diff options
Diffstat (limited to '')
| -rw-r--r-- | src/udev/udevd.c | 2083 |
1 files changed, 2083 insertions, 0 deletions
diff --git a/src/udev/udevd.c b/src/udev/udevd.c new file mode 100644 index 0000000..2095062 --- /dev/null +++ b/src/udev/udevd.c @@ -0,0 +1,2083 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later */ +/* + * Copyright © 2004 Chris Friesen <chris_friesen@sympatico.ca> + * Copyright © 2009 Canonical Ltd. + * Copyright © 2009 Scott James Remnant <scott@netsplit.com> + */ + +#include <errno.h> +#include <fcntl.h> +#include <getopt.h> +#include <stdbool.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <sys/epoll.h> +#include <sys/file.h> +#include <sys/inotify.h> +#include <sys/ioctl.h> +#include <sys/mount.h> +#include <sys/prctl.h> +#include <sys/signalfd.h> +#include <sys/stat.h> +#include <sys/time.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "sd-daemon.h" +#include "sd-event.h" + +#include "alloc-util.h" +#include "blockdev-util.h" +#include "cgroup-setup.h" +#include "cgroup-util.h" +#include "cpu-set-util.h" +#include "dev-setup.h" +#include "device-monitor-private.h" +#include "device-private.h" +#include "device-util.h" +#include "errno-list.h" +#include "event-util.h" +#include "fd-util.h" +#include "fileio.h" +#include "format-util.h" +#include "fs-util.h" +#include "hashmap.h" +#include "inotify-util.h" +#include "io-util.h" +#include "limits-util.h" +#include "list.h" +#include "main-func.h" +#include "mkdir.h" +#include "netlink-util.h" +#include "parse-util.h" +#include "path-util.h" +#include "pretty-print.h" +#include "proc-cmdline.h" +#include "process-util.h" +#include "rlimit-util.h" +#include "selinux-util.h" +#include "signal-util.h" +#include "socket-util.h" +#include "string-util.h" +#include "strv.h" +#include "strxcpyx.h" +#include "syslog-util.h" +#include "udevd.h" +#include "udev-builtin.h" +#include "udev-ctrl.h" +#include "udev-event.h" +#include "udev-node.h" +#include "udev-util.h" +#include "udev-watch.h" +#include "user-util.h" +#include "version.h" + +#define WORKER_NUM_MAX 2048U +#define EVENT_RETRY_INTERVAL_USEC (200 * USEC_PER_MSEC) +#define EVENT_RETRY_TIMEOUT_USEC (3 * USEC_PER_MINUTE) + +static bool arg_debug = false; +static int arg_daemonize = false; +static ResolveNameTiming arg_resolve_name_timing = RESOLVE_NAME_EARLY; +static unsigned arg_children_max = 0; +static usec_t arg_exec_delay_usec = 0; +static usec_t arg_event_timeout_usec = 180 * USEC_PER_SEC; +static int arg_timeout_signal = SIGKILL; +static bool arg_blockdev_read_only = false; + +typedef struct Event Event; +typedef struct Worker Worker; + +typedef struct Manager { + sd_event *event; + Hashmap *workers; + LIST_HEAD(Event, events); + char *cgroup; + pid_t pid; /* the process that originally allocated the manager object */ + int log_level; + + UdevRules *rules; + Hashmap *properties; + + sd_netlink *rtnl; + + sd_device_monitor *monitor; + UdevCtrl *ctrl; + int worker_watch[2]; + + /* used by udev-watch */ + int inotify_fd; + sd_event_source *inotify_event; + + sd_event_source *kill_workers_event; + + usec_t last_usec; + + bool udev_node_needs_cleanup; + bool stop_exec_queue; + bool exit; +} Manager; + +typedef enum EventState { + EVENT_UNDEF, + EVENT_QUEUED, + EVENT_RUNNING, +} EventState; + +typedef struct Event { + Manager *manager; + Worker *worker; + EventState state; + + sd_device *dev; + + sd_device_action_t action; + uint64_t seqnum; + uint64_t blocker_seqnum; + const char *id; + const char *devpath; + const char *devpath_old; + const char *devnode; + + /* Used when the device is locked by another program. */ + usec_t retry_again_next_usec; + usec_t retry_again_timeout_usec; + sd_event_source *retry_event_source; + + sd_event_source *timeout_warning_event; + sd_event_source *timeout_event; + + LIST_FIELDS(Event, event); +} Event; + +typedef enum WorkerState { + WORKER_UNDEF, + WORKER_RUNNING, + WORKER_IDLE, + WORKER_KILLED, + WORKER_KILLING, +} WorkerState; + +typedef struct Worker { + Manager *manager; + pid_t pid; + sd_event_source *child_event_source; + sd_device_monitor *monitor; + WorkerState state; + Event *event; +} Worker; + +/* passed from worker to main process */ +typedef enum EventResult { + EVENT_RESULT_NERRNO_MIN = -ERRNO_MAX, + EVENT_RESULT_NERRNO_MAX = -1, + EVENT_RESULT_SUCCESS = 0, + EVENT_RESULT_EXIT_STATUS_BASE = 0, + EVENT_RESULT_EXIT_STATUS_MAX = 255, + EVENT_RESULT_TRY_AGAIN = 256, /* when the block device is locked by another process. */ + EVENT_RESULT_SIGNAL_BASE = 257, + EVENT_RESULT_SIGNAL_MAX = EVENT_RESULT_SIGNAL_BASE + _NSIG, + _EVENT_RESULT_MAX, + _EVENT_RESULT_INVALID = -EINVAL, +} EventResult; + +static Event *event_free(Event *event) { + if (!event) + return NULL; + + assert(event->manager); + + LIST_REMOVE(event, event->manager->events, event); + sd_device_unref(event->dev); + + /* Do not use sd_event_source_disable_unref() here, as this is called by both workers and the + * main process. */ + sd_event_source_unref(event->retry_event_source); + sd_event_source_unref(event->timeout_warning_event); + sd_event_source_unref(event->timeout_event); + + if (event->worker) + event->worker->event = NULL; + + return mfree(event); +} + +static void event_queue_cleanup(Manager *manager, EventState match_state) { + LIST_FOREACH(event, event, manager->events) { + if (match_state != EVENT_UNDEF && match_state != event->state) + continue; + + event_free(event); + } +} + +static Worker *worker_free(Worker *worker) { + if (!worker) + return NULL; + + if (worker->manager) + hashmap_remove(worker->manager->workers, PID_TO_PTR(worker->pid)); + + sd_event_source_unref(worker->child_event_source); + sd_device_monitor_unref(worker->monitor); + event_free(worker->event); + + return mfree(worker); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(Worker*, worker_free); +DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(worker_hash_op, void, trivial_hash_func, trivial_compare_func, Worker, worker_free); + +static void manager_clear_for_worker(Manager *manager) { + assert(manager); + + /* Do not use sd_event_source_disable_unref() here, as this is called by both workers and the + * main process. */ + manager->inotify_event = sd_event_source_unref(manager->inotify_event); + manager->kill_workers_event = sd_event_source_unref(manager->kill_workers_event); + + manager->event = sd_event_unref(manager->event); + + manager->workers = hashmap_free(manager->workers); + event_queue_cleanup(manager, EVENT_UNDEF); + + manager->monitor = sd_device_monitor_unref(manager->monitor); + manager->ctrl = udev_ctrl_unref(manager->ctrl); + + manager->worker_watch[READ_END] = safe_close(manager->worker_watch[READ_END]); +} + +static