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-rw-r--r--src/udev/udevd.c2083
1 files changed, 2083 insertions, 0 deletions
diff --git a/src/udev/udevd.c b/src/udev/udevd.c
new file mode 100644
index 0000000..2095062
--- /dev/null
+++ b/src/udev/udevd.c
@@ -0,0 +1,2083 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * 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 <stdbool.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.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/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 "blockdev-util.h"
+#include "cgroup-setup.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 "errno-list.h"
+#include "event-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "format-util.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "inotify-util.h"
+#include "io-util.h"
+#include "limits-util.h"
+#include "list.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "netlink-util.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "pretty-print.h"
+#include "proc-cmdline.h"
+#include "process-util.h"
+#include "rlimit-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 "udevd.h"
+#include "udev-builtin.h"
+#include "udev-ctrl.h"
+#include "udev-event.h"
+#include "udev-node.h"
+#include "udev-util.h"
+#include "udev-watch.h"
+#include "user-util.h"
+#include "version.h"
+
+#define WORKER_NUM_MAX 2048U
+#define EVENT_RETRY_INTERVAL_USEC (200 * USEC_PER_MSEC)
+#define EVENT_RETRY_TIMEOUT_USEC (3 * USEC_PER_MINUTE)
+
+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;
+static int arg_timeout_signal = SIGKILL;
+static bool arg_blockdev_read_only = false;
+
+typedef struct Event Event;
+typedef struct Worker Worker;
+
+typedef struct Manager {
+ sd_event *event;
+ Hashmap *workers;
+ LIST_HEAD(Event, events);
+ char *cgroup;
+ pid_t pid; /* the process that originally allocated the manager object */
+ int log_level;
+
+ UdevRules *rules;
+ Hashmap *properties;
+
+ sd_netlink *rtnl;
+
+ sd_device_monitor *monitor;
+ UdevCtrl *ctrl;
+ int worker_watch[2];
+
+ /* used by udev-watch */
+ int inotify_fd;
+ sd_event_source *inotify_event;
+
+ sd_event_source *kill_workers_event;
+
+ usec_t last_usec;
+
+ bool udev_node_needs_cleanup;
+ bool stop_exec_queue;
+ bool exit;
+} Manager;
+
+typedef enum EventState {
+ EVENT_UNDEF,
+ EVENT_QUEUED,
+ EVENT_RUNNING,
+} EventState;
+
+typedef struct Event {
+ Manager *manager;
+ Worker *worker;
+ EventState state;
+
+ sd_device *dev;
+
+ sd_device_action_t action;
+ uint64_t seqnum;
+ uint64_t blocker_seqnum;
+ const char *id;
+ const char *devpath;
+ const char *devpath_old;
+ const char *devnode;
+
+ /* Used when the device is locked by another program. */
+ usec_t retry_again_next_usec;
+ usec_t retry_again_timeout_usec;
+ sd_event_source *retry_event_source;
+
+ sd_event_source *timeout_warning_event;
+ sd_event_source *timeout_event;
+
+ LIST_FIELDS(Event, event);
+} Event;
+
+typedef enum WorkerState {
+ WORKER_UNDEF,
+ WORKER_RUNNING,
+ WORKER_IDLE,
+ WORKER_KILLED,
+ WORKER_KILLING,
+} WorkerState;
+
+typedef struct Worker {
+ Manager *manager;
+ pid_t pid;
+ sd_event_source *child_event_source;
+ sd_device_monitor *monitor;
+ WorkerState state;
+ Event *event;
+} Worker;
+
+/* passed from worker to main process */
+typedef enum EventResult {
+ EVENT_RESULT_NERRNO_MIN = -ERRNO_MAX,
+ EVENT_RESULT_NERRNO_MAX = -1,
+ EVENT_RESULT_SUCCESS = 0,
+ EVENT_RESULT_EXIT_STATUS_BASE = 0,
+ EVENT_RESULT_EXIT_STATUS_MAX = 255,
+ EVENT_RESULT_TRY_AGAIN = 256, /* when the block device is locked by another process. */
+ EVENT_RESULT_SIGNAL_BASE = 257,
+ EVENT_RESULT_SIGNAL_MAX = EVENT_RESULT_SIGNAL_BASE + _NSIG,
+ _EVENT_RESULT_MAX,
+ _EVENT_RESULT_INVALID = -EINVAL,
+} EventResult;
+
+static Event *event_free(Event *event) {
+ if (!event)
+ return NULL;
+
+ assert(event->manager);
+
+ LIST_REMOVE(event, event->manager->events, event);
+ sd_device_unref(event->dev);
+
+ /* Do not use sd_event_source_disable_unref() here, as this is called by both workers and the
+ * main process. */
+ sd_event_source_unref(event->retry_event_source);
+ sd_event_source_unref(event->timeout_warning_event);
+ sd_event_source_unref(event->timeout_event);
+
+ if (event->worker)
+ event->worker->event = NULL;
+
+ return mfree(event);
+}
+
+static void event_queue_cleanup(Manager *manager, EventState match_state) {
+ LIST_FOREACH(event, event, manager->events) {
+ if (match_state != EVENT_UNDEF && match_state != event->state)
+ continue;
+
+ event_free(event);
+ }
+}
+
+static Worker *worker_free(Worker *worker) {
+ if (!worker)
+ return NULL;
+
+ if (worker->manager)
+ hashmap_remove(worker->manager->workers, PID_TO_PTR(worker->pid));
+
+ sd_event_source_unref(worker->child_event_source);
+ sd_device_monitor_unref(worker->monitor);
+ event_free(worker->event);
+
+ return mfree(worker);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Worker*, worker_free);
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(worker_hash_op, void, trivial_hash_func, trivial_compare_func, Worker, worker_free);
+
+static void manager_clear_for_worker(Manager *manager) {
+ assert(manager);
+
+ /* Do not use sd_event_source_disable_unref() here, as this is called by both workers and the
+ * main process. */
+ 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 = udev_ctrl_unref(manager->ctrl);
+
+ manager->worker_watch[READ_END] = safe_close(manager->worker_watch[READ_END]);
+}
+
+static Manager* manager_free(Manager *manager) {
+ if (!manager)
+ return NULL;
+
+ 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->inotify_fd);
