/* SPDX-License-Identifier: GPL-2.0+ */ /* * 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 "build.h" #include "cgroup-util.h" #include "cpu-set-util.h" #include "dev-setup.h" #include "device-monitor-private.h" #include "device-private.h" #include "device-util.h" #include "event-util.h" #include "fd-util.h" #include "fileio.h" #include "format-util.h" #include "fs-util.h" #include "hashmap.h" #include "io-util.h" #include "libudev-device-internal.h" #include "limits-util.h" #include "list.h" #include "main-func.h" #include "mkdir.h" #include "netlink-util.h" #include "parse-util.h" #include "pretty-print.h" #include "proc-cmdline.h" #include "process-util.h" #include "selinux-util.h" #include "signal-util.h" #include "socket-util.h" #include "string-util.h" #include "strv.h" #include "strxcpyx.h" #include "syslog-util.h" #include "udev-builtin.h" #include "udev-ctrl.h" #include "udev-event.h" #include "udev-util.h" #include "udev-watch.h" #include "user-util.h" #define WORKER_NUM_MAX 2048U static bool arg_debug = false; static int arg_daemonize = false; static ResolveNameTiming arg_resolve_name_timing = RESOLVE_NAME_EARLY; static unsigned arg_children_max = 0; static usec_t arg_exec_delay_usec = 0; static usec_t arg_event_timeout_usec = 180 * USEC_PER_SEC; typedef struct Manager { sd_event *event; Hashmap *workers; LIST_HEAD(struct event, events); const char *cgroup; pid_t pid; /* the process that originally allocated the manager object */ UdevRules *rules; Hashmap *properties; sd_netlink *rtnl; sd_device_monitor *monitor; struct udev_ctrl *ctrl; int fd_inotify; int worker_watch[2]; sd_event_source *inotify_event; sd_event_source *kill_workers_event; usec_t last_usec; bool stop_exec_queue:1; bool exit:1; } Manager; enum event_state { EVENT_UNDEF, EVENT_QUEUED, EVENT_RUNNING, }; struct event { Manager *manager; struct worker *worker; enum event_state state; sd_device *dev; sd_device *dev_kernel; /* clone of originally received device */ uint64_t seqnum; uint64_t delaying_seqnum; sd_event_source *timeout_warning_event; sd_event_source *timeout_event; LIST_FIELDS(struct event, event); }; static void event_queue_cleanup(Manager *manager, enum event_state type); enum worker_state { WORKER_UNDEF, WORKER_RUNNING, WORKER_IDLE, WORKER_KILLED, }; struct worker { Manager *manager; pid_t pid; sd_device_monitor *monitor; enum worker_state state; struct event *event; }; /* passed from worker to main process */ struct worker_message { }; static void event_free(struct event *event) { if (!event) return; assert(event->manager); LIST_REMOVE(event, event->manager->events, event); sd_device_unref(event->dev); sd_device_unref(event->dev_kernel); sd_event_source_unref(event->timeout_warning_event); sd_event_source_unref(event->timeout_event); if (event->worker) event->worker->event = NULL; /* only clean up the queue from the process that created it */ if (LIST_IS_EMPTY(event->manager->events) && event->manager->pid == getpid_cached()) if (unlink("/run/udev/queue") < 0) log_warning_errno(errno, "Failed to unlink /run/udev/queue: %m"); free(event); } static void worker_free(struct worker *worker) { if (!worker) return; assert(worker->manager); hashmap_remove(worker->manager->workers, PID_TO_PTR(worker->pid)); sd_device_monitor_unref(worker->monitor); event_free(worker->event); free(worker); } DEFINE_TRIVIAL_CLEANUP_FUNC(struct worker *, worker_free); DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(worker_hash_op, void, trivial_hash_func, trivial_compare_func, struct worker, worker_free); static int worker_new(struct worker **ret, Manager *manager, sd_device_monitor *worker_monitor, pid_t pid) { _cleanup_(worker_freep) struct worker *worker = NULL; int r; assert(ret); assert(manager); assert(worker_monitor); assert(pid > 1); /* close monitor, but keep address around */ device_monitor_disconnect(worker_monitor); worker = new(struct worker, 1); if (!worker) return -ENOMEM; *worker = (struct worker) { .manager = manager, .monitor = sd_device_monitor_ref(worker_monitor), .pid = pid, }; r = hashmap_ensure_allocated(&manager->workers, &worker_hash_op); if (r < 0) return r; r = hashmap_put(manager->workers, PID_TO_PTR(pid), worker); if (r < 0) return r; *ret = TAKE_PTR(worker); return 0; } static int on_event_timeout(sd_event_source *s, uint64_t usec, void *userdata) { struct event *event = userdata; assert(event); assert(event->worker); kill_and_sigcont(event->worker->pid, SIGKILL); event->worker->state = WORKER_KILLED; log_device_error(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" killed", event->worker->pid, event->seqnum); return 1; } static int on_event_timeout_warning(sd_event_source *s, uint64_t usec, void *userdata) { struct event *event = userdata; assert(event); assert(event->worker); log_device_warning(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" is taking a long time", event->worker->pid, event->seqnum); return 1; } static void worker_attach_event(struct worker *worker, struct event *event) { sd_event *e; uint64_t usec; assert(worker); assert(worker->manager); assert(event); assert(!event->worker); assert(!worker->event); worker->state = WORKER_RUNNING; worker->event = event; event->state = EVENT_RUNNING; event->worker = worker; e = worker->manager->event; assert_se(sd_event_now(e, CLOCK_MONOTONIC, &usec) >= 0); (void) sd_event_add_time(e, &event->timeout_warning_event, CLOCK_MONOTONIC, usec + udev_warn_timeout(arg_event_timeout_usec), USEC_PER_SEC, on_event_timeout_warning, event); (void) sd_event_add_time(e, &event->timeout_event, CLOCK_MONOTONIC, usec + arg_event_timeout_usec, USEC_PER_SEC, on_event_timeout, event); } static void manager_clear_for_worker(Manager *manager) { assert(manager); manager->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 void manager_free(Manager *manager) { if (!manager) return; udev_builtin_exit(); if (manager->pid == getpid_cached()) udev_ctrl_cleanup(manager->ctrl); manager_clear_for_worker(manager); sd_netlink_unref(manager->rtnl); hashmap_free_free_free(manager->properties); udev_rules_free(manager->rules); safe_close(manager->fd_inotify); safe_close_pair(manager->worker_watch); free(manager); } DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); static int worker_send_message(int fd) { struct worker_message message = {}; return loop_write(fd, &message, sizeof(message), false); } static int worker_lock_block_device(sd_device *dev, int *ret_fd) { _cleanup_close_ int fd = -1; const char *val; int r; assert(dev); assert(ret_fd); /* * Take a shared lock on the device node; this establishes * a concept of device "ownership" to serialize device * access. External processes holding an exclusive lock will * cause udev to skip the event handling; in the case udev * acquired the lock, the external process can block until * udev has finished its event handling. */ if (device_for_action(dev, DEVICE_ACTION_REMOVE)) return 0; r = sd_device_get_subsystem(dev, &val); if (r < 0) return log_device_debug_errno(dev, r, "Failed to get subsystem: %m"); if (!streq(val, "block")) return 0; r = sd_device_get_sysname(dev, &val); if (r < 0) return log_device_debug_errno(dev, r, "Failed to get sysname: %m"); if (STARTSWITH_SET(val, "dm-", "md", "drbd")) return 0; r = sd_device_get_devtype(dev, &val); if (r < 0 && r != -ENOENT) return log_device_debug_errno(dev, r, "Failed to get devtype: %m"); if (r >= 0 && streq(val, "partition")) { r = sd_device_get_parent(dev, &dev); if (r < 0) return log_device_debug_errno(dev, r, "Failed to get parent device: %m"); } r = sd_device_get_devname(dev, &val); if (r == -ENOENT) return 0; if (r < 0) return log_device_debug_errno(dev, r, "Failed to get devname: %m"); fd = open(val, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK); if (fd < 0) { log_device_debug_errno(dev, errno, "Failed to open '%s', ignoring: %m", val); return 0; } if (flock(fd, LOCK_SH|LOCK_NB) < 0) return log_device_debug_errno(dev, errno, "Failed to flock(%s): %m", val); *ret_fd = TAKE_FD(fd); return 1; } static int worker_process_device(Manager *manager, sd_device *dev) { _cleanup_(udev_event_freep) UdevEvent *udev_event = NULL; _cleanup_close_ int fd_lock = -1; DeviceAction action; uint64_t seqnum; int r; assert(manager); assert(dev); r = device_get_seqnum(dev, &seqnum); if (r < 0) return log_device_debug_errno(dev, r, "Failed to get SEQNUM: %m"); r = device_get_action(dev, &action); if (r < 0) return log_device_debug_errno(dev, r, "Failed to get ACTION: %m"); log_device_debug(dev, "Processing device (SEQNUM=%"PRIu64", ACTION=%s)", seqnum, device_action_to_string(action)); udev_event = udev_event_new(dev, arg_exec_delay_usec, manager->rtnl); if (!udev_event) return -ENOMEM; r = worker_lock_block_device(dev, &fd_lock); if (r < 0) return r; /* apply rules, create node, symlinks */ r = udev_event_execute_rules(udev_event, arg_event_timeout_usec, manager->properties, manager->rules); if (r < 0) return r; udev_event_execute_run(udev_event, arg_event_timeout_usec); if (!manager->rtnl) /* in case rtnl was initialized */ manager->rtnl = sd_netlink_ref(udev_event->rtnl); /* apply/restore inotify watch */ if (udev_event->inotify_watch) { (void) udev_watch_begin(dev); r = device_update_db(dev); if (r < 0) return log_device_debug_errno(dev, r, "Failed to update database under /run/udev/data/: %m"); } log_device_debug(dev, "Device (SEQNUM=%"PRIu64", ACTION=%s) processed", seqnum, device_action_to_string(action)); return 0; } static int worker_device_monitor_handler(sd_device_monitor *monitor, sd_device *dev, void *userdata) { Manager *manager = userdata; int r; assert(dev); assert(manager); r = worker_process_device(manager, dev); if (r < 0) log_device_warning_errno(dev, r, "Failed to process device, ignoring: %m"); /* send processed event back to libudev listeners */ r = device_monitor_send_device(monitor, NULL, dev); if (r < 0) log_device_warning_errno(dev, r, "Failed to send device, ignoring: %m"); /* send udevd the result of the event execution */ r = worker_send_message(manager->worker_watch[WRITE_END]); if (r < 0) log_device_warning_errno(dev, r, "Failed to send signal to main daemon, ignoring: %m"); return 1; } static int worker_main(Manager *_manager, sd_device_monitor *monitor, sd_device *first_device) { _cleanup_(sd_device_unrefp) sd_device *dev = first_device; _cleanup_(manager_freep) Manager *manager = _manager; int r; assert(manager); assert(monitor); assert(dev); unsetenv("NOTIFY_SOCKET"); assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, -1) >= 0); /* Reset OOM score, we only protect the main daemon. */ r = set_oom_score_adjust(0); if (r < 0) log_debug_errno(r, "Failed to reset OOM score, ignoring: %m"); /* Clear unnecessary data in Manager object.