13380515387

Committed 17 Feb 2025 09:20PM UTC coverage: 71.822% (+0.1%) from 71.714%

Build # 13380515387

Build Type

push

github

Committed by

DaanDeMeyer

Commit Message

ukify: print all remaining log-like output to stderr

We want to be able to capture stdout for json and such, so convert
all remaining logging to stderr.

Coverage Stats

293883 of 409184 relevant lines covered (71.82%)

716959.33 hits per line

Source File
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77.12

/src/core/manager.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <errno.h>
#include <fcntl.h>
#include <linux/kd.h>
#include <sys/epoll.h>
#include <sys/inotify.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/reboot.h>
#include <sys/timerfd.h>
#include <sys/wait.h>
#include <unistd.h>

#if HAVE_AUDIT
#include <libaudit.h>
#endif

#include "sd-daemon.h"
#include "sd-messages.h"
#include "sd-path.h"

#include "all-units.h"
#include "alloc-util.h"
#include "audit-fd.h"
#include "boot-timestamps.h"
#include "build-path.h"
#include "bus-common-errors.h"
#include "bus-error.h"
#include "bus-kernel.h"
#include "bus-util.h"
#include "clean-ipc.h"
#include "clock-util.h"
#include "common-signal.h"
#include "confidential-virt.h"
#include "constants.h"
#include "core-varlink.h"
#include "creds-util.h"
#include "daemon-util.h"
#include "dbus-job.h"
#include "dbus-manager.h"
#include "dbus-unit.h"
#include "dbus.h"
#include "dirent-util.h"
#include "env-util.h"
#include "escape.h"
#include "event-util.h"
#include "exec-util.h"
#include "execute.h"
#include "exit-status.h"
#include "fd-util.h"
#include "fileio.h"
#include "generator-setup.h"
#include "hashmap.h"
#include "initrd-util.h"
#include "inotify-util.h"
#include "install.h"
#include "io-util.h"
#include "iovec-util.h"
#include "label-util.h"
#include "load-fragment.h"
#include "locale-setup.h"
#include "log.h"
#include "macro.h"
#include "manager.h"
#include "manager-dump.h"
#include "manager-serialize.h"
#include "memory-util.h"
#include "mkdir-label.h"
#include "mount-util.h"
#include "os-util.h"
#include "parse-util.h"
#include "path-lookup.h"
#include "path-util.h"
#include "plymouth-util.h"
#include "pretty-print.h"
#include "process-util.h"
#include "psi-util.h"
#include "ratelimit.h"
#include "rlimit-util.h"
#include "rm-rf.h"
#include "selinux-util.h"
#include "serialize.h"
#include "signal-util.h"
#include "socket-util.h"
#include "special.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "strxcpyx.h"
#include "sysctl-util.h"
#include "syslog-util.h"
#include "taint.h"
#include "terminal-util.h"
#include "time-util.h"
#include "transaction.h"
#include "uid-range.h"
#include "umask-util.h"
#include "unit-name.h"
#include "user-util.h"
#include "virt.h"
#include "watchdog.h"

/* Make sure clients notifying us don't block */
#define MANAGER_SOCKET_RCVBUF_SIZE (8*U64_MB)

/* Initial delay and the interval for printing status messages about running jobs */
#define JOBS_IN_PROGRESS_WAIT_USEC (2*USEC_PER_SEC)
#define JOBS_IN_PROGRESS_QUIET_WAIT_USEC (25*USEC_PER_SEC)
#define JOBS_IN_PROGRESS_PERIOD_USEC (USEC_PER_SEC / 3)
#define JOBS_IN_PROGRESS_PERIOD_DIVISOR 3

/* If there are more than 1K bus messages queue across our API and direct buses, then let's not add more on top until
 * the queue gets more empty. */
#define MANAGER_BUS_BUSY_THRESHOLD 1024LU

/* How many units and jobs to process of the bus queue before returning to the event loop. */
#define MANAGER_BUS_MESSAGE_BUDGET 100U

#define DEFAULT_TASKS_MAX ((CGroupTasksMax) { 15U, 100U }) /* 15% */

static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_time_change_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_idle_pipe_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_user_lookup_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_handoff_timestamp_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_pidref_transport_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata);
static int manager_dispatch_jobs_in_progress(sd_event_source *source, usec_t usec, void *userdata);
static int manager_dispatch_run_queue(sd_event_source *source, void *userdata);
static int manager_dispatch_sigchld(sd_event_source *source, void *userdata);
static int manager_dispatch_timezone_change(sd_event_source *source, const struct inotify_event *event, void *userdata);
static int manager_run_environment_generators(Manager *m);
static int manager_run_generators(Manager *m);
static void manager_vacuum(Manager *m);

static usec_t manager_watch_jobs_next_time(Manager *m) {
        usec_t timeout;

        if (MANAGER_IS_USER(m))
                /* Let the user manager without a timeout show status quickly, so the system manager can make
                 * use of it, if it wants to. */
                timeout = JOBS_IN_PROGRESS_WAIT_USEC * 2 / 3;
        else if (show_status_on(m->show_status))
                /* When status is on, just use the usual timeout. */
                timeout = JOBS_IN_PROGRESS_WAIT_USEC;
        else
                timeout = JOBS_IN_PROGRESS_QUIET_WAIT_USEC;

        return usec_add(now(CLOCK_MONOTONIC), timeout);
}

static bool manager_is_confirm_spawn_disabled(Manager *m) {
        assert(m);

        if (!m->confirm_spawn)
                return true;

        return access("/run/systemd/confirm_spawn_disabled", F_OK) >= 0;
}

static void manager_watch_jobs_in_progress(Manager *m) {
        usec_t next;
        int r;

        assert(m);

        /* We do not want to show the cylon animation if the user
         * needs to confirm service executions otherwise confirmation
         * messages will be screwed by the cylon animation. */
        if (!manager_is_confirm_spawn_disabled(m))
                return;

        if (m->jobs_in_progress_event_source)
                return;

        next = manager_watch_jobs_next_time(m);
        r = sd_event_add_time(
                        m->event,
                        &m->jobs_in_progress_event_source,
                        CLOCK_MONOTONIC,
                        next, 0,
                        manager_dispatch_jobs_in_progress, m);
        if (r < 0)
                return;

        (void) sd_event_source_set_description(m->jobs_in_progress_event_source, "manager-jobs-in-progress");
}

static void manager_flip_auto_status(Manager *m, bool enable, const char *reason) {
        assert(m);

        if (enable) {
                if (m->show_status == SHOW_STATUS_AUTO)
                        manager_set_show_status(m, SHOW_STATUS_TEMPORARY, reason);
        } else {
                if (m->show_status == SHOW_STATUS_TEMPORARY)
                        manager_set_show_status(m, SHOW_STATUS_AUTO, reason);
        }
}

static void manager_print_jobs_in_progress(Manager *m) {
        Job *j;
        unsigned counter = 0, print_nr;
        char cylon[6 + CYLON_BUFFER_EXTRA + 1];
        unsigned cylon_pos;
        uint64_t timeout = 0;

        assert(m);
        assert(m->n_running_jobs > 0);

        manager_flip_auto_status(m, true, "delay");

        print_nr = (m->jobs_in_progress_iteration / JOBS_IN_PROGRESS_PERIOD_DIVISOR) % m->n_running_jobs;

        HASHMAP_FOREACH(j, m->jobs)
                if (j->state == JOB_RUNNING && counter++ == print_nr)
                        break;

        /* m->n_running_jobs must be consistent with the contents of m->jobs,
         * so the above loop must have succeeded in finding j. */
        assert(counter == print_nr + 1);
        assert(j);

        cylon_pos = m->jobs_in_progress_iteration % 14;
        if (cylon_pos >= 8)
                cylon_pos = 14 - cylon_pos;
        draw_cylon(cylon, sizeof(cylon), 6, cylon_pos);

        m->jobs_in_progress_iteration++;

        char job_of_n[STRLEN("( of ) ") + DECIMAL_STR_MAX(unsigned)*2] = "";
        if (m->n_running_jobs > 1)
                xsprintf(job_of_n, "(%u of %u) ", counter, m->n_running_jobs);

        (void) job_get_timeout(j, &timeout);

        /* We want to use enough information for the user to identify previous lines talking about the same
         * unit, but keep the message as short as possible. So if 'Starting foo.service' or 'Starting
         * foo.service - Description' were used, 'foo.service' is enough here. On the other hand, if we used
         * 'Starting Description' before, then we shall also use 'Description' here. So we pass NULL as the
         * second argument to unit_status_string(). */
        const char *ident = unit_status_string(j->unit, NULL);

        const char *time = FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - j->begin_usec, 1*USEC_PER_SEC);
        const char *limit = timeout > 0 ? FORMAT_TIMESPAN(timeout - j->begin_usec, 1*USEC_PER_SEC) : "no limit";

        if (m->status_unit_format == STATUS_UNIT_FORMAT_DESCRIPTION)
                /* When using 'Description', we effectively don't have enough space to show the nested status
                 * without ellipsization, so let's not even try. */
                manager_status_printf(m, STATUS_TYPE_EPHEMERAL, cylon,
                                      "%sA %s job is running for %s (%s / %s)",
                                      job_of_n,
                                      job_type_to_string(j->type),
                                      ident,
                                      time, limit);
        else {
                const char *status_text = unit_status_text(j->unit);

                manager_status_printf(m, STATUS_TYPE_EPHEMERAL, cylon,
                                      "%sJob %s/%s running (%s / %s)%s%s",
                                      job_of_n,
                                      ident,
                                      job_type_to_string(j->type),
                                      time, limit,
                                      status_text ? ": " : "",
                                      strempty(status_text));
        }

        (void) sd_notifyf(/* unset_environment= */ false,
                          "STATUS=%sUser job %s/%s running (%s / %s)...",
                          job_of_n,
                          ident, job_type_to_string(j->type),
                          time, limit);
        m->status_ready = false;
}

static int have_ask_password(void) {
        _cleanup_closedir_ DIR *dir = NULL;

        dir = opendir("/run/systemd/ask-password");
        if (!dir) {
                if (errno == ENOENT)
                        return false;

                return -errno;
        }

        FOREACH_DIRENT_ALL(de, dir, return -errno) {
                if (!IN_SET(de->d_type, DT_REG, DT_UNKNOWN))
                        continue;

                if (startswith(de->d_name, "ask."))
                        return true;
        }

        return false;
}

static int manager_dispatch_ask_password_fd(sd_event_source *source,
                                            int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);

        (void) flush_fd(fd);

        m->have_ask_password = have_ask_password();
        if (m->have_ask_password < 0)
                /* Log error but continue. Negative have_ask_password is treated as unknown status. */
                log_warning_errno(m->have_ask_password, "Failed to list /run/systemd/ask-password/, ignoring: %m");

        return 0;
}

static void manager_close_ask_password(Manager *m) {
        assert(m);

        m->ask_password_event_source = sd_event_source_disable_unref(m->ask_password_event_source);
        m->have_ask_password = -EINVAL;
}

static int manager_check_ask_password(Manager *m) {
        int r;

        assert(m);

        /* We only care about passwords prompts when running in system mode (because that's the only time we
         * manage a console) */
        if (!MANAGER_IS_SYSTEM(m))
                return 0;

        if (!m->ask_password_event_source) {
                _cleanup_close_ int inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
                if (inotify_fd < 0)
                        return log_error_errno(errno, "Failed to create inotify object: %m");

                (void) mkdir_p_label("/run/systemd/ask-password", 0755);
                r = inotify_add_watch_and_warn(inotify_fd, "/run/systemd/ask-password", IN_CLOSE_WRITE|IN_DELETE|IN_MOVED_TO|IN_ONLYDIR);
                if (r < 0)
                        return r;

                _cleanup_(sd_event_source_disable_unrefp) sd_event_source *event_source = NULL;
                r = sd_event_add_io(
                                m->event,
                                &event_source,
                                inotify_fd,
                                EPOLLIN,
                                manager_dispatch_ask_password_fd,
                                m);
                if (r < 0)
                        return log_error_errno(r, "Failed to add event source for /run/systemd/ask-password/: %m");

                r = sd_event_source_set_io_fd_own(event_source, true);
                if (r < 0)
                        return log_error_errno(r, "Failed to pass ownership of /run/systemd/ask-password/ inotify fd to event source: %m");
                TAKE_FD(inotify_fd);

                (void) sd_event_source_set_description(event_source, "manager-ask-password");

                m->ask_password_event_source = TAKE_PTR(event_source);

                /* Queries might have been added meanwhile... */
                (void) manager_dispatch_ask_password_fd(m->ask_password_event_source, sd_event_source_get_io_fd(m->ask_password_event_source), EPOLLIN, m);
        }

        return m->have_ask_password;
}

static int manager_watch_idle_pipe(Manager *m) {
        int r;

        assert(m);

        if (m->idle_pipe_event_source)
                return 0;

        if (m->idle_pipe[2] < 0)
                return 0;

        r = sd_event_add_io(m->event, &m->idle_pipe_event_source, m->idle_pipe[2], EPOLLIN, manager_dispatch_idle_pipe_fd, m);
        if (r < 0)
                return log_error_errno(r, "Failed to watch idle pipe: %m");

        (void) sd_event_source_set_description(m->idle_pipe_event_source, "manager-idle-pipe");

        return 0;
}

static void manager_close_idle_pipe(Manager *m) {
        assert(m);

        m->idle_pipe_event_source = sd_event_source_disable_unref(m->idle_pipe_event_source);

        safe_close_pair(m->idle_pipe);
        safe_close_pair(m->idle_pipe + 2);
}

static int manager_setup_time_change(Manager *m) {
        int r;

        assert(m);

        if (MANAGER_IS_TEST_RUN(m))
                return 0;

        m->time_change_event_source = sd_event_source_disable_unref(m->time_change_event_source);

        r = event_add_time_change(m->event, &m->time_change_event_source, manager_dispatch_time_change_fd, m);
        if (r < 0)
                return log_error_errno(r, "Failed to create time change event source: %m");

        /* Schedule this slightly earlier than the .timer event sources */
        r = sd_event_source_set_priority(m->time_change_event_source, EVENT_PRIORITY_TIME_CHANGE);
        if (r < 0)
                return log_error_errno(r, "Failed to set priority of time change event sources: %m");

        log_debug("Set up TFD_TIMER_CANCEL_ON_SET timerfd.");

        return 0;
}

static int manager_read_timezone_stat(Manager *m) {
        struct stat st;
        bool changed;

        assert(m);

        /* Read the current stat() data of /etc/localtime so that we detect changes */
        if (lstat("/etc/localtime", &st) < 0) {
                log_debug_errno(errno, "Failed to stat /etc/localtime, ignoring: %m");
                changed = m->etc_localtime_accessible;
                m->etc_localtime_accessible = false;
        } else {
                usec_t k;

                k = timespec_load(&st.st_mtim);
                changed = !m->etc_localtime_accessible || k != m->etc_localtime_mtime;

                m->etc_localtime_mtime = k;
                m->etc_localtime_accessible = true;
        }

        return changed;
}

static int manager_setup_timezone_change(Manager *m) {
        _cleanup_(sd_event_source_unrefp) sd_event_source *new_event = NULL;
        int r;

        assert(m);

        if (MANAGER_IS_TEST_RUN(m))
                return 0;

        /* We watch /etc/localtime for three events: change of the link count (which might mean removal from /etc even
         * though another link might be kept), renames, and file close operations after writing. Note we don't bother
         * with IN_DELETE_SELF, as that would just report when the inode is removed entirely, i.e. after the link count
         * went to zero and all fds to it are closed.
         *
         * Note that we never follow symlinks here. This is a simplification, but should cover almost all cases
         * correctly.
         *
         * Note that we create the new event source first here, before releasing the old one. This should optimize
         * behaviour as this way sd-event can reuse the old watch in case the inode didn't change. */

        r = sd_event_add_inotify(m->event, &new_event, "/etc/localtime",
                                 IN_ATTRIB|IN_MOVE_SELF|IN_CLOSE_WRITE|IN_DONT_FOLLOW, manager_dispatch_timezone_change, m);
        if (r == -ENOENT) {
                /* If the file doesn't exist yet, subscribe to /etc instead, and wait until it is created either by
                 * O_CREATE or by rename() */

                log_debug_errno(r, "/etc/localtime doesn't exist yet, watching /etc instead.");
                r = sd_event_add_inotify(m->event, &new_event, "/etc",
                                         IN_CREATE|IN_MOVED_TO|IN_ONLYDIR, manager_dispatch_timezone_change, m);
        }
        if (r < 0)
                return log_error_errno(r, "Failed to create timezone change event source: %m");

        /* Schedule this slightly earlier than the .timer event sources */
        r = sd_event_source_set_priority(new_event, EVENT_PRIORITY_TIME_ZONE);
        if (r < 0)
                return log_error_errno(r, "Failed to set priority of timezone change event sources: %m");

        sd_event_source_unref(m->timezone_change_event_source);
        m->timezone_change_event_source = TAKE_PTR(new_event);

        return 0;
}

static int manager_enable_special_signals(Manager *m) {
        _cleanup_close_ int fd = -EBADF;

        assert(m);

        if (!MANAGER_IS_SYSTEM(m) || MANAGER_IS_TEST_RUN(m))
                return 0;

        /* Enable that we get SIGINT on control-alt-del. In containers this will fail with EPERM (older) or
         * EINVAL (newer), so ignore that. */
        if (reboot(RB_DISABLE_CAD) < 0 && !IN_SET(errno, EPERM, EINVAL))
                log_warning_errno(errno, "Failed to enable ctrl-alt-del handling, ignoring: %m");

        fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY|O_CLOEXEC);
        if (fd < 0)
                /* Support systems without virtual console (ENOENT) gracefully */
                log_full_errno(fd == -ENOENT ? LOG_DEBUG : LOG_WARNING, fd, "Failed to open /dev/tty0, ignoring: %m");
        else {
                /* Enable that we get SIGWINCH on kbrequest */
                if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
                        log_warning_errno(errno, "Failed to enable kbrequest handling, ignoring: %m");
        }

        return 0;
}

#define RTSIG_IF_AVAILABLE(signum) (signum <= SIGRTMAX ? signum : -1)

static int manager_setup_signals(Manager *m) {
        static const struct sigaction sa = {
                .sa_handler = SIG_DFL,
                .sa_flags = SA_NOCLDSTOP|SA_RESTART,
        };
        sigset_t mask;
        int r;

        assert(m);

        assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);

        /* We make liberal use of realtime signals here. On
         * Linux/glibc we have 30 of them (with the exception of Linux
         * on hppa, see below), between SIGRTMIN+0 ... SIGRTMIN+30
         * (aka SIGRTMAX). */

        assert_se(sigemptyset(&mask) == 0);
        sigset_add_many(&mask,
                        SIGCHLD,     /* Child died */
                        SIGTERM,     /* Reexecute daemon */
                        SIGHUP,      /* Reload configuration */
                        SIGUSR1,     /* systemd: reconnect to D-Bus */
                        SIGUSR2,     /* systemd: dump status */
                        SIGINT,      /* Kernel sends us this on control-alt-del */
                        SIGWINCH,    /* Kernel sends us this on kbrequest (alt-arrowup) */
                        SIGPWR,      /* Some kernel drivers and upsd send us this on power failure */

                        SIGRTMIN+0,  /* systemd: start default.target */
                        SIGRTMIN+1,  /* systemd: isolate rescue.target */
                        SIGRTMIN+2,  /* systemd: isolate emergency.target */
                        SIGRTMIN+3,  /* systemd: start halt.target */
                        SIGRTMIN+4,  /* systemd: start poweroff.target */
                        SIGRTMIN+5,  /* systemd: start reboot.target */
                        SIGRTMIN+6,  /* systemd: start kexec.target */
                        SIGRTMIN+7,  /* systemd: start soft-reboot.target */

                        /* ... space for more special targets ... */

                        SIGRTMIN+13, /* systemd: Immediate halt */
                        SIGRTMIN+14, /* systemd: Immediate poweroff */
                        SIGRTMIN+15, /* systemd: Immediate reboot */
                        SIGRTMIN+16, /* systemd: Immediate kexec */
                        SIGRTMIN+17, /* systemd: Immediate soft-reboot */
                        SIGRTMIN+18, /* systemd: control command */

                        /* ... space ... */

                        SIGRTMIN+20, /* systemd: enable status messages */
                        SIGRTMIN+21, /* systemd: disable status messages */
                        SIGRTMIN+22, /* systemd: set log level to LOG_DEBUG */
                        SIGRTMIN+23, /* systemd: set log level to LOG_INFO */
                        SIGRTMIN+24, /* systemd: Immediate exit (--user only) */
                        SIGRTMIN+25, /* systemd: reexecute manager */

                        /* Apparently Linux on hppa had fewer RT signals until v3.18,
                         * SIGRTMAX was SIGRTMIN+25, and then SIGRTMIN was lowered,
                         * see commit v3.17-7614-g1f25df2eff.
                         *
                         * We cannot unconditionally make use of those signals here,
                         * so let's use a runtime check. Since these commands are
                         * accessible by different means and only really a safety
                         * net, the missing functionality on hppa shouldn't matter.
                         */

                        RTSIG_IF_AVAILABLE(SIGRTMIN+26), /* systemd: set log target to journal-or-kmsg */
                        RTSIG_IF_AVAILABLE(SIGRTMIN+27), /* systemd: set log target to console */
                        RTSIG_IF_AVAILABLE(SIGRTMIN+28), /* systemd: set log target to kmsg */
                        RTSIG_IF_AVAILABLE(SIGRTMIN+29), /* systemd: set log target to syslog-or-kmsg (obsolete) */

                        /* ... one free signal here SIGRTMIN+30 ... */
                        -1);
        assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);

        m->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
        if (m->signal_fd < 0)
                return -errno;

        r = sd_event_add_io(m->event, &m->signal_event_source, m->signal_fd, EPOLLIN, manager_dispatch_signal_fd, m);
        if (r < 0)
                return r;

        (void) sd_event_source_set_description(m->signal_event_source, "manager-signal");

        /* Process signals a bit earlier than the rest of things, but later than notify_fd processing, so that the
         * notify processing can still figure out to which process/service a message belongs, before we reap the
         * process. Also, process this before handling cgroup notifications, so that we always collect child exit
         * status information before detecting that there's no process in a cgroup. */
        r = sd_event_source_set_priority(m->signal_event_source, EVENT_PRIORITY_SIGNALS);
        if (r < 0)
                return r;

