gio/gnetworkmonitor.c

   1 /* GIO - GLib Input, Output and Streaming Library
   2  *
   3  * Copyright 2011 Red Hat, Inc
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General
  16  * Public License along with this library; if not, write to the
  17  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  18  * Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include "config.h"
  22 #include "glib.h"
  23 #include "glibintl.h"
  24
  25 #include "gnetworkmonitor.h"
  26 #include "ginetaddress.h"
  27 #include "ginetsocketaddress.h"
  28 #include "ginitable.h"
  29 #include "gioenumtypes.h"
  30 #include "giomodule-priv.h"
  31 #include "gtask.h"
  32
  33 /**
  34  * SECTION:gnetworkmonitor
  35  * @title: GNetworkMonitor
  36  * @short_description: Network status monitor
  37  * @include: gio/gio.h
  38  *
  39  * #GNetworkMonitor provides an easy-to-use cross-platform API
  40  * for monitoring network connectivity. On Linux, the implementation
  41  * is based on the kernel's netlink interface.
  42  */
  43
  44 /**
  45  * GNetworkMonitor:
  46  *
  47  * #GNetworkMonitor monitors the status of network connections and
  48  * indicates when a possibly-user-visible change has occurred.
  49  *
  50  * Since: 2.32
  51  */
  52
  53 G_DEFINE_INTERFACE_WITH_CODE (GNetworkMonitor, g_network_monitor, G_TYPE_OBJECT,
  54                               g_type_interface_add_prerequisite (g_define_type_id, G_TYPE_INITABLE);)
  55
  56
  57 enum {
  58   NETWORK_CHANGED,
  59   LAST_SIGNAL
  60 };
  61
  62 static guint signals[LAST_SIGNAL] = { 0 };
  63
  64 /**
  65  * g_network_monitor_get_default:
  66  *
  67  * Gets the default #GNetworkMonitor for the system.
  68  *
  69  * Returns: (transfer none): a #GNetworkMonitor
  70  *
  71  * Since: 2.32
  72  */
  73 GNetworkMonitor *
  74 g_network_monitor_get_default (void)
  75 {
  76   return _g_io_module_get_default (G_NETWORK_MONITOR_EXTENSION_POINT_NAME,
  77                                    "GIO_USE_NETWORK_MONITOR",
  78                                    NULL);
  79 }
  80
  81 /**
  82  * g_network_monitor_get_network_available:
  83  * @monitor: the #GNetworkMonitor
  84  *
  85  * Checks if the network is available. "Available" here means that the
  86  * system has a default route available for at least one of IPv4 or
  87  * IPv6. It does not necessarily imply that the public Internet is
  88  * reachable. See #GNetworkMonitor:network-available for more details.
  89  *
  90  * Return value: whether the network is available
  91  *
  92  * Since: 2.32
  93  */
  94 gboolean
  95 g_network_monitor_get_network_available (GNetworkMonitor *monitor)
  96 {
  97   gboolean available = FALSE;
  98
  99   g_object_get (G_OBJECT (monitor), "network-available", &available, NULL);
 100   return available;
 101 }
 102
 103 /**
 104  * g_network_monitor_can_reach:
 105  * @monitor: a #GNetworkMonitor
 106  * @connectable: a #GSocketConnectable
 107  * @cancellable: (allow-none): a #GCancellable, or %NULL
 108  * @error: return location for a #GError, or %NULL
 109  *
 110  * Attempts to determine whether or not the host pointed to by
 111  * @connectable can be reached, without actually trying to connect to
 112  * it.
 113  *
 114  * This may return %TRUE even when #GNetworkMonitor:network-available
 115  * is %FALSE, if, for example, @monitor can determine that
 116  * @connectable refers to a host on a local network.
 117  *
 118  * If @monitor believes that an attempt to connect to @connectable
 119  * will succeed, it will return %TRUE. Otherwise, it will return
 120  * %FALSE and set @error to an appropriate error (such as
 121  * %G_IO_ERROR_HOST_UNREACHABLE).
 122  *
 123  * Note that although this does not attempt to connect to
 124  * @connectable, it may still block for a brief period of time (eg,
 125  * trying to do multicast DNS on the local network), so if you do not
 126  * want to block, you should use g_network_monitor_can_reach_async().
 127  *
 128  * Return value: %TRUE if @connectable is reachable, %FALSE if not.
 129  *
 130  * Since: 2.32
 131  */
 132 gboolean
 133 g_network_monitor_can_reach (GNetworkMonitor     *monitor,
 134                              GSocketConnectable  *connectable,
 135                              GCancellable        *cancellable,
 136                              GError             **error)
 137 {
 138   GNetworkMonitorInterface *iface;
 139
 140   iface = G_NETWORK_MONITOR_GET_INTERFACE (monitor);
 141   return iface->can_reach (monitor, connectable, cancellable, error);
 142 }
 143
 144 static void
 145 g_network_monitor_real_can_reach_async (GNetworkMonitor     *monitor,
 146                                         GSocketConnectable  *connectable,
 147                                         GCancellable        *cancellable,
 148                                         GAsyncReadyCallback  callback,
 149                                         gpointer             user_data)
 150 {
 151   GTask *task;
 152   GError *error = NULL;
 153
 154   task = g_task_new (monitor, cancellable, callback, user_data);
 155   if (g_network_monitor_can_reach (monitor, connectable, cancellable, &error))
 156     g_task_return_boolean (task, TRUE);
 157   else
 158     g_task_return_error (task, error);
 159   g_object_unref (task);
 160 }
 161
 162 /**
 163  * g_network_monitor_can_reach_async:
 164  * @monitor: a #GNetworkMonitor
 165  * @connectable: a #GSocketConnectable
 166  * @cancellable: (allow-none): a #GCancellable, or %NULL
 167  * @callback: (scope async): a #GAsyncReadyCallback to call when the
 168  *     request is satisfied
 169  * @user_data: (closure): the data to pass to callback function
 170  *
 171  * Asynchronously attempts to determine whether or not the host
 172  * pointed to by @connectable can be reached, without actually
 173  * trying to connect to it.
