New upstream version 1.29.90 upstream/1.29.90

1 files changed, 501 insertions, 0 deletions

diff --git a/src/core/nm-keep-alive.c b/src/core/nm-keep-alive.c
new file mode 100644
index 00000000..197e30ea
--- /dev/null
+++ b/src/core/nm-keep-alive.c
@@ -0,0 +1,501 @@
+/* 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);
+}