./tools/notsd-move

1 files changed, 1275 insertions, 0 deletions

diff --git a/src/grp-login/systemd-logind/logind-session.c b/src/grp-login/systemd-logind/logind-session.c
new file mode 100644
index 0000000000..58ac2aeeb7
--- /dev/null
+++ b/src/grp-login/systemd-logind/logind-session.c
@@ -0,0 +1,1275 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2011 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+#include <linux/kd.h>
+#include <linux/vt.h>
+
+#include <systemd/sd-messages.h>
+
+#include "sd-bus/bus-error.h"
+#include "sd-bus/bus-util.h"
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/audit-util.h"
+#include "systemd-basic/escape.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/fileio.h"
+#include "systemd-basic/formats-util.h"
+#include "systemd-basic/io-util.h"
+#include "systemd-basic/mkdir.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/path-util.h"
+#include "systemd-basic/string-table.h"
+#include "systemd-basic/terminal-util.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+
+#include "logind-session.h"
+
+#define RELEASE_USEC (20*USEC_PER_SEC)
+
+static void session_remove_fifo(Session *s);
+
+Session* session_new(Manager *m, const char *id) {
+        Session *s;
+
+        assert(m);
+        assert(id);
+        assert(session_id_valid(id));
+
+        s = new0(Session, 1);
+        if (!s)
+                return NULL;
+
+        s->state_file = strappend("/run/systemd/sessions/", id);
+        if (!s->state_file) {
+                free(s);
+                return NULL;
+        }
+
+        s->devices = hashmap_new(&devt_hash_ops);
+        if (!s->devices) {
+                free(s->state_file);
+                free(s);
+                return NULL;
+        }
+
+        s->id = basename(s->state_file);
+
+        if (hashmap_put(m->sessions, s->id, s) < 0) {
+                hashmap_free(s->devices);
+                free(s->state_file);
+                free(s);
+                return NULL;
+        }
+
+        s->manager = m;
+        s->fifo_fd = -1;
+        s->vtfd = -1;
+
+        return s;
+}
+
+void session_free(Session *s) {
+        SessionDevice *sd;
+
+        assert(s);
+
+        if (s->in_gc_queue)
+                LIST_REMOVE(gc_queue, s->manager->session_gc_queue, s);
+
+        s->timer_event_source = sd_event_source_unref(s->timer_event_source);
+
+        session_remove_fifo(s);
+
+        session_drop_controller(s);
+
+        while ((sd = hashmap_first(s->devices)))
+                session_device_free(sd);
+
+        hashmap_free(s->devices);
+
+        if (s->user) {
+                LIST_REMOVE(sessions_by_user, s->user->sessions, s);
+
+                if (s->user->display == s)
+                        s->user->display = NULL;
+        }
+
+        if (s->seat) {
+                if (s->seat->active == s)
+                        s->seat->active = NULL;
+                if (s->seat->pending_switch == s)
+                        s->seat->pending_switch = NULL;
+
+                seat_evict_position(s->seat, s);
+                LIST_REMOVE(sessions_by_seat, s->seat->sessions, s);
+        }
+
+        if (s->scope) {
+                hashmap_remove(s->manager->session_units, s->scope);
+                free(s->scope);
+        }
+
+        free(s->scope_job);
+
+        sd_bus_message_unref(s->create_message);
+
+        free(s->tty);
+        free(s->display);
+        free(s->remote_host);
+        free(s->remote_user);
+        free(s->service);
+        free(s->desktop);
+
+        hashmap_remove(s->manager->sessions, s->id);
+
+        free(s->state_file);
+        free(s);
+}
+
+void session_set_user(Session *s, User *u) {
+        assert(s);
+        assert(!s->user);
+
+        s->user = u;
+        LIST_PREPEND(sessions_by_user, u->sessions, s);
+}
+
+int session_save(Session *s) {
+        _cleanup_free_ char *temp_path = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r = 0;
+
+        assert(s);
+
+        if (!s->user)
+                return -ESTALE;
+
+        if (!s->started)
+                return 0;
+
+        r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
+        if (r < 0)
+                goto fail;
+
+        r = fopen_temporary(s->state_file, &f, &temp_path);
+        if (r < 0)
+                goto fail;
+
+        assert(s->user);
+
+        fchmod(fileno(f), 0644);
+
+        fprintf(f,
+                "# This is private data. Do not parse.\n"
+                "UID="UID_FMT"\n"
+                "USER=%s\n"
+                "ACTIVE=%i\n"
+                "STATE=%s\n"
