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"
42 #include "formats-util.h"
43 #include "terminal-util.h"
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);
123 sd_bus_message_unref(s->create_message);
127 free(s->remote_host);
128 free(s->remote_user);
132 hashmap_remove(s->manager->sessions, s->id);
138 void session_set_user(Session *s, User *u) {
143 LIST_PREPEND(sessions_by_user, u->sessions, s);
146 int session_save(Session *s) {
147 _cleanup_free_ char *temp_path = NULL;
148 _cleanup_fclose_ FILE *f = NULL;
159 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
163 r = fopen_temporary(s->state_file, &f, &temp_path);
169 fchmod(fileno(f), 0644);
172 "# This is private data. Do not parse.\n"
180 session_is_active(s),
181 session_state_to_string(session_get_state(s)),
185 fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
188 fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
191 fprintf(f, "FIFO=%s\n", s->fifo_path);
194 fprintf(f, "SEAT=%s\n", s->seat->id);
197 fprintf(f, "TTY=%s\n", s->tty);
200 fprintf(f, "DISPLAY=%s\n", s->display);
202 if (s->remote_host) {
203 _cleanup_free_ char *escaped;
205 escaped = cescape(s->remote_host);
211 fprintf(f, "REMOTE_HOST=%s\n", escaped);
214 if (s->remote_user) {
215 _cleanup_free_ char *escaped;
217 escaped = cescape(s->remote_user);
223 fprintf(f, "REMOTE_USER=%s\n", escaped);
227 _cleanup_free_ char *escaped;
229 escaped = cescape(s->service);
235 fprintf(f, "SERVICE=%s\n", escaped);
239 _cleanup_free_ char *escaped;
242 escaped = cescape(s->desktop);
248 fprintf(f, "DESKTOP=%s\n", escaped);
251 if (s->seat && seat_has_vts(s->seat))
252 fprintf(f, "VTNR=%u\n", s->vtnr);
255 fprintf(f, "POS=%u\n", s->pos);
258 fprintf(f, "LEADER="PID_FMT"\n", s->leader);
261 fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
263 if (dual_timestamp_is_set(&s->timestamp))
265 "REALTIME="USEC_FMT"\n"
266 "MONOTONIC="USEC_FMT"\n",
267 s->timestamp.realtime,
268 s->timestamp.monotonic);
271 fprintf(f, "CONTROLLER=%s\n", s->controller);
275 if (ferror(f) || rename(temp_path, s->state_file) < 0) {
277 unlink(s->state_file);
283 log_error_errno(r, "Failed to save session data %s: %m", s->state_file);
288 int session_load(Session *s) {
289 _cleanup_free_ char *remote = NULL,
306 r = parse_env_file(s->state_file, NEWLINE,
308 "FIFO", &s->fifo_path,
311 "DISPLAY", &s->display,
312 "REMOTE_HOST", &s->remote_host,
313 "REMOTE_USER", &s->remote_user,
314 "SERVICE", &s->service,
315 "DESKTOP", &s->desktop,
323 "REALTIME", &realtime,
324 "MONOTONIC", &monotonic,
325 "CONTROLLER", &controller,
329 return log_error_errno(r, "Failed to read %s: %m", s->state_file);
336 log_error("UID not specified for session %s", s->id);
340 r = parse_uid(uid, &u);
342 log_error("Failed to parse UID value %s for session %s.", uid, s->id);
346 user = hashmap_get(s->manager->users, UID_TO_PTR(u));
348 log_error("User of session %s not known.", s->id);
352 session_set_user(s, user);
356 k = parse_boolean(remote);
362 safe_atou(vtnr, &s->vtnr);
364 if (seat && !s->seat) {
367 o = hashmap_get(s->manager->seats, seat);
369 r = seat_attach_session(o, s);
371 log_error("Cannot attach session %s to seat %s", s->id, seat);
374 if (!s->seat || !seat_has_vts(s->seat))
377 if (pos && s->seat) {
380 safe_atou(pos, &npos);
381 seat_claim_position(s->seat, s, npos);
385 k = parse_pid(leader, &s->leader);
387 audit_session_from_pid(s->leader, &s->audit_id);
393 t = session_type_from_string(type);
401 c = session_class_from_string(class);
406 if (state && streq(state, "closing"))
412 /* If we open an unopened pipe for reading we will not
413 get an EOF. to trigger an EOF we hence open it for
414 writing, but close it right away which then will
415 trigger the EOF. This will happen immediately if no
416 other process has the FIFO open for writing, i. e.
