move imported udev into place

1 files changed, 1746 insertions, 0 deletions

diff --git a/src/udev/udevd.c b/src/udev/udevd.c
new file mode 100644
index 0000000000..694e758777
--- /dev/null
+++ b/src/udev/udevd.c
@@ -0,0 +1,1746 @@
+/*
+ * Copyright (C) 2004-2011 Kay Sievers <kay.sievers@vrfy.org>
+ * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
+ * Copyright (C) 2009 Canonical Ltd.
+ * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stddef.h>
+#include <signal.h>
+#include <unistd.h>
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdbool.h>
+#include <string.h>
+#include <ctype.h>
+#include <fcntl.h>
+#include <time.h>
+#include <getopt.h>
+#include <dirent.h>
+#include <sys/time.h>
+#include <sys/prctl.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/signalfd.h>
+#include <sys/epoll.h>
+#include <sys/poll.h>
+#include <sys/wait.h>
+#include <sys/stat.h>
+#include <sys/ioctl.h>
+#include <sys/inotify.h>
+#include <sys/utsname.h>
+
+#include "udev.h"
+#include "sd-daemon.h"
+
+static bool debug;
+
+void udev_main_log(struct udev *udev, int priority,
+                   const char *file, int line, const char *fn,
+                   const char *format, va_list args)
+{
+        if (debug) {
+                char buf[1024];
+                struct timespec ts;
+
+                vsnprintf(buf, sizeof(buf), format, args);
+                clock_gettime(CLOCK_MONOTONIC, &ts);
+                fprintf(stderr, "[%llu.%06u] [%u] %s: %s",
+                        (unsigned long long) ts.tv_sec, (unsigned int) ts.tv_nsec/1000,
+                        (int) getpid(), fn, buf);
+        } else {
+                vsyslog(priority, format, args);
+        }
+}
+
+static struct udev_rules *rules;
+static struct udev_queue_export *udev_queue_export;
+static struct udev_ctrl *udev_ctrl;
+static struct udev_monitor *monitor;
+static int worker_watch[2] = { -1, -1 };
+static int fd_signal = -1;
+static int fd_ep = -1;
+static int fd_inotify = -1;
+static bool stop_exec_queue;
+static bool reload;
+static int children;
+static int children_max;
+static int exec_delay;
+static sigset_t sigmask_orig;
+static UDEV_LIST(event_list);
+static UDEV_LIST(worker_list);
+static bool udev_exit;
+
+enum event_state {
+        EVENT_UNDEF,
+        EVENT_QUEUED,
+        EVENT_RUNNING,
+};
+
+struct event {
+        struct udev_list_node node;
+        struct udev *udev;
+        struct udev_device *dev;
+        enum event_state state;
+        int exitcode;
+        unsigned long long int delaying_seqnum;
+        unsigned long long int seqnum;
+        const char *devpath;
+        size_t devpath_len;
+        const char *devpath_old;
+        dev_t devnum;
+        bool is_block;
+        int ifindex;
+};
+
+static struct event *node_to_event(struct udev_list_node *node)
+{
+        char *event;
+
+        event = (char *)node;
+        event -= offsetof(struct event, node);
+        return (struct event *)event;
+}
+
+static void event_queue_cleanup(struct udev *udev, enum event_state type);
+
+enum worker_state {
+        WORKER_UNDEF,
+        WORKER_RUNNING,
+        WORKER_IDLE,
+        WORKER_KILLED,
+};
+
+struct worker {
+        struct udev_list_node node;
+        struct udev *udev;
+        int refcount;
+        pid_t pid;
+        struct udev_monitor *monitor;
+        enum worker_state state;
+        struct event *event;
+        unsigned long long event_start_usec;
+};
+
+/* passed from worker to main process */
+struct worker_message {
+        pid_t pid;
+        int exitcode;
+};
+
+static struct worker *node_to_worker(struct udev_list_node *node)
+{
+        char *worker;
+
+        worker = (char *)node;
+        worker -= offsetof(struct worker, node);
+        return (struct worker *)worker;
+}
+
+static void event_queue_delete(struct event *event, bool export)
+{
+        udev_list_node_remove(&event->node);
+
+        if (export) {
+                udev_queue_export_device_finished(udev_queue_export, event->dev);
+                info(event->udev, "seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode);
+        }
+        udev_device_unref(event->dev);
+        free(event);
+}
+
+static struct worker *worker_ref(struct worker *worker)
+{
+        worker->refcount++;
+        return worker;
+}
+
+static void worker_cleanup(struct worker *worker)
+{
+        udev_list_node_remove(&worker->node);
+        udev_monitor_unref(worker->monitor);
+        children--;
+        free(worker);
+}
+
+static void worker_unref(struct worker *worker)
+{
+        worker->refcount--;
+        if (worker->refcount > 0)
+                return;
+        info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
+        worker_cleanup(worker);
+}
+
+static void worker_list_cleanup(struct udev *udev)
+{
+        struct udev_list_node *loop, *tmp;
+
+        udev_list_node_foreach_safe(loop, tmp, &worker_list) {
+                struct worker *worker = node_to_worker(loop);
+
+                worker_cleanup(worker);
+        }
+}
+
+static void worker_new(struct event *event)
+{
+        struct udev *udev = event->udev;
+        struct worker *worker;
+        struct udev_monitor *worker_monitor;
+        pid_t pid;
+
+        /* listen for new events */
+        worker_monitor = udev_monitor_new_from_netlink(udev, NULL);
+        if (worker_monitor == NULL)
+                return;
+        /* allow the main daemon netlink address to send devices to the worker */
+        udev_monitor_allow_unicast_sender(worker_monitor, monitor);
+        udev_monitor_enable_receiving(worker_monitor);
+
+        worker = calloc(1, sizeof(struct worker));
+        if (worker == NULL) {
+                udev_monitor_unref(worker_monitor);
+                return;
+        }
+        /* worker + event reference */
+        worker->refcount = 2;
+        worker->udev = udev;
+
+        pid = fork();
+        switch (pid) {
+        case 0: {
+                struct udev_device *dev = NULL;
+                int fd_monitor;
+                struct epoll_event ep_signal, ep_monitor;
+                sigset_t mask;
+                int rc = EXIT_SUCCESS;
+
+                /* take initial device from queue */
+                dev = event->dev;
+                event->dev = NULL;
+
+                free(worker);
+                worker_list_cleanup(udev);
+                event_queue_cleanup(udev, EVENT_UNDEF);
+                udev_queue_export_unref(udev_queue_export);
+                udev_monitor_unref(monitor);
+                udev_ctrl_unref(udev_ctrl);
+                close(fd_signal);
+                close(fd_ep);
+                close(worker_watch[READ_END]);
+
+                sigfillset(&mask);
+                fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
+                if (fd_signal < 0) {
+                        err(udev, "error creating signalfd %m\n");
+                        rc = 2;
+                        goto out;
+                }
+
+                fd_ep = epoll_create1(EPOLL_CLOEXEC);
+                if (fd_ep < 0) {
+                        err(udev, "error creating epoll fd: %m\n");
+                        rc = 3;
+                        goto out;
+                }
+
+                memset(&ep_signal, 0, sizeof(struct epoll_event));
+                ep_signal.events = EPOLLIN;
+                ep_signal.data.fd = fd_signal;
+
+                fd_monitor = udev_monitor_get_fd(worker_monitor);
+                memset(&ep_monitor, 0, sizeof(struct epoll_event));
+                ep_monitor.events = EPOLLIN;
+                ep_monitor.data.fd = fd_monitor;
+
+                if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
+                    epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) {
+                        err(udev, "fail to add fds to epoll: %m\n");
