/* GIO - GLib Input, Output and Streaming Library

 *

 * Copyright 2014-2018 Jan-Michael Brummer <jan.brummer@tabos.org>

 *

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

 *

 * This 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 this library; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place, Suite 330,

 * Boston, MA 02111-1307, USA.

 */

#include "config.h"

#include <errno.h>

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include <winsock2.h>

#include <ws2tcpip.h>

#include <iphlpapi.h>

#include <stdio.h>

#include "gwin32networkmonitor.h"

#include "ginetaddress.h"

#include "ginetaddressmask.h"

#include "ginitable.h"

#include "giomodule-priv.h"

#include "glibintl.h"

#include "glib/gstdio.h"

#include "gnetworkingprivate.h"

#include "gsocket.h"

#include "gnetworkmonitor.h"

#include "gioerror.h"

static void g_win32_network_monitor_iface_init (GNetworkMonitorInterface *iface);

static void g_win32_network_monitor_initable_iface_init (GInitableIface *iface);

struct _GWin32NetworkMonitorPrivate

{

  gboolean initialized;

  GError *init_error;

  GMainContext *main_context;

  GSource *route_change_source;

  HANDLE handle;

};

#define g_win32_network_monitor_get_type _g_win32_network_monitor_get_type

G_DEFINE_TYPE_WITH_CODE (GWin32NetworkMonitor, g_win32_network_monitor, G_TYPE_NETWORK_MONITOR_BASE,

                         G_ADD_PRIVATE (GWin32NetworkMonitor)

                         G_IMPLEMENT_INTERFACE (G_TYPE_NETWORK_MONITOR,

                                                g_win32_network_monitor_iface_init)

                         G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,

                                                g_win32_network_monitor_initable_iface_init)

                         _g_io_modules_ensure_extension_points_registered ();

                         g_io_extension_point_implement (G_NETWORK_MONITOR_EXTENSION_POINT_NAME,

                                                         g_define_type_id,

                                                         "win32",

                                                         20))

static void

g_win32_network_monitor_init (GWin32NetworkMonitor *win)

{

  win->priv = g_win32_network_monitor_get_instance_private (win);

}

static gboolean

win_network_monitor_get_ip_info (IP_ADDRESS_PREFIX  prefix,

                                 GSocketFamily     *family,

                                 const guint8     **dest,

                                 gsize             *len)

{

  switch (prefix.Prefix.si_family)

    {

      case AF_UNSPEC:

        /* Fall-through: AF_UNSPEC deliveres both IPV4 and IPV6 infos, let`s stick with IPV4 here */

      case AF_INET:

        *family = G_SOCKET_FAMILY_IPV4;

        *dest = (guint8 *) &prefix.Prefix.Ipv4.sin_addr;

        *len = prefix.PrefixLength;

        break;

      case AF_INET6:

        *family = G_SOCKET_FAMILY_IPV6;

        *dest = (guint8 *) &prefix.Prefix.Ipv6.sin6_addr;

        *len = prefix.PrefixLength;

        break;

      default:

        return FALSE;

    }

  return TRUE;

}

static GInetAddressMask *

get_network_mask (GSocketFamily  family,

                  const guint8  *dest,

                  gsize          len)

{

  GInetAddressMask *network;

  GInetAddress *dest_addr;

  if (dest != NULL)

    dest_addr = g_inet_address_new_from_bytes (dest, family);

  else

    dest_addr = g_inet_address_new_any (family);

  network = g_inet_address_mask_new (dest_addr, len, NULL);

  g_object_unref (dest_addr);

  return network;

}

static gboolean

win_network_monitor_process_table (GWin32NetworkMonitor  *win,

                                   GError                 **error)

{

  DWORD ret = 0;

  GPtrArray *networks;

  gsize i;

  MIB_IPFORWARD_TABLE2 *routes = NULL;

  MIB_IPFORWARD_ROW2 *route;

  ret = GetIpForwardTable2 (AF_UNSPEC, &routes);

  if (ret != ERROR_SUCCESS)

    {

      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,

                   "GetIpForwardTable2 () failed: %ld", ret);

      return FALSE;

    }

  networks = g_ptr_array_new_full (routes->NumEntries, g_object_unref);

  for (i = 0; i < routes->NumEntries; i++)

    {

      GInetAddressMask *network;

      const guint8 *dest;

      gsize len;

      GSocketFamily family;

      route = routes->Table + i;

      if (!win_network_monitor_get_ip_info (route->DestinationPrefix, &family, &dest, &len))

        continue;

      network = get_network_mask (family, dest, len);

      if (network == NULL)

        continue;

      g_ptr_array_add (networks, network);

    }

  g_network_monitor_base_set_networks (G_NETWORK_MONITOR_BASE (win),

                                       (GInetAddressMask **) networks->pdata,

                                       networks->len);

  return TRUE;

