Imported Upstream version 0.9.5.95 upstream/0.9.5.95

1 files changed, 868 insertions, 0 deletions

diff --git a/src/settings/plugins/example/plugin.c b/src/settings/plugins/example/plugin.c
new file mode 100644
index 00000000..04af03e7
--- /dev/null
+++ b/src/settings/plugins/example/plugin.c
@@ -0,0 +1,868 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* NetworkManager system settings service - keyfile plugin
+ *
+ * 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.
+ *
+ * Copyright (C) 2012 Red Hat, Inc.
+ */
+
+#include <config.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <netinet/ether.h>
+#include <string.h>
+
+#include <gmodule.h>
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <gio/gio.h>
+
+#include <nm-connection.h>
+#include <nm-setting.h>
+#include <nm-setting-connection.h>
+
+#include "plugin.h"
+#include "nm-system-config-interface.h"
+#include "common.h"
+#include "nm-example-connection.h"
+
+static char *plugin_get_hostname (SCPluginExample *plugin);
+static void system_config_interface_init (NMSystemConfigInterface *system_config_interface_class);
+
+/* GObject object definition.  This actually defines the object and tells
+ * GObject about the interfaces this object provides.  Here we provide
+ * the "system config interface" which is the API that NetworkManager uses
+ * to communicate with this plugin.
+ *
+ * Interface and super/sub-class access with GObject works via casting and
+ * GObject magically figures out what needs to be called.  So, given:
+ *
+ *    SCPluginExample *plugin = <new plugin>;
+ *
+ * you can call GObject methods since SCPluginExample inherits from GObject
+ * via the G_TYPE_OBJECT argument of G_DEFINE_TYPE_EXTENDED below:
+ *
+ *    g_object_set_data (G_OBJECT (plugin), ...);
+ *
+ * and since SCPluginExample implements NMSystemConfigInterface via the
+ * G_IMPLEMENT_INTERFACE bit below, we can also call any methods of
+ * NMSystemConfigInterface (defined in NM sources in nm-system-config-interface.c):
+ *
+ *    connections = nm_system_config_interface_get_connections (NM_SYSTEM_CONFIG_INTERFACE (plugin));
+ *
+ * For the call to nm_system_config_interface_get_connections() that eventually
+ * ends up in the get_connections() method in this file because the
+ * system_config_interface_init() function sets up the vtable for this objects
+ * implementation of NMSystemConfigInterface.
+ */
+G_DEFINE_TYPE_EXTENDED (SCPluginExample, sc_plugin_example, G_TYPE_OBJECT, 0,
+                        G_IMPLEMENT_INTERFACE (NM_TYPE_SYSTEM_CONFIG_INTERFACE, system_config_interface_init))
+
+/* Quick define to access the object's private data pointer; this pointer
+ * points to the object's instance data.
+ */
+#define SC_PLUGIN_EXAMPLE_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), SC_TYPE_PLUGIN_EXAMPLE, SCPluginExamplePrivate))
+
+/* Instance data.  When the object is created, a new structure of this type
+ * will be created and zeroed for this instance of the object to use.  This
+ * is actually done by g_type_class_add_private() when called from the object's
+ * class init function.
+ */
+typedef struct {
+	/* This hash holds each connection known to this plugin */
+	GHashTable *connections;
+
+	/* A watch for changes on the directory that holds the configuration files
+	 * so the plugin can respond to configuration changes on-the-fly and
+	 * tell NM that the connection data has changed.  Typically the plugin
+	 * needs to monitor the directory itself (to watch for completely new files)
+	 * while the individual connections watch their individual config files.
+	 */
+	GFileMonitor *monitor;
+	guint monitor_id;
+
+	/* Tracks changes to the global NM config file, just in case our
+	 * plugin has some specific options (like unmanaged devices) that
+	 * might be changed at runtime.