+                        rc = 4;
+                        goto out;
+                }
+
+                /* request TERM signal if parent exits */
+                prctl(PR_SET_PDEATHSIG, SIGTERM);
+
+                for (;;) {
+                        struct udev_event *udev_event;
+                        struct worker_message msg;
+                        int err;
+
+                        info(udev, "seq %llu running\n", udev_device_get_seqnum(dev));
+                        udev_event = udev_event_new(dev);
+                        if (udev_event == NULL) {
+                                rc = 5;
+                                goto out;
+                        }
+
+                        /* needed for SIGCHLD/SIGTERM in spawn() */
+                        udev_event->fd_signal = fd_signal;
+
+                        if (exec_delay > 0)
+                                udev_event->exec_delay = exec_delay;
+
+                        /* apply rules, create node, symlinks */
+                        err = udev_event_execute_rules(udev_event, rules, &sigmask_orig);
+
+                        if (err == 0)
+                                udev_event_execute_run(udev_event, &sigmask_orig);
+
+                        /* apply/restore inotify watch */
+                        if (err == 0 && udev_event->inotify_watch) {
+                                udev_watch_begin(udev, dev);
+                                udev_device_update_db(dev);
+                        }
+
+                        /* send processed event back to libudev listeners */
+                        udev_monitor_send_device(worker_monitor, NULL, dev);
+
+                        /* send udevd the result of the event execution */
+                        memset(&msg, 0, sizeof(struct worker_message));
+                        if (err != 0)
+                                msg.exitcode = err;
+                        msg.pid = getpid();
+                        send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
+
+                        info(udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
+
+                        udev_device_unref(dev);
+                        dev = NULL;
+
+                        if (udev_event->sigterm) {
+                                udev_event_unref(udev_event);
+                                goto out;
+                        }
+
+                        udev_event_unref(udev_event);
+
+                        /* wait for more device messages from main udevd, or term signal */
+                        while (dev == NULL) {
+                                struct epoll_event ev[4];
+                                int fdcount;
+                                int i;
+
+                                fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1);
+                                if (fdcount < 0) {
+                                        if (errno == EINTR)
+                                                continue;
+                                        err = -errno;
+                                        err(udev, "failed to poll: %m\n");
+                                        goto out;
+                                }
+
+                                for (i = 0; i < fdcount; i++) {
+                                        if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) {
+                                                dev = udev_monitor_receive_device(worker_monitor);
+                                                break;
+                                        } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) {
+                                                struct signalfd_siginfo fdsi;
+                                                ssize_t size;
+
+                                                size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
+                                                if (size != sizeof(struct signalfd_siginfo))
+                                                        continue;
+                                                switch (fdsi.ssi_signo) {
+                                                case SIGTERM:
+                                                        goto out;
+                                                }
+                                        }
+                                }
+                        }
+                }
+out:
+                udev_device_unref(dev);
+                if (fd_signal >= 0)
+                        close(fd_signal);
+                if (fd_ep >= 0)
+                        close(fd_ep);
+                close(fd_inotify);
+                close(worker_watch[WRITE_END]);
+                udev_rules_unref(rules);
+                udev_builtin_exit(udev);
+                udev_monitor_unref(worker_monitor);
+                udev_unref(udev);
+                udev_log_close();
+                exit(rc);
+        }
+        case -1:
+                udev_monitor_unref(worker_monitor);
+                event->state = EVENT_QUEUED;
+                free(worker);
+                err(udev, "fork of child failed: %m\n");
+                break;
+        default:
+                /* close monitor, but keep address around */
+                udev_monitor_disconnect(worker_monitor);
+                worker->monitor = worker_monitor;
+                worker->pid = pid;
+                worker->state = WORKER_RUNNING;
+                worker->event_start_usec = now_usec();
+                worker->event = event;
+                event->state = EVENT_RUNNING;
+                udev_list_node_append(&worker->node, &worker_list);
+                children++;
+                info(udev, "seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid);
+                break;
+        }
+}
+
+static void event_run(struct event *event)
+{
+        struct udev_list_node *loop;
+
+        udev_list_node_foreach(loop, &worker_list) {
+                struct worker *worker = node_to_worker(loop);
+                ssize_t count;
+
+                if (worker->state != WORKER_IDLE)
+                        continue;
+
+                count = udev_monitor_send_device(monitor, worker->monitor, event->dev);
+                if (count < 0) {
+                        err(event->udev, "worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count);
+                        kill(worker->pid, SIGKILL);
+                        worker->state = WORKER_KILLED;
+                        continue;
+                }
+                worker_ref(worker);
+                worker->event = event;
+                worker->state = WORKER_RUNNING;
+                worker->event_start_usec = now_usec();
+                event->state = EVENT_RUNNING;
+                return;
+        }
+
+        if (children >= children_max) {
+                if (children_max > 1)
+                        info(event->udev, "maximum number (%i) of children reached\n", children);
+                return;
+        }
+
+        /* start new worker and pass initial device */
+        worker_new(event);
+}
+
+static int event_queue_insert(struct udev_device *dev)
+{
+        struct event *event;
+
+        event = calloc(1, sizeof(struct event));
+        if (event == NULL)
+                return -1;
+
+        event->udev = udev_device_get_udev(dev);
+        event->dev = dev;
+        event->seqnum = udev_device_get_seqnum(dev);
+        event->devpath = udev_device_get_devpath(dev);
+        event->devpath_len = strlen(event->devpath);
+        event->devpath_old = udev_device_get_devpath_old(dev);
+        event->devnum = udev_device_get_devnum(dev);
+        event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
+        event->ifindex = udev_device_get_ifindex(dev);
