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);
285 r = fflush_and_check(f);
289 if (rename(temp_path, s->state_file) < 0) {
297 (void) unlink(s->state_file);
300 (void) unlink(temp_path);
302 return log_error_errno(r, "Failed to save session data %s: %m", s->state_file);
306 int session_load(Session *s) {
307 _cleanup_free_ char *remote = NULL,
324 r = parse_env_file(s->state_file, NEWLINE,
327 "SCOPE_JOB", &s->scope_job,
328 "FIFO", &s->fifo_path,
331 "DISPLAY", &s->display,
332 "REMOTE_HOST", &s->remote_host,
333 "REMOTE_USER", &s->remote_user,
334 "SERVICE", &s->service,
335 "DESKTOP", &s->desktop,
338 "POSITION", &position,
343 "REALTIME", &realtime,
344 "MONOTONIC", &monotonic,
345 "CONTROLLER", &controller,
349 return log_error_errno(r, "Failed to read %s: %m", s->state_file);
356 log_error("UID not specified for session %s", s->id);
360 r = parse_uid(uid, &u);
362 log_error("Failed to parse UID value %s for session %s.", uid, s->id);
366 user = hashmap_get(s->manager->users, UID_TO_PTR(u));
368 log_error("User of session %s not known.", s->id);
372 session_set_user(s, user);
376 k = parse_boolean(remote);
382 safe_atou(vtnr, &s->vtnr);
384 if (seat && !s->seat) {
387 o = hashmap_get(s->manager->seats, seat);
389 r = seat_attach_session(o, s);
391 log_error("Cannot attach session %s to seat %s", s->id, seat);
394 if (!s->seat || !seat_has_vts(s->seat))
397 if (position && s->seat) {
400 safe_atou(position, &npos);
401 seat_claim_position(s->seat, s, npos);
405 k = parse_pid(leader, &s->leader);
407 audit_session_from_pid(s->leader, &s->audit_id);
413 t = session_type_from_string(type);
421 c = session_class_from_string(class);
426 if (state && streq(state, "closing"))
432 /* If we open an unopened pipe for reading we will not
433 get an EOF. to trigger an EOF we hence open it for
434 writing, but close it right away which then will
435 trigger the EOF. This will happen immediately if no
436 other process has the FIFO open for writing, i. e.
437 when the session died before logind (re)started. */
439 fd = session_create_fifo(s);
444 unsigned long long l;
445 if (sscanf(realtime, "%llu", &l) > 0)
446 s->timestamp.realtime = l;
450 unsigned long long l;
451 if (sscanf(monotonic, "%llu", &l) > 0)
452 s->timestamp.monotonic = l;
456 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
457 session_set_controller(s, controller, false);
459 session_restore_vt(s);
465 int session_activate(Session *s) {
466 unsigned int num_pending;
474 if (s->seat->active == s)
477 /* on seats with VTs, we let VTs manage session-switching */
478 if (seat_has_vts(s->seat)) {
482 return chvt(s->vtnr);
485 /* On seats without VTs, we implement session-switching in logind. We
486 * try to pause all session-devices and wait until the session
487 * controller acknowledged them. Once all devices are asleep, we simply
488 * switch the active session and be done.
489 * We save the session we want to switch to in seat->pending_switch and
490 * seat_complete_switch() will perform the final switch. */
492 s->seat->pending_switch = s;
494 /* if no devices are running, immediately perform the session switch */
495 num_pending = session_device_try_pause_all(s);
497 seat_complete_switch(s->seat);
502 static int session_start_scope(Session *s) {
507 assert(s->user->slice);
510 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
511 _cleanup_free_ char *description = NULL;
512 char *scope, *job = NULL;
514 description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
518 scope = strjoin("session-", s->id, ".scope", NULL);
522 r = manager_start_scope(s->manager, scope, s->leader, s->user->slice, description, "systemd-logind.service", "systemd-user-sessions.service", &error, &job);
524 log_error("Failed to start session scope %s: %s %s",
525 scope, bus_error_message(&error, r), error.name);
537 hashmap_put(s->manager->session_units, s->scope, s);
542 int session_start(Session *s) {
553 r = user_start(s->user);
558 r = session_start_scope(s);
562 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
563 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
564 "SESSION_ID=%s", s->id,
565 "USER_ID=%s", s->user->name,
566 "LEADER="PID_FMT, s->leader,
567 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
570 if (!dual_timestamp_is_set(&s->timestamp))
571 dual_timestamp_get(&s->timestamp);
574 seat_read_active_vt(s->seat);
578 user_elect_display(s->user);
587 session_send_signal(s, true);
588 user_send_changed(s->user, "Sessions", "Display", NULL);
590 if (s->seat->active == s)
591 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
593 seat_send_changed(s->seat, "Sessions", NULL);
599 static int session_stop_scope(Session *s, bool force) {
600 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
609 if (force || manager_shall_kill(s->manager, s->user->name)) {
610 r = manager_stop_unit(s->manager, s->scope, &error, &job);
612 log_error("Failed to stop session scope: %s", bus_error_message(&error, r));
619 r = manager_abandon_scope(s->manager, s->scope, &error);
621 log_error("Failed to abandon session scope: %s", bus_error_message(&error, r));
629 int session_stop(Session *s, bool force) {
637 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
640 seat_evict_position(s->seat, s);
642 /* We are going down, don't care about FIFOs anymore */
643 session_remove_fifo(s);
646 r = session_stop_scope(s, force);
650 user_elect_display(s->user);
658 int session_finalize(Session *s) {
667 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
668 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
669 "SESSION_ID=%s", s->id,
670 "USER_ID=%s", s->user->name,
671 "LEADER="PID_FMT, s->leader,
672 LOG_MESSAGE("Removed session %s.", s->id),
675 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