+ safe_close_pair(manager->worker_watch);
+
+ free(manager->cgroup);
+ return mfree(manager);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free);
+
+static int on_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata);
+
+static int worker_new(Worker **ret, Manager *manager, sd_device_monitor *worker_monitor, pid_t pid) {
+ _cleanup_(worker_freep) 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(Worker, 1);
+ if (!worker)
+ return -ENOMEM;
+
+ *worker = (Worker) {
+ .monitor = sd_device_monitor_ref(worker_monitor),
+ .pid = pid,
+ };
+
+ r = sd_event_add_child(manager->event, &worker->child_event_source, pid, WEXITED, on_sigchld, worker);
+ if (r < 0)
+ return r;
+
+ r = hashmap_ensure_put(&manager->workers, &worker_hash_op, PID_TO_PTR(pid), worker);
+ if (r < 0)
+ return r;
+
+ worker->manager = manager;
+
+ *ret = TAKE_PTR(worker);
+ return 0;
+}
+
+static void manager_kill_workers(Manager *manager, bool force) {
+ Worker *worker;
+
+ assert(manager);
+
+ HASHMAP_FOREACH(worker, manager->workers) {
+ if (worker->state == WORKER_KILLED)
+ continue;
+
+ if (worker->state == WORKER_RUNNING && !force) {
+ worker->state = WORKER_KILLING;
+ continue;
+ }
+
+ worker->state = WORKER_KILLED;
+ (void) kill(worker->pid, SIGTERM);
+ }
+}
+
+static void manager_exit(Manager *manager) {
+ 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 = udev_ctrl_unref(manager->ctrl);
+
+ manager->inotify_event = sd_event_source_disable_unref(manager->inotify_event);
+ manager->inotify_fd = safe_close(manager->inotify_fd);
+
+ manager->monitor = sd_device_monitor_unref(manager->monitor);
+
+ /* discard queued events and kill workers */
+ event_queue_cleanup(manager, EVENT_QUEUED);
+ manager_kill_workers(manager, true);
+}
+
+static void notify_ready(void) {
+ int r;
+
+ r = sd_notifyf(false,
+ "READY=1\n"
+ "STATUS=Processing with %u children at max", arg_children_max);
+ if (r < 0)
+ log_warning_errno(r, "Failed to send readiness notification, ignoring: %m");
+}
+
+/* reload requested, HUP signal received, rules changed, builtin changed */
+static void manager_reload(Manager *manager, bool force) {
+ _cleanup_(udev_rules_freep) UdevRules *rules = NULL;
+ usec_t now_usec;
+ int r;
+
+ assert(manager);
+
+ assert_se(sd_event_now(manager->event, CLOCK_MONOTONIC, &now_usec) >= 0);
+ if (!force && now_usec < usec_add(manager->last_usec, 3 * USEC_PER_SEC))
+ /* check for changed config, every 3 seconds at most */
+ return;
+ manager->last_usec = now_usec;
+
+ /* Reload SELinux label database, to make the child inherit the up-to-date database. */
+ mac_selinux_maybe_reload();
+
+ /* Nothing changed. It is not necessary to reload. */
+ if (!udev_rules_should_reload(manager->rules) && !udev_builtin_should_reload())
+ return;
+
+ sd_notify(false,
+ "RELOADING=1\n"
+ "STATUS=Flushing configuration...");
+
+ manager_kill_workers(manager, false);
+
+ udev_builtin_exit();
+ udev_builtin_init();
+
+ r = udev_rules_load(&rules, arg_resolve_name_timing);
+ if (r < 0)
+ log_warning_errno(r, "Failed to read udev rules, using the previously loaded rules, ignoring: %m");
+ else
+ udev_rules_free_and_replace(manager->rules, rules);
+
+ notify_ready();
+}
+
+static int on_kill_workers_event(sd_event_source *s, uint64_t usec, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ log_debug("Cleanup idle workers");
+ manager_kill_workers(manager, false);
+
+ return 1;
+}
+
+static void device_broadcast(sd_device_monitor *monitor, sd_device *dev, EventResult result) {
+ int r;
+
+ assert(dev);
+
+ /* On exit, manager->monitor is already NULL. */
+ if (!monitor)
+ return;
+
+ if (result != EVENT_RESULT_SUCCESS) {
+ (void) device_add_property(dev, "UDEV_WORKER_FAILED", "1");
+
+ switch (result) {
+ case EVENT_RESULT_NERRNO_MIN ... EVENT_RESULT_NERRNO_MAX: {
+ const char *str;
+
+ (void) device_add_propertyf(dev, "UDEV_WORKER_ERRNO", "%i", -result);
+
+ str = errno_to_name(result);
+ if (str)
+ (void) device_add_property(dev, "UDEV_WORKER_ERRNO_NAME", str);
+ break;
+ }
+ case EVENT_RESULT_EXIT_STATUS_BASE ... EVENT_RESULT_EXIT_STATUS_MAX:
+ (void) device_add_propertyf(dev, "UDEV_WORKER_EXIT_STATUS", "%i", result - EVENT_RESULT_EXIT_STATUS_BASE);
+ break;
+
+ case EVENT_RESULT_TRY_AGAIN:
+ assert_not_reached();
+ break;
+
+ case EVENT_RESULT_SIGNAL_BASE ... EVENT_RESULT_SIGNAL_MAX: {
+ const char *str;
+
+ (void) device_add_propertyf(dev, "UDEV_WORKER_SIGNAL", "%i", result - EVENT_RESULT_SIGNAL_BASE);
+
+ str = signal_to_string(result - EVENT_RESULT_SIGNAL_BASE);
+ if (str)
+ (void) device_add_property(dev, "UDEV_WORKER_SIGNAL_NAME", str);
+ break;
+ }
+ default:
+ log_device_warning(dev, "Unknown event result \"%i\", ignoring.", result);
+ }
+ }
+
+ r = device_monitor_send_device(monitor, NULL, dev);
+ if (r < 0)
+ log_device_warning_errno(dev, r,
+ "Failed to broadcast event to libudev listeners, ignoring: %m");
+}
+
+static int worker_send_result(Manager *manager, EventResult result) {
+ assert(manager);
+ assert(manager->worker_watch[WRITE_END] >= 0);
+
+ return loop_write(manager->worker_watch[WRITE_END], &result, sizeof(result), false);
+}
+
+static int device_get_whole_disk(sd_device *dev, sd_device **ret_device, const char **ret_devname) {
+ const char *val;
+ int r;
+
+ assert(dev);
+
+ if (device_for_action(dev, SD_DEVICE_REMOVE))
+ goto irrelevant;
+
+ r = sd_device_get_sysname(dev, &val);
+ if (r < 0)
+ return log_device_debug_errno(dev, r, "Failed to get sysname: %m");
+
+ /* Exclude the following devices:
+ * For "dm-", see the comment added by e918a1b5a94f270186dca59156354acd2a596494.
