Mercurial > hg > nginx
view src/stream/ngx_stream_upstream_hash_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 | d964b0aee8e7 |
children |
line wrap: on
line source
/* * Copyright (C) Roman Arutyunyan * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_stream.h> typedef struct { uint32_t hash; ngx_str_t *server; } ngx_stream_upstream_chash_point_t; typedef struct { ngx_uint_t number; ngx_stream_upstream_chash_point_t point[1]; } ngx_stream_upstream_chash_points_t; typedef struct { ngx_stream_complex_value_t key; ngx_stream_upstream_chash_points_t *points; } ngx_stream_upstream_hash_srv_conf_t; typedef struct { /* the round robin data must be first */ ngx_stream_upstream_rr_peer_data_t rrp; ngx_stream_upstream_hash_srv_conf_t *conf; ngx_str_t key; ngx_uint_t tries; ngx_uint_t rehash; uint32_t hash; ngx_event_get_peer_pt get_rr_peer; } ngx_stream_upstream_hash_peer_data_t; static ngx_int_t ngx_stream_upstream_init_hash(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_init_hash_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data); static ngx_int_t ngx_stream_upstream_init_chash(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us); static int ngx_libc_cdecl ngx_stream_upstream_chash_cmp_points(const void *one, const void *two); static ngx_uint_t ngx_stream_upstream_find_chash_point( ngx_stream_upstream_chash_points_t *points, uint32_t hash); static ngx_int_t ngx_stream_upstream_init_chash_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us); static ngx_int_t ngx_stream_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data); static void *ngx_stream_upstream_hash_create_conf(ngx_conf_t *cf); static char *ngx_stream_upstream_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_stream_upstream_hash_commands[] = { { ngx_string("hash"), NGX_STREAM_UPS_CONF|NGX_CONF_TAKE12, ngx_stream_upstream_hash, NGX_STREAM_SRV_CONF_OFFSET, 0, NULL }, ngx_null_command }; static ngx_stream_module_t ngx_stream_upstream_hash_module_ctx = { NULL, /* preconfiguration */ NULL, /* postconfiguration */ NULL, /* create main configuration */ NULL, /* init main configuration */ ngx_stream_upstream_hash_create_conf, /* create server configuration */ NULL /* merge server configuration */ }; ngx_module_t ngx_stream_upstream_hash_module = { NGX_MODULE_V1, &ngx_stream_upstream_hash_module_ctx, /* module context */ ngx_stream_upstream_hash_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_hash(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us) { if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_stream_upstream_init_hash_peer; return NGX_OK; } static ngx_int_t ngx_stream_upstream_init_hash_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us) { ngx_stream_upstream_hash_srv_conf_t *hcf; ngx_stream_upstream_hash_peer_data_t *hp; hp = ngx_palloc(s->connection->pool, sizeof(ngx_stream_upstream_hash_peer_data_t)); if (hp == NULL) { return NGX_ERROR; } s->upstream->peer.data = &hp->rrp; if (ngx_stream_upstream_init_round_robin_peer(s, us) != NGX_OK) { return NGX_ERROR; } s->upstream->peer.get = ngx_stream_upstream_get_hash_peer; hcf = ngx_stream_conf_upstream_srv_conf(us, ngx_stream_upstream_hash_module); if (ngx_stream_complex_value(s, &hcf->key, &hp->key) != NGX_OK) { return NGX_ERROR; } ngx_log_debug1(NGX_LOG_DEBUG_STREAM, s->connection->log, 0, "upstream hash key:\"%V\"", &hp->key); hp->conf = hcf; hp->tries = 0; hp->rehash = 0; hp->hash = 0; hp->get_rr_peer = ngx_stream_upstream_get_round_robin_peer; return NGX_OK; } static ngx_int_t ngx_stream_upstream_get_hash_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_hash_peer_data_t *hp = data; time_t now; u_char buf[NGX_INT_T_LEN]; size_t size; uint32_t hash; ngx_int_t w; uintptr_t m; ngx_uint_t n, p; ngx_stream_upstream_rr_peer_t *peer; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get hash peer, try: %ui", pc->tries); ngx_stream_upstream_rr_peers_rlock(hp->rrp.peers); if (hp->tries > 20 || hp->rrp.peers->single || hp->key.len == 0) { ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } now = ngx_time(); pc->connection = NULL; for ( ;; ) { /* * Hash expression is compatible with Cache::Memcached: * ((crc32([REHASH] KEY) >> 16) & 0x7fff) + PREV_HASH * with REHASH omitted at the first iteration. */ ngx_crc32_init(hash); if (hp->rehash > 0) { size = ngx_sprintf(buf, "%ui", hp->rehash) - buf; ngx_crc32_update(&hash, buf, size); } ngx_crc32_update(&hash, hp->key.data, hp->key.len); ngx_crc32_final(hash); hash = (hash >> 16) & 0x7fff; hp->hash += hash; hp->rehash++; w = hp->hash % hp->rrp.peers->total_weight; peer = hp->rrp.peers->peer; p = 0; while (w >= peer->weight) { w -= peer->weight; peer = peer->next; p++; } n = p / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << p % (8 * sizeof(uintptr_t)); if (hp->rrp.tried[n] & m) { goto next; } ngx_stream_upstream_rr_peer_lock(hp->rrp.peers, peer); ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get hash peer, value:%uD, peer:%ui", hp->hash, p); if (peer->down) { ngx_stream_upstream_rr_peer_unlock(hp->rrp.