Fix checks for logind

It is possible to build systemd without logind or run logind without systemd
init, in both cases testing for systemd init is wrong.  Check for
/run/systemd/seats in the parts which talk to logind instead, as recommended by
systemd upstream.

For details, see:
<https://mail.gnome.org/archives/desktop-devel-list/2013-March/msg00092.html>

https://bugzilla.gnome.org/show_bug.cgi?id=696266

8 files changed, 24 insertions, 29 deletions

diff --git a/common/gdm-common.h b/common/gdm-common.h
index 00012743..f9033aa5 100644
--- a/common/gdm-common.h
+++ b/common/gdm-common.h
@@ -33,6 +33,9 @@
 
 #define GDM_CUSTOM_SESSION  "custom"
 
+/* check if logind is running */
+#define LOGIND_RUNNING() (access("/run/systemd/seats/", F_OK) >= 0)
+
 G_BEGIN_DECLS
 
 gboolean       gdm_is_version_unstable            (void);
diff --git a/daemon/gdm-local-display-factory.c b/daemon/gdm-local-display-factory.c
index 90950f92..7457fc38 100644
--- a/daemon/gdm-local-display-factory.c
+++ b/daemon/gdm-local-display-factory.c
@@ -28,10 +28,7 @@
 #include <glib-object.h>
 #include <gio/gio.h>
 
-#ifdef WITH_SYSTEMD
-#include <systemd/sd-daemon.h>
-#endif
-
+#include "gdm-common.h"
 #include "gdm-manager.h"
 #include "gdm-display-factory.h"
 #include "gdm-local-display-factory.h"
@@ -521,7 +518,7 @@ gdm_local_display_factory_start (GdmDisplayFactory *base_factory)
         g_return_val_if_fail (GDM_IS_LOCAL_DISPLAY_FACTORY (factory), FALSE);
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 gdm_local_display_factory_start_monitor (factory);
                 return gdm_local_display_factory_sync_seats (factory);
         }
diff --git a/daemon/gdm-manager.c b/daemon/gdm-manager.c
index 5888f351..6e1eaba7 100644
--- a/daemon/gdm-manager.c
+++ b/daemon/gdm-manager.c
@@ -35,7 +35,6 @@
 #include <glib-object.h>
 
 #ifdef WITH_SYSTEMD
-#include <systemd/sd-daemon.h>
 #include <systemd/sd-login.h>
 #endif
 
@@ -166,7 +165,7 @@ get_session_id_for_pid (GDBusConnection  *connection,
                         GError          **error)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return get_session_id_for_pid_systemd (pid, error);
         }
 #endif
@@ -242,7 +241,7 @@ get_uid_for_session_id (GDBusConnection  *connection,
                         GError          **error)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return get_uid_for_systemd_session_id (session_id, uid, error);
         }
 #endif
@@ -487,7 +486,7 @@ get_session_id_for_user_on_seat (GDBusConnection  *connection,
                                  GError          **error)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return get_session_id_for_user_on_seat_systemd (username, seat, error);
         }
 #endif
@@ -601,7 +600,7 @@ get_seat_id_for_pid (GDBusConnection  *connection,
                      GError          **error)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return get_seat_id_for_pid_systemd (pid, error);
         }
 #endif
diff --git a/daemon/gdm-server.c b/daemon/gdm-server.c
index 01fc5d48..91a04e63 100644
--- a/daemon/gdm-server.c
+++ b/daemon/gdm-server.c
@@ -39,10 +39,6 @@
 #include <sys/prctl.h>
 #endif
 
-#ifdef WITH_SYSTEMD
-#include <systemd/sd-daemon.h>
-#endif
-
 #ifdef WITH_PLYMOUTH
 #include <linux/vt.h>
 #endif
@@ -173,7 +169,7 @@ char *
 gdm_server_get_display_device (GdmServer *server)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 /* systemd finds the display device out on its own based on the display */
                 return NULL;
         }
@@ -275,7 +271,7 @@ gdm_server_init_command (GdmServer *server)
          * wasn't booted using systemd, or b) the wrapper tool is
          * missing, or c) we are running for the main seat 'seat0'. */
 
-        if (sd_booted () <= 0) {
+        if (!LOGIND_RUNNING()) {
                 goto fallback;
         }
 
