gio/gnetworkmonitorbase.c - third_party/glib - Git at Google

 /* GIO - GLib Input, Output and Streaming Library
  *
  * Copyright 2011 Red Hat, Inc.
  *
  * 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 2.1 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, see <http://www.gnu.org/licenses/>.
  */

 #include "config.h"

 #include "gnetworkmonitorbase.h"
 #include "ginetaddress.h"
 #include "ginetaddressmask.h"
 #include "ginetsocketaddress.h"
 #include "ginitable.h"
 #include "gioerror.h"
 #include "giomodule-priv.h"
 #include "gnetworkmonitor.h"
 #include "gsocketaddressenumerator.h"
 #include "gsocketconnectable.h"
 #include "gtask.h"
 #include "glibintl.h"

 static void g_network_monitor_base_iface_init (GNetworkMonitorInterface *iface);
 static void g_network_monitor_base_initable_iface_init (GInitableIface *iface);

 enum
 {
   PROP_0,

   PROP_NETWORK_AVAILABLE,
   PROP_NETWORK_METERED,
   PROP_CONNECTIVITY
 };

 struct _GNetworkMonitorBasePrivate
 {
   GPtrArray    *networks;
   gboolean      have_ipv4_default_route;
   gboolean      have_ipv6_default_route;
   gboolean      is_available;

   GMainContext *context;
   GSource      *network_changed_source;
   gboolean      initializing;
 };

 static guint network_changed_signal = 0;

 static void queue_network_changed (GNetworkMonitorBase *monitor);

 G_DEFINE_TYPE_WITH_CODE (GNetworkMonitorBase, g_network_monitor_base, G_TYPE_OBJECT,
                          G_ADD_PRIVATE (GNetworkMonitorBase)
                          G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
                                                 g_network_monitor_base_initable_iface_init)
                          G_IMPLEMENT_INTERFACE (G_TYPE_NETWORK_MONITOR,
                                                 g_network_monitor_base_iface_init)
                          _g_io_modules_ensure_extension_points_registered ();
                          g_io_extension_point_implement (G_NETWORK_MONITOR_EXTENSION_POINT_NAME,
                                                          g_define_type_id,
                                                          "base",
                                                          0))

 static void
 g_network_monitor_base_init (GNetworkMonitorBase *monitor)
 {
   monitor->priv = g_network_monitor_base_get_instance_private (monitor);
   monitor->priv->networks = g_ptr_array_new_with_free_func (g_object_unref);
   monitor->priv->context = g_main_context_get_thread_default ();
   if (monitor->priv->context)
     g_main_context_ref (monitor->priv->context);

   monitor->priv->initializing = TRUE;
 }

 static void
 g_network_monitor_base_constructed (GObject *object)
 {
   GNetworkMonitorBase *monitor = G_NETWORK_MONITOR_BASE (object);

   if (G_OBJECT_TYPE (monitor) == G_TYPE_NETWORK_MONITOR_BASE)
     {
       GInetAddressMask *mask;

       /* We're the dumb base class, not a smarter subclass. So just
        * assume that the network is available.
        */
       mask = g_inet_address_mask_new_from_string ("0.0.0.0/0", NULL);
       g_network_monitor_base_add_network (monitor, mask);
       g_object_unref (mask);

       mask = g_inet_address_mask_new_from_string ("::/0", NULL);
       if (mask)
         {
           /* On some environments (for example Windows without IPv6 support
            * enabled) the string "::/0" can't be processed and causes
            * g_inet_address_mask_new_from_string to return NULL */
           g_network_monitor_base_add_network (monitor, mask);
           g_object_unref (mask);
         }
     }
 }

 static void
 g_network_monitor_base_get_property (GObject    *object,
                                      guint       prop_id,
                                      GValue     *value,
                                      GParamSpec *pspec)
 {
   GNetworkMonitorBase *monitor = G_NETWORK_MONITOR_BASE (object);

   switch (prop_id)
     {
     case PROP_NETWORK_AVAILABLE:
       g_value_set_boolean (value, monitor->priv->is_available);
       break;

     case PROP_NETWORK_METERED:
       /* Default to FALSE in the unknown case. */
       g_value_set_boolean (value, FALSE);
       break;

     case PROP_CONNECTIVITY:
       g_value_set_enum (value,
                         monitor->priv->is_available ?
                         G_NETWORK_CONNECTIVITY_FULL :
                         G_NETWORK_CONNECTIVITY_LOCAL);
       break;

