core: move session monitor to core

We'll need it for agent authentication too, so move it out of
system settings specific code.

1 files changed, 521 insertions, 0 deletions

diff --git a/src/nm-session-monitor.c b/src/nm-session-monitor.c
new file mode 100644
index 0000000000..3bbdb9ed39
--- /dev/null
+++ b/src/nm-session-monitor.c
@@ -0,0 +1,521 @@
+/* -*- Mode: C; tab-width: 4; indent-tabs-mode: t; c-basic-offset: 4 -*- */
+/* 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 2008 - 2010 Red Hat, Inc.
+ * Author: David Zeuthen <davidz@redhat.com>
+ * Author: Dan Williams <dcbw@redhat.com>
+ */
+
+#include "config.h"
+#include <errno.h>
+#include <pwd.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <gio/gio.h>
+#include "nm-logging.h"
+
+#include "nm-session-monitor.h"
+
+#define CKDB_PATH "/var/run/ConsoleKit/database"
+
+/* <internal>
+ * SECTION:nm-session-monitor
+ * @title: NMSessionMonitor
+ * @short_description: Monitor sessions
+ *
+ * The #NMSessionMonitor class is a utility class to track and monitor sessions.
+ */
+
+struct _NMSessionMonitor {
+	GObject parent_instance;
+
+	GKeyFile *database;
+	GFileMonitor *database_monitor;
+	time_t database_mtime;
+	GHashTable *sessions_by_uid;
+	GHashTable *sessions_by_user;
+};
+
+struct _NMSessionMonitorClass {
+	GObjectClass parent_class;
+
+	void (*changed) (NMSessionMonitor *monitor);
+};
+
+
+enum {
+	CHANGED,
+	LAST_SIGNAL,
+};
+static guint signals[LAST_SIGNAL] = {0};
+
+G_DEFINE_TYPE (NMSessionMonitor, nm_session_monitor, G_TYPE_OBJECT);
+
+/********************************************************************/
+
+#define NM_SESSION_MONITOR_ERROR         (nm_session_monitor_error_quark ())
+GQuark nm_session_monitor_error_quark    (void) G_GNUC_CONST;
+GType  nm_session_monitor_error_get_type (void) G_GNUC_CONST;
+
+typedef enum {
+	NM_SESSION_MONITOR_ERROR_IO_ERROR = 0,
+	NM_SESSION_MONITOR_ERROR_MALFORMED_DATABASE,
+	NM_SESSION_MONITOR_ERROR_UNKNOWN_USER,
+} NMSessionMonitorError;
+
+GQuark
+nm_session_monitor_error_quark (void)
+{
+	static GQuark ret = 0;
+
+	if (G_UNLIKELY (ret == 0))
+		ret = g_quark_from_static_string ("nm-session-monitor-error");
+	return ret;
+}
+
+#define ENUM_ENTRY(NAME, DESC) { NAME, "" #NAME "", DESC }
+
+GType
+nm_session_monitor_error_get_type (void)
+{
+	static GType etype = 0;
+
+	if (etype == 0) {
+		static const GEnumValue values[] = {
+			/* Some I/O operation on the CK database failed */
+			ENUM_ENTRY (NM_SESSION_MONITOR_ERROR_IO_ERROR, "IOError"),
+			/* Error parsing the CK database */
+			ENUM_ENTRY (NM_SESSION_MONITOR_ERROR_MALFORMED_DATABASE, "MalformedDatabase"),
+			/* Username or UID could could not be found */
+			ENUM_ENTRY (NM_SESSION_MONITOR_ERROR_UNKNOWN_USER, "UnknownUser"),
+			{ 0, 0, 0 }
+		};
+
+		etype = g_enum_register_static ("NMSessionMonitorError", values);
+	}
+	return etype;
+}
+/********************************************************************/
+
+typedef struct {
+	char *user;
+	uid_t uid;
+	gboolean local;
+	gboolean active;
+} Session;
+
+static void
+session_free (Session *s)
+{
+	g_free (s->user);
+	memset (s, 0, sizeof (Session));
+	g_free (s);
+}
+
+static gboolean
+check_key (GKeyFile *keyfile, const char *group, const char *key, GError **error)
+{
+	if (g_key_file_has_key (keyfile, group, key, error))
+		return TRUE;
+
+	if (!error) {
+		g_set_error (error,
+			         NM_SESSION_MONITOR_ERROR,