+                "REMOTE=%i\n",
+                s->user->uid,
+                s->user->name,
+                session_is_active(s),
+                session_state_to_string(session_get_state(s)),
+                s->remote);
+
+        if (s->type >= 0)
+                fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
+
+        if (s->class >= 0)
+                fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
+
+        if (s->scope)
+                fprintf(f, "SCOPE=%s\n", s->scope);
+        if (s->scope_job)
+                fprintf(f, "SCOPE_JOB=%s\n", s->scope_job);
+
+        if (s->fifo_path)
+                fprintf(f, "FIFO=%s\n", s->fifo_path);
+
+        if (s->seat)
+                fprintf(f, "SEAT=%s\n", s->seat->id);
+
+        if (s->tty)
+                fprintf(f, "TTY=%s\n", s->tty);
+
+        if (s->display)
+                fprintf(f, "DISPLAY=%s\n", s->display);
+
+        if (s->remote_host) {
+                _cleanup_free_ char *escaped;
+
+                escaped = cescape(s->remote_host);
+                if (!escaped) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                fprintf(f, "REMOTE_HOST=%s\n", escaped);
+        }
+
+        if (s->remote_user) {
+                _cleanup_free_ char *escaped;
+
+                escaped = cescape(s->remote_user);
+                if (!escaped) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                fprintf(f, "REMOTE_USER=%s\n", escaped);
+        }
+
+        if (s->service) {
+                _cleanup_free_ char *escaped;
+
+                escaped = cescape(s->service);
+                if (!escaped) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                fprintf(f, "SERVICE=%s\n", escaped);
+        }
+
+        if (s->desktop) {
+                _cleanup_free_ char *escaped;
+
+
+                escaped = cescape(s->desktop);
+                if (!escaped) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                fprintf(f, "DESKTOP=%s\n", escaped);
+        }
+
+        if (s->seat && seat_has_vts(s->seat))
+                fprintf(f, "VTNR=%u\n", s->vtnr);
+
+        if (!s->vtnr)
+                fprintf(f, "POSITION=%u\n", s->position);
+
+        if (s->leader > 0)
+                fprintf(f, "LEADER="PID_FMT"\n", s->leader);
+
+        if (s->audit_id > 0)
+                fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
+
+        if (dual_timestamp_is_set(&s->timestamp))
+                fprintf(f,
+                        "REALTIME="USEC_FMT"\n"
+                        "MONOTONIC="USEC_FMT"\n",
+                        s->timestamp.realtime,
+                        s->timestamp.monotonic);
+
+        if (s->controller)
+                fprintf(f, "CONTROLLER=%s\n", s->controller);
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                goto fail;
+
+        if (rename(temp_path, s->state_file) < 0) {
+                r = -errno;
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        (void) unlink(s->state_file);
+
+        if (temp_path)
+                (void) unlink(temp_path);
+
+        return log_error_errno(r, "Failed to save session data %s: %m", s->state_file);
+}
+
+
+int session_load(Session *s) {
+        _cleanup_free_ char *remote = NULL,
+                *seat = NULL,
+                *vtnr = NULL,
+                *state = NULL,
+                *position = NULL,
+                *leader = NULL,
+                *type = NULL,
+                *class = NULL,
+                *uid = NULL,
+                *realtime = NULL,
+                *monotonic = NULL,
+                *controller = NULL;
+
+        int k, r;
+
+        assert(s);
+
+        r = parse_env_file(s->state_file, NEWLINE,
+                           "REMOTE",         &remote,
+                           "SCOPE",          &s->scope,
+                           "SCOPE_JOB",      &s->scope_job,
+                           "FIFO",           &s->fifo_path,
+                           "SEAT",           &seat,
+                           "TTY",            &s->tty,
+                           "DISPLAY",        &s->display,
+                           "REMOTE_HOST",    &s->remote_host,
+                           "REMOTE_USER",    &s->remote_user,
+                           "SERVICE",        &s->service,
+                           "DESKTOP",        &s->desktop,
+                           "VTNR",           &vtnr,
+                           "STATE",          &state,
+                           "POSITION",       &position,
+                           "LEADER",         &leader,