+	 */
+	char *conf_file;
+	GFileMonitor *conf_file_monitor;
+	guint conf_file_monitor_id;
+
+	/* Persistent hostname if the plugin supports hostnames.  Normally used
+	 * for distro plugins; ie Red Hat uses /etc/sysconfig/hostname while
+	 * Debian uses /etc/hostname.  Plugins can abstract the storage location
+	 * and just tell NM what the persisten hostname is and when its backing
+	 * file has changed.  NM handles actually setting the hostname.
+	 */
+	char *hostname;
+} SCPluginExamplePrivate;
+
+static NMSettingsConnection *
+_internal_new_connection (SCPluginExample *self,
+                          const char *full_path,
+                          NMConnection *source,
+                          GError **error)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (self);
+	NMExampleConnection *connection;
+
+	g_return_val_if_fail (full_path != NULL, NULL);
+
+	/* 'source' will usually be NULL if we're going to read the connection
+	 * off disk.  But if the new connection is coming from NetworkManager
+	 * (ie, from a D-Bus AddConnection request) then we'll have 'source' too.
+	 * This function expects the connection to already be written to disk
+	 * so that the NMExampleConnection object can re-read it and intialize
+	 * state in the same manner as when getting a change notification from
+	 * the config directory.  That simplifies things somewhat.
+	 */
+
+	connection = nm_example_connection_new (full_path, source, error);
+	if (connection) {
+		g_hash_table_insert (priv->connections,
+		                     (gpointer) nm_example_connection_get_path (connection),
+		                     connection);
+	}
+
+	return (NMSettingsConnection *) connection;
+}
+
+/* Read each file in our config directory and try to create a new
+ * NMExamplePlugin for it.
+ */
+static void
+read_connections (NMSystemConfigInterface *config)
+{
+	SCPluginExample *self = SC_PLUGIN_EXAMPLE (config);
+	GDir *dir;
+	GError *error = NULL;
+	const char *item;
+
+	dir = g_dir_open (EXAMPLE_DIR, 0, &error);
+	if (!dir) {
+		PLUGIN_WARN (EXAMPLE_PLUGIN_NAME, "Cannot read directory '%s': (%d) %s",
+		             EXAMPLE_DIR,
+		             error ? error->code : -1,
+		             error && error->message ? error->message : "(unknown)");
+		g_clear_error (&error);
+		return;
+	}
+
+	while ((item = g_dir_read_name (dir))) {
+		NMSettingsConnection *connection;
+		char *full_path;
+
+		/* XXX: Check file extension and ignore "~", ".tmp", ".bak", etc */
+
+		full_path = g_build_filename (EXAMPLE_DIR, item, NULL);
+		PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "parsing %s ... ", item);
+
+		connection = _internal_new_connection (self, full_path, NULL, &error);
+		if (connection) {
+			PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "    read connection '%s'",
+			              nm_connection_get_id (NM_CONNECTION (connection)));
+		} else {
+			PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "    error: %s",
+				          (error && error->message) ? error->message : "(unknown)");
+		}
+		g_clear_error (&error);
+		g_free (full_path);
+	}
+	g_dir_close (dir);
+}
+
+static void
+update_connection_settings_commit_cb (NMSettingsConnection *orig, GError *error, gpointer user_data)
+{
+	/* If there was an error updating the connection's internal stuff, then
+	 * we can't do anything except log it and remove the connection.  This might
+	 * happen due to invalid data, but as the data would already have been
+	 * verified before it ever got to this plugin, we shouldn't ever get
+	 * an error here.
+	 */
+	if (error) {
+		g_warning ("%s: '%s' / '%s' invalid: %d",
+		       	   __func__,
+		       	   error ? g_type_name (nm_connection_lookup_setting_type_by_quark (error->domain)) : "(none)",
+		       	   (error && error->message) ? error->message : "(none)",
+		       	   error ? error->code : -1);
+		g_clear_error (&error);
+
+		nm_settings_connection_signal_remove (orig);
+	}
+}
+
+static void
+update_connection_settings (NMExampleConnection *orig,
+                            NMExampleConnection *new)
+{
+	/* This just replaces the orig's internal settings with those from new */
+	nm_settings_connection_replace_and_commit (NM_SETTINGS_CONNECTION (orig),
+	                                           NM_CONNECTION (new),
+	                                           update_connection_settings_commit_cb, NULL);
+}
+
+/* Monitoring */
+
+static void
+remove_connection (SCPluginExample *self,
+                   NMExampleConnection *connection,
+                   const char *name)
+{
+	g_return_if_fail (connection != NULL);
+	g_return_if_fail (name != NULL);
+
+	/* Removing from the hash table should drop the last reference, but since
+	 * we need the object to stay alive across the signal emission to NM,
+	 * we grab a temporary reference.
