Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1855 insertions, 0 deletions

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
new file mode 100644
index 0000000..0303f36
--- /dev/null
+++ b/src/udev/udevd.c
@@ -0,0 +1,1855 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright © 2004 Chris Friesen <chris_friesen@sympatico.ca>
+ * Copyright © 2009 Canonical Ltd.
+ * Copyright © 2009 Scott James Remnant <scott@netsplit.com>
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <signal.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/file.h>
+#include <sys/inotify.h>
+#include <sys/ioctl.h>
+#include <sys/mount.h>
+#include <sys/prctl.h>
+#include <sys/signalfd.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#include "sd-daemon.h"
+#include "sd-event.h"
+
+#include "alloc-util.h"
+#include "build.h"
+#include "cgroup-util.h"
+#include "cpu-set-util.h"
+#include "dev-setup.h"
+#include "device-monitor-private.h"
+#include "device-private.h"
+#include "device-util.h"
+#include "event-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "io-util.h"
+#include "libudev-device-internal.h"
+#include "list.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "pretty-print.h"
+#include "proc-cmdline.h"
+#include "process-util.h"
+#include "selinux-util.h"
+#include "signal-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "strxcpyx.h"
+#include "syslog-util.h"
+#include "udev-builtin.h"
+#include "udev-ctrl.h"
+#include "udev-util.h"
+#include "udev-watch.h"
+#include "udev.h"
+#include "user-util.h"
+
+static bool arg_debug = false;
+static int arg_daemonize = false;
+static ResolveNameTiming arg_resolve_name_timing = RESOLVE_NAME_EARLY;
+static unsigned arg_children_max = 0;
+static usec_t arg_exec_delay_usec = 0;
+static usec_t arg_event_timeout_usec = 180 * USEC_PER_SEC;
+
+typedef struct Manager {
+        sd_event *event;
+        Hashmap *workers;
+        LIST_HEAD(struct event, events);
+        const char *cgroup;
+        pid_t pid; /* the process that originally allocated the manager object */
+
+        UdevRules *rules;
+        Hashmap *properties;
+
+        sd_netlink *rtnl;
+
+        sd_device_monitor *monitor;
+        struct udev_ctrl *ctrl;
+        struct udev_ctrl_connection *ctrl_conn_blocking;
+        int fd_inotify;
+        int worker_watch[2];
+
+        sd_event_source *ctrl_event;
+        sd_event_source *uevent_event;
+        sd_event_source *inotify_event;
+        sd_event_source *kill_workers_event;
+
+        usec_t last_usec;
+
+        bool stop_exec_queue:1;
+        bool exit:1;
+} Manager;
+
+enum event_state {
+        EVENT_UNDEF,
+        EVENT_QUEUED,
+        EVENT_RUNNING,
+};
+
+struct event {
+        Manager *manager;
+        struct worker *worker;
+        enum event_state state;
+
+        sd_device *dev;
+        sd_device *dev_kernel; /* clone of originally received device */
+
+        uint64_t seqnum;
+        uint64_t delaying_seqnum;
+
+        sd_event_source *timeout_warning_event;
+        sd_event_source *timeout_event;
+
+        LIST_FIELDS(struct event, event);
+};
+
+static void event_queue_cleanup(Manager *manager, enum event_state type);
+
+enum worker_state {
+        WORKER_UNDEF,
+        WORKER_RUNNING,
+        WORKER_IDLE,
+        WORKER_KILLED,
+};
+
+struct worker {
+        Manager *manager;
+        pid_t pid;
+        sd_device_monitor *monitor;
+        enum worker_state state;
+        struct event *event;
+};
+
+/* passed from worker to main process */
+struct worker_message {
+};
+
+static void event_free(struct event *event) {
+        if (!event)
+                return;
+
+        assert(event->manager);
+
+        LIST_REMOVE(event, event->manager->events, event);
+        sd_device_unref(event->dev);
+        sd_device_unref(event->dev_kernel);
+
+        sd_event_source_unref(event->timeout_warning_event);
+        sd_event_source_unref(event->timeout_event);
+
+        if (event->worker)
+                event->worker->event = NULL;
+
+        /* only clean up the queue from the process that created it */
+        if (LIST_IS_EMPTY(event->manager->events) &&
+            event->manager->pid == getpid_cached())
+                if (unlink("/run/udev/queue") < 0)
+                        log_warning_errno(errno, "Failed to unlink /run/udev/queue: %m");
+
+        free(event);
+}
+
+static void worker_free(struct worker *worker) {
+        if (!worker)
+                return;
+
+        assert(worker->manager);
+
+        hashmap_remove(worker->manager->workers, PID_TO_PTR(worker->pid));
+        sd_device_monitor_unref(worker->monitor);
+        event_free(worker->event);
+
+        free(worker);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(struct worker *, worker_free);
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(worker_hash_op, void, trivial_hash_func, trivial_compare_func, struct worker, worker_free);
+
+static int worker_new(struct worker **ret, Manager *manager, sd_device_monitor *worker_monitor, pid_t pid) {
+        _cleanup_(worker_freep) struct worker *worker = NULL;
+        int r;
+
+        assert(ret);
+        assert(manager);
+        assert(worker_monitor);
+        assert(pid > 1);
+
+        /* close monitor, but keep address around */
+        device_monitor_disconnect(worker_monitor);
+
+        worker = new(struct worker, 1);
+        if (!worker)
+                return -ENOMEM;
+
+        *worker = (struct worker) {
+                .manager = manager,
+                .monitor = sd_device_monitor_ref(worker_monitor),
+                .pid = pid,
+        };
+
+        r = hashmap_ensure_allocated(&manager->workers, &worker_hash_op);
+        if (r < 0)
+                return r;
+
+        r = hashmap_put(manager->workers, PID_TO_PTR(pid), worker);
+        if (r < 0)
+                return r;
+
+        *ret = TAKE_PTR(worker);
+
+        return 0;
+}
+
+static int on_event_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
+        struct event *event = userdata;
+
+        assert(event);
+        assert(event->worker);
+
+        kill_and_sigcont(event->worker->pid, SIGKILL);
+        event->worker->state = WORKER_KILLED;
+
+        log_device_error(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" killed", event->worker->pid, event->seqnum);
+
+        return 1;
+}
+
+static int on_event_timeout_warning(sd_event_source *s, uint64_t usec, void *userdata) {
+        struct event *event = userdata;
+
+        assert(event);
+        assert(event->worker);
+
+        log_device_warning(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" is taking a long time", event->worker->pid, event->seqnum);
+
+        return 1;
+}
+
+static void worker_attach_event(struct worker *worker, struct event *event) {
+        sd_event *e;
+        uint64_t usec;
+
+        assert(worker);
+        assert(worker->manager);
+        assert(event);
+        assert(!event->worker);
+        assert(!worker->event);
+
+        worker->state = WORKER_RUNNING;
+        worker->event = event;
+        event->state = EVENT_RUNNING;
+        event->worker = worker;
+
+        e = worker->manager->event;
+
+        assert_se(sd_event_now(e, CLOCK_MONOTONIC, &usec) >= 0);
+
+        (void) sd_event_add_time(e, &event->timeout_warning_event, CLOCK_MONOTONIC,
+                                 usec + udev_warn_timeout(arg_event_timeout_usec), USEC_PER_SEC, on_event_timeout_warning, event);
+
+        (void) sd_event_add_time(e, &event->timeout_event, CLOCK_MONOTONIC,
+                                 usec + arg_event_timeout_usec, USEC_PER_SEC, on_event_timeout, event);
+}
+
+static void manager_clear_for_worker(Manager *manager) {
