Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_zone_module.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 | 3b1b81e248bc |
children |
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/* * Copyright (C) Ruslan Ermilov * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> static char *ngx_stream_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_int_t ngx_stream_upstream_init_zone(ngx_shm_zone_t *shm_zone, void *data); static ngx_stream_upstream_rr_peers_t *ngx_stream_upstream_zone_copy_peers( ngx_slab_pool_t *shpool, ngx_stream_upstream_srv_conf_t *uscf); static ngx_stream_upstream_rr_peer_t *ngx_stream_upstream_zone_copy_peer( ngx_stream_upstream_rr_peers_t *peers, ngx_stream_upstream_rr_peer_t *src); static ngx_command_t ngx_stream_upstream_zone_commands[] = { { ngx_string("zone"), NGX_STREAM_UPS_CONF|NGX_CONF_TAKE12, ngx_stream_upstream_zone, 0, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_upstream_zone_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_upstream_zone_module = { NGX_MODULE_V1, &ngx_stream_upstream_zone_module_ctx, /* module context */ ngx_stream_upstream_zone_commands, /* module directives */ NGX_STREAM_MODULE, /* module type */ NULL, /* init master */ NULL, /* init module */ NULL, /* init process */ NULL, /* init thread */ NULL, /* exit thread */ NULL, /* exit process */ NULL, /* exit master */ NGX_MODULE_V1_PADDING }; static char * ngx_stream_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ssize_t size; ngx_str_t *value; ngx_stream_upstream_srv_conf_t *uscf; ngx_stream_upstream_main_conf_t *umcf; uscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_upstream_module); umcf = ngx_stream_conf_get_module_main_conf(cf, ngx_stream_upstream_module); value = cf->args->elts; if (!value[1].len) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid zone name \"%V\"", &value[1]); return NGX_CONF_ERROR; } if (cf->args->nelts == 3) { size = ngx_parse_size(&value[2]); if (size == NGX_ERROR) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid zone size \"%V\"", &value[2]); return NGX_CONF_ERROR; } if (size < (ssize_t) (8 * ngx_pagesize)) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "zone \"%V\" is too small", &value[1]); return NGX_CONF_ERROR; } } else { size = 0; } uscf->shm_zone = ngx_shared_memory_add(cf, &value[1], size, &ngx_stream_upstream_module); if (uscf->shm_zone == NULL) { return NGX_CONF_ERROR; } uscf->shm_zone->init = ngx_stream_upstream_init_zone; uscf->shm_zone->data = umcf; uscf->shm_zone->noreuse = 1; return NGX_CONF_OK; } static ngx_int_t ngx_stream_upstream_init_zone(ngx_shm_zone_t *shm_zone, void *data) { size_t len; ngx_uint_t i; ngx_slab_pool_t *shpool; ngx_stream_upstream_rr_peers_t *peers, **peersp; ngx_stream_upstream_srv_conf_t *uscf, **uscfp; ngx_stream_upstream_main_conf_t *umcf; shpool = (ngx_slab_pool_t *) shm_zone->shm.addr; umcf = shm_zone->data; uscfp = umcf->upstreams.elts; if (shm_zone->shm.exists) { peers = shpool->data; for (i = 0; i < umcf->upstreams.nelts; i++) { uscf = uscfp[i]; if (uscf->shm_zone != shm_zone) { continue; } uscf->peer.data = peers; peers = peers->zone_next; } return NGX_OK; } len = sizeof(" in upstream zone \"\"") + shm_zone->shm.name.len; shpool->log_ctx = ngx_slab_alloc(shpool, len); if (shpool->log_ctx == NULL) { return NGX_ERROR; } ngx_sprintf(shpool->log_ctx, " in upstream zone \"%V\"%Z", &shm_zone->shm.name); /* copy peers to shared memory */ peersp = (ngx_stream_upstream_rr_peers_t **) (void *) &shpool->data; for (i = 0; i < umcf->upstreams.nelts; i++) { uscf = uscfp[i]; if (uscf->shm_zone != shm_zone) { continue; } peers = ngx_stream_upstream_zone_copy_peers(shpool, uscf); if (peers == NULL) { return NGX_ERROR; } *peersp = peers; peersp = &peers->zone_next; } return NGX_OK; } static ngx_stream_upstream_rr_peers_t * ngx_stream_upstream_zone_copy_peers(ngx_slab_pool_t *shpool, ngx_stream_upstream_srv_conf_t *uscf) { ngx_str_t *name; ngx_stream_upstream_rr_peer_t *peer, **peerp; ngx_stream_upstream_rr_peers_t *peers, *backup; peers = ngx_slab_alloc(shpool, sizeof(ngx_stream_upstream_rr_peers_t)); if (peers == NULL) { return NULL; } ngx_memcpy(peers, uscf->peer.data, sizeof(ngx_stream_upstream_rr_peers_t)); name = ngx_slab_alloc(shpool, sizeof(ngx_str_t)); if (name == NULL) { return NULL; } name->data = ngx_slab_alloc(shpool, peers->name->len); if (name->data == NULL) { return NULL; } ngx_memcpy(name->data, peers->name->data, peers->name->len); name->len = peers->name->len; peers->name = name; peers->shpool = shpool; for (peerp = &peers->peer; *peerp; peerp = &peer->next) { /* pool is unlocked */ peer = ngx_stream_upstream_zone_copy_peer(peers, *peerp); if (peer == NULL) { return NULL; } *peerp = peer; } if (peers->next == NULL) { goto done; } backup = ngx_slab_alloc(shpool, sizeof(ngx_stream_upstream_rr_peers_t)); if (backup == NULL) { return NULL; } ngx_memcpy(backup, peers->next, sizeof(ngx_stream_upstream_rr_peers_t)); backup->name = name; backup->shpool = shpool; for (peerp = &backup->peer; *peerp; peerp = &peer->next) { /* pool is unlocked */ peer = ngx_stream_upstream_zone_copy_peer(backup, *peerp); if (peer == NULL) { return NULL; } *peerp = peer; } peers->next = backup; done: uscf->peer.data = peers; return peers; } static ngx_stream_upstream_rr_peer_t * ngx_stream_upstream_zone_copy_peer(ngx_stream_upstream_rr_peers_t *peers, ngx_stream_upstream_rr_peer_t *src) { ngx_slab_pool_t *pool; ngx_stream_upstream_rr_peer_t *dst; pool = peers->shpool; dst = ngx_slab_calloc_locked(pool, sizeof(ngx_stream_upstream_rr_peer_t)); if (dst == NULL) { return NULL; } if (src) { ngx_memcpy(dst, src, sizeof(ngx_stream_upstream_rr_peer_t)); dst->sockaddr = NULL; dst->name.data = NULL; dst->server.data = NULL; } dst->sockaddr = ngx_slab_calloc_locked(pool, sizeof(ngx_sockaddr_t)); if (dst->sockaddr == NULL) { goto failed; } dst->name.data = ngx_slab_calloc_locked(pool, NGX_SOCKADDR_STRLEN); if (dst->name.data == NULL) { goto failed; } if (src) { ngx_memcpy(dst->sockaddr, src->sockaddr, src->socklen); ngx_memcpy(dst->name.data, src->name.data, src->name.len); dst->server.data = ngx_slab_alloc_locked(pool, src->server.len); if (dst->server.data == NULL) { goto failed; } ngx_memcpy(dst->server.data, src->server.data, src->server.len); } return dst; failed: if (dst->server.data) { ngx_slab_free_locked(pool, dst->server.data); } if (dst->name.data) { ngx_slab_free_locked(pool, dst->name.data); } if (dst->sockaddr) { ngx_slab_free_locked(pool, dst->sockaddr); } ngx_slab_free_locked(pool, dst); return NULL; }