From d3823a5084e12d8f342fd4cbec29e23bdb646de7 Mon Sep 17 00:00:00 2001

From: Alan Coopersmith <alan.coopersmith@oracle.com>

Date: Thu, 7 Oct 2021 18:22:11 -0700

Subject: [PATCH 2/2] daemon: Support X servers built with -Dlisten_tcp=true

Xorg since version 1.17 doesn't listen to tcp sockets by default

unless it's explicitly built with -Dlisten_tcp=true.

GDM currently assumes X servers 1.17 and later are always built

without specifying -Dlisten_tcp=true and doesn't work properly

otherwise.

This commit enhances GDM to better handle these non-standard builds by

always passing '-nolisten tcp' on the command line when tcp should

be disabled, and likewise always passing '-listen tcp' on the command

line, assuming the X server is new enough to support it, when tcp

should be enabled.

Related #704

---

 daemon/gdm-server.c    | 21 +++++++++++----------

 daemon/gdm-x-session.c | 12 ++++++------

 meson.build            |  4 ++--

 3 files changed, 19 insertions(+), 18 deletions(-)

diff --git a/daemon/gdm-server.c b/daemon/gdm-server.c

index 1ba00d45..e5d23521 100644

--- a/daemon/gdm-server.c

+++ b/daemon/gdm-server.c

@@ -290,72 +290,73 @@ gdm_server_resolve_command_line (GdmServer  *server,

                 if (strcmp (arg, "-query") == 0 ||

                     strcmp (arg, "-indirect") == 0)

                         query_in_arglist = TRUE;

         }

         argv = g_renew (char *, argv, len + 12);

         /* shift args down one */

         for (i = len - 1; i >= 1; i--) {

                 argv[i+1] = argv[i];

         }

         /* server number is the FIRST argument, before any others */

         argv[1] = g_strdup (server->display_name);

         len++;

         if (server->auth_file != NULL) {

                 argv[len++] = g_strdup ("-auth");

                 argv[len++] = g_strdup (server->auth_file);

         }

         if (server->display_seat_id != NULL) {

                 argv[len++] = g_strdup ("-seat");

                 argv[len++] = g_strdup (server->display_seat_id);

         }

         /* If we were compiled with Xserver >= 1.17 we need to specify

          * '-listen tcp' as the X server dosen't listen on tcp sockets

          * by default anymore. In older versions we need to pass

          * -nolisten tcp to disable listening on tcp sockets.

          */

-#ifdef HAVE_XSERVER_THAT_DEFAULTS_TO_LOCAL_ONLY

-        if (!server->disable_tcp && ! query_in_arglist) {

-                argv[len++] = g_strdup ("-listen");

-                argv[len++] = g_strdup ("tcp");

-        }

-#else

-        if (server->disable_tcp && ! query_in_arglist) {

-                argv[len++] = g_strdup ("-nolisten");

-                argv[len++] = g_strdup ("tcp");

-        }

+        if (!query_in_arglist) {

+                if (server->disable_tcp) {

+                        argv[len++] = g_strdup ("-nolisten");

+                        argv[len++] = g_strdup ("tcp");

+                }

+#ifdef HAVE_XSERVER_WITH_LISTEN

+                if (!server->disable_tcp) {

+                        argv[len++] = g_strdup ("-listen");

+                        argv[len++] = g_strdup ("tcp");

+                }

 #endif

+        }

         if (vtarg != NULL && ! gotvtarg) {

                 argv[len++] = g_strdup (vtarg);

         }

         argv[len++] = NULL;

         *argvp = argv;

         *argcp = len;

         return TRUE;

 }

 static void

 rotate_logs (const char *path,

              guint       n_copies)

 {

         int i;

         for (i = n_copies - 1; i > 0; i--) {

                 char *name_n;

                 char *name_n1;

                 name_n = g_strdup_printf ("%s.%d", path, i);

                 if (i > 1) {

                         name_n1 = g_strdup_printf ("%s.%d", path, i - 1);

                 } else {

                         name_n1 = g_strdup (path);

                 }

diff --git a/daemon/gdm-x-session.c b/daemon/gdm-x-session.c

index b1548361..d2a8aeb3 100644

--- a/daemon/gdm-x-session.c

+++ b/daemon/gdm-x-session.c

@@ -233,70 +233,70 @@ spawn_x_server (State        *state,

         if (g_getenv ("XDG_VTNR") != NULL) {

                 int vt;

                 vt = atoi (g_getenv ("XDG_VTNR"));

                 if (vt > 0 && vt < 64) {

                         vt_string = g_strdup_printf ("vt%d", vt);

                 }

         }

         display_fd_string = g_strdup_printf ("%d", DISPLAY_FILENO);

         g_ptr_array_add (arguments, X_SERVER);

         if (vt_string != NULL) {

                 g_ptr_array_add (arguments, vt_string);

         }

         g_ptr_array_add (arguments, "-displayfd");

         g_ptr_array_add (arguments, display_fd_string);

         g_ptr_array_add (arguments, "-auth");

         g_ptr_array_add (arguments, auth_file);

         /* If we were compiled with Xserver >= 1.17 we need to specify

          * '-listen tcp' as the X server doesn't listen on tcp sockets

          * by default anymore. In older versions we need to pass

          * -nolisten tcp to disable listening on tcp sockets.