417 when the session died before logind (re)started. */
419 fd = session_create_fifo(s);
424 unsigned long long l;
425 if (sscanf(realtime, "%llu", &l) > 0)
426 s->timestamp.realtime = l;
430 unsigned long long l;
431 if (sscanf(monotonic, "%llu", &l) > 0)
432 s->timestamp.monotonic = l;
436 if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
437 session_set_controller(s, controller, false);
439 session_restore_vt(s);
445 int session_activate(Session *s) {
446 unsigned int num_pending;
454 if (s->seat->active == s)
457 /* on seats with VTs, we let VTs manage session-switching */
458 if (seat_has_vts(s->seat)) {
462 return chvt(s->vtnr);
465 /* On seats without VTs, we implement session-switching in logind. We
466 * try to pause all session-devices and wait until the session
467 * controller acknowledged them. Once all devices are asleep, we simply
468 * switch the active session and be done.
469 * We save the session we want to switch to in seat->pending_switch and
470 * seat_complete_switch() will perform the final switch. */
472 s->seat->pending_switch = s;
474 /* if no devices are running, immediately perform the session switch */
475 num_pending = session_device_try_pause_all(s);
477 seat_complete_switch(s->seat);
482 static int session_start_cgroup(Session *s) {
487 assert(s->leader > 0);
489 /* First, create our own group */
490 r = cg_create(SYSTEMD_CGROUP_CONTROLLER, s->id);
492 return log_error_errno(r, "Failed to create cgroup %s: %m", s->id);
494 r = cg_attach(SYSTEMD_CGROUP_CONTROLLER, s->id, s->leader);
496 log_warning_errno(r, "Failed to attach PID %d to cgroup %s: %m", s->leader, s->id);
501 int session_start(Session *s) {
512 r = user_start(s->user);
516 r = session_start_cgroup(s);
520 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
521 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
522 "SESSION_ID=%s", s->id,
523 "USER_ID=%s", s->user->name,
524 "LEADER="PID_FMT, s->leader,
525 LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
528 if (!dual_timestamp_is_set(&s->timestamp))
529 dual_timestamp_get(&s->timestamp);
532 seat_read_active_vt(s->seat);
536 user_elect_display(s->user);
545 session_send_signal(s, true);
546 user_send_changed(s->user, "Sessions", "Display", NULL);
548 if (s->seat->active == s)
549 seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
551 seat_send_changed(s->seat, "Sessions", NULL);
557 static int session_stop_cgroup(Session *s, bool force) {
558 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
563 if (force || manager_shall_kill(s->manager, s->user->name)) {
564 r = session_kill(s, KILL_ALL, SIGTERM);
572 int session_stop(Session *s, bool force) {
580 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
582 /* We are going down, don't care about FIFOs anymore */
583 session_remove_fifo(s);
586 r = session_stop_cgroup(s, force);
590 user_elect_display(s->user);
598 int session_finalize(Session *s) {
608 log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
609 LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
610 "SESSION_ID=%s", s->id,
611 "USER_ID=%s", s->user->name,
612 "LEADER="PID_FMT, s->leader,
613 LOG_MESSAGE("Removed session %s.", s->id),
616 s->timer_event_source = sd_event_source_unref(s->timer_event_source);
618 /* Kill session devices */
619 while ((sd = hashmap_first(s->devices)))
620 session_device_free(sd);
622 unlink(s->state_file);
623 session_add_to_gc_queue(s);
624 user_add_to_gc_queue(s->user);
627 session_send_signal(s, false);
632 if (s->seat->active == s)
633 seat_set_active(s->seat, NULL);
636 seat_send_changed(s->seat, "Sessions", NULL);
640 user_send_changed(s->user, "Sessions", "Display", NULL);
645 int session_release(Session *s) {
648 if (!s->started || s->stopping)
651 if (s->timer_event_source)
654 /* In systemd, session release is triggered by user jobs
655 dying. In elogind we don't have that so go ahead and stop
657 return session_stop(s, false);
660 bool session_is_active(Session *s) {
666 return s->seat->active == s;
669 static int get_tty_atime(const char *tty, usec_t *atime) {
670 _cleanup_free_ char *p = NULL;
