From 9a3e9cb9a6bbf68ed6eb9f13d143a63af940f3ae Mon Sep 17 00:00:00 2001

From: Ray Strode <rstrode@redhat.com>

Date: Mon, 30 Jul 2018 16:21:29 -0400

Subject: [PATCH 12/51] daemon: try harder to get to a login screen at logout

commit 22c332ba and some follow up commits try to ensure the

user never stays on a blank VT by jumping to a login screen in

the event they'd end up on one.

Unfortunately, that part of the code can't start a login screen

if there's not one running at all.

This commit moves the code to GdmLocalDisplyFactory where the

login screens are created, so users won't end up on a blank

VT even if no login screen is yet running.

---

 daemon/gdm-local-display-factory.c |  36 +++++++-

 daemon/gdm-manager.c               | 143 -----------------------------

 2 files changed, 31 insertions(+), 148 deletions(-)

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

index e52360a56..0e454c880 100644

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

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

@@ -1,60 +1,62 @@

 /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*-

  *

  * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu>

  *

  * This program is free software; you can redistribute it and/or modify

  * it under the terms of the GNU General Public License as published by

  * the Free Software Foundation; either version 2 of the License, or

  * (at your option) any later version.

  *

  * This program is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  * GNU General Public License for more details.

  *

  * You should have received a copy of the GNU General Public License

  * along with this program; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

  *

  */

 #include "config.h"

 #include <stdlib.h>

 #include <stdio.h>

 #include <glib.h>

 #include <glib/gi18n.h>

 #include <glib-object.h>

 #include <gio/gio.h>

+#include <systemd/sd-login.h>

+

 #include "gdm-common.h"

 #include "gdm-manager.h"

 #include "gdm-display-factory.h"

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

 #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

 struct GdmLocalDisplayFactoryPrivate

 {

         GdmDBusLocalDisplayFactory *skeleton;

         GDBusConnection *connection;

         GHashTable      *used_display_numbers;

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

         guint            num_failures;

         guint            seat_new_id;

@@ -240,174 +242,198 @@ gdm_local_display_factory_create_transient_display (GdmLocalDisplayFactory *fact

         store_display (factory, display);

         if (! gdm_display_manage (display)) {

                 display = NULL;

                 goto out;

         }

         if (! gdm_display_get_id (display, id, NULL)) {

                 display = NULL;

                 goto out;

         }

         ret = TRUE;

  out:

         /* ref either held by store or not at all */

         g_object_unref (display);

         return ret;

 }

 static void

 on_display_status_changed (GdmDisplay             *display,

                            GParamSpec             *arg1,

                            GdmLocalDisplayFactory *factory)

 {

         int              status;

         int              num;

         char            *seat_id = NULL;

         char            *session_type = NULL;

+        char            *session_class = NULL;

         gboolean         is_initial = TRUE;

         gboolean         is_local = TRUE;

         num = -1;

         gdm_display_get_x11_display_number (display, &num, NULL);

         g_object_get (display,

                       "seat-id", &seat_id,

                       "is-initial", &is_initial,

                       "is-local", &is_local,

                       "session-type", &session_type,

+                      "session-class", &session_class,

                       NULL);

         status = gdm_display_get_status (display);

         g_debug ("GdmLocalDisplayFactory: display status changed: %d", status);

         switch (status) {

         case GDM_DISPLAY_FINISHED:

                 /* remove the display number from factory->priv->used_display_numbers

                    so that it may be reused */

                 if (num != -1) {

                         g_hash_table_remove (factory->priv->used_display_numbers, GUINT_TO_POINTER (num));

                 }

                 gdm_display_factory_queue_purge_displays (GDM_DISPLAY_FACTORY (factory));

                 /* if this is a local display, do a full resync.  Only

                  * seats without displays will get created anyway.  This

                  * ensures we get a new login screen when the user logs out,

                  * if there isn't one.