+                           "TYPE",           &type,
+                           "CLASS",          &class,
+                           "UID",            &uid,
+                           "REALTIME",       &realtime,
+                           "MONOTONIC",      &monotonic,
+                           "CONTROLLER",     &controller,
+                           NULL);
+
+        if (r < 0)
+                return log_error_errno(r, "Failed to read %s: %m", s->state_file);
+
+        if (!s->user) {
+                uid_t u;
+                User *user;
+
+                if (!uid) {
+                        log_error("UID not specified for session %s", s->id);
+                        return -ENOENT;
+                }
+
+                r = parse_uid(uid, &u);
+                if (r < 0)  {
+                        log_error("Failed to parse UID value %s for session %s.", uid, s->id);
+                        return r;
+                }
+
+                user = hashmap_get(s->manager->users, UID_TO_PTR(u));
+                if (!user) {
+                        log_error("User of session %s not known.", s->id);
+                        return -ENOENT;
+                }
+
+                session_set_user(s, user);
+        }
+
+        if (remote) {
+                k = parse_boolean(remote);
+                if (k >= 0)
+                        s->remote = k;
+        }
+
+        if (vtnr)
+                safe_atou(vtnr, &s->vtnr);
+
+        if (seat && !s->seat) {
+                Seat *o;
+
+                o = hashmap_get(s->manager->seats, seat);
+                if (o)
+                        r = seat_attach_session(o, s);
+                if (!o || r < 0)
+                        log_error("Cannot attach session %s to seat %s", s->id, seat);
+        }
+
+        if (!s->seat || !seat_has_vts(s->seat))
+                s->vtnr = 0;
+
+        if (position && s->seat) {
+                unsigned int npos;
+
+                safe_atou(position, &npos);
+                seat_claim_position(s->seat, s, npos);
+        }
+
+        if (leader) {
+                k = parse_pid(leader, &s->leader);
+                if (k >= 0)
+                        audit_session_from_pid(s->leader, &s->audit_id);
+        }
+
+        if (type) {
+                SessionType t;
+
+                t = session_type_from_string(type);
+                if (t >= 0)
+                        s->type = t;
+        }
+
+        if (class) {
+                SessionClass c;
+
+                c = session_class_from_string(class);
+                if (c >= 0)
+                        s->class = c;
+        }
+
+        if (state && streq(state, "closing"))
+                s->stopping = true;
+
+        if (s->fifo_path) {
+                int fd;
+
+                /* If we open an unopened pipe for reading we will not
+                   get an EOF. to trigger an EOF we hence open it for
+                   writing, but close it right away which then will
+                   trigger the EOF. This will happen immediately if no
+                   other process has the FIFO open for writing, i. e.
+                   when the session died before logind (re)started. */
+
+                fd = session_create_fifo(s);
+                safe_close(fd);
+        }
+
+        if (realtime)
+                timestamp_deserialize(realtime, &s->timestamp.realtime);
+        if (monotonic)
+                timestamp_deserialize(monotonic, &s->timestamp.monotonic);
+
+        if (controller) {
+                if (bus_name_has_owner(s->manager->bus, controller, NULL) > 0)
+                        session_set_controller(s, controller, false);
+                else
+                        session_restore_vt(s);
+        }
+
+        return r;
+}
+
+int session_activate(Session *s) {
+        unsigned int num_pending;
+
+        assert(s);
+        assert(s->user);
+
+        if (!s->seat)
+                return -EOPNOTSUPP;
+
+        if (s->seat->active == s)
+                return 0;
+
+        /* on seats with VTs, we let VTs manage session-switching */
+        if (seat_has_vts(s->seat)) {
+                if (!s->vtnr)
+                        return -EOPNOTSUPP;
+
+                return chvt(s->vtnr);
+        }
+
+        /* On seats without VTs, we implement session-switching in logind. We
+         * try to pause all session-devices and wait until the session
+         * controller acknowledged them. Once all devices are asleep, we simply
+         * switch the active session and be done.
