NetworkManager/src/NetworkManagerDbus.c

/* NetworkManager -- Network link manager
 *
 * Dan Williams <dcbw@redhat.com>
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * (C) Copyright 2004 Red Hat, Inc.
 */

#include <glib.h>
#include <dbus/dbus.h>
#include <dbus/dbus-glib-lowlevel.h>
#include <dbus/dbus-glib.h>
#include <stdarg.h>
#include <signal.h>
#include <iwlib.h>
#include <netinet/ether.h>

#include "NetworkManager.h"
#include "NetworkManagerUtils.h"
#include "nm-device.h"
#include "NetworkManagerDbus.h"
#include "NetworkManagerDbusUtils.h"
#include "NetworkManagerAP.h"
#include "NetworkManagerAPList.h"
#include "NetworkManagerPolicy.h"
#include "nm-dbus-nm.h"
#include "nm-dbus-device.h"
#include "nm-dbus-net.h"
#include "nm-dbus-vpn.h"
#include "nm-dbus-nmi.h"
#include "nm-utils.h"
#include "nm-dhcp-manager.h"

static char *get_nmi_match_string (const char *owner);

/*
 * nm_dbus_create_error_message
 *
 * Make a DBus error message
 *
 */
DBusMessage *nm_dbus_create_error_message (DBusMessage *message, const char *exception_namespace,
										const char *exception, const char *format, ...)
{
	char *exception_text;
	DBusMessage	*reply_message;
	va_list		 args;
	char			 error_text[512];

	va_start (args, format);
	vsnprintf (error_text, 512, format, args);
	va_end (args);

	exception_text = g_strdup_printf ("%s.%s", exception_namespace, exception);
	reply_message = dbus_message_new_error (message, exception_text, error_text);
	g_free (exception_text);

	return (reply_message);
}


/*
 * nm_dbus_get_object_path_for_device
 *
 * Copies the object path for a device object.  Caller must free returned string.
 *
 */
char * nm_dbus_get_object_path_for_device (NMDevice *dev)
{
	char *object_path, *escaped_object_path;

	g_return_val_if_fail (dev != NULL, NULL);

	object_path = g_strdup_printf ("%s/%s", NM_DBUS_PATH_DEVICES, nm_device_get_iface (dev));
	escaped_object_path = nm_dbus_escape_object_path (object_path);
	g_free (object_path);

	return escaped_object_path;
}


/*
 * nm_dbus_get_object_path_for_network
 *
 * Copies the object path for a network object.  Caller must free returned string.
 *
 */
char * nm_dbus_get_object_path_for_network (NMDevice *dev, NMAccessPoint *ap)
{
	char *object_path, *escaped_object_path;

	g_return_val_if_fail (dev != NULL, NULL);
	g_return_val_if_fail (ap != NULL, NULL);

	if (!nm_ap_get_essid (ap))
		return NULL;

	object_path = g_strdup_printf ("%s/%s/Networks/%s", NM_DBUS_PATH_DEVICES, nm_device_get_iface (dev), nm_ap_get_essid (ap));
	escaped_object_path = nm_dbus_escape_object_path (object_path);
	g_free (object_path);

	return escaped_object_path;
}


/*
 * nm_dbus_get_device_from_object_path
 *
 * Returns the device associated with a dbus object path
 *
 */
NMDevice *nm_dbus_get_device_from_object_path (NMData *data, const char *path)
{
	NMDevice	*dev = NULL;

	g_return_val_if_fail (path != NULL, NULL);
	g_return_val_if_fail (data != NULL, NULL);

	/* FIXME
	 * This function could be much more efficient, for example we could
	 * actually _parse_ the object path, but that's a lot more code and
	 * stupid stuff.  The approach below is slower, less efficient, but
	 * less code and less error-prone.
	 */

