	if runtime.GOOS == "darwin" {
+		return DarwinRemoveRoute(serverIP)
+	}
+	// else if runtime.GOOS == "windows" {
+	// 	return WindowsRemoveRoute(serverIP)
+	// } else if runtime.GOOS == "linux" {
+	// 	return LinuxRemoveRoute(serverIP)
+	// }
+	return nil
+}
+
+func AddRouteForNetworkConfig(destination string) error {
+	// Parse the subnet to extract IP and mask
+	_, ipNet, err := net.ParseCIDR(destination)
+	if err != nil {
+		return fmt.Errorf("failed to parse subnet %s: %v", destination, err)
+	}
+
+	// Convert CIDR mask to dotted decimal format (e.g., 255.255.255.0)
+	mask := net.IP(ipNet.Mask).String()
+	destinationAddress := ipNet.IP.String()
+
+	AddIPv4IncludedRoute(IPv4Route{DestinationAddress: destinationAddress, SubnetMask: mask})
+
+	return nil
+}
+
+func RemoveRouteForNetworkConfig(destination string) error {
+	// Parse the subnet to extract IP and mask
+	_, ipNet, err := net.ParseCIDR(destination)
+	if err != nil {
+		return fmt.Errorf("failed to parse subnet %s: %v", destination, err)
+	}
+
+	// Convert CIDR mask to dotted decimal format (e.g., 255.255.255.0)
+	mask := net.IP(ipNet.Mask).String()
+	destinationAddress := ipNet.IP.String()
+
+	RemoveIPv4IncludedRoute(IPv4Route{DestinationAddress: destinationAddress, SubnetMask: mask})
+
+	return nil
+}
+
+// addRoutes adds routes for each subnet in RemoteSubnets
+func AddRoutes(remoteSubnets []string, interfaceName string) error {
+	if len(remoteSubnets) == 0 {
+		return nil
+	}
+
+	// Add routes for each subnet
+	for _, subnet := range remoteSubnets {
+		subnet = strings.TrimSpace(subnet)
+		if subnet == "" {
+			continue
+		}
+
+		if err := AddRouteForNetworkConfig(subnet); err != nil {
+			logger.Error("Failed to add network config for subnet %s: %v", subnet, err)
+			continue
+		}
+
+		// Add route based on operating system
+		if interfaceName == "" {
+			continue
+		}
+
+		if runtime.GOOS == "darwin" {
+			if err := DarwinAddRoute(subnet, "", interfaceName); err != nil {
+				logger.Error("Failed to add Darwin route for subnet %s: %v", subnet, err)
+				return err
+			}
+		} else if runtime.GOOS == "windows" {
+			if err := WindowsAddRoute(subnet, "", interfaceName); err != nil {
+				logger.Error("Failed to add Windows route for subnet %s: %v", subnet, err)
+				return err
+			}
+		} else if runtime.GOOS == "linux" {
+			if err := LinuxAddRoute(subnet, "", interfaceName); err != nil {
+				logger.Error("Failed to add Linux route for subnet %s: %v", subnet, err)
+				return err
+			}
+		}
+
+		logger.Info("Added route for remote subnet: %s", subnet)
+	}
+	return nil
+}
+
+// removeRoutesForRemoteSubnets removes routes for each subnet in RemoteSubnets
+func RemoveRoutes(remoteSubnets []string) error {
+	if len(remoteSubnets) == 0 {
+		return nil
+	}
+
+	// Remove routes for each subnet
+	for _, subnet := range remoteSubnets {
+		subnet = strings.TrimSpace(subnet)
+		if subnet == "" {
+			continue
+		}
+
+		if err := RemoveRouteForNetworkConfig(subnet); err != nil {
+			logger.Error("Failed to remove network config for subnet %s: %v", subnet, err)
+			continue
+		}
+
+		// Remove route based on operating system
+		if runtime.GOOS == "darwin" {
+			if err := DarwinRemoveRoute(subnet); err != nil {
+				logger.Error("Failed to remove Darwin route for subnet %s: %v", subnet, err)
+				return err
+			}
+		} else if runtime.GOOS == "windows" {
+			if err := WindowsRemoveRoute(subnet); err != nil {
+				logger.Error("Failed to remove Windows route for subnet %s: %v", subnet, err)
+				return err
+			}
+		} else if runtime.GOOS == "linux" {
+			if err := LinuxRemoveRoute(subnet); err != nil {
+				logger.Error("Failed to remove Linux route for subnet %s: %v", subnet, err)
+				return err
+			}
+		}
+
+		logger.Info("Removed route for remote subnet: %s", subnet)
+	}
+
+	return nil
+}

network/route_notwindows.go

@@ -0,0 +1,11 @@
+//go:build !windows
+
+package network
+
+func WindowsAddRoute(destination string, gateway string, interfaceName string) error {
+	return nil
+}
+
+func WindowsRemoveRoute(destination string) error {
+	return nil
+}

network/route_windows.go

@@ -0,0 +1,148 @@
+//go:build windows
+
+package network
+
+import (
+	"fmt"
+	"net"
+	"net/netip"
+	"runtime"
+
+	"github.com/fosrl/newt/logger"
+	"golang.zx2c4.com/wireguard/windows/tunnel/winipcfg"
+)
+
+func WindowsAddRoute(destination string, gateway string, interfaceName string) error {
+	if runtime.GOOS != "windows" {
+		return nil
+	}
+
+	// Parse destination CIDR
+	_, ipNet, err := net.ParseCIDR(destination)
+	if err != nil {
+		return fmt.Errorf("invalid destination address: %v", err)
+	}
+
+	// Convert to netip.Prefix
+	maskBits, _ := ipNet.Mask.Size()
+
+	// Ensure we convert to the correct IP version (IPv4 vs IPv6)
+	var addr netip.Addr
+	if ip4 := ipNet.IP.To4(); ip4 != nil {
+		// IPv4 address
+		addr, _ = netip.AddrFromSlice(ip4)
+	} else {
+		// IPv6 address
+		addr, _ = netip.AddrFromSlice(ipNet.IP)
+	}
+	if !addr.IsValid() {
+		return fmt.Errorf("failed to convert destination IP")
+	}
+	prefix := netip.PrefixFrom(addr, maskBits)
+
+	var luid winipcfg.LUID
+	var nextHop netip.Addr
+
+	if interfaceName != "" {
+		// Get the interface LUID - needed for both gateway and interface-only routes
+		iface, err := net.InterfaceByName(interfaceName)
+		if err != nil {
+			return fmt.Errorf("failed to get interface %s: %v", interfaceName, err)
+		}
+
+		luid, err = winipcfg.LUIDFromIndex(uint32(iface.Index))
+		if err != nil {
+			return fmt.Errorf("failed to get LUID for interface %s: %v", interfaceName, err)
+		}
+	}
+
+	if gateway != "" {
+		// Route with specific gateway
+		gwIP := net.ParseIP(gateway)
+		if gwIP == nil {
+			return fmt.Errorf("invalid gateway address: %s", gateway)
+		}
+		// Convert to correct IP version
+		if ip4 := gwIP.To4(); ip4 != nil {
+			nextHop, _ = netip.AddrFromSlice(ip4)
+		} else {
+			nextHop, _ = netip.AddrFromSlice(gwIP)
+		}
+		if !nextHop.IsValid() {
+			return fmt.Errorf("failed to convert gateway IP")
+		}
+		logger.Info("Adding route to %s via gateway %s on interface %s", destination, gateway, interfaceName)
+	} else if interfaceName != "" {
+		// Route via interface only
+		if addr.Is4() {
+			nextHop = netip.IPv4Unspecified()
+		} else {
+			nextHop = netip.IPv6Unspecified()
+		}
+		logger.Info("Adding route to %s via interface %s", destination, interfaceName)
+	} else {
+		return fmt.Errorf("either gateway or interface must be specified")
+	}
+
+	// Add the route using winipcfg
+	err = luid.AddRoute(prefix, nextHop, 1)
+	if err != nil {
+		return fmt.Errorf("failed to add route: %v", err)
+	}
+
+	return nil
+}
+
+func WindowsRemoveRoute(destination string) error {
+	// Parse destination CIDR
+	_, ipNet, err := net.ParseCIDR(destination)
+	if err != nil {
+		return fmt.Errorf("invalid destination address: %v", err)
+	}
+
+	// Convert to netip.Prefix
+	maskBits, _ := ipNet.Mask.Size()
+
+	// Ensure we convert to the correct IP version (IPv4 vs IPv6)
+	var addr netip.Addr
+	if ip4 := ipNet.IP.To4(); ip4 != nil {
+		// IPv4 address
+		addr, _ = netip.AddrFromSlice(ip4)
+	} else {
+		// IPv6 address
+		addr, _ = netip.AddrFromSlice(ipNet.IP)
+	}
+	if !addr.IsValid() {
+		return fmt.Errorf("failed to convert destination IP")
+	}
+	prefix := netip.PrefixFrom(addr, maskBits)
+
+	// Get all routes and find the one to delete
+	// We need to get the LUID from the existing route
+	var family winipcfg.AddressFamily
+	if addr.Is4() {
+		family = 2 // AF_INET
+	} else {
+		family = 23 // AF_INET6
+	}
+
+	routes, err := winipcfg.GetIPForwardTable2(family)
+	if err != nil {
+		return fmt.Errorf("failed to get route table: %v", err)
+	}
+
+	// Find and delete matching route
+	for _, route := range routes {
+		routePrefix := route.DestinationPrefix.Prefix()
+		if routePrefix == prefix {
+			logger.Info("Removing route to %s", destination)
+			err = route.Delete()
+			if err != nil {
+				return fmt.Errorf("failed to delete route: %v", err)
+			}
+			return nil
+		}
+	}
+
+	return fmt.Errorf("route to %s not found", destination)
+}

