view src/os/win32/ngx_process.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 8b84d60ef13d
children
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/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#ifndef _NGX_PROCESS_H_INCLUDED_
#define _NGX_PROCESS_H_INCLUDED_


typedef DWORD               ngx_pid_t;
#define NGX_INVALID_PID     0


#define ngx_getpid          GetCurrentProcessId
#define ngx_getppid()       0
#define ngx_log_pid         ngx_pid


#define NGX_PROCESS_SYNC_NAME                                                 \
    (sizeof("ngx_cache_manager_mutex_") + NGX_INT32_LEN)


typedef uint64_t            ngx_cpuset_t;


typedef struct {
    HANDLE                  handle;
    ngx_pid_t               pid;
    char                   *name;

    HANDLE                  term;
    HANDLE                  quit;
    HANDLE                  reopen;

    u_char                  term_event[NGX_PROCESS_SYNC_NAME];
    u_char                  quit_event[NGX_PROCESS_SYNC_NAME];
    u_char                  reopen_event[NGX_PROCESS_SYNC_NAME];

    unsigned                just_spawn:1;
    unsigned                exiting:1;
} ngx_process_t;


typedef struct {
    char                   *path;
    char                   *name;
    char                   *args;
    char *const            *argv;
    char *const            *envp;
    HANDLE                  child;
} ngx_exec_ctx_t;


ngx_pid_t ngx_spawn_process(ngx_cycle_t *cycle, char *name, ngx_int_t respawn);
ngx_pid_t ngx_execute(ngx_cycle_t *cycle, ngx_exec_ctx_t *ctx);

#define ngx_debug_point()
#define ngx_sched_yield()   SwitchToThread()


#define NGX_MAX_PROCESSES         (MAXIMUM_WAIT_OBJECTS - 4)

#define NGX_PROCESS_RESPAWN       -2
#define NGX_PROCESS_JUST_RESPAWN  -3


extern int                  ngx_argc;
extern char               **ngx_argv;
extern char               **ngx_os_argv;

extern ngx_int_t            ngx_last_process;
extern ngx_process_t        ngx_processes[NGX_MAX_PROCESSES];

extern ngx_pid_t            ngx_pid;
extern ngx_pid_t            ngx_parent;


#endif /* _NGX_PROCESS_H_INCLUDED_ */