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"
41 #define RELEASE_USEC (20*USEC_PER_SEC)
43 static void session_remove_fifo(Session *s);
45 Session* session_new(Manager *m, const char *id) {
50 assert(session_id_valid(id));
56 s->state_file = strappend("/run/systemd/sessions/", id);
62 s->devices = hashmap_new(&devt_hash_ops);
69 s->id = basename(s->state_file);
71 if (hashmap_put(m->sessions, s->id, s) < 0) {
72 hashmap_free(s->devices);
85 void session_free(Session *s) {
91 LIST_REMOVE(gc_queue, s->manager->session_gc_queue, s);
93 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
95 session_remove_fifo(s);
97 session_drop_controller(s);
99 while ((sd = hashmap_first(s->devices)))
100 session_device_free(sd);
102 hashmap_free(s->devices);
105 LIST_REMOVE(sessions_by_user, s->user->sessions, s);
107 if (s->user->display == s)
108 s->user->display = NULL;
112 if (s->seat->active == s)
113 s->seat->active = NULL;
114 if (s->seat->pending_switch == s)
115 s->seat->pending_switch = NULL;
117 seat_evict_position(s->seat, s);
118 LIST_REMOVE(sessions_by_seat, s->seat->sessions, s);
121 sd_bus_message_unref(s->create_message);
125 free(s->remote_host);
126 free(s->remote_user);
130 hashmap_remove(s->manager->sessions, s->id);
136 void session_set_user(Session *s, User *u) {
141 LIST_PREPEND(sessions_by_user, u->sessions, s);
144 int session_save(Session *s) {
145 _cleanup_free_ char *temp_path = NULL;
146 _cleanup_fclose_ FILE *f = NULL;
157 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
161 r = fopen_temporary(s->state_file, &f, &temp_path);
167 fchmod(fileno(f), 0644);
170 "# This is private data. Do not parse.\n"
178 session_is_active(s),
179 session_state_to_string(session_get_state(s)),
183 fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
186 fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
189 fprintf(f, "FIFO=%s\n", s->fifo_path);
192 fprintf(f, "SEAT=%s\n", s->seat->id);
195 fprintf(f, "TTY=%s\n", s->tty);
198 fprintf(f, "DISPLAY=%s\n", s->display);
200 if (s->remote_host) {
201 _cleanup_free_ char *escaped;
203 escaped = cescape(s->remote_host);
209 fprintf(f, "REMOTE_HOST=%s\n", escaped);
212 if (s->remote_user) {
213 _cleanup_free_ char *escaped;
215 escaped = cescape(s->remote_user);
221 fprintf(f, "REMOTE_USER=%s\n", escaped);
225 _cleanup_free_ char *escaped;
227 escaped = cescape(s->service);
233 fprintf(f, "SERVICE=%s\n", escaped);
237 _cleanup_free_ char *escaped;
240 escaped = cescape(s->desktop);
246 fprintf(f, "DESKTOP=%s\n", escaped);
249 if (s->seat && seat_has_vts(s->seat))
250 fprintf(f, "VTNR=%u\n", s->vtnr);
253 fprintf(f, "POS=%u\n", s->pos);
256 fprintf(f, "LEADER="PID_FMT"\n", s->leader);
259 fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
261 if (dual_timestamp_is_set(&s->timestamp))
263 "REALTIME="USEC_FMT"\n"
264 "MONOTONIC="USEC_FMT"\n",
265 s->timestamp.realtime,
266 s->timestamp.monotonic);
269 fprintf(f, "CONTROLLER=%s\n", s->controller);
273 if (ferror(f) || rename(temp_path, s->state_file) < 0) {
275 unlink(s->state_file);
281 log_error_errno(r, "Failed to save session data %s: %m", s->state_file);
286 int session_load(Session *s) {
287 _cleanup_free_ char *remote = NULL,
304 r = parse_env_file(s->state_file, NEWLINE,
306 "FIFO", &s->fifo_path,
309 "DISPLAY", &s->display,
310 "REMOTE_HOST", &s->remote_host,
311 "REMOTE_USER", &s->remote_user,
312 "SERVICE", &s->service,
313 "DESKTOP", &s->desktop,
321 "REALTIME", &realtime,
322 "MONOTONIC", &monotonic,
323 "CONTROLLER", &controller,
327 return log_error_errno(r, "Failed to read %s: %m", s->state_file);
334 log_error("UID not specified for session %s", s->id);
338 r = parse_uid(uid, &u);
340 log_error("Failed to parse UID value %s for session %s.", uid, s->id);
344 user = hashmap_get(s->manager->users, UID_TO_PTR(u));
346 log_error("User of session %s not known.", s->id);
350 session_set_user(s, user);
354 k = parse_boolean(remote);
360 safe_atou(vtnr, &s->vtnr);
362 if (seat && !s->seat) {
365 o = hashmap_get(s->manager->seats, seat);
367 r = seat_attach_session(o, s);
369 log_error("Cannot attach session %s to seat %s", s->id, seat);
372 if (!s->seat || !seat_has_vts(s->seat))
375 if (pos && s->seat) {
378 safe_atou(pos, &npos);
379 seat_claim_position(s->seat, s, npos);