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(hp->rrp.peers, peer); goto next; } if (peer->max_conns && peer->conns >= peer->max_conns) { ngx_stream_upstream_rr_peer_unlock(hp->rrp.peers, peer); goto next; } break; next: if (++hp->tries > 20) { ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } } hp->rrp.current = peer; pc->sockaddr = peer->sockaddr; pc->socklen = peer->socklen; pc->name = &peer->name; peer->conns++; if (now - peer->checked > peer->fail_timeout) { peer->checked = now; } ngx_stream_upstream_rr_peer_unlock(hp->rrp.peers, peer); ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); hp->rrp.tried[n] |= m; return NGX_OK; } static ngx_int_t ngx_stream_upstream_init_chash(ngx_conf_t *cf, ngx_stream_upstream_srv_conf_t *us) { u_char *host, *port, c; size_t host_len, port_len, size; uint32_t hash, base_hash; ngx_str_t *server; ngx_uint_t npoints, i, j; ngx_stream_upstream_rr_peer_t *peer; ngx_stream_upstream_rr_peers_t *peers; ngx_stream_upstream_chash_points_t *points; ngx_stream_upstream_hash_srv_conf_t *hcf; union { uint32_t value; u_char byte[4]; } prev_hash; if (ngx_stream_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_stream_upstream_init_chash_peer; peers = us->peer.data; npoints = peers->total_weight * 160; size = sizeof(ngx_stream_upstream_chash_points_t) + sizeof(ngx_stream_upstream_chash_point_t) * (npoints - 1); points = ngx_palloc(cf->pool, size); if (points == NULL) { return NGX_ERROR; } points->number = 0; for (peer = peers->peer; peer; peer = peer->next) { server = &peer->server; /* * Hash expression is compatible with Cache::Memcached::Fast: * crc32(HOST \0 PORT PREV_HASH). */ if (server->len >= 5 && ngx_strncasecmp(server->data, (u_char *) "unix:", 5) == 0) { host = server->data + 5; host_len = server->len - 5; port = NULL; port_len = 0; goto done; } for (j = 0; j < server->len; j++) { c = server->data[server->len - j - 1]; if (c == ':') { host = server->data; host_len = server->len - j - 1; port = server->data + server->len - j; port_len = j; goto done; } if (c < '0' || c > '9') { break; } } host = server->data; host_len = server->len; port = NULL; port_len = 0; done: ngx_crc32_init(base_hash); ngx_crc32_update(&base_hash, host, host_len); ngx_crc32_update(&base_hash, (u_char *) "", 1); ngx_crc32_update(&base_hash, port, port_len); prev_hash.value = 0; npoints = peer->weight * 160; for (j = 0; j < npoints; j++) { hash = base_hash; ngx_crc32_update(&hash, prev_hash.byte, 4); ngx_crc32_final(hash); points->point[points->number].hash = hash; points->point[points->number].server = server; points->number++; #if (NGX_HAVE_LITTLE_ENDIAN) prev_hash.value = hash; #else prev_hash.byte[0] = (u_char) (hash & 0xff); prev_hash.byte[1] = (u_char) ((hash >> 8) & 0xff); prev_hash.byte[2] = (u_char) ((hash >> 16) & 0xff); prev_hash.byte[3] = (u_char) ((hash >> 24) & 0xff); #endif } } ngx_qsort(points->point, points->number, sizeof(ngx_stream_upstream_chash_point_t), ngx_stream_upstream_chash_cmp_points); for (i = 0, j = 1; j < points->number; j++) { if (points->point[i].hash != points->point[j].hash) { points->point[++i] = points->point[j]; } } points->number = i + 1; hcf = ngx_stream_conf_upstream_srv_conf(us, ngx_stream_upstream_hash_module); hcf->points = points; return NGX_OK; } static int ngx_libc_cdecl ngx_stream_upstream_chash_cmp_points(const void *one, const void *two) { ngx_stream_upstream_chash_point_t *first = (ngx_stream_upstream_chash_point_t *) one; ngx_stream_upstream_chash_point_t *second = (ngx_stream_upstream_chash_point_t *) two; if (first->hash < second->hash) { return -1; } else if (first->hash > second->hash) { return 1; } else { return 0; } } static ngx_uint_t ngx_stream_upstream_find_chash_point(ngx_stream_upstream_chash_points_t *points, uint32_t hash) { ngx_uint_t i, j, k; ngx_stream_upstream_chash_point_t *point; /* find