Manager* manager_free(Manager *manager) { + if (!manager) + return NULL; + + udev_builtin_exit(); + + manager_clear_for_worker(manager); + + sd_netlink_unref(manager->rtnl); + + hashmap_free_free_free(manager->properties); + udev_rules_free(manager->rules); + + safe_close(manager->inotify_fd); + safe_close_pair(manager->worker_watch); + + free(manager->cgroup); + return mfree(manager); +} + +DEFINE_TRIVIAL_CLEANUP_FUNC(Manager*, manager_free); + +static int on_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata); + +static int worker_new(Worker **ret, Manager *manager, sd_device_monitor *worker_monitor, pid_t pid) { + _cleanup_(worker_freep) Worker *worker = NULL; + int r; + + assert(ret); + assert(manager); + assert(worker_monitor); + assert(pid > 1); + + /* close monitor, but keep address around */ + device_monitor_disconnect(worker_monitor); + + worker = new(Worker, 1); + if (!worker) + return -ENOMEM; + + *worker = (Worker) { + .monitor = sd_device_monitor_ref(worker_monitor), + .pid = pid, + }; + + r = sd_event_add_child(manager->event, &worker->child_event_source, pid, WEXITED, on_sigchld, worker); + if (r < 0) + return r; + + r = hashmap_ensure_put(&manager->workers, &worker_hash_op, PID_TO_PTR(pid), worker); + if (r < 0) + return r; + + worker->manager = manager; + + *ret = TAKE_PTR(worker); + return 0; +} + +static void manager_kill_workers(Manager *manager, bool force) { + Worker *worker; + + assert(manager); + + HASHMAP_FOREACH(worker, manager->workers) { + if (worker->state == WORKER_KILLED) + continue; + + if (worker->state == WORKER_RUNNING && !force) { + worker->state = WORKER_KILLING; + continue; + } + + worker->state = WORKER_KILLED; + (void) kill(worker->pid, SIGTERM); + } +} + +static void manager_exit(Manager *manager) { + assert(manager); + + manager->exit = true; + + sd_notify(false, + "STOPPING=1\n" + "STATUS=Starting shutdown..."); + + /* close sources of new events and discard buffered events */ + manager->ctrl = udev_ctrl_unref(manager->ctrl); + + manager->inotify_event = sd_event_source_disable_unref(manager->inotify_event); + manager->inotify_fd = safe_close(manager->inotify_fd); + + manager->monitor = sd_device_monitor_unref(manager->monitor); + + /* discard queued events and kill workers */ + event_queue_cleanup(manager, EVENT_QUEUED); + manager_kill_workers(manager, true); +} + +static void notify_ready(void) { + int r; + + r = sd_notifyf(false, + "READY=1\n" + "STATUS=Processing with %u children at max", arg_children_max); + if (r < 0) + log_warning_errno(r, "Failed to send readiness notification, ignoring: %m"); +} + +/* reload requested, HUP signal received, rules changed, builtin changed */ +static void manager_reload(Manager *manager, bool force) { + _cleanup_(udev_rules_freep) UdevRules *rules = NULL; + usec_t now_usec; + int r; + + assert(manager); + + assert_se(sd_event_now(manager->event, CLOCK_MONOTONIC, &now_usec) >= 0); + if (!force && now_usec < usec_add(manager->last_usec, 3 * USEC_PER_SEC)) + /* check for changed config, every 3 seconds at most */ + return; + manager->last_usec = now_usec; + + /* Reload SELinux label database, to make the child inherit the up-to-date database. */ + mac_selinux_maybe_reload(); + + /* Nothing changed. It is not necessary to reload. */ + if (!udev_rules_should_reload(manager->rules) && !udev_builtin_should_reload()) + return; + + sd_notify(false, + "RELOADING=1\n" + "STATUS=Flushing configuration..."); + + manager_kill_workers(manager, false); + + udev_builtin_exit(); + udev_builtin_init(); + + r = udev_rules_load(&rules, arg_resolve_name_timing); + if (r < 0) + log_warning_errno(r, "Failed to read udev rules, using the previously loaded rules, ignoring: %m"); + else + udev_rules_free_and_replace(manager->rules, rules); + + notify_ready(); +} + +static int on_kill_workers_event(sd_event_source *s, uint64_t usec, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + + log_debug("Cleanup idle workers"); + manager_kill_workers(manager, false); + + return 1; +} + +static void device_broadcast(sd_device_monitor *monitor, sd_device *dev, EventResult result) { + int r; + + assert(dev); + + /* On exit, manager->monitor is already NULL. */ + if (!monitor) + return; + + if (result != EVENT_RESULT_SUCCESS) { + (void) device_add_property(dev, "UDEV_WORKER_FAILED", "1"); + + switch (result) { + case EVENT_RESULT_NERRNO_MIN ... EVENT_RESULT_NERRNO_MAX: { + const char *str; + + (void) device_add_propertyf(dev, "UDEV_WORKER_ERRNO", "%i", -result); + + str = errno_to_name(result); + if (str) + (void) device_add_property(dev, "UDEV_WORKER_ERRNO_NAME", str); + break; + } + case EVENT_RESULT_EXIT_STATUS_BASE ... EVENT_RESULT_EXIT_STATUS_MAX: + (void) device_add_propertyf(dev, "UDEV_WORKER_EXIT_STATUS", "%i", result - EVENT_RESULT_EXIT_STATUS_BASE); + break; + + case EVENT_RESULT_TRY_AGAIN: + assert_not_reached(); + break; + + case EVENT_RESULT_SIGNAL_BASE ... EVENT_RESULT_SIGNAL_MAX: { + const char *str; + + (void) device_add_propertyf(dev, "UDEV_WORKER_SIGNAL", "%i", result - EVENT_RESULT_SIGNAL_BASE); + + str = signal_to_string(result - EVENT_RESULT_SIGNAL_BASE); + if (str) + (void) device_add_property(dev, "UDEV_WORKER_SIGNAL_NAME", str); + break; + } + default: + log_device_warning(dev, "Unknown event result \"%i\", ignoring.", result); + } + } + + r = device_monitor_send_device(monitor, NULL, dev); + if (r < 0) + log_device_warning_errno(dev, r, + "Failed to broadcast event to libudev listeners, ignoring: %m"); +} + +static int worker_send_result(Manager *manager, EventResult result) { + assert(manager); + assert(manager->worker_watch[WRITE_END] >= 0); + + return loop_write(manager->worker_watch[WRITE_END], &result, sizeof(result), false); +} + +static int device_get_whole_disk(sd_device *dev, sd_device **ret_device, const char **ret_devname) { + const char *val; + int r; + + assert(dev); + + if (device_for_action(dev, SD_DEVICE_REMOVE)) + goto irrelevant; + + r = sd_device_get_sysname(dev, &val); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to get sysname: %m"); + + /* Exclude the following devices: + * For "dm-", see the comment added by e918a1b5a94f270186dca59156354acd2a596494. + * For "md", see the commit message of 2e5b17d01347d3c3118be2b8ad63d20415dbb1f0, + * but not sure the assumption is still valid even when partitions are created on the md + * devices, surprisingly which seems to be possible, see PR #22973. + * For "drbd", see the commit message of fee854ee8ccde0cd28e0f925dea18cce35f3993d. */ + if (STARTSWITH_SET(val, "dm-", "md", "drbd")) + goto irrelevant; + + r = block_device_get_whole_disk(dev, &dev); + if (IN_SET(r, + -ENOTBLK, /* The device is not a block device. */ + -ENODEV /* The whole disk device was not found, it may already be removed. */)) + goto irrelevant; + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to get whole disk device: %m"); + + r = sd_device_get_devname(dev, &val); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to get devname: %m"); + + if (ret_device) + *ret_device = dev; + if (ret_devname) + *ret_devname = val; + return 1; + +irrelevant: + if (ret_device) + *ret_device = NULL; + if (ret_devname) + *ret_devname = NULL; + return 0; +} + +static int worker_lock_whole_disk(sd_device *dev, int *ret_fd) { + _cleanup_close_ int fd = -1; + sd_device *dev_whole_disk; + const char *val; + int r; + + assert(dev); + assert(ret_fd); + + /* Take a shared lock on the device node; this establishes a concept of device "ownership" to + * serialize device access. External processes holding an exclusive lock will cause udev to skip the + * event handling; in the case udev acquired the lock, the external process can block until udev has + * finished its event handling. */ + + r = device_get_whole_disk(dev, &dev_whole_disk, &val); + if (r < 0) + return r; + if (r == 0) + goto nolock; + + fd = sd_device_open(dev_whole_disk, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); + if (fd < 0) { + bool ignore = ERRNO_IS_DEVICE_ABSENT(fd); + + log_device_debug_errno(dev, fd, "Failed to open '%s'%s: %m", val, ignore ? ", ignoring" : ""); + if (!ignore) + return fd; + + goto nolock; + } + + if (flock(fd, LOCK_SH|LOCK_NB) < 0) + return log_device_debug_errno(dev, errno, "Failed to flock(%s): %m", val); + + *ret_fd = TAKE_FD(fd); + return 1; + +nolock: + *ret_fd = -1; + return 0; +} + +static int worker_mark_block_device_read_only(sd_device *dev) { + _cleanup_close_ int fd = -1; + const char *val; + int state = 1, r; + + assert(dev); + + if (!arg_blockdev_read_only) + return 0; + + /* Do this only once, when the block device is new. If the device is later retriggered let's not + * toggle the bit again, so that people can boot up with full read-only mode and then unset the bit + * for specific devices only. */ + if (!device_for_action(dev, SD_DEVICE_ADD)) + return 0; + + r = sd_device_get_subsystem(dev, &val); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to get subsystem: %m"); + + if (!streq(val, "block")) + return 0; + + r = sd_device_get_sysname(dev, &val); + if (r < 0) + return log_device_debug_errno(dev, r, "Failed to get sysname: %m"); + + /* Exclude synthetic devices for now, this is supposed to be a safety feature to avoid modification + * of physical devices, and what sits on top of those doesn't really matter if we don't allow the + * underlying block devices to receive changes. */ + if (STARTSWITH_SET(val, "dm-", "md", "drbd", "loop", "nbd", "zram")) + return 0; + + fd = sd_device_open(dev, O_RDONLY|O_CLOEXEC|O_NONBLOCK|O_NOCTTY); + if (fd < 0) + return log_device_debug_errno(dev, fd, "Failed to open '%s', ignoring: %m", val); + + if (ioctl(fd, BLKROSET, &state) < 0) + return log_device_warning_errno(dev, errno, "Failed to mark block device '%s' read-only: %m", val); + + log_device_info(dev, "Successfully marked block device '%s' read-only.", val); + return 0; +} + +static int worker_process_device(Manager *manager, sd_device *dev) { + _cleanup_(udev_event_freep) UdevEvent *udev_event = NULL; + _cleanup_close_ int fd_lock = -1; + int r; + + assert(manager); + assert(dev); + + log_device_uevent(dev, "Processing device"); + + udev_event = udev_event_new(dev, arg_exec_delay_usec, manager->rtnl, manager->log_level); + if (!udev_event) + return -ENOMEM; + + /* If this is a block device and the device is locked currently via the BSD advisory locks, + * someone else is using it exclusively. We don't run our udev rules now to not interfere. + * Instead of processing the event, we requeue the event and will try again after a delay. + * + * The user-facing side of this: https://systemd.io/BLOCK_DEVICE_LOCKING */ + r = worker_lock_whole_disk(dev, &fd_lock); + if (r == -EAGAIN) + return EVENT_RESULT_TRY_AGAIN; + if (r < 0) + return r; + + (void) worker_mark_block_device_read_only(dev); + + /* apply rules, create node, symlinks */ + r = udev_event_execute_rules( + udev_event, + manager->inotify_fd, + arg_event_timeout_usec, + arg_timeout_signal, + manager->properties, + manager->rules); + if (r < 0) + return r; + + udev_event_execute_run(udev_event, arg_event_timeout_usec, arg_timeout_signal); + + if (!manager->rtnl) + /* in case rtnl was initialized */ + manager->rtnl = sd_netlink_ref(udev_event->rtnl); + + udev_event_process_inotify_watch(udev_event, manager->inotify_fd); + + log_device_uevent(dev, "Device processed"); + return 0; +} + +static int worker_device_monitor_handler(sd_device_monitor *monitor, sd_device *dev, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + int r; + + assert(dev); + + r = worker_process_device(manager, dev); + if (r == EVENT_RESULT_TRY_AGAIN) + /* if we couldn't acquire the flock(), then requeue the event */ + log_device_debug(dev, "Block device is currently locked, requeueing the event."); + else { + if (r < 0) + log_device_warning_errno(dev, r, "Failed to process device, ignoring: %m"); + + /* send processed event back to libudev listeners */ + device_broadcast(monitor, dev, r); + } + + /* send udevd the result of the event execution */ + r = worker_send_result(manager, r); + if (r < 0) + log_device_warning_errno(dev, r, "Failed to send signal to main daemon, ignoring: %m"); + + /* Reset the log level, as it might be changed by "OPTIONS=log_level=". */ + log_set_max_level(manager->log_level); + + return 1; +} + +static int worker_main(Manager *_manager, sd_device_monitor *monitor, sd_device *first_device) { + _cleanup_(sd_device_unrefp) sd_device *dev = first_device; + _cleanup_(manager_freep) Manager *manager = _manager; + int r; + + assert(manager); + assert(monitor); + assert(dev); + + assert_se(unsetenv("NOTIFY_SOCKET") == 0); + + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, -1) >= 0); + + /* Reset OOM score, we only protect the main daemon. */ + r = set_oom_score_adjust(0); + if (r < 0) + log_debug_errno(r, "Failed to reset OOM score, ignoring: %m"); + + /* Clear unnecessary data in Manager object. */ + manager_clear_for_worker(manager); + + r = sd_event_new(&manager->event); + if (r < 0) + return log_error_errno(r, "Failed to allocate event loop: %m"); + + r = sd_event_add_signal(manager->event, NULL, SIGTERM, NULL, NULL); + if (r < 0) + return log_error_errno(r, "Failed to set SIGTERM event: %m"); + + r = sd_device_monitor_attach_event(monitor, manager->event); + if (r < 0) + return