From 30ab9247f57b270d46b1c2c5c194f834bf8aafff Mon Sep 17 00:00:00 2001
From: Olivier Fourdan <ofourdan@redhat.com>
Date: Mon, 9 Jan 2023 15:40:03 +0100
Subject: [PATCH 2/2] xwayland: Add support for byte-swapped clients

Instructs Xwayland to allow/disallow connections from X11 clients with a
different endianess based on the "xwayland-allow-byte-swapped-clients"
setting.

This option has no effect if Xwayland does not support the command
option +byteswappedclients/-byteswappedclients.

Closes: https://gitlab.gnome.org/GNOME/mutter/-/issues/2576
---
 config.h.meson              |  3 +++
 meson.build                 | 12 ++++++++++++
 src/wayland/meta-xwayland.c |  7 +++++++
 3 files changed, 22 insertions(+)

diff --git a/config.h.meson b/config.h.meson
index c7724b24f..5f9ea696e 100644
--- a/config.h.meson
+++ b/config.h.meson
@@ -109,3 +109,6 @@
 
 /* Whether the Xwayland -terminate supports a delay */
 #mesondefine HAVE_XWAYLAND_TERMINATE_DELAY
+
+/* Whether the Xwayland supports +/-byteswappedclients */
+#mesondefine HAVE_XWAYLAND_BYTE_SWAPPED_CLIENTS
diff --git a/meson.build b/meson.build
index 07460c0f1..a9608a9fd 100644
--- a/meson.build
+++ b/meson.build
@@ -526,6 +526,7 @@ endif
 have_xwayland_initfd = false
 have_xwayland_listenfd = false
 have_xwayland_terminate_delay = false
+have_xwayland_byte_swapped_clients = false
 if have_xwayland
   xwayland_dep = dependency('xwayland', required: false)
 
@@ -587,6 +588,16 @@ if have_xwayland
   if (have_xwayland_terminate_delay)
     cdata.set('HAVE_XWAYLAND_TERMINATE_DELAY', 1)
   endif
+
+  # For Xwayland +/-byteswappedclients usage
+  if xwayland_dep.found()
+    have_xwayland_byte_swapped_clients = xwayland_dep.get_variable('have_byteswappedclients',
+                                                                   default_value: 'false') == 'true'
+  endif
+
+  if (have_xwayland_byte_swapped_clients)
+    cdata.set('HAVE_XWAYLAND_BYTE_SWAPPED_CLIENTS', 1)
+  endif
 endif
 
 have_xsetioerrorexithandler = false
@@ -675,6 +686,7 @@ summary('Xwayland initfd', have_xwayland_initfd, section: 'Options')
 summary('Xwayland listenfd', have_xwayland_listenfd, section: 'Options')
 summary('Safe X11 I/O errors', have_xsetioerrorexithandler, section: 'Options')
 summary('Xwayland terminate delay', have_xwayland_terminate_delay, section: 'Options')
+summary('Xwayland byte-swapped clients', have_xwayland_byte_swapped_clients, section: 'Options')
 
 summary('Enabled', have_tests, section: 'Tests')
 summary('Core tests', have_core_tests, section: 'Tests')
diff --git a/src/wayland/meta-xwayland.c b/src/wayland/meta-xwayland.c
index c9d94b2e3..8e8de1441 100644
--- a/src/wayland/meta-xwayland.c
+++ b/src/wayland/meta-xwayland.c
@@ -880,6 +880,13 @@ meta_xwayland_start_xserver (MetaXWaylandManager *manager,
   args[i++] = "7";
 #endif
 
+#ifdef HAVE_XWAYLAND_BYTE_SWAPPED_CLIENTS
+  if (meta_settings_are_xwayland_byte_swapped_clients_allowed (settings))
+    args[i++] = "+byteswappedclients";
+  else
+    args[i++] = "-byteswappedclients";
+#endif
+
   if (meta_settings_is_experimental_feature_enabled (settings,
                                                      META_EXPERIMENTAL_FEATURE_AUTOCLOSE_XWAYLAND))
 #ifdef HAVE_XWAYLAND_TERMINATE_DELAY
-- 
2.39.0