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 static unsigned long devt_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) {
48 uint64_t u = *(const dev_t*)p;
50 return uint64_hash_func(&u, hash_key);
53 static int devt_compare_func(const void *_a, const void *_b) {
56 a = *(const dev_t*) _a;
57 b = *(const dev_t*) _b;
59 return a < b ? -1 : (a > b ? 1 : 0);
62 Session* session_new(Manager *m, const char *id) {
67 assert(session_id_valid(id));
73 s->state_file = strappend("/run/systemd/sessions/", id);
79 s->devices = hashmap_new(devt_hash_func, devt_compare_func);
86 s->id = basename(s->state_file);
88 if (hashmap_put(m->sessions, s->id, s) < 0) {
89 hashmap_free(s->devices);
102 void session_free(Session *s) {
108 LIST_REMOVE(gc_queue, s->manager->session_gc_queue, s);
110 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
112 session_remove_fifo(s);
114 session_drop_controller(s);
116 while ((sd = hashmap_first(s->devices)))
117 session_device_free(sd);
119 hashmap_free(s->devices);
122 LIST_REMOVE(sessions_by_user, s->user->sessions, s);
124 if (s->user->display == s)
125 s->user->display = NULL;
129 if (s->seat->active == s)
130 s->seat->active = NULL;
131 if (s->seat->pending_switch == s)
132 s->seat->pending_switch = NULL;
134 seat_evict_position(s->seat, s);
135 LIST_REMOVE(sessions_by_seat, s->seat->sessions, s);
139 hashmap_remove(s->manager->session_units, s->scope);
145 sd_bus_message_unref(s->create_message);
149 free(s->remote_host);
150 free(s->remote_user);
154 hashmap_remove(s->manager->sessions, s->id);
156 s->vt_source = sd_event_source_unref(s->vt_source);
162 void session_set_user(Session *s, User *u) {
167 LIST_PREPEND(sessions_by_user, u->sessions, s);
170 int session_save(Session *s) {
171 _cleanup_free_ char *temp_path = NULL;
172 _cleanup_fclose_ FILE *f = NULL;
183 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
187 r = fopen_temporary(s->state_file, &f, &temp_path);
193 fchmod(fileno(f), 0644);
196 "# This is private data. Do not parse.\n"
204 session_is_active(s),
205 session_state_to_string(session_get_state(s)),
209 fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
212 fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
215 fprintf(f, "SCOPE=%s\n", s->scope);
218 fprintf(f, "SCOPE_JOB=%s\n", s->scope_job);
221 fprintf(f, "FIFO=%s\n", s->fifo_path);
224 fprintf(f, "SEAT=%s\n", s->seat->id);
227 fprintf(f, "TTY=%s\n", s->tty);
230 fprintf(f, "DISPLAY=%s\n", s->display);
233 fprintf(f, "REMOTE_HOST=%s\n", s->remote_host);
236 fprintf(f, "REMOTE_USER=%s\n", s->remote_user);
239 fprintf(f, "SERVICE=%s\n", s->service);
242 fprintf(f, "DESKTOP=%s\n", s->desktop);
244 if (s->seat && seat_has_vts(s->seat))
245 fprintf(f, "VTNR=%u\n", s->vtnr);
248 fprintf(f, "POS=%u\n", s->pos);
251 fprintf(f, "LEADER="PID_FMT"\n", s->leader);
254 fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
256 if (dual_timestamp_is_set(&s->timestamp))
258 "REALTIME="USEC_FMT"\n"
259 "MONOTONIC="USEC_FMT"\n",
260 s->timestamp.realtime,
261 s->timestamp.monotonic);
264 fprintf(f, "CONTROLLER=%s\n", s->controller);
268 if (ferror(f) || rename(temp_path, s->state_file) < 0) {
270 unlink(s->state_file);
276 log_error("Failed to save session data %s: %s", s->state_file, strerror(-r));
281 int session_load(Session *s) {
282 _cleanup_free_ char *remote = NULL,
298 r = parse_env_file(s->state_file, NEWLINE,
301 "SCOPE_JOB", &s->scope_job,
302 "FIFO", &s->fifo_path,
305 "DISPLAY", &s->display,
306 "REMOTE_HOST", &s->remote_host,
307 "REMOTE_USER", &s->remote_user,
308 "SERVICE", &s->service,
309 "DESKTOP", &s->desktop,
316 "REALTIME", &realtime,
317 "MONOTONIC", &monotonic,
318 "CONTROLLER", &controller,
322 log_error("Failed to read %s: %s", s->state_file, strerror(-r));
331 log_error("UID not specified for session %s", s->id);
335 r = parse_uid(uid, &u);
337 log_error("Failed to parse UID value %s for session %s.", uid, s->id);
341 user = hashmap_get(s->manager->users, ULONG_TO_PTR((unsigned long) u));
343 log_error("User of session %s not known.", s->id);
347 session_set_user(s, user);
351 k = parse_boolean(remote);
357 safe_atou(vtnr, &s->vtnr);
359 if (seat && !s->seat) {
