Mercurial > hg > nginx
view src/core/ngx_regex.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 | d07456044b61 |
children |
line wrap: on
line source
/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_REGEX_H_INCLUDED_ #define _NGX_REGEX_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #if (NGX_PCRE2) #define PCRE2_CODE_UNIT_WIDTH 8 #include <pcre2.h> #define NGX_REGEX_NO_MATCHED PCRE2_ERROR_NOMATCH /* -1 */ typedef pcre2_code ngx_regex_t; #else #include <pcre.h> #define NGX_REGEX_NO_MATCHED PCRE_ERROR_NOMATCH /* -1 */ typedef struct { pcre *code; pcre_extra *extra; } ngx_regex_t; #endif #define NGX_REGEX_CASELESS 0x00000001 #define NGX_REGEX_MULTILINE 0x00000002 typedef struct { ngx_str_t pattern; ngx_pool_t *pool; ngx_uint_t options; ngx_regex_t *regex; int captures; int named_captures; int name_size; u_char *names; ngx_str_t err; } ngx_regex_compile_t; typedef struct { ngx_regex_t *regex; u_char *name; } ngx_regex_elt_t; void ngx_regex_init(void); ngx_int_t ngx_regex_compile(ngx_regex_compile_t *rc); ngx_int_t ngx_regex_exec(ngx_regex_t *re, ngx_str_t *s, int *captures, ngx_uint_t size); #if (NGX_PCRE2) #define ngx_regex_exec_n "pcre2_match()" #else #define ngx_regex_exec_n "pcre_exec()" #endif ngx_int_t ngx_regex_exec_array(ngx_array_t *a, ngx_str_t *s, ngx_log_t *log); #endif /* _NGX_REGEX_H_INCLUDED_ */