678 seat_evict_position(s->seat, s);
680 /* Kill session devices */
681 while ((sd = hashmap_first(s->devices)))
682 session_device_free(sd);
684 (void) unlink(s->state_file);
685 session_add_to_gc_queue(s);
686 user_add_to_gc_queue(s->user);
689 session_send_signal(s, false);
694 if (s->seat->active == s)
695 seat_set_active(s->seat, NULL);
698 seat_send_changed(s->seat, "Sessions", NULL);
702 user_send_changed(s->user, "Sessions", "Display", NULL);
707 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
708 Session *s = userdata;
713 session_stop(s, false);
717 int session_release(Session *s) {
720 if (!s->started || s->stopping)
723 if (s->timer_event_source)
726 return sd_event_add_time(s->manager->event,
727 &s->timer_event_source,
729 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
730 release_timeout_callback, s);
733 bool session_is_active(Session *s) {
739 return s->seat->active == s;
742 static int get_tty_atime(const char *tty, usec_t *atime) {
743 _cleanup_free_ char *p = NULL;
749 if (!path_is_absolute(tty)) {
750 p = strappend("/dev/", tty);
755 } else if (!path_startswith(tty, "/dev/"))
758 if (lstat(tty, &st) < 0)
761 *atime = timespec_load(&st.st_atim);
765 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
766 _cleanup_free_ char *p = NULL;
772 r = get_ctty(pid, NULL, &p);
776 return get_tty_atime(p, atime);
779 int session_get_idle_hint(Session *s, dual_timestamp *t) {
785 /* Explicit idle hint is set */
788 *t = s->idle_hint_timestamp;
793 /* Graphical sessions should really implement a real
798 /* For sessions with an explicitly configured tty, let's check
801 r = get_tty_atime(s->tty, &atime);
806 /* For sessions with a leader but no explicitly configured
807 * tty, let's check the controlling tty of the leader */
809 r = get_process_ctty_atime(s->leader, &atime);
816 *t = s->idle_hint_timestamp;
822 dual_timestamp_from_realtime(t, atime);
824 n = now(CLOCK_REALTIME);
826 if (s->manager->idle_action_usec <= 0)
829 return atime + s->manager->idle_action_usec <= n;
832 void session_set_idle_hint(Session *s, bool b) {
835 if (s->idle_hint == b)
839 dual_timestamp_get(&s->idle_hint_timestamp);
841 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
844 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
846 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
847 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
850 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
851 Session *s = userdata;
854 assert(s->fifo_fd == fd);
856 /* EOF on the FIFO means the session died abnormally. */
858 session_remove_fifo(s);
859 session_stop(s, false);
864 int session_create_fifo(Session *s) {
871 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
875 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
878 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
882 /* Open reading side */
883 if (s->fifo_fd < 0) {
884 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
890 if (!s->fifo_event_source) {
891 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
895 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
900 /* Open writing side */
901 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
908 static void session_remove_fifo(Session *s) {
911 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
912 s->fifo_fd = safe_close(s->fifo_fd);
915 unlink(s->fifo_path);
921 bool session_check_gc(Session *s, bool drop_not_started) {
924 if (drop_not_started && !s->started)
930 if (s->fifo_fd >= 0) {
931 if (pipe_eof(s->fifo_fd) <= 0)
935 if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
938 if (s->scope && manager_unit_is_active(s->manager, s->scope))
944 void session_add_to_gc_queue(Session *s) {
950 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
951 s->in_gc_queue = true;
954 SessionState session_get_state(Session *s) {
957 /* always check closing first */
958 if (s->stopping || s->timer_event_source)
959 return SESSION_CLOSING;
961 if (s->scope_job || s->fifo_fd < 0)
962 return SESSION_OPENING;
964 if (session_is_active(s))
965 return SESSION_ACTIVE;
967 return SESSION_ONLINE;
970 int session_kill(Session *s, KillWho who, int signo) {
976 return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
979 static int session_open_vt(Session *s) {
980 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
988 sprintf(path, "/dev/tty%u", s->vtnr);
989 s->vtfd = open_terminal(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
991 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
996 int session_prepare_vt(Session *s) {
998 struct vt_mode mode = { 0 };
1003 vt = session_open_vt(s);
1007 r = fchown(vt, s->user->uid, -1);
1010 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
1014 r = ioctl(vt, KDSKBMODE, K_OFF);
1017 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
1021 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
1024 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
1028 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1029 * So we need a dummy handler here which just acknowledges *all* VT
1030 * switch requests. */
1031 mode.mode = VT_PROCESS;
1032 mode.relsig = SIGRTMIN;
1033 mode.acqsig = SIGRTMIN + 1;
1034 r = ioctl(vt, VT_SETMODE, &mode);
1037 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
1044 session_restore_vt(s);
1048 void session_restore_vt(Session *s) {
1049 _cleanup_free_ char *utf8 = NULL;
1050 int vt, kb = K_XLATE;
1051 struct vt_mode mode = { 0 };
1053 /* We need to get a fresh handle to the virtual terminal,
1054 * since the old file-descriptor is potentially in a hung-up
1055 * state after the controlling process exited; we do a
1056 * little dance to avoid having the terminal be available
1057 * for reuse before we've cleaned it up.
