/* SPDX-License-Identifier: GPL-2.0-or-later */ #include "blockdev-util.h" #include "cgroup-util.h" #include "common-signal.h" #include "cpu-set-util.h" #include "daemon-util.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 "fs-util.h" #include "hashmap.h" #include "inotify-util.h" #include "iovec-util.h" #include "limits-util.h" #include "list.h" #include "mkdir.h" #include "process-util.h" #include "selinux-util.h" #include "signal-util.h" #include "socket-util.h" #include "string-util.h" #include "syslog-util.h" #include "udev-builtin.h" #include "udev-ctrl.h" #include "udev-event.h" #include "udev-manager.h" #include "udev-node.h" #include "udev-spawn.h" #include "udev-trace.h" #include "udev-util.h" #include "udev-watch.h" #include "udev-worker.h" #define WORKER_NUM_MAX UINT64_C(2048) #define EVENT_RETRY_INTERVAL_USEC (200 * USEC_PER_MSEC) #define EVENT_RETRY_TIMEOUT_USEC (3 * USEC_PER_MINUTE) 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; 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); 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); Manager* manager_free(Manager *manager) { if (!manager) return NULL; udev_builtin_exit(); hashmap_free_free_free(manager->properties); udev_rules_free(manager->rules); hashmap_free(manager->workers); event_queue_cleanup(manager, EVENT_UNDEF); safe_close(manager->inotify_fd); safe_close_pair(manager->worker_watch); sd_device_monitor_unref(manager->monitor); udev_ctrl_unref(manager->ctrl); sd_event_source_unref(manager->inotify_event); sd_event_source_unref(manager->kill_workers_event); sd_event_source_unref(manager->memory_pressure_event_source); sd_event_source_unref(manager->sigrtmin18_event_source); sd_event_unref(manager->event); free(manager->cgroup); return mfree(manager); } 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; (void) sd_notify(/* unset= */ false, NOTIFY_STOPPING); /* 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(Manager *manager) { int r; assert(manager); r = sd_notifyf(/* unset= */ false, "READY=1\n" "STATUS=Processing with %u children at max", manager->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()) { if (!force) return; /* If we eat this up, then tell our service manager to just continue */ (void) sd_notifyf(/* unset= */ false, "RELOADING=1\n" "STATUS=Skipping configuration reloading, nothing changed.\n" "MONOTONIC_USEC=" USEC_FMT, now(CLOCK_MONOTONIC)); } else { (void) sd_notifyf(/* unset= */ false, "RELOADING=1\n" "STATUS=Flushing configuration...\n" "MONOTONIC_USEC=" USEC_FMT, now(CLOCK_MONOTONIC)); manager_kill_workers(manager, false); udev_builtin_exit(); udev_builtin_init(); r = udev_rules_load(&rules, manager->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(manager); } static int on_kill_workers_event(sd_event_source *s, uint64_t usec, void *userdata) { Manager *manager = ASSERT_PTR(userdata); log_debug("Cleaning up idle workers."); manager_kill_workers(manager, false); return 1; } static int on_event_timeout(sd_event_source *s, uint64_t usec, void *userdata) { Event *event = ASSERT_PTR(userdata); assert(event->manager); assert(event->worker); kill_and_sigcont(event->worker->pid, event->manager->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) { Manager *manager; 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; manager = worker->manager; e = manager->event; (void) sd_event_add_time_relative(e, &event->timeout_warning_event, CLOCK_MONOTONIC, udev_warn_timeout(manager->timeout_usec), USEC_PER_SEC, on_event_timeout_warning, event); (void) sd_event_add_time_relative(e, &event->timeout_event, CLOCK_MONOTONIC, manager->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_SIGTERM, &pid); if (r < 0) { event->state = EVENT_QUEUED; return log_error_errno(r, "Failed to fork() worker: %m"); } if (r == 0) { _cleanup_(udev_worker_done) UdevWorker w = { .monitor = TAKE_PTR(worker_monitor), .properties = TAKE_PTR(manager->properties), .rules = TAKE_PTR(manager->rules), .pipe_fd = TAKE_FD(manager->worker_watch[WRITE_END]), .inotify_fd = TAKE_FD(manager->inotify_fd), .exec_delay_usec = manager->exec_delay_usec, .timeout_usec = manager->timeout_usec, .timeout_signal = manager->timeout_signal, .log_level = manager->log_level, .blockdev_read_only = manager->blockdev_read_only, }; /* Worker process */ r = udev_worker_main(&w, 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) >= manager->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 && manager->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. */ } bool devpath_conflict(const char *a, const char *b) { /* This returns true when two paths are equivalent, or one is a child of another. */ if (!a || !b) return false; for (; *a != '\0' && *b != '\0'; a++, b++) if (*a != *b) return false; return *a == '/' || *b == '/' || *a == *b; } 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 = udev_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 (udev_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); /* 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) udev_broadcast_result(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; } static void manager_set_default_children_max(Manager *manager) { uint64_t cpu_limit, mem_limit, cpu_count = 1; int r; assert(manager); if (manager->children_max != 0) return; 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() / (128*1024*1024), UINT64_C(10)); manager->children_max = MIN3(cpu_limit, mem_limit, WORKER_NUM_MAX); log_debug("Set children_max to %u", manager->children_max); } /* 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, *old_key = NULL; _cleanup_free_ char *key = NULL, *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); 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); manager->children_max = value->intval; /* When 0 is specified, determine the maximum based on the system resources. */ manager_set_default_children_max(manager); notify_ready(manager); 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; 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 */ udev_broadcast_result(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, removed /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(manager->cgroup, SIGKILL, CGROUP_IGNORE_SELF, /* set=*/ NULL, /* kill_log= */ NULL, /* userdata= */ NULL); return 1; } Manager* manager_new(void) { Manager *manager; manager = new(Manager, 1); if (!manager) return NULL; *manager = (Manager) { .inotify_fd = -EBADF, .worker_watch = EBADF_PAIR, .log_level = LOG_INFO, .resolve_name_timing = RESOLVE_NAME_EARLY, .timeout_usec = 180 * USEC_PER_SEC, .timeout_signal = SIGKILL, }; return manager; } int manager_init(Manager *manager, int fd_ctrl, int fd_uevent) { _cleanup_free_ char *cgroup = NULL; int r; assert(manager); 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"); (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(); r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup); if (r < 0) log_debug_errno(r, "Failed to get cgroup, ignoring: %m"); else if (endswith(cgroup, "/udev")) { /* If we are in a subcgroup /udev/ we assume it was delegated to us */ log_debug("Running in delegated subcgroup '%s'.", cgroup); manager->cgroup = TAKE_PTR(cgroup); } return 0; } int manager_main(Manager *manager) { int fd_worker, r; manager_set_default_children_max(manager); /* 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, SIGRTMIN+18, -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 udev control: %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"); /* Eventually, we probably want to do more here on memory pressure, for example, kill idle workers immediately */ r = sd_event_add_memory_pressure(manager->event, &manager->memory_pressure_event_source, NULL, NULL); if (r < 0) log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) || ERRNO_IS_PRIVILEGE(r) || (r == -EHOSTDOWN) ? LOG_DEBUG : LOG_WARNING, r, "Failed to allocate memory pressure watch, ignoring: %m"); r = sd_event_add_signal(manager->event, &manager->memory_pressure_event_source, SIGRTMIN+18, sigrtmin18_handler, NULL); if (r < 0) return log_error_errno(r, "Failed to allocate SIGRTMIN+18 event source, ignoring: %m"); manager->last_usec = now(CLOCK_MONOTONIC); udev_builtin_init(); r = udev_rules_load(&manager->rules, manager->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(manager); r = sd_event_loop(manager->event); if (r < 0) log_error_errno(r, "Event loop failed: %m"); (void) sd_notify(/* unset= */ false, NOTIFY_STOPPING); return r; }