	/* Iterate over device list */
	if (nm_try_acquire_mutex (data->dev_list_mutex, __FUNCTION__))
	{
		GSList	*elt;
		char		 compare_path[100];
		char    *escaped_compare_path;

		for (elt = data->dev_list; elt; elt = g_slist_next (elt))
		{
			if ((dev = (NMDevice *)(elt->data)))
			{
				snprintf (compare_path, 100, "%s/%s", NM_DBUS_PATH_DEVICES, nm_device_get_iface (dev));
				escaped_compare_path = nm_dbus_escape_object_path (compare_path);
				/* Compare against our constructed path, but ignore any trailing elements */
				if (strncmp (path, compare_path, strlen (escaped_compare_path)) == 0)
				{
					g_free (escaped_compare_path);
					break;
				}
				g_free (escaped_compare_path);
				dev = NULL;
			}
		}
		nm_unlock_mutex (data->dev_list_mutex, __FUNCTION__);
	}

	return (dev);
}


/*-------------------------------------------------------------*/
/* Handler code */
/*-------------------------------------------------------------*/

typedef struct NMStatusChangeData
{
	NMData *			data;
	NMDevice *		dev;
	NMAccessPoint *	ap;
	DeviceStatus	 	status;
} NMStatusChangeData;


typedef struct
{
	DeviceStatus	status;
	const char *	signal;
} DeviceStatusSignals;

static DeviceStatusSignals dev_status_signals[] = 
{
	{ DEVICE_NO_LONGER_ACTIVE, 	"DeviceNoLongerActive"	},
	{ DEVICE_NOW_ACTIVE,		"DeviceNowActive"		},
	{ DEVICE_ACTIVATING,		"DeviceActivating"		},
	{ DEVICE_ACTIVATION_FAILED,	"DeviceActivationFailed"	},
	{ DEVICE_ADDED,			"DeviceAdded"			},
	{ DEVICE_REMOVED,			"DeviceRemoved"		},
	{ DEVICE_CARRIER_ON,		"DeviceCarrierOn"		},
	{ DEVICE_CARRIER_OFF,		"DeviceCarrierOff"		},
	{ DEVICE_STATUS_INVALID,		NULL					}
};

/*
 * nm_dbus_signal_device_status_change
 *
 * Notifies the bus that a particular device has had a status change
 *
 */
static gboolean nm_dbus_signal_device_status_change (gpointer user_data)
{
	NMStatusChangeData *cb_data = (NMStatusChangeData *)user_data;
	DBusMessage *		message;
	char *			dev_path;
	const char *		sig = NULL;
	int				i = 0;

	g_return_val_if_fail (cb_data->data, FALSE);
	g_return_val_if_fail (cb_data->data->dbus_connection, FALSE);
	g_return_val_if_fail (cb_data->dev, FALSE);

	while ((dev_status_signals[i].status != DEVICE_STATUS_INVALID) && (dev_status_signals[i].status != cb_data->status))
		i++;

	if (!(sig = dev_status_signals[i].signal))
		return FALSE;

	if (!(dev_path = nm_dbus_get_object_path_for_device (cb_data->dev)))
		return FALSE;

	if (!(message = dbus_message_new_signal (NM_DBUS_PATH, NM_DBUS_INTERFACE, sig)))
	{
		nm_warning ("nm_dbus_signal_device_status_change(): Not enough memory for new dbus message!");
		g_free (dev_path);
		return FALSE;
	}

	/* If the device was wireless, attach the name of the wireless network that failed to activate */
	if (cb_data->ap)
	{
		const char *essid = nm_ap_get_essid (cb_data->ap);
		if (essid)
			dbus_message_append_args (message, DBUS_TYPE_OBJECT_PATH, &dev_path, DBUS_TYPE_STRING, &essid, DBUS_TYPE_INVALID);
		nm_ap_unref (cb_data->ap);
	}
	else
		dbus_message_append_args (message, DBUS_TYPE_OBJECT_PATH, &dev_path, DBUS_TYPE_INVALID);

	g_free (dev_path);

	if (!dbus_connection_send (cb_data->data->dbus_connection, message, NULL))
		nm_warning ("nm_dbus_signal_device_status_change(): Could not raise the signal!");

	dbus_message_unref (message);

	g_object_unref (G_OBJECT (cb_data->dev));
	g_free (cb_data);