log_error_errno(r, "Failed to attach event loop to device monitor: %m"); + + r = sd_device_monitor_start(monitor, worker_device_monitor_handler, manager); + if (r < 0) + return log_error_errno(r, "Failed to start device monitor: %m"); + + /* Process first device */ + (void) worker_device_monitor_handler(monitor, dev, manager); + + r = sd_event_loop(manager->event); + if (r < 0) + return log_error_errno(r, "Event loop failed: %m"); + + return 0; +} + +static int on_event_timeout(sd_event_source *s, uint64_t usec, void *userdata) { + Event *event = ASSERT_PTR(userdata); + + assert(event->worker); + + kill_and_sigcont(event->worker->pid, arg_timeout_signal); + event->worker->state = WORKER_KILLED; + + log_device_error(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" killed", event->worker->pid, event->seqnum); + + return 1; +} + +static int on_event_timeout_warning(sd_event_source *s, uint64_t usec, void *userdata) { + Event *event = ASSERT_PTR(userdata); + + assert(event->worker); + + log_device_warning(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" is taking a long time", event->worker->pid, event->seqnum); + + return 1; +} + +static void worker_attach_event(Worker *worker, Event *event) { + sd_event *e; + + assert(worker); + assert(worker->manager); + assert(event); + assert(!event->worker); + assert(!worker->event); + + worker->state = WORKER_RUNNING; + worker->event = event; + event->state = EVENT_RUNNING; + event->worker = worker; + + e = worker->manager->event; + + (void) sd_event_add_time_relative(e, &event->timeout_warning_event, CLOCK_MONOTONIC, + udev_warn_timeout(arg_event_timeout_usec), USEC_PER_SEC, + on_event_timeout_warning, event); + + (void) sd_event_add_time_relative(e, &event->timeout_event, CLOCK_MONOTONIC, + arg_event_timeout_usec, USEC_PER_SEC, + on_event_timeout, event); +} + +static int worker_spawn(Manager *manager, Event *event) { + _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *worker_monitor = NULL; + Worker *worker; + pid_t pid; + int r; + + /* listen for new events */ + r = device_monitor_new_full(&worker_monitor, MONITOR_GROUP_NONE, -1); + if (r < 0) + return r; + + (void) sd_device_monitor_set_description(worker_monitor, "worker"); + + /* allow the main daemon netlink address to send devices to the worker */ + r = device_monitor_allow_unicast_sender(worker_monitor, manager->monitor); + if (r < 0) + return log_error_errno(r, "Worker: Failed to set unicast sender: %m"); + + r = device_monitor_enable_receiving(worker_monitor); + if (r < 0) + return log_error_errno(r, "Worker: Failed to enable receiving of device: %m"); + + r = safe_fork("(udev-worker)", FORK_DEATHSIG, &pid); + if (r < 0) { + event->state = EVENT_QUEUED; + return log_error_errno(r, "Failed to fork() worker: %m"); + } + if (r == 0) { + DEVICE_TRACE_POINT(worker_spawned, event->dev, getpid()); + + /* Worker process */ + r = worker_main(manager, worker_monitor, sd_device_ref(event->dev)); + log_close(); + _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS); + } + + r = worker_new(&worker, manager, worker_monitor, pid); + if (r < 0) + return log_error_errno(r, "Failed to create worker object: %m"); + + worker_attach_event(worker, event); + + log_device_debug(event->dev, "Worker ["PID_FMT"] is forked for processing SEQNUM=%"PRIu64".", pid, event->seqnum); + return 0; +} + +static int event_run(Event *event) { + static bool log_children_max_reached = true; + Manager *manager; + Worker *worker; + int r; + + assert(event); + assert(event->manager); + + log_device_uevent(event->dev, "Device ready for processing"); + + (void) event_source_disable(event->retry_event_source); + + manager = event->manager; + HASHMAP_FOREACH(worker, manager->workers) { + if (worker->state != WORKER_IDLE) + continue; + + r = device_monitor_send_device(manager->monitor, worker->monitor, event->dev); + if (r < 0) { + log_device_error_errno(event->dev, r, "Worker ["PID_FMT"] did not accept message, killing the worker: %m", + worker->pid); + (void) kill(worker->pid, SIGKILL); + worker->state = WORKER_KILLED; + continue; + } + worker_attach_event(worker, event); + return 1; /* event is now processing. */ + } + + if (hashmap_size(manager->workers) >= arg_children_max) { + /* Avoid spamming the debug logs if the limit is already reached and + * many events still need to be processed */ + if (log_children_max_reached && arg_children_max > 1) { + log_debug("Maximum number (%u) of children reached.", hashmap_size(manager->workers)); + log_children_max_reached = false; + } + return 0; /* no free worker */ + } + + /* Re-enable the debug message for the next batch of events */ + log_children_max_reached = true; + + /* start new worker and pass initial device */ + r = worker_spawn(manager, event); + if (r < 0) + return r; + + return 1; /* event is now processing. */ +} + +static int event_is_blocked(Event *event) { + Event *loop_event = NULL; + int r; + + /* lookup event for identical, parent, child device */ + + assert(event); + assert(event->manager); + assert(event->blocker_seqnum <= event->seqnum); + + if (event->retry_again_next_usec > 0) { + usec_t now_usec; + + r = sd_event_now(event->manager->event, CLOCK_BOOTTIME, &now_usec); + if (r < 0) + return r; + + if (event->retry_again_next_usec > now_usec) + return true; + } + + if (event->blocker_seqnum == event->seqnum) + /* we have checked previously and no blocker found */ + return false; + + LIST_FOREACH(event, e, event->manager->events) { + loop_event = e; + + /* we already found a later event, earlier cannot block us, no need to check again */ + if (loop_event->seqnum < event->blocker_seqnum) + continue; + + /* event we checked earlier still exists, no need to check again */ + if (loop_event->seqnum == event->blocker_seqnum) + return true; + + /* found ourself, no later event can block us */ + if (loop_event->seqnum >= event->seqnum) + goto no_blocker; + + /* found event we have not checked */ + break; + } + + assert(loop_event); + assert(loop_event->seqnum > event->blocker_seqnum && + loop_event->seqnum < event->seqnum); + + /* check if queue contains events we depend on */ + LIST_FOREACH(event, e, loop_event) { + loop_event = e; + + /* found ourself, no later event can block us */ + if (loop_event->seqnum >= event->seqnum) + goto no_blocker; + + if (streq_ptr(loop_event->id, event->id)) + break; + + if (devpath_conflict(event->devpath, loop_event->devpath) || + devpath_conflict(event->devpath, loop_event->devpath_old) || + devpath_conflict(event->devpath_old, loop_event->devpath)) + break; + + if (event->devnode && streq_ptr(event->devnode, loop_event->devnode)) + break; + } + + assert(loop_event); + + log_device_debug(event->dev, "SEQNUM=%" PRIu64 " blocked by SEQNUM=%" PRIu64, + event->seqnum, loop_event->seqnum); + + event->blocker_seqnum = loop_event->seqnum; + return true; + +no_blocker: + event->blocker_seqnum = event->seqnum; + return false; +} + +static int event_queue_start(Manager *manager) { + int r; + + assert(manager); + + if (!manager->events || manager->exit || manager->stop_exec_queue) + return 0; + + /* To make the stack directory /run/udev/links cleaned up later. */ + manager->udev_node_needs_cleanup = true; + + r = event_source_disable(manager->kill_workers_event); + if (r < 0) + log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m"); + + manager_reload(manager, /* force = */ false); + + LIST_FOREACH(event, event, manager->events) { + if (event->state != EVENT_QUEUED) + continue; + + /* do not start event if parent or child event is still running or queued */ + r = event_is_blocked(event); + if (r > 0) + continue; + if (r < 0) + log_device_warning_errno(event->dev, r, + "Failed to check dependencies for event (SEQNUM=%"PRIu64", ACTION=%s), " + "assuming there is no blocking event, ignoring: %m", + event->seqnum, + strna(device_action_to_string(event->action))); + + r = event_run(event); + if (r <= 0) /* 0 means there are no idle workers. Let's escape from the loop. */ + return r; + } + + return 0; +} + +static int on_event_retry(sd_event_source *s, uint64_t usec, void *userdata) { + /* This does nothing. The on_post() callback will start the event if there exists an idle worker. */ + return 1; +} + +static int event_requeue(Event *event) { + usec_t now_usec; + int r; + + assert(event); + assert(event->manager); + assert(event->manager->event); + + event->timeout_warning_event = sd_event_source_disable_unref(event->timeout_warning_event); + event->timeout_event = sd_event_source_disable_unref(event->timeout_event); + + /* add a short delay to suppress busy loop */ + r = sd_event_now(event->manager->event, CLOCK_BOOTTIME, &now_usec); + if (r < 0) + return log_device_warning_errno(event->dev, r, + "Failed to get current time, " + "skipping event (SEQNUM=%"PRIu64", ACTION=%s): %m", + event->seqnum, strna(device_action_to_string(event->action))); + + if (event->retry_again_timeout_usec > 0 && event->retry_again_timeout_usec <= now_usec) + return log_device_warning_errno(event->dev, SYNTHETIC_ERRNO(ETIMEDOUT), + "The underlying block device is locked by a process more than %s, " + "skipping event (SEQNUM=%"PRIu64", ACTION=%s).", + FORMAT_TIMESPAN(EVENT_RETRY_TIMEOUT_USEC, USEC_PER_MINUTE), + event->seqnum, strna(device_action_to_string(event->action))); + + event->retry_again_next_usec = usec_add(now_usec, EVENT_RETRY_INTERVAL_USEC); + if (event->retry_again_timeout_usec == 0) + event->retry_again_timeout_usec = usec_add(now_usec, EVENT_RETRY_TIMEOUT_USEC); + + r = event_reset_time_relative(event->manager->event, &event->retry_event_source, + CLOCK_MONOTONIC, EVENT_RETRY_INTERVAL_USEC, 0, + on_event_retry, NULL, + 0, "retry-event", true); + if (r < 0) + return log_device_warning_errno(event->dev, r, "Failed to reset timer event source for retrying event, " + "skipping event (SEQNUM=%"PRIu64", ACTION=%s): %m", + event->seqnum, strna(device_action_to_string(event->action))); + + if (event->worker && event->worker->event == event) + event->worker->event = NULL; + event->worker = NULL; + + event->state = EVENT_QUEUED; + return 0; +} + +static int event_queue_assume_block_device_unlocked(Manager *manager, sd_device *dev) { + const char *devname; + int r; + + /* When a new event for a block device is queued or we get an inotify event, assume that the + * device is not locked anymore. The assumption may not be true, but that should not cause any + * issues, as in that case events will be requeued soon. */ + + r = device_get_whole_disk(dev, NULL, &devname); + if (r <= 0) + return r; + + LIST_FOREACH(event, event, manager->events) { + const char *event_devname; + + if (event->state != EVENT_QUEUED) + continue; + + if (event->retry_again_next_usec == 0) + continue; + + if (device_get_whole_disk(event->dev, NULL, &event_devname) <= 0) + continue; + + if (!streq(devname, event_devname)) + continue; + + event->retry_again_next_usec = 0; + } + + return 0; +} + +static int event_queue_insert(Manager *manager, sd_device *dev) { + const char *devpath, *devpath_old = NULL, *id = NULL, *devnode = NULL; + sd_device_action_t action; + uint64_t seqnum; + Event *event; + int r; + + assert(manager); + assert(dev); + + /* only one process can add events to the queue */ + assert(manager->pid == getpid_cached()); + + /* We only accepts devices received by device monitor. */ + r = sd_device_get_seqnum(dev, &seqnum); + if (r < 0) + return r; + + r = sd_device_get_action(dev, &action); + if (r < 0) + return r; + + r = sd_device_get_devpath(dev, &devpath); + if (r < 0) + return r; + + r = sd_device_get_property_value(dev, "DEVPATH_OLD", &devpath_old); + if (r < 0 && r != -ENOENT) + return r; + + r = device_get_device_id(dev, &id); + if (r < 0 && r != -ENOENT) + return r; + + r = sd_device_get_devname(dev, &devnode); + if (r < 0 && r != -ENOENT) + return r; + + event = new(Event, 1); + if (!event) + return -ENOMEM; + + *event = (Event) { + .manager = manager, + .dev = sd_device_ref(dev), + .seqnum = seqnum, + .action = action, + .id = id, + .devpath = devpath, + .devpath_old = devpath_old, + .devnode = devnode, + .state = EVENT_QUEUED, + }; + + if (!manager->events) { + r = touch("/run/udev/queue"); + if (r < 0) + log_warning_errno(r, "Failed to touch /run/udev/queue, ignoring: %m"); + } + + LIST_APPEND(event, manager->events, event); + + log_device_uevent(dev, "Device is queued"); + + return 0; +} + +static int on_uevent(sd_device_monitor *monitor, sd_device *dev, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + int r; + + DEVICE_TRACE_POINT(kernel_uevent_received, dev); + + device_ensure_usec_initialized(dev, NULL); + + r = event_queue_insert(manager, dev); + if (r < 0) { + log_device_error_errno(dev, r, "Failed to insert device into event queue: %m"); + return 1; + } + + (void) event_queue_assume_block_device_unlocked(manager, dev); + + return 1; +} + +static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + + for (;;) { + EventResult result; + struct iovec iovec = IOVEC_MAKE(&result, sizeof(result)); + CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control; + struct msghdr msghdr = { + .msg_iov = &iovec, + .msg_iovlen = 1, + .msg_control = &control, + .msg_controllen = sizeof(control), + }; + ssize_t size; + struct ucred *ucred; + Worker *worker; + + size = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT); + if (size == -EINTR) + continue; + if (size == -EAGAIN) + /* nothing more to read */ + break; + if (size < 0) + return log_error_errno(size, "Failed to receive message: %m"); + + cmsg_close_all(&msghdr); + + if (size != sizeof(result)) { + log_warning("Ignoring worker message with invalid size %zi bytes", size); + continue; + } + + ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred); + if (!ucred || ucred->pid <= 0) { + log_warning("Ignoring worker message without valid PID"); + continue; + } + + /* lookup worker who sent the signal */ + worker = hashmap_get(manager->workers, PID_TO_PTR(ucred->pid)); + if (!worker) { + log_debug("Worker ["PID_FMT"] returned, but is no longer tracked", ucred->pid); + continue; + } + + if (worker->state == WORKER_KILLING) { + worker->state = WORKER_KILLED; + (void) kill(worker->pid, SIGTERM); + } else if (worker->state != WORKER_KILLED) + worker->state = WORKER_IDLE; + + /* worker returned */ + if (result == EVENT_RESULT_TRY_AGAIN && + event_requeue(worker->event) < 0) + device_broadcast(manager->monitor, worker->event->dev, -ETIMEDOUT); + + /* When event_requeue() succeeds, worker->event is NULL, and event_free() handles NULL gracefully. */ + event_free(worker->event); + } + + return 1; +} + +/* receive the udevd message from userspace */ +static int on_ctrl_msg(UdevCtrl *uctrl, UdevCtrlMessageType type, const UdevCtrlMessageValue *value, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + int r; + + assert(value); + + switch (type) { + case UDEV_CTRL_SET_LOG_LEVEL: + if ((value->intval & LOG_PRIMASK) != value->intval) { + log_debug("Received invalid udev control message (SET_LOG_LEVEL, %i), ignoring.", value->intval); + break; + } + + log_debug("Received udev control message (SET_LOG_LEVEL), setting log_level=%i", value->intval); + + r = log_get_max_level(); + if (r == value->intval) + break; + + log_set_max_level(value->intval); + manager->log_level = value->intval; + manager_kill_workers(manager, false); + break; + case UDEV_CTRL_STOP_EXEC_QUEUE: + log_debug("Received udev control message (STOP_EXEC_QUEUE)"); + manager->stop_exec_queue = true; + break; + case UDEV_CTRL_START_EXEC_QUEUE: + log_debug("Received udev control message (START_EXEC_QUEUE)"); + manager->stop_exec_queue = false; + /* It is not necessary to call event_queue_start() here, as it will be called in on_post() if necessary. */ + break; + case UDEV_CTRL_RELOAD: + log_debug("Received udev control message (RELOAD)"); + manager_reload(manager, /* force = */ true); + break; + case UDEV_CTRL_SET_ENV: { + _unused_ _cleanup_free_ char *old_val = NULL; + _cleanup_free_ char *key = NULL, *val = NULL, *old_key = NULL; + const char *eq; + + eq = strchr(value->buf, '='); + if (!eq) { + log_error("Invalid key format '%s'", value->buf); + return 1; + } + + key = strndup(value->buf, eq - value->buf); + if (!key) { + log_oom(); + return 1; + } + + old_val = hashmap_remove2(manager->properties, key, (void **) &old_key); + + r = hashmap_ensure_allocated(&manager->properties, &string_hash_ops); + if (r < 0) { + log_oom(); + return 1; + } + + eq++; + if (isempty(eq)) { + log_debug("Received udev control message (ENV), unsetting '%s'", key); + + r = hashmap_put(manager->properties, key, NULL); + if (r < 0) { + log_oom(); + return 1; + } + } else { + val = strdup(eq); + if (!val) { + log_oom(); + return 1; + } + + log_debug("Received udev control message (ENV), setting '%s=%s'", key, val); + + r = hashmap_put(manager->properties, key, val); + if (r < 0) { + log_oom(); + return 1; + } + } + + key = val = NULL; + manager_kill_workers(manager, false); + break; + } + case UDEV_CTRL_SET_CHILDREN_MAX: + if (value->intval <= 0) { + log_debug("Received invalid udev control message (SET_MAX_CHILDREN, %i), ignoring.", value->intval); + return 0; + } + + log_debug("Received udev control message (SET_MAX_CHILDREN), setting children_max=%i", value->intval); + arg_children_max = value->intval; + + notify_ready(); + break; + case UDEV_CTRL_PING: + log_debug("Received udev control message (PING)"); + break; + case UDEV_CTRL_EXIT: + log_debug("Received udev control message (EXIT)"); + manager_exit(manager); + break; + default: + log_debug("Received unknown udev control message, ignoring"); + } + + return 1; +} + +static int synthesize_change_one(sd_device *dev, sd_device *target) { + int r; + + if (DEBUG_LOGGING) { + const char *syspath = NULL; + (void) sd_device_get_syspath(target, &syspath); + log_device_debug(dev, "device is closed, synthesising 'change' on %s", strna(syspath)); + } + + r = sd_device_trigger(target, SD_DEVICE_CHANGE); + if (r < 0) + return log_device_debug_errno(target, r, "Failed to trigger 'change' uevent: %m"); + + DEVICE_TRACE_POINT(synthetic_change_event, dev); + + return 0; +} + +static int synthesize_change(sd_device *dev) { + _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; + bool part_table_read; + const char *sysname; + sd_device *d; + int r, k; + + r = sd_device_get_sysname(dev, &sysname); + if (r < 0) + return r; + + if (startswith(sysname, "dm-") || block_device_is_whole_disk(dev) <= 0) + return synthesize_change_one(dev, dev); + + r = blockdev_reread_partition_table(dev); + if (r < 0) + log_device_debug_errno(dev, r, "Failed to re-read partition table, ignoring: %m"); + part_table_read = r >= 0; + + /* search for partitions */ + r = partition_enumerator_new(dev, &e); + if (r < 0) + return r; + + /* We have partitions and re-read the table, the kernel already sent out a "change" + * event for the disk, and "remove/add" for all partitions. */ + if (part_table_read && sd_device_enumerator_get_device_first(e)) + return 0; + + /* We have partitions but re-reading the partition table did not work, synthesize + * "change" for the disk and all partitions. */ + r = synthesize_change_one(dev, dev); + FOREACH_DEVICE(e, d) { + k = synthesize_change_one(dev, d); + if (k < 0 && r >= 0) + r = k; + } + + return r; +} + +static int on_inotify(sd_event_source *s, int fd, uint32_t revents, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + union inotify_event_buffer buffer; + ssize_t l; + int r; + + l = read(fd, &buffer, sizeof(buffer)); + if (l < 0) { + if (ERRNO_IS_TRANSIENT(errno)) + return 0; + + return log_error_errno(errno, "Failed to read inotify fd: %m"); + } + + FOREACH_INOTIFY_EVENT_WARN(e, buffer, l) { + _cleanup_(sd_device_unrefp) sd_device *dev = NULL; + const char *devnode; + + /* Do not handle IN_IGNORED here. Especially, do not try to call udev_watch_end() from the + * main process. Otherwise, the pair of the symlinks may become inconsistent, and several + * garbage may remain. The old symlinks are removed by a worker that processes the + * corresponding 