+			         NM_SESSION_MONITOR_ERROR_MALFORMED_DATABASE,
+			         "ConsoleKit database " CKDB_PATH " group '%s' had no '%s' key",
+			         group, key);
+	}
+	return FALSE;
+}
+
+static Session *
+session_new (GKeyFile *keyfile, const char *group, GError **error)
+{
+	Session *s;
+	struct passwd *pw;
+
+	s = g_new0 (Session, 1);
+	g_assert (s);
+
+	if (!check_key (keyfile, group, "uid", error))
+		return FALSE;
+	s->uid = (uid_t) g_key_file_get_integer (keyfile, group, "uid", error);
+	if (error)
+		goto error;
+
+	if (!check_key (keyfile, group, "is_active", error))
+		return FALSE;
+	s->active = g_key_file_get_boolean (keyfile, group, "is_active", error);
+	if (error)
+		goto error;
+
+	if (!check_key (keyfile, group, "is_local", error))
+		return FALSE;
+	s->local = g_key_file_get_boolean (keyfile, group, "is_local", error);
+	if (error)
+		goto error;
+
+	pw = getpwuid (s->uid);
+	if (!pw) {
+		g_set_error (error,
+			         NM_SESSION_MONITOR_ERROR,
+			         NM_SESSION_MONITOR_ERROR_UNKNOWN_USER,
+			         "Could not get username for UID %d",
+			         s->uid);
+		goto error;
+	}
+	s->user = g_strdup (pw->pw_name);
+
+	return s;
+
+error:
+	session_free (s);
+	return NULL;
+}
+
+/********************************************************************/
+
+static void
+free_database (NMSessionMonitor *self)
+{
+	if (self->database != NULL) {
+		g_key_file_free (self->database);
+		self->database = NULL;
+	}
+
+	g_hash_table_remove_all (self->sessions_by_uid);
+	g_hash_table_remove_all (self->sessions_by_user);
+}
+
+static gboolean
+reload_database (NMSessionMonitor *self, GError **error)
+{
+	struct stat statbuf;
+	char **groups;
+	gsize len = 0, i;
+	Session *s;
+
+	free_database (self);
+
+	if (stat (CKDB_PATH, &statbuf) != 0) {
+		g_set_error (error,
+		             NM_SESSION_MONITOR_ERROR,
+		             NM_SESSION_MONITOR_ERROR_IO_ERROR,
+		             "Error statting file " CKDB_PATH ": %s",
+		             strerror (errno));
+		goto error;
+	}
+	self->database_mtime = statbuf.st_mtime;
+
+	self->database = g_key_file_new ();
+	if (!g_key_file_load_from_file (self->database, CKDB_PATH, G_KEY_FILE_NONE, error))
+		goto error;
+
+	groups = g_key_file_get_groups (self->database, &len);
+	if (!groups) {
+		g_set_error_literal (error,
+		                     NM_SESSION_MONITOR_ERROR,
+		                     NM_SESSION_MONITOR_ERROR_IO_ERROR,
+		                     "Could not load groups from " CKDB_PATH "");
+		goto error;
+	}
+
+	for (i = 0; i < len; i++) {
+		if (!g_str_has_prefix (groups[i], "Session "))
+			continue;
+
+		s = session_new (self->database, groups[i], error);
+		if (!s)
+			goto error;
+		g_hash_table_insert (self->sessions_by_user, (gpointer) s->user, s);
+		g_hash_table_insert (self->sessions_by_uid, GUINT_TO_POINTER (s->uid), s);
+	}
+
+	g_strfreev (groups);
+	return TRUE;
+
+error:
+	if (groups)
+		g_strfreev (groups);
+	free_database (self);
+	return FALSE;
+}
+
+static gboolean
+ensure_database (NMSessionMonitor *self, GError **error)
+{
+	gboolean ret = FALSE;
+
+	if (self->database != NULL) {
+		struct stat statbuf;
+
+		if (stat (CKDB_PATH, &statbuf) != 0) {
+			g_set_error (error,
+			             NM_SESSION_MONITOR_ERROR,
+			             NM_SESSION_MONITOR_ERROR_IO_ERROR,
+			             "Error statting file " CKDB_PATH " to check timestamp: %s",
+			             strerror (errno));