	return FALSE;
}


void nm_dbus_schedule_device_status_change_signal (NMData *data, NMDevice *dev, NMAccessPoint *ap, DeviceStatus status)
{
	NMStatusChangeData	*cb_data = NULL;
	GSource			*source;

	g_return_if_fail (data != NULL);
	g_return_if_fail (dev != NULL);

	cb_data = g_malloc0 (sizeof (NMStatusChangeData));
	g_object_ref (G_OBJECT (dev));
	cb_data->data = data;
	cb_data->dev = dev;
	if (ap)
	{
		nm_ap_ref (ap);
		cb_data->ap = ap;
	}
	cb_data->status = status;

	source = g_idle_source_new ();
	g_source_set_priority (source, G_PRIORITY_HIGH_IDLE);
	g_source_set_callback (source, nm_dbus_signal_device_status_change, cb_data, NULL);
	g_source_attach (source, data->main_context);
	g_source_unref (source);
}


/*
 * nm_dbus_network_status_from_data
 *
 * Return a network status string based on our network data
 *
 * Caller MUST free returned value
 *
 */
NMState nm_get_app_state_from_data (NMData *data)
{
	NMDevice *	act_dev = NULL;

	g_return_val_if_fail (data != NULL, NM_STATE_DISCONNECTED);

	if (data->asleep == TRUE)
		return NM_STATE_ASLEEP;

	act_dev = nm_get_active_device (data);
	if (!act_dev)
		return NM_STATE_DISCONNECTED;

	if (nm_device_is_activating (act_dev))
		return NM_STATE_CONNECTING;
	else
		return NM_STATE_CONNECTED;
}


/*
 * nm_dbus_signal_state_change
 *
 * Signal a change in state
 *
 */
void nm_dbus_signal_state_change (DBusConnection *connection, NMData *data)
{
	DBusMessage *	message;
	NMState		state;

	g_return_if_fail (connection != NULL);
	g_return_if_fail (data != NULL);

	if (!(message = dbus_message_new_signal (NM_DBUS_PATH, NM_DBUS_INTERFACE, NM_DBUS_SIGNAL_STATE_CHANGE)))
	{
		nm_warning ("nm_dbus_signal_state_change(): Not enough memory for new dbus message!");
		return;
	}

	state = nm_get_app_state_from_data (data);
	dbus_message_append_args (message, DBUS_TYPE_UINT32, &state, DBUS_TYPE_INVALID);
	if (!dbus_connection_send (connection, message, NULL))
		nm_warning ("nm_dbus_signal_state_change(): Could not raise the signal!");

	dbus_message_unref (message);
}


/*
 * nm_dbus_signal_wireless_network_change
 *
 * Notifies the bus that a new wireless network has come into range
 *
 */
void nm_dbus_signal_wireless_network_change (DBusConnection *connection, NMDevice80211Wireless *dev, NMAccessPoint *ap, NMNetworkStatus status, gint strength)
{
	DBusMessage *	message;
	char *		dev_path = NULL;
	char *		net_path = NULL;
	const char *	sig = NULL;

	g_return_if_fail (connection != NULL);
	g_return_if_fail (dev != NULL);
	g_return_if_fail (ap != NULL);

	if (!(dev_path = nm_dbus_get_object_path_for_device (NM_DEVICE (dev))))
		goto out;

	if (!(net_path = nm_dbus_get_object_path_for_network (NM_DEVICE (dev), ap)))
		goto out;

	switch (status)
	{
		case NETWORK_STATUS_DISAPPEARED:
			sig = "WirelessNetworkDisappeared";
			break;
		case NETWORK_STATUS_APPEARED:
			sig = "WirelessNetworkAppeared";
			break;
		case NETWORK_STATUS_STRENGTH_CHANGED:
			sig = "WirelessNetworkStrengthChanged";
			break;
		default:
			break;
	}

	if (!sig)
	{
		nm_warning ("nm_dbus_signal_wireless_network_change(): tried to broadcast unknown signal.");
		goto out;
	}

	if (!(message = dbus_message_new_signal (NM_DBUS_PATH, NM_DBUS_INTERFACE, sig)))
	{
		nm_warning ("nm_dbus_signal_wireless_network_change(): Not enough memory for new dbus message!");
		goto out;
	}