+
+        udev_queue_export_device_queued(udev_queue_export, dev);
+        info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
+             udev_device_get_action(dev), udev_device_get_subsystem(dev));
+
+        event->state = EVENT_QUEUED;
+        udev_list_node_append(&event->node, &event_list);
+        return 0;
+}
+
+static void worker_kill(struct udev *udev, int retain)
+{
+        struct udev_list_node *loop;
+        int max;
+
+        if (children <= retain)
+                return;
+
+        max = children - retain;
+
+        udev_list_node_foreach(loop, &worker_list) {
+                struct worker *worker = node_to_worker(loop);
+
+                if (max-- <= 0)
+                        break;
+
+                if (worker->state == WORKER_KILLED)
+                        continue;
+
+                worker->state = WORKER_KILLED;
+                kill(worker->pid, SIGTERM);
+        }
+}
+
+/* lookup event for identical, parent, child device */
+static bool is_devpath_busy(struct event *event)
+{
+        struct udev_list_node *loop;
+        size_t common;
+
+        /* check if queue contains events we depend on */
+        udev_list_node_foreach(loop, &event_list) {
+                struct event *loop_event = node_to_event(loop);
+
+                /* we already found a later event, earlier can not 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(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
+                        return true;
+
+                /* check network device ifindex */
+                if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
+                        return true;
+
+                /* check our old name */
+                if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                /* compare devpath */
+                common = MIN(loop_event->devpath_len, event->devpath_len);
+
+                /* one devpath is contained in the other? */
+                if (memcmp(loop_event->devpath, event->devpath, common) != 0)
+                        continue;
+
+                /* identical device event found */
+                if (loop_event->devpath_len == event->devpath_len) {
+                        /* devices names might have changed/swapped in the meantime */
+                        if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
+                                continue;
+                        if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
+                                continue;
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                /* parent device event found */
+                if (event->devpath[common] == '/') {
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                /* child device event found */
+                if (loop_event->devpath[common] == '/') {
+                        event->delaying_seqnum = loop_event->seqnum;
+                        return true;
+                }
+
+                /* no matching device */
+                continue;
+        }
+
+        return false;
+}
+
+static void event_queue_start(struct udev *udev)
+{
+        struct udev_list_node *loop;
+
+        udev_list_node_foreach(loop, &event_list) {
+                struct event *event = node_to_event(loop);
+
+                if (event->state != EVENT_QUEUED)
+                        continue;
+
+                /* do not start event if parent or child event is still running */
+                if (is_devpath_busy(event)) {
+                        dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath);
+                        continue;
+                }
+
+                event_run(event);
+        }
+}
+
+static void event_queue_cleanup(struct udev *udev, enum event_state match_type)
+{
+        struct udev_list_node *loop, *tmp;
+
+        udev_list_node_foreach_safe(loop, tmp, &event_list) {
+                struct event *event = node_to_event(loop);
+
+                if (match_type != EVENT_UNDEF && match_type != event->state)
+                        continue;
+
+                event_queue_delete(event, false);
+        }
+}
+
+static void worker_returned(int fd_worker)
+{
+        for (;;) {
+                struct worker_message msg;
+                ssize_t size;
+                struct udev_list_node *loop;
+
+                size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT);
+                if (size != sizeof(struct worker_message))
+                        break;
+
+                /* lookup worker who sent the signal */
+                udev_list_node_foreach(loop, &worker_list) {
+                        struct worker *worker = node_to_worker(loop);
+
+                        if (worker->pid != msg.pid)
+                                continue;
+
+                        /* worker returned */
+                        if (worker->event) {
+                                worker->event->exitcode = msg.exitcode;
+                                event_queue_delete(worker->event, true);
+                                worker->event = NULL;
+                        }
+                        if (worker->state != WORKER_KILLED)
+                                worker->state = WORKER_IDLE;
+                        worker_unref(worker);
+                        break;
+                }
+        }
+}
+
+/* receive the udevd message from userspace */
+static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl)
+{
+        struct udev *udev = udev_ctrl_get_udev(uctrl);
+        struct udev_ctrl_connection *ctrl_conn;
+        struct udev_ctrl_msg *ctrl_msg = NULL;
+        const char *str;
+        int i;
+
+        ctrl_conn = udev_ctrl_get_connection(uctrl);
+        if (ctrl_conn == NULL)
+                goto out;
+
+        ctrl_msg = udev_ctrl_receive_msg(ctrl_conn);
+        if (ctrl_msg == NULL)
+                goto out;
+
+        i = udev_ctrl_get_set_log_level(ctrl_msg);
+        if (i >= 0) {
+                info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i);
+                udev_set_log_priority(udev, i);
+                worker_kill(udev, 0);
+        }
+
+        if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
+                info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
+                stop_exec_queue = true;
+        }
+
+        if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
+                info(udev, "udevd message (START_EXEC_QUEUE) received\n");
+                stop_exec_queue = false;
+        }
+
+        if (udev_ctrl_get_reload(ctrl_msg) > 0) {
+                info(udev, "udevd message (RELOAD) received\n");
+                reload = true;
+        }
+
+        str = udev_ctrl_get_set_env(ctrl_msg);
+        if (str != NULL) {
+                char *key;
+
+                key = strdup(str);
+                if (key != NULL) {
+                        char *val;
+
+                        val = strchr(key, '=');
+                        if (val != NULL) {
+                                val[0] = '\0';
+                                val = &val[1];
+                                if (val[0] == '\0') {
+                                        info(udev, "udevd message (ENV) received, unset '%s'\n", key);
+                                        udev_add_property(udev, key, NULL);
+                                } else {
+                                        info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val);
+                                        udev_add_property(udev, key, val);
+                                }
+                        } else {
+                                err(udev, "wrong key format '%s'\n", key);
+                        }
+                        free(key);
+                }
