/* Test that garbage packets do not affect timeout handling.

   Copyright (C) 2017-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library; if not, see

   <http://www.gnu.org/licenses/>.  */

#include <netinet/in.h>

#include <rpc/clnt.h>

#include <rpc/svc.h>

#include <stdbool.h>

#include <support/check.h>

#include <support/namespace.h>

#include <support/xsocket.h>

#include <support/xthread.h>

#include <sys/socket.h>

#include <unistd.h>

/* Descriptor for the server UDP socket.  */

static int server_fd;

static void *

garbage_sender_thread (void *unused)

{

  while (true)

    {

      struct sockaddr_storage sa;

      socklen_t salen = sizeof (sa);

      char buf[1];

      if (recvfrom (server_fd, buf, sizeof (buf), 0,

                    (struct sockaddr *) &sa, &salen) < 0)

        FAIL_EXIT1 ("recvfrom: %m");

      /* Send garbage packets indefinitely.  */

      buf[0] = 0;

      while (true)

        {

          /* sendto can fail if the client closed the socket.  */

          if (sendto (server_fd, buf, sizeof (buf), 0,

                      (struct sockaddr *) &sa, salen) < 0)

            break;

          /* Wait a bit, to avoid burning too many CPU cycles in a

             tight loop.  The wait period must be much shorter than

             the client timeouts configured below.  */

          usleep (50 * 1000);

        }

    }

}

static int

do_test (void)

{

  support_become_root ();

  support_enter_network_namespace ();

  server_fd = xsocket (AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, IPPROTO_UDP);

  struct sockaddr_in server_address =

    {

      .sin_family = AF_INET,

      .sin_addr.s_addr = htonl (INADDR_LOOPBACK),

    };

  xbind (server_fd,

         (struct sockaddr *) &server_address, sizeof (server_address));

  {

    socklen_t sinlen = sizeof (server_address);

    xgetsockname (server_fd, (struct sockaddr *) &server_address, &sinlen);

    TEST_VERIFY (sizeof (server_address) == sinlen);

  }

  /* Garbage packet source.  */

  xpthread_detach (xpthread_create (NULL, garbage_sender_thread, NULL));

  /* Test client.  Use an arbitrary timeout of one second, which is

     much longer than the garbage packet interval, but still

     reasonably short, so that the test completes quickly.  */

  int client_fd = RPC_ANYSOCK;

  CLIENT *clnt = clntudp_create (&server_address,

                                 1, 2, /* Arbitrary RPC endpoint numbers.  */

                                 (struct timeval) { 1, 0 },

                                 &client_fd);

  if (clnt == NULL)

    FAIL_EXIT1 ("clntudp_create: %m");

  TEST_VERIFY (clnt_call (clnt, 3, /* Arbitrary RPC procedure number.  */

                          (xdrproc_t) xdr_void, NULL,

                          (xdrproc_t) xdr_void, NULL,

                          ((struct timeval) { 1, 0 })));

  return 0;

}

#include <support/test-driver.c>