     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
     }

 }

 static void
 g_network_monitor_base_finalize (GObject *object)
 {
   GNetworkMonitorBase *monitor = G_NETWORK_MONITOR_BASE (object);

   g_ptr_array_free (monitor->priv->networks, TRUE);
   if (monitor->priv->network_changed_source)
     {
       g_source_destroy (monitor->priv->network_changed_source);
       g_source_unref (monitor->priv->network_changed_source);
     }
   if (monitor->priv->context)
     g_main_context_unref (monitor->priv->context);

   G_OBJECT_CLASS (g_network_monitor_base_parent_class)->finalize (object);
 }

 static void
 g_network_monitor_base_class_init (GNetworkMonitorBaseClass *monitor_class)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (monitor_class);

   gobject_class->constructed  = g_network_monitor_base_constructed;
   gobject_class->get_property = g_network_monitor_base_get_property;
   gobject_class->finalize     = g_network_monitor_base_finalize;

   g_object_class_override_property (gobject_class, PROP_NETWORK_AVAILABLE, "network-available");
   g_object_class_override_property (gobject_class, PROP_NETWORK_METERED, "network-metered");
   g_object_class_override_property (gobject_class, PROP_CONNECTIVITY, "connectivity");
 }

 static gboolean
 g_network_monitor_base_can_reach_sockaddr (GNetworkMonitorBase *base,
                                            GSocketAddress *sockaddr)
 {
   GInetAddress *iaddr;
   int i;

   if (!G_IS_INET_SOCKET_ADDRESS (sockaddr))
     return FALSE;

   iaddr = g_inet_socket_address_get_address (G_INET_SOCKET_ADDRESS (sockaddr));
   for (i = 0; i < base->priv->networks->len; i++)
     {
       if (g_inet_address_mask_matches (base->priv->networks->pdata[i], iaddr))
         return TRUE;
     }

   return FALSE;
 }

 static gboolean
 g_network_monitor_base_can_reach (GNetworkMonitor      *monitor,
                                   GSocketConnectable   *connectable,
                                   GCancellable         *cancellable,
                                   GError              **error)
 {
   GNetworkMonitorBase *base = G_NETWORK_MONITOR_BASE (monitor);
   GSocketAddressEnumerator *enumerator;
   GSocketAddress *addr;

   if (base->priv->networks->len == 0)
     {
       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NETWORK_UNREACHABLE,
                            _("Network unreachable"));
       return FALSE;
     }

   enumerator = g_socket_connectable_proxy_enumerate (connectable);
   addr = g_socket_address_enumerator_next (enumerator, cancellable, error);
   if (!addr)
     {
       /* Either the user cancelled, or DNS resolution failed */
       g_object_unref (enumerator);
       return FALSE;
     }

   if (base->priv->have_ipv4_default_route &&
       base->priv->have_ipv6_default_route)
     {
       g_object_unref (enumerator);
       g_object_unref (addr);
       return TRUE;
     }

   while (addr)
     {
       if (g_network_monitor_base_can_reach_sockaddr (base, addr))
         {
           g_object_unref (addr);
           g_object_unref (enumerator);
           return TRUE;
         }

       g_object_unref (addr);
       addr = g_socket_address_enumerator_next (enumerator, cancellable, error);
     }
   g_object_unref (enumerator);

   if (error && !*error)
     {
       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_HOST_UNREACHABLE,
                            _("Host unreachable"));
     }
   return FALSE;
 }

 static void
 can_reach_async_got_address (GObject      *object,
                              GAsyncResult *result,
                              gpointer      user_data)
 {
   GSocketAddressEnumerator *enumerator = G_SOCKET_ADDRESS_ENUMERATOR (object);
   GTask *task = user_data;
   GNetworkMonitorBase *base = g_task_get_source_object (task);
   GSocketAddress *addr;
   GError *error = NULL;

