/*
     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 2, 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 rootservers 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
    {
#if DEBUG_RESOLVER
      GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
                  "Received invalid hostname `%s'.\n", hostname);
#endif
      GNUNET_break (0);
    }
}

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_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,
     struct GNUNET_SCHEDULER_Handle *sched,
     char *const *args,
     const char *cfgfile, const struct GNUNET_CONFIGURATION_Handle *cfg)
{
  struct sockaddr_in sa;
  struct GNUNET_TIME_Relative timeout =
    GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
                                   2500);
  memset (&sa, 0, sizeof (sa));
  sa.sin_family = AF_INET;
  sa.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
  GNUNET_RESOLVER_ip_get (sched,
                          cfg,
                          "localhost", AF_INET, timeout, &check_127, cls);
  GNUNET_RESOLVER_hostname_get (sched,
                                cfg,
                                (const struct sockaddr *) &sa,
                                sizeof (struct sockaddr),
                                GNUNET_YES, timeout, &check_localhost, cls);
  GNUNET_RESOLVER_hostname_get (sched,
                                cfg,
                                (const struct sockaddr *) &sa,
                                sizeof (struct sockaddr),
                                GNUNET_NO,
                                timeout, &check_localhost_num, cls);
  GNUNET_RESOLVER_hostname_resolve (sched,
                                    cfg,
                                    AF_UNSPEC, timeout, &check_hostname, cls);
  // Testing non-local dns resolution
  // DNS Rootserver to test: a.root-servers.net - 198.41.0.4  
  
  char const * rootserver_name = ROOTSERVER_NAME;
  
  struct hostent *rootserver;
  
  rootserver = gethostbyname(rootserver_name);
  if (rootserver == NULL)
    {
      // Error: resolving ip addresses does not work
      #if DEBUG_RESOLVER
      switch (h_errno)
	{
	
	case HOST_NOT_FOUND: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyname() could not lookup ip address: HOST_NOT_FOUND\n");break;
	case NO_ADDRESS: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyname() could not lookup ip address: NO_ADDRESS\n");break;
	case NO_RECOVERY: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyname() could not lookup ip address: NO_RECOVERY\n");break;
	case TRY_AGAIN: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyname() could not lookup ip address: TRY_AGAIN\n");break;
	}
      #endif
      GNUNET_break (0);
    }
  else 
  {
    // Counting returned ip addresses
    int count_ips =0 ;
    while (rootserver->h_addr_list[count_ips]!=NULL)
    {
      count_ips++;
    }    
    if ( count_ips > 1) 
    {
      #if DEBUG_RESOLVER
	GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Received ip range for root name server, but a root nameserver has only 1 ip\n");
      #endif
      GNUNET_break (0);
    }
    
    // Comparing to resolved address to the address the root nameserver 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, "Received ip 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 (sched, cfg, ROOTSERVER_NAME, AF_INET, timeout, &check_rootserver_ip, cls);
    
    // Success: forward lookups work as exptected
    
    
    // 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 nameserver ip addressr\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
      switch (h_errno)
	{
	
	case HOST_NOT_FOUND: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyaddr() could not lookup ip address: HOST_NOT_FOUND\n");break;
	case NO_ADDRESS: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyaddr() could not lookup ip address: NO_ADDRESS\n");break;
	case NO_RECOVERY: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyaddr() could not lookup ip address: NO_RECOVERY\n");break;
	case TRY_AGAIN: GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "gethostbyaddr() could not lookup ip address: TRY_AGAIN\n");break;
	}
      #endif
      GNUNET_break (0);
    }

    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;
    inet_aton(ROOTSERVER_IP, &sa.sin_addr.s_addr);
    
    GNUNET_RESOLVER_hostname_get (sched,
                                cfg,
                                (const struct sockaddr *) &sa,
                                sizeof (struct sockaddr),
                                GNUNET_YES,
                                timeout, &check_rootserver_name, cls);
    
    // Success: reverse lookups work as exptected    
  } 
}

static int
check ()
{
  int ok = 1 + 2 + 4 + 8;
  char *fn;
  char *pfx;
  pid_t pid;
  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);
  pid = GNUNET_OS_start_process (NULL, NULL, fn,
                                 "gnunet-service-resolver",
#if VERBOSE
                                 "-L", "DEBUG",
#endif
                                 "-c", "test_resolver_api_data.conf", NULL);
  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 != PLIBC_KILL (pid, SIGTERM))
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
      ok = 1;
    }
  GNUNET_OS_process_wait (pid);
  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 */