network/settings.go

@@ -0,0 +1,190 @@
+package network
+
+import (
+	"encoding/json"
+	"sync"
+
+	"github.com/fosrl/newt/logger"
+)
+
+// NetworkSettings represents the network configuration for the tunnel
+type NetworkSettings struct {
+	TunnelRemoteAddress string      `json:"tunnel_remote_address,omitempty"`
+	MTU                 *int        `json:"mtu,omitempty"`
+	DNSServers          []string    `json:"dns_servers,omitempty"`
+	IPv4Addresses       []string    `json:"ipv4_addresses,omitempty"`
+	IPv4SubnetMasks     []string    `json:"ipv4_subnet_masks,omitempty"`
+	IPv4IncludedRoutes  []IPv4Route `json:"ipv4_included_routes,omitempty"`
+	IPv4ExcludedRoutes  []IPv4Route `json:"ipv4_excluded_routes,omitempty"`
+	IPv6Addresses       []string    `json:"ipv6_addresses,omitempty"`
+	IPv6NetworkPrefixes []string    `json:"ipv6_network_prefixes,omitempty"`
+	IPv6IncludedRoutes  []IPv6Route `json:"ipv6_included_routes,omitempty"`
+	IPv6ExcludedRoutes  []IPv6Route `json:"ipv6_excluded_routes,omitempty"`
+}
+
+// IPv4Route represents an IPv4 route
+type IPv4Route struct {
+	DestinationAddress string `json:"destination_address"`
+	SubnetMask         string `json:"subnet_mask,omitempty"`
+	GatewayAddress     string `json:"gateway_address,omitempty"`
+	IsDefault          bool   `json:"is_default,omitempty"`
+}
+
+// IPv6Route represents an IPv6 route
+type IPv6Route struct {
+	DestinationAddress  string `json:"destination_address"`
+	NetworkPrefixLength int    `json:"network_prefix_length,omitempty"`
+	GatewayAddress      string `json:"gateway_address,omitempty"`
+	IsDefault           bool   `json:"is_default,omitempty"`
+}
+
+var (
+	networkSettings      NetworkSettings
+	networkSettingsMutex sync.RWMutex
+	incrementor          int
+)
+
+// SetTunnelRemoteAddress sets the tunnel remote address
+func SetTunnelRemoteAddress(address string) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.TunnelRemoteAddress = address
+	incrementor++
+	logger.Info("Set tunnel remote address: %s", address)
+}
+
+// SetMTU sets the MTU value
+func SetMTU(mtu int) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.MTU = &mtu
+	incrementor++
+	logger.Info("Set MTU: %d", mtu)
+}
+
+// SetDNSServers sets the DNS servers
+func SetDNSServers(servers []string) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.DNSServers = servers
+	incrementor++
+	logger.Info("Set DNS servers: %v", servers)
+}
+
+// SetIPv4Settings sets IPv4 addresses and subnet masks
+func SetIPv4Settings(addresses []string, subnetMasks []string) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.IPv4Addresses = addresses
+	networkSettings.IPv4SubnetMasks = subnetMasks
+	incrementor++
+	logger.Info("Set IPv4 addresses: %v, subnet masks: %v", addresses, subnetMasks)
+}
+
+// SetIPv4IncludedRoutes sets the included IPv4 routes
+func SetIPv4IncludedRoutes(routes []IPv4Route) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.IPv4IncludedRoutes = routes
+	incrementor++
+	logger.Info("Set IPv4 included routes: %d routes", len(routes))
+}
+
+func AddIPv4IncludedRoute(route IPv4Route) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+
+	// make sure it does not already exist
+	for _, r := range networkSettings.IPv4IncludedRoutes {
+		if r == route {
+			logger.Info("IPv4 included route already exists: %+v", route)
+			return
+		}
+	}
+
+	networkSettings.IPv4IncludedRoutes = append(networkSettings.IPv4IncludedRoutes, route)
+	incrementor++
+	logger.Info("Added IPv4 included route: %+v", route)
+}
+
+func RemoveIPv4IncludedRoute(route IPv4Route) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	routes := networkSettings.IPv4IncludedRoutes
+	for i, r := range routes {
+		if r == route {
+			networkSettings.IPv4IncludedRoutes = append(routes[:i], routes[i+1:]...)
+			logger.Info("Removed IPv4 included route: %+v", route)
+			return
+		}
+	}
+	incrementor++
+	logger.Info("IPv4 included route not found for removal: %+v", route)
+}
+
+func SetIPv4ExcludedRoutes(routes []IPv4Route) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.IPv4ExcludedRoutes = routes
+	incrementor++
+	logger.Info("Set IPv4 excluded routes: %d routes", len(routes))
+}
+
+// SetIPv6Settings sets IPv6 addresses and network prefixes
+func SetIPv6Settings(addresses []string, networkPrefixes []string) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.IPv6Addresses = addresses
+	networkSettings.IPv6NetworkPrefixes = networkPrefixes
+	incrementor++
+	logger.Info("Set IPv6 addresses: %v, network prefixes: %v", addresses, networkPrefixes)
+}
+
+// SetIPv6IncludedRoutes sets the included IPv6 routes
+func SetIPv6IncludedRoutes(routes []IPv6Route) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.IPv6IncludedRoutes = routes
+	incrementor++
+	logger.Info("Set IPv6 included routes: %d routes", len(routes))
+}
+
+// SetIPv6ExcludedRoutes sets the excluded IPv6 routes
+func SetIPv6ExcludedRoutes(routes []IPv6Route) {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings.IPv6ExcludedRoutes = routes
+	incrementor++
+	logger.Info("Set IPv6 excluded routes: %d routes", len(routes))
+}
+
+// ClearNetworkSettings clears all network settings
+func ClearNetworkSettings() {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	networkSettings = NetworkSettings{}
+	incrementor++
+	logger.Info("Cleared all network settings")
+}
+
+func GetJSON() (string, error) {
+	networkSettingsMutex.RLock()
+	defer networkSettingsMutex.RUnlock()
+	data, err := json.MarshalIndent(networkSettings, "", "  ")
+	if err != nil {
+		return "", err
+	}
+	return string(data), nil
+}
+
+func GetSettings() NetworkSettings {
+	networkSettingsMutex.RLock()
+	defer networkSettingsMutex.RUnlock()
+	return networkSettings
+}
+
+func GetIncrementor() int {
+	networkSettingsMutex.Lock()
+	defer networkSettingsMutex.Unlock()
+	return incrementor
+}

proxy/manager.go

@@ -1,18 +1,28 @@
 package proxy
 
 import (
+	"context"
+	"errors"
 	"fmt"
 	"io"
 	"net"
+	"os"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"time"
 
+	"github.com/fosrl/newt/internal/state"
+	"github.com/fosrl/newt/internal/telemetry"
 	"github.com/fosrl/newt/logger"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
 	"golang.zx2c4.com/wireguard/tun/netstack"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 )
 
+const errUnsupportedProtoFmt = "unsupported protocol: %s"
+
 // Target represents a proxy target with its address and port
 type Target struct {
 	Address string
@@ -28,6 +38,90 @@ type ProxyManager struct {
 	udpConns   []*gonet.UDPConn
 	running    bool
 	mutex      sync.RWMutex
+
+	// telemetry (multi-tunnel)
+	currentTunnelID string
+	tunnels         map[string]*tunnelEntry
+	asyncBytes      bool
+	flushStop       chan struct{}
+}
+
+// tunnelEntry holds per-tunnel attributes and (optional) async counters.
+type tunnelEntry struct {
+	attrInTCP  attribute.Set
+	attrOutTCP attribute.Set
+	attrInUDP  attribute.Set
+	attrOutUDP attribute.Set
+
+	bytesInTCP  atomic.Uint64
+	bytesOutTCP atomic.Uint64
+	bytesInUDP  atomic.Uint64
+	bytesOutUDP atomic.Uint64
+
+	activeTCP atomic.Int64
+	activeUDP atomic.Int64
+}
+
+// countingWriter wraps an io.Writer and adds bytes to OTel counter using a pre-built attribute set.
+type countingWriter struct {
+	ctx   context.Context
+	w     io.Writer
+	set   attribute.Set
+	pm    *ProxyManager
+	ent   *tunnelEntry
+	out   bool   // false=in, true=out
+	proto string // "tcp" or "udp"
+}
+
+func (cw *countingWriter) Write(p []byte) (int, error) {
+	n, err := cw.w.Write(p)
+	if n > 0 {
+		if cw.pm != nil && cw.pm.asyncBytes && cw.ent != nil {
+			switch cw.proto {
+			case "tcp":
+				if cw.out {
+					cw.ent.bytesOutTCP.Add(uint64(n))
+				} else {
+					cw.ent.bytesInTCP.Add(uint64(n))
+				}
+			case "udp":
+				if cw.out {
+					cw.ent.bytesOutUDP.Add(uint64(n))
+				} else {
+					cw.ent.bytesInUDP.Add(uint64(n))
+				}
+			}
+		} else {
+			telemetry.AddTunnelBytesSet(cw.ctx, int64(n), cw.set)
+		}
+	}
+	return n, err
+}
+
+func classifyProxyError(err error) string {
+	if err == nil {
+		return ""
+	}
+	if errors.Is(err, net.ErrClosed) {
+		return "closed"
+	}
+	if ne, ok := err.(net.Error); ok {
+		if ne.Timeout() {
+			return "timeout"
+		}
+		if ne.Temporary() {
+			return "temporary"
+		}
+	}
+	msg := strings.ToLower(err.Error())
+	switch {
+	case strings.Contains(msg, "refused"):
+		return "refused"
+	case strings.Contains(msg, "reset"):
+		return "reset"
+	default:
+		return "io_error"
+	}
 }
 
 // NewProxyManager creates a new proxy manager instance
@@ -38,9 +132,77 @@ func NewProxyManager(tnet *netstack.Net) *ProxyManager {
 		udpTargets: make(map[string]map[int]string),
 		listeners:  make([]*gonet.TCPListener, 0),
 		udpConns:   make([]*gonet.UDPConn, 0),
+		tunnels:    make(map[string]*tunnelEntry),
 	}
 }
 
+// SetTunnelID sets the WireGuard peer public key used as tunnel_id label.
+func (pm *ProxyManager) SetTunnelID(id string) {
+	pm.mutex.Lock()
+	defer pm.mutex.Unlock()
+	pm.currentTunnelID = id
+	if _, ok := pm.tunnels[id]; !ok {
+		pm.tunnels[id] = &tunnelEntry{}
+	}
+	e := pm.tunnels[id]
+	// include site labels if available
+	site := telemetry.SiteLabelKVs()
+	build := func(base []attribute.KeyValue) attribute.Set {
+		if telemetry.ShouldIncludeTunnelID() {
+			base = append([]attribute.KeyValue{attribute.String("tunnel_id", id)}, base...)
+		}
+		base = append(site, base...)
+		return attribute.NewSet(base...)
+	}
+	e.attrInTCP = build([]attribute.KeyValue{
+		attribute.String("direction", "ingress"),
+		attribute.String("protocol", "tcp"),
+	})
+	e.attrOutTCP = build([]attribute.KeyValue{
+		attribute.String("direction", "egress"),
+		attribute.String("protocol", "tcp"),
+	})
+	e.attrInUDP = build([]attribute.KeyValue{
+		attribute.String("direction", "ingress"),
+		attribute.String("protocol", "udp"),
+	})
+	e.attrOutUDP = build([]attribute.KeyValue{
+		attribute.String("direction", "egress"),
+		attribute.String("protocol", "udp"),
+	})
+}
+
+// ClearTunnelID clears cached attribute sets for the current tunnel.
+func (pm *ProxyManager) ClearTunnelID() {
+	pm.mutex.Lock()
+	defer pm.mutex.Unlock()
+	id := pm.currentTunnelID
+	if id == "" {
+		return
+	}
+	if e, ok := pm.tunnels[id]; ok {
+		// final flush for this tunnel
+		inTCP := e.bytesInTCP.Swap(0)
+		outTCP := e.bytesOutTCP.Swap(0)
+		inUDP := e.bytesInUDP.Swap(0)
+		outUDP := e.bytesOutUDP.Swap(0)
+		if inTCP > 0 {
+			telemetry.AddTunnelBytesSet(context.Background(), int64(inTCP), e.attrInTCP)
+		}
+		if outTCP > 0 {
+			telemetry.AddTunnelBytesSet(context.Background(), int64(outTCP), e.attrOutTCP)
+		}
+		if inUDP > 0 {
+			telemetry.AddTunnelBytesSet(context.Background(), int64(inUDP), e.attrInUDP)
+		}
+		if outUDP > 0 {
+			telemetry.AddTunnelBytesSet(context.Background(), int64(outUDP), e.attrOutUDP)
+		}
+		delete(pm.tunnels, id)
+	}
+	pm.currentTunnelID = ""
+}
+
 // init function without tnet
 func NewProxyManagerWithoutTNet() *ProxyManager {
 	return &ProxyManager{
@@ -75,7 +237,7 @@ func (pm *ProxyManager) AddTarget(proto, listenIP string, port int, targetAddr s
 		}
 		pm.udpTargets[listenIP][port] = targetAddr
 	default:
-		return fmt.Errorf("unsupported protocol: %s", proto)
+		return fmt.Errorf(errUnsupportedProtoFmt, proto)
 	}
 
 	if pm.running {
@@ -124,13 +286,28 @@ func (pm *ProxyManager) RemoveTarget(proto, listenIP string, port int) error {
 			return fmt.Errorf("target not found: %s:%d", listenIP, port)
 		}
 	default:
-		return fmt.Errorf("unsupported protocol: %s", proto)
+		return fmt.Errorf(errUnsupportedProtoFmt, proto)
 	}
 	return nil
 }
 