                  */

-                if (is_local) {

+                if (is_local && g_strcmp0 (session_class, "greeter") != 0) {

                         /* reset num failures */

                         factory->priv->num_failures = 0;

                         gdm_local_display_factory_sync_seats (factory);

                 }

                 break;

         case GDM_DISPLAY_FAILED:

                 /* leave the display number in factory->priv->used_display_numbers

                    so that it doesn't get reused */

                 gdm_display_factory_queue_purge_displays (GDM_DISPLAY_FACTORY (factory));

                 /* Create a new equivalent display if it was static */

                 if (is_local) {

                         factory->priv->num_failures++;

                         if (factory->priv->num_failures > MAX_DISPLAY_FAILURES) {

                                 /* oh shit */

                                 g_warning ("GdmLocalDisplayFactory: maximum number of X display failures reached: check X server log for errors");

                         } else {

 #ifdef ENABLE_WAYLAND_SUPPORT

                                 if (g_strcmp0 (session_type, "wayland") == 0) {

                                         g_free (session_type);

                                         session_type = NULL;

                                         /* workaround logind race for now

                                          * bug 1643874

                                          */

                                         g_usleep (2 * G_USEC_PER_SEC);

                                 }

 #endif

                                 create_display (factory, seat_id, session_type, is_initial);

                         }

                 }

                 break;

         case GDM_DISPLAY_UNMANAGED:

                 break;

         case GDM_DISPLAY_PREPARED:

                 break;

         case GDM_DISPLAY_MANAGED:

                 break;

         default:

                 g_assert_not_reached ();

                 break;

         }

         g_free (seat_id);

         g_free (session_type);

+        g_free (session_class);

 }

 static gboolean

 lookup_by_seat_id (const char *id,

                    GdmDisplay *display,

                    gpointer    user_data)

 {

         const char *looking_for = user_data;

         char *current;

         gboolean res;

         g_object_get (G_OBJECT (display), "seat-id", &current, NULL);

         res = g_strcmp0 (current, looking_for) == 0;

         g_free(current);

         return res;

 }

 static GdmDisplay *

 create_display (GdmLocalDisplayFactory *factory,

                 const char             *seat_id,

                 const char             *session_type,

                 gboolean                initial)

 {

         GdmDisplayStore *store;

         GdmDisplay      *display = NULL;

+        char            *active_session_id = NULL;

+        int              ret;

-        /* Ensure we don't create the same display more than once */

         store = gdm_display_factory_get_display_store (GDM_DISPLAY_FACTORY (factory));

-        display = gdm_display_store_find (store, lookup_by_seat_id, (gpointer) seat_id);

-        if (display != NULL) {

-                return NULL;

+

+        ret = sd_seat_get_active (seat_id, &active_session_id, NULL);

+

+        if (ret == 0) {

+                char *login_session_id = NULL;

+

+                /* If we already have a login window, switch to it */

+                if (gdm_get_login_window_session_id (seat_id, &login_session_id)) {

+                        if (g_strcmp0 (active_session_id, login_session_id) != 0) {

+                                gdm_activate_session_by_id (factory->priv->connection, seat_id, login_session_id);

+                        }

+                        g_clear_pointer (&login_session_id, g_free);

+                        g_clear_pointer (&active_session_id, g_free);

+                        return NULL;

+                }

+                g_clear_pointer (&active_session_id, g_free);

+        } else {

+                /* Ensure we don't create the same display more than once */

+                display = gdm_display_store_find (store, lookup_by_seat_id, (gpointer) seat_id);

+

+                if (display != NULL) {

+                        return NULL;

+                }

         }

         g_debug ("GdmLocalDisplayFactory: Adding display on seat %s", seat_id);

 #ifdef ENABLE_USER_DISPLAY_SERVER

         if (g_strcmp0 (seat_id, "seat0") == 0) {

                 display = gdm_local_display_new ();

                 if (session_type != NULL) {

                         g_object_set (G_OBJECT (display), "session-type", session_type, NULL);

                 }

         }

 #endif

         if (display == NULL) {

                 guint32 num;

                 num = take_next_display_number (factory);

                 display = gdm_legacy_display_new (num);