	dbus_message_append_args (message, DBUS_TYPE_OBJECT_PATH, &dev_path, DBUS_TYPE_OBJECT_PATH, &net_path, DBUS_TYPE_INVALID);
	if (status == NETWORK_STATUS_STRENGTH_CHANGED)
		dbus_message_append_args (message, DBUS_TYPE_INT32, &strength, DBUS_TYPE_INVALID);

	if (!dbus_connection_send (connection, message, NULL))
		nm_warning ("nm_dbus_signal_wireless_network_change(): Could not raise the WirelessNetwork* signal!");

	dbus_message_unref (message);

out:
	g_free (net_path);
	g_free (dev_path);
}


void nm_dbus_signal_device_strength_change (DBusConnection *connection, NMDevice80211Wireless *dev, gint strength)
{
	DBusMessage *	message;
	char *		dev_path = NULL;

	g_return_if_fail (connection != NULL);
	g_return_if_fail (dev != NULL);

	if (!(dev_path = nm_dbus_get_object_path_for_device (NM_DEVICE (dev))))
		goto out;

	if (!(message = dbus_message_new_signal (NM_DBUS_PATH, NM_DBUS_INTERFACE, "DeviceStrengthChanged")))
	{
		nm_warning ("nm_dbus_signal_device_strength_change(): Not enough memory for new dbus message!");
		goto out;
	}

	dbus_message_append_args (message, DBUS_TYPE_OBJECT_PATH, &dev_path, DBUS_TYPE_INT32, &strength, DBUS_TYPE_INVALID);
	if (!dbus_connection_send (connection, message, NULL))
		nm_warning ("nm_dbus_signal_device_strength_change(): Could not raise the DeviceStrengthChanged signal!");

	dbus_message_unref (message);

out:
	g_free (dev_path);
}


/*
 * nm_dbus_signal_filter
 *
 * Respond to NetworkManagerInfo signals about changing Allowed Networks
 *
 */
static DBusHandlerResult nm_dbus_signal_filter (DBusConnection *connection, DBusMessage *message, void *user_data)
{
	NMData *		data = (NMData *)user_data;
	const char *	object_path;
	const char *	method;
	gboolean		handled = FALSE;
	DBusError		error;

	g_return_val_if_fail (data != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (connection != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (message != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);

	method = dbus_message_get_member (message);
	if (!(object_path = dbus_message_get_path (message)))
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	if (dbus_message_get_type (message) != DBUS_MESSAGE_TYPE_SIGNAL)
		return DBUS_HANDLER_RESULT_NOT_YET_HANDLED;

	/* nm_debug ("nm_dbus_nmi_filter() got method %s for path %s", method, object_path); */

	dbus_error_init (&error);

	if (strcmp (object_path, NMI_DBUS_PATH) == 0)
	{
		if (dbus_message_is_signal (message, NMI_DBUS_INTERFACE, "WirelessNetworkUpdate"))
		{
			char			*network = NULL;

			if (dbus_message_get_args (message, &error, DBUS_TYPE_STRING, &network, DBUS_TYPE_INVALID))
			{
				/* Update a single wireless network's data */
				nm_debug ("NetworkManagerInfo triggered update of wireless network '%s'", network);
				nm_dbus_update_one_allowed_network (connection, network, data);
				handled = TRUE;
			}
		}
		else if (dbus_message_is_signal (message, NMI_DBUS_INTERFACE, "VPNConnectionUpdate"))
		{
			char	*name = NULL;

			if (dbus_message_get_args (message, &error, DBUS_TYPE_STRING, &name, DBUS_TYPE_INVALID))
			{
				nm_debug ("NetworkManagerInfo triggered update of VPN connection '%s'", name);
				nm_dbus_vpn_update_one_vpn_connection (data->dbus_connection, name, data);
				handled = TRUE;
			}
		}
		else if (dbus_message_is_signal (message, NMI_DBUS_INTERFACE, "UserInterfaceActivated"))
		{
			nm_device_802_11_wireless_set_scan_interval (data, NULL, NM_WIRELESS_SCAN_INTERVAL_ACTIVE);
			handled = TRUE;
		}
	}
	else if (dbus_message_is_signal (message, DBUS_INTERFACE_DBUS, "Disconnected"))
	{
		/* FIXME: try to recover from disconnection */
		data->dbus_connection = NULL;
		handled = TRUE;
	}
	else if (dbus_message_is_signal (message, DBUS_INTERFACE_DBUS, "NameOwnerChanged"))
	{
		char 	*service;
		char		*old_owner;
		char		*new_owner;