+ * For "md", see the commit message of 2e5b17d01347d3c3118be2b8ad63d20415dbb1f0,
+ * but not sure the assumption is still valid even when partitions are created on the md
+ * devices, surprisingly which seems to be possible, see PR #22973.
+ * For "drbd", see the commit message of fee854ee8ccde0cd28e0f925dea18cce35f3993d. */
+ if (STARTSWITH_SET(val, "dm-", "md", "drbd"))
+ goto irrelevant;
+
+ r = block_device_get_whole_disk(dev, &dev);
+ if (IN_SET(r,
+ -ENOTBLK, /* The device is not a block device. */
+ -ENODEV /* The whole disk device was not found, it may already be removed. */))
+ goto irrelevant;
+ if (r < 0)
+ return log_device_debug_errno(dev, r, "Failed to get whole disk device: %m");
+
+ r = sd_device_get_devname(dev, &val);
+ if (r < 0)
+ return log_device_debug_errno(dev, r, "Failed to get devname: %m");
+
+ if (ret_device)
+ *ret_device = dev;
+ if (ret_devname)
+ *ret_devname = val;
+ return 1;
+
+irrelevant:
+ if (ret_device)
+ *ret_device = NULL;
+ if (ret_devname)
+ *ret_devname = NULL;
+ return 0;
+}
+
+static int worker_lock_whole_disk(sd_device *dev, int *ret_fd) {
+ _cleanup_close_ int fd = -1;
+ sd_device *dev_whole_disk;
+ 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 = device_get_whole_disk(dev, &dev_whole_disk, &val);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ goto nolock;
+
+ fd = sd_device_open(dev_whole_disk, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+ if (fd < 0) {
+ bool ignore = ERRNO_IS_DEVICE_ABSENT(fd);
+
+ log_device_debug_errno(dev, fd, "Failed to open '%s'%s: %m", val, ignore ? ", ignoring" : "");
+ if (!ignore)
+ return fd;
+
+ goto nolock;
+ }
+
+ 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;
+
+nolock:
+ *ret_fd = -1;
+ return 0;
+}
+
+static int worker_mark_block_device_read_only(sd_device *dev) {
+ _cleanup_close_ int fd = -1;
+ const char *val;
+ int state = 1, r;
+
+ assert(dev);
+
+ if (!arg_blockdev_read_only)
+ return 0;
+
+ /* Do this only once, when the block device is new. If the device is later retriggered let's not
+ * toggle the bit again, so that people can boot up with full read-only mode and then unset the bit
+ * for specific devices only. */
+ if (!device_for_action(dev, SD_DEVICE_ADD))
+ 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");
+
+ /* Exclude synthetic devices for now, this is supposed to be a safety feature to avoid modification
+ * of physical devices, and what sits on top of those doesn't really matter if we don't allow the
+ * underlying block devices to receive changes. */
+ if (STARTSWITH_SET(val, "dm-", "md", "drbd", "loop", "nbd", "zram"))
+ return 0;
+
+ fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY);
+ if (fd < 0)
+ return log_device_debug_errno(dev, fd, "Failed to open '%s', ignoring: %m", val);
+
+ if (ioctl(fd, BLKROSET, &state) < 0)
+ return log_device_warning_errno(dev, errno, "Failed to mark block device '%s' read-only: %m", val);
+
+ log_device_info(dev, "Successfully marked block device '%s' read-only.", val);
+ return 0;
+}
+
+static int worker_process_device(Manager *manager, sd_device *dev) {
+ _cleanup_(udev_event_freep) UdevEvent *udev_event = NULL;
+ _cleanup_close_ int fd_lock = -1;
+ int r;
+
+ assert(manager);
+ assert(dev);
+
+ log_device_uevent(dev, "Processing device");
+
+ udev_event = udev_event_new(dev, arg_exec_delay_usec, manager->rtnl, manager->log_level);
+ if (!udev_event)
+ return -ENOMEM;
+
+ /* If this is a block device and the device is locked currently via the BSD advisory locks,
+ * someone else is using it exclusively. We don't run our udev rules now to not interfere.
+ * Instead of processing the event, we requeue the event and will try again after a delay.