+                worker_kill(udev, 0);
+        }
+
+        i = udev_ctrl_get_set_children_max(ctrl_msg);
+        if (i >= 0) {
+                info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
+                children_max = i;
+        }
+
+        if (udev_ctrl_get_ping(ctrl_msg) > 0)
+                info(udev, "udevd message (SYNC) received\n");
+
+        if (udev_ctrl_get_exit(ctrl_msg) > 0) {
+                info(udev, "udevd message (EXIT) received\n");
+                udev_exit = true;
+                /* keep reference to block the client until we exit */
+                udev_ctrl_connection_ref(ctrl_conn);
+        }
+out:
+        udev_ctrl_msg_unref(ctrl_msg);
+        return udev_ctrl_connection_unref(ctrl_conn);
+}
+
+/* read inotify messages */
+static int handle_inotify(struct udev *udev)
+{
+        int nbytes, pos;
+        char *buf;
+        struct inotify_event *ev;
+
+        if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
+                return 0;
+
+        buf = malloc(nbytes);
+        if (buf == NULL) {
+                err(udev, "error getting buffer for inotify\n");
+                return -1;
+        }
+
+        nbytes = read(fd_inotify, buf, nbytes);
+
+        for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
+                struct udev_device *dev;
+
+                ev = (struct inotify_event *)(buf + pos);
+                dev = udev_watch_lookup(udev, ev->wd);
+                if (dev != NULL) {
+                        info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
+                        if (ev->mask & IN_CLOSE_WRITE) {
+                                char filename[UTIL_PATH_SIZE];
+                                int fd;
+
+                                info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
+                                util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
+                                fd = open(filename, O_WRONLY);
+                                if (fd >= 0) {
+                                        if (write(fd, "change", 6) < 0)
+                                                info(udev, "error writing uevent: %m\n");
+                                        close(fd);
+                                }
+                        }
+                        if (ev->mask & IN_IGNORED)
+                                udev_watch_end(udev, dev);
+
+                        udev_device_unref(dev);
+                }
+
+        }
+
+        free(buf);
+        return 0;
+}
+
+static void handle_signal(struct udev *udev, int signo)
+{
+        switch (signo) {
+        case SIGINT:
+        case SIGTERM:
+                udev_exit = true;
+                break;
+        case SIGCHLD:
+                for (;;) {
+                        pid_t pid;
+                        int status;
+                        struct udev_list_node *loop, *tmp;
+
+                        pid = waitpid(-1, &status, WNOHANG);
+                        if (pid <= 0)
+                                break;
+
+                        udev_list_node_foreach_safe(loop, tmp, &worker_list) {
+                                struct worker *worker = node_to_worker(loop);
+
+                                if (worker->pid != pid)
+                                        continue;
+                                info(udev, "worker [%u] exit\n", pid);
+
+                                if (WIFEXITED(status)) {
+                                        if (WEXITSTATUS(status) != 0)
+                                                err(udev, "worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status));
+                                } else if (WIFSIGNALED(status)) {
+                                        err(udev, "worker [%u] terminated by signal %i (%s)\n",
+                                            pid, WTERMSIG(status), strsignal(WTERMSIG(status)));
+                                } else if (WIFSTOPPED(status)) {
+                                        err(udev, "worker [%u] stopped\n", pid);
+                                } else if (WIFCONTINUED(status)) {
+                                        err(udev, "worker [%u] continued\n", pid);
+                                } else {
+                                        err(udev, "worker [%u] exit with status 0x%04x\n", pid, status);
+                                }
+
+                                if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+                                        if (worker->event) {
+                                                err(udev, "worker [%u] failed while handling '%s'\n",
+                                                    pid, worker->event->devpath);
+                                                worker->event->exitcode = -32;
+                                                event_queue_delete(worker->event, true);
+                                                /* drop reference taken for state 'running' */
+                                                worker_unref(worker);
+                                        }
+                                }
+                                worker_unref(worker);
+                                break;
+                        }
+                }
+                break;
+        case SIGHUP:
+                reload = true;
+                break;
+        }
+}
+
+static void static_dev_create_from_modules(struct udev *udev)
+{
+        struct utsname kernel;
+        char modules[UTIL_PATH_SIZE];
+        char buf[4096];
+        FILE *f;
+
+        uname(&kernel);
+        util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
+        f = fopen(modules, "r");
+        if (f == NULL)
+                return;
+
+        while (fgets(buf, sizeof(buf), f) != NULL) {
+                char *s;
+                const char *modname;
+                const char *devname;
+                const char *devno;
+                int maj, min;
+                char type;
+                mode_t mode;
+                char filename[UTIL_PATH_SIZE];
+
+                if (buf[0] == '#')
+                        continue;
+
+                modname = buf;
+                s = strchr(modname, ' ');
+                if (s == NULL)
+                        continue;
+                s[0] = '\0';
+
+                devname = &s[1];
+                s = strchr(devname, ' ');
+                if (s == NULL)
+                        continue;
+                s[0] = '\0';
+
+                devno = &s[1];
+                s = strchr(devno, ' ');
+                if (s == NULL)
+                        s = strchr(devno, '\n');
+                if (s != NULL)
+                        s[0] = '\0';
+                if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
+                        continue;
+
+                if (type == 'c')
+                        mode = S_IFCHR;
+                else if (type == 'b')
+                        mode = S_IFBLK;
+                else
+                        continue;
+
+                util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
+                util_create_path_selinux(udev, filename);
+                udev_selinux_setfscreatecon(udev, filename, mode);
+                info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
+                if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
+                        utimensat(AT_FDCWD, filename, NULL, 0);
+                udev_selinux_resetfscreatecon(udev);
+        }
+
+        fclose(f);
+}
+
+static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
+{
+        struct dirent *dent;
+
+        for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
+                struct stat stats;
+
+                if (dent->d_name[0] == '.')