+         * We save the session we want to switch to in seat->pending_switch and
+         * seat_complete_switch() will perform the final switch. */
+
+        s->seat->pending_switch = s;
+
+        /* if no devices are running, immediately perform the session switch */
+        num_pending = session_device_try_pause_all(s);
+        if (!num_pending)
+                seat_complete_switch(s->seat);
+
+        return 0;
+}
+
+static int session_start_scope(Session *s) {
+        int r;
+
+        assert(s);
+        assert(s->user);
+
+        if (!s->scope) {
+                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+                char *scope, *job = NULL;
+                const char *description;
+
+                scope = strjoin("session-", s->id, ".scope", NULL);
+                if (!scope)
+                        return log_oom();
+
+                description = strjoina("Session ", s->id, " of user ", s->user->name);
+
+                r = manager_start_scope(
+                                s->manager,
+                                scope,
+                                s->leader,
+                                s->user->slice,
+                                description,
+                                "systemd-logind.service",
+                                "systemd-user-sessions.service",
+                                (uint64_t) -1, /* disable TasksMax= for the scope, rely on the slice setting for it */
+                                &error,
+                                &job);
+                if (r < 0) {
+                        log_error_errno(r, "Failed to start session scope %s: %s", scope, bus_error_message(&error, r));
+                        free(scope);
+                        return r;
+                } else {
+                        s->scope = scope;
+
+                        free(s->scope_job);
+                        s->scope_job = job;
+                }
+        }
+
+        if (s->scope)
+                (void) hashmap_put(s->manager->session_units, s->scope, s);
+
+        return 0;
+}
+
+int session_start(Session *s) {
+        int r;
+
+        assert(s);
+
+        if (!s->user)
+                return -ESTALE;
+
+        if (s->started)
+                return 0;
+
+        r = user_start(s->user);
+        if (r < 0)
+                return r;
+
+        /* Create cgroup */
+        r = session_start_scope(s);
+        if (r < 0)
+                return r;
+
+        log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
+                   LOG_MESSAGE_ID(SD_MESSAGE_SESSION_START),
+                   "SESSION_ID=%s", s->id,
+                   "USER_ID=%s", s->user->name,
+                   "LEADER="PID_FMT, s->leader,
+                   LOG_MESSAGE("New session %s of user %s.", s->id, s->user->name),
+                   NULL);
+
+        if (!dual_timestamp_is_set(&s->timestamp))
+                dual_timestamp_get(&s->timestamp);
+
+        if (s->seat)
+                seat_read_active_vt(s->seat);
+
+        s->started = true;
+
+        user_elect_display(s->user);
+
+        /* Save data */
+        session_save(s);
+        user_save(s->user);
+        if (s->seat)
+                seat_save(s->seat);
+
+        /* Send signals */
+        session_send_signal(s, true);
+        user_send_changed(s->user, "Sessions", "Display", NULL);
+        if (s->seat) {
+                if (s->seat->active == s)
+                        seat_send_changed(s->seat, "Sessions", "ActiveSession", NULL);
+                else
+                        seat_send_changed(s->seat, "Sessions", NULL);
+        }
+
+        return 0;
+}
+
+static int session_stop_scope(Session *s, bool force) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        int r;
+
+        assert(s);
+
+        if (!s->scope)
+                return 0;
+
+        /* Let's always abandon the scope first. This tells systemd that we are not interested anymore, and everything
+         * that is left in in the scope is "left-over". Informing systemd about this has the benefit that it will log
+         * when killing any processes left after this point. */
+        r = manager_abandon_scope(s->manager, s->scope, &error);
+        if (r < 0)
+                log_warning_errno(r, "Failed to abandon session scope, ignoring: %s", bus_error_message(&error, r));
+
+        /* Optionally, let's kill everything that's left now. */
+        if (force || manager_shall_kill(s->manager, s->user->name)) {
+                char *job = NULL;
+
