Mercurial > hg > nginx-quic
view src/stream/ngx_stream_upstream_round_robin.c @ 8867:5119c8150478
Fixed runtime handling of systems without EPOLLRDHUP support.
In 7583:efd71d49bde0 (nginx 1.17.5) along with introduction of the
ioctl(FIONREAD) support proper handling of systems without EPOLLRDHUP
support in the kernel (but with EPOLLRDHUP in headers) was broken.
Before the change, rev->available was never set to 0 unless
ngx_use_epoll_rdhup was also set (that is, runtime test for EPOLLRDHUP
introduced in 6536:f7849bfb6d21 succeeded). After the change,
rev->available might reach 0 on systems without runtime EPOLLRDHUP
support, stopping further reading in ngx_readv_chain() and ngx_unix_recv().
And, if EOF happened to be already reported along with the last event,
it is not reported again by epoll_wait(), leading to connection hangs
and timeouts on such systems.
This affects Linux kernels before 2.6.17 if nginx was compiled
with newer headers, and, more importantly, emulation layers, such as
DigitalOcean's App Platform's / gVisor's epoll emulation layer.
Fix is to explicitly check ngx_use_epoll_rdhup before the corresponding
rev->pending_eof tests in ngx_readv_chain() and ngx_unix_recv().
author | Marcus Ball <marcus.ball@live.com> |
---|---|
date | Mon, 30 May 2022 02:38:07 +0300 |
parents | 90cc7194e993 |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> #define ngx_stream_upstream_tries(p) ((p)->tries \ + ((p)->next ? (p)->next->tries : 0)) static ngx_stream_upstream_rr_peer_t *ngx_stream_upstream_get_peer( ngx_stream_upstream_rr_peer_data_t *rrp); static void ngx_stream_upstream_notify_round_robin_peer( ngx_peer_connection_t *pc, void *data, ngx_uint_t state); #if (NGX_STREAM_SSL) static ngx_int_t ngx_stream_upstream_set_round_robin_peer_session( ngx_peer_connection_t *pc, void *data); static void ngx_stream_upstream_save_round_robin_peer_session( ngx_peer_connection_t *pc, void *data); static ngx_int_t ngx_stream_upstream_empty_set_session( ngx_peer_connection_t *pc, void *data); static void ngx_stream_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data); #endif ngx_int_t ngx_stream_upstream_init_round_robin(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us) { ngx_url_t u; ngx_uint_t i, j, n, w, t; ngx_stream_upstream_server_t *server; ngx_stream_upstream_rr_peer_t *peer, **peerp; ngx_stream_upstream_rr_peers_t *peers, *backup; us->peer.init = ngx_stream_upstream_init_round_robin_peer; if (us->servers) { server = us->servers->elts; n = 0; w = 0; t = 0; for (i = 0; i < us->servers->nelts; i++) { if (server[i].backup) { continue; } n += server[i].naddrs; w += server[i].naddrs * server[i].weight; if (!server[i].down) { t += server[i].naddrs; } } if (n == 0) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no servers in upstream \"%V\" in %s:%ui", &us->host, us->file_name, us->line); return NGX_ERROR; } peers = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peer_t) * n); if (peer == NULL) { return NGX_ERROR; } peers->single = (n == 1); peers->number = n; peers->weighted = (w != n); peers->total_weight = w; peers->tries = t; peers->name = &us->host; n = 0; peerp = &peers->peer; for (i = 0; i < us->servers->nelts; i++) { if (server[i].backup) { continue; } for (j = 0; j < server[i].naddrs; j++) { peer[n].sockaddr = server[i].addrs[j].sockaddr; peer[n].socklen = server[i].addrs[j].socklen; peer[n].name = server[i].addrs[j].name; peer[n].weight = server[i].weight; peer[n].effective_weight = server[i].weight; peer[n].current_weight = 0; peer[n].max_conns = server[i].max_conns; peer[n].max_fails = server[i].max_fails; peer[n].fail_timeout = server[i].fail_timeout; peer[n].down = server[i].down; peer[n].server = server[i].name; *peerp = &peer[n]; peerp = &peer[n].next; n++; } } us->peer.data = peers; /* backup servers */ n = 0; w = 0; t = 0; for (i = 0; i < us->servers->nelts; i++) { if (!server[i].backup) { continue; } n += server[i].naddrs; w += server[i].naddrs * server[i].weight; if (!server[i].down) { t += server[i].naddrs; } } if (n == 0) { return NGX_OK; } backup = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t)); if (backup == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peer_t) * n); if (peer == NULL) { return NGX_ERROR; } peers->single = 0; backup->single = 0; backup->number = n; backup->weighted = (w != n); backup->total_weight = w; backup->tries = t; backup->name = &us->host; n = 0; peerp = &backup->peer; for (i = 0; i < us->servers->nelts; i++) { if (!server[i].backup) { continue; } for (j = 0; j < server[i].naddrs; j++) { peer[n].sockaddr = server[i].addrs[j].sockaddr; peer[n].socklen = server[i].addrs[j].socklen; peer[n].name = server[i].addrs[j].name; peer[n].weight = server[i].weight; peer[n].effective_weight = server[i].weight; peer[n].current_weight = 0; peer[n].max_conns = server[i].max_conns; peer[n].max_fails = server[i].max_fails; peer[n].fail_timeout = server[i].fail_timeout; peer[n].down = server[i].down; peer[n].server = server[i].name; *peerp = &peer[n]; peerp = &peer[n].next; n++; } } peers->next = backup; return NGX_OK; } /* an upstream implicitly defined by proxy_pass, etc. */ if (us->port == 0) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "no port in upstream \"%V\" in %s:%ui", &us->host, us->file_name, us->line); return NGX_ERROR; } ngx_memzero(&u, sizeof(ngx_url_t)); u.host = us->host; u.port = us->port; if (ngx_inet_resolve_host(cf->pool, &u) != NGX_OK) { if (u.err) { ngx_log_error(NGX_LOG_EMERG, cf->log, 0, "%s in upstream \"%V\" in %s:%ui", u.err, &us->host, us->file_name, us->line); } return NGX_ERROR; } n = u.naddrs; peers = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_rr_peer_t) * n); if (peer == NULL) { return NGX_ERROR; } peers->single = (n == 1); peers->number = n; peers->weighted = 0; peers->total_weight = n; peers->tries = n; peers->name = &us->host; peerp = &peers->peer; for (i = 0; i < u.naddrs; i++) { peer[i].sockaddr = u.addrs[i].sockaddr; peer[i].socklen = u.addrs[i].socklen; peer[i].name = u.addrs[i].name; peer[i].weight = 1; peer[i].effective_weight = 1; peer[i].current_weight = 0; peer[i].max_conns = 0; peer[i].max_fails = 1; peer[i].fail_timeout = 10; *peerp = &peer[i]; peerp = &peer[i].next; } us->peer.data = peers; /* implicitly defined upstream has no backup servers */ return NGX_OK; } ngx_int_t ngx_stream_upstream_init_round_robin_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us) { ngx_uint_t n; ngx_stream_upstream_rr_peer_data_t *rrp; rrp = s->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } s->upstream->peer.data = rrp; } rrp->peers = us->peer.data; rrp->current = NULL; rrp->config = 0; n = rrp->peers->number; if (rrp->peers->next && rrp->peers->next->number > n) { n = rrp->peers->next->number; } if (n <= 8 * sizeof(uintptr_t)) { rrp->tried = &rrp->data; rrp->data = 0; } else { n = (n + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t)); rrp->tried = ngx_pcalloc(s->connection->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer; s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer; s->upstream->peer.notify = ngx_stream_upstream_notify_round_robin_peer; s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers); #if (NGX_STREAM_SSL) s->upstream->peer.set_session = ngx_stream_upstream_set_round_robin_peer_session; s->upstream->peer.save_session = ngx_stream_upstream_save_round_robin_peer_session; #endif return NGX_OK; } ngx_int_t ngx_stream_upstream_create_round_robin_peer(ngx_stream_session_t *s, ngx_stream_upstream_resolved_t *ur) { u_char *p; size_t len; socklen_t socklen; ngx_uint_t i, n; struct sockaddr *sockaddr; ngx_stream_upstream_rr_peer_t *peer, **peerp; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_rr_peer_data_t *rrp; rrp = s->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } s->upstream->peer.data = rrp; } peers = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(s->connection->pool, sizeof(ngx_stream_upstream_rr_peer_t) * ur->naddrs); if (peer == NULL) { return NGX_ERROR; } peers->single = (ur->naddrs == 1); peers->number = ur->naddrs; peers->tries = ur->naddrs; peers->name = &ur->host; if (ur->sockaddr) { peer[0].sockaddr = ur->sockaddr; peer[0].socklen = ur->socklen; peer[0].name = ur->name; peer[0].weight = 1; peer[0].effective_weight = 1; peer[0].current_weight = 0; peer[0].max_conns = 0; peer[0].max_fails = 1; peer[0].fail_timeout = 10; peers->peer = peer; } else { peerp = &peers->peer; for (i = 0; i < ur->naddrs; i++) { socklen = ur->addrs[i].socklen; sockaddr = ngx_palloc(s->connection->pool, socklen); if (sockaddr == NULL) { return NGX_ERROR; } ngx_memcpy(sockaddr, ur->addrs[i].sockaddr, socklen); ngx_inet_set_port(sockaddr, ur->port); p = ngx_pnalloc(s->connection->pool, NGX_SOCKADDR_STRLEN); if (p == NULL) { return NGX_ERROR; } len = ngx_sock_ntop(sockaddr, socklen, p, NGX_SOCKADDR_STRLEN, 1); peer[i].sockaddr = sockaddr; peer[i].socklen = socklen; peer[i].name.len = len; peer[i].name.data = p; peer[i].weight = 1; peer[i].effective_weight = 1; peer[i].current_weight = 0; peer[i].max_conns = 0; peer[i].max_fails = 1; peer[i].fail_timeout = 10; *peerp = &peer[i]; peerp = &peer[i].next; } } rrp->peers = peers; rrp->current = NULL; rrp->config = 0; if (rrp->peers->number <= 8 * sizeof(uintptr_t)) { rrp->tried = &rrp->data; rrp->data = 0; } else { n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t)); rrp->tried = ngx_pcalloc(s->connection->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } s->upstream->peer.get = ngx_stream_upstream_get_round_robin_peer; s->upstream->peer.free = ngx_stream_upstream_free_round_robin_peer; s->upstream->peer.tries = ngx_stream_upstream_tries(rrp->peers); #if (NGX_STREAM_SSL) s->upstream->peer.set_session = ngx_stream_upstream_empty_set_session; s->upstream->peer.save_session = ngx_stream_upstream_empty_save_session; #endif return NGX_OK; } ngx_int_t ngx_stream_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_uint_t i, n; ngx_stream_upstream_rr_peer_t *peer; ngx_stream_upstream_rr_peers_t *peers; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get rr peer, try: %ui", pc->tries); pc->connection = NULL; peers = rrp->peers; ngx_stream_upstream_rr_peers_wlock(peers); if (peers->single) { peer = peers->peer; if (peer->down) { goto failed; } if (peer->max_conns && peer->conns >= peer->max_conns) { goto failed; } rrp->current = peer; } else { /* there are several peers */ peer = ngx_stream_upstream_get_peer(rrp); if (peer == NULL) { goto failed; } ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get rr peer, current: %p %i", peer, peer->current_weight); } pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; peer->conns++; ngx_stream_upstream_rr_peers_unlock(peers); return NGX_OK; failed: if (peers->next) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, pc->log, 0, "backup servers"); rrp->peers = peers->next; n = (rrp->peers->number + (8 * sizeof(uintptr_t) - 1)) / (8 * sizeof(uintptr_t)); for (i = 0; i < n; i++) { rrp->tried[i] = 0; } ngx_stream_upstream_rr_peers_unlock(peers); rc = ngx_stream_upstream_get_round_robin_peer(pc, rrp); if (rc != NGX_BUSY) { return rc; } ngx_stream_upstream_rr_peers_wlock(peers); } ngx_stream_upstream_rr_peers_unlock(peers); pc->name = peers->name; return NGX_BUSY; } static ngx_stream_upstream_rr_peer_t * ngx_stream_upstream_get_peer(ngx_stream_upstream_rr_peer_data_t *rrp) { time_t now; uintptr_t m; ngx_int_t total; ngx_uint_t i, n, p; ngx_stream_upstream_rr_peer_t *peer, *best; now = ngx_time(); best = NULL; total = 0; #if (NGX_SUPPRESS_WARN) p = 0; #endif for (peer = rrp->peers->peer, i = 0; peer; peer = peer->next, i++) { n = i / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); if (rrp->tried[n] & m) { continue; } if (peer->down) { continue; } if (peer->max_fails && peer->fails >= peer->max_fails && now - peer->checked <= peer->fail_timeout) { continue; } if (peer->max_conns && peer->conns >= peer->max_conns) { continue; } peer->current_weight += peer->effective_weight; total += peer->effective_weight; if (peer->effective_weight < peer->weight) { peer->effective_weight++; } if (best == NULL || peer->current_weight > best->current_weight) { best = peer; p = i; } } if (best == NULL) { return NULL; } rrp->current = best; n = p / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); rrp->tried[n] |= m; best->current_weight -= total; if (now - best->checked > best->fail_timeout) { best->checked = now; } return best; } void ngx_stream_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state) { ngx_stream_upstream_rr_peer_data_t *rrp = data; time_t now; ngx_stream_upstream_rr_peer_t *peer; ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0, "free rr peer %ui %ui", pc->tries, state); peer = rrp->current; ngx_stream_upstream_rr_peers_rlock(rrp->peers); ngx_stream_upstream_rr_peer_lock(rrp->peers, peer); if (rrp->peers->single) { peer->conns--; ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer); ngx_stream_upstream_rr_peers_unlock(rrp->peers); pc->tries = 0; return; } if (state & NGX_PEER_FAILED) { now = ngx_time(); peer->fails++; peer->accessed = now; peer->checked = now; if (peer->max_fails) { peer->effective_weight -= peer->weight / peer->max_fails; if (peer->fails >= peer->max_fails) { ngx_log_error(NGX_LOG_WARN, pc->log, 0, "upstream server temporarily disabled"); } } ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0, "free rr peer failed: %p %i", peer, peer->effective_weight); if (peer->effective_weight < 0) { peer->effective_weight = 0; } } else { /* mark peer live if check passed */ if (peer->accessed < peer->checked) { peer->fails = 0; } } peer->conns--; ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer); ngx_stream_upstream_rr_peers_unlock(rrp->peers); if (pc->tries) { pc->tries--; } } static void ngx_stream_upstream_notify_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t type) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_stream_upstream_rr_peer_t *peer; peer = rrp->current; if (type == NGX_STREAM_UPSTREAM_NOTIFY_CONNECT && pc->connection->type == SOCK_STREAM) { ngx_stream_upstream_rr_peers_rlock(rrp->peers); ngx_stream_upstream_rr_peer_lock(rrp->peers, peer); if (peer->accessed < peer->checked) { peer->fails = 0; } ngx_stream_upstream_rr_peer_unlock(rrp->peers, peer); ngx_stream_upstream_rr_peers_unlock(rrp->peers); } } #if (NGX_STREAM_SSL) static ngx_int_t ngx_stream_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_ssl_session_t *ssl_session; ngx_stream_upstream_rr_peer_t *peer; #if (NGX_STREAM_UPSTREAM_ZONE) int len; const u_char *p; ngx_stream_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif peer = rrp->current; #if (NGX_STREAM_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ngx_stream_upstream_rr_peers_rlock(peers); ngx_stream_upstream_rr_peer_lock(peers, peer); if (peer->ssl_session == NULL) { ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); return NGX_OK; } len = peer->ssl_session_len; ngx_memcpy(buf, peer->ssl_session, len); ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); p = buf; ssl_session = d2i_SSL_SESSION(NULL, &p, len); rc = ngx_ssl_set_session(pc->connection, ssl_session); ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "set session: %p", ssl_session); ngx_ssl_free_session(ssl_session); return rc; } #endif ssl_session = peer->ssl_session; rc = ngx_ssl_set_session(pc->connection, ssl_session); ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "set session: %p", ssl_session); return rc; } static void ngx_stream_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_rr_peer_data_t *rrp = data; ngx_ssl_session_t *old_ssl_session, *ssl_session; ngx_stream_upstream_rr_peer_t *peer; #if (NGX_STREAM_UPSTREAM_ZONE) int len; u_char *p; ngx_stream_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif #if (NGX_STREAM_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ssl_session = ngx_ssl_get0_session(pc->connection); if (ssl_session == NULL) { return; } ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "save session: %p", ssl_session); len = i2d_SSL_SESSION(ssl_session, NULL); /* do not cache too big session */ if (len > NGX_SSL_MAX_SESSION_SIZE) { return; } p = buf; (void) i2d_SSL_SESSION(ssl_session, &p); peer = rrp->current; ngx_stream_upstream_rr_peers_rlock(peers); ngx_stream_upstream_rr_peer_lock(peers, peer); if (len > peer->ssl_session_len) { ngx_shmtx_lock(&peers->shpool->mutex); if (peer->ssl_session) { ngx_slab_free_locked(peers->shpool, peer->ssl_session); } peer->ssl_session = ngx_slab_alloc_locked(peers->shpool, len); ngx_shmtx_unlock(&peers->shpool->mutex); if (peer->ssl_session == NULL) { peer->ssl_session_len = 0; ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); return; } peer->ssl_session_len = len; } ngx_memcpy(peer->ssl_session, buf, len); ngx_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); return; } #endif ssl_session = ngx_ssl_get_session(pc->connection); if (ssl_session == NULL) { return; } ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "save session: %p", ssl_session); peer = rrp->current; old_ssl_session = peer->ssl_session; peer->ssl_session = ssl_session; if (old_ssl_session) { ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "old session: %p", old_ssl_session); /* TODO: may block */ ngx_ssl_free_session(old_ssl_session); } } static ngx_int_t ngx_stream_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data) { return NGX_OK; } static void ngx_stream_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data) { return; } #endif