From: Ondřej Surý Date: Tue, 6 Aug 2019 15:35:20 +0000 (+0200) Subject: Have the dns_client hold a .references until all external references are removed X-Git-Tag: v9.15.3~8^2 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4db3189de253403c31a0a0188c676441c2c164f1;p=thirdparty%2Fbind9.git Have the dns_client hold a .references until all external references are removed so that cleanup can all be done in dns_client_destroy(). (cherry picked from commit e80c4c3431504a462ce03bffbb9229b9b34395d1) (cherry picked from commit ebc48cda26ff3935406f48bb745561cc00fed046) --- diff --git a/lib/dns/client.c b/lib/dns/client.c index 2bd667e6f3b..8e765d989f1 100644 --- a/lib/dns/client.c +++ b/lib/dns/client.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -92,8 +93,9 @@ 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; @@ -498,12 +500,13 @@ dns_client_createx(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, &dispatchmgr); if (result != ISC_R_SUCCESS) - goto cleanup; + goto cleanup_task; client->dispatchmgr = dispatchmgr; (void)setsourceports(mctx, dispatchmgr); @@ -516,8 +519,9 @@ dns_client_createx(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; @@ -525,22 +529,27 @@ dns_client_createx(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; } + isc_refcount_init(&client->references, 1); + /* 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); @@ -560,32 +569,38 @@ dns_client_createx(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: - if (dispatchv4 != NULL) + cleanup_references: + isc_refcount_decrement(&client->references); + isc_refcount_destroy(&client->references); + cleanup_dispatchmgr: + if (dispatchv4 != NULL) { dns_dispatch_detach(&dispatchv4); - if (dispatchv6 != NULL) + } + if (dispatchv6 != NULL) { dns_dispatch_detach(&dispatchv6); - if (dispatchmgr != NULL) - dns_dispatchmgr_destroy(&dispatchmgr); - if (client->task != NULL) - isc_task_detach(&client->task); + } + dns_dispatchmgr_destroy(&dispatchmgr); + cleanup_task: + isc_task_detach(&client->task); + cleanup_lock: + isc_mutex_destroy(&client->lock); 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); @@ -617,32 +632,20 @@ 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; 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; + if (isc_refcount_decrement(&client->references) == 1) { + destroyclient(client); } - UNLOCK(&client->lock); - - if (destroyok) - destroyclient(&client); - - *clientp = NULL; } isc_result_t @@ -1428,6 +1431,7 @@ dns_client_startresolve(dns_client_t *client, const dns_name_t *name, rctx->event = event; rctx->magic = RCTX_MAGIC; + isc_refcount_increment(&client->references); LOCK(&client->lock); ISC_LIST_APPEND(client->resctxs, rctx, link); @@ -1498,10 +1502,10 @@ 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); @@ -1523,11 +1527,6 @@ 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)); @@ -1537,10 +1536,8 @@ 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 @@ -1804,6 +1801,7 @@ 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); UNLOCK(&client->lock); ctx->request = NULL; @@ -1818,6 +1816,8 @@ dns_client_startrequest(dns_client_t *client, dns_message_t *qmessage, return (ISC_R_SUCCESS); } + isc_refcount_decrement(&client->references); + cleanup: if (ctx != NULL) { LOCK(&client->lock); @@ -1858,10 +1858,10 @@ 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)); @@ -1876,12 +1876,6 @@ 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); isc_mutex_destroy(&ctx->lock); @@ -1889,10 +1883,7 @@ 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); } /*% @@ -2962,6 +2953,7 @@ 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); UNLOCK(&client->lock); *transp = (dns_clientupdatetrans_t *)uctx; @@ -2980,6 +2972,8 @@ dns_client_startupdate(dns_client_t *client, dns_rdataclass_t rdclass, } if (result == ISC_R_SUCCESS) return (result); + + isc_refcount_decrement(&client->references); *transp = NULL; fail: @@ -3037,11 +3031,11 @@ 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)); @@ -3062,11 +3056,6 @@ 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); isc_mutex_destroy(&uctx->lock); @@ -3074,10 +3063,7 @@ 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 *