+ *
+ * The user-facing side of this: https://systemd.io/BLOCK_DEVICE_LOCKING */
+ r = worker_lock_whole_disk(dev, &fd_lock);
+ if (r == -EAGAIN)
+ return EVENT_RESULT_TRY_AGAIN;
+ if (r < 0)
+ return r;
+
+ (void) worker_mark_block_device_read_only(dev);
+
+ /* apply rules, create node, symlinks */
+ r = udev_event_execute_rules(
+ udev_event,
+ manager->inotify_fd,
+ arg_event_timeout_usec,
+ arg_timeout_signal,
+ manager->properties,
+ manager->rules);
+ if (r < 0)
+ return r;
+
+ udev_event_execute_run(udev_event, arg_event_timeout_usec, arg_timeout_signal);
+
+ if (!manager->rtnl)
+ /* in case rtnl was initialized */
+ manager->rtnl = sd_netlink_ref(udev_event->rtnl);
+
+ udev_event_process_inotify_watch(udev_event, manager->inotify_fd);
+
+ log_device_uevent(dev, "Device processed");
+ return 0;
+}
+
+static int worker_device_monitor_handler(sd_device_monitor *monitor, sd_device *dev, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ int r;
+
+ assert(dev);
+
+ r = worker_process_device(manager, dev);
+ if (r == EVENT_RESULT_TRY_AGAIN)
+ /* if we couldn't acquire the flock(), then requeue the event */
+ log_device_debug(dev, "Block device is currently locked, requeueing the event.");
+ else {
+ if (r < 0)
+ log_device_warning_errno(dev, r, "Failed to process device, ignoring: %m");
+
+ /* send processed event back to libudev listeners */
+ device_broadcast(monitor, dev, r);
+ }
+
+ /* send udevd the result of the event execution */
+ r = worker_send_result(manager, r);
+ if (r < 0)
+ log_device_warning_errno(dev, r, "Failed to send signal to main daemon, ignoring: %m");
+
+ /* Reset the log level, as it might be changed by "OPTIONS=log_level=". */
+ log_set_max_level(manager->log_level);
+
+ 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);
+
+ assert_se(unsetenv("NOTIFY_SOCKET") == 0);
+
+ 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");
+
+ /* 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 on_event_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
+ Event *event = ASSERT_PTR(userdata);
+
+ assert(event->worker);
+
+ kill_and_sigcont(event->worker->pid, arg_timeout_signal);
+ 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) {
+ Event *event = ASSERT_PTR(userdata);
+
+ 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(Worker *worker, Event *event) {
+ sd_event *e;
+
+ 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;
+
+ (void) sd_event_add_time_relative(e, &event->timeout_warning_event, CLOCK_MONOTONIC,
+ udev_warn_timeout(arg_event_timeout_usec), USEC_PER_SEC,
+ on_event_timeout_warning, event);
+
+ (void) sd_event_add_time_relative(e, &event->timeout_event, CLOCK_MONOTONIC,
+ arg_event_timeout_usec, USEC_PER_SEC,
+ on_event_timeout, event);
+}
+
+static int worker_spawn(Manager *manager, Event *event) {
+ _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *worker_monitor = NULL;
+ 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;
+
+ (void) sd_device_monitor_set_description(worker_monitor, "worker");
+
+ /* 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("(udev-worker)", FORK_DEATHSIG, &pid);
+ if (r < 0) {
+ event->state = EVENT_QUEUED;
+ return log_error_errno(r, "Failed to fork() worker: %m");
+ }
+ if (r == 0) {
+ DEVICE_TRACE_POINT(worker_spawned, event->dev, getpid());
+
+ /* 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 int event_run(Event *event) {
+ static bool log_children_max_reached = true;
+ Manager *manager;
+ Worker *worker;
+ int r;
+
+ assert(event);
+ assert(event->manager);
+
+ log_device_uevent(event->dev, "Device ready for processing");
+
+ (void) event_source_disable(event->retry_event_source);
+
+ manager = event->manager;
+ HASHMAP_FOREACH(worker, manager->workers) {
+ 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 1; /* event is now processing. */
+ }
+
+ if (hashmap_size(manager->workers) >= arg_children_max) {
+ /* Avoid spamming the debug logs if the limit is already reached and
+ * many events still need to be processed */
+ if (log_children_max_reached && arg_children_max > 1) {
+ log_debug("Maximum number (%u) of children reached.", hashmap_size(manager->workers));
+ log_children_max_reached = false;
+ }
+ return 0; /* no free worker */
+ }
+
+ /* Re-enable the debug message for the next batch of events */
+ log_children_max_reached = true;
+
+ /* start new worker and pass initial device */
+ r = worker_spawn(manager, event);
+ if (r < 0)
+ return r;
+
+ return 1; /* event is now processing. */
+}
+
+static int event_is_blocked(Event *event) {
+ Event *loop_event = NULL;
+ int r;
+
+ /* lookup event for identical, parent, child device */
+
+ assert(event);
+ assert(event->manager);
+ assert(event->blocker_seqnum <= event->seqnum);
+
+ if (event->retry_again_next_usec > 0) {
+ usec_t now_usec;
+
+ r = sd_event_now(event->manager->event, CLOCK_BOOTTIME, &now_usec);
+ if (r < 0)
+ return r;
+
+ if (event->retry_again_next_usec > now_usec)
+ return true;
+ }
+
+ if (event->blocker_seqnum == event->seqnum)
+ /* we have checked previously and no blocker found */
+ return false;
+
+ LIST_FOREACH(event, e, event->manager->events) {
+ loop_event = e;
+
+ /* we already found a later event, earlier cannot block us, no need to check again */
+ if (loop_event->seqnum < event->blocker_seqnum)
+ continue;
+
+ /* event we checked earlier still exists, no need to check again */
+ if (loop_event->seqnum == event->blocker_seqnum)
+ return true;
+
+ /* found ourself, no later event can block us */
+ if (loop_event->seqnum >= event->seqnum)
+ goto no_blocker;
+
+ /* found event we have not checked */
+ break;
+ }
+
+ assert(loop_event);
+ assert(loop_event->seqnum > event->blocker_seqnum &&
+ loop_event->seqnum < event->seqnum);
+
