1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
12 #include "sd-messages.h"
14 #include "alloc-util.h"
15 #include "audit-util.h"
16 #include "bus-error.h"
18 #include "daemon-util.h"
19 #include "devnum-util.h"
24 #include "format-util.h"
27 #include "logind-dbus.h"
28 #include "logind-seat-dbus.h"
29 #include "logind-session-dbus.h"
30 #include "logind-session.h"
31 #include "logind-user-dbus.h"
32 #include "mkdir-label.h"
33 #include "parse-util.h"
34 #include "path-util.h"
35 #include "process-util.h"
36 #include "serialize.h"
37 #include "string-table.h"
39 #include "terminal-util.h"
40 #include "tmpfile-util.h"
41 #include "uid-classification.h"
42 #include "user-util.h"
44 #define RELEASE_USEC (20*USEC_PER_SEC)
46 static void session_remove_fifo(Session
*s
);
47 static void session_restore_vt(Session
*s
);
49 int session_new(Session
**ret
, Manager
*m
, const char *id
) {
50 _cleanup_(session_freep
) Session
*s
= NULL
;
57 if (!session_id_valid(id
))
68 .audit_id
= AUDIT_SESSION_INVALID
,
69 .tty_validity
= _TTY_VALIDITY_INVALID
,
70 .leader
= PIDREF_NULL
,
73 s
->state_file
= path_join("/run/systemd/sessions", id
);
77 s
->id
= basename(s
->state_file
);
79 s
->devices
= hashmap_new(&devt_hash_ops
);
83 r
= hashmap_put(m
->sessions
, s
->id
, s
);
91 static int session_dispatch_leader_pidfd(sd_event_source
*es
, int fd
, uint32_t revents
, void *userdata
) {
92 Session
*s
= ASSERT_PTR(userdata
);
94 assert(s
->leader
.fd
== fd
);
95 session_stop(s
, /* force= */ false);
100 static int session_watch_pidfd(Session
*s
) {
105 assert(pidref_is_set(&s
->leader
));
107 if (s
->leader
.fd
< 0)
110 r
= sd_event_add_io(s
->manager
->event
, &s
->leader_pidfd_event_source
, s
->leader
.fd
, EPOLLIN
, session_dispatch_leader_pidfd
, s
);
114 r
= sd_event_source_set_priority(s
->leader_pidfd_event_source
, SD_EVENT_PRIORITY_IMPORTANT
);
118 (void) sd_event_source_set_description(s
->leader_pidfd_event_source
, "session-pidfd");
123 static void session_reset_leader(Session
*s
, bool keep_fdstore
) {
127 /* Clear fdstore if we're asked to, no matter if s->leader is set or not, so that when
128 * initially deserializing leader fd we clear the old fd too. */
129 (void) notify_remove_fd_warnf("session-%s-leader-fd", s
->id
);
130 s
->leader_fd_saved
= false;
133 if (!pidref_is_set(&s
->leader
))
136 s
->leader_pidfd_event_source
= sd_event_source_disable_unref(s
->leader_pidfd_event_source
);
138 (void) hashmap_remove_value(s
->manager
->sessions_by_leader
, &s
->leader
, s
);
140 return pidref_done(&s
->leader
);
143 Session
* session_free(Session
*s
) {
150 LIST_REMOVE(gc_queue
, s
->manager
->session_gc_queue
, s
);
152 s
->timer_event_source
= sd_event_source_unref(s
->timer_event_source
);
154 session_drop_controller(s
);
156 while ((sd
= hashmap_first(s
->devices
)))
157 session_device_free(sd
);
159 hashmap_free(s
->devices
);
162 LIST_REMOVE(sessions_by_user
, s
->user
->sessions
, s
);
164 if (s
->user
->display
== s
)
165 s
->user
->display
= NULL
;
167 user_update_last_session_timer(s
->user
);
171 if (s
->seat
->active
== s
)
172 s
->seat
->active
= NULL
;
173 if (s
->seat
->pending_switch
== s
)
174 s
->seat
->pending_switch
= NULL
;
176 seat_evict_position(s
->seat
, s
);
177 LIST_REMOVE(sessions_by_seat
, s
->seat
->sessions
, s
);
181 hashmap_remove(s
->manager
->session_units
, s
->scope
);
187 session_reset_leader(s
, /* keep_fdstore = */ true);
189 sd_bus_message_unref(s
->create_message
);
193 free(s
->remote_host
);
194 free(s
->remote_user
);
198 hashmap_remove(s
->manager
->sessions
, s
->id
);
200 sd_event_source_unref(s
->fifo_event_source
);
201 safe_close(s
->fifo_fd
);
203 /* Note that we remove neither the state file nor the fifo path here, since we want both to survive
208 sd_event_source_unref(s
->stop_on_idle_event_source
);
213 void session_set_user(Session
*s
, User
*u
) {
218 LIST_PREPEND(sessions_by_user
, u
->sessions
, s
);
220 user_update_last_session_timer(u
);
223 int session_set_leader_consume(Session
*s
, PidRef _leader
) {
224 _cleanup_(pidref_done
) PidRef pidref
= _leader
;
228 assert(pidref_is_set(&pidref
));
230 if (pidref_equal(&s
->leader
, &pidref
))
