1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2011 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
28 #include <sys/ioctl.h>
31 #include "sd-messages.h"
34 #include "path-util.h"
38 #include "bus-error.h"
39 #include "logind-session.h"
40 #include "formats-util.h"
41 #include "terminal-util.h"
43 #define RELEASE_USEC (20*USEC_PER_SEC)
45 static void session_remove_fifo(Session *s);
47 Session* session_new(Manager *m, const char *id) {
52 assert(session_id_valid(id));
58 s->state_file = strappend("/run/systemd/sessions/", id);
64 s->devices = hashmap_new(&devt_hash_ops);
71 s->id = basename(s->state_file);
73 if (hashmap_put(m->sessions, s->id, s) < 0) {
74 hashmap_free(s->devices);
87 void session_free(Session *s) {
93 LIST_REMOVE(gc_queue, s->manager->session_gc_queue, s);
95 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
97 session_remove_fifo(s);
99 session_drop_controller(s);
101 while ((sd = hashmap_first(s->devices)))
102 session_device_free(sd);
104 hashmap_free(s->devices);
107 LIST_REMOVE(sessions_by_user, s->user->sessions, s);
109 if (s->user->display == s)
110 s->user->display = NULL;
114 if (s->seat->active == s)
115 s->seat->active = NULL;
116 if (s->seat->pending_switch == s)
117 s->seat->pending_switch = NULL;
119 seat_evict_position(s->seat, s);
120 LIST_REMOVE(sessions_by_seat, s->seat->sessions, s);
124 hashmap_remove(s->manager->session_units, s->scope);
130 sd_bus_message_unref(s->create_message);
134 free(s->remote_host);
135 free(s->remote_user);
139 hashmap_remove(s->manager->sessions, s->id);
145 void session_set_user(Session *s, User *u) {
150 LIST_PREPEND(sessions_by_user, u->sessions, s);
153 int session_save(Session *s) {
154 _cleanup_free_ char *temp_path = NULL;
155 _cleanup_fclose_ FILE *f = NULL;
166 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
170 r = fopen_temporary(s->state_file, &f, &temp_path);
176 fchmod(fileno(f), 0644);
179 "# This is private data. Do not parse.\n"
187 session_is_active(s),
188 session_state_to_string(session_get_state(s)),
192 fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
195 fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
198 fprintf(f, "SCOPE=%s\n", s->scope);
200 fprintf(f, "SCOPE_JOB=%s\n", s->scope_job);
203 fprintf(f, "FIFO=%s\n", s->fifo_path);
206 fprintf(f, "SEAT=%s\n", s->seat->id);
209 fprintf(f, "TTY=%s\n", s->tty);
212 fprintf(f, "DISPLAY=%s\n", s->display);
214 if (s->remote_host) {
215 _cleanup_free_ char *escaped;
217 escaped = cescape(s->remote_host);
223 fprintf(f, "REMOTE_HOST=%s\n", escaped);
226 if (s->remote_user) {
227 _cleanup_free_ char *escaped;
229 escaped = cescape(s->remote_user);
235 fprintf(f, "REMOTE_USER=%s\n", escaped);
239 _cleanup_free_ char *escaped;
241 escaped = cescape(s->service);
247 fprintf(f, "SERVICE=%s\n", escaped);
251 _cleanup_free_ char *escaped;
254 escaped = cescape(s->desktop);
260 fprintf(f, "DESKTOP=%s\n", escaped);
263 if (s->seat && seat_has_vts(s->seat))
264 fprintf(f, "VTNR=%u\n", s->vtnr);
267 fprintf(f, "POSITION=%u\n", s->position);
270 fprintf(f, "LEADER="PID_FMT"\n", s->leader);
273 fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
275 if (dual_timestamp_is_set(&s->timestamp))
277 "REALTIME="USEC_FMT"\n"
278 "MONOTONIC="USEC_FMT"\n",
279 s->timestamp.realtime,
280 s->timestamp.monotonic);
283 fprintf(f, "CONTROLLER=%s\n", s->controller);
287 if (ferror(f) || rename(temp_path, s->state_file) < 0) {
289 unlink(s->state_file);
295 log_error_errno(r, "Failed to save session data %s: %m", s->state_file);
300 int session_load(Session *s) {
301 _cleanup_free_ char *remote = NULL,
318 r = parse_env_file(s->state_file, NEWLINE,
321 "SCOPE_JOB", &s->scope_job,
322 "FIFO", &s->fifo_path,
325 "DISPLAY", &s->display,
326 "REMOTE_HOST", &s->remote_host,
327 "REMOTE_USER", &s->remote_user,
328 "SERVICE", &s->service,
329 "DESKTOP", &s->desktop,
332 "POSITION", &position,
337 "REALTIME", &realtime,
338 "MONOTONIC", &monotonic,
339 "CONTROLLER", &controller,
343 return log_error_errno(r, "Failed to read %s: %m", s->state_file);
350 log_error("UID not specified for session %s", s->id);
354 r = parse_uid(uid, &u);
356 log_error("Failed to parse UID value %s for session %s.", uid, s->id);
360 user = hashmap_get(s->manager->users, UID_TO_PTR(u));
362 log_error("User of session %s not known.", s->id);
366 session_set_user(s, user);
370 k = parse_boolean(remote);
376 safe_atou(vtnr, &s->vtnr);
378 if (seat && !s->seat) {
381 o = hashmap_get(s->manager->seats, seat);
383 r = seat_attach_session(o, s);
