--- /dev/null
+/*
+ * This file is part of strace test suite.
+ *
+ * Copyright (c) 2016 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+#include <assert.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/param.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);
+}