+        assert(manager);
+
+        manager->ctrl_event = sd_event_source_unref(manager->ctrl_event);
+        manager->uevent_event = sd_event_source_unref(manager->uevent_event);
+        manager->inotify_event = sd_event_source_unref(manager->inotify_event);
+        manager->kill_workers_event = sd_event_source_unref(manager->kill_workers_event);
+
+        manager->event = sd_event_unref(manager->event);
+
+        manager->workers = hashmap_free(manager->workers);
+        event_queue_cleanup(manager, EVENT_UNDEF);
+
+        manager->monitor = sd_device_monitor_unref(manager->monitor);
+        manager->ctrl_conn_blocking = udev_ctrl_connection_unref(manager->ctrl_conn_blocking);
+        manager->ctrl = udev_ctrl_unref(manager->ctrl);
+
+        manager->worker_watch[READ_END] = safe_close(manager->worker_watch[READ_END]);
+}
+
+static void manager_free(Manager *manager) {
+        if (!manager)
+                return;
+
+        udev_builtin_exit();
+
+        manager_clear_for_worker(manager);
+
+        sd_netlink_unref(manager->rtnl);
+
+        hashmap_free_free_free(manager->properties);
+        udev_rules_free(manager->rules);
+
+        safe_close(manager->fd_inotify);
+        safe_close_pair(manager->worker_watch);
+
+        free(manager);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
+
+static int worker_send_message(int fd) {
+        struct worker_message message = {};
+
+        return loop_write(fd, &message, sizeof(message), false);
+}
+
+static int worker_lock_block_device(sd_device *dev, int *ret_fd) {
+        _cleanup_close_ int fd = -1;
+        const char *val;
+        int r;
+
+        assert(dev);
+        assert(ret_fd);
+
+        /*
+         * Take a shared lock on the device node; this establishes
+         * a concept of device "ownership" to serialize device
+         * access. External processes holding an exclusive lock will
+         * cause udev to skip the event handling; in the case udev
+         * acquired the lock, the external process can block until
+         * udev has finished its event handling.
+         */
+
+        r = sd_device_get_property_value(dev, "ACTION", &val);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get the value of property 'ACTION': %m");
+
+        if (streq(val, "remove"))
+                return 0;
+
+        r = sd_device_get_subsystem(dev, &val);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get subsystem: %m");
+
+        if (!streq(val, "block"))
+                return 0;
+
+        r = sd_device_get_sysname(dev, &val);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get sysname: %m");
+
+        if (STARTSWITH_SET(val, "dm-", "md", "drbd"))
+                return 0;
+
+        r = sd_device_get_devtype(dev, &val);
+        if (r < 0 && r != -ENOENT)
+                return log_device_debug_errno(dev, r, "Failed to get devtype: %m");
+        if (r >= 0 && streq(val, "partition")) {
+                r = sd_device_get_parent(dev, &dev);
+                if (r < 0)
+                        return log_device_debug_errno(dev, r, "Failed to get parent device: %m");
+        }
+
+        r = sd_device_get_devname(dev, &val);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get devname: %m");
+
+        fd = open(val, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
+        if (fd < 0) {
+                log_device_debug_errno(dev, errno, "Failed to open '%s', ignoring: %m", val);
+                return 0;
+        }
+
+        if (flock(fd, LOCK_SH|LOCK_NB) < 0)
+                return log_device_debug_errno(dev, errno, "Failed to flock(%s): %m", val);
+
+        *ret_fd = TAKE_FD(fd);
+        return 1;
+}
+
+static int worker_process_device(Manager *manager, sd_device *dev) {
+        _cleanup_(udev_event_freep) UdevEvent *udev_event = NULL;
+        _cleanup_close_ int fd_lock = -1;
+        const char *seqnum, *action;
+        int r;
+
+        assert(manager);
+        assert(dev);
+
+        r = sd_device_get_property_value(dev, "SEQNUM", &seqnum);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get SEQNUM: %m");
+
+        r = sd_device_get_property_value(dev, "ACTION", &action);
+        if (r < 0)
+                return log_device_debug_errno(dev, r, "Failed to get ACTION: %m");
+
+        log_device_debug(dev, "Processing device (SEQNUM=%s, ACTION=%s)", seqnum, action);
+
+        udev_event = udev_event_new(dev, arg_exec_delay_usec, manager->rtnl);
+        if (!udev_event)
+                return -ENOMEM;
+
+        r = worker_lock_block_device(dev, &fd_lock);
+        if (r < 0)
+                return r;
+
+        /* apply rules, create node, symlinks */
+        udev_event_execute_rules(udev_event, arg_event_timeout_usec, manager->properties, manager->rules);
+        udev_event_execute_run(udev_event, arg_event_timeout_usec);
+
+        if (!manager->rtnl)
+                /* in case rtnl was initialized */
+                manager->rtnl = sd_netlink_ref(udev_event->rtnl);
+
+        /* apply/restore inotify watch */
+        if (udev_event->inotify_watch) {
+                (void) udev_watch_begin(dev);
+                r = device_update_db(dev);
+                if (r < 0)
+                        return log_device_debug_errno(dev, r, "Failed to update database under /run/udev/data/: %m");
+        }
+
+        log_device_debug(dev, "Device (SEQNUM=%s, ACTION=%s) processed", seqnum, action);
+
+        return 0;
+}
+
+static int worker_device_monitor_handler(sd_device_monitor *monitor, sd_device *dev, void *userdata) {
+        Manager *manager = userdata;
+        int r;
+
+        assert(dev);
+        assert(manager);
+
+        r = worker_process_device(manager, dev);
+        if (r < 0)
+                log_device_warning_errno(dev, r, "Failed to process device, ignoring: %m");
+
+        /* send processed event back to libudev listeners */
+        r = device_monitor_send_device(monitor, NULL, dev);
+        if (r < 0)
+                log_device_warning_errno(dev, r, "Failed to send device, ignoring: %m");
+
+        /* send udevd the result of the event execution */
+        r = worker_send_message(manager->worker_watch[WRITE_END]);
+        if (r < 0)
+                log_device_warning_errno(dev, r, "Failed to send signal to main daemon, ignoring: %m");
+
+        return 1;
+}
+
+static int worker_main(Manager *_manager, sd_device_monitor *monitor, sd_device *first_device) {
+        _cleanup_(sd_device_unrefp) sd_device *dev = first_device;
+        _cleanup_(manager_freep) Manager *manager = _manager;
+        int r;
+
+        assert(manager);
+        assert(monitor);
+        assert(dev);
+
+        unsetenv("NOTIFY_SOCKET");
+
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, -1) >= 0);
+
+        /* Reset OOM score, we only protect the main daemon. */
+        r = set_oom_score_adjust(0);
+        if (r < 0)
+                log_debug_errno(r, "Failed to reset OOM score, ignoring: %m");
+
+        /* Clear unnecessary data in Manager object.*/
+        manager_clear_for_worker(manager);
+
+        r = sd_event_new(&manager->event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate event loop: %m");
+
+        r = sd_event_add_signal(manager->event, NULL, SIGTERM, NULL, NULL);
+        if (r < 0)
+                return log_error_errno(r, "Failed to set SIGTERM event: %m");
+
+        r = sd_device_monitor_attach_event(monitor, manager->event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to attach event loop to device monitor: %m");
+
+        r = sd_device_monitor_start(monitor, worker_device_monitor_handler, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to start device monitor: %m");
