From 3cf5b4b12d3d39fa858ff593adeecfe711cdddaf Mon Sep 17 00:00:00 2001

From: Iain Lane <iainl@gnome.org>

Date: Tue, 7 May 2019 15:35:23 +0100

Subject: [PATCH 42/51] GdmLocalDisplayFactory: Store VT number, not tty

 identifier

This makes the code a fair bit simpler.

---

 configure.ac                       |  6 ++--

 daemon/gdm-local-display-factory.c | 50 ++++++++++++++++--------------

 daemon/gdm-server.c                |  2 +-

 daemon/gdm-session-worker.c        |  2 +-

 4 files changed, 31 insertions(+), 29 deletions(-)

diff --git a/configure.ac b/configure.ac

index c549146ce..0c138ab38 100644

--- a/configure.ac

+++ b/configure.ac

@@ -1477,66 +1477,66 @@ fi

 AC_SUBST(DEBUG_CFLAGS)

 #

 # Enable Profiling

 #

 AC_ARG_ENABLE(profiling,

               AS_HELP_STRING([--enable-profiling],

                              [turn on profiling]),,

               enable_profiling=yes)

 if test "$enable_profiling" = "yes"; then

     AC_DEFINE(ENABLE_PROFILING,1,[enable profiling])

 fi

 #

 # Set SHELL to use in scripts.

 #

 if test x$os_solaris = xyes ; then

    XSESSION_SHELL=/bin/ksh

 else

    XSESSION_SHELL=/bin/sh

 fi

 #

 # Set VT to use for initial server

 #

 AC_ARG_WITH(initial-vt,

         AS_HELP_STRING([--with-initial-vt=<nr>],

                 [Initial virtual terminal to use]))

 if ! test -z "$with_initial_vt"; then

-        GDM_INITIAL_VT="$with_initial_vt"

+        GDM_INITIAL_VT=$with_initial_vt

 else

-        GDM_INITIAL_VT="1"

+        GDM_INITIAL_VT=1

 fi

 AC_SUBST(GDM_INITIAL_VT)

-AC_DEFINE_UNQUOTED(GDM_INITIAL_VT, "$GDM_INITIAL_VT", [Initial Virtual Terminal])

+AC_DEFINE_UNQUOTED(GDM_INITIAL_VT, $GDM_INITIAL_VT, [Initial Virtual Terminal])

 # Set configuration choices.

 #

 AC_SUBST(XSESSION_SHELL)

 AC_DEFINE_UNQUOTED(XSESSION_SHELL,"$XSESSION_SHELL",[xsession shell])

 AC_SUBST(SOUND_PROGRAM)

 AC_DEFINE_UNQUOTED(SOUND_PROGRAM,"$SOUND_PROGRAM",[])

 AC_SUBST(X_PATH)

 AC_SUBST(X_SERVER)

 AC_SUBST(X_SERVER_PATH)

 AC_DEFINE_UNQUOTED(X_SERVER,"$X_SERVER",[])

 AC_DEFINE_UNQUOTED(X_SERVER_PATH,"$X_SERVER_PATH",[])

 ## Stuff for debian/changelog.in

 #if test -e "debian/changelog"; then

 #  DEBIAN_DATESTAMP=`head -1 debian/changelog| sed -e 's/.*cvs.//' -e 's/).*//'`

 #  DEBIAN_DATE=`grep '^ --' debian/changelog | head -1 | sed -e 's/.*  //'`

 #else

 #  DEBIAN_DATESTAMP=`date +%Y%m%d%H%M%s`

 #  DEBIAN_DATE=`date -R`

 #fi

 #

 #AC_SUBST(DEBIAN_DATESTAMP)

 #AC_SUBST(DEBIAN_DATE)

 AC_CONFIG_FILES([

 Makefile

 pam-extensions/Makefile

 pam-extensions/gdm-pam-extensions.pc

diff --git a/daemon/gdm-local-display-factory.c b/daemon/gdm-local-display-factory.c

index d999596b5..7a013c694 100644

--- a/daemon/gdm-local-display-factory.c

+++ b/daemon/gdm-local-display-factory.c

@@ -37,61 +37,61 @@

 #include "gdm-local-display-factory-glue.h"

 #include "gdm-settings-keys.h"