+ /* check if queue contains events we depend on */
+ LIST_FOREACH(event, e, loop_event) {
+ loop_event = e;
+
+ /* found ourself, no later event can block us */
+ if (loop_event->seqnum >= event->seqnum)
+ goto no_blocker;
+
+ if (streq_ptr(loop_event->id, event->id))
+ break;
+
+ if (devpath_conflict(event->devpath, loop_event->devpath) ||
+ devpath_conflict(event->devpath, loop_event->devpath_old) ||
+ devpath_conflict(event->devpath_old, loop_event->devpath))
+ break;
+
+ if (event->devnode && streq_ptr(event->devnode, loop_event->devnode))
+ break;
+ }
+
+ assert(loop_event);
+
+ log_device_debug(event->dev, "SEQNUM=%" PRIu64 " blocked by SEQNUM=%" PRIu64,
+ event->seqnum, loop_event->seqnum);
+
+ event->blocker_seqnum = loop_event->seqnum;
+ return true;
+
+no_blocker:
+ event->blocker_seqnum = event->seqnum;
+ return false;
+}
+
+static int event_queue_start(Manager *manager) {
+ int r;
+
+ assert(manager);
+
+ if (!manager->events || manager->exit || manager->stop_exec_queue)
+ return 0;
+
+ /* To make the stack directory /run/udev/links cleaned up later. */
+ manager->udev_node_needs_cleanup = true;
+
+ 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");
+
+ manager_reload(manager, /* force = */ false);
+
+ LIST_FOREACH(event, event, manager->events) {
+ if (event->state != EVENT_QUEUED)
+ continue;
+
+ /* do not start event if parent or child event is still running or queued */
+ r = event_is_blocked(event);
+ if (r > 0)
+ continue;
+ if (r < 0)
+ log_device_warning_errno(event->dev, r,
+ "Failed to check dependencies for event (SEQNUM=%"PRIu64", ACTION=%s), "
+ "assuming there is no blocking event, ignoring: %m",
+ event->seqnum,
+ strna(device_action_to_string(event->action)));
+
+ r = event_run(event);
+ if (r <= 0) /* 0 means there are no idle workers. Let's escape from the loop. */
+ return r;
+ }
+
+ return 0;
+}
+
+static int on_event_retry(sd_event_source *s, uint64_t usec, void *userdata) {
+ /* This does nothing. The on_post() callback will start the event if there exists an idle worker. */
+ return 1;
+}
+
+static int event_requeue(Event *event) {
+ usec_t now_usec;
+ int r;
+
+ assert(event);
+ assert(event->manager);
+ assert(event->manager->event);
+
+ event->timeout_warning_event = sd_event_source_disable_unref(event->timeout_warning_event);
+ event->timeout_event = sd_event_source_disable_unref(event->timeout_event);
+
+ /* add a short delay to suppress busy loop */
+ r = sd_event_now(event->manager->event, CLOCK_BOOTTIME, &now_usec);
+ if (r < 0)
+ return log_device_warning_errno(event->dev, r,
+ "Failed to get current time, "
+ "skipping event (SEQNUM=%"PRIu64", ACTION=%s): %m",
+ event->seqnum, strna(device_action_to_string(event->action)));
+
+ if (event->retry_again_timeout_usec > 0 && event->retry_again_timeout_usec <= now_usec)
+ return log_device_warning_errno(event->dev, SYNTHETIC_ERRNO(ETIMEDOUT),
+ "The underlying block device is locked by a process more than %s, "
+ "skipping event (SEQNUM=%"PRIu64", ACTION=%s).",
+ FORMAT_TIMESPAN(EVENT_RETRY_TIMEOUT_USEC, USEC_PER_MINUTE),
+ event->seqnum, strna(device_action_to_string(event->action)));
+
+ event->retry_again_next_usec = usec_add(now_usec, EVENT_RETRY_INTERVAL_USEC);
+ if (event->retry_again_timeout_usec == 0)
+ event->retry_again_timeout_usec = usec_add(now_usec, EVENT_RETRY_TIMEOUT_USEC);
+
+ r = event_reset_time_relative(event->manager->event, &event->retry_event_source,
+ CLOCK_MONOTONIC, EVENT_RETRY_INTERVAL_USEC, 0,
+ on_event_retry, NULL,
+ 0, "retry-event", true);
+ if (r < 0)
+ return log_device_warning_errno(event->dev, r, "Failed to reset timer event source for retrying event, "
+ "skipping event (SEQNUM=%"PRIu64", ACTION=%s): %m",
+ event->seqnum, strna(device_action_to_string(event->action)));
+
+ if (event->worker && event->worker->event == event)
+ event->worker->event = NULL;
+ event->worker = NULL;
+
+ event->state = EVENT_QUEUED;
+ return 0;
+}
+
+static int event_queue_assume_block_device_unlocked(Manager *manager, sd_device *dev) {
+ const char *devname;
+ int r;
+
+ /* When a new event for a block device is queued or we get an inotify event, assume that the
+ * device is not locked anymore. The assumption may not be true, but that should not cause any
+ * issues, as in that case events will be requeued soon. */
+
+ r = device_get_whole_disk(dev, NULL, &devname);
+ if (r <= 0)
+ return r;
+
+ LIST_FOREACH(event, event, manager->events) {
+ const char *event_devname;
+
+ if (event->state != EVENT_QUEUED)
+ continue;
+
+ if (event->retry_again_next_usec == 0)
+ continue;
+
+ if (device_get_whole_disk(event->dev, NULL, &event_devname) <= 0)
+ continue;
+
+ if (!streq(devname, event_devname))
+ continue;
+
+ event->retry_again_next_usec = 0;
+ }
+
+ return 0;
+}
+
+static int event_queue_insert(Manager *manager, sd_device *dev) {
+ const char *devpath, *devpath_old = NULL, *id = NULL, *devnode = NULL;
+ sd_device_action_t action;
+ uint64_t seqnum;
+ Event *event;
+ int r;
+
+ assert(manager);
+ assert(dev);
+
+ /* only one process can add events to the queue */
+ assert(manager->pid == getpid_cached());
+
+ /* We only accepts devices received by device monitor. */
+ r = sd_device_get_seqnum(dev, &seqnum);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_action(dev, &action);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_devpath(dev, &devpath);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_property_value(dev, "DEVPATH_OLD", &devpath_old);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ r = device_get_device_id(dev, &id);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ r = sd_device_get_devname(dev, &devnode);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ event = new(Event, 1);
+ if (!event)
