/* SPDX-License-Identifier: LGPL-2.1-or-later */
/*
* Copyright (C) 2018 Red Hat, Inc.
*/
#include "src/core/nm-default-daemon.h"
#include "nm-keep-alive.h"
#include "settings/nm-settings-connection.h"
#include "nm-glib-aux/nm-dbus-aux.h"
/*****************************************************************************/
NM_GOBJECT_PROPERTIES_DEFINE(NMKeepAlive, PROP_ALIVE, );
typedef struct {
GObject *owner;
NMSettingsConnection *connection;
GDBusConnection * dbus_connection;
char * dbus_client;
GCancellable *dbus_client_confirm_cancellable;
guint subscription_id;
bool armed : 1;
bool disarmed : 1;
bool alive : 1;
bool dbus_client_confirmed : 1;
bool dbus_client_watching : 1;
bool connection_was_visible : 1;
} NMKeepAlivePrivate;
struct _NMKeepAlive {
GObject parent;
NMKeepAlivePrivate _priv;
};
struct _NMKeepAliveClass {
GObjectClass parent;
};
G_DEFINE_TYPE(NMKeepAlive, nm_keep_alive, G_TYPE_OBJECT)
#define NM_KEEP_ALIVE_GET_PRIVATE(self) _NM_GET_PRIVATE(self, NMKeepAlive, NM_IS_KEEP_ALIVE)
/*****************************************************************************/
#define _NMLOG_DOMAIN LOGD_CORE
#define _NMLOG(level, ...) __NMLOG_DEFAULT(level, _NMLOG_DOMAIN, "keep-alive", __VA_ARGS__)
/*****************************************************************************/
static gboolean _is_alive_dbus_client(NMKeepAlive *self);
static void cleanup_dbus_watch(NMKeepAlive *self);
/*****************************************************************************/
static gboolean
_is_alive(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
nm_assert(!priv->disarmed);
if (!priv->armed) {
/* before arming, the instance is always alive. */
return TRUE;
}
if (priv->dbus_client_watching) {
if (_is_alive_dbus_client(self)) {
/* no matter what, the keep-alive is alive, because there is a D-Bus client
* still around keeping it alive. */
return TRUE;
}
/* the D-Bus client is gone. The only other binding (below) for the connection's
* visibility cannot keep the instance alive.
*
* As such, a D-Bus client watch is authoritative and overrules other conditions (that
* we have so far). */
return FALSE;
}
if (priv->connection && priv->connection_was_visible
&& !NM_FLAGS_HAS(nm_settings_connection_get_flags(priv->connection),
NM_SETTINGS_CONNECTION_INT_FLAGS_VISIBLE)) {
/* note that we only declare the keep-alive as dead due to invisible
* connection, if
* (1) we monitor a connection, obviously
* (2) the connection was visible earlier and is no longer. It was
* was invisible all the time, it does not suffice.
*/
return FALSE;
}
/* by default, the instance is alive. */
return TRUE;
}
static void
_notify_alive(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (priv->disarmed) {
/* once disarmed, the alive state is frozen. */
return;
}
if (priv->alive == _is_alive(self))
return;
priv->alive = !priv->alive;
_LOGD("instance is now %s", priv->alive ? "alive" : "dead");
_notify(self, PROP_ALIVE);
}
gboolean
nm_keep_alive_is_alive(NMKeepAlive *self)
{
return NM_KEEP_ALIVE_GET_PRIVATE(self)->alive;
}
/*****************************************************************************/
static void
connection_flags_changed(NMSettingsConnection *connection, NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (!priv->connection_was_visible
&& NM_FLAGS_HAS(nm_settings_connection_get_flags(priv->connection),
NM_SETTINGS_CONNECTION_INT_FLAGS_VISIBLE)) {
/* the profile was never visible but now it becomes visible.
* Remember that.
*
* Before this happens (that is, if the device was invisible all along),
* the keep alive instance is considered alive (w.r.t. watching the connection).
*
* The reason is to allow a user to manually activate an invisible profile and keep
* it alive. At least, as long until the user logs out the first time (which is the
* first time, the profiles changes from visible to invisible).
