1  /* Test entering namespaces.
       2     Copyright (C) 2016-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <errno.h>
      20  #include <netdb.h>
      21  #include <stdio.h>
      22  #include <support/check.h>
      23  #include <support/namespace.h>
      24  #include <support/xsocket.h>
      25  #include <support/xunistd.h>
      26  
      27  /* Check that the loopback interface provides multiple addresses which
      28     can be used to run independent servers.  */
      29  static void
      30  test_localhost_bind (void)
      31  {
      32    printf ("info: testing loopback interface with multiple addresses\n");
      33  
      34    /* Create the two server addresses.  */
      35    static const struct addrinfo hints =
      36      {
      37        .ai_family = AF_INET,
      38        .ai_socktype = SOCK_DGRAM,
      39        .ai_protocol = IPPROTO_UDP,
      40      };
      41    struct addrinfo *ai[3];
      42    TEST_VERIFY_EXIT (getaddrinfo ("127.0.0.1", "53", &hints, ai + 0) == 0);
      43    TEST_VERIFY_EXIT (getaddrinfo ("127.0.0.2", "53", &hints, ai + 1) == 0);
      44    TEST_VERIFY_EXIT (getaddrinfo ("127.0.0.3", "53", &hints, ai + 2) == 0);
      45  
      46    /* Create the server scokets and bind them to these addresses.  */
      47    int sockets[3];
      48    for (int i = 0; i < 3; ++i)
      49      {
      50        sockets[i] = xsocket
      51          (ai[i]->ai_family, ai[i]->ai_socktype, ai[i]->ai_protocol);
      52        xbind (sockets[i], ai[i]->ai_addr, ai[i]->ai_addrlen);
      53      }
      54  
      55    /* Send two packets to each server.  */
      56    int client = xsocket (AF_INET, SOCK_DGRAM, IPPROTO_UDP);
      57    for (int i = 0; i < 3; ++i)
      58      {
      59        TEST_VERIFY (sendto (client, &i, sizeof (i), 0,
      60                             ai[i]->ai_addr, ai[i]->ai_addrlen) == sizeof (i));
      61        int j = i + 256;
      62        TEST_VERIFY (sendto (client, &j, sizeof (j), 0,
      63                             ai[i]->ai_addr, ai[i]->ai_addrlen) == sizeof (j));
      64      }
      65  
      66    /* Check that the packets can be received with the expected
      67       contents.  Note that the receive calls interleave differently,
      68       which hopefully proves that the sockets are, indeed,
      69       independent.  */
      70    for (int i = 0; i < 3; ++i)
      71      {
      72        int buf;
      73        TEST_VERIFY (recv (sockets[i], &buf, sizeof (buf), 0) == sizeof (buf));
      74        TEST_VERIFY (buf == i);
      75      }
      76    for (int i = 0; i < 3; ++i)
      77      {
      78        int buf;
      79        TEST_VERIFY (recv (sockets[i], &buf, sizeof (buf), 0) == sizeof (buf));
      80        TEST_VERIFY (buf == i + 256);
      81        /* Check that there is no more data to receive.  */
      82        TEST_VERIFY (recv (sockets[i], &buf, sizeof (buf), MSG_DONTWAIT) == -1);
      83        TEST_VERIFY (errno == EWOULDBLOCK || errno == EAGAIN);
      84      }
      85  
      86    /* Close all sockets and free the addresses.  */
      87    for (int i = 0; i < 3; ++i)
      88      {
      89        freeaddrinfo (ai[i]);
      90        xclose (sockets[i]);
      91      }
      92    xclose (client);
      93  }
      94  
      95  
      96  static int
      97  do_test (void)
      98  {
      99    bool root = support_become_root ();
     100    if (root)
     101      printf ("info: acquired root-like privileges\n");
     102    bool netns = support_enter_network_namespace ();
     103    if (netns)
     104      printf ("info: entered network namespace\n");
     105    if (support_in_uts_namespace ())
     106      printf ("info: also entered UTS namespace\n");
     107  
     108    if (root && netns)
     109      test_localhost_bind ();
     110  
     111    return 0;
     112  }
     113  
     114  #include <support/test-driver.c>