Mercurial > hg > nginx
view src/event/ngx_event_udp.c @ 8106:8852f39311de
Fixed segfault when switching off master process during upgrade.
Binary upgrades are not supported without master process, but it is,
however, possible, that nginx running with master process is asked
to upgrade binary, and the configuration file as available on disk
at this time includes "master_process off;".
If this happens, listening sockets inherited from the previous binary
will have ls[i].previous set. But the old cycle on initial process
startup, including startup after binary upgrade, is destroyed by
ngx_init_cycle() once configuration parsing is complete. As a result,
an attempt to dereference ls[i].previous in ngx_event_process_init()
accesses already freed memory.
Fix is to avoid looking into ls[i].previous if the old cycle is already
freed.
With this change it is also no longer needed to clear ls[i].previous in
worker processes, so the relevant code was removed.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Wed, 23 Nov 2022 23:48:53 +0300 |
parents | 32b0ba4855a6 |
children | 3108d4d668e4 ce6d9cf0f567 |
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/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_event.h> #if !(NGX_WIN32) struct ngx_udp_connection_s { ngx_rbtree_node_t node; ngx_connection_t *connection; ngx_buf_t *buffer; }; static void ngx_close_accepted_udp_connection(ngx_connection_t *c); static ssize_t ngx_udp_shared_recv(ngx_connection_t *c, u_char *buf, size_t size); static ngx_int_t ngx_insert_udp_connection(ngx_connection_t *c); static ngx_connection_t *ngx_lookup_udp_connection(ngx_listening_t *ls, struct sockaddr *sockaddr, socklen_t socklen, struct sockaddr *local_sockaddr, socklen_t local_socklen); void ngx_event_recvmsg(ngx_event_t *ev) { ssize_t n; ngx_buf_t buf; ngx_log_t *log; ngx_err_t err; socklen_t socklen, local_socklen; ngx_event_t *rev, *wev; struct iovec iov[1]; struct msghdr msg; ngx_sockaddr_t sa, lsa; struct sockaddr *sockaddr, *local_sockaddr; ngx_listening_t *ls; ngx_event_conf_t *ecf; ngx_connection_t *c, *lc; static u_char buffer[65535]; #if (NGX_HAVE_ADDRINFO_CMSG) u_char msg_control[CMSG_SPACE(sizeof(ngx_addrinfo_t))]; #endif if (ev->timedout) { if (ngx_enable_accept_events((ngx_cycle_t *) ngx_cycle) != NGX_OK) { return; } ev->timedout = 0; } ecf = ngx_event_get_conf(ngx_cycle->conf_ctx, ngx_event_core_module); if (!(ngx_event_flags & NGX_USE_KQUEUE_EVENT)) { ev->available = ecf->multi_accept; } lc = ev->data; ls = lc->listening; ev->ready = 0; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, ev->log, 0, "recvmsg on %V, ready: %d", &ls->addr_text, ev->available); do { ngx_memzero(&msg, sizeof(struct msghdr)); iov[0].iov_base = (void *) buffer; iov[0].iov_len = sizeof(buffer); msg.msg_name = &sa; msg.msg_namelen = sizeof(ngx_sockaddr_t); msg.msg_iov = iov; msg.msg_iovlen = 1; #if (NGX_HAVE_ADDRINFO_CMSG) if (ls->wildcard) { msg.msg_control = &msg_control; msg.msg_controllen = sizeof(msg_control); ngx_memzero(&msg_control, sizeof(msg_control)); } #endif n = recvmsg(lc->fd, &msg, 0); if (n == -1) { err = ngx_socket_errno; if (err == NGX_EAGAIN) { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ev->log, err, "recvmsg() not ready"); return; } ngx_log_error(NGX_LOG_ALERT, ev->log, err, "recvmsg() failed"); return; } #if (NGX_HAVE_ADDRINFO_CMSG) if (msg.msg_flags & (MSG_TRUNC|MSG_CTRUNC)) { ngx_log_error(NGX_LOG_ALERT, ev->log, 0, "recvmsg() truncated data"); continue; } #endif sockaddr = msg.msg_name; socklen = msg.msg_namelen; if (socklen > (socklen_t) sizeof(ngx_sockaddr_t)) { socklen = sizeof(ngx_sockaddr_t); } if (socklen == 0) { /* * on Linux recvmsg() returns zero msg_namelen * when receiving packets from unbound AF_UNIX sockets */ socklen = sizeof(struct sockaddr); ngx_memzero(&sa, sizeof(struct sockaddr)); sa.sockaddr.sa_family = ls->sockaddr->sa_family; } local_sockaddr = ls->sockaddr; local_socklen = ls->socklen; #if (NGX_HAVE_ADDRINFO_CMSG) if (ls->wildcard) { struct cmsghdr *cmsg; ngx_memcpy(&lsa, local_sockaddr, local_socklen); local_sockaddr = &lsa.sockaddr; for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL; cmsg = CMSG_NXTHDR(&msg, cmsg)) { if (ngx_get_srcaddr_cmsg(cmsg, local_sockaddr) == NGX_OK) { break; } } } #endif c = ngx_lookup_udp_connection(ls, sockaddr, socklen, local_sockaddr, local_socklen); if (c) { #if (NGX_DEBUG) if (c->log->log_level & NGX_LOG_DEBUG_EVENT) { ngx_log_handler_pt handler; handler = c->log->handler; c->log->handler = NULL; ngx_log_debug2(NGX_LOG_DEBUG_EVENT, c->log, 0, "recvmsg: fd:%d n:%z", c->fd, n); c->log->handler = handler; } #endif ngx_memzero(&buf, sizeof(ngx_buf_t)); buf.pos = buffer; buf.last = buffer + n; rev = c->read; c->udp->buffer = &buf; rev->ready = 1; rev->active = 0; rev->handler(rev); if (c->udp) { c->udp->buffer = NULL; } rev->ready = 0; rev->active = 1; goto next; } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_accepted, 1); #endif ngx_accept_disabled = ngx_cycle->connection_n / 8 - ngx_cycle->free_connection_n; c = ngx_get_connection(lc->fd, ev->log); if (c == NULL) { return; } c->shared = 1; c->type = SOCK_DGRAM; c->socklen = socklen; #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, 1); #endif c->pool = ngx_create_pool(ls->pool_size, ev->log); if (c->pool == NULL) { ngx_close_accepted_udp_connection(c); return; } c->sockaddr = ngx_palloc(c->pool, socklen); if (c->sockaddr == NULL) { ngx_close_accepted_udp_connection(c); return; } ngx_memcpy(c->sockaddr, sockaddr, socklen); log = ngx_palloc(c->pool, sizeof(ngx_log_t)); if (log == NULL) { ngx_close_accepted_udp_connection(c); return; } *log = ls->log; c->recv = ngx_udp_shared_recv; c->send = ngx_udp_send; c->send_chain = ngx_udp_send_chain; c->need_flush_buf = 1; c->log = log; c->pool->log = log; c->listening = ls; if (local_sockaddr == &lsa.sockaddr) { local_sockaddr = ngx_palloc(c->pool, local_socklen); if (local_sockaddr == NULL) { ngx_close_accepted_udp_connection(c); return; } ngx_memcpy(local_sockaddr, &lsa, local_socklen); } c->local_sockaddr = local_sockaddr; c->local_socklen = local_socklen; c->buffer = ngx_create_temp_buf(c->pool, n); if (c->buffer == NULL) { ngx_close_accepted_udp_connection(c); return; } c->buffer->last = ngx_cpymem(c->buffer->last, buffer, n); rev = c->read; wev = c->write; rev->active = 1; wev->ready = 1; rev->log = log; wev->log = log; /* * TODO: MT: - ngx_atomic_fetch_add() * or protection by critical section or light mutex * * TODO: MP: - allocated in a shared memory * - ngx_atomic_fetch_add() * or protection by critical section or light mutex */ c->number = ngx_atomic_fetch_add(ngx_connection_counter, 1); c->start_time = ngx_current_msec; #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_handled, 1); #endif if (ls->addr_ntop) { c->addr_text.data = ngx_pnalloc(c->pool, ls->addr_text_max_len); if (c->addr_text.data == NULL) { ngx_close_accepted_udp_connection(c); return; } c->addr_text.len = ngx_sock_ntop(c->sockaddr, c->socklen, c->addr_text.data, ls->addr_text_max_len, 0); if (c->addr_text.len == 0) { ngx_close_accepted_udp_connection(c); return; } } #if (NGX_DEBUG) { ngx_str_t addr; u_char text[NGX_SOCKADDR_STRLEN]; ngx_debug_accepted_connection(ecf, c); if (log->log_level & NGX_LOG_DEBUG_EVENT) { addr.data = text; addr.len = ngx_sock_ntop(c->sockaddr, c->socklen, text, NGX_SOCKADDR_STRLEN, 1); ngx_log_debug4(NGX_LOG_DEBUG_EVENT, log, 0, "*%uA recvmsg: %V fd:%d n:%z", c->number, &addr, c->fd, n); } } #endif if (ngx_insert_udp_connection(c) != NGX_OK) { ngx_close_accepted_udp_connection(c); return; } log->data = NULL; log->handler = NULL; ls->handler(c); next: if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) { ev->available -= n; } } while (ev->available); } static void ngx_close_accepted_udp_connection(ngx_connection_t *c) { ngx_free_connection(c); c->fd = (ngx_socket_t) -1; if (c->pool) { ngx_destroy_pool(c->pool); } #if (NGX_STAT_STUB) (void) ngx_atomic_fetch_add(ngx_stat_active, -1); #endif } static ssize_t ngx_udp_shared_recv(ngx_connection_t *c, u_char *buf, size_t size) { ssize_t n; ngx_buf_t *b; if (c->udp == NULL || c->udp->buffer == NULL) { return NGX_AGAIN; } b = c->udp->buffer; n = ngx_min(b->last - b->pos, (ssize_t) size); ngx_memcpy(buf, b->pos, n); c->udp->buffer = NULL; c->read->ready = 0; c->read->active = 1; return n; } void ngx_udp_rbtree_insert_value(ngx_rbtree_node_t *temp, ngx_rbtree_node_t *node, ngx_rbtree_node_t *sentinel) { ngx_int_t rc; ngx_connection_t *c, *ct; ngx_rbtree_node_t **p; ngx_udp_connection_t *udp, *udpt; for ( ;; ) { if (node->key < temp->key) { p = &temp->left; } else if (node->key > temp->key) { p = &temp->right; } else { /* node->key == temp->key */ udp = (ngx_udp_connection_t *) node; c = udp->connection; udpt = (ngx_udp_connection_t *) temp; ct = udpt->connection; rc = ngx_cmp_sockaddr(c->sockaddr, c->socklen, ct->sockaddr, ct->socklen, 1); if (rc == 0 && c->listening->wildcard) { rc = ngx_cmp_sockaddr(c->local_sockaddr, c->local_socklen, ct->local_sockaddr, ct->local_socklen, 1); } p = (rc < 0) ? &temp->left : &temp->right; } if (*p == sentinel) { break; } temp = *p; } *p = node; node->parent = temp; node->left = sentinel; node->right = sentinel; ngx_rbt_red(node); } static ngx_int_t ngx_insert_udp_connection(ngx_connection_t *c) { uint32_t hash; ngx_pool_cleanup_t *cln; ngx_udp_connection_t *udp; if (c->udp) { return NGX_OK; } udp = ngx_pcalloc(c->pool, sizeof(ngx_udp_connection_t)); if (udp == NULL) { return NGX_ERROR; } udp->connection = c; ngx_crc32_init(hash); ngx_crc32_update(&hash, (u_char *) c->sockaddr, c->socklen); if (c->listening->wildcard) { ngx_crc32_update(&hash, (u_char *) c->local_sockaddr, c->local_socklen); } ngx_crc32_final(hash); udp->node.key = hash; cln = ngx_pool_cleanup_add(c->pool, 0); if (cln == NULL) { return NGX_ERROR; } cln->data = c; cln->handler = ngx_delete_udp_connection; ngx_rbtree_insert(&c->listening->rbtree, &udp->node); c->udp = udp; return NGX_OK; } void ngx_delete_udp_connection(void *data) { ngx_connection_t *c = data; if (c->udp == NULL) { return; } ngx_rbtree_delete(&c->listening->rbtree, &c->udp->node); c->udp = NULL; } static ngx_connection_t * ngx_lookup_udp_connection(ngx_listening_t *ls, struct sockaddr *sockaddr, socklen_t socklen, struct sockaddr *local_sockaddr, socklen_t local_socklen) { uint32_t hash; ngx_int_t rc; ngx_connection_t *c; ngx_rbtree_node_t *node, *sentinel; ngx_udp_connection_t *udp; #if (NGX_HAVE_UNIX_DOMAIN) if (sockaddr->sa_family == AF_UNIX) { struct sockaddr_un *saun = (struct sockaddr_un *) sockaddr; if (socklen <= (socklen_t) offsetof(struct sockaddr_un, sun_path) || saun->sun_path[0] == '\0') { ngx_log_debug0(NGX_LOG_DEBUG_EVENT, ngx_cycle->log, 0, "unbound unix socket"); return NULL; } } #endif node = ls->rbtree.root; sentinel = ls->rbtree.sentinel; ngx_crc32_init(hash); ngx_crc32_update(&hash, (u_char *) sockaddr, socklen); if (ls->wildcard) { ngx_crc32_update(&hash, (u_char *) local_sockaddr, local_socklen); } ngx_crc32_final(hash); while (node != sentinel) { if (hash < node->key) { node = node->left; continue; } if (hash > node->key) { node = node->right; continue; } /* hash == node->key */ udp = (ngx_udp_connection_t *) node; c = udp->connection; rc = ngx_cmp_sockaddr(sockaddr, socklen, c->sockaddr, c->socklen, 1); if (rc == 0 && ls->wildcard) { rc = ngx_cmp_sockaddr(local_sockaddr, local_socklen, c->local_sockaddr, c->local_socklen, 1); } if (rc == 0) { return c; } node = (rc < 0) ? node->left : node->right; } return NULL; } #else void ngx_delete_udp_connection(void *data) { return; } #endif