        /* Report to supervisor that we now process the above signals. We report this as level "2", to
         * indicate that we support more than sysvinit's signals (of course, sysvinit never sent this
         * message, but conceptually it makes sense to consider level "1" to be equivalent to sysvinit's
         * signal handling). Also, by setting this to "2" people looking for this hopefully won't
         * misunderstand this as a boolean concept. Signal level 2 shall refer to the signals PID 1
         * understands at the time of release of systemd v256, i.e. including basic SIGRTMIN+18 handling for
         * memory pressure and stuff. When more signals are hooked up (or more SIGRTMIN+18 multiplex
         * operations added, this level should be increased). */
        (void) sd_notify(/* unset_environment= */ false,
                         "X_SYSTEMD_SIGNALS_LEVEL=2");

        return manager_enable_special_signals(m);
}

static char** sanitize_environment(char **l) {

        /* Let's remove some environment variables that we need ourselves to communicate with our clients */
        strv_env_unset_many(
                        l,
                        "CACHE_DIRECTORY",
                        "CONFIGURATION_DIRECTORY",
                        "CREDENTIALS_DIRECTORY",
                        "EXIT_CODE",
                        "EXIT_STATUS",
                        "INVOCATION_ID",
                        "JOURNAL_STREAM",
                        "LISTEN_FDNAMES",
                        "LISTEN_FDS",
                        "LISTEN_PID",
                        "LOGS_DIRECTORY",
                        "LOG_NAMESPACE",
                        "MAINPID",
                        "MANAGERPID",
                        "MEMORY_PRESSURE_WATCH",
                        "MEMORY_PRESSURE_WRITE",
                        "MONITOR_EXIT_CODE",
                        "MONITOR_EXIT_STATUS",
                        "MONITOR_INVOCATION_ID",
                        "MONITOR_SERVICE_RESULT",
                        "MONITOR_UNIT",
                        "NOTIFY_SOCKET",
                        "PIDFILE",
                        "REMOTE_ADDR",
                        "REMOTE_PORT",
                        "RUNTIME_DIRECTORY",
                        "SERVICE_RESULT",
                        "STATE_DIRECTORY",
                        "SYSTEMD_EXEC_PID",
                        "TRIGGER_PATH",
                        "TRIGGER_TIMER_MONOTONIC_USEC",
                        "TRIGGER_TIMER_REALTIME_USEC",
                        "TRIGGER_UNIT",
                        "WATCHDOG_PID",
                        "WATCHDOG_USEC");

        /* Let's order the environment alphabetically, just to make it pretty */
        return strv_sort(l);
}

int manager_default_environment(Manager *m) {
        assert(m);

        m->transient_environment = strv_free(m->transient_environment);

        if (MANAGER_IS_SYSTEM(m)) {
                /* The system manager always starts with a clean environment for its children. It does not
                 * import the kernel's or the parents' exported variables.
                 *
                 * The initial passed environment is untouched to keep /proc/self/environ valid; it is used
                 * for tagging the init process inside containers. */
                char *path = strjoin("PATH=", default_PATH());
                if (!path)
                        return log_oom();

                if (strv_consume(&m->transient_environment, path) < 0)
                        return log_oom();

                /* Import locale variables LC_*= from configuration */
                (void) locale_setup(&m->transient_environment);
        } else {
                /* The user manager passes its own environment along to its children, except for $PATH and
                 * session envs. */

                m->transient_environment = strv_copy(environ);
                if (!m->transient_environment)
                        return log_oom();

                char *path = strjoin("PATH=", default_user_PATH());
                if (!path)
                        return log_oom();

                if (strv_env_replace_consume(&m->transient_environment, path) < 0)
                        return log_oom();

                /* Envvars set for our 'manager' class session are private and should not be propagated
                 * to children. Also it's likely that the graphical session will set these on their own. */
                strv_env_unset_many(m->transient_environment,
                                    "XDG_SESSION_ID",
                                    "XDG_SESSION_CLASS",
                                    "XDG_SESSION_TYPE",
                                    "XDG_SESSION_DESKTOP",
                                    "XDG_SEAT",
                                    "XDG_VTNR");
        }

        sanitize_environment(m->transient_environment);
        return 0;
}

static int manager_setup_prefix(Manager *m) {
        struct table_entry {
                uint64_t type;
                const char *suffix;
        };

        static const struct table_entry paths_system[_EXEC_DIRECTORY_TYPE_MAX] = {
                [EXEC_DIRECTORY_RUNTIME]       = { SD_PATH_SYSTEM_RUNTIME,       NULL },
                [EXEC_DIRECTORY_STATE]         = { SD_PATH_SYSTEM_STATE_PRIVATE, NULL },
                [EXEC_DIRECTORY_CACHE]         = { SD_PATH_SYSTEM_STATE_CACHE,   NULL },
                [EXEC_DIRECTORY_LOGS]          = { SD_PATH_SYSTEM_STATE_LOGS,    NULL },
                [EXEC_DIRECTORY_CONFIGURATION] = { SD_PATH_SYSTEM_CONFIGURATION, NULL },
        };

        static const struct table_entry paths_user[_EXEC_DIRECTORY_TYPE_MAX] = {
                [EXEC_DIRECTORY_RUNTIME]       = { SD_PATH_USER_RUNTIME,       NULL  },
                [EXEC_DIRECTORY_STATE]         = { SD_PATH_USER_STATE_PRIVATE, NULL  },
                [EXEC_DIRECTORY_CACHE]         = { SD_PATH_USER_STATE_CACHE,   NULL  },
                [EXEC_DIRECTORY_LOGS]          = { SD_PATH_USER_STATE_PRIVATE, "log" },
                [EXEC_DIRECTORY_CONFIGURATION] = { SD_PATH_USER_CONFIGURATION, NULL  },
        };

        assert(m);

        const struct table_entry *p = MANAGER_IS_SYSTEM(m) ? paths_system : paths_user;
        int r;

        for (ExecDirectoryType i = 0; i < _EXEC_DIRECTORY_TYPE_MAX; i++) {
                r = sd_path_lookup(p[i].type, p[i].suffix, &m->prefix[i]);
                if (r < 0)
                        return log_warning_errno(r, "Failed to lookup %s path: %m",
                                                 exec_directory_type_to_string(i));
        }

        return 0;
}

static void manager_free_unit_name_maps(Manager *m) {
        m->unit_id_map = hashmap_free(m->unit_id_map);
        m->unit_name_map = hashmap_free(m->unit_name_map);
        m->unit_path_cache = set_free(m->unit_path_cache);
        m->unit_cache_timestamp_hash = 0;
}

static int manager_setup_run_queue(Manager *m) {
        int r;

        assert(m);
        assert(!m->run_queue_event_source);

        r = sd_event_add_defer(m->event, &m->run_queue_event_source, manager_dispatch_run_queue, m);
        if (r < 0)
                return r;

        r = sd_event_source_set_priority(m->run_queue_event_source, EVENT_PRIORITY_RUN_QUEUE);
        if (r < 0)
                return r;

        r = sd_event_source_set_enabled(m->run_queue_event_source, SD_EVENT_OFF);
        if (r < 0)
                return r;

        (void) sd_event_source_set_description(m->run_queue_event_source, "manager-run-queue");

        return 0;
}

static int manager_setup_sigchld_event_source(Manager *m) {
        int r;

        assert(m);
        assert(!m->sigchld_event_source);

        r = sd_event_add_defer(m->event, &m->sigchld_event_source, manager_dispatch_sigchld, m);
        if (r < 0)
                return r;

        r = sd_event_source_set_priority(m->sigchld_event_source, EVENT_PRIORITY_SIGCHLD);
        if (r < 0)
                return r;

        r = sd_event_source_set_enabled(m->sigchld_event_source, SD_EVENT_OFF);
        if (r < 0)
                return r;

        (void) sd_event_source_set_description(m->sigchld_event_source, "manager-sigchld");

        return 0;
}

int manager_setup_memory_pressure_event_source(Manager *m) {
        int r;

        assert(m);

        m->memory_pressure_event_source = sd_event_source_disable_unref(m->memory_pressure_event_source);

        r = sd_event_add_memory_pressure(m->event, &m->memory_pressure_event_source, NULL, NULL);
        if (r < 0)
                log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) || ERRNO_IS_PRIVILEGE(r) || (r == -EHOSTDOWN) ? LOG_DEBUG : LOG_NOTICE, r,
                               "Failed to establish memory pressure event source, ignoring: %m");
        else if (m->defaults.memory_pressure_threshold_usec != USEC_INFINITY) {

                /* If there's a default memory pressure threshold set, also apply it to the service manager itself */
                r = sd_event_source_set_memory_pressure_period(
                                m->memory_pressure_event_source,
                                m->defaults.memory_pressure_threshold_usec,
                                MEMORY_PRESSURE_DEFAULT_WINDOW_USEC);
                if (r < 0)
                        log_warning_errno(r, "Failed to adjust memory pressure threshold, ignoring: %m");
        }

        return 0;
}

static int manager_find_credentials_dirs(Manager *m) {
        const char *e;
        int r;

        assert(m);

        r = get_credentials_dir(&e);
        if (r < 0) {
                if (r != -ENXIO)
                        log_debug_errno(r, "Failed to determine credentials directory, ignoring: %m");
        } else {
                m->received_credentials_directory = strdup(e);
                if (!m->received_credentials_directory)
                        return -ENOMEM;
        }

        r = get_encrypted_credentials_dir(&e);
        if (r < 0) {
                if (r != -ENXIO)
                        log_debug_errno(r, "Failed to determine encrypted credentials directory, ignoring: %m");
        } else {
                m->received_encrypted_credentials_directory = strdup(e);
                if (!m->received_encrypted_credentials_directory)
                        return -ENOMEM;
        }

        return 0;
}

void manager_set_switching_root(Manager *m, bool switching_root) {
        assert(m);

        m->switching_root = MANAGER_IS_SYSTEM(m) && switching_root;
}

double manager_get_progress(Manager *m) {
        assert(m);

        if (MANAGER_IS_FINISHED(m) || m->n_installed_jobs == 0)
                return 1.0;

        return 1.0 - ((double) hashmap_size(m->jobs) / (double) m->n_installed_jobs);
}

static int compare_job_priority(const void *a, const void *b) {
        const Job *x = a, *y = b;

        return unit_compare_priority(x->unit, y->unit);
}

int manager_new(RuntimeScope runtime_scope, ManagerTestRunFlags test_run_flags, Manager **ret) {
        _cleanup_(manager_freep) Manager *m = NULL;
        int r;

        assert(IN_SET(runtime_scope, RUNTIME_SCOPE_SYSTEM, RUNTIME_SCOPE_USER));
        assert(ret);

        m = new(Manager, 1);
        if (!m)
                return -ENOMEM;

        *m = (Manager) {
                .runtime_scope = runtime_scope,
                .objective = _MANAGER_OBJECTIVE_INVALID,
                .previous_objective = _MANAGER_OBJECTIVE_INVALID,

                .status_unit_format = STATUS_UNIT_FORMAT_DEFAULT,

                .original_log_level = -1,
                .original_log_target = _LOG_TARGET_INVALID,

                .watchdog_overridden[WATCHDOG_RUNTIME] = USEC_INFINITY,
                .watchdog_overridden[WATCHDOG_REBOOT] = USEC_INFINITY,
                .watchdog_overridden[WATCHDOG_KEXEC] = USEC_INFINITY,
                .watchdog_overridden[WATCHDOG_PRETIMEOUT] = USEC_INFINITY,

                .show_status_overridden = _SHOW_STATUS_INVALID,

                .notify_fd = -EBADF,
                .cgroups_agent_fd = -EBADF,
                .signal_fd = -EBADF,
                .user_lookup_fds = EBADF_PAIR,
                .handoff_timestamp_fds = EBADF_PAIR,
                .pidref_transport_fds = EBADF_PAIR,
                .private_listen_fd = -EBADF,
                .dev_autofs_fd = -EBADF,
                .cgroup_inotify_fd = -EBADF,
                .pin_cgroupfs_fd = -EBADF,
                .idle_pipe = { -EBADF, -EBADF, -EBADF, -EBADF},

                 /* start as id #1, so that we can leave #0 around as "null-like" value */
                .current_job_id = 1,

                .have_ask_password = -EINVAL, /* we don't know */
                .first_boot = -1,
                .test_run_flags = test_run_flags,

                .dump_ratelimit = (const RateLimit) { .interval = 10 * USEC_PER_MINUTE, .burst = 10 },

                .executor_fd = -EBADF,
        };

        unit_defaults_init(&m->defaults, runtime_scope);

#if ENABLE_EFI
        if (MANAGER_IS_SYSTEM(m) && detect_container() <= 0)
                boot_timestamps(m->timestamps + MANAGER_TIMESTAMP_USERSPACE,
                                m->timestamps + MANAGER_TIMESTAMP_FIRMWARE,
                                m->timestamps + MANAGER_TIMESTAMP_LOADER);
#endif

        /* Prepare log fields we can use for structured logging */
        if (MANAGER_IS_SYSTEM(m)) {
                m->unit_log_field = "UNIT=";
                m->unit_log_format_string = "UNIT=%s";

                m->invocation_log_field = "INVOCATION_ID=";
                m->invocation_log_format_string = "INVOCATION_ID=%s";
        } else {
                m->unit_log_field = "USER_UNIT=";
                m->unit_log_format_string = "USER_UNIT=%s";

                m->invocation_log_field = "USER_INVOCATION_ID=";
                m->invocation_log_format_string = "USER_INVOCATION_ID=%s";
        }

        /* Reboot immediately if the user hits C-A-D more often than 7x per 2s */
        m->ctrl_alt_del_ratelimit = (const RateLimit) { .interval = 2 * USEC_PER_SEC, .burst = 7 };

        r = manager_default_environment(m);
        if (r < 0)
                return r;

        r = hashmap_ensure_allocated(&m->units, &string_hash_ops);
        if (r < 0)
                return r;

        r = hashmap_ensure_allocated(&m->cgroup_unit, &path_hash_ops);
        if (r < 0)
                return r;

        r = hashmap_ensure_allocated(&m->watch_bus, &string_hash_ops);
        if (r < 0)
                return r;

        r = prioq_ensure_allocated(&m->run_queue, compare_job_priority);
        if (r < 0)
                return r;

        r = manager_setup_prefix(m);
        if (r < 0)
                return r;

        r = manager_find_credentials_dirs(m);
        if (r < 0)
                return r;

        r = sd_event_default(&m->event);
        if (r < 0)
                return r;

        r = manager_setup_run_queue(m);
        if (r < 0)
                return r;

        if (FLAGS_SET(test_run_flags, MANAGER_TEST_RUN_MINIMAL)) {
                m->cgroup_root = strdup("");
                if (!m->cgroup_root)
                        return -ENOMEM;
        } else {
                r = manager_setup_signals(m);
                if (r < 0)
                        return r;

                r = manager_setup_cgroup(m);
                if (r < 0)
                        return r;

                r = manager_setup_time_change(m);
                if (r < 0)
                        return r;

                r = manager_read_timezone_stat(m);
                if (r < 0)
                        return r;

                (void) manager_setup_timezone_change(m);

                r = manager_setup_sigchld_event_source(m);
                if (r < 0)
                        return r;

                r = manager_setup_memory_pressure_event_source(m);
                if (r < 0)
                        return r;

#if HAVE_LIBBPF
                if (MANAGER_IS_SYSTEM(m) && bpf_restrict_fs_supported(/* initialize = */ true)) {
                        r = bpf_restrict_fs_setup(m);
                        if (r < 0)
                                log_warning_errno(r, "Failed to setup LSM BPF, ignoring: %m");
                }
#endif
        }

        if (test_run_flags == 0) {
                if (MANAGER_IS_SYSTEM(m))
                        r = mkdir_label("/run/systemd/units", 0755);
                else {
                        _cleanup_free_ char *units_path = NULL;
                        r = xdg_user_runtime_dir("/systemd/units", &units_path);
                        if (r < 0)
                                return r;

                        r = mkdir_p_label(units_path, 0755);
                }
                if (r < 0 && r != -EEXIST)
                        return r;
        }

        if (!FLAGS_SET(test_run_flags, MANAGER_TEST_DONT_OPEN_EXECUTOR)) {
                m->executor_fd = pin_callout_binary(SYSTEMD_EXECUTOR_BINARY_PATH);
                if (m->executor_fd < 0)
                        return log_debug_errno(m->executor_fd, "Failed to pin executor binary: %m");

                if (DEBUG_LOGGING) {
                        _cleanup_free_ char *executor_path = NULL;

                        (void) fd_get_path(m->executor_fd, &executor_path);
                        log_debug("Using systemd-executor binary from '%s'.", strna(executor_path));
                }
        }

        /* Note that we do not set up the notify fd here. We do that after deserialization,
         * since they might have gotten serialized across the reexec. */

        *ret = TAKE_PTR(m);

        return 0;
}

static int manager_setup_notify(Manager *m) {
        int r;

        if (MANAGER_IS_TEST_RUN(m))
                return 0;

        if (m->notify_fd < 0) {
                _cleanup_close_ int fd = -EBADF;
                union sockaddr_union sa;
                socklen_t sa_len;

                /* First free all secondary fields */
                m->notify_socket = mfree(m->notify_socket);
                m->notify_event_source = sd_event_source_disable_unref(m->notify_event_source);

                fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                if (fd < 0)
                        return log_error_errno(errno, "Failed to allocate notification socket: %m");

                (void) fd_increase_rxbuf(fd, MANAGER_SOCKET_RCVBUF_SIZE);

                m->notify_socket = path_join(m->prefix[EXEC_DIRECTORY_RUNTIME], "systemd/notify");
                if (!m->notify_socket)
                        return log_oom();

                r = sockaddr_un_set_path(&sa.un, m->notify_socket);
                if (r < 0)
                        return log_error_errno(r, "Notify socket '%s' not valid for AF_UNIX socket address, refusing.",
                                               m->notify_socket);
                sa_len = r;

                (void) mkdir_parents_label(m->notify_socket, 0755);
                (void) sockaddr_un_unlink(&sa.un);

                r = mac_selinux_bind(fd, &sa.sa, sa_len);
                if (r < 0)
                        return log_error_errno(r, "Failed to bind notify fd to '%s': %m", m->notify_socket);

                r = setsockopt_int(fd, SOL_SOCKET, SO_PASSCRED, true);
                if (r < 0)
                        return log_error_errno(r, "Failed to enable SO_PASSCRED for notify socket: %m");

                r = setsockopt_int(fd, SOL_SOCKET, SO_PASSPIDFD, true);
                if (r < 0 && r != -ENOPROTOOPT)
                        log_warning_errno(r, "Failed to enable SO_PASSPIDFD for notify socket, ignoring: %m");
                // TODO: maybe enforce SO_PASSPIDFD?

                m->notify_fd = TAKE_FD(fd);

                log_debug("Using notification socket %s", m->notify_socket);
        }

        if (!m->notify_event_source) {
                r = sd_event_add_io(m->event, &m->notify_event_source, m->notify_fd, EPOLLIN, manager_dispatch_notify_fd, m);
                if (r < 0)
                        return log_error_errno(r, "Failed to allocate notify event source: %m");

                /* Process notification messages a bit earlier than SIGCHLD, so that we can still identify to which
                 * service an exit message belongs. */
                r = sd_event_source_set_priority(m->notify_event_source, EVENT_PRIORITY_NOTIFY);
                if (r < 0)
                        return log_error_errno(r, "Failed to set priority of notify event source: %m");

                (void) sd_event_source_set_description(m->notify_event_source, "manager-notify");
        }

        return 0;
}

static int manager_setup_cgroups_agent(Manager *m) {

        static const union sockaddr_union sa = {
                .un.sun_family = AF_UNIX,
                .un.sun_path = "/run/systemd/cgroups-agent",
        };
        int r;

        /* This creates a listening socket we receive cgroups agent messages on. We do not use D-Bus for delivering
         * these messages from the cgroups agent binary to PID 1, as the cgroups agent binary is very short-living, and
         * each instance of it needs a new D-Bus connection. Since D-Bus connections are SOCK_STREAM/AF_UNIX, on
         * overloaded systems the backlog of the D-Bus socket becomes relevant, as not more than the configured number
         * of D-Bus connections may be queued until the kernel will start dropping further incoming connections,
         * possibly resulting in lost cgroups agent messages. To avoid this, we'll use a private SOCK_DGRAM/AF_UNIX
         * socket, where no backlog is relevant as communication may take place without an actual connect() cycle, and
         * we thus won't lose messages.
         *
         * Note that PID 1 will forward the agent message to system bus, so that the user systemd instance may listen
         * to it. The system instance hence listens on this special socket, but the user instances listen on the system
         * bus for these messages. */

        if (MANAGER_IS_TEST_RUN(m))
                return 0;

        if (!MANAGER_IS_SYSTEM(m))
                return 0;

        r = cg_unified_controller(SYSTEMD_CGROUP_CONTROLLER);
        if (r < 0)
                return log_error_errno(r, "Failed to determine whether unified cgroups hierarchy is used: %m");
        if (r > 0) /* We don't need this anymore on the unified hierarchy */
                return 0;

        if (m->cgroups_agent_fd < 0) {
                _cleanup_close_ int fd = -EBADF;

                /* First free all secondary fields */
                m->cgroups_agent_event_source = sd_event_source_disable_unref(m->cgroups_agent_event_source);

                fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
                if (fd < 0)
                        return log_error_errno(errno, "Failed to allocate cgroups agent socket: %m");

                (void) fd_increase_rxbuf(fd, MANAGER_SOCKET_RCVBUF_SIZE);

                (void) sockaddr_un_unlink(&sa.un);

                /* Only allow root to connect to this socket */
                WITH_UMASK(0077)
                        r = bind(fd, &sa.sa, SOCKADDR_UN_LEN(sa.un));
                if (r < 0)
                        return log_error_errno(errno, "bind(%s) failed: %m", sa.un.sun_path);

                m->cgroups_agent_fd = TAKE_FD(fd);
        }

        if (!m->cgroups_agent_event_source) {
                r = sd_event_add_io(m->event, &m->cgroups_agent_event_source, m->cgroups_agent_fd, EPOLLIN, manager_dispatch_cgroups_agent_fd, m);
                if (r < 0)
                        return log_error_errno(r, "Failed to allocate cgroups agent event source: %m");

                /* Process cgroups notifications early. Note that when the agent notification is received
                 * we'll just enqueue the unit in the cgroup empty queue, hence pick a high priority than
                 * that. Also see handling of cgroup inotify for the unified cgroup stuff. */
                r = sd_event_source_set_priority(m->cgroups_agent_event_source, EVENT_PRIORITY_CGROUP_AGENT);
                if (r < 0)
                        return log_error_errno(r, "Failed to set priority of cgroups agent event source: %m");

                (void) sd_event_source_set_description(m->cgroups_agent_event_source, "manager-cgroups-agent");
        }

        return 0;
}

static int manager_setup_user_lookup_fd(Manager *m) {
        int r;

        assert(m);

        /* Set up the socket pair used for passing UID/GID resolution results from forked off processes to PID
         * 1. Background: we can't do name lookups (NSS) from PID 1, since it might involve IPC and thus activation,
         * and we might hence deadlock on ourselves. Hence we do all user/group lookups asynchronously from the forked
         * off processes right before executing the binaries to start. In order to be able to clean up any IPC objects
         * created by a unit (see RemoveIPC=) we need to know in PID 1 the used UID/GID of the executed processes,
         * hence we establish this communication channel so that forked off processes can pass their UID/GID
         * information back to PID 1. The forked off processes send their resolved UID/GID to PID 1 in a simple
         * datagram, along with their unit name, so that we can share one communication socket pair among all units for
         * this purpose.
         *
         * You might wonder why we need a communication channel for this that is independent of the usual notification
         * socket scheme (i.e. $NOTIFY_SOCKET). The primary difference is about trust: data sent via the $NOTIFY_SOCKET
         * channel is only accepted if it originates from the right unit and if reception was enabled for it. The user
         * lookup socket OTOH is only accessible by PID 1 and its children until they exec(), and always available.
         *
         * Note that this function is called under two circumstances: when we first initialize (in which case we
         * allocate both the socket pair and the event source to listen on it), and when we deserialize after a reload
         * (in which case the socket pair already exists but we still need to allocate the event source for it). */

        if (m->user_lookup_fds[0] < 0) {

                /* Free all secondary fields */
                safe_close_pair(m->user_lookup_fds);
                m->user_lookup_event_source = sd_event_source_disable_unref(m->user_lookup_event_source);

                if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, m->user_lookup_fds) < 0)
                        return log_error_errno(errno, "Failed to allocate user lookup socket: %m");