233 session_reset_leader(s
, /* keep_fdstore = */ false);
235 s
->leader
= TAKE_PIDREF(pidref
);
237 r
= session_watch_pidfd(s
);
239 return log_error_errno(r
, "Failed to watch leader pidfd for session '%s': %m", s
->id
);
241 r
= hashmap_ensure_put(&s
->manager
->sessions_by_leader
, &pidref_hash_ops
, &s
->leader
, s
);
246 if (s
->leader
.fd
>= 0) {
247 r
= notify_push_fdf(s
->leader
.fd
, "session-%s-leader-fd", s
->id
);
249 log_warning_errno(r
, "Failed to push leader pidfd for session '%s', ignoring: %m", s
->id
);
251 s
->leader_fd_saved
= true;
254 (void) audit_session_from_pid(s
->leader
.pid
, &s
->audit_id
);
259 static void session_save_devices(Session
*s
, FILE *f
) {
262 if (!hashmap_isempty(s
->devices
)) {
263 fprintf(f
, "DEVICES=");
264 HASHMAP_FOREACH(sd
, s
->devices
)
265 fprintf(f
, DEVNUM_FORMAT_STR
" ", DEVNUM_FORMAT_VAL(sd
->dev
));
270 int session_save(Session
*s
) {
271 _cleanup_(unlink_and_freep
) char *temp_path
= NULL
;
272 _cleanup_fclose_
FILE *f
= NULL
;
283 r
= mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0, MKDIR_WARN_MODE
);
287 r
= fopen_temporary(s
->state_file
, &f
, &temp_path
);
291 (void) fchmod(fileno(f
), 0644);
294 "# This is private data. Do not parse.\n"
301 "LEADER_FD_SAVED=%s\n",
302 s
->user
->user_record
->uid
,
303 s
->user
->user_record
->user_name
,
304 one_zero(session_is_active(s
)),
305 one_zero(s
->user
->display
== s
),
306 session_state_to_string(session_get_state(s
)),
308 one_zero(s
->leader_fd_saved
));
311 fprintf(f
, "TYPE=%s\n", session_type_to_string(s
->type
));
313 if (s
->original_type
>= 0)
314 fprintf(f
, "ORIGINAL_TYPE=%s\n", session_type_to_string(s
->original_type
));
317 fprintf(f
, "CLASS=%s\n", session_class_to_string(s
->class));
320 fprintf(f
, "SCOPE=%s\n", s
->scope
);
322 fprintf(f
, "SCOPE_JOB=%s\n", s
->scope_job
);
325 fprintf(f
, "FIFO=%s\n", s
->fifo_path
);
328 fprintf(f
, "SEAT=%s\n", s
->seat
->id
);
331 fprintf(f
, "TTY=%s\n", s
->tty
);
333 if (s
->tty_validity
>= 0)
334 fprintf(f
, "TTY_VALIDITY=%s\n", tty_validity_to_string(s
->tty_validity
));
337 fprintf(f
, "DISPLAY=%s\n", s
->display
);
339 if (s
->remote_host
) {
340 _cleanup_free_
char *escaped
= NULL
;
342 escaped
= cescape(s
->remote_host
);
348 fprintf(f
, "REMOTE_HOST=%s\n", escaped
);
351 if (s
->remote_user
) {
352 _cleanup_free_
char *escaped
= NULL
;
354 escaped
= cescape(s
->remote_user
);
360 fprintf(f
, "REMOTE_USER=%s\n", escaped
);
364 _cleanup_free_
char *escaped
= NULL
;
366 escaped
= cescape(s
->service
);
372 fprintf(f
, "SERVICE=%s\n", escaped
);
376 _cleanup_free_
char *escaped
= NULL
;
378 escaped
= cescape(s
->desktop
);
384 fprintf(f
, "DESKTOP=%s\n", escaped
);
387 if (s
->seat
&& seat_has_vts(s
->seat
))
388 fprintf(f
, "VTNR=%u\n", s
->vtnr
);
391 fprintf(f
, "POSITION=%u\n", s
->position
);
393 if (pidref_is_set(&s
->leader
))
394 fprintf(f
, "LEADER="PID_FMT
"\n", s
->leader
.pid
);
396 if (audit_session_is_valid(s
->audit_id
))
397 fprintf(f
, "AUDIT=%"PRIu32
"\n", s
->audit_id
);
399 if (dual_timestamp_is_set(&s
->timestamp
))
401 "REALTIME="USEC_FMT
"\n"
402 "MONOTONIC="USEC_FMT
"\n",
403 s
->timestamp
.realtime
,
404 s
->timestamp
.monotonic
);
407 fprintf(f
, "CONTROLLER=%s\n", s
->controller
);
408 session_save_devices(s
, f
);
411 r
= fflush_and_check(f
);
415 if (rename(temp_path
, s
->state_file
) < 0) {
420 temp_path
= mfree(temp_path
);
424 (void) unlink(s
->state_file
);
426 return log_error_errno(r
, "Failed to save session data %s: %m", s
->state_file
);
429 static int session_load_devices(Session
*s
, const char *devices
) {
434 for (const char *p
= devices
;;) {
435 _cleanup_free_
char *word
= NULL
;
439 k
= extract_first_word(&p
, &word
, NULL
, 0);
445 k
= parse_devnum(word
, &dev
);
451 /* The file descriptors for loaded devices will be reattached later. */
452 RET_GATHER(r
, session_device_new(s
, dev
, /* open_device = */ false, /* ret = */ NULL
));
456 log_error_errno(r
, "Failed to load some session devices for session '%s': %m", s
->id
);
460 int session_load(Session
*s
) {
461 _cleanup_free_
char *remote
= NULL
,
463 *tty_validity
= NULL
,
468 *leader_fd_saved
= NULL
,
470 *original_type
= NULL
,
484 r