 #include "gdm-settings-direct.h"

 #include "gdm-display-store.h"

 #include "gdm-local-display.h"

 #include "gdm-legacy-display.h"

 #define GDM_LOCAL_DISPLAY_FACTORY_GET_PRIVATE(o) (G_TYPE_INSTANCE_GET_PRIVATE ((o), GDM_TYPE_LOCAL_DISPLAY_FACTORY, GdmLocalDisplayFactoryPrivate))

 #define GDM_DBUS_PATH                       "/org/gnome/DisplayManager"

 #define GDM_LOCAL_DISPLAY_FACTORY_DBUS_PATH GDM_DBUS_PATH "/LocalDisplayFactory"

 #define GDM_MANAGER_DBUS_NAME               "org.gnome.DisplayManager.LocalDisplayFactory"

 #define MAX_DISPLAY_FAILURES 5

 #define WAIT_TO_FINISH_TIMEOUT 10 /* seconds */

 struct GdmLocalDisplayFactoryPrivate

 {

         GdmDBusLocalDisplayFactory *skeleton;

         GDBusConnection *connection;

         GHashTable      *used_display_numbers;

         /* FIXME: this needs to be per seat? */

         guint            num_failures;

         guint            seat_new_id;

         guint            seat_removed_id;

 #if defined(ENABLE_WAYLAND_SUPPORT) && defined(ENABLE_USER_DISPLAY_SERVER)

-        char            *tty_of_active_vt;

+        unsigned int     active_vt;

         guint            active_vt_watch_id;

         guint            wait_to_finish_timeout_id;

 #endif

 };

 enum {

         PROP_0,

 };

 static void     gdm_local_display_factory_class_init    (GdmLocalDisplayFactoryClass *klass);

 static void     gdm_local_display_factory_init          (GdmLocalDisplayFactory      *factory);

 static void     gdm_local_display_factory_finalize      (GObject                     *object);

 static GdmDisplay *create_display                       (GdmLocalDisplayFactory      *factory,

                                                          const char                  *seat_id,

                                                          const char                  *session_type,

                                                          gboolean                    initial_display);

 static void     on_display_status_changed               (GdmDisplay                  *display,

                                                          GParamSpec                  *arg1,

                                                          GdmLocalDisplayFactory      *factory);

 static gboolean gdm_local_display_factory_sync_seats    (GdmLocalDisplayFactory *factory);

 static gpointer local_display_factory_object = NULL;

 static gboolean lookup_by_session_id (const char *id,

                                       GdmDisplay *display,

                                       gpointer    user_data);

 G_DEFINE_TYPE (GdmLocalDisplayFactory, gdm_local_display_factory, GDM_TYPE_DISPLAY_FACTORY)

@@ -641,157 +641,161 @@ maybe_stop_greeter_in_background (GdmLocalDisplayFactory *factory,

                 g_debug ("GdmLocalDisplayFactory: login window is performing initial-setup, so ignoring");

                 return;

         }

         /* we can only stop greeter for wayland sessions, since

          * X server would jump back on exit */

         if (g_strcmp0 (display_session_type, "wayland") != 0) {

                 g_debug ("GdmLocalDisplayFactory: login window is running on Xorg, so ignoring");

                 return;

         }

         g_debug ("GdmLocalDisplayFactory: killing login window once its unused");

         g_object_set (G_OBJECT (display), "status", GDM_DISPLAY_WAITING_TO_FINISH, NULL);

         /* We stop the greeter after a timeout to avoid flicker */

         if (factory->priv->wait_to_finish_timeout_id != 0)

                 g_source_remove (factory->priv->wait_to_finish_timeout_id);

         factory->priv->wait_to_finish_timeout_id =

                 g_timeout_add_seconds (WAIT_TO_FINISH_TIMEOUT,

                                        (GSourceFunc)wait_to_finish_timeout,

                                        factory);

 }

 static gboolean

 on_vt_changed (GIOChannel    *source,

                GIOCondition   condition,

                GdmLocalDisplayFactory *factory)

 {

         GIOStatus status;

-        static const char *tty_of_initial_vt = "tty" GDM_INITIAL_VT;

-        g_autofree char *tty_of_previous_vt = NULL;

         g_autofree char *tty_of_active_vt = NULL;

         g_autofree char *login_session_id = NULL;

         g_autofree char *active_session_id = NULL;