 // Start begins listening for all configured proxy targets
 func (pm *ProxyManager) Start() error {
+	// Register proxy observables once per process
+	telemetry.SetProxyObservableCallback(func(ctx context.Context, o metric.Observer) error {
+		pm.mutex.RLock()
+		defer pm.mutex.RUnlock()
+		for _, e := range pm.tunnels {
+			// active connections
+			telemetry.ObserveProxyActiveConnsObs(o, e.activeTCP.Load(), e.attrOutTCP.ToSlice())
+			telemetry.ObserveProxyActiveConnsObs(o, e.activeUDP.Load(), e.attrOutUDP.ToSlice())
+			// backlog bytes (sum of unflushed counters)
+			b := int64(e.bytesInTCP.Load() + e.bytesOutTCP.Load() + e.bytesInUDP.Load() + e.bytesOutUDP.Load())
+			telemetry.ObserveProxyAsyncBacklogObs(o, b, e.attrOutTCP.ToSlice())
+			telemetry.ObserveProxyBufferBytesObs(o, b, e.attrOutTCP.ToSlice())
+		}
+		return nil
+	})
 	pm.mutex.Lock()
 	defer pm.mutex.Unlock()
 
@@ -160,6 +337,75 @@ func (pm *ProxyManager) Start() error {
 	return nil
 }
 
+func (pm *ProxyManager) SetAsyncBytes(b bool) {
+	pm.mutex.Lock()
+	defer pm.mutex.Unlock()
+	pm.asyncBytes = b
+	if b && pm.flushStop == nil {
+		pm.flushStop = make(chan struct{})
+		go pm.flushLoop()
+	}
+}
+func (pm *ProxyManager) flushLoop() {
+	flushInterval := 2 * time.Second
+	if v := os.Getenv("OTEL_METRIC_EXPORT_INTERVAL"); v != "" {
+		if d, err := time.ParseDuration(v); err == nil && d > 0 {
+			if d/2 < flushInterval {
+				flushInterval = d / 2
+			}
+		}
+	}
+	ticker := time.NewTicker(flushInterval)
+	defer ticker.Stop()
+	for {
+		select {
+		case <-ticker.C:
+			pm.mutex.RLock()
+			for _, e := range pm.tunnels {
+				inTCP := e.bytesInTCP.Swap(0)
+				outTCP := e.bytesOutTCP.Swap(0)
+				inUDP := e.bytesInUDP.Swap(0)
+				outUDP := e.bytesOutUDP.Swap(0)
+				if inTCP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(inTCP), e.attrInTCP)
+				}
+				if outTCP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(outTCP), e.attrOutTCP)
+				}
+				if inUDP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(inUDP), e.attrInUDP)
+				}
+				if outUDP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(outUDP), e.attrOutUDP)
+				}
+			}
+			pm.mutex.RUnlock()
+		case <-pm.flushStop:
+			pm.mutex.RLock()
+			for _, e := range pm.tunnels {
+				inTCP := e.bytesInTCP.Swap(0)
+				outTCP := e.bytesOutTCP.Swap(0)
+				inUDP := e.bytesInUDP.Swap(0)
+				outUDP := e.bytesOutUDP.Swap(0)
+				if inTCP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(inTCP), e.attrInTCP)
+				}
+				if outTCP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(outTCP), e.attrOutTCP)
+				}
+				if inUDP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(inUDP), e.attrInUDP)
+				}
+				if outUDP > 0 {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(outUDP), e.attrOutUDP)
+				}
+			}
+			pm.mutex.RUnlock()
+			return
+		}
+	}
+}
+
 func (pm *ProxyManager) Stop() error {
 	pm.mutex.Lock()
 	defer pm.mutex.Unlock()
@@ -227,7 +473,7 @@ func (pm *ProxyManager) startTarget(proto, listenIP string, port int, targetAddr
 		go pm.handleUDPProxy(conn, targetAddr)
 
 	default:
-		return fmt.Errorf("unsupported protocol: %s", proto)
+		return fmt.Errorf(errUnsupportedProtoFmt, proto)
 	}
 
 	logger.Info("Started %s proxy to %s", proto, targetAddr)
@@ -236,54 +482,84 @@ func (pm *ProxyManager) startTarget(proto, listenIP string, port int, targetAddr
 	return nil
 }
 
+// getEntry returns per-tunnel entry or nil.
+func (pm *ProxyManager) getEntry(id string) *tunnelEntry {
+	pm.mutex.RLock()
+	e := pm.tunnels[id]
+	pm.mutex.RUnlock()
+	return e
+}
+
 func (pm *ProxyManager) handleTCPProxy(listener net.Listener, targetAddr string) {
 	for {
 		conn, err := listener.Accept()
 		if err != nil {
-			// Check if we're shutting down or the listener was closed
+			telemetry.IncProxyAccept(context.Background(), pm.currentTunnelID, "tcp", "failure", classifyProxyError(err))
 			if !pm.running {
 				return
 			}
-
-			// Check for specific network errors that indicate the listener is closed
 			if ne, ok := err.(net.Error); ok && !ne.Temporary() {
 				logger.Info("TCP listener closed, stopping proxy handler for %v", listener.Addr())
 				return
 			}
-
 			logger.Error("Error accepting TCP connection: %v", err)
-			// Don't hammer the CPU if we hit a temporary error
 			time.Sleep(100 * time.Millisecond)
 			continue
 		}
 
-		go func() {
+		tunnelID := pm.currentTunnelID
+		telemetry.IncProxyAccept(context.Background(), tunnelID, "tcp", "success", "")
+		telemetry.IncProxyConnectionEvent(context.Background(), tunnelID, "tcp", telemetry.ProxyConnectionOpened)
+		if tunnelID != "" {
+			state.Global().IncSessions(tunnelID)
+			if e := pm.getEntry(tunnelID); e != nil {
+				e.activeTCP.Add(1)
+			}
+		}
+
+		go func(tunnelID string, accepted net.Conn) {
+			connStart := time.Now()
 			target, err := net.Dial("tcp", targetAddr)
 			if err != nil {
 				logger.Error("Error connecting to target: %v", err)
-				conn.Close()
+				accepted.Close()
+				telemetry.IncProxyAccept(context.Background(), tunnelID, "tcp", "failure", classifyProxyError(err))
+				telemetry.IncProxyConnectionEvent(context.Background(), tunnelID, "tcp", telemetry.ProxyConnectionClosed)
+				telemetry.ObserveProxyConnectionDuration(context.Background(), tunnelID, "tcp", "failure", time.Since(connStart).Seconds())
 				return
 			}
 
-			// Create a WaitGroup to ensure both copy operations complete
+			entry := pm.getEntry(tunnelID)
+			if entry == nil {
+				entry = &tunnelEntry{}
+			}
 			var wg sync.WaitGroup
 			wg.Add(2)
 
-			go func() {
+			go func(ent *tunnelEntry) {
 				defer wg.Done()
-				io.Copy(target, conn)
-				target.Close()
-			}()
+				cw := &countingWriter{ctx: context.Background(), w: target, set: ent.attrInTCP, pm: pm, ent: ent, out: false, proto: "tcp"}
+				_, _ = io.Copy(cw, accepted)
+				_ = target.Close()
+			}(entry)
 
-			go func() {
+			go func(ent *tunnelEntry) {
 				defer wg.Done()
-				io.Copy(conn, target)
-				conn.Close()
-			}()
+				cw := &countingWriter{ctx: context.Background(), w: accepted, set: ent.attrOutTCP, pm: pm, ent: ent, out: true, proto: "tcp"}
+				_, _ = io.Copy(cw, target)
+				_ = accepted.Close()
+			}(entry)
 
-			// Wait for both copies to complete
 			wg.Wait()
-		}()
+			if tunnelID != "" {
+				state.Global().DecSessions(tunnelID)
+				if e := pm.getEntry(tunnelID); e != nil {
+					e.activeTCP.Add(-1)
+				}
+			}
+			telemetry.ObserveProxyConnectionDuration(context.Background(), tunnelID, "tcp", "success", time.Since(connStart).Seconds())
+			telemetry.IncProxyConnectionEvent(context.Background(), tunnelID, "tcp", telemetry.ProxyConnectionClosed)
+		}(tunnelID, conn)
 	}
 }
 
@@ -326,6 +602,18 @@ func (pm *ProxyManager) handleUDPProxy(conn *gonet.UDPConn, targetAddr string) {
 		}
 
 		clientKey := remoteAddr.String()
+		// bytes from client -> target (direction=in)
+		if pm.currentTunnelID != "" && n > 0 {
+			if pm.asyncBytes {
+				if e := pm.getEntry(pm.currentTunnelID); e != nil {
+					e.bytesInUDP.Add(uint64(n))
+				}
+			} else {
+				if e := pm.getEntry(pm.currentTunnelID); e != nil {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(n), e.attrInUDP)
+				}
+			}
+		}
 		clientsMutex.RLock()
 		targetConn, exists := clientConns[clientKey]
 		clientsMutex.RUnlock()
@@ -334,28 +622,44 @@ func (pm *ProxyManager) handleUDPProxy(conn *gonet.UDPConn, targetAddr string) {
 			targetUDPAddr, err := net.ResolveUDPAddr("udp", targetAddr)
 			if err != nil {
 				logger.Error("Error resolving target address: %v", err)
+				telemetry.IncProxyAccept(context.Background(), pm.currentTunnelID, "udp", "failure", "resolve")
 				continue
 			}
 
 			targetConn, err = net.DialUDP("udp", nil, targetUDPAddr)
 			if err != nil {
 				logger.Error("Error connecting to target: %v", err)
+				telemetry.IncProxyAccept(context.Background(), pm.currentTunnelID, "udp", "failure", classifyProxyError(err))
 				continue
 			}
+			tunnelID := pm.currentTunnelID
+			telemetry.IncProxyAccept(context.Background(), tunnelID, "udp", "success", "")
+			telemetry.IncProxyConnectionEvent(context.Background(), tunnelID, "udp", telemetry.ProxyConnectionOpened)
+			// Only increment activeUDP after a successful DialUDP
+			if e := pm.getEntry(tunnelID); e != nil {
+				e.activeUDP.Add(1)
+			}
 
 			clientsMutex.Lock()
 			clientConns[clientKey] = targetConn
 			clientsMutex.Unlock()
 
-			go func(clientKey string, targetConn *net.UDPConn, remoteAddr net.Addr) {
+			go func(clientKey string, targetConn *net.UDPConn, remoteAddr net.Addr, tunnelID string) {
+				start := time.Now()
+				result := "success"
 				defer func() {
 					// Always clean up when this goroutine exits
 					clientsMutex.Lock()
 					if storedConn, exists := clientConns[clientKey]; exists && storedConn == targetConn {
 						delete(clientConns, clientKey)
 						targetConn.Close()
+						if e := pm.getEntry(tunnelID); e != nil {
+							e.activeUDP.Add(-1)
+						}
 					}
 					clientsMutex.Unlock()
+					telemetry.ObserveProxyConnectionDuration(context.Background(), tunnelID, "udp", result, time.Since(start).Seconds())
+					telemetry.IncProxyConnectionEvent(context.Background(), tunnelID, "udp", telemetry.ProxyConnectionClosed)
 				}()
 
 				buffer := make([]byte, 65507)
@@ -363,25 +667,52 @@ func (pm *ProxyManager) handleUDPProxy(conn *gonet.UDPConn, targetAddr string) {
 					n, _, err := targetConn.ReadFromUDP(buffer)
 					if err != nil {
 						logger.Error("Error reading from target: %v", err)
+						result = "failure"
 						return // defer will handle cleanup
 					}
 
+					// bytes from target -> client (direction=out)
+					if pm.currentTunnelID != "" && n > 0 {
+						if pm.asyncBytes {
+							if e := pm.getEntry(pm.currentTunnelID); e != nil {
+								e.bytesOutUDP.Add(uint64(n))
+							}
+						} else {
+							if e := pm.getEntry(pm.currentTunnelID); e != nil {
+								telemetry.AddTunnelBytesSet(context.Background(), int64(n), e.attrOutUDP)
+							}
+						}
+					}
+
 					_, err = conn.WriteTo(buffer[:n], remoteAddr)
 					if err != nil {
 						logger.Error("Error writing to client: %v", err)
+						telemetry.IncProxyDrops(context.Background(), pm.currentTunnelID, "udp")
+						result = "failure"
 						return // defer will handle cleanup
 					}
 				}
-			}(clientKey, targetConn, remoteAddr)
+			}(clientKey, targetConn, remoteAddr, tunnelID)
 		}
 