= parse_env_file(NULL
, s
->state_file
,
487 "SCOPE_JOB", &s
->scope_job
,
488 "FIFO", &s
->fifo_path
,
491 "TTY_VALIDITY", &tty_validity
,
492 "DISPLAY", &s
->display
,
493 "REMOTE_HOST", &s
->remote_host
,
494 "REMOTE_USER", &s
->remote_user
,
495 "SERVICE", &s
->service
,
496 "DESKTOP", &s
->desktop
,
499 "POSITION", &position
,
500 "LEADER", &leader_pid
,
501 "LEADER_FD_SAVED", &leader_fd_saved
,
503 "ORIGINAL_TYPE", &original_type
,
506 "REALTIME", &realtime
,
507 "MONOTONIC", &monotonic
,
508 "CONTROLLER", &controller
,
511 "IS_DISPLAY", &is_display
);
513 return log_error_errno(r
, "Failed to read %s: %m", s
->state_file
);
520 return log_error_errno(SYNTHETIC_ERRNO(ENOENT
),
521 "UID not specified for session %s",
524 r
= parse_uid(uid
, &u
);
526 log_error("Failed to parse UID value %s for session %s.", uid
, s
->id
);
530 user
= hashmap_get(s
->manager
->users
, UID_TO_PTR(u
));
532 return log_error_errno(SYNTHETIC_ERRNO(ENOENT
),
533 "User of session %s not known.",
536 session_set_user(s
, user
);
540 k
= parse_boolean(remote
);
546 safe_atou(vtnr
, &s
->vtnr
);
548 if (seat
&& !s
->seat
) {
551 o
= hashmap_get(s
->manager
->seats
, seat
);
553 r
= seat_attach_session(o
, s
);
555 log_error("Cannot attach session %s to seat %s", s
->id
, seat
);
558 if (!s
->seat
|| !seat_has_vts(s
->seat
))
561 if (position
&& s
->seat
) {
564 safe_atou(position
, &npos
);
565 seat_claim_position(s
->seat
, s
, npos
);
571 v
= tty_validity_from_string(tty_validity
);
573 log_debug("Failed to parse TTY validity: %s", tty_validity
);
581 t
= session_type_from_string(type
);
589 ot
= session_type_from_string(original_type
);
591 s
->original_type
= ot
;
593 /* Pre-v246 compat: initialize original_type if not set in the state file */
594 s
->original_type
= s
->type
;
599 c
= session_class_from_string(class);
604 if (streq_ptr(state
, "closing"))
610 /* If we open an unopened pipe for reading we will not
611 get an EOF. to trigger an EOF we hence open it for
612 writing, but close it right away which then will
613 trigger the EOF. This will happen immediately if no
614 other process has the FIFO open for writing, i. e.
615 when the session died before logind (re)started. */
617 fd
= session_create_fifo(s
);
622 (void) deserialize_usec(realtime
, &s
->timestamp
.realtime
);
624 (void) deserialize_usec(monotonic
, &s
->timestamp
.monotonic
);
627 k
= parse_boolean(active
);
633 /* Note that when enumerating users are loaded before sessions, hence the display session to use is
634 * something we have to store along with the session and not the user, as in that case we couldn't
635 * apply it at the time we load the user. */
637 k
= parse_boolean(is_display
);
639 log_warning_errno(k
, "Failed to parse IS_DISPLAY session property: %m");
641 s
->user
->display
= s
;
645 if (bus_name_has_owner(s
->manager
->bus
, controller
, NULL
) > 0) {
646 session_set_controller(s
, controller
, false, false);
647 session_load_devices(s
, devices
);
649 session_restore_vt(s
);
653 assert(!pidref_is_set(&s
->leader
));
655 r
= parse_pid(leader_pid
, &s
->deserialized_pid
);
657 return log_error_errno(r
, "Failed to parse LEADER=%s: %m", leader_pid
);
659 if (leader_fd_saved
) {
660 r
= parse_boolean(leader_fd_saved
);
662 return log_error_errno(r
, "Failed to parse LEADER_FD_SAVED=%s: %m", leader_fd_saved
);
663 s
->leader_fd_saved
= r
> 0;
665 if (s
->leader_fd_saved
)
666 /* The leader fd will be acquired from fdstore later */
670 _cleanup_(pidref_done
) PidRef p
= PIDREF_NULL
;
672 r
= pidref_set_pid(&p
, s
->deserialized_pid
);
674 r
= session_set_leader_consume(s
, TAKE_PIDREF(p
));
676 log_warning_errno(r
, "Failed to set leader PID for session '%s': %m", s
->id
);
682 int session_activate(Session
*s
) {
683 unsigned num_pending
;
691 if (s
->seat
->active
== s
)
694 /* on seats with VTs, we let VTs manage session-switching */
695 if (seat_has_vts(s
->seat
)) {
699 return chvt(s
->vtnr
);
702 /* On seats without VTs, we implement session-switching in logind. We
703 * try to pause all session-devices and wait until the session
704 * controller acknowledged them. Once all devices are asleep, we simply
705 * switch the active session and be done.