@@ -345,7 +341,7 @@ gdm_server_resolve_command_line (GdmServer  *server,
         }
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0 && server->priv->display_seat_id != NULL) {
+        if (LOGIND_RUNNING() && server->priv->display_seat_id != NULL) {
                 argv[len++] = g_strdup ("-seat");
                 argv[len++] = g_strdup (server->priv->display_seat_id);
         }
@@ -745,7 +741,7 @@ gdm_server_start (GdmServer *server)
 
 #ifdef WITH_SYSTEMD
                 /* undo the hardcoding if we are an auxillary seat */
-                if (sd_booted () > 0) {
+                if (LOGIND_RUNNING()) {
                      if (strcmp (server->priv->display_seat_id, "seat0") != 0) {
                          vtarg = NULL;
                      }
diff --git a/daemon/gdm-session-worker.c b/daemon/gdm-session-worker.c
index ab84182b..da901973 100644
--- a/daemon/gdm-session-worker.c
+++ b/daemon/gdm-session-worker.c
@@ -1089,7 +1089,7 @@ gdm_session_worker_initialize_pam (GdmSessionWorker *worker,
 
 #ifdef WITH_SYSTEMD
         /* set seat ID */
-        if (seat_id != NULL && seat_id[0] != '\0' && sd_booted() > 0) {
+        if (seat_id != NULL && seat_id[0] != '\0' && LOGIND_RUNNING()) {
                 gdm_session_worker_set_environment_variable (worker, "XDG_SEAT", seat_id);
         }
 #endif
@@ -1556,7 +1556,7 @@ static void
 register_ck_session (GdmSessionWorker *worker)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted() > 0) {
+        if (LOGIND_RUNNING()) {
                 return;
         }
 #endif
diff --git a/daemon/gdm-slave.c b/daemon/gdm-slave.c
index 94747723..ba292a34 100644
--- a/daemon/gdm-slave.c
+++ b/daemon/gdm-slave.c
@@ -46,7 +46,6 @@
 
 #ifdef WITH_SYSTEMD
 #include <systemd/sd-login.h>
-#include <systemd/sd-daemon.h>
 #endif
 
 #include "gdm-common.h"
@@ -1411,7 +1410,7 @@ gdm_slave_get_primary_session_id_for_user (GdmSlave   *slave,
         }
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return gdm_slave_get_primary_session_id_for_user_from_systemd (slave, username);
         }
 #endif
@@ -1496,7 +1495,7 @@ activate_session_id (GdmSlave   *slave,
 {
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return activate_session_id_for_systemd (slave, seat_id, session_id);
         }
 #endif
@@ -1549,7 +1548,7 @@ session_is_active (GdmSlave   *slave,
                    const char *session_id)
 {
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return sd_session_is_active (session_id) > 0;
         }
 #endif
@@ -1633,7 +1632,7 @@ session_unlock (GdmSlave   *slave,
         g_debug ("Unlocking session %s", ssid);
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return session_unlock_for_systemd (slave, ssid);
         }
 #endif
diff --git a/gui/libgdm/gdm-user-switching.c b/gui/libgdm/gdm-user-switching.c
index c4342f27..ebfef1c3 100644
--- a/gui/libgdm/gdm-user-switching.c
+++ b/gui/libgdm/gdm-user-switching.c
@@ -32,10 +32,10 @@
 #include <gio/gio.h>
 
 #ifdef WITH_SYSTEMD
-#include <systemd/sd-daemon.h>
 #include <systemd/sd-login.h>
 #endif
 
+#include "common/gdm-common.h"
 #include "gdm-user-switching.h"
 #include "gdm-client.h"
 
@@ -578,7 +578,7 @@ gdm_goto_login_session_sync (GCancellable  *cancellable,
                 return FALSE;
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 retval = goto_login_session_for_systemd (connection,
                                                          cancellable,
                                                          error);
diff --git a/utils/gdmflexiserver.c b/utils/gdmflexiserver.c
index d1b72fe6..cfeb1757 100644
--- a/utils/gdmflexiserver.c
+++ b/utils/gdmflexiserver.c
@@ -29,8 +29,9 @@
 #include <glib/gi18n.h>
 #include <gtk/gtk.h>
 
+#include "common/gdm-common.h"
+
 #ifdef WITH_SYSTEMD
-#include <systemd/sd-daemon.h>
 #include <systemd/sd-login.h>
 #endif
 
@@ -680,7 +681,7 @@ goto_login_session (GError **error)
         }
 
 #ifdef WITH_SYSTEMD
-        if (sd_booted () > 0) {
+        if (LOGIND_RUNNING()) {
                 return goto_login_session_for_systemd (connection, error);
         }
 #endif