+
+        (void) sd_event_source_set_description(sd_device_monitor_get_event_source(monitor), "worker-device-monitor");
+
+        /* Process first device */
+        (void) worker_device_monitor_handler(monitor, dev, manager);
+
+        r = sd_event_loop(manager->event);
+        if (r < 0)
+                return log_error_errno(r, "Event loop failed: %m");
+
+        return 0;
+}
+
+static int worker_spawn(Manager *manager, struct event *event) {
+        _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *worker_monitor = NULL;
+        struct worker *worker;
+        pid_t pid;
+        int r;
+
+        /* listen for new events */
+        r = device_monitor_new_full(&worker_monitor, MONITOR_GROUP_NONE, -1);
+        if (r < 0)
+                return r;
+
+        /* allow the main daemon netlink address to send devices to the worker */
+        r = device_monitor_allow_unicast_sender(worker_monitor, manager->monitor);
+        if (r < 0)
+                return log_error_errno(r, "Worker: Failed to set unicast sender: %m");
+
+        r = device_monitor_enable_receiving(worker_monitor);
+        if (r < 0)
+                return log_error_errno(r, "Worker: Failed to enable receiving of device: %m");
+
+        r = safe_fork(NULL, FORK_DEATHSIG, &pid);
+        if (r < 0) {
+                event->state = EVENT_QUEUED;
+                return log_error_errno(r, "Failed to fork() worker: %m");
+        }
+        if (r == 0) {
+                /* Worker process */
+                r = worker_main(manager, worker_monitor, sd_device_ref(event->dev));
+                log_close();
+                _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+        }
+
+        r = worker_new(&worker, manager, worker_monitor, pid);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create worker object: %m");
+
+        worker_attach_event(worker, event);
+
+        log_device_debug(event->dev, "Worker ["PID_FMT"] is forked for processing SEQNUM=%"PRIu64".", pid, event->seqnum);
+        return 0;
+}
+
+static void event_run(Manager *manager, struct event *event) {
+        struct worker *worker;
+        Iterator i;
+        int r;
+
+        assert(manager);
+        assert(event);
+
+        HASHMAP_FOREACH(worker, manager->workers, i) {
+                if (worker->state != WORKER_IDLE)
+                        continue;
+
+                r = device_monitor_send_device(manager->monitor, worker->monitor, event->dev);
+                if (r < 0) {
+                        log_device_error_errno(event->dev, r, "Worker ["PID_FMT"] did not accept message, killing the worker: %m",
+                                               worker->pid);
+                        (void) kill(worker->pid, SIGKILL);
+                        worker->state = WORKER_KILLED;
+                        continue;
+                }
+                worker_attach_event(worker, event);
+                return;
+        }
+
+        if (hashmap_size(manager->workers) >= arg_children_max) {
+                if (arg_children_max > 1)
+                        log_debug("Maximum number (%u) of children reached.", hashmap_size(manager->workers));
+                return;
+        }
+
+        /* start new worker and pass initial device */
+        worker_spawn(manager, event);
+}
+
+static int event_queue_insert(Manager *manager, sd_device *dev) {
+        _cleanup_(sd_device_unrefp) sd_device *clone = NULL;
+        const char *val, *action;
+        struct event *event;
+        uint64_t seqnum;
+        int r;
+
+        assert(manager);
+        assert(dev);
+
+        /* only one process can add events to the queue */
+        if (manager->pid == 0)
+                manager->pid = getpid_cached();
+
+        assert(manager->pid == getpid_cached());
+
+        /* We only accepts devices received by device monitor. */
+        r = sd_device_get_property_value(dev, "SEQNUM", &val);
+        if (r < 0)
+                return r;
+
+        r = safe_atou64(val, &seqnum);
+        if (r < 0)
+                return r;
+
+        if (seqnum == 0)
+                return -EINVAL;
+
+        /* Refuse devices do not have ACTION property. */
+        r = sd_device_get_property_value(dev, "ACTION", &action);
+        if (r < 0)
+                return r;
+
+        /* Save original device to restore the state on failures. */
+        r = device_shallow_clone(dev, &clone);
+        if (r < 0)
+                return r;
+
+        r = device_copy_properties(clone, dev);
+        if (r < 0)
+                return r;
+
+        event = new(struct event, 1);
+        if (!event)
+                return -ENOMEM;
+
+        *event = (struct event) {
+                .manager = manager,
+                .dev = sd_device_ref(dev),
+                .dev_kernel = TAKE_PTR(clone),
+                .seqnum = seqnum,
+                .state = EVENT_QUEUED,
+        };
+
+        if (LIST_IS_EMPTY(manager->events)) {
+                r = touch("/run/udev/queue");
+                if (r < 0)
+                        log_warning_errno(r, "Failed to touch /run/udev/queue: %m");
+        }
+
+        LIST_APPEND(event, manager->events, event);
+
+        log_device_debug(dev, "Device (SEQNUM=%"PRIu64", ACTION=%s) is queued", seqnum, action);
+
+        return 0;
+}
+
+static void manager_kill_workers(Manager *manager) {
+        struct worker *worker;
+        Iterator i;
+
+        assert(manager);
+
+        HASHMAP_FOREACH(worker, manager->workers, i) {
+                if (worker->state == WORKER_KILLED)
+                        continue;
+
+                worker->state = WORKER_KILLED;
+                (void) kill(worker->pid, SIGTERM);
+        }
+}
+
+/* lookup event for identical, parent, child device */
+static int is_device_busy(Manager *manager, struct event *event) {
+        const char *subsystem, *devpath, *devpath_old = NULL;
+        dev_t devnum = makedev(0, 0);
+        struct event *loop_event;
+        size_t devpath_len;
+        int r, ifindex = 0;
+        bool is_block;
+
+        r = sd_device_get_subsystem(event->dev, &subsystem);
+        if (r < 0)
+                return r;
+
+        is_block = streq(subsystem, "block");
+
+        r = sd_device_get_devpath(event->dev, &devpath);
+        if (r < 0)
+                return r;
+
+        devpath_len = strlen(devpath);
+
+        r = sd_device_get_property_value(event->dev, "DEVPATH_OLD", &devpath_old);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        r = sd_device_get_devnum(event->dev, &devnum);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        r = sd_device_get_ifindex(event->dev, &ifindex);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        /* check if queue contains events we depend on */
+        LIST_FOREACH(event, loop_event, manager->events) {
+                size_t loop_devpath_len, common;
+                const char *loop_devpath;
+
+                /* we already found a later event, earlier cannot block us, no need to check again */
+                if (loop_event->seqnum < event->delaying_seqnum)
+                        continue;
+
+                /* event we checked earlier still exists, no need to check again */
+                if (loop_event->seqnum == event->delaying_seqnum)
+                        return true;
+
+                /* found ourself, no later event can block us */
+                if (loop_event->seqnum >= event->seqnum)
+                        break;
+
+                /* check major/minor */
+                if (major(devnum) != 0) {
+                        const char *s;
