Merge branch 'dev'

1.8.0-rc.0

.github/workflows/cicd.yml

@@ -587,28 +587,28 @@ jobs:
       #     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: Build binaries
+        env:
+          CGO_ENABLED: "0"
+          GOFLAGS: "-trimpath"
+        run: |
+          set -euo pipefail
+          TAG_VAR="${TAG}"
+          make -j 10 go-build-release tag=$TAG_VAR
+        shell: bash
 
-      # - name: Create GitHub Release
-      #   uses: softprops/action-gh-release@5be0e66d93ac7ed76da52eca8bb058f665c3a5fe # v2.4.2
-      #   with:
-      #     tag_name: ${{ env.TAG }}
-      #     generate_release_notes: true
-      #     prerelease: ${{ env.IS_RC == 'true' }}
-      #     files: |
-      #       bin/*
-      #     fail_on_unmatched_files: true
-      #     draft: true
-      #     body: |
-      #       ## Container Images
-      #       - GHCR: `${{ env.GHCR_REF }}`
-      #       - Docker Hub: `${{ env.DH_REF || 'N/A' }}`
-      #       **Digest:** `${{ steps.build.outputs.digest }}`
+      - name: Create GitHub Release
+        uses: softprops/action-gh-release@5be0e66d93ac7ed76da52eca8bb058f665c3a5fe # v2.4.2
+        with:
+          tag_name: ${{ env.TAG }}
+          generate_release_notes: true
+          prerelease: ${{ env.IS_RC == 'true' }}
+          files: |
+            bin/*
+          fail_on_unmatched_files: true
+          draft: true
+          body: |
+            ## Container Images
+            - GHCR: `${{ env.GHCR_REF }}`
+            - Docker Hub: `${{ env.DH_REF || 'N/A' }}`
+            **Digest:** `${{ steps.build.outputs.digest }}`

.github/workflows/test.yml

@@ -10,22 +10,30 @@ on:
       - dev
 
 jobs:
-  test:
-    runs-on: amd64-runner
-
+  build:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        target:
+          - local
+          - docker-build
+          - go-build-release-darwin-amd64
+          - go-build-release-darwin-arm64
+          - go-build-release-freebsd-amd64
+          - go-build-release-freebsd-arm64
+          - go-build-release-linux-amd64
+          - go-build-release-linux-arm32-v6
+          - go-build-release-linux-arm32-v7
+          - go-build-release-linux-riscv64
+          - go-build-release-windows-amd64
     steps:
-      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+      - name: Checkout repository
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
 
       - name: Set up Go
         uses: actions/setup-go@4dc6199c7b1a012772edbd06daecab0f50c9053c # v6.1.0
         with:
           go-version: 1.25
 
-      - name: Build go
-        run: go build
-
-      - name: Build Docker image
-        run: make docker-build-release
-
-      - name: Build binaries
-        run: make go-build-release
+      - name: Build targets via `make`
+        run: make ${{ matrix.target }}

Dockerfile

@@ -20,7 +20,7 @@ RUN CGO_ENABLED=0 GOOS=linux go build -ldflags="-s -w" -o /newt
 
 FROM alpine:3.23 AS runner
 
-RUN apk --no-cache add ca-certificates tzdata
+RUN apk --no-cache add ca-certificates tzdata iputils
 
 COPY --from=builder /newt /usr/local/bin/
 COPY entrypoint.sh /

Makefile

@@ -1,25 +1,70 @@
+.PHONY: all local docker-build docker-build-release
 
 all: local
 
+local:
+	CGO_ENABLED=0 go build -o ./bin/newt
+
+docker-build:
+	docker build -t fosrl/newt:latest .
+
 docker-build-release:
 	@if [ -z "$(tag)" ]; then \
 		echo "Error: tag is required. Usage: make docker-build-release tag=<tag>"; \
 		exit 1; \
 	fi
-	docker buildx build --platform linux/arm/v7,linux/arm64,linux/amd64 -t fosrl/newt:latest -f Dockerfile --push .
-	docker buildx build --platform linux/arm/v7,linux/arm64,linux/amd64 -t fosrl/newt:$(tag) -f Dockerfile --push .
+	docker buildx build . \
+		--platform linux/arm/v7,linux/arm64,linux/amd64 \
+		-t fosrl/newt:latest \
+		-t fosrl/newt:$(tag) \
+		-f Dockerfile \
+		--push
 
-local: 
-	CGO_ENABLED=0 go build -o ./bin/newt
+.PHONY: go-build-release \
+        go-build-release-linux-arm64 go-build-release-linux-arm32-v7 \
+        go-build-release-linux-arm32-v6 go-build-release-linux-amd64 \
+        go-build-release-linux-riscv64 go-build-release-darwin-arm64 \
+        go-build-release-darwin-amd64 go-build-release-windows-amd64 \
+        go-build-release-freebsd-amd64 go-build-release-freebsd-arm64
 
-go-build-release:
+go-build-release: \
+    go-build-release-linux-arm64 \
+    go-build-release-linux-arm32-v7 \
+    go-build-release-linux-arm32-v6 \
+    go-build-release-linux-amd64 \
+    go-build-release-linux-riscv64 \
+    go-build-release-darwin-arm64 \
+    go-build-release-darwin-amd64 \
+    go-build-release-windows-amd64 \
+    go-build-release-freebsd-amd64 \
+    go-build-release-freebsd-arm64
+
+go-build-release-linux-arm64:
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm64 go build -o bin/newt_linux_arm64
+
+go-build-release-linux-arm32-v7:
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=7 go build -o bin/newt_linux_arm32
+
+go-build-release-linux-arm32-v6:
 	CGO_ENABLED=0 GOOS=linux GOARCH=arm GOARM=6 go build -o bin/newt_linux_arm32v6
+
+go-build-release-linux-amd64:
 	CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -o bin/newt_linux_amd64
+
+go-build-release-linux-riscv64:
 	CGO_ENABLED=0 GOOS=linux GOARCH=riscv64 go build -o bin/newt_linux_riscv64
+
+go-build-release-darwin-arm64:
 	CGO_ENABLED=0 GOOS=darwin GOARCH=arm64 go build -o bin/newt_darwin_arm64
+
+go-build-release-darwin-amd64:
 	CGO_ENABLED=0 GOOS=darwin GOARCH=amd64 go build -o bin/newt_darwin_amd64
+
+go-build-release-windows-amd64:
 	CGO_ENABLED=0 GOOS=windows GOARCH=amd64 go build -o bin/newt_windows_amd64.exe
+
+go-build-release-freebsd-amd64:
 	CGO_ENABLED=0 GOOS=freebsd GOARCH=amd64 go build -o bin/newt_freebsd_amd64
-	CGO_ENABLED=0 GOOS=freebsd GOARCH=arm64 go build -o bin/newt_freebsd_arm64
+
+go-build-release-freebsd-arm64:
+	CGO_ENABLED=0 GOOS=freebsd GOARCH=arm64 go build -o bin/newt_freebsd_arm64

clients.go

@@ -24,7 +24,7 @@ func setupClients(client *websocket.Client) {
 
 	host = strings.TrimSuffix(host, "/")
 
-	logger.Info("Setting up clients with netstack2...")
+	logger.Debug("Setting up clients with netstack2...")
 