+	 */
+	g_object_ref (connection);
+	g_hash_table_remove (SC_PLUGIN_EXAMPLE_GET_PRIVATE (self)->connections, name);
+
+	/* Tell NM the connection is gone */
+	nm_settings_connection_signal_remove (NM_SETTINGS_CONNECTION (connection));
+
+	/* Remove the temporary reference; connection will now be destroyed */
+	g_object_unref (connection);
+}
+
+/* Look through all connections we know about and return one with a given UUID */
+static NMExampleConnection *
+find_by_uuid (SCPluginExample *self, const char *uuid)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (self);
+	GHashTableIter iter;
+	gpointer data = NULL;
+
+	g_return_val_if_fail (uuid != NULL, NULL);
+
+	g_hash_table_iter_init (&iter, priv->connections);
+	while (g_hash_table_iter_next (&iter, NULL, &data)) {
+		NMConnection *candidate = NM_CONNECTION (data);
+
+		if (strcmp (uuid, nm_connection_get_uuid (candidate)) == 0)
+			return NM_EXAMPLE_CONNECTION (candidate);
+	}
+	return NULL;
+}
+
+
+static void
+dir_changed (GFileMonitor *monitor,
+             GFile *file,
+             GFile *other_file,
+             GFileMonitorEvent event_type,
+             gpointer user_data)
+{
+	NMSystemConfigInterface *config = NM_SYSTEM_CONFIG_INTERFACE (user_data);
+	SCPluginExample *self = SC_PLUGIN_EXAMPLE (config);
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (self);
+	char *full_path;
+	NMExampleConnection *connection;
+	GError *error = NULL;
+
+	full_path = g_file_get_path (file);
+	/* XXX: Check here if you need to ignore this file, ie by checking for
+	 * extensions like "~" and ".bak" or ".tmp".  If so just return;
+	 */
+
+	/* Check if we know about this connection already */
+	connection = g_hash_table_lookup (priv->connections, full_path);
+
+	switch (event_type) {
+	case G_FILE_MONITOR_EVENT_DELETED:
+		if (connection) {
+			PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "removed %s.", full_path);
+			remove_connection (SC_PLUGIN_EXAMPLE (config), connection, full_path);
+		}
+		break;
+	case G_FILE_MONITOR_EVENT_CREATED:
+	case G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT:
+		if (connection) {
+			/* Update of an existing connection.  Here we re-read the file and
+			 * compare it against the existing connection to check if anything
+			 * actually changed.
+			 */
+			NMExampleConnection *tmp;
+
+			tmp = nm_example_connection_new (full_path, NULL, &error);
+			if (tmp) {
+				if (!nm_connection_compare (NM_CONNECTION (connection),
+				                            NM_CONNECTION (tmp),
+				                            NM_SETTING_COMPARE_FLAG_IGNORE_AGENT_OWNED_SECRETS |
+				                              NM_SETTING_COMPARE_FLAG_IGNORE_NOT_SAVED_SECRETS)) {
+					/* Connection changed; update our internal connection object */
+					PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "updating %s", full_path);
+					update_connection_settings (connection, tmp);
+				}
+				g_object_unref (tmp);
+			} else {
+				/* There was an error parsing the updated connection; it may
+				 * no longer be valid and thus we've got to delete it.  If it
+				 * becomes valid again later we'll get another change
+				 * notification, we'll re-read it, and we'll treat it as new.
