Mercurial > hg > nginx
view src/http/modules/ngx_http_upstream_zone_module.c @ 9282:acb8548c00e9
HTTP/3: fixed dynamic table overflow.
While inserting a new entry into the dynamic table, first the entry is added,
and then older entries are evicted until table size is within capacity. After
the first step, the number of entries may temporarily exceed the maximum
calculated from capacity by one entry, which previously caused table overflow.
The easiest way to trigger the issue is to keep adding entries with empty names
and values until first eviction.
The issue was introduced by 987bee4363d1.
author | Roman Arutyunyan <arut@nginx.com> |
---|---|
date | Tue, 28 May 2024 17:18:50 +0400 |
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_http.h> static char *ngx_http_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_int_t ngx_http_upstream_init_zone(ngx_shm_zone_t *shm_zone, void *data); static ngx_http_upstream_rr_peers_t *ngx_http_upstream_zone_copy_peers( ngx_slab_pool_t *shpool, ngx_http_upstream_srv_conf_t *uscf); static ngx_http_upstream_rr_peer_t *ngx_http_upstream_zone_copy_peer( ngx_http_upstream_rr_peers_t *peers, ngx_http_upstream_rr_peer_t *src); static ngx_command_t ngx_http_upstream_zone_commands[] = { { ngx_string("zone"), NGX_HTTP_UPS_CONF|NGX_CONF_TAKE12, ngx_http_upstream_zone, 0, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_upstream_zone_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ NULL, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_upstream_zone_module = { NGX_MODULE_V1, &ngx_http_upstream_zone_module_ctx, /* module context */ ngx_http_upstream_zone_commands, /* module directives */ NGX_HTTP_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_http_upstream_zone(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ssize_t size; ngx_str_t *value; ngx_http_upstream_srv_conf_t *uscf; ngx_http_upstream_main_conf_t *umcf; uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module); umcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_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_http_upstream_module); if (uscf->shm_zone == NULL) { return NGX_CONF_ERROR; } uscf->shm_zone->init = ngx_http_upstream_init_zone; uscf->shm_zone->data = umcf; uscf->shm_zone->noreuse = 1; return NGX_CONF_OK; } static ngx_int_t ngx_http_upstream_init_zone(ngx_shm_zone_t *shm_zone, void *data) { size_t len; ngx_uint_t i; ngx_slab_pool_t *shpool; ngx_http_upstream_rr_peers_t *peers, **peersp; ngx_http_upstream_srv_conf_t *uscf, **uscfp; ngx_http_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_http_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_http_upstream_zone_copy_peers(shpool, uscf); if (peers == NULL) { return NGX_ERROR; } *peersp = peers; peersp = &peers->zone_next; } return NGX_OK; } static ngx_http_upstream_rr_peers_t * ngx_http_upstream_zone_copy_peers(ngx_slab_pool_t *shpool, ngx_http_upstream_srv_conf_t *uscf) { ngx_str_t *name; ngx_http_upstream_rr_peer_t *peer, **peerp; ngx_http_upstream_rr_peers_t *peers, *backup; peers = ngx_slab_alloc(shpool, sizeof(ngx_http_upstream_rr_peers_t)); if (peers == NULL) { return NULL; } ngx_memcpy(peers, uscf->peer.data, sizeof(ngx_http_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_http_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_http_upstream_rr_peers_t)); if (backup == NULL) { return NULL; } ngx_memcpy(backup, peers->next, sizeof(ngx_http_upstream_rr_peers_t)); backup->name = name; backup->shpool = shpool; for (peerp = &backup->peer; *peerp; peerp = &peer->next) { /* pool is unlocked */ peer = ngx_http_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_http_upstream_rr_peer_t * ngx_http_upstream_zone_copy_peer(ngx_http_upstream_rr_peers_t *peers, ngx_http_upstream_rr_peer_t *src) { ngx_slab_pool_t *pool; ngx_http_upstream_rr_peer_t *dst; pool = peers->shpool; dst = ngx_slab_calloc_locked(pool, sizeof(ngx_http_upstream_rr_peer_t)); if (dst == NULL) { return NULL; } if (src) { ngx_memcpy(dst, src, sizeof(ngx_http_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; }