 	// if useNativeInterface is true make sure we have permission to use native interface
 	if useNativeInterface {
@@ -63,7 +63,7 @@ func closeClients() {
 	}
 }
 
-func clientsHandleNewtConnection(publicKey string, endpoint string) {
+func clientsHandleNewtConnection(publicKey string, endpoint string, relayPort uint16) {
 	if !ready {
 		return
 	}
@@ -77,7 +77,7 @@ func clientsHandleNewtConnection(publicKey string, endpoint string) {
 	endpoint = strings.Join(parts[:len(parts)-1], ":")
 
 	if wgService != nil {
-		wgService.StartHolepunch(publicKey, endpoint)
+		wgService.StartHolepunch(publicKey, endpoint, relayPort)
 	}
 }
 

clients/clients.go

@@ -40,12 +40,13 @@ type Target struct {
 	SourcePrefix string      `json:"sourcePrefix"`
 	DestPrefix   string      `json:"destPrefix"`
 	RewriteTo    string      `json:"rewriteTo,omitempty"`
+	DisableIcmp  bool        `json:"disableIcmp,omitempty"`
 	PortRange    []PortRange `json:"portRange,omitempty"`
 }
 
 type PortRange struct {
-	Min uint16 `json:"min"`
-	Max uint16 `json:"max"`
+	Min      uint16 `json:"min"`
+	Max      uint16 `json:"max"`
 	Protocol string `json:"protocol"` // "tcp" or "udp"
 }
 
@@ -140,7 +141,7 @@ func NewWireGuardService(interfaceName string, port uint16, mtu int, host string
 	// Add a reference for the hole punch manager (creator already has one reference for WireGuard)
 	sharedBind.AddRef()
 
-	logger.Info("Created shared UDP socket on port %d (refcount: %d)", port, sharedBind.GetRefCount())
+	logger.Debug("Created shared UDP socket on port %d (refcount: %d)", port, sharedBind.GetRefCount())
 
 	// Parse DNS addresses
 	dnsAddrs := []netip.Addr{netip.MustParseAddr(dns)}
@@ -269,16 +270,21 @@ func (s *WireGuardService) SetOnNetstackClose(callback func()) {
 }
 
 // StartHolepunch starts hole punching to a specific endpoint
-func (s *WireGuardService) StartHolepunch(publicKey string, endpoint string) {
+func (s *WireGuardService) StartHolepunch(publicKey string, endpoint string, relayPort uint16) {
 	if s.holePunchManager == nil {
 		logger.Warn("Hole punch manager not initialized")
 		return
 	}
 
+	if relayPort == 0 {
+	    relayPort = 21820
+	}
+
 	// Convert websocket.ExitNode to holepunch.ExitNode
 	hpExitNodes := []holepunch.ExitNode{
 		{
 			Endpoint:  endpoint,
+			RelayPort: relayPort,
 			PublicKey: publicKey,
 		},
 	}
@@ -288,7 +294,7 @@ func (s *WireGuardService) StartHolepunch(publicKey string, endpoint string) {
 		logger.Warn("Failed to start hole punch: %v", err)
 	}
 
-	logger.Info("Starting hole punch to %s with public key: %s", endpoint, publicKey)
+	logger.Debug("Starting hole punch to %s with public key: %s", endpoint, publicKey)
 }
 
 // StartDirectUDPRelay starts a direct UDP relay from the main tunnel netstack to the clients' WireGuard.
@@ -335,7 +341,7 @@ func (s *WireGuardService) StartDirectUDPRelay(tunnelIP string) error {
 	// Set the netstack connection on the SharedBind so responses go back through the tunnel
 	s.sharedBind.SetNetstackConn(listener)
 
-	logger.Info("Started direct UDP relay on %s:%d (bidirectional via SharedBind)", tunnelIP, s.Port)
+	logger.Debug("Started direct UDP relay on %s:%d (bidirectional via SharedBind)", tunnelIP, s.Port)
 
 	// Start the relay goroutine to read from netstack and inject into SharedBind
 	s.directRelayWg.Add(1)
@@ -353,7 +359,7 @@ func (s *WireGuardService) runDirectUDPRelay(listener net.PacketConn) {
 	// Note: Don't close listener here - it's also used by SharedBind for sending responses
 	// It will be closed when the relay is stopped
 
-	logger.Info("Direct UDP relay started (bidirectional through SharedBind)")
+	logger.Debug("Direct UDP relay started (bidirectional through SharedBind)")
 
 	buf := make([]byte, 65535) // Max UDP packet size
 
@@ -439,7 +445,7 @@ func (s *WireGuardService) LoadRemoteConfig() error {
 		"port":      s.Port,
 	}, 2*time.Second)
 
-	logger.Info("Requesting WireGuard configuration from remote server")
+	logger.Debug("Requesting WireGuard configuration from remote server")
 	go s.periodicBandwidthCheck()
 
 	return nil
@@ -449,7 +455,7 @@ 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")
+	logger.Debug("Received WireGuard clients configuration from remote server")
 
 	jsonData, err := json.Marshal(msg.Data)
 	if err != nil {
@@ -471,6 +477,8 @@ func (s *WireGuardService) handleConfig(msg websocket.WSMessage) {
 	// Ensure the WireGuard interface and peers are configured
 	if err := s.ensureWireguardInterface(config); err != nil {
 		logger.Error("Failed to ensure WireGuard interface: %v", err)
+		logger.Error("Clients functionality will be disabled until the interface can be created")
+		return
 	}
 
 	if err := s.ensureWireguardPeers(config.Peers); err != nil {
@@ -480,6 +488,8 @@ func (s *WireGuardService) handleConfig(msg websocket.WSMessage) {
 	if err := s.ensureTargets(config.Targets); err != nil {
 		logger.Error("Failed to ensure WireGuard targets: %v", err)
 	}
+
+	logger.Info("Client connectivity setup. Ready to accept connections from clients!")
 }
 
 func (s *WireGuardService) ensureWireguardInterface(wgconfig WgConfig) error {
@@ -593,8 +603,9 @@ func (s *WireGuardService) ensureWireguardInterface(wgconfig WgConfig) error {
 		s.dns,
 		s.mtu,
 		netstack2.NetTunOptions{
-			EnableTCPProxy: true,
-			EnableUDPProxy: true,
+			EnableTCPProxy:  true,
+			EnableUDPProxy:  true,
+			EnableICMPProxy: true,
 		},
 	)
 	if err != nil {
@@ -626,7 +637,7 @@ func (s *WireGuardService) ensureWireguardInterface(wgconfig WgConfig) error {
 		return fmt.Errorf("failed to bring up WireGuard device: %v", err)
 	}
 
