Mercurial > hg > nginx-quic
view src/http/modules/ngx_http_upstream_random_module.c @ 7977:7731c710796f
Memcached: protect from too long responses.
If a memcached response was followed by a correct trailer, and then
the NUL character followed by some extra data - this was accepted by
the trailer checking code. This in turn resulted in ctx->rest underflow
and caused negative size buffer on the next reading from the upstream,
followed by the "negative size buf in writer" alert.
Fix is to always check for too long responses, so a correct trailer cannot
be followed by extra data.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Mon, 06 Jul 2020 18:36:17 +0300 |
parents | f2396ecf608b |
children |
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/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { ngx_http_upstream_rr_peer_t *peer; ngx_uint_t range; } ngx_http_upstream_random_range_t; typedef struct { ngx_uint_t two; ngx_http_upstream_random_range_t *ranges; } ngx_http_upstream_random_srv_conf_t; typedef struct { /* the round robin data must be first */ ngx_http_upstream_rr_peer_data_t rrp; ngx_http_upstream_random_srv_conf_t *conf; u_char tries; } ngx_http_upstream_random_peer_data_t; static ngx_int_t ngx_http_upstream_init_random(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_update_random(ngx_pool_t *pool, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_init_random_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_get_random_peer(ngx_peer_connection_t *pc, void *data); static ngx_int_t ngx_http_upstream_get_random2_peer(ngx_peer_connection_t *pc, void *data); static ngx_uint_t ngx_http_upstream_peek_random_peer( ngx_http_upstream_rr_peers_t *peers, ngx_http_upstream_random_peer_data_t *rp); static void *ngx_http_upstream_random_create_conf(ngx_conf_t *cf); static char *ngx_http_upstream_random(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_upstream_random_commands[] = { { ngx_string("random"), NGX_HTTP_UPS_CONF|NGX_CONF_NOARGS|NGX_CONF_TAKE12, ngx_http_upstream_random, NGX_HTTP_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_upstream_random_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_http_upstream_random_create_conf, /* create server configuration */ NULL, /* merge server configuration */ NULL, /* create location configuration */ NULL /* merge location configuration */ }; ngx_module_t ngx_http_upstream_random_module = { NGX_MODULE_V1, &ngx_http_upstream_random_module_ctx, /* module context */ ngx_http_upstream_random_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 ngx_int_t ngx_http_upstream_init_random(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us) { ngx_log_debug0(NGX_LOG_DEBUG_HTTP, cf->log, 0, "init random"); if (ngx_http_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_http_upstream_init_random_peer; #if (NGX_HTTP_UPSTREAM_ZONE) if (us->shm_zone) { return NGX_OK; } #endif return ngx_http_upstream_update_random(cf->pool, us); } static ngx_int_t ngx_http_upstream_update_random(ngx_pool_t *pool, ngx_http_upstream_srv_conf_t *us) { size_t size; ngx_uint_t i, total_weight; ngx_http_upstream_rr_peer_t *peer; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_random_range_t *ranges; ngx_http_upstream_random_srv_conf_t *rcf; rcf = ngx_http_conf_upstream_srv_conf(us, ngx_http_upstream_random_module); peers = us->peer.data; size = peers->number * sizeof(ngx_http_upstream_random_range_t); ranges = pool ? ngx_palloc(pool, size) : ngx_alloc(size, ngx_cycle->log); if (ranges == NULL) { return NGX_ERROR; } total_weight = 0; for (peer = peers->peer, i = 0; peer; peer = peer->next, i++) { ranges[i].peer = peer; ranges[i].range = total_weight; total_weight += peer->weight; } rcf->ranges = ranges; return NGX_OK; } static ngx_int_t ngx_http_upstream_init_random_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { ngx_http_upstream_random_srv_conf_t *rcf; ngx_http_upstream_random_peer_data_t *rp; ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0, "init random peer"); rcf = ngx_http_conf_upstream_srv_conf(us, ngx_http_upstream_random_module); rp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_random_peer_data_t)); if (rp == NULL) { return NGX_ERROR; } r->upstream->peer.data = &rp->rrp; if (ngx_http_upstream_init_round_robin_peer(r, us) != NGX_OK) { return NGX_ERROR; } if (rcf->two) { r->upstream->peer.get = ngx_http_upstream_get_random2_peer; } else { r->upstream->peer.get = ngx_http_upstream_get_random_peer; } rp->conf = rcf; rp->tries = 0; ngx_http_upstream_rr_peers_rlock(rp->rrp.peers); #if (NGX_HTTP_UPSTREAM_ZONE) if (rp->rrp.peers->shpool && rcf->ranges == NULL) { if (ngx_http_upstream_update_random(NULL, us) != NGX_OK) { ngx_http_upstream_rr_peers_unlock(rp->rrp.peers); return NGX_ERROR; } } #endif ngx_http_upstream_rr_peers_unlock(rp->rrp.peers); return NGX_OK; } static ngx_int_t ngx_http_upstream_get_random_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_random_peer_data_t *rp = data; time_t now; uintptr_t m; ngx_uint_t i, n; ngx_http_upstream_rr_peer_t *peer; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_rr_peer_data_t *rrp; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get random peer, try: %ui", pc->tries); rrp = &rp->rrp; peers = rrp->peers; ngx_http_upstream_rr_peers_rlock(peers); if (rp->tries > 20 || peers->single) { ngx_http_upstream_rr_peers_unlock(peers); return ngx_http_upstream_get_round_robin_peer(pc, rrp); } pc->cached = 0; pc->connection = NULL; now = ngx_time(); for ( ;; ) { i = ngx_http_upstream_peek_random_peer(peers, rp); peer = rp->conf->ranges[i].peer; n = i / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); if (rrp->tried[n] & m) { goto next; } ngx_http_upstream_rr_peer_lock(peers, peer); if (peer->down) { ngx_http_upstream_rr_peer_unlock(peers, peer); goto next; } if (peer->max_fails && peer->fails >= peer->max_fails && now - peer->checked <= peer->fail_timeout) { ngx_http_upstream_rr_peer_unlock(peers, peer); goto next; } if (peer->max_conns && peer->conns >= peer->max_conns) { ngx_http_upstream_rr_peer_unlock(peers, peer); goto next; } break; next: if (++rp->tries > 20) { ngx_http_upstream_rr_peers_unlock(peers); return ngx_http_upstream_get_round_robin_peer(pc, rrp); } } rrp->current = peer; if (now - peer->checked > peer->fail_timeout) { peer->checked = now; } pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; peer->conns++; ngx_http_upstream_rr_peer_unlock(peers, peer); ngx_http_upstream_rr_peers_unlock(peers); rrp->tried[n] |= m; return NGX_OK; } static ngx_int_t ngx_http_upstream_get_random2_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_random_peer_data_t *rp = data; time_t now; uintptr_t m; ngx_uint_t i, n, p; ngx_http_upstream_rr_peer_t *peer, *prev; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_rr_peer_data_t *rrp; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get random2 peer, try: %ui", pc->tries); rrp = &rp->rrp; peers = rrp->peers; ngx_http_upstream_rr_peers_wlock(peers); if (rp->tries > 20 || peers->single) { ngx_http_upstream_rr_peers_unlock(peers); return ngx_http_upstream_get_round_robin_peer(pc, rrp); } pc->cached = 0; pc->connection = NULL; now = ngx_time(); prev = NULL; #if (NGX_SUPPRESS_WARN) p = 0; #endif for ( ;; ) { i = ngx_http_upstream_peek_random_peer(peers, rp); peer = rp->conf->ranges[i].peer; if (peer == prev) { goto next; } n = i / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); if (rrp->tried[n] & m) { goto next; } if (peer->down) { goto next; } if (peer->max_fails && peer->fails >= peer->max_fails && now - peer->checked <= peer->fail_timeout) { goto next; } if (peer->max_conns && peer->conns >= peer->max_conns) { goto next; } if (prev) { if (peer->conns * prev->weight > prev->conns * peer->weight) { peer = prev; n = p / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); } break; } prev = peer; p = i; next: if (++rp->tries > 20) { ngx_http_upstream_rr_peers_unlock(peers); return ngx_http_upstream_get_round_robin_peer(pc, rrp); } } rrp->current = peer; if (now - peer->checked > peer->fail_timeout) { peer->checked = now; } pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; peer->conns++; ngx_http_upstream_rr_peers_unlock(peers); rrp->tried[n] |= m; return NGX_OK; } static ngx_uint_t ngx_http_upstream_peek_random_peer(ngx_http_upstream_rr_peers_t *peers, ngx_http_upstream_random_peer_data_t *rp) { ngx_uint_t i, j, k, x; x = ngx_random() % peers->total_weight; i = 0; j = peers->number; while (j - i > 1) { k = (i + j) / 2; if (x < rp->conf->ranges[k].range) { j = k; } else { i = k; } } return i; } static void * ngx_http_upstream_random_create_conf(ngx_conf_t *cf) { ngx_http_upstream_random_srv_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_http_upstream_random_srv_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->two = 0; */ return conf; } static char * ngx_http_upstream_random(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_http_upstream_random_srv_conf_t *rcf = conf; ngx_str_t *value; ngx_http_upstream_srv_conf_t *uscf; uscf = ngx_http_conf_get_module_srv_conf(cf, ngx_http_upstream_module); if (uscf->peer.init_upstream) { ngx_conf_log_error(NGX_LOG_WARN, cf, 0, "load balancing method redefined"); } uscf->peer.init_upstream = ngx_http_upstream_init_random; uscf->flags = NGX_HTTP_UPSTREAM_CREATE |NGX_HTTP_UPSTREAM_WEIGHT |NGX_HTTP_UPSTREAM_MAX_CONNS |NGX_HTTP_UPSTREAM_MAX_FAILS |NGX_HTTP_UPSTREAM_FAIL_TIMEOUT |NGX_HTTP_UPSTREAM_DOWN; if (cf->args->nelts == 1) { return NGX_CONF_OK; } value = cf->args->elts; if (ngx_strcmp(value[1].data, "two") == 0) { rcf->two = 1; } else { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[1]); return NGX_CONF_ERROR; } if (cf->args->nelts == 2) { return NGX_CONF_OK; } if (ngx_strcmp(value[2].data, "least_conn") != 0) { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[2]); return NGX_CONF_ERROR; } return NGX_CONF_OK; }