./tools/notsd-move

1 files changed, 931 insertions, 0 deletions

diff --git a/src/grp-login/systemd-logind/logind-user.c b/src/grp-login/systemd-logind/logind-user.c
new file mode 100644
index 0000000000..0308a78d42
--- /dev/null
+++ b/src/grp-login/systemd-logind/logind-user.c
@@ -0,0 +1,931 @@
+/***
+  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 <string.h>
+#include <sys/mount.h>
+#include <unistd.h>
+
+#include "sd-bus/bus-common-errors.h"
+#include "sd-bus/bus-error.h"
+#include "sd-bus/bus-util.h"
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/cgroup-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/fs-util.h"
+#include "systemd-basic/hashmap.h"
+#include "systemd-basic/label.h"
+#include "systemd-basic/mkdir.h"
+#include "systemd-basic/mount-util.h"
+#include "systemd-basic/parse-util.h"
+#include "systemd-basic/path-util.h"
+#include "systemd-basic/rm-rf.h"
+#include "systemd-basic/smack-util.h"
+#include "systemd-basic/special.h"
+#include "systemd-basic/stdio-util.h"
+#include "systemd-basic/string-table.h"
+#include "systemd-basic/unit-name.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/util.h"
+#include "systemd-shared/clean-ipc.h"
+#include "systemd-shared/conf-parser.h"
+
+#include "logind-user.h"
+
+int user_new(User **out, Manager *m, uid_t uid, gid_t gid, const char *name) {
+        _cleanup_(user_freep) User *u = NULL;
+        char lu[DECIMAL_STR_MAX(uid_t) + 1];
+        int r;
+
+        assert(out);
+        assert(m);
+        assert(name);
+
+        u = new0(User, 1);
+        if (!u)
+                return -ENOMEM;
+
+        u->manager = m;
+        u->uid = uid;
+        u->gid = gid;
+        xsprintf(lu, UID_FMT, uid);
+
+        u->name = strdup(name);
+        if (!u->name)
+                return -ENOMEM;
+
+        if (asprintf(&u->state_file, "/run/systemd/users/"UID_FMT, uid) < 0)
+                return -ENOMEM;
+
+        if (asprintf(&u->runtime_path, "/run/user/"UID_FMT, uid) < 0)
+                return -ENOMEM;
+
+        r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice);
+        if (r < 0)
+                return r;
+
+        r = unit_name_build("user", lu, ".service", &u->service);
+        if (r < 0)
+                return r;
+
+        r = hashmap_put(m->users, UID_TO_PTR(uid), u);
+        if (r < 0)
+                return r;
+
+        r = hashmap_put(m->user_units, u->slice, u);
+        if (r < 0)
+                return r;
+
+        r = hashmap_put(m->user_units, u->service, u);
+        if (r < 0)
+                return r;
+
+        *out = u;
+        u = NULL;
+        return 0;
+}
+
+User *user_free(User *u) {
+        if (!u)
+                return NULL;
+
+        if (u->in_gc_queue)
+                LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u);
+
+        while (u->sessions)
+                session_free(u->sessions);
+
+        if (u->service)
+                hashmap_remove_value(u->manager->user_units, u->service, u);
+
+        if (u->slice)
+                hashmap_remove_value(u->manager->user_units, u->slice, u);
+
+        hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u);
+
+        u->slice_job = mfree(u->slice_job);
+        u->service_job = mfree(u->service_job);
+
+        u->service = mfree(u->service);
+        u->slice = mfree(u->slice);
+        u->runtime_path = mfree(u->runtime_path);
+        u->state_file = mfree(u->state_file);
+        u->name = mfree(u->name);
+
+        return mfree(u);
+}
+
+static int user_save_internal(User *u) {
+        _cleanup_free_ char *temp_path = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        int r;
+
+        assert(u);
+        assert(u->state_file);
+
+        r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0);
+        if (r < 0)
+                goto fail;
+
+        r = fopen_temporary(u->state_file, &f, &temp_path);
+        if (r < 0)
+                goto fail;
+
+        fchmod(fileno(f), 0644);
+
+        fprintf(f,
+                "# This is private data. Do not parse.\n"
+                "NAME=%s\n"
+                "STATE=%s\n",
+                u->name,
+                user_state_to_string(user_get_state(u)));
+
+        /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */
+        if (u->runtime_path)
+                fprintf(f, "RUNTIME=%s\n", u->runtime_path);
+
+        if (u->service_job)
+                fprintf(f, "SERVICE_JOB=%s\n", u->service_job);
+
+        if (u->slice_job)
+                fprintf(f, "SLICE_JOB=%s\n", u->slice_job);
+
+        if (u->display)
+                fprintf(f, "DISPLAY=%s\n", u->display->id);