-	logger.Info("WireGuard netstack device created and configured")
+	logger.Debug("WireGuard netstack device created and configured")
 
 	// Release the mutex before calling the callback
 	s.mu.Unlock()
@@ -645,6 +656,11 @@ func (s *WireGuardService) ensureWireguardPeers(peers []Peer) error {
 	// For netstack, we need to manage peers differently
 	// We'll configure peers directly on the device using IPC
 
+	// Check if device is initialized
+	if s.device == nil {
+		return fmt.Errorf("WireGuard device is not initialized")
+	}
+
 	// First, clear all existing peers by getting current config and removing them
 	currentConfig, err := s.device.IpcGet()
 	if err != nil {
@@ -700,13 +716,13 @@ func (s *WireGuardService) ensureTargets(targets []Target) error {
 		var portRanges []netstack2.PortRange
 		for _, pr := range target.PortRange {
 			portRanges = append(portRanges, netstack2.PortRange{
-				Min: pr.Min,
-				Max: pr.Max,
+				Min:      pr.Min,
+				Max:      pr.Max,
 				Protocol: pr.Protocol,
 			})
 		}
 
-		s.tnet.AddProxySubnetRule(sourcePrefix, destPrefix, target.RewriteTo, portRanges)
+		s.tnet.AddProxySubnetRule(sourcePrefix, destPrefix, target.RewriteTo, portRanges, target.DisableIcmp)
 
 		logger.Info("Added target subnet from %s to %s rewrite to %s with port ranges: %v", target.SourcePrefix, target.DestPrefix, target.RewriteTo, target.PortRange)
 	}
@@ -1094,10 +1110,11 @@ func (s *WireGuardService) handleAddTarget(msg websocket.WSMessage) {
 			portRanges = append(portRanges, netstack2.PortRange{
 				Min: pr.Min,
 				Max: pr.Max,
+				Protocol:    pr.Protocol,
 			})
 		}
 
-		s.tnet.AddProxySubnetRule(sourcePrefix, destPrefix, target.RewriteTo, portRanges)
+		s.tnet.AddProxySubnetRule(sourcePrefix, destPrefix, target.RewriteTo, portRanges, target.DisableIcmp)
 
 		logger.Info("Added target subnet from %s to %s rewrite to %s with port ranges: %v", target.SourcePrefix, target.DestPrefix, target.RewriteTo, target.PortRange)
 	}
@@ -1209,12 +1226,13 @@ func (s *WireGuardService) handleUpdateTarget(msg websocket.WSMessage) {
 		var portRanges []netstack2.PortRange
 		for _, pr := range target.PortRange {
 			portRanges = append(portRanges, netstack2.PortRange{
-				Min: pr.Min,
-				Max: pr.Max,
+				Min:         pr.Min,
+				Max:         pr.Max,
+				Protocol:    pr.Protocol,
 			})
 		}
 
-		s.tnet.AddProxySubnetRule(sourcePrefix, destPrefix, target.RewriteTo, portRanges)
+		s.tnet.AddProxySubnetRule(sourcePrefix, destPrefix, target.RewriteTo, portRanges, target.DisableIcmp)
 		logger.Info("Added target subnet from %s to %s rewrite to %s with port ranges: %v", target.SourcePrefix, target.DestPrefix, target.RewriteTo, target.PortRange)
 	}
 }

holepunch/holepunch.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"net"
+	"strconv"
 	"sync"
 	"time"
 
@@ -19,7 +20,9 @@ import (
 // ExitNode represents a WireGuard exit node for hole punching
 type ExitNode struct {
 	Endpoint  string `json:"endpoint"`
+	RelayPort uint16 `json:"relayPort"`
 	PublicKey string `json:"publicKey"`
+	SiteIds   []int  `json:"siteIds,omitempty"`
 }
 
 // Manager handles UDP hole punching operations
@@ -140,6 +143,51 @@ func (m *Manager) RemoveExitNode(endpoint string) bool {
 	return true
 }
 
+/*
+RemoveExitNodesByPeer removes the peer ID from the SiteIds list in each exit node.
+If the SiteIds list becomes empty after removal, the exit node is removed entirely.
+Returns the number of exit nodes removed.
+*/
+func (m *Manager) RemoveExitNodesByPeer(peerID int) int {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	removed := 0
+	for endpoint, node := range m.exitNodes {
+		// Remove peerID from SiteIds if present
+		newSiteIds := make([]int, 0, len(node.SiteIds))
+		for _, id := range node.SiteIds {
+			if id != peerID {
+				newSiteIds = append(newSiteIds, id)
+			}
+		}
+		if len(newSiteIds) != len(node.SiteIds) {
+			node.SiteIds = newSiteIds
+			if len(node.SiteIds) == 0 {
+				delete(m.exitNodes, endpoint)
+				logger.Info("Removed exit node %s as no more site IDs remain after removing peer %d", endpoint, peerID)
+				removed++
+			} else {
+				m.exitNodes[endpoint] = node
+				logger.Info("Removed peer %d from exit node %s site IDs", peerID, endpoint)
+			}
+		}
+	}
+
+	if removed > 0 {
+		// 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 removed
+}
+
 // GetExitNodes returns a copy of the current exit nodes
 func (m *Manager) GetExitNodes() []ExitNode {
 	m.mu.Lock()
@@ -202,7 +250,7 @@ func (m *Manager) TriggerHolePunch() error {
 			continue
 		}
 
-		serverAddr := net.JoinHostPort(host, "21820")
+		serverAddr := net.JoinHostPort(host, strconv.Itoa(int(exitNode.RelayPort)))
 		remoteAddr, err := net.ResolveUDPAddr("udp", serverAddr)
 		if err != nil {
 			logger.Error("Failed to resolve UDP address %s: %v", serverAddr, err)
@@ -247,7 +295,7 @@ func (m *Manager) StartMultipleExitNodes(exitNodes []ExitNode) error {
 	m.updateChan = make(chan struct{}, 1)
 	m.mu.Unlock()
 
-	logger.Info("Starting UDP hole punch to %d exit nodes with shared bind", len(exitNodes))
+	logger.Debug("Starting UDP hole punch to %d exit nodes with shared bind", len(exitNodes))
 
 	go m.runMultipleExitNodes()
 
@@ -313,7 +361,7 @@ func (m *Manager) runMultipleExitNodes() {
 				continue
 			}
 