         }

         g_object_set (display, "seat-id", seat_id, NULL);

         g_object_set (display, "is-initial", initial, NULL);

         store_display (factory, display);

         /* let store own the ref */

         g_object_unref (display);

         if (! gdm_display_manage (display)) {

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

index ede22e771..80f60d24c 100644

--- a/daemon/gdm-manager.c

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

@@ -1322,202 +1322,60 @@ maybe_start_pending_initial_login (GdmManager *manager,

         char *user_session_seat_id = NULL;

         /* There may be a user session waiting to be started.

          * This would happen if we couldn't start it earlier because

          * the login screen X server was coming up and two X servers

          * can't be started on the same seat at the same time.

          */

         if (manager->priv->initial_login_operation == NULL) {

                 return;

         }

         operation = manager->priv->initial_login_operation;

         g_object_get (G_OBJECT (greeter_display),

                       "seat-id", &greeter_seat_id,

                       NULL);

         g_object_get (G_OBJECT (operation->session),

                       "display-seat-id", &user_session_seat_id,

                       NULL);

         if (g_strcmp0 (greeter_seat_id, user_session_seat_id) == 0) {

                 start_user_session (manager, operation);

                 manager->priv->initial_login_operation = NULL;

         }

         g_free (greeter_seat_id);

         g_free (user_session_seat_id);

 }

-static gboolean

-get_login_window_session_id (const char  *seat_id,

-                             char       **session_id)

-{

-        gboolean   ret;

-        int        res, i;

-        char     **sessions;

-        char      *service_id;

-        char      *service_class;

-        char      *state;

-

-        res = sd_seat_get_sessions (seat_id, &sessions, NULL, NULL);

-        if (res < 0) {

-                g_debug ("Failed to determine sessions: %s", strerror (-res));

-                return FALSE;

-        }

-

-        if (sessions == NULL || sessions[0] == NULL) {

-                *session_id = NULL;

-                ret = FALSE;

-                goto out;

-        }

-

-        for (i = 0; sessions[i]; i ++) {

-

-                res = sd_session_get_class (sessions[i], &service_class);

-                if (res < 0) {

-                        if (res == -ENOENT) {

-                                free (service_class);

-                                continue;

-                        }

-

-                        g_debug ("failed to determine class of session %s: %s", sessions[i], strerror (-res));

-                        ret = FALSE;

-                        goto out;

-                }

-

-                if (strcmp (service_class, "greeter") != 0) {

-                        free (service_class);

-                        continue;

-                }

-

-                free (service_class);

-

-                ret = sd_session_get_state (sessions[i], &state);

-                if (ret < 0) {

-                        if (res == -ENOENT)

-                                continue;

-

-                        g_debug ("failed to determine state of session %s: %s", sessions[i], strerror (-res));

-                        ret = FALSE;

-                        goto out;

-                }

-

-                if (g_strcmp0 (state, "closing") == 0) {

-                        free (state);

-                        continue;

-                }

-                free (state);

-

-                res = sd_session_get_service (sessions[i], &service_id);

-                if (res < 0) {

-                        if (res == -ENOENT)

-                                continue;

-                        g_debug ("failed to determine service of session %s: %s", sessions[i], strerror (-res));

-                        ret = FALSE;

-                        goto out;

-                }

-

-                if (strcmp (service_id, "gdm-launch-environment") == 0) {

-                        *session_id = g_strdup (sessions[i]);

-                        ret = TRUE;

-

-                        free (service_id);

-                        goto out;

-                }

-

-                free (service_id);

-        }

-

-        *session_id = NULL;

-        ret = FALSE;

-

-out:

-        if (sessions) {

-                for (i = 0; sessions[i]; i ++) {

-                        free (sessions[i]);

-                }

-

-                free (sessions);

-        }

-

-        return ret;

-}

-

-static void

-activate_login_window_session_on_seat (GdmManager *self,

-                                       const char *seat_id)