383 k = parse_pid(leader, &s->leader);
385 audit_session_from_pid(s->leader, &s->audit_id);
391 t = session_type_from_string(type);
399 c = session_class_from_string(class);
404 if (state && streq(state, "closing"))
410 /* If we open an unopened pipe for reading we will not
411 get an EOF. to trigger an EOF we hence open it for
412 writing, but close it right away which then will
413 trigger the EOF. This will happen immediately if no
414 other process has the FIFO open for writing, i. e.
415 when the session died before logind (re)started. */
417 fd = session_create_fifo(s);
422 unsigned long long l;
423 if (sscanf(realtime, "%llu", &l) > 0)
424 s->timestamp.realtime = l;
428 unsigned long long l;
429 if (sscanf(monotonic, "%llu", &l) > 0)
430 s->timestamp.monotonic = l;
434 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
435 session_set_controller(s, controller, false);
437 session_restore_vt(s);
443 int session_activate(Session *s) {
444 unsigned int num_pending;
452 if (s->seat->active == s)
455 /* on seats with VTs, we let VTs manage session-switching */
456 if (seat_has_vts(s->seat)) {
460 return chvt(s->vtnr);
463 /* On seats without VTs, we implement session-switching in logind. We
464 * try to pause all session-devices and wait until the session
465 * controller acknowledged them. Once all devices are asleep, we simply
466 * switch the active session and be done.
467 * We save the session we want to switch to in seat->pending_switch and
468 * seat_complete_switch() will perform the final switch. */
470 s->seat->pending_switch = s;
472 /* if no devices are running, immediately perform the session switch */
473 num_pending = session_device_try_pause_all(s);
475 seat_complete_switch(s->seat);
480 int session_start(Session *s) {
491 r = user_start(s->user);
495 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
496 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
497 "SESSION_ID=%s", s->id,
498 "USER_ID=%s", s->user->name,
499 "LEADER="PID_FMT, s->leader,
500 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
503 if (!dual_timestamp_is_set(&s->timestamp))
504 dual_timestamp_get(&s->timestamp);
507 seat_read_active_vt(s->seat);
511 user_elect_display(s->user);
520 session_send_signal(s, true);
521 user_send_changed(s->user, "Sessions", "Display", NULL);
523 if (s->seat->active == s)
524 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
526 seat_send_changed(s->seat, "Sessions", NULL);
532 int session_stop(Session *s, bool force) {
540 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
542 /* We are going down, don't care about FIFOs anymore */
543 session_remove_fifo(s);
547 user_elect_display(s->user);
555 int session_finalize(Session *s) {
565 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
566 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
567 "SESSION_ID=%s", s->id,
568 "USER_ID=%s", s->user->name,
569 "LEADER="PID_FMT, s->leader,
570 LOG_MESSAGE("Removed session %s.", s->id),
573 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
575 /* Kill session devices */
576 while ((sd = hashmap_first(s->devices)))
577 session_device_free(sd);
579 unlink(s->state_file);
580 session_add_to_gc_queue(s);
581 user_add_to_gc_queue(s->user);
584 session_send_signal(s, false);
589 if (s->seat->active == s)
590 seat_set_active(s->seat, NULL);
593 seat_send_changed(s->seat, "Sessions", NULL);
597 user_send_changed(s->user, "Sessions", "Display", NULL);
602 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
603 Session *s = userdata;
608 session_stop(s, false);
612 int session_release(Session *s) {
615 if (!s->started || s->stopping)
618 if (s->timer_event_source)
621 return sd_event_add_time(s->manager->event,
622 &s->timer_event_source,
624 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
625 release_timeout_callback, s);
628 bool session_is_active(Session *s) {
634 return s->seat->active == s;
637 static int get_tty_atime(const char *tty, usec_t *atime) {
638 _cleanup_free_ char *p = NULL;
644 if (!path_is_absolute(tty)) {
645 p = strappend("/dev/", tty);
650 } else if (!path_startswith(tty, "/dev/"))
653 if (lstat(tty, &st) < 0)
656 *atime = timespec_load(&st.st_atim);
660 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
661 _cleanup_free_ char *p = NULL;
