support/tst-support-namespace.c

   1 /* Test entering namespaces.
   2    Copyright (C) 2016-2020 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>