/*
     This file is part of GNUnet.
     (C) 2010 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 src/setup/gnunet-setup-transport.c
 * @brief support for transport (NAT) configuration
 * @author Christian Grothoff
 */
#include "gnunet-setup.h"
#include <gnunet/gnunet_util_lib.h>
#include <gnunet/gnunet_resolver_service.h>
#include <gnunet/gnunet_nat_lib.h>

/**
 * How long do we wait for the NAT test to report success?
 */
#define TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 1)

/**
 * Handle to the active NAT test.
 */
static struct GNUNET_NAT_Test *tst;

/**
 * Task identifier for the timeout.
 */
static GNUNET_SCHEDULER_TaskIdentifier tsk;

static struct GNUNET_OS_Process *resolver;


/**
 * Update the ICMP server button based on the result.
 *
 * @param on GNUNET_YES to enable, GNUNET_NO to disable
 */
static void
update_icmp_server_enable_button (int on)
{
  GtkToggleButton *button;

  button =
      GTK_TOGGLE_BUTTON (GNUNET_SETUP_get_object
                         ("GNUNET_setup_transport_icmp_server_enable_checkbutton"));
  if (button == NULL)
  {
    GNUNET_break (0);
    return;
  }
  gtk_toggle_button_set_active (button, on ? TRUE : FALSE);
}


/**
 * Function called by NAT on success.
 * Clean up and update GUI (with success).
 *
 * @param cls closure (unused)
 * @param success currently always GNUNET_OK
 */
static void
result_callback (void *cls, int success)
{
  GNUNET_SCHEDULER_cancel (tsk);
  tsk = GNUNET_SCHEDULER_NO_TASK;
  GNUNET_NAT_test_stop (tst);
  tst = NULL;
  if (NULL != resolver)
  {
    GNUNET_break (0 == GNUNET_OS_process_kill (resolver, SIGTERM));
    GNUNET_OS_process_destroy (resolver);
  }
  update_icmp_server_enable_button (success);
}


/**
 * Function called if NAT failed to confirm success.
 * Clean up and update GUI (with failure).
 *
 * @param cls closure (unused)
 * @param tc scheduler callback
 */
static void
fail_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  GNUNET_assert (NULL != tst);
  tsk = GNUNET_SCHEDULER_NO_TASK;
  GNUNET_NAT_test_stop (tst);
  tst = NULL;
  update_icmp_server_enable_button (GNUNET_NO);
}


/**
 * Main function for the connection reversal test.
 *
 * @param cls the 'int*' for the result
 * @param tc scheduler context
 */
static void
reversal_test (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  int *ok = cls;

  GNUNET_assert (NULL != cfg);
  GNUNET_RESOLVER_connect (cfg);
  tst = GNUNET_NAT_test_start (cfg, GNUNET_YES, 0, 0, &result_callback, ok);
  if (NULL == tst)
  {
    *ok = GNUNET_SYSERR;
    return;
  }
  tsk = GNUNET_SCHEDULER_add_delayed (TIMEOUT, &fail_timeout, ok);
}

/**
 * Test if connection reversal (ICMP method) works.
 */
static void
test_connection_reversal ()
{
  if (NULL != resolver)
    return;                     /* test already active!? */
  resolver =
    GNUNET_OS_start_process (GNUNET_YES, NULL, NULL, "gnunet-service-resolver",
                               "gnunet-service-resolver", NULL);
  GNUNET_SCHEDULER_add_now (&reversal_test, NULL);
}


/**
 * Process list of local IP addresses.  Find and set the
 * one of the default interface.
 *
 * @param cls closure (not used)
 * @param name name of the interface (can be NULL for unknown)
 * @param isDefault is this presumably the default interface
 * @param addr address of this interface (can be NULL for unknown or unassigned)
 * @param broadcast_addr the broadcast address (can be NULL for unknown or unassigned)
 * @param netmask the network mask (can be NULL for unknown or unassigned))
 * @param addrlen length of the address
 * @return GNUNET_OK to continue iteration, GNUNET_SYSERR to abort
 */
static int
nipo (void *cls, const char *name, int isDefault, const struct sockaddr *addr,
      const struct sockaddr *broadcast_addr, const struct sockaddr *netmask,
      socklen_t addrlen)
{
  const struct sockaddr_in *in;
  char buf[INET_ADDRSTRLEN];
  GtkEntry *entry;

  if (!isDefault)
    return GNUNET_OK;
  if (addrlen != sizeof (struct sockaddr_in))
    return GNUNET_OK;
  in = (const struct sockaddr_in *) addr;