706 * We save the session we want to switch to in seat->pending_switch and
707 * seat_complete_switch() will perform the final switch. */
709 s
->seat
->pending_switch
= s
;
711 /* if no devices are running, immediately perform the session switch */
712 num_pending
= session_device_try_pause_all(s
);
714 seat_complete_switch(s
->seat
);
719 static int session_start_scope(Session
*s
, sd_bus_message
*properties
, sd_bus_error
*error
) {
725 if (!SESSION_CLASS_WANTS_SCOPE(s
->class))
729 _cleanup_strv_free_
char **wants
= NULL
, **after
= NULL
;
730 _cleanup_free_
char *scope
= NULL
;
731 const char *description
;
733 s
->scope_job
= mfree(s
->scope_job
);
735 scope
= strjoin("session-", s
->id
, ".scope");
739 description
= strjoina("Session ", s
->id
, " of User ", s
->user
->user_record
->user_name
);
741 /* These two have StopWhenUnneeded= set, hence add a dep towards them */
742 wants
= strv_new(s
->user
->runtime_dir_service
,
743 SESSION_CLASS_WANTS_SERVICE_MANAGER(s
->class) ? s
->user
->service
: STRV_IGNORE
);
747 /* We usually want to order session scopes after systemd-user-sessions.service since the
748 * latter unit is used as login session barrier for unprivileged users. However the barrier
749 * doesn't apply for root as sysadmin should always be able to log in (and without waiting
750 * for any timeout to expire) in case something goes wrong during the boot process. Since
751 * ordering after systemd-user-sessions.service and the user instance is optional we make use
752 * of STRV_IGNORE with strv_new() to skip these order constraints when needed. */
753 after
= strv_new("systemd-logind.service",
754 s
->user
->runtime_dir_service
,
755 SESSION_CLASS_IS_EARLY(s
->class) ? STRV_IGNORE
: "systemd-user-sessions.service",
760 r
= manager_start_scope(
768 user_record_home_directory(s
->user
->user_record
),
773 return log_error_errno(r
, "Failed to start session scope %s: %s",
774 scope
, bus_error_message(error
, r
));
776 s
->scope
= TAKE_PTR(scope
);
779 (void) hashmap_put(s
->manager
->session_units
, s
->scope
, s
);
784 static int session_dispatch_stop_on_idle(sd_event_source
*source
, uint64_t t
, void *userdata
) {
785 Session
*s
= userdata
;
794 idle
= session_get_idle_hint(s
, &ts
);
796 log_info("Session \"%s\" of user \"%s\" is idle, stopping.", s
->id
, s
->user
->user_record
->user_name
);
798 return session_stop(s
, /* force */ true);
801 r
= sd_event_source_set_time(
803 usec_add(dual_timestamp_is_set(&ts
) ? ts
.monotonic
: now(CLOCK_MONOTONIC
),
804 s
->manager
->stop_idle_session_usec
));
806 return log_error_errno(r
, "Failed to configure stop on idle session event source: %m");
808 r
= sd_event_source_set_enabled(source
, SD_EVENT_ONESHOT
);
810 return log_error_errno(r
, "Failed to enable stop on idle session event source: %m");
815 static int session_setup_stop_on_idle_timer(Session
*s
) {
820 if (s
->manager
->stop_idle_session_usec
== USEC_INFINITY
|| !SESSION_CLASS_CAN_STOP_ON_IDLE(s
->class))
823 r
= sd_event_add_time_relative(
825 &s
->stop_on_idle_event_source
,
827 s
->manager
->stop_idle_session_usec
,
829 session_dispatch_stop_on_idle
, s
);
831 return log_error_errno(r
, "Failed to add stop on idle session event source: %m");
836 int session_start(Session
*s
, sd_bus_message
*properties
, sd_bus_error
*error
) {
850 r
= user_start(s
->user
);
854 r
= session_start_scope(s
, properties
, error
);
858 r
= session_setup_stop_on_idle_timer(s
);
862 log_struct(s
->class == SESSION_BACKGROUND
? LOG_DEBUG
: LOG_INFO
,
863 "MESSAGE_ID=" SD_MESSAGE_SESSION_START_STR
,
864 "SESSION_ID=%s", s
->id
,
865 "USER_ID=%s", s
->user
->user_record
->user_name
,
866 "LEADER="PID_FMT
, s
->leader
.pid
,
867 LOG_MESSAGE("New session %s of user %s.", s
->id
, s
->user
->user_record
->user_name
));
869 if (!dual_timestamp_is_set(&s
->timestamp
))
870 dual_timestamp_now(&s
->timestamp
);
873 seat_read_active_vt(s
->seat
);
877 user_elect_display(s
->user
);
880 (void) session_save(s
);
881 (void) user_save(s
->user
);
883 (void) seat_save(s
->seat
);
886 session_send_signal(s
, true);
887 user_send_changed(s
->user
, "Display", NULL
);
889 if (s
->seat
&& s
->seat
->active
== s
)
890 (void) seat_send_changed(s
->seat
, "ActiveSession", NULL
);
895 static int session_stop_scope(Session
*s
, bool force
) {
896 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
904 /* Let's always abandon the scope first. This tells systemd that we are not interested anymore, and everything
905 * that is left in the scope is "left-over". Informing systemd about this has the benefit that it will log
906 * when killing any processes left after this point. */
907 r
= manager_abandon_scope(s
->manager
, s
->scope
, &error
);
909 log_warning_errno(r
, "Failed to abandon session scope, ignoring: %s", bus_error_message(&error
, r
));
910 sd_bus_error_free(&error
);
913 s
->scope_job
= mfree(s
->scope_job
);
915 /* Optionally, let's kill everything that's left now. */
917 (s
->user
->user_record
->kill_processes
!= 0 &&
918 (s
->user
->user_record
->kill_processes
> 0 ||
919 manager_shall_kill(s
->manager
, s
->user
->user_record
->user_name
)))) {
921 r
= manager_stop_unit(s
->manager
, s
->scope
, force
? "replace" : "fail", &error
, &s
->scope_job
);
924 return log_error_errno(r
, "Failed to stop session scope: %s", bus_error_message(&error
, r
));
926 log_warning_errno(r
, "Failed to stop session scope, ignoring: %s", bus_error_message(&error
, r
));
930 /* With no killing, this session is allowed to persist in "closing" state indefinitely.