*
* Yes, that is odd. How to improve? */
priv->connection_was_visible = TRUE;
}
_notify_alive(self);
}
static void
_set_settings_connection_watch_visible(NMKeepAlive * self,
NMSettingsConnection *connection,
gboolean emit_signal)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
gs_unref_object NMSettingsConnection *old_connection = NULL;
if (priv->connection == connection)
return;
if (priv->connection) {
g_signal_handlers_disconnect_by_func(priv->connection,
G_CALLBACK(connection_flags_changed),
self);
old_connection = g_steal_pointer(&priv->connection);
}
if (connection && !priv->disarmed) {
priv->connection = g_object_ref(connection);
priv->connection_was_visible =
NM_FLAGS_HAS(nm_settings_connection_get_flags(priv->connection),
NM_SETTINGS_CONNECTION_INT_FLAGS_VISIBLE);
g_signal_connect(priv->connection,
NM_SETTINGS_CONNECTION_FLAGS_CHANGED,
G_CALLBACK(connection_flags_changed),
self);
}
if (emit_signal)
_notify_alive(self);
}
void
nm_keep_alive_set_settings_connection_watch_visible(NMKeepAlive * self,
NMSettingsConnection *connection)
{
_set_settings_connection_watch_visible(self, connection, TRUE);
}
/*****************************************************************************/
static void
get_name_owner_cb(const char *name_owner, GError *error, gpointer user_data)
{
NMKeepAlive * self;
NMKeepAlivePrivate *priv;
if (!name_owner && g_error_matches(error, G_IO_ERROR, G_IO_ERROR_CANCELLED))
return;
self = user_data;
priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (name_owner && nm_streq(name_owner, priv->dbus_client)) {
/* all good, the name is confirmed. */
return;
}
_LOGD("DBus client for keep alive is not on the bus");
cleanup_dbus_watch(self);
_notify_alive(self);
}
static gboolean
_is_alive_dbus_client(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (!priv->dbus_client)
return FALSE;
if (!priv->dbus_client_confirmed) {
/* it's unconfirmed that the D-Bus client is really alive.
* It looks like it is, but as we are claiming that to be
* the case, issue an async GetNameOwner call to make sure. */
priv->dbus_client_confirmed = TRUE;
priv->dbus_client_confirm_cancellable = g_cancellable_new();
nm_dbus_connection_call_get_name_owner(priv->dbus_connection,
priv->dbus_client,
-1,
priv->dbus_client_confirm_cancellable,
get_name_owner_cb,
self);
}
return TRUE;
}
static void
cleanup_dbus_watch(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (!priv->dbus_client)
return;
_LOGD("Cleanup DBus client watch");
nm_clear_g_cancellable(&priv->dbus_client_confirm_cancellable);
nm_clear_g_free(&priv->dbus_client);
if (priv->dbus_connection) {
g_dbus_connection_signal_unsubscribe(priv->dbus_connection,
nm_steal_int(&priv->subscription_id));
g_clear_object(&priv->dbus_connection);
}
}
static void
name_owner_changed_cb(GDBusConnection *connection,
const char * sender_name,
const char * object_path,
const char * interface_name,
const char * signal_name,
GVariant * parameters,
gpointer user_data)
{
NMKeepAlive *self = NM_KEEP_ALIVE(user_data);
const char * old_owner;
const char * new_owner;
g_variant_get(parameters, "(&s&s&s)", NULL, &old_owner, &new_owner);
if (!nm_streq0(new_owner, ""))
return;
_LOGD("DBus client for keep alive disappeared from bus");
cleanup_dbus_watch(self);
_notify_alive(self);
}
void
nm_keep_alive_set_dbus_client_watch(NMKeepAlive * self,
GDBusConnection *connection,
const char * client_address)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (priv->disarmed)
return;
cleanup_dbus_watch(self);
if (client_address) {
_LOGD("Registering dbus client watch for keep alive");
priv->dbus_client = g_strdup(client_address);
priv->dbus_client_watching = TRUE;
priv->dbus_client_confirmed = FALSE;
priv->dbus_connection = g_object_ref(connection);
priv->subscription_id =
nm_dbus_connection_signal_subscribe_name_owner_changed(priv->dbus_connection,
priv->dbus_client,
name_owner_changed_cb,
self,
NULL);
} else
priv->dbus_client_watching = FALSE;
_notify_alive(self);
}
/*****************************************************************************/
/**
* nm_keep_alive_arm:
* @self: the #NMKeepAlive
*
* A #NMKeepAlive instance is unarmed by default. That means, it's
* alive and stays alive until being armed. Arming means, that the conditions
* start to be actively evaluated, that the alive state may change, and
* that property changed signals are emitted.