*/ manager_clear_for_worker(manager); r = sd_event_new(&manager->event); if (r < 0) return log_error_errno(r, "Failed to allocate event loop: %m"); r = sd_event_add_signal(manager->event, NULL, SIGTERM, NULL, NULL); if (r < 0) return log_error_errno(r, "Failed to set SIGTERM event: %m"); r = sd_device_monitor_attach_event(monitor, manager->event); if (r < 0) return log_error_errno(r, "Failed to attach event loop to device monitor: %m"); r = sd_device_monitor_start(monitor, worker_device_monitor_handler, manager); if (r < 0) return log_error_errno(r, "Failed to start device monitor: %m"); (void) sd_event_source_set_description(sd_device_monitor_get_event_source(monitor), "worker-device-monitor"); /* Process first device */ (void) worker_device_monitor_handler(monitor, dev, manager); r = sd_event_loop(manager->event); if (r < 0) return log_error_errno(r, "Event loop failed: %m"); return 0; } static int worker_spawn(Manager *manager, struct event *event) { _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *worker_monitor = NULL; struct worker *worker; pid_t pid; int r; /* listen for new events */ r = device_monitor_new_full(&worker_monitor, MONITOR_GROUP_NONE, -1); if (r < 0) return r; /* allow the main daemon netlink address to send devices to the worker */ r = device_monitor_allow_unicast_sender(worker_monitor, manager->monitor); if (r < 0) return log_error_errno(r, "Worker: Failed to set unicast sender: %m"); r = device_monitor_enable_receiving(worker_monitor); if (r < 0) return log_error_errno(r, "Worker: Failed to enable receiving of device: %m"); r = safe_fork(NULL, FORK_DEATHSIG, &pid); if (r < 0) { event->state = EVENT_QUEUED; return log_error_errno(r, "Failed to fork() worker: %m"); } if (r == 0) { /* Worker process */ r = worker_main(manager, worker_monitor, sd_device_ref(event->dev)); log_close(); _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); } r = worker_new(&worker, manager, worker_monitor, pid); if (r < 0) return log_error_errno(r, "Failed to create worker object: %m"); worker_attach_event(worker, event); log_device_debug(event->dev, "Worker ["PID_FMT"] is forked for processing SEQNUM=%"PRIu64".", pid, event->seqnum); return 0; } static void event_run(Manager *manager, struct event *event) { static bool log_children_max_reached = true; struct worker *worker; Iterator i; int r; assert(manager); assert(event); if (DEBUG_LOGGING) { DeviceAction action; r = device_get_action(event->dev, &action); log_device_debug(event->dev, "Device (SEQNUM=%"PRIu64", ACTION=%s) ready for processing", event->seqnum, r >= 0 ? device_action_to_string(action) : ""); } HASHMAP_FOREACH(worker, manager->workers, i) { if (worker->state != WORKER_IDLE) continue; r = device_monitor_send_device(manager->monitor, worker->monitor, event->dev); if (r < 0) { log_device_error_errno(event->dev, r, "Worker ["PID_FMT"] did not accept message, killing the worker: %m", worker->pid); (void) kill(worker->pid, SIGKILL); worker->state = WORKER_KILLED; continue; } worker_attach_event(worker, event); return; } if (hashmap_size(manager->workers) >= arg_children_max) { /* 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; } /* Re-enable the debug message for the next batch of events */ log_children_max_reached = true; /* start new worker and pass initial device */ worker_spawn(manager, event); } static int event_queue_insert(Manager *manager, sd_device *dev) { _cleanup_(sd_device_unrefp) sd_device *clone = NULL; struct event *event; DeviceAction action; uint64_t seqnum; 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 = device_get_seqnum(dev, &seqnum); if (r < 0) return r; /* Refuse devices do not have ACTION property. */ r = device_get_action(dev, &action); if (r < 0) return r; /* Save original device to restore the state on failures. */ r = device_shallow_clone(dev, &clone); if (r < 0) return r; r = device_copy_properties(clone, dev); if (r < 0) return r; event = new(struct event, 1); if (!event) return -ENOMEM; *event = (struct event) { .manager = manager, .dev = sd_device_ref(dev), .dev_kernel = TAKE_PTR(clone), .seqnum = seqnum, .state = EVENT_QUEUED, }; if (LIST_IS_EMPTY(manager->events)) { r = touch("/run/udev/queue"); if (r < 0) log_warning_errno(r, "Failed to touch /run/udev/queue: %m"); } LIST_APPEND(event, manager->events, event); log_device_debug(dev, "Device (SEQNUM=%"PRIu64", ACTION=%s) is queued", seqnum, device_action_to_string(action)); return 0; } static void manager_kill_workers(Manager *manager) { struct worker *worker; Iterator i; assert(manager); HASHMAP_FOREACH(worker, manager->workers, i) { if (worker->state == WORKER_KILLED) continue; worker->state = WORKER_KILLED; (void) kill(worker->pid, SIGTERM); } } /* lookup event for identical, parent, child device */ static int is_device_busy(Manager *manager, struct event *event) { const char *subsystem, *devpath, *devpath_old = NULL; dev_t devnum = makedev(0, 0); struct event *loop_event; size_t devpath_len; int r, ifindex = 0; bool is_block; r = sd_device_get_subsystem(event->dev, &subsystem); if (r < 0) return r; is_block = streq(subsystem, "block"); r = sd_device_get_devpath(event->dev, &devpath); if (r < 0) return r; devpath_len = strlen(devpath); r = sd_device_get_property_value(event->dev, "DEVPATH_OLD", &devpath_old); if (r < 0 && r != -ENOENT) return r; r = sd_device_get_devnum(event->dev, &devnum); if (r < 0 && r != -ENOENT) return r; r = sd_device_get_ifindex(event->dev, &ifindex); if (r < 0 && r != -ENOENT) return r; /* check if queue contains events we depend on */ LIST_FOREACH(event, loop_event, manager->events) { size_t loop_devpath_len, common; const char *loop_devpath; /* we already found a later event, earlier cannot block us, no need to check again */ if (loop_event->seqnum < event->delaying_seqnum) continue; /* event we checked earlier still exists, no need to check again */ if (loop_event->seqnum == event->delaying_seqnum) return true; /* found ourself, no later event can block us */ if (loop_event->seqnum >= event->seqnum) break; /* check major/minor */ if (major(devnum) != 0) { const char *s; dev_t d; if (sd_device_get_subsystem(loop_event->dev, &s) < 0) continue; if (sd_device_get_devnum(loop_event->dev, &d) >= 0 && devnum == d && is_block == streq(s, "block")) goto set_delaying_seqnum; } /* check network device ifindex */ if (ifindex > 0) { int i; if (sd_device_get_ifindex(loop_event->dev, &i) >= 0 && ifindex == i) goto set_delaying_seqnum; } if (sd_device_get_devpath(loop_event->dev, &loop_devpath) < 0) continue; /* check our old name */ if (devpath_old && streq(devpath_old, loop_devpath)) goto set_delaying_seqnum; loop_devpath_len = strlen(loop_devpath); /* compare devpath */ common = MIN(devpath_len, loop_devpath_len); /* one devpath is contained in the other? */ if (!strneq(devpath, loop_devpath, common)) continue; /* identical device event found */ if (devpath_len == loop_devpath_len) goto set_delaying_seqnum; /* parent device event found */ if (devpath[common] == '/') goto set_delaying_seqnum; /* child device event found */ if (loop_devpath[common] == '/') goto set_delaying_seqnum; } return false; set_delaying_seqnum: log_device_debug(event->dev, "SEQNUM=%" PRIu64 " blocked by SEQNUM=%" PRIu64, event->seqnum, loop_event->seqnum); event->delaying_seqnum = loop_event->seqnum; return true; } 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_unref(manager->inotify_event); manager->fd_inotify = safe_close(manager->fd_inotify); manager->monitor = sd_device_monitor_unref(manager->monitor); /* discard queued events and kill workers */ event_queue_cleanup(manager, EVENT_QUEUED); manager_kill_workers(manager); } /* reload requested, HUP signal received, rules changed, builtin changed */ static void manager_reload(Manager *manager) { assert(manager); sd_notify(false, "RELOADING=1\n" "STATUS=Flushing configuration..."); manager_kill_workers(manager); manager->rules = udev_rules_free(manager->rules); udev_builtin_exit(); sd_notifyf(false, "READY=1\n" "STATUS=Processing with %u children at max", arg_children_max); } static int on_kill_workers_event(sd_event_source *s, uint64_t usec, void *userdata) { Manager *manager = userdata; assert(manager); log_debug("Cleanup idle workers"); manager_kill_workers(manager); return 1; } static void event_queue_start(Manager *manager) { struct event *event; usec_t usec; int r; assert(manager); if (LIST_IS_EMPTY(manager->events) || manager->exit || manager->stop_exec_queue) return; assert_se(sd_event_now(manager->event, CLOCK_MONOTONIC, &usec) >= 0); /* check for changed config, every 3 seconds at most */ if (manager->last_usec == 0 || usec - manager->last_usec > 3 * USEC_PER_SEC) { if (udev_rules_check_timestamp(manager->rules) || udev_builtin_validate()) manager_reload(manager); manager->last_usec = usec; } r = event_source_disable(manager->kill_workers_event); if (r < 0) log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m"); udev_builtin_init(); if (!manager->rules) { r = udev_rules_new(&manager->rules, arg_resolve_name_timing); if (r < 0) { log_warning_errno(r, "Failed to read udev rules: %m"); return; } } LIST_FOREACH(event, event, manager->events) { if (event->state != EVENT_QUEUED) continue; /* do not start event if parent or child event is still running */ if (is_device_busy(manager, event) != 