-		_, err = targetConn.Write(buffer[:n])
+		written, err := targetConn.Write(buffer[:n])
 		if err != nil {
 			logger.Error("Error writing to target: %v", err)
+			telemetry.IncProxyDrops(context.Background(), pm.currentTunnelID, "udp")
 			targetConn.Close()
 			clientsMutex.Lock()
 			delete(clientConns, clientKey)
 			clientsMutex.Unlock()
+		} else if pm.currentTunnelID != "" && written > 0 {
+			if pm.asyncBytes {
+				if e := pm.getEntry(pm.currentTunnelID); e != nil {
+					e.bytesInUDP.Add(uint64(written))
+				}
+			} else {
+				if e := pm.getEntry(pm.currentTunnelID); e != nil {
+					telemetry.AddTunnelBytesSet(context.Background(), int64(written), e.attrInUDP)
+				}
+			}
 		}
 	}
 }

stub.go

@@ -8,25 +8,32 @@ import (
 )
 
 func setupClientsNative(client *websocket.Client, host string) {
-	return // This function is not implemented for non-Linux systems.
+	_ = client
+	_ = host
+	// No-op for non-Linux systems
 }
 
 func closeWgServiceNative() {
 	// No-op for non-Linux systems
-	return
 }
 
 func clientsOnConnectNative() {
 	// No-op for non-Linux systems
-	return
 }
 
 func clientsHandleNewtConnectionNative(publicKey, endpoint string) {
+	_ = publicKey
+	_ = endpoint
 	// No-op for non-Linux systems
-	return
 }
 
 func clientsAddProxyTargetNative(pm *proxy.ProxyManager, tunnelIp string) {
+	_ = pm
+	_ = tunnelIp
+	// No-op for non-Linux systems
+}
+
+func clientsStartDirectRelayNative(tunnelIP string) {
+	_ = tunnelIP
 	// No-op for non-Linux systems
-	return
 }

util/util.go

@@ -0,0 +1,213 @@
+package util
+
+import (
+	"encoding/base64"
+	"encoding/binary"
+	"encoding/hex"
+	"fmt"
+	"net"
+	"strings"
+
+	mathrand "math/rand/v2"
+
+	"github.com/fosrl/newt/logger"
+	"golang.zx2c4.com/wireguard/device"
+)
+
+func ResolveDomain(domain string) (string, error) {
+	// trim whitespace
+	domain = strings.TrimSpace(domain)
+
+	// Remove any protocol prefix if present (do this first, before splitting host/port)
+	domain = strings.TrimPrefix(domain, "http://")
+	domain = strings.TrimPrefix(domain, "https://")
+
+	// if there are any trailing slashes, remove them
+	domain = strings.TrimSuffix(domain, "/")
+
+	// Check if there's a port in the domain
+	host, port, err := net.SplitHostPort(domain)
+	if err != nil {
+		// No port found, use the domain as is
+		host = domain
+		port = ""
+	}
+
+	// Lookup IP addresses
+	ips, err := net.LookupIP(host)
+	if err != nil {
+		return "", fmt.Errorf("DNS lookup failed: %v", err)
+	}
+
+	if len(ips) == 0 {
+		return "", fmt.Errorf("no IP addresses found for domain %s", host)
+	}
+
+	// Get the first IPv4 address if available
+	var ipAddr string
+	for _, ip := range ips {
+		if ipv4 := ip.To4(); ipv4 != nil {
+			ipAddr = ipv4.String()
+			break
+		}
+	}
+
+	// If no IPv4 found, use the first IP (might be IPv6)
+	if ipAddr == "" {
+		ipAddr = ips[0].String()
+	}
+
+	// Add port back if it existed
+	if port != "" {
+		ipAddr = net.JoinHostPort(ipAddr, port)
+	}
+
+	return ipAddr, nil
+}
+
+func ParseLogLevel(level string) logger.LogLevel {
+	switch strings.ToUpper(level) {
+	case "DEBUG":
+		return logger.DEBUG
+	case "INFO":
+		return logger.INFO
+	case "WARN":
+		return logger.WARN
+	case "ERROR":
+		return logger.ERROR
+	case "FATAL":
+		return logger.FATAL
+	default:
+		return logger.INFO // default to INFO if invalid level provided
+	}
+}
+
+// find an available UDP port in the range [minPort, maxPort] and also the next port for the wgtester
+func FindAvailableUDPPort(minPort, maxPort uint16) (uint16, error) {
+	if maxPort < minPort {
+		return 0, fmt.Errorf("invalid port range: min=%d, max=%d", minPort, maxPort)
+	}
+
+	// We need to check port+1 as well, so adjust the max port to avoid going out of range
+	adjustedMaxPort := maxPort - 1
+	if adjustedMaxPort < minPort {
+		return 0, fmt.Errorf("insufficient port range to find consecutive ports: min=%d, max=%d", minPort, maxPort)
+	}
+
+	// Create a slice of all ports in the range (excluding the last one)
+	portRange := make([]uint16, adjustedMaxPort-minPort+1)
+	for i := range portRange {
+		portRange[i] = minPort + uint16(i)
+	}
+
+	// Fisher-Yates shuffle to randomize the port order
+	for i := len(portRange) - 1; i > 0; i-- {
+		j := mathrand.IntN(i + 1)
+		portRange[i], portRange[j] = portRange[j], portRange[i]
+	}
+
+	// Try each port in the randomized order
+	for _, port := range portRange {
+		// Check if port is available
+		addr1 := &net.UDPAddr{
+			IP:   net.ParseIP("127.0.0.1"),
+			Port: int(port),
+		}
+		conn1, err1 := net.ListenUDP("udp", addr1)
+		if err1 != nil {
+			continue // Port is in use or there was an error, try next port
+		}
+
+		conn1.Close()
+		return port, nil
+	}
+
+	return 0, fmt.Errorf("no available consecutive UDP ports found in range %d-%d", minPort, maxPort)
+}
+
+func FixKey(key string) string {
+	// Remove any whitespace
+	key = strings.TrimSpace(key)
+
+	// Decode from base64
+	decoded, err := base64.StdEncoding.DecodeString(key)
+	if err != nil {
+		logger.Fatal("Error decoding base64: %v", err)
+	}
+
+	// Convert to hex
+	return hex.EncodeToString(decoded)
+}
+
+// this is the opposite of FixKey
+func UnfixKey(hexKey string) string {
+	// Decode from hex
+	decoded, err := hex.DecodeString(hexKey)
+	if err != nil {
+		logger.Fatal("Error decoding hex: %v", err)
+	}
+
+	// Convert to base64
+	return base64.StdEncoding.EncodeToString(decoded)
+}
+
+func MapToWireGuardLogLevel(level logger.LogLevel) int {
+	switch level {
+	case logger.DEBUG:
+		return device.LogLevelVerbose
+	// case logger.INFO:
+	// return device.LogLevel
+	case logger.WARN:
+		return device.LogLevelError
+	case logger.ERROR, logger.FATAL:
+		return device.LogLevelSilent
+	default:
+		return device.LogLevelSilent
+	}
+}
+
+// GetProtocol returns protocol number from IPv4 packet (fast path)
+func GetProtocol(packet []byte) (uint8, bool) {
+	if len(packet) < 20 {
+		return 0, false
+	}
+	version := packet[0] >> 4
+	if version == 4 {
+		return packet[9], true
+	} else if version == 6 {
+		if len(packet) < 40 {
+			return 0, false
+		}
+		return packet[6], true
+	}
+	return 0, false
+}
+
+// GetDestPort returns destination port from TCP/UDP packet (fast path)
+func GetDestPort(packet []byte) (uint16, bool) {
+	if len(packet) < 20 {
+		return 0, false
+	}
+
+	version := packet[0] >> 4
+	var headerLen int
+
+	if version == 4 {
+		ihl := packet[0] & 0x0F
+		headerLen = int(ihl) * 4
+		if len(packet) < headerLen+4 {
+			return 0, false
+		}
+	} else if version == 6 {
+		headerLen = 40
+		if len(packet) < headerLen+4 {
+			return 0, false
+		}
+	} else {
+		return 0, false
+	}
+
+	// Destination port is at bytes 2-3 of TCP/UDP header
+	port := binary.BigEndian.Uint16(packet[headerLen+2 : headerLen+4])
+	return port, true
+}

websocket/client.go

@@ -7,6 +7,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"net"
 	"net/http"
 	"net/url"
 	"os"
@@ -18,6 +19,11 @@ import (
 
 	"github.com/fosrl/newt/logger"
 	"github.com/gorilla/websocket"
+
+	"context"
+
+	"github.com/fosrl/newt/internal/telemetry"
+	"go.opentelemetry.io/otel"
 )
 
 type Client struct {
@@ -37,6 +43,8 @@ type Client struct {
 	writeMux          sync.Mutex
 	clientType        string // Type of client (e.g., "newt", "olm")
 	tlsConfig         TLSConfig
+	metricsCtxMu      sync.RWMutex
+	metricsCtx        context.Context
 	configNeedsSave   bool // Flag to track if config needs to be saved
 }
 
@@ -81,6 +89,26 @@ func (c *Client) OnTokenUpdate(callback func(token string)) {
 	c.onTokenUpdate = callback
 }
 
+func (c *Client) metricsContext() context.Context {
+	c.metricsCtxMu.RLock()
+	defer c.metricsCtxMu.RUnlock()
+	if c.metricsCtx != nil {
+		return c.metricsCtx
+	}
+	return context.Background()
+}
+
+func (c *Client) setMetricsContext(ctx context.Context) {
+	c.metricsCtxMu.Lock()
+	c.metricsCtx = ctx
+	c.metricsCtxMu.Unlock()
+}
+
+// MetricsContext exposes the context used for telemetry emission when a connection is active.
+func (c *Client) MetricsContext() context.Context {
+	return c.metricsContext()
+}
+
 // NewClient creates a new websocket client
 func NewClient(clientType string, ID, secret string, endpoint string, pingInterval time.Duration, pingTimeout time.Duration, opts ...ClientOption) (*Client, error) {
 	config := &Config{
@@ -140,6 +168,7 @@ func (c *Client) Close() error {
 
 	// Set connection status to false
 	c.setConnected(false)
+	telemetry.SetWSConnectionState(false)
 
 	// Close the WebSocket connection gracefully
 	if c.conn != nil {
@@ -170,7 +199,31 @@ func (c *Client) SendMessage(messageType string, data interface{}) error {
 
 	c.writeMux.Lock()
 	defer c.writeMux.Unlock()
-	return c.conn.WriteJSON(msg)
+	if err := c.conn.WriteJSON(msg); err != nil {
+		return err
+	}
+	telemetry.IncWSMessage(c.metricsContext(), "out", "text")
+	return nil
+}
+
+// SendMessage sends a message through the WebSocket connection
+func (c *Client) SendMessageNoLog(messageType string, data interface{}) error {
+	if c.conn == nil {
+		return fmt.Errorf("not connected")
+	}
+
+	msg := WSMessage{
+		Type: messageType,
+		Data: data,
+	}
+
+	c.writeMux.Lock()
+	defer c.writeMux.Unlock()
+	if err := c.conn.WriteJSON(msg); err != nil {
+		return err
+	}
+	telemetry.IncWSMessage(c.metricsContext(), "out", "text")
+	return nil
 }
 
 func (c *Client) SendMessageInterval(messageType string, data interface{}, interval time.Duration) (stop func()) {
@@ -265,8 +318,12 @@ func (c *Client) getToken() (string, error) {
 		return "", fmt.Errorf("failed to marshal token request data: %w", err)
 	}
 