   addr = g_socket_address_enumerator_next_finish (enumerator, result, &error);
   if (!addr)
     {
       if (error)
         {
           /* Either the user cancelled, or DNS resolution failed */
           g_task_return_error (task, error);
           g_object_unref (task);
           return;
         }
       else
         {
           /* Resolved all addresses, none matched */
           g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_HOST_UNREACHABLE,
                                    _("Host unreachable"));
           g_object_unref (task);
           return;
         }
     }

   if (g_network_monitor_base_can_reach_sockaddr (base, addr))
     {
       g_object_unref (addr);
       g_task_return_boolean (task, TRUE);
       g_object_unref (task);
       return;
     }
   g_object_unref (addr);

   g_socket_address_enumerator_next_async (enumerator,
                                           g_task_get_cancellable (task),
                                           can_reach_async_got_address, task);
 }

 static void
 g_network_monitor_base_can_reach_async (GNetworkMonitor     *monitor,
                                         GSocketConnectable  *connectable,
                                         GCancellable        *cancellable,
                                         GAsyncReadyCallback  callback,
                                         gpointer             user_data)
 {
   GTask *task;
   GSocketAddressEnumerator *enumerator;

   task = g_task_new (monitor, cancellable, callback, user_data);
   g_task_set_source_tag (task, g_network_monitor_base_can_reach_async);

   if (G_NETWORK_MONITOR_BASE (monitor)->priv->networks->len == 0)
     {
       g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NETWORK_UNREACHABLE,
                                _("Network unreachable"));
       g_object_unref (task);
       return;
     }

   enumerator = g_socket_connectable_proxy_enumerate (connectable);
   g_socket_address_enumerator_next_async (enumerator, cancellable,
                                           can_reach_async_got_address, task);
   g_object_unref (enumerator);
 }

 static gboolean
 g_network_monitor_base_can_reach_finish (GNetworkMonitor  *monitor,
                                          GAsyncResult     *result,
                                          GError          **error)
 {
   g_return_val_if_fail (g_task_is_valid (result, monitor), FALSE);

   return g_task_propagate_boolean (G_TASK (result), error);
 }

 static void
 g_network_monitor_base_iface_init (GNetworkMonitorInterface *monitor_iface)
 {
   monitor_iface->can_reach = g_network_monitor_base_can_reach;
   monitor_iface->can_reach_async = g_network_monitor_base_can_reach_async;
   monitor_iface->can_reach_finish = g_network_monitor_base_can_reach_finish;

   network_changed_signal = g_signal_lookup ("network-changed", G_TYPE_NETWORK_MONITOR);
 }

 static gboolean
 g_network_monitor_base_initable_init (GInitable     *initable,
                                       GCancellable  *cancellable,
                                       GError       **error)
 {
   GNetworkMonitorBase *base = G_NETWORK_MONITOR_BASE (initable);

   base->priv->initializing = FALSE;

   return TRUE;
 }

 static void
 g_network_monitor_base_initable_iface_init (GInitableIface *iface)
 {
   iface->init = g_network_monitor_base_initable_init;
 }

 static gboolean
 emit_network_changed (gpointer user_data)
 {
   GNetworkMonitorBase *monitor = user_data;
   gboolean is_available;

   if (g_source_is_destroyed (g_main_current_source ()))
     return FALSE;

   g_object_ref (monitor);

   is_available = (monitor->priv->have_ipv4_default_route ||
                   monitor->priv->have_ipv6_default_route);
   if (monitor->priv->is_available != is_available)
     {
       monitor->priv->is_available = is_available;
       g_object_notify (G_OBJECT (monitor), "network-available");
     }

   g_signal_emit (monitor, network_changed_signal, 0, is_available);

   g_source_unref (monitor->priv->network_changed_source);
   monitor->priv->network_changed_source = NULL;

   g_object_unref (monitor);
   return FALSE;
 }

 static void
 queue_network_changed (GNetworkMonitorBase *monitor)
 {
   if (!monitor->priv->network_changed_source &&
       !monitor->priv->initializing)
     {
       GSource *source;

       source = g_idle_source_new ();
       /* Use G_PRIORITY_HIGH_IDLE priority so that multiple
        * network-change-related notifications coming in at
        * G_PRIORITY_DEFAULT will get coalesced into one signal
        * emission.
        */
       g_source_set_priority (source, G_PRIORITY_HIGH_IDLE);
       g_source_set_callback (source, emit_network_changed, monitor, NULL);
       g_source_set_name (source, "[gio] emit_network_changed");
       g_source_attach (source, monitor->priv->context);
       monitor->priv->network_changed_source = source;
     }