676 if (!path_is_absolute(tty)) {
677 p = strappend("/dev/", tty);
682 } else if (!path_startswith(tty, "/dev/"))
685 if (lstat(tty, &st) < 0)
688 *atime = timespec_load(&st.st_atim);
692 static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
693 _cleanup_free_ char *p = NULL;
699 r = get_ctty(pid, NULL, &p);
703 return get_tty_atime(p, atime);
706 int session_get_idle_hint(Session *s, dual_timestamp *t) {
712 /* Explicit idle hint is set */
715 *t = s->idle_hint_timestamp;
720 /* Graphical sessions should really implement a real
725 /* For sessions with an explicitly configured tty, let's check
728 r = get_tty_atime(s->tty, &atime);
733 /* For sessions with a leader but no explicitly configured
734 * tty, let's check the controlling tty of the leader */
736 r = get_process_ctty_atime(s->leader, &atime);
743 *t = s->idle_hint_timestamp;
749 dual_timestamp_from_realtime(t, atime);
751 n = now(CLOCK_REALTIME);
753 if (s->manager->idle_action_usec <= 0)
756 return atime + s->manager->idle_action_usec <= n;
759 void session_set_idle_hint(Session *s, bool b) {
762 if (s->idle_hint == b)
766 dual_timestamp_get(&s->idle_hint_timestamp);
768 session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
771 seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
773 user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
774 manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
777 static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
778 Session *s = userdata;
781 assert(s->fifo_fd == fd);
783 /* EOF on the FIFO means the session died abnormally. */
785 session_remove_fifo(s);
786 session_stop(s, false);
791 int session_create_fifo(Session *s) {
798 r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
802 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
805 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
809 /* Open reading side */
810 if (s->fifo_fd < 0) {
811 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
817 if (!s->fifo_event_source) {
818 r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
822 r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_IDLE);
827 /* Open writing side */
828 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
835 static void session_remove_fifo(Session *s) {
838 s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
839 s->fifo_fd = safe_close(s->fifo_fd);
842 unlink(s->fifo_path);
848 bool session_check_gc(Session *s, bool drop_not_started) {
851 if (drop_not_started && !s->started)
857 if (s->fifo_fd >= 0) {
858 if (pipe_eof(s->fifo_fd) <= 0)
862 if (cg_is_empty_recursive (SYSTEMD_CGROUP_CONTROLLER, s->id, false) > 0)
868 void session_add_to_gc_queue(Session *s) {
874 LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
875 s->in_gc_queue = true;
878 SessionState session_get_state(Session *s) {
881 /* always check closing first */
882 if (s->stopping || s->timer_event_source)
883 return SESSION_CLOSING;
886 return SESSION_OPENING;
888 if (session_is_active(s))
889 return SESSION_ACTIVE;
891 return SESSION_ONLINE;
894 int session_kill(Session *s, KillWho who, int signo) {
897 if (who == KILL_LEADER) {
901 /* FIXME: verify that leader is in cgroup? */
903 if (kill(s->leader, signo) < 0) {
904 return log_error_errno(errno, "Failed to kill process leader %d for session %s: %m", s->leader, s->id);
908 bool sigcont = false;
909 bool ignore_self = true;
911 return cg_kill_recursive (SYSTEMD_CGROUP_CONTROLLER, s->id, signo,
912 sigcont, ignore_self, rem, NULL);
916 static int session_open_vt(Session *s) {
917 char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
925 sprintf(path, "/dev/tty%u", s->vtnr);
926 s->vtfd = open(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
928 return log_error_errno(errno, "cannot open VT %s of session %s: %m", path, s->id);
933 int session_prepare_vt(Session *s) {
935 struct vt_mode mode = { 0 };
940 vt = session_open_vt(s);
944 r = fchown(vt, s->user->uid, -1);
947 log_error_errno(errno, "Cannot change owner of /dev/tty%u: %m", s->vtnr);
951 r = ioctl(vt, KDSKBMODE, K_OFF);
954 log_error_errno(errno, "Cannot set K_OFF on /dev/tty%u: %m", s->vtnr);
