GNetworkMonitor

GNetworkMonitor — Network status monitor

Signals

Object Hierarchy

    GInterface
    ╰── GNetworkMonitor

Prerequisites

GNetworkMonitor requires GInitable and GObject.

Includes

#include <gio/gio.h>

Description

GNetworkMonitor provides an easy-to-use cross-platform API for monitoring network connectivity. On Linux, the implementation is based on the kernel's netlink interface.

Functions

g_network_monitor_get_default ()

GNetworkMonitor *
g_network_monitor_get_default (void);

Gets the default GNetworkMonitor for the system.

Returns

a GNetworkMonitor.

[transfer none]

Since: 2.32


g_network_monitor_get_network_available ()

gboolean
g_network_monitor_get_network_available
                               (GNetworkMonitor *monitor);

Checks if the network is available. "Available" here means that the system has a default route available for at least one of IPv4 or IPv6. It does not necessarily imply that the public Internet is reachable. See “network-available” for more details.

Parameters

monitor

the GNetworkMonitor

 

Returns

whether the network is available

Since: 2.32


g_network_monitor_get_network_metered ()

gboolean
g_network_monitor_get_network_metered (GNetworkMonitor *monitor);

Checks if the network is metered. See “network-metered” for more details.

Parameters

monitor

the GNetworkMonitor

 

Returns

whether the connection is metered

Since: 2.46


g_network_monitor_can_reach ()

gboolean
g_network_monitor_can_reach (GNetworkMonitor *monitor,
                             GSocketConnectable *connectable,
                             GCancellable *cancellable,
                             GError **error);

Attempts to determine whether or not the host pointed to by connectable can be reached, without actually trying to connect to it.

This may return TRUE even when “network-available” is FALSE, if, for example, monitor can determine that connectable refers to a host on a local network.

If monitor believes that an attempt to connect to connectable will succeed, it will return TRUE. Otherwise, it will return FALSE and set error to an appropriate error (such as G_IO_ERROR_HOST_UNREACHABLE).

Note that although this does not attempt to connect to connectable , it may still block for a brief period of time (eg, trying to do multicast DNS on the local network), so if you do not want to block, you should use g_network_monitor_can_reach_async().

Parameters

monitor

a GNetworkMonitor

 

connectable

a GSocketConnectable

 

cancellable

a GCancellable, or NULL.

[nullable]

error

return location for a GError, or NULL

 

Returns

TRUE if connectable is reachable, FALSE if not.

Since: 2.32


g_network_monitor_can_reach_async ()

void
g_network_monitor_can_reach_async (GNetworkMonitor *monitor,
                                   GSocketConnectable *connectable,
                                   GCancellable *cancellable,
                                   GAsyncReadyCallback callback,
                                   gpointer user_data);

Asynchronously attempts to determine whether or not the host pointed to by connectable can be reached, without actually trying to connect to it.

For more details, see g_network_monitor_can_reach().

When the operation is finished, callback will be called. You can then call g_network_monitor_can_reach_finish() to get the result of the operation.

Parameters

monitor

a GNetworkMonitor

 

connectable

a GSocketConnectable

 

cancellable

a GCancellable, or NULL.

[nullable]

callback

a GAsyncReadyCallback to call when the request is satisfied.

[scope async]

user_data

the data to pass to callback function.

[closure]

g_network_monitor_can_reach_finish ()

gboolean
g_network_monitor_can_reach_finish (GNetworkMonitor *monitor,
                                    GAsyncResult *result,
                                    GError **error);

Finishes an async network connectivity test. See g_network_monitor_can_reach_async().

Parameters

monitor

a GNetworkMonitor

 

result

a GAsyncResult

 

error

return location for errors, or NULL

 

Returns

TRUE if network is reachable, FALSE if not.


g_network_monitor_get_connectivity ()

GNetworkConnectivity
g_network_monitor_get_connectivity (GNetworkMonitor *monitor);

Gets a more detailed networking state than g_network_monitor_get_network_available().

If “network-available” is FALSE, then the connectivity state will be G_NETWORK_CONNECTIVITY_LOCAL.

If “network-available” is TRUE, then the connectivity state will be G_NETWORK_CONNECTIVITY_FULL (if there is full Internet connectivity), G_NETWORK_CONNECTIVITY_LIMITED (if the host has a default route, but appears to be unable to actually reach the full Internet), or G_NETWORK_CONNECTIVITY_PORTAL (if the host is trapped behind a "captive portal" that requires some sort of login or acknowledgement before allowing full Internet access).

Note that in the case of G_NETWORK_CONNECTIVITY_LIMITED and G_NETWORK_CONNECTIVITY_PORTAL, it is possible that some sites are reachable but others are not. In this case, applications can attempt to connect to remote servers, but should gracefully fall back to their "offline" behavior if the connection attempt fails.