+                        dev_t d;
+
+                        if (sd_device_get_subsystem(loop_event->dev, &s) < 0)
+                                continue;
+
+                        if (sd_device_get_devnum(loop_event->dev, &d) >= 0 &&
+                            devnum == d && is_block == streq(s, "block"))
+                                return true;
+                }
+
+                /* check network device ifindex */
+                if (ifindex > 0) {
+                        int i;
+
+                        if (sd_device_get_ifindex(loop_event->dev, &i) >= 0 &&
+                            ifindex == i)
+                                return true;
+                }
+
+                if (sd_device_get_devpath(loop_event->dev, &loop_devpath) < 0)
+                        continue;
+
+                /* check our old name */
+                if (devpath_old && streq(devpath_old, loop_devpath)) {
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                loop_devpath_len = strlen(loop_devpath);
+
+                /* compare devpath */
+                common = MIN(devpath_len, loop_devpath_len);
+
+                /* one devpath is contained in the other? */
+                if (!strneq(devpath, loop_devpath, common))
+                        continue;
+
+                /* identical device event found */
+                if (devpath_len == loop_devpath_len) {
+                        /* devices names might have changed/swapped in the meantime */
+                        if (major(devnum) != 0 || ifindex > 0)
+                                continue;
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                /* parent device event found */
+                if (devpath[common] == '/') {
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                /* child device event found */
+                if (loop_devpath[common] == '/') {
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+        }
+
+        return false;
+}
+
+static int on_exit_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
+        Manager *manager = userdata;
+
+        assert(manager);
+
+        log_error("Giving up waiting for workers to finish.");
+        sd_event_exit(manager->event, -ETIMEDOUT);
+
+        return 1;
+}
+
+static void manager_exit(Manager *manager) {
+        uint64_t usec;
+        int r;
+
+        assert(manager);
+
+        manager->exit = true;
+
+        sd_notify(false,
+                  "STOPPING=1\n"
+                  "STATUS=Starting shutdown...");
+
+        /* close sources of new events and discard buffered events */
+        manager->ctrl_event = sd_event_source_unref(manager->ctrl_event);
+        manager->ctrl = udev_ctrl_unref(manager->ctrl);
+
+        manager->inotify_event = sd_event_source_unref(manager->inotify_event);
+        manager->fd_inotify = safe_close(manager->fd_inotify);
+
+        manager->uevent_event = sd_event_source_unref(manager->uevent_event);
+        manager->monitor = sd_device_monitor_unref(manager->monitor);
+
+        /* discard queued events and kill workers */
+        event_queue_cleanup(manager, EVENT_QUEUED);
+        manager_kill_workers(manager);
+
+        assert_se(sd_event_now(manager->event, CLOCK_MONOTONIC, &usec) >= 0);
+
+        r = sd_event_add_time(manager->event, NULL, CLOCK_MONOTONIC,
+                              usec + 30 * USEC_PER_SEC, USEC_PER_SEC, on_exit_timeout, manager);
+        if (r < 0)
+                return;
+}
+
+/* reload requested, HUP signal received, rules changed, builtin changed */
+static void manager_reload(Manager *manager) {
+
+        assert(manager);
+
+        sd_notify(false,
+                  "RELOADING=1\n"
+                  "STATUS=Flushing configuration...");
+
+        manager_kill_workers(manager);
+        manager->rules = udev_rules_free(manager->rules);
+        udev_builtin_exit();
+
+        sd_notifyf(false,
+                   "READY=1\n"
+                   "STATUS=Processing with %u children at max", arg_children_max);
+}
+
+static int on_kill_workers_event(sd_event_source *s, uint64_t usec, void *userdata) {
+        Manager *manager = userdata;
+
+        assert(manager);
+
+        log_debug("Cleanup idle workers");
+        manager_kill_workers(manager);
+
+        return 1;
+}
+
+static void event_queue_start(Manager *manager) {
+        struct event *event;
+        usec_t usec;
+        int r;
+
+        assert(manager);
+
+        if (LIST_IS_EMPTY(manager->events) ||
+            manager->exit || manager->stop_exec_queue)
+                return;
+
+        assert_se(sd_event_now(manager->event, CLOCK_MONOTONIC, &usec) >= 0);
+        /* check for changed config, every 3 seconds at most */
+        if (manager->last_usec == 0 ||
+            usec - manager->last_usec > 3 * USEC_PER_SEC) {
+                if (udev_rules_check_timestamp(manager->rules) ||
+                    udev_builtin_validate())
+                        manager_reload(manager);
+
+                manager->last_usec = usec;
+        }
+
+        r = event_source_disable(manager->kill_workers_event);
+        if (r < 0)
+                log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m");
+
+        udev_builtin_init();
+
+        if (!manager->rules) {
+                r = udev_rules_new(&manager->rules, arg_resolve_name_timing);
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to read udev rules: %m");
+                        return;
+                }
+        }
+
+        LIST_FOREACH(event, event, manager->events) {
+                if (event->state != EVENT_QUEUED)
+                        continue;
+
+                /* do not start event if parent or child event is still running */
+                if (is_device_busy(manager, event) != 0)
+                        continue;
+
+                event_run(manager, event);
+        }
+}
+
+static void event_queue_cleanup(Manager *manager, enum event_state match_type) {
+        struct event *event, *tmp;
+
+        LIST_FOREACH_SAFE(event, event, tmp, manager->events) {
+                if (match_type != EVENT_UNDEF && match_type != event->state)
+                        continue;
+
+                event_free(event);
+        }
+}
+
+static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Manager *manager = userdata;
+
+        assert(manager);
+
+        for (;;) {
+                struct worker_message msg;
+                struct iovec iovec = {
+                        .iov_base = &msg,
+                        .iov_len = sizeof(msg),
+                };
+                union {
+                        struct cmsghdr cmsghdr;
+                        uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
+                } control = {};
+                struct msghdr msghdr = {
+                        .msg_iov = &iovec,
+                        .msg_iovlen = 1,
+                        .msg_control = &control,
+                        .msg_controllen = sizeof(control),
+                };
+                struct cmsghdr *cmsg;
+                ssize_t size;
+                struct ucred *ucred = NULL;
+                struct worker *worker;
+
+                size = recvmsg(fd, &msghdr, MSG_DONTWAIT);
+                if (size < 0) {
+                        if (errno == EINTR)
+                                continue;
+                        else if (errno == EAGAIN)
+                                /* nothing more to read */
+                                break;
+
+                        return log_error_errno(errno, "Failed to receive message: %m");
+                } else if (size != sizeof(struct worker_message)) {