958 r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
961 log_error_errno(errno, "Cannot set KD_GRAPHICS on /dev/tty%u: %m", s->vtnr);
965 /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
966 * So we need a dummy handler here which just acknowledges *all* VT
967 * switch requests. */
968 mode.mode = VT_PROCESS;
969 mode.relsig = SIGRTMIN;
970 mode.acqsig = SIGRTMIN + 1;
971 r = ioctl(vt, VT_SETMODE, &mode);
974 log_error_errno(errno, "Cannot set VT_PROCESS on /dev/tty%u: %m", s->vtnr);
981 session_restore_vt(s);
985 void session_restore_vt(Session *s) {
986 _cleanup_free_ char *utf8 = NULL;
987 int vt, kb = K_XLATE;
988 struct vt_mode mode = { 0 };
990 vt = session_open_vt(s);
994 (void) ioctl(vt, KDSETMODE, KD_TEXT);
996 if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
999 (void) ioctl(vt, KDSKBMODE, kb);
1001 mode.mode = VT_AUTO;
1002 (void) ioctl(vt, VT_SETMODE, &mode);
1006 s->vtfd = safe_close(s->vtfd);
1009 void session_leave_vt(Session *s) {
1014 /* This is called whenever we get a VT-switch signal from the kernel.
1015 * We acknowledge all of them unconditionally. Note that session are
1016 * free to overwrite those handlers and we only register them for
1017 * sessions with controllers. Legacy sessions are not affected.
1018 * However, if we switch from a non-legacy to a legacy session, we must
1019 * make sure to pause all device before acknowledging the switch. We
1020 * process the real switch only after we are notified via sysfs, so the
1021 * legacy session might have already started using the devices. If we
1022 * don't pause the devices before the switch, we might confuse the
1023 * session we switch to. */
1028 session_device_pause_all(s);
1029 r = ioctl(s->vtfd, VT_RELDISP, 1);
1031 log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
1034 bool session_is_controller(Session *s, const char *sender) {
1037 return streq_ptr(s->controller, sender);
1040 static void session_release_controller(Session *s, bool notify) {
1041 _cleanup_free_ char *name = NULL;
1047 name = s->controller;
1049 /* By resetting the controller before releasing the devices, we won't
1050 * send notification signals. This avoids sending useless notifications
1051 * if the controller is released on disconnects. */
1053 s->controller = NULL;
1055 while ((sd = hashmap_first(s->devices)))
1056 session_device_free(sd);
1058 s->controller = NULL;
1059 manager_drop_busname(s->manager, name);
1062 int session_set_controller(Session *s, const char *sender, bool force) {
1063 _cleanup_free_ char *name = NULL;
1069 if (session_is_controller(s, sender))
1071 if (s->controller && !force)
1074 name = strdup(sender);
1078 r = manager_watch_busname(s->manager, name);
1082 /* When setting a session controller, we forcibly mute the VT and set
1083 * it into graphics-mode. Applications can override that by changing
1084 * VT state after calling TakeControl(). However, this serves as a good
1085 * default and well-behaving controllers can now ignore VTs entirely.
1086 * Note that we reset the VT on ReleaseControl() and if the controller
1088 * If logind crashes/restarts, we restore the controller during restart
1089 * or reset the VT in case it crashed/exited, too. */
1090 r = session_prepare_vt(s);
1092 manager_drop_busname(s->manager, name);
1096 session_release_controller(s, true);
1097 s->controller = name;
1104 void session_drop_controller(Session *s) {
1110 session_release_controller(s, false);
1112 session_restore_vt(s);
1115 static const char* const session_state_table[_SESSION_STATE_MAX] = {
1116 [SESSION_OPENING] = "opening",
1117 [SESSION_ONLINE] = "online",
1118 [SESSION_ACTIVE] = "active",
1119 [SESSION_CLOSING] = "closing"
1122 DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
1124 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
1125 [SESSION_UNSPECIFIED] = "unspecified",
1126 [SESSION_TTY] = "tty",
1127 [SESSION_X11] = "x11",
1128 [SESSION_WAYLAND] = "wayland",
1129 [SESSION_MIR] = "mir",
1130 [SESSION_WEB] = "web",
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);