+                r = manager_stop_unit(s->manager, s->scope, &error, &job);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to stop session scope: %s", bus_error_message(&error, r));
+
+                free(s->scope_job);
+                s->scope_job = job;
+        } else
+                s->scope_job = mfree(s->scope_job);
+
+        return 0;
+}
+
+int session_stop(Session *s, bool force) {
+        int r;
+
+        assert(s);
+
+        if (!s->user)
+                return -ESTALE;
+
+        s->timer_event_source = sd_event_source_unref(s->timer_event_source);
+
+        if (s->seat)
+                seat_evict_position(s->seat, s);
+
+        /* We are going down, don't care about FIFOs anymore */
+        session_remove_fifo(s);
+
+        /* Kill cgroup */
+        r = session_stop_scope(s, force);
+
+        s->stopping = true;
+
+        user_elect_display(s->user);
+
+        session_save(s);
+        user_save(s->user);
+
+        return r;
+}
+
+int session_finalize(Session *s) {
+        SessionDevice *sd;
+
+        assert(s);
+
+        if (!s->user)
+                return -ESTALE;
+
+        if (s->started)
+                log_struct(s->class == SESSION_BACKGROUND ? LOG_DEBUG : LOG_INFO,
+                           LOG_MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
+                           "SESSION_ID=%s", s->id,
+                           "USER_ID=%s", s->user->name,
+                           "LEADER="PID_FMT, s->leader,
+                           LOG_MESSAGE("Removed session %s.", s->id),
+                           NULL);
+
+        s->timer_event_source = sd_event_source_unref(s->timer_event_source);
+
+        if (s->seat)
+                seat_evict_position(s->seat, s);
+
+        /* Kill session devices */
+        while ((sd = hashmap_first(s->devices)))
+                session_device_free(sd);
+
+        (void) unlink(s->state_file);
+        session_add_to_gc_queue(s);
+        user_add_to_gc_queue(s->user);
+
+        if (s->started) {
+                session_send_signal(s, false);
+                s->started = false;
+        }
+
+        if (s->seat) {
+                if (s->seat->active == s)
+                        seat_set_active(s->seat, NULL);
+
+                seat_save(s->seat);
+                seat_send_changed(s->seat, "Sessions", NULL);
+        }
+
+        user_save(s->user);
+        user_send_changed(s->user, "Sessions", "Display", NULL);
+
+        return 0;
+}
+
+static int release_timeout_callback(sd_event_source *es, uint64_t usec, void *userdata) {
+        Session *s = userdata;
+
+        assert(es);
+        assert(s);
+
+        session_stop(s, false);
+        return 0;
+}
+
+int session_release(Session *s) {
+        assert(s);
+
+        if (!s->started || s->stopping)
+                return 0;
+
+        if (s->timer_event_source)
+                return 0;
+
+        return sd_event_add_time(s->manager->event,
+                                 &s->timer_event_source,
+                                 CLOCK_MONOTONIC,
+                                 now(CLOCK_MONOTONIC) + RELEASE_USEC, 0,
+                                 release_timeout_callback, s);
+}
+
+bool session_is_active(Session *s) {
+        assert(s);
+
+        if (!s->seat)
+                return true;
+
+        return s->seat->active == s;
+}
+
+static int get_tty_atime(const char *tty, usec_t *atime) {
+        _cleanup_free_ char *p = NULL;
+        struct stat st;
+
+        assert(tty);
+        assert(atime);
+
+        if (!path_is_absolute(tty)) {
+                p = strappend("/dev/", tty);
+                if (!p)
+                        return -ENOMEM;
+
+                tty = p;
+        } else if (!path_startswith(tty, "/dev/"))
+                return -ENOENT;
+
+        if (lstat(tty, &st) < 0)
+                return -errno;
+
+        *atime = timespec_load(&st.st_atim);
+        return 0;
+}
+
+static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
+        _cleanup_free_ char *p = NULL;
+        int r;
+
+        assert(pid > 0);
+        assert(atime);
+
+        r = get_ctty(pid, NULL, &p);
+        if (r < 0)
+                return r;
+
+        return get_tty_atime(p, atime);
+}
+
+int session_get_idle_hint(Session *s, dual_timestamp *t) {
+        usec_t atime = 0, n;
+        int r;
+
+        assert(s);
+
+        /* Explicit idle hint is set */
+        if (s->idle_hint) {
+                if (t)
+                        *t = s->idle_hint_timestamp;
+
+                return s->idle_hint;
+        }
+
+        /* Graphical sessions should really implement a real
+         * idle hint logic */
+        if (SESSION_TYPE_IS_GRAPHICAL(s->type))
