Negotiate UNIX file descriptor passing

We actually don't support this yet, this commit is only the authentication bits.

6 files changed, 188 insertions, 13 deletions

diff --git a/docs/reference/gdbus/gdbus-standalone-sections.txt b/docs/reference/gdbus/gdbus-standalone-sections.txt
index 783499e..a2d0819 100644
--- a/docs/reference/gdbus/gdbus-standalone-sections.txt
+++ b/docs/reference/gdbus/gdbus-standalone-sections.txt
@@ -88,6 +88,8 @@ g_dbus_connection_new_sync
 g_dbus_connection_new_for_address
 g_dbus_connection_new_for_address_finish
 g_dbus_connection_new_for_address_sync
+GDBusConnectionCapabilityFlags
+g_dbus_connection_get_capabilities
 g_dbus_connection_close
 g_dbus_connection_is_closed
 g_dbus_connection_get_exit_on_close
diff --git a/gdbus/gdbusauth.c b/gdbus/gdbusauth.c
index 9d361e9..6ccae42 100644
--- a/gdbus/gdbusauth.c
+++ b/gdbus/gdbusauth.c
@@ -347,11 +347,14 @@ typedef enum
 {
   CLIENT_STATE_WAITING_FOR_DATA,
   CLIENT_STATE_WAITING_FOR_OK,
-  CLIENT_STATE_WAITING_FOR_REJECT
+  CLIENT_STATE_WAITING_FOR_REJECT,
+  CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD
 } ClientState;
 
 gchar *
 _g_dbus_auth_run_client (GDBusAuth     *auth,
+                         GDBusConnectionCapabilityFlags offered_capabilities,
+                         GDBusConnectionCapabilityFlags *out_negotiated_capabilities,
                          GCancellable  *cancellable,
                          GError       **error)
 {
@@ -364,11 +367,13 @@ _g_dbus_auth_run_client (GDBusAuth     *auth,
   GPtrArray *attempted_auth_mechs;
   GDBusAuthMechanism *mech;
   ClientState state;
+  GDBusConnectionCapabilityFlags negotiated_capabilities;
 
   ret_guid = NULL;
   supported_auth_mechs = NULL;
   attempted_auth_mechs = g_ptr_array_new ();
   mech = NULL;
+  negotiated_capabilities = 0;
 
   dis = G_DATA_INPUT_STREAM (g_data_input_stream_new (g_io_stream_get_input_stream (auth->priv->stream)));
   dos = G_DATA_OUTPUT_STREAM (g_data_output_stream_new (g_io_stream_get_output_stream (auth->priv->stream)));
@@ -447,10 +452,19 @@ _g_dbus_auth_run_client (GDBusAuth     *auth,
               ret_guid = g_strdup (line + 3);
               g_free (line);
 
-              if (!g_data_output_stream_put_string (dos, "BEGIN\r\n", cancellable, error))
-                goto out;
-
-              goto out;
+              if (offered_capabilities & G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING)
+                {
+                  if (!g_data_output_stream_put_string (dos, "NEGOTIATE_UNIX_FD\r\n", cancellable, error))
+                    goto out;
+                  state = CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD;
+                }
+              else
+                {
+                  if (!g_data_output_stream_put_string (dos, "BEGIN\r\n", cancellable, error))
+                    goto out;
+                  /* and we're done! */
+                  goto out;
+                }
             }
           else if (g_str_has_prefix (line, "REJECTED "))
             {
@@ -469,6 +483,40 @@ _g_dbus_auth_run_client (GDBusAuth     *auth,
             }
           break;
 