                (void) fd_increase_rxbuf(m->user_lookup_fds[0], MANAGER_SOCKET_RCVBUF_SIZE);
        }

        if (!m->user_lookup_event_source) {
                r = sd_event_add_io(m->event, &m->user_lookup_event_source, m->user_lookup_fds[0], EPOLLIN, manager_dispatch_user_lookup_fd, m);
                if (r < 0)
                        return log_error_errno(r, "Failed to allocate user lookup event source: %m");

                /* Process even earlier than the notify event source, so that we always know first about valid UID/GID
                 * resolutions */
                r = sd_event_source_set_priority(m->user_lookup_event_source, EVENT_PRIORITY_USER_LOOKUP);
                if (r < 0)
                        return log_error_errno(r, "Failed to set priority of user lookup event source: %m");

                (void) sd_event_source_set_description(m->user_lookup_event_source, "user-lookup");
        }

        return 0;
}

static int manager_setup_handoff_timestamp_fd(Manager *m) {
        int r;

        assert(m);

        /* Set up the socket pair used for passing timestamps back when the executor processes we fork
         * off invokes execve(), i.e. when we hand off control to our payload processes. */

        if (m->handoff_timestamp_fds[0] < 0) {
                m->handoff_timestamp_event_source = sd_event_source_disable_unref(m->handoff_timestamp_event_source);
                safe_close_pair(m->handoff_timestamp_fds);

                if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, m->handoff_timestamp_fds) < 0)
                        return log_error_errno(errno, "Failed to allocate handoff timestamp socket: %m");

                /* Make sure children never have to block */
                (void) fd_increase_rxbuf(m->handoff_timestamp_fds[0], MANAGER_SOCKET_RCVBUF_SIZE);

                r = setsockopt_int(m->handoff_timestamp_fds[0], SOL_SOCKET, SO_PASSCRED, true);
                if (r < 0)
                        return log_error_errno(r, "SO_PASSCRED failed: %m");

                /* Mark the receiving socket as O_NONBLOCK (but leave sending side as-is) */
                r = fd_nonblock(m->handoff_timestamp_fds[0], true);
                if (r < 0)
                        return log_error_errno(r, "Failed to make handoff timestamp socket O_NONBLOCK: %m");
        }

        if (!m->handoff_timestamp_event_source) {
                r = sd_event_add_io(m->event, &m->handoff_timestamp_event_source, m->handoff_timestamp_fds[0], EPOLLIN, manager_dispatch_handoff_timestamp_fd, m);
                if (r < 0)
                        return log_error_errno(r, "Failed to allocate handoff timestamp event source: %m");

                r = sd_event_source_set_priority(m->handoff_timestamp_event_source, EVENT_PRIORITY_HANDOFF_TIMESTAMP);
                if (r < 0)
                        return log_error_errno(r, "Failed to set priority of handoff timestamp event source: %m");

                (void) sd_event_source_set_description(m->handoff_timestamp_event_source, "handoff-timestamp");
        }

        return 0;
}

static int manager_setup_pidref_transport_fd(Manager *m) {
        int r;

        assert(m);

        /* Set up the socket pair used for passing parent and child pidrefs back when the executor unshares
         * a PID namespace and forks again when using PrivatePIDs=yes. */

        if (m->pidref_transport_fds[0] < 0) {
                m->pidref_event_source = sd_event_source_disable_unref(m->pidref_event_source);
                safe_close_pair(m->pidref_transport_fds);

                if (socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, m->pidref_transport_fds) < 0)
                        return log_error_errno(errno, "Failed to allocate pidref socket: %m");

                /* Make sure children never have to block */
                (void) fd_increase_rxbuf(m->pidref_transport_fds[0], MANAGER_SOCKET_RCVBUF_SIZE);

                r = setsockopt_int(m->pidref_transport_fds[0], SOL_SOCKET, SO_PASSCRED, true);
                if (r < 0)
                        return log_error_errno(r, "Failed to enable SO_PASSCRED for pidref socket: %m");

                r = setsockopt_int(m->pidref_transport_fds[0], SOL_SOCKET, SO_PASSPIDFD, true);
                if (ERRNO_IS_NEG_NOT_SUPPORTED(r))
                        log_debug("SO_PASSPIDFD is not supported for pidref socket, ignoring.");
                else if (r < 0)
                        log_warning_errno(r, "Failed to enable SO_PASSPIDFD for pidref socket, ignoring: %m");

                /* Mark the receiving socket as O_NONBLOCK (but leave sending side as-is) */
                r = fd_nonblock(m->pidref_transport_fds[0], true);
                if (r < 0)
                        return log_error_errno(r, "Failed to make pidref socket O_NONBLOCK: %m");
        }

        if (!m->pidref_event_source) {
                r = sd_event_add_io(m->event, &m->pidref_event_source, m->pidref_transport_fds[0], EPOLLIN, manager_dispatch_pidref_transport_fd, m);
                if (r < 0)
                        return log_error_errno(r, "Failed to allocate pidref event source: %m");

                r = sd_event_source_set_priority(m->pidref_event_source, EVENT_PRIORITY_PIDREF);
                if (r < 0)
                        return log_error_errno(r, "Failed to set priority of pidref event source: %m");

                (void) sd_event_source_set_description(m->pidref_event_source, "pidref");
        }

        return 0;
}

static unsigned manager_dispatch_cleanup_queue(Manager *m) {
        Unit *u;
        unsigned n = 0;

        assert(m);

        while ((u = m->cleanup_queue)) {
                assert(u->in_cleanup_queue);

                unit_free(u);
                n++;
        }

        return n;
}

static unsigned manager_dispatch_release_resources_queue(Manager *m) {
        unsigned n = 0;
        Unit *u;

        assert(m);

        while ((u = LIST_POP(release_resources_queue, m->release_resources_queue))) {
                assert(u->in_release_resources_queue);
                u->in_release_resources_queue = false;

                n++;

                unit_release_resources(u);
        }

        return n;
}

enum {
        GC_OFFSET_IN_PATH,  /* This one is on the path we were traveling */
        GC_OFFSET_UNSURE,   /* No clue */
        GC_OFFSET_GOOD,     /* We still need this unit */
        GC_OFFSET_BAD,      /* We don't need this unit anymore */
        _GC_OFFSET_MAX
};

static void unit_gc_mark_good(Unit *u, unsigned gc_marker) {
        Unit *other;

        u->gc_marker = gc_marker + GC_OFFSET_GOOD;

        /* Recursively mark referenced units as GOOD as well */
        UNIT_FOREACH_DEPENDENCY(other, u, UNIT_ATOM_REFERENCES)
                if (other->gc_marker == gc_marker + GC_OFFSET_UNSURE)
                        unit_gc_mark_good(other, gc_marker);
}

static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
        Unit *other;
        bool is_bad;

        assert(u);

        if (IN_SET(u->gc_marker - gc_marker,
                   GC_OFFSET_GOOD, GC_OFFSET_BAD, GC_OFFSET_UNSURE, GC_OFFSET_IN_PATH))
                return;

        if (u->in_cleanup_queue)
                goto bad;

        if (!unit_may_gc(u))
                goto good;

        u->gc_marker = gc_marker + GC_OFFSET_IN_PATH;

        is_bad = true;

        UNIT_FOREACH_DEPENDENCY(other, u, UNIT_ATOM_REFERENCED_BY) {
                unit_gc_sweep(other, gc_marker);

                if (other->gc_marker == gc_marker + GC_OFFSET_GOOD)
                        goto good;

                if (other->gc_marker != gc_marker + GC_OFFSET_BAD)
                        is_bad = false;
        }

        LIST_FOREACH(refs_by_target, ref, u->refs_by_target) {
                unit_gc_sweep(ref->source, gc_marker);

                if (ref->source->gc_marker == gc_marker + GC_OFFSET_GOOD)
                        goto good;

                if (ref->source->gc_marker != gc_marker + GC_OFFSET_BAD)
                        is_bad = false;
        }

        if (is_bad)
                goto bad;

        /* We were unable to find anything out about this entry, so
         * let's investigate it later */
        u->gc_marker = gc_marker + GC_OFFSET_UNSURE;
        unit_add_to_gc_queue(u);
        return;

bad:
        /* We definitely know that this one is not useful anymore, so
         * let's mark it for deletion */
        u->gc_marker = gc_marker + GC_OFFSET_BAD;
        unit_add_to_cleanup_queue(u);
        return;

good:
        unit_gc_mark_good(u, gc_marker);
}

static unsigned manager_dispatch_gc_unit_queue(Manager *m) {
        unsigned n = 0, gc_marker;
        Unit *u;

        assert(m);

        /* log_debug("Running GC..."); */

        m->gc_marker += _GC_OFFSET_MAX;
        if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
                m->gc_marker = 1;

        gc_marker = m->gc_marker;

        while ((u = LIST_POP(gc_queue, m->gc_unit_queue))) {
                assert(u->in_gc_queue);

                unit_gc_sweep(u, gc_marker);

                u->in_gc_queue = false;

                n++;

                if (IN_SET(u->gc_marker - gc_marker,
                           GC_OFFSET_BAD, GC_OFFSET_UNSURE)) {
                        if (u->id)
                                log_unit_debug(u, "Collecting.");
                        u->gc_marker = gc_marker + GC_OFFSET_BAD;
                        unit_add_to_cleanup_queue(u);
                }
        }

        return n;
}

static unsigned manager_dispatch_gc_job_queue(Manager *m) {
        unsigned n = 0;
        Job *j;

        assert(m);

        while ((j = LIST_POP(gc_queue, m->gc_job_queue))) {
                assert(j->in_gc_queue);
                j->in_gc_queue = false;

                n++;

                if (!job_may_gc(j))
                        continue;

                log_unit_debug(j->unit, "Collecting job.");
                (void) job_finish_and_invalidate(j, JOB_COLLECTED, false, false);
        }

        return n;
}

static int manager_ratelimit_requeue(sd_event_source *s, uint64_t usec, void *userdata) {
        Unit *u = userdata;

        assert(u);
        assert(s == u->auto_start_stop_event_source);

        u->auto_start_stop_event_source = sd_event_source_unref(u->auto_start_stop_event_source);

        /* Re-queue to all queues, if the rate limit hit we might have been throttled on any of them. */
        unit_submit_to_stop_when_unneeded_queue(u);
        unit_submit_to_start_when_upheld_queue(u);
        unit_submit_to_stop_when_bound_queue(u);

        return 0;
}

static int manager_ratelimit_check_and_queue(Unit *u) {
        int r;

        assert(u);

        if (ratelimit_below(&u->auto_start_stop_ratelimit))
                return 1;

        /* Already queued, no need to requeue */
        if (u->auto_start_stop_event_source)
                return 0;

        r = sd_event_add_time(
                        u->manager->event,
                        &u->auto_start_stop_event_source,
                        CLOCK_MONOTONIC,
                        ratelimit_end(&u->auto_start_stop_ratelimit),
                        0,
                        manager_ratelimit_requeue,
                        u);
        if (r < 0)
                return log_unit_error_errno(u, r, "Failed to queue timer on event loop: %m");

        return 0;
}

static unsigned manager_dispatch_stop_when_unneeded_queue(Manager *m) {
        unsigned n = 0;
        Unit *u;
        int r;

        assert(m);

        while ((u = LIST_POP(stop_when_unneeded_queue, m->stop_when_unneeded_queue))) {
                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;

                assert(u->in_stop_when_unneeded_queue);
                u->in_stop_when_unneeded_queue = false;

                n++;

                if (!unit_is_unneeded(u))
                        continue;

                log_unit_debug(u, "Unit is not needed anymore.");

                /* If stopping a unit fails continuously we might enter a stop loop here, hence stop acting on the
                 * service being unnecessary after a while. */

                r = manager_ratelimit_check_and_queue(u);
                if (r <= 0) {
                        log_unit_warning(u,
                                         "Unit not needed anymore, but not stopping since we tried this too often recently.%s",
                                         r == 0 ? " Will retry later." : "");
                        continue;
                }

                /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
                r = manager_add_job(u->manager, JOB_STOP, u, JOB_FAIL, &error, /* ret = */ NULL);
                if (r < 0)
                        log_unit_warning_errno(u, r, "Failed to enqueue stop job, ignoring: %s", bus_error_message(&error, r));
        }

        return n;
}

static unsigned manager_dispatch_start_when_upheld_queue(Manager *m) {
        unsigned n = 0;
        Unit *u;
        int r;

        assert(m);

        while ((u = LIST_POP(start_when_upheld_queue, m->start_when_upheld_queue))) {
                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
                Unit *culprit = NULL;

                assert(u->in_start_when_upheld_queue);
                u->in_start_when_upheld_queue = false;

                n++;

                if (!unit_is_upheld_by_active(u, &culprit))
                        continue;

                log_unit_debug(u, "Unit is started because upheld by active unit %s.", culprit->id);

                /* If stopping a unit fails continuously we might enter a stop loop here, hence stop acting on the
                 * service being unnecessary after a while. */

                r = manager_ratelimit_check_and_queue(u);
                if (r <= 0) {
                        log_unit_warning(u,
                                         "Unit needs to be started because active unit %s upholds it, but not starting since we tried this too often recently.%s",
                                         culprit->id,
                                         r == 0 ? " Will retry later." : "");
                        continue;
                }

                r = manager_add_job(u->manager, JOB_START, u, JOB_FAIL, &error, /* ret = */ NULL);
                if (r < 0)
                        log_unit_warning_errno(u, r, "Failed to enqueue start job, ignoring: %s", bus_error_message(&error, r));
        }

        return n;
}

static unsigned manager_dispatch_stop_when_bound_queue(Manager *m) {
        unsigned n = 0;
        Unit *u;
        int r;

        assert(m);

        while ((u = LIST_POP(stop_when_bound_queue, m->stop_when_bound_queue))) {
                _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
                Unit *culprit = NULL;

                assert(u->in_stop_when_bound_queue);
                u->in_stop_when_bound_queue = false;

                n++;

                if (!unit_is_bound_by_inactive(u, &culprit))
                        continue;

                log_unit_debug(u, "Unit is stopped because bound to inactive unit %s.", culprit->id);

                /* If stopping a unit fails continuously we might enter a stop loop here, hence stop acting on the
                 * service being unnecessary after a while. */

                r = manager_ratelimit_check_and_queue(u);
                if (r <= 0) {
                        log_unit_warning(u,
                                         "Unit needs to be stopped because it is bound to inactive unit %s it, but not stopping since we tried this too often recently.%s",
                                         culprit->id,
                                         r == 0 ? " Will retry later." : "");
                        continue;
                }

                r = manager_add_job(u->manager, JOB_STOP, u, JOB_REPLACE, &error, /* ret = */ NULL);
                if (r < 0)
                        log_unit_warning_errno(u, r, "Failed to enqueue stop job, ignoring: %s", bus_error_message(&error, r));
        }

        return n;
}

static void manager_clear_jobs_and_units(Manager *m) {
        Unit *u;

        assert(m);

        while ((u = hashmap_first(m->units)))
                unit_free(u);

        manager_dispatch_cleanup_queue(m);

        assert(!m->load_queue);
        assert(prioq_isempty(m->run_queue));
        assert(!m->dbus_unit_queue);
        assert(!m->dbus_job_queue);
        assert(!m->cleanup_queue);
        assert(!m->gc_unit_queue);
        assert(!m->gc_job_queue);
        assert(!m->cgroup_realize_queue);
        assert(!m->cgroup_empty_queue);
        assert(!m->cgroup_oom_queue);
        assert(!m->target_deps_queue);
        assert(!m->stop_when_unneeded_queue);
        assert(!m->start_when_upheld_queue);
        assert(!m->stop_when_bound_queue);
        assert(!m->release_resources_queue);

        assert(hashmap_isempty(m->jobs));
        assert(hashmap_isempty(m->units));

        m->n_on_console = 0;
        m->n_running_jobs = 0;
        m->n_installed_jobs = 0;
        m->n_failed_jobs = 0;
}

Manager* manager_free(Manager *m) {
        if (!m)
                return NULL;

        manager_clear_jobs_and_units(m);

        for (UnitType c = 0; c < _UNIT_TYPE_MAX; c++)
                if (unit_vtable[c]->shutdown)
                        unit_vtable[c]->shutdown(m);

        /* Keep the cgroup hierarchy in place except when we know we are going down for good */
        manager_shutdown_cgroup(m, /* delete= */ IN_SET(m->objective, MANAGER_EXIT, MANAGER_REBOOT, MANAGER_POWEROFF, MANAGER_HALT, MANAGER_KEXEC));

        lookup_paths_flush_generator(&m->lookup_paths);

        bus_done(m);
        manager_varlink_done(m);

        exec_shared_runtime_vacuum(m);
        hashmap_free(m->exec_shared_runtime_by_id);

        dynamic_user_vacuum(m, false);
        hashmap_free(m->dynamic_users);

        hashmap_free(m->units);
        hashmap_free(m->units_by_invocation_id);
        hashmap_free(m->jobs);
        hashmap_free(m->watch_pids);
        hashmap_free(m->watch_pids_more);
        hashmap_free(m->watch_bus);

        prioq_free(m->run_queue);

        set_free(m->startup_units);
        set_free(m->failed_units);

        sd_event_source_unref(m->signal_event_source);
        sd_event_source_unref(m->sigchld_event_source);
        sd_event_source_unref(m->notify_event_source);
        sd_event_source_unref(m->cgroups_agent_event_source);
        sd_event_source_unref(m->time_change_event_source);
        sd_event_source_unref(m->timezone_change_event_source);
        sd_event_source_unref(m->jobs_in_progress_event_source);
        sd_event_source_unref(m->run_queue_event_source);
        sd_event_source_unref(m->user_lookup_event_source);
        sd_event_source_unref(m->handoff_timestamp_event_source);
        sd_event_source_unref(m->pidref_event_source);
        sd_event_source_unref(m->memory_pressure_event_source);

        safe_close(m->signal_fd);
        safe_close(m->notify_fd);
        safe_close(m->cgroups_agent_fd);
        safe_close_pair(m->user_lookup_fds);
        safe_close_pair(m->handoff_timestamp_fds);
        safe_close_pair(m->pidref_transport_fds);

        manager_close_ask_password(m);

        manager_close_idle_pipe(m);

        sd_event_unref(m->event);

        free(m->notify_socket);

        lookup_paths_done(&m->lookup_paths);
        strv_free(m->transient_environment);
        strv_free(m->client_environment);

        hashmap_free(m->cgroup_unit);
        manager_free_unit_name_maps(m);

        free(m->switch_root);
        free(m->switch_root_init);

        sd_bus_track_unref(m->subscribed);
        strv_free(m->subscribed_as_strv);

        unit_defaults_done(&m->defaults);

        FOREACH_ARRAY(map, m->units_needing_mounts_for, _UNIT_MOUNT_DEPENDENCY_TYPE_MAX) {
                assert(hashmap_isempty(*map));
                hashmap_free(*map);
        }

        hashmap_free(m->uid_refs);
        hashmap_free(m->gid_refs);

        FOREACH_ARRAY(i, m->prefix, _EXEC_DIRECTORY_TYPE_MAX)
                free(*i);

        free(m->received_credentials_directory);
        free(m->received_encrypted_credentials_directory);

        free(m->watchdog_pretimeout_governor);
        free(m->watchdog_pretimeout_governor_overridden);

        fw_ctx_free(m->fw_ctx);

#if BPF_FRAMEWORK
        bpf_restrict_fs_destroy(m->restrict_fs);
#endif

        safe_close(m->executor_fd);

        return mfree(m);
}

static void manager_enumerate_perpetual(Manager *m) {
        assert(m);

        if (FLAGS_SET(m->test_run_flags, MANAGER_TEST_RUN_MINIMAL))
                return;

        /* Let's ask every type to load all units from disk/kernel that it might know */
        for (UnitType c = 0; c < _UNIT_TYPE_MAX; c++) {
                if (!unit_type_supported(c)) {
                        log_debug("Unit type .%s is not supported on this system.", unit_type_to_string(c));
                        continue;
                }

                if (unit_vtable[c]->enumerate_perpetual)
                        unit_vtable[c]->enumerate_perpetual(m);
        }
}

static void manager_enumerate(Manager *m) {
        assert(m);

        if (FLAGS_SET(m->test_run_flags, MANAGER_TEST_RUN_MINIMAL))
                return;

        /* Let's ask every type to load all units from disk/kernel that it might know */
        for (UnitType c = 0; c < _UNIT_TYPE_MAX; c++) {
                if (!unit_type_supported(c)) {
                        log_debug("Unit type .%s is not supported on this system.", unit_type_to_string(c));
                        continue;
                }

                if (unit_vtable[c]->enumerate)
                        unit_vtable[c]->enumerate(m);
        }

        manager_dispatch_load_queue(m);
}

static void manager_coldplug(Manager *m) {
        Unit *u;
        char *k;
        int r;

        assert(m);

        log_debug("Invoking unit coldplug() handlers%s", special_glyph(SPECIAL_GLYPH_ELLIPSIS));

        /* Let's place the units back into their deserialized state */
        HASHMAP_FOREACH_KEY(u, k, m->units) {

                /* ignore aliases */
                if (u->id != k)
                        continue;

                r = unit_coldplug(u);
                if (r < 0)
                        log_warning_errno(r, "We couldn't coldplug %s, proceeding anyway: %m", u->id);
        }
}

static void manager_catchup(Manager *m) {
        Unit *u;
        char *k;

        assert(m);

        log_debug("Invoking unit catchup() handlers%s", special_glyph(SPECIAL_GLYPH_ELLIPSIS));

        /* Let's catch up on any state changes that happened while we were reloading/reexecing */
        HASHMAP_FOREACH_KEY(u, k, m->units) {

                /* ignore aliases */
                if (u->id != k)
                        continue;

                unit_catchup(u);
        }
}

static void manager_distribute_fds(Manager *m, FDSet *fds) {
        Unit *u;

        assert(m);

        HASHMAP_FOREACH(u, m->units) {

                if (fdset_isempty(fds))
                        break;

                if (!UNIT_VTABLE(u)->distribute_fds)
                        continue;

                UNIT_VTABLE(u)->distribute_fds(u, fds);
        }
}

static bool manager_dbus_is_running(Manager *m, bool deserialized) {
        Unit *u;

        assert(m);