   /* Normally we wait to update is_available until we emit the signal,
    * to keep things consistent. But when we're first creating the
    * object, we want it to be correct right away.
    */
   if (monitor->priv->initializing)
     {
       monitor->priv->is_available = (monitor->priv->have_ipv4_default_route ||
                                      monitor->priv->have_ipv6_default_route);
     }
 }

 /**
  * g_network_monitor_base_add_network:
  * @monitor: the #GNetworkMonitorBase
  * @network: a #GInetAddressMask
  *
  * Adds @network to @monitor's list of available networks.
  *
  * Since: 2.32
  */
 void
 g_network_monitor_base_add_network (GNetworkMonitorBase *monitor,
                                     GInetAddressMask    *network)
 {
   int i;

   for (i = 0; i < monitor->priv->networks->len; i++)
     {
       if (g_inet_address_mask_equal (monitor->priv->networks->pdata[i], network))
         return;
     }

   g_ptr_array_add (monitor->priv->networks, g_object_ref (network));
   if (g_inet_address_mask_get_length (network) == 0)
     {
       switch (g_inet_address_mask_get_family (network))
         {
         case G_SOCKET_FAMILY_IPV4:
           monitor->priv->have_ipv4_default_route = TRUE;
           break;
         case G_SOCKET_FAMILY_IPV6:
           monitor->priv->have_ipv6_default_route = TRUE;
           break;
         default:
           break;
         }
     }

   /* Don't emit network-changed when multicast-link-local routing
    * changes. This rather arbitrary decision is mostly because it
    * seems to change quite often...
    */
   if (g_inet_address_get_is_mc_link_local (g_inet_address_mask_get_address (network)))
     return;

   queue_network_changed (monitor);
 }

 /**
  * g_network_monitor_base_remove_network:
  * @monitor: the #GNetworkMonitorBase
  * @network: a #GInetAddressMask
  *
  * Removes @network from @monitor's list of available networks.
  *
  * Since: 2.32
  */
 void
 g_network_monitor_base_remove_network (GNetworkMonitorBase *monitor,
                                        GInetAddressMask    *network)
 {
   int i;

   for (i = 0; i < monitor->priv->networks->len; i++)
     {
       if (g_inet_address_mask_equal (monitor->priv->networks->pdata[i], network))
         {
           g_ptr_array_remove_index_fast (monitor->priv->networks, i);

           if (g_inet_address_mask_get_length (network) == 0)
             {
               switch (g_inet_address_mask_get_family (network))
                 {
                 case G_SOCKET_FAMILY_IPV4:
                   monitor->priv->have_ipv4_default_route = FALSE;
                   break;
                 case G_SOCKET_FAMILY_IPV6:
                   monitor->priv->have_ipv6_default_route = FALSE;
                   break;
                 default:
                   break;
                 }
             }

           queue_network_changed (monitor);
           return;
         }
     }
 }

 /**
  * g_network_monitor_base_set_networks:
  * @monitor: the #GNetworkMonitorBase
  * @networks: (array length=length): an array of #GInetAddressMask
  * @length: length of @networks
  *
  * Drops @monitor's current list of available networks and replaces
  * it with @networks.
  */
 void
 g_network_monitor_base_set_networks (GNetworkMonitorBase  *monitor,
                                      GInetAddressMask    **networks,
                                      gint                  length)
 {
   int i;

   g_ptr_array_set_size (monitor->priv->networks, 0);
   monitor->priv->have_ipv4_default_route = FALSE;
   monitor->priv->have_ipv6_default_route = FALSE;

   for (i = 0; i < length; i++)
     g_network_monitor_base_add_network (monitor, networks[i]);
 }
	/* GIO - GLib Input, Output and Streaming Library
	*
	* Copyright 2011 Red Hat, Inc.
	*
	* 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 2.1 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, see <http://www.gnu.org/licenses/>.
	*/