+        case CLIENT_STATE_WAITING_FOR_AGREE_UNIX_FD:
+          line = g_data_input_stream_read_line (dis, &line_length, cancellable, error);
+          if (line == NULL)
+            goto out;
+          if (g_strcmp0 (line, "AGREE_UNIX_FD") == 0)
+            {
+              negotiated_capabilities |= G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING;
+              if (!g_data_output_stream_put_string (dos, "BEGIN\r\n", cancellable, error))
+                goto out;
+              /* and we're done! */
+              goto out;
+            }
+          else if (g_str_has_prefix (line, "ERROR") && (line[5] == 0 || g_ascii_isspace (line[5])))
+            {
+              //g_strstrip (line + 5); g_debug ("bah, no unix_fd: `%s'", line + 5);
+              g_free (line);
+              if (!g_data_output_stream_put_string (dos, "BEGIN\r\n", cancellable, error))
+                goto out;
+              /* and we're done! */
+              goto out;
+            }
+          else
+            {
+              /* TODO: handle other valid responses */
+              g_set_error (error,
+                           G_IO_ERROR,
+                           G_IO_ERROR_FAILED,
+                           "In WaitingForAgreeUnixFd: unexpected response `%s'",
+                           line);
+              g_free (line);
+              goto out;
+            }
+          break;
+
         case CLIENT_STATE_WAITING_FOR_DATA:
           /* TODO: handle */
           g_assert_not_reached ();
@@ -488,6 +536,20 @@ _g_dbus_auth_run_client (GDBusAuth     *auth,
   g_strfreev (supported_auth_mechs);
   g_object_ref (dis);
   g_object_ref (dos);
+
+  /* ensure return value is NULL if error is set */
+  if (error != NULL && *error != NULL)
+    {
+      g_free (ret_guid);
+      ret_guid = NULL;
+    }
+
+  if (ret_guid != NULL)
+    {
+      if (out_negotiated_capabilities != NULL)
+        *out_negotiated_capabilities = negotiated_capabilities;
+    }
+
   return ret_guid;
 }
 
@@ -538,6 +600,8 @@ gboolean
 _g_dbus_auth_run_server (GDBusAuth     *auth,
                          const gchar   *guid,
                          gboolean       allow_anonymous,
+                         GDBusConnectionCapabilityFlags offered_capabilities,
+                         GDBusConnectionCapabilityFlags *out_negotiated_capabilities,
                          GCancellable  *cancellable,
                          GError       **error)
 {
@@ -551,11 +615,13 @@ _g_dbus_auth_run_server (GDBusAuth     *auth,
   gsize line_length;
   GDBusAuthMechanism *mech;
   gchar *s;
+  GDBusConnectionCapabilityFlags negotiated_capabilities;
 
   ret = FALSE;
   dis = NULL;
   dos = NULL;
   mech = NULL;
+  negotiated_capabilities = 0;
 
   if (!g_dbus_is_guid (guid))
     {
@@ -760,16 +826,28 @@ _g_dbus_auth_run_server (GDBusAuth     *auth,
               g_free (line);
               goto out;
             }
+          else if (g_strcmp0 (line, "NEGOTIATE_UNIX_FD") == 0)
+            {
+              if (offered_capabilities & G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING)
+                {
+                  negotiated_capabilities |= G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING;
+                  if (!g_data_output_stream_put_string (dos, "AGREE_UNIX_FD\r\n", cancellable, error))
+                    goto out;
+                }
+              else
+                {
+                  if (!g_data_output_stream_put_string (dos, "ERROR \"fd passing not offered\"\r\n", cancellable, error))
+                    goto out;
+                }
+            }
           else
             {
-              g_set_error (error,
-                           G_IO_ERROR,
-                           G_IO_ERROR_FAILED,
-                           "Unexpected line `%s' while in WaitingForBegin state",
-                           line);
+              g_debug ("Unexpected line `%s' while in WaitingForBegin state", line);
               g_free (line);
+              if (!g_data_output_stream_put_string (dos, "ERROR \"Unknown Command\"\r\n", cancellable, error))
+                goto out;
             }
-          goto out;
+          break;
 
         default:
           g_assert_not_reached ();
@@ -790,6 +868,19 @@ _g_dbus_auth_run_server (GDBusAuth     *auth,
     g_object_ref (dis);
   if (dis != NULL)
     g_object_ref (dos);
+
+  /* ensure return value is FALSE if error is set */
+  if (error != NULL && *error != NULL)
+    {
+      ret = FALSE;
+    }
+
+  if (ret)
+    {
+      if (out_negotiated_capabilities != NULL)
+        *out_negotiated_capabilities = negotiated_capabilities;
+    }
+
   return ret;
 }
 
