From e8b56acb49f65b5143cd3f0d6f5e863df625a4c7 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ond=C5=99ej=20Sur=C3=BD?= Date: Fri, 18 Sep 2020 12:27:40 +0200 Subject: [PATCH] Clone the csock in accept_connection(), not in callback If we clone the csock (children socket) in TCP accept_connection() instead of passing the ssock (server socket) to the call back and cloning it there we unbreak the assumption that every socket is handled inside it's own worker thread and therefore we can get rid of (at least) callback locking. --- lib/isc/netmgr/netmgr.c | 1 + lib/isc/netmgr/tcp.c | 82 +++++++++++++++++++---------------------- lib/isc/netmgr/tcpdns.c | 14 ++----- lib/isc/netmgr/udp.c | 7 +--- 4 files changed, 42 insertions(+), 62 deletions(-) diff --git a/lib/isc/netmgr/netmgr.c b/lib/isc/netmgr/netmgr.c index 6ee8bb7288..c1eb14005a 100644 --- a/lib/isc/netmgr/netmgr.c +++ b/lib/isc/netmgr/netmgr.c @@ -1040,6 +1040,7 @@ isc__nmsocket_init(isc_nmsocket_t *sock, isc_nm_t *mgr, isc_nmsocket_type type, void isc__nmsocket_clearcb(isc_nmsocket_t *sock) { REQUIRE(VALID_NMSOCK(sock)); + REQUIRE(!isc__nm_in_netthread() || sock->tid == isc_nm_tid()); sock->recv_cb = NULL; sock->recv_cbarg = NULL; diff --git a/lib/isc/netmgr/tcp.c b/lib/isc/netmgr/tcp.c index cb7331d342..208e703d07 100644 --- a/lib/isc/netmgr/tcp.c +++ b/lib/isc/netmgr/tcp.c @@ -431,8 +431,7 @@ void isc__nm_async_tcpchildaccept(isc__networker_t *worker, isc__netievent_t *ev0) { isc__netievent_tcpchildaccept_t *ievent = (isc__netievent_tcpchildaccept_t *)ev0; - isc_nmsocket_t *ssock = ievent->sock; - isc_nmsocket_t *csock = NULL; + isc_nmsocket_t *sock = ievent->sock; isc_nmhandle_t *handle; isc_result_t result; struct sockaddr_storage ss; @@ -442,20 +441,15 @@ isc__nm_async_tcpchildaccept(isc__networker_t *worker, isc__netievent_t *ev0) { void *accept_cbarg; REQUIRE(isc__nm_in_netthread()); - REQUIRE(ssock->type == isc_nm_tcplistener); + REQUIRE(sock->tid == isc_nm_tid()); - csock = isc_mem_get(ssock->mgr->mctx, sizeof(isc_nmsocket_t)); - isc__nmsocket_init(csock, ssock->mgr, isc_nm_tcpsocket, ssock->iface); - csock->tid = isc_nm_tid(); - csock->extrahandlesize = ssock->extrahandlesize; - - csock->quota = ievent->quota; + sock->quota = ievent->quota; ievent->quota = NULL; - worker = &ssock->mgr->workers[isc_nm_tid()]; - uv_tcp_init(&worker->loop, &csock->uv_handle.tcp); + worker = &sock->mgr->workers[isc_nm_tid()]; + uv_tcp_init(&worker->loop, &sock->uv_handle.tcp); - r = isc_uv_import(&csock->uv_handle.stream, &ievent->streaminfo); + r = isc_uv_import(&sock->uv_handle.stream, &ievent->streaminfo); if (r != 0) { isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, ISC_LOGMODULE_NETMGR, ISC_LOG_ERROR, @@ -465,20 +459,19 @@ isc__nm_async_tcpchildaccept(isc__networker_t *worker, isc__netievent_t *ev0) { goto error; } - r = uv_tcp_getpeername(&csock->uv_handle.tcp, (struct sockaddr *)&ss, + r = uv_tcp_getpeername(&sock->uv_handle.tcp, (struct sockaddr *)&ss, &(int){ sizeof(ss) }); if (r != 0) { result = isc__nm_uverr2result(r); goto error; } - result = isc_sockaddr_fromsockaddr(&csock->peer, - (struct sockaddr *)&ss); + result = isc_sockaddr_fromsockaddr(&sock->peer, (struct sockaddr *)&ss); if (result != ISC_R_SUCCESS) { goto error; } - r = uv_tcp_getsockname(&csock->uv_handle.tcp, (struct sockaddr *)&ss, + r = uv_tcp_getsockname(&sock->uv_handle.tcp, (struct sockaddr *)&ss, &(int){ sizeof(ss) }); if (r != 0) { result = isc__nm_uverr2result(r); @@ -490,23 +483,19 @@ isc__nm_async_tcpchildaccept(isc__networker_t *worker, isc__netievent_t *ev0) { goto error; } - isc__nmsocket_attach(ssock, &csock->server); + handle = isc__nmhandle_get(sock, NULL, &local); - handle = isc__nmhandle_get(csock, NULL, &local); + INSIST(sock->accept_cb != NULL); + accept_cb = sock->accept_cb; + accept_cbarg = sock->accept_cbarg; - LOCK(&ssock->lock); - INSIST(ssock->accept_cb != NULL); - accept_cb = ssock->accept_cb; - accept_cbarg = ssock->accept_cbarg; - UNLOCK(&ssock->lock); - - csock->read_timeout = ssock->mgr->init; + sock->read_timeout = sock->mgr->init; accept_cb(handle, ISC_R_SUCCESS, accept_cbarg); /* - * csock is now attached to the handle. + * sock is now attached to the handle. */ - isc__nmsocket_detach(&csock); + isc__nmsocket_detach(&sock); /* * The accept callback should have attached to the handle. @@ -521,8 +510,8 @@ error: * otherwise it'd be detached later asynchronously, and clog * the quota unnecessarily. */ - if (csock->quota != NULL) { - isc_quota_detach(&csock->quota); + if (sock->quota != NULL) { + isc_quota_detach(&sock->quota); } isc_log_write(isc_lctx, ISC_LOGCATEGORY_GENERAL, ISC_LOGMODULE_NETMGR, ISC_LOG_ERROR, "Accepting TCP connection failed: %s", @@ -531,7 +520,7 @@ error: /* * Detach the socket properly to make sure uv_close() is called. */ - isc__nmsocket_detach(&csock); + isc__nmsocket_detach(&sock); } void @@ -616,11 +605,9 @@ readtimeout_cb(uv_timer_t *handle) { isc_quota_detach(&sock->quota); } - LOCK(&sock->lock); cb = sock->recv_cb; cbarg = sock->recv_cbarg; isc__nmsocket_clearcb(sock); - UNLOCK(&sock->lock); if (cb != NULL) { cb(sock->statichandle, ISC_R_TIMEDOUT, NULL, cbarg); @@ -637,10 +624,9 @@ isc__nm_tcp_read(isc_nmhandle_t *handle, isc_nm_recv_cb_t cb, void *cbarg) { sock = handle->sock; - LOCK(&sock->lock); + REQUIRE(sock->tid == isc_nm_tid()); sock->recv_cb = cb; sock->recv_cbarg = cbarg; - UNLOCK(&sock->lock); ievent = isc__nm_get_ievent(sock->mgr, netievent_tcpstartread); ievent->sock = sock; @@ -749,12 +735,11 @@ isc__nm_tcp_resumeread(isc_nmsocket_t *sock) { isc__netievent_startread_t *ievent = NULL; REQUIRE(VALID_NMSOCK(sock)); - LOCK(&sock->lock); + REQUIRE(sock->tid == isc_nm_tid()); + if (sock->recv_cb == NULL) { - UNLOCK(&sock->lock); return (ISC_R_CANCELED); } - UNLOCK(&sock->lock); if (!atomic_load(&sock->readpaused)) { return (ISC_R_SUCCESS); @@ -784,12 +769,11 @@ read_cb(uv_stream_t *stream, ssize_t nread, const uv_buf_t *buf) { void *cbarg; REQUIRE(VALID_NMSOCK(sock)); + REQUIRE(sock->tid == isc_nm_tid()); REQUIRE(buf != NULL); - LOCK(&sock->lock); cb = sock->recv_cb; cbarg = sock->recv_cbarg; - UNLOCK(&sock->lock); if (nread >= 0) { isc_region_t region = { .base = (unsigned char *)buf->base, @@ -895,7 +879,6 @@ accept_connection(isc_nmsocket_t *ssock, isc_quota_t *quota) { int r, w; REQUIRE(VALID_NMSOCK(ssock)); - REQUIRE(ssock->tid == isc_nm_tid()); if (!atomic_load_relaxed(&ssock->active) || atomic_load_relaxed(&ssock->mgr->closing)) @@ -955,7 +938,18 @@ accept_connection(isc_nmsocket_t *ssock, isc_quota_t *quota) { /* We have an accepted TCP socket, pass it to a random worker */ w = isc_random_uniform(ssock->mgr->nworkers); event = isc__nm_get_ievent(ssock->mgr, netievent_tcpchildaccept); - event->sock = ssock; + + /* Duplicate the server socket */ + isc_nmsocket_t *csock = isc_mem_get(ssock->mgr->mctx, + sizeof(isc_nmsocket_t)); + isc__nmsocket_init(csock, ssock->mgr, isc_nm_tcpsocket, ssock->iface); + csock->tid = w; + csock->extrahandlesize = ssock->extrahandlesize; + isc__nmsocket_attach(ssock, &csock->server); + csock->accept_cb = ssock->accept_cb; + csock->accept_cbarg = ssock->accept_cbarg; + + event->sock = csock; event->quota = quota; r = isc_uv_export((uv_stream_t *)uvstream, &event->streaminfo); @@ -1149,16 +1143,15 @@ isc__nm_async_tcpclose(isc__networker_t *worker, isc__netievent_t *ev0) { void isc__nm_tcp_shutdown(isc_nmsocket_t *sock) { REQUIRE(VALID_NMSOCK(sock)); + REQUIRE(sock->tid == isc_nm_tid()); if (sock->type == isc_nm_tcpsocket && sock->statichandle != NULL) { isc_nm_recv_cb_t cb; void *cbarg; - LOCK(&sock->lock); cb = sock->recv_cb; cbarg = sock->recv_cbarg; isc__nmsocket_clearcb(sock); - UNLOCK(&sock->lock); if (cb != NULL) { cb(sock->statichandle, ISC_R_CANCELED, NULL, cbarg); @@ -1176,16 +1169,15 @@ isc__nm_tcp_cancelread(isc_nmhandle_t *handle) { REQUIRE(VALID_NMSOCK(sock)); REQUIRE(sock->type == isc_nm_tcpsocket); + REQUIRE(sock->tid == isc_nm_tid()); if (atomic_load(&sock->client)) { isc_nm_recv_cb_t cb; void *cbarg; - LOCK(&sock->lock); cb = sock->recv_cb; cbarg = sock->recv_cbarg; isc__nmsocket_clearcb(sock); - UNLOCK(&sock->lock); cb(handle, ISC_R_EOF, NULL, cbarg); } diff --git a/lib/isc/netmgr/tcpdns.c b/lib/isc/netmgr/tcpdns.c index 8060bbfe9a..283f77665e 100644 --- a/lib/isc/netmgr/tcpdns.c +++ b/lib/isc/netmgr/tcpdns.c @@ -119,10 +119,8 @@ dnslisten_acceptcb(isc_nmhandle_t *handle, isc_result_t result, void *cbarg) { return (result); } - LOCK(&dnslistensock->lock); accept_cb = dnslistensock->accept_cb; accept_cbarg = dnslistensock->accept_cbarg; - UNLOCK(&dnslistensock->lock); if (accept_cb != NULL) { result = accept_cb(handle, ISC_R_SUCCESS, accept_cbarg); @@ -184,6 +182,7 @@ processbuffer(isc_nmsocket_t *dnssock, isc_nmhandle_t **handlep) { size_t