385 log_error("Cannot attach session %s to seat %s", s->id, seat);
388 if (!s->seat || !seat_has_vts(s->seat))
391 if (position && s->seat) {
394 safe_atou(position, &npos);
395 seat_claim_position(s->seat, s, npos);
399 k = parse_pid(leader, &s->leader);
401 audit_session_from_pid(s->leader, &s->audit_id);
407 t = session_type_from_string(type);
415 c = session_class_from_string(class);
420 if (state && streq(state, "closing"))
426 /* If we open an unopened pipe for reading we will not
427 get an EOF. to trigger an EOF we hence open it for
428 writing, but close it right away which then will
429 trigger the EOF. This will happen immediately if no
430 other process has the FIFO open for writing, i. e.
431 when the session died before logind (re)started. */
433 fd = session_create_fifo(s);
438 unsigned long long l;
439 if (sscanf(realtime, "%llu", &l) > 0)
440 s->timestamp.realtime = l;
444 unsigned long long l;
445 if (sscanf(monotonic, "%llu", &l) > 0)
446 s->timestamp.monotonic = l;
450 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
451 session_set_controller(s, controller, false);
453 session_restore_vt(s);
459 int session_activate(Session *s) {
460 unsigned int num_pending;
468 if (s->seat->active == s)
471 /* on seats with VTs, we let VTs manage session-switching */
472 if (seat_has_vts(s->seat)) {
476 return chvt(s->vtnr);
479 /* On seats without VTs, we implement session-switching in logind. We
480 * try to pause all session-devices and wait until the session
481 * controller acknowledged them. Once all devices are asleep, we simply
482 * switch the active session and be done.
483 * We save the session we want to switch to in seat->pending_switch and
484 * seat_complete_switch() will perform the final switch. */
486 s->seat->pending_switch = s;
488 /* if no devices are running, immediately perform the session switch */
489 num_pending = session_device_try_pause_all(s);
491 seat_complete_switch(s->seat);
496 static int session_start_scope(Session *s) {
501 assert(s->user->slice);
504 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
505 _cleanup_free_ char *description = NULL;
506 char *scope, *job = NULL;
508 description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
512 scope = strjoin("session-", s->id, ".scope", NULL);
516 r = manager_start_scope(s->manager, scope, s->leader, s->user->slice, description, "systemd-logind.service", "systemd-user-sessions.service", &error, &job);
518 log_error("Failed to start session scope %s: %s %s",
519 scope, bus_error_message(&error, r), error.name);
531 hashmap_put(s->manager->session_units, s->scope, s);
536 int session_start(Session *s) {
547 r = user_start(s->user);
552 r = session_start_scope(s);
556 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
557 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
558 "SESSION_ID=%s", s->id,
559 "USER_ID=%s", s->user->name,
560 "LEADER="PID_FMT, s->leader,
561 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
564 if (!dual_timestamp_is_set(&s->timestamp))
565 dual_timestamp_get(&s->timestamp);
568 seat_read_active_vt(s->seat);
572 user_elect_display(s->user);
581 session_send_signal(s, true);
582 user_send_changed(s->user, "Sessions", "Display", NULL);
584 if (s->seat->active == s)
585 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
587 seat_send_changed(s->seat, "Sessions", NULL);
593 static int session_stop_scope(Session *s, bool force) {
594 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
603 if (force || manager_shall_kill(s->manager, s->user->name)) {
604 r = manager_stop_unit(s->manager, s->scope, &error, &job);
606 log_error("Failed to stop session scope: %s", bus_error_message(&error, r));
613 r = manager_abandon_scope(s->manager, s->scope, &error);
615 log_error("Failed to abandon session scope: %s", bus_error_message(&error, r));
623 int session_stop(Session *s, bool force) {
631 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
634 seat_evict_position(s->seat, s);
636 /* We are going down, don't care about FIFOs anymore */
637 session_remove_fifo(s);
640 r = session_stop_scope(s, force);
644 user_elect_display(s->user);
652 int session_finalize(Session *s) {
662 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
663 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
664 "SESSION_ID=%s", s->id,
665 "USER_ID=%s", s->user->name,
666 "LEADER="PID_FMT, s->leader,
667 LOG_MESSAGE("Removed session %s.", s->id),
670 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
673 seat_evict_position(s->seat, s);
675 /* Kill session devices */