        /* This checks whether the dbus instance we are supposed to expose our APIs on is up. We check both the socket
         * and the service unit. If the 'deserialized' parameter is true we'll check the deserialized state of the unit
         * rather than the current one. */

        if (MANAGER_IS_TEST_RUN(m))
                return false;

        u = manager_get_unit(m, SPECIAL_DBUS_SOCKET);
        if (!u)
                return false;
        if ((deserialized ? SOCKET(u)->deserialized_state : SOCKET(u)->state) != SOCKET_RUNNING)
                return false;

        u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
        if (!u)
                return false;
        if (!IN_SET((deserialized ? SERVICE(u)->deserialized_state : SERVICE(u)->state),
                    SERVICE_RUNNING,
                    SERVICE_MOUNTING,
                    SERVICE_RELOAD,
                    SERVICE_RELOAD_NOTIFY,
                    SERVICE_RELOAD_SIGNAL))
                return false;

        return true;
}

static void manager_setup_bus(Manager *m) {
        assert(m);

        /* Let's set up our private bus connection now, unconditionally */
        (void) bus_init_private(m);

        /* If we are in --user mode also connect to the system bus now */
        if (MANAGER_IS_USER(m))
                (void) bus_init_system(m);

        /* Let's connect to the bus now, but only if the unit is supposed to be up */
        if (manager_dbus_is_running(m, MANAGER_IS_RELOADING(m))) {
                (void) bus_init_api(m);

                if (MANAGER_IS_SYSTEM(m))
                        (void) bus_init_system(m);
        }
}

static void manager_preset_all(Manager *m) {
        int r;

        assert(m);

        if (m->first_boot <= 0)
                return;

        if (!MANAGER_IS_SYSTEM(m))
                return;

        if (MANAGER_IS_TEST_RUN(m))
                return;

        /* If this is the first boot, and we are in the host system, then preset everything */
        UnitFilePresetMode mode =
                ENABLE_FIRST_BOOT_FULL_PRESET ? UNIT_FILE_PRESET_FULL : UNIT_FILE_PRESET_ENABLE_ONLY;

        r = unit_file_preset_all(RUNTIME_SCOPE_SYSTEM, 0, NULL, mode, NULL, NULL);
        if (r < 0)
                log_full_errno(r == -EEXIST ? LOG_NOTICE : LOG_WARNING, r,
                               "Failed to populate /etc with preset unit settings, ignoring: %m");
        else
                log_info("Populated /etc with preset unit settings.");
}

static void manager_ready(Manager *m) {
        assert(m);

        /* After having loaded everything, do the final round of catching up with what might have changed */

        m->objective = MANAGER_OK; /* Tell everyone we are up now */

        /* It might be safe to log to the journal now and connect to dbus */
        manager_recheck_journal(m);
        manager_recheck_dbus(m);

        /* Let's finally catch up with any changes that took place while we were reloading/reexecing */
        manager_catchup(m);

        /* Create a file which will indicate when the manager started loading units the last time. */
        if (MANAGER_IS_SYSTEM(m))
                (void) touch_file("/run/systemd/systemd-units-load", false,
                        m->timestamps[MANAGER_TIMESTAMP_UNITS_LOAD].realtime ?: now(CLOCK_REALTIME),
                        UID_INVALID, GID_INVALID, 0444);
}

Manager* manager_reloading_start(Manager *m) {
        m->n_reloading++;
        dual_timestamp_now(m->timestamps + MANAGER_TIMESTAMP_UNITS_LOAD);
        return m;
}

void manager_reloading_stopp(Manager **m) {
        if (*m) {
                assert((*m)->n_reloading > 0);
                (*m)->n_reloading--;
        }
}

int manager_startup(Manager *m, FILE *serialization, FDSet *fds, const char *root) {
        int r;

        assert(m);

        /* If we are running in test mode, we still want to run the generators,
         * but we should not touch the real generator directories. */
        r = lookup_paths_init_or_warn(&m->lookup_paths, m->runtime_scope,
                                      MANAGER_IS_TEST_RUN(m) ? LOOKUP_PATHS_TEMPORARY_GENERATED : 0,
                                      root);
        if (r < 0)
                return r;

        dual_timestamp_now(m->timestamps + manager_timestamp_initrd_mangle(MANAGER_TIMESTAMP_GENERATORS_START));
        r = manager_run_environment_generators(m);
        if (r >= 0)
                r = manager_run_generators(m);
        dual_timestamp_now(m->timestamps + manager_timestamp_initrd_mangle(MANAGER_TIMESTAMP_GENERATORS_FINISH));
        if (r < 0)
                return r;

        manager_preset_all(m);

        lookup_paths_log(&m->lookup_paths);

        {
                /* This block is (optionally) done with the reloading counter bumped */
                _unused_ _cleanup_(manager_reloading_stopp) Manager *reloading = NULL;

                /* Make sure we don't have a left-over from a previous run */
                if (!serialization)
                        (void) rm_rf(m->lookup_paths.transient, 0);

                /* If we will deserialize make sure that during enumeration this is already known, so we increase the
                 * counter here already */
                if (serialization)
                        reloading = manager_reloading_start(m);

                /* First, enumerate what we can from all config files */
                dual_timestamp_now(m->timestamps + manager_timestamp_initrd_mangle(MANAGER_TIMESTAMP_UNITS_LOAD_START));
                manager_enumerate_perpetual(m);
                manager_enumerate(m);
                dual_timestamp_now(m->timestamps + manager_timestamp_initrd_mangle(MANAGER_TIMESTAMP_UNITS_LOAD_FINISH));

                /* Second, deserialize if there is something to deserialize */
                if (serialization) {
                        r = manager_deserialize(m, serialization, fds);
                        if (r < 0)
                                return log_error_errno(r, "Deserialization failed: %m");
                }

                if (m->previous_objective >= 0) {
                        if (IN_SET(m->previous_objective, MANAGER_REEXECUTE, MANAGER_SOFT_REBOOT, MANAGER_SWITCH_ROOT))
                                log_debug("Launching as effect of a '%s' operation.",
                                          manager_objective_to_string(m->previous_objective));
                        else
                                log_warning("Got unexpected previous objective '%s', ignoring.",
                                            manager_objective_to_string(m->previous_objective));
                }

                /* If we are in a new soft-reboot iteration bump the counter now before starting units, so
                 * that they can reliably read it. We get the previous objective from serialized state. */
                if (m->previous_objective == MANAGER_SOFT_REBOOT)
                        m->soft_reboots_count++;

                /* Any fds left? Find some unit which wants them. This is useful to allow container managers to pass
                 * some file descriptors to us pre-initialized. This enables socket-based activation of entire
                 * containers. */
                manager_distribute_fds(m, fds);

                /* We might have deserialized the notify fd, but if we didn't then let's create it now */
                r = manager_setup_notify(m);
                if (r < 0)
                        /* No sense to continue without notifications, our children would fail anyway. */
                        return r;

                r = manager_setup_cgroups_agent(m);
                if (r < 0)
                        /* Likewise, no sense to continue without empty cgroup notifications. */
                        return r;

                r = manager_setup_user_lookup_fd(m);
                if (r < 0)
                        /* This shouldn't fail, except if things are really broken. */
                        return r;

                r = manager_setup_handoff_timestamp_fd(m);
                if (r < 0)
                        /* This shouldn't fail, except if things are really broken. */
                        return r;

                r = manager_setup_pidref_transport_fd(m);
                if (r < 0)
                        /* This shouldn't fail, except if things are really broken. */
                        return r;

                /* Connect to the bus if we are good for it */
                manager_setup_bus(m);

                r = manager_varlink_init(m);
                if (r < 0)
                        log_warning_errno(r, "Failed to set up Varlink, ignoring: %m");

                /* Third, fire things up! */
                manager_coldplug(m);

                /* Clean up runtime objects */
                manager_vacuum(m);

                if (serialization)
                        /* Let's wait for the UnitNew/JobNew messages being sent, before we notify that the
                         * reload is finished */
                        m->send_reloading_done = true;
        }

        manager_ready(m);

        manager_set_switching_root(m, false);

        return 0;
}

int manager_add_job_full(
                Manager *m,
                JobType type,
                Unit *unit,
                JobMode mode,
                TransactionAddFlags extra_flags,
                Set *affected_jobs,
                sd_bus_error *error,
                Job **ret) {

        _cleanup_(transaction_abort_and_freep) Transaction *tr = NULL;
        int r;

        assert(m);
        assert(type >= 0 && type < _JOB_TYPE_MAX);
        assert(unit);
        assert(mode >= 0 && mode < _JOB_MODE_MAX);
        assert((extra_flags & ~_TRANSACTION_FLAGS_MASK_PUBLIC) == 0);

        if (mode == JOB_ISOLATE && type != JOB_START)
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "Isolate is only valid for start.");

        if (mode == JOB_ISOLATE && !unit->allow_isolate)
                return sd_bus_error_set(error, BUS_ERROR_NO_ISOLATION, "Operation refused, unit may not be isolated.");

        if (mode == JOB_TRIGGERING && type != JOB_STOP)
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "--job-mode=triggering is only valid for stop.");

        if (mode == JOB_RESTART_DEPENDENCIES && type != JOB_START)
                return sd_bus_error_set(error, SD_BUS_ERROR_INVALID_ARGS, "--job-mode=restart-dependencies is only valid for start.");

        log_unit_debug(unit, "Trying to enqueue job %s/%s/%s", unit->id, job_type_to_string(type), job_mode_to_string(mode));

        type = job_type_collapse(type, unit);

        tr = transaction_new(mode == JOB_REPLACE_IRREVERSIBLY);
        if (!tr)
                return -ENOMEM;

        r = transaction_add_job_and_dependencies(
                        tr,
                        type,
                        unit,
                        /* by= */ NULL,
                        TRANSACTION_MATTERS |
                        (IN_SET(mode, JOB_IGNORE_DEPENDENCIES, JOB_IGNORE_REQUIREMENTS) ? TRANSACTION_IGNORE_REQUIREMENTS : 0) |
                        (mode == JOB_IGNORE_DEPENDENCIES ? TRANSACTION_IGNORE_ORDER : 0) |
                        (mode == JOB_RESTART_DEPENDENCIES ? TRANSACTION_PROPAGATE_START_AS_RESTART : 0) |
                        extra_flags,
                        error);
        if (r < 0)
                return r;

        if (mode == JOB_ISOLATE) {
                r = transaction_add_isolate_jobs(tr, m);
                if (r < 0)
                        return r;
        }

        if (mode == JOB_TRIGGERING) {
                r = transaction_add_triggering_jobs(tr, unit);
                if (r < 0)
                        return r;
        }

        r = transaction_activate(tr, m, mode, affected_jobs, error);
        if (r < 0)
                return r;

        log_unit_debug(unit,
                       "Enqueued job %s/%s as %u", unit->id,
                       job_type_to_string(type), (unsigned) tr->anchor_job->id);

        if (ret)
                *ret = tr->anchor_job;

        tr = transaction_free(tr);
        return 0;
}

int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, Set *affected_jobs, sd_bus_error *e, Job **ret) {
        Unit *unit = NULL;  /* just to appease gcc, initialization is not really necessary */
        int r;

        assert(m);
        assert(type < _JOB_TYPE_MAX);
        assert(name);
        assert(mode < _JOB_MODE_MAX);

        r = manager_load_unit(m, name, NULL, NULL, &unit);
        if (r < 0)
                return r;
        assert(unit);

        return manager_add_job_full(m, type, unit, mode, /* extra_flags = */ 0, affected_jobs, e, ret);
}

int manager_add_job_by_name_and_warn(Manager *m, JobType type, const char *name, JobMode mode, Set *affected_jobs, Job **ret) {
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        int r;

        assert(m);
        assert(type < _JOB_TYPE_MAX);
        assert(name);
        assert(mode < _JOB_MODE_MAX);

        r = manager_add_job_by_name(m, type, name, mode, affected_jobs, &error, ret);
        if (r < 0)
                return log_warning_errno(r, "Failed to enqueue %s job for %s: %s", job_mode_to_string(mode), name, bus_error_message(&error, r));

        return r;
}

int manager_propagate_reload(Manager *m, Unit *unit, JobMode mode, sd_bus_error *e) {
        int r;
        _cleanup_(transaction_abort_and_freep) Transaction *tr = NULL;

        assert(m);
        assert(unit);
        assert(mode < _JOB_MODE_MAX);
        assert(mode != JOB_ISOLATE); /* Isolate is only valid for start */

        tr = transaction_new(mode == JOB_REPLACE_IRREVERSIBLY);
        if (!tr)
                return -ENOMEM;

        /* We need an anchor job */
        r = transaction_add_job_and_dependencies(tr, JOB_NOP, unit, NULL, TRANSACTION_IGNORE_REQUIREMENTS|TRANSACTION_IGNORE_ORDER, e);
        if (r < 0)
                return r;

        /* Failure in adding individual dependencies is ignored, so this always succeeds. */
        transaction_add_propagate_reload_jobs(
                        tr,
                        unit,
                        tr->anchor_job,
                        mode == JOB_IGNORE_DEPENDENCIES ? TRANSACTION_IGNORE_ORDER : 0);

        r = transaction_activate(tr, m, mode, NULL, e);
        if (r < 0)
                return r;

        tr = transaction_free(tr);
        return 0;
}

Job *manager_get_job(Manager *m, uint32_t id) {
        assert(m);

        return hashmap_get(m->jobs, UINT32_TO_PTR(id));
}

Unit *manager_get_unit(Manager *m, const char *name) {
        assert(m);
        assert(name);

        return hashmap_get(m->units, name);
}

static int manager_dispatch_target_deps_queue(Manager *m) {
        Unit *u;
        int r = 0;

        assert(m);

        while ((u = LIST_POP(target_deps_queue, m->target_deps_queue))) {
                _cleanup_free_ Unit **targets = NULL;
                int n_targets;

                assert(u->in_target_deps_queue);

                u->in_target_deps_queue = false;

                /* Take an "atomic" snapshot of dependencies here, as the call below will likely modify the
                 * dependencies, and we can't have it that hash tables we iterate through are modified while
                 * we are iterating through them. */
                n_targets = unit_get_dependency_array(u, UNIT_ATOM_DEFAULT_TARGET_DEPENDENCIES, &targets);
                if (n_targets < 0)
                        return n_targets;

                FOREACH_ARRAY(i, targets, n_targets) {
                        r = unit_add_default_target_dependency(u, *i);
                        if (r < 0)
                                return r;
                }
        }

        return r;
}

unsigned manager_dispatch_load_queue(Manager *m) {
        Unit *u;
        unsigned n = 0;

        assert(m);

        /* Make sure we are not run recursively */
        if (m->dispatching_load_queue)
                return 0;

        m->dispatching_load_queue = true;

        /* Dispatches the load queue. Takes a unit from the queue and
         * tries to load its data until the queue is empty */

        while ((u = m->load_queue)) {
                assert(u->in_load_queue);

                unit_load(u);
                n++;
        }

        m->dispatching_load_queue = false;

        /* Dispatch the units waiting for their target dependencies to be added now, as all targets that we know about
         * should be loaded and have aliases resolved */
        (void) manager_dispatch_target_deps_queue(m);

        return n;
}

bool manager_unit_cache_should_retry_load(Unit *u) {
        assert(u);

        /* Automatic reloading from disk only applies to units which were not found sometime in the past, and
         * the not-found stub is kept pinned in the unit graph by dependencies. For units that were
         * previously loaded, we don't do automatic reloading, and daemon-reload is necessary to update. */
        if (u->load_state != UNIT_NOT_FOUND)
                return false;

        /* The cache has been updated since the last time we tried to load the unit. There might be new
         * fragment paths to read. */
        if (u->manager->unit_cache_timestamp_hash != u->fragment_not_found_timestamp_hash)
                return true;

        /* The cache needs to be updated because there are modifications on disk. */
        return !lookup_paths_timestamp_hash_same(&u->manager->lookup_paths, u->manager->unit_cache_timestamp_hash, NULL);
}

int manager_load_unit_prepare(
                Manager *m,
                const char *name,
                const char *path,
                sd_bus_error *e,
                Unit **ret) {

        _cleanup_(unit_freep) Unit *cleanup_unit = NULL;
        _cleanup_free_ char *nbuf = NULL;
        int r;

        assert(m);
        assert(ret);
        assert(name || path);

        /* This will prepare the unit for loading, but not actually load anything from disk. */

        if (path && !path_is_absolute(path))
                return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Path %s is not absolute.", path);

        if (!name) {
                r = path_extract_filename(path, &nbuf);
                if (r < 0)
                        return r;
                if (r == O_DIRECTORY)
                        return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Path '%s' refers to directory, refusing.", path);

                name = nbuf;
        }

        UnitType t = unit_name_to_type(name);

        if (t == _UNIT_TYPE_INVALID || !unit_name_is_valid(name, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE)) {
                if (unit_name_is_valid(name, UNIT_NAME_TEMPLATE))
                        return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Unit name %s is missing the instance name.", name);

                return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Unit name %s is not valid.", name);
        }

        Unit *unit = manager_get_unit(m, name);
        if (unit) {
                /* The time-based cache allows new units to be started without daemon-reload,
                 * but if they are already referenced (because of dependencies or ordering)
                 * then we have to force a load of the fragment. As an optimization, check
                 * first if anything in the usual paths was modified since the last time
                 * the cache was loaded. Also check if the last time an attempt to load the
                 * unit was made was before the most recent cache refresh, so that we know
                 * we need to try again — even if the cache is current, it might have been
                 * updated in a different context before we had a chance to retry loading
                 * this particular unit. */
                if (manager_unit_cache_should_retry_load(unit))
                        unit->load_state = UNIT_STUB;
                else {
                        *ret = unit;
                        return 0;  /* The unit was already loaded */
                }
        } else {
                unit = cleanup_unit = unit_new(m, unit_vtable[t]->object_size);
                if (!unit)
                        return -ENOMEM;
        }

        if (path) {
                r = free_and_strdup(&unit->fragment_path, path);
                if (r < 0)
                        return r;
        }

        r = unit_add_name(unit, name);
        if (r < 0)
                return r;

        unit_add_to_load_queue(unit);
        unit_add_to_dbus_queue(unit);
        unit_add_to_gc_queue(unit);

        *ret = unit;
        TAKE_PTR(cleanup_unit);

        return 1;  /* The unit was added the load queue */
}

int manager_load_unit(
                Manager *m,
                const char *name,
                const char *path,
                sd_bus_error *e,
                Unit **ret) {
        int r;

        assert(m);
        assert(ret);

        /* This will load the unit config, but not actually start any services or anything. */

        r = manager_load_unit_prepare(m, name, path, e, ret);
        if (r <= 0)
                return r;

        /* Unit was newly loaded */
        manager_dispatch_load_queue(m);
        *ret = unit_follow_merge(*ret);
        return 0;
}

int manager_load_startable_unit_or_warn(
                Manager *m,
                const char *name,
                const char *path,
                Unit **ret) {

        /* Load a unit, make sure it loaded fully and is not masked. */

        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        Unit *unit;
        int r;

        r = manager_load_unit(m, name, path, &error, &unit);
        if (r < 0)
                return log_error_errno(r, "Failed to load %s %s: %s",
                                       name ? "unit" : "unit file", name ?: path,
                                       bus_error_message(&error, r));

        r = bus_unit_validate_load_state(unit, &error);
        if (r < 0)
                return log_error_errno(r, "%s", bus_error_message(&error, r));

        *ret = unit;
        return 0;
}

void manager_clear_jobs(Manager *m) {
        Job *j;

        assert(m);

        while ((j = hashmap_first(m->jobs)))
                /* No need to recurse. We're cancelling all jobs. */
                job_finish_and_invalidate(j, JOB_CANCELED, false, false);
}

void manager_unwatch_pidref(Manager *m, const PidRef *pid) {
        assert(m);

        for (;;) {
                Unit *u;

                u = manager_get_unit_by_pidref_watching(m, pid);
                if (!u)
                        break;

                unit_unwatch_pidref(u, pid);
        }
}

static int manager_dispatch_run_queue(sd_event_source *source, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        Job *j;

        assert(source);

        while ((j = prioq_peek(m->run_queue))) {
                assert(j->installed);
                assert(j->in_run_queue);

                (void) job_run_and_invalidate(j);
        }

        if (m->n_running_jobs > 0)
                manager_watch_jobs_in_progress(m);

        if (m->n_on_console > 0)
                manager_watch_idle_pipe(m);

        return 1;
}

void manager_trigger_run_queue(Manager *m) {
        int r;

        assert(m);

        r = sd_event_source_set_enabled(
                        m->run_queue_event_source,
                        prioq_isempty(m->run_queue) ? SD_EVENT_OFF : SD_EVENT_ONESHOT);
        if (r < 0)
                log_warning_errno(r, "Failed to enable job run queue event source, ignoring: %m");
}

static unsigned manager_dispatch_dbus_queue(Manager *m) {
        unsigned n = 0, budget;
        Unit *u;
        Job *j;

        assert(m);

        /* When we are reloading, let's not wait with generating signals, since we need to exit the manager as quickly
         * as we can. There's no point in throttling generation of signals in that case. */
        if (MANAGER_IS_RELOADING(m) || m->send_reloading_done || m->pending_reload_message)
                budget = UINT_MAX; /* infinite budget in this case */
        else {
                /* Anything to do at all? */
                if (!m->dbus_unit_queue && !m->dbus_job_queue)
                        return 0;

                /* Do we have overly many messages queued at the moment? If so, let's not enqueue more on top, let's
                 * sit this cycle out, and process things in a later cycle when the queues got a bit emptier. */
                if (manager_bus_n_queued_write(m) > MANAGER_BUS_BUSY_THRESHOLD)
                        return 0;

                /* Only process a certain number of units/jobs per event loop iteration. Even if the bus queue wasn't
                 * overly full before this call we shouldn't increase it in size too wildly in one step, and we
                 * shouldn't monopolize CPU time with generating these messages. Note the difference in counting of
                 * this "budget" and the "threshold" above: the "budget" is decreased only once per generated message,
                 * regardless how many buses/direct connections it is enqueued on, while the "threshold" is applied to
                 * each queued instance of bus message, i.e. if the same message is enqueued to five buses/direct
                 * connections it will be counted five times. This difference in counting ("references"
                 * vs. "instances") is primarily a result of the fact that it's easier to implement it this way,
                 * however it also reflects the thinking that the "threshold" should put a limit on used queue memory,
                 * i.e. space, while the "budget" should put a limit on time. Also note that the "threshold" is
                 * currently chosen much higher than the "budget". */
                budget = MANAGER_BUS_MESSAGE_BUDGET;
        }

        while (budget != 0 && (u = m->dbus_unit_queue)) {

                assert(u->in_dbus_queue);

                bus_unit_send_change_signal(u);
                n++;

                if (budget != UINT_MAX)
                        budget--;
        }

        while (budget != 0 && (j = m->dbus_job_queue)) {
                assert(j->in_dbus_queue);

                bus_job_send_change_signal(j);
                n++;

                if (budget != UINT_MAX)
                        budget--;
        }

        if (m->send_reloading_done) {
                m->send_reloading_done = false;
                bus_manager_send_reloading(m, false);
                n++;
        }

        if (m->pending_reload_message) {
                bus_send_pending_reload_message(m);
                n++;
        }

        return n;
}

static int manager_dispatch_cgroups_agent_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = userdata;
        char buf[PATH_MAX];
        ssize_t n;

        n = recv(fd, buf, sizeof(buf), 0);
        if (n < 0)
                return log_error_errno(errno, "Failed to read cgroups agent message: %m");
        if (n == 0) {
                log_error("Got zero-length cgroups agent message, ignoring.");
                return 0;
        }
        if ((size_t) n >= sizeof(buf)) {
                log_error("Got overly long cgroups agent message, ignoring.");
                return 0;
        }

        if (memchr(buf, 0, n)) {
                log_error("Got cgroups agent message with embedded NUL byte, ignoring.");
                return 0;
        }
        buf[n] = 0;

        manager_notify_cgroup_empty(m, buf);
        (void) bus_forward_agent_released(m, buf);

        return 0;
}

static bool manager_process_barrier_fd(char * const *tags, FDSet *fds) {

        /* nothing else must be sent when using BARRIER=1 */
        if (strv_contains(tags, "BARRIER=1")) {
                if (strv_length(tags) != 1)
                        log_warning("Extra notification messages sent with BARRIER=1, ignoring everything.");
                else if (fdset_size(fds) != 1)
                        log_warning("Got incorrect number of fds with BARRIER=1, closing them.");