+                goto dont_know;
+
+        /* For sessions with an explicitly configured tty, let's check
+         * its atime */
+        if (s->tty) {
+                r = get_tty_atime(s->tty, &atime);
+                if (r >= 0)
+                        goto found_atime;
+        }
+
+        /* For sessions with a leader but no explicitly configured
+         * tty, let's check the controlling tty of the leader */
+        if (s->leader > 0) {
+                r = get_process_ctty_atime(s->leader, &atime);
+                if (r >= 0)
+                        goto found_atime;
+        }
+
+dont_know:
+        if (t)
+                *t = s->idle_hint_timestamp;
+
+        return 0;
+
+found_atime:
+        if (t)
+                dual_timestamp_from_realtime(t, atime);
+
+        n = now(CLOCK_REALTIME);
+
+        if (s->manager->idle_action_usec <= 0)
+                return 0;
+
+        return atime + s->manager->idle_action_usec <= n;
+}
+
+void session_set_idle_hint(Session *s, bool b) {
+        assert(s);
+
+        if (s->idle_hint == b)
+                return;
+
+        s->idle_hint = b;
+        dual_timestamp_get(&s->idle_hint_timestamp);
+
+        session_send_changed(s, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
+
+        if (s->seat)
+                seat_send_changed(s->seat, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
+
+        user_send_changed(s->user, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
+        manager_send_changed(s->manager, "IdleHint", "IdleSinceHint", "IdleSinceHintMonotonic", NULL);
+}
+
+int session_get_locked_hint(Session *s) {
+        assert(s);
+
+        return s->locked_hint;
+}
+
+void session_set_locked_hint(Session *s, bool b) {
+        assert(s);
+
+        if (s->locked_hint == b)
+                return;
+
+        s->locked_hint = b;
+
+        session_send_changed(s, "LockedHint", NULL);
+}
+
+static int session_dispatch_fifo(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
+        Session *s = userdata;
+
+        assert(s);
+        assert(s->fifo_fd == fd);
+
+        /* EOF on the FIFO means the session died abnormally. */
+
+        session_remove_fifo(s);
+        session_stop(s, false);
+
+        return 1;
+}
+
+int session_create_fifo(Session *s) {
+        int r;
+
+        assert(s);
+
+        /* Create FIFO */
+        if (!s->fifo_path) {
+                r = mkdir_safe_label("/run/systemd/sessions", 0755, 0, 0);
+                if (r < 0)
+                        return r;
+
+                if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
+                        return -ENOMEM;
+
+                if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
+                        return -errno;
+        }
+
+        /* Open reading side */
+        if (s->fifo_fd < 0) {
+                s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
+                if (s->fifo_fd < 0)
+                        return -errno;
+
+        }
+
+        if (!s->fifo_event_source) {
+                r = sd_event_add_io(s->manager->event, &s->fifo_event_source, s->fifo_fd, 0, session_dispatch_fifo, s);
+                if (r < 0)
+                        return r;
+
+                /* Let's make sure we noticed dead sessions before we process new bus requests (which might create new
+                 * sessions). */
+                r = sd_event_source_set_priority(s->fifo_event_source, SD_EVENT_PRIORITY_NORMAL-10);
+                if (r < 0)
+                        return r;
+        }
+
+        /* Open writing side */
+        r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
+        if (r < 0)
+                return -errno;
+
+        return r;
+}
+
+static void session_remove_fifo(Session *s) {
+        assert(s);
+
+        s->fifo_event_source = sd_event_source_unref(s->fifo_event_source);
+        s->fifo_fd = safe_close(s->fifo_fd);
+
+        if (s->fifo_path) {
+                unlink(s->fifo_path);
+                s->fifo_path = mfree(s->fifo_path);
+        }
+}
+
+bool session_check_gc(Session *s, bool drop_not_started) {
+        assert(s);
+
+        if (drop_not_started && !s->started)
+                return false;
+
+        if (!s->user)
+                return false;
+
+        if (s->fifo_fd >= 0) {
+                if (pipe_eof(s->fifo_fd) <= 0)
+                        return true;
+        }
+
+        if (s->scope_job && manager_job_is_active(s->manager, s->scope_job))
+                return true;
+
+        if (s->scope && manager_unit_is_active(s->manager, s->scope))
+                return true;