	#include "config.h"

	#include "gnetworkmonitorbase.h"
	#include "ginetaddress.h"
	#include "ginetaddressmask.h"
	#include "ginetsocketaddress.h"
	#include "ginitable.h"
	#include "gioerror.h"
	#include "giomodule-priv.h"
	#include "gnetworkmonitor.h"
	#include "gsocketaddressenumerator.h"
	#include "gsocketconnectable.h"
	#include "gtask.h"
	#include "glibintl.h"

	static void g_network_monitor_base_iface_init (GNetworkMonitorInterface *iface);
	static void g_network_monitor_base_initable_iface_init (GInitableIface *iface);

	enum
	{
	PROP_0,

	PROP_NETWORK_AVAILABLE,
	PROP_NETWORK_METERED,
	PROP_CONNECTIVITY
	};

	struct _GNetworkMonitorBasePrivate
	{
	GPtrArray *networks;
	gboolean have_ipv4_default_route;
	gboolean have_ipv6_default_route;
	gboolean is_available;

	GMainContext *context;
	GSource *network_changed_source;
	gboolean initializing;
	};

	static guint network_changed_signal = 0;

	static void queue_network_changed (GNetworkMonitorBase *monitor);

	G_DEFINE_TYPE_WITH_CODE (GNetworkMonitorBase, g_network_monitor_base, G_TYPE_OBJECT,
	G_ADD_PRIVATE (GNetworkMonitorBase)
	G_IMPLEMENT_INTERFACE (G_TYPE_INITABLE,
	g_network_monitor_base_initable_iface_init)
	G_IMPLEMENT_INTERFACE (G_TYPE_NETWORK_MONITOR,
	g_network_monitor_base_iface_init)
	_g_io_modules_ensure_extension_points_registered ();
	g_io_extension_point_implement (G_NETWORK_MONITOR_EXTENSION_POINT_NAME,
	g_define_type_id,
	"base",
	0))

	static void
	g_network_monitor_base_init (GNetworkMonitorBase *monitor)
	{
	monitor->priv = g_network_monitor_base_get_instance_private (monitor);
	monitor->priv->networks = g_ptr_array_new_with_free_func (g_object_unref);
	monitor->priv->context = g_main_context_get_thread_default ();
	if (monitor->priv->context)
	g_main_context_ref (monitor->priv->context);

	monitor->priv->initializing = TRUE;
	}

	static void
	g_network_monitor_base_constructed (GObject *object)
	{
	GNetworkMonitorBase *monitor = G_NETWORK_MONITOR_BASE (object);

	if (G_OBJECT_TYPE (monitor) == G_TYPE_NETWORK_MONITOR_BASE)
	{
	GInetAddressMask *mask;

	/* We're the dumb base class, not a smarter subclass. So just
	* assume that the network is available.
	*/
	mask = g_inet_address_mask_new_from_string ("0.0.0.0/0", NULL);
	g_network_monitor_base_add_network (monitor, mask);
	g_object_unref (mask);

	mask = g_inet_address_mask_new_from_string ("::/0", NULL);
	if (mask)
	{
	/* On some environments (for example Windows without IPv6 support
	* enabled) the string "::/0" can't be processed and causes
	* g_inet_address_mask_new_from_string to return NULL */
	g_network_monitor_base_add_network (monitor, mask);
	g_object_unref (mask);
	}
	}
	}

	static void
	g_network_monitor_base_get_property (GObject *object,
	guint prop_id,
	GValue *value,
	GParamSpec *pspec)
	{
	GNetworkMonitorBase *monitor = G_NETWORK_MONITOR_BASE (object);

	switch (prop_id)
	{
	case PROP_NETWORK_AVAILABLE:
	g_value_set_boolean (value, monitor->priv->is_available);
	break;

	case PROP_NETWORK_METERED:
	/* Default to FALSE in the unknown case. */
	g_value_set_boolean (value, FALSE);
	break;