667 r = get_ctty(pid, NULL, &p);
671 return get_tty_atime(p, atime);
674 int session_get_idle_hint(Session *s, dual_timestamp *t) {
680 /* Explicit idle hint is set */
683 *t = s->idle_hint_timestamp;
688 /* Graphical sessions should really implement a real
693 /* For sessions with an explicitly configured tty, let's check
696 r = get_tty_atime(s->tty, &atime);
701 /* For sessions with a leader but no explicitly configured
702 * tty, let's check the controlling tty of the leader */
704 r = get_process_ctty_atime(s->leader, &atime);
711 *t = s->idle_hint_timestamp;
717 dual_timestamp_from_realtime(t, atime);
719 n = now(CLOCK_REALTIME);
721 if (s->manager->idle_action_usec <= 0)
724 return atime + s->manager->idle_action_usec <= n;
727 void session_set_idle_hint(Session *s, bool b) {
730 if (s->idle_hint == b)
734 dual_timestamp_get(&s->idle_hint_timestamp);
736 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
739 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
741 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
742 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
745 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
746 Session *s = userdata;
749 assert(s->fifo_fd == fd);
751 /* EOF on the FIFO means the session died abnormally. */
753 session_remove_fifo(s);
754 session_stop(s, false);
759 int session_create_fifo(Session *s) {
766 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
770 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
773 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
777 /* Open reading side */
778 if (s->fifo_fd < 0) {
779 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
785 if (!s->fifo_event_source) {
786 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
790 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
795 /* Open writing side */
796 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
803 static void session_remove_fifo(Session *s) {
806 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
807 s->fifo_fd = safe_close(s->fifo_fd);
810 unlink(s->fifo_path);
816 bool session_check_gc(Session *s, bool drop_not_started) {
819 if (drop_not_started && !s->started)
825 if (s->fifo_fd >= 0) {
826 if (pipe_eof(s->fifo_fd) <= 0)
833 void session_add_to_gc_queue(Session *s) {
839 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
840 s->in_gc_queue = true;
843 SessionState session_get_state(Session *s) {
846 /* always check closing first */
847 if (s->stopping || s->timer_event_source)
848 return SESSION_CLOSING;
851 return SESSION_OPENING;
853 if (session_is_active(s))
854 return SESSION_ACTIVE;
856 return SESSION_ONLINE;
859 int session_kill(Session *s, KillWho who, int signo) {
862 /* No way to kill the session without cgroups. */
866 static int session_open_vt(Session *s) {
867 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
875 sprintf(path, "/dev/tty%u", s->vtnr);
876 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
878 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
883 int session_prepare_vt(Session *s) {
885 struct vt_mode mode = { 0 };
890 vt = session_open_vt(s);
894 r = fchown(vt, s->user->uid, -1);
897 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
901 r = ioctl(vt, KDSKBMODE, K_OFF);
904 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
908 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
911 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
915 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
916 * So we need a dummy handler here which just acknowledges *all* VT
917 * switch requests. */
918 mode.mode = VT_PROCESS;
919 mode.relsig = SIGRTMIN;
920 mode.acqsig = SIGRTMIN + 1;
921 r = ioctl(vt, VT_SETMODE, &mode);
924 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
931 session_restore_vt(s);
935 void session_restore_vt(Session *s) {
936 _cleanup_free_ char *utf8 = NULL;
937 int vt, kb = K_XLATE;
938 struct vt_mode mode = { 0 };
940 vt = session_open_vt(s);
944 (void) ioctl(vt, KDSETMODE, KD_TEXT);
946 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
949 (void) ioctl(vt, KDSKBMODE, kb);
952 (void) ioctl(vt, VT_SETMODE, &mode);
956 s->vtfd = safe_close(s->vtfd);
959 void session_leave_vt(Session *s) {
964 /* This is called whenever we get a VT-switch signal from the kernel.