+        unsigned int previous_vt, new_vt;

         const char *session_type = NULL;

-        int ret;

+        int ret, n_returned;

         g_debug ("GdmLocalDisplayFactory: received VT change event");

         g_io_channel_seek_position (source, 0, G_SEEK_SET, NULL);

         if (condition & G_IO_PRI) {

                 g_autoptr (GError) error = NULL;

                 status = g_io_channel_read_line (source, &tty_of_active_vt, NULL, NULL, &error);

                 if (error != NULL) {

                         g_warning ("could not read active VT from kernel: %s", error->message);

                 }

                 switch (status) {

                         case G_IO_STATUS_ERROR:

                             return G_SOURCE_REMOVE;

                         case G_IO_STATUS_EOF:

                             return G_SOURCE_REMOVE;

                         case G_IO_STATUS_AGAIN:

                             return G_SOURCE_CONTINUE;

                         case G_IO_STATUS_NORMAL:

                             break;

                 }

         }

         if ((condition & G_IO_ERR) || (condition & G_IO_HUP)) {

                 g_debug ("GdmLocalDisplayFactory: kernel hung up active vt watch");

                 return G_SOURCE_REMOVE;

         }

         if (tty_of_active_vt == NULL) {

                 g_debug ("GdmLocalDisplayFactory: unable to read active VT from kernel");

                 return G_SOURCE_CONTINUE;

         }

         g_strchomp (tty_of_active_vt);

+        errno = 0;

+        n_returned = sscanf (tty_of_active_vt, "tty%u", &new_vt);

+

+        if (n_returned != 1 || errno != 0) {

+                g_critical ("GdmLocalDisplayFactory: Couldn't read active VT (got '%s')",

+                            tty_of_active_vt);

+                return G_SOURCE_CONTINUE;

+        }

+

         /* don't do anything if we're on the same VT we were before */

-        if (g_strcmp0 (tty_of_active_vt, factory->priv->tty_of_active_vt) == 0) {

+        if (new_vt == factory->priv->active_vt) {

                 g_debug ("GdmLocalDisplayFactory: VT changed to the same VT, ignoring");

                 return G_SOURCE_CONTINUE;

         }

-        tty_of_previous_vt = g_steal_pointer (&factory->priv->tty_of_active_vt);

-        factory->priv->tty_of_active_vt = g_steal_pointer (&tty_of_active_vt);

+        previous_vt = factory->priv->active_vt;

+        factory->priv->active_vt = new_vt;

         /* don't do anything at start up */

-        if (tty_of_previous_vt == NULL) {

-                g_debug ("GdmLocalDisplayFactory: VT is %s at startup",

-                         factory->priv->tty_of_active_vt);

+        if (previous_vt == 0) {

+                g_debug ("GdmLocalDisplayFactory: VT is %u at startup",

+                         factory->priv->active_vt);

                 return G_SOURCE_CONTINUE;

         }

-        g_debug ("GdmLocalDisplayFactory: VT changed from %s to %s",

-                 tty_of_previous_vt, factory->priv->tty_of_active_vt);

+        g_debug ("GdmLocalDisplayFactory: VT changed from %u to %u",

+                 previous_vt, factory->priv->active_vt);

         /* if the old VT was running a wayland login screen kill it

          */

         if (gdm_get_login_window_session_id ("seat0", &login_session_id)) {

-                unsigned int vt;

+                unsigned int login_window_vt;

-                ret = sd_session_get_vt (login_session_id, &vt;;

-                if (ret == 0 && vt != 0) {

-                        g_autofree char *tty_of_login_window_vt = NULL;

-

-                        tty_of_login_window_vt = g_strdup_printf ("tty%u", vt);

-

-                        g_debug ("GdmLocalDisplayFactory: tty of login window is %s", tty_of_login_window_vt);

-                        if (g_strcmp0 (tty_of_login_window_vt, tty_of_previous_vt) == 0) {

+                ret = sd_session_get_vt (login_session_id, &login_window_vt);

+                if (ret == 0 && login_window_vt != 0) {

+                        g_debug ("GdmLocalDisplayFactory: VT of login window is %u", login_window_vt);