+                        continue;
+                if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
+                        continue;
+
+                if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
+                        udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
+                        if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
+                                fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
+                                fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
+                        } else {
+                                utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
+                        }
+                        udev_selinux_resetfscreatecon(udev);
+                } else if (S_ISLNK(stats.st_mode)) {
+                        char target[UTIL_PATH_SIZE];
+                        ssize_t len;
+
+                        len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
+                        if (len <= 0 || len == (ssize_t)sizeof(target))
+                                continue;
+                        target[len] = '\0';
+                        udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
+                        if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
+                                utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
+                        udev_selinux_resetfscreatecon(udev);
+                } else if (S_ISDIR(stats.st_mode)) {
+                        DIR *dir2_from, *dir2_to;
+
+                        if (maxdepth == 0)
+                                continue;
+
+                        udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
+                        mkdirat(dirfd(dir_to), dent->d_name, 0755);
+                        udev_selinux_resetfscreatecon(udev);
+
+                        dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
+                        if (dir2_to == NULL)
+                                continue;
+
+                        dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
+                        if (dir2_from == NULL) {
+                                closedir(dir2_to);
+                                continue;
+                        }
+
+                        copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1);
+
+                        closedir(dir2_to);
+                        closedir(dir2_from);
+                }
+        }
+
+        return 0;
+}
+
+static void static_dev_create_links(struct udev *udev, DIR *dir)
+{
+        struct stdlinks {
+                const char *link;
+                const char *target;
+        };
+        static const struct stdlinks stdlinks[] = {
+                { "core", "/proc/kcore" },
+                { "fd", "/proc/self/fd" },
+                { "stdin", "/proc/self/fd/0" },
+                { "stdout", "/proc/self/fd/1" },
+                { "stderr", "/proc/self/fd/2" },
+        };
+        unsigned int i;
+
+        for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
+                struct stat sb;
+
+                if (stat(stdlinks[i].target, &sb) == 0) {
+                        udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
+                        if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
+                                utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
+                        udev_selinux_resetfscreatecon(udev);
+                }
+        }
+}
+
+static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
+{
+        DIR *dir_from;
+
+        dir_from = opendir(UDEVLIBEXECDIR "/devices");
+        if (dir_from == NULL)
+                return;
+        copy_dev_dir(udev, dir_from, dir, 8);
+        closedir(dir_from);
+}
+
+static void static_dev_create(struct udev *udev)
+{
+        DIR *dir;
+
+        dir = opendir(udev_get_dev_path(udev));
+        if (dir == NULL)
+                return;
+
+        static_dev_create_links(udev, dir);
+        static_dev_create_from_devices(udev, dir);
+
+        closedir(dir);
+}
+
+static int mem_size_mb(void)
+{
+        FILE *f;
+        char buf[4096];
+        long int memsize = -1;
+
+        f = fopen("/proc/meminfo", "r");
+        if (f == NULL)
+                return -1;
+
+        while (fgets(buf, sizeof(buf), f) != NULL) {
+                long int value;
+
+                if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
+                        memsize = value / 1024;
+                        break;
+                }
+        }
+
+        fclose(f);
+        return memsize;
+}
+
+static int convert_db(struct udev *udev)
+{
+        char filename[UTIL_PATH_SIZE];
+        FILE *f;
+        struct udev_enumerate *udev_enumerate;
+        struct udev_list_entry *list_entry;
+
+        /* current database */
+        util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
+        if (access(filename, F_OK) >= 0)
+                return 0;
+
+        /* make sure we do not get here again */
+        util_create_path(udev, filename);
+        mkdir(filename, 0755);
+
+        /* old database */
+        util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
+        if (access(filename, F_OK) < 0)
+                return 0;
+
+        f = fopen("/dev/kmsg", "w");
+        if (f != NULL) {
+                fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid());
+                fclose(f);
+        }
+
+        udev_enumerate = udev_enumerate_new(udev);
+        if (udev_enumerate == NULL)
+                return -1;
+        udev_enumerate_scan_devices(udev_enumerate);
+        udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
+                struct udev_device *device;
+
+                device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
+                if (device == NULL)
+                        continue;
+
+                /* try to find the old database for devices without a current one */
+                if (udev_device_read_db(device, NULL) < 0) {
+                        bool have_db;
+                        const char *id;
+                        struct stat stats;
+                        char devpath[UTIL_PATH_SIZE];
+                        char from[UTIL_PATH_SIZE];
+
+                        have_db = false;
+
+                        /* find database in old location */
+                        id = udev_device_get_id_filename(device);
+                        util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
+                        if (lstat(from, &stats) == 0) {
+                                if (!have_db) {
+                                        udev_device_read_db(device, from);
+                                        have_db = true;
+                                }
+                                unlink(from);
+                        }
+
+                        /* find old database with $subsys:$sysname name */
+                        util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
+                                     "/.udev/db/", udev_device_get_subsystem(device), ":",
+                                     udev_device_get_sysname(device), NULL);
+                        if (lstat(from, &stats) == 0) {
+                                if (!have_db) {
+                                        udev_device_read_db(device, from);
+                                        have_db = true;
+                                }
+                                unlink(from);
+                        }
+
+                        /* find old database with the encoded devpath name */
+                        util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
+                        util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
+                        if (lstat(from, &stats) == 0) {
+                                if (!have_db) {
+                                        udev_device_read_db(device, from);
+                                        have_db = true;
+                                }
+                                unlink(from);
