Mercurial > hg > nginx
view src/os/unix/ngx_process.h @ 5356:acd51b0f6fd4
Disable symlinks: use O_PATH to open path components.
It was introduced in Linux 2.6.39, glibc 2.14 and allows to obtain
file descriptors without actually opening files. Thus made it possible
to traverse path with openat() syscalls without the need to have read
permissions for path components. It is effectively emulates O_SEARCH
which is missing on Linux.
O_PATH is used in combination with O_RDONLY. The last one is ignored
if O_PATH is used, but it allows nginx to not fail when it was built on
modern system (i.e. glibc 2.14+) and run with a kernel older than 2.6.39.
Then O_PATH is unknown to the kernel and ignored, while O_RDONLY is used.
Sadly, fstat() is not working with O_PATH descriptors till Linux 3.6.
As a workaround we fallback to fstatat() with the AT_EMPTY_PATH flag
that was introduced at the same time as O_PATH.
author | Valentin Bartenev <vbart@nginx.com> |
---|---|
date | Mon, 02 Sep 2013 08:07:59 +0400 |
parents | f31162fefe01 |
children | 8b84d60ef13d |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_PROCESS_H_INCLUDED_ #define _NGX_PROCESS_H_INCLUDED_ #include <ngx_setaffinity.h> #include <ngx_setproctitle.h> typedef pid_t ngx_pid_t; #define NGX_INVALID_PID -1 typedef void (*ngx_spawn_proc_pt) (ngx_cycle_t *cycle, void *data); typedef struct { ngx_pid_t pid; int status; ngx_socket_t channel[2]; ngx_spawn_proc_pt proc; void *data; char *name; unsigned respawn:1; unsigned just_spawn:1; unsigned detached:1; unsigned exiting:1; unsigned exited:1; } ngx_process_t; typedef struct { char *path; char *name; char *const *argv; char *const *envp; } ngx_exec_ctx_t; #define NGX_MAX_PROCESSES 1024 #define NGX_PROCESS_NORESPAWN -1 #define NGX_PROCESS_JUST_SPAWN -2 #define NGX_PROCESS_RESPAWN -3 #define NGX_PROCESS_JUST_RESPAWN -4 #define NGX_PROCESS_DETACHED -5 #define ngx_getpid getpid #ifndef ngx_log_pid #define ngx_log_pid ngx_pid #endif ngx_pid_t ngx_spawn_process(ngx_cycle_t *cycle, ngx_spawn_proc_pt proc, void *data, char *name, ngx_int_t respawn); ngx_pid_t ngx_execute(ngx_cycle_t *cycle, ngx_exec_ctx_t *ctx); ngx_int_t ngx_init_signals(ngx_log_t *log); void ngx_debug_point(void); #if (NGX_HAVE_SCHED_YIELD) #define ngx_sched_yield() sched_yield() #else #define ngx_sched_yield() usleep(1) #endif extern int ngx_argc; extern char **ngx_argv; extern char **ngx_os_argv; extern ngx_pid_t ngx_pid; extern ngx_socket_t ngx_channel; extern ngx_int_t ngx_process_slot; extern ngx_int_t ngx_last_process; extern ngx_process_t ngx_processes[NGX_MAX_PROCESSES]; #endif /* _NGX_PROCESS_H_INCLUDED_ */