Parameters

monitor

the GNetworkMonitor

 

Returns

the network connectivity state

Since: 2.44

Types and Values

GNetworkMonitor

typedef struct _GNetworkMonitor GNetworkMonitor;

GNetworkMonitor monitors the status of network connections and indicates when a possibly-user-visible change has occurred.

Since: 2.32


struct GNetworkMonitorInterface

struct GNetworkMonitorInterface {
  GTypeInterface g_iface;

  void     (*network_changed)  (GNetworkMonitor      *monitor,
				gboolean              available);

  gboolean (*can_reach)        (GNetworkMonitor      *monitor,
				GSocketConnectable   *connectable,
				GCancellable         *cancellable,
				GError              **error);
  void     (*can_reach_async)  (GNetworkMonitor      *monitor,
				GSocketConnectable   *connectable,
				GCancellable         *cancellable,
				GAsyncReadyCallback   callback,
				gpointer              user_data);
  gboolean (*can_reach_finish) (GNetworkMonitor      *monitor,
				GAsyncResult         *result,
				GError              **error);
};

The virtual function table for GNetworkMonitor.

Members

network_changed ()

the virtual function pointer for the GNetworkMonitor::network-changed signal.

 

can_reach ()

the virtual function pointer for g_network_monitor_can_reach()

 

can_reach_async ()

the virtual function pointer for g_network_monitor_can_reach_async()

 

can_reach_finish ()

the virtual function pointer for g_network_monitor_can_reach_finish()

 

Since: 2.32


G_NETWORK_MONITOR_EXTENSION_POINT_NAME

#define G_NETWORK_MONITOR_EXTENSION_POINT_NAME "gio-network-monitor"

Extension point for network status monitoring functionality. See Extending GIO.

Since: 2.30


enum GNetworkConnectivity

The host's network connectivity state, as reported by GNetworkMonitor.

Members

G_NETWORK_CONNECTIVITY_LOCAL

The host is not configured with a route to the Internet; it may or may not be connected to a local network.

 

G_NETWORK_CONNECTIVITY_LIMITED

The host is connected to a network, but does not appear to be able to reach the full Internet, perhaps due to upstream network problems.

 

G_NETWORK_CONNECTIVITY_PORTAL

The host is behind a captive portal and cannot reach the full Internet.

 

G_NETWORK_CONNECTIVITY_FULL

The host is connected to a network, and appears to be able to reach the full Internet.

 

Since: 2.44

Property Details

The “connectivity” property

  “connectivity”             GNetworkConnectivity

More detailed information about the host's network connectivity. See g_network_monitor_get_connectivity() and GNetworkConnectivity for more details.

Flags: Read

Default value: G_NETWORK_CONNECTIVITY_FULL

Since: 2.44


The “network-available” property

  “network-available”        gboolean

Whether the network is considered available. That is, whether the system has a default route for at least one of IPv4 or IPv6.

Real-world networks are of course much more complicated than this; the machine may be connected to a wifi hotspot that requires payment before allowing traffic through, or may be connected to a functioning router that has lost its own upstream connectivity. Some hosts might only be accessible when a VPN is active. Other hosts might only be accessible when the VPN is not active. Thus, it is best to use g_network_monitor_can_reach() or g_network_monitor_can_reach_async() to test for reachability on a host-by-host basis. (On the other hand, when the property is FALSE, the application can reasonably expect that no remote hosts at all are reachable, and should indicate this to the user in its UI.)

See also “network-changed”.

Flags: Read

Default value: FALSE

Since: 2.32


The “network-metered” property

  “network-metered”          gboolean

Whether the network is considered metered. That is, whether the system has traffic flowing through the default connection that is subject to limitations set by service providers. For example, traffic might be billed by the amount of data transmitted, or there might be a quota on the amount of traffic per month. This is typical with tethered connections (3G and 4G) and in such situations, bandwidth intensive applications may wish to avoid network activity where possible if it will cost the user money or use up their limited quota.

If more information is required about specific devices then the system network management API should be used instead (for example, NetworkManager or ConnMan).

If this information is not available then no networks will be marked as metered.

See also “network-available”.

Flags: Read

Default value: FALSE

Since: 2.46

Signal Details

The “network-changed” signal

void
user_function (GNetworkMonitor *monitor,
               gboolean         available,
               gpointer         user_data)

Emitted when the network configuration changes. If available is TRUE, then some hosts may be reachable that were not reachable before, while others that were reachable before may no longer be reachable. If available is FALSE, then no remote hosts are reachable.

Parameters

monitor

a GNetworkMonitor

 

available

the current value of “network-available”

 

user_data

user data set when the signal handler was connected.

 

Flags: Run Last

Since: 2.32