931 * Therefore session stop and session removal may be two distinct events.
932 * Session stop is quite significant on its own, let's log it. */
933 log_struct(s
->class == SESSION_BACKGROUND
? LOG_DEBUG
: LOG_INFO
,
934 "SESSION_ID=%s", s
->id
,
935 "USER_ID=%s", s
->user
->user_record
->user_name
,
936 "LEADER="PID_FMT
, s
->leader
.pid
,
937 LOG_MESSAGE("Session %s logged out. Waiting for processes to exit.", s
->id
));
943 int session_stop(Session
*s
, bool force
) {
948 /* This is called whenever we begin with tearing down a session record. It's called in four cases: explicit API
949 * request via the bus (either directly for the session object or for the seat or user object this session
950 * belongs to; 'force' is true), or due to automatic GC (i.e. scope vanished; 'force' is false), or because the
951 * session FIFO saw an EOF ('force' is false), or because the release timer hit ('force' is false). */
960 s
->timer_event_source
= sd_event_source_unref(s
->timer_event_source
);
961 s
->leader_pidfd_event_source
= sd_event_source_unref(s
->leader_pidfd_event_source
);
964 seat_evict_position(s
->seat
, s
);
966 /* We are going down, don't care about FIFOs anymore */
967 session_remove_fifo(s
);
970 r
= session_stop_scope(s
, force
);
974 user_elect_display(s
->user
);
976 (void) session_save(s
);
977 (void) user_save(s
->user
);
982 int session_finalize(Session
*s
) {
991 log_struct(s
->class == SESSION_BACKGROUND
? LOG_DEBUG
: LOG_INFO
,
992 "MESSAGE_ID=" SD_MESSAGE_SESSION_STOP_STR
,
993 "SESSION_ID=%s", s
->id
,
994 "USER_ID=%s", s
->user
->user_record
->user_name
,
995 "LEADER="PID_FMT
, s
->leader
.pid
,
996 LOG_MESSAGE("Removed session %s.", s
->id
));
998 s
->timer_event_source
= sd_event_source_unref(s
->timer_event_source
);
1001 seat_evict_position(s
->seat
, s
);
1003 /* Kill session devices */
1004 while ((sd
= hashmap_first(s
->devices
)))
1005 session_device_free(sd
);
1007 (void) unlink(s
->state_file
);
1008 session_add_to_gc_queue(s
);
1009 user_add_to_gc_queue(s
->user
);
1012 session_send_signal(s
, false);
1017 if (s
->seat
->active
== s
)
1018 seat_set_active(s
->seat
, NULL
);
1023 session_reset_leader(s
, /* keep_fdstore = */ false);
1025 (void) user_save(s
->user
);
1026 (void) user_send_changed(s
->user
, "Display", NULL
);
1031 static int release_timeout_callback(sd_event_source
*es
, uint64_t usec
, void *userdata
) {
1032 Session
*s
= ASSERT_PTR(userdata
);
1036 session_stop(s
, /* force = */ false);
1040 int session_release(Session
*s
) {
1043 if (!s
->started
|| s
->stopping
)
1046 if (s
->timer_event_source
)
1049 return sd_event_add_time_relative(
1051 &s
->timer_event_source
,
1054 release_timeout_callback
, s
);
1057 bool session_is_active(Session
*s
) {
1063 return s
->seat
->active
== s
;
1066 static int get_tty_atime(const char *tty
, usec_t
*atime
) {
1067 _cleanup_free_
char *p
= NULL
;
1073 if (!path_is_absolute(tty
)) {
1074 p
= path_join("/dev", tty
);
1079 } else if (!path_startswith(tty
, "/dev/"))
1082 if (lstat(tty
, &st
) < 0)
1085 *atime
= timespec_load(&st
.st_atim
);
1089 static int get_process_ctty_atime(pid_t pid
, usec_t
*atime
) {
1090 _cleanup_free_
char *p
= NULL
;
1096 r
= get_ctty(pid
, NULL
, &p
);
1100 return get_tty_atime(p
, atime
);
1103 int session_get_idle_hint(Session
*s
, dual_timestamp
*t
) {
1104 usec_t atime
= 0, dtime
= 0;
1109 /* Graphical sessions have an explicit idle hint */
1110 if (SESSION_TYPE_IS_GRAPHICAL(s
->type
)) {
1112 *t
= s
->idle_hint_timestamp
;
1114 return s
->idle_hint
;
1117 if (s
->type
== SESSION_TTY
) {
1118 /* For sessions with an explicitly configured tty, let's check its atime */
1120 r
= get_tty_atime(s
->tty
, &atime
);
1125 /* For sessions with a leader but no explicitly configured tty, let's check the controlling tty of
1127 if (pidref_is_set(&s
->leader
)) {
1128 r
