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 "cgroup-util.h"
41 #include "logind-session.h"
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 static int session_start_cgroup(Session *s) {
485 assert(s->leader > 0);
487 /* First, create our own group */
488 r = cg_create(SYSTEMD_CGROUP_CONTROLLER, s->id);
490 return log_error_errno(r, "Failed to create cgroup %s: %m", s->id);
492 r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, s->id, s->leader);
494 log_warning_errno(r, "Failed to attach PID %d to cgroup %s: %m", s->leader, s->id);
499 int session_start(Session *s) {
510 r = user_start(s->user);
514 r = session_start_cgroup(s);
518 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
519 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
520 "SESSION_ID=%s", s->id,
521 "USER_ID=%s", s->user->name,
522 "LEADER="PID_FMT, s->leader,
523 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
526 if (!dual_timestamp_is_set(&s->timestamp))
527 dual_timestamp_get(&s->timestamp);
530 seat_read_active_vt(s->seat);
534 user_elect_display(s->user);
543 session_send_signal(s, true);
544 user_send_changed(s->user, "Sessions", "Display", NULL);
546 if (s->seat->active == s)
547 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
549 seat_send_changed(s->seat, "Sessions", NULL);
555 static int session_stop_cgroup(Session *s, bool force) {
556 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
561 if (force || manager_shall_kill(s->manager, s->user->name)) {
562 r = session_kill(s, KILL_ALL, SIGTERM);
570 int session_stop(Session *s, bool force) {
578 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
580 /* We are going down, don't care about FIFOs anymore */
581 session_remove_fifo(s);
584 r = session_stop_cgroup(s, force);
588 user_elect_display(s->user);
596 int session_finalize(Session *s) {
606 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
607 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
608 "SESSION_ID=%s", s->id,
609 "USER_ID=%s", s->user->name,
610 "LEADER="PID_FMT, s->leader,
611 LOG_MESSAGE("Removed session %s.", s->id),
614 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
616 /* Kill session devices */
617 while ((sd = hashmap_first(s->devices)))
618 session_device_free(sd);
620 unlink(s->state_file);
621 session_add_to_gc_queue(s);
622 user_add_to_gc_queue(s->user);
625 session_send_signal(s, false);
630 if (s->seat->active == s)
631 seat_set_active(s->seat, NULL);
634 seat_send_changed(s->seat, "Sessions", NULL);
638 user_send_changed(s->user, "Sessions", "Display", NULL);
643 int session_release(Session *s) {
646 if (!s->started || s->stopping)
649 if (s->timer_event_source)
652 /* In systemd, session release is triggered by user jobs
653 dying. In elogind we don't have that so go ahead and stop
655 return session_stop(s, false);
658 bool session_is_active(Session *s) {
664 return s->seat->active == s;
667 static int get_tty_atime(const char *tty, usec_t *atime) {
668 _cleanup_free_ char *p = NULL;
674 if (!path_is_absolute(tty)) {
675 p = strappend("/dev/", tty);
680 } else if (!path_startswith(tty, "/dev/"))
683 if (lstat(tty, &st) < 0)
686 *atime = timespec_load(&st.st_atim);
690 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
691 _cleanup_free_ char *p = NULL;
697 r = get_ctty(pid, NULL, &p);
701 return get_tty_atime(p, atime);
704 int session_get_idle_hint(Session *s, dual_timestamp *t) {
710 /* Explicit idle hint is set */
713 *t = s->idle_hint_timestamp;
718 /* Graphical sessions should really implement a real
723 /* For sessions with an explicitly configured tty, let's check
726 r = get_tty_atime(s->tty, &atime);
731 /* For sessions with a leader but no explicitly configured
732 * tty, let's check the controlling tty of the leader */
734 r = get_process_ctty_atime(s->leader, &atime);
741 *t = s->idle_hint_timestamp;
747 dual_timestamp_from_realtime(t, atime);
749 n = now(CLOCK_REALTIME);
751 if (s->manager->idle_action_usec <= 0)
754 return atime + s->manager->idle_action_usec <= n;
757 void session_set_idle_hint(Session *s, bool b) {
760 if (s->idle_hint == b)
764 dual_timestamp_get(&s->idle_hint_timestamp);
766 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
769 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
771 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
772 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
775 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
776 Session *s = userdata;
779 assert(s->fifo_fd == fd);
781 /* EOF on the FIFO means the session died abnormally. */
783 session_remove_fifo(s);
784 session_stop(s, false);
789 int session_create_fifo(Session *s) {
796 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
800 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
803 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
807 /* Open reading side */
808 if (s->fifo_fd < 0) {
809 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
815 if (!s->fifo_event_source) {
816 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
820 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
825 /* Open writing side */
826 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
833 static void session_remove_fifo(Session *s) {
836 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
837 s->fifo_fd = safe_close(s->fifo_fd);
840 unlink(s->fifo_path);
846 bool session_check_gc(Session *s, bool drop_not_started) {
849 if (drop_not_started && !s->started)
855 if (s->fifo_fd >= 0) {
856 if (pipe_eof(s->fifo_fd) <= 0)
860 if (cg_is_empty_recursive (SYSTEMD_CGROUP_CONTROLLER, s->id, false) > 0)
866 void session_add_to_gc_queue(Session *s) {
872 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