676 while ((sd = hashmap_first(s->devices)))
677 session_device_free(sd);
679 unlink(s->state_file);
680 session_add_to_gc_queue(s);
681 user_add_to_gc_queue(s->user);
684 session_send_signal(s, false);
689 if (s->seat->active == s)
690 seat_set_active(s->seat, NULL);
693 seat_send_changed(s->seat, "Sessions", NULL);
697 user_send_changed(s->user, "Sessions", "Display", NULL);
702 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
703 Session *s = userdata;
708 session_stop(s, false);
712 int session_release(Session *s) {
715 if (!s->started || s->stopping)
718 if (s->timer_event_source)
721 return sd_event_add_time(s->manager->event,
722 &s->timer_event_source,
724 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
725 release_timeout_callback, s);
728 bool session_is_active(Session *s) {
734 return s->seat->active == s;
737 static int get_tty_atime(const char *tty, usec_t *atime) {
738 _cleanup_free_ char *p = NULL;
744 if (!path_is_absolute(tty)) {
745 p = strappend("/dev/", tty);
750 } else if (!path_startswith(tty, "/dev/"))
753 if (lstat(tty, &st) < 0)
756 *atime = timespec_load(&st.st_atim);
760 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
761 _cleanup_free_ char *p = NULL;
767 r = get_ctty(pid, NULL, &p);
771 return get_tty_atime(p, atime);
774 int session_get_idle_hint(Session *s, dual_timestamp *t) {
780 /* Explicit idle hint is set */
783 *t = s->idle_hint_timestamp;
788 /* Graphical sessions should really implement a real
793 /* For sessions with an explicitly configured tty, let's check
796 r = get_tty_atime(s->tty, &atime);
801 /* For sessions with a leader but no explicitly configured
802 * tty, let's check the controlling tty of the leader */
804 r = get_process_ctty_atime(s->leader, &atime);
811 *t = s->idle_hint_timestamp;
817 dual_timestamp_from_realtime(t, atime);
819 n = now(CLOCK_REALTIME);
821 if (s->manager->idle_action_usec <= 0)
824 return atime + s->manager->idle_action_usec <= n;
827 void session_set_idle_hint(Session *s, bool b) {
830 if (s->idle_hint == b)
834 dual_timestamp_get(&s->idle_hint_timestamp);
836 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
839 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
841 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
842 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
845 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
846 Session *s = userdata;
849 assert(s->fifo_fd == fd);
851 /* EOF on the FIFO means the session died abnormally. */
853 session_remove_fifo(s);
854 session_stop(s, false);
859 int session_create_fifo(Session *s) {
866 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
870 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
873 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
877 /* Open reading side */
878 if (s->fifo_fd < 0) {
879 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
885 if (!s->fifo_event_source) {
886 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
890 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
895 /* Open writing side */
896 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
903 static void session_remove_fifo(Session *s) {
906 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
907 s->fifo_fd = safe_close(s->fifo_fd);
910 unlink(s->fifo_path);
916 bool session_check_gc(Session *s, bool drop_not_started) {
919 if (drop_not_started && !s->started)
925 if (s->fifo_fd >= 0) {
926 if (pipe_eof(s->fifo_fd) <= 0)
930 if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
933 if (s->scope && manager_unit_is_active(s->manager, s->scope))
939 void session_add_to_gc_queue(Session *s) {
945 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
946 s->in_gc_queue = true;
949 SessionState session_get_state(Session *s) {
952 /* always check closing first */
953 if (s->stopping || s->timer_event_source)
954 return SESSION_CLOSING;
956 if (s->scope_job || s->fifo_fd < 0)
957 return SESSION_OPENING;
959 if (session_is_active(s))
960 return SESSION_ACTIVE;
962 return SESSION_ONLINE;
965 int session_kill(Session *s, KillWho who, int signo) {
971 return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
974 static int session_open_vt(Session *s) {
975 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
983 sprintf(path, "/dev/tty%u", s->vtnr);
984 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
986 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
991 int session_prepare_vt(Session *s) {
993 struct vt_mode mode = { 0 };
998 vt = session_open_vt(s);
1002 r = fchown(vt, s->user->uid, -1);