+
+        if (dual_timestamp_is_set(&u->timestamp))
+                fprintf(f,
+                        "REALTIME="USEC_FMT"\n"
+                        "MONOTONIC="USEC_FMT"\n",
+                        u->timestamp.realtime,
+                        u->timestamp.monotonic);
+
+        if (u->sessions) {
+                Session *i;
+                bool first;
+
+                fputs("SESSIONS=", f);
+                first = true;
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        if (first)
+                                first = false;
+                        else
+                                fputc(' ', f);
+
+                        fputs(i->id, f);
+                }
+
+                fputs("\nSEATS=", f);
+                first = true;
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        if (!i->seat)
+                                continue;
+
+                        if (first)
+                                first = false;
+                        else
+                                fputc(' ', f);
+
+                        fputs(i->seat->id, f);
+                }
+
+                fputs("\nACTIVE_SESSIONS=", f);
+                first = true;
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        if (!session_is_active(i))
+                                continue;
+
+                        if (first)
+                                first = false;
+                        else
+                                fputc(' ', f);
+
+                        fputs(i->id, f);
+                }
+
+                fputs("\nONLINE_SESSIONS=", f);
+                first = true;
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        if (session_get_state(i) == SESSION_CLOSING)
+                                continue;
+
+                        if (first)
+                                first = false;
+                        else
+                                fputc(' ', f);
+
+                        fputs(i->id, f);
+                }
+
+                fputs("\nACTIVE_SEATS=", f);
+                first = true;
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        if (!session_is_active(i) || !i->seat)
+                                continue;
+
+                        if (first)
+                                first = false;
+                        else
+                                fputc(' ', f);
+
+                        fputs(i->seat->id, f);
+                }
+
+                fputs("\nONLINE_SEATS=", f);
+                first = true;
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        if (session_get_state(i) == SESSION_CLOSING || !i->seat)
+                                continue;
+
+                        if (first)
+                                first = false;
+                        else
+                                fputc(' ', f);
+
+                        fputs(i->seat->id, f);
+                }
+                fputc('\n', f);
+        }
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                goto fail;
+
+        if (rename(temp_path, u->state_file) < 0) {
+                r = -errno;
+                goto fail;
+        }
+
+        return 0;
+
+fail:
+        (void) unlink(u->state_file);
+
+        if (temp_path)
+                (void) unlink(temp_path);
+
+        return log_error_errno(r, "Failed to save user data %s: %m", u->state_file);
+}
+
+int user_save(User *u) {
+        assert(u);
+
+        if (!u->started)
+                return 0;
+
+        return user_save_internal (u);
+}
+
+int user_load(User *u) {
+        _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL;
+        Session *s = NULL;
+        int r;
+
+        assert(u);
+
+        r = parse_env_file(u->state_file, NEWLINE,
+                           "SERVICE_JOB", &u->service_job,
+                           "SLICE_JOB",   &u->slice_job,
+                           "DISPLAY",     &display,
+                           "REALTIME",    &realtime,
+                           "MONOTONIC",   &monotonic,
+                           NULL);
+        if (r < 0) {
+                if (r == -ENOENT)
+                        return 0;
+
+                return log_error_errno(r, "Failed to read %s: %m", u->state_file);
+        }
+
+        if (display)
+                s = hashmap_get(u->manager->sessions, display);
+
+        if (s && s->display && display_is_local(s->display))
+                u->display = s;
+
+        if (realtime)
+                timestamp_deserialize(realtime, &u->timestamp.realtime);
+        if (monotonic)
