sunrpc/tst-udp-garbage.c

   1 /* Test that garbage packets do not affect timeout handling.
   2    Copyright (C) 2017-2023 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 <netinet/in.h>
  20 #include <rpc/clnt.h>
  21 #include <rpc/svc.h>
  22 #include <stdbool.h>
  23 #include <support/check.h>
  24 #include <support/namespace.h>
  25 #include <support/xsocket.h>
  26 #include <support/xthread.h>
  27 #include <sys/socket.h>
  28 #include <unistd.h>
  29
  30 /* Descriptor for the server UDP socket.  */
  31 static int server_fd;
  32
  33 static void *
  34 garbage_sender_thread (void *unused)
  35 {
  36   while (true)
  37     {
  38       struct sockaddr_storage sa;
  39       socklen_t salen = sizeof (sa);
  40       char buf[1];
  41       if (recvfrom (server_fd, buf, sizeof (buf), 0,
  42                     (struct sockaddr *) &sa, &salen) < 0)
  43         FAIL_EXIT1 ("recvfrom: %m");
  44
  45       /* Send garbage packets indefinitely.  */
  46       buf[0] = 0;
  47       while (true)
  48         {
  49           /* sendto can fail if the client closed the socket.  */
  50           if (sendto (server_fd, buf, sizeof (buf), 0,
  51                       (struct sockaddr *) &sa, salen) < 0)
  52             break;
  53
  54           /* Wait a bit, to avoid burning too many CPU cycles in a
  55              tight loop.  The wait period must be much shorter than
  56              the client timeouts configured below.  */
  57           usleep (50 * 1000);
  58         }
  59     }
  60 }
  61
  62 static int
  63 do_test (void)
  64 {
  65   support_become_root ();
  66   support_enter_network_namespace ();
  67
  68   server_fd = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);
  69   struct sockaddr_in server_address =
  70     {
  71       .sin_family = AF_INET,
  72       .sin_addr.s_addr = htonl (INADDR_LOOPBACK),
  73     };
  74   xbind (server_fd,
  75          (struct sockaddr *) &server_address, sizeof (server_address));
  76   {
  77     socklen_t sinlen = sizeof (server_address);
  78     xgetsockname (server_fd, (struct sockaddr *) &server_address, &sinlen);
  79     TEST_VERIFY (sizeof (server_address) == sinlen);
  80   }
  81
  82   /* Garbage packet source.  */
  83   xpthread_detach (xpthread_create (NULL, garbage_sender_thread, NULL));
  84
  85   /* Test client.  Use an arbitrary timeout of one second, which is
  86      much longer than the garbage packet interval, but still
  87      reasonably short, so that the test completes quickly.  */
  88   int client_fd = RPC_ANYSOCK;
  89   CLIENT *clnt = clntudp_create (&server_address,
  90                                  1, 2, /* Arbitrary RPC endpoint numbers.  */
  91                                  (struct timeval) { 1, 0 },
  92                                  &client_fd);
  93   if (clnt == NULL)
  94     FAIL_EXIT1 ("clntudp_create: %m");
  95
  96   TEST_VERIFY (clnt_call (clnt, 3, /* Arbitrary RPC procedure number.  */
  97                           (xdrproc_t) xdr_void, NULL,
  98                           (xdrproc_t) xdr_void, NULL,
  99                           ((struct timeval) { 1, 0 })));
 100
 101   return 0;
 102 }
 103
 104 #include <support/test-driver.c>