1059 int old_fd = s->vtfd;
1062 vt = session_open_vt(s);
1068 (void) ioctl(vt, KDSETMODE, KD_TEXT);
1070 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
1073 (void) ioctl(vt, KDSKBMODE, kb);
1075 mode.mode = VT_AUTO;
1076 (void) ioctl(vt, VT_SETMODE, &mode);
1080 s->vtfd = safe_close(s->vtfd);
1083 void session_leave_vt(Session *s) {
1088 /* This is called whenever we get a VT-switch signal from the kernel.
1089 * We acknowledge all of them unconditionally. Note that session are
1090 * free to overwrite those handlers and we only register them for
1091 * sessions with controllers. Legacy sessions are not affected.
1092 * However, if we switch from a non-legacy to a legacy session, we must
1093 * make sure to pause all device before acknowledging the switch. We
1094 * process the real switch only after we are notified via sysfs, so the
1095 * legacy session might have already started using the devices. If we
1096 * don't pause the devices before the switch, we might confuse the
1097 * session we switch to. */
1102 session_device_pause_all(s);
1103 r = ioctl(s->vtfd, VT_RELDISP, 1);
1105 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1108 bool session_is_controller(Session *s, const char *sender) {
1111 return streq_ptr(s->controller, sender);
1114 static void session_release_controller(Session *s, bool notify) {
1115 _cleanup_free_ char *name = NULL;
1121 name = s->controller;
1123 /* By resetting the controller before releasing the devices, we won't
1124 * send notification signals. This avoids sending useless notifications
1125 * if the controller is released on disconnects. */
1127 s->controller = NULL;
1129 while ((sd = hashmap_first(s->devices)))
1130 session_device_free(sd);
1132 s->controller = NULL;
1133 s->track = sd_bus_track_unref(s->track);
1136 static int on_bus_track(sd_bus_track *track, void *userdata) {
1137 Session *s = userdata;
1142 session_drop_controller(s);
1147 int session_set_controller(Session *s, const char *sender, bool force) {
1148 _cleanup_free_ char *name = NULL;
1154 if (session_is_controller(s, sender))
1156 if (s->controller && !force)
1159 name = strdup(sender);
1163 s->track = sd_bus_track_unref(s->track);
1164 r = sd_bus_track_new(s->manager->bus, &s->track, on_bus_track, s);
1168 r = sd_bus_track_add_name(s->track, name);
1172 /* When setting a session controller, we forcibly mute the VT and set
1173 * it into graphics-mode. Applications can override that by changing
1174 * VT state after calling TakeControl(). However, this serves as a good
1175 * default and well-behaving controllers can now ignore VTs entirely.
1176 * Note that we reset the VT on ReleaseControl() and if the controller
1178 * If logind crashes/restarts, we restore the controller during restart
1179 * or reset the VT in case it crashed/exited, too. */
1180 r = session_prepare_vt(s);
1182 s->track = sd_bus_track_unref(s->track);
1186 session_release_controller(s, true);
1187 s->controller = name;
1194 void session_drop_controller(Session *s) {
1200 s->track = sd_bus_track_unref(s->track);
1201 session_release_controller(s, false);
1203 session_restore_vt(s);
1206 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1207 [SESSION_OPENING] = "opening",
1208 [SESSION_ONLINE] = "online",
1209 [SESSION_ACTIVE] = "active",
1210 [SESSION_CLOSING] = "closing"
1213 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1215 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1216 [SESSION_UNSPECIFIED] = "unspecified",
1217 [SESSION_TTY] = "tty",
1218 [SESSION_X11] = "x11",
1219 [SESSION_WAYLAND] = "wayland",
1220 [SESSION_MIR] = "mir",
1221 [SESSION_WEB] = "web",
1224 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1226 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1227 [SESSION_USER] = "user",
1228 [SESSION_GREETER] = "greeter",
1229 [SESSION_LOCK_SCREEN] = "lock-screen",
1230 [SESSION_BACKGROUND] = "background"
1233 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1235 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1236 [KILL_LEADER] = "leader",
1240 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);