first point >= hash */ point = &points->point[0]; i = 0; j = points->number; while (i < j) { k = (i + j) / 2; if (hash > point[k].hash) { i = k + 1; } else if (hash < point[k].hash) { j = k; } else { return k; } } return i; } static ngx_int_t ngx_stream_upstream_init_chash_peer(ngx_stream_session_t *s, ngx_stream_upstream_srv_conf_t *us) { uint32_t hash; ngx_stream_upstream_hash_srv_conf_t *hcf; ngx_stream_upstream_hash_peer_data_t *hp; if (ngx_stream_upstream_init_hash_peer(s, us) != NGX_OK) { return NGX_ERROR; } s->upstream->peer.get = ngx_stream_upstream_get_chash_peer; hp = s->upstream->peer.data; hcf = ngx_stream_conf_upstream_srv_conf(us, ngx_stream_upstream_hash_module); hash = ngx_crc32_long(hp->key.data, hp->key.len); ngx_stream_upstream_rr_peers_rlock(hp->rrp.peers); hp->hash = ngx_stream_upstream_find_chash_point(hcf->points, hash); ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); return NGX_OK; } static ngx_int_t ngx_stream_upstream_get_chash_peer(ngx_peer_connection_t *pc, void *data) { ngx_stream_upstream_hash_peer_data_t *hp = data; time_t now; intptr_t m; ngx_str_t *server; ngx_int_t total; ngx_uint_t i, n, best_i; ngx_stream_upstream_rr_peer_t *peer, *best; ngx_stream_upstream_chash_point_t *point; ngx_stream_upstream_chash_points_t *points; ngx_stream_upstream_hash_srv_conf_t *hcf; ngx_log_debug1(NGX_LOG_DEBUG_STREAM, pc->log, 0, "get consistent hash peer, try: %ui", pc->tries); ngx_stream_upstream_rr_peers_wlock(hp->rrp.peers); if (hp->tries > 20 || hp->rrp.peers->single || hp->key.len == 0) { ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } pc->connection = NULL; now = ngx_time(); hcf = hp->conf; points = hcf->points; point = &points->point[0]; for ( ;; ) { server = point[hp->hash % points->number].server; ngx_log_debug2(NGX_LOG_DEBUG_STREAM, pc->log, 0, "consistent hash peer:%uD, server:\"%V\"", hp->hash, server); best = NULL; best_i = 0; total = 0; for (peer = hp->rrp.peers->peer, i = 0; peer; peer = peer->next, i++) { n = i / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << i % (8 * sizeof(uintptr_t)); if (hp->rrp.tried[n] & m) { continue; } if (peer->down) { continue; } if (peer->max_fails && peer->fails >= peer->max_fails && now - peer->checked <= peer->fail_timeout) { continue; } if (peer->max_conns && peer->conns >= peer->max_conns) { continue; } if (peer->server.len != server->len || ngx_strncmp(peer->server.data, server->data, server->len) != 0) { continue; } peer->current_weight += peer->effective_weight; total += peer->effective_weight; if (peer->effective_weight < peer->weight) { peer->effective_weight++; } if (best == NULL || peer->current_weight > best->current_weight) { best = peer; best_i = i; } } if (best) { best->current_weight -= total; break; } hp->hash++; hp->tries++; if (hp->tries > 20) { ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); return hp->get_rr_peer(pc, &hp->rrp); } } hp->rrp.current = best; pc->sockaddr = best->sockaddr; pc->socklen = best->socklen; pc->name = &best->name; best->conns++; if (now - best->checked > best->fail_timeout) { best->checked = now; } ngx_stream_upstream_rr_peers_unlock(hp->rrp.peers); n = best_i / (8 * sizeof(uintptr_t)); m = (uintptr_t) 1 << best_i % (8 * sizeof(uintptr_t)); hp->rrp.tried[n] |= m; return NGX_OK; } static void * ngx_stream_upstream_hash_create_conf(ngx_conf_t *cf) { ngx_stream_upstream_hash_srv_conf_t *conf; conf = ngx_palloc(cf->pool, sizeof(ngx_stream_upstream_hash_srv_conf_t)); if (conf == NULL) { return NULL; } conf->points = NULL; return conf; } static char * ngx_stream_upstream_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { ngx_stream_upstream_hash_srv_conf_t *hcf = conf; ngx_str_t *value; ngx_stream_upstream_srv_conf_t *uscf; ngx_stream_compile_complex_value_t ccv; value = cf->args->elts; ngx_memzero(&ccv, sizeof(ngx_stream_compile_complex_value_t)); ccv.cf = cf; ccv.value = &value[1]; ccv.complex_value = &hcf->key; if (ngx_stream_compile_complex_value(&ccv) != NGX_OK) { return NGX_CONF_ERROR; } 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->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 == 2) { uscf->peer.init_upstream = ngx_stream_upstream_init_hash; } else if (ngx_strcmp(value[2].data, "consistent") == 0) { uscf->peer.init_upstream = ngx_stream_upstream_init_chash; } else { ngx_conf_log_error(NGX_LOG_EMERG, cf, 0, "invalid parameter \"%V\"", &value[2]); return NGX_CONF_ERROR; } return NGX_CONF_OK; }