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);
122 hashmap_remove(s->manager->session_units, s->scope);
128 sd_bus_message_unref(s->create_message);
132 free(s->remote_host);
133 free(s->remote_user);
137 hashmap_remove(s->manager->sessions, s->id);
143 void session_set_user(Session *s, User *u) {
148 LIST_PREPEND(sessions_by_user, u->sessions, s);
151 int session_save(Session *s) {
152 _cleanup_free_ char *temp_path = NULL;
153 _cleanup_fclose_ FILE *f = NULL;
164 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
168 r = fopen_temporary(s->state_file, &f, &temp_path);
174 fchmod(fileno(f), 0644);
177 "# This is private data. Do not parse.\n"
185 session_is_active(s),
186 session_state_to_string(session_get_state(s)),
190 fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
193 fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
196 fprintf(f, "SCOPE=%s\n", s->scope);
198 fprintf(f, "SCOPE_JOB=%s\n", s->scope_job);
201 fprintf(f, "FIFO=%s\n", s->fifo_path);
204 fprintf(f, "SEAT=%s\n", s->seat->id);
207 fprintf(f, "TTY=%s\n", s->tty);
210 fprintf(f, "DISPLAY=%s\n", s->display);
212 if (s->remote_host) {
213 _cleanup_free_ char *escaped;
215 escaped = cescape(s->remote_host);
221 fprintf(f, "REMOTE_HOST=%s\n", escaped);
224 if (s->remote_user) {
225 _cleanup_free_ char *escaped;
227 escaped = cescape(s->remote_user);
233 fprintf(f, "REMOTE_USER=%s\n", escaped);
237 _cleanup_free_ char *escaped;
239 escaped = cescape(s->service);
245 fprintf(f, "SERVICE=%s\n", escaped);
249 _cleanup_free_ char *escaped;
252 escaped = cescape(s->desktop);
258 fprintf(f, "DESKTOP=%s\n", escaped);
261 if (s->seat && seat_has_vts(s->seat))
262 fprintf(f, "VTNR=%u\n", s->vtnr);
265 fprintf(f, "POS=%u\n", s->pos);
268 fprintf(f, "LEADER="PID_FMT"\n", s->leader);
271 fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
273 if (dual_timestamp_is_set(&s->timestamp))
275 "REALTIME="USEC_FMT"\n"
276 "MONOTONIC="USEC_FMT"\n",
277 s->timestamp.realtime,
278 s->timestamp.monotonic);
281 fprintf(f, "CONTROLLER=%s\n", s->controller);
285 if (ferror(f) || rename(temp_path, s->state_file) < 0) {
287 unlink(s->state_file);
293 log_error_errno(r, "Failed to save session data %s: %m", s->state_file);
298 int session_load(Session *s) {
299 _cleanup_free_ char *remote = NULL,
316 r = parse_env_file(s->state_file, NEWLINE,
319 "SCOPE_JOB", &s->scope_job,
320 "FIFO", &s->fifo_path,
323 "DISPLAY", &s->display,
324 "REMOTE_HOST", &s->remote_host,
325 "REMOTE_USER", &s->remote_user,
326 "SERVICE", &s->service,
327 "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, UID_TO_PTR(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);
418 if (state && streq(state, "closing"))
424 /* If we open an unopened pipe for reading we will not
425 get an EOF. to trigger an EOF we hence open it for
426 writing, but close it right away which then will
427 trigger the EOF. This will happen immediately if no
428 other process has the FIFO open for writing, i. e.
