1 /*
2 * This file is part of strace test suite.
3 *
4 * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
5 * Copyright (c) 2016-2018 The strace developers.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 * derived from this software without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 #include "tests.h"
32 #include <assert.h>
33 #include <limits.h>
34 #include <stdio.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <unistd.h>
38
39 unsigned long
inode_of_sockfd(const int fd)40 inode_of_sockfd(const int fd)
41 {
42 assert(fd >= 0);
43
44 char linkpath[sizeof("/proc/self/fd/%u") + sizeof(int) * 3];
45 assert(snprintf(linkpath, sizeof(linkpath), "/proc/self/fd/%u", fd)
46 < (int) sizeof(linkpath));
47
48 char path[PATH_MAX + 1];
49 const ssize_t path_len = readlink(linkpath, path, sizeof(path) - 1);
50 if (path_len < 0)
51 perror_msg_and_fail("readlink: %s", linkpath);
52 path[path_len] = '\0';
53
54 static const char prefix[] = "socket:[";
55 const size_t prefix_len = sizeof(prefix) - 1;
56 assert(strncmp(path, prefix, prefix_len) == 0
57 && path[path_len - 1] == ']');
58
59 return strtoul(path + prefix_len, NULL, 10);
60 }
61