	case PROP_CONNECTIVITY:
	g_value_set_enum (value,
	monitor->priv->is_available ?
	G_NETWORK_CONNECTIVITY_FULL :
	G_NETWORK_CONNECTIVITY_LOCAL);
	break;

	default:
	G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
	break;
	}

	}

	static void
	g_network_monitor_base_finalize (GObject *object)
	{
	GNetworkMonitorBase *monitor = G_NETWORK_MONITOR_BASE (object);

	g_ptr_array_free (monitor->priv->networks, TRUE);
	if (monitor->priv->network_changed_source)
	{
	g_source_destroy (monitor->priv->network_changed_source);
	g_source_unref (monitor->priv->network_changed_source);
	}
	if (monitor->priv->context)
	g_main_context_unref (monitor->priv->context);

	G_OBJECT_CLASS (g_network_monitor_base_parent_class)->finalize (object);
	}

	static void
	g_network_monitor_base_class_init (GNetworkMonitorBaseClass *monitor_class)
	{
	GObjectClass *gobject_class = G_OBJECT_CLASS (monitor_class);

	gobject_class->constructed = g_network_monitor_base_constructed;
	gobject_class->get_property = g_network_monitor_base_get_property;
	gobject_class->finalize = g_network_monitor_base_finalize;

	g_object_class_override_property (gobject_class, PROP_NETWORK_AVAILABLE, "network-available");
	g_object_class_override_property (gobject_class, PROP_NETWORK_METERED, "network-metered");
	g_object_class_override_property (gobject_class, PROP_CONNECTIVITY, "connectivity");
	}

	static gboolean
	g_network_monitor_base_can_reach_sockaddr (GNetworkMonitorBase *base,
	GSocketAddress *sockaddr)
	{
	GInetAddress *iaddr;
	int i;

	if (!G_IS_INET_SOCKET_ADDRESS (sockaddr))
	return FALSE;

	iaddr = g_inet_socket_address_get_address (G_INET_SOCKET_ADDRESS (sockaddr));
	for (i = 0; i < base->priv->networks->len; i++)
	{
	if (g_inet_address_mask_matches (base->priv->networks->pdata[i], iaddr))
	return TRUE;
	}

	return FALSE;
	}

	static gboolean
	g_network_monitor_base_can_reach (GNetworkMonitor *monitor,
	GSocketConnectable *connectable,
	GCancellable *cancellable,
	GError **error)
	{
	GNetworkMonitorBase *base = G_NETWORK_MONITOR_BASE (monitor);
	GSocketAddressEnumerator *enumerator;
	GSocketAddress *addr;

	if (base->priv->networks->len == 0)
	{
	g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NETWORK_UNREACHABLE,
	_("Network unreachable"));
	return FALSE;
	}

	enumerator = g_socket_connectable_proxy_enumerate (connectable);
	addr = g_socket_address_enumerator_next (enumerator, cancellable, error);
	if (!addr)
	{
	/* Either the user cancelled, or DNS resolution failed */
	g_object_unref (enumerator);
	return FALSE;
	}

	if (base->priv->have_ipv4_default_route &&
	base->priv->have_ipv6_default_route)
	{
	g_object_unref (enumerator);
	g_object_unref (addr);
	return TRUE;
	}

	while (addr)
	{
	if (g_network_monitor_base_can_reach_sockaddr (base, addr))
	{
	g_object_unref (addr);
	g_object_unref (enumerator);
	return TRUE;
	}

	g_object_unref (addr);
	addr = g_socket_address_enumerator_next (enumerator, cancellable, error);
	}
	g_object_unref (enumerator);

	if (error && !*error)
	{
	g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_HOST_UNREACHABLE,
	_("Host unreachable"));
	}
	return FALSE;
	}

	static void
	can_reach_async_got_address (GObject *object,
	GAsyncResult *result,
	gpointer user_data)
	{
	GSocketAddressEnumerator *enumerator = G_SOCKET_ADDRESS_ENUMERATOR (object);
	GTask *task = user_data;
	GNetworkMonitorBase *base = g_task_get_source_object (task);
	GSocketAddress *addr;
	GError *error = NULL;