diff --git a/gdbus/gdbusauth.h b/gdbus/gdbusauth.h
index ce8d33f..d91e413 100644
--- a/gdbus/gdbusauth.h
+++ b/gdbus/gdbusauth.h
@@ -76,14 +76,17 @@ GDBusAuth  *_g_dbus_auth_new      (GIOStream *stream);
 gboolean    _g_dbus_auth_run_server (GDBusAuth     *auth,
                                      const gchar   *guid,
                                      gboolean       allow_anonymous,
+                                     GDBusConnectionCapabilityFlags offered_capabilities,
+                                     GDBusConnectionCapabilityFlags *out_negotiated_capabilities,
                                      GCancellable  *cancellable,
                                      GError       **error);
 
 gchar      *_g_dbus_auth_run_client (GDBusAuth     *auth,
+                                     GDBusConnectionCapabilityFlags offered_capabilities,
+                                     GDBusConnectionCapabilityFlags *out_negotiated_capabilities,
                                      GCancellable  *cancellable,
                                      GError       **error);
 
-
 G_END_DECLS
 
 #endif /* __G_DBUS_AUTH_H__ */
diff --git a/gdbus/gdbusconnection.c b/gdbus/gdbusconnection.c
index 19a49d7..bc6f028 100644
--- a/gdbus/gdbusconnection.c
+++ b/gdbus/gdbusconnection.c
@@ -26,6 +26,10 @@
 
 #include <glib/gi18n.h>
 
+#ifdef G_OS_UNIX
+#include <gio/gunixconnection.h>
+#endif
+
 #include <unistd.h>
 #include <sys/types.h>
 #include <stdlib.h>
@@ -183,6 +187,9 @@ struct _GDBusConnectionPrivate
 
   /* Whether to exit on close */
   gboolean exit_on_close;
+
+  /* Capabilities negotiated during authentication */
+  GDBusConnectionCapabilityFlags capabilities;
 };
 
 typedef struct ExportedObject ExportedObject;
@@ -207,6 +214,7 @@ enum
   PROP_UNIQUE_NAME,
   PROP_CLOSED,
   PROP_EXIT_ON_CLOSE,
+  PROP_CAPABILITY_FLAGS,
 };
 
 static void distribute_signals (GDBusConnection  *connection,
@@ -352,6 +360,10 @@ g_dbus_connection_get_property (GObject    *object,
       g_value_set_boolean (value, g_dbus_connection_get_exit_on_close (connection));
       break;
 
+    case PROP_CAPABILITY_FLAGS:
+      g_value_set_flags (value, g_dbus_connection_get_capabilities (connection));
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
       break;
@@ -558,6 +570,23 @@ g_dbus_connection_class_init (GDBusConnectionClass *klass)
                                                          G_PARAM_STATIC_BLURB |
                                                          G_PARAM_STATIC_NICK));
 
+  /**
+   * GDBusConnection:capabilities:
+   *
+   * Flags from the #GDBusConnectionCapabilityFlags enumeration
+   * representing connection features negotiated with the other peer.
+   */
+  g_object_class_install_property (gobject_class,
+                                   PROP_CAPABILITY_FLAGS,
+                                   g_param_spec_flags ("capabilities",
+                                                       _("Capabilities"),
+                                                       _("Capabilities"),
+                                                       G_TYPE_DBUS_CONNECTION_CAPABILITY_FLAGS,
+                                                       G_DBUS_CONNECTION_CAPABILITY_FLAGS_NONE,
+                                                       G_PARAM_READABLE |
+                                                       G_PARAM_STATIC_NAME |
+                                                       G_PARAM_STATIC_BLURB |
+                                                       G_PARAM_STATIC_NICK));
 
   /**
    * GDBusConnection::closed:
@@ -668,6 +697,21 @@ g_dbus_connection_is_closed (GDBusConnection *connection)
   return connection->priv->closed;
 }
 