= get_process_ctty_atime(s
->leader
.pid
, &atime
);
1135 *t
= DUAL_TIMESTAMP_NULL
;
1141 dual_timestamp_from_realtime(t
, atime
);
1143 if (s
->manager
->idle_action_usec
> 0 && s
->manager
->stop_idle_session_usec
!= USEC_INFINITY
)
1144 dtime
= MIN(s
->manager
->idle_action_usec
, s
->manager
->stop_idle_session_usec
);
1145 else if (s
->manager
->idle_action_usec
> 0)
1146 dtime
= s
->manager
->idle_action_usec
;
1147 else if (s
->manager
->stop_idle_session_usec
!= USEC_INFINITY
)
1148 dtime
= s
->manager
->stop_idle_session_usec
;
1152 return usec_add(atime
, dtime
) <= now(CLOCK_REALTIME
);
1155 int session_set_idle_hint(Session
*s
, bool b
) {
1158 if (!SESSION_CLASS_CAN_IDLE(s
->class)) /* Only some session classes know the idle concept at all */
1160 if (!SESSION_TYPE_IS_GRAPHICAL(s
->type
)) /* And only graphical session types can set the field explicitly */
1163 if (s
->idle_hint
== b
)
1167 dual_timestamp_now(&s
->idle_hint_timestamp
);
1169 session_send_changed(s
, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL
);
1172 seat_send_changed(s
->seat
, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL
);
1174 user_send_changed(s
->user
, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL
);
1175 manager_send_changed(s
->manager
, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL
);
1180 int session_get_locked_hint(Session
*s
) {
1183 return s
->locked_hint
;
1186 int session_set_locked_hint(Session
*s
, bool b
) {
1189 if (!SESSION_CLASS_CAN_LOCK(s
->class))
1192 if (s
->locked_hint
== b
)
1196 (void) session_save(s
);
1197 (void) session_send_changed(s
, "LockedHint", NULL
);
1202 void session_set_type(Session
*s
, SessionType t
) {
1209 (void) session_save(s
);
1210 (void) session_send_changed(s
, "Type", NULL
);
1213 int session_set_display(Session
*s
, const char *display
) {
1219 r
= free_and_strdup(&s
->display
, display
);
1220 if (r
<= 0) /* 0 means the strings were equal */
1223 (void) session_save(s
);
1224 (void) session_send_changed(s
, "Display", NULL
);
1229 int session_set_tty(Session
*s
, const char *tty
) {
1235 r
= free_and_strdup(&s
->tty
, tty
);
1236 if (r
<= 0) /* 0 means the strings were equal */
1239 (void) session_save(s
);
1240 (void) session_send_changed(s
, "TTY", NULL
);
1245 static int session_dispatch_fifo(sd_event_source
*es
, int fd
, uint32_t revents
, void *userdata
) {
1246 Session
*s
= ASSERT_PTR(userdata
);
1248 assert(s
->fifo_fd
== fd
);
1250 /* EOF on the FIFO means the session died abnormally. */
1252 session_remove_fifo(s
);
1253 session_stop(s
, /* force = */ false);
1258 int session_create_fifo(Session
*s
) {
1264 if (!s
->fifo_path
) {
1265 r
= mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0, MKDIR_WARN_MODE
);
1269 s
->fifo_path
= strjoin("/run/systemd/sessions/", s
->id
, ".ref");
1273 if (mkfifo(s
->fifo_path
, 0600) < 0 && errno
!= EEXIST
)
1277 /* Open reading side */
1278 if (s
->fifo_fd
< 0) {
1279 s
->fifo_fd
= open(s
->fifo_path
, O_RDONLY
|O_CLOEXEC
|O_NONBLOCK
);
1284 if (!s
->fifo_event_source
) {
1285 r
= sd_event_add_io(s
->manager
->event
, &s
->fifo_event_source
, s
->fifo_fd
, 0, session_dispatch_fifo
, s
);
1289 /* Let's make sure we noticed dead sessions before we process new bus requests (which might
1290 * create new sessions). */
1291 r
= sd_event_source_set_priority(s
->fifo_event_source
, SD_EVENT_PRIORITY_NORMAL
-10);
1296 /* Open writing side */
1297 return RET_NERRNO(open(s
->fifo_path
, O_WRONLY
|O_CLOEXEC
|O_NONBLOCK
));
1300 static void session_remove_fifo(Session
*s
) {
1303 s
->fifo_event_source
= sd_event_source_unref(s
->fifo_event_source
);
1304 s
->fifo_fd
= safe_close(s
->fifo_fd
);
1305 s
->fifo_path
= unlink_and_free(s
->fifo_path
);
1308 bool session_may_gc(Session
*s
, bool drop_not_started
) {
1313 if (drop_not_started
&& !s
->started
)
1319 r