	addr = g_socket_address_enumerator_next_finish (enumerator, result, &error);
	if (!addr)
	{
	if (error)
	{
	/* Either the user cancelled, or DNS resolution failed */
	g_task_return_error (task, error);
	g_object_unref (task);
	return;
	}
	else
	{
	/* Resolved all addresses, none matched */
	g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_HOST_UNREACHABLE,
	_("Host unreachable"));
	g_object_unref (task);
	return;
	}
	}

	if (g_network_monitor_base_can_reach_sockaddr (base, addr))
	{
	g_object_unref (addr);
	g_task_return_boolean (task, TRUE);
	g_object_unref (task);
	return;
	}
	g_object_unref (addr);

	g_socket_address_enumerator_next_async (enumerator,
	g_task_get_cancellable (task),
	can_reach_async_got_address, task);
	}

	static void
	g_network_monitor_base_can_reach_async (GNetworkMonitor *monitor,
	GSocketConnectable *connectable,
	GCancellable *cancellable,
	GAsyncReadyCallback callback,
	gpointer user_data)
	{
	GTask *task;
	GSocketAddressEnumerator *enumerator;

	task = g_task_new (monitor, cancellable, callback, user_data);
	g_task_set_source_tag (task, g_network_monitor_base_can_reach_async);

	if (G_NETWORK_MONITOR_BASE (monitor)->priv->networks->len == 0)
	{
	g_task_return_new_error (task, G_IO_ERROR, G_IO_ERROR_NETWORK_UNREACHABLE,
	_("Network unreachable"));
	g_object_unref (task);
	return;
	}

	enumerator = g_socket_connectable_proxy_enumerate (connectable);
	g_socket_address_enumerator_next_async (enumerator, cancellable,
	can_reach_async_got_address, task);
	g_object_unref (enumerator);
	}

	static gboolean
	g_network_monitor_base_can_reach_finish (GNetworkMonitor *monitor,
	GAsyncResult *result,
	GError **error)
	{
	g_return_val_if_fail (g_task_is_valid (result, monitor), FALSE);

	return g_task_propagate_boolean (G_TASK (result), error);
	}

	static void
	g_network_monitor_base_iface_init (GNetworkMonitorInterface *monitor_iface)
	{
	monitor_iface->can_reach = g_network_monitor_base_can_reach;
	monitor_iface->can_reach_async = g_network_monitor_base_can_reach_async;
	monitor_iface->can_reach_finish = g_network_monitor_base_can_reach_finish;

	network_changed_signal = g_signal_lookup ("network-changed", G_TYPE_NETWORK_MONITOR);
	}

	static gboolean
	g_network_monitor_base_initable_init (GInitable *initable,
	GCancellable *cancellable,
	GError **error)
	{
	GNetworkMonitorBase *base = G_NETWORK_MONITOR_BASE (initable);

	base->priv->initializing = FALSE;

	return TRUE;
	}

	static void
	g_network_monitor_base_initable_iface_init (GInitableIface *iface)
	{
	iface->init = g_network_monitor_base_initable_init;
	}

	static gboolean
	emit_network_changed (gpointer user_data)
	{
	GNetworkMonitorBase *monitor = user_data;
	gboolean is_available;

	if (g_source_is_destroyed (g_main_current_source ()))
	return FALSE;

	g_object_ref (monitor);

	is_available = (monitor->priv->have_ipv4_default_route \|\|
	monitor->priv->have_ipv6_default_route);
	if (monitor->priv->is_available != is_available)
	{
	monitor->priv->is_available = is_available;
	g_object_notify (G_OBJECT (monitor), "network-available");
	}

	g_signal_emit (monitor, network_changed_signal, 0, is_available);

	g_source_unref (monitor->priv->network_changed_source);
	monitor->priv->network_changed_source = NULL;

	g_object_unref (monitor);
	return FALSE;
	}

	static void
	queue_network_changed (GNetworkMonitorBase *monitor)
	{
	if (!monitor->priv->network_changed_source &&
	!monitor->priv->initializing)
	{
	GSource *source;

	source = g_idle_source_new ();
	/* Use G_PRIORITY_HIGH_IDLE priority so that multiple
	* network-change-related notifications coming in at
	* G_PRIORITY_DEFAULT will get coalesced into one signal
	* emission.
	*/
	g_source_set_priority (source, G_PRIORITY_HIGH_IDLE);
	g_source_set_callback (source, emit_network_changed, monitor, NULL);
	g_source_set_name (source, "[gio] emit_network_changed");
	g_source_attach (source, monitor->priv->context);
	monitor->priv->network_changed_source = source;
	}