+                        log_warning("Ignoring worker message with invalid size %zi bytes", size);
+                        continue;
+                }
+
+                CMSG_FOREACH(cmsg, &msghdr)
+                        if (cmsg->cmsg_level == SOL_SOCKET &&
+                            cmsg->cmsg_type == SCM_CREDENTIALS &&
+                            cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred)))
+                                ucred = (struct ucred*) CMSG_DATA(cmsg);
+
+                if (!ucred || ucred->pid <= 0) {
+                        log_warning("Ignoring worker message without valid PID");
+                        continue;
+                }
+
+                /* lookup worker who sent the signal */
+                worker = hashmap_get(manager->workers, PID_TO_PTR(ucred->pid));
+                if (!worker) {
+                        log_debug("Worker ["PID_FMT"] returned, but is no longer tracked", ucred->pid);
+                        continue;
+                }
+
+                if (worker->state != WORKER_KILLED)
+                        worker->state = WORKER_IDLE;
+
+                /* worker returned */
+                event_free(worker->event);
+        }
+
+        /* we have free workers, try to schedule events */
+        event_queue_start(manager);
+
+        return 1;
+}
+
+static int on_uevent(sd_device_monitor *monitor, sd_device *dev, void *userdata) {
+        Manager *manager = userdata;
+        int r;
+
+        assert(manager);
+
+        device_ensure_usec_initialized(dev, NULL);
+
+        r = event_queue_insert(manager, dev);
+        if (r < 0) {
+                log_device_error_errno(dev, r, "Failed to insert device into event queue: %m");
+                return 1;
+        }
+
+        /* we have fresh events, try to schedule them */
+        event_queue_start(manager);
+
+        return 1;
+}
+
+/* receive the udevd message from userspace */
+static int on_ctrl_msg(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Manager *manager = userdata;
+        _cleanup_(udev_ctrl_connection_unrefp) struct udev_ctrl_connection *ctrl_conn = NULL;
+        _cleanup_(udev_ctrl_msg_unrefp) struct udev_ctrl_msg *ctrl_msg = NULL;
+        const char *str;
+        int i, r;
+
+        assert(manager);
+
+        ctrl_conn = udev_ctrl_get_connection(manager->ctrl);
+        if (!ctrl_conn)
+                return 1;
+
+        ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
+        if (!ctrl_msg)
+                return 1;
+
+        i = udev_ctrl_get_set_log_level(ctrl_msg);
+        if (i >= 0) {
+                log_debug("Received udev control message (SET_LOG_LEVEL), setting log_priority=%i", i);
+                log_set_max_level_realm(LOG_REALM_UDEV, i);
+                log_set_max_level_realm(LOG_REALM_SYSTEMD, i);
+                manager_kill_workers(manager);
+        }
+
+        if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
+                log_debug("Received udev control message (STOP_EXEC_QUEUE)");
+                manager->stop_exec_queue = true;
+        }
+
+        if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
+                log_debug("Received udev control message (START_EXEC_QUEUE)");
+                manager->stop_exec_queue = false;
+                event_queue_start(manager);
+        }
+
+        if (udev_ctrl_get_reload(ctrl_msg) > 0) {
+                log_debug("Received udev control message (RELOAD)");
+                manager_reload(manager);
+        }
+
+        str = udev_ctrl_get_set_env(ctrl_msg);
+        if (str) {
+                _cleanup_free_ char *key = NULL, *val = NULL, *old_key = NULL, *old_val = NULL;
+                char *eq;
+
+                eq = strchr(str, '=');
+                if (!eq) {
+                        log_error("Invalid key format '%s'", str);
+                        return 1;
+                }
+
+                key = strndup(str, eq - str);
+                if (!key) {
+                        log_oom();
+                        return 1;
+                }
+
+                old_val = hashmap_remove2(manager->properties, key, (void **) &old_key);
+
+                r = hashmap_ensure_allocated(&manager->properties, &string_hash_ops);
+                if (r < 0) {
+                        log_oom();
+                        return 1;
+                }
+
+                eq++;
+                if (!isempty(eq)) {
+                        log_debug("Received udev control message (ENV), unsetting '%s'", key);
+
+                        r = hashmap_put(manager->properties, key, NULL);
+                        if (r < 0) {
+                                log_oom();
+                                return 1;
+                        }
+                } else {
+                        val = strdup(eq);
+                        if (!val) {
+                                log_oom();
+                                return 1;
+                        }
+
+                        log_debug("Received udev control message (ENV), setting '%s=%s'", key, val);
+
+                        r = hashmap_put(manager->properties, key, val);
+                        if (r < 0) {
+                                log_oom();
+                                return 1;
+                        }
+                }
+
+                key = val = NULL;
+                manager_kill_workers(manager);
+        }
+
+        i = udev_ctrl_get_set_children_max(ctrl_msg);
+        if (i >= 0) {
+                log_debug("Receivd udev control message (SET_MAX_CHILDREN), setting children_max=%i", i);
+                arg_children_max = i;
+
+                (void) sd_notifyf(false,
+                                  "READY=1\n"
+                                  "STATUS=Processing with %u children at max", arg_children_max);
+        }
+
+        if (udev_ctrl_get_ping(ctrl_msg) > 0)
+                log_debug("Received udev control message (PING)");
+
+        if (udev_ctrl_get_exit(ctrl_msg) > 0) {
+                log_debug("Received udev control message (EXIT)");
+                manager_exit(manager);
+                /* keep reference to block the client until we exit
+                   TODO: deal with several blocking exit requests */
+                manager->ctrl_conn_blocking = udev_ctrl_connection_ref(ctrl_conn);
+        }
+
+        return 1;
+}
+
+static int synthesize_change(sd_device *dev) {
+        const char *subsystem, *sysname, *devname, *syspath, *devtype;
+        char filename[PATH_MAX];
+        int r;
+
+        r = sd_device_get_subsystem(dev, &subsystem);
+        if (r < 0)
+                return r;
+
+        r = sd_device_get_sysname(dev, &sysname);
+        if (r < 0)
+                return r;
+
+        r = sd_device_get_devname(dev, &devname);
+        if (r < 0)
+                return r;
+
+        r = sd_device_get_syspath(dev, &syspath);
+        if (r < 0)
+                return r;
+
+        r = sd_device_get_devtype(dev, &devtype);
+        if (r < 0)
+                return r;
+
+        if (streq_ptr("block", subsystem) &&
+            streq_ptr("disk", devtype) &&
+            !startswith(sysname, "dm-")) {
+                _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+                bool part_table_read = false, has_partitions = false;
+                sd_device *d;
+                int fd;
+
+                /*
+                 * Try to re-read the partition table. This only succeeds if
+                 * none of the devices is busy. The kernel returns 0 if no
+                 * partition table is found, and we will not get an event for
+                 * the disk.