		if (dbus_message_get_args (message, &error, DBUS_TYPE_STRING, &service, DBUS_TYPE_STRING, &old_owner,
									DBUS_TYPE_STRING, &new_owner, DBUS_TYPE_INVALID))
		{
			gboolean old_owner_good = (old_owner && (strlen (old_owner) > 0));
			gboolean new_owner_good = (new_owner && (strlen (new_owner) > 0));

			if (strcmp (service, NMI_DBUS_SERVICE) == 0)
			{
				if (!old_owner_good && new_owner_good) /* NMI just appeared */
				{
					char *match = get_nmi_match_string (new_owner);
					dbus_bus_add_match (connection, match, NULL);
					nm_policy_schedule_allowed_ap_list_update (data);
					nm_dbus_vpn_schedule_vpn_connections_update (data);
					g_free (match);
					handled = TRUE;
				}
				else if (old_owner_good && !new_owner_good)	/* NMI went away */
				{
					char *match = get_nmi_match_string (old_owner);
					dbus_bus_remove_match (connection, match, NULL);
					g_free (match);
				}
			}
			else if (strcmp (service, "org.freedesktop.Hal") == 0)
			{
				if (!old_owner_good && new_owner_good) /* Hal just appeared */
				{
					nm_hal_init (data);
					handled = TRUE;
				}
				else if (old_owner_good && !new_owner_good)	/* Hal went away */
				{
					nm_hal_deinit (data);
					handled = TRUE;
				}
			}
			else if (nm_dhcp_manager_process_name_owner_changed (data->dhcp_manager, service, old_owner, new_owner) == TRUE)
				handled = TRUE;
			else if (nm_vpn_manager_process_name_owner_changed (data->vpn_manager, service, old_owner, new_owner) == TRUE)
				handled = TRUE;
			else if (nm_named_manager_process_name_owner_changed (data->named_manager, service, old_owner, new_owner) == TRUE)
				handled = TRUE;
		}
	}
	else if (nm_dhcp_manager_process_signal (data->dhcp_manager, message) == TRUE)
		handled = TRUE;
	else if (nm_vpn_manager_process_signal (data->vpn_manager, message) == TRUE)
		handled = TRUE;

	if (dbus_error_is_set (&error))
		dbus_error_free (&error);

	return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}


/*
 * nm_dbus_nm_message_handler
 *
 * Dispatch messages against our NetworkManager object
 *
 */
static DBusHandlerResult nm_dbus_nm_message_handler (DBusConnection *connection, DBusMessage *message, void *user_data)
{
	NMData			*data = (NMData *)user_data;
	gboolean			 handled = TRUE;
	DBusMessage		*reply = NULL;
	NMDbusCBData		 cb_data;

	g_return_val_if_fail (data != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (data->nm_methods != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (connection != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (message != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);

	cb_data.data = data;
	cb_data.dev = NULL;
	handled = nm_dbus_method_dispatch (data->nm_methods, connection, message, &cb_data, &reply);
	if (reply)
	{
		dbus_connection_send (connection, reply, NULL);
		dbus_message_unref (reply);
	}

	return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}


/*
 * nm_dbus_devices_message_handler
 *
 * Dispatch messages against individual network devices
 *
 */
static DBusHandlerResult nm_dbus_devices_message_handler (DBusConnection *connection, DBusMessage *message, void *user_data)
{
	NMData			*data = (NMData *)user_data;
	gboolean			 handled = FALSE;
	const char		*path;
	DBusMessage		*reply = NULL;
	NMDevice			*dev;

	g_return_val_if_fail (data != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (connection != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (message != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);

	path = dbus_message_get_path (message);

	if (!(dev = nm_dbus_get_device_from_object_path (data, path)))
		reply = nm_dbus_create_error_message (message, NM_DBUS_INTERFACE, "DeviceNotFound", "The requested network device does not exist.");
	else
	{
		char			*object_path, *escaped_object_path;
		NMDbusCBData	 cb_data;

		cb_data.data = data;
		cb_data.dev = dev;