+	ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
+	defer cancel()
+
 	// Create a new request
-	req, err := http.NewRequest(
+	req, err := http.NewRequestWithContext(
+		ctx,
 		"POST",
 		baseEndpoint+"/api/v1/auth/"+c.clientType+"/get-token",
 		bytes.NewBuffer(jsonData),
@@ -288,6 +345,8 @@ func (c *Client) getToken() (string, error) {
 	}
 	resp, err := client.Do(req)
 	if err != nil {
+		telemetry.IncConnAttempt(ctx, "auth", "failure")
+		telemetry.IncConnError(ctx, "auth", classifyConnError(err))
 		return "", fmt.Errorf("failed to request new token: %w", err)
 	}
 	defer resp.Body.Close()
@@ -295,6 +354,16 @@ func (c *Client) getToken() (string, error) {
 	if resp.StatusCode != http.StatusOK {
 		body, _ := io.ReadAll(resp.Body)
 		logger.Error("Failed to get token with status code: %d, body: %s", resp.StatusCode, string(body))
+		telemetry.IncConnAttempt(ctx, "auth", "failure")
+		etype := "io_error"
+		if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+			etype = "auth_failed"
+		}
+		telemetry.IncConnError(ctx, "auth", etype)
+		// Reconnect reason mapping for auth failures
+		if resp.StatusCode == http.StatusUnauthorized || resp.StatusCode == http.StatusForbidden {
+			telemetry.IncReconnect(ctx, c.config.ID, "client", telemetry.ReasonAuthError)
+		}
 		return "", fmt.Errorf("failed to get token with status code: %d, body: %s", resp.StatusCode, string(body))
 	}
 
@@ -313,10 +382,55 @@ func (c *Client) getToken() (string, error) {
 	}
 
 	logger.Debug("Received token: %s", tokenResp.Data.Token)
+	telemetry.IncConnAttempt(ctx, "auth", "success")
 
 	return tokenResp.Data.Token, nil
 }
 
+// classifyConnError maps to fixed, low-cardinality error_type values.
+// Allowed enum: dial_timeout, tls_handshake, auth_failed, io_error
+func classifyConnError(err error) string {
+	if err == nil {
+		return ""
+	}
+	msg := strings.ToLower(err.Error())
+	switch {
+	case strings.Contains(msg, "tls") || strings.Contains(msg, "certificate"):
+		return "tls_handshake"
+	case strings.Contains(msg, "timeout") || strings.Contains(msg, "i/o timeout") || strings.Contains(msg, "deadline exceeded"):
+		return "dial_timeout"
+	case strings.Contains(msg, "unauthorized") || strings.Contains(msg, "forbidden"):
+		return "auth_failed"
+	default:
+		// Group remaining network/socket errors as io_error to avoid label explosion
+		return "io_error"
+	}
+}
+
+func classifyWSDisconnect(err error) (result, reason string) {
+	if err == nil {
+		return "success", "normal"
+	}
+	if websocket.IsCloseError(err, websocket.CloseNormalClosure) {
+		return "success", "normal"
+	}
+	if ne, ok := err.(net.Error); ok && ne.Timeout() {
+		return "error", "timeout"
+	}
+	if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure) {
+		return "error", "unexpected_close"
+	}
+	msg := strings.ToLower(err.Error())
+	switch {
+	case strings.Contains(msg, "eof"):
+		return "error", "eof"
+	case strings.Contains(msg, "reset"):
+		return "error", "connection_reset"
+	default:
+		return "error", "read_error"
+	}
+}
+
 func (c *Client) connectWithRetry() {
 	for {
 		select {
@@ -335,9 +449,13 @@ func (c *Client) connectWithRetry() {
 }
 
 func (c *Client) establishConnection() error {
+	ctx := context.Background()
+
 	// Get token for authentication
 	token, err := c.getToken()
 	if err != nil {
+		telemetry.IncConnAttempt(ctx, "websocket", "failure")
+		telemetry.IncConnError(ctx, "websocket", classifyConnError(err))
 		return fmt.Errorf("failed to get token: %w", err)
 	}
 
@@ -370,7 +488,12 @@ func (c *Client) establishConnection() error {
 	q.Set("clientType", c.clientType)
 	u.RawQuery = q.Encode()
 
-	// Connect to WebSocket
+	// Connect to WebSocket (optional span)
+	tr := otel.Tracer("newt")
+	ctx, span := tr.Start(ctx, "ws.connect")
+	defer span.End()
+
+	start := time.Now()
 	dialer := websocket.DefaultDialer
 
 	// Use new TLS configuration method
@@ -392,18 +515,42 @@ func (c *Client) establishConnection() error {
 		logger.Debug("WebSocket TLS certificate verification disabled via SKIP_TLS_VERIFY environment variable")
 	}
 
-	conn, _, err := dialer.Dial(u.String(), nil)
+	conn, _, err := dialer.DialContext(ctx, u.String(), nil)
+	lat := time.Since(start).Seconds()
 	if err != nil {
+		telemetry.IncConnAttempt(ctx, "websocket", "failure")
+		etype := classifyConnError(err)
+		telemetry.IncConnError(ctx, "websocket", etype)
+		telemetry.ObserveWSConnectLatency(ctx, lat, "failure", etype)
+		// Map handshake-related errors to reconnect reasons where appropriate
+		if etype == "tls_handshake" {
+			telemetry.IncReconnect(ctx, c.config.ID, "client", telemetry.ReasonHandshakeError)
+		} else if etype == "dial_timeout" {
+			telemetry.IncReconnect(ctx, c.config.ID, "client", telemetry.ReasonTimeout)
+		} else {
+			telemetry.IncReconnect(ctx, c.config.ID, "client", telemetry.ReasonError)
+		}
+		telemetry.IncWSReconnect(ctx, etype)
 		return fmt.Errorf("failed to connect to WebSocket: %w", err)
 	}
 
+	telemetry.IncConnAttempt(ctx, "websocket", "success")
+	telemetry.ObserveWSConnectLatency(ctx, lat, "success", "")
 	c.conn = conn
 	c.setConnected(true)
+	telemetry.SetWSConnectionState(true)
+	c.setMetricsContext(ctx)
+	sessionStart := time.Now()
+	// Wire up pong handler for metrics
+	c.conn.SetPongHandler(func(appData string) error {
+		telemetry.IncWSMessage(c.metricsContext(), "in", "pong")
+		return nil
+	})
 
 	// Start the ping monitor
 	go c.pingMonitor()
 	// Start the read pump with disconnect detection
-	go c.readPumpWithDisconnectDetection()
+	go c.readPumpWithDisconnectDetection(sessionStart)
 
 	if c.onConnect != nil {
 		err := c.saveConfig()
@@ -496,6 +643,9 @@ func (c *Client) pingMonitor() {
 			}
 			c.writeMux.Lock()
 			err := c.conn.WriteControl(websocket.PingMessage, []byte{}, time.Now().Add(c.pingTimeout))
+			if err == nil {
+				telemetry.IncWSMessage(c.metricsContext(), "out", "ping")
+			}
 			c.writeMux.Unlock()
 			if err != nil {
 				// Check if we're shutting down before logging error and reconnecting
@@ -505,6 +655,8 @@ func (c *Client) pingMonitor() {
 					return
 				default:
 					logger.Error("Ping failed: %v", err)
+					telemetry.IncWSKeepaliveFailure(c.metricsContext(), "ping_write")
+					telemetry.IncWSReconnect(c.metricsContext(), "ping_write")
 					c.reconnect()
 					return
 				}
@@ -514,17 +666,26 @@ func (c *Client) pingMonitor() {
 }
 
 // readPumpWithDisconnectDetection reads messages and triggers reconnect on error
-func (c *Client) readPumpWithDisconnectDetection() {
+func (c *Client) readPumpWithDisconnectDetection(started time.Time) {
+	ctx := c.metricsContext()
+	disconnectReason := "shutdown"
+	disconnectResult := "success"
+
 	defer func() {
 		if c.conn != nil {
 			c.conn.Close()
 		}
+		if !started.IsZero() {
+			telemetry.ObserveWSSessionDuration(ctx, time.Since(started).Seconds(), disconnectResult)
+		}
+		telemetry.IncWSDisconnect(ctx, disconnectReason, disconnectResult)
 		// Only attempt reconnect if we're not shutting down
 		select {
 		case <-c.done:
 			// Shutting down, don't reconnect
 			return
 		default:
+			telemetry.IncWSReconnect(ctx, disconnectReason)
 			c.reconnect()
 		}
 	}()
@@ -532,23 +693,33 @@ func (c *Client) readPumpWithDisconnectDetection() {
 	for {
 		select {
 		case <-c.done:
+			disconnectReason = "shutdown"
+			disconnectResult = "success"
 			return
 		default:
 			var msg WSMessage
 			err := c.conn.ReadJSON(&msg)
+			if err == nil {
+				telemetry.IncWSMessage(c.metricsContext(), "in", "text")
+			}
 			if err != nil {
 				// Check if we're shutting down before logging error
 				select {
 				case <-c.done:
 					// Expected during shutdown, don't log as error
 					logger.Debug("WebSocket connection closed during shutdown")
+					disconnectReason = "shutdown"
+					disconnectResult = "success"
 					return
 				default:
 					// Unexpected error during normal operation
-					if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure, websocket.CloseNormalClosure) {
-						logger.Error("WebSocket read error: %v", err)
-					} else {
-						logger.Debug("WebSocket connection closed: %v", err)
+					disconnectResult, disconnectReason = classifyWSDisconnect(err)
+					if disconnectResult == "error" {
+						if websocket.IsUnexpectedCloseError(err, websocket.CloseGoingAway, websocket.CloseAbnormalClosure, websocket.CloseNormalClosure) {
+							logger.Error("WebSocket read error: %v", err)
+						} else {
+							logger.Debug("WebSocket connection closed: %v", err)
+						}
 					}
 					return // triggers reconnect via defer
 				}
@@ -565,6 +736,7 @@ func (c *Client) readPumpWithDisconnectDetection() {
 
 func (c *Client) reconnect() {
 	c.setConnected(false)
+	telemetry.SetWSConnectionState(false)
 	if c.conn != nil {
 		c.conn.Close()
 		c.conn = nil

