/* Test for __libc_res_nsend buffer mismanagent (bug 18665), UDP case.

   Copyright (C) 2016-2018 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 <errno.h>

#include <netdb.h>

#include <resolv.h>

#include <stdio.h>

#include <string.h>

#include <support/check.h>

#include <support/resolv_test.h>

#include <support/xthread.h>

static pthread_mutex_t lock = PTHREAD_MUTEX_INITIALIZER;

static int initial_address_count;

static int response_count;

static void

response (const struct resolv_response_context *ctx,

          struct resolv_response_builder *b,

          const char *qname, uint16_t qclass, uint16_t qtype)

{

  TEST_VERIFY_EXIT (qname != NULL);

  struct resolv_response_flags flags = {};

  resolv_response_init (b, flags);

  resolv_response_add_question (b, qname, qclass, qtype);

  resolv_response_section (b, ns_s_an);

  /* Add many A/AAAA records to the second response.  */

  int address_count;

  xpthread_mutex_lock (&lock);

  if (response_count == 0)

    address_count = initial_address_count;

  else

    address_count = 2000;

  ++response_count;

  xpthread_mutex_unlock (&lock);

  for (int i = 0; i < address_count; ++i)

    {

      resolv_response_open_record (b, qname, qclass, qtype, 0);

      switch (qtype)

        {

        case T_A:

          {

            char ipv4[4] = {10, i >> 8, i, 0};

            ipv4[3] = 2 * ctx->tcp + 4 * ctx->server_index;

            resolv_response_add_data (b, &ipv4, sizeof (ipv4));

          }

          break;

        case T_AAAA:

          {

            char ipv6[16]

              = {0x20, 0x01, 0xd, 0xb8, 0, 0, 0, 0, 0, 0, 0, 0, 0,

                 i >> 8, i, 0};

            ipv6[15] = 2 * ctx->tcp + 4 * ctx->server_index;

            resolv_response_add_data (b, &ipv6, sizeof (ipv6));

          }

          break;

        default:

          support_record_failure ();

          printf ("error: unexpected QTYPE: %s/%u/%u\n",

                  qname, qclass, qtype);

        }

      resolv_response_close_record (b);

    }

}

static void

test_different_sizes (void)

{

  struct addrinfo hints = { .ai_family = AF_UNSPEC, };

  struct addrinfo *ai;

  int ret;

  /* This magic number produces a response size close to 2048

     bytes.  */

  initial_address_count = 126;

  response_count = 0;

  ret = getaddrinfo ("www.example", "80", &hints, &ai;;

  if (ret == 0)

    freeaddrinfo (ai);

  response_count = 0;

  ret = getaddrinfo ("www123.example", "80", &hints, &ai;;

  if (ret == 0)

    freeaddrinfo (ai);

  response_count = 0;

  ret = getaddrinfo ("www1234.example", "80", &hints, &ai;;

  if (ret == 0)

    freeaddrinfo (ai);

  response_count = 0;

  ret = getaddrinfo ("www12345.example", "80", &hints, &ai;;

  if (ret == 0)

    freeaddrinfo (ai);

}

static int

do_test (void)

{

  struct resolv_test *obj = resolv_test_start

    ((struct resolv_redirect_config)

     {

       .response_callback = response

     });

  test_different_sizes ();

  _res.options |= RES_SNGLKUP;

  test_different_sizes ();

  _res.options |= RES_SNGLKUPREOP;

  test_different_sizes ();

  resolv_test_end (obj);

  return 0;

}

#include <support/test-driver.c>