-			serverAddr := net.JoinHostPort(host, "21820")
+			serverAddr := net.JoinHostPort(host, strconv.Itoa(int(exitNode.RelayPort)))
 			remoteAddr, err := net.ResolveUDPAddr("udp", serverAddr)
 			if err != nil {
 				logger.Error("Failed to resolve UDP address %s: %v", serverAddr, err)
@@ -325,7 +373,7 @@ func (m *Manager) runMultipleExitNodes() {
 				publicKey:    exitNode.PublicKey,
 				endpointName: exitNode.Endpoint,
 			})
-			logger.Info("Resolved exit node: %s -> %s", exitNode.Endpoint, remoteAddr.String())
+			logger.Debug("Resolved exit node: %s -> %s", exitNode.Endpoint, remoteAddr.String())
 		}
 		return resolvedNodes
 	}

main.go

@@ -37,6 +37,7 @@ import (
 
 type WgData struct {
 	Endpoint           string               `json:"endpoint"`
+	RelayPort          uint16               `json:"relayPort"`
 	PublicKey          string               `json:"publicKey"`
 	ServerIP           string               `json:"serverIP"`
 	TunnelIP           string               `json:"tunnelIP"`
@@ -419,7 +420,7 @@ func runNewtMain(ctx context.Context) {
 	}
 	if tel != nil {
 		// Admin HTTP server (exposes /metrics when Prometheus exporter is enabled)
-		logger.Info("Starting metrics server on %s", tcfg.AdminAddr)
+		logger.Debug("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 {
@@ -691,7 +692,12 @@ func runNewtMain(ctx context.Context) {
 			return
 		}
 
-		clientsHandleNewtConnection(wgData.PublicKey, endpoint)
+		relayPort := wgData.RelayPort
+		if relayPort == 0 {
+            relayPort = 21820
+        }
+
+		clientsHandleNewtConnection(wgData.PublicKey, endpoint, relayPort)
 
 		// Configure WireGuard
 		config := fmt.Sprintf(`private_key=%s

netstack2/handlers.go

@@ -10,12 +10,18 @@ import (
 	"fmt"
 	"io"
 	"net"
+	"net/netip"
+	"os/exec"
 	"sync"
 	"time"
 
 	"github.com/fosrl/newt/logger"
+	"golang.org/x/net/icmp"
+	"golang.org/x/net/ipv4"
 	"gvisor.dev/gvisor/pkg/tcpip"
 	"gvisor.dev/gvisor/pkg/tcpip/adapters/gonet"
+	"gvisor.dev/gvisor/pkg/tcpip/checksum"
+	"gvisor.dev/gvisor/pkg/tcpip/header"
 	"gvisor.dev/gvisor/pkg/tcpip/stack"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/tcp"
 	"gvisor.dev/gvisor/pkg/tcpip/transport/udp"
@@ -58,6 +64,9 @@ const (
 
 	// Buffer size for copying data
 	bufferSize = 32 * 1024
+
+	// icmpTimeout is the default timeout for ICMP ping requests.
+	icmpTimeout = 5 * time.Second
 )
 
 // TCPHandler handles TCP connections from netstack
@@ -72,6 +81,12 @@ type UDPHandler struct {
 	proxyHandler *ProxyHandler
 }
 
+// ICMPHandler handles ICMP packets from netstack
+type ICMPHandler 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}
@@ -82,6 +97,11 @@ func NewUDPHandler(s *stack.Stack, ph *ProxyHandler) *UDPHandler {
 	return &UDPHandler{stack: s, proxyHandler: ph}
 }
 
