tools/testing/selftests/net/so_netns_cookie.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #define _GNU_SOURCE
   3 #include <sched.h>
   4 #include <unistd.h>
   5 #include <stdio.h>
   6 #include <errno.h>
   7 #include <string.h>
   8 #include <stdlib.h>
   9 #include <stdint.h>
  10 #include <sys/types.h>
  11 #include <sys/socket.h>
  12
  13 #ifndef SO_NETNS_COOKIE
  14 #define SO_NETNS_COOKIE 71
  15 #endif
  16
  17 #define pr_err(fmt, ...) \
  18         ({ \
  19                 fprintf(stderr, "%s:%d:" fmt ": %m\n", \
  20                         __func__, __LINE__, ##__VA_ARGS__); \
  21                 1; \
  22         })
  23
  24 int main(int argc, char *argvp[])
  25 {
  26         uint64_t cookie1, cookie2;
  27         socklen_t vallen;
  28         int sock1, sock2;
  29
  30         sock1 = socket(AF_INET, SOCK_STREAM, 0);
  31         if (sock1 < 0)
  32                 return pr_err("Unable to create TCP socket");
  33
  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)");
  37
  38         if (!cookie1)
  39                 return pr_err("SO_NETNS_COOKIE returned zero cookie");
  40
  41         if (unshare(CLONE_NEWNET))
  42                 return pr_err("unshare");
  43
  44         sock2 = socket(AF_INET, SOCK_STREAM, 0);
  45         if (sock2 < 0)
  46                 return pr_err("Unable to create TCP socket");
  47
  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)");
  51
  52         if (!cookie2)
  53                 return pr_err("SO_NETNS_COOKIE returned zero cookie");
  54
  55         if (cookie1 == cookie2)
  56                 return pr_err("SO_NETNS_COOKIE returned identical cookies for distinct ns");
  57
  58         close(sock1);
  59         close(sock2);
  60         return 0;
  61 }