Mercurial > hg > nginx
view src/core/ngx_open_file_cache.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 | 47ece8818978 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #include <ngx_config.h> #include <ngx_core.h> #ifndef _NGX_OPEN_FILE_CACHE_H_INCLUDED_ #define _NGX_OPEN_FILE_CACHE_H_INCLUDED_ #define NGX_OPEN_FILE_DIRECTIO_OFF NGX_MAX_OFF_T_VALUE typedef struct { ngx_fd_t fd; ngx_file_uniq_t uniq; time_t mtime; off_t size; off_t fs_size; off_t directio; size_t read_ahead; ngx_err_t err; char *failed; time_t valid; ngx_uint_t min_uses; #if (NGX_HAVE_OPENAT) size_t disable_symlinks_from; unsigned disable_symlinks:2; #endif unsigned test_dir:1; unsigned test_only:1; unsigned log:1; unsigned errors:1; unsigned events:1; unsigned is_dir:1; unsigned is_file:1; unsigned is_link:1; unsigned is_exec:1; unsigned is_directio:1; } ngx_open_file_info_t; typedef struct ngx_cached_open_file_s ngx_cached_open_file_t; struct ngx_cached_open_file_s { ngx_rbtree_node_t node; ngx_queue_t queue; u_char *name; time_t created; time_t accessed; ngx_fd_t fd; ngx_file_uniq_t uniq; time_t mtime; off_t size; ngx_err_t err; uint32_t uses; #if (NGX_HAVE_OPENAT) size_t disable_symlinks_from; unsigned disable_symlinks:2; #endif unsigned count:24; unsigned close:1; unsigned use_event:1; unsigned is_dir:1; unsigned is_file:1; unsigned is_link:1; unsigned is_exec:1; unsigned is_directio:1; ngx_event_t *event; }; typedef struct { ngx_rbtree_t rbtree; ngx_rbtree_node_t sentinel; ngx_queue_t expire_queue; ngx_uint_t current; ngx_uint_t max; time_t inactive; } ngx_open_file_cache_t; typedef struct { ngx_open_file_cache_t *cache; ngx_cached_open_file_t *file; ngx_uint_t min_uses; ngx_log_t *log; } ngx_open_file_cache_cleanup_t; typedef struct { /* ngx_connection_t stub to allow use c->fd as event ident */ void *data; ngx_event_t *read; ngx_event_t *write; ngx_fd_t fd; ngx_cached_open_file_t *file; ngx_open_file_cache_t *cache; } ngx_open_file_cache_event_t; ngx_open_file_cache_t *ngx_open_file_cache_init(ngx_pool_t *pool, ngx_uint_t max, time_t inactive); ngx_int_t ngx_open_cached_file(ngx_open_file_cache_t *cache, ngx_str_t *name, ngx_open_file_info_t *of, ngx_pool_t *pool); #endif /* _NGX_OPEN_FILE_CACHE_H_INCLUDED_ */