+// NewICMPHandler creates a new ICMP handler
+func NewICMPHandler(s *stack.Stack, ph *ProxyHandler) *ICMPHandler {
+	return &ICMPHandler{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) {
@@ -348,3 +368,334 @@ func copyPacketData(dst, src net.PacketConn, to net.Addr, timeout time.Duration)
 		dst.SetReadDeadline(time.Now().Add(timeout))
 	}
 }
+
+// InstallICMPHandler installs the ICMP handler on the stack
+func (h *ICMPHandler) InstallICMPHandler() error {
+	h.stack.SetTransportProtocolHandler(header.ICMPv4ProtocolNumber, h.handleICMPPacket)
+	logger.Debug("ICMP Handler: Installed ICMP protocol handler")
+	return nil
+}
+
+// handleICMPPacket handles incoming ICMP packets
+func (h *ICMPHandler) handleICMPPacket(id stack.TransportEndpointID, pkt *stack.PacketBuffer) bool {
+	logger.Debug("ICMP Handler: Received ICMP packet from %s to %s", id.RemoteAddress, id.LocalAddress)
+
+	// Get the ICMP header from the packet
+	icmpData := pkt.TransportHeader().Slice()
+	if len(icmpData) < header.ICMPv4MinimumSize {
+		logger.Debug("ICMP Handler: Packet too small for ICMP header: %d bytes", len(icmpData))
+		return false
+	}
+
+	icmpHdr := header.ICMPv4(icmpData)
+	icmpType := icmpHdr.Type()
+	icmpCode := icmpHdr.Code()
+
+	logger.Debug("ICMP Handler: Type=%d, Code=%d, Ident=%d, Seq=%d",
+		icmpType, icmpCode, icmpHdr.Ident(), icmpHdr.Sequence())
+
+	// Only handle Echo Request (ping)
+	if icmpType != header.ICMPv4Echo {
+		logger.Debug("ICMP Handler: Ignoring non-echo ICMP type: %d", icmpType)
+		return false
+	}
+
+	// Extract source and destination addresses
+	srcIP := id.RemoteAddress.String()
+	dstIP := id.LocalAddress.String()
+
+	logger.Info("ICMP Handler: Echo Request from %s to %s (ident=%d, seq=%d)",
+		srcIP, dstIP, icmpHdr.Ident(), icmpHdr.Sequence())
+
+	// Convert to netip.Addr for subnet matching
+	srcAddr, err := netip.ParseAddr(srcIP)
+	if err != nil {
+		logger.Debug("ICMP Handler: Failed to parse source IP %s: %v", srcIP, err)
+		return false
+	}
+	dstAddr, err := netip.ParseAddr(dstIP)
+	if err != nil {
+		logger.Debug("ICMP Handler: Failed to parse dest IP %s: %v", dstIP, err)
+		return false
+	}
+
+	// Check subnet rules (use port 0 for ICMP since it doesn't have ports)
+	if h.proxyHandler == nil {
+		logger.Debug("ICMP Handler: No proxy handler configured")
+		return false
+	}
+
+	matchedRule := h.proxyHandler.subnetLookup.Match(srcAddr, dstAddr, 0, header.ICMPv4ProtocolNumber)
+	if matchedRule == nil {
+		logger.Debug("ICMP Handler: No matching subnet rule for %s -> %s", srcIP, dstIP)
+		return false
+	}
+
+	logger.Info("ICMP Handler: Matched subnet rule for %s -> %s", srcIP, dstIP)
+
+	// Determine actual destination (with possible rewrite)
+	actualDstIP := dstIP
+	if matchedRule.RewriteTo != "" {
+		resolvedAddr, err := h.proxyHandler.resolveRewriteAddress(matchedRule.RewriteTo)
+		if err != nil {
+			logger.Info("ICMP Handler: Failed to resolve rewrite address %s: %v", matchedRule.RewriteTo, err)
+		} else {
+			actualDstIP = resolvedAddr.String()
+			logger.Info("ICMP Handler: Using rewritten destination %s (original: %s)", actualDstIP, dstIP)
+		}
+	}
+
+	// Get the full ICMP payload (including the data after the header)
+	icmpPayload := pkt.Data().AsRange().ToSlice()
+
+	// Handle the ping in a goroutine to avoid blocking
+	go h.proxyPing(srcIP, dstIP, actualDstIP, icmpHdr.Ident(), icmpHdr.Sequence(), icmpPayload)
+
+	return true
+}
+
+// proxyPing sends a ping to the actual destination and injects the reply back
+func (h *ICMPHandler) proxyPing(srcIP, originalDstIP, actualDstIP string, ident, seq uint16, payload []byte) {
+	logger.Debug("ICMP Handler: Proxying ping from %s to %s (actual: %s), ident=%d, seq=%d",
+		srcIP, originalDstIP, actualDstIP, ident, seq)
+
+	// Try three methods in order: ip4:icmp -> udp4 -> ping command
+	// Track which method succeeded so we can handle identifier matching correctly
+	method, success := h.tryICMPMethods(actualDstIP, ident, seq, payload)
+
+	if !success {
+		logger.Info("ICMP Handler: All ping methods failed for %s", actualDstIP)
+		return
+	}
+
+	logger.Info("ICMP Handler: Ping successful to %s using %s, injecting reply (ident=%d, seq=%d)",
+		actualDstIP, method, ident, seq)
+
+	// Build the reply packet to inject back into the netstack
+	// The reply should appear to come from the original destination (before rewrite)
+	h.injectICMPReply(srcIP, originalDstIP, ident, seq, payload)
+}
+
+// tryICMPMethods tries all available ICMP methods in order
+func (h *ICMPHandler) tryICMPMethods(actualDstIP string, ident, seq uint16, payload []byte) (string, bool) {
+	if h.tryRawICMP(actualDstIP, ident, seq, payload, false) {
+		return "raw ICMP", true
+	}
+	if h.tryUnprivilegedICMP(actualDstIP, ident, seq, payload) {
+		return "unprivileged ICMP", true
+	}
+	if h.tryPingCommand(actualDstIP, ident, seq, payload) {
+		return "ping command", true
+	}
+	return "", false
+}
+
+// tryRawICMP attempts to ping using raw ICMP sockets (requires CAP_NET_RAW or root)
+func (h *ICMPHandler) tryRawICMP(actualDstIP string, ident, seq uint16, payload []byte, ignoreIdent bool) bool {
+	conn, err := icmp.ListenPacket("ip4:icmp", "0.0.0.0")
+	if err != nil {
+		logger.Debug("ICMP Handler: Raw ICMP socket not available: %v", err)
+		return false
+	}
+	defer conn.Close()
+
+	logger.Debug("ICMP Handler: Using raw ICMP socket")
+	return h.sendAndReceiveICMP(conn, actualDstIP, ident, seq, payload, false, ignoreIdent)
+}
+
+// tryUnprivilegedICMP attempts to ping using unprivileged ICMP (requires ping_group_range configured)
+func (h *ICMPHandler) tryUnprivilegedICMP(actualDstIP string, ident, seq uint16, payload []byte) bool {
+	conn, err := icmp.ListenPacket("udp4", "0.0.0.0")
+	if err != nil {
+		logger.Debug("ICMP Handler: Unprivileged ICMP socket not available: %v", err)
+		return false
+	}
+	defer conn.Close()
+
+	logger.Debug("ICMP Handler: Using unprivileged ICMP socket")
+	// Unprivileged ICMP doesn't let us control the identifier, so we ignore it in matching
+	return h.sendAndReceiveICMP(conn, actualDstIP, ident, seq, payload, true, true)
+}
+
+// sendAndReceiveICMP sends an ICMP echo request and waits for the reply
+func (h *ICMPHandler) sendAndReceiveICMP(conn *icmp.PacketConn, actualDstIP string, ident, seq uint16, payload []byte, isUnprivileged bool, ignoreIdent bool) bool {
+	// Build the ICMP echo request message
+	echoMsg := &icmp.Message{
+		Type: ipv4.ICMPTypeEcho,
+		Code: 0,
+		Body: &icmp.Echo{
+			ID:   int(ident),
+			Seq:  int(seq),
+			Data: payload,
+		},
+	}
+
+	msgBytes, err := echoMsg.Marshal(nil)
+	if err != nil {
+		logger.Debug("ICMP Handler: Failed to marshal ICMP message: %v", err)
+		return false
+	}
+
+	// Resolve destination address based on socket type
+	var writeErr error
+	if isUnprivileged {
+		// For unprivileged ICMP, use UDP-style addressing
+		udpAddr := &net.UDPAddr{IP: net.ParseIP(actualDstIP)}
+		logger.Debug("ICMP Handler: Sending ping to %s (unprivileged)", udpAddr.String())
+		conn.SetDeadline(time.Now().Add(icmpTimeout))
+		_, writeErr = conn.WriteTo(msgBytes, udpAddr)
+	} else {
+		// For raw ICMP, use IP addressing
+		dst, err := net.ResolveIPAddr("ip4", actualDstIP)
+		if err != nil {
+			logger.Debug("ICMP Handler: Failed to resolve destination %s: %v", actualDstIP, err)
+			return false
+		}
+		logger.Debug("ICMP Handler: Sending ping to %s (raw)", dst.String())
+		conn.SetDeadline(time.Now().Add(icmpTimeout))
+		_, writeErr = conn.WriteTo(msgBytes, dst)
+	}
+
+	if writeErr != nil {
+		logger.Debug("ICMP Handler: Failed to send ping to %s: %v", actualDstIP, writeErr)
+		return false
+	}
+
+	logger.Debug("ICMP Handler: Ping sent to %s, waiting for reply (ident=%d, seq=%d)", actualDstIP, ident, seq)
+
+	// Wait for reply - loop to filter out non-matching packets
+	replyBuf := make([]byte, 1500)
+
+	for {
+		n, peer, err := conn.ReadFrom(replyBuf)
+		if err != nil {
+			logger.Debug("ICMP Handler: Failed to receive ping reply from %s: %v", actualDstIP, err)
+			return false
+		}
+
+		logger.Debug("ICMP Handler: Received %d bytes from %s", n, peer.String())
+
+		// Parse the reply
+		replyMsg, err := icmp.ParseMessage(1, replyBuf[:n])
+		if err != nil {
+			logger.Debug("ICMP Handler: Failed to parse ICMP message: %v", err)
+			continue
+		}
+
+		// Check if it's an echo reply (type 0), not an echo request (type 8)
+		if replyMsg.Type != ipv4.ICMPTypeEchoReply {
+			logger.Debug("ICMP Handler: Received non-echo-reply type: %v, continuing to wait", replyMsg.Type)
+			continue
+		}
+
+		reply, ok := replyMsg.Body.(*icmp.Echo)
+		if !ok {
+			logger.Debug("ICMP Handler: Invalid echo reply body type, continuing to wait")
+			continue
+		}
+
+		// Verify the sequence matches what we sent
+		// For unprivileged ICMP, the kernel controls the identifier, so we only check sequence
+		if reply.Seq != int(seq) {
+			logger.Debug("ICMP Handler: Reply seq mismatch: got seq=%d, want seq=%d", reply.Seq, seq)
+			continue
+		}
+
+		if !ignoreIdent && reply.ID != int(ident) {
+			logger.Debug("ICMP Handler: Reply ident mismatch: got ident=%d, want ident=%d", reply.ID, ident)
+			continue
+		}
+
+		// Found matching reply
+		logger.Debug("ICMP Handler: Received valid echo reply")
+		return true
+	}
+}
+
+// tryPingCommand attempts to ping using the system ping command (always works, but less control)
+func (h *ICMPHandler) tryPingCommand(actualDstIP string, ident, seq uint16, payload []byte) bool {
+	logger.Debug("ICMP Handler: Attempting to use system ping command")
+
+	ctx, cancel := context.WithTimeout(context.Background(), icmpTimeout)
+	defer cancel()
+
+	// Send one ping with timeout
+	// -c 1: count = 1 packet
+	// -W 5: timeout = 5 seconds
+	// -q: quiet output (just summary)
+	cmd := exec.CommandContext(ctx, "ping", "-c", "1", "-W", "5", "-q", actualDstIP)
+	output, err := cmd.CombinedOutput()
+
+	if err != nil {
+		logger.Debug("ICMP Handler: System ping command failed: %v, output: %s", err, string(output))
+		return false
+	}
+
+	logger.Debug("ICMP Handler: System ping command succeeded")
+	return true
+}
+
+// injectICMPReply creates an ICMP echo reply packet and queues it to be sent back through the tunnel
+func (h *ICMPHandler) injectICMPReply(dstIP, srcIP string, ident, seq uint16, payload []byte) {
+	logger.Debug("ICMP Handler: Creating reply from %s to %s (ident=%d, seq=%d)",
+		srcIP, dstIP, ident, seq)
+
+	// Parse addresses
+	srcAddr, err := netip.ParseAddr(srcIP)
+	if err != nil {
+		logger.Info("ICMP Handler: Failed to parse source IP for reply: %v", err)
+		return
+	}
+	dstAddr, err := netip.ParseAddr(dstIP)
+	if err != nil {
+		logger.Info("ICMP Handler: Failed to parse dest IP for reply: %v", err)
+		return
+	}
+
+	// Calculate total packet size
+	ipHeaderLen := header.IPv4MinimumSize
+	icmpHeaderLen := header.ICMPv4MinimumSize
+	totalLen := ipHeaderLen + icmpHeaderLen + len(payload)
+
+	// Create the packet buffer
+	pkt := make([]byte, totalLen)
+
+	// Build IPv4 header
+	ipHdr := header.IPv4(pkt[:ipHeaderLen])
+	ipHdr.Encode(&header.IPv4Fields{
+		TotalLength: uint16(totalLen),
+		TTL:         64,
+		Protocol:    uint8(header.ICMPv4ProtocolNumber),
+		SrcAddr:     tcpip.AddrFrom4(srcAddr.As4()),
+		DstAddr:     tcpip.AddrFrom4(dstAddr.As4()),
+	})
+	ipHdr.SetChecksum(^ipHdr.CalculateChecksum())
+
+	// Build ICMP header
+	icmpHdr := header.ICMPv4(pkt[ipHeaderLen : ipHeaderLen+icmpHeaderLen])
+	icmpHdr.SetType(header.ICMPv4EchoReply)
+	icmpHdr.SetCode(0)
+	icmpHdr.SetIdent(ident)
+	icmpHdr.SetSequence(seq)
+
+	// Copy payload
+	copy(pkt[ipHeaderLen+icmpHeaderLen:], payload)
+
+	// Calculate ICMP checksum (covers ICMP header + payload)
+	icmpHdr.SetChecksum(0)
+	icmpData := pkt[ipHeaderLen:]
+	icmpHdr.SetChecksum(^checksum.Checksum(icmpData, 0))
+
+	logger.Debug("ICMP Handler: Built reply packet, total length=%d", totalLen)
+
+	// Queue the packet to be sent back through the tunnel
+	if h.proxyHandler != nil {
+		if h.proxyHandler.QueueICMPReply(pkt) {
+			logger.Info("ICMP Handler: Queued echo reply packet for transmission")
+		} else {
+			logger.Info("ICMP Handler: Failed to queue echo reply packet")
+		}
+	} else {
+		logger.Info("ICMP Handler: Cannot queue reply - proxy handler not available")
+	}
+}

