From e80c4c3431504a462ce03bffbb9229b9b34395d1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= Date: Tue, 6 Aug 2019 17:35:20 +0200 Subject: [PATCH] Have the dns_client hold a .references until all external references are removed so that cleanup can all be done in dns_client_destroy(). --- lib/dns/client.c | 121 ++++++++++++++++++++++------------------------- 1 file changed, 56 insertions(+), 65 deletions(-) diff --git a/lib/dns/client.c b/lib/dns/client.c index 6cef2a5ae7..5140956f17 100644 --- a/lib/dns/client.c +++ b/lib/dns/client.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -94,8 +95,9 @@ struct dns_client { unsigned int find_timeout; unsigned int find_udpretries; + isc_refcount_t references; + /* Locked */ - unsigned int references; dns_viewlist_t viewlist; ISC_LIST(struct resctx) resctxs; ISC_LIST(struct reqctx) reqctxs; @@ -508,8 +510,7 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx, result = isc_mutex_init(&client->lock); if (result != ISC_R_SUCCESS) { - isc_mem_put(mctx, client, sizeof(*client)); - return (result); + goto cleanup_client; } client->actx = actx; @@ -519,12 +520,14 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx, client->task = NULL; result = isc_task_create(client->taskmgr, 0, &client->task); - if (result != ISC_R_SUCCESS) - goto cleanup; + if (result != ISC_R_SUCCESS) { + goto cleanup_lock; + } result = dns_dispatchmgr_create(mctx, NULL, &dispatchmgr); - if (result != ISC_R_SUCCESS) - goto cleanup; + if (result != ISC_R_SUCCESS) { + goto cleanup_task; + } client->dispatchmgr = dispatchmgr; (void)setsourceports(mctx, dispatchmgr); @@ -537,8 +540,9 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx, result = getudpdispatch(AF_INET, dispatchmgr, socketmgr, taskmgr, true, &dispatchv4, localaddr4); - if (result == ISC_R_SUCCESS) + if (result == ISC_R_SUCCESS) { client->dispatchv4 = dispatchv4; + } } client->dispatchv6 = NULL; @@ -546,22 +550,30 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx, result = getudpdispatch(AF_INET6, dispatchmgr, socketmgr, taskmgr, true, &dispatchv6, localaddr6); - if (result == ISC_R_SUCCESS) + if (result == ISC_R_SUCCESS) { client->dispatchv6 = dispatchv6; + } } /* We need at least one of the dispatchers */ if (dispatchv4 == NULL && dispatchv6 == NULL) { INSIST(result != ISC_R_SUCCESS); - goto cleanup; + goto cleanup_dispatchmgr; + } + + result = isc_refcount_init(&client->references, 1); + if (result != ISC_R_SUCCESS) { + goto cleanup_dispatches; } /* Create the default view for class IN */ result = createview(mctx, dns_rdataclass_in, options, taskmgr, RESOLVER_NTASKS, socketmgr, timermgr, dispatchmgr, dispatchv4, dispatchv6, &view); - if (result != ISC_R_SUCCESS) - goto cleanup; + if (result != ISC_R_SUCCESS) { + goto cleanup_references; + } + ISC_LIST_INIT(client->viewlist); ISC_LIST_APPEND(client->viewlist, view, link); @@ -581,32 +593,38 @@ dns_client_createx2(isc_mem_t *mctx, isc_appctx_t *actx, client->find_udpretries = DEF_FIND_UDPRETRIES; client->attributes = 0; - client->references = 1; client->magic = DNS_CLIENT_MAGIC; *clientp = client; return (ISC_R_SUCCESS); - cleanup: + cleanup_references: + isc_refcount_decrement(&client->references, NULL); + isc_refcount_destroy(&client->references); + cleanup_dispatches: if (dispatchv4 != NULL) dns_dispatch_detach(&dispatchv4); if (dispatchv6 != NULL) dns_dispatch_detach(&dispatchv6); - if (dispatchmgr != NULL) - dns_dispatchmgr_destroy(&dispatchmgr); - if (client->task != NULL) - isc_task_detach(&client->task); + cleanup_dispatchmgr: + dns_dispatchmgr_destroy(&dispatchmgr); + cleanup_task: + isc_task_detach(&client->task); + cleanup_lock: + DESTROYLOCK(&client->lock); + cleanup_client: isc_mem_put(mctx, client, sizeof(*client)); return (result); } static void -destroyclient(dns_client_t **clientp) { - dns_client_t *client = *clientp; +destroyclient(dns_client_t *client) { dns_view_t *view; + isc_refcount_destroy(&client->references); + while ((view = ISC_LIST_HEAD(client->viewlist)) != NULL) { ISC_LIST_UNLINK(client->viewlist, view, link); dns_view_detach(&view); @@ -638,32 +656,22 @@ destroyclient(dns_client_t **clientp) { client->magic = 0; isc_mem_putanddetach(&client->mctx, client, sizeof(*client)); - - *clientp = NULL; } void dns_client_destroy(dns_client_t **clientp) { dns_client_t *client; - bool destroyok = false; + uint32_t references; REQUIRE(clientp != NULL); client = *clientp; + *clientp = NULL; REQUIRE(DNS_CLIENT_VALID(client)); - LOCK(&client->lock); - client->references--; - if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) && - ISC_LIST_EMPTY(client->reqctxs) && - ISC_LIST_EMPTY(client->updatectxs)) { - destroyok = true; + isc_refcount_decrement(&client->references, &references); + if (references == 0U) { + destroyclient(client); } - UNLOCK(&client->lock); - - if (destroyok) - destroyclient(&client); - - *clientp = NULL; } isc_result_t @@ -1459,6 +1467,7 @@ dns_client_startresolve(dns_client_t *client, dns_name_t *name, rctx->event = event; rctx->magic = RCTX_MAGIC; + isc_refcount_increment(&client->references, NULL); LOCK(&client->lock); ISC_LIST_APPEND(client->resctxs, rctx, link); @@ -1529,10 +1538,10 @@ dns_client_destroyrestrans(dns_clientrestrans_t **transp) { resctx_t *rctx; isc_mem_t *mctx; dns_client_t *client; - bool need_destroyclient = false; REQUIRE(transp != NULL); rctx = (resctx_t *)*transp; + *transp = NULL; REQUIRE(RCTX_VALID(rctx)); REQUIRE(rctx->fetch == NULL); REQUIRE(rctx->event == NULL); @@ -1554,11 +1563,6 @@ dns_client_destroyrestrans(dns_clientrestrans_t **transp) { INSIST(ISC_LINK_LINKED(rctx, link)); ISC_LIST_UNLINK(client->resctxs, rctx, link); - if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) && - ISC_LIST_EMPTY(client->reqctxs) && - ISC_LIST_EMPTY(client->updatectxs)) - need_destroyclient = true; - UNLOCK(&client->lock); INSIST(ISC_LIST_EMPTY(rctx->namelist)); @@ -1568,10 +1572,8 @@ dns_client_destroyrestrans(dns_clientrestrans_t **transp) { isc_mem_put(mctx, rctx, sizeof(*rctx)); - if (need_destroyclient) - destroyclient(&client); + dns_client_destroy(&client); - *transp = NULL; } isc_result_t @@ -1845,6 +1847,7 @@ dns_client_startrequest(dns_client_t *client, dns_message_t *qmessage, LOCK(&client->lock); ISC_LIST_APPEND(client->reqctxs, ctx, link); + isc_refcount_increment(&client->references, NULL); UNLOCK(&client->lock); ctx->request = NULL; @@ -1859,6 +1862,8 @@ dns_client_startrequest(dns_client_t *client, dns_message_t *qmessage, return (ISC_R_SUCCESS); } + isc_refcount_decrement(&client->references, NULL); + cleanup: if (ctx != NULL) { LOCK(&client->lock); @@ -1899,10 +1904,10 @@ dns_client_destroyreqtrans(dns_clientreqtrans_t **transp) { reqctx_t *ctx; isc_mem_t *mctx; dns_client_t *client; - bool need_destroyclient = false; REQUIRE(transp != NULL); ctx = (reqctx_t *)*transp; + *transp = NULL; REQUIRE(REQCTX_VALID(ctx)); client = ctx->client; REQUIRE(DNS_CLIENT_VALID(client)); @@ -1917,12 +1922,6 @@ dns_client_destroyreqtrans(dns_clientreqtrans_t **transp) { INSIST(ISC_LINK_LINKED(ctx, link)); ISC_LIST_UNLINK(client->reqctxs, ctx, link); - if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) && - ISC_LIST_EMPTY(client->reqctxs) && - ISC_LIST_EMPTY(client->updatectxs)) { - need_destroyclient = true; - } - UNLOCK(&client->lock); DESTROYLOCK(&ctx->lock); @@ -1930,10 +1929,7 @@ dns_client_destroyreqtrans(dns_clientreqtrans_t **transp) { isc_mem_put(mctx, ctx, sizeof(*ctx)); - if (need_destroyclient) - destroyclient(&client); - - *transp = NULL; + dns_client_destroy(&client); } /*% @@ -3023,6 +3019,7 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass, LOCK(&client->lock); ISC_LIST_APPEND(client->updatectxs, uctx, link); + isc_refcount_increment(&client->references, NULL); UNLOCK(&client->lock); *transp = (dns_clientupdatetrans_t *)uctx; @@ -3041,6 +3038,8 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass, } if (result == ISC_R_SUCCESS) return (result); + + isc_refcount_decrement(&client->references, NULL); *transp = NULL; fail: @@ -3098,11 +3097,11 @@ dns_client_destroyupdatetrans(dns_clientupdatetrans_t **transp) { updatectx_t *uctx; isc_mem_t *mctx; dns_client_t *client; - bool need_destroyclient = false; isc_sockaddr_t *sa; REQUIRE(transp != NULL); uctx = (updatectx_t *)*transp; + *transp = NULL; REQUIRE(UCTX_VALID(uctx)); client = uctx->client; REQUIRE(DNS_CLIENT_VALID(client)); @@ -3123,11 +3122,6 @@ dns_client_destroyupdatetrans(dns_clientupdatetrans_t **transp) { INSIST(ISC_LINK_LINKED(uctx, link)); ISC_LIST_UNLINK(client->updatectxs, uctx, link); - if (client->references == 0 && ISC_LIST_EMPTY(client->resctxs) && - ISC_LIST_EMPTY(client->reqctxs) && - ISC_LIST_EMPTY(client->updatectxs)) - need_destroyclient = true; - UNLOCK(&client->lock); DESTROYLOCK(&uctx->lock); @@ -3135,10 +3129,7 @@ dns_client_destroyupdatetrans(dns_clientupdatetrans_t **transp) { isc_mem_put(mctx, uctx, sizeof(*uctx)); - if (need_destroyclient) - destroyclient(&client); - - *transp = NULL; + dns_client_destroy(&client); } isc_mem_t *