362 o = hashmap_get(s->manager->seats, seat);
364 r = seat_attach_session(o, s);
366 log_error("Cannot attach session %s to seat %s", s->id, seat);
369 if (!s->seat || !seat_has_vts(s->seat))
372 if (pos && s->seat) {
375 safe_atou(pos, &npos);
376 seat_claim_position(s->seat, s, npos);
380 k = parse_pid(leader, &s->leader);
382 audit_session_from_pid(s->leader, &s->audit_id);
388 t = session_type_from_string(type);
396 c = session_class_from_string(class);
404 /* If we open an unopened pipe for reading we will not
405 get an EOF. to trigger an EOF we hence open it for
406 reading, but close it right-away which then will
409 fd = session_create_fifo(s);
414 unsigned long long l;
415 if (sscanf(realtime, "%llu", &l) > 0)
416 s->timestamp.realtime = l;
420 unsigned long long l;
421 if (sscanf(monotonic, "%llu", &l) > 0)
422 s->timestamp.monotonic = l;
426 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
427 session_set_controller(s, controller, false);
429 session_restore_vt(s);
435 int session_activate(Session *s) {
436 unsigned int num_pending;
444 if (s->seat->active == s)
447 /* on seats with VTs, we let VTs manage session-switching */
448 if (seat_has_vts(s->seat)) {
452 return chvt(s->vtnr);
455 /* On seats without VTs, we implement session-switching in logind. We
456 * try to pause all session-devices and wait until the session
457 * controller acknowledged them. Once all devices are asleep, we simply
458 * switch the active session and be done.
459 * We save the session we want to switch to in seat->pending_switch and
460 * seat_complete_switch() will perform the final switch. */
462 s->seat->pending_switch = s;
464 /* if no devices are running, immediately perform the session switch */
465 num_pending = session_device_try_pause_all(s);
467 seat_complete_switch(s->seat);
472 static int session_start_scope(Session *s) {
477 assert(s->user->slice);
480 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
481 _cleanup_free_ char *description = NULL;
482 char *scope, *job = NULL;
484 description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
488 scope = strjoin("session-", s->id, ".scope", NULL);
492 r = manager_start_scope(s->manager, scope, s->leader, s->user->slice, description, "systemd-logind.service", "systemd-user-sessions.service", &error, &job);
494 log_error("Failed to start session scope %s: %s %s",
495 scope, bus_error_message(&error, r), error.name);
507 hashmap_put(s->manager->session_units, s->scope, s);
512 int session_start(Session *s) {
523 r = user_start(s->user);
528 r = session_start_scope(s);
532 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
533 MESSAGE_ID(SD_MESSAGE_SESSION_START),
534 "SESSION_ID=%s", s->id,
535 "USER_ID=%s", s->user->name,
536 "LEADER="PID_FMT, s->leader,
537 "MESSAGE=New session %s of user %s.", s->id, s->user->name,
540 if (!dual_timestamp_is_set(&s->timestamp))
541 dual_timestamp_get(&s->timestamp);
544 seat_read_active_vt(s->seat);
548 user_elect_display(s->user);
557 session_send_signal(s, true);
558 user_send_changed(s->user, "Sessions", "Display", NULL);
560 if (s->seat->active == s)
561 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
563 seat_send_changed(s->seat, "Sessions", NULL);
569 static int session_stop_scope(Session *s, bool force) {
570 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
579 if (force || manager_shall_kill(s->manager, s->user->name)) {
580 r = manager_stop_unit(s->manager, s->scope, &error, &job);
582 log_error("Failed to stop session scope: %s", bus_error_message(&error, r));
589 r = manager_abandon_scope(s->manager, s->scope, &error);
591 log_error("Failed to abandon session scope: %s", bus_error_message(&error, r));
599 int session_stop(Session *s, bool force) {
607 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
609 /* We are going down, don't care about FIFOs anymore */
610 session_remove_fifo(s);
613 r = session_stop_scope(s, force);
617 user_elect_display(s->user);
625 int session_finalize(Session *s) {
635 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
636 MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
637 "SESSION_ID=%s", s->id,
638 "USER_ID=%s", s->user->name,
