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>
32 #include "sd-messages.h"
36 #include "path-util.h"
40 #include "bus-error.h"
41 #include "logind-session.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, "POS=%u\n", s->pos);
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,
317 r = parse_env_file(s->state_file, NEWLINE,
320 "SCOPE_JOB", &s->scope_job,
321 "FIFO", &s->fifo_path,
324 "DISPLAY", &s->display,
325 "REMOTE_HOST", &s->remote_host,
326 "REMOTE_USER", &s->remote_user,
327 "SERVICE", &s->service,
328 "DESKTOP", &s->desktop,
335 "REALTIME", &realtime,
336 "MONOTONIC", &monotonic,
337 "CONTROLLER", &controller,
341 return log_error_errno(r, "Failed to read %s: %m", s->state_file);
348 log_error("UID not specified for session %s", s->id);
352 r = parse_uid(uid, &u);
354 log_error("Failed to parse UID value %s for session %s.", uid, s->id);
358 user = hashmap_get(s->manager->users, ULONG_TO_PTR((unsigned long) u));
360 log_error("User of session %s not known.", s->id);
364 session_set_user(s, user);
368 k = parse_boolean(remote);
374 safe_atou(vtnr, &s->vtnr);
376 if (seat && !s->seat) {
379 o = hashmap_get(s->manager->seats, seat);
381 r = seat_attach_session(o, s);
383 log_error("Cannot attach session %s to seat %s", s->id, seat);
386 if (!s->seat || !seat_has_vts(s->seat))
389 if (pos && s->seat) {
392 safe_atou(pos, &npos);
393 seat_claim_position(s->seat, s, npos);
397 k = parse_pid(leader, &s->leader);
399 audit_session_from_pid(s->leader, &s->audit_id);
405 t = session_type_from_string(type);
413 c = session_class_from_string(class);
421 /* If we open an unopened pipe for reading we will not
422 get an EOF. to trigger an EOF we hence open it for
423 reading, but close it right-away which then will
426 fd = session_create_fifo(s);
431 unsigned long long l;
432 if (sscanf(realtime, "%llu", &l) > 0)
433 s->timestamp.realtime = l;
437 unsigned long long l;
438 if (sscanf(monotonic, "%llu", &l) > 0)
439 s->timestamp.monotonic = l;
443 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
444 session_set_controller(s, controller, false);
446 session_restore_vt(s);
452 int session_activate(Session *s) {
453 unsigned int num_pending;
461 if (s->seat->active == s)
464 /* on seats with VTs, we let VTs manage session-switching */
465 if (seat_has_vts(s->seat)) {
469 return chvt(s->vtnr);
472 /* On seats without VTs, we implement session-switching in logind. We
473 * try to pause all session-devices and wait until the session
474 * controller acknowledged them. Once all devices are asleep, we simply
475 * switch the active session and be done.
476 * We save the session we want to switch to in seat->pending_switch and
477 * seat_complete_switch() will perform the final switch. */
479 s->seat->pending_switch = s;
481 /* if no devices are running, immediately perform the session switch */
482 num_pending = session_device_try_pause_all(s);
484 seat_complete_switch(s->seat);
489 static int session_start_scope(Session *s) {
494 assert(s->user->slice);
497 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
498 _cleanup_free_ char *description = NULL;
499 char *scope, *job = NULL;
501 description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
505 scope = strjoin("session-", s->id, ".scope", NULL);
509 r = manager_start_scope(s->manager, scope, s->leader, s->user->slice, description, "systemd-logind.service", "systemd-user-sessions.service", &error, &job);
511 log_error("Failed to start session scope %s: %s %s",
512 scope, bus_error_message(&error, r), error.name);
524 hashmap_put(s->manager->session_units, s->scope, s);
529 int session_start(Session *s) {
540 r = user_start(s->user);
545 r = session_start_scope(s);
549 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
550 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
551 "SESSION_ID=%s", s->id,
552 "USER_ID=%s", s->user->name,
553 "LEADER="PID_FMT, s->leader,
554 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
557 if (!dual_timestamp_is_set(&s->timestamp))
558 dual_timestamp_get(&s->timestamp);
561 seat_read_active_vt(s->seat);
565 user_elect_display(s->user);
574 session_send_signal(s, true);
575 user_send_changed(s->user, "Sessions", "Display", NULL);
577 if (s->seat->active == s)
578 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
580 seat_send_changed(s->seat, "Sessions", NULL);
586 static int session_stop_scope(Session *s, bool force) {
587 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
596 if (force || manager_shall_kill(s->manager, s->user->name)) {
597 r = manager_stop_unit(s->manager, s->scope, &error, &job);
599 log_error("Failed to stop session scope: %s", bus_error_message(&error, r));
606 r = manager_abandon_scope(s->manager, s->scope, &error);
608 log_error("Failed to abandon session scope: %s", bus_error_message(&error, r));
616 int session_stop(Session *s, bool force) {