+ return -ENOMEM;
+
+ *event = (Event) {
+ .manager = manager,
+ .dev = sd_device_ref(dev),
+ .seqnum = seqnum,
+ .action = action,
+ .id = id,
+ .devpath = devpath,
+ .devpath_old = devpath_old,
+ .devnode = devnode,
+ .state = EVENT_QUEUED,
+ };
+
+ if (!manager->events) {
+ r = touch("/run/udev/queue");
+ if (r < 0)
+ log_warning_errno(r, "Failed to touch /run/udev/queue, ignoring: %m");
+ }
+
+ LIST_APPEND(event, manager->events, event);
+
+ log_device_uevent(dev, "Device is queued");
+
+ return 0;
+}
+
+static int on_uevent(sd_device_monitor *monitor, sd_device *dev, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ int r;
+
+ DEVICE_TRACE_POINT(kernel_uevent_received, dev);
+
+ 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;
+ }
+
+ (void) event_queue_assume_block_device_unlocked(manager, dev);
+
+ return 1;
+}
+
+static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ for (;;) {
+ EventResult result;
+ struct iovec iovec = IOVEC_MAKE(&result, sizeof(result));
+ CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control;
+ struct msghdr msghdr = {
+ .msg_iov = &iovec,
+ .msg_iovlen = 1,
+ .msg_control = &control,
+ .msg_controllen = sizeof(control),
+ };
+ ssize_t size;
+ struct ucred *ucred;
+ Worker *worker;
+
+ size = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT);
+ if (size == -EINTR)
+ continue;
+ if (size == -EAGAIN)
+ /* nothing more to read */
+ break;
+ if (size < 0)
+ return log_error_errno(size, "Failed to receive message: %m");
+
+ cmsg_close_all(&msghdr);
+
+ if (size != sizeof(result)) {
+ log_warning("Ignoring worker message with invalid size %zi bytes", size);
+ continue;
+ }
+
+ ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
+ 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_KILLING) {
+ worker->state = WORKER_KILLED;
+ (void) kill(worker->pid, SIGTERM);
+ } else if (worker->state != WORKER_KILLED)
+ worker->state = WORKER_IDLE;
+
+ /* worker returned */
+ if (result == EVENT_RESULT_TRY_AGAIN &&
+ event_requeue(worker->event) < 0)
+ device_broadcast(manager->monitor, worker->event->dev, -ETIMEDOUT);
+
+ /* When event_requeue() succeeds, worker->event is NULL, and event_free() handles NULL gracefully. */
+ event_free(worker->event);
+ }
+
+ return 1;
+}
+
+/* receive the udevd message from userspace */
+static int on_ctrl_msg(UdevCtrl *uctrl, UdevCtrlMessageType type, const UdevCtrlMessageValue *value, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ int r;
+
+ assert(value);
+
+ switch (type) {
+ case UDEV_CTRL_SET_LOG_LEVEL:
+ if ((value->intval & LOG_PRIMASK) != value->intval) {
+ log_debug("Received invalid udev control message (SET_LOG_LEVEL, %i), ignoring.", value->intval);
+ break;
+ }
+
+ log_debug("Received udev control message (SET_LOG_LEVEL), setting log_level=%i", value->intval);
+
+ r = log_get_max_level();
+ if (r == value->intval)
+ break;
+
+ log_set_max_level(value->intval);
+ manager->log_level = value->intval;
+ manager_kill_workers(manager, false);
+ break;
+ case UDEV_CTRL_STOP_EXEC_QUEUE:
+ log_debug("Received udev control message (STOP_EXEC_QUEUE)");
+ manager->stop_exec_queue = true;
+ break;
+ case UDEV_CTRL_START_EXEC_QUEUE:
+ log_debug("Received udev control message (START_EXEC_QUEUE)");
+ manager->stop_exec_queue = false;
+ /* It is not necessary to call event_queue_start() here, as it will be called in on_post() if necessary. */
+ break;
+ case UDEV_CTRL_RELOAD:
+ log_debug("Received udev control message (RELOAD)");
+ manager_reload(manager, /* force = */ true);
+ break;
+ case UDEV_CTRL_SET_ENV: {
+ _unused_ _cleanup_free_ char *old_val = NULL;
+ _cleanup_free_ char *key = NULL, *val = NULL, *old_key = NULL;
+ const char *eq;
+
+ eq = strchr(value->buf, '=');
+ if (!eq) {
+ log_error("Invalid key format '%s'", value->buf);
+ return 1;
+ }
+
+ key = strndup(value->buf, eq - value->buf);
+ 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, false);
+ break;
+ }
+ case UDEV_CTRL_SET_CHILDREN_MAX:
+ if (value->intval <= 0) {
+ log_debug("Received invalid udev control message (SET_MAX_CHILDREN, %i), ignoring.", value->intval);
+ return 0;
+ }
+
+ log_debug("Received udev control message (SET_MAX_CHILDREN), setting children_max=%i", value->intval);
+ arg_children_max = value->intval;
+
+ notify_ready();
+ break;
+ case UDEV_CTRL_PING:
+ log_debug("Received udev control message (PING)");
+ break;
+ case UDEV_CTRL_EXIT:
+ log_debug("Received udev control message (EXIT)");
+ manager_exit(manager);
+ break;
+ default:
+ log_debug("Received unknown udev control message, ignoring");
+ }
+
+ return 1;
+}
+
+static int synthesize_change_one(sd_device *dev, sd_device *target) {
+ int r;
+
+ if (DEBUG_LOGGING) {
+ const char *syspath = NULL;
+ (void) sd_device_get_syspath(target, &syspath);
+ log_device_debug(dev, "device is closed, synthesising 'change' on %s", strna(syspath));
+ }
+
+ r = sd_device_trigger(target, SD_DEVICE_CHANGE);
+ if (r < 0)
+ return log_device_debug_errno(target, r, "Failed to trigger 'change' uevent: %m");
+
+ DEVICE_TRACE_POINT(synthetic_change_event, dev);
+
+ return 0;
+}
+
+static int synthesize_change(sd_device *dev) {
+ _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+ bool part_table_read;
+ const char *sysname;
+ sd_device *d;
+ int r, k;
+
+ r = sd_device_get_sysname(dev, &sysname);
+ if (r < 0)
+ return r;
+
+ if (startswith(sysname, "dm-") || block_device_is_whole_disk(dev) <= 0)
+ return synthesize_change_one(dev, dev);
+
+ r = blockdev_reread_partition_table(dev);
+ if (r < 0)
+ log_device_debug_errno(dev, r, "Failed to re-read partition table, ignoring: %m");
+ part_table_read = r >= 0;
+
+ /* search for partitions */
+ r = partition_enumerator_new(dev, &e);
+ if (r < 0)
+ return r;
+