'remove' uevent; + * udev_event_execute_rules() -> event_execute_rules_on_remove() -> udev_watch_end(). */ + + if (!FLAGS_SET(e->mask, IN_CLOSE_WRITE)) + continue; + + r = device_new_from_watch_handle(&dev, e->wd); + if (r < 0) { + /* Device may be removed just after closed. */ + log_debug_errno(r, "Failed to create sd_device object from watch handle, ignoring: %m"); + continue; + } + + r = sd_device_get_devname(dev, &devnode); + if (r < 0) { + /* Also here, device may be already removed. */ + log_device_debug_errno(dev, r, "Failed to get device node, ignoring: %m"); + continue; + } + + log_device_debug(dev, "Received inotify event for %s.", devnode); + + (void) event_queue_assume_block_device_unlocked(manager, dev); + (void) synthesize_change(dev); + } + + return 0; +} + +static int on_sigterm(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + + manager_exit(manager); + + return 1; +} + +static int on_sighup(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + + manager_reload(manager, /* force = */ true); + + return 1; +} + +static int on_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata) { + Worker *worker = ASSERT_PTR(userdata); + Manager *manager = ASSERT_PTR(worker->manager); + sd_device *dev = worker->event ? ASSERT_PTR(worker->event->dev) : NULL; + EventResult result; + + assert(si); + + switch (si->si_code) { + case CLD_EXITED: + if (si->si_status == 0) + log_device_debug(dev, "Worker ["PID_FMT"] exited.", si->si_pid); + else + log_device_warning(dev, "Worker ["PID_FMT"] exited with return code %i.", + si->si_pid, si->si_status); + result = EVENT_RESULT_EXIT_STATUS_BASE + si->si_status; + break; + + case CLD_KILLED: + case CLD_DUMPED: + log_device_warning(dev, "Worker ["PID_FMT"] terminated by signal %i (%s).", + si->si_pid, si->si_status, signal_to_string(si->si_status)); + result = EVENT_RESULT_SIGNAL_BASE + si->si_status; + break; + + default: + assert_not_reached(); + } + + if (result != EVENT_RESULT_SUCCESS && dev) { + /* delete state from disk */ + device_delete_db(dev); + device_tag_index(dev, NULL, false); + + /* Forward kernel event to libudev listeners */ + device_broadcast(manager->monitor, dev, result); + } + + worker_free(worker); + + return 1; +} + +static int on_post(sd_event_source *s, void *userdata) { + Manager *manager = ASSERT_PTR(userdata); + + if (manager->events) { + /* Try to process pending events if idle workers exist. Why is this necessary? + * When a worker finished an event and became idle, even if there was a pending event, + * the corresponding device might have been locked and the processing of the event + * delayed for a while, preventing the worker from processing the event immediately. + * Now, the device may be unlocked. Let's try again! */ + event_queue_start(manager); + return 1; + } + + /* There are no queued events. Let's remove /run/udev/queue and clean up the idle processes. */ + + if (unlink("/run/udev/queue") < 0) { + if (errno != ENOENT) + log_warning_errno(errno, "Failed to unlink /run/udev/queue, ignoring: %m"); + } else + log_debug("No events are queued, removing /run/udev/queue."); + + if (!hashmap_isempty(manager->workers)) { + /* There are idle workers */ + (void) event_reset_time_relative(manager->event, &manager->kill_workers_event, + CLOCK_MONOTONIC, 3 * USEC_PER_SEC, USEC_PER_SEC, + on_kill_workers_event, manager, + 0, "kill-workers-event", false); + return 1; + } + + /* There are no idle workers. */ + + if (manager->udev_node_needs_cleanup) { + (void) udev_node_cleanup(); + manager->udev_node_needs_cleanup = false; + } + + if (manager->exit) + return sd_event_exit(manager->event, 0); + + if (manager->cgroup) + /* cleanup possible left-over processes in our cgroup */ + (void) cg_kill(SYSTEMD_CGROUP_CONTROLLER, manager->cgroup, SIGKILL, CGROUP_IGNORE_SELF, NULL, NULL, NULL); + + return 1; +} + +static int listen_fds(int *ret_ctrl, int *ret_netlink) { + int ctrl_fd = -1, netlink_fd = -1; + int fd, n; + + assert(ret_ctrl); + assert(ret_netlink); + + n = sd_listen_fds(true); + if (n < 0) + return n; + + for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) { + if (sd_is_socket(fd, AF_UNIX, SOCK_SEQPACKET, -1) > 0) { + if (ctrl_fd >= 0) + return -EINVAL; + ctrl_fd = fd; + continue; + } + + if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1) > 0) { + if (netlink_fd >= 0) + return -EINVAL; + netlink_fd = fd; + continue; + } + + return -EINVAL; + } + + *ret_ctrl = ctrl_fd; + *ret_netlink = netlink_fd; + + return 0; +} + +/* + * read the kernel command line, in case we need to get into debug mode + * udev.log_level=<level> syslog priority + * udev.children_max=<number of workers> events are fully serialized if set to 1 + * udev.exec_delay=<number of seconds> delay execution of every executed program + * udev.event_timeout=<number of seconds> seconds to wait before terminating an event + * udev.blockdev_read_only<=bool> mark all block devices read-only when they appear + */ +static int parse_proc_cmdline_item(const char *key, const char *value, void *data) { + int r; + + assert(key); + + if (proc_cmdline_key_streq(key, "udev.log_level") || + proc_cmdline_key_streq(key, "udev.log_priority")) { /* kept for backward compatibility */ + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = log_level_from_string(value); + if (r >= 0) + log_set_max_level(r); + + } else if (proc_cmdline_key_streq(key, "udev.event_timeout")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = parse_sec(value, &arg_event_timeout_usec); + + } else if (proc_cmdline_key_streq(key, "udev.children_max")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = safe_atou(value, &arg_children_max); + + } else if (proc_cmdline_key_streq(key, "udev.exec_delay")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = parse_sec(value, &arg_exec_delay_usec); + + } else if (proc_cmdline_key_streq(key, "udev.timeout_signal")) { + + if (proc_cmdline_value_missing(key, value)) + return 0; + + r = signal_from_string(value); + if (r > 0) + arg_timeout_signal = r; + + } else if (proc_cmdline_key_streq(key, "udev.blockdev_read_only")) { + + if (!value) + arg_blockdev_read_only = true; + else { + r = parse_boolean(value); + if (r < 0) + log_warning_errno(r, "Failed to parse udev.blockdev-read-only argument, ignoring: %s", value); + else + arg_blockdev_read_only = r; + } + + if (arg_blockdev_read_only) + log_notice("All physical block devices will be marked read-only."); + + return 0; + + } else { + if (startswith(key, "udev.")) + log_warning("Unknown udev kernel command line option \"%s\", ignoring.", key); + + return 0; + } + + if (r < 0) + log_warning_errno(r, "Failed to parse \"%s=%s\", ignoring: %m", key, value); + + return 0; +} + +static int help(void) { + _cleanup_free_ char *link = NULL; + int r; + + r = terminal_urlify_man("systemd-udevd.service", "8", &link); + if (r < 0) + return log_oom(); + + printf("%s [OPTIONS...]