Mercurial > hg > nginx
view src/http/ngx_http_upstream_round_robin.h @ 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 | 90cc7194e993 |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ #define _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #include <ngx_http.h> typedef struct ngx_http_upstream_rr_peer_s ngx_http_upstream_rr_peer_t; struct ngx_http_upstream_rr_peer_s { struct sockaddr *sockaddr; socklen_t socklen; ngx_str_t name; ngx_str_t server; ngx_int_t current_weight; ngx_int_t effective_weight; ngx_int_t weight; ngx_uint_t conns; ngx_uint_t max_conns; ngx_uint_t fails; time_t accessed; time_t checked; ngx_uint_t max_fails; time_t fail_timeout; ngx_msec_t slow_start; ngx_msec_t start_time; ngx_uint_t down; #if (NGX_HTTP_SSL || NGX_COMPAT) void *ssl_session; int ssl_session_len; #endif #if (NGX_HTTP_UPSTREAM_ZONE) ngx_atomic_t lock; #endif ngx_http_upstream_rr_peer_t *next; NGX_COMPAT_BEGIN(32) NGX_COMPAT_END }; typedef struct ngx_http_upstream_rr_peers_s ngx_http_upstream_rr_peers_t; struct ngx_http_upstream_rr_peers_s { ngx_uint_t number; #if (NGX_HTTP_UPSTREAM_ZONE) ngx_slab_pool_t *shpool; ngx_atomic_t rwlock; ngx_http_upstream_rr_peers_t *zone_next; #endif ngx_uint_t total_weight; ngx_uint_t tries; unsigned single:1; unsigned weighted:1; ngx_str_t *name; ngx_http_upstream_rr_peers_t *next; ngx_http_upstream_rr_peer_t *peer; }; #if (NGX_HTTP_UPSTREAM_ZONE) #define ngx_http_upstream_rr_peers_rlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_rlock(&peers->rwlock); \ } #define ngx_http_upstream_rr_peers_wlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_wlock(&peers->rwlock); \ } #define ngx_http_upstream_rr_peers_unlock(peers) \ \ if (peers->shpool) { \ ngx_rwlock_unlock(&peers->rwlock); \ } #define ngx_http_upstream_rr_peer_lock(peers, peer) \ \ if (peers->shpool) { \ ngx_rwlock_wlock(&peer->lock); \ } #define ngx_http_upstream_rr_peer_unlock(peers, peer) \ \ if (peers->shpool) { \ ngx_rwlock_unlock(&peer->lock); \ } #else #define ngx_http_upstream_rr_peers_rlock(peers) #define ngx_http_upstream_rr_peers_wlock(peers) #define ngx_http_upstream_rr_peers_unlock(peers) #define ngx_http_upstream_rr_peer_lock(peers, peer) #define ngx_http_upstream_rr_peer_unlock(peers, peer) #endif typedef struct { ngx_uint_t config; ngx_http_upstream_rr_peers_t *peers; ngx_http_upstream_rr_peer_t *current; uintptr_t *tried; uintptr_t data; } ngx_http_upstream_rr_peer_data_t; ngx_int_t ngx_http_upstream_init_round_robin(ngx_conf_t *cf, ngx_http_upstream_srv_conf_t *us); ngx_int_t ngx_http_upstream_init_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_srv_conf_t *us); ngx_int_t ngx_http_upstream_create_round_robin_peer(ngx_http_request_t *r, ngx_http_upstream_resolved_t *ur); ngx_int_t ngx_http_upstream_get_round_robin_peer(ngx_peer_connection_t *pc, void *data); void ngx_http_upstream_free_round_robin_peer(ngx_peer_connection_t *pc, void *data, ngx_uint_t state); #if (NGX_HTTP_SSL) ngx_int_t ngx_http_upstream_set_round_robin_peer_session(ngx_peer_connection_t *pc, void *data); void ngx_http_upstream_save_round_robin_peer_session(ngx_peer_connection_t *pc, void *data); #endif #endif /* _NGX_HTTP_UPSTREAM_ROUND_ROBIN_H_INCLUDED_ */