+				 */
+				PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "    error: %s",
+						      (error && error->message) ? error->message : "(unknown)");
+				remove_connection (SC_PLUGIN_EXAMPLE (config), connection, full_path);
+			}
+			g_clear_error (&error);
+		} else {
+			PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "updating %s", full_path);
+
+			/* We don't know about the connection yet, so the change represents
+			 * a completely new connection.
+			 */
+			connection = nm_example_connection_new (full_path, NULL, &error);
+			if (connection) {
+				NMExampleConnection *found = NULL;
+
+				/* Connection renames will show up as different files but with
+				 * the same UUID.  Try to find the original connection.
+				 * A connection rename is treated just like an update except
+				 * there's a bit more housekeeping with the hash table.
+				 */
+				found = find_by_uuid (self, nm_connection_get_uuid (NM_CONNECTION (connection)));
+				if (found) {
+					const char *old_path = nm_example_connection_get_path (connection);
+
+					/* Removing from the hash table should drop the last reference,
+					 * but of course we want to keep the connection around.
+					 */
+					g_object_ref (found);
+					g_hash_table_remove (priv->connections, old_path);
+
+					/* Updating settings should update the NMExampleConnection's
+					 * filename property too.
+					 */
+					update_connection_settings (found, connection);
+
+					/* Re-insert the connection back into the hash with the new filename */
+					g_hash_table_insert (priv->connections,
+					                     (gpointer) nm_example_connection_get_path (found),
+					                     found);
+
+					/* Get rid of the temporary connection */
+					g_object_unref (connection);
+				} else {
+					/* Completely new connection, not a rename. */
+					g_hash_table_insert (priv->connections,
+					                     (gpointer) nm_example_connection_get_path (connection),
+					                     connection);
+					/* Tell NM we found a new connection */
+					g_signal_emit_by_name (config, NM_SYSTEM_CONFIG_INTERFACE_CONNECTION_ADDED, connection);
+				}
+			} else {
+				PLUGIN_PRINT (EXAMPLE_PLUGIN_NAME, "    error: %s",
+						      (error && error->message) ? error->message : "(unknown)");
+				g_clear_error (&error);
+			}
+		}
+		break;
+	default:
+		break;
+	}
+
+	g_free (full_path);
+}
+
+static void
+conf_file_changed (GFileMonitor *monitor,
+				   GFile *file,
+				   GFile *other_file,
+				   GFileMonitorEvent event_type,
+				   gpointer data)
+{
+	SCPluginExample *self = SC_PLUGIN_EXAMPLE (data);
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (self);
+	char *tmp;
+
+	switch (event_type) {
+	case G_FILE_MONITOR_EVENT_DELETED:
+	case G_FILE_MONITOR_EVENT_CREATED:
+	case G_FILE_MONITOR_EVENT_CHANGES_DONE_HINT:
+		/* Unmanaged devices option may have changed; just emit the changed
+		 * signal for unmanaged specs and when NM calls back in to get the
+		 * updated specs we'll re-read the config file then.
+		 */
+		g_signal_emit_by_name (self, NM_SYSTEM_CONFIG_INTERFACE_UNMANAGED_SPECS_CHANGED);
+
+		/* Hostname may also have changed; read it and if it did actually
+		 * change, notify NM.
+		 */
+		tmp = plugin_get_hostname (self);
+		if (g_strcmp0 (tmp, priv->hostname) != 0) {
+			g_free (priv->hostname);
+			priv->hostname = tmp;
+			tmp = NULL;
+			g_object_notify (G_OBJECT (self), NM_SYSTEM_CONFIG_INTERFACE_HOSTNAME);
+		}
+		g_free (tmp);
+		break;
+	default:
+		break;
+	}
+}
+
+/* This function starts the inotify monitors that watch the plugin's config
+ * file directory for new connections and changes to existing connections.
+ * At this time all plugins are expected to make NM aware of changes on-the-fly
+ * instead of requiring a SIGHUP or SIGUSR1 or some D-Bus method to say
+ * "reload".
