/* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Copyright © 2004 Chris Friesen * Copyright © 2009 Canonical Ltd. * Copyright © 2009 Scott James Remnant */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #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= syslog priority * udev.children_max= events are fully serialized if set to 1 * udev.exec_delay= delay execution of every executed program * udev.event_timeout= 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); }