624 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
626 /* We are going down, don't care about FIFOs anymore */
627 session_remove_fifo(s);
630 r = session_stop_scope(s, force);
634 user_elect_display(s->user);
642 int session_finalize(Session *s) {
652 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
653 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
654 "SESSION_ID=%s", s->id,
655 "USER_ID=%s", s->user->name,
656 "LEADER="PID_FMT, s->leader,
657 LOG_MESSAGE("Removed session %s.", s->id),
660 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
662 /* Kill session devices */
663 while ((sd = hashmap_first(s->devices)))
664 session_device_free(sd);
666 unlink(s->state_file);
667 session_add_to_gc_queue(s);
668 user_add_to_gc_queue(s->user);
671 session_send_signal(s, false);
676 if (s->seat->active == s)
677 seat_set_active(s->seat, NULL);
680 seat_send_changed(s->seat, "Sessions", NULL);
684 user_send_changed(s->user, "Sessions", "Display", NULL);
689 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
690 Session *s = userdata;
695 session_stop(s, false);
699 void session_release(Session *s) {
702 if (!s->started || s->stopping)
705 if (!s->timer_event_source)
706 sd_event_add_time(s->manager->event,
707 &s->timer_event_source,
709 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
710 release_timeout_callback, s);
713 bool session_is_active(Session *s) {
719 return s->seat->active == s;
722 static int get_tty_atime(const char *tty, usec_t *atime) {
723 _cleanup_free_ char *p = NULL;
729 if (!path_is_absolute(tty)) {
730 p = strappend("/dev/", tty);
735 } else if (!path_startswith(tty, "/dev/"))
738 if (lstat(tty, &st) < 0)
741 *atime = timespec_load(&st.st_atim);
745 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
746 _cleanup_free_ char *p = NULL;
752 r = get_ctty(pid, NULL, &p);
756 return get_tty_atime(p, atime);
759 int session_get_idle_hint(Session *s, dual_timestamp *t) {
765 /* Explicit idle hint is set */
768 *t = s->idle_hint_timestamp;
773 /* Graphical sessions should really implement a real
778 /* For sessions with an explicitly configured tty, let's check
781 r = get_tty_atime(s->tty, &atime);
786 /* For sessions with a leader but no explicitly configured
787 * tty, let's check the controlling tty of the leader */
789 r = get_process_ctty_atime(s->leader, &atime);
796 *t = s->idle_hint_timestamp;
802 dual_timestamp_from_realtime(t, atime);
804 n = now(CLOCK_REALTIME);
806 if (s->manager->idle_action_usec <= 0)
809 return atime + s->manager->idle_action_usec <= n;
812 void session_set_idle_hint(Session *s, bool b) {
815 if (s->idle_hint == b)
819 dual_timestamp_get(&s->idle_hint_timestamp);
821 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
824 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
826 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
827 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
830 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
831 Session *s = userdata;
834 assert(s->fifo_fd == fd);
836 /* EOF on the FIFO means the session died abnormally. */
838 session_remove_fifo(s);
839 session_stop(s, false);
844 int session_create_fifo(Session *s) {
851 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
855 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
858 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
862 /* Open reading side */
863 if (s->fifo_fd < 0) {
864 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
870 if (!s->fifo_event_source) {
871 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
875 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
880 /* Open writing side */
881 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
888 static void session_remove_fifo(Session *s) {
891 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
892 s->fifo_fd = safe_close(s->fifo_fd);
895 unlink(s->fifo_path);
901 bool session_check_gc(Session *s, bool drop_not_started) {
904 if (drop_not_started && !s->started)
910 if (s->fifo_fd >= 0) {
911 if (pipe_eof(s->fifo_fd) <= 0)
915 if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
918 if (s->scope && manager_unit_is_active(s->manager, s->scope))
924 void session_add_to_gc_queue(Session *s) {
930 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
931 s->in_gc_queue = true;
934 SessionState session_get_state(Session *s) {
937 /* always check closing first */
938 if (s->stopping || s->timer_event_source)
939 return SESSION_CLOSING;
941 if (s->scope_job || s->fifo_fd < 0)
942 return SESSION_OPENING;
944 if (session_is_active(s))
945 return SESSION_ACTIVE;
947 return SESSION_ONLINE;
950 int session_kill(Session *s, KillWho who, int signo) {
956 return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
959 static int session_open_vt(Session *s) {
960 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