+
+        return false;
+}
+
+void session_add_to_gc_queue(Session *s) {
+        assert(s);
+
+        if (s->in_gc_queue)
+                return;
+
+        LIST_PREPEND(gc_queue, s->manager->session_gc_queue, s);
+        s->in_gc_queue = true;
+}
+
+SessionState session_get_state(Session *s) {
+        assert(s);
+
+        /* always check closing first */
+        if (s->stopping || s->timer_event_source)
+                return SESSION_CLOSING;
+
+        if (s->scope_job || s->fifo_fd < 0)
+                return SESSION_OPENING;
+
+        if (session_is_active(s))
+                return SESSION_ACTIVE;
+
+        return SESSION_ONLINE;
+}
+
+int session_kill(Session *s, KillWho who, int signo) {
+        assert(s);
+
+        if (!s->scope)
+                return -ESRCH;
+
+        return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
+}
+
+static int session_open_vt(Session *s) {
+        char path[sizeof("/dev/tty") + DECIMAL_STR_MAX(s->vtnr)];
+
+        if (s->vtnr < 1)
+                return -ENODEV;
+
+        if (s->vtfd >= 0)
+                return s->vtfd;
+
+        sprintf(path, "/dev/tty%u", s->vtnr);
+        s->vtfd = open_terminal(path, O_RDWR | O_CLOEXEC | O_NONBLOCK | O_NOCTTY);
+        if (s->vtfd < 0)
+                return log_error_errno(s->vtfd, "cannot open VT %s of session %s: %m", path, s->id);
+
+        return s->vtfd;
+}
+
+int session_prepare_vt(Session *s) {
+        int vt, r;
+        struct vt_mode mode = { 0 };
+
+        if (s->vtnr < 1)
+                return 0;
+
+        vt = session_open_vt(s);
+        if (vt < 0)
+                return vt;
+
+        r = fchown(vt, s->user->uid, -1);
+        if (r < 0) {
+                r = log_error_errno(errno,
+                                    "Cannot change owner of /dev/tty%u: %m",
+                                    s->vtnr);
+                goto error;
+        }
+
+        r = ioctl(vt, KDSKBMODE, K_OFF);
+        if (r < 0) {
+                r = log_error_errno(errno,
+                                    "Cannot set K_OFF on /dev/tty%u: %m",
+                                    s->vtnr);
+                goto error;
+        }
+
+        r = ioctl(vt, KDSETMODE, KD_GRAPHICS);
+        if (r < 0) {
+                r = log_error_errno(errno,
+                                    "Cannot set KD_GRAPHICS on /dev/tty%u: %m",
+                                    s->vtnr);
+                goto error;
+        }
+
+        /* Oh, thanks to the VT layer, VT_AUTO does not work with KD_GRAPHICS.
+         * So we need a dummy handler here which just acknowledges *all* VT
+         * switch requests. */
+        mode.mode = VT_PROCESS;
+        mode.relsig = SIGRTMIN;
+        mode.acqsig = SIGRTMIN + 1;
+        r = ioctl(vt, VT_SETMODE, &mode);
+        if (r < 0) {
+                r = log_error_errno(errno,
+                                    "Cannot set VT_PROCESS on /dev/tty%u: %m",
+                                    s->vtnr);
+                goto error;
+        }
+
+        return 0;
+
+error:
+        session_restore_vt(s);
+        return r;
+}
+
+void session_restore_vt(Session *s) {
+
+        static const struct vt_mode mode = {
+                .mode = VT_AUTO,
+        };
+
+        _cleanup_free_ char *utf8 = NULL;
+        int vt, kb, old_fd;
+
+        /* We need to get a fresh handle to the virtual terminal,
+         * since the old file-descriptor is potentially in a hung-up
+         * state after the controlling process exited; we do a
+         * little dance to avoid having the terminal be available
+         * for reuse before we've cleaned it up.
+         */
+        old_fd = s->vtfd;
+        s->vtfd = -1;
+
+        vt = session_open_vt(s);
+        safe_close(old_fd);
+
+        if (vt < 0)
+                return;
+
+        (void) ioctl(vt, KDSETMODE, KD_TEXT);
+
+        if (read_one_line_file("/sys/module/vt/parameters/default_utf8", &utf8) >= 0 && *utf8 == '1')
+                kb = K_UNICODE;
+        else
+                kb = K_XLATE;
+
+        (void) ioctl(vt, KDSKBMODE, kb);
+
+        (void) ioctl(vt, VT_SETMODE, &mode);
+        (void) fchown(vt, 0, (gid_t) -1);
+
+        s->vtfd = safe_close(s->vtfd);
+}
+
+void session_leave_vt(Session *s) {
+        int r;
+
+        assert(s);
+
+        /* This is called whenever we get a VT-switch signal from the kernel.
+         * We acknowledge all of them unconditionally. Note that session are
+         * free to overwrite those handlers and we only register them for
+         * sessions with controllers. Legacy sessions are not affected.
