Mercurial > hg > nginx
view src/http/ngx_http_upstream_round_robin.c @ 8164:b71e69247483
Variables: avoid possible buffer overrun with some "$sent_http_*".
The existing logic to evaluate multi header "$sent_http_*" variables,
such as $sent_http_cache_control, as previously introduced in 1.23.0,
doesn't take into account that one or more elements can be cleared,
yet still present in a linked list, pointed to by the next field.
Such elements don't contribute to the resulting variable length, an
attempt to append a separator for them ends up in out of bounds write.
This is not possible with standard modules, though at least one third
party module is known to override multi header values this way, so it
makes sense to harden the logic.
The fix restores a generic boundary check.
author | Sergey Kandaurov <pluknet@nginx.com> |
---|---|
date | Mon, 01 May 2023 19:16:05 +0400 |
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_http.h> #define ngx_http_upstream_tries(p) ((p)->tries \ + ((p)->next ? (p)->next->tries : 0)) static ngx_http_upstream_rr_peer_t *ngx_http_upstream_get_peer( ngx_http_upstream_rr_peer_data_t *rrp); #if (NGX_HTTP_SSL) static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data); static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data); #endif ngx_int_t ngx_http_upstream_init_round_robin(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us) { ngx_url_t u; ngx_uint_t i, j, n, w, t; ngx_http_upstream_server_t *server; ngx_http_upstream_rr_peer_t *peer, **peerp; ngx_http_upstream_rr_peers_t *peers, *backup; us->peer.init = ngx_http_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_http_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_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_http_upstream_rr_peers_t)); if (backup == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_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_http_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(cf->pool, sizeof(ngx_http_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_http_upstream_init_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { ngx_uint_t n; ngx_http_upstream_rr_peer_data_t *rrp; rrp = r->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } r->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(r->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer; r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer; r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers); #if (NGX_HTTP_SSL) r->upstream->peer.set_session = ngx_http_upstream_set_round_robin_peer_session; r->upstream->peer.save_session = ngx_http_upstream_save_round_robin_peer_session; #endif return NGX_OK; } ngx_int_t ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_resolved_t *ur) { u_char *p; size_t len; socklen_t socklen; ngx_uint_t i, n; struct sockaddr *sockaddr; ngx_http_upstream_rr_peer_t *peer, **peerp; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_rr_peer_data_t *rrp; rrp = r->upstream->peer.data; if (rrp == NULL) { rrp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_rr_peer_data_t)); if (rrp == NULL) { return NGX_ERROR; } r->upstream->peer.data = rrp; } peers = ngx_pcalloc(r->pool, sizeof(ngx_http_upstream_rr_peers_t)); if (peers == NULL) { return NGX_ERROR; } peer = ngx_pcalloc(r->pool, sizeof(ngx_http_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.data ? ur->name : ur->host; 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(r->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(r->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(r->pool, n * sizeof(uintptr_t)); if (rrp->tried == NULL) { return NGX_ERROR; } } r->upstream->peer.get = ngx_http_upstream_get_round_robin_peer; r->upstream->peer.free = ngx_http_upstream_free_round_robin_peer; r->upstream->peer.tries = ngx_http_upstream_tries(rrp->peers); #if (NGX_HTTP_SSL) r->upstream->peer.set_session = ngx_http_upstream_empty_set_session; r->upstream->peer.save_session = ngx_http_upstream_empty_save_session; #endif return NGX_OK; } ngx_int_t ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_uint_t i, n; ngx_http_upstream_rr_peer_t *peer; ngx_http_upstream_rr_peers_t *peers; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get rr peer, try: %ui", pc->tries); pc->cached = 0; pc->connection = NULL; peers = rrp->peers; ngx_http_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_http_upstream_get_peer(rrp); if (peer == NULL) { goto failed; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, 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_http_upstream_rr_peers_unlock(peers); return NGX_OK; failed: if (peers->next) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, 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_http_upstream_rr_peers_unlock(peers); rc = ngx_http_upstream_get_round_robin_peer(pc, rrp); if (rc != NGX_BUSY) { return rc; } ngx_http_upstream_rr_peers_wlock(peers); } ngx_http_upstream_rr_peers_unlock(peers); pc->name = peers->name; return NGX_BUSY; } static ngx_http_upstream_rr_peer_t * ngx_http_upstream_get_peer(ngx_http_upstream_rr_peer_data_t *rrp) { time_t now; uintptr_t m; ngx_int_t total; ngx_uint_t i, n, p; ngx_http_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_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state) { ngx_http_upstream_rr_peer_data_t *rrp = data; time_t now; ngx_http_upstream_rr_peer_t *peer; ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "free rr peer %ui %ui", pc->tries, state); /* TODO: NGX_PEER_KEEPALIVE */ peer = rrp->current; ngx_http_upstream_rr_peers_rlock(rrp->peers); ngx_http_upstream_rr_peer_lock(rrp->peers, peer); if (rrp->peers->single) { peer->conns--; ngx_http_upstream_rr_peer_unlock(rrp->peers, peer); ngx_http_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_HTTP, 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_http_upstream_rr_peer_unlock(rrp->peers, peer); ngx_http_upstream_rr_peers_unlock(rrp->peers); if (pc->tries) { pc->tries--; } } #if (NGX_HTTP_SSL) ngx_int_t ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; ngx_int_t rc; ngx_ssl_session_t *ssl_session; ngx_http_upstream_rr_peer_t *peer; #if (NGX_HTTP_UPSTREAM_ZONE) int len; const u_char *p; ngx_http_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif peer = rrp->current; #if (NGX_HTTP_UPSTREAM_ZONE) peers = rrp->peers; if (peers->shpool) { ngx_http_upstream_rr_peers_rlock(peers); ngx_http_upstream_rr_peer_lock(peers, peer); if (peer->ssl_session == NULL) { ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); return NGX_OK; } len = peer->ssl_session_len; ngx_memcpy(buf, peer->ssl_session, len); ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_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_HTTP, 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_HTTP, pc->log, 0, "set session: %p", ssl_session); return rc; } void ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_rr_peer_data_t *rrp = data; ngx_ssl_session_t *old_ssl_session, *ssl_session; ngx_http_upstream_rr_peer_t *peer; #if (NGX_HTTP_UPSTREAM_ZONE) int len; u_char *p; ngx_http_upstream_rr_peers_t *peers; u_char buf[NGX_SSL_MAX_SESSION_SIZE]; #endif #if (NGX_HTTP_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_HTTP, 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_http_upstream_rr_peers_rlock(peers); ngx_http_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_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); return; } peer->ssl_session_len = len; } ngx_memcpy(peer->ssl_session, buf, len); ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_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_HTTP, 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_HTTP, pc->log, 0, "old session: %p", old_ssl_session); /* TODO: may block */ ngx_ssl_free_session(old_ssl_session); } } static ngx_int_t ngx_http_upstream_empty_set_session(ngx_peer_connection_t *pc, void *data) { return NGX_OK; } static void ngx_http_upstream_empty_save_session(ngx_peer_connection_t *pc, void *data) { return; } #endif