                /* Drop the message if BARRIER=1 was found */
                return true;
        }

        return false;
}

static void manager_invoke_notify_message(
                Manager *m,
                Unit *u,
                PidRef *pidref,
                const struct ucred *ucred,
                char * const *tags,
                FDSet *fds) {

        assert(m);
        assert(u);
        assert(pidref_is_set(pidref));
        assert(ucred);
        assert(pidref->pid == ucred->pid);
        assert(tags);

        if (u->notifygen == m->notifygen) /* Already invoked on this same unit in this same iteration? */
                return;
        u->notifygen = m->notifygen;

        if (UNIT_VTABLE(u)->notify_message)
                UNIT_VTABLE(u)->notify_message(u, pidref, ucred, tags, fds);

        else if (DEBUG_LOGGING) {
                _cleanup_free_ char *joined = strv_join(tags, ", ");
                char buf[CELLESCAPE_DEFAULT_LENGTH];

                log_unit_debug(u, "Got notification message from unexpected unit type, ignoring: %s",
                               joined ? cellescape(buf, sizeof(buf), joined) : "(null)");
        }
}

static int manager_get_units_for_pidref(Manager *m, const PidRef *pidref, Unit ***ret_units) {
        /* Determine array of every unit that is interested in the specified process */

        assert(m);
        assert(pidref_is_set(pidref));

        Unit *u1, *u2, **array;
        u1 = manager_get_unit_by_pidref_cgroup(m, pidref);
        u2 = hashmap_get(m->watch_pids, pidref);
        array = hashmap_get(m->watch_pids_more, pidref);

        size_t n = 0;
        if (u1)
                n++;
        if (u2)
                n++;
        if (array)
                for (size_t j = 0; array[j]; j++)
                        n++;

        assert(n <= INT_MAX); /* Make sure we can reasonably return the counter as "int" */

        if (ret_units) {
                _cleanup_free_ Unit **units = NULL;

                if (n > 0) {
                        units = new(Unit*, n + 1);
                        if (!units)
                                return -ENOMEM;

                        /* We return a dense array, and put the "main" unit first, i.e. unit in whose cgroup
                         * the process currently is. Note that we do not bother with filtering duplicates
                         * here. */

                        size_t i = 0;
                        if (u1)
                                units[i++] = u1;
                        if (u2)
                                units[i++] = u2;
                        if (array)
                                for (size_t j = 0; array[j]; j++)
                                        units[i++] = array[j];
                        assert(i == n);

                        units[i] = NULL; /* end array in an extra NULL */
                }

                *ret_units = TAKE_PTR(units);
        }

        return (int) n;
}

static int manager_dispatch_notify_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        char buf[NOTIFY_BUFFER_MAX+1];
        struct iovec iovec = {
                .iov_base = buf,
                .iov_len = sizeof(buf)-1,
        };
        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) + CMSG_SPACE(sizeof(int)) /* SCM_PIDFD */ +
                         CMSG_SPACE(sizeof(int) * NOTIFY_FD_MAX)) control;
        struct msghdr msghdr = {
                .msg_iov = &iovec,
                .msg_iovlen = 1,
                .msg_control = &control,
                .msg_controllen = sizeof(control),
        };
        ssize_t n;
        int r;

        assert(m->notify_fd == fd);

        if (revents != EPOLLIN) {
                log_warning("Got unexpected poll event for notify fd.");
                return 0;
        }

        n = recvmsg_safe(m->notify_fd, &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
        if (ERRNO_IS_NEG_TRANSIENT(n))
                return 0; /* Spurious wakeup, try again */
        if (n == -ECHRNG) {
                log_warning_errno(n, "Got message with truncated control data (too many fds sent?), ignoring.");
                return 0;
        }
        if (n == -EXFULL) {
                log_warning_errno(n, "Got message with truncated payload data, ignoring.");
                return 0;
        }
        if (n < 0)
                /* If this is any other, real error, then stop processing this socket. This of course means
                 * we won't take notification messages anymore, but that's still better than busy looping:
                 * being woken up over and over again, but being unable to actually read the message from the
                 * socket. */
                return log_error_errno(n, "Failed to receive notification message: %m");

        _cleanup_close_ int pidfd = -EBADF;
        struct ucred *ucred = NULL;
        int *fd_array = NULL;
        size_t n_fds = 0;

        struct cmsghdr *cmsg;
        CMSG_FOREACH(cmsg, &msghdr) {
                if (cmsg->cmsg_level != SOL_SOCKET)
                        continue;

                if (cmsg->cmsg_type == SCM_RIGHTS) {
                        assert(!fd_array);
                        fd_array = CMSG_TYPED_DATA(cmsg, int);
                        n_fds = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(int);
                } else if (cmsg->cmsg_type == SCM_CREDENTIALS &&
                           cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {

                        assert(!ucred);
                        ucred = CMSG_TYPED_DATA(cmsg, struct ucred);
                } else if (cmsg->cmsg_type == SCM_PIDFD) {
                        assert(pidfd < 0);
                        pidfd = *CMSG_TYPED_DATA(cmsg, int);
                }
        }

        _cleanup_(fdset_free_asyncp) FDSet *fds = NULL;

        if (n_fds > 0) {
                assert(fd_array);

                r = fdset_new_array(&fds, fd_array, n_fds);
                if (r < 0) {
                        close_many(fd_array, n_fds);
                        log_oom_warning();
                        return 0;
                }
        }

        if (!ucred || !pid_is_valid(ucred->pid)) {
                log_warning("Received notify message without valid credentials. Ignoring.");
                return 0;
        }

        _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;

        if (pidfd >= 0)
                r = pidref_set_pidfd_consume(&pidref, TAKE_FD(pidfd));
        else
                r = pidref_set_pid(&pidref, ucred->pid);
        if (r < 0) {
                if (r == -ESRCH)
                        log_debug_errno(r, "Notify sender died before message is processed. Ignoring.");
                else
                        log_warning_errno(r, "Failed to pin notify sender, ignoring message: %m");
                return 0;
        }

        if (pidref.pid != ucred->pid) {
                assert(pidref.fd >= 0);

                log_warning("Got SCM_PIDFD for process " PID_FMT " but SCM_CREDENTIALS for process " PID_FMT ". Ignoring.",
                            pidref.pid, ucred->pid);
                return 0;
        }

        /* As extra safety check, let's make sure the string we get doesn't contain embedded NUL bytes.
         * We permit one trailing NUL byte in the message, but don't expect it. */
        if (n > 1 && memchr(buf, 0, n-1)) {
                log_warning("Received notify message with embedded NUL bytes. Ignoring.");
                return 0;
        }

        /* Make sure it's NUL-terminated, then parse it to obtain the tags list. */
        buf[n] = 0;

        _cleanup_strv_free_ char **tags = strv_split_newlines(buf);
        if (!tags) {
                log_oom_warning();
                return 0;
        }

        /* Possibly a barrier fd, let's see. */
        if (manager_process_barrier_fd(tags, fds)) {
                log_debug("Received barrier notification message from PID " PID_FMT ".", ucred->pid);
                return 0;
        }

        /* Increase the generation counter used for filtering out duplicate unit invocations. */
        m->notifygen++;

        /* Notify every unit that might be interested, which might be multiple. */
        _cleanup_free_ Unit **array = NULL;

        int n_array = manager_get_units_for_pidref(m, &pidref, &array);
        if (n_array < 0) {
                log_warning_errno(n_array, "Failed to determine units for PID " PID_FMT ", ignoring: %m", ucred->pid);
                return 0;
        }
        if (n_array == 0)
                log_debug("Cannot find unit for notify message of PID "PID_FMT", ignoring.", ucred->pid);
        else
                /* And now invoke the per-unit callbacks. Note that manager_invoke_notify_message() will handle
                 * duplicate units – making sure we only invoke each unit's handler once. */
                FOREACH_ARRAY(u, array, n_array)
                        manager_invoke_notify_message(m, *u, &pidref, ucred, tags, fds);

        if (!fdset_isempty(fds))
                log_warning("Got extra auxiliary fds with notification message, closing them.");

        return 0;
}

static void manager_invoke_sigchld_event(
                Manager *m,
                Unit *u,
                const siginfo_t *si) {

        assert(m);
        assert(u);
        assert(si);

        /* Already invoked the handler of this unit in this iteration? Then don't process this again */
        if (u->sigchldgen == m->sigchldgen)
                return;
        u->sigchldgen = m->sigchldgen;

        log_unit_debug(u, "Child "PID_FMT" belongs to %s.", si->si_pid, u->id);
        unit_unwatch_pid(u, si->si_pid);

        if (UNIT_VTABLE(u)->sigchld_event)
                UNIT_VTABLE(u)->sigchld_event(u, si->si_pid, si->si_code, si->si_status);
}

static int manager_dispatch_sigchld(sd_event_source *source, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        siginfo_t si = {};
        int r;

        assert(source);

        /* First we call waitid() for a PID and do not reap the zombie. That way we can still access
         * /proc/$PID for it while it is a zombie. */

        if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {

                if (errno != ECHILD)
                        log_error_errno(errno, "Failed to peek for child with waitid(), ignoring: %m");

                goto turn_off;
        }

        if (si.si_pid <= 0)
                goto turn_off;

        if (IN_SET(si.si_code, CLD_EXITED, CLD_KILLED, CLD_DUMPED)) {
                _cleanup_free_ char *name = NULL;
                (void) pid_get_comm(si.si_pid, &name);

                log_debug("Child "PID_FMT" (%s) died (code=%s, status=%i/%s)",
                          si.si_pid, strna(name),
                          sigchld_code_to_string(si.si_code),
                          si.si_status,
                          strna(si.si_code == CLD_EXITED
                                ? exit_status_to_string(si.si_status, EXIT_STATUS_FULL)
                                : signal_to_string(si.si_status)));

                /* Increase the generation counter used for filtering out duplicate unit invocations */
                m->sigchldgen++;

                /* We look this up by a PidRef that only consists of the PID. After all we couldn't create a
                 * pidfd here any more even if we wanted (since the process just exited). */
                PidRef pidref = PIDREF_MAKE_FROM_PID(si.si_pid);

                /* And now figure out the units this belongs to, there might be multiple... */
                _cleanup_free_ Unit **array = NULL;
                int n_array = manager_get_units_for_pidref(m, &pidref, &array);
                if (n_array < 0)
                        log_warning_errno(n_array, "Failed to get units for process " PID_FMT ", ignoring: %m", si.si_pid);
                else if (n_array == 0)
                        log_debug("Got SIGCHLD for process " PID_FMT " we weren't interested in, ignoring.", si.si_pid);
                else {
                        /* We check for an OOM condition, in case we got SIGCHLD before the OOM notification.
                         * We only do this for the cgroup the PID belonged to, which is the f */
                        (void) unit_check_oom(array[0]);

                        /* We check if systemd-oomd performed a kill so that we log and notify appropriately */
                        (void) unit_check_oomd_kill(array[0]);

                        /* Finally, execute them all. Note that the array might contain duplicates, but that's fine,
                         * manager_invoke_sigchld_event() will ensure we only invoke the handlers once for each
                         * iteration. */
                        FOREACH_ARRAY(u, array, n_array)
                                manager_invoke_sigchld_event(m, *u, &si);
                }
        }

        /* And now, we actually reap the zombie. */
        if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
                log_error_errno(errno, "Failed to dequeue child, ignoring: %m");
                return 0;
        }

        return 0;

turn_off:
        /* All children processed for now, turn off event source */

        r = sd_event_source_set_enabled(m->sigchld_event_source, SD_EVENT_OFF);
        if (r < 0)
                return log_error_errno(r, "Failed to disable SIGCHLD event source: %m");

        return 0;
}

static void manager_start_special(Manager *m, const char *name, JobMode mode) {
        Job *job;

        if (manager_add_job_by_name_and_warn(m, JOB_START, name, mode, NULL, &job) < 0)
                return;

        const char *s = unit_status_string(job->unit, NULL);

        log_info("Activating special unit %s...", s);

        (void) sd_notifyf(/* unset_environment= */ false,
                          "STATUS=Activating special unit %s...", s);
        m->status_ready = false;
}

static void manager_handle_ctrl_alt_del(Manager *m) {
        assert(m);

        /* If the user presses C-A-D more than 7 times within 2s, we reboot/shutdown immediately,
         * unless it was disabled in system.conf. */

        if (ratelimit_below(&m->ctrl_alt_del_ratelimit) || m->cad_burst_action == EMERGENCY_ACTION_NONE)
                manager_start_special(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE_IRREVERSIBLY);
        else
                emergency_action(m, m->cad_burst_action, EMERGENCY_ACTION_WARN, NULL, -1,
                                 "Ctrl-Alt-Del was pressed more than 7 times within 2s");
}

static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        ssize_t n;
        struct signalfd_siginfo sfsi;
        int r;

        assert(m->signal_fd == fd);

        if (revents != EPOLLIN) {
                log_warning("Got unexpected events from signal file descriptor.");
                return 0;
        }

        n = read(m->signal_fd, &sfsi, sizeof(sfsi));
        if (n < 0) {
                if (ERRNO_IS_TRANSIENT(errno))
                        return 0;

                /* We return an error here, which will kill this handler,
                 * to avoid a busy loop on read error. */
                return log_error_errno(errno, "Reading from signal fd failed: %m");
        }
        if (n != sizeof(sfsi)) {
                log_warning("Truncated read from signal fd (%zi bytes), ignoring!", n);
                return 0;
        }

        log_received_signal(sfsi.ssi_signo == SIGCHLD ||
                            (sfsi.ssi_signo == SIGTERM && MANAGER_IS_USER(m))
                            ? LOG_DEBUG : LOG_INFO,
                            &sfsi);

        switch (sfsi.ssi_signo) {

        case SIGCHLD:
                r = sd_event_source_set_enabled(m->sigchld_event_source, SD_EVENT_ON);
                if (r < 0)
                        log_warning_errno(r, "Failed to enable SIGCHLD event source, ignoring: %m");

                break;

        case SIGTERM:
                if (MANAGER_IS_SYSTEM(m)) {
                        /* This is for compatibility with the original sysvinit */
                        m->objective = MANAGER_REEXECUTE;
                        break;
                }

                _fallthrough_;
        case SIGINT:
                if (MANAGER_IS_SYSTEM(m))
                        manager_handle_ctrl_alt_del(m);
                else
                        manager_start_special(m, SPECIAL_EXIT_TARGET, JOB_REPLACE_IRREVERSIBLY);
                break;

        case SIGWINCH:
                /* This is a nop on non-init */
                if (MANAGER_IS_SYSTEM(m))
                        manager_start_special(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);

                break;

        case SIGPWR:
                /* This is a nop on non-init */
                if (MANAGER_IS_SYSTEM(m))
                        manager_start_special(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);

                break;

        case SIGUSR1:
                if (manager_dbus_is_running(m, false)) {
                        log_info("Trying to reconnect to bus...");

                        (void) bus_init_api(m);

                        if (MANAGER_IS_SYSTEM(m))
                                (void) bus_init_system(m);
                } else
                        manager_start_special(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);

                break;

        case SIGUSR2: {
                _cleanup_free_ char *dump = NULL;

                r = manager_get_dump_string(m, /* patterns= */ NULL, &dump);
                if (r < 0) {
                        log_warning_errno(r, "Failed to acquire manager dump: %m");
                        break;
                }

                log_dump(LOG_INFO, dump);
                break;
        }

        case SIGHUP:
                m->objective = MANAGER_RELOAD;
                break;

        default: {

                if (MANAGER_IS_SYSTEM(m)) {
                        /* Starting SIGRTMIN+0 */
                        static const struct {
                                const char *target;
                                JobMode mode;
                        } target_table[] = {
                                [0] = { SPECIAL_DEFAULT_TARGET,     JOB_ISOLATE              },
                                [1] = { SPECIAL_RESCUE_TARGET,      JOB_ISOLATE              },
                                [2] = { SPECIAL_EMERGENCY_TARGET,   JOB_ISOLATE              },
                                [3] = { SPECIAL_HALT_TARGET,        JOB_REPLACE_IRREVERSIBLY },
                                [4] = { SPECIAL_POWEROFF_TARGET,    JOB_REPLACE_IRREVERSIBLY },
                                [5] = { SPECIAL_REBOOT_TARGET,      JOB_REPLACE_IRREVERSIBLY },
                                [6] = { SPECIAL_KEXEC_TARGET,       JOB_REPLACE_IRREVERSIBLY },
                                [7] = { SPECIAL_SOFT_REBOOT_TARGET, JOB_REPLACE_IRREVERSIBLY },
                        };

                        /* Starting SIGRTMIN+13, so that target halt and system halt are 10 apart */
                        static const ManagerObjective objective_table[] = {
                                [0] = MANAGER_HALT,
                                [1] = MANAGER_POWEROFF,
                                [2] = MANAGER_REBOOT,
                                [3] = MANAGER_KEXEC,
                                [4] = MANAGER_SOFT_REBOOT,
                        };

                        if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
                            (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(target_table)) {
                                int idx = (int) sfsi.ssi_signo - SIGRTMIN;
                                manager_start_special(m, target_table[idx].target, target_table[idx].mode);
                                break;
                        }

                        if ((int) sfsi.ssi_signo >= SIGRTMIN+13 &&
                            (int) sfsi.ssi_signo < SIGRTMIN+13+(int) ELEMENTSOF(objective_table)) {
                                m->objective = objective_table[sfsi.ssi_signo - SIGRTMIN - 13];
                                break;
                        }
                }

                switch (sfsi.ssi_signo - SIGRTMIN) {

                case 18: {
                        bool generic = false;

                        if (sfsi.ssi_code != SI_QUEUE)
                                generic = true;
                        else {
                                /* Override a few select commands by our own PID1-specific logic */

                                switch (sfsi.ssi_int) {

                                case _COMMON_SIGNAL_COMMAND_LOG_LEVEL_BASE..._COMMON_SIGNAL_COMMAND_LOG_LEVEL_END:
                                        manager_override_log_level(m, sfsi.ssi_int - _COMMON_SIGNAL_COMMAND_LOG_LEVEL_BASE);
                                        break;

                                case COMMON_SIGNAL_COMMAND_CONSOLE:
                                        manager_override_log_target(m, LOG_TARGET_CONSOLE);
                                        break;

                                case COMMON_SIGNAL_COMMAND_JOURNAL:
                                        manager_override_log_target(m, LOG_TARGET_JOURNAL);
                                        break;

                                case COMMON_SIGNAL_COMMAND_KMSG:
                                        manager_override_log_target(m, LOG_TARGET_KMSG);
                                        break;

                                case COMMON_SIGNAL_COMMAND_NULL:
                                        manager_override_log_target(m, LOG_TARGET_NULL);
                                        break;

                                case MANAGER_SIGNAL_COMMAND_DUMP_JOBS: {
                                        _cleanup_free_ char *dump_jobs = NULL;

                                        r = manager_get_dump_jobs_string(m, /* patterns= */ NULL, "  ", &dump_jobs);
                                        if (r < 0) {
                                                log_warning_errno(r, "Failed to acquire manager jobs dump: %m");
                                                break;
                                        }

                                        log_dump(LOG_INFO, dump_jobs);
                                        break;
                                }

                                default:
                                        generic = true;
                                }
                        }

                        if (generic)
                                return sigrtmin18_handler(source, &sfsi, NULL);

                        break;
                }

                case 20:
                        manager_override_show_status(m, SHOW_STATUS_YES, "signal");
                        break;

                case 21:
                        manager_override_show_status(m, SHOW_STATUS_NO, "signal");
                        break;

                case 22:
                        manager_override_log_level(m, LOG_DEBUG);
                        break;

                case 23:
                        manager_restore_original_log_level(m);
                        break;

                case 24:
                        if (MANAGER_IS_USER(m)) {
                                m->objective = MANAGER_EXIT;
                                return 0;
                        }

                        /* This is a nop on init */
                        break;

                case 25:
                        m->objective = MANAGER_REEXECUTE;
                        break;

                case 26:
                case 29: /* compatibility: used to be mapped to LOG_TARGET_SYSLOG_OR_KMSG */
                        manager_restore_original_log_target(m);
                        break;

                case 27:
                        manager_override_log_target(m, LOG_TARGET_CONSOLE);
                        break;

                case 28:
                        manager_override_log_target(m, LOG_TARGET_KMSG);
                        break;

                default:
                        log_warning("Got unhandled signal <%s>.", signal_to_string(sfsi.ssi_signo));
                }
        }}

        return 0;
}

static int manager_dispatch_time_change_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        Unit *u;

        log_struct(LOG_DEBUG,
                   "MESSAGE_ID=" SD_MESSAGE_TIME_CHANGE_STR,
                   LOG_MESSAGE("Time has been changed"));

        /* Restart the watch */
        (void) manager_setup_time_change(m);

        HASHMAP_FOREACH(u, m->units)
                if (UNIT_VTABLE(u)->time_change)
                        UNIT_VTABLE(u)->time_change(u);

        return 0;
}

static int manager_dispatch_timezone_change(
                sd_event_source *source,
                const struct inotify_event *e,
                void *userdata) {

        Manager *m = ASSERT_PTR(userdata);
        int changed;
        Unit *u;

        log_debug("inotify event for /etc/localtime");

        changed = manager_read_timezone_stat(m);
        if (changed <= 0)
                return changed;

        /* Something changed, restart the watch, to ensure we watch the new /etc/localtime if it changed */
        (void) manager_setup_timezone_change(m);

        /* Read the new timezone */
        tzset();

        log_debug("Timezone has been changed (now: %s).", tzname[daylight]);

        HASHMAP_FOREACH(u, m->units)
                if (UNIT_VTABLE(u)->timezone_change)
                        UNIT_VTABLE(u)->timezone_change(u);

        return 0;
}

static int manager_dispatch_idle_pipe_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);

        assert(m->idle_pipe[2] == fd);

        /* There's at least one Type=idle child that just gave up on us waiting for the boot process to
         * complete. Let's now turn off any further console output if there's at least one service that needs
         * console access, so that from now on our own output should not spill into that service's output
         * anymore. After all, we support Type=idle only to beautify console output and it generally is set
         * on services that want to own the console exclusively without our interference. */
        m->no_console_output = m->n_on_console > 0;