+ */
+static void
+setup_monitoring (NMSystemConfigInterface *config)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (config);
+	GFileMonitor *monitor;
+	GFile *file;
+
+	/* Initialize connection hash here; we use the connection hash as the 
+	 * "are we initialized yet" variable.
+	 */
+	priv->connections = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, g_object_unref);
+
+	/* Set up the watch for our config directory */
+	file = g_file_new_for_path (EXAMPLE_DIR);
+	monitor = g_file_monitor_directory (file, G_FILE_MONITOR_NONE, NULL, NULL);
+	g_object_unref (file);
+	if (monitor) {
+		/* This registers the dir_changed() function to be called whenever
+		 * the GFileMonitor object notices a change in the directory.
+		 */
+		priv->monitor_id = g_signal_connect (monitor, "changed", G_CALLBACK (dir_changed), config);
+		priv->monitor = monitor;
+	}
+
+	/* Set up a watch on our configuration file, basically just for watching
+	 * whether the user has changed the unmanaged devices option or the
+	 * persistent hostname.
+	 */
+	if (priv->conf_file) {
+		file = g_file_new_for_path (priv->conf_file);
+		monitor = g_file_monitor_file (file, G_FILE_MONITOR_NONE, NULL, NULL);
+		g_object_unref (file);
+
+		if (monitor) {
+			priv->conf_file_monitor_id = g_signal_connect (monitor, "changed", G_CALLBACK (conf_file_changed), config);
+			priv->conf_file_monitor = monitor;
+		}
+	}
+}
+
+/*******************************************************************/
+
+/* Return to NM the full list of connections this plugin owns */
+static GSList *
+get_connections (NMSystemConfigInterface *config)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (config);
+	GHashTableIter iter;
+	NMSettingsConnection *connection;
+	GSList *list = NULL;
+
+	if (!priv->connections) {
+		/* If we haven't read connections in yet, do so now */
+		setup_monitoring (config);
+		read_connections (config);
+	}
+
+	/* Add each connection from our internal hash table to a list returned
+	 * to NetworkManager.
+	 */
+	g_hash_table_iter_init (&iter, priv->connections);
+	while (g_hash_table_iter_next (&iter, NULL, (gpointer) &connection))
+		list = g_slist_prepend (list, connection);
+	return list;
+}
+
+/* Called by NetworkManager when a user adds a new connection via D-Bus.
+ * The plugin should convert the data in 'connection' to its on-disk format
+ * write it out to disk, and return an object that's a subclass of
+ * NMSettingsConnection.  Typically plugins will subclass NMSettingsConnection
+ * and use that class to handle any plugin-specific stuff like monitoring
+ * the on-disk config files for changes, and/or parsing the file-format and
+ * converting back and forth from that to NMConnection.
+ */
+static NMSettingsConnection *
+add_connection (NMSystemConfigInterface *config,
+                NMConnection *connection,
+                GError **error)
+{
+	SCPluginExample *self = SC_PLUGIN_EXAMPLE (config);
+	NMSettingsConnection *added = NULL;
+	char *path = NULL;
+
+	/* Write it out first, then add the connection to our internal list; that
+	 * way we don't trigger the new NMSettingsConnection subclass' file watch
+	 * functions needlessly.
+	 */
+	if (write_connection (connection, NULL, &path, error)) {
+		added = _internal_new_connection (self, path, connection, error);
+		g_free (path);
+	}
+	return added;
+}
+
+/* This function returns a list of "unmanaged device specs" which represent
+ * a list of devices that NetworkManager should not manage.  Each unmanaged
+ * spec item has a specific format starting with a "tag" and followed by
+ * tag-specific data.  The only currently specified item is "mac:" followed
+ * by the MAC address of the interface NM should not manage.  This function
+ * reads the list of unmanaged devices from wherever the plugin wants to
+ * store them and returns that list to NetworkManager.