+                        }
+
+                        /* write out new database */
+                        if (have_db)
+                                udev_device_update_db(device);
+                }
+                udev_device_unref(device);
+        }
+        udev_enumerate_unref(udev_enumerate);
+        return 0;
+}
+
+static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink)
+{
+        int ctrl = -1, netlink = -1;
+        int fd, n;
+
+        n = sd_listen_fds(true);
+        if (n <= 0)
+                return -1;
+
+        for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) {
+                if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) {
+                        if (ctrl >= 0)
+                                return -1;
+                        ctrl = fd;
+                        continue;
+                }
+
+                if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) {
+                        if (netlink >= 0)
+                                return -1;
+                        netlink = fd;
+                        continue;
+                }
+
+                return -1;
+        }
+
+        if (ctrl < 0 || netlink < 0)
+                return -1;
+
+        info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink);
+        *rctrl = ctrl;
+        *rnetlink = netlink;
+        return 0;
+}
+
+static bool check_rules_timestamp(struct udev *udev)
+{
+        char **p;
+        unsigned long long *stamp_usec;
+        int i, n;
+        bool changed = false;
+
+        n = udev_get_rules_path(udev, &p, &stamp_usec);
+        for (i = 0; i < n; i++) {
+                struct stat stats;
+
+                if (stat(p[i], &stats) < 0)
+                        continue;
+
+                if (stamp_usec[i] == ts_usec(&stats.st_mtim))
+                        continue;
+
+                /* first check */
+                if (stamp_usec[i] != 0) {
+                        info(udev, "reload - timestamp of '%s' changed\n", p[i]);
+                        changed = true;
+                }
+
+                /* update timestamp */
+                stamp_usec[i] = ts_usec(&stats.st_mtim);
+        }
+
+        return changed;
+}
+
+int main(int argc, char *argv[])
+{
+        struct udev *udev;
+        FILE *f;
+        sigset_t mask;
+        int daemonize = false;
+        int resolve_names = 1;
+        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' },
+                { "resolve-names", required_argument, NULL, 'N' },
+                { "help", no_argument, NULL, 'h' },
+                { "version", no_argument, NULL, 'V' },
+                {}
+        };
+        int fd_ctrl = -1;
+        int fd_netlink = -1;
+        int fd_worker = -1;
+        struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker;
+        struct udev_ctrl_connection *ctrl_conn = NULL;
+        char **s;
+        int rc = 1;
+
+        udev = udev_new();
+        if (udev == NULL)
+                goto exit;
+
+        udev_log_init("udevd");
+        udev_set_log_fn(udev, udev_main_log);
+        info(udev, "version %s\n", VERSION);
+        udev_selinux_init(udev);
+
+        for (;;) {
+                int option;
+
+                option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL);
+                if (option == -1)
+                        break;
+
+                switch (option) {
+                case 'd':
+                        daemonize = true;
+                        break;
+                case 'c':
+                        children_max = strtoul(optarg, NULL, 0);
+                        break;
+                case 'e':
+                        exec_delay = strtoul(optarg, NULL, 0);
+                        break;
+                case 'D':
+                        debug = true;
+                        if (udev_get_log_priority(udev) < LOG_INFO)
+                                udev_set_log_priority(udev, LOG_INFO);
+                        break;
+                case 'N':
+                        if (strcmp (optarg, "early") == 0) {
+                                resolve_names = 1;
+                        } else if (strcmp (optarg, "late") == 0) {
+                                resolve_names = 0;
+                        } else if (strcmp (optarg, "never") == 0) {
+                                resolve_names = -1;
+                        } else {
+                                fprintf(stderr, "resolve-names must be early, late or never\n");
+                                err(udev, "resolve-names must be early, late or never\n");
+                                goto exit;
+                        }
+                        break;
+                case 'h':
+                        printf("Usage: udevd OPTIONS\n"
+                               "  --daemon\n"
+                               "  --debug\n"
+                               "  --children-max=<maximum number of workers>\n"
+                               "  --exec-delay=<seconds to wait before executing RUN=>\n"
+                               "  --resolve-names=early|late|never\n"
+                               "  --version\n"
+                               "  --help\n"
+                               "\n");
+                        goto exit;
+                case 'V':
+                        printf("%s\n", VERSION);
+                        goto exit;
+                default:
+                        goto exit;
+                }
+        }
+
+        /*
+         * read the kernel commandline, 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
+         *
+         */
+        f = fopen("/proc/cmdline", "r");
+        if (f != NULL) {
+                char cmdline[4096];
+
+                if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
+                        char *pos;
+
+                        pos = strstr(cmdline, "udev.log-priority=");
+                        if (pos != NULL) {
+                                pos += strlen("udev.log-priority=");
+                                udev_set_log_priority(udev, util_log_priority(pos));
+                        }
+
+                        pos = strstr(cmdline, "udev.children-max=");
+                        if (pos != NULL) {
+                                pos += strlen("udev.children-max=");
+                                children_max = strtoul(pos, NULL, 0);
+                        }
+
+                        pos = strstr(cmdline, "udev.exec-delay=");
+                        if (pos != NULL) {
+                                pos += strlen("udev.exec-delay=");
+                                exec_delay = strtoul(pos, NULL, 0);
+                        }
+                }
+                fclose(f);
+        }
+
+        if (getuid() != 0) {
+                fprintf(stderr, "root privileges required\n");
+                err(udev, "root privileges required\n");
+                goto exit;
+        }
+
+        /* set umask before creating any file/directory */
+        chdir("/");
+        umask(022);
+
+        /* /run/udev */
+        mkdir(udev_get_run_path(udev), 0755);
+
+        /* create standard links, copy static nodes, create nodes from modules */
+        static_dev_create(udev);
+        static_dev_create_from_modules(udev);
+
+        /* before opening new files, make sure std{in,out,err} fds are in a sane state */
+        if (daemonize) {
+                int fd;
+
+                fd = open("/dev/null", O_RDWR);
+                if (fd >= 0) {
+                        if (write(STDOUT_FILENO, 0, 0) < 0)
+                                dup2(fd, STDOUT_FILENO);
+                        if (write(STDERR_FILENO, 0, 0) < 0)
+                                dup2(fd, STDERR_FILENO);
+                        if (fd > STDERR_FILENO)
+                                close(fd);
+                } else {
+                        fprintf(stderr, "cannot open /dev/null\n");
+                        err(udev, "cannot open /dev/null\n");
+                }
+        }
+
+        if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) {
+                /* get control and netlink socket from from systemd */
