1 // SPDX-License-Identifier: GPL-2.0
10 #include <sys/types.h>
11 #include <sys/socket.h>
13 #ifndef SO_NETNS_COOKIE
14 #define SO_NETNS_COOKIE 71
17 #define pr_err(fmt, ...) \
19 fprintf(stderr, "%s:%d:" fmt ": %m\n", \
20 __func__, __LINE__, ##__VA_ARGS__); \
24 int main(int argc, char *argvp[])
26 uint64_t cookie1, cookie2;
30 sock1 = socket(AF_INET, SOCK_STREAM, 0);
32 return pr_err("Unable to create TCP socket");
34 vallen = sizeof(cookie1);
35 if (getsockopt(sock1, SOL_SOCKET, SO_NETNS_COOKIE, &cookie1, &vallen) != 0)
36 return pr_err("getsockopt(SOL_SOCKET, SO_NETNS_COOKIE)");
39 return pr_err("SO_NETNS_COOKIE returned zero cookie");
41 if (unshare(CLONE_NEWNET))
42 return pr_err("unshare");
44 sock2 = socket(AF_INET, SOCK_STREAM, 0);
46 return pr_err("Unable to create TCP socket");
48 vallen = sizeof(cookie2);
49 if (getsockopt(sock2, SOL_SOCKET, SO_NETNS_COOKIE, &cookie2, &vallen) != 0)
50 return pr_err("getsockopt(SOL_SOCKET, SO_NETNS_COOKIE)");
53 return pr_err("SO_NETNS_COOKIE returned zero cookie");
55 if (cookie1 == cookie2)
56 return pr_err("SO_NETNS_COOKIE returned identical cookies for distinct ns");