+                timestamp_deserialize(monotonic, &u->timestamp.monotonic);
+
+        return r;
+}
+
+static int user_mkdir_runtime_path(User *u) {
+        int r;
+
+        assert(u);
+
+        r = mkdir_safe_label("/run/user", 0755, 0, 0);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create /run/user: %m");
+
+        if (path_is_mount_point(u->runtime_path, 0) <= 0) {
+                _cleanup_free_ char *t = NULL;
+
+                (void) mkdir_label(u->runtime_path, 0700);
+
+                if (mac_smack_use())
+                        r = asprintf(&t, "mode=0700,smackfsroot=*,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
+                else
+                        r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size);
+                if (r < 0) {
+                        r = log_oom();
+                        goto fail;
+                }
+
+                r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t);
+                if (r < 0) {
+                        if (errno != EPERM && errno != EACCES) {
+                                r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path);
+                                goto fail;
+                        }
+
+                        log_debug_errno(errno, "Failed to mount per-user tmpfs directory %s, assuming containerized execution, ignoring: %m", u->runtime_path);
+
+                        r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid);
+                        if (r < 0) {
+                                log_error_errno(r, "Failed to change runtime directory ownership and mode: %m");
+                                goto fail;
+                        }
+                }
+
+                r = label_fix(u->runtime_path, false, false);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path);
+        }
+
+        return 0;
+
+fail:
+        /* Try to clean up, but ignore errors */
+        (void) rmdir(u->runtime_path);
+        return r;
+}
+
+static int user_start_slice(User *u) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        const char *description;
+        char *job;
+        int r;
+
+        assert(u);
+
+        u->slice_job = mfree(u->slice_job);
+        description = strjoina("User Slice of ", u->name);
+
+        r = manager_start_slice(
+                        u->manager,
+                        u->slice,
+                        description,
+                        "systemd-logind.service",
+                        "systemd-user-sessions.service",
+                        u->manager->user_tasks_max,
+                        &error,
+                        &job);
+        if (r >= 0)
+                u->slice_job = job;
+        else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS))
+                /* we don't fail due to this, let's try to continue */
+                log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)",
+                                u->slice, bus_error_message(&error, r), error.name);
+
+        return 0;
+}
+
+static int user_start_service(User *u) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        char *job;
+        int r;
+
+        assert(u);
+
+        u->service_job = mfree(u->service_job);
+
+        r = manager_start_unit(
+                        u->manager,
+                        u->service,
+                        &error,
+                        &job);
+        if (r < 0) {
+                /* we don't fail due to this, let's try to continue */
+                log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r));
+        } else {
+                u->service_job = job;
+        }
+
+        return 0;
+}
+
+int user_start(User *u) {
+        int r;
+
+        assert(u);
+
+        if (u->started && !u->stopping)
+                return 0;
+
+        /*
+         * If u->stopping is set, the user is marked for removal and the slice
+         * and service stop-jobs are queued. We have to clear that flag before
+         * queing the start-jobs again. If they succeed, the user object can be
+         * re-used just fine (pid1 takes care of job-ordering and proper
+         * restart), but if they fail, we want to force another user_stop() so
+         * possibly pending units are stopped.
+         * Note that we don't clear u->started, as we have no clue what state
+         * the user is in on failure here. Hence, we pretend the user is
+         * running so it will be properly taken down by GC. However, we clearly
+         * return an error from user_start() in that case, so no further
+         * reference to the user is taken.