wg/wg.go

@@ -1,999 +0,0 @@
-//go:build linux
-
-package wg
-
-import (
-	"encoding/json"
-	"errors"
-	"fmt"
-	"net"
-	"os"
-	"strconv"
-	"strings"
-	"sync"
-	"time"
-
-	"github.com/fosrl/newt/logger"
-	"github.com/fosrl/newt/network"
-	"github.com/fosrl/newt/websocket"
-	"github.com/vishvananda/netlink"
-	"golang.org/x/crypto/chacha20poly1305"
-	"golang.org/x/crypto/curve25519"
-	"golang.org/x/exp/rand"
-	"golang.zx2c4.com/wireguard/conn"
-	"golang.zx2c4.com/wireguard/wgctrl"
-	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
-)
-
-type WgConfig struct {
-	IpAddress string `json:"ipAddress"`
-	Peers     []Peer `json:"peers"`
-}
-
-type Peer struct {
-	PublicKey  string   `json:"publicKey"`
-	AllowedIPs []string `json:"allowedIps"`
-	Endpoint   string   `json:"endpoint"`
-}
-
-type PeerBandwidth struct {
-	PublicKey string  `json:"publicKey"`
-	BytesIn   float64 `json:"bytesIn"`
-	BytesOut  float64 `json:"bytesOut"`
-}
-
-type PeerReading struct {
-	BytesReceived    int64
-	BytesTransmitted int64
-	LastChecked      time.Time
-}
-
-type WireGuardService struct {
-	interfaceName     string
-	mtu               int
-	client            *websocket.Client
-	wgClient          *wgctrl.Client
-	config            WgConfig
-	key               wgtypes.Key
-	keyFilePath       string
-	newtId            string
-	lastReadings      map[string]PeerReading
-	mu                sync.Mutex
-	Port              uint16
-	stopHolepunch     chan struct{}
-	host              string
-	serverPubKey      string
-	holePunchEndpoint string
-	token             string
-	stopGetConfig     func()
-	interfaceCreated  bool
-}
-
-// Add this type definition
-type fixedPortBind struct {
-	port uint16
-	conn.Bind
-}
-
-func (b *fixedPortBind) Open(port uint16) ([]conn.ReceiveFunc, uint16, error) {
-	// Ignore the requested port and use our fixed port
-	return b.Bind.Open(b.port)
-}
-
-func NewFixedPortBind(port uint16) conn.Bind {
-	return &fixedPortBind{
-		port: port,
-		Bind: conn.NewDefaultBind(),
-	}
-}
-
-// find an available UDP port in the range [minPort, maxPort] and also the next port for the wgtester
-func FindAvailableUDPPort(minPort, maxPort uint16) (uint16, error) {
-	if maxPort < minPort {
-		return 0, fmt.Errorf("invalid port range: min=%d, max=%d", minPort, maxPort)
-	}
-
-	// We need to check port+1 as well, so adjust the max port to avoid going out of range
-	adjustedMaxPort := maxPort - 1
-	if adjustedMaxPort < minPort {
-		return 0, fmt.Errorf("insufficient port range to find consecutive ports: min=%d, max=%d", minPort, maxPort)
-	}
-
-	// Create a slice of all ports in the range (excluding the last one)
-	portRange := make([]uint16, adjustedMaxPort-minPort+1)
-	for i := range portRange {
-		portRange[i] = minPort + uint16(i)
-	}
-
-	// Fisher-Yates shuffle to randomize the port order
-	rand.Seed(uint64(time.Now().UnixNano()))
-	for i := len(portRange) - 1; i > 0; i-- {
-		j := rand.Intn(i + 1)
-		portRange[i], portRange[j] = portRange[j], portRange[i]
-	}
-
-	// Try each port in the randomized order
-	for _, port := range portRange {
-		// Check if port is available
-		addr1 := &net.UDPAddr{
-			IP:   net.ParseIP("127.0.0.1"),
-			Port: int(port),
-		}
-		conn1, err1 := net.ListenUDP("udp", addr1)
-		if err1 != nil {
-			continue // Port is in use or there was an error, try next port
-		}
-
-		// Check if port+1 is also available
-		addr2 := &net.UDPAddr{
-			IP:   net.ParseIP("127.0.0.1"),
-			Port: int(port + 1),
-		}
-		conn2, err2 := net.ListenUDP("udp", addr2)
-		if err2 != nil {
-			// The next port is not available, so close the first connection and try again
-			conn1.Close()
-			continue
-		}
-
-		// Both ports are available, close connections and return the first port
-		conn1.Close()
-		conn2.Close()
-		return port, nil
-	}
-
-	return 0, fmt.Errorf("no available consecutive UDP ports found in range %d-%d", minPort, maxPort)
-}
-
-func NewWireGuardService(interfaceName string, mtu int, generateAndSaveKeyTo string, host string, newtId string, wsClient *websocket.Client) (*WireGuardService, error) {
-	wgClient, err := wgctrl.New()
-	if err != nil {
-		return nil, fmt.Errorf("failed to create WireGuard client: %v", err)
-	}
-
-	var key wgtypes.Key
-	var port uint16
-	// if generateAndSaveKeyTo is provided, generate a private key and save it to the file. if the file already exists, load the key from the file
-	key, err = wgtypes.GeneratePrivateKey()
-	if err != nil {
-		return nil, fmt.Errorf("failed to generate private key: %v", err)
-	}
-
-	// Load or generate private key
-	if generateAndSaveKeyTo != "" {
-		if _, err := os.Stat(generateAndSaveKeyTo); os.IsNotExist(err) {
-			keyData, err := os.ReadFile(generateAndSaveKeyTo)
-			if err != nil {
-				return nil, fmt.Errorf("failed to read private key: %v", err)
-			}
-			key, err = wgtypes.ParseKey(strings.TrimSpace(string(keyData)))
-			if err != nil {
-				return nil, fmt.Errorf("failed to parse private key: %v", err)
-			}
-		} else {
-			err = os.WriteFile(generateAndSaveKeyTo, []byte(key.String()), 0600)
-			if err != nil {
-				return nil, fmt.Errorf("failed to save private key: %v", err)
-			}
-		}
-	}
-
-	// Get the existing wireguard port
-	device, err := wgClient.Device(interfaceName)
-	if err == nil {
-		port = uint16(device.ListenPort)
-		// also set the private key to the existing key
-		key = device.PrivateKey
-		if port != 0 {
-			logger.Info("WireGuard interface %s already exists with port %d\n", interfaceName, port)
-		} else {
-			port, err = FindAvailableUDPPort(49152, 65535)
-			if err != nil {
-				fmt.Printf("Error finding available port: %v\n", err)
-				return nil, err
-			}
-		}
-	} else {
-		port, err = FindAvailableUDPPort(49152, 65535)
-		if err != nil {
-			fmt.Printf("Error finding available port: %v\n", err)
-			return nil, err
-		}
-	}
-
-	service := &WireGuardService{
-		interfaceName: interfaceName,
-		mtu:           mtu,
-		client:        wsClient,
-		wgClient:      wgClient,
-		key:           key,
-		Port:          port,
-		keyFilePath:   generateAndSaveKeyTo,
-		newtId:        newtId,
-		host:          host,
-		lastReadings:  make(map[string]PeerReading),
-		stopHolepunch: make(chan struct{}),
-	}
-
-	// Register websocket handlers
-	wsClient.RegisterHandler("newt/wg/receive-config", service.handleConfig)
-	wsClient.RegisterHandler("newt/wg/peer/add", service.handleAddPeer)
-	wsClient.RegisterHandler("newt/wg/peer/remove", service.handleRemovePeer)
-	wsClient.RegisterHandler("newt/wg/peer/update", service.handleUpdatePeer)
-
-	return service, nil
-}
-
-func (s *WireGuardService) Close(rm bool) {
-	if s.stopGetConfig != nil {
-		s.stopGetConfig()
-		s.stopGetConfig = nil
-	}
-
-	s.wgClient.Close()
-	// Remove the WireGuard interface
-	if rm {
-		if err := s.removeInterface(); err != nil {
-			logger.Error("Failed to remove WireGuard interface: %v", err)
-		}
-
-		// Remove the private key file
-		// if s.keyFilePath != "" {
-		// 	if err := os.Remove(s.keyFilePath); err != nil {
-		// 		logger.Error("Failed to remove private key file: %v", err)
-		// 	}
-		// }
-	}
-}
-
-func (s *WireGuardService) StartHolepunch(serverPubKey string, endpoint string) {
-	// if the device is already created dont start a new holepunch
-	if s.interfaceCreated {
-		return
-	}
-
-	s.serverPubKey = serverPubKey
-	s.holePunchEndpoint = endpoint
-
-	logger.Debug("Starting UDP hole punch to %s", s.holePunchEndpoint)
-
-	s.stopHolepunch = make(chan struct{})
-
-	// start the UDP holepunch
-	go s.keepSendingUDPHolePunch(s.holePunchEndpoint)
-}
-
-func (s *WireGuardService) SetToken(token string) {
-	s.token = token
-}
-
-func (s *WireGuardService) LoadRemoteConfig() error {
-	s.stopGetConfig = s.client.SendMessageInterval("newt/wg/get-config", map[string]interface{}{
-		"publicKey": s.key.PublicKey().String(),
-		"port":      s.Port,
-	}, 2*time.Second)
-
-	logger.Info("Requesting WireGuard configuration from remote server")
-	go s.periodicBandwidthCheck()
-
-	return nil
-}
-
-func (s *WireGuardService) handleConfig(msg websocket.WSMessage) {
-	var config WgConfig
-
-	logger.Debug("Received message: %v", msg)
-	logger.Info("Received WireGuard clients configuration from remote server")
-
-	jsonData, err := json.Marshal(msg.Data)
-	if err != nil {
-		logger.Info("Error marshaling data: %v", err)
-		return
-	}
-
-	if err := json.Unmarshal(jsonData, &config); err != nil {
-		logger.Info("Error unmarshaling target data: %v", err)
-		return
-	}
-	s.config = config
-
-	if s.stopGetConfig != nil {
-		s.stopGetConfig()
-		s.stopGetConfig = nil
-	}
-
-	// Ensure the WireGuard interface and peers are configured
-	if err := s.ensureWireguardInterface(config); err != nil {
-		logger.Error("Failed to ensure WireGuard interface: %v", err)
-	}
-
-	if err := s.ensureWireguardPeers(config.Peers); err != nil {
-		logger.Error("Failed to ensure WireGuard peers: %v", err)
-	}
-}
-
-func (s *WireGuardService) ensureWireguardInterface(wgconfig WgConfig) error {
-	// Check if the WireGuard interface exists
-	_, err := netlink.LinkByName(s.interfaceName)
-	if err != nil {
-		if _, ok := err.(netlink.LinkNotFoundError); ok {
-			// Interface doesn't exist, so create it
-			err = s.createWireGuardInterface()
-			if err != nil {
-				logger.Fatal("Failed to create WireGuard interface: %v", err)
-			}
-			s.interfaceCreated = true
-			logger.Info("Created WireGuard interface %s\n", s.interfaceName)
-		} else {
-			logger.Fatal("Error checking for WireGuard interface: %v", err)
-		}
-	} else {
-		logger.Info("WireGuard interface %s already exists\n", s.interfaceName)
-
-		// get the exising wireguard port
-		device, err := s.wgClient.Device(s.interfaceName)
-		if err != nil {
-			return fmt.Errorf("failed to get device: %v", err)
-		}
-
-		// get the existing port
-		s.Port = uint16(device.ListenPort)
-		logger.Info("WireGuard interface %s already exists with port %d\n", s.interfaceName, s.Port)
-
-		s.interfaceCreated = true
-		return nil
-	}
-
-	// stop the holepunch its a channel
-	if s.stopHolepunch != nil {
-		close(s.stopHolepunch)
-		s.stopHolepunch = nil
-	}
-
-	logger.Info("Assigning IP address %s to interface %s\n", wgconfig.IpAddress, s.interfaceName)
-	// Assign IP address to the interface
-	err = s.assignIPAddress(wgconfig.IpAddress)
-	if err != nil {
-		logger.Fatal("Failed to assign IP address: %v", err)
-	}
-
-	// Check if the interface already exists
-	_, err = s.wgClient.Device(s.interfaceName)
-	if err != nil {
-		if errors.Is(err, os.ErrNotExist) {
-			return fmt.Errorf("interface %s does not exist", s.interfaceName)
-		}
-		return fmt.Errorf("failed to get device: %v", err)
-	}
-
-	// Parse the private key
-	key, err := wgtypes.ParseKey(s.key.String())
-	if err != nil {
-		return fmt.Errorf("failed to parse private key: %v", err)
-	}
-
-	config := wgtypes.Config{
-		PrivateKey: &key,
-		ListenPort: new(int),
-	}
-
-	// Use the service's fixed port instead of the config port
-	*config.ListenPort = int(s.Port)
-
-	// Create and configure the WireGuard interface
-	err = s.wgClient.ConfigureDevice(s.interfaceName, config)
-	if err != nil {
-		return fmt.Errorf("failed to configure WireGuard device: %v", err)
-	}
-
-	// bring up the interface
-	link, err := netlink.LinkByName(s.interfaceName)
-	if err != nil {
-		return fmt.Errorf("failed to get interface: %v", err)
-	}
-
-	if err := netlink.LinkSetMTU(link, s.mtu); err != nil {
-		return fmt.Errorf("failed to set MTU: %v", err)
-	}
-
-	if err := netlink.LinkSetUp(link); err != nil {
-		return fmt.Errorf("failed to bring up interface: %v", err)
-	}
-
-	// if err := s.ensureMSSClamping(); err != nil {
-	// 	logger.Warn("Failed to ensure MSS clamping: %v", err)
-	// }
-
-	logger.Info("WireGuard interface %s created and configured", s.interfaceName)
-
-	return nil
-}
-
-func (s *WireGuardService) createWireGuardInterface() error {
-	wgLink := &netlink.GenericLink{
-		LinkAttrs: netlink.LinkAttrs{Name: s.interfaceName},
-		LinkType:  "wireguard",
-	}
-	return netlink.LinkAdd(wgLink)
-}
-
-func (s *WireGuardService) assignIPAddress(ipAddress string) error {
-	link, err := netlink.LinkByName(s.interfaceName)
-	if err != nil {
-		return fmt.Errorf("failed to get interface: %v", err)
-	}
-
-	addr, err := netlink.ParseAddr(ipAddress)
-	if err != nil {
-		return fmt.Errorf("failed to parse IP address: %v", err)
-	}
-
-	return netlink.AddrAdd(link, addr)
-}
-
-func (s *WireGuardService) ensureWireguardPeers(peers []Peer) error {
-	// get the current peers
-	device, err := s.wgClient.Device(s.interfaceName)
-	if err != nil {
-		return fmt.Errorf("failed to get device: %v", err)
-	}
-
-	// get the peer public keys
-	var currentPeers []string
-	for _, peer := range device.Peers {
-		currentPeers = append(currentPeers, peer.PublicKey.String())
-	}
-
-	// remove any peers that are not in the config
-	for _, peer := range currentPeers {
-		found := false
-		for _, configPeer := range peers {
-			if peer == configPeer.PublicKey {
-				found = true
-				break
-			}
-		}
-		if !found {
-			err := s.removePeer(peer)
-			if err != nil {
-				return fmt.Errorf("failed to remove peer: %v", err)
-			}
-		}
-	}
-
-	// add any peers that are in the config but not in the current peers
-	for _, configPeer := range peers {
-		found := false
-		for _, peer := range currentPeers {
-			if configPeer.PublicKey == peer {
-				found = true
-				break
-			}
-		}
-		if !found {
-			err := s.addPeer(configPeer)
-			if err != nil {
-				return fmt.Errorf("failed to add peer: %v", err)
-			}
-		}
-	}
-
-	return nil
-}
-
-func (s *WireGuardService) handleAddPeer(msg websocket.WSMessage) {
-	logger.Debug("Received message: %v", msg.Data)
-	var peer Peer
-
-	jsonData, err := json.Marshal(msg.Data)
-	if err != nil {
-		logger.Info("Error marshaling data: %v", err)
-	}
-
-	if err := json.Unmarshal(jsonData, &peer); err != nil {
-		logger.Info("Error unmarshaling target data: %v", err)
-	}
-
-	err = s.addPeer(peer)
-	if err != nil {
-		logger.Info("Error adding peer: %v", err)
-		return
-	}
-}
-
-func (s *WireGuardService) addPeer(peer Peer) error {
-	pubKey, err := wgtypes.ParseKey(peer.PublicKey)
-	if err != nil {