+         * However, if we switch from a non-legacy to a legacy session, we must
+         * make sure to pause all device before acknowledging the switch. We
+         * process the real switch only after we are notified via sysfs, so the
+         * legacy session might have already started using the devices. If we
+         * don't pause the devices before the switch, we might confuse the
+         * session we switch to. */
+
+        if (s->vtfd < 0)
+                return;
+
+        session_device_pause_all(s);
+        r = ioctl(s->vtfd, VT_RELDISP, 1);
+        if (r < 0)
+                log_debug_errno(errno, "Cannot release VT of session %s: %m", s->id);
+}
+
+bool session_is_controller(Session *s, const char *sender) {
+        assert(s);
+
+        return streq_ptr(s->controller, sender);
+}
+
+static void session_release_controller(Session *s, bool notify) {
+        _cleanup_free_ char *name = NULL;
+        SessionDevice *sd;
+
+        if (!s->controller)
+                return;
+
+        name = s->controller;
+
+        /* By resetting the controller before releasing the devices, we won't
+         * send notification signals. This avoids sending useless notifications
+         * if the controller is released on disconnects. */
+        if (!notify)
+                s->controller = NULL;
+
+        while ((sd = hashmap_first(s->devices)))
+                session_device_free(sd);
+
+        s->controller = NULL;
+        s->track = sd_bus_track_unref(s->track);
+}
+
+static int on_bus_track(sd_bus_track *track, void *userdata) {
+        Session *s = userdata;
+
+        assert(track);
+        assert(s);
+
+        session_drop_controller(s);
+
+        return 0;
+}
+
+int session_set_controller(Session *s, const char *sender, bool force) {
+        _cleanup_free_ char *name = NULL;
+        int r;
+
+        assert(s);
+        assert(sender);
+
+        if (session_is_controller(s, sender))
+                return 0;
+        if (s->controller && !force)
+                return -EBUSY;
+
+        name = strdup(sender);
+        if (!name)
+                return -ENOMEM;
+
+        s->track = sd_bus_track_unref(s->track);
+        r = sd_bus_track_new(s->manager->bus, &s->track, on_bus_track, s);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_track_add_name(s->track, name);
+        if (r < 0)
+                return r;
+
+        /* When setting a session controller, we forcibly mute the VT and set
+         * it into graphics-mode. Applications can override that by changing
+         * VT state after calling TakeControl(). However, this serves as a good
+         * default and well-behaving controllers can now ignore VTs entirely.
+         * Note that we reset the VT on ReleaseControl() and if the controller
+         * exits.
+         * If logind crashes/restarts, we restore the controller during restart
+         * or reset the VT in case it crashed/exited, too. */
+        r = session_prepare_vt(s);
+        if (r < 0) {
+                s->track = sd_bus_track_unref(s->track);
+                return r;
+        }
+
+        session_release_controller(s, true);
+        s->controller = name;
+        name = NULL;
+        session_save(s);
+
+        return 0;
+}
+
+void session_drop_controller(Session *s) {
+        assert(s);
+
+        if (!s->controller)
+                return;
+
+        s->track = sd_bus_track_unref(s->track);
+        session_release_controller(s, false);
+        session_save(s);
+        session_restore_vt(s);
+}
+
+static const char* const session_state_table[_SESSION_STATE_MAX] = {
+        [SESSION_OPENING] = "opening",
+        [SESSION_ONLINE] = "online",
+        [SESSION_ACTIVE] = "active",
+        [SESSION_CLOSING] = "closing"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(session_state, SessionState);
+
+static const char* const session_type_table[_SESSION_TYPE_MAX] = {
+        [SESSION_UNSPECIFIED] = "unspecified",
+        [SESSION_TTY] = "tty",
+        [SESSION_X11] = "x11",
+        [SESSION_WAYLAND] = "wayland",
+        [SESSION_MIR] = "mir",
+        [SESSION_WEB] = "web",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
+
+static const char* const session_class_table[_SESSION_CLASS_MAX] = {
+        [SESSION_USER] = "user",
+        [SESSION_GREETER] = "greeter",
+        [SESSION_LOCK_SCREEN] = "lock-screen",
+        [SESSION_BACKGROUND] = "background"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);
+
+static const char* const kill_who_table[_KILL_WHO_MAX] = {
+        [KILL_LEADER] = "leader",
+        [KILL_ALL] = "all"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);