+         */
+        u->stopping = false;
+
+        if (!u->started) {
+                log_debug("New user %s logged in.", u->name);
+
+                /* Make XDG_RUNTIME_DIR */
+                r = user_mkdir_runtime_path(u);
+                if (r < 0)
+                        return r;
+        }
+
+        /* Create cgroup */
+        r = user_start_slice(u);
+        if (r < 0)
+                return r;
+
+        /* Save the user data so far, because pam_systemd will read the
+         * XDG_RUNTIME_DIR out of it while starting up systemd --user.
+         * We need to do user_save_internal() because we have not
+         * "officially" started yet. */
+        user_save_internal(u);
+
+        /* Spawn user systemd */
+        r = user_start_service(u);
+        if (r < 0)
+                return r;
+
+        if (!u->started) {
+                if (!dual_timestamp_is_set(&u->timestamp))
+                        dual_timestamp_get(&u->timestamp);
+                user_send_signal(u, true);
+                u->started = true;
+        }
+
+        /* Save new user data */
+        user_save(u);
+
+        return 0;
+}
+
+static int user_stop_slice(User *u) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        char *job;
+        int r;
+
+        assert(u);
+
+        r = manager_stop_unit(u->manager, u->slice, &error, &job);
+        if (r < 0) {
+                log_error("Failed to stop user slice: %s", bus_error_message(&error, r));
+                return r;
+        }
+
+        free(u->slice_job);
+        u->slice_job = job;
+
+        return r;
+}
+
+static int user_stop_service(User *u) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        char *job;
+        int r;
+
+        assert(u);
+
+        r = manager_stop_unit(u->manager, u->service, &error, &job);
+        if (r < 0) {
+                log_error("Failed to stop user service: %s", bus_error_message(&error, r));
+                return r;
+        }
+
+        free(u->service_job);
+        u->service_job = job;
+
+        return r;
+}
+
+static int user_remove_runtime_path(User *u) {
+        int r;
+
+        assert(u);
+
+        r = rm_rf(u->runtime_path, 0);
+        if (r < 0)
+                log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
+
+        /* Ignore cases where the directory isn't mounted, as that's
+         * quite possible, if we lacked the permissions to mount
+         * something */
+        r = umount2(u->runtime_path, MNT_DETACH);
+        if (r < 0 && errno != EINVAL && errno != ENOENT)
+                log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path);
+
+        r = rm_rf(u->runtime_path, REMOVE_ROOT);
+        if (r < 0)
+                log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path);
+
+        return r;
+}
+
+int user_stop(User *u, bool force) {
+        Session *s;
+        int r = 0, k;
+        assert(u);
+
+        /* Stop jobs have already been queued */
+        if (u->stopping) {
+                user_save(u);
+                return r;
+        }
+
+        LIST_FOREACH(sessions_by_user, s, u->sessions) {
+                k = session_stop(s, force);
+                if (k < 0)
+                        r = k;
+        }
+
+        /* Kill systemd */
+        k = user_stop_service(u);
+        if (k < 0)
+                r = k;
+
+        /* Kill cgroup */
+        k = user_stop_slice(u);
+        if (k < 0)
+                r = k;
+
+        u->stopping = true;
+
+        user_save(u);
+
+        return r;
+}
+
+int user_finalize(User *u) {
+        Session *s;
+        int r = 0, k;
+
+        assert(u);
+
+        if (u->started)
+                log_debug("User %s logged out.", u->name);
+
+        LIST_FOREACH(sessions_by_user, s, u->sessions) {
+                k = session_finalize(s);
+                if (k < 0)
+                        r = k;
+        }
+
+        /* Kill XDG_RUNTIME_DIR */
+        k = user_remove_runtime_path(u);
+        if (k < 0)
+                r = k;
+
+        /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs
+         * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to
+         * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such
+         * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because
+         * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up,
+         * and do it only for normal users. */