 174  *
 175  * For more details, see g_network_monitor_can_reach().
 176  *
 177  * When the operation is finished, @callback will be called.
 178  * You can then call g_network_monitor_can_reach_finish()
 179  * to get the result of the operation.
 180  */
 181 void
 182 g_network_monitor_can_reach_async (GNetworkMonitor     *monitor,
 183                                    GSocketConnectable  *connectable,
 184                                    GCancellable        *cancellable,
 185                                    GAsyncReadyCallback  callback,
 186                                    gpointer             user_data)
 187 {
 188   GNetworkMonitorInterface *iface;
 189
 190   iface = G_NETWORK_MONITOR_GET_INTERFACE (monitor);
 191   iface->can_reach_async (monitor, connectable, cancellable, callback, user_data);
 192 }
 193
 194 static gboolean
 195 g_network_monitor_real_can_reach_finish (GNetworkMonitor  *monitor,
 196                                          GAsyncResult     *result,
 197                                          GError          **error)
 198 {
 199   g_return_val_if_fail (g_task_is_valid (result, monitor), FALSE);
 200
 201   return g_task_propagate_boolean (G_TASK (result), error);
 202 }
 203
 204 /**
 205  * g_network_monitor_can_reach_finish:
 206  * @monitor: a #GNetworkMonitor
 207  * @result: a #GAsyncResult
 208  * @error: return location for errors, or %NULL
 209  *
 210  * Finishes an async network connectivity test.
 211  * See g_network_monitor_can_reach_async().
 212  *
 213  * Return value: %TRUE if network is reachable, %FALSE if not.
 214  */
 215 gboolean
 216 g_network_monitor_can_reach_finish (GNetworkMonitor     *monitor,
 217                                     GAsyncResult        *result,
 218                                     GError             **error)
 219 {
 220   GNetworkMonitorInterface *iface;
 221
 222   iface = G_NETWORK_MONITOR_GET_INTERFACE (monitor);
 223   return iface->can_reach_finish (monitor, result, error);
 224 }
 225
 226 static void
 227 g_network_monitor_default_init (GNetworkMonitorInterface *iface)
 228 {
 229   iface->can_reach_async  = g_network_monitor_real_can_reach_async;
 230   iface->can_reach_finish = g_network_monitor_real_can_reach_finish;
 231
 232   /**
 233    * GNetworkMonitor::network-changed:
 234    * @monitor: a #GNetworkMonitor
 235    * @available: the current value of #GNetworkMonitor:network-available
 236    *
 237    * Emitted when the network configuration changes. If @available is
 238    * %TRUE, then some hosts may be reachable that were not reachable
 239    * before, while others that were reachable before may no longer be
 240    * reachable. If @available is %FALSE, then no remote hosts are
 241    * reachable.
 242    *
 243    * Since: 2.32
 244    */
 245   signals[NETWORK_CHANGED] =
 246     g_signal_new (I_("network-changed"),
 247                   G_TYPE_NETWORK_MONITOR,
 248                   G_SIGNAL_RUN_LAST,
 249                   G_STRUCT_OFFSET (GNetworkMonitorInterface, network_changed),
 250                   NULL, NULL,
 251                   g_cclosure_marshal_VOID__BOOLEAN,
 252                   G_TYPE_NONE, 1,
 253                   G_TYPE_BOOLEAN);
 254
 255   /**
 256    * GNetworkMonitor:network-available:
 257    *
 258    * Whether the network is considered available. That is, whether the
 259    * system has a default route for at least one of IPv4 or IPv6.
 260    *
 261    * Real-world networks are of course much more complicated than
 262    * this; the machine may be connected to a wifi hotspot that
 263    * requires payment before allowing traffic through, or may be
 264    * connected to a functioning router that has lost its own upstream
 265    * connectivity. Some hosts might only be accessible when a VPN is
 266    * active. Other hosts might only be accessible when the VPN is
 267    * <emphasis>not</emphasis> active. Thus, it is best to use
 268    * g_network_monitor_can_reach() or
 269    * g_network_monitor_can_reach_async() to test for reachability on a
 270    * host-by-host basis. (On the other hand, when the property is
 271    * %FALSE, the application can reasonably expect that no remote
 272    * hosts at all are reachable, and should indicate this to the user
 273    * in its UI.)
 274    *
 275    * See also #GNetworkMonitor::network-changed.
 276    *
 277    * Since: 2.32
 278    */
 279   g_object_interface_install_property (iface,
 280                                        g_param_spec_boolean ("network-available",
 281                                                              P_("Network available"),
 282                                                              P_("Whether the network is available"),
 283                                                              FALSE,
 284                                                              G_PARAM_READABLE |
 285                                                              G_PARAM_STATIC_STRINGS));
 286 }