logind: add service for per-user shared systemd daemon

Makefile.am

@@ -353,7 +353,8 @@ nodist_systemunit_DATA = \
 	units/fsck@.service \
 	units/fsck-root.service \
 	units/quotacheck.service \
-	units/rescue.service
+	units/rescue.service \
+        units/user@.service
 
 if ENABLE_BINFMT
 nodist_systemunit_DATA += \
@@ -404,6 +405,7 @@ EXTRA_DIST = \
 	units/fsck@.service.in \
 	units/fsck-root.service.in \
 	units/quotacheck.service.in \
+        units/user@.service.in \
 	systemd.pc.in \
 	introspect.awk \
 	src/org.freedesktop.systemd1.policy.in \

src/pam-module.c

@@ -361,6 +361,13 @@ _public_ PAM_EXTERN int pam_sm_open_session(
         if (sd_booted() <= 0)
                 return PAM_SUCCESS;
 
+        /* Make sure we don't enter a loop by talking to
+         * systemd-logind when it is actually waiting for the
+         * background to finish start-up, */
+        pam_get_item(handle, PAM_SERVICE, (const void**) &service);
+        if (streq_ptr(service, "systemd-shared"))
+                return PAM_SUCCESS;
+
         if (parse_argv(handle,
                        argc, argv,
                        &controllers, &reset_controllers,
@@ -401,7 +408,6 @@ _public_ PAM_EXTERN int pam_sm_open_session(
         uid = pw->pw_uid;
         pid = getpid();
 
-        pam_get_item(handle, PAM_SERVICE, (const void**) &service);
         pam_get_item(handle, PAM_XDISPLAY, (const void**) &display);
         pam_get_item(handle, PAM_TTY, (const void**) &tty);
         pam_get_item(handle, PAM_RUSER, (const void**) &remote_user);

units/.gitignore

@@ -1,3 +1,4 @@
+user@.service
 systemd-logind.service
 systemd-localed.service
 systemd-timedated.service

units/user@.service.in

@@ -0,0 +1,18 @@
+#  This file is part of systemd.
+#
+#  systemd 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.
+
+[Unit]
+Description=User Manager for %I
+After=systemd-user-sessions.service
+
+[Service]
+User=%I
+PAMName=systemd-shared
+ControlGroup=/user/%I/shared
+ControlGroupModify=yes
+Type=notify
+ExecStart=-@rootbindir@/systemd --user