strace/tests/inode_of_sockfd.c
Dmitry V. Levin c6782f144a tests: change the license to GPL-2.0-or-later
strace test suite is now provided under the terms of the GNU General
Public License version 2 or later, see tests/COPYING for more details.
2018-12-10 00:00:00 +00:00

41 lines
1017 B
C

/*
* This file is part of strace test suite.
*
* Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
* Copyright (c) 2016-2018 The strace developers.
* All rights reserved.
*
* SPDX-License-Identifier: GPL-2.0-or-later
*/
#include "tests.h"
#include <assert.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
unsigned long
inode_of_sockfd(const int fd)
{
assert(fd >= 0);
char linkpath[sizeof("/proc/self/fd/%u") + sizeof(int) * 3];
assert(snprintf(linkpath, sizeof(linkpath), "/proc/self/fd/%u", fd)
< (int) sizeof(linkpath));
char path[PATH_MAX + 1];
const ssize_t path_len = readlink(linkpath, path, sizeof(path) - 1);
if (path_len < 0)
perror_msg_and_fail("readlink: %s", linkpath);
path[path_len] = '\0';
static const char prefix[] = "socket:[";
const size_t prefix_len = sizeof(prefix) - 1;
assert(strncmp(path, prefix, prefix_len) == 0
&& path[path_len - 1] == ']');
return strtoul(path + prefix_len, NULL, 10);
}