Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_random_module.c @ 9300:5be23505292b
SSI: fixed incorrect or duplicate stub output.
Following 3518:eb3aaf8bd2a9 (0.8.37), r->request_output is only set
if there are data in the first buffer sent in the subrequest. As a
result, following the change mentioned this flag cannot be used to
prevent duplicate ngx_http_ssi_stub_output() calls, since it is not
set if there was already some output, but the first buffer was empty.
Still, when there are multiple subrequests, even an empty subrequest
response might be delayed by the postpone filter, leading to a second
call of ngx_http_ssi_stub_output() during finalization from
ngx_http_writer() the subreqest buffers are released by the postpone
filter. Since r->request_output is not set after the first call, this
resulted in duplicate stub output.
Additionally, checking only the first buffer might be wrong in some
unusual cases. For example, the first buffer might be empty if
$r->flush() is called before printing any data in the embedded Perl
module.
Depending on the postpone_output value and corresponding sizes, this
issue can result in either duplicate or unexpected stub output, or
"zero size buf in writer" alerts.
Following 8124:f5515e727656 (1.23.4), it became slightly easier to
reproduce the issue, as empty static files and empty cache items now
result in a response with an empty buffer. Before the change, an empty
proxied response can be used to reproduce the issue.
Fix is check all buffers and set r->request_output if any non-empty
buffers are sent. This ensures that all unusual cases of non-empty
responses are covered, and also that r->request_output will be set
after the first stub output, preventing duplicate output.
Reported by Jan Gassen.
author | Maxim Dounin <mdounin@mdounin.ru> |
---|---|
date | Thu, 04 Jul 2024 17:41:28 +0300 |
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; }