1 /* Test entering namespaces.
2    Copyright (C) 2016-2022 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
test_localhost_bind(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
do_test(void)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>
115