From e6f1871af73fe4315bfa5f37cb39a41c494e68a7 Mon Sep 17 00:00:00 2001
From: Bastien Nocera <hadess@hadess.net>
Date: Wed, 2 May 2018 11:47:34 +0200
Subject: [PATCH] service-client: Delay "no agent" authorization decision

To avoid applications being denied access to location services when
gnome-shell hasn't had a chance to register its agent, either because
Geoclue got auto-started by the application, or because the shell hasn't
finished starting up, delay the authorization check until either an
agent appears, or 5 seconds after the application requested the
authorization.

https://bugs.freedesktop.org/show_bug.cgi?id=106236
---
 src/gclue-service-client.c | 74 ++++++++++++++++++++++++++++++++++----
 1 file changed, 67 insertions(+), 7 deletions(-)

diff --git a/src/gclue-service-client.c b/src/gclue-service-client.c
index 03219ad..f7b428e 100644
--- a/src/gclue-service-client.c
+++ b/src/gclue-service-client.c
@@ -29,6 +29,7 @@
 #include "gclue-config.h"
 
 #define DEFAULT_ACCURACY_LEVEL GCLUE_ACCURACY_LEVEL_CITY
+#define DEFAULT_AGENT_STARTUP_WAIT_SECS 5
 
 static void
 gclue_service_client_client_iface_init (GClueDBusClientIface *iface);
@@ -49,6 +50,8 @@ struct _GClueServiceClientPrivate
         const char *path;
         GDBusConnection *connection;
         GClueAgent *agent_proxy;
+        gpointer pending_auth_start_data;
+        guint pending_auth_timeout_id;
 
         GClueServiceLocation *location;
         GClueServiceLocation *prev_location;
@@ -448,6 +451,56 @@ handle_post_agent_check_auth (StartData *data)
                                         data);
 }
 
+static gboolean
+handle_pending_auth (gpointer user_data)
+{
+        GClueServiceClientPrivate *priv = GCLUE_SERVICE_CLIENT (user_data)->priv;
+        StartData *data = priv->pending_auth_start_data;
+        guint32 uid;
+
+        uid = gclue_client_info_get_user_id (priv->client_info);
+        if (priv->agent_proxy == NULL) {
+                g_dbus_method_invocation_return_error (data->invocation,
+                                                       G_DBUS_ERROR,
+                                                       G_DBUS_ERROR_ACCESS_DENIED,
+                                                       "'%s' disallowed, no agent "
+                                                       "for UID %u",
+                                                       data->desktop_id,
+                                                       uid);
+                start_data_free (data);
+        } else {
+                handle_post_agent_check_auth (data);
+        }
+
+        priv->pending_auth_timeout_id = 0;
+        priv->pending_auth_start_data = NULL;
+
+        return G_SOURCE_REMOVE;
+}
+
+static void
+set_pending_auth_timeout_enable (GClueDBusClient *client)
+{
+        GClueServiceClientPrivate *priv = GCLUE_SERVICE_CLIENT (client)->priv;
+
+        if (priv->pending_auth_timeout_id > 0)
+                return;
+        priv->pending_auth_timeout_id = g_timeout_add_seconds
+                (DEFAULT_AGENT_STARTUP_WAIT_SECS, handle_pending_auth, client);
+}
+
+static void
+set_pending_auth_timeout_disable (GClueDBusClient *client)
+{
+        GClueServiceClientPrivate *priv = GCLUE_SERVICE_CLIENT (client)->priv;
+
+        if (priv->pending_auth_timeout_id == 0)
+                return;
+
+        g_source_remove (priv->pending_auth_timeout_id);
+        priv->pending_auth_timeout_id = 0;
+}
+
 static gboolean
 gclue_service_client_handle_start (GClueDBusClient       *client,
                                    GDBusMethodInvocation *invocation)
@@ -527,13 +580,17 @@ gclue_service_client_handle_start (GClueDBusClient       *client,
 
         /* No agent == No authorization */
         if (priv->agent_proxy == NULL) {
-                g_dbus_method_invocation_return_error (invocation,
-                                                       G_DBUS_ERROR,
-                                                       G_DBUS_ERROR_ACCESS_DENIED,
-                                                       "'%s' disallowed, no agent "
-                                                       "for UID %u",
-                                                       desktop_id,
-                                                       uid);
+                /* Already a pending Start()? Denied! */
+                if (priv->pending_auth_start_data) {
+                        g_dbus_method_invocation_return_error_literal
+                                (invocation,
+                                 G_DBUS_ERROR,
+                                 G_DBUS_ERROR_ACCESS_DENIED,
+                                 "An authorization request is already pending");
+                } else {
+                        priv->pending_auth_start_data = data;
+                        set_pending_auth_timeout_enable (client);
+                }
                 return TRUE;
         }
 
@@ -560,6 +617,8 @@ gclue_service_client_finalize (GObject *object)
 
         g_clear_pointer (&priv->path, g_free);
         g_clear_object (&priv->connection);
+        set_pending_auth_timeout_disable (GCLUE_DBUS_CLIENT (object));
+        g_clear_pointer (&priv->pending_auth_start_data, start_data_free);
         if (priv->agent_proxy != NULL)
                 g_signal_handlers_disconnect_by_func
                                 (priv->agent_proxy,
@@ -633,6 +692,7 @@ gclue_service_client_set_property (GObject      *object,
                                           "g-properties-changed",
                                           G_CALLBACK (on_agent_props_changed),
                                           object);
+                handle_pending_auth (client);
                 break;
 
         default:
-- 
2.17.0