Mercurial > hg > nginx
view src/os/unix/ngx_os.h @ 9300:5be23505292b default tip
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 | 3d455e37abf8 |
children |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_OS_H_INCLUDED_ #define _NGX_OS_H_INCLUDED_ #include <ngx_config.h> #include <ngx_core.h> #define NGX_IO_SENDFILE 1 typedef ssize_t (*ngx_recv_pt)(ngx_connection_t *c, u_char *buf, size_t size); typedef ssize_t (*ngx_recv_chain_pt)(ngx_connection_t *c, ngx_chain_t *in, off_t limit); typedef ssize_t (*ngx_send_pt)(ngx_connection_t *c, u_char *buf, size_t size); typedef ngx_chain_t *(*ngx_send_chain_pt)(ngx_connection_t *c, ngx_chain_t *in, off_t limit); typedef struct { ngx_recv_pt recv; ngx_recv_chain_pt recv_chain; ngx_recv_pt udp_recv; ngx_send_pt send; ngx_send_pt udp_send; ngx_send_chain_pt udp_send_chain; ngx_send_chain_pt send_chain; ngx_uint_t flags; } ngx_os_io_t; ngx_int_t ngx_os_init(ngx_log_t *log); void ngx_os_status(ngx_log_t *log); ngx_int_t ngx_os_specific_init(ngx_log_t *log); void ngx_os_specific_status(ngx_log_t *log); ngx_int_t ngx_daemon(ngx_log_t *log); ngx_int_t ngx_daemon_sync(ngx_log_t *log); ngx_int_t ngx_os_signal_process(ngx_cycle_t *cycle, char *sig, ngx_pid_t pid); ssize_t ngx_unix_recv(ngx_connection_t *c, u_char *buf, size_t size); ssize_t ngx_readv_chain(ngx_connection_t *c, ngx_chain_t *entry, off_t limit); ssize_t ngx_udp_unix_recv(ngx_connection_t *c, u_char *buf, size_t size); ssize_t ngx_unix_send(ngx_connection_t *c, u_char *buf, size_t size); ngx_chain_t *ngx_writev_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit); ssize_t ngx_udp_unix_send(ngx_connection_t *c, u_char *buf, size_t size); ngx_chain_t *ngx_udp_unix_sendmsg_chain(ngx_connection_t *c, ngx_chain_t *in, off_t limit); #if (IOV_MAX > 64) #define NGX_IOVS_PREALLOCATE 64 #else #define NGX_IOVS_PREALLOCATE IOV_MAX #endif typedef struct { struct iovec *iovs; ngx_uint_t count; size_t size; ngx_uint_t nalloc; } ngx_iovec_t; ngx_chain_t *ngx_output_chain_to_iovec(ngx_iovec_t *vec, ngx_chain_t *in, size_t limit, ngx_log_t *log); ssize_t ngx_writev(ngx_connection_t *c, ngx_iovec_t *vec); extern ngx_os_io_t ngx_os_io; extern ngx_int_t ngx_ncpu; extern ngx_int_t ngx_max_sockets; extern ngx_uint_t ngx_inherited_nonblocking; extern ngx_uint_t ngx_tcp_nodelay_and_tcp_nopush; #if (NGX_FREEBSD) #include <ngx_freebsd.h> #elif (NGX_LINUX) #include <ngx_linux.h> #elif (NGX_SOLARIS) #include <ngx_solaris.h> #elif (NGX_DARWIN) #include <ngx_darwin.h> #endif #endif /* _NGX_OS_H_INCLUDED_ */