-		return fmt.Errorf("failed to parse public key: %v", err)
-	}
-
-	// parse allowed IPs into array of net.IPNet
-	var allowedIPs []net.IPNet
-	for _, ipStr := range peer.AllowedIPs {
-		_, ipNet, err := net.ParseCIDR(ipStr)
-		if err != nil {
-			return fmt.Errorf("failed to parse allowed IP: %v", err)
-		}
-		allowedIPs = append(allowedIPs, *ipNet)
-	}
-	// add keep alive using *time.Duration	 of 1 second
-	keepalive := time.Second
-
-	var peerConfig wgtypes.PeerConfig
-	if peer.Endpoint != "" {
-		endpoint, err := net.ResolveUDPAddr("udp", peer.Endpoint)
-		if err != nil {
-			return fmt.Errorf("failed to resolve endpoint address: %w", err)
-		}
-
-		peerConfig = wgtypes.PeerConfig{
-			PublicKey:                   pubKey,
-			AllowedIPs:                  allowedIPs,
-			PersistentKeepaliveInterval: &keepalive,
-			Endpoint:                    endpoint,
-		}
-	} else {
-		peerConfig = wgtypes.PeerConfig{
-			PublicKey:                   pubKey,
-			AllowedIPs:                  allowedIPs,
-			PersistentKeepaliveInterval: &keepalive,
-		}
-		logger.Info("Added peer with no endpoint!")
-	}
-
-	config := wgtypes.Config{
-		Peers: []wgtypes.PeerConfig{peerConfig},
-	}
-
-	if err := s.wgClient.ConfigureDevice(s.interfaceName, config); err != nil {
-		return fmt.Errorf("failed to add peer: %v", err)
-	}
-
-	logger.Info("Peer %s added successfully", peer.PublicKey)
-
-	return nil
-}
-
-func (s *WireGuardService) handleRemovePeer(msg websocket.WSMessage) {
-	logger.Debug("Received message: %v", msg.Data)
-	// parse the publicKey from the message which is json { "publicKey": "asdfasdfl;akjsdf" }
-	type RemoveRequest struct {
-		PublicKey string `json:"publicKey"`
-	}
-
-	jsonData, err := json.Marshal(msg.Data)
-	if err != nil {
-		logger.Info("Error marshaling data: %v", err)
-	}
-
-	var request RemoveRequest
-	if err := json.Unmarshal(jsonData, &request); err != nil {
-		logger.Info("Error unmarshaling data: %v", err)
-		return
-	}
-
-	if err := s.removePeer(request.PublicKey); err != nil {
-		logger.Info("Error removing peer: %v", err)
-		return
-	}
-}
-
-func (s *WireGuardService) removePeer(publicKey string) error {
-	pubKey, err := wgtypes.ParseKey(publicKey)
-	if err != nil {
-		return fmt.Errorf("failed to parse public key: %v", err)
-	}
-
-	peerConfig := wgtypes.PeerConfig{
-		PublicKey: pubKey,
-		Remove:    true,
-	}
-
-	config := wgtypes.Config{
-		Peers: []wgtypes.PeerConfig{peerConfig},
-	}
-
-	if err := s.wgClient.ConfigureDevice(s.interfaceName, config); err != nil {
-		return fmt.Errorf("failed to remove peer: %v", err)
-	}
-
-	logger.Info("Peer %s removed successfully", publicKey)
-
-	return nil
-}
-
-func (s *WireGuardService) handleUpdatePeer(msg websocket.WSMessage) {
-	logger.Debug("Received message: %v", msg.Data)
-	// Define a struct to match the incoming message structure with optional fields
-	type UpdatePeerRequest struct {
-		PublicKey  string   `json:"publicKey"`
-		AllowedIPs []string `json:"allowedIps,omitempty"`
-		Endpoint   string   `json:"endpoint,omitempty"`
-	}
-	jsonData, err := json.Marshal(msg.Data)
-	if err != nil {
-		logger.Info("Error marshaling data: %v", err)
-		return
-	}
-	var request UpdatePeerRequest
-	if err := json.Unmarshal(jsonData, &request); err != nil {
-		logger.Info("Error unmarshaling peer data: %v", err)
-		return
-	}
-	// First, get the current peer configuration to preserve any unmodified fields
-	device, err := s.wgClient.Device(s.interfaceName)
-	if err != nil {
-		logger.Info("Error getting WireGuard device: %v", err)
-		return
-	}
-	pubKey, err := wgtypes.ParseKey(request.PublicKey)
-	if err != nil {
-		logger.Info("Error parsing public key: %v", err)
-		return
-	}
-	// Find the existing peer configuration
-	var currentPeer *wgtypes.Peer
-	for _, p := range device.Peers {
-		if p.PublicKey == pubKey {
-			currentPeer = &p
-			break
-		}
-	}
-	if currentPeer == nil {
-		logger.Info("Peer %s not found, cannot update", request.PublicKey)
-		return
-	}
-	// Create the update peer config
-	peerConfig := wgtypes.PeerConfig{
-		PublicKey:  pubKey,
-		UpdateOnly: true,
-	}
-	// Keep the default persistent keepalive of 1 second
-	keepalive := time.Second
-	peerConfig.PersistentKeepaliveInterval = &keepalive
-
-	// Handle Endpoint field special case
-	// If Endpoint is included in the request but empty, we want to remove the endpoint
-	// If Endpoint is not included, we don't modify it
-	endpointSpecified := false
-	for key := range msg.Data.(map[string]interface{}) {
-		if key == "endpoint" {
-			endpointSpecified = true
-			break
-		}
-	}
-
-	// Only update AllowedIPs if provided in the request
-	if len(request.AllowedIPs) > 0 {
-		var allowedIPs []net.IPNet
-		for _, ipStr := range request.AllowedIPs {
-			_, ipNet, err := net.ParseCIDR(ipStr)
-			if err != nil {
-				logger.Info("Error parsing allowed IP %s: %v", ipStr, err)
-				return
-			}
-			allowedIPs = append(allowedIPs, *ipNet)
-		}
-		peerConfig.AllowedIPs = allowedIPs
-		peerConfig.ReplaceAllowedIPs = true
-		logger.Info("Updating AllowedIPs for peer %s", request.PublicKey)
-	} else if endpointSpecified && request.Endpoint == "" {
-		peerConfig.ReplaceAllowedIPs = false
-	}
-
-	if endpointSpecified {
-		if request.Endpoint != "" {
-			// Update to new endpoint
-			endpoint, err := net.ResolveUDPAddr("udp", request.Endpoint)
-			if err != nil {
-				logger.Info("Error resolving endpoint address %s: %v", request.Endpoint, err)
-				return
-			}
-			peerConfig.Endpoint = endpoint
-			logger.Info("Updating Endpoint for peer %s to %s", request.PublicKey, request.Endpoint)
-		} else {
-			// specify any address to listen for any incoming packets
-			peerConfig.Endpoint = &net.UDPAddr{
-				IP: net.IPv4(127, 0, 0, 1),
-			}
-			logger.Info("Removing Endpoint for peer %s", request.PublicKey)
-		}
-	}
-
-	// Apply the configuration update
-	config := wgtypes.Config{
-		Peers: []wgtypes.PeerConfig{peerConfig},
-	}
-	if err := s.wgClient.ConfigureDevice(s.interfaceName, config); err != nil {
-		logger.Info("Error updating peer configuration: %v", err)
-		return
-	}
-	logger.Info("Peer %s updated successfully", request.PublicKey)
-}
-
-func (s *WireGuardService) periodicBandwidthCheck() {
-	ticker := time.NewTicker(10 * time.Second)
-	defer ticker.Stop()
-
-	for range ticker.C {
-		if err := s.reportPeerBandwidth(); err != nil {
-			logger.Info("Failed to report peer bandwidth: %v", err)
-		}
-	}
-}
-
-func (s *WireGuardService) calculatePeerBandwidth() ([]PeerBandwidth, error) {
-	device, err := s.wgClient.Device(s.interfaceName)
-	if err != nil {
-		return nil, fmt.Errorf("failed to get device: %v", err)
-	}
-
-	peerBandwidths := []PeerBandwidth{}
-	now := time.Now()
-
-	s.mu.Lock()
-	defer s.mu.Unlock()
-
-	for _, peer := range device.Peers {
-		publicKey := peer.PublicKey.String()
-		currentReading := PeerReading{
-			BytesReceived:    peer.ReceiveBytes,
-			BytesTransmitted: peer.TransmitBytes,
-			LastChecked:      now,
-		}
-
-		var bytesInDiff, bytesOutDiff float64
-		lastReading, exists := s.lastReadings[publicKey]
-
-		if exists {
-			timeDiff := currentReading.LastChecked.Sub(lastReading.LastChecked).Seconds()
-			if timeDiff > 0 {
-				// Calculate bytes transferred since last reading
-				bytesInDiff = float64(currentReading.BytesReceived - lastReading.BytesReceived)
-				bytesOutDiff = float64(currentReading.BytesTransmitted - lastReading.BytesTransmitted)
-
-				// Handle counter wraparound (if the counter resets or overflows)
-				if bytesInDiff < 0 {
-					bytesInDiff = float64(currentReading.BytesReceived)
-				}
-				if bytesOutDiff < 0 {
-					bytesOutDiff = float64(currentReading.BytesTransmitted)
-				}
-
-				// Convert to MB
-				bytesInMB := bytesInDiff / (1024 * 1024)
-				bytesOutMB := bytesOutDiff / (1024 * 1024)
-
-				peerBandwidths = append(peerBandwidths, PeerBandwidth{
-					PublicKey: publicKey,
-					BytesIn:   bytesInMB,
-					BytesOut:  bytesOutMB,
-				})
-			} else {
-				// If readings are too close together or time hasn't passed, report 0
-				peerBandwidths = append(peerBandwidths, PeerBandwidth{
-					PublicKey: publicKey,
-					BytesIn:   0,
-					BytesOut:  0,
-				})
-			}
-		} else {
-			// For first reading of a peer, report 0 to establish baseline
-			peerBandwidths = append(peerBandwidths, PeerBandwidth{
-				PublicKey: publicKey,
-				BytesIn:   0,
-				BytesOut:  0,
-			})
-		}
-
-		// Update the last reading
-		s.lastReadings[publicKey] = currentReading
-	}
-
-	// Clean up old peers
-	for publicKey := range s.lastReadings {
-		found := false
-		for _, peer := range device.Peers {
-			if peer.PublicKey.String() == publicKey {
-				found = true
-				break
-			}
-		}
-		if !found {
-			delete(s.lastReadings, publicKey)
-		}
-	}
-
-	return peerBandwidths, nil
-}
-
-func (s *WireGuardService) reportPeerBandwidth() error {
-	bandwidths, err := s.calculatePeerBandwidth()
-	if err != nil {
-		return fmt.Errorf("failed to calculate peer bandwidth: %v", err)
-	}
-
-	err = s.client.SendMessage("newt/receive-bandwidth", map[string]interface{}{
-		"bandwidthData": bandwidths,
-	})
-	if err != nil {
-		return fmt.Errorf("failed to send bandwidth data: %v", err)
-	}
-
-	return nil
-}
-
-func (s *WireGuardService) sendUDPHolePunch(serverAddr string) error {
-
-	if s.serverPubKey == "" || s.token == "" {
-		logger.Debug("Server public key or token not set, skipping UDP hole punch")
-		return nil
-	}
-
-	// Parse server address
-	serverSplit := strings.Split(serverAddr, ":")
-	if len(serverSplit) < 2 {
-		return fmt.Errorf("invalid server address format, expected hostname:port")
-	}
-
-	serverHostname := serverSplit[0]
-	serverPort, err := strconv.ParseUint(serverSplit[1], 10, 16)
-	if err != nil {
-		return fmt.Errorf("failed to parse server port: %v", err)
-	}
-
-	// Resolve server hostname to IP
-	serverIPAddr := network.HostToAddr(serverHostname)
-	if serverIPAddr == nil {
-		return fmt.Errorf("failed to resolve server hostname")
-	}
-
-	// Get client IP based on route to server
-	clientIP := network.GetClientIP(serverIPAddr.IP)
-
-	// Create server and client configs
-	server := &network.Server{
-		Hostname: serverHostname,
-		Addr:     serverIPAddr,
-		Port:     uint16(serverPort),
-	}
-
-	client := &network.PeerNet{
-		IP:     clientIP,
-		Port:   s.Port,
-		NewtID: s.newtId,
-	}
-
-	// Setup raw connection with BPF filtering
-	rawConn := network.SetupRawConn(server, client)
-	defer rawConn.Close()
-
-	// Create JSON payload
-	payload := struct {
-		NewtID string `json:"newtId"`
-		Token  string `json:"token"`
-	}{
-		NewtID: s.newtId,
-		Token:  s.token,
-	}
-
-	// Convert payload to JSON
-	payloadBytes, err := json.Marshal(payload)
-	if err != nil {
-		return fmt.Errorf("failed to marshal payload: %v", err)
-	}
-
-	// Encrypt the payload using the server's WireGuard public key
-	encryptedPayload, err := s.encryptPayload(payloadBytes)
-	if err != nil {
-		return fmt.Errorf("failed to encrypt payload: %v", err)
-	}
-
-	// Send the encrypted packet using the raw connection
-	err = network.SendDataPacket(encryptedPayload, rawConn, server, client)
-	if err != nil {
-		return fmt.Errorf("failed to send UDP packet: %v", err)
-	}
-
-	return nil
-}
-
-func (s *WireGuardService) encryptPayload(payload []byte) (interface{}, error) {
-	// Generate an ephemeral keypair for this message
-	ephemeralPrivateKey, err := wgtypes.GeneratePrivateKey()
-	if err != nil {
-		return nil, fmt.Errorf("failed to generate ephemeral private key: %v", err)
-	}
-	ephemeralPublicKey := ephemeralPrivateKey.PublicKey()
-
-	// Parse the server's public key
-	serverPubKey, err := wgtypes.ParseKey(s.serverPubKey)
-	if err != nil {
-		return nil, fmt.Errorf("failed to parse server public key: %v", err)
-	}
-
-	// Use X25519 for key exchange (replacing deprecated ScalarMult)
-	var ephPrivKeyFixed [32]byte
-	copy(ephPrivKeyFixed[:], ephemeralPrivateKey[:])
-
-	// Perform X25519 key exchange
-	sharedSecret, err := curve25519.X25519(ephPrivKeyFixed[:], serverPubKey[:])
-	if err != nil {
-		return nil, fmt.Errorf("failed to perform X25519 key exchange: %v", err)
-	}
-
-	// Create an AEAD cipher using the shared secret
-	aead, err := chacha20poly1305.New(sharedSecret)
-	if err != nil {
-		return nil, fmt.Errorf("failed to create AEAD cipher: %v", err)
-	}
-
-	// Generate a random nonce
-	nonce := make([]byte, aead.NonceSize())
-	if _, err := rand.Read(nonce); err != nil {
-		return nil, fmt.Errorf("failed to generate nonce: %v", err)
-	}
-
-	// Encrypt the payload
-	ciphertext := aead.Seal(nil, nonce, payload, nil)
-
-	// Prepare the final encrypted message
-	encryptedMsg := struct {
-		EphemeralPublicKey string `json:"ephemeralPublicKey"`
-		Nonce              []byte `json:"nonce"`
-		Ciphertext         []byte `json:"ciphertext"`
-	}{
-		EphemeralPublicKey: ephemeralPublicKey.String(),
-		Nonce:              nonce,
-		Ciphertext:         ciphertext,
-	}
-
-	return encryptedMsg, nil
-}
-
-func (s *WireGuardService) keepSendingUDPHolePunch(host string) {
-	logger.Info("Starting UDP hole punch routine to %s:21820", host)
-
-	// send initial hole punch
-	if err := s.sendUDPHolePunch(host + ":21820"); err != nil {
-		logger.Debug("Failed to send initial UDP hole punch: %v", err)
-	}
-
-	ticker := time.NewTicker(3 * time.Second)
-	defer ticker.Stop()
-
-	timeout := time.NewTimer(15 * time.Second)
-	defer timeout.Stop()
-
-	for {
-		select {
-		case <-s.stopHolepunch:
-			logger.Info("Stopping UDP holepunch")
-			return
-		case <-timeout.C:
-			logger.Info("UDP holepunch routine timed out after 15 seconds")
-			return
-		case <-ticker.C:
-			if err := s.sendUDPHolePunch(host + ":21820"); err != nil {
-				logger.Debug("Failed to send UDP hole punch: %v", err)
-			}
-		}
-	}
-}
-
-func (s *WireGuardService) removeInterface() error {
-	// Remove the WireGuard interface
-	link, err := netlink.LinkByName(s.interfaceName)
-	if err != nil {
-		return fmt.Errorf("failed to get interface: %v", err)
-	}
-
-	err = netlink.LinkDel(link)
-	if err != nil {
-		return fmt.Errorf("failed to delete interface: %v", err)
-	}
-
-	logger.Info("WireGuard interface %s removed successfully", s.interfaceName)
-
-	return nil
-}