429 when the session died before logind (re)started. */
431 fd = session_create_fifo(s);
436 unsigned long long l;
437 if (sscanf(realtime, "%llu", &l) > 0)
438 s->timestamp.realtime = l;
442 unsigned long long l;
443 if (sscanf(monotonic, "%llu", &l) > 0)
444 s->timestamp.monotonic = l;
448 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
449 session_set_controller(s, controller, false);
451 session_restore_vt(s);
457 int session_activate(Session *s) {
458 unsigned int num_pending;
466 if (s->seat->active == s)
469 /* on seats with VTs, we let VTs manage session-switching */
470 if (seat_has_vts(s->seat)) {
474 return chvt(s->vtnr);
477 /* On seats without VTs, we implement session-switching in logind. We
478 * try to pause all session-devices and wait until the session
479 * controller acknowledged them. Once all devices are asleep, we simply
480 * switch the active session and be done.
481 * We save the session we want to switch to in seat->pending_switch and
482 * seat_complete_switch() will perform the final switch. */
484 s->seat->pending_switch = s;
486 /* if no devices are running, immediately perform the session switch */
487 num_pending = session_device_try_pause_all(s);
489 seat_complete_switch(s->seat);
494 static int session_start_scope(Session *s) {
499 assert(s->user->slice);
502 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
503 _cleanup_free_ char *description = NULL;
504 char *scope, *job = NULL;
506 description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
510 scope = strjoin("session-", s->id, ".scope", NULL);
514 r = manager_start_scope(s->manager, scope, s->leader, s->user->slice, description, "logind.service", "systemd-user-sessions.service", &error, &job);
516 log_error("Failed to start session scope %s: %s %s",
517 scope, bus_error_message(&error, r), error.name);
529 hashmap_put(s->manager->session_units, s->scope, s);
534 int session_start(Session *s) {
545 r = user_start(s->user);
550 r = session_start_scope(s);
554 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
555 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
556 "SESSION_ID=%s", s->id,
557 "USER_ID=%s", s->user->name,
558 "LEADER="PID_FMT, s->leader,
559 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
562 if (!dual_timestamp_is_set(&s->timestamp))
563 dual_timestamp_get(&s->timestamp);
566 seat_read_active_vt(s->seat);
570 user_elect_display(s->user);
579 session_send_signal(s, true);
580 user_send_changed(s->user, "Sessions", "Display", NULL);
582 if (s->seat->active == s)
583 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
585 seat_send_changed(s->seat, "Sessions", NULL);
591 static int session_stop_scope(Session *s, bool force) {
592 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
601 if (force || manager_shall_kill(s->manager, s->user->name)) {
602 r = manager_stop_unit(s->manager, s->scope, &error, &job);
604 log_error("Failed to stop session scope: %s", bus_error_message(&error, r));
611 r = manager_abandon_scope(s->manager, s->scope, &error);
613 log_error("Failed to abandon session scope: %s", bus_error_message(&error, r));
621 int session_stop(Session *s, bool force) {
629 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
631 /* We are going down, don't care about FIFOs anymore */
632 session_remove_fifo(s);
635 r = session_stop_scope(s, force);
639 user_elect_display(s->user);
647 int session_finalize(Session *s) {
657 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
658 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
659 "SESSION_ID=%s", s->id,
660 "USER_ID=%s", s->user->name,
661 "LEADER="PID_FMT, s->leader,
662 LOG_MESSAGE("Removed session %s.", s->id),
665 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
667 /* Kill session devices */
668 while ((sd = hashmap_first(s->devices)))
669 session_device_free(sd);
671 unlink(s->state_file);
672 session_add_to_gc_queue(s);
673 user_add_to_gc_queue(s->user);
676 session_send_signal(s, false);
681 if (s->seat->active == s)
682 seat_set_active(s->seat, NULL);
685 seat_send_changed(s->seat, "Sessions", NULL);
689 user_send_changed(s->user, "Sessions", "Display", NULL);
694 static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
695 Session *s = userdata;
700 session_stop(s, false);
704 int session_release(Session *s) {
707 if (!s->started || s->stopping)
710 if (s->timer_event_source)
713 return sd_event_add_time(s->manager->event,
714 &s->timer_event_source,
716 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
717 release_timeout_callback, s);
720 bool session_is_active(Session *s) {
726 return s->seat->active == s;
729 static int get_tty_atime(const char *tty, usec_t *atime) {
730 _cleanup_free_ char *p = NULL;
736 if (!path_is_absolute(tty)) {