1005 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
1009 r = ioctl(vt, KDSKBMODE, K_OFF);
1012 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
1016 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
1019 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
1023 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1024 * So we need a dummy handler here which just acknowledges *all* VT
1025 * switch requests. */
1026 mode.mode = VT_PROCESS;
1027 mode.relsig = SIGRTMIN;
1028 mode.acqsig = SIGRTMIN + 1;
1029 r = ioctl(vt, VT_SETMODE, &mode);
1032 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
1039 session_restore_vt(s);
1043 void session_restore_vt(Session *s) {
1044 _cleanup_free_ char *utf8 = NULL;
1045 int vt, kb = K_XLATE;
1046 struct vt_mode mode = { 0 };
1048 vt = session_open_vt(s);
1052 (void) ioctl(vt, KDSETMODE, KD_TEXT);
1054 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
1057 (void) ioctl(vt, KDSKBMODE, kb);
1059 mode.mode = VT_AUTO;
1060 (void) ioctl(vt, VT_SETMODE, &mode);
1064 s->vtfd = safe_close(s->vtfd);
1067 void session_leave_vt(Session *s) {
1072 /* This is called whenever we get a VT-switch signal from the kernel.
1073 * We acknowledge all of them unconditionally. Note that session are
1074 * free to overwrite those handlers and we only register them for
1075 * sessions with controllers. Legacy sessions are not affected.
1076 * However, if we switch from a non-legacy to a legacy session, we must
1077 * make sure to pause all device before acknowledging the switch. We
1078 * process the real switch only after we are notified via sysfs, so the
1079 * legacy session might have already started using the devices. If we
1080 * don't pause the devices before the switch, we might confuse the
1081 * session we switch to. */
1086 session_device_pause_all(s);
1087 r = ioctl(s->vtfd, VT_RELDISP, 1);
1089 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1092 bool session_is_controller(Session *s, const char *sender) {
1095 return streq_ptr(s->controller, sender);
1098 static void session_release_controller(Session *s, bool notify) {
1099 _cleanup_free_ char *name = NULL;
1105 name = s->controller;
1107 /* By resetting the controller before releasing the devices, we won't
1108 * send notification signals. This avoids sending useless notifications
1109 * if the controller is released on disconnects. */
1111 s->controller = NULL;
1113 while ((sd = hashmap_first(s->devices)))
1114 session_device_free(sd);
1116 s->controller = NULL;
1117 manager_drop_busname(s->manager, name);
1120 int session_set_controller(Session *s, const char *sender, bool force) {
1121 _cleanup_free_ char *name = NULL;
1127 if (session_is_controller(s, sender))
1129 if (s->controller && !force)
1132 name = strdup(sender);
1136 r = manager_watch_busname(s->manager, name);
1140 /* When setting a session controller, we forcibly mute the VT and set
1141 * it into graphics-mode. Applications can override that by changing
1142 * VT state after calling TakeControl(). However, this serves as a good
1143 * default and well-behaving controllers can now ignore VTs entirely.
1144 * Note that we reset the VT on ReleaseControl() and if the controller
1146 * If logind crashes/restarts, we restore the controller during restart
1147 * or reset the VT in case it crashed/exited, too. */
1148 r = session_prepare_vt(s);
1150 manager_drop_busname(s->manager, name);
1154 session_release_controller(s, true);
1155 s->controller = name;
1162 void session_drop_controller(Session *s) {
1168 session_release_controller(s, false);
1170 session_restore_vt(s);
1173 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1174 [SESSION_OPENING] = "opening",
1175 [SESSION_ONLINE] = "online",
1176 [SESSION_ACTIVE] = "active",
1177 [SESSION_CLOSING] = "closing"
1180 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1182 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1183 [SESSION_UNSPECIFIED] = "unspecified",
1184 [SESSION_TTY] = "tty",
1185 [SESSION_X11] = "x11",
1186 [SESSION_WAYLAND] = "wayland",
1187 [SESSION_MIR] = "mir",
1188 [SESSION_WEB] = "web",
1191 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1193 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1194 [SESSION_USER] = "user",
1195 [SESSION_GREETER] = "greeter",
1196 [SESSION_LOCK_SCREEN] = "lock-screen",
1197 [SESSION_BACKGROUND] = "background"
1200 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1202 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1203 [KILL_LEADER] = "leader",
1207 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);