          */

-#ifdef HAVE_XSERVER_THAT_DEFAULTS_TO_LOCAL_ONLY

-        if (allow_remote_connections) {

-                g_ptr_array_add (arguments, "-listen");

-                g_ptr_array_add (arguments, "tcp");

-        }

-#else

         if (!allow_remote_connections) {

                 g_ptr_array_add (arguments, "-nolisten");

                 g_ptr_array_add (arguments, "tcp");

         }

+

+#ifdef HAVE_XSERVER_WITH_LISTEN

+        if (allow_remote_connections) {

+                g_ptr_array_add (arguments, "-listen");

+                g_ptr_array_add (arguments, "tcp");

+        }

 #endif

         g_ptr_array_add (arguments, "-background");

         g_ptr_array_add (arguments, "none");

         g_ptr_array_add (arguments, "-noreset");

         g_ptr_array_add (arguments, "-keeptty");

         g_ptr_array_add (arguments, "-novtswitch");

         g_ptr_array_add (arguments, "-verbose");

         if (state->debug_enabled) {

                 g_ptr_array_add (arguments, "7");

         } else {

                 g_ptr_array_add (arguments, "3");

         }

         if (state->debug_enabled) {

                 g_ptr_array_add (arguments, "-core");

         }

         g_ptr_array_add (arguments, NULL);

         subprocess = g_subprocess_launcher_spawnv (launcher,

                                                    (const char * const *) arguments->pdata,

                                                    &error);

         g_free (display_fd_string);

         g_clear_object (&launcher);

         g_ptr_array_free (arguments, TRUE);

         if (subprocess == NULL) {

                 g_debug ("could not start X server: %s", error->message);

diff --git a/meson.build b/meson.build

index 06d09659..8328dd97 100644

--- a/meson.build

+++ b/meson.build

@@ -44,61 +44,61 @@ glib_min_version = '2.56.0'

 glib_dep = dependency('glib-2.0', version: '>=' + glib_min_version)

 gobject_dep = dependency('gobject-2.0', version: '>=' + glib_min_version)

 gio_dep = dependency('gio-2.0', version: '>=' + glib_min_version)

 gio_unix_dep = dependency('gio-unix-2.0', version: '>=' + glib_min_version)

 gtk_dep = dependency('gtk+-3.0', version: '>= 2.91.1')

 libcanberra_gtk_dep = dependency('libcanberra-gtk3', version: '>= 0.4')

 accountsservice_dep = dependency('accountsservice', version: '>= 0.6.35')

 xcb_dep = dependency('xcb')

 keyutils_dep = dependency('libkeyutils', required: false)

 libselinux_dep = dependency('libselinux', required: get_option('selinux'))

 # udev

 if udev_dir == ''

   if udev_dep.found()

     udev_prefix = udev_dep.get_pkgconfig_variable('udevdir')

   else

     udev_prefix = gdm_prefix / 'lib' / 'udev'

   endif

   udev_dir = udev_prefix / 'rules.d'

 endif

 # X11

 x_deps = declare_dependency(

   dependencies: [

     dependency('x11'),

     dependency('xau'),

   ],

 )

 # Xserver 1.17 & later default to -nolisten and require -listen for remote access

 xserver_deps = dependency('xorg-server', version : '>=1.17', required : false)

-xserver_nolisten_default = xserver_deps.found()

+xserver_has_listen = xserver_deps.found()

 find_x_server_script = find_program('build-aux/find-x-server.sh', native: true)

 find_x_server_out = run_command(find_x_server_script).stdout().strip()

 if find_x_server_out != ''

   x_bin = find_x_server_out

   x_bin_path_split = x_bin.split('/')

   i = 0

   x_path = '/'

   foreach dir : x_bin_path_split

     if i < x_bin_path_split.length() - 1

       x_path = x_path / dir

     endif

     i = i + 1

   endforeach

 else

   # what to do, what to do, this is wrong, but this just sets the

   # defaults, perhaps this user is cross compiling or some such

   x_path = '/usr/bin/X11:/usr/X11R6/bin:/opt/X11R6/bin'

   x_bin = '/usr/bin/X'

 endif

 xdmcp_dep = cc.find_library('Xdmcp', required: get_option('xdmcp'))

 if xdmcp_dep.found() and get_option('tcp-wrappers')

   libwrap_dep = cc.find_library('libwrap')

 endif

 # systemd

 systemd_dep = dependency('systemd')

 libsystemd_dep = dependency('libsystemd')

 if meson.version().version_compare('>= 0.53')

   systemd_multiseat_x = find_program('systemd-multi-seat-x',

     required: false,

     dirs: [

@@ -200,61 +200,61 @@ conf.set_quoted('SYSCONFDIR', gdm_prefix / get_option('sysconfdir'))

 conf.set_quoted('BINDIR', gdm_prefix / get_option('bindir'))