+                        if (login_window_vt == previous_vt) {

                                 GdmDisplayStore *store;

                                 GdmDisplay *display;

                                 g_debug ("GdmLocalDisplayFactory: VT switched from login window");

                                 store = gdm_display_factory_get_display_store (GDM_DISPLAY_FACTORY (factory));

                                 display = gdm_display_store_find (store,

                                                                   lookup_by_session_id,

                                                                   (gpointer) login_session_id);

                                 if (display != NULL)

                                         maybe_stop_greeter_in_background (factory, display);

                         } else {

                                 g_debug ("GdmLocalDisplayFactory: VT not switched from login window");

                         }

                 }

         }

         /* if user jumped back to initial vt and it's empty put a login screen

          * on it (unless a login screen is already running elsewhere, then

          * jump to that login screen)

          */

-        if (strcmp (factory->priv->tty_of_active_vt, tty_of_initial_vt) != 0) {

+        if (factory->priv->active_vt != GDM_INITIAL_VT) {

                 g_debug ("GdmLocalDisplayFactory: active VT is not initial VT, so ignoring");

                 return G_SOURCE_CONTINUE;

         }

         if (gdm_local_display_factory_use_wayland ())

                 session_type = "wayland";

         g_debug ("GdmLocalDisplayFactory: creating new display on seat0 because of VT change");

         create_display (factory, "seat0", session_type, TRUE);

         return G_SOURCE_CONTINUE;

 }

 #endif

 static void

 gdm_local_display_factory_start_monitor (GdmLocalDisplayFactory *factory)

 {

         g_autoptr (GIOChannel) io_channel = NULL;

         factory->priv->seat_new_id = g_dbus_connection_signal_subscribe (factory->priv->connection,

                                                                          "org.freedesktop.login1",

                                                                          "org.freedesktop.login1.Manager",

                                                                          "SeatNew",

                                                                          "/org/freedesktop/login1",

                                                                          NULL,

                                                                          G_DBUS_SIGNAL_FLAGS_NONE,

                                                                          on_seat_new,

                                                                          g_object_ref (factory),

                                                                          g_object_unref);

@@ -815,62 +819,60 @@ gdm_local_display_factory_start_monitor (GdmLocalDisplayFactory *factory)

                                         G_IO_PRI,

                                         (GIOFunc)

                                         on_vt_changed,

                                         factory);

         }

 #endif

 }

 static void

 gdm_local_display_factory_stop_monitor (GdmLocalDisplayFactory *factory)

 {

         if (factory->priv->seat_new_id) {

                 g_dbus_connection_signal_unsubscribe (factory->priv->connection,

                                                       factory->priv->seat_new_id);

                 factory->priv->seat_new_id = 0;

         }

         if (factory->priv->seat_removed_id) {

                 g_dbus_connection_signal_unsubscribe (factory->priv->connection,

                                                       factory->priv->seat_removed_id);

                 factory->priv->seat_removed_id = 0;

         }

 #if defined(ENABLE_WAYLAND_SUPPORT) && defined(ENABLE_USER_DISPLAY_SERVER)

         if (factory->priv->wait_to_finish_timeout_id != 0) {

                 g_source_remove (factory->priv->wait_to_finish_timeout_id);

                 factory->priv->wait_to_finish_timeout_id = 0;

         }

         if (factory->priv->active_vt_watch_id) {

                 g_source_remove (factory->priv->active_vt_watch_id);

                 factory->priv->active_vt_watch_id = 0;

         }

-

-        g_clear_pointer (&factory->priv->tty_of_active_vt, g_free);

 #endif

 }

 static void

 on_display_added (GdmDisplayStore        *display_store,

                   const char             *id,

                   GdmLocalDisplayFactory *factory)

 {

         GdmDisplay *display;

         display = gdm_display_store_lookup (display_store, id);

         if (display != NULL) {

                 g_signal_connect_object (display, "notify::status",

                                          G_CALLBACK (on_display_status_changed),

                                          factory,

                                          0);

                 g_object_weak_ref (G_OBJECT (display), (GWeakNotify)on_display_disposed, factory);

         }

 }

 static void

 on_display_removed (GdmDisplayStore        *display_store,

                     GdmDisplay             *display,

                     GdmLocalDisplayFactory *factory)