+                udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl);
+                if (udev_ctrl == NULL) {
+                        err(udev, "error taking over udev control socket");
+                        rc = 1;
+                        goto exit;
+                }
+
+                monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink);
+                if (monitor == NULL) {
+                        err(udev, "error taking over netlink socket\n");
+                        rc = 3;
+                        goto exit;
+                }
+        } else {
+                /* open control and netlink socket */
+                udev_ctrl = udev_ctrl_new(udev);
+                if (udev_ctrl == NULL) {
+                        fprintf(stderr, "error initializing udev control socket");
+                        err(udev, "error initializing udev control socket");
+                        rc = 1;
+                        goto exit;
+                }
+                fd_ctrl = udev_ctrl_get_fd(udev_ctrl);
+
+                monitor = udev_monitor_new_from_netlink(udev, "kernel");
+                if (monitor == NULL) {
+                        fprintf(stderr, "error initializing netlink socket\n");
+                        err(udev, "error initializing netlink socket\n");
+                        rc = 3;
+                        goto exit;
+                }
+                fd_netlink = udev_monitor_get_fd(monitor);
+        }
+
+        if (udev_monitor_enable_receiving(monitor) < 0) {
+                fprintf(stderr, "error binding netlink socket\n");
+                err(udev, "error binding netlink socket\n");
+                rc = 3;
+                goto exit;
+        }
+
+        if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
+                fprintf(stderr, "error binding udev control socket\n");
+                err(udev, "error binding udev control socket\n");
+                rc = 1;
+                goto exit;
+        }
+
+        udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
+
+        /* create queue file before signalling 'ready', to make sure we block 'settle' */
+        udev_queue_export = udev_queue_export_new(udev);
+        if (udev_queue_export == NULL) {
+                err(udev, "error creating queue file\n");
+                goto exit;
+        }
+
+        if (daemonize) {
+                pid_t pid;
+                int fd;
+
+                pid = fork();
+                switch (pid) {
+                case 0:
+                        break;
+                case -1:
+                        err(udev, "fork of daemon failed: %m\n");
+                        rc = 4;
+                        goto exit;
+                default:
+                        rc = EXIT_SUCCESS;
+                        goto exit_daemonize;
+                }
+
+                setsid();
+
+                fd = open("/proc/self/oom_score_adj", O_RDWR);
+                if (fd < 0) {
+                        /* Fallback to old interface */
+                        fd = open("/proc/self/oom_adj", O_RDWR);
+                        if (fd < 0) {
+                                err(udev, "error disabling OOM: %m\n");
+                        } else {
+                                /* OOM_DISABLE == -17 */
+                                write(fd, "-17", 3);
+                                close(fd);
+                        }
+                } else {
+                        write(fd, "-1000", 5);
+                        close(fd);
+                }
+        } else {
+                sd_notify(1, "READY=1");
+        }
+
+        f = fopen("/dev/kmsg", "w");
+        if (f != NULL) {
+                fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid());
+                fclose(f);
+        }
+
+        if (!debug) {
+                int fd;
+
+                fd = open("/dev/null", O_RDWR);
+                if (fd >= 0) {
+                        dup2(fd, STDIN_FILENO);
+                        dup2(fd, STDOUT_FILENO);
+                        dup2(fd, STDERR_FILENO);
+                        close(fd);
+                }
+        }
+
+        fd_inotify = udev_watch_init(udev);
+        if (fd_inotify < 0) {
+                fprintf(stderr, "error initializing inotify\n");
+                err(udev, "error initializing inotify\n");
+                rc = 4;
+                goto exit;
+        }
+        udev_watch_restore(udev);
+
+        /* block and listen to all signals on signalfd */
+        sigfillset(&mask);
+        sigprocmask(SIG_SETMASK, &mask, &sigmask_orig);
+        fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC);
+        if (fd_signal < 0) {
+                fprintf(stderr, "error creating signalfd\n");
+                err(udev, "error creating signalfd\n");
+                rc = 5;
+                goto exit;
+        }
+
+        /* unnamed socket from workers to the main daemon */
+        if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) {
+                fprintf(stderr, "error creating socketpair\n");
+                err(udev, "error creating socketpair\n");
+                rc = 6;
+                goto exit;
+        }
+        fd_worker = worker_watch[READ_END];
+
+        udev_builtin_init(udev);
+
+        rules = udev_rules_new(udev, resolve_names);
+        if (rules == NULL) {
+                err(udev, "error reading rules\n");
+                goto exit;
+        }
+
+        memset(&ep_ctrl, 0, sizeof(struct epoll_event));
+        ep_ctrl.events = EPOLLIN;
+        ep_ctrl.data.fd = fd_ctrl;
+
+        memset(&ep_inotify, 0, sizeof(struct epoll_event));
+        ep_inotify.events = EPOLLIN;
+        ep_inotify.data.fd = fd_inotify;
+
+        memset(&ep_signal, 0, sizeof(struct epoll_event));
+        ep_signal.events = EPOLLIN;
+        ep_signal.data.fd = fd_signal;
+
+        memset(&ep_netlink, 0, sizeof(struct epoll_event));
+        ep_netlink.events = EPOLLIN;
+        ep_netlink.data.fd = fd_netlink;
+
+        memset(&ep_worker, 0, sizeof(struct epoll_event));
+        ep_worker.events = EPOLLIN;
+        ep_worker.data.fd = fd_worker;
+
+        fd_ep = epoll_create1(EPOLL_CLOEXEC);
+        if (fd_ep < 0) {
+                err(udev, "error creating epoll fd: %m\n");
+                goto exit;
+        }
+        if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 ||
+            epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 ||
+            epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 ||
+            epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 ||
+            epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) {
+                err(udev, "fail to add fds to epoll: %m\n");
+                goto exit;
+        }
+
+        /* if needed, convert old database from earlier udev version */
+        convert_db(udev);
+
+        if (children_max <= 0) {
+                int memsize = mem_size_mb();
+
+                /* set value depending on the amount of RAM */
+                if (memsize > 0)
+                        children_max = 128 + (memsize / 8);
+                else
+                        children_max = 128;
+        }
+        info(udev, "set children_max to %u\n", children_max);
+
+        udev_rules_apply_static_dev_perms(rules);
+
+        udev_list_node_init(&event_list);
+        udev_list_node_init(&worker_list);
+
+        for (;;) {
+                static unsigned long long last_usec;
+                struct epoll_event ev[8];
+                int fdcount;
+                int timeout;
+                bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl;
+                int i;
+
+                if (udev_exit) {
+                        /* close sources of new events and discard buffered events */
+                        if (fd_ctrl >= 0) {
+                                epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL);
+                                fd_ctrl = -1;
+                        }
+                        if (monitor != NULL) {
+                                epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL);