netstack2/proxy.go

@@ -43,6 +43,7 @@ type PortRange struct {
 type SubnetRule struct {
 	SourcePrefix netip.Prefix // Source IP prefix (who is sending)
 	DestPrefix   netip.Prefix // Destination IP prefix (where it's going)
+	DisableIcmp  bool         // If true, ICMP traffic is blocked for this subnet
 	RewriteTo    string       // Optional rewrite address for DNAT - can be IP/CIDR or domain name
 	PortRanges   []PortRange  // empty slice means all ports allowed
 }
@@ -69,7 +70,7 @@ func NewSubnetLookup() *SubnetLookup {
 // 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) {
+func (sl *SubnetLookup) AddSubnet(sourcePrefix, destPrefix netip.Prefix, rewriteTo string, portRanges []PortRange, disableIcmp bool) {
 	sl.mu.Lock()
 	defer sl.mu.Unlock()
 
@@ -81,6 +82,7 @@ func (sl *SubnetLookup) AddSubnet(sourcePrefix, destPrefix netip.Prefix, rewrite
 	sl.rules[key] = &SubnetRule{
 		SourcePrefix: sourcePrefix,
 		DestPrefix:   destPrefix,
+		DisableIcmp:  disableIcmp,
 		RewriteTo:    rewriteTo,
 		PortRanges:   portRanges,
 	}
@@ -123,6 +125,11 @@ func (sl *SubnetLookup) Match(srcIP, dstIP netip.Addr, port uint16, proto tcpip.
 			continue
 		}
 
