/*
 This file is part of GNUnet.
 (C) 2009 Christian Grothoff (and other contributing authors)

 GNUnet is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published
 by the Free Software Foundation; either version 3, or (at your
 option) any later version.

 GNUnet 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
 General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with GNUnet; see the file COPYING.  If not, write to the
 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 Boston, MA 02111-1307, USA.
 */
/**
 * @file resolver/test_resolver_api.c
 * @brief testcase for resolver_api.c
 */
#include "platform.h"
#include "gnunet_common.h"
#include "gnunet_getopt_lib.h"
#include "gnunet_os_lib.h"
#include "gnunet_program_lib.h"
#include "gnunet_scheduler_lib.h"
#include "gnunet_resolver_service.h"
#include "resolver.h"

#define VERBOSE GNUNET_NO

/** 
 * Using DNS root servers to check gnunet's resolver service
 * a.root-servers.net <-> 198.41.0.4 is a fix 1:1 mapping that should not change over years
 * For more information have a look at IANA's website http://www.root-servers.org/
 */
#define ROOTSERVER_NAME "a.root-servers.net"
#define ROOTSERVER_IP 	"198.41.0.4"

static void
check_hostname(void *cls, const struct sockaddr *sa, socklen_t salen)
{
  int *ok = cls;

  if (salen == 0)
    {
      (*ok) &= ~8;
      return;
    }
  GNUNET_log(GNUNET_ERROR_TYPE_INFO, _("Got IP address `%s' for our host.\n"),
      GNUNET_a2s(sa, salen));
}

static void
check_localhost_num(void *cls, const char *hostname)
{
  int *ok = cls;
  if (hostname == NULL)
    return;
  if (0 == strcmp(hostname, "127.0.0.1"))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
          "Received correct hostname `%s'.\n", hostname);
#endif
      (*ok) &= ~4;
    }
  else
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
          "Received invalid hostname `%s'.\n", hostname);
#endif
      GNUNET_break(0);
    }
}

static void
check_localhost(void *cls, const char *hostname)
{
  int *ok = cls;
  if (hostname == NULL)
    return;
  if (0 == strcmp(hostname, "localhost"))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
          "Received correct hostname `%s'.\n", hostname);
#endif
      (*ok) &= ~2;
    }
  else
    {
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
		  "Received unexpected hostname `%s', expected `localhost' (this could be OK).\n", 
		  hostname);
    }
}

static void
check_127(void *cls, const struct sockaddr *sa, socklen_t salen)
{
  int *ok = cls;
  const struct sockaddr_in *sai = (const struct sockaddr_in *) sa;

  if (sa == NULL)
    return;
  GNUNET_assert(sizeof(struct sockaddr_in) == salen);
  if (sai->sin_addr.s_addr == htonl(INADDR_LOOPBACK))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received correct address.\n");
#endif
      (*ok) &= ~1;
    }
  else
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received incorrect address.\n");
#endif
      GNUNET_break(0);
    }
}

static void
check_local_fqdn(void *cls, const char *gnunet_fqdn)
{
  int result = 0;

  struct hostent *host;
  char hostname[GNUNET_OS_get_hostname_max_length() + 1];

  if (0 != gethostname (hostname, sizeof (hostname) - 1))
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR |
                           GNUNET_ERROR_TYPE_BULK, "gethostname");
      return;
    }
#if DEBUG_RESOLVER
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              _("Resolving our FQDN `%s'\n"), hostname);
#endif
  host = gethostbyname ( hostname );
  if ( NULL == host)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _("Could not resolve our FQDN : %s %u\n"),
                hstrerror (h_errno), h_errno);
    return;
  }

  GNUNET_assert( 0 != host);

  result = strcmp(host->h_name, gnunet_fqdn);
  if ( 0 != result )
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
        "Local resolved and resolver resolved fqdns are not equal\n");
  }
  GNUNET_assert( 0 == result);
}



static void
check_rootserver_ip(void *cls, const struct sockaddr *sa, socklen_t salen)
{
  int *ok = cls;
  const struct sockaddr_in *sai = (const struct sockaddr_in *) sa;

  if (sa == NULL)
    return;
  GNUNET_assert(sizeof(struct sockaddr_in) == salen);

  if (0 == strcmp(inet_ntoa(sai->sin_addr), ROOTSERVER_IP))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received correct rootserver ip address.\n");
#endif
      (*ok) &= ~1;
    }
  else
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received incorrect rootserver ip address.\n");
#endif
      GNUNET_break(0);
    }
}

static void
check_rootserver_name(void *cls, const char *hostname)
{
  int *ok = cls;
  if (hostname == NULL)
    return;

  if (0 == strcmp(hostname, ROOTSERVER_NAME))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
          "Received correct rootserver hostname `%s'.\n", hostname);
#endif
      (*ok) &= ~2;
    }
  else
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
          "Received invalid rootserver hostname `%s'.\n", hostname);
#endif
      GNUNET_break(0);
    }
}

static void
run(void *cls, char * const *args,
    const char *cfgfile, const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  int *ok = cls;
  struct sockaddr_in sa;
  struct GNUNET_TIME_Relative timeout = GNUNET_TIME_relative_multiply(
      GNUNET_TIME_UNIT_MILLISECONDS, 2500);
  int count_ips = 0;
  char * own_fqdn;

  memset(&sa, 0, sizeof(sa));
  sa.sin_family = AF_INET;
  sa.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
  GNUNET_RESOLVER_ip_get(cfg, "localhost", AF_INET, timeout, &check_127,
      cls);
  GNUNET_RESOLVER_hostname_get(cfg, (const struct sockaddr *) &sa,
      sizeof(struct sockaddr), GNUNET_YES, timeout, &check_localhost, cls);
  GNUNET_RESOLVER_hostname_get(cfg, (const struct sockaddr *) &sa,
      sizeof(struct sockaddr), GNUNET_NO, timeout, &check_localhost_num, cls);
  GNUNET_RESOLVER_hostname_resolve(cfg, AF_UNSPEC, timeout,
      &check_hostname, cls);