+                                udev_monitor_unref(monitor);
+                                monitor = NULL;
+                        }
+                        if (fd_inotify >= 0) {
+                                epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL);
+                                close(fd_inotify);
+                                fd_inotify = -1;
+                        }
+
+                        /* discard queued events and kill workers */
+                        event_queue_cleanup(udev, EVENT_QUEUED);
+                        worker_kill(udev, 0);
+
+                        /* exit after all has cleaned up */
+                        if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list))
+                                break;
+
+                        /* timeout at exit for workers to finish */
+                        timeout = 30 * 1000;
+                } else if (udev_list_node_is_empty(&event_list) && children <= 2) {
+                        /* we are idle */
+                        timeout = -1;
+                } else {
+                        /* kill idle or hanging workers */
+                        timeout = 3 * 1000;
+                }
+                fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout);
+                if (fdcount < 0)
+                        continue;
+
+                if (fdcount == 0) {
+                        struct udev_list_node *loop;
+
+                        /* timeout */
+                        if (udev_exit) {
+                                err(udev, "timeout, giving up waiting for workers to finish\n");
+                                break;
+                        }
+
+                        /* kill idle workers */
+                        if (udev_list_node_is_empty(&event_list)) {
+                                info(udev, "cleanup idle workers\n");
+                                worker_kill(udev, 2);
+                        }
+
+                        /* check for hanging events */
+                        udev_list_node_foreach(loop, &worker_list) {
+                                struct worker *worker = node_to_worker(loop);
+
+                                if (worker->state != WORKER_RUNNING)
+                                        continue;
+
+                                if ((now_usec() - worker->event_start_usec) > 30 * 1000 * 1000) {
+                                        err(udev, "worker [%u] timeout, kill it\n", worker->pid,
+                                            worker->event ? worker->event->devpath : "<idle>");
+                                        kill(worker->pid, SIGKILL);
+                                        worker->state = WORKER_KILLED;
+                                        /* drop reference taken for state 'running' */
+                                        worker_unref(worker);
+                                        if (worker->event) {
+                                                err(udev, "seq %llu '%s' killed\n",
+                                                    udev_device_get_seqnum(worker->event->dev), worker->event->devpath);
+                                                worker->event->exitcode = -64;
+                                                event_queue_delete(worker->event, true);
+                                                worker->event = NULL;
+                                        }
+                                }
+                        }
+
+                }
+
+                is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false;
+                for (i = 0; i < fdcount; i++) {
+                        if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN)
+                                is_worker = true;
+                        else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN)
+                                is_netlink = true;
+                        else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN)
+                                is_signal = true;
+                        else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN)
+                                is_inotify = true;
+                        else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN)
+                                is_ctrl = true;
+                }
+
+                /* check for changed config, every 3 seconds at most */
+                if ((now_usec() - last_usec) > 3 * 1000 * 1000) {
+                        if (check_rules_timestamp(udev))
+                                reload = true;
+                        if (udev_builtin_validate(udev))
+                                reload = true;
+
+                        last_usec = now_usec();
+                }
+
+                /* reload requested, HUP signal received, rules changed, builtin changed */
+                if (reload) {
+                        worker_kill(udev, 0);
+                        rules = udev_rules_unref(rules);
+                        udev_builtin_exit(udev);
+                        reload = 0;
+                }
+
+                /* event has finished */
+                if (is_worker)
+                        worker_returned(fd_worker);
+
+                if (is_netlink) {
+                        struct udev_device *dev;
+
+                        dev = udev_monitor_receive_device(monitor);
+                        if (dev != NULL) {
+                                udev_device_set_usec_initialized(dev, now_usec());
+                                if (event_queue_insert(dev) < 0)
+                                        udev_device_unref(dev);
+                        }
+                }
+
+                /* start new events */
+                if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) {
+                        if (rules == NULL)
+                                rules = udev_rules_new(udev, resolve_names);
+                        if (rules != NULL)
+                                event_queue_start(udev);
+                }
+
+                if (is_signal) {
+                        struct signalfd_siginfo fdsi;
+                        ssize_t size;
+
+                        size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo));
+                        if (size == sizeof(struct signalfd_siginfo))
+                                handle_signal(udev, fdsi.ssi_signo);
+                }
+
+                /* we are shutting down, the events below are not handled anymore */
+                if (udev_exit)
+                        continue;
+
+                /* device node watch */
+                if (is_inotify)
+                        handle_inotify(udev);
+
+                /*
+                 * This needs to be after the inotify handling, to make sure,
+                 * that the ping is send back after the possibly generated
+                 * "change" events by the inotify device node watch.
+                 *
+                 * A single time we may receive a client connection which we need to
+                 * keep open to block the client. It will be closed right before we
+                 * exit.
+                 */
+                if (is_ctrl)
+                        ctrl_conn = handle_ctrl_msg(udev_ctrl);
+        }
+
+        rc = EXIT_SUCCESS;
+exit:
+        udev_queue_export_cleanup(udev_queue_export);
+        udev_ctrl_cleanup(udev_ctrl);
+exit_daemonize:
+        if (fd_ep >= 0)
+                close(fd_ep);
+        worker_list_cleanup(udev);
+        event_queue_cleanup(udev, EVENT_UNDEF);
+        udev_rules_unref(rules);
+        udev_builtin_exit(udev);
+        if (fd_signal >= 0)
+                close(fd_signal);
+        if (worker_watch[READ_END] >= 0)
+                close(worker_watch[READ_END]);
+        if (worker_watch[WRITE_END] >= 0)
+                close(worker_watch[WRITE_END]);
+        udev_monitor_unref(monitor);
+        udev_queue_export_unref(udev_queue_export);
+        udev_ctrl_connection_unref(ctrl_conn);
+        udev_ctrl_unref(udev_ctrl);
+        udev_selinux_exit(udev);
+        udev_unref(udev);
+        udev_log_close();
+        return rc;
+}