+        if (u->manager->remove_ipc && u->uid > SYSTEM_UID_MAX) {
+                k = clean_ipc_by_uid(u->uid);
+                if (k < 0)
+                        r = k;
+        }
+
+        unlink(u->state_file);
+        user_add_to_gc_queue(u);
+
+        if (u->started) {
+                user_send_signal(u, false);
+                u->started = false;
+        }
+
+        return r;
+}
+
+int user_get_idle_hint(User *u, dual_timestamp *t) {
+        Session *s;
+        bool idle_hint = true;
+        dual_timestamp ts = DUAL_TIMESTAMP_NULL;
+
+        assert(u);
+
+        LIST_FOREACH(sessions_by_user, s, u->sessions) {
+                dual_timestamp k;
+                int ih;
+
+                ih = session_get_idle_hint(s, &k);
+                if (ih < 0)
+                        return ih;
+
+                if (!ih) {
+                        if (!idle_hint) {
+                                if (k.monotonic < ts.monotonic)
+                                        ts = k;
+                        } else {
+                                idle_hint = false;
+                                ts = k;
+                        }
+                } else if (idle_hint) {
+
+                        if (k.monotonic > ts.monotonic)
+                                ts = k;
+                }
+        }
+
+        if (t)
+                *t = ts;
+
+        return idle_hint;
+}
+
+int user_check_linger_file(User *u) {
+        _cleanup_free_ char *cc = NULL;
+        char *p = NULL;
+
+        cc = cescape(u->name);
+        if (!cc)
+                return -ENOMEM;
+
+        p = strjoina("/var/lib/systemd/linger/", cc);
+
+        return access(p, F_OK) >= 0;
+}
+
+bool user_check_gc(User *u, bool drop_not_started) {
+        assert(u);
+
+        if (drop_not_started && !u->started)
+                return false;
+
+        if (u->sessions)
+                return true;
+
+        if (user_check_linger_file(u) > 0)
+                return true;
+
+        if (u->slice_job && manager_job_is_active(u->manager, u->slice_job))
+                return true;
+
+        if (u->service_job && manager_job_is_active(u->manager, u->service_job))
+                return true;
+
+        return false;
+}
+
+void user_add_to_gc_queue(User *u) {
+        assert(u);
+
+        if (u->in_gc_queue)
+                return;
+
+        LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u);
+        u->in_gc_queue = true;
+}
+
+UserState user_get_state(User *u) {
+        Session *i;
+
+        assert(u);
+
+        if (u->stopping)
+                return USER_CLOSING;
+
+        if (!u->started || u->slice_job || u->service_job)
+                return USER_OPENING;
+
+        if (u->sessions) {
+                bool all_closing = true;
+
+                LIST_FOREACH(sessions_by_user, i, u->sessions) {
+                        SessionState state;
+
+                        state = session_get_state(i);
+                        if (state == SESSION_ACTIVE)
+                                return USER_ACTIVE;
+                        if (state != SESSION_CLOSING)
+                                all_closing = false;
+                }
+
+                return all_closing ? USER_CLOSING : USER_ONLINE;
+        }
+
+        if (user_check_linger_file(u) > 0)
+                return USER_LINGERING;
+
+        return USER_CLOSING;
+}
+
+int user_kill(User *u, int signo) {
+        assert(u);
+
+        return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL);
+}
+
+static bool elect_display_filter(Session *s) {
+        /* Return true if the session is a candidate for the user’s ‘primary
+         * session’ or ‘display’. */
+        assert(s);
+
+        return (s->class == SESSION_USER && !s->stopping);
+}
+
+static int elect_display_compare(Session *s1, Session *s2) {
+        /* Indexed by SessionType. Lower numbers mean more preferred. */
+        const int type_ranks[_SESSION_TYPE_MAX] = {
+                [SESSION_UNSPECIFIED] = 0,
+                [SESSION_TTY] = -2,
+                [SESSION_X11] = -3,
+                [SESSION_WAYLAND] = -3,
+                [SESSION_MIR] = -3,
+                [SESSION_WEB] = -1,
+        };
+
+        /* Calculate the partial order relationship between s1 and s2,
+         * returning < 0 if s1 is preferred as the user’s ‘primary session’,
+         * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2
+         * is preferred.