        /* Acknowledge the child's request, and let all other children know too that they shouldn't wait
         * any longer by closing the pipes towards them, which is what they are waiting for. */
        manager_close_idle_pipe(m);

        return 0;
}

static int manager_dispatch_jobs_in_progress(sd_event_source *source, usec_t usec, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        int r;

        assert(source);

        manager_print_jobs_in_progress(m);

        r = sd_event_source_set_time_relative(source, JOBS_IN_PROGRESS_PERIOD_USEC);
        if (r < 0)
                return r;

        return sd_event_source_set_enabled(source, SD_EVENT_ONESHOT);
}

int manager_loop(Manager *m) {
        RateLimit rl = { .interval = 1*USEC_PER_SEC, .burst = 50000 };
        int r;

        assert(m);
        assert(m->objective == MANAGER_OK); /* Ensure manager_startup() has been called */

        manager_check_finished(m);

        /* There might still be some zombies hanging around from before we were exec()'ed. Let's reap them. */
        r = sd_event_source_set_enabled(m->sigchld_event_source, SD_EVENT_ON);
        if (r < 0)
                return log_error_errno(r, "Failed to enable SIGCHLD event source: %m");

        while (m->objective == MANAGER_OK) {

                (void) watchdog_ping();

                if (!ratelimit_below(&rl)) {
                        /* Yay, something is going seriously wrong, pause a little */
                        log_warning("Looping too fast. Throttling execution a little.");
                        sleep(1);
                }

                if (manager_dispatch_load_queue(m) > 0)
                        continue;

                if (manager_dispatch_gc_job_queue(m) > 0)
                        continue;

                if (manager_dispatch_gc_unit_queue(m) > 0)
                        continue;

                if (manager_dispatch_cleanup_queue(m) > 0)
                        continue;

                if (manager_dispatch_cgroup_realize_queue(m) > 0)
                        continue;

                if (manager_dispatch_start_when_upheld_queue(m) > 0)
                        continue;

                if (manager_dispatch_stop_when_bound_queue(m) > 0)
                        continue;

                if (manager_dispatch_stop_when_unneeded_queue(m) > 0)
                        continue;

                if (manager_dispatch_release_resources_queue(m) > 0)
                        continue;

                if (manager_dispatch_dbus_queue(m) > 0)
                        continue;

                /* Sleep for watchdog runtime wait time */
                r = sd_event_run(m->event, watchdog_runtime_wait());
                if (r < 0)
                        return log_error_errno(r, "Failed to run event loop: %m");
        }

        return m->objective;
}

int manager_load_unit_from_dbus_path(Manager *m, const char *s, sd_bus_error *e, Unit **_u) {
        _cleanup_free_ char *n = NULL;
        sd_id128_t invocation_id;
        Unit *u;
        int r;

        assert(m);
        assert(s);
        assert(_u);

        r = unit_name_from_dbus_path(s, &n);
        if (r < 0)
                return r;

        /* Permit addressing units by invocation ID: if the passed bus path is suffixed by a 128-bit ID then
         * we use it as invocation ID. */
        r = sd_id128_from_string(n, &invocation_id);
        if (r >= 0) {
                u = hashmap_get(m->units_by_invocation_id, &invocation_id);
                if (u) {
                        *_u = u;
                        return 0;
                }

                return sd_bus_error_setf(e, BUS_ERROR_NO_UNIT_FOR_INVOCATION_ID,
                                         "No unit with the specified invocation ID " SD_ID128_FORMAT_STR " known.",
                                         SD_ID128_FORMAT_VAL(invocation_id));
        }

        /* If this didn't work, we check if this is a unit name */
        if (!unit_name_is_valid(n, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE)) {
                _cleanup_free_ char *nn = NULL;

                nn = cescape(n);
                return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS,
                                         "Unit name %s is neither a valid invocation ID nor unit name.", strnull(nn));
        }

        r = manager_load_unit(m, n, NULL, e, &u);
        if (r < 0)
                return r;

        *_u = u;
        return 0;
}

int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
        const char *p;
        unsigned id;
        Job *j;
        int r;

        assert(m);
        assert(s);
        assert(_j);

        p = startswith(s, "/org/freedesktop/systemd1/job/");
        if (!p)
                return -EINVAL;

        r = safe_atou(p, &id);
        if (r < 0)
                return r;

        j = manager_get_job(m, id);
        if (!j)
                return -ENOENT;

        *_j = j;

        return 0;
}

void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {

#if HAVE_AUDIT
        _cleanup_free_ char *p = NULL;
        const char *msg;
        int audit_fd, r;

        assert(m);
        assert(u);

        if (!MANAGER_IS_SYSTEM(m))
                return;

        /* Don't generate audit events if the service was already started and we're just deserializing */
        if (MANAGER_IS_RELOADING(m))
                return;

        audit_fd = get_core_audit_fd();
        if (audit_fd < 0)
                return;

        r = unit_name_to_prefix_and_instance(u->id, &p);
        if (r < 0) {
                log_warning_errno(r, "Failed to extract prefix and instance of unit name, ignoring: %m");
                return;
        }

        msg = strjoina("unit=", p);
        if (audit_log_user_comm_message(audit_fd, type, msg, "systemd", NULL, NULL, NULL, success) < 0) {
                if (ERRNO_IS_PRIVILEGE(errno)) {
                        /* We aren't allowed to send audit messages?  Then let's not retry again. */
                        log_debug_errno(errno, "Failed to send audit message, closing audit socket: %m");
                        close_core_audit_fd();
                } else
                        log_warning_errno(errno, "Failed to send audit message, ignoring: %m");
        }
#endif
}

void manager_send_unit_plymouth(Manager *m, Unit *u) {
        _cleanup_free_ char *message = NULL;
        int c, r;

        assert(m);
        assert(u);

        if (!MANAGER_IS_SYSTEM(m))
                return;

        /* Don't generate plymouth events if the service was already started and we're just deserializing */
        if (MANAGER_IS_RELOADING(m))
                return;

        if (detect_container() > 0)
                return;

        if (!UNIT_VTABLE(u)->notify_plymouth)
                return;

        c = asprintf(&message, "U\x02%c%s%c", (int) (strlen(u->id) + 1), u->id, '\x00');
        if (c < 0)
                return (void) log_oom();

        /* We set SOCK_NONBLOCK here so that we rather drop the message then wait for plymouth */
        r = plymouth_send_raw(message, c, SOCK_NONBLOCK);
        if (r < 0)
                log_full_errno(ERRNO_IS_NO_PLYMOUTH(r) ? LOG_DEBUG : LOG_WARNING, r,
                               "Failed to communicate with plymouth: %m");
}

void manager_send_unit_supervisor(Manager *m, Unit *u, bool active) {
        assert(m);
        assert(u);

        /* Notify a "supervisor" process about our progress, i.e. a container manager, hypervisor, or
         * surrounding service manager. */

        if (MANAGER_IS_RELOADING(m))
                return;

        if (!UNIT_VTABLE(u)->notify_supervisor)
                return;

        if (in_initrd()) /* Only send these once we left the initrd */
                return;

        (void) sd_notifyf(/* unset_environment= */ false,
                          active ? "X_SYSTEMD_UNIT_ACTIVE=%s" : "X_SYSTEMD_UNIT_INACTIVE=%s",
                          u->id);
}

usec_t manager_get_watchdog(Manager *m, WatchdogType t) {
        assert(m);

        if (MANAGER_IS_USER(m))
                return USEC_INFINITY;

        if (m->watchdog_overridden[t] != USEC_INFINITY)
                return m->watchdog_overridden[t];

        return m->watchdog[t];
}

void manager_set_watchdog(Manager *m, WatchdogType t, usec_t timeout) {

        assert(m);

        if (MANAGER_IS_USER(m))
                return;

        if (m->watchdog[t] == timeout)
                return;

        if (m->watchdog_overridden[t] == USEC_INFINITY) {
                if (t == WATCHDOG_RUNTIME)
                        (void) watchdog_setup(timeout);
                else if (t == WATCHDOG_PRETIMEOUT)
                        (void) watchdog_setup_pretimeout(timeout);
        }

        m->watchdog[t] = timeout;
}

void manager_override_watchdog(Manager *m, WatchdogType t, usec_t timeout) {
        usec_t usec;

        assert(m);

        if (MANAGER_IS_USER(m))
                return;

        if (m->watchdog_overridden[t] == timeout)
                return;

        usec = timeout == USEC_INFINITY ? m->watchdog[t] : timeout;
        if (t == WATCHDOG_RUNTIME)
                (void) watchdog_setup(usec);
        else if (t == WATCHDOG_PRETIMEOUT)
                (void) watchdog_setup_pretimeout(usec);

        m->watchdog_overridden[t] = timeout;
}

int manager_set_watchdog_pretimeout_governor(Manager *m, const char *governor) {
        _cleanup_free_ char *p = NULL;
        int r;

        assert(m);

        if (MANAGER_IS_USER(m))
                return 0;

        if (streq_ptr(m->watchdog_pretimeout_governor, governor))
                return 0;

        p = strdup(governor);
        if (!p)
                return -ENOMEM;

        r = watchdog_setup_pretimeout_governor(governor);
        if (r < 0)
                return r;

        return free_and_replace(m->watchdog_pretimeout_governor, p);
}

int manager_override_watchdog_pretimeout_governor(Manager *m, const char *governor) {
        _cleanup_free_ char *p = NULL;
        int r;

        assert(m);

        if (MANAGER_IS_USER(m))
                return 0;

        if (streq_ptr(m->watchdog_pretimeout_governor_overridden, governor))
                return 0;

        p = strdup(governor);
        if (!p)
                return -ENOMEM;

        r = watchdog_setup_pretimeout_governor(governor);
        if (r < 0)
                return r;

        return free_and_replace(m->watchdog_pretimeout_governor_overridden, p);
}

int manager_reload(Manager *m) {
        _unused_ _cleanup_(manager_reloading_stopp) Manager *reloading = NULL;
        _cleanup_fdset_free_ FDSet *fds = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        assert(m);

        r = manager_open_serialization(m, &f);
        if (r < 0)
                return log_error_errno(r, "Failed to create serialization file: %m");

        fds = fdset_new();
        if (!fds)
                return log_oom();

        /* We are officially in reload mode from here on. */
        reloading = manager_reloading_start(m);

        r = manager_serialize(m, f, fds, false);
        if (r < 0)
                return r;

        r = finish_serialization_file(f);
        if (r < 0)
                return log_error_errno(r, "Failed to finish serialization: %m");

        /* 💀 This is the point of no return, from here on there is no way back. 💀 */
        reloading = NULL;

        bus_manager_send_reloading(m, true);

        /* Start by flushing out all jobs and units, all generated units, all runtime environments, all dynamic users
         * and everything else that is worth flushing out. We'll get it all back from the serialization — if we need
         * it. */

        manager_clear_jobs_and_units(m);
        lookup_paths_flush_generator(&m->lookup_paths);
        exec_shared_runtime_vacuum(m);
        dynamic_user_vacuum(m, false);
        m->uid_refs = hashmap_free(m->uid_refs);
        m->gid_refs = hashmap_free(m->gid_refs);

        (void) manager_run_environment_generators(m);
        (void) manager_run_generators(m);

        /* We flushed out generated files, for which we don't watch mtime, so we should flush the old map. */
        manager_free_unit_name_maps(m);
        m->unit_file_state_outdated = false;

        /* First, enumerate what we can from kernel and suchlike */
        manager_enumerate_perpetual(m);
        manager_enumerate(m);

        /* Second, deserialize our stored data */
        r = manager_deserialize(m, f, fds);
        if (r < 0)
                log_warning_errno(r, "Deserialization failed, proceeding anyway: %m");

        /* We don't need the serialization anymore */
        f = safe_fclose(f);

        /* Re-register notify_fd as event source, and set up other sockets/communication channels we might need */
        (void) manager_setup_notify(m);
        (void) manager_setup_cgroups_agent(m);
        (void) manager_setup_user_lookup_fd(m);
        (void) manager_setup_handoff_timestamp_fd(m);
        (void) manager_setup_pidref_transport_fd(m);

        /* Clean up deserialized bus track information. They're never consumed during reload (as opposed to
         * reexec) since we do not disconnect from the bus. */
        m->subscribed_as_strv = strv_free(m->subscribed_as_strv);
        m->deserialized_bus_id = SD_ID128_NULL;

        /* Third, fire things up! */
        manager_coldplug(m);

        /* Clean up runtime objects no longer referenced */
        manager_vacuum(m);

        /* Consider the reload process complete now. */
        assert(m->n_reloading > 0);
        m->n_reloading--;

        manager_ready(m);

        m->send_reloading_done = true;
        return 0;
}

void manager_reset_failed(Manager *m) {
        Unit *u;

        assert(m);

        HASHMAP_FOREACH(u, m->units)
                unit_reset_failed(u);
}

bool manager_unit_inactive_or_pending(Manager *m, const char *name) {
        Unit *u;

        assert(m);
        assert(name);

        /* Returns true if the unit is inactive or going down */
        u = manager_get_unit(m, name);
        if (!u)
                return true;

        return unit_inactive_or_pending(u);
}

static void log_taint_string(Manager *m) {
        assert(m);

        if (MANAGER_IS_USER(m) || m->taint_logged)
                return;

        m->taint_logged = true; /* only check for taint once */

        _cleanup_free_ char *taint = taint_string();
        if (isempty(taint))
                return;

        log_struct(LOG_NOTICE,
                   LOG_MESSAGE("System is tainted: %s", taint),
                   "TAINT=%s", taint,
                   "MESSAGE_ID=" SD_MESSAGE_TAINTED_STR);
}

static void manager_notify_finished(Manager *m) {
        usec_t firmware_usec, loader_usec, kernel_usec, initrd_usec, userspace_usec, total_usec;

        if (MANAGER_IS_TEST_RUN(m))
                return;

        if (MANAGER_IS_SYSTEM(m) && m->soft_reboots_count > 0) {
                /* The soft-reboot case, where we only report data for the last reboot */
                firmware_usec = loader_usec = initrd_usec = kernel_usec = 0;
                total_usec = userspace_usec = usec_sub_unsigned(m->timestamps[MANAGER_TIMESTAMP_FINISH].monotonic,
                                                                m->timestamps[MANAGER_TIMESTAMP_SHUTDOWN_START].monotonic);

                log_struct(LOG_INFO,
                           "MESSAGE_ID=" SD_MESSAGE_STARTUP_FINISHED_STR,
                           "USERSPACE_USEC="USEC_FMT, userspace_usec,
                           LOG_MESSAGE("Soft-reboot finished in %s, counter is now at %u.",
                                       FORMAT_TIMESPAN(total_usec, USEC_PER_MSEC),
                                       m->soft_reboots_count));
        } else if (MANAGER_IS_SYSTEM(m) && detect_container() <= 0) {
                char buf[FORMAT_TIMESPAN_MAX + STRLEN(" (firmware) + ") + FORMAT_TIMESPAN_MAX + STRLEN(" (loader) + ")]
                        = {};
                char *p = buf;
                size_t size = sizeof buf;

                /* Note that MANAGER_TIMESTAMP_KERNEL's monotonic value is always at 0, and
                 * MANAGER_TIMESTAMP_FIRMWARE's and MANAGER_TIMESTAMP_LOADER's monotonic value should be considered
                 * negative values. */

                firmware_usec = m->timestamps[MANAGER_TIMESTAMP_FIRMWARE].monotonic - m->timestamps[MANAGER_TIMESTAMP_LOADER].monotonic;
                loader_usec = m->timestamps[MANAGER_TIMESTAMP_LOADER].monotonic - m->timestamps[MANAGER_TIMESTAMP_KERNEL].monotonic;
                userspace_usec = m->timestamps[MANAGER_TIMESTAMP_FINISH].monotonic - m->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic;
                total_usec = m->timestamps[MANAGER_TIMESTAMP_FIRMWARE].monotonic + m->timestamps[MANAGER_TIMESTAMP_FINISH].monotonic;

                if (firmware_usec > 0)
                        size = strpcpyf(&p, size, "%s (firmware) + ", FORMAT_TIMESPAN(firmware_usec, USEC_PER_MSEC));
                if (loader_usec > 0)
                        size = strpcpyf(&p, size, "%s (loader) + ", FORMAT_TIMESPAN(loader_usec, USEC_PER_MSEC));

                if (dual_timestamp_is_set(&m->timestamps[MANAGER_TIMESTAMP_INITRD])) {

                        /* The initrd case on bare-metal */
                        kernel_usec = m->timestamps[MANAGER_TIMESTAMP_INITRD].monotonic - m->timestamps[MANAGER_TIMESTAMP_KERNEL].monotonic;
                        initrd_usec = m->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic - m->timestamps[MANAGER_TIMESTAMP_INITRD].monotonic;

                        log_struct(LOG_INFO,
                                   "MESSAGE_ID=" SD_MESSAGE_STARTUP_FINISHED_STR,
                                   "KERNEL_USEC="USEC_FMT, kernel_usec,
                                   "INITRD_USEC="USEC_FMT, initrd_usec,
                                   "USERSPACE_USEC="USEC_FMT, userspace_usec,
                                   LOG_MESSAGE("Startup finished in %s%s (kernel) + %s (initrd) + %s (userspace) = %s.",
                                               buf,
                                               FORMAT_TIMESPAN(kernel_usec, USEC_PER_MSEC),
                                               FORMAT_TIMESPAN(initrd_usec, USEC_PER_MSEC),
                                               FORMAT_TIMESPAN(userspace_usec, USEC_PER_MSEC),
                                               FORMAT_TIMESPAN(total_usec, USEC_PER_MSEC)));
                } else {
                        /* The initrd-less case on bare-metal */

                        kernel_usec = m->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic - m->timestamps[MANAGER_TIMESTAMP_KERNEL].monotonic;
                        initrd_usec = 0;

                        log_struct(LOG_INFO,
                                   "MESSAGE_ID=" SD_MESSAGE_STARTUP_FINISHED_STR,
                                   "KERNEL_USEC="USEC_FMT, kernel_usec,
                                   "USERSPACE_USEC="USEC_FMT, userspace_usec,
                                   LOG_MESSAGE("Startup finished in %s%s (kernel) + %s (userspace) = %s.",
                                               buf,
                                               FORMAT_TIMESPAN(kernel_usec, USEC_PER_MSEC),
                                               FORMAT_TIMESPAN(userspace_usec, USEC_PER_MSEC),
                                               FORMAT_TIMESPAN(total_usec, USEC_PER_MSEC)));
                }
        } else {
                /* The container and --user case */
                firmware_usec = loader_usec = initrd_usec = kernel_usec = 0;
                total_usec = userspace_usec = m->timestamps[MANAGER_TIMESTAMP_FINISH].monotonic - m->timestamps[MANAGER_TIMESTAMP_USERSPACE].monotonic;

                log_struct(LOG_INFO,
                           "MESSAGE_ID=" SD_MESSAGE_USER_STARTUP_FINISHED_STR,
                           "USERSPACE_USEC="USEC_FMT, userspace_usec,
                           LOG_MESSAGE("Startup finished in %s.",
                                       FORMAT_TIMESPAN(total_usec, USEC_PER_MSEC)));
        }

        bus_manager_send_finished(m, firmware_usec, loader_usec, kernel_usec, initrd_usec, userspace_usec, total_usec);

        log_taint_string(m);
}

static void manager_send_ready_on_basic_target(Manager *m) {
        int r;

        assert(m);

        /* We send READY=1 on reaching basic.target only when running in --user mode. */
        if (!MANAGER_IS_USER(m) || m->ready_sent)
                return;

        r = sd_notify(/* unset_environment= */ false,
                      "READY=1\n"
                      "STATUS=Reached " SPECIAL_BASIC_TARGET ".");
        if (r < 0)
                log_warning_errno(r, "Failed to send readiness notification, ignoring: %m");

        m->ready_sent = true;
        m->status_ready = false;
}

static void manager_send_ready_on_idle(Manager *m) {
        int r;

        assert(m);

        /* Skip the notification if nothing changed. */
        if (m->ready_sent && m->status_ready)
                return;

        /* Note that for user managers, we might have already sent READY=1 in manager_send_ready_user_scope().
         * But we still need to flush STATUS=. The second READY=1 will be treated as a noop so it doesn't
         * hurt to send it twice. */
        r = sd_notify(/* unset_environment= */ false,
                      "READY=1\n"
                      "STATUS=Ready.");
        if (r < 0)
                log_full_errno(m->ready_sent ? LOG_DEBUG : LOG_WARNING, r,
                               "Failed to send readiness notification, ignoring: %m");

        m->ready_sent = m->status_ready = true;
}

static void manager_check_basic_target(Manager *m) {
        Unit *u;

        assert(m);

        /* Small shortcut */
        if (m->ready_sent && m->taint_logged)
                return;

        u = manager_get_unit(m, SPECIAL_BASIC_TARGET);
        if (!u || !UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u)))
                return;

        /* For user managers, send out READY=1 as soon as we reach basic.target */
        manager_send_ready_on_basic_target(m);

        /* Log the taint string as soon as we reach basic.target */
        log_taint_string(m);
}

void manager_check_finished(Manager *m) {
        assert(m);

        if (MANAGER_IS_RELOADING(m))
                return;

        /* Verify that we have entered the event loop already, and not left it again. */
        if (!MANAGER_IS_RUNNING(m))
                return;

        manager_check_basic_target(m);

        if (!hashmap_isempty(m->jobs)) {
                if (m->jobs_in_progress_event_source)
                        /* Ignore any failure, this is only for feedback */
                        (void) sd_event_source_set_time(m->jobs_in_progress_event_source,
                                                        manager_watch_jobs_next_time(m));
                return;
        }

        /* The jobs hashmap tends to grow a lot during boot, and then it's not reused until shutdown. Let's
           kill the hashmap if it is relatively large. */
        if (hashmap_buckets(m->jobs) > hashmap_size(m->units) / 10)
                m->jobs = hashmap_free(m->jobs);

        manager_send_ready_on_idle(m);

        /* Notify Type=idle units that we are done now */
        manager_close_idle_pipe(m);

        if (MANAGER_IS_FINISHED(m))
                return;

        manager_flip_auto_status(m, false, "boot finished");

        /* Turn off confirm spawn now */
        m->confirm_spawn = NULL;

        /* No need to update ask password status when we're going non-interactive */
        manager_close_ask_password(m);

        /* This is no longer the first boot */
        manager_set_first_boot(m, false);

        dual_timestamp_now(m->timestamps + MANAGER_TIMESTAMP_FINISH);

        manager_notify_finished(m);

        manager_invalidate_startup_units(m);
}

void manager_send_reloading(Manager *m) {
        assert(m);

        /* Let whoever invoked us know that we are now reloading */
        (void) notify_reloading_full(/* status = */ NULL);

        /* And ensure that we'll send READY=1 again as soon as we are ready again */
        m->ready_sent = false;
}

static bool generator_path_any(char * const *paths) {

        /* Optimize by skipping the whole process by not creating output directories if no generators are found. */