*
* The opposite is nm_keep_alive_disarm() which freezes the alive state
* for good. Once disarmed, the instance cannot be armed again. Arming an
* instance multiple times has no effect. Arming an already disarmed instance
* also has no effect. */
void
nm_keep_alive_arm(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
if (!priv->armed) {
priv->armed = TRUE;
_notify_alive(self);
}
}
/**
* nm_keep_alive_disarm:
* @self: the #NMKeepAlive instance
*
* Once the instance is disarmed, it will not change its alive state
* anymore and will not emit anymore property changed signals about
* alive state changed.
*
* As such, it will also free internal resources (since they no longer
* affect the externally visible state).
*
* Once disarmed, the instance is frozen and cannot change anymore.
*/
void
nm_keep_alive_disarm(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
priv->disarmed = TRUE;
/* release internal data. */
_set_settings_connection_watch_visible(self, NULL, FALSE);
cleanup_dbus_watch(self);
}
/**
* nm_keep_alive_destroy:
* @self: (allow-none): the #NMKeepAlive instance to destroy.
*
* This does 3 things in one:
*
* - set owner to %NULL
* - disarm the instance.
* - unref @self.
*/
void
nm_keep_alive_destroy(NMKeepAlive *self)
{
if (!self)
return;
_nm_keep_alive_set_owner(self, NULL);
nm_keep_alive_disarm(self);
g_object_unref(self);
}
/*****************************************************************************/
static void
get_property(GObject *object, guint prop_id, GValue *value, GParamSpec *pspec)
{
NMKeepAlive *self = NM_KEEP_ALIVE(object);
switch (prop_id) {
case PROP_ALIVE:
g_value_set_boolean(value, nm_keep_alive_is_alive(self));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
break;
}
}
/*****************************************************************************/
/**
* nm_keep_alive_get_owner:
* @self: the #NMKeepAlive
*
* Returns: the owner instance associated with this @self. This commonly
* is set to be the target instance, which @self guards for being alive.
* Returns a gpointer, but of course it's some GObject instance. */
gpointer /* GObject * */
nm_keep_alive_get_owner(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
nm_assert(!priv->owner || G_IS_OBJECT(priv->owner));
return priv->owner;
}
/**
* _nm_keep_alive_set_owner:
* @self: the #NMKeepAlive
* @owner: the owner to set or unset.
*
* Sets or unsets the owner instance. Think of the owner the target
* instance that is guarded by @self. It's the responsibility of the
* owner to set and properly unset this pointer. As the owner also
* controls the lifetime of the NMKeepAlive instance.
*
* This API is not to be called by everybody, but only the owner of
* @self.
*/
void
_nm_keep_alive_set_owner(NMKeepAlive *self, GObject *owner)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
nm_assert(!owner || G_IS_OBJECT(owner));
/* it's bad style to reset the owner object. You are supposed to
* set it once, and clear it once. That's it. */
nm_assert(!owner || !priv->owner);
/* optimally, we would take a reference to @owner. But the
* owner already owns a reference to the keep-alive, so we cannot
* just own a reference back.
*
* We could register a weak-pointer here. But instead, declare that
* owner is required to set itself as owner when creating the
* keep-alive instance, and unset itself when it lets go of the
* keep-alive instance (at latest, when the owner itself gets destroyed).
*/
priv->owner = owner;
}
/*****************************************************************************/
static void
nm_keep_alive_init(NMKeepAlive *self)
{
NMKeepAlivePrivate *priv = NM_KEEP_ALIVE_GET_PRIVATE(self);
priv->alive = TRUE;
nm_assert(priv->alive == _is_alive(self));
}
NMKeepAlive *
nm_keep_alive_new(void)
{
return g_object_new(NM_TYPE_KEEP_ALIVE, NULL);
}
static void
dispose(GObject *object)
{
NMKeepAlive *self = NM_KEEP_ALIVE(object);
nm_assert(!NM_KEEP_ALIVE_GET_PRIVATE(self)->owner);
/* disarm also happens to free all resources. */
nm_keep_alive_disarm(self);
}
static void
nm_keep_alive_class_init(NMKeepAliveClass *keep_alive_class)
{
GObjectClass *object_class = G_OBJECT_CLASS(keep_alive_class);
object_class->get_property = get_property;
object_class->dispose = dispose;
obj_properties[PROP_ALIVE] = g_param_spec_string(NM_KEEP_ALIVE_ALIVE,
"",
"",
NULL,
G_PARAM_READABLE | G_PARAM_STATIC_STRINGS);
g_object_class_install_properties(object_class, _PROPERTY_ENUMS_LAST, obj_properties);
}