965 * We acknowledge all of them unconditionally. Note that session are
966 * free to overwrite those handlers and we only register them for
967 * sessions with controllers. Legacy sessions are not affected.
968 * However, if we switch from a non-legacy to a legacy session, we must
969 * make sure to pause all device before acknowledging the switch. We
970 * process the real switch only after we are notified via sysfs, so the
971 * legacy session might have already started using the devices. If we
972 * don't pause the devices before the switch, we might confuse the
973 * session we switch to. */
978 session_device_pause_all(s);
979 r = ioctl(s->vtfd, VT_RELDISP, 1);
981 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
984 bool session_is_controller(Session *s, const char *sender) {
987 return streq_ptr(s->controller, sender);
990 static void session_release_controller(Session *s, bool notify) {
991 _cleanup_free_ char *name = NULL;
997 name = s->controller;
999 /* By resetting the controller before releasing the devices, we won't
1000 * send notification signals. This avoids sending useless notifications
1001 * if the controller is released on disconnects. */
1003 s->controller = NULL;
1005 while ((sd = hashmap_first(s->devices)))
1006 session_device_free(sd);
1008 s->controller = NULL;
1009 manager_drop_busname(s->manager, name);
1012 int session_set_controller(Session *s, const char *sender, bool force) {
1013 _cleanup_free_ char *name = NULL;
1019 if (session_is_controller(s, sender))
1021 if (s->controller && !force)
1024 name = strdup(sender);
1028 r = manager_watch_busname(s->manager, name);
1032 /* When setting a session controller, we forcibly mute the VT and set
1033 * it into graphics-mode. Applications can override that by changing
1034 * VT state after calling TakeControl(). However, this serves as a good
1035 * default and well-behaving controllers can now ignore VTs entirely.
1036 * Note that we reset the VT on ReleaseControl() and if the controller
1038 * If logind crashes/restarts, we restore the controller during restart
1039 * or reset the VT in case it crashed/exited, too. */
1040 r = session_prepare_vt(s);
1042 manager_drop_busname(s->manager, name);
1046 session_release_controller(s, true);
1047 s->controller = name;
1054 void session_drop_controller(Session *s) {
1060 session_release_controller(s, false);
1062 session_restore_vt(s);
1065 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1066 [SESSION_OPENING] = "opening",
1067 [SESSION_ONLINE] = "online",
1068 [SESSION_ACTIVE] = "active",
1069 [SESSION_CLOSING] = "closing"
1072 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1074 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1075 [SESSION_UNSPECIFIED] = "unspecified",
1076 [SESSION_TTY] = "tty",
1077 [SESSION_X11] = "x11",
1078 [SESSION_WAYLAND] = "wayland",
1079 [SESSION_MIR] = "mir",
1080 [SESSION_WEB] = "web",
1083 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1085 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1086 [SESSION_USER] = "user",
1087 [SESSION_GREETER] = "greeter",
1088 [SESSION_LOCK_SCREEN] = "lock-screen",
1089 [SESSION_BACKGROUND] = "background"
1092 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1094 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1095 [KILL_LEADER] = "leader",
1099 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);