        STRV_FOREACH(i, paths) {
                if (access(*i, F_OK) >= 0)
                        return true;
                if (errno != ENOENT)
                        log_warning_errno(errno, "Failed to check if generator dir '%s' exists, assuming not: %m", *i);
        }

        return false;
}

static int manager_run_environment_generators(Manager *m) {
        _cleanup_strv_free_ char **paths = NULL;
        int r;

        assert(m);

        if (MANAGER_IS_TEST_RUN(m) && !(m->test_run_flags & MANAGER_TEST_RUN_ENV_GENERATORS))
                return 0;

        paths = env_generator_binary_paths(m->runtime_scope);
        if (!paths)
                return log_oom();

        if (!generator_path_any(paths))
                return 0;

        char **tmp = NULL; /* this is only used in the forked process, no cleanup here */
        void *args[_STDOUT_CONSUME_MAX] = {
                [STDOUT_GENERATE] = &tmp,
                [STDOUT_COLLECT]  = &tmp,
                [STDOUT_CONSUME]  = &m->transient_environment,
        };

        WITH_UMASK(0022)
                r = execute_directories((const char* const*) paths, DEFAULT_TIMEOUT_USEC, gather_environment,
                                        args, NULL, m->transient_environment,
                                        EXEC_DIR_PARALLEL | EXEC_DIR_IGNORE_ERRORS | EXEC_DIR_SET_SYSTEMD_EXEC_PID);
        return r;
}

static int build_generator_environment(Manager *m, char ***ret) {
        _cleanup_strv_free_ char **nl = NULL;
        Virtualization v;
        ConfidentialVirtualization cv;
        int r;

        assert(m);
        assert(ret);

        /* Generators oftentimes want to know some basic facts about the environment they run in, in order to
         * adjust generated units to that. Let's pass down some bits of information that are easy for us to
         * determine (but a bit harder for generator scripts to determine), as environment variables. */

        nl = strv_copy(m->transient_environment);
        if (!nl)
                return -ENOMEM;

        r = strv_env_assign(&nl, "SYSTEMD_SCOPE", runtime_scope_to_string(m->runtime_scope));
        if (r < 0)
                return r;

        if (MANAGER_IS_SYSTEM(m)) {
                /* Note that $SYSTEMD_IN_INITRD may be used to override the initrd detection in much of our
                 * codebase. This is hence more than purely informational. It will shortcut detection of the
                 * initrd state if generators invoke our own tools. But that's OK, as it would come to the
                 * same results (hopefully). */
                r = strv_env_assign(&nl, "SYSTEMD_IN_INITRD", one_zero(in_initrd()));
                if (r < 0)
                        return r;

                if (m->soft_reboots_count > 0) {
                        r = strv_env_assignf(&nl, "SYSTEMD_SOFT_REBOOTS_COUNT", "%u", m->soft_reboots_count);
                        if (r < 0)
                                return r;
                }

                if (m->first_boot >= 0) {
                        r = strv_env_assign(&nl, "SYSTEMD_FIRST_BOOT", one_zero(m->first_boot));
                        if (r < 0)
                                return r;
                }
        }

        v = detect_virtualization();
        if (v < 0)
                log_debug_errno(v, "Failed to detect virtualization, ignoring: %m");
        else if (v > 0) {
                const char *s;

                s = strjoina(VIRTUALIZATION_IS_VM(v) ? "vm:" :
                             VIRTUALIZATION_IS_CONTAINER(v) ? "container:" : ":",
                             virtualization_to_string(v));

                r = strv_env_assign(&nl, "SYSTEMD_VIRTUALIZATION", s);
                if (r < 0)
                        return r;
        }

        cv = detect_confidential_virtualization();
        if (cv < 0)
                log_debug_errno(cv, "Failed to detect confidential virtualization, ignoring: %m");
        else if (cv > 0) {
                r = strv_env_assign(&nl, "SYSTEMD_CONFIDENTIAL_VIRTUALIZATION", confidential_virtualization_to_string(cv));
                if (r < 0)
                        return r;
        }

        r = strv_env_assign(&nl, "SYSTEMD_ARCHITECTURE", architecture_to_string(uname_architecture()));
        if (r < 0)
                return r;

        *ret = TAKE_PTR(nl);
        return 0;
}

static int manager_execute_generators(Manager *m, char * const *paths, bool remount_ro) {
        _cleanup_strv_free_ char **ge = NULL;
        int r;

        assert(m);

        r = build_generator_environment(m, &ge);
        if (r < 0)
                return log_error_errno(r, "Failed to build generator environment: %m");

        if (remount_ro) {
                /* Remount most of the filesystem tree read-only. We leave /sys/ as-is, because our code
                 * checks whether it is read-only to detect containerized execution environments. We leave
                 * /run/ as-is too, because that's where our output goes. We also leave /proc/ and /dev/shm/
                 * because they're API, and /tmp/ that safe_fork() mounted for us.
                 */
                r = bind_remount_recursive("/", MS_RDONLY, MS_RDONLY,
                                           STRV_MAKE("/sys", "/run", "/proc", "/dev/shm", "/tmp"));
                if (r < 0)
                        log_warning_errno(r, "Read-only bind remount failed, ignoring: %m");
        }

        const char *argv[] = {
                NULL, /* Leave this empty, execute_directory() will fill something in */
                m->lookup_paths.generator,
                m->lookup_paths.generator_early,
                m->lookup_paths.generator_late,
                NULL,
        };

        BLOCK_WITH_UMASK(0022);
        return execute_directories(
                        (const char* const*) paths,
                        DEFAULT_TIMEOUT_USEC,
                        /* callbacks= */ NULL, /* callback_args= */ NULL,
                        (char**) argv,
                        ge,
                        EXEC_DIR_PARALLEL | EXEC_DIR_IGNORE_ERRORS | EXEC_DIR_SET_SYSTEMD_EXEC_PID | EXEC_DIR_WARN_WORLD_WRITABLE);
}

static int manager_run_generators(Manager *m) {
        ForkFlags flags = FORK_RESET_SIGNALS | FORK_WAIT | FORK_NEW_MOUNTNS | FORK_MOUNTNS_SLAVE;
        _cleanup_strv_free_ char **paths = NULL;
        int r;

        assert(m);

        if (MANAGER_IS_TEST_RUN(m) && !(m->test_run_flags & MANAGER_TEST_RUN_GENERATORS))
                return 0;

        paths = generator_binary_paths(m->runtime_scope);
        if (!paths)
                return log_oom();

        if (!generator_path_any(paths))
                return 0;

        r = lookup_paths_mkdir_generator(&m->lookup_paths);
        if (r < 0) {
                log_error_errno(r, "Failed to create generator directories: %m");
                goto finish;
        }

        /* If we are the system manager, we fork and invoke the generators in a sanitized mount namespace. If
         * we are the user manager, let's just execute the generators directly. We might not have the
         * necessary privileges, and the system manager has already mounted /tmp/ and everything else for us.
         */
        if (MANAGER_IS_USER(m)) {
                r = manager_execute_generators(m, paths, /* remount_ro= */ false);
                goto finish;
        }

        /* On some systems /tmp/ doesn't exist, and on some other systems we cannot create it at all. Avoid
         * trying to mount a private tmpfs on it as there's no one size fits all. */
        if (is_dir("/tmp", /* follow= */ false) > 0 && !MANAGER_IS_TEST_RUN(m))
                flags |= FORK_PRIVATE_TMP;

        r = safe_fork("(sd-gens)", flags, NULL);
        if (r == 0) {
                r = manager_execute_generators(m, paths, /* remount_ro= */ true);
                _exit(r >= 0 ? EXIT_SUCCESS : EXIT_FAILURE);
        }
        if (r < 0) {
                if (!ERRNO_IS_PRIVILEGE(r) && r != -EINVAL) {
                        log_error_errno(r, "Failed to fork off sandboxing environment for executing generators: %m");
                        goto finish;
                }

                /* Failed to fork with new mount namespace? Maybe, running in a container environment with
                 * seccomp or without capability.
                 *
                 * We also allow -EINVAL to allow running without CLONE_NEWNS.
                 *
                 * Also, when running on non-native userland architecture via systemd-nspawn and
                 * qemu-user-static QEMU-emulator, clone() with CLONE_NEWNS fails with EINVAL, see
                 * https://github.com/systemd/systemd/issues/28901.
                 */
                log_debug_errno(r,
                                "Failed to fork off sandboxing environment for executing generators. "
                                "Falling back to execute generators without sandboxing: %m");
                r = manager_execute_generators(m, paths, /* remount_ro= */ false);
        }

finish:
        lookup_paths_trim_generator(&m->lookup_paths);
        return r;
}

int manager_transient_environment_add(Manager *m, char **plus) {
        char **a;

        assert(m);

        if (strv_isempty(plus))
                return 0;

        a = strv_env_merge(m->transient_environment, plus);
        if (!a)
                return log_oom();

        sanitize_environment(a);

        return strv_free_and_replace(m->transient_environment, a);
}

int manager_client_environment_modify(
                Manager *m,
                char **minus,
                char **plus) {

        char **a = NULL, **b = NULL, **l;

        assert(m);

        if (strv_isempty(minus) && strv_isempty(plus))
                return 0;

        l = m->client_environment;

        if (!strv_isempty(minus)) {
                a = strv_env_delete(l, 1, minus);
                if (!a)
                        return -ENOMEM;

                l = a;
        }

        if (!strv_isempty(plus)) {
                b = strv_env_merge(l, plus);
                if (!b) {
                        strv_free(a);
                        return -ENOMEM;
                }

                l = b;
        }

        if (m->client_environment != l)
                strv_free(m->client_environment);

        if (a != l)
                strv_free(a);
        if (b != l)
                strv_free(b);

        m->client_environment = sanitize_environment(l);
        return 0;
}

int manager_get_effective_environment(Manager *m, char ***ret) {
        char **l;

        assert(m);
        assert(ret);

        l = strv_env_merge(m->transient_environment, m->client_environment);
        if (!l)
                return -ENOMEM;

        *ret = l;
        return 0;
}

int manager_set_unit_defaults(Manager *m, const UnitDefaults *defaults) {
        _cleanup_free_ char *label = NULL;
        struct rlimit *rlimit[_RLIMIT_MAX];
        int r;

        assert(m);
        assert(defaults);

        if (streq_ptr(defaults->smack_process_label, "/"))
                label = NULL;
        else  {
                const char *l = defaults->smack_process_label;
#ifdef SMACK_DEFAULT_PROCESS_LABEL
                if (!l)
                        l = SMACK_DEFAULT_PROCESS_LABEL;
#endif
                if (l) {
                        label = strdup(l);
                        if (!label)
                                return -ENOMEM;
                } else
                        label = NULL;
        }

        r = rlimit_copy_all(rlimit, defaults->rlimit);
        if (r < 0)
                return r;

        m->defaults.std_output = defaults->std_output;
        m->defaults.std_error = defaults->std_error;

        m->defaults.restart_usec = defaults->restart_usec;
        m->defaults.timeout_start_usec = defaults->timeout_start_usec;
        m->defaults.timeout_stop_usec = defaults->timeout_stop_usec;
        m->defaults.timeout_abort_usec = defaults->timeout_abort_usec;
        m->defaults.timeout_abort_set = defaults->timeout_abort_set;
        m->defaults.device_timeout_usec = defaults->device_timeout_usec;

        m->defaults.start_limit = defaults->start_limit;

        m->defaults.cpu_accounting = defaults->cpu_accounting;
        m->defaults.memory_accounting = defaults->memory_accounting;
        m->defaults.io_accounting = defaults->io_accounting;
        m->defaults.blockio_accounting = defaults->blockio_accounting;
        m->defaults.tasks_accounting = defaults->tasks_accounting;
        m->defaults.ip_accounting = defaults->ip_accounting;

        m->defaults.tasks_max = defaults->tasks_max;
        m->defaults.timer_accuracy_usec = defaults->timer_accuracy_usec;

        m->defaults.oom_policy = defaults->oom_policy;
        m->defaults.oom_score_adjust = defaults->oom_score_adjust;
        m->defaults.oom_score_adjust_set = defaults->oom_score_adjust_set;

        m->defaults.memory_pressure_watch = defaults->memory_pressure_watch;
        m->defaults.memory_pressure_threshold_usec = defaults->memory_pressure_threshold_usec;

        free_and_replace(m->defaults.smack_process_label, label);
        rlimit_free_all(m->defaults.rlimit);
        memcpy(m->defaults.rlimit, rlimit, sizeof(struct rlimit*) * _RLIMIT_MAX);

        return 0;
}

void manager_recheck_dbus(Manager *m) {
        assert(m);

        /* Connects to the bus if the dbus service and socket are running. If we are running in user mode
         * this is all it does. In system mode we'll also connect to the system bus (which will most likely
         * just reuse the connection of the API bus). That's because the system bus after all runs as service
         * of the system instance, while in the user instance we can assume it's already there. */

        if (MANAGER_IS_RELOADING(m))
                return; /* don't check while we are reloading… */

        if (manager_dbus_is_running(m, false)) {
                (void) bus_init_api(m);

                if (MANAGER_IS_SYSTEM(m))
                        (void) bus_init_system(m);
        } else {
                (void) bus_done_api(m);

                if (MANAGER_IS_SYSTEM(m))
                        (void) bus_done_system(m);
        }
}

static bool manager_journal_is_running(Manager *m) {
        Unit *u;

        assert(m);

        if (MANAGER_IS_TEST_RUN(m))
                return false;

        /* If we are the user manager we can safely assume that the journal is up */
        if (!MANAGER_IS_SYSTEM(m))
                return true;

        /* Check that the socket is not only up, but in RUNNING state */
        u = manager_get_unit(m, SPECIAL_JOURNALD_SOCKET);
        if (!u)
                return false;
        if (SOCKET(u)->state != SOCKET_RUNNING)
                return false;

        /* Similar, check if the daemon itself is fully up, too */
        u = manager_get_unit(m, SPECIAL_JOURNALD_SERVICE);
        if (!u)
                return false;
        if (!IN_SET(SERVICE(u)->state, SERVICE_RELOAD, SERVICE_RUNNING))
                return false;

        return true;
}

void disable_printk_ratelimit(void) {
        /* Disable kernel's printk ratelimit.
         *
         * Logging to /dev/kmsg is most useful during early boot and shutdown, where normal logging
         * mechanisms are not available. The semantics of this sysctl are such that any kernel command-line
         * setting takes precedence. */
        int r;

        r = sysctl_write("kernel/printk_devkmsg", "on");
        if (r < 0)
                log_debug_errno(r, "Failed to set sysctl kernel.printk_devkmsg=on: %m");
}

void manager_recheck_journal(Manager *m) {

        assert(m);

        /* Don't bother with this unless we are in the special situation of being PID 1 */
        if (getpid_cached() != 1)
                return;

        /* Don't check this while we are reloading, things might still change */
        if (MANAGER_IS_RELOADING(m))
                return;

        /* The journal is fully and entirely up? If so, let's permit logging to it, if that's configured. If
         * the journal is down, don't ever log to it, otherwise we might end up deadlocking ourselves as we
         * might trigger an activation ourselves we can't fulfill. */
        log_set_prohibit_ipc(!manager_journal_is_running(m));
        log_open();
}

static ShowStatus manager_get_show_status(Manager *m) {
        assert(m);

        if (MANAGER_IS_USER(m))
                return _SHOW_STATUS_INVALID;

        if (m->show_status_overridden != _SHOW_STATUS_INVALID)
                return m->show_status_overridden;

        return m->show_status;
}

bool manager_get_show_status_on(Manager *m) {
        assert(m);

        return show_status_on(manager_get_show_status(m));
}

static void set_show_status_marker(bool b) {
        if (b)
                (void) touch("/run/systemd/show-status");
        else
                (void) unlink("/run/systemd/show-status");
}

void manager_set_show_status(Manager *m, ShowStatus mode, const char *reason) {
        assert(m);
        assert(reason);
        assert(mode >= 0 && mode < _SHOW_STATUS_MAX);

        if (MANAGER_IS_USER(m))
                return;

        if (mode == m->show_status)
                return;

        if (m->show_status_overridden == _SHOW_STATUS_INVALID) {
                bool enabled;

                enabled = show_status_on(mode);
                log_debug("%s (%s) showing of status (%s).",
                          enabled ? "Enabling" : "Disabling",
                          strna(show_status_to_string(mode)),
                          reason);

                set_show_status_marker(enabled);
        }

        m->show_status = mode;
}

void manager_override_show_status(Manager *m, ShowStatus mode, const char *reason) {
        assert(m);
        assert(mode < _SHOW_STATUS_MAX);

        if (MANAGER_IS_USER(m))
                return;

        if (mode == m->show_status_overridden)
                return;

        m->show_status_overridden = mode;

        if (mode == _SHOW_STATUS_INVALID)
                mode = m->show_status;

        log_debug("%s (%s) showing of status (%s).",
                  m->show_status_overridden != _SHOW_STATUS_INVALID ? "Overriding" : "Restoring",
                  strna(show_status_to_string(mode)),
                  reason);

        set_show_status_marker(show_status_on(mode));
}

const char* manager_get_confirm_spawn(Manager *m) {
        static int last_errno = 0;
        struct stat st;
        int r;

        assert(m);

        /* Here's the deal: we want to test the validity of the console but don't want
         * PID1 to go through the whole console process which might block. But we also
         * want to warn the user only once if something is wrong with the console so we
         * cannot do the sanity checks after spawning our children. So here we simply do
         * really basic tests to hopefully trap common errors.
         *
         * If the console suddenly disappear at the time our children will really it
         * then they will simply fail to acquire it and a positive answer will be
         * assumed. New children will fall back to /dev/console though.
         *
         * Note: TTYs are devices that can come and go any time, and frequently aren't
         * available yet during early boot (consider a USB rs232 dongle...). If for any
         * reason the configured console is not ready, we fall back to the default
         * console. */

        if (!m->confirm_spawn || path_equal(m->confirm_spawn, "/dev/console"))
                return m->confirm_spawn;

        if (stat(m->confirm_spawn, &st) < 0) {
                r = -errno;
                goto fail;
        }

        if (!S_ISCHR(st.st_mode)) {
                r = -ENOTTY;
                goto fail;
        }

        last_errno = 0;
        return m->confirm_spawn;

fail:
        if (last_errno != r)
                last_errno = log_warning_errno(r, "Failed to open %s, using default console: %m", m->confirm_spawn);

        return "/dev/console";
}

void manager_set_first_boot(Manager *m, bool b) {
        assert(m);

        if (!MANAGER_IS_SYSTEM(m))
                return;

        if (m->first_boot != (int) b) {
                if (b)
                        (void) touch("/run/systemd/first-boot");
                else
                        (void) unlink("/run/systemd/first-boot");
        }

        m->first_boot = b;
}

void manager_disable_confirm_spawn(void) {
        (void) touch("/run/systemd/confirm_spawn_disabled");
}

static bool manager_should_show_status(Manager *m, StatusType type) {
        assert(m);

        if (!MANAGER_IS_SYSTEM(m))
                return false;

        if (m->no_console_output)
                return false;

        if (!IN_SET(manager_state(m), MANAGER_INITIALIZING, MANAGER_STARTING, MANAGER_STOPPING))
                return false;

        /* If we cannot find out the status properly, just proceed. */
        if (type != STATUS_TYPE_EMERGENCY && manager_check_ask_password(m) > 0)
                return false;

        if (type == STATUS_TYPE_NOTICE && m->show_status != SHOW_STATUS_NO)
                return true;

        return manager_get_show_status_on(m);
}

void manager_status_printf(Manager *m, StatusType type, const char *status, const char *format, ...) {
        va_list ap;

        /* If m is NULL, assume we're after shutdown and let the messages through. */

        if (m && !manager_should_show_status(m, type))
                return;

        /* XXX We should totally drop the check for ephemeral here
         * and thus effectively make 'Type=idle' pointless. */
        if (type == STATUS_TYPE_EPHEMERAL && m && m->n_on_console > 0)
                return;

        va_start(ap, format);
        status_vprintf(status, SHOW_STATUS_ELLIPSIZE|(type == STATUS_TYPE_EPHEMERAL ? SHOW_STATUS_EPHEMERAL : 0), format, ap);
        va_end(ap);
}

Set* manager_get_units_needing_mounts_for(Manager *m, const char *path, UnitMountDependencyType t) {
        assert(m);
        assert(path);
        assert(t >= 0 && t < _UNIT_MOUNT_DEPENDENCY_TYPE_MAX);

        if (path_equal(path, "/"))
                path = "";

        return hashmap_get(m->units_needing_mounts_for[t], path);
}

int manager_update_failed_units(Manager *m, Unit *u, bool failed) {
        unsigned size;
        int r;

        assert(m);
        assert(u->manager == m);

        size = set_size(m->failed_units);

        if (failed) {
                r = set_ensure_put(&m->failed_units, NULL, u);
                if (r < 0)
                        return log_oom();
        } else
                (void) set_remove(m->failed_units, u);

        if (set_size(m->failed_units) != size)
                bus_manager_send_change_signal(m);

        return 0;
}

ManagerState manager_state(Manager *m) {
        Unit *u;

        assert(m);

        /* Is the special shutdown target active or queued? If so, we are in shutdown state */
        u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET);
        if (u && unit_active_or_pending(u))
                return MANAGER_STOPPING;

        /* Did we ever finish booting? If not then we are still starting up */
        if (!MANAGER_IS_FINISHED(m)) {

                u = manager_get_unit(m, SPECIAL_BASIC_TARGET);
                if (!u || !UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u)))
                        return MANAGER_INITIALIZING;

                return MANAGER_STARTING;
        }

        if (MANAGER_IS_SYSTEM(m)) {
                /* Are the rescue or emergency targets active or queued? If so we are in maintenance state */
                u = manager_get_unit(m, SPECIAL_RESCUE_TARGET);
                if (u && unit_active_or_pending(u))
                        return MANAGER_MAINTENANCE;

                u = manager_get_unit(m, SPECIAL_EMERGENCY_TARGET);
                if (u && unit_active_or_pending(u))
                        return MANAGER_MAINTENANCE;
        }

        /* Are there any failed units? If so, we are in degraded mode */
        if (!set_isempty(m->failed_units))
                return MANAGER_DEGRADED;

        return MANAGER_RUNNING;
}

static void manager_unref_uid_internal(
                Hashmap *uid_refs,
                uid_t uid,
                bool destroy_now,
                int (*_clean_ipc)(uid_t uid)) {

        uint32_t c, n;

        assert(uid_is_valid(uid));
        assert(_clean_ipc);