+			goto out;
+		}
+
+		if (statbuf.st_mtime == self->database_mtime) {
+			ret = TRUE;
+			goto out;
+		}
+	}
+
+	ret = reload_database (self, error);
+
+out:
+	return ret;
+}
+
+static void
+on_file_monitor_changed (GFileMonitor *    file_monitor,
+                         GFile *           file,
+                         GFile *           other_file,
+                         GFileMonitorEvent event_type,
+                         gpointer          user_data)
+{
+	NMSessionMonitor *self = NM_SESSION_MONITOR (user_data);
+
+	/* throw away cache */
+	free_database (self);
+
+	g_signal_emit (self, signals[CHANGED], 0);
+}
+
+static void
+nm_session_monitor_init (NMSessionMonitor *self)
+{
+	GError *error = NULL;
+	GFile *file;
+
+	/* Sessions-by-user is responsible for destroying the Session objects */
+	self->sessions_by_user = g_hash_table_new_full (g_str_hash, g_str_equal,
+	                                                NULL, (GDestroyNotify) session_free);
+	self->sessions_by_uid = g_hash_table_new (g_direct_hash, g_direct_equal);
+
+
+	error = NULL;
+	if (!ensure_database (self, &error)) {
+		nm_log_err (LOGD_SYS_SET, "Error loading " CKDB_PATH ": %s", error->message);
+		g_error_free (error);
+	}
+
+	error = NULL;
+	file = g_file_new_for_path (CKDB_PATH);
+	self->database_monitor = g_file_monitor_file (file, G_FILE_MONITOR_NONE, NULL, &error);
+	g_object_unref (file);
+	if (self->database_monitor == NULL) {
+		nm_log_err (LOGD_SYS_SET, "Error monitoring " CKDB_PATH ": %s", error->message);
+		g_error_free (error);
+	} else {
+		g_signal_connect (self->database_monitor,
+		                  "changed",
+		                  G_CALLBACK (on_file_monitor_changed),
+		                  self);
+	}
+}
+
+static void
+finalize (GObject *object)
+{
+	NMSessionMonitor *self = NM_SESSION_MONITOR (object);
+
+	if (self->database_monitor != NULL)
+		g_object_unref (self->database_monitor);
+
+	free_database (self);
+
+	if (G_OBJECT_CLASS (nm_session_monitor_parent_class)->finalize != NULL)
+		G_OBJECT_CLASS (nm_session_monitor_parent_class)->finalize (object);
+}
+
+static void
+nm_session_monitor_class_init (NMSessionMonitorClass *klass)
+{
+	GObjectClass *gobject_class;
+
+	gobject_class = G_OBJECT_CLASS (klass);
+
+	gobject_class->finalize = finalize;
+
+	/**
+	 * NMSessionMonitor::changed:
+	 * @monitor: A #NMSessionMonitor
+	 *
+	 * Emitted when something changes.
+	 */
+	signals[CHANGED] = g_signal_new ("changed",
+	                                 NM_TYPE_SESSION_MONITOR,
+	                                 G_SIGNAL_RUN_LAST,
+	                                 G_STRUCT_OFFSET (NMSessionMonitorClass, changed),
+	                                 NULL,                   /* accumulator      */
+	                                 NULL,                   /* accumulator data */
+	                                 g_cclosure_marshal_VOID__VOID,
+	                                 G_TYPE_NONE, 0);
+}
+
+NMSessionMonitor *
+nm_session_monitor_get (void)
+{
+	static NMSessionMonitor *singleton = NULL;
+
+	if (singleton)
+		return NM_SESSION_MONITOR (g_object_ref (singleton));
+
+	return NM_SESSION_MONITOR (g_object_new (NM_TYPE_SESSION_MONITOR, NULL));
+}
+
+/* ---------------------------------------------------------------------------------------------------- */
+
+/**
+ * nm_session_monitor_user_has_session:
+ * @monitor: A #NMSessionMonitor.