wgtester/wgtester.go

@@ -3,12 +3,13 @@ package wgtester
 import (
 	"encoding/binary"
 	"fmt"
+	"io"
 	"net"
 	"sync"
 	"time"
 
 	"github.com/fosrl/newt/logger"
-	"golang.zx2c4.com/wireguard/tun/netstack"
+	"github.com/fosrl/newt/netstack2"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
 )
 
@@ -39,7 +40,7 @@ type Server struct {
 	newtID       string
 	outputPrefix string
 	useNetstack  bool
-	tnet         interface{} // Will be *netstack.Net when using netstack
+	tnet         interface{} // Will be *netstack2.Net when using netstack
 }
 
 // NewServer creates a new connection test server using UDP
@@ -56,7 +57,7 @@ func NewServer(serverAddr string, serverPort uint16, newtID string) *Server {
 }
 
 // NewServerWithNetstack creates a new connection test server using WireGuard netstack
-func NewServerWithNetstack(serverAddr string, serverPort uint16, newtID string, tnet *netstack.Net) *Server {
+func NewServerWithNetstack(serverAddr string, serverPort uint16, newtID string, tnet *netstack2.Net) *Server {
 	return &Server{
 		serverAddr:   serverAddr,
 		serverPort:   serverPort + 1, // use the next port for the server
@@ -82,7 +83,7 @@ func (s *Server) Start() error {
 
 	if s.useNetstack && s.tnet != nil {
 		// Use WireGuard netstack
-		tnet := s.tnet.(*netstack.Net)
+		tnet := s.tnet.(*netstack2.Net)
 		udpAddr := &net.UDPAddr{Port: int(s.serverPort)}
 		netstackConn, err := tnet.ListenUDP(udpAddr)
 		if err != nil {
@@ -126,11 +127,11 @@ func (s *Server) Stop() {
 		s.conn.Close()
 	}
 	s.isRunning = false
-	logger.Info(s.outputPrefix + "Server stopped")
+	logger.Info("%sServer stopped", s.outputPrefix)
 }
 
 // RestartWithNetstack stops the current server and restarts it with netstack
-func (s *Server) RestartWithNetstack(tnet *netstack.Net) error {
+func (s *Server) RestartWithNetstack(tnet *netstack2.Net) error {
 	s.Stop()
 
 	// Update configuration to use netstack
@@ -161,7 +162,7 @@ func (s *Server) handleConnections() {
 			// Set read deadline to avoid blocking forever
 			err := s.conn.SetReadDeadline(time.Now().Add(1 * time.Second))
 			if err != nil {
-				logger.Error(s.outputPrefix+"Error setting read deadline: %v", err)
+				logger.Error("%sError setting read deadline: %v", s.outputPrefix, err)
 				continue
 			}
 
@@ -187,7 +188,11 @@ func (s *Server) handleConnections() {
 				case <-s.shutdownCh:
 					return // Don't log error if we're shutting down
 				default:
-					logger.Error(s.outputPrefix+"Error reading from UDP: %v", err)
+					// Don't log EOF errors during shutdown - these are expected when connection is closed
+					if err == io.EOF {
+						return
+					}
+					logger.Error("%sError reading from UDP: %v", s.outputPrefix, err)
 				}
 				continue
 			}
@@ -219,7 +224,7 @@ func (s *Server) handleConnections() {
 			copy(responsePacket[5:13], buffer[5:13])
 
 			// Log response being sent for debugging
-			logger.Debug(s.outputPrefix+"Sending response to %s", addr.String())
+			// logger.Debug("%sSending response to %s", s.outputPrefix, addr.String())
 
 			// Send the response packet - handle both regular UDP and netstack UDP
 			if s.useNetstack {
@@ -233,9 +238,9 @@ func (s *Server) handleConnections() {
 			}
 
 			if err != nil {
-				logger.Error(s.outputPrefix+"Error sending response: %v", err)
+				logger.Error("%sError sending response: %v", s.outputPrefix, err)
 			} else {
-				logger.Debug(s.outputPrefix + "Response sent successfully")
+				// logger.Debug("%sResponse sent successfully", s.outputPrefix)
 			}
 		}
 	}