= pidref_is_alive(&s
->leader
);
1321 /* Session has no leader. This is probably because the leader vanished before deserializing
1322 * pidfd from FD store. */
1325 log_debug_errno(r
, "Unable to determine if leader PID " PID_FMT
" is still alive, assuming not: %m", s
->leader
.pid
);
1329 if (s
->fifo_fd
>= 0 && pipe_eof(s
->fifo_fd
) <= 0)
1333 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
1335 r
= manager_job_is_active(s
->manager
, s
->scope_job
, &error
);
1337 log_debug_errno(r
, "Failed to determine whether job '%s' is pending, ignoring: %s", s
->scope_job
, bus_error_message(&error
, r
));
1343 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
1345 r
= manager_unit_is_active(s
->manager
, s
->scope
, &error
);
1347 log_debug_errno(r
, "Failed to determine whether unit '%s' is active, ignoring: %s", s
->scope
, bus_error_message(&error
, r
));
1355 void session_add_to_gc_queue(Session
*s
) {
1361 LIST_PREPEND(gc_queue
, s
->manager
->session_gc_queue
, s
);
1362 s
->in_gc_queue
= true;
1365 SessionState
session_get_state(Session
*s
) {
1368 /* always check closing first */
1369 if (s
->stopping
|| s
->timer_event_source
)
1370 return SESSION_CLOSING
;
1372 if (s
->scope_job
|| (!pidref_is_set(&s
->leader
) && s
->fifo_fd
< 0))
1373 return SESSION_OPENING
;
1375 if (session_is_active(s
))
1376 return SESSION_ACTIVE
;
1378 return SESSION_ONLINE
;
1381 int session_kill(Session
*s
, KillWho who
, int signo
) {
1387 return manager_kill_unit(s
->manager
, s
->scope
, who
, signo
, NULL
);
1390 static int session_open_vt(Session
*s
, bool reopen
) {
1391 _cleanup_close_
int fd
= -EBADF
;
1392 char path
[sizeof("/dev/tty") + DECIMAL_STR_MAX(s
->vtnr
)];
1399 if (!reopen
&& s
->vtfd
>= 0)
1402 sprintf(path
, "/dev/tty%u", s
->vtnr
);
1404 fd
= open_terminal(path
, O_RDWR
| O_CLOEXEC
| O_NONBLOCK
| O_NOCTTY
);
1406 return log_error_errno(fd
, "Cannot open VT %s of session %s: %m", path
, s
->id
);
1408 close_and_replace(s
->vtfd
, fd
);
1412 static int session_prepare_vt(Session
*s
) {
1414 struct vt_mode mode
= {};
1421 vt
= session_open_vt(s
, /* reopen = */ false);
1425 r
= fchown(vt
, s
->user
->user_record
->uid
, -1);
1427 r
= log_error_errno(errno
,
1428 "Cannot change owner of /dev/tty%u: %m",
1433 r
= ioctl(vt
, KDSKBMODE
, K_OFF
);
1435 r
= log_error_errno(errno
,
1436 "Cannot set K_OFF on /dev/tty%u: %m",
1441 r
= ioctl(vt
, KDSETMODE
, KD_GRAPHICS
);
1443 r
= log_error_errno(errno
,
1444 "Cannot set KD_GRAPHICS on /dev/tty%u: %m",
1449 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1450 * So we need a dummy handler here which just acknowledges *all* VT
1451 * switch requests. */
1452 mode
.mode
= VT_PROCESS
;
1453 mode
.relsig
= SIGRTMIN
;
1454 mode
.acqsig
= SIGRTMIN
+ 1;
1455 r
= ioctl(vt
, VT_SETMODE
, &mode
);
1457 r
= log_error_errno(errno
,
1458 "Cannot set VT_PROCESS on /dev/tty%u: %m",
1466 session_restore_vt(s
);
1470 static void session_restore_vt(Session
*s
) {
1478 r
= vt_restore(s
->vtfd
);
1480 /* It might happen if the controlling process exited before or while we were
1481 * restoring the VT as it would leave the old file-descriptor in a hung-up
1482 * state. In this case let's retry with a fresh handle to the virtual terminal. */
1484 /* We do a little dance to avoid having the terminal be available
1485 * for reuse before we've cleaned it up. */
1487 int fd
= session_open_vt(s
, /* reopen = */ true);
1492 log_warning_errno(r
, "Failed to restore VT, ignoring: %m");
1494 s
->vtfd
= safe_close(s
->vtfd
);
1497 void session_leave_vt(Session
*s
) {
1502 /* This is called whenever we get a VT-switch signal from the kernel.
1503 * We acknowledge all of them unconditionally. Note that session are
1504 * free to overwrite those handlers and we only register them for
1505 * sessions with controllers. Legacy sessions are not affected.