        /* A generic implementation, covering both manager_unref_uid() and manager_unref_gid(), under the
         * assumption that uid_t and gid_t are actually defined the same way, with the same validity rules.
         *
         * We store a hashmap where the key is the UID/GID and the value is a 32-bit reference counter, whose
         * highest bit is used as flag for marking UIDs/GIDs whose IPC objects to remove when the last
         * reference to the UID/GID is dropped. The flag is set to on, once at least one reference from a
         * unit where RemoveIPC= is set is added on a UID/GID. It is reset when the UID's/GID's reference
         * counter drops to 0 again. */

        assert_cc(sizeof(uid_t) == sizeof(gid_t));
        assert_cc(UID_INVALID == (uid_t) GID_INVALID);

        if (uid == 0) /* We don't keep track of root, and will never destroy it */
                return;

        c = PTR_TO_UINT32(hashmap_get(uid_refs, UID_TO_PTR(uid)));

        n = c & ~DESTROY_IPC_FLAG;
        assert(n > 0);
        n--;

        if (destroy_now && n == 0) {
                hashmap_remove(uid_refs, UID_TO_PTR(uid));

                if (c & DESTROY_IPC_FLAG) {
                        log_debug("%s " UID_FMT " is no longer referenced, cleaning up its IPC.",
                                  _clean_ipc == clean_ipc_by_uid ? "UID" : "GID",
                                  uid);
                        (void) _clean_ipc(uid);
                }
        } else {
                c = n | (c & DESTROY_IPC_FLAG);
                assert_se(hashmap_update(uid_refs, UID_TO_PTR(uid), UINT32_TO_PTR(c)) >= 0);
        }
}

void manager_unref_uid(Manager *m, uid_t uid, bool destroy_now) {
        manager_unref_uid_internal(m->uid_refs, uid, destroy_now, clean_ipc_by_uid);
}

void manager_unref_gid(Manager *m, gid_t gid, bool destroy_now) {
        manager_unref_uid_internal(m->gid_refs, (uid_t) gid, destroy_now, clean_ipc_by_gid);
}

static int manager_ref_uid_internal(
                Hashmap **uid_refs,
                uid_t uid,
                bool clean_ipc) {

        uint32_t c, n;
        int r;

        assert(uid_refs);
        assert(uid_is_valid(uid));

        /* A generic implementation, covering both manager_ref_uid() and manager_ref_gid(), under the
         * assumption that uid_t and gid_t are actually defined the same way, with the same validity
         * rules. */

        assert_cc(sizeof(uid_t) == sizeof(gid_t));
        assert_cc(UID_INVALID == (uid_t) GID_INVALID);

        if (uid == 0) /* We don't keep track of root, and will never destroy it */
                return 0;

        r = hashmap_ensure_allocated(uid_refs, &trivial_hash_ops);
        if (r < 0)
                return r;

        c = PTR_TO_UINT32(hashmap_get(*uid_refs, UID_TO_PTR(uid)));

        n = c & ~DESTROY_IPC_FLAG;
        n++;

        if (n & DESTROY_IPC_FLAG) /* check for overflow */
                return -EOVERFLOW;

        c = n | (c & DESTROY_IPC_FLAG) | (clean_ipc ? DESTROY_IPC_FLAG : 0);

        return hashmap_replace(*uid_refs, UID_TO_PTR(uid), UINT32_TO_PTR(c));
}

int manager_ref_uid(Manager *m, uid_t uid, bool clean_ipc) {
        return manager_ref_uid_internal(&m->uid_refs, uid, clean_ipc);
}

int manager_ref_gid(Manager *m, gid_t gid, bool clean_ipc) {
        return manager_ref_uid_internal(&m->gid_refs, (uid_t) gid, clean_ipc);
}

static void manager_vacuum_uid_refs_internal(
                Hashmap *uid_refs,
                int (*_clean_ipc)(uid_t uid)) {

        void *p, *k;

        assert(_clean_ipc);

        HASHMAP_FOREACH_KEY(p, k, uid_refs) {
                uint32_t c, n;
                uid_t uid;

                uid = PTR_TO_UID(k);
                c = PTR_TO_UINT32(p);

                n = c & ~DESTROY_IPC_FLAG;
                if (n > 0)
                        continue;

                if (c & DESTROY_IPC_FLAG) {
                        log_debug("Found unreferenced %s " UID_FMT " after reload/reexec. Cleaning up.",
                                  _clean_ipc == clean_ipc_by_uid ? "UID" : "GID",
                                  uid);
                        (void) _clean_ipc(uid);
                }

                assert_se(hashmap_remove(uid_refs, k) == p);
        }
}

static void manager_vacuum_uid_refs(Manager *m) {
        manager_vacuum_uid_refs_internal(m->uid_refs, clean_ipc_by_uid);
}

static void manager_vacuum_gid_refs(Manager *m) {
        manager_vacuum_uid_refs_internal(m->gid_refs, clean_ipc_by_gid);
}

static void manager_vacuum(Manager *m) {
        assert(m);

        /* Release any dynamic users no longer referenced */
        dynamic_user_vacuum(m, true);

        /* Release any references to UIDs/GIDs no longer referenced, and destroy any IPC owned by them */
        manager_vacuum_uid_refs(m);
        manager_vacuum_gid_refs(m);

        /* Release any runtimes no longer referenced */
        exec_shared_runtime_vacuum(m);
}

static int manager_dispatch_user_lookup_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        struct buffer {
                uid_t uid;
                gid_t gid;
                char unit_name[UNIT_NAME_MAX+1];
        } _packed_ buffer;

        Manager *m = ASSERT_PTR(userdata);
        ssize_t l;
        size_t n;
        Unit *u;

        assert(source);

        /* Invoked whenever a child process succeeded resolving its user/group to use and sent us the
         * resulting UID/GID in a datagram. We parse the datagram here and pass it off to the unit, so that
         * it can add a reference to the UID/GID so that it can destroy the UID/GID's IPC objects when the
         * reference counter drops to 0. */

        l = recv(fd, &buffer, sizeof(buffer), MSG_DONTWAIT);
        if (l < 0) {
                if (ERRNO_IS_TRANSIENT(errno))
                        return 0;

                return log_error_errno(errno, "Failed to read from user lookup fd: %m");
        }

        if ((size_t) l <= offsetof(struct buffer, unit_name)) {
                log_warning("Received too short user lookup message, ignoring.");
                return 0;
        }

        if ((size_t) l > offsetof(struct buffer, unit_name) + UNIT_NAME_MAX) {
                log_warning("Received too long user lookup message, ignoring.");
                return 0;
        }

        if (!uid_is_valid(buffer.uid) && !gid_is_valid(buffer.gid)) {
                log_warning("Got user lookup message with invalid UID/GID pair, ignoring.");
                return 0;
        }

        n = (size_t) l - offsetof(struct buffer, unit_name);
        if (memchr(buffer.unit_name, 0, n)) {
                log_warning("Received lookup message with embedded NUL character, ignoring.");
                return 0;
        }

        buffer.unit_name[n] = 0;
        u = manager_get_unit(m, buffer.unit_name);
        if (!u) {
                log_debug("Got user lookup message but unit doesn't exist, ignoring.");
                return 0;
        }

        log_unit_debug(u, "User lookup succeeded: uid=" UID_FMT " gid=" GID_FMT, buffer.uid, buffer.gid);

        unit_notify_user_lookup(u, buffer.uid, buffer.gid);
        return 0;
}

static int manager_dispatch_handoff_timestamp_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        usec_t ts[2] = {};
        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control;
        struct msghdr msghdr = {
                .msg_iov = &IOVEC_MAKE(ts, sizeof(ts)),
                .msg_iovlen = 1,
                .msg_control = &control,
                .msg_controllen = sizeof(control),
        };
        ssize_t n;

        assert(source);

        n = recvmsg_safe(m->handoff_timestamp_fds[0], &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC);
        if (ERRNO_IS_NEG_TRANSIENT(n))
                return 0; /* Spurious wakeup, try again */
        if (n == -ECHRNG) {
                log_warning_errno(n, "Got message with truncated control data (unexpected fds sent?), ignoring.");
                return 0;
        }
        if (n == -EXFULL) {
                log_warning_errno(n, "Got message with truncated payload data, ignoring.");
                return 0;
        }
        if (n < 0)
                return log_error_errno(n, "Failed to receive handoff timestamp message: %m");

        cmsg_close_all(&msghdr);

        if (n != sizeof(ts)) {
                log_warning("Got handoff timestamp message of unexpected size %zi (expected %zu), ignoring.", n, sizeof(ts));
                return 0;
        }

        struct ucred *ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
        if (!ucred || !pid_is_valid(ucred->pid)) {
                log_warning("Received handoff timestamp message without valid credentials. Ignoring.");
                return 0;
        }

        log_debug("Got handoff timestamp event for PID " PID_FMT ".", ucred->pid);

        _cleanup_free_ Unit **units = NULL;
        int n_units = manager_get_units_for_pidref(m, &PIDREF_MAKE_FROM_PID(ucred->pid), &units);
        if (n_units < 0) {
                log_warning_errno(n_units, "Unable to determine units for PID " PID_FMT ", ignoring: %m", ucred->pid);
                return 0;
        }
        if (n_units == 0) {
                log_debug("Got handoff timestamp for process " PID_FMT " we are not interested in, ignoring.", ucred->pid);
                return 0;
        }

        dual_timestamp dt = {
                .realtime = ts[0],
                .monotonic = ts[1],
        };

        FOREACH_ARRAY(u, units, n_units) {
                if (!UNIT_VTABLE(*u)->notify_handoff_timestamp)
                        continue;

                UNIT_VTABLE(*u)->notify_handoff_timestamp(*u, ucred, &dt);
        }

        return 0;
}

static int manager_dispatch_pidref_transport_fd(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        Manager *m = ASSERT_PTR(userdata);
        _cleanup_(pidref_done) PidRef child_pidref = PIDREF_NULL, parent_pidref = PIDREF_NULL;
        _cleanup_close_ int child_pidfd = -EBADF, parent_pidfd = -EBADF;
        struct ucred *ucred = NULL;
        CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred)) + CMSG_SPACE(sizeof(int)) * 2) control;
        pid_t child_pid = 0; /* silence false-positive warning by coverity */
        struct msghdr msghdr = {
                .msg_iov = &IOVEC_MAKE(&child_pid, sizeof(child_pid)),
                .msg_iovlen = 1,
                .msg_control = &control,
                .msg_controllen = sizeof(control),
        };
        struct cmsghdr *cmsg;
        ssize_t n;
        int r;

        assert(source);

        /* Server expects:
         * - Parent PID in ucreds enabled via SO_PASSCRED
         * - Parent PIDFD in SCM_PIDFD message enabled via SO_PASSPIDFD
         * - Child PIDFD in SCM_RIGHTS in message body
         * - Child PID in message IOV
         *
         * SO_PASSPIDFD may not be supported by the kernel so we fall back to using parent PID from ucreds
         * and accept some raciness. */
        n = recvmsg_safe(m->pidref_transport_fds[0], &msghdr, MSG_DONTWAIT|MSG_CMSG_CLOEXEC|MSG_TRUNC);
        if (ERRNO_IS_NEG_TRANSIENT(n))
                return 0; /* Spurious wakeup, try again */
        if (n == -ECHRNG) {
                log_warning_errno(n, "Got message with truncated control data (unexpected fds sent?), ignoring.");
                return 0;
        }
        if (n == -EXFULL) {
                log_warning_errno(n, "Got message with truncated payload data, ignoring.");
                return 0;
        }
        if (n < 0)
                return log_error_errno(n, "Failed to receive pidref message: %m");

        if (n != sizeof(child_pid)) {
                log_warning("Got pidref message of unexpected size %zi (expected %zu), ignoring.", n, sizeof(child_pid));
                return 0;
        }

        CMSG_FOREACH(cmsg, &msghdr) {
                if (cmsg->cmsg_level != SOL_SOCKET)
                        continue;

                if (cmsg->cmsg_type == SCM_CREDENTIALS && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) {
                        assert(!ucred);
                        ucred = CMSG_TYPED_DATA(cmsg, struct ucred);
                } else if (cmsg->cmsg_type == SCM_PIDFD) {
                        assert(parent_pidfd < 0);
                        parent_pidfd = *CMSG_TYPED_DATA(cmsg, int);
                } else if (cmsg->cmsg_type == SCM_RIGHTS) {
                        assert(child_pidfd < 0);
                        child_pidfd = *CMSG_TYPED_DATA(cmsg, int);
                }
        }

        /* Verify and set parent pidref. */
        if (!ucred || !pid_is_valid(ucred->pid)) {
                log_warning("Received pidref message without valid credentials. Ignoring.");
                return 0;
        }

        /* Need to handle kernels without SO_PASSPIDFD where SCM_PIDFD will not be set. */
        if (parent_pidfd >= 0)
                r = pidref_set_pidfd_consume(&parent_pidref, TAKE_FD(parent_pidfd));
        else
                r = pidref_set_pid(&parent_pidref, ucred->pid);
        if (r < 0) {
                if (r == -ESRCH)
                        log_debug_errno(r, "PidRef child process died before message is processed. Ignoring.");
                else
                        log_warning_errno(r, "Failed to pin pidref child process, ignoring message: %m");
                return 0;
        }

        if (parent_pidref.pid != ucred->pid) {
                assert(parent_pidref.fd >= 0);
                log_warning("Got SCM_PIDFD for parent process " PID_FMT " but got SCM_CREDENTIALS for parent process " PID_FMT ". Ignoring.",
                            parent_pidref.pid, ucred->pid);
                return 0;
        }

        /* Verify and set child pidref. */
        if (!pid_is_valid(child_pid)) {
                log_warning("Received pidref message without valid child PID. Ignoring.");
                return 0;
        }

        /* Need to handle kernels without PIDFD support. */
        if (child_pidfd >= 0)
                r = pidref_set_pidfd_consume(&child_pidref, TAKE_FD(child_pidfd));
        else
                r = pidref_set_pid(&child_pidref, child_pid);
        if (r < 0) {
                if (r == -ESRCH)
                        log_debug_errno(r, "PidRef child process died before message is processed. Ignoring.");
                else
                        log_warning_errno(r, "Failed to pin pidref child process, ignoring message: %m");
                return 0;
        }

        if (child_pidref.pid != child_pid) {
                assert(child_pidref.fd >= 0);
                log_warning("Got SCM_RIGHTS for child process " PID_FMT " but PID in IOV message is " PID_FMT ". Ignoring.",
                            child_pidref.pid, child_pid);
                return 0;
        }

        log_debug("Got pidref event with parent PID " PID_FMT " and child PID " PID_FMT ".", parent_pidref.pid, child_pidref.pid);

        /* Try finding cgroup of parent process. But if parent process exited and we're not using PIDFD, this could return NULL.
         * Then fall back to finding cgroup of the child process. */
        Unit *u = manager_get_unit_by_pidref_cgroup(m, &parent_pidref);
        if (!u)
                u = manager_get_unit_by_pidref_cgroup(m, &child_pidref);
        if (!u) {
                log_debug("Got pidref for parent process " PID_FMT " and child process " PID_FMT " we are not interested in, ignoring.", parent_pidref.pid, child_pidref.pid);
                return 0;
        }

        if (!UNIT_VTABLE(u)->notify_pidref) {
                log_unit_warning(u, "Received pidref event from unexpected unit type '%s'.", unit_type_to_string(u->type));
                return 0;
        }

        UNIT_VTABLE(u)->notify_pidref(u, &parent_pidref, &child_pidref);

        return 0;
}

void manager_ref_console(Manager *m) {
        assert(m);

        m->n_on_console++;
}

void manager_unref_console(Manager *m) {

        assert(m->n_on_console > 0);
        m->n_on_console--;

        if (m->n_on_console == 0)
                m->no_console_output = false; /* unset no_console_output flag, since the console is definitely free now */
}

void manager_override_log_level(Manager *m, int level) {
        _cleanup_free_ char *s = NULL;
        assert(m);

        if (!m->log_level_overridden) {
                m->original_log_level = log_get_max_level();
                m->log_level_overridden = true;
        }

        (void) log_level_to_string_alloc(level, &s);
        log_info("Setting log level to %s.", strna(s));

        log_set_max_level(level);
}

void manager_restore_original_log_level(Manager *m) {
        _cleanup_free_ char *s = NULL;
        assert(m);

        if (!m->log_level_overridden)
                return;

        (void) log_level_to_string_alloc(m->original_log_level, &s);
        log_info("Restoring log level to original (%s).", strna(s));

        log_set_max_level(m->original_log_level);
        m->log_level_overridden = false;
}

void manager_override_log_target(Manager *m, LogTarget target) {
        assert(m);

        if (!m->log_target_overridden) {
                m->original_log_target = log_get_target();
                m->log_target_overridden = true;
        }

        log_info("Setting log target to %s.", log_target_to_string(target));
        log_set_target(target);
}

void manager_restore_original_log_target(Manager *m) {
        assert(m);

        if (!m->log_target_overridden)
                return;

        log_info("Restoring log target to original %s.", log_target_to_string(m->original_log_target));

        log_set_target(m->original_log_target);
        m->log_target_overridden = false;
}

ManagerTimestamp manager_timestamp_initrd_mangle(ManagerTimestamp s) {
        if (in_initrd() &&
            s >= MANAGER_TIMESTAMP_SECURITY_START &&
            s <= MANAGER_TIMESTAMP_UNITS_LOAD_FINISH)
                return s - MANAGER_TIMESTAMP_SECURITY_START + MANAGER_TIMESTAMP_INITRD_SECURITY_START;
        return s;
}

int manager_allocate_idle_pipe(Manager *m) {
        int r;

        assert(m);

        if (m->idle_pipe[0] >= 0) {
                assert(m->idle_pipe[1] >= 0);
                assert(m->idle_pipe[2] >= 0);
                assert(m->idle_pipe[3] >= 0);
                return 0;
        }

        assert(m->idle_pipe[1] < 0);
        assert(m->idle_pipe[2] < 0);
        assert(m->idle_pipe[3] < 0);

        r = RET_NERRNO(pipe2(m->idle_pipe + 0, O_NONBLOCK|O_CLOEXEC));
        if (r < 0)
                return r;

        r = RET_NERRNO(pipe2(m->idle_pipe + 2, O_NONBLOCK|O_CLOEXEC));
        if (r < 0) {
                safe_close_pair(m->idle_pipe + 0);
                return r;
        }

        return 1;
}

void unit_defaults_init(UnitDefaults *defaults, RuntimeScope scope) {
        assert(defaults);
        assert(scope >= 0);
        assert(scope < _RUNTIME_SCOPE_MAX);

        *defaults = (UnitDefaults) {
                .std_output = EXEC_OUTPUT_JOURNAL,
                .std_error = EXEC_OUTPUT_INHERIT,
                .restart_usec = DEFAULT_RESTART_USEC,
                .timeout_start_usec = manager_default_timeout(scope),
                .timeout_stop_usec = manager_default_timeout(scope),
                .timeout_abort_usec = manager_default_timeout(scope),
                .timeout_abort_set = false,
                .device_timeout_usec = manager_default_timeout(scope),
                .start_limit = { DEFAULT_START_LIMIT_INTERVAL, DEFAULT_START_LIMIT_BURST },

                /* On 4.15+ with unified hierarchy, CPU accounting is essentially free as it doesn't require the CPU
                 * controller to be enabled, so the default is to enable it unless we got told otherwise. */
                .cpu_accounting = cpu_accounting_is_cheap(),
                .memory_accounting = MEMORY_ACCOUNTING_DEFAULT,
                .io_accounting = false,
                .blockio_accounting = false,
                .tasks_accounting = true,
                .ip_accounting = false,

                .tasks_max = DEFAULT_TASKS_MAX,
                .timer_accuracy_usec = 1 * USEC_PER_MINUTE,

                .memory_pressure_watch = CGROUP_PRESSURE_WATCH_AUTO,
                .memory_pressure_threshold_usec = MEMORY_PRESSURE_DEFAULT_THRESHOLD_USEC,

                .oom_policy = OOM_STOP,
                .oom_score_adjust_set = false,
        };
}

void unit_defaults_done(UnitDefaults *defaults) {
        assert(defaults);

        defaults->smack_process_label = mfree(defaults->smack_process_label);
        rlimit_free_all(defaults->rlimit);
}

LogTarget manager_get_executor_log_target(Manager *m) {
        assert(m);

        /* If journald is not available tell sd-executor to go to kmsg, as it might be starting journald */
        if (!MANAGER_IS_TEST_RUN(m) && !manager_journal_is_running(m))
                return LOG_TARGET_KMSG;

        return log_get_target();
}

static const char* const manager_state_table[_MANAGER_STATE_MAX] = {
        [MANAGER_INITIALIZING] = "initializing",
        [MANAGER_STARTING]     = "starting",
        [MANAGER_RUNNING]      = "running",
        [MANAGER_DEGRADED]     = "degraded",
        [MANAGER_MAINTENANCE]  = "maintenance",
        [MANAGER_STOPPING]     = "stopping",
};

DEFINE_STRING_TABLE_LOOKUP(manager_state, ManagerState);

static const char* const manager_objective_table[_MANAGER_OBJECTIVE_MAX] = {
        [MANAGER_OK]          = "ok",
        [MANAGER_EXIT]        = "exit",
        [MANAGER_RELOAD]      = "reload",
        [MANAGER_REEXECUTE]   = "reexecute",
        [MANAGER_REBOOT]      = "reboot",
        [MANAGER_SOFT_REBOOT] = "soft-reboot",
        [MANAGER_POWEROFF]    = "poweroff",
        [MANAGER_HALT]        = "halt",
        [MANAGER_KEXEC]       = "kexec",
        [MANAGER_SWITCH_ROOT] = "switch-root",
};

DEFINE_STRING_TABLE_LOOKUP(manager_objective, ManagerObjective);

static const char* const manager_timestamp_table[_MANAGER_TIMESTAMP_MAX] = {
        [MANAGER_TIMESTAMP_FIRMWARE]                 = "firmware",
        [MANAGER_TIMESTAMP_LOADER]                   = "loader",
        [MANAGER_TIMESTAMP_KERNEL]                   = "kernel",
        [MANAGER_TIMESTAMP_INITRD]                   = "initrd",
        [MANAGER_TIMESTAMP_USERSPACE]                = "userspace",
        [MANAGER_TIMESTAMP_FINISH]                   = "finish",
        [MANAGER_TIMESTAMP_SECURITY_START]           = "security-start",
        [MANAGER_TIMESTAMP_SECURITY_FINISH]          = "security-finish",
        [MANAGER_TIMESTAMP_GENERATORS_START]         = "generators-start",
        [MANAGER_TIMESTAMP_GENERATORS_FINISH]        = "generators-finish",
        [MANAGER_TIMESTAMP_UNITS_LOAD_START]         = "units-load-start",
        [MANAGER_TIMESTAMP_UNITS_LOAD_FINISH]        = "units-load-finish",
        [MANAGER_TIMESTAMP_UNITS_LOAD]               = "units-load",
        [MANAGER_TIMESTAMP_INITRD_SECURITY_START]    = "initrd-security-start",
        [MANAGER_TIMESTAMP_INITRD_SECURITY_FINISH]   = "initrd-security-finish",
        [MANAGER_TIMESTAMP_INITRD_GENERATORS_START]  = "initrd-generators-start",
        [MANAGER_TIMESTAMP_INITRD_GENERATORS_FINISH] = "initrd-generators-finish",
        [MANAGER_TIMESTAMP_INITRD_UNITS_LOAD_START]  = "initrd-units-load-start",
        [MANAGER_TIMESTAMP_INITRD_UNITS_LOAD_FINISH] = "initrd-units-load-finish",
        [MANAGER_TIMESTAMP_SHUTDOWN_START]           = "shutdown-start",
};

DEFINE_STRING_TABLE_LOOKUP(manager_timestamp, ManagerTimestamp);

static const char* const oom_policy_table[_OOM_POLICY_MAX] = {
        [OOM_CONTINUE] = "continue",
        [OOM_STOP]     = "stop",
        [OOM_KILL]     = "kill",
};

DEFINE_STRING_TABLE_LOOKUP(oom_policy, OOMPolicy);

systemd / systemd / 13380515387

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