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, "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);
633 /* We are going down, don't care about FIFOs anymore */
634 session_remove_fifo(s);
637 r = session_stop_scope(s, force);
641 user_elect_display(s->user);
649 int session_finalize(Session *s) {
659 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
660 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
661 "SESSION_ID=%s", s->id,
662 "USER_ID=%s", s->user->name,
663 "LEADER="PID_FMT, s->leader,
664 LOG_MESSAGE("Removed session %s.", s->id),
667 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
669 /* Kill session devices */
670 while ((sd = hashmap_first(s->devices)))
671 session_device_free(sd);
673 unlink(s->state_file);
674 session_add_to_gc_queue(s);
675 user_add_to_gc_queue(s->user);
678 session_send_signal(s, false);
683 if (s->seat->active == s)
684 seat_set_active(s->seat, NULL);
687 seat_send_changed(s->seat, "Sessions", NULL);
691 user_send_changed(s->user, "Sessions", "Display", NULL);
696 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
697 Session *s = userdata;
702 session_stop(s, false);
706 int session_release(Session *s) {
709 if (!s->started || s->stopping)
712 if (s->timer_event_source)
715 return sd_event_add_time(s->manager->event,
716 &s->timer_event_source,
718 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
719 release_timeout_callback, s);
722 bool session_is_active(Session *s) {
728 return s->seat->active == s;
731 static int get_tty_atime(const char *tty, usec_t *atime) {
732 _cleanup_free_ char *p = NULL;
738 if (!path_is_absolute(tty)) {
739 p = strappend("/dev/", tty);
744 } else if (!path_startswith(tty, "/dev/"))
747 if (lstat(tty, &st) < 0)
750 *atime = timespec_load(&st.st_atim);
754 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
755 _cleanup_free_ char *p = NULL;
761 r = get_ctty(pid, NULL, &p);
765 return get_tty_atime(p, atime);
768 int session_get_idle_hint(Session *s, dual_timestamp *t) {
774 /* Explicit idle hint is set */
777 *t = s->idle_hint_timestamp;
782 /* Graphical sessions should really implement a real
787 /* For sessions with an explicitly configured tty, let's check
790 r = get_tty_atime(s->tty, &atime);
795 /* For sessions with a leader but no explicitly configured
796 * tty, let's check the controlling tty of the leader */
798 r = get_process_ctty_atime(s->leader, &atime);
805 *t = s->idle_hint_timestamp;
811 dual_timestamp_from_realtime(t, atime);
813 n = now(CLOCK_REALTIME);
815 if (s->manager->idle_action_usec <= 0)
818 return atime + s->manager->idle_action_usec <= n;
821 void session_set_idle_hint(Session *s, bool b) {
824 if (s->idle_hint == b)
828 dual_timestamp_get(&s->idle_hint_timestamp);
830 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
833 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
835 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
836 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
839 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
840 Session *s = userdata;
843 assert(s->fifo_fd == fd);
845 /* EOF on the FIFO means the session died abnormally. */
847 session_remove_fifo(s);
848 session_stop(s, false);
853 int session_create_fifo(Session *s) {
860 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
864 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
867 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
871 /* Open reading side */
872 if (s->fifo_fd < 0) {
873 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
879 if (!s->fifo_event_source) {
880 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
884 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
889 /* Open writing side */
890 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
897 static void session_remove_fifo(Session *s) {
900 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
901 s->fifo_fd = safe_close(s->fifo_fd);
904 unlink(s->fifo_path);
910 bool session_check_gc(Session *s, bool drop_not_started) {
913 if (drop_not_started && !s->started)
919 if (s->fifo_fd >= 0) {
920 if (pipe_eof(s->fifo_fd) <= 0)
924 if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
927 if (s->scope && manager_unit_is_active(s->manager, s->scope))
933 void session_add_to_gc_queue(Session *s) {
939 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
940 s->in_gc_queue = true;
943 SessionState session_get_state(Session *s) {
946 /* always check closing first */
947 if (s->stopping || s->timer_event_source)
948 return SESSION_CLOSING;
950 if (s->scope_job || s->fifo_fd < 0)
951 return SESSION_OPENING;
953 if (session_is_active(s))
954 return SESSION_ACTIVE;
956 return SESSION_ONLINE;
959 int session_kill(Session *s, KillWho who, int signo) {
965 return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
968 static int session_open_vt(Session *s) {
969 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