  /* set internal IP address */
  if (NULL == inet_ntop (AF_INET, &in->sin_addr, buf, sizeof (buf)))
  {
    GNUNET_break (0);
    return GNUNET_OK;
  }
  GNUNET_CONFIGURATION_set_value_string (cfg, "nat", "INTERNAL_ADDRESS", buf);
  entry =
      GTK_ENTRY (GNUNET_SETUP_get_object
                 ("GNUNET_setup_transport_internal_ip_entry"));
  if (entry == NULL)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  gtk_entry_set_text (entry, buf);
  /* no need to continue iteration */
  return GNUNET_SYSERR;
}


/**
 * Set our external IPv4 address.
 *
 * @param cls closure
 * @param addr the address, NULL on errors
 */
static void
set_external_ipv4 (void *cls, const struct in_addr *addr)
{
  char buf[INET_ADDRSTRLEN];
  GObject *o;
  GtkEntry *entry;
  GtkToggleButton *button;

  if (NULL != addr)
  {
    /* enable 'behind nat' */
    if (NULL != cfg)
      GNUNET_CONFIGURATION_set_value_string (cfg, "nat", "BEHIND_NAT", "YES");
    o = GNUNET_SETUP_get_object ("GNUNET_setup_transport_nat_checkbutton");
    if (NULL != o)
    {
      button = GTK_TOGGLE_BUTTON (o);
      if (button == NULL)
      {
        GNUNET_break (0);
        return;
      }
      gtk_toggle_button_set_active (button, TRUE);
    }

    /* set external IP address */
    if (NULL == inet_ntop (AF_INET, addr, buf, sizeof (buf)))
    {
      GNUNET_break (0);
      return;
    }
    if (NULL != cfg)
      GNUNET_CONFIGURATION_set_value_string (cfg, "nat", "EXTERNAL_ADDRESS",
                                             buf);
    o = GNUNET_SETUP_get_object
        ("GNUNET_setup_transport_external_ip_address_entry");
    if (NULL != o)
    {
      entry = GTK_ENTRY (o);
      if (entry == NULL)
      {
        GNUNET_break (0);
        return;
      }
      gtk_entry_set_text (entry, buf);
    }
  }
}


/**
 * User asked for autoconfiguration.  Try the full program.
 */
void
GNUNET_setup_transport_autoconfig_button_clicked_cb ()
{
  GtkToggleButton *button;
  int hns;
  int hnc;
  char *tmp;

  /* try to detect external IP */
  (void) GNUNET_NAT_mini_get_external_ipv4 (TIMEOUT, &set_external_ipv4, NULL);
  /* Try to detect internal IP */
  GNUNET_OS_network_interfaces_list (&nipo, NULL);

  /* FIXME: do more: test if UPnP works */

  /* test gnunet-helper-nat-server */
  tmp = NULL;
  hns =
      ((GNUNET_OK ==
        GNUNET_CONFIGURATION_get_value_string (cfg, "nat", "EXTERNAL_ADDRESS",
                                               &tmp)) && (0 < strlen (tmp)) &&
       (GNUNET_YES ==
        GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "BEHIND_NAT")) &&
       (GNUNET_YES ==
        GNUNET_OS_check_helper_binary ("gnunet-helper-nat-server")));
  GNUNET_free_non_null (tmp);
  if (hns)
    test_connection_reversal ();

  /* test gnunet-helper-nat-client */
  tmp = NULL;
  hnc =
      ((GNUNET_OK ==
        GNUNET_CONFIGURATION_get_value_string (cfg, "nat", "INTERNAL_ADDRESS",
                                               &tmp)) && (0 < strlen (tmp)) &&
       (GNUNET_YES !=
        GNUNET_CONFIGURATION_get_value_yesno (cfg, "nat", "BEHIND_NAT")) &&
       (GNUNET_YES ==
        GNUNET_OS_check_helper_binary ("gnunet-helper-nat-client")));
  GNUNET_free_non_null (tmp);
  button =
      GTK_TOGGLE_BUTTON (GNUNET_SETUP_get_object
                         ("GNUNET_setup_transport_icmp_client_enable_checkbutton"));
  if (button == NULL)
  {
    GNUNET_break (0);
    return;
  }
  gtk_toggle_button_set_active (button, hnc ? TRUE : FALSE);
}

/* end of gnunet-setup-transport.c */