873 s->in_gc_queue = true;
876 SessionState session_get_state(Session *s) {
879 /* always check closing first */
880 if (s->stopping || s->timer_event_source)
881 return SESSION_CLOSING;
884 return SESSION_OPENING;
886 if (session_is_active(s))
887 return SESSION_ACTIVE;
889 return SESSION_ONLINE;
892 int session_kill(Session *s, KillWho who, int signo) {
895 if (who == KILL_LEADER) {
899 /* FIXME: verify that leader is in cgroup? */
901 if (kill(s->leader, signo) < 0) {
902 return log_error_errno(errno, "Failed to kill process leader %d for session %s: %m", s->leader, s->id);
906 bool sigcont = false;
907 bool ignore_self = true;
909 return cg_kill_recursive (SYSTEMD_CGROUP_CONTROLLER, s->id, signo,
910 sigcont, ignore_self, rem, NULL);
914 static int session_open_vt(Session *s) {
915 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
923 sprintf(path, "/dev/tty%u", s->vtnr);
924 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
926 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
931 int session_prepare_vt(Session *s) {
933 struct vt_mode mode = { 0 };
938 vt = session_open_vt(s);
942 r = fchown(vt, s->user->uid, -1);
945 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
949 r = ioctl(vt, KDSKBMODE, K_OFF);
952 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
956 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
959 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
963 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
964 * So we need a dummy handler here which just acknowledges *all* VT
965 * switch requests. */
966 mode.mode = VT_PROCESS;
967 mode.relsig = SIGRTMIN;
968 mode.acqsig = SIGRTMIN + 1;
969 r = ioctl(vt, VT_SETMODE, &mode);
972 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
979 session_restore_vt(s);
983 void session_restore_vt(Session *s) {
984 _cleanup_free_ char *utf8 = NULL;
985 int vt, kb = K_XLATE;
986 struct vt_mode mode = { 0 };
988 vt = session_open_vt(s);
992 (void) ioctl(vt, KDSETMODE, KD_TEXT);
994 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
997 (void) ioctl(vt, KDSKBMODE, kb);
1000 (void) ioctl(vt, VT_SETMODE, &mode);
1004 s->vtfd = safe_close(s->vtfd);
1007 void session_leave_vt(Session *s) {
1012 /* This is called whenever we get a VT-switch signal from the kernel.
1013 * We acknowledge all of them unconditionally. Note that session are
1014 * free to overwrite those handlers and we only register them for
1015 * sessions with controllers. Legacy sessions are not affected.
1016 * However, if we switch from a non-legacy to a legacy session, we must
1017 * make sure to pause all device before acknowledging the switch. We
1018 * process the real switch only after we are notified via sysfs, so the
1019 * legacy session might have already started using the devices. If we
1020 * don't pause the devices before the switch, we might confuse the
1021 * session we switch to. */
1026 session_device_pause_all(s);
1027 r = ioctl(s->vtfd, VT_RELDISP, 1);
1029 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1032 bool session_is_controller(Session *s, const char *sender) {
1035 return streq_ptr(s->controller, sender);
1038 static void session_release_controller(Session *s, bool notify) {
1039 _cleanup_free_ char *name = NULL;
1045 name = s->controller;
1047 /* By resetting the controller before releasing the devices, we won't
1048 * send notification signals. This avoids sending useless notifications
1049 * if the controller is released on disconnects. */
1051 s->controller = NULL;
1053 while ((sd = hashmap_first(s->devices)))
1054 session_device_free(sd);
1056 s->controller = NULL;
1057 manager_drop_busname(s->manager, name);
1060 int session_set_controller(Session *s, const char *sender, bool force) {
1061 _cleanup_free_ char *name = NULL;
1067 if (session_is_controller(s, sender))
1069 if (s->controller && !force)
1072 name = strdup(sender);
1076 r = manager_watch_busname(s->manager, name);
1080 /* When setting a session controller, we forcibly mute the VT and set
1081 * it into graphics-mode. Applications can override that by changing
1082 * VT state after calling TakeControl(). However, this serves as a good
1083 * default and well-behaving controllers can now ignore VTs entirely.
1084 * Note that we reset the VT on ReleaseControl() and if the controller
1086 * If logind crashes/restarts, we restore the controller during restart
1087 * or reset the VT in case it crashed/exited, too. */
1088 r = session_prepare_vt(s);
1090 manager_drop_busname(s->manager, name);
1094 session_release_controller(s, true);
1095 s->controller = name;
1102 void session_drop_controller(Session *s) {
1108 session_release_controller(s, false);
1110 session_restore_vt(s);
1113 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1114 [SESSION_OPENING] = "opening",
1115 [SESSION_ONLINE] = "online",
1116 [SESSION_ACTIVE] = "active",
1117 [SESSION_CLOSING] = "closing"
1120 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1122 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1123 [SESSION_UNSPECIFIED] = "unspecified",
1124 [SESSION_TTY] = "tty",
1125 [SESSION_X11] = "x11",
1126 [SESSION_WAYLAND] = "wayland",
1127 [SESSION_MIR] = "mir",
1128 [SESSION_WEB] = "web",
1131 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1133 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1134 [SESSION_USER] = "user",
1135 [SESSION_GREETER] = "greeter",
1136 [SESSION_LOCK_SCREEN] = "lock-screen",
1137 [SESSION_BACKGROUND] = "background"
1140 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1142 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1143 [KILL_LEADER] = "leader",
1147 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);