From a68f5dfd7662767b7b9822090b70bc5bd145c50c Mon Sep 17 00:00:00 2001
From: Kay Sievers <kay@vrfy.org>
Date: Mon, 19 May 2014 10:19:49 +0900
Subject: [PATCH] sessionmonitor-systemd: prepare for D-Bus "user bus" model

In the D-Bus "user bus" model, all sessions of a user share the same
D-Bus instance, a polkit requesting process might live outside the
login session which registered the user's polkit agent.

In case a polkit requesting process is not part of the user's login
session, we ask systemd-logind for the the user's "display" session
instead.

https://bugs.freedesktop.org/show_bug.cgi?id=78905
---
 configure.ac                                       |  4 ++++
 .../polkitbackendsessionmonitor-systemd.c          | 27 ++++++++++++++++++----
 2 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/configure.ac b/configure.ac
index a7b0148..e783ea5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -202,6 +202,10 @@ if test "$enable_libsystemd_login" != "no"; then
   if test "$have_libsystemd_login" = "yes"; then
     SESSION_TRACKING=libsystemd-login
     AC_DEFINE([HAVE_LIBSYSTEMD_LOGIN], 1, [Define to 1 if libsystemd-login is available])
+    save_LIBS=$LIBS
+    LIBS=$LIBSYSTEMD_LOGIN_LIBS
+    AC_CHECK_FUNCS(sd_uid_get_display)
+    LIBS=$save_LIBS
   else
     if test "$enable_libsystemd_login" = "yes"; then
       AC_MSG_ERROR([libsystemd-login support requested but libsystemd-login library not found])
diff --git a/src/polkitbackend/polkitbackendsessionmonitor-systemd.c b/src/polkitbackend/polkitbackendsessionmonitor-systemd.c
index 756b728..9995f87 100644
--- a/src/polkitbackend/polkitbackendsessionmonitor-systemd.c
+++ b/src/polkitbackend/polkitbackendsessionmonitor-systemd.c
@@ -318,6 +318,9 @@ polkit_backend_session_monitor_get_session_for_subject (PolkitBackendSessionMoni
   PolkitSubject *session = NULL;
   char *session_id = NULL;
   pid_t pid;
+#if HAVE_SD_UID_GET_DISPLAY
+  uid_t uid;
+#endif
 
   if (POLKIT_IS_UNIX_PROCESS (subject))
     process = POLKIT_UNIX_PROCESS (subject); /* We already have a process */
@@ -338,16 +341,30 @@ polkit_backend_session_monitor_get_session_for_subject (PolkitBackendSessionMoni
                    g_type_name (G_TYPE_FROM_INSTANCE (subject)));
     }
 
-  /* Now do process -> pid -> session */
+  /* Now do process -> pid -> same session */
   g_assert (process != NULL);
   pid = polkit_unix_process_get_pid (process);
 
-  if (sd_pid_get_session (pid, &session_id) < 0)
+  if (sd_pid_get_session (pid, &session_id) >= 0)
+    {
+      session = polkit_unix_session_new (session_id);
+      goto out;
+    }
+
+#if HAVE_SD_UID_GET_DISPLAY
+  /* Now do process -> uid -> graphical session (systemd version 213)*/
+  if (sd_pid_get_owner_uid (pid, &uid) < 0)
     goto out;
-  
-  session = polkit_unix_session_new (session_id);
-  free (session_id);
+
+  if (sd_uid_get_display (uid, &session_id) >= 0)
+    {
+      session = polkit_unix_session_new (session_id);
+      goto out;
+    }
+#endif
+
  out:
+  free (session_id);
   if (tmp_process) g_object_unref (tmp_process);
   return session;
 }
-- 
2.0.0