	/* Normally we wait to update is_available until we emit the signal,
	* to keep things consistent. But when we're first creating the
	* object, we want it to be correct right away.
	*/
	if (monitor->priv->initializing)
	{
	monitor->priv->is_available = (monitor->priv->have_ipv4_default_route \|\|
	monitor->priv->have_ipv6_default_route);
	}
	}

	/**
	* g_network_monitor_base_add_network:
	* @monitor: the #GNetworkMonitorBase
	* @network: a #GInetAddressMask
	*
	* Adds @network to @monitor's list of available networks.
	*
	* Since: 2.32
	*/
	void
	g_network_monitor_base_add_network (GNetworkMonitorBase *monitor,
	GInetAddressMask *network)
	{
	int i;

	for (i = 0; i < monitor->priv->networks->len; i++)
	{
	if (g_inet_address_mask_equal (monitor->priv->networks->pdata[i], network))
	return;
	}

	g_ptr_array_add (monitor->priv->networks, g_object_ref (network));
	if (g_inet_address_mask_get_length (network) == 0)
	{
	switch (g_inet_address_mask_get_family (network))
	{
	case G_SOCKET_FAMILY_IPV4:
	monitor->priv->have_ipv4_default_route = TRUE;
	break;
	case G_SOCKET_FAMILY_IPV6:
	monitor->priv->have_ipv6_default_route = TRUE;
	break;
	default:
	break;
	}
	}

	/* Don't emit network-changed when multicast-link-local routing
	* changes. This rather arbitrary decision is mostly because it
	* seems to change quite often...
	*/
	if (g_inet_address_get_is_mc_link_local (g_inet_address_mask_get_address (network)))
	return;

	queue_network_changed (monitor);
	}

	/**
	* g_network_monitor_base_remove_network:
	* @monitor: the #GNetworkMonitorBase
	* @network: a #GInetAddressMask
	*
	* Removes @network from @monitor's list of available networks.
	*
	* Since: 2.32
	*/
	void
	g_network_monitor_base_remove_network (GNetworkMonitorBase *monitor,
	GInetAddressMask *network)
	{
	int i;

	for (i = 0; i < monitor->priv->networks->len; i++)
	{
	if (g_inet_address_mask_equal (monitor->priv->networks->pdata[i], network))
	{
	g_ptr_array_remove_index_fast (monitor->priv->networks, i);

	if (g_inet_address_mask_get_length (network) == 0)
	{
	switch (g_inet_address_mask_get_family (network))
	{
	case G_SOCKET_FAMILY_IPV4:
	monitor->priv->have_ipv4_default_route = FALSE;
	break;
	case G_SOCKET_FAMILY_IPV6:
	monitor->priv->have_ipv6_default_route = FALSE;
	break;
	default:
	break;
	}
	}

	queue_network_changed (monitor);
	return;
	}
	}
	}

	/**
	* g_network_monitor_base_set_networks:
	* @monitor: the #GNetworkMonitorBase
	* @networks: (array length=length): an array of #GInetAddressMask
	* @length: length of @networks
	*
	* Drops @monitor's current list of available networks and replaces
	* it with @networks.
	*/
	void
	g_network_monitor_base_set_networks (GNetworkMonitorBase *monitor,
	GInetAddressMask **networks,
	gint length)
	{
	int i;

	g_ptr_array_set_size (monitor->priv->networks, 0);
	monitor->priv->have_ipv4_default_route = FALSE;
	monitor->priv->have_ipv6_default_route = FALSE;

	for (i = 0; i < length; i++)
	g_network_monitor_base_add_network (monitor, networks[i]);
	}