+		if rule.DisableIcmp && (proto == header.ICMPv4ProtocolNumber || proto == header.ICMPv6ProtocolNumber) {
+		    // ICMP is disabled for this subnet
+			return nil
+		}
+
 		// Both IPs match - now check port restrictions
 		// If no port ranges specified, all ports are allowed
 		if len(rule.PortRanges) == 0 {
@@ -180,23 +187,27 @@ type ProxyHandler struct {
 	proxyNotifyHandle *channel.NotificationHandle
 	tcpHandler        *TCPHandler
 	udpHandler        *UDPHandler
+	icmpHandler       *ICMPHandler
 	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
+	icmpReplies       chan []byte          // Channel for ICMP reply packets to be sent back through the tunnel
+	notifiable        channel.Notification // Notification handler for triggering reads
 }
 
 // ProxyHandlerOptions configures the proxy handler
 type ProxyHandlerOptions struct {
-	EnableTCP bool
-	EnableUDP bool
-	MTU       int
+	EnableTCP  bool
+	EnableUDP  bool
+	EnableICMP bool
+	MTU        int
 }
 
 // NewProxyHandler creates a new proxy handler for promiscuous mode
 func NewProxyHandler(options ProxyHandlerOptions) (*ProxyHandler, error) {
-	if !options.EnableTCP && !options.EnableUDP {
+	if !options.EnableTCP && !options.EnableUDP && !options.EnableICMP {
 		return nil, nil // No proxy needed
 	}
 
@@ -205,6 +216,7 @@ func NewProxyHandler(options ProxyHandlerOptions) (*ProxyHandler, error) {
 		subnetLookup:     NewSubnetLookup(),
 		natTable:         make(map[connKey]*natState),
 		destRewriteTable: make(map[destKey]netip.Addr),
+		icmpReplies:      make(chan []byte, 256), // Buffer for ICMP reply packets
 		proxyEp:          channel.New(1024, uint32(options.MTU), ""),
 		proxyStack: stack.New(stack.Options{
 			NetworkProtocols: []stack.NetworkProtocolFactory{
@@ -236,6 +248,15 @@ func NewProxyHandler(options ProxyHandlerOptions) (*ProxyHandler, error) {
 		}
 	}
 
+	// Initialize ICMP handler if enabled
+	if options.EnableICMP {
+		handler.icmpHandler = NewICMPHandler(handler.proxyStack, handler)
+		if err := handler.icmpHandler.InstallICMPHandler(); err != nil {
+			return nil, fmt.Errorf("failed to install ICMP handler: %v", err)
+		}
+		logger.Debug("ProxyHandler: ICMP handler enabled")
+	}
+
 	// // 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")
@@ -260,11 +281,11 @@ func NewProxyHandler(options ProxyHandlerOptions) (*ProxyHandler, error) {
 // 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) {
+func (p *ProxyHandler) AddSubnetRule(sourcePrefix, destPrefix netip.Prefix, rewriteTo string, portRanges []PortRange, disableIcmp bool) {
 	if p == nil || !p.enabled {
 		return
 	}
-	p.subnetLookup.AddSubnet(sourcePrefix, destPrefix, rewriteTo, portRanges)
+	p.subnetLookup.AddSubnet(sourcePrefix, destPrefix, rewriteTo, portRanges, disableIcmp)
 }
 
 // RemoveSubnetRule removes a subnet from the proxy handler
@@ -343,6 +364,9 @@ func (p *ProxyHandler) Initialize(notifiable channel.Notification) error {
 		return nil
 	}
 
+	// Store notifiable for triggering notifications on ICMP replies
+	p.notifiable = notifiable
+
 	// Add notification handler
 	p.proxyNotifyHandle = p.proxyEp.AddNotify(notifiable)
 
@@ -421,14 +445,21 @@ func (p *ProxyHandler) HandleIncomingPacket(packet []byte) bool {
 		}
 		udpHeader := header.UDP(packet[headerLen:])
 		dstPort = udpHeader.DestinationPort()
-	default:
-		// For other protocols (ICMP, etc.), use port 0 (must match rules with no port restrictions)
+	case header.ICMPv4ProtocolNumber:
+		// ICMP doesn't have ports, use port 0 (must match rules with no port restrictions)
 		dstPort = 0
+		logger.Debug("HandleIncomingPacket: ICMP packet from %s to %s", srcAddr, dstAddr)
+	default:
+		// For other protocols, use port 0 (must match rules with no port restrictions)
+		dstPort = 0
+		logger.Debug("HandleIncomingPacket: Unknown protocol %d from %s to %s", protocol, srcAddr, dstAddr)
 	}
 
 	// Check if the source IP, destination IP, port, and protocol match any subnet rule
 	matchedRule := p.subnetLookup.Match(srcAddr, dstAddr, dstPort, protocol)
 	if matchedRule != nil {
+		logger.Debug("HandleIncomingPacket: Matched rule for %s -> %s (proto=%d, port=%d)",
+			srcAddr, dstAddr, protocol, dstPort)
 		// Check if we need to perform DNAT
 		if matchedRule.RewriteTo != "" {
 			// Create connection tracking key using original destination
@@ -515,9 +546,12 @@ func (p *ProxyHandler) HandleIncomingPacket(packet []byte) bool {
 			Payload: buffer.MakeWithData(packet),
 		})
 		p.proxyEp.InjectInbound(header.IPv4ProtocolNumber, pkb)
+		logger.Debug("HandleIncomingPacket: Injected packet into proxy stack (proto=%d)", protocol)
 		return true
 	}
 
+	logger.Debug("HandleIncomingPacket: No matching rule for %s -> %s (proto=%d, port=%d)",
+		srcAddr, dstAddr, protocol, dstPort)
 	return false
 }
 
@@ -640,6 +674,15 @@ func (p *ProxyHandler) ReadOutgoingPacket() *buffer.View {
 		return nil
 	}
 
+	// First check for ICMP reply packets (non-blocking)
+	select {
+	case icmpReply := <-p.icmpReplies:
+		logger.Debug("ReadOutgoingPacket: Returning ICMP reply packet (%d bytes)", len(icmpReply))
+		return buffer.NewViewWithData(icmpReply)
+	default:
+		// No ICMP reply available, continue to check proxy endpoint
+	}
+
 	pkt := p.proxyEp.Read()
 	if pkt != nil {
 		view := pkt.ToView()
@@ -669,6 +712,11 @@ func (p *ProxyHandler) ReadOutgoingPacket() *buffer.View {
 					srcPort = udpHeader.SourcePort()
 					dstPort = udpHeader.DestinationPort()
 				}
+			case header.ICMPv4ProtocolNumber:
+				// ICMP packets don't need NAT translation in our implementation
+				// since we construct reply packets with the correct addresses
+				logger.Debug("ReadOutgoingPacket: ICMP packet from %s to %s", srcIP, dstIP)
+				return view
 			}
 
 			// Look up NAT state for reverse translation
@@ -702,12 +750,37 @@ func (p *ProxyHandler) ReadOutgoingPacket() *buffer.View {
 	return nil
 }
 