+         *
+         * s1 or s2 may be NULL. */
+        if (!s1 && !s2)
+                return 0;
+
+        if ((s1 == NULL) != (s2 == NULL))
+                return (s1 == NULL) - (s2 == NULL);
+
+        if (s1->stopping != s2->stopping)
+                return s1->stopping - s2->stopping;
+
+        if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER))
+                return (s1->class != SESSION_USER) - (s2->class != SESSION_USER);
+
+        if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID))
+                return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID);
+
+        if (s1->type != s2->type)
+                return type_ranks[s1->type] - type_ranks[s2->type];
+
+        return 0;
+}
+
+void user_elect_display(User *u) {
+        Session *s;
+
+        assert(u);
+
+        /* This elects a primary session for each user, which we call
+         * the "display". We try to keep the assignment stable, but we
+         * "upgrade" to better choices. */
+        log_debug("Electing new display for user %s", u->name);
+
+        LIST_FOREACH(sessions_by_user, s, u->sessions) {
+                if (!elect_display_filter(s)) {
+                        log_debug("Ignoring session %s", s->id);
+                        continue;
+                }
+
+                if (elect_display_compare(s, u->display) < 0) {
+                        log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-");
+                        u->display = s;
+                }
+        }
+}
+
+static const char* const user_state_table[_USER_STATE_MAX] = {
+        [USER_OFFLINE] = "offline",
+        [USER_OPENING] = "opening",
+        [USER_LINGERING] = "lingering",
+        [USER_ONLINE] = "online",
+        [USER_ACTIVE] = "active",
+        [USER_CLOSING] = "closing"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(user_state, UserState);
+
+int config_parse_tmpfs_size(
+                const char* unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        size_t *sz = data;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        /* First, try to parse as percentage */
+        r = parse_percent(rvalue);
+        if (r > 0 && r < 100)
+                *sz = physical_memory_scale(r, 100U);
+        else {
+                uint64_t k;
+
+                /* If the passed argument was not a percentage, or out of range, parse as byte size */
+
+                r = parse_size(rvalue, 1024, &k);
+                if (r < 0 || k <= 0 || (uint64_t) (size_t) k != k) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue);
+                        return 0;
+                }
+
+                *sz = PAGE_ALIGN((size_t) k);
+        }
+
+        return 0;
+}
+
+int config_parse_user_tasks_max(
+                const char* unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        uint64_t *m = data;
+        uint64_t k;
+        int r;
+
+        assert(filename);
+        assert(lvalue);
+        assert(rvalue);
+        assert(data);
+
+        if (isempty(rvalue)) {
+                *m = system_tasks_max_scale(DEFAULT_USER_TASKS_MAX_PERCENTAGE, 100U);
+                return 0;
+        }
+
+        if (streq(rvalue, "infinity")) {
+                *m = CGROUP_LIMIT_MAX;
+                return 0;
+        }
+
+        /* Try to parse as percentage */
+        r = parse_percent(rvalue);
+        if (r >= 0)
+                k = system_tasks_max_scale(r, 100U);
+        else {
+
+                /* If the passed argument was not a percentage, or out of range, parse as byte size */
+
+                r = safe_atou64(rvalue, &k);
+                if (r < 0) {
+                        log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse tasks maximum, ignoring: %s", rvalue);
+                        return 0;
+                }
+        }
+
+        if (k <= 0 || k >= UINT64_MAX) {
+                log_syntax(unit, LOG_ERR, filename, line, 0, "Tasks maximum out of range, ignoring: %s", rvalue);
+                return 0;
+        }
+
+        *m = k;
+        return 0;
+}