Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_random_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 | f2396ecf608b |
children |
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/* * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { ngx_stream_upstream_rr_peer_t *peer; ngx_uint_t range; } ngx_stream_upstream_random_range_t; typedef struct { ngx_uint_t two; ngx_stream_upstream_random_range_t *ranges; } ngx_stream_upstream_random_srv_conf_t; typedef struct { /* the round robin data must be first */ ngx_stream_upstream_rr_peer_data_t rrp; ngx_stream_upstream_random_srv_conf_t *conf; u_char tries; } ngx_stream_upstream_random_peer_data_t; static ngx_int_t ngx_stream_upstream_init_random(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_update_random(ngx_pool_t *pool, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_init_random_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_get_random_peer(ngx_peer_connection_t *pc, void *data); static ngx_int_t ngx_stream_upstream_get_random2_peer(ngx_peer_connection_t *pc, void *data); static ngx_uint_t ngx_stream_upstream_peek_random_peer( ngx_stream_upstream_rr_peers_t *peers, ngx_stream_upstream_random_peer_data_t *rp); static void *ngx_stream_upstream_random_create_conf(ngx_conf_t *cf); static char *ngx_stream_upstream_random(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_stream_upstream_random_commands[] = { { ngx_string("random"), NGX_STREAM_UPS_CONF|NGX_CONF_NOARGS|NGX_CONF_TAKE12, ngx_stream_upstream_random, NGX_STREAM_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_upstream_random_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_stream_upstream_random_create_conf, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_upstream_random_module = { NGX_MODULE_V1, &ngx_stream_upstream_random_module_ctx, /* module context */ ngx_stream_upstream_random_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 ngx_int_t ngx_stream_upstream_init_random(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us) { ngx_log_debug0(NGX_LOG_DEBUG_STREAM, cf->log, 0, "init random"); if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_stream_upstream_init_random_peer; #if (NGX_STREAM_UPSTREAM_ZONE) if (us->shm_zone) { return NGX_OK; } #endif return ngx_stream_upstream_update_random(cf->pool, us); } static ngx_int_t ngx_stream_upstream_update_random(ngx_pool_t *pool, ngx_stream_upstream_srv_conf_t *us) { size_t size; ngx_uint_t i, total_weight; ngx_stream_upstream_rr_peer_t *peer; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_random_range_t *ranges; ngx_stream_upstream_random_srv_conf_t *rcf; rcf = ngx_stream_conf_upstream_srv_conf(us, ngx_stream_upstream_random_module); peers = us->peer.data; size = peers->number * sizeof(ngx_stream_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_stream_upstream_init_random_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us) { ngx_stream_upstream_random_srv_conf_t *rcf; ngx_stream_upstream_random_peer_data_t *rp; ngx_log_debug0(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "init random peer"); rcf = ngx_stream_conf_upstream_srv_conf(us, ngx_stream_upstream_random_module); rp = ngx_palloc(s->connection->pool, sizeof(ngx_stream_upstream_random_peer_data_t)); if (rp == NULL) { return NGX_ERROR; } s->upstream->peer.data = &rp->rrp; if (ngx_stream_upstream_init_round_robin_peer(s, us) != NGX_OK) { return NGX_ERROR; } if (rcf->two) { s->upstream->peer.get = ngx_stream_upstream_get_random2_peer; } else { s->upstream->peer.get = ngx_stream_upstream_get_random_peer; } rp->conf = rcf; rp->tries = 0; ngx_stream_upstream_rr_peers_rlock(rp->rrp.peers); #if (NGX_STREAM_UPSTREAM_ZONE) if (rp->rrp.peers->shpool && rcf->ranges == NULL) { if (ngx_stream_upstream_update_random(NULL, us) != NGX_OK) { ngx_stream_upstream_rr_peers_unlock(rp->rrp.peers); return NGX_ERROR; } } #endif ngx_stream_upstream_rr_peers_unlock(rp->rrp.peers); return NGX_OK; } static ngx_int_t ngx_stream_upstream_get_random_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_random_peer_data_t *rp = data; time_t now; uintptr_t m; ngx_uint_t i, n; ngx_stream_upstream_rr_peer_t *peer; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_rr_peer_data_t *rrp; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get random peer, try: %ui", pc->tries); rrp = &rp->rrp; peers = rrp->peers; ngx_stream_upstream_rr_peers_rlock(peers); if (rp->tries > 20 || peers->single) { ngx_stream_upstream_rr_peers_unlock(peers); return ngx_stream_upstream_get_round_robin_peer(pc, rrp); } pc->cached = 0; pc->connection = NULL; now = ngx_time(); for ( ;; ) { i = ngx_stream_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_stream_upstream_rr_peer_lock(peers, peer); if (peer->down) { ngx_stream_upstream_rr_peer_unlock(peers, peer); goto next; } if (peer->max_fails && peer->fails >= peer->max_fails && now - peer->checked <= peer->fail_timeout) { ngx_stream_upstream_rr_peer_unlock(peers, peer); goto next; } if (peer->max_conns && peer->conns >= peer->max_conns) { ngx_stream_upstream_rr_peer_unlock(peers, peer); goto next; } break; next: if (++rp->tries > 20) { ngx_stream_upstream_rr_peers_unlock(peers); return ngx_stream_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_stream_upstream_rr_peer_unlock(peers, peer); ngx_stream_upstream_rr_peers_unlock(peers); rrp->tried[n] |= m; return NGX_OK; } static ngx_int_t ngx_stream_upstream_get_random2_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_random_peer_data_t *rp = data; time_t now; uintptr_t m; ngx_uint_t i, n, p; ngx_stream_upstream_rr_peer_t *peer, *prev; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_rr_peer_data_t *rrp; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get random2 peer, try: %ui", pc->tries); rrp = &rp->rrp; peers = rrp->peers; ngx_stream_upstream_rr_peers_wlock(peers); if (rp->tries > 20 || peers->single) { ngx_stream_upstream_rr_peers_unlock(peers); return ngx_stream_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_stream_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_stream_upstream_rr_peers_unlock(peers); return ngx_stream_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_stream_upstream_rr_peers_unlock(peers); rrp->tried[n] |= m; return NGX_OK; } static ngx_uint_t ngx_stream_upstream_peek_random_peer(ngx_stream_upstream_rr_peers_t *peers, ngx_stream_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_stream_upstream_random_create_conf(ngx_conf_t *cf) { ngx_stream_upstream_random_srv_conf_t *conf; conf = ngx_pcalloc(cf->pool, sizeof(ngx_stream_upstream_random_srv_conf_t)); if (conf == NULL) { return NULL; } /* * set by ngx_pcalloc(): * * conf->two = 0; */ return conf; } static char * ngx_stream_upstream_random(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_upstream_random_srv_conf_t *rcf = conf; ngx_str_t *value; ngx_stream_upstream_srv_conf_t *uscf; uscf = ngx_stream_conf_get_module_srv_conf(cf, ngx_stream_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_stream_upstream_init_random; uscf->flags = NGX_STREAM_UPSTREAM_CREATE |NGX_STREAM_UPSTREAM_WEIGHT |NGX_STREAM_UPSTREAM_MAX_CONNS |NGX_STREAM_UPSTREAM_MAX_FAILS |NGX_STREAM_UPSTREAM_FAIL_TIMEOUT |NGX_STREAM_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; }