		/* Test whether or not the _networks_ of a device were queried instead of the device itself */
		object_path = g_strdup_printf ("%s/%s/Networks/", NM_DBUS_PATH_DEVICES, nm_device_get_iface (dev));
		escaped_object_path = nm_dbus_escape_object_path (object_path);
		g_free (object_path);
		if (strncmp (path, escaped_object_path, strlen (escaped_object_path)) == 0)
			handled = nm_dbus_method_dispatch (data->net_methods, connection, message, &cb_data, &reply);
		else
			handled = nm_dbus_method_dispatch (data->device_methods, connection, message, &cb_data, &reply);
		g_free (escaped_object_path);
	}

	if (reply)
	{
		dbus_connection_send (connection, reply, NULL);
		dbus_message_unref (reply);
		handled = TRUE;
	}

	return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}


/*
 * nm_dbus_vpn_message_handler
 *
 * Dispatch messages against our NetworkManager VPNConnections object
 *
 */
static DBusHandlerResult nm_dbus_vpn_message_handler (DBusConnection *connection, DBusMessage *message, void *user_data)
{
	NMData			*data = (NMData *)user_data;
	gboolean			 handled = TRUE;
	DBusMessage		*reply = NULL;
	NMDbusCBData		 cb_data;

	g_return_val_if_fail (data != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (data->vpn_methods != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (connection != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
	g_return_val_if_fail (message != NULL, DBUS_HANDLER_RESULT_NOT_YET_HANDLED);

	cb_data.data = data;
	cb_data.dev = NULL;
	handled = nm_dbus_method_dispatch (data->vpn_methods, connection, message, &cb_data, &reply);
	if (reply)
	{
		dbus_connection_send (connection, reply, NULL);
		dbus_message_unref (reply);
	}

	return (handled ? DBUS_HANDLER_RESULT_HANDLED : DBUS_HANDLER_RESULT_NOT_YET_HANDLED);
}


/*
 * nm_dbus_is_info_daemon_running
 *
 * Ask dbus whether or not the info daemon is providing its dbus service
 *
 */
gboolean nm_dbus_is_info_daemon_running (DBusConnection *connection)
{
	DBusError		error;
	gboolean		running = FALSE;

	g_return_val_if_fail (connection != NULL, FALSE);

	dbus_error_init (&error);
	running = dbus_bus_name_has_owner (connection, NMI_DBUS_SERVICE, &error);
	if (dbus_error_is_set (&error))
	{
		running = FALSE;
		dbus_error_free (&error);
	}
	return running;
}


char *get_name_owner (DBusConnection *con, const char *name)
{
	DBusMessage *	message;
	DBusMessage *	reply;
	char *		owner = NULL;

	g_return_val_if_fail (con != NULL, NULL);
	g_return_val_if_fail (name != NULL, NULL);

	if ((message = dbus_message_new_method_call (DBUS_SERVICE_DBUS, DBUS_PATH_DBUS, DBUS_INTERFACE_DBUS, "GetNameOwner")))
	{
		dbus_message_append_args (message, DBUS_TYPE_STRING, &name, DBUS_TYPE_INVALID);
		if ((reply = dbus_connection_send_with_reply_and_block (con, message, -1, NULL)))
		{
			const char *tmp_name = NULL;
			if (dbus_message_get_args (reply, NULL, DBUS_TYPE_STRING, &tmp_name, DBUS_TYPE_INVALID))
				owner = g_strdup (tmp_name);
			dbus_message_unref (reply);
		}
		dbus_message_unref (message);
	}

	return owner;
}


static char *get_nmi_match_string (const char *owner)
{
	g_return_val_if_fail (owner != NULL, NULL);

	return g_strdup_printf ("type='signal',interface='" NMI_DBUS_INTERFACE "',sender='%s',path='" NMI_DBUS_PATH "'", owner);
}