0) continue; event_run(manager, event); } } static void event_queue_cleanup(Manager *manager, enum event_state match_type) { struct event *event, *tmp; LIST_FOREACH_SAFE(event, event, tmp, manager->events) { if (match_type != EVENT_UNDEF && match_type != event->state) continue; event_free(event); } } static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdata) { Manager *manager = userdata; assert(manager); for (;;) { struct worker_message msg; struct iovec iovec = { .iov_base = &msg, .iov_len = sizeof(msg), }; union { struct cmsghdr cmsghdr; uint8_t buf[CMSG_SPACE(sizeof(struct ucred))]; } control = {}; struct msghdr msghdr = { .msg_iov = &iovec, .msg_iovlen = 1, .msg_control = &control, .msg_controllen = sizeof(control), }; struct cmsghdr *cmsg; ssize_t size; struct ucred *ucred = NULL; struct worker *worker; size = recvmsg(fd, &msghdr, MSG_DONTWAIT); if (size < 0) { if (errno == EINTR) continue; else if (errno == EAGAIN) /* nothing more to read */ break; return log_error_errno(errno, "Failed to receive message: %m"); } else if (size != sizeof(struct worker_message)) { log_warning("Ignoring worker message with invalid size %zi bytes", size); continue; } CMSG_FOREACH(cmsg, &msghdr) if (cmsg->cmsg_level == SOL_SOCKET && cmsg->cmsg_type == SCM_CREDENTIALS && cmsg->cmsg_len == CMSG_LEN(sizeof(struct ucred))) ucred = (struct ucred*) CMSG_DATA(cmsg); if (!ucred || ucred->pid <= 0) { log_warning("Ignoring worker message without valid PID"); continue; } /* lookup worker who sent the signal */ worker = hashmap_get(manager->workers, PID_TO_PTR(ucred->pid)); if (!worker) { log_debug("Worker ["PID_FMT"] returned, but is no longer tracked", ucred->pid); continue; } if (worker->state != WORKER_KILLED) worker->state = WORKER_IDLE; /* worker returned */ event_free(worker->event); } /* we have free workers, try to schedule events */ event_queue_start(manager); return 1; } static int on_uevent(sd_device_monitor *monitor, sd_device *dev, void *userdata) { Manager *manager = userdata; int r; assert(manager); device_ensure_usec_initialized(dev, NULL); r = event_queue_insert(manager, dev); if (r < 0) { log_device_error_errno(dev, r, "Failed to insert device into event queue: %m"); return 1; } /* we have fresh events, try to schedule them */ event_queue_start(manager); return 1; } /* receive the udevd message from userspace */ static int on_ctrl_msg(struct udev_ctrl *uctrl, enum udev_ctrl_msg_type type, const union udev_ctrl_msg_value *value, void *userdata) { Manager *manager = userdata; int r; assert(value); assert(manager); switch (type) { case UDEV_CTRL_SET_LOG_LEVEL: log_debug("Received udev control message (SET_LOG_LEVEL), setting log_priority=%i", value->intval); log_set_max_level_realm(LOG_REALM_UDEV, value->intval); log_set_max_level_realm(LOG_REALM_SYSTEMD, value->intval); manager_kill_workers(manager); 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; event_queue_start(manager); break; case UDEV_CTRL_RELOAD: log_debug("Received udev control message (RELOAD)"); manager_reload(manager); break; case UDEV_CTRL_SET_ENV: { _cleanup_free_ char *key = NULL, *val = NULL, *old_key = NULL, *old_val = 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); 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; (void) sd_notifyf(false, "READY=1\n" "STATUS=Processing with %u children at max", arg_children_max); 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, const char *syspath) { const char *filename; int r; filename = strjoina(syspath, "/uevent"); log_device_debug(dev, "device is closed, synthesising 'change' on %s", syspath); r = write_string_file(filename, "change", WRITE_STRING_FILE_DISABLE_BUFFER); if (r < 0) return log_device_debug_errno(dev, r, "Failed to write 'change' to %s: %m", filename); return 0; } static int synthesize_change(sd_device *dev) { const char *subsystem, *sysname, *devname, *syspath, *devtype; int r; r = sd_device_get_subsystem(dev, &subsystem); if (r < 0) return r; r = sd_device_get_sysname(dev, &sysname); if (r < 0) return r; r = sd_device_get_devname(dev, &devname); if (r < 0) return r; r = sd_device_get_syspath(dev, &syspath); if (r < 0) return r; r = sd_device_get_devtype(dev, &devtype); if (r < 0) return r; if (streq_ptr("block", subsystem) && streq_ptr("disk", devtype) && !startswith(sysname, "dm-")) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; bool part_table_read = false, has_partitions = false; sd_device *d; int fd; /* * Try to re-read the partition table. This only succeeds if * none of the devices is busy. The kernel returns 0 if no * partition table is found, and we will not get an event for * the disk. */ fd = open(devname, O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK); if (fd >= 0) { r = flock(fd, LOCK_EX|LOCK_NB); if (r >= 0) r = ioctl(fd, BLKRRPART, 0); close(fd); if (r >= 0) part_table_read = true; } /* search for partitions */ r = sd_device_enumerator_new(&e); if (r < 0) return r; r = sd_device_enumerator_allow_uninitialized(e); if (r < 0) return r; r = sd_device_enumerator_add_match_parent(e, dev); if (r < 0) return r; r = sd_device_enumerator_add_match_subsystem(e, "block", true); if (r < 0) return r; FOREACH_DEVICE(e, d) { const char *t; if (sd_device_get_devtype(d, &t) < 0 || !streq("partition", t)) continue; has_partitions = true; break; } /* * We have partitions and re-read the table, the kernel already sent * out a "change" event for the disk, and "remove/add" for all * partitions. */ if (part_table_read && has_partitions) return 0; /* * We have partitions but re-reading the partition table did not * work, synthesize "change" for the disk and all partitions. */ (void) synthesize_change_one(dev, syspath); FOREACH_DEVICE(e, d) { const char *t, *n, *s; if (sd_device_get_devtype(d, &t) < 0 || !streq("partition", t)) continue; if (sd_device_get_devname(d, &n) < 0 || sd_device_get_syspath(d, &s) < 0) continue; (void) synthesize_change_one(dev, s); } } else (void) synthesize_change_one(dev, syspath); return 0; } static int on_inotify(sd_event_source *s, int fd, uint32_t revents, void *userdata) { Manager *manager = userdata; union inotify_event_buffer buffer; struct inotify_event *e; ssize_t l; int r; assert(manager); r = event_source_disable(manager->kill_workers_event); if (r < 0) log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m"); l = read(fd, &buffer, sizeof(buffer)); if (l < 0) { if (IN_SET(errno, EAGAIN, EINTR)) return 1; return log_error_errno(errno, "Failed to read inotify fd: %m"); } FOREACH_INOTIFY_EVENT(e, buffer, l) { _cleanup_(sd_device_unrefp) sd_device *dev = NULL; const char *devnode; if (udev_watch_lookup(e->wd, &dev) <= 0) continue; if (sd_device_get_devname(dev, &devnode) < 0) continue; log_device_debug(dev, "Inotify event: %x for %s", e->mask, devnode); if (e->mask & IN_CLOSE_WRITE) synthesize_change(dev); else if (e->mask & IN_IGNORED) udev_watch_end(dev); } return 1; } static int on_sigterm(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { Manager *manager = userdata; assert(manager); manager_exit(manager); return 1; } static int on_sighup(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { Manager *manager = userdata; assert(manager); manager_reload(manager); return 1; } static int on_sigchld(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { Manager *manager = userdata; int r; assert(manager); for (;;) { pid_t pid; int status; struct worker *worker; pid = waitpid(-1, &status, WNOHANG); if (pid <= 0) break; worker = hashmap_get(manager->workers, PID_TO_PTR(pid)); if (!worker) { log_warning("Worker ["PID_FMT"] is unknown, ignoring", pid); continue; } if (WIFEXITED(status)) { if (WEXITSTATUS(status) == 0) log_debug("Worker ["PID_FMT"] exited", pid); else log_warning("Worker ["PID_FMT"] exited with return code %i", pid, WEXITSTATUS(status)); } else if (WIFSIGNALED(status)) log_warning("Worker ["PID_FMT"] terminated by signal %i (%s)", pid, WTERMSIG(status), signal_to_string(WTERMSIG(status))); else if (WIFSTOPPED(status)) { log_info("Worker ["PID_FMT"] stopped", pid); continue; } else if (WIFCONTINUED(status)) { log_info("Worker ["PID_FMT"] continued", pid); continue; } else log_warning("Worker ["PID_FMT"] exit with status 0x%04x", pid, status); if ((!WIFEXITED(status) || WEXITSTATUS(status) != 0) && worker->event) { log_device_error(worker->event->dev, "Worker ["PID_FMT"] failed", pid); /* delete state from disk */ device_delete_db(worker->event->dev); device_tag_index(worker->event->dev, NULL, false); if (manager->monitor) { /* forward kernel event without amending it */ r = device_monitor_send_device(manager->monitor, NULL, worker->event->dev_kernel); if (r < 0) log_device_error_errno(worker->event->dev_kernel, r, "Failed to send back device to kernel: %m"); } } worker_free(worker); } /* we can start new workers, try to schedule events */ event_queue_start(manager); /* Disable unnecessary cleanup event */ if (hashmap_isempty(manager->workers)) { r = event_source_disable(manager->kill_workers_event); if (r < 0) log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m"); } return 1; } static int on_post(sd_event_source *s, void *userdata) { Manager *manager = userdata; assert(manager); if (!LIST_IS_EMPTY(manager->events)) return 1; /* There are no pending events. Let's cleanup idle process. */ if (!hashmap_isempty(manager->workers)) { /* There are idle workers */ (void) event_reset_time(manager->event, &manager->kill_workers_event, CLOCK_MONOTONIC, now(CLOCK_MONOTONIC) + 3 * USEC_PER_SEC, USEC_PER_SEC, on_kill_workers_event, manager, 0, "kill-workers-event", false); return 1; } /* There are no idle workers. */ if (manager->exit) return sd_event_exit(manager->event, 0); if (manager->cgroup) /* cleanup possible left-over processes in our cgroup */ (void) cg_kill(SYSTEMD_CGROUP_CONTROLLER, manager->cgroup, SIGKILL, CGROUP_IGNORE_SELF, NULL, NULL, NULL); return 1; } static int listen_fds(int *ret_ctrl, int *ret_netlink) { int ctrl_fd = -1, netlink_fd = -1; int fd, n; assert(ret_ctrl); assert(ret_netlink); n = sd_listen_fds(true); if (n < 0) return n; for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) { if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1) > 0) { if (ctrl_fd >= 0) return -EINVAL; ctrl_fd = fd; continue; } if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1) > 0) { if (netlink_fd >= 0) return -EINVAL; netlink_fd = fd; continue; } return -EINVAL; } *ret_ctrl = ctrl_fd; *ret_netlink = netlink_fd; return 0; } /* * read the kernel command line, in case we need to get into debug mode * udev.log_priority= 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 */ static int parse_proc_cmdline_item(const char *key, const char *value, void *data) { int r = 0; assert(key); if (!value) return 0; if (proc_cmdline_key_streq(key, "udev.log_priority")) { if (proc_cmdline_value_missing(key, value)) return 0; r = log_level_from_string(value); if (r >= 0) log_set_max_level(r); } else if (proc_cmdline_key_streq(key, "udev.event_timeout")) { if (proc_cmdline_value_missing(key, value)) return 0; r = parse_sec(value, &arg_event_timeout_usec); } else if (proc_cmdline_key_streq(key, "udev.children_max")) { if (proc_cmdline_value_missing(key, value)) return 0; r = safe_atou(value, &arg_children_max); } else if (proc_cmdline_key_streq(key, "udev.exec_delay")) { if (proc_cmdline_value_missing(key, value)) return 0; r = parse_sec(value, &arg_exec_delay_usec); } else if (startswith(key, "udev.")) log_warning("Unknown udev kernel command line option \"%s\", ignoring", key); if (r < 0) log_warning_errno(r, "Failed to parse \"%s=%s\", ignoring: %m", key, value); return 0; } static int help(void) { _cleanup_free_ char *link = NULL; int r; r = terminal_urlify_man("systemd-udevd.service", "8", &link); if (r < 0) return log_oom(); printf("%s [OPTIONS...]\n\n" "Manages devices.\n\n" " -h --help Print this message\n" " -V --version Print version of the program\n" " -d --daemon Detach and run in the background\n" " -D --debug Enable debug output\n" " -c --children-max=INT Set maximum number of workers\n" " -e --exec-delay=SECONDS Seconds to wait before executing RUN=\n" " -t --event-timeout=SECONDS Seconds to wait before terminating an event\n" " -N --resolve-names=early|late|never\n" " When to resolve users and groups\n" "\nSee the %s for details.\n" , program_invocation_short_name , link ); return 0; } static int parse_argv(int argc, char *argv[]) { static const struct option options[] = { { "daemon", no_argument, NULL, 'd' }, { "debug", no_argument, NULL, 'D' }, { "children-max", required_argument, NULL, 'c' }, { "exec-delay", required_argument, NULL, 'e' }, { "event-timeout", required_argument, NULL, 't' }, { "resolve-names", required_argument, NULL, 'N' }, { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, 'V' }, {} }; int c, r; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "c:de:Dt:N:hV", options, NULL)) >= 0) { switch (c) { case 'd': arg_daemonize = true; break; case 'c': r = safe_atou(optarg, &arg_children_max); if (r < 0) log_warning_errno(r, "Failed to parse --children-max= value '%s', ignoring: %m", optarg); break; case 'e': r = parse_sec(optarg, &arg_exec_delay_usec); if (r < 0) log_warning_errno(r, "Failed to parse --exec-delay= value '%s', ignoring: %m", optarg); break; case 't': r = parse_sec(optarg, &arg_event_timeout_usec); if (r < 0) log_warning_errno(r, "Failed to parse --event-timeout= value '%s', ignoring: %m", optarg); break; case 'D': arg_debug = true; break; case 'N': { ResolveNameTiming t; t = resolve_name_timing_from_string(optarg); if (t < 0) log_warning("Invalid --resolve-names= value '%s', ignoring.", optarg); else arg_resolve_name_timing = t; break; } case 'h': return help(); case 'V': printf("%s\n", GIT_VERSION); return 0; case '?': return -EINVAL; default: assert_not_reached("Unhandled option"); } } return 1; } static int manager_new(Manager **ret, int fd_ctrl, int fd_uevent, const char *cgroup) { _cleanup_(manager_freep) Manager *manager = NULL; int r; assert(ret); manager = new(Manager, 1); if (!manager) return log_oom(); *manager = (Manager) { .fd_inotify = -1, .worker_watch = { -1, -1 }, .cgroup = cgroup, }; 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) (void) sd_device_monitor_set_receive_buffer_size(manager->monitor, 128 * 1024 * 1024); r = device_monitor_enable_receiving(manager->monitor); if (r < 0) return log_error_errno(r, "Failed to bind netlink socket: %m"); *ret = TAKE_PTR(manager); return 0; } static int main_loop(Manager *manager) { int fd_worker, r; manager->pid = getpid_cached(); /* unnamed socket from workers to the main daemon */ r = socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, manager->worker_watch); if (r < 0) return log_error_errno(errno, "Failed to create socketpair for communicating with workers: %m"); fd_worker = manager->worker_watch[READ_END]; r = setsockopt_int(fd_worker, SOL_SOCKET, SO_PASSCRED, true); if (r < 0) return log_error_errno(r, "Failed to enable SO_PASSCRED: %m"); r = udev_watch_init(); if (r < 0) return log_error_errno(r, "Failed to create