Mercurial > hg > nginx
view src/http/modules/ngx_http_upstream_ip_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 | ed599ea6c1f1 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct { /* the round robin data must be first */ ngx_http_upstream_rr_peer_data_t rrp; ngx_uint_t hash; u_char addrlen; u_char *addr; u_char tries; ngx_event_get_peer_pt get_rr_peer; } ngx_http_upstream_ip_hash_peer_data_t; static ngx_int_t ngx_http_upstream_init_ip_hash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); static ngx_int_t ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data); static char *ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf); static ngx_command_t ngx_http_upstream_ip_hash_commands[] = { { ngx_string("ip_hash"), NGX_HTTP_UPS_CONF|NGX_CONF_NOARGS, ngx_http_upstream_ip_hash, 0, 0, NULL }, ngx_null_command }; static ngx_http_module_t ngx_http_upstream_ip_hash_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_ip_hash_module = { NGX_MODULE_V1, &ngx_http_upstream_ip_hash_module_ctx, /* module context */ ngx_http_upstream_ip_hash_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 u_char ngx_http_upstream_ip_hash_pseudo_addr[3]; static ngx_int_t ngx_http_upstream_init_ip_hash(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us) { if (ngx_http_upstream_init_round_robin(cf, us) != NGX_OK) { return NGX_ERROR; } us->peer.init = ngx_http_upstream_init_ip_hash_peer; return NGX_OK; } static ngx_int_t ngx_http_upstream_init_ip_hash_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us) { struct sockaddr_in *sin; #if (NGX_HAVE_INET6) struct sockaddr_in6 *sin6; #endif ngx_http_upstream_ip_hash_peer_data_t *iphp; iphp = ngx_palloc(r->pool, sizeof(ngx_http_upstream_ip_hash_peer_data_t)); if (iphp == NULL) { return NGX_ERROR; } r->upstream->peer.data = &iphp->rrp; if (ngx_http_upstream_init_round_robin_peer(r, us) != NGX_OK) { return NGX_ERROR; } r->upstream->peer.get = ngx_http_upstream_get_ip_hash_peer; switch (r->connection->sockaddr->sa_family) { case AF_INET: sin = (struct sockaddr_in *) r->connection->sockaddr; iphp->addr = (u_char *) &sin->sin_addr.s_addr; iphp->addrlen = 3; break; #if (NGX_HAVE_INET6) case AF_INET6: sin6 = (struct sockaddr_in6 *) r->connection->sockaddr; iphp->addr = (u_char *) &sin6->sin6_addr.s6_addr; iphp->addrlen = 16; break; #endif default: iphp->addr = ngx_http_upstream_ip_hash_pseudo_addr; iphp->addrlen = 3; } iphp->hash = 89; iphp->tries = 0; iphp->get_rr_peer = ngx_http_upstream_get_round_robin_peer; return NGX_OK; } static ngx_int_t ngx_http_upstream_get_ip_hash_peer(ngx_peer_connection_t *pc, void *data) { ngx_http_upstream_ip_hash_peer_data_t *iphp = data; time_t now; ngx_int_t w; uintptr_t m; ngx_uint_t i, n, p, hash; ngx_http_upstream_rr_peer_t *peer; ngx_log_debug1(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get ip hash peer, try: %ui", pc->tries); /* TODO: cached */ ngx_http_upstream_rr_peers_rlock(iphp->rrp.peers); if (iphp->tries > 20 || iphp->rrp.peers->single) { ngx_http_upstream_rr_peers_unlock(iphp->rrp.peers); return iphp->get_rr_peer(pc, &iphp->rrp); } now = ngx_time(); pc->cached = 0; pc->connection = NULL; hash = iphp->hash; for ( ;; ) { for (i = 0; i < (ngx_uint_t) iphp->addrlen; i++) { hash = (hash * 113 + iphp->addr[i]) % 6271; } w = hash % iphp->rrp.peers->total_weight; peer = iphp->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 (iphp->rrp.tried[n] & m) { goto next; } ngx_log_debug2(NGX_LOG_DEBUG_HTTP, pc->log, 0, "get ip hash peer, hash: %ui %04XL", p, (uint64_t) m); ngx_http_upstream_rr_peer_lock(iphp->rrp.peers, peer); if (peer->down) { ngx_http_upstream_rr_peer_unlock(iphp->rrp.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(iphp->rrp.peers, peer); goto next; } if (peer->max_conns && peer->conns >= peer->max_conns) { ngx_http_upstream_rr_peer_unlock(iphp->rrp.peers, peer); goto next; } break; next: if (++iphp->tries > 20) { ngx_http_upstream_rr_peers_unlock(iphp->rrp.peers); return iphp->get_rr_peer(pc, &iphp->rrp); } } iphp->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_http_upstream_rr_peer_unlock(iphp->rrp.peers, peer); ngx_http_upstream_rr_peers_unlock(iphp->rrp.peers); iphp->rrp.tried[n] |= m; iphp->hash = hash; return NGX_OK; } static char * ngx_http_upstream_ip_hash(ngx_conf_t *cf, ngx_command_t *cmd, void *conf) { 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_ip_hash; 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; return NGX_CONF_OK; }