  /*
   * Looking up our own fqdn
   */
  own_fqdn = GNUNET_RESOLVER_local_fqdn_get();
  check_local_fqdn( NULL, own_fqdn);
  GNUNET_free_non_null (own_fqdn);

  /*
   * Testing non-local DNS resolution
   * DNS rootserver to test: a.root-servers.net - 198.41.0.4
   */

  const char * rootserver_name = ROOTSERVER_NAME;
  struct hostent *rootserver;

  rootserver = gethostbyname(rootserver_name);
  if (rootserver == NULL)
    {
      /* Error: resolving ip addresses does not work */
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
          _("gethostbyname() could not lookup IP address: %s\n"),
          hstrerror (h_errno));
#endif
      fprintf (stderr,
	       "System seems to be off-line, will not run all DNS tests\n");
      *ok = 0; /* mark test as passing anyway */
      return;
    }

  /* Counting returned IP addresses */
  while (rootserver->h_addr_list[count_ips] != NULL)
    count_ips++;
  if (count_ips > 1)
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "IP received range for root name server, but a root name server has only 1 IP\n");
#endif
      GNUNET_break(0);
    }

  /* Comparing to resolved address to the address the root name server should have */
  if (strcmp(inet_ntoa(*(struct in_addr *) rootserver->h_addr_list[0]),
      ROOTSERVER_IP) != 0)
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "IP received and IP for root name server differ\n");
#endif
      GNUNET_break(0);
    }
#if DEBUG_RESOLVER
  GNUNET_log (GNUNET_ERROR_TYPE_INFO, "System's own forward name resolution is working\n");
#endif

  /* Resolve the same using GNUNET */
  GNUNET_RESOLVER_ip_get(cfg, ROOTSERVER_NAME, AF_INET, timeout,
      &check_rootserver_ip, cls);

  /*
   * Success: forward lookups work as expected
   * Next step: reverse lookups
   */

  struct in_addr rootserver_addr;
  rootserver->h_name = "";
  if (1 != inet_pton(AF_INET, ROOTSERVER_IP, &rootserver_addr))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Could not transform root name server IP address\n");
#endif
      GNUNET_break(0);
    }

  rootserver
      = gethostbyaddr(&rootserver_addr, sizeof(rootserver_addr), AF_INET);
  if (rootserver == NULL)
    {
      /* Error: resolving IP addresses does not work */
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
          _("gethostbyaddr() could not lookup hostname: %s\n"),
          hstrerror (h_errno));
#endif
      GNUNET_break(0);
    }
  else
  {
    if (0 != strcmp(rootserver->h_name, ROOTSERVER_NAME))
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received hostname and hostname for root name server differ\n");
#endif
      GNUNET_break(0);
    }
  }

#if DEBUG_RESOLVER
  GNUNET_log (GNUNET_ERROR_TYPE_INFO, "System's own reverse name resolution is working\n");
#endif
  /* Resolve the same using GNUNET */

  memset(&sa, 0, sizeof(sa));
  sa.sin_family = AF_INET;
#ifndef MINGW
  inet_aton(ROOTSERVER_IP, &sa.sin_addr);
#else
  sa.sin_addr.S_un.S_addr = inet_addr(ROOTSERVER_IP);
#endif
  GNUNET_RESOLVER_hostname_get(cfg, (const struct sockaddr *) &sa,
      sizeof(struct sockaddr), GNUNET_YES, timeout, &check_rootserver_name, cls);
}

static int
check()
{
  int ok = 1 + 2 + 4 + 8;
  char *fn;
  char *pfx;
  struct GNUNET_OS_Process *proc;
  char * const argv[] =
    { "test-resolver-api", "-c", "test_resolver_api_data.conf",
#if VERBOSE
        "-L", "DEBUG",
#endif
        NULL };
  struct GNUNET_GETOPT_CommandLineOption options[] =
    { GNUNET_GETOPT_OPTION_END };
  pfx = GNUNET_OS_installation_get_path(GNUNET_OS_IPK_BINDIR);
  GNUNET_asprintf(&fn, "%s%cgnunet-service-resolver", pfx, DIR_SEPARATOR);
  GNUNET_free(pfx);
  proc = GNUNET_OS_start_process(NULL, NULL, fn, "gnunet-service-resolver",
#if VERBOSE
      "-L", "DEBUG",
#endif
      "-c", "test_resolver_api_data.conf", NULL);
  GNUNET_assert (NULL != proc);
  GNUNET_free(fn);
  GNUNET_assert(GNUNET_OK == GNUNET_PROGRAM_run((sizeof(argv) / sizeof(char *))
      - 1, argv, "test-resolver-api", "nohelp", options, &run, &ok));
  if (0 != GNUNET_OS_process_kill (proc, SIGTERM))
    {
      GNUNET_log_strerror(GNUNET_ERROR_TYPE_WARNING, "kill");
      ok = 1;
    }
  GNUNET_OS_process_wait (proc);
  GNUNET_OS_process_close (proc);
  proc = NULL;
  if (ok != 0)
    fprintf(stderr, "Missed some resolutions: %u\n", ok);
  return ok;
}

int
main(int argc, char *argv[])
{
  int ret;

  GNUNET_log_setup("test-resolver-api",
#if VERBOSE
      "DEBUG",
#else
      "WARNING",
#endif
      NULL);
  ret = check();

  return ret;
}

/* end of test_resolver_api.c */