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 General Public License as published by
10 the Free Software Foundation; either version 2 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 General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
25 #include <sys/epoll.h>
28 #include "logind-session.h"
31 #include "cgroup-util.h"
33 #define IDLE_THRESHOLD_USEC (5*USEC_PER_MINUTE)
35 Session* session_new(Manager *m, User *u, const char *id) {
45 s->state_file = strappend("/run/systemd/sessions/", id);
51 s->id = file_name_from_path(s->state_file);
53 if (hashmap_put(m->sessions, s->id, s) < 0) {
63 LIST_PREPEND(Session, sessions_by_user, u->sessions, s);
68 void session_free(Session *s) {
72 LIST_REMOVE(Session, gc_queue, s->manager->session_gc_queue, s);
75 LIST_REMOVE(Session, sessions_by_user, s->user->sessions, s);
77 if (s->user->display == s)
78 s->user->display = NULL;
82 if (s->seat->active == s)
83 s->seat->active = NULL;
85 LIST_REMOVE(Session, sessions_by_seat, s->seat->sessions, s);
89 hashmap_remove(s->manager->cgroups, s->cgroup_path);
92 strv_free(s->controllers);
100 hashmap_remove(s->manager->sessions, s->id);
102 session_remove_fifo(s);
108 int session_save(Session *s) {
118 r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
122 r = fopen_temporary(s->state_file, &f, &temp_path);
128 fchmod(fileno(f), 0644);
131 "# This is private data. Do not parse.\n"
136 "KILL_PROCESSES=%i\n",
137 (unsigned long) s->user->uid,
139 session_is_active(s),
146 session_type_to_string(s->type));
151 session_class_to_string(s->class));
193 if (s->seat && seat_can_multi_session(s->seat))
201 (unsigned long) s->leader);
206 (unsigned long long) s->audit_id);
210 if (ferror(f) || rename(temp_path, s->state_file) < 0) {
212 unlink(s->state_file);
221 log_error("Failed to save session data for %s: %s", s->id, strerror(-r));
226 int session_load(Session *s) {
228 *kill_processes = NULL,
240 r = parse_env_file(s->state_file, NEWLINE,
242 "KILL_PROCESSES", &kill_processes,
243 "CGROUP", &s->cgroup_path,
244 "FIFO", &s->fifo_path,
247 "DISPLAY", &s->display,
248 "REMOTE_HOST", &s->remote_host,
249 "REMOTE_USER", &s->remote_user,
250 "SERVICE", &s->service,
261 k = parse_boolean(remote);
266 if (kill_processes) {
267 k = parse_boolean(kill_processes);
269 s->kill_processes = k;
272 if (seat && !s->seat) {
275 o = hashmap_get(s->manager->seats, seat);
277 seat_attach_session(o, s);
280 if (vtnr && s->seat && seat_can_multi_session(s->seat)) {
283 k = safe_atoi(vtnr, &v);
284 if (k >= 0 && v >= 1)
291 k = parse_pid(leader, &pid);
292 if (k >= 0 && pid >= 1) {
295 audit_session_from_pid(pid, &s->audit_id);
302 t = session_type_from_string(type);
310 c = session_class_from_string(class);
318 /* If we open an unopened pipe for reading we will not
319 get an EOF. to trigger an EOF we hence open it for
320 reading, but close it right-away which then will
323 fd = session_create_fifo(s);
325 close_nointr_nofail(fd);
331 free(kill_processes);
340 int session_activate(Session *s) {
351 if (s->seat->active == s)
354 assert(seat_is_vtconsole(s->seat));
360 return seat_set_active(s->seat, s);
363 static int session_link_x11_socket(Session *s) {
369 assert(s->user->runtime_path);
371 if (s->user->display)
374 if (!s->display || !display_is_local(s->display))
377 k = strspn(s->display+1, "0123456789");
378 f = new(char, sizeof("/tmp/.X11-unix/X") + k);
380 log_error("Out of memory");
384 c = stpcpy(f, "/tmp/.X11-unix/X");
385 memcpy(c, s->display+1, k);
388 if (access(f, F_OK) < 0) {
389 log_warning("Session %s has display %s with nonexisting socket %s.", s->id, s->display, f);
394 /* Note that this cannot be in a subdir to avoid
395 * vulnerabilities since we are privileged but the runtime
396 * path is owned by the user */
398 t = strappend(s->user->runtime_path, "/X11-display");
400 log_error("Out of memory");
405 if (link(f, t) < 0) {
406 if (errno == EEXIST) {
413 if (symlink(f, t) < 0) {
415 if (errno == EEXIST) {