inotify descriptor: %m"); manager->fd_inotify = r; udev_watch_restore(); /* block and listen to all signals on signalfd */ assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGHUP, SIGCHLD, -1) >= 0); r = sd_event_default(&manager->event); if (r < 0) return log_error_errno(r, "Failed to allocate event loop: %m"); r = sd_event_add_signal(manager->event, NULL, SIGINT, on_sigterm, manager); if (r < 0) return log_error_errno(r, "Failed to create SIGINT event source: %m"); r = sd_event_add_signal(manager->event, NULL, SIGTERM, on_sigterm, manager); if (r < 0) return log_error_errno(r, "Failed to create SIGTERM event source: %m"); r = sd_event_add_signal(manager->event, NULL, SIGHUP, on_sighup, manager); if (r < 0) return log_error_errno(r, "Failed to create SIGHUP event source: %m"); r = sd_event_add_signal(manager->event, NULL, SIGCHLD, on_sigchld, manager); if (r < 0) return log_error_errno(r, "Failed to create SIGCHLD event source: %m"); r = sd_event_set_watchdog(manager->event, true); if (r < 0) return log_error_errno(r, "Failed to create watchdog event source: %m"); 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->fd_inotify, EPOLLIN, on_inotify, manager); if (r < 0) return log_error_errno(r, "Failed to create inotify event source: %m"); r = sd_device_monitor_attach_event(manager->monitor, manager->event); if (r < 0) return log_error_errno(r, "Failed to attach event to device monitor: %m"); r = sd_device_monitor_start(manager->monitor, on_uevent, manager); if (r < 0) return log_error_errno(r, "Failed to start device monitor: %m"); (void) sd_event_source_set_description(sd_device_monitor_get_event_source(manager->monitor), "device-monitor"); r = sd_event_add_io(manager->event, NULL, fd_worker, EPOLLIN, on_worker, manager); if (r < 0) return log_error_errno(r, "Failed to create worker event source: %m"); r = sd_event_add_post(manager->event, NULL, on_post, manager); if (r < 0) return log_error_errno(r, "Failed to create post event source: %m"); udev_builtin_init(); r = udev_rules_new(&manager->rules, arg_resolve_name_timing); if (!manager->rules) return log_error_errno(r, "Failed to read udev rules: %m"); r = udev_rules_apply_static_dev_perms(manager->rules); if (r < 0) log_error_errno(r, "Failed to apply permissions on static device nodes: %m"); (void) sd_notifyf(false, "READY=1\n" "STATUS=Processing with %u children at max", arg_children_max); r = sd_event_loop(manager->event); if (r < 0) log_error_errno(r, "Event loop failed: %m"); sd_notify(false, "STOPPING=1\n" "STATUS=Shutting down..."); return r; } static int run(int argc, char *argv[]) { _cleanup_free_ char *cgroup = NULL; _cleanup_(manager_freep) Manager *manager = NULL; int fd_ctrl = -1, fd_uevent = -1; int r; log_set_target(LOG_TARGET_AUTO); log_open(); udev_parse_config_full(&arg_children_max, &arg_exec_delay_usec, &arg_event_timeout_usec, &arg_resolve_name_timing); 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); } log_set_max_level_realm(LOG_REALM_SYSTEMD, log_get_max_level()); r = must_be_root(); if (r < 0) return r; if (arg_children_max == 0) { unsigned long cpu_limit, mem_limit; unsigned long cpu_count = 1; cpu_set_t cpu_set; if (sched_getaffinity(0, sizeof(cpu_set), &cpu_set) == 0) cpu_count = CPU_COUNT(&cpu_set); 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 */ r = chdir("/"); if (r < 0) return log_error_errno(errno, "Failed to change dir to '/': %m"); umask(022); r = mac_selinux_init(); if (r < 0) return log_error_errno(r, "Could not initialize labelling: %m"); r = mkdir_errno_wrapper("/run/udev", 0755); if (r < 0 && r != -EEXIST) return log_error_errno(r, "Failed to create /run/udev: %m"); dev_setup(NULL, UID_INVALID, GID_INVALID); if (getppid() == 1 && sd_booted() > 0) { /* Get our own cgroup, we regularly kill everything udev has left behind. * We only do this on systemd systems, and only if we are directly spawned * by PID1. Otherwise we are not guaranteed to have a dedicated cgroup. */ r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup); if (r < 0) { if (IN_SET(r, -ENOENT, -ENOMEDIUM)) log_debug_errno(r, "Dedicated cgroup not found: %m"); else log_warning_errno(r, "Failed to get cgroup: %m"); } } r = listen_fds(&fd_ctrl, &fd_uevent); if (r < 0) return log_error_errno(r, "Failed to listen on fds: %m"); r = manager_new(&manager, fd_ctrl, fd_uevent, cgroup); if (r < 0) return log_error_errno(r, "Failed to create manager: %m"); if (arg_daemonize) { pid_t pid; log_info("Starting version " GIT_VERSION); /* connect /dev/null to stdin, stdout, stderr */ if (log_get_max_level() < LOG_DEBUG) { r = make_null_stdio(); if (r < 0) log_warning_errno(r, "Failed to redirect standard streams to /dev/null: %m"); } pid = fork(); if (pid < 0) return log_error_errno(errno, "Failed to fork daemon: %m"); if (pid > 0) /* parent */ return 0; /* child */ (void) setsid(); r = set_oom_score_adjust(-1000); if (r < 0) log_debug_errno(r, "Failed to adjust OOM score, ignoring: %m"); } return main_loop(manager); } DEFINE_MAIN_FUNCTION(run);