+ */
+static GSList *
+get_unmanaged_specs (NMSystemConfigInterface *config)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (config);
+	GKeyFile *key_file;
+	GSList *specs = NULL;
+	GError *error = NULL;
+	char *str, **macs;
+	int i;
+
+	if (!priv->conf_file)
+		return NULL;
+
+	key_file = g_key_file_new ();
+	if (!g_key_file_load_from_file (key_file, priv->conf_file, G_KEY_FILE_NONE, &error)) {
+		g_warning ("Error parsing file '%s': %s", priv->conf_file, error->message);
+		g_error_free (error);
+		goto out;
+	}
+
+
+	str = g_key_file_get_value (key_file, "keyfile", "unmanaged-devices", NULL);
+	if (!str)
+		goto out;
+
+	macs = g_strsplit (str, ";", -1);
+	for (i = 0; macs[i] != NULL; i++) {
+		/* Verify unmanaged specification and add it to the list */
+		if (strlen (macs[i]) > 4 && !strncmp (macs[i], "mac:", 4) && ether_aton (macs[i] + 4)) {
+			char *p = macs[i];
+
+			/* To accept uppercase MACs in configuration file, we have to
+			 * convert values to lowercase here. Unmanaged MACs in specs are
+			 * always in lowercase.
+			 */
+			while (*p) {
+				*p = g_ascii_tolower (*p);
+				p++;
+			}
+
+			specs = g_slist_append (specs, macs[i]);
+		} else {
+			g_warning ("Error in file '%s': invalid unmanaged-devices entry: '%s'", priv->conf_file, macs[i]);
+			g_free (macs[i]);
+		}
+	}
+
+	g_free (macs); /* Yes, g_free, not g_strfreev because we need the strings in the list */
+	g_free (str);
+
+out:
+	g_key_file_free (key_file);
+	return specs;
+}
+
+
+static char *
+plugin_get_hostname (SCPluginExample *plugin)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (plugin);
+	GKeyFile *key_file;
+	char *hostname = NULL;
+	GError *error = NULL;
+
+	if (!priv->conf_file)
+		return NULL;
+
+	/* Read the persistent hostname out of backing storage, which happens
+	 * to be the NM config file.  Other plugins (like distro-specific ones)
+	 * should read it from the distro-specific location like /etc/hostname.
+	 */
+	key_file = g_key_file_new ();
+	if (g_key_file_load_from_file (key_file, priv->conf_file, G_KEY_FILE_NONE, &error))
+		hostname = g_key_file_get_value (key_file, "keyfile", "hostname", NULL);
+	else {
+		g_warning ("Error parsing file '%s': %s", priv->conf_file, error->message);
+		g_error_free (error);
+	}
+
+	g_key_file_free (key_file);
+	return hostname;
+}
+
+static gboolean
+plugin_set_hostname (SCPluginExample *plugin, const char *hostname)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (plugin);
+	GKeyFile *key_file;
+	GError *error = NULL;
+	gboolean success = FALSE;
+	char *data;
+	gsize len;
+
+	if (!priv->conf_file) {
+		g_warning ("Error saving hostname: no config file");
+		return FALSE;
+	}
+
+	/* This just saves the hostname to the NM config file in a section
+	 * private to this plugin.
+	 */
+	key_file = g_key_file_new ();
+	if (!g_key_file_load_from_file (key_file, priv->conf_file, G_KEY_FILE_NONE, &error)) {
+		g_warning ("Error parsing file '%s': %s", priv->conf_file, error->message);
+		g_error_free (error);
+		goto out;
+	}
+
+	g_key_file_set_string (key_file, "example", "hostname", hostname);
+
+	data = g_key_file_to_data (key_file, &len, &error);
+	if (data) {
+		/* Save updated file to disk */
+		g_file_set_contents (priv->conf_file, data, len, &error);
+		g_free (data);
+
+		/* Update internal copy of hostname */
+		g_free (priv->hostname);
+		priv->hostname = g_strdup (hostname);
+		success = TRUE;
+	}
+
+	if (error) {
+		g_warning ("Error saving hostname: %s", error->message);
+		g_error_free (error);
+	}
+
+out:
+	g_key_file_free (key_file);
+	return success;
+}
+
+/* GObject */
+
+static void
+sc_plugin_example_init (SCPluginExample *plugin)
+{
+	/* Here we'd do any instance-specific initialization like setting
+	 * members of SCPluginExamplePrivate to default values.  But we
+	 * don't have anything to do here since most initialization is done
+	 * when NM calls the various entry points.