1506 * However, if we switch from a non-legacy to a legacy session, we must
1507 * make sure to pause all device before acknowledging the switch. We
1508 * process the real switch only after we are notified via sysfs, so the
1509 * legacy session might have already started using the devices. If we
1510 * don't pause the devices before the switch, we might confuse the
1511 * session we switch to. */
1516 session_device_pause_all(s
);
1517 r
= vt_release(s
->vtfd
, /* restore = */ false);
1519 /* Handle the same VT hung-up case as in session_restore_vt */
1521 int fd
= session_open_vt(s
, /* reopen = */ true);
1523 r
= vt_release(fd
, /* restore = */ false);
1526 log_debug_errno(r
, "Cannot release VT of session %s: %m", s
->id
);
1529 bool session_is_controller(Session
*s
, const char *sender
) {
1530 return streq_ptr(ASSERT_PTR(s
)->controller
, sender
);
1533 static void session_release_controller(Session
*s
, bool notify
) {
1534 _unused_ _cleanup_free_
char *name
= NULL
;
1542 name
= s
->controller
;
1544 /* By resetting the controller before releasing the devices, we won't send notification signals.
1545 * This avoids sending useless notifications if the controller is released on disconnects. */
1547 s
->controller
= NULL
;
1549 while ((sd
= hashmap_first(s
->devices
)))
1550 session_device_free(sd
);
1552 s
->controller
= NULL
;
1553 s
->track
= sd_bus_track_unref(s
->track
);
1556 static int on_bus_track(sd_bus_track
*track
, void *userdata
) {
1557 Session
*s
= ASSERT_PTR(userdata
);
1561 session_drop_controller(s
);
1566 int session_set_controller(Session
*s
, const char *sender
, bool force
, bool prepare
) {
1567 _cleanup_free_
char *name
= NULL
;
1573 if (session_is_controller(s
, sender
))
1575 if (s
->controller
&& !force
)
1578 name
= strdup(sender
);
1582 s
->track
= sd_bus_track_unref(s
->track
);
1583 r
= sd_bus_track_new(s
->manager
->bus
, &s
->track
, on_bus_track
, s
);
1587 r
= sd_bus_track_add_name(s
->track
, name
);
1591 /* When setting a session controller, we forcibly mute the VT and set
1592 * it into graphics-mode. Applications can override that by changing
1593 * VT state after calling TakeControl(). However, this serves as a good
1594 * default and well-behaving controllers can now ignore VTs entirely.
1595 * Note that we reset the VT on ReleaseControl() and if the controller
1597 * If logind crashes/restarts, we restore the controller during restart
1598 * (without preparing the VT since the controller has probably overridden
1599 * VT state by now) or reset the VT in case it crashed/exited, too. */
1601 r
= session_prepare_vt(s
);
1603 s
->track
= sd_bus_track_unref(s
->track
);
1608 session_release_controller(s
, true);
1609 s
->controller
= TAKE_PTR(name
);
1610 (void) session_save(s
);
1615 void session_drop_controller(Session
*s
) {
1621 s
->track
= sd_bus_track_unref(s
->track
);
1622 session_set_type(s
, s
->original_type
);
1623 session_release_controller(s
, false);
1624 (void) session_save(s
);
1625 session_restore_vt(s
);
1628 static const char* const session_state_table
[_SESSION_STATE_MAX
] = {
1629 [SESSION_OPENING
] = "opening",
1630 [SESSION_ONLINE
] = "online",
1631 [SESSION_ACTIVE
] = "active",
1632 [SESSION_CLOSING
] = "closing",
1635 DEFINE_STRING_TABLE_LOOKUP(session_state
, SessionState
);
1637 static const char* const session_type_table
[_SESSION_TYPE_MAX
] = {
1638 [SESSION_UNSPECIFIED
] = "unspecified",
1639 [SESSION_TTY
] = "tty",
1640 [SESSION_X11
] = "x11",
1641 [SESSION_WAYLAND
] = "wayland",
1642 [SESSION_MIR
] = "mir",
1643 [SESSION_WEB
] = "web",
1646 DEFINE_STRING_TABLE_LOOKUP(session_type
, SessionType
);
1648 static const char* const session_class_table
[_SESSION_CLASS_MAX
] = {
1649 [SESSION_USER
] = "user",
1650 [SESSION_USER_EARLY
] = "user-early",
1651 [SESSION_GREETER
] = "greeter",
1652 [SESSION_LOCK_SCREEN
] = "lock-screen",
1653 [SESSION_BACKGROUND
] = "background",
1654 [SESSION_BACKGROUND_LIGHT
] = "background-light",
1655 [SESSION_MANAGER
] = "manager",
1656 [SESSION_MANAGER_EARLY
] = "manager-early",
1659 DEFINE_STRING_TABLE_LOOKUP(session_class
, SessionClass
);
1661 static const char* const kill_who_table
[_KILL_WHO_MAX
] = {
1662 [KILL_LEADER
] = "leader",
1666 DEFINE_STRING_TABLE_LOOKUP(kill_who
, KillWho
);
1668 static const char* const tty_validity_table
[_TTY_VALIDITY_MAX
] = {
1669 [TTY_FROM_PAM
] = "from-pam",
1670 [TTY_FROM_UTMP
] = "from-utmp",
1671 [TTY_UTMP_INCONSISTENT
] = "utmp-inconsistent",
1674 DEFINE_STRING_TABLE_LOOKUP(tty_validity
, TTYValidity
);