737 p = strappend("/dev/", tty);
742 } else if (!path_startswith(tty, "/dev/"))
745 if (lstat(tty, &st) < 0)
748 *atime = timespec_load(&st.st_atim);
752 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
753 _cleanup_free_ char *p = NULL;
759 r = get_ctty(pid, NULL, &p);
763 return get_tty_atime(p, atime);
766 int session_get_idle_hint(Session *s, dual_timestamp *t) {
772 /* Explicit idle hint is set */
775 *t = s->idle_hint_timestamp;
780 /* Graphical sessions should really implement a real
785 /* For sessions with an explicitly configured tty, let's check
788 r = get_tty_atime(s->tty, &atime);
793 /* For sessions with a leader but no explicitly configured
794 * tty, let's check the controlling tty of the leader */
796 r = get_process_ctty_atime(s->leader, &atime);
803 *t = s->idle_hint_timestamp;
809 dual_timestamp_from_realtime(t, atime);
811 n = now(CLOCK_REALTIME);
813 if (s->manager->idle_action_usec <= 0)
816 return atime + s->manager->idle_action_usec <= n;
819 void session_set_idle_hint(Session *s, bool b) {
822 if (s->idle_hint == b)
826 dual_timestamp_get(&s->idle_hint_timestamp);
828 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
831 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
833 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
834 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
837 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
838 Session *s = userdata;
841 assert(s->fifo_fd == fd);
843 /* EOF on the FIFO means the session died abnormally. */
845 session_remove_fifo(s);
846 session_stop(s, false);
851 int session_create_fifo(Session *s) {
858 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
862 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
865 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
869 /* Open reading side */
870 if (s->fifo_fd < 0) {
871 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
877 if (!s->fifo_event_source) {
878 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
882 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
887 /* Open writing side */
888 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
895 static void session_remove_fifo(Session *s) {
898 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
899 s->fifo_fd = safe_close(s->fifo_fd);
902 unlink(s->fifo_path);
908 bool session_check_gc(Session *s, bool drop_not_started) {
911 if (drop_not_started && !s->started)
917 if (s->fifo_fd >= 0) {
918 if (pipe_eof(s->fifo_fd) <= 0)
922 if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
925 if (s->scope && manager_unit_is_active(s->manager, s->scope))
931 void session_add_to_gc_queue(Session *s) {
937 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
938 s->in_gc_queue = true;
941 SessionState session_get_state(Session *s) {
944 /* always check closing first */
945 if (s->stopping || s->timer_event_source)
946 return SESSION_CLOSING;
948 if (s->scope_job || s->fifo_fd < 0)
949 return SESSION_OPENING;
951 if (session_is_active(s))
952 return SESSION_ACTIVE;
954 return SESSION_ONLINE;
957 int session_kill(Session *s, KillWho who, int signo) {
963 return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
966 static int session_open_vt(Session *s) {
967 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
975 sprintf(path, "/dev/tty%u", s->vtnr);
976 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
978 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
983 int session_prepare_vt(Session *s) {
985 struct vt_mode mode = { 0 };
990 vt = session_open_vt(s);
994 r = fchown(vt, s->user->uid, -1);
997 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
1001 r = ioctl(vt, KDSKBMODE, K_OFF);
1004 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
1008 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
1011 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
1015 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
1016 * So we need a dummy handler here which just acknowledges *all* VT
1017 * switch requests. */
1018 mode.mode = VT_PROCESS;
1019 mode.relsig = SIGRTMIN;
1020 mode.acqsig = SIGRTMIN + 1;
1021 r = ioctl(vt, VT_SETMODE, &mode);
1024 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
1031 session_restore_vt(s);
1035 void session_restore_vt(Session *s) {
1036 _cleanup_free_ char *utf8 = NULL;
1037 int vt, kb = K_XLATE;
1038 struct vt_mode mode = { 0 };
1040 vt = session_open_vt(s);
1044 (void) ioctl(vt, KDSETMODE, KD_TEXT);
1046 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
1049 (void) ioctl(vt, KDSKBMODE, kb);
1051 mode.mode = VT_AUTO;
1052 (void) ioctl(vt, VT_SETMODE, &mode);
1056 s->vtfd = safe_close(s->vtfd);
1059 void session_leave_vt(Session *s) {
1064 /* This is called whenever we get a VT-switch signal from the kernel.