639 "LEADER="PID_FMT, s->leader,
640 "MESSAGE=Removed session %s.", s->id,
643 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
645 /* Kill session devices */
646 while ((sd = hashmap_first(s->devices)))
647 session_device_free(sd);
649 unlink(s->state_file);
650 session_add_to_gc_queue(s);
651 user_add_to_gc_queue(s->user);
654 session_send_signal(s, false);
659 if (s->seat->active == s)
660 seat_set_active(s->seat, NULL);
663 seat_send_changed(s->seat, "Sessions", NULL);
667 user_send_changed(s->user, "Sessions", "Display", NULL);
672 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
673 Session *s = userdata;
678 session_stop(s, false);
682 void session_release(Session *s) {
685 if (!s->started || s->stopping)
688 if (!s->timer_event_source)
689 sd_event_add_time(s->manager->event,
690 &s->timer_event_source,
692 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
693 release_timeout_callback, s);
696 bool session_is_active(Session *s) {
702 return s->seat->active == s;
705 static int get_tty_atime(const char *tty, usec_t *atime) {
706 _cleanup_free_ char *p = NULL;
712 if (!path_is_absolute(tty)) {
713 p = strappend("/dev/", tty);
718 } else if (!path_startswith(tty, "/dev/"))
721 if (lstat(tty, &st) < 0)
724 *atime = timespec_load(&st.st_atim);
728 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
729 _cleanup_free_ char *p = NULL;
735 r = get_ctty(pid, NULL, &p);
739 return get_tty_atime(p, atime);
742 int session_get_idle_hint(Session *s, dual_timestamp *t) {
748 /* Explicit idle hint is set */
751 *t = s->idle_hint_timestamp;
756 /* Graphical sessions should really implement a real
761 /* For sessions with an explicitly configured tty, let's check
764 r = get_tty_atime(s->tty, &atime);
769 /* For sessions with a leader but no explicitly configured
770 * tty, let's check the controlling tty of the leader */
772 r = get_process_ctty_atime(s->leader, &atime);
779 *t = s->idle_hint_timestamp;
785 dual_timestamp_from_realtime(t, atime);
787 n = now(CLOCK_REALTIME);
789 if (s->manager->idle_action_usec <= 0)
792 return atime + s->manager->idle_action_usec <= n;
795 void session_set_idle_hint(Session *s, bool b) {
798 if (s->idle_hint == b)
802 dual_timestamp_get(&s->idle_hint_timestamp);
804 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
807 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
809 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
810 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
813 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
814 Session *s = userdata;
817 assert(s->fifo_fd == fd);
819 /* EOF on the FIFO means the session died abnormally. */
821 session_remove_fifo(s);
822 session_stop(s, false);
827 int session_create_fifo(Session *s) {
834 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
838 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
841 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
845 /* Open reading side */
846 if (s->fifo_fd < 0) {
847 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
853 if (!s->fifo_event_source) {
854 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
858 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
863 /* Open writing side */
864 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
871 static void session_remove_fifo(Session *s) {
874 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
875 s->fifo_fd = safe_close(s->fifo_fd);
878 unlink(s->fifo_path);
884 bool session_check_gc(Session *s, bool drop_not_started) {
887 if (drop_not_started && !s->started)
893 if (s->fifo_fd >= 0) {
894 if (pipe_eof(s->fifo_fd) <= 0)
898 if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
901 if (s->scope && manager_unit_is_active(s->manager, s->scope))
907 void session_add_to_gc_queue(Session *s) {
913 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
914 s->in_gc_queue = true;
917 SessionState session_get_state(Session *s) {
920 /* always check closing first */
921 if (s->stopping || s->timer_event_source)
922 return SESSION_CLOSING;
924 if (s->scope_job || s->fifo_fd < 0)
925 return SESSION_OPENING;
927 if (session_is_active(s))
928 return SESSION_ACTIVE;
930 return SESSION_ONLINE;