+ /* 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 && sd_device_enumerator_get_device_first(e))
+ return 0;
+
+ /* We have partitions but re-reading the partition table did not work, synthesize
+ * "change" for the disk and all partitions. */
+ r = synthesize_change_one(dev, dev);
+ FOREACH_DEVICE(e, d) {
+ k = synthesize_change_one(dev, d);
+ if (k < 0 && r >= 0)
+ r = k;
+ }
+
+ return r;
+}
+
+static int on_inotify(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ union inotify_event_buffer buffer;
+ ssize_t l;
+ int r;
+
+ l = read(fd, &buffer, sizeof(buffer));
+ if (l < 0) {
+ if (ERRNO_IS_TRANSIENT(errno))
+ return 0;
+
+ return log_error_errno(errno, "Failed to read inotify fd: %m");
+ }
+
+ FOREACH_INOTIFY_EVENT_WARN(e, buffer, l) {
+ _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+ const char *devnode;
+
+ /* Do not handle IN_IGNORED here. Especially, do not try to call udev_watch_end() from the
+ * main process. Otherwise, the pair of the symlinks may become inconsistent, and several
+ * garbage may remain. The old symlinks are removed by a worker that processes the
+ * corresponding 'remove' uevent;
+ * udev_event_execute_rules() -> event_execute_rules_on_remove() -> udev_watch_end(). */
+
+ if (!FLAGS_SET(e->mask, IN_CLOSE_WRITE))
+ continue;
+
+ r = device_new_from_watch_handle(&dev, e->wd);
+ if (r < 0) {
+ /* Device may be removed just after closed. */
+ log_debug_errno(r, "Failed to create sd_device object from watch handle, ignoring: %m");
+ continue;
+ }
+
+ r = sd_device_get_devname(dev, &devnode);
+ if (r < 0) {
+ /* Also here, device may be already removed. */
+ log_device_debug_errno(dev, r, "Failed to get device node, ignoring: %m");
+ continue;
+ }
+
+ log_device_debug(dev, "Received inotify event for %s.", devnode);
+
+ (void) event_queue_assume_block_device_unlocked(manager, dev);
+ (void) synthesize_change(dev);
+ }
+
+ return 0;
+}
+
+static int on_sigterm(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ manager_exit(manager);
+
+ return 1;
+}
+
+static int on_sighup(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ manager_reload(manager, /* force = */ true);
+
+ return 1;
+}
+
+static int on_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata) {
+ Worker *worker = ASSERT_PTR(userdata);
+ Manager *manager = ASSERT_PTR(worker->manager);
+ sd_device *dev = worker->event ? ASSERT_PTR(worker->event->dev) : NULL;
+ EventResult result;
+
+ assert(si);
+
+ switch (si->si_code) {
+ case CLD_EXITED:
+ if (si->si_status == 0)
+ log_device_debug(dev, "Worker ["PID_FMT"] exited.", si->si_pid);
+ else
+ log_device_warning(dev, "Worker ["PID_FMT"] exited with return code %i.",
+ si->si_pid, si->si_status);
+ result = EVENT_RESULT_EXIT_STATUS_BASE + si->si_status;
+ break;
+
+ case CLD_KILLED:
+ case CLD_DUMPED:
+ log_device_warning(dev, "Worker ["PID_FMT"] terminated by signal %i (%s).",
+ si->si_pid, si->si_status, signal_to_string(si->si_status));
+ result = EVENT_RESULT_SIGNAL_BASE + si->si_status;
+ break;
+
+ default:
+ assert_not_reached();
+ }
+
+ if (result != EVENT_RESULT_SUCCESS && dev) {
+ /* delete state from disk */
+ device_delete_db(dev);
+ device_tag_index(dev, NULL, false);
+
+ /* Forward kernel event to libudev listeners */
+ device_broadcast(manager->monitor, dev, result);
+ }
+
+ worker_free(worker);
+
+ return 1;
+}
+
+static int on_post(sd_event_source *s, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ if (manager->events) {
+ /* Try to process pending events if idle workers exist. Why is this necessary?
+ * When a worker finished an event and became idle, even if there was a pending event,
+ * the corresponding device might have been locked and the processing of the event
+ * delayed for a while, preventing the worker from processing the event immediately.
+ * Now, the device may be unlocked. Let's try again! */
+ event_queue_start(manager);
+ return 1;
+ }
+
+ /* There are no queued events. Let's remove /run/udev/queue and clean up the idle processes. */
+
+ if (unlink("/run/udev/queue") < 0) {
+ if (errno != ENOENT)
+ log_warning_errno(errno, "Failed to unlink /run/udev/queue, ignoring: %m");
+ } else
+ log_debug("No events are queued, removing /run/udev/queue.");
+
+ if (!hashmap_isempty(manager->workers)) {
+ /* There are idle workers */
+ (void) event_reset_time_relative(manager->event, &manager->kill_workers_event,
+ 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->udev_node_needs_cleanup) {
+ (void) udev_node_cleanup();
+ manager->udev_node_needs_cleanup = false;
+ }
+
+ 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_UNIX, 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_level=<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
+ * udev.blockdev_read_only<=bool> mark all block devices read-only when they appear
+ */
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+ int r;
+
+ assert(key);
+
+ if (proc_cmdline_key_streq(key, "udev.log_level") ||
+ proc_cmdline_key_streq(key, "udev.log_priority")) { /* kept for backward compatibility */
+
+ 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 (proc_cmdline_key_streq(key, "udev.timeout_signal")) {
+
+ if (proc_cmdline_value_missing(key, value))
+ return 0;
+
+ r = signal_from_string(value);
+ if (r > 0)
+ arg_timeout_signal = r;
+
+ } else if (proc_cmdline_key_streq(key, "udev.blockdev_read_only")) {
+
+ if (!value)
+ arg_blockdev_read_only = true;
+ else {
+ r = parse_boolean(value);
+ if (r < 0)
+ log_warning_errno(r, "Failed to parse udev.blockdev-read-only argument, ignoring: %s", value);
+ else
+ arg_blockdev_read_only = r;
+ }
+
+ if (arg_blockdev_read_only)
+ log_notice("All physical block devices will be marked read-only.");
+
+ return 0;
+
+ } else {
+ if (startswith(key, "udev."))