 {

         g_signal_handlers_disconnect_by_func (display, G_CALLBACK (on_display_status_changed), factory);

         g_object_weak_unref (G_OBJECT (display), (GWeakNotify)on_display_disposed, factory);

 }

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

index 83fba99c8..04406a61a 100644

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

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

@@ -726,61 +726,61 @@ gdm_server_spawn (GdmServer    *server,

                                                           (GChildWatchFunc)server_child_watch,

                                                           server);

         ret = TRUE;

  out:

         g_strfreev (argv);

         if (env) {

                 g_ptr_array_foreach (env, (GFunc)g_free, NULL);

                 g_ptr_array_free (env, TRUE);

         }

         return ret;

 }

 /**

  * gdm_server_start:

  * @disp: Pointer to a GdmDisplay structure

  *

  * Starts a local X server. Handles retries and fatal errors properly.

  */

 gboolean

 gdm_server_start (GdmServer *server)

 {

         gboolean res = FALSE;

         const char *vtarg = NULL;

         GError *local_error = NULL;

         GError **error = &local_error;

         /* Hardcode the VT for the initial X server, but nothing else */

         if (server->priv->is_initial) {

-                vtarg = "vt" GDM_INITIAL_VT;

+                vtarg = "vt" G_STRINGIFY (GDM_INITIAL_VT);

         }

         /* fork X server process */

         if (!gdm_server_spawn (server, vtarg, error)) {

                 goto out;

         }

         res = TRUE;

  out:

         if (local_error) {

                 g_printerr ("%s\n", local_error->message);

                 g_clear_error (&local_error);

         }

         return res;

 }

 static void

 server_died (GdmServer *server)

 {

         int exit_status;

         g_debug ("GdmServer: Waiting on process %d", server->priv->pid);

         exit_status = gdm_wait_on_pid (server->priv->pid);

         if (WIFEXITED (exit_status) && (WEXITSTATUS (exit_status) != 0)) {

                 g_debug ("GdmServer: Wait on child process failed");

         } else {

                 /* exited normally */

         }

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

index 7ed2789da..b4befaa83 100644

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

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

@@ -2202,61 +2202,61 @@ gdm_session_worker_start_session (GdmSessionWorker  *worker,

         g_debug ("GdmSessionWorker: state SESSION_STARTED");

         gdm_session_worker_set_state (worker, GDM_SESSION_WORKER_STATE_SESSION_STARTED);

         gdm_session_worker_watch_child (worker);

  out:

         if (error_code != PAM_SUCCESS) {

                 gdm_session_worker_uninitialize_pam (worker, error_code);

                 return FALSE;

         }

         return TRUE;

 }

 static gboolean

 set_up_for_new_vt (GdmSessionWorker *worker)

 {

         int fd;

         char vt_string[256], tty_string[256];

         int session_vt = 0;

         fd = open ("/dev/tty0", O_RDWR | O_NOCTTY);

         if (fd < 0) {

                 g_debug ("GdmSessionWorker: couldn't open VT master: %m");

                 return FALSE;

         }

         if (worker->priv->display_is_initial) {

-                session_vt = atoi (GDM_INITIAL_VT);

+                session_vt = GDM_INITIAL_VT;

         } else {

                 if (ioctl(fd, VT_OPENQRY, &session_vt) < 0) {

                         g_debug ("GdmSessionWorker: couldn't open new VT: %m");

                         goto fail;

                 }

         }

         worker->priv->session_vt = session_vt;

         close (fd);

         fd = -1;

         g_assert (session_vt > 0);

         g_snprintf (vt_string, sizeof (vt_string), "%d", session_vt);

         /* Set the VTNR. This is used by logind to configure a session in

          * the logind-managed case, but it doesn't hurt to set it always.

          * When logind gains support for XDG_VTNR=auto, we can make the

          * OPENQRY and this whole path only used by the new VT code. */

         gdm_session_worker_set_environment_variable (worker,

                                                      "XDG_VTNR",

                                                      vt_string);

         g_snprintf (tty_string, 256, "/dev/tty%d", session_vt);

         worker->priv->session_tty_fd = open (tty_string, O_RDWR | O_NOCTTY);

         pam_set_item (worker->priv->pam_handle, PAM_TTY, tty_string);

         return TRUE;

-- 

2.27.0