/*
 * nm_dbus_init
 *
 * Connect to the system messagebus and register ourselves as a service.
 *
 */
DBusConnection *nm_dbus_init (NMData *data)
{
	DBusError		 		error;
	DBusConnection *		connection;
	DBusObjectPathVTable	nm_vtable = {NULL, &nm_dbus_nm_message_handler, NULL, NULL, NULL, NULL};
	DBusObjectPathVTable	devices_vtable = {NULL, &nm_dbus_devices_message_handler, NULL, NULL, NULL, NULL};
	DBusObjectPathVTable	vpn_vtable = {NULL, &nm_dbus_vpn_message_handler, NULL, NULL, NULL, NULL};
	char *				owner;
	int					flags, ret;

	dbus_connection_set_change_sigpipe (TRUE);

	dbus_error_init (&error);
	connection = dbus_bus_get (DBUS_BUS_SYSTEM, &error);
	if ((connection == NULL) || dbus_error_is_set (&error))
	{
		nm_warning ("nm_dbus_init() could not get the system bus.  Make sure the message bus daemon is running!");
		connection = NULL;
		goto out;
	}

	//dbus_connection_set_exit_on_disconnect (connection, FALSE);
	dbus_connection_setup_with_g_main (connection, data->main_context);

	data->nm_methods = nm_dbus_nm_methods_setup ();
	data->device_methods = nm_dbus_device_methods_setup ();
	data->net_methods = nm_dbus_net_methods_setup ();
	data->vpn_methods = nm_dbus_vpn_methods_setup ();

	if (    !dbus_connection_register_object_path (connection, NM_DBUS_PATH, &nm_vtable, data)
		|| !dbus_connection_register_fallback (connection, NM_DBUS_PATH_DEVICES, &devices_vtable, data)
		|| !dbus_connection_register_object_path (connection, NM_DBUS_PATH_VPN, &vpn_vtable, data))
	{
		nm_error ("nm_dbus_init() could not register D-BUS handlers.  Cannot continue.");
		connection = NULL;
		goto out;
	}

	if (!dbus_connection_add_filter (connection, nm_dbus_signal_filter, data, NULL))
	{
		nm_error ("nm_dbus_init() could not attach a dbus message filter.  The NetworkManager dbus security policy may not be loaded.  Restart dbus?");
		connection = NULL;
		goto out;
	}

	dbus_bus_add_match (connection,
				"type='signal',"
				"interface='" DBUS_INTERFACE_DBUS "',"
				"sender='" DBUS_SERVICE_DBUS "'",
				NULL);

	if ((owner = get_name_owner (connection, NMI_DBUS_SERVICE)))
	{
		char *match = get_nmi_match_string (owner);

		dbus_bus_add_match (connection, match, NULL);
		g_free (match);
		g_free (owner);
	}

	dbus_error_init (&error);
#if (DBUS_VERSION_MAJOR == 0) && (DBUS_VERSION_MINOR >= 60)
	flags = DBUS_NAME_FLAG_DO_NOT_QUEUE;	/* Prohibit replacement is now the default */
#else
	flags = DBUS_NAME_FLAG_PROHIBIT_REPLACEMENT;
#endif
	ret = dbus_bus_request_name (connection, NM_DBUS_SERVICE, flags, &error);
	if (dbus_error_is_set (&error))
	{
		nm_warning ("nm_dbus_init() could not acquire the NetworkManager service.\n  Message: '%s'", error.message);
		connection = NULL;
		goto out;
	}
	else if (ret != DBUS_REQUEST_NAME_REPLY_PRIMARY_OWNER)
	{
		nm_warning ("nm_dbus_init() could not acquire the NetworkManager service as it is already taken (ret=%d). Is the daemon already running?",
				  ret);
		connection = NULL;
		goto out;
	}

out:
	if (dbus_error_is_set (&error))
		dbus_error_free (&error);

	return (connection);
}