+ log_warning("Unknown udev kernel command line option \"%s\", ignoring.", key);
+
+ return 0;
+ }
+
+ 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"
+ "Rule-based manager for device events and files.\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[]) {
+ enum {
+ ARG_TIMEOUT_SIGNAL,
+ };
+
+ 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' },
+ { "timeout-signal", required_argument, NULL, ARG_TIMEOUT_SIGNAL },
+ {}
+ };
+
+ 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 ARG_TIMEOUT_SIGNAL:
+ r = signal_from_string(optarg);
+ if (r <= 0)
+ log_warning_errno(r, "Failed to parse --timeout-signal= value '%s', ignoring: %m", optarg);
+ else
+ arg_timeout_signal = r;
+
+ 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();
+
+ }
+ }
+
+ return 1;
+}
+
+static int create_subcgroup(char **ret) {
+ _cleanup_free_ char *cgroup = NULL, *subcgroup = NULL;
+ int r;
+
+ if (getppid() != 1)
+ return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Not invoked by PID1.");
+
+ r = sd_booted();
+ if (r < 0)
+ return log_debug_errno(r, "Failed to check if systemd is running: %m");
+ if (r == 0)
+ return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "systemd is not running.");
+
+ /* 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))
+ return log_debug_errno(r, "Dedicated cgroup not found: %m");
+ return log_debug_errno(r, "Failed to get cgroup: %m");
+ }
+
+ r = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, cgroup, "trusted.delegate");
+ if (r == 0 || (r < 0 && ERRNO_IS_XATTR_ABSENT(r)))
+ return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "The cgroup %s is not delegated to us.", cgroup);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to read trusted.delegate attribute: %m");
+
+ /* We are invoked with our own delegated cgroup tree, let's move us one level down, so that we
+ * don't collide with the "no processes in inner nodes" rule of cgroups, when the service
+ * manager invokes the ExecReload= job in the .control/ subcgroup. */
+
+ subcgroup = path_join(cgroup, "/udev");
+ if (!subcgroup)
+ return log_oom_debug();
+
+ r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, subcgroup, 0);
+ if (r < 0)
+ return log_debug_errno(r, "Failed to create %s subcgroup: %m", subcgroup);
+
+ log_debug("Created %s subcgroup.", subcgroup);
+ if (ret)
+ *ret = TAKE_PTR(subcgroup);
+ return 0;
+}
+
+static int manager_new(Manager **ret, int fd_ctrl, int fd_uevent) {
+ _cleanup_(manager_freep) Manager *manager = NULL;
+ _cleanup_free_ char *cgroup = NULL;
+ int r;
+
+ assert(ret);
+
+ (void) create_subcgroup(&cgroup);
+
+ manager = new(Manager, 1);
+ if (!manager)
+ return log_oom();
+
+ *manager = (Manager) {
+ .inotify_fd = -1,
+ .worker_watch = { -1, -1 },
+ .cgroup = TAKE_PTR(cgroup),
+ };
+
+ r = udev_ctrl_new_from_fd(&manager->ctrl, fd_ctrl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to initialize udev control socket: %m");
+
+ 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");
+
+ /* Bump receiver buffer, but only if we are not called via socket activation, as in that
+ * case systemd sets the receive buffer size for us, and the value in the .socket unit
+ * should take full effect. */
+ if (fd_uevent < 0) {
+ r = sd_device_monitor_set_receive_buffer_size(manager->monitor, 128 * 1024 * 1024);
+ if (r < 0)
+ log_warning_errno(r, "Failed to set receive buffer size for device monitor, ignoring: %m");
+ }
+
+ (void) sd_device_monitor_set_description(manager->monitor, "manager");
+
+ r = device_monitor_enable_receiving(manager->monitor);
+ if (r < 0)
+ return log_error_errno(r, "Failed to bind netlink socket: %m");
+
+ manager->log_level = log_get_max_level();
+
+ *ret = TAKE_PTR(manager);
+
+ return 0;
+}
+
+static int main_loop(Manager *manager) {
+ int fd_worker, r;
+
+ manager->pid = getpid_cached();
+
+ /* unnamed socket from workers to the main daemon */
+ r = socketpair(AF_UNIX, 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");
+
+ manager->inotify_fd = inotify_init1(IN_CLOEXEC);
+ if (manager->inotify_fd < 0)
+ return log_error_errno(errno, "Failed to create inotify descriptor: %m");
+
+ udev_watch_restore(manager->inotify_fd);
+
+ /* 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_set_watchdog(manager->event, true);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create watchdog event source: %m");
+
+ r = udev_ctrl_attach_event(manager->ctrl, manager->event);
+ if (r < 0)
+ return log_error_errno(r, "Failed to attach event to udev control: %m");
+
+ r = udev_ctrl_start(manager->ctrl, on_ctrl_msg, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to start device monitor: %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(udev_ctrl_get_event_source(manager->ctrl), 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->inotify_fd, 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");
+
+ 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");
+
+ manager->last_usec = now(CLOCK_MONOTONIC);
+
+ udev_builtin_init();
+
+ r = udev_rules_load(&manager->rules, arg_resolve_name_timing);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read udev rules: %m");
+
+ r = udev_rules_apply_static_dev_perms(manager->rules);
+ if (r < 0)
+ log_warning_errno(r, "Failed to apply permissions on static device nodes, ignoring: %m");
+
+ notify_ready();
+
+ 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;
+}
+
+int run_udevd(int argc, char *argv[]) {
+ _cleanup_(manager_freep) Manager *manager = NULL;
+ int fd_ctrl = -1, fd_uevent = -1;
+ int r;
+
+ log_set_target(LOG_TARGET_AUTO);
+ log_open();
+ udev_parse_config_full(&arg_children_max, &arg_exec_delay_usec, &arg_event_timeout_usec, &arg_resolve_name_timing, &arg_timeout_signal);
+ log_parse_environment();
+ log_open(); /* Done again to update after reading configuration. */
+
+ 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);
+ }
+
+ r = must_be_root();
+ if (r < 0)
+ return r;
+
+ if (arg_children_max == 0) {
+ unsigned long cpu_limit, mem_limit, cpu_count = 1;
+
+ r = cpus_in_affinity_mask();
+ if (r < 0)
+ log_warning_errno(r, "Failed to determine number of local CPUs, ignoring: %m");
+ else
+ cpu_count = r;
+
+ cpu_limit = cpu_count * 2 + 16;
+ mem_limit = MAX(physical_memory() / (128UL*1024*1024), 10U);
+
+ arg_children_max = MIN(cpu_limit, mem_limit);
+ arg_children_max = MIN(WORKER_NUM_MAX, arg_children_max);
+
+ log_debug("Set children_max to %u", arg_children_max);
+ }
+
+ /* set umask before creating any file/directory */
+ umask(022);
+
+ r = mac_selinux_init();
+ if (r < 0)
+ return r;
+
+ /* Make sure we can have plenty fds (for example for pidfds) */
+ (void) rlimit_nofile_bump(-1);
+
+ r = RET_NERRNO(mkdir("/run/udev", 0755));
+ if (r < 0 && r != -EEXIST)
+ return log_error_errno(r, "Failed to create /run/udev: %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);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create manager: %m");
+
+ if (arg_daemonize) {
+ pid_t pid;
+
+ log_info("Starting systemd-udevd 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();
+ }
+
+ return main_loop(manager);
+}