418 if (symlink(f, t) >= 0)
422 log_error("Failed to link %s to %s: %m", f, t);
430 log_info("Linked %s to %s.", f, t);
434 s->user->display = s;
439 static int session_create_one_group(Session *s, const char *controller, const char *path) {
447 r = cg_create_and_attach(controller, path, s->leader);
449 r = cg_create(controller, path);
451 r = cg_create(controller, path);
456 r = cg_set_task_access(controller, path, 0644, s->user->uid, s->user->gid, -1);
458 r = cg_set_group_access(controller, path, 0755, s->user->uid, s->user->gid);
463 static int session_create_cgroup(Session *s) {
470 assert(s->user->cgroup_path);
472 if (!s->cgroup_path) {
473 if (asprintf(&p, "%s/%s", s->user->cgroup_path, s->id) < 0) {
474 log_error("Out of memory");
480 r = session_create_one_group(s, SYSTEMD_CGROUP_CONTROLLER, p);
482 log_error("Failed to create "SYSTEMD_CGROUP_CONTROLLER":%s: %s", p, strerror(-r));
484 s->cgroup_path = NULL;
490 STRV_FOREACH(k, s->controllers) {
492 if (strv_contains(s->reset_controllers, *k))
495 r = session_create_one_group(s, *k, p);
497 log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
500 STRV_FOREACH(k, s->manager->controllers) {
502 if (strv_contains(s->reset_controllers, *k) ||
503 strv_contains(s->manager->reset_controllers, *k) ||
504 strv_contains(s->controllers, *k))
507 r = session_create_one_group(s, *k, p);
509 log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
514 STRV_FOREACH(k, s->reset_controllers) {
515 r = cg_attach(*k, "/", s->leader);
517 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
521 STRV_FOREACH(k, s->manager->reset_controllers) {
523 if (strv_contains(s->reset_controllers, *k) ||
524 strv_contains(s->controllers, *k))
527 r = cg_attach(*k, "/", s->leader);
529 log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
534 hashmap_put(s->manager->cgroups, s->cgroup_path, s);
539 int session_start(Session *s) {
548 r = user_start(s->user);
552 log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
553 "New session %s of user %s.", s->id, s->user->name);
556 r = session_create_cgroup(s);
560 /* Create X11 symlink */
561 session_link_x11_socket(s);
563 dual_timestamp_get(&s->timestamp);
566 seat_read_active_vt(s->seat);
570 /* Save session data */
574 session_send_signal(s, true);
579 if (s->seat->active == s)
580 seat_send_changed(s->seat, "Sessions\0ActiveSession\0");
582 seat_send_changed(s->seat, "Sessions\0");
585 user_send_changed(s->user, "Sessions\0");
590 static bool session_shall_kill(Session *s) {
593 if (!s->kill_processes)
596 if (strv_contains(s->manager->kill_exclude_users, s->user->name))
599 if (strv_isempty(s->manager->kill_only_users))
602 return strv_contains(s->manager->kill_only_users, s->user->name);
605 static int session_terminate_cgroup(Session *s) {
614 cg_trim(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
616 if (session_shall_kill(s)) {
618 r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
620 log_error("Failed to kill session cgroup: %s", strerror(-r));
626 /* We still send a HUP to the leader process,
627 * even if we are not supposed to kill the
628 * whole cgroup. But let's first check the
629 * leader still exists and belongs to our
632 r = manager_get_session_by_pid(s->manager, s->leader, &t);
633 if (r > 0 && t == s) {
634 kill(s->leader, SIGTERM); /* for normal processes */
635 kill(s->leader, SIGHUP); /* for shells */
636 kill(s->leader, SIGCONT); /* in case they are stopped */
640 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
642 log_error("Failed to check session cgroup: %s", strerror(-r));
644 r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path);
646 log_error("Failed to delete session cgroup: %s", strerror(-r));
650 STRV_FOREACH(k, s->user->manager->controllers)
651 cg_trim(*k, s->cgroup_path, true);
653 hashmap_remove(s->manager->cgroups, s->cgroup_path);
655 free(s->cgroup_path);
656 s->cgroup_path = NULL;
661 static int session_unlink_x11_socket(Session *s) {
668 if (s->user->display != s)