 conf.set_quoted('LIBDIR', gdm_prefix / get_option('libdir'))

 conf.set_quoted('LIBEXECDIR', gdm_prefix / get_option('libexecdir'))

 conf.set_quoted('LOGDIR', get_option('log-dir'))

 conf.set_quoted('DMCONFDIR', dmconfdir)

 conf.set_quoted('GDMCONFDIR', gdmconfdir)

 conf.set_quoted('GDM_SCREENSHOT_DIR', gdm_screenshot_dir)

 conf.set_quoted('GDM_XAUTH_DIR', gdm_xauth_dir)

 conf.set_quoted('GDM_RAN_ONCE_MARKER_DIR', ran_once_marker_dir)

 conf.set_quoted('GDM_RUN_DIR', gdm_run_dir)

 conf.set_quoted('GNOMELOCALEDIR', gdm_prefix / get_option('localedir'))

 conf.set_quoted('AT_SPI_REGISTRYD_DIR', at_spi_registryd_dir)

 conf.set_quoted('GDM_PID_FILE', gdm_pid_file)

 conf.set_quoted('GNOME_SETTINGS_DAEMON_DIR', gnome_settings_daemon_dir)

 conf.set_quoted('LANG_CONFIG_FILE', lang_config_file)

 conf.set('HAVE_ADT', have_adt)

 conf.set('HAVE_UTMP_H', have_utmp_header)

 conf.set('HAVE_UTMPX_H', have_utmpx_header)

 conf.set('HAVE_POSIX_GETPWNAM_R', have_posix_getpwnam_r)

 conf.set('UTMP', utmp_struct)

 conf.set('HAVE_GETUTXENT', cc.has_function('getutxent'))

 conf.set('HAVE_UPDWTMP', cc.has_function('updwtmp'))

 conf.set('HAVE_UPDWTMPX', cc.has_function('updwtmpx'))

 conf.set('HAVE_LOGIN', cc.has_function('login', args: '-lutil'))

 conf.set('HAVE_LOGOUT', cc.has_function('logout', args: '-lutil'))

 conf.set('HAVE_LOGWTMP', cc.has_function('logwtmp', args: '-lutil'))

 conf.set('HAVE_PAM_SYSLOG', have_pam_syslog)

 conf.set('HAVE_KEYUTILS', keyutils_dep.found())

 conf.set('SUPPORTS_PAM_EXTENSIONS', pam_extensions_supported)

 conf.set('HAVE_SELINUX', libselinux_dep.found())

-conf.set('HAVE_XSERVER_THAT_DEFAULTS_TO_LOCAL_ONLY', xserver_nolisten_default)

+conf.set('HAVE_XSERVER_WITH_LISTEN', xserver_has_listen)

 conf.set('ENABLE_USER_DISPLAY_SERVER', get_option('user-display-server'))

 conf.set('ENABLE_SYSTEMD_JOURNAL', get_option('systemd-journal'))

 conf.set('ENABLE_WAYLAND_SUPPORT', get_option('wayland-support'))

 conf.set('ENABLE_PROFILING', get_option('profiling'))

 conf.set('GDM_INITIAL_VT', get_option('initial-vt'))

 conf.set_quoted('GDM_DEFAULTS_CONF', gdm_defaults_conf)

 conf.set_quoted('GDM_CUSTOM_CONF', gdm_custom_conf)

 conf.set_quoted('GDM_RUNTIME_CONF', gdm_runtime_conf)

 conf.set_quoted('GDM_SESSION_DEFAULT_PATH', get_option('default-path'))

 conf.set_quoted('GDM_USERNAME', get_option('user'))

 conf.set_quoted('GDM_GROUPNAME', get_option('group'))

 conf.set('HAVE_LIBXDMCP', xdmcp_dep.found())

 conf.set_quoted('SYSTEMD_X_SERVER', systemd_x_server)

 conf.set('WITH_PLYMOUTH', plymouth_dep.found())

 conf.set_quoted('X_SERVER', x_bin)

 conf.set_quoted('X_PATH', x_path)

 conf.set('HAVE_UT_UT_HOST', utmp_has_host_field)

 conf.set('HAVE_UT_UT_PID', utmp_has_pid_field)

 conf.set('HAVE_UT_UT_ID', utmp_has_id_field)

 conf.set('HAVE_UT_UT_NAME', utmp_has_name_field)

 conf.set('HAVE_UT_UT_TYPE', utmp_has_type_field)

 conf.set('HAVE_UT_UT_EXIT_E_TERMINATION', utmp_has_exit_e_termination_field)

 conf.set('HAVE_UT_UT_USER', utmp_has_user_field)

 conf.set('HAVE_UT_UT_TIME', utmp_has_time_field)

 conf.set('HAVE_UT_UT_TV', utmp_has_tv_field)

 conf.set('HAVE_UT_UT_SYSLEN', utmp_has_syslen_field)

 conf.set('ENABLE_IPV6', get_option('ipv6'))

 configure_file(output: 'config.h', configuration: conf)

 # Subdirs

-- 

2.33.1