}

static void

add_network (GWin32NetworkMonitor *win,

             GSocketFamily         family,

             const guint8         *dest,

             gsize                 dest_len)

{

  GInetAddressMask *network;

  network = get_network_mask (family, dest, dest_len);

  if (network != NULL)

    {

      g_network_monitor_base_add_network (G_NETWORK_MONITOR_BASE (win), network);

      g_object_unref (network);

    }

}

static void

remove_network (GWin32NetworkMonitor *win,

                GSocketFamily         family,

                const guint8         *dest,

                gsize                 dest_len)

{

  GInetAddressMask *network;

  network = get_network_mask (family, dest, dest_len);

  if (network != NULL)

    {

      g_network_monitor_base_remove_network (G_NETWORK_MONITOR_BASE (win), network);

      g_object_unref (network);

    }

}

typedef struct {

  PMIB_IPFORWARD_ROW2 route;

  MIB_NOTIFICATION_TYPE type;

  GWin32NetworkMonitor *win;

} RouteData;

static gboolean

win_network_monitor_invoke_route_changed (gpointer user_data)

{

  GSocketFamily family;

  RouteData *route_data = user_data;

  const guint8 *dest;

  gsize len;

  switch (route_data->type)

    {

      case MibDeleteInstance:

        if (!win_network_monitor_get_ip_info (route_data->route->DestinationPrefix, &family, &dest, &len))

          break;

        remove_network (route_data->win, family, dest, len);

        break;

      case MibAddInstance:

        if (!win_network_monitor_get_ip_info (route_data->route->DestinationPrefix, &family, &dest, &len))

            break;

        add_network (route_data->win, family, dest, len);

        break;

      case MibInitialNotification:

      default:

        break;

    }

  return G_SOURCE_REMOVE;

}

static VOID WINAPI

win_network_monitor_route_changed_cb (PVOID                 context,

                                      PMIB_IPFORWARD_ROW2   route,

                                      MIB_NOTIFICATION_TYPE type)

{

  GWin32NetworkMonitor *win = context;

  RouteData *route_data;

  route_data = g_new0 (RouteData, 1);

  route_data->route = route;

  route_data->type = type;

  route_data->win = win;

  win->priv->route_change_source = g_idle_source_new ();

  g_source_set_priority (win->priv->route_change_source, G_PRIORITY_DEFAULT);

  g_source_set_callback (win->priv->route_change_source,

                         win_network_monitor_invoke_route_changed,

                         route_data,

                         g_free);

  g_source_attach (win->priv->route_change_source, win->priv->main_context);

}

static gboolean

g_win32_network_monitor_initable_init (GInitable     *initable,

                                       GCancellable  *cancellable,

                                       GError       **error)

{

  GWin32NetworkMonitor *win = G_WIN32_NETWORK_MONITOR (initable);

  NTSTATUS status;

  gboolean read;

  if (!win->priv->initialized)

    {

      win->priv->main_context = g_main_context_ref_thread_default ();

      /* Read current IP routing table. */

      read = win_network_monitor_process_table (win, &win->priv->init_error);

      if (read)

        {

          /* Register for IPv4 and IPv6 route updates. */

          status = NotifyRouteChange2 (AF_UNSPEC, (PIPFORWARD_CHANGE_CALLBACK) win_network_monitor_route_changed_cb, win, FALSE, &win->priv->handle);

          if (status != NO_ERROR)

            g_set_error (&win->priv->init_error, G_IO_ERROR, G_IO_ERROR_FAILED,

                         "NotifyRouteChange2() error: %ld", status);

        }

      win->priv->initialized = TRUE;

    }

  /* Forward the results. */

  if (win->priv->init_error != NULL)

    {

      g_propagate_error (error, g_error_copy (win->priv->init_error));

      return FALSE;

    }

  return TRUE;

}

static void

g_win32_network_monitor_finalize (GObject *object)

{

  GWin32NetworkMonitor *win = G_WIN32_NETWORK_MONITOR (object);

  /* Cancel notification event */

  if (win->priv->handle)

    CancelMibChangeNotify2 (win->priv->handle);

  g_clear_error (&win->priv->init_error);

  if (win->priv->route_change_source != NULL)

    {

      g_source_destroy (win->priv->route_change_source);

      g_source_unref (win->priv->route_change_source);

    }

  g_main_context_unref (win->priv->main_context);

  G_OBJECT_CLASS (g_win32_network_monitor_parent_class)->finalize (object);

}

static void

g_win32_network_monitor_class_init (GWin32NetworkMonitorClass *win_class)

{

  GObjectClass *gobject_class = G_OBJECT_CLASS (win_class);

  gobject_class->finalize = g_win32_network_monitor_finalize;

}

static void

g_win32_network_monitor_iface_init (GNetworkMonitorInterface *monitor_iface)

{

}

static void

g_win32_network_monitor_initable_iface_init (GInitableIface *iface)

{

  iface->init = g_win32_network_monitor_initable_init;

}