+// QueueICMPReply queues an ICMP reply packet to be sent back through the tunnel
+func (p *ProxyHandler) QueueICMPReply(packet []byte) bool {
+	if p == nil || !p.enabled {
+		return false
+	}
+
+	select {
+	case p.icmpReplies <- packet:
+		logger.Debug("QueueICMPReply: Queued ICMP reply packet (%d bytes)", len(packet))
+		// Trigger notification so WriteNotify picks up the packet
+		if p.notifiable != nil {
+			p.notifiable.WriteNotify()
+		}
+		return true
+	default:
+		logger.Info("QueueICMPReply: ICMP reply channel full, dropping packet")
+		return false
+	}
+}
+
 // Close cleans up the proxy handler resources
 func (p *ProxyHandler) Close() error {
 	if p == nil || !p.enabled {
 		return nil
 	}
 
+	// Close ICMP replies channel
+	if p.icmpReplies != nil {
+		close(p.icmpReplies)
+	}
+
 	if p.proxyStack != nil {
 		p.proxyStack.RemoveNIC(1)
 		p.proxyStack.Close()

netstack2/tun.go

@@ -56,15 +56,17 @@ type Net netTun
 
 // NetTunOptions contains options for creating a NetTUN device
 type NetTunOptions struct {
-	EnableTCPProxy bool
-	EnableUDPProxy bool
+	EnableTCPProxy  bool
+	EnableUDPProxy  bool
+	EnableICMPProxy bool
 }
 
 // CreateNetTUN creates a new TUN device with netstack without proxying
 func CreateNetTUN(localAddresses, dnsServers []netip.Addr, mtu int) (tun.Device, *Net, error) {
 	return CreateNetTUNWithOptions(localAddresses, dnsServers, mtu, NetTunOptions{
-		EnableTCPProxy: true,
-		EnableUDPProxy: true,
+		EnableTCPProxy:  true,
+		EnableUDPProxy:  true,
+		EnableICMPProxy: true,
 	})
 }
 
@@ -84,13 +86,14 @@ func CreateNetTUNWithOptions(localAddresses, dnsServers []netip.Addr, mtu int, o
 		mtu:            mtu,
 	}
 
-	// Initialize proxy handler if TCP or UDP proxying is enabled
-	if options.EnableTCPProxy || options.EnableUDPProxy {
+	// Initialize proxy handler if TCP, UDP, or ICMP proxying is enabled
+	if options.EnableTCPProxy || options.EnableUDPProxy || options.EnableICMPProxy {
 		var err error
 		dev.proxyHandler, err = NewProxyHandler(ProxyHandlerOptions{
-			EnableTCP: options.EnableTCPProxy,
-			EnableUDP: options.EnableUDPProxy,
-			MTU:       mtu,
+			EnableTCP:  options.EnableTCPProxy,
+			EnableUDP:  options.EnableUDPProxy,
+			EnableICMP: options.EnableICMPProxy,
+			MTU:        mtu,
 		})
 		if err != nil {
 			return nil, nil, fmt.Errorf("failed to create proxy handler: %v", err)
@@ -351,10 +354,10 @@ func (net *Net) ListenUDP(laddr *net.UDPAddr) (*gonet.UDPConn, error) {
 // AddProxySubnetRule adds a subnet rule to the proxy handler
 // 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 (net *Net) AddProxySubnetRule(sourcePrefix, destPrefix netip.Prefix, rewriteTo string, portRanges []PortRange) {
+func (net *Net) AddProxySubnetRule(sourcePrefix, destPrefix netip.Prefix, rewriteTo string, portRanges []PortRange, disableIcmp bool) {
 	tun := (*netTun)(net)
 	if tun.proxyHandler != nil {
-		tun.proxyHandler.AddSubnetRule(sourcePrefix, destPrefix, rewriteTo, portRanges)
+		tun.proxyHandler.AddSubnetRule(sourcePrefix, destPrefix, rewriteTo, portRanges, disableIcmp)
 	}
 }
 

wgtester/wgtester.go

@@ -38,7 +38,6 @@ type Server struct {
 	isRunning    bool
 	runningLock  sync.Mutex
 	newtID       string
-	outputPrefix string
 	useNetstack  bool
 	tnet         interface{} // Will be *netstack2.Net when using netstack
 }
@@ -50,7 +49,6 @@ func NewServer(serverAddr string, serverPort uint16, newtID string) *Server {
 		serverPort:   serverPort + 1, // use the next port for the server
 		shutdownCh:   make(chan struct{}),
 		newtID:       newtID,
-		outputPrefix: "[WGTester] ",
 		useNetstack:  false,
 		tnet:         nil,
 	}
@@ -63,7 +61,6 @@ func NewServerWithNetstack(serverAddr string, serverPort uint16, newtID string,
 		serverPort:   serverPort + 1, // use the next port for the server
 		shutdownCh:   make(chan struct{}),
 		newtID:       newtID,
-		outputPrefix: "[WGTester] ",
 		useNetstack:  true,
 		tnet:         tnet,
 	}
@@ -109,7 +106,7 @@ func (s *Server) Start() error {
 	s.isRunning = true
 	go s.handleConnections()
 
-	logger.Info("%sServer started on %s:%d", s.outputPrefix, s.serverAddr, s.serverPort)
+	logger.Debug("WGTester Server started on %s:%d", s.serverAddr, s.serverPort)
 	return nil
 }
 
@@ -127,7 +124,7 @@ func (s *Server) Stop() {
 		s.conn.Close()
 	}
 	s.isRunning = false
-	logger.Info("%sServer stopped", s.outputPrefix)
+	logger.Info("WGTester Server stopped")
 }
 
 // RestartWithNetstack stops the current server and restarts it with netstack
@@ -162,7 +159,7 @@ 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("%sError setting read deadline: %v", s.outputPrefix, err)
+				logger.Error("Error setting read deadline: %v", err)
 				continue
 			}
 
@@ -192,7 +189,7 @@ func (s *Server) handleConnections() {
 					if err == io.EOF {
 						return
 					}
-					logger.Error("%sError reading from UDP: %v", s.outputPrefix, err)
+					logger.Error("Error reading from UDP: %v", err)
 				}
 				continue
 			}
@@ -224,7 +221,7 @@ func (s *Server) handleConnections() {
 			copy(responsePacket[5:13], buffer[5:13])
 
 			// Log response being sent for debugging
-			// logger.Debug("%sSending response to %s", s.outputPrefix, addr.String())
+			// logger.Debug("Sending response to %s", addr.String())
 
 			// Send the response packet - handle both regular UDP and netstack UDP
 			if s.useNetstack {
@@ -238,9 +235,9 @@ func (s *Server) handleConnections() {
 			}
 
 			if err != nil {
-				logger.Error("%sError sending response: %v", s.outputPrefix, err)
+				logger.Error("Error sending response: %v", err)
 			} else {
-				// logger.Debug("%sResponse sent successfully", s.outputPrefix)
+				// logger.Debug("Response sent successfully")
 			}
 		}
 	}