From 24439b08e3a3437b423553c385cde1d4cddf18f6 Mon Sep 17 00:00:00 2001

From: Michal Sekletar <msekleta@redhat.com>

Date: Mon, 8 Aug 2022 09:13:50 +0200

Subject: [PATCH] logind: add option to stop idle sessions after specified

 timeout

Thanks to Jan Pazdziora <jpazdziora@redhat.com> for providing a patch

which implemeted a PoC of this feature.

(cherry picked from commit 82325af3ae41bc7efb3d5cd8f56a4652fef498c2)

Resolves: #2122288

---

 man/logind.conf.xml          | 11 ++++++

 src/login/logind-core.c      |  2 +

 src/login/logind-dbus.c      |  1 +

 src/login/logind-gperf.gperf |  1 +

 src/login/logind-session.c   | 72 +++++++++++++++++++++++++++++++++---

 src/login/logind-session.h   |  2 +

 src/login/logind.conf.in     |  1 +

 src/login/logind.h           |  2 +

 8 files changed, 86 insertions(+), 6 deletions(-)

diff --git a/man/logind.conf.xml b/man/logind.conf.xml

index 0cf8a7d1f2..00b5b1f2e8 100644

--- a/man/logind.conf.xml

+++ b/man/logind.conf.xml

@@ -333,6 +333,17 @@

         are excluded from the effect of this setting. Defaults to <literal>no</literal>.</para></listitem>

       </varlistentry>

+      <varlistentry>

+        <term><varname>StopIdleSessionSec=</varname></term>

+

+        <listitem><para>Specifies a timeout in seconds, or a time span value after which

+        <filename>systemd-logind</filename> checks the idle state of all sessions. Every session that is idle for

+        longer then the timeout will be stopped. Defaults to <literal>infinity</literal>

+        (<filename>systemd-logind</filename> is not checking the idle state of sessions). For details about the syntax

+        of time spans, see

+        <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>.

+        </para></listitem>

+      </varlistentry>

     </variablelist>

   </refsect1>

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

index a1943b6f9d..abe6eecffb 100644

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

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

@@ -58,6 +58,8 @@ void manager_reset_config(Manager *m) {

         m->kill_only_users = strv_free(m->kill_only_users);

         m->kill_exclude_users = strv_free(m->kill_exclude_users);

+

+        m->stop_idle_session_usec = USEC_INFINITY;

 }

 int manager_parse_config_file(Manager *m) {

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

index 01bfef4ff7..81aacb4eed 100644

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

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

@@ -2720,6 +2720,7 @@ const sd_bus_vtable manager_vtable[] = {

         SD_BUS_PROPERTY("SessionsMax", "t", NULL, offsetof(Manager, sessions_max), SD_BUS_VTABLE_PROPERTY_CONST),

         SD_BUS_PROPERTY("NCurrentSessions", "t", property_get_hashmap_size, offsetof(Manager, sessions), 0),

         SD_BUS_PROPERTY("UserTasksMax", "t", property_get_compat_user_tasks_max, 0, SD_BUS_VTABLE_PROPERTY_CONST|SD_BUS_VTABLE_HIDDEN),

+        SD_BUS_PROPERTY("StopIdleSessionUSec", "t", NULL, offsetof(Manager, stop_idle_session_usec), SD_BUS_VTABLE_PROPERTY_CONST),

         SD_BUS_METHOD_WITH_NAMES("GetSession",

                                  "s",

diff --git a/src/login/logind-gperf.gperf b/src/login/logind-gperf.gperf

index 8829ce7d85..214ac5c4a3 100644

--- a/src/login/logind-gperf.gperf

+++ b/src/login/logind-gperf.gperf

@@ -42,3 +42,4 @@ Login.RemoveIPC,                    config_parse_bool,                  0, offse

 Login.InhibitorsMax,                config_parse_uint64,                0, offsetof(Manager, inhibitors_max)

 Login.SessionsMax,                  config_parse_uint64,                0, offsetof(Manager, sessions_max)

 Login.UserTasksMax,                 config_parse_compat_user_tasks_max, 0, offsetof(Manager, user_tasks_max)

+Login.StopIdleSessionSec,           config_parse_sec_fix_0,             0, offsetof(Manager, stop_idle_session_usec)

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

index cc838ca383..56f40fbec4 100644

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

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

@@ -29,6 +29,7 @@

 #include "string-table.h"

 #include "strv.h"

 #include "terminal-util.h"

+#include "time-util.h"

 #include "user-util.h"

 #include "util.h"

@@ -139,6 +140,8 @@ Session* session_free(Session *s) {

         free(s->state_file);

+        sd_event_source_unref(s->stop_on_idle_event_source);

+

         return mfree(s);