+                 */
+                fd = open(devname, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK);
+                if (fd >= 0) {
+                        r = flock(fd, LOCK_EX|LOCK_NB);
+                        if (r >= 0)
+                                r = ioctl(fd, BLKRRPART, 0);
+
+                        close(fd);
+                        if (r >= 0)
+                                part_table_read = true;
+                }
+
+                /* search for partitions */
+                r = sd_device_enumerator_new(&e);
+                if (r < 0)
+                        return r;
+
+                r = sd_device_enumerator_allow_uninitialized(e);
+                if (r < 0)
+                        return r;
+
+                r = sd_device_enumerator_add_match_parent(e, dev);
+                if (r < 0)
+                        return r;
+
+                r = sd_device_enumerator_add_match_subsystem(e, "block", true);
+                if (r < 0)
+                        return r;
+
+                FOREACH_DEVICE(e, d) {
+                        const char *t;
+
+                        if (sd_device_get_devtype(d, &t) < 0 ||
+                            !streq("partition", t))
+                                continue;
+
+                        has_partitions = true;
+                        break;
+                }
+
+                /*
+                 * We have partitions and re-read the table, the kernel already sent
+                 * out a "change" event for the disk, and "remove/add" for all
+                 * partitions.
+                 */
+                if (part_table_read && has_partitions)
+                        return 0;
+
+                /*
+                 * We have partitions but re-reading the partition table did not
+                 * work, synthesize "change" for the disk and all partitions.
+                 */
+                log_debug("Device '%s' is closed, synthesising 'change'", devname);
+                strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
+                write_string_file(filename, "change", WRITE_STRING_FILE_DISABLE_BUFFER);
+
+                FOREACH_DEVICE(e, d) {
+                        const char *t, *n, *s;
+
+                        if (sd_device_get_devtype(d, &t) < 0 ||
+                            !streq("partition", t))
+                                continue;
+
+                        if (sd_device_get_devname(d, &n) < 0 ||
+                            sd_device_get_syspath(d, &s) < 0)
+                                continue;
+
+                        log_debug("Device '%s' is closed, synthesising partition '%s' 'change'", devname, n);
+                        strscpyl(filename, sizeof(filename), s, "/uevent", NULL);
+                        write_string_file(filename, "change", WRITE_STRING_FILE_DISABLE_BUFFER);
+                }
+
+                return 0;
+        }
+
+        log_debug("Device %s is closed, synthesising 'change'", devname);
+        strscpyl(filename, sizeof(filename), syspath, "/uevent", NULL);
+        write_string_file(filename, "change", WRITE_STRING_FILE_DISABLE_BUFFER);
+
+        return 0;
+}
+
+static int on_inotify(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+        Manager *manager = userdata;
+        union inotify_event_buffer buffer;
+        struct inotify_event *e;
+        ssize_t l;
+        int r;
+
+        assert(manager);
+
+        r = event_source_disable(manager->kill_workers_event);
+        if (r < 0)
+                log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m");
+
+        l = read(fd, &buffer, sizeof(buffer));
+        if (l < 0) {
+                if (IN_SET(errno, EAGAIN, EINTR))
+                        return 1;
+
+                return log_error_errno(errno, "Failed to read inotify fd: %m");
+        }
+
+        FOREACH_INOTIFY_EVENT(e, buffer, l) {
+                _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+                const char *devnode;
+
+                if (udev_watch_lookup(e->wd, &dev) <= 0)
+                        continue;
+
+                if (sd_device_get_devname(dev, &devnode) < 0)
+                        continue;
+
+                log_device_debug(dev, "Inotify event: %x for %s", e->mask, devnode);
+                if (e->mask & IN_CLOSE_WRITE)
+                        synthesize_change(dev);
+                else if (e->mask & IN_IGNORED)
+                        udev_watch_end(dev);
+        }
+
+        return 1;
+}
+
+static int on_sigterm(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        Manager *manager = userdata;
+
+        assert(manager);
+
+        manager_exit(manager);
+
+        return 1;
+}
+
+static int on_sighup(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        Manager *manager = userdata;
+
+        assert(manager);
+
+        manager_reload(manager);
+
+        return 1;
+}
+
+static int on_sigchld(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        Manager *manager = userdata;
+        int r;
+
+        assert(manager);
+
+        for (;;) {
+                pid_t pid;
+                int status;
+                struct worker *worker;
+
+                pid = waitpid(-1, &status, WNOHANG);
+                if (pid <= 0)
+                        break;
+
+                worker = hashmap_get(manager->workers, PID_TO_PTR(pid));
+                if (!worker) {
+                        log_warning("Worker ["PID_FMT"] is unknown, ignoring", pid);
+                        continue;
+                }
+
+                if (WIFEXITED(status)) {
+                        if (WEXITSTATUS(status) == 0)
+                                log_debug("Worker ["PID_FMT"] exited", pid);
+                        else
+                                log_warning("Worker ["PID_FMT"] exited with return code %i", pid, WEXITSTATUS(status));
+                } else if (WIFSIGNALED(status))
+                        log_warning("Worker ["PID_FMT"] terminated by signal %i (%s)", pid, WTERMSIG(status), signal_to_string(WTERMSIG(status)));
+                else if (WIFSTOPPED(status)) {
+                        log_info("Worker ["PID_FMT"] stopped", pid);
+                        continue;
+                } else if (WIFCONTINUED(status)) {
+                        log_info("Worker ["PID_FMT"] continued", pid);
+                        continue;
+                } else
+                        log_warning("Worker ["PID_FMT"] exit with status 0x%04x", pid, status);
+
+                if ((!WIFEXITED(status) || WEXITSTATUS(status) != 0) && worker->event) {
+                        log_device_error(worker->event->dev, "Worker ["PID_FMT"] failed", pid);
+
+                        /* delete state from disk */
+                        device_delete_db(worker->event->dev);
+                        device_tag_index(worker->event->dev, NULL, false);
+
+                        /* forward kernel event without amending it */
+                        r = device_monitor_send_device(manager->monitor, NULL, worker->event->dev_kernel);
+                        if (r < 0)
+                                log_device_error_errno(worker->event->dev_kernel, r, "Failed to send back device to kernel: %m");
+                }
+
+                worker_free(worker);
+        }
+
+        /* we can start new workers, try to schedule events */
+        event_queue_start(manager);
+
+        /* Disable unnecessary cleanup event */
+        if (hashmap_isempty(manager->workers)) {
+                r = event_source_disable(manager->kill_workers_event);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m");
+        }
+
+        return 1;
+}
+
+static int on_post(sd_event_source *s, void *userdata) {
+        Manager *manager = userdata;
+
+        assert(manager);
+
+        if (!LIST_IS_EMPTY(manager->events))
+                return 1;
+
+        /* There are no pending events. Let's cleanup idle process. */
+
+        if (!hashmap_isempty(manager->workers)) {
+                /* There are idle workers */
+                (void) event_reset_time(manager->event, &manager->kill_workers_event, CLOCK_MONOTONIC,
+                                        now(CLOCK_MONOTONIC) + 3 * USEC_PER_SEC, USEC_PER_SEC,
+                                        on_kill_workers_event, manager, 0, "kill-workers-event", false);
+                return 1;
+        }
+
+        /* There are no idle workers. */
+
+        if (manager->exit)
+                return sd_event_exit(manager->event, 0);
+
+        if (manager->cgroup)
+                /* cleanup possible left-over processes in our cgroup */
+                (void) cg_kill(SYSTEMD_CGROUP_CONTROLLER, manager->cgroup, SIGKILL, CGROUP_IGNORE_SELF, NULL, NULL, NULL);
+
+        return 1;
+}
+
+static int listen_fds(int *ret_ctrl, int *ret_netlink) {
+        int ctrl_fd = -1, netlink_fd = -1;
+        int fd, n;
+
+        assert(ret_ctrl);
+        assert(ret_netlink);
+
+        n = sd_listen_fds(true);
+        if (n < 0)
+                return n;
+
+        for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
+                if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1) > 0) {
+                        if (ctrl_fd >= 0)
+                                return -EINVAL;
+                        ctrl_fd = fd;
+                        continue;
+                }
+
+                if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1) > 0) {
+                        if (netlink_fd >= 0)
+                                return -EINVAL;
+                        netlink_fd = fd;
+                        continue;
+                }
+
+                return -EINVAL;
+        }
+
+        *ret_ctrl = ctrl_fd;
+        *ret_netlink = netlink_fd;
+
+        return 0;
+}
+
+/*
+ * read the kernel command line, in case we need to get into debug mode
+ *   udev.log_priority=<level>                 syslog priority
+ *   udev.children_max=<number of workers>     events are fully serialized if set to 1
+ *   udev.exec_delay=<number of seconds>       delay execution of every executed program
+ *   udev.event_timeout=<number of seconds>    seconds to wait before terminating an event
+ */
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+        int r = 0;
+
+        assert(key);
+
+        if (!value)
+                return 0;
+
+        if (proc_cmdline_key_streq(key, "udev.log_priority")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = log_level_from_string(value);
+                if (r >= 0)
+                        log_set_max_level(r);
+
+        } else if (proc_cmdline_key_streq(key, "udev.event_timeout")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = parse_sec(value, &arg_event_timeout_usec);
+
+        } else if (proc_cmdline_key_streq(key, "udev.children_max")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = safe_atou(value, &arg_children_max);
+
+        } else if (proc_cmdline_key_streq(key, "udev.exec_delay")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = parse_sec(value, &arg_exec_delay_usec);
+
+        } else if (startswith(key, "udev."))