len; REQUIRE(VALID_NMSOCK(dnssock)); + REQUIRE(dnssock->tid == isc_nm_tid()); REQUIRE(handlep != NULL && *handlep == NULL); /* @@ -214,12 +213,9 @@ processbuffer(isc_nmsocket_t *dnssock, isc_nmhandle_t **handlep) { listener = dnssock->listener; if (listener != NULL) { - LOCK(&listener->lock); cb = listener->recv_cb; cbarg = listener->recv_cbarg; - UNLOCK(&listener->lock); } else if (dnssock->recv_cb != NULL) { - LOCK(&dnssock->lock); cb = dnssock->recv_cb; cbarg = dnssock->recv_cbarg; /* @@ -228,7 +224,6 @@ processbuffer(isc_nmsocket_t *dnssock, isc_nmhandle_t **handlep) { * call to isc_nm_read() and set up a new callback. */ isc__nmsocket_clearcb(dnssock); - UNLOCK(&dnssock->lock); } if (cb != NULL) { @@ -265,6 +260,7 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult, size_t len; REQUIRE(VALID_NMSOCK(dnssock)); + REQUIRE(dnssock->tid == isc_nm_tid()); REQUIRE(VALID_NMHANDLE(handle)); if (region == NULL || eresult != ISC_R_SUCCESS) { @@ -314,10 +310,8 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult, uv_timer_stop(&dnssock->timer); } - LOCK(&dnssock->lock); if (atomic_load(&dnssock->sequential) || dnssock->recv_cb == NULL) { - UNLOCK(&dnssock->lock); /* * There are two reasons we might want to pause here: * - We're in sequential mode and we've received @@ -328,7 +322,6 @@ dnslisten_readcb(isc_nmhandle_t *handle, isc_result_t eresult, isc_nm_pauseread(dnssock->outerhandle); done = true; } else { - UNLOCK(&dnssock->lock); /* * We're pipelining, so we now resume processing * packets until the clients-per-connection limit @@ -364,12 +357,10 @@ isc_nm_listentcpdns(isc_nm_t *mgr, isc_nmiface_t *iface, isc_nm_recv_cb_t cb, REQUIRE(VALID_NM(mgr)); isc__nmsocket_init(dnslistensock, mgr, isc_nm_tcpdnslistener, iface); - LOCK(&dnslistensock->lock); dnslistensock->recv_cb = cb; dnslistensock->recv_cbarg = cbarg; dnslistensock->accept_cb = accept_cb; dnslistensock->accept_cbarg = accept_cbarg; - UNLOCK(&dnslistensock->lock); dnslistensock->extrahandlesize = extrahandlesize; /* @@ -558,6 +549,7 @@ isc__nm_async_tcpdnssend(isc__networker_t *worker, isc__netievent_t *ev0) { isc_nmsocket_t *sock = ievent->sock; REQUIRE(worker->id == sock->tid); + REQUIRE(sock->tid == isc_nm_tid()); result = ISC_R_NOTCONNECTED; if (atomic_load(&sock->active) && sock->outerhandle != NULL) { diff --git a/lib/isc/netmgr/udp.c b/lib/isc/netmgr/udp.c index b6785935f1..f87ab95a5f 100644 --- a/lib/isc/netmgr/udp.c +++ b/lib/isc/netmgr/udp.c @@ -379,12 +379,7 @@ udp_recv_cb(uv_udp_t *handle, ssize_t nrecv, const uv_buf_t *buf, region.base = (unsigned char *)buf->base; region.length = nrecv; - /* - * In tcp.c and tcpdns.c, this would need to be locked - * by sock->lock because callbacks may be set to NULL - * unexpectedly when the connection drops, but that isn't - * a factor in the UDP case. - */ + INSIST(sock->tid == isc_nm_tid()); INSIST(sock->recv_cb != NULL); cb = sock->recv_cb; cbarg = sock->recv_cbarg;