Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_zone_module.c @ 6957:83bae3d354ab
HTTP/2: fixed connection finalization.
All streams in connection must be finalized before the connection
itself can be finalized and all related memory is freed. That's
not always possible on the current event loop iteration.
Thus when the last stream is finalized, it sets the special read
event handler ngx_http_v2_handle_connection_handler() and posts
the event.
Previously, this handler didn't check the connection state and
could call the regular event handler on a connection that was
already in finalization stage. In the worst case that could
lead to a segmentation fault, since some data structures aren't
supposed to be used during connection finalization. Particularly,
the waiting queue can contain already freed streams, so the
WINDOW_UPDATE frame received by that moment could trigger
accessing to these freed streams.
Now, the connection error flag is explicitly checked in
ngx_http_v2_handle_connection_handler().
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Wed, 29 Mar 2017 20:21:01 +0300 |
parents | 8ed51b02f655 |
children | 1eb753aa8e5e |
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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_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_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)); peers->shpool = shpool; for (peerp = &peers->peer; *peerp; peerp = &peer->next) { /* pool is unlocked */ peer = ngx_slab_calloc_locked(shpool, sizeof(ngx_stream_upstream_rr_peer_t)); if (peer == NULL) { return NULL; } ngx_memcpy(peer, *peerp, sizeof(ngx_stream_upstream_rr_peer_t)); *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->shpool = shpool; for (peerp = &backup->peer; *peerp; peerp = &peer->next) { /* pool is unlocked */ peer = ngx_slab_calloc_locked(shpool, sizeof(ngx_stream_upstream_rr_peer_t)); if (peer == NULL) { return NULL; } ngx_memcpy(peer, *peerp, sizeof(ngx_stream_upstream_rr_peer_t)); *peerp = peer; } peers->next = backup; done: uscf->peer.data = peers; return peers; }