+                log_warning("Unknown udev kernel command line option \"%s\", ignoring", key);
+
+        if (r < 0)
+                log_warning_errno(r, "Failed to parse \"%s=%s\", ignoring: %m", key, value);
+
+        return 0;
+}
+
+static int help(void) {
+        _cleanup_free_ char *link = NULL;
+        int r;
+
+        r = terminal_urlify_man("systemd-udevd.service", "8", &link);
+        if (r < 0)
+                return log_oom();
+
+        printf("%s [OPTIONS...]\n\n"
+               "Manages devices.\n\n"
+               "  -h --help                   Print this message\n"
+               "  -V --version                Print version of the program\n"
+               "  -d --daemon                 Detach and run in the background\n"
+               "  -D --debug                  Enable debug output\n"
+               "  -c --children-max=INT       Set maximum number of workers\n"
+               "  -e --exec-delay=SECONDS     Seconds to wait before executing RUN=\n"
+               "  -t --event-timeout=SECONDS  Seconds to wait before terminating an event\n"
+               "  -N --resolve-names=early|late|never\n"
+               "                              When to resolve users and groups\n"
+               "\nSee the %s for details.\n"
+               , program_invocation_short_name
+               , link
+        );
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+        static const struct option options[] = {
+                { "daemon",             no_argument,            NULL, 'd' },
+                { "debug",              no_argument,            NULL, 'D' },
+                { "children-max",       required_argument,      NULL, 'c' },
+                { "exec-delay",         required_argument,      NULL, 'e' },
+                { "event-timeout",      required_argument,      NULL, 't' },
+                { "resolve-names",      required_argument,      NULL, 'N' },
+                { "help",               no_argument,            NULL, 'h' },
+                { "version",            no_argument,            NULL, 'V' },
+                {}
+        };
+
+        int c, r;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "c:de:Dt:N:hV", options, NULL)) >= 0) {
+                switch (c) {
+
+                case 'd':
+                        arg_daemonize = true;
+                        break;
+                case 'c':
+                        r = safe_atou(optarg, &arg_children_max);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to parse --children-max= value '%s', ignoring: %m", optarg);
+                        break;
+                case 'e':
+                        r = parse_sec(optarg, &arg_exec_delay_usec);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to parse --exec-delay= value '%s', ignoring: %m", optarg);
+                        break;
+                case 't':
+                        r = parse_sec(optarg, &arg_event_timeout_usec);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to parse --event-timeout= value '%s', ignoring: %m", optarg);
+                        break;
+                case 'D':
+                        arg_debug = true;
+                        break;
+                case 'N': {
+                        ResolveNameTiming t;
+
+                        t = resolve_name_timing_from_string(optarg);
+                        if (t < 0)
+                                log_warning("Invalid --resolve-names= value '%s', ignoring.", optarg);
+                        else
+                                arg_resolve_name_timing = t;
+                        break;
+                }
+                case 'h':
+                        return help();
+                case 'V':
+                        printf("%s\n", GIT_VERSION);
+                        return 0;
+                case '?':
+                        return -EINVAL;
+                default:
+                        assert_not_reached("Unhandled option");
+
+                }
+        }
+
+        return 1;
+}
+
+static int manager_new(Manager **ret, int fd_ctrl, int fd_uevent, const char *cgroup) {
+        _cleanup_(manager_freep) Manager *manager = NULL;
+        int r;
+
+        assert(ret);
+
+        manager = new(Manager, 1);
+        if (!manager)
+                return log_oom();
+
+        *manager = (Manager) {
+                .fd_inotify = -1,
+                .worker_watch = { -1, -1 },
+                .cgroup = cgroup,
+        };
+
+        manager->ctrl = udev_ctrl_new_from_fd(fd_ctrl);
+        if (!manager->ctrl)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize udev control socket");
+
+        r = udev_ctrl_enable_receiving(manager->ctrl);
+        if (r < 0)
+                return log_error_errno(r, "Failed to bind udev control socket: %m");
+
+        r = device_monitor_new_full(&manager->monitor, MONITOR_GROUP_KERNEL, fd_uevent);
+        if (r < 0)
+                return log_error_errno(r, "Failed to initialize device monitor: %m");
+
+        (void) sd_device_monitor_set_receive_buffer_size(manager->monitor, 128 * 1024 * 1024);
+
+        r = device_monitor_enable_receiving(manager->monitor);
+        if (r < 0)
+                return log_error_errno(r, "Failed to bind netlink socket: %m");
+
+        *ret = TAKE_PTR(manager);
+
+        return 0;
+}
+
+static int main_loop(Manager *manager) {
+        int fd_worker, fd_ctrl, r;
+
+        /* unnamed socket from workers to the main daemon */
+        r = socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, manager->worker_watch);
+        if (r < 0)
+                return log_error_errno(errno, "Failed to create socketpair for communicating with workers: %m");
+
+        fd_worker = manager->worker_watch[READ_END];
+
+        r = setsockopt_int(fd_worker, SOL_SOCKET, SO_PASSCRED, true);
+        if (r < 0)
+                return log_error_errno(r, "Failed to enable SO_PASSCRED: %m");
+
+        r = udev_watch_init();
+        if (r < 0)
+                return log_error_errno(r, "Failed to create inotify descriptor: %m");
+        manager->fd_inotify = r;
+
+        udev_watch_restore();
+
+        /* block and listen to all signals on signalfd */
+        assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGHUP, SIGCHLD, -1) >= 0);
+
+        r = sd_event_default(&manager->event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to allocate event loop: %m");
+
+        r = sd_event_add_signal(manager->event, NULL, SIGINT, on_sigterm, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create SIGINT event source: %m");
+
+        r = sd_event_add_signal(manager->event, NULL, SIGTERM, on_sigterm, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create SIGTERM event source: %m");
+
+        r = sd_event_add_signal(manager->event, NULL, SIGHUP, on_sighup, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create SIGHUP event source: %m");
+
+        r = sd_event_add_signal(manager->event, NULL, SIGCHLD, on_sigchld, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create SIGCHLD event source: %m");
+
+        r = sd_event_set_watchdog(manager->event, true);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create watchdog event source: %m");
+
+        fd_ctrl = udev_ctrl_get_fd(manager->ctrl);
+        if (fd_ctrl < 0)
+                return log_error_errno(fd_ctrl, "Failed to get udev control socket fd: %m");
+
+        r = sd_event_add_io(manager->event, &manager->ctrl_event, fd_ctrl, EPOLLIN, on_ctrl_msg, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create udev control event source: %m");
+
+        /* This needs to be after the inotify and uevent handling, to make sure
+         * that the ping is send back after fully processing the pending uevents
+         * (including the synthetic ones we may create due to inotify events).