+ * @username: A username.
+ * @error: Return location for error.
+ *
+ * Checks whether the given @username is logged into a session or not.
+ *
+ * Returns: %FALSE if @error is set otherwise %TRUE if the given @username is
+ * currently logged into a session.
+ */
+gboolean
+nm_session_monitor_user_has_session (NMSessionMonitor *monitor,
+                                     const char *username,
+                                     GError **error)
+{
+	Session *s;
+
+	if (!ensure_database (monitor, error))
+		return FALSE;
+
+	s = g_hash_table_lookup (monitor->sessions_by_user, (gpointer) username);
+	if (!s) {
+		g_set_error (error,
+		             NM_SESSION_MONITOR_ERROR,
+		             NM_SESSION_MONITOR_ERROR_UNKNOWN_USER,
+		             "No session found for user '%s'",
+		             username);
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+/**
+ * nm_session_monitor_uid_has_session:
+ * @monitor: A #NMSessionMonitor.
+ * @uid: A user ID.
+ * @error: Return location for error.
+ *
+ * Checks whether the given @uid is logged into a session or not.
+ *
+ * Returns: %FALSE if @error is set otherwise %TRUE if the given @uid is
+ * currently logged into a session.
+ */
+gboolean
+nm_session_monitor_uid_has_session (NMSessionMonitor *monitor,
+                                    uid_t uid,
+                                    GError **error)
+{
+	Session *s;
+
+	if (!ensure_database (monitor, error))
+		return FALSE;
+
+	s = g_hash_table_lookup (monitor->sessions_by_uid, GUINT_TO_POINTER (uid));
+	if (!s) {
+		g_set_error (error,
+		             NM_SESSION_MONITOR_ERROR,
+		             NM_SESSION_MONITOR_ERROR_UNKNOWN_USER,
+		             "No session found for uid %d",
+		             uid);
+		return FALSE;
+	}
+
+	return TRUE;
+}
+
+/**
+ * nm_session_monitor_user_active:
+ * @monitor: A #NMSessionMonitor.
+ * @username: A username.
+ * @error: Return location for error.
+ *
+ * Checks whether the given @username is logged into a active session or not.
+ *
+ * Returns: %FALSE if @error is set otherwise %TRUE if the given @username is
+ * logged into an active session.
+ */
+gboolean
+nm_session_monitor_user_active (NMSessionMonitor *monitor,
+                                const char *username,
+                                GError **error)
+{
+	Session *s;
+
+	if (!ensure_database (monitor, error))
+		return FALSE;
+
+	s = g_hash_table_lookup (monitor->sessions_by_user, (gpointer) username);
+	if (!s) {
+		g_set_error (error,
+		             NM_SESSION_MONITOR_ERROR,
+		             NM_SESSION_MONITOR_ERROR_UNKNOWN_USER,
+		             "No session found for user '%s'",
+		             username);
+		return FALSE;
+	}
+
+	return s->active;
+}
+
+/**
+ * nm_session_monitor_uid_active:
+ * @monitor: A #NMSessionMonitor.
+ * @uid: A user ID.
+ * @error: Return location for error.
+ *
+ * Checks whether the given @uid is logged into a active session or not.
+ *
+ * Returns: %FALSE if @error is set otherwise %TRUE if the given @uid is
+ * logged into an active session.
+ */
+gboolean
+nm_session_monitor_uid_active (NMSessionMonitor *monitor,
+                               uid_t uid,
+                               GError **error)
+{
+	Session *s;
+
+	if (!ensure_database (monitor, error))
+		return FALSE;
+
+	s = g_hash_table_lookup (monitor->sessions_by_uid, GUINT_TO_POINTER (uid));
+	if (!s) {
+		g_set_error (error,
+		             NM_SESSION_MONITOR_ERROR,
+		             NM_SESSION_MONITOR_ERROR_UNKNOWN_USER,
+		             "No session found for uid '%d'",
+		             uid);
+		return FALSE;
+	}
+
+	return s->active;
+}
+