671 s->user->display = NULL;
673 t = strappend(s->user->runtime_path, "/X11-display");
675 log_error("Out of memory");
682 return r < 0 ? -errno : 0;
685 int session_stop(Session *s) {
691 log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
692 "Removed session %s.", s->id);
695 k = session_terminate_cgroup(s);
699 /* Remove X11 symlink */
700 session_unlink_x11_socket(s);
702 unlink(s->state_file);
703 session_add_to_gc_queue(s);
704 user_add_to_gc_queue(s->user);
707 session_send_signal(s, false);
710 if (s->seat->active == s)
711 seat_set_active(s->seat, NULL);
713 seat_send_changed(s->seat, "Sessions\0");
716 user_send_changed(s->user, "Sessions\0");
723 bool session_is_active(Session *s) {
729 return s->seat->active == s;
732 int session_get_idle_hint(Session *s, dual_timestamp *t) {
743 *t = s->idle_hint_timestamp;
751 if (s->tty[0] != '/') {
752 p = strappend("/dev/", s->tty);
758 if (!startswith(p ? p : s->tty, "/dev/")) {
763 k = lstat(p ? p : s->tty, &st);
769 u = timespec_load(&st.st_atim);
770 n = now(CLOCK_REALTIME);
771 b = u + IDLE_THRESHOLD_USEC < n;
774 dual_timestamp_from_realtime(t, u + b ? IDLE_THRESHOLD_USEC : 0);
780 *t = s->idle_hint_timestamp;
785 void session_set_idle_hint(Session *s, bool b) {
788 if (s->idle_hint == b)
792 dual_timestamp_get(&s->idle_hint_timestamp);
794 session_send_changed(s,
797 "IdleSinceHintMonotonic\0");
800 seat_send_changed(s->seat,
803 "IdleSinceHintMonotonic\0");
805 user_send_changed(s->user,
808 "IdleSinceHintMonotonic\0");
810 manager_send_changed(s->manager,
813 "IdleSinceHintMonotonic\0");
816 int session_create_fifo(Session *s) {
823 r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
827 if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
830 if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
834 /* Open reading side */
835 if (s->fifo_fd < 0) {
836 struct epoll_event ev;
838 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
842 r = hashmap_put(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1), s);
848 ev.data.u32 = FD_FIFO_BASE + s->fifo_fd;
850 if (epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_ADD, s->fifo_fd, &ev) < 0)
854 /* Open writing side */
855 r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
862 void session_remove_fifo(Session *s) {
865 if (s->fifo_fd >= 0) {
866 assert_se(hashmap_remove(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1)) == s);
867 assert_se(epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_DEL, s->fifo_fd, NULL) == 0);
868 close_nointr_nofail(s->fifo_fd);
873 unlink(s->fifo_path);
879 int session_check_gc(Session *s, bool drop_not_started) {
884 if (drop_not_started && !s->started)
887 if (s->fifo_fd >= 0) {
889 r = pipe_eof(s->fifo_fd);
897 if (s->cgroup_path) {
899 r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
910 void session_add_to_gc_queue(Session *s) {
916 LIST_PREPEND(Session, gc_queue, s->manager->session_gc_queue, s);
917 s->in_gc_queue = true;
920 int session_kill(Session *s, KillWho who, int signo) {
929 if (s->leader <= 0 && who == KILL_LEADER)
933 if (kill(s->leader, signo) < 0)
936 if (who == KILL_ALL) {
939 pid_set = set_new(trivial_hash_func, trivial_compare_func);
944 q = set_put(pid_set, LONG_TO_PTR(s->leader));
949 q = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, signo, false, true, false, pid_set);
951 if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
961 static const char* const session_type_table[_SESSION_TYPE_MAX] = {
962 [SESSION_TTY] = "tty",
963 [SESSION_X11] = "x11",
964 [SESSION_UNSPECIFIED] = "unspecified"
967 DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
969 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
970 [SESSION_USER] = "user",
971 [SESSION_GREETER] = "greeter",
972 [SESSION_LOCK_SCREEN] = "lock-screen"
975 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
977 static const char* const kill_who_table[_KILL_WHO_MAX] = {
978 [KILL_LEADER] = "leader",
982 DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);