+         */
+        r = sd_event_source_set_priority(manager->ctrl_event, SD_EVENT_PRIORITY_IDLE);
+        if (r < 0)
+                return log_error_errno(r, "Failed to set IDLE event priority for udev control event source: %m");
+
+        r = sd_event_add_io(manager->event, &manager->inotify_event, manager->fd_inotify, EPOLLIN, on_inotify, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create inotify event source: %m");
+
+        r = sd_device_monitor_attach_event(manager->monitor, manager->event);
+        if (r < 0)
+                return log_error_errno(r, "Failed to attach event to device monitor: %m");
+
+        r = sd_device_monitor_start(manager->monitor, on_uevent, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to start device monitor: %m");
+
+        (void) sd_event_source_set_description(sd_device_monitor_get_event_source(manager->monitor), "device-monitor");
+
+        r = sd_event_add_io(manager->event, NULL, fd_worker, EPOLLIN, on_worker, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create worker event source: %m");
+
+        r = sd_event_add_post(manager->event, NULL, on_post, manager);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create post event source: %m");
+
+        udev_builtin_init();
+
+        r = udev_rules_new(&manager->rules, arg_resolve_name_timing);
+        if (!manager->rules)
+                return log_error_errno(r, "Failed to read udev rules: %m");
+
+        r = udev_rules_apply_static_dev_perms(manager->rules);
+        if (r < 0)
+                log_error_errno(r, "Failed to apply permissions on static device nodes: %m");
+
+        (void) sd_notifyf(false,
+                          "READY=1\n"
+                          "STATUS=Processing with %u children at max", arg_children_max);
+
+        r = sd_event_loop(manager->event);
+        if (r < 0)
+                log_error_errno(r, "Event loop failed: %m");
+
+        sd_notify(false,
+                  "STOPPING=1\n"
+                  "STATUS=Shutting down...");
+        return r;
+}
+
+static int run(int argc, char *argv[]) {
+        _cleanup_free_ char *cgroup = NULL;
+        _cleanup_(manager_freep) Manager *manager = NULL;
+        int fd_ctrl = -1, fd_uevent = -1;
+        int r;
+
+        log_set_target(LOG_TARGET_AUTO);
+        udev_parse_config_full(&arg_children_max, &arg_exec_delay_usec, &arg_event_timeout_usec, &arg_resolve_name_timing);
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                return r;
+
+        r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
+        if (r < 0)
+                log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
+
+        if (arg_debug) {
+                log_set_target(LOG_TARGET_CONSOLE);
+                log_set_max_level(LOG_DEBUG);
+        }
+
+        log_set_max_level_realm(LOG_REALM_SYSTEMD, log_get_max_level());
+
+        r = must_be_root();
+        if (r < 0)
+                return r;
+
+        if (arg_children_max == 0) {
+                cpu_set_t cpu_set;
+                unsigned long mem_limit;
+
+                arg_children_max = 8;
+
+                if (sched_getaffinity(0, sizeof(cpu_set), &cpu_set) == 0)
+                        arg_children_max += CPU_COUNT(&cpu_set) * 8;
+
+                mem_limit = physical_memory() / (128LU*1024*1024);
+                arg_children_max = MAX(10U, MIN(arg_children_max, mem_limit));
+
+                log_debug("Set children_max to %u", arg_children_max);
+        }
+
+        /* set umask before creating any file/directory */
+        r = chdir("/");
+        if (r < 0)
+                return log_error_errno(errno, "Failed to change dir to '/': %m");
+
+        umask(022);
+
+        r = mac_selinux_init();
+        if (r < 0)
+                return log_error_errno(r, "Could not initialize labelling: %m");
+
+        r = mkdir_errno_wrapper("/run/udev", 0755);
+        if (r < 0 && r != -EEXIST)
+                return log_error_errno(r, "Failed to create /run/udev: %m");
+
+        dev_setup(NULL, UID_INVALID, GID_INVALID);
+
+        if (getppid() == 1 && sd_booted() > 0) {
+                /* Get our own cgroup, we regularly kill everything udev has left behind.
+                 * We only do this on systemd systems, and only if we are directly spawned
+                 * by PID1. Otherwise we are not guaranteed to have a dedicated cgroup. */
+                r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
+                if (r < 0) {
+                        if (IN_SET(r, -ENOENT, -ENOMEDIUM))
+                                log_debug_errno(r, "Dedicated cgroup not found: %m");
+                        else
+                                log_warning_errno(r, "Failed to get cgroup: %m");
+                }
+        }
+
+        r = listen_fds(&fd_ctrl, &fd_uevent);
+        if (r < 0)
+                return log_error_errno(r, "Failed to listen on fds: %m");
+
+        r = manager_new(&manager, fd_ctrl, fd_uevent, cgroup);
+        if (r < 0)
+                return log_error_errno(r, "Failed to create manager: %m");
+
+        if (arg_daemonize) {
+                pid_t pid;
+
+                log_info("Starting version " GIT_VERSION);
+
+                /* connect /dev/null to stdin, stdout, stderr */
+                if (log_get_max_level() < LOG_DEBUG) {
+                        r = make_null_stdio();
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to redirect standard streams to /dev/null: %m");
+                }
+
+                pid = fork();
+                if (pid < 0)
+                        return log_error_errno(errno, "Failed to fork daemon: %m");
+                if (pid > 0)
+                        /* parent */
+                        return 0;
+
+                /* child */
+                (void) setsid();
+
+                r = set_oom_score_adjust(-1000);
+                if (r < 0)
+                        log_debug_errno(r, "Failed to adjust OOM score, ignoring: %m");
+        }
+
+        r = main_loop(manager);
+        /* FIXME: move this into manager_free() */
+        udev_ctrl_cleanup(manager->ctrl);
+        return r;
+}
+
+DEFINE_MAIN_FUNCTION(run);