From 0314e68fe961cec941b1b0eb1cbcca4546cfdfdb Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Fri, 3 Aug 2018 19:04:35 +0200

Subject: [PATCH] logind: fix serialization/deserialization of user's "display

 session"

Previously this was serialized as part of the user object. This didn't

work however, as we load users first, and sessions seconds and hence

referencing a session from the user load logic cannot work.

Fix this by storing an IS_DISPLAY property along with each session, and

make the session with this set display session when it is loaded.

(cherry picked from commit 1c8280fd47b6561d35b15b3b6d49bdeacf891bfd)

Related: #1642460

---

 src/login/logind-session.c | 18 +++++++++++++++++-

 src/login/logind-user.c    | 18 ++++--------------

 2 files changed, 21 insertions(+), 15 deletions(-)

diff --git a/src/login/logind-session.c b/src/login/logind-session.c

index 5621d59a41..0afb065b2b 100644

--- a/src/login/logind-session.c

+++ b/src/login/logind-session.c

@@ -184,11 +184,13 @@ int session_save(Session *s) {

                 "UID="UID_FMT"\n"

                 "USER=%s\n"

                 "ACTIVE=%i\n"

+                "IS_DISPLAY=%i\n"

                 "STATE=%s\n"

                 "REMOTE=%i\n",

                 s->user->uid,

                 s->user->name,

                 session_is_active(s),

+                s->user->display == s,

                 session_state_to_string(session_get_state(s)),

                 s->remote);

@@ -359,7 +361,8 @@ int session_load(Session *s) {

                 *monotonic = NULL,

                 *controller = NULL,

                 *active = NULL,

-                *devices = NULL;

+                *devices = NULL,

+                *is_display = NULL;

         int k, r;

@@ -389,6 +392,7 @@ int session_load(Session *s) {

                            "CONTROLLER",     &controller,

                            "ACTIVE",         &active,

                            "DEVICES",        &devices,

+                           "IS_DISPLAY",     &is_display,

                            NULL);

         if (r < 0)

@@ -496,6 +500,18 @@ int session_load(Session *s) {

                         s->was_active = k;

         }

+        if (is_display) {

+                /* Note that when enumerating users are loaded before sessions, hence the display session to use is

+                 * something we have to store along with the session and not the user, as in that case we couldn't

+                 * apply it at the time we load the user. */

+

+                k = parse_boolean(is_display);

+                if (k < 0)

+                        log_warning_errno(k, "Failed to parse IS_DISPLAY session property: %m");

+                else if (k > 0)

+                        s->user->display = s;

+        }

+

         if (controller) {

                 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0) {

                         session_set_controller(s, controller, false, false);

diff --git a/src/login/logind-user.c b/src/login/logind-user.c

index 60ccd62abb..17ed361411 100644

--- a/src/login/logind-user.c

+++ b/src/login/logind-user.c

@@ -277,8 +277,7 @@ int user_save(User *u) {

 }

 int user_load(User *u) {

-        _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;

-        Session *s = NULL;

+        _cleanup_free_ char *realtime = NULL, *monotonic = NULL;

         int r;

         assert(u);

@@ -286,22 +285,13 @@ int user_load(User *u) {

         r = parse_env_file(NULL, u->state_file, NEWLINE,

                            "SERVICE_JOB", &u->service_job,

                            "SLICE_JOB",   &u->slice_job,

-                           "DISPLAY",     &display,

                            "REALTIME",    &realtime,

                            "MONOTONIC",   &monotonic,

                            NULL);

-        if (r < 0) {

-                if (r == -ENOENT)

-                        return 0;

-

+        if (r == -ENOENT)

+                return 0;

+        if (r < 0)

                 return log_error_errno(r, "Failed to read %s: %m", u->state_file);

-        }

-

-        if (display)

-                s = hashmap_get(u->manager->sessions, display);

-

-        if (s && s->display && display_is_local(s->display))

-                u->display = s;

         if (realtime)

                 timestamp_deserialize(realtime, &u->timestamp.realtime);