977 sprintf(path, "/dev/tty%u", s->vtnr);
978 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
980 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
985 int session_prepare_vt(Session *s) {
987 struct vt_mode mode = { 0 };
992 vt = session_open_vt(s);
996 r = fchown(vt, s->user->uid, -1);
999 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
1003 r = ioctl(vt, KDSKBMODE, K_OFF);
1006 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
1010 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
1013 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
1017 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1018 * So we need a dummy handler here which just acknowledges *all* VT
1019 * switch requests. */
1020 mode.mode = VT_PROCESS;
1021 mode.relsig = SIGRTMIN;
1022 mode.acqsig = SIGRTMIN + 1;
1023 r = ioctl(vt, VT_SETMODE, &mode);
1026 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
1033 session_restore_vt(s);
1037 void session_restore_vt(Session *s) {
1038 _cleanup_free_ char *utf8 = NULL;
1039 int vt, kb = K_XLATE;
1040 struct vt_mode mode = { 0 };
1042 vt = session_open_vt(s);
1046 (void) ioctl(vt, KDSETMODE, KD_TEXT);
1048 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
1051 (void) ioctl(vt, KDSKBMODE, kb);
1053 mode.mode = VT_AUTO;
1054 (void) ioctl(vt, VT_SETMODE, &mode);
1058 s->vtfd = safe_close(s->vtfd);
1061 void session_leave_vt(Session *s) {
1066 /* This is called whenever we get a VT-switch signal from the kernel.
1067 * We acknowledge all of them unconditionally. Note that session are
1068 * free to overwrite those handlers and we only register them for
1069 * sessions with controllers. Legacy sessions are not affected.
1070 * However, if we switch from a non-legacy to a legacy session, we must
1071 * make sure to pause all device before acknowledging the switch. We
1072 * process the real switch only after we are notified via sysfs, so the
1073 * legacy session might have already started using the devices. If we
1074 * don't pause the devices before the switch, we might confuse the
1075 * session we switch to. */
1080 session_device_pause_all(s);
1081 r = ioctl(s->vtfd, VT_RELDISP, 1);
1083 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1086 bool session_is_controller(Session *s, const char *sender) {
1089 return streq_ptr(s->controller, sender);
1092 static void session_release_controller(Session *s, bool notify) {
1093 _cleanup_free_ char *name = NULL;
1099 name = s->controller;
1101 /* By resetting the controller before releasing the devices, we won't
1102 * send notification signals. This avoids sending useless notifications
1103 * if the controller is released on disconnects. */
1105 s->controller = NULL;
1107 while ((sd = hashmap_first(s->devices)))
1108 session_device_free(sd);
1110 s->controller = NULL;
1111 manager_drop_busname(s->manager, name);
1114 int session_set_controller(Session *s, const char *sender, bool force) {
1115 _cleanup_free_ char *name = NULL;
1121 if (session_is_controller(s, sender))
1123 if (s->controller && !force)
1126 name = strdup(sender);
1130 r = manager_watch_busname(s->manager, name);
1134 /* When setting a session controller, we forcibly mute the VT and set
1135 * it into graphics-mode. Applications can override that by changing
1136 * VT state after calling TakeControl(). However, this serves as a good
1137 * default and well-behaving controllers can now ignore VTs entirely.
1138 * Note that we reset the VT on ReleaseControl() and if the controller
1140 * If logind crashes/restarts, we restore the controller during restart
1141 * or reset the VT in case it crashed/exited, too. */
1142 r = session_prepare_vt(s);
1144 manager_drop_busname(s->manager, name);
1148 session_release_controller(s, true);
1149 s->controller = name;
1156 void session_drop_controller(Session *s) {
1162 session_release_controller(s, false);
1164 session_restore_vt(s);
1167 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1168 [SESSION_OPENING] = "opening",
1169 [SESSION_ONLINE] = "online",
1170 [SESSION_ACTIVE] = "active",
1171 [SESSION_CLOSING] = "closing"
1174 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1176 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1177 [SESSION_UNSPECIFIED] = "unspecified",
1178 [SESSION_TTY] = "tty",
1179 [SESSION_X11] = "x11",
1180 [SESSION_WAYLAND] = "wayland",
1181 [SESSION_MIR] = "mir",
1182 [SESSION_WEB] = "web",
1185 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1187 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1188 [SESSION_USER] = "user",
1189 [SESSION_GREETER] = "greeter",
1190 [SESSION_LOCK_SCREEN] = "lock-screen",
1191 [SESSION_BACKGROUND] = "background"
1194 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1196 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1197 [KILL_LEADER] = "leader",
1201 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);