+	 */
+}
+
+static void
+get_property (GObject *object, guint prop_id,
+		    GValue *value, GParamSpec *pspec)
+{
+	switch (prop_id) {
+	case NM_SYSTEM_CONFIG_INTERFACE_PROP_NAME:
+		g_value_set_string (value, EXAMPLE_PLUGIN_NAME);
+		break;
+	case NM_SYSTEM_CONFIG_INTERFACE_PROP_INFO:
+		g_value_set_string (value, EXAMPLE_PLUGIN_INFO);
+		break;
+	case NM_SYSTEM_CONFIG_INTERFACE_PROP_CAPABILITIES:
+		/* Return capabilities to NM; this plugin supports changing connections
+		 * as well as being capable of saving the hostname to persistent storage.
+		 * If the plugin can't write out updated configuration, then obviously
+		 * it shouldn't advertise that capability.  If it can't save hostnames
+		 * to persistent storage, it shouldn't advertise that capability either.
+		 */
+		g_value_set_uint (value, NM_SYSTEM_CONFIG_INTERFACE_CAP_MODIFY_CONNECTIONS | 
+						  NM_SYSTEM_CONFIG_INTERFACE_CAP_MODIFY_HOSTNAME);
+		break;
+	case NM_SYSTEM_CONFIG_INTERFACE_PROP_HOSTNAME:
+		/* Return the hostname we've read from persistent storage */
+		g_value_set_string (value, SC_PLUGIN_EXAMPLE_GET_PRIVATE (object)->hostname);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+set_property (GObject *object, guint prop_id,
+			  const GValue *value, GParamSpec *pspec)
+{
+	const char *hostname;
+
+	switch (prop_id) {
+	case NM_SYSTEM_CONFIG_INTERFACE_PROP_HOSTNAME:
+		/* We'll get here when the user has changed the hostname via NM's
+		 * D-Bus interface and we're requested to save this hostname to
+		 * persistent storage.
+		 */
+		hostname = g_value_get_string (value);
+		if (hostname && strlen (hostname) < 1)
+			hostname = NULL;
+		plugin_set_hostname (SC_PLUGIN_EXAMPLE (object), hostname);
+		break;
+	default:
+		G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+		break;
+	}
+}
+
+static void
+dispose (GObject *object)
+{
+	SCPluginExamplePrivate *priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (object);
+
+	/* GObject has a two-stage object destruction process: dispose and finalize.
+	 * In dispose the object should free any references it might have on other
+	 * objects to break circular refs, then it's finally cleaned up by finalize.
+	 * We don't bother to implement a finalize, so we just make sure that we
+	 * clean everything up (including clearing pointers) in dispose so that
+	 * if GObject decides to revive this object post-dispose (yes, legal)
+	 * we don't crash on dangling pointers.
+	 */
+
+	if (priv->monitor) {
+		if (priv->monitor_id) {
+			g_signal_handler_disconnect (priv->monitor, priv->monitor_id);
+			priv->monitor_id = 0;
+		}
+
+		g_file_monitor_cancel (priv->monitor);
+		g_object_unref (priv->monitor);
+		priv->monitor = NULL;
+	}
+
+	if (priv->conf_file_monitor) {
+		if (priv->conf_file_monitor_id) {
+			g_signal_handler_disconnect (priv->conf_file_monitor, priv->conf_file_monitor_id);
+			priv->conf_file_monitor_id = 0;
+		}
+
+		g_file_monitor_cancel (priv->conf_file_monitor);
+		g_object_unref (priv->conf_file_monitor);
+		priv->conf_file_monitor = NULL;
+	}
+
+	if (priv->connections) {
+		/* Destroying the connections hash unrefs each connection in it
+		 * due to the GHashTable value_destroy_func that we passed into
+		 * g_hash_table_new_full().