-{

-        char *session_id;

-

-        if (!gdm_get_login_window_session_id (seat_id, &session_id)) {

-                return;

-        }

-

-        if (session_id) {

-                activate_session_id (self, seat_id, session_id);

-                g_free (session_id);

-        }

-}

-

-static void

-maybe_activate_other_session (GdmManager *self,

-                              GdmDisplay *old_display)

-{

-        char *seat_id = NULL;

-        char *session_id = NULL;

-        int ret;

-

-        g_object_get (G_OBJECT (old_display),

-                      "seat-id", &seat_id,

-                      NULL);

-

-        ret = sd_seat_get_active (seat_id, &session_id, NULL);

-

-        if (ret == 0) {

-                GdmDisplay *display;

-

-                display = gdm_display_store_find (self->priv->display_store,

-                                                  lookup_by_session_id,

-                                                  (gpointer) session_id);

-

-                if (display == NULL || gdm_display_get_status (display) == GDM_DISPLAY_FINISHED) {

-                        activate_login_window_session_on_seat (self, seat_id);

-                }

-

-                g_free (session_id);

-        }

-

-        g_free (seat_id);

-}

-

 static const char *

 get_username_for_greeter_display (GdmManager *manager,

                                   GdmDisplay *display)

 {

         gboolean doing_initial_setup = FALSE;

         g_object_get (G_OBJECT (display),

                       "doing-initial-setup", &doing_initial_setup,

                       NULL);

         if (doing_initial_setup) {

                 return INITIAL_SETUP_USERNAME;

         } else {

                 return GDM_USERNAME;

         }

 }

 static void

 set_up_automatic_login_session (GdmManager *manager,

                                 GdmDisplay *display)

 {

         GdmSession *session;

         char       *display_session_type = NULL;

         gboolean is_initial;

         /* 0 is root user; since the daemon talks to the session object

          * directly, itself, for automatic login

          */

         session = create_user_session_for_display (manager, display, 0);

@@ -1709,61 +1567,60 @@ on_display_status_changed (GdmDisplay *display,

                         if ((display_number == -1 && status == GDM_DISPLAY_PREPARED) ||

                             (display_number != -1 && status == GDM_DISPLAY_MANAGED)) {

                                 char *session_class;

                                 g_object_get (display,

                                               "session-class", &session_class,

                                               NULL);

                                 if (g_strcmp0 (session_class, "greeter") == 0)

                                         set_up_session (manager, display);

                                 g_free (session_class);

                         }

                         if (status == GDM_DISPLAY_MANAGED) {

                                 greeter_display_started (manager, display);

                         }

                         break;

                 case GDM_DISPLAY_FAILED:

                 case GDM_DISPLAY_UNMANAGED:

                 case GDM_DISPLAY_FINISHED:

 #ifdef WITH_PLYMOUTH

                         if (quit_plymouth) {

                                 plymouth_quit_without_transition ();

                                 manager->priv->plymouth_is_running = FALSE;

                         }

 #endif

                         if (status == GDM_DISPLAY_FINISHED || g_strcmp0 (session_type, "x11") == 0) {

                                 manager->priv->ran_once = TRUE;

                         }

                         maybe_start_pending_initial_login (manager, display);

-                        maybe_activate_other_session (manager, display);

                         break;

                 default:

                         break;

         }

 }

 static void

 on_display_removed (GdmDisplayStore *display_store,

                     GdmDisplay      *display,

                     GdmManager      *manager)

 {

         char    *id;

         gdm_display_get_id (display, &id, NULL);

         g_dbus_object_manager_server_unexport (manager->priv->object_manager, id);

         g_free (id);

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

         g_signal_emit (manager, signals[DISPLAY_REMOVED], 0, display);

 }

 static void

 destroy_start_user_session_operation (StartUserSessionOperation *operation)

 {

         g_object_set_data (G_OBJECT (operation->session),

                            "start-user-session-operation",

                            NULL);

         g_object_unref (operation->session);

-- 

2.27.0