1065 * We acknowledge all of them unconditionally. Note that session are
1066 * free to overwrite those handlers and we only register them for
1067 * sessions with controllers. Legacy sessions are not affected.
1068 * However, if we switch from a non-legacy to a legacy session, we must
1069 * make sure to pause all device before acknowledging the switch. We
1070 * process the real switch only after we are notified via sysfs, so the
1071 * legacy session might have already started using the devices. If we
1072 * don't pause the devices before the switch, we might confuse the
1073 * session we switch to. */
1078 session_device_pause_all(s);
1079 r = ioctl(s->vtfd, VT_RELDISP, 1);
1081 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1084 bool session_is_controller(Session *s, const char *sender) {
1087 return streq_ptr(s->controller, sender);
1090 static void session_release_controller(Session *s, bool notify) {
1091 _cleanup_free_ char *name = NULL;
1097 name = s->controller;
1099 /* By resetting the controller before releasing the devices, we won't
1100 * send notification signals. This avoids sending useless notifications
1101 * if the controller is released on disconnects. */
1103 s->controller = NULL;
1105 while ((sd = hashmap_first(s->devices)))
1106 session_device_free(sd);
1108 s->controller = NULL;
1109 manager_drop_busname(s->manager, name);
1112 int session_set_controller(Session *s, const char *sender, bool force) {
1113 _cleanup_free_ char *name = NULL;
1119 if (session_is_controller(s, sender))
1121 if (s->controller && !force)
1124 name = strdup(sender);
1128 r = manager_watch_busname(s->manager, name);
1132 /* When setting a session controller, we forcibly mute the VT and set
1133 * it into graphics-mode. Applications can override that by changing
1134 * VT state after calling TakeControl(). However, this serves as a good
1135 * default and well-behaving controllers can now ignore VTs entirely.
1136 * Note that we reset the VT on ReleaseControl() and if the controller
1138 * If logind crashes/restarts, we restore the controller during restart
1139 * or reset the VT in case it crashed/exited, too. */
1140 r = session_prepare_vt(s);
1142 manager_drop_busname(s->manager, name);
1146 session_release_controller(s, true);
1147 s->controller = name;
1154 void session_drop_controller(Session *s) {
1160 session_release_controller(s, false);
1162 session_restore_vt(s);
1165 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1166 [SESSION_OPENING] = "opening",
1167 [SESSION_ONLINE] = "online",
1168 [SESSION_ACTIVE] = "active",
1169 [SESSION_CLOSING] = "closing"
1172 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1174 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1175 [SESSION_UNSPECIFIED] = "unspecified",
1176 [SESSION_TTY] = "tty",
1177 [SESSION_X11] = "x11",
1178 [SESSION_WAYLAND] = "wayland",
1179 [SESSION_MIR] = "mir",
1180 [SESSION_WEB] = "web",
1183 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
1185 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
1186 [SESSION_USER] = "user",
1187 [SESSION_GREETER] = "greeter",
1188 [SESSION_LOCK_SCREEN] = "lock-screen",
1189 [SESSION_BACKGROUND] = "background"
1192 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
1194 static const char* const kill_who_table[_KILL_WHO_MAX] = {
1195 [KILL_LEADER] = "leader",
1199 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);