968 sprintf(path, "/dev/tty%u", s->vtnr);
969 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
971 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
976 int session_prepare_vt(Session *s) {
978 struct vt_mode mode = { 0 };
983 vt = session_open_vt(s);
987 r = fchown(vt, s->user->uid, -1);
990 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
994 r = ioctl(vt, KDSKBMODE, K_OFF);
997 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
1001 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
1004 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
1008 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1009 * So we need a dummy handler here which just acknowledges *all* VT
1010 * switch requests. */
1011 mode.mode = VT_PROCESS;
1012 mode.relsig = SIGRTMIN;
1013 mode.acqsig = SIGRTMIN + 1;
1014 r = ioctl(vt, VT_SETMODE, &mode);
1017 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
1024 session_restore_vt(s);
1028 void session_restore_vt(Session *s) {
1029 _cleanup_free_ char *utf8 = NULL;
1030 int vt, kb = K_XLATE;
1031 struct vt_mode mode = { 0 };
1033 vt = session_open_vt(s);
1037 ioctl(vt, KDSETMODE, KD_TEXT);
1039 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
1042 ioctl(vt, KDSKBMODE, kb);
1044 mode.mode = VT_AUTO;
1045 ioctl(vt, VT_SETMODE, &mode);
1049 s->vtfd = safe_close(s->vtfd);
1052 void session_leave_vt(Session *s) {
1057 /* This is called whenever we get a VT-switch signal from the kernel.
1058 * We acknowledge all of them unconditionally. Note that session are
1059 * free to overwrite those handlers and we only register them for
1060 * sessions with controllers. Legacy sessions are not affected.
1061 * However, if we switch from a non-legacy to a legacy session, we must
1062 * make sure to pause all device before acknowledging the switch. We
1063 * process the real switch only after we are notified via sysfs, so the
1064 * legacy session might have already started using the devices. If we
1065 * don't pause the devices before the switch, we might confuse the
1066 * session we switch to. */
1071 session_device_pause_all(s);
1072 r = ioctl(s->vtfd, VT_RELDISP, 1);
1074 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1077 bool session_is_controller(Session *s, const char *sender) {
1080 return streq_ptr(s->controller, sender);
1083 static void session_release_controller(Session *s, bool notify) {
1084 _cleanup_free_ char *name = NULL;
1090 name = s->controller;
1092 /* By resetting the controller before releasing the devices, we won't
1093 * send notification signals. This avoids sending useless notifications
1094 * if the controller is released on disconnects. */
1096 s->controller = NULL;
1098 while ((sd = hashmap_first(s->devices)))
1099 session_device_free(sd);
1101 s->controller = NULL;
1102 manager_drop_busname(s->manager, name);
1105 int session_set_controller(Session *s, const char *sender, bool force) {
1106 _cleanup_free_ char *name = NULL;
1112 if (session_is_controller(s, sender))
1114 if (s->controller && !force)
1117 name = strdup(sender);
1121 r = manager_watch_busname(s->manager, name);
1125 /* When setting a session controller, we forcibly mute the VT and set
1126 * it into graphics-mode. Applications can override that by changing
1127 * VT state after calling TakeControl(). However, this serves as a good
1128 * default and well-behaving controllers can now ignore VTs entirely.
1129 * Note that we reset the VT on ReleaseControl() and if the controller
1131 * If logind crashes/restarts, we restore the controller during restart
1132 * or reset the VT in case it crashed/exited, too. */
1133 r = session_prepare_vt(s);
1135 manager_drop_busname(s->manager, name);
1139 session_release_controller(s, true);
1140 s->controller = name;
1147 void session_drop_controller(Session *s) {
1153 session_release_controller(s, false);
1155 session_restore_vt(s);
1158 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1159 [SESSION_OPENING] = "opening",
1160 [SESSION_ONLINE] = "online",
1161 [SESSION_ACTIVE] = "active",
1162 [SESSION_CLOSING] = "closing"
1165 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1167 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1168 [SESSION_UNSPECIFIED] = "unspecified",
1169 [SESSION_TTY] = "tty",
1170 [SESSION_X11] = "x11",
1171 [SESSION_WAYLAND] = "wayland",
1172 [SESSION_MIR] = "mir",
1173 [SESSION_WEB] = "web",
1176 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1178 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1179 [SESSION_USER] = "user",
1180 [SESSION_GREETER] = "greeter",
1181 [SESSION_LOCK_SCREEN] = "lock-screen",
1182 [SESSION_BACKGROUND] = "background"
1185 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1187 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1188 [KILL_LEADER] = "leader",
1192 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);