 }

@@ -658,6 +661,55 @@ static int session_start_scope(Session *s, sd_bus_message *properties, sd_bus_er

         return 0;

 }

+static int session_dispatch_stop_on_idle(sd_event_source *source, uint64_t t, void *userdata) {

+        Session *s = userdata;

+        dual_timestamp ts;

+        int r, idle;

+

+        assert(s);

+

+        if (s->stopping)

+                return 0;

+

+        idle = session_get_idle_hint(s, &ts);

+        if (idle) {

+                log_debug("Session \"%s\" of user \"%s\" is idle, stopping.", s->id, s->user->name);

+

+                return session_stop(s, /* force */ true);

+        }

+

+        r = sd_event_source_set_time(source, usec_add(ts.monotonic, s->manager->stop_idle_session_usec));

+        if (r < 0)

+                return log_error_errno(r, "Failed to configure stop on idle session event source: %m");

+

+        r = sd_event_source_set_enabled(source, SD_EVENT_ONESHOT);

+        if (r < 0)

+                return log_error_errno(r, "Failed to enable stop on idle session event source: %m");

+

+        return 1;

+}

+

+static int session_setup_stop_on_idle_timer(Session *s) {

+        int r;

+

+        assert(s);

+

+        if (s->manager->stop_idle_session_usec == USEC_INFINITY)

+                return 0;

+

+        r = sd_event_add_time_relative(

+                        s->manager->event,

+                        &s->stop_on_idle_event_source,

+                        CLOCK_MONOTONIC,

+                        s->manager->stop_idle_session_usec,

+                        0,

+                        session_dispatch_stop_on_idle, s);

+        if (r < 0)

+                return log_error_errno(r, "Failed to add stop on idle session event source: %m");

+

+        return 0;

+}

+

 int session_start(Session *s, sd_bus_message *properties, sd_bus_error *error) {

         int r;

@@ -680,6 +732,10 @@ int session_start(Session *s, sd_bus_message *properties, sd_bus_error *error) {

         if (r < 0)

                 return r;

+        r = session_setup_stop_on_idle_timer(s);

+        if (r < 0)

+                return r;

+

         log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,

                    "MESSAGE_ID=" SD_MESSAGE_SESSION_START_STR,

                    "SESSION_ID=%s", s->id,

@@ -917,7 +973,7 @@ static int get_process_ctty_atime(pid_t pid, usec_t *atime) {

 }

 int session_get_idle_hint(Session *s, dual_timestamp *t) {

-        usec_t atime = 0, n;

+        usec_t atime = 0, dtime = 0;

         int r;

         assert(s);

@@ -961,12 +1017,16 @@ found_atime:

         if (t)

                 dual_timestamp_from_realtime(t, atime);

-        n = now(CLOCK_REALTIME);

-

-        if (s->manager->idle_action_usec <= 0)

-                return 0;

+        if (s->manager->idle_action_usec > 0 && s->manager->stop_idle_session_usec != USEC_INFINITY)

+                dtime = MIN(s->manager->idle_action_usec, s->manager->stop_idle_session_usec);

+        else if (s->manager->idle_action_usec > 0)

+                dtime = s->manager->idle_action_usec;

+        else if (s->manager->stop_idle_session_usec != USEC_INFINITY)

+                dtime = s->manager->stop_idle_session_usec;

+        else

+                return false;

-        return atime + s->manager->idle_action_usec <= n;

+        return usec_add(atime, dtime) <= now(CLOCK_REALTIME);

 }

 void session_set_idle_hint(Session *s, bool b) {

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

index 8c7d0301f2..6678441bb9 100644

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

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

@@ -112,6 +112,8 @@ struct Session {

         Hashmap *devices;

         sd_bus_track *track;

+        sd_event_source *stop_on_idle_event_source;

+

         LIST_FIELDS(Session, sessions_by_user);

         LIST_FIELDS(Session, sessions_by_seat);

diff --git a/src/login/logind.conf.in b/src/login/logind.conf.in

index c7346f9819..a62c2b0b57 100644

--- a/src/login/logind.conf.in

+++ b/src/login/logind.conf.in

@@ -35,3 +35,4 @@

 #RemoveIPC=no

 #InhibitorsMax=8192

 #SessionsMax=8192

+#StopIdleSessionSec=infinity

diff --git a/src/login/logind.h b/src/login/logind.h

index 7f94dea2f6..606adf4fe6 100644

--- a/src/login/logind.h

+++ b/src/login/logind.h

@@ -102,6 +102,8 @@ struct Manager {

         usec_t idle_action_not_before_usec;

         HandleAction idle_action;

+        usec_t stop_idle_session_usec;

+

         HandleAction handle_power_key;

         HandleAction handle_suspend_key;

         HandleAction handle_hibernate_key;