+/**
+ * g_dbus_connection_get_capabilities:
+ * @connection: A #GDBusConnection.
+ *
+ * Gets the capabilities negotiated with the remote peer
+ *
+ * Returns: One or more flags from the #GDBusConnectionCapabilityFlags.
+ */
+GDBusConnectionCapabilityFlags
+g_dbus_connection_get_capabilities (GDBusConnection *connection)
+{
+  return connection->priv->capabilities;
+}
+
+
 /* ---------------------------------------------------------------------------------------------------- */
 
 typedef struct
@@ -1407,6 +1451,22 @@ on_worker_closed (GDBusWorker *worker,
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+/* Determines the biggest set of capabilities we can support on this connection */
+static GDBusConnectionCapabilityFlags
+get_offered_capabilities_max (GDBusConnection *connection)
+{
+      GDBusConnectionCapabilityFlags ret;
+      ret = G_DBUS_CONNECTION_CAPABILITY_FLAGS_NONE;
+#ifdef G_OS_UNIX
+      if (G_IS_UNIX_CONNECTION (connection->priv->stream))
+        {
+          ret |= G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING;
+        }
+#endif
+      return ret;
+}
+
+
 static gboolean
 initable_init (GInitable       *initable,
                GCancellable    *cancellable,
@@ -1475,6 +1535,8 @@ initable_init (GInitable       *initable,
       if (!_g_dbus_auth_run_server (connection->priv->auth,
                                     connection->priv->guid,
                                     (connection->priv->flags & G_DBUS_CONNECTION_FLAGS_AUTHENTICATION_ALLOW_ANONYMOUS),
+                                    get_offered_capabilities_max (connection),
+                                    &connection->priv->capabilities,
                                     cancellable,
                                     &connection->priv->initialization_error))
         goto out;
@@ -1485,12 +1547,16 @@ initable_init (GInitable       *initable,
       g_assert (connection->priv->guid == NULL);
       connection->priv->auth = _g_dbus_auth_new (connection->priv->stream);
       connection->priv->guid = _g_dbus_auth_run_client (connection->priv->auth,
+                                                        get_offered_capabilities_max (connection),
+                                                        &connection->priv->capabilities,
                                                         cancellable,
                                                         &connection->priv->initialization_error);
       if (connection->priv->guid == NULL)
         goto out;
     }
 
+  //g_debug ("haz unix fd passing powers: %d", connection->priv->capabilities & G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING);
+
   /* Hack used until
    *
    *  https://bugzilla.gnome.org/show_bug.cgi?id=616458
diff --git a/gdbus/gdbusconnection.h b/gdbus/gdbusconnection.h
index bc6a86b..aa868b4 100644
--- a/gdbus/gdbusconnection.h
+++ b/gdbus/gdbusconnection.h
@@ -136,7 +136,7 @@ const gchar     *g_dbus_connection_get_unique_name            (GDBusConnection
 gboolean         g_dbus_connection_get_exit_on_close          (GDBusConnection    *connection);
 void             g_dbus_connection_set_exit_on_close          (GDBusConnection    *connection,
                                                                gboolean            exit_on_close);
-
+GDBusConnectionCapabilityFlags g_dbus_connection_get_capabilities (GDBusConnection    *connection);
 /* ---------------------------------------------------------------------------------------------------- */
 
 gboolean         g_dbus_connection_send_message                   (GDBusConnection     *connection,
diff --git a/gdbus/gdbusenums.h b/gdbus/gdbusenums.h
index 4641b05..4d15ed2 100644
--- a/gdbus/gdbusenums.h
+++ b/gdbus/gdbusenums.h
@@ -256,6 +256,19 @@ typedef enum {
 } GDBusConnectionFlags;
 
 /**
+ * GDBusConnectionCapabilityFlags:
+ * @G_DBUS_CONNECTION_CAPABILITY_FLAGS_NONE: No flags set.
+ * @G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING: The connection
+ * supports exchanging UNIX file descriptors with the remote peer.
+ *
+ * Capabilities negotiated with the remote peer.
+ */
+typedef enum {
+  G_DBUS_CONNECTION_CAPABILITY_FLAGS_NONE = 0,
+  G_DBUS_CONNECTION_CAPABILITY_FLAGS_UNIX_FD_PASSING = (1<<0),
+} GDBusConnectionCapabilityFlags;
+
+/**
  * GDBusMessageType:
  * @G_DBUS_MESSAGE_TYPE_INVALID: Message is of invalid type.
  * @G_DBUS_MESSAGE_TYPE_METHOD_CALL: Method call.