933 int session_kill(Session *s, KillWho who, int signo) {
939 return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
942 static int session_open_vt(Session *s) {
943 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
951 sprintf(path, "/dev/tty%u", s->vtnr);
952 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
954 log_error("cannot open VT %s of session %s: %m", path, s->id);
961 static int session_vt_fn(sd_event_source *source, const struct signalfd_siginfo *si, void *data) {
965 ioctl(s->vtfd, VT_RELDISP, 1);
970 void session_prepare_vt(Session *s) {
972 struct vt_mode mode = { 0 };
975 vt = session_open_vt(s);
979 r = fchown(vt, s->user->uid, -1);
983 r = ioctl(vt, KDSKBMODE, K_OFF);
987 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
992 sigaddset(&mask, SIGUSR1);
993 sigprocmask(SIG_BLOCK, &mask, NULL);
995 r = sd_event_add_signal(s->manager->event, &s->vt_source, SIGUSR1, session_vt_fn, s);
999 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1000 * So we need a dummy handler here which just acknowledges *all* VT
1001 * switch requests. */
1002 mode.mode = VT_PROCESS;
1003 mode.relsig = SIGUSR1;
1004 mode.acqsig = SIGUSR1;
1005 r = ioctl(vt, VT_SETMODE, &mode);
1012 log_error("cannot mute VT %u for session %s (%d/%d)", s->vtnr, s->id, r, errno);
1013 session_restore_vt(s);
1016 void session_restore_vt(Session *s) {
1017 _cleanup_free_ char *utf8 = NULL;
1018 int vt, kb = K_XLATE;
1019 struct vt_mode mode = { 0 };
1021 vt = session_open_vt(s);
1025 s->vt_source = sd_event_source_unref(s->vt_source);
1027 ioctl(vt, KDSETMODE, KD_TEXT);
1029 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
1032 ioctl(vt, KDSKBMODE, kb);
1034 mode.mode = VT_AUTO;
1035 ioctl(vt, VT_SETMODE, &mode);
1039 s->vtfd = safe_close(s->vtfd);
1042 bool session_is_controller(Session *s, const char *sender) {
1045 return streq_ptr(s->controller, sender);
1048 static void session_swap_controller(Session *s, char *name) {
1051 if (s->controller) {
1052 manager_drop_busname(s->manager, s->controller);
1053 free(s->controller);
1054 s->controller = NULL;
1056 /* Drop all devices as they're now unused. Do that after the
1057 * controller is released to avoid sending out useles
1059 while ((sd = hashmap_first(s->devices)))
1060 session_device_free(sd);
1063 session_restore_vt(s);
1066 s->controller = name;
1070 int session_set_controller(Session *s, const char *sender, bool force) {
1077 if (session_is_controller(s, sender))
1079 if (s->controller && !force)
1086 r = manager_watch_busname(s->manager, sender);
1092 session_swap_controller(s, t);
1094 /* When setting a session controller, we forcibly mute the VT and set
1095 * it into graphics-mode. Applications can override that by changing
1096 * VT state after calling TakeControl(). However, this serves as a good
1097 * default and well-behaving controllers can now ignore VTs entirely.
1098 * Note that we reset the VT on ReleaseControl() and if the controller
1100 * If logind crashes/restarts, we restore the controller during restart
1101 * or reset the VT in case it crashed/exited, too. */
1102 session_prepare_vt(s);
1107 void session_drop_controller(Session *s) {
1113 session_swap_controller(s, NULL);
1116 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1117 [SESSION_OPENING] = "opening",
1118 [SESSION_ONLINE] = "online",
1119 [SESSION_ACTIVE] = "active",
1120 [SESSION_CLOSING] = "closing"
1123 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1125 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1126 [SESSION_UNSPECIFIED] = "unspecified",
1127 [SESSION_TTY] = "tty",
1128 [SESSION_X11] = "x11",
1129 [SESSION_WAYLAND] = "wayland",
1130 [SESSION_MIR] = "mir",
1133 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1135 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1136 [SESSION_USER] = "user",
1137 [SESSION_GREETER] = "greeter",
1138 [SESSION_LOCK_SCREEN] = "lock-screen",
1139 [SESSION_BACKGROUND] = "background"
1142 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1144 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1145 [KILL_LEADER] = "leader",
1149 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);