+		 */
+		g_hash_table_destroy (priv->connections);
+		priv->connections = NULL;
+	}
+
+	g_free (priv->hostname);
+	priv->hostname = NULL;
+	g_free (priv->conf_file);
+	priv->conf_file = NULL;
+
+	/* Chain up to the superclass */
+	G_OBJECT_CLASS (sc_plugin_example_parent_class)->dispose (object);
+}
+
+/* This function gets called to set up any method and property overrides
+ * of superclasses, and also (if we actually had any) to set up any
+ * custom properties and signals this object might have.  This is called before
+ * the object is actually instantiated; it just sets up the generic class
+ * stuff, not anything related to a specific object instance.
+ */
+static void
+sc_plugin_example_class_init (SCPluginExampleClass *req_class)
+{
+	GObjectClass *object_class = G_OBJECT_CLASS (req_class);
+
+	/* This actually creates and zeros the object's instance data struct */
+	g_type_class_add_private (req_class, sizeof (SCPluginExamplePrivate));
+
+	/* Override GObject base class methods with our custom implementations */
+	object_class->dispose = dispose;
+	object_class->get_property = get_property;
+	object_class->set_property = set_property;
+
+	/* Override various GObject properties that we need to change.  Here we
+	 * just tell GObject that we will be handling the get/set operations for
+	 * these specific properties.  They are actually defined by the
+	 * NMSystemConfigInterface interface in nm-system-config-interface.c.
+	 * What happens here is that we tell GObject that for a given property
+	 * name (ie NM_SYSTEM_CONFIG_INTERFACE_NAME) we'll be using the enum value
+	 * NM_SYSTEM_CONFIG_INTERFACE_PROP_NAME locally in get_property() and
+	 * set_property().
+	 */
+	g_object_class_override_property (object_class,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_PROP_NAME,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_NAME);
+
+	g_object_class_override_property (object_class,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_PROP_INFO,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_INFO);
+
+	g_object_class_override_property (object_class,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_PROP_CAPABILITIES,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_CAPABILITIES);
+
+	g_object_class_override_property (object_class,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_PROP_HOSTNAME,
+	                                  NM_SYSTEM_CONFIG_INTERFACE_HOSTNAME);
+}
+
+static void
+system_config_interface_init (NMSystemConfigInterface *sci_intf)
+{
+	/* Interface implementation for NMSystemConfigInterface.  This sets
+	 * up the GInterface vtable that lets GObject know what functions to
+	 * call for each method of the NMSystemConfigInterface interface.
+	 */
+	sci_intf->get_connections = get_connections;
+	sci_intf->add_connection = add_connection;
+	sci_intf->get_unmanaged_specs = get_unmanaged_specs;
+}
+
+/*******************************************************************/
+
+/* Factory function: this is the first entry point for NetworkManager, which
+ * gets called during NM startup to create the the instance of this plugin
+ * that NetworkManager will actually use.  Since every plugin is a singleton
+ * we just return a singleton instance.  This function should never be called
+ * twice.
+ */
+G_MODULE_EXPORT GObject *
+nm_system_config_factory (const char *config_file)
+{
+	static SCPluginExample *singleton = NULL;
+	SCPluginExamplePrivate *priv;
+
+	if (!singleton) {
+		/* Instantiate our plugin */
+		singleton = SC_PLUGIN_EXAMPLE (g_object_new (SC_TYPE_PLUGIN_EXAMPLE, NULL));
+		if (singleton) {
+			priv = SC_PLUGIN_EXAMPLE_GET_PRIVATE (singleton);
+
+			/* Cache the config file path */
+			priv->conf_file = g_strdup (config_file);
+		}
+	} else {
+		/* This function should never be called twice */
+		g_assert_not_reached ();
+	}
+
+	return G_OBJECT (singleton);
+}
+