Mercurial > hg > nginx
view src/os/unix/ngx_socket.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 | d620f497c50f |
children | efd71d49bde0 |
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/* * Copyright (C) Igor Sysoev * Copyright (C) Nginx, Inc. */ #ifndef _NGX_SOCKET_H_INCLUDED_ #define _NGX_SOCKET_H_INCLUDED_ #include <ngx_config.h> #define NGX_WRITE_SHUTDOWN SHUT_WR typedef int ngx_socket_t; #define ngx_socket socket #define ngx_socket_n "socket()" #if (NGX_HAVE_FIONBIO) int ngx_nonblocking(ngx_socket_t s); int ngx_blocking(ngx_socket_t s); #define ngx_nonblocking_n "ioctl(FIONBIO)" #define ngx_blocking_n "ioctl(!FIONBIO)" #else #define ngx_nonblocking(s) fcntl(s, F_SETFL, fcntl(s, F_GETFL) | O_NONBLOCK) #define ngx_nonblocking_n "fcntl(O_NONBLOCK)" #define ngx_blocking(s) fcntl(s, F_SETFL, fcntl(s, F_GETFL) & ~O_NONBLOCK) #define ngx_blocking_n "fcntl(!O_NONBLOCK)" #endif int ngx_tcp_nopush(ngx_socket_t s); int ngx_tcp_push(ngx_socket_t s); #if (NGX_LINUX) #define ngx_tcp_nopush_n "setsockopt(TCP_CORK)" #define ngx_tcp_push_n "setsockopt(!TCP_CORK)" #else #define ngx_tcp_nopush_n "setsockopt(TCP_NOPUSH)" #define ngx_tcp_push_n "setsockopt(!TCP_NOPUSH)" #endif #define ngx_shutdown_socket shutdown #define ngx_shutdown_socket_n "shutdown()" #define ngx_close_socket close #define ngx_close_socket_n "close() socket" #endif /* _NGX_SOCKET_H_INCLUDED_ */