Re: Need help with the NetworkManager DBUS API

[Jirka Klimes <jklimes redhat com>]

On Monday 14 of February 2011 05:52:16 Anurup Raveendran wrote:
> i'm trying to establish a wireless network connection using the DBUS
> API but i have failed miserably. i have attached the code that I'm
> using.
> 
> 
> Regards,

Instead 'failed miserably' you should say what is the real problem ;)

And it is that the segmentation fault happens due to bad types of s_wireless 
properties. SSID is not string but a byte array (it can generaly contain 0) 
and the mode should be "adhoc" or "infrastructure".
See corrected example in the attachment.

Jirka

/*
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * (C) Copyright 2011 Red Hat, Inc.
 */

/*
 * The example shows how to call AddConnection() D-Bus method to add
 * a connection to system settings service. It uses dbus-glib and libnm-util
 * libraries.
 *
 * Compile with:
 *   gcc -Wall `pkg-config --libs --cflags glib-2.0 dbus-glib-1 libnm-util` add-wireless-connection-glib.c -o add-wireless-connection-glib
 */

#include <glib.h>
#include <dbus/dbus-glib.h>

#include <nm-connection.h>
#include <nm-setting-connection.h>
#include <nm-setting-wireless.h>
#include <nm-setting-ip4-config.h>
#include <NetworkManager.h>
#include <nm-utils.h>

#define DBUS_TYPE_G_MAP_OF_VARIANT          (dbus_g_type_get_map ("GHashTable", G_TYPE_STRING, G_TYPE_VALUE))
#define DBUS_TYPE_G_MAP_OF_MAP_OF_VARIANT   (dbus_g_type_get_map ("GHashTable", G_TYPE_STRING, DBUS_TYPE_G_MAP_OF_VARIANT))

static void
add_connection (DBusGProxy *proxy, const char *con_name)
{
	NMConnection *connection;
	NMSettingConnection *s_con;
	NMSettingWireless *s_wireless;
	NMSettingIP4Config *s_ip4;
	char *uuid;
	GHashTable *hash;
	GByteArray *ssid;
	const unsigned char ssid_data[] = { 'T', 'e', 's', 't' };
	GError *error = NULL;

	/* Create a new connection object */
	connection = (NMConnection *) nm_connection_new ();

	/* Build up the 'connection' Setting */
	s_con = (NMSettingConnection *) nm_setting_connection_new ();
	uuid = nm_utils_uuid_generate ();
	g_object_set (G_OBJECT (s_con),
	              NM_SETTING_CONNECTION_UUID, uuid,
	              NM_SETTING_CONNECTION_ID, con_name,
	              NM_SETTING_CONNECTION_TYPE, "802-11-wireless",
	              NULL);
	g_free (uuid);
	nm_connection_add_setting (connection, NM_SETTING (s_con));

	/* Build up the 'wireless' Setting */
	s_wireless = (NMSettingWireless *) nm_setting_wireless_new ();
	nm_connection_add_setting (connection, NM_SETTING (s_wireless));

	ssid = g_byte_array_sized_new (sizeof (ssid_data));
	g_byte_array_append (ssid, ssid_data, sizeof (ssid_data));

	g_object_set(s_wireless, NM_SETTING_WIRELESS_SSID, ssid, NULL);
	g_object_set(s_wireless, NM_SETTING_WIRELESS_MODE, "adhoc", NULL);
	g_byte_array_free (ssid, TRUE);

	/* Build up the 'ipv4' Setting */
	s_ip4 = (NMSettingIP4Config *) nm_setting_ip4_config_new ();
	g_object_set (G_OBJECT (s_ip4),
	              NM_SETTING_IP4_CONFIG_METHOD, NM_SETTING_IP4_CONFIG_METHOD_AUTO,
	              NULL);
	nm_connection_add_setting (connection, NM_SETTING (s_ip4));

	hash = nm_connection_to_hash (connection);

	/* Call AddConnection with the hash as argument */
	dbus_g_proxy_call (proxy, "AddConnection", &error,
	                   DBUS_TYPE_G_MAP_OF_MAP_OF_VARIANT, hash,
	                   G_TYPE_INVALID);

	g_hash_table_destroy (hash);
	g_object_unref (connection);
}


int main (int argc, char *argv[])
{
	DBusGConnection *bus;
	DBusGProxy *proxy;

	/* Initialize GType system */
	g_type_init ();

	/* Get system bus */
	bus = dbus_g_bus_get (DBUS_BUS_SYSTEM, NULL);

	/* Create a D-Bus proxy; NM_DBUS_* defined in NetworkManager.h */
	proxy = dbus_g_proxy_new_for_name (bus,
	                                   NM_DBUS_SERVICE_SYSTEM_SETTINGS,
	                                   NM_DBUS_PATH_SETTINGS,
	                                   NM_DBUS_IFACE_SETTINGS);

	/* Add a connection */
	add_connection (proxy, "__Test connection__");

	g_object_unref (proxy);
	dbus_g_connection_unref (bus);

	return 0;
}