2 * Copyright © 2019 Alexey Dobriyan <adobriyan@gmail.com>
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 * Test that setns(CLONE_NEWNET) points to new /proc/net content even
18 * if old one is in dcache.
20 * FIXME /proc/net/unix is under CONFIG_UNIX which can be disabled.
31 #include <sys/types.h>
34 #include <sys/socket.h>
36 static pid_t pid = -1;
53 /* Check for priviledges and syscall availability straight away. */
54 if (unshare(CLONE_NEWNET) == -1) {
55 if (errno == ENOSYS || errno == EPERM) {
60 /* Distinguisher between two otherwise empty net namespaces. */
61 if (socket(AF_UNIX, SOCK_STREAM, 0) == -1) {
75 if (unshare(CLONE_NEWNET) == -1) {
79 if (write(fd[1], &_, 1) != 1) {
88 if (read(fd[0], &_, 1) != 1) {
94 snprintf(buf, sizeof(buf), "/proc/%u/ns/net", pid);
95 nsfd = open(buf, O_RDONLY);
101 /* Reliably pin dentry into dcache. */
102 (void)open("/proc/net/unix", O_RDONLY);
104 if (setns(nsfd, CLONE_NEWNET) == -1) {
116 fd = open("/proc/net/unix", O_RDONLY);
121 #define S "Num RefCount Protocol Flags Type St Inode Path\n"
122 rv = read(fd, buf, sizeof(buf));
124 assert(rv == strlen(S));
125 assert(memcmp(buf, S, strlen(S)) == 0);