\n\n" + "Rule-based manager for device events and files.\n\n" + " -h --help Print this message\n" + " -V --version Print version of the program\n" + " -d --daemon Detach and run in the background\n" + " -D --debug Enable debug output\n" + " -c --children-max=INT Set maximum number of workers\n" + " -e --exec-delay=SECONDS Seconds to wait before executing RUN=\n" + " -t --event-timeout=SECONDS Seconds to wait before terminating an event\n" + " -N --resolve-names=early|late|never\n" + " When to resolve users and groups\n" + "\nSee the %s for details.\n", + program_invocation_short_name, + link); + + return 0; +} + +static int parse_argv(int argc, char *argv[]) { + enum { + ARG_TIMEOUT_SIGNAL, + }; + + static const struct option options[] = { + { "daemon", no_argument, NULL, 'd' }, + { "debug", no_argument, NULL, 'D' }, + { "children-max", required_argument, NULL, 'c' }, + { "exec-delay", required_argument, NULL, 'e' }, + { "event-timeout", required_argument, NULL, 't' }, + { "resolve-names", required_argument, NULL, 'N' }, + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, 'V' }, + { "timeout-signal", required_argument, NULL, ARG_TIMEOUT_SIGNAL }, + {} + }; + + int c, r; + + assert(argc >= 0); + assert(argv); + + while ((c = getopt_long(argc, argv, "c:de:Dt:N:hV", options, NULL)) >= 0) { + switch (c) { + + case 'd': + arg_daemonize = true; + break; + case 'c': + r = safe_atou(optarg, &arg_children_max); + if (r < 0) + log_warning_errno(r, "Failed to parse --children-max= value '%s', ignoring: %m", optarg); + break; + case 'e': + r = parse_sec(optarg, &arg_exec_delay_usec); + if (r < 0) + log_warning_errno(r, "Failed to parse --exec-delay= value '%s', ignoring: %m", optarg); + break; + case ARG_TIMEOUT_SIGNAL: + r = signal_from_string(optarg); + if (r <= 0) + log_warning_errno(r, "Failed to parse --timeout-signal= value '%s', ignoring: %m", optarg); + else + arg_timeout_signal = r; + + break; + case 't': + r = parse_sec(optarg, &arg_event_timeout_usec); + if (r < 0) + log_warning_errno(r, "Failed to parse --event-timeout= value '%s', ignoring: %m", optarg); + break; + case 'D': + arg_debug = true; + break; + case 'N': { + ResolveNameTiming t; + + t = resolve_name_timing_from_string(optarg); + if (t < 0) + log_warning("Invalid --resolve-names= value '%s', ignoring.", optarg); + else + arg_resolve_name_timing = t; + break; + } + case 'h': + return help(); + case 'V': + printf("%s\n", GIT_VERSION); + return 0; + case '?': + return -EINVAL; + default: + assert_not_reached(); + + } + } + + return 1; +} + +static int create_subcgroup(char **ret) { + _cleanup_free_ char *cgroup = NULL, *subcgroup = NULL; + int r; + + if (getppid() != 1) + return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Not invoked by PID1."); + + r = sd_booted(); + if (r < 0) + return log_debug_errno(r, "Failed to check if systemd is running: %m"); + if (r == 0) + return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "systemd is not running."); + + /* Get our own cgroup, we regularly kill everything udev has left behind. + * We only do this on systemd systems, and only if we are directly spawned + * by PID1. Otherwise we are not guaranteed to have a dedicated cgroup. */ + + r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup); + if (r < 0) { + if (IN_SET(r, -ENOENT, -ENOMEDIUM)) + return log_debug_errno(r, "Dedicated cgroup not found: %m"); + return log_debug_errno(r, "Failed to get cgroup: %m"); + } + + r = cg_get_xattr_bool(SYSTEMD_CGROUP_CONTROLLER, cgroup, "trusted.delegate"); + if (r == 0 || (r < 0 && ERRNO_IS_XATTR_ABSENT(r))) + return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "The cgroup %s is not delegated to us.", cgroup); + if (r < 0) + return log_debug_errno(r, "Failed to read trusted.delegate attribute: %m"); + + /* We are invoked with our own delegated cgroup tree, let's move us one level down, so that we + * don't collide with the "no processes in inner nodes" rule of cgroups, when the service + * manager invokes the ExecReload= job in the .control/ subcgroup. */ + + subcgroup = path_join(cgroup, "/udev"); + if (!subcgroup) + return log_oom_debug(); + + r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, subcgroup, 0); + if (r < 0) + return log_debug_errno(r, "Failed to create %s subcgroup: %m", subcgroup); + + log_debug("Created %s subcgroup.", subcgroup); + if (ret) + *ret = TAKE_PTR(subcgroup); + return 0; +} + +static int manager_new(Manager **ret, int fd_ctrl, int fd_uevent) { + _cleanup_(manager_freep) Manager *manager = NULL; + _cleanup_free_ char *cgroup = NULL; + int r; + + assert(ret); + + (void) create_subcgroup(&cgroup); + + manager = new(Manager, 1); + if (!manager) + return log_oom(); + + *manager = (Manager) { + .inotify_fd = -1, + .worker_watch = { -1, -1 }, + .cgroup = TAKE_PTR(cgroup), + }; + + r = udev_ctrl_new_from_fd(&manager->ctrl, fd_ctrl); + if (r < 0) + return log_error_errno(r, "Failed to initialize udev control socket: %m"); + + r = udev_ctrl_enable_receiving(manager->ctrl); + if (r < 0) + return log_error_errno(r, "Failed to bind udev control socket: %m"); + + r = device_monitor_new_full(&manager->monitor, MONITOR_GROUP_KERNEL, fd_uevent); + if (r < 0) + return log_error_errno(r, "Failed to initialize device monitor: %m"); + + /* Bump receiver buffer, but only if we are not called via socket activation, as in that + * case systemd sets the receive buffer size for us, and the value in the .socket unit + * should take full effect. */ + if (fd_uevent < 0) { + r = sd_device_monitor_set_receive_buffer_size(manager->monitor, 128 * 1024 * 1024); + if (r < 0) + log_warning_errno(r, "Failed to set receive buffer size for device monitor, ignoring: %m"); + } + + (void) sd_device_monitor_set_description(manager->monitor, "manager"); + + r = device_monitor_enable_receiving(manager->monitor); + if (r < 0) + return log_error_errno(r, "Failed to bind netlink socket: %m"); + + manager->log_level = log_get_max_level(); + + *ret = TAKE_PTR(manager); + + return 0; +} + +static int main_loop(Manager *manager) { + int fd_worker, r; + + manager->pid = getpid_cached(); + + /* unnamed socket from workers to the main daemon */ + r = socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, manager->worker_watch); + if (r < 0) + return log_error_errno(errno, "Failed to create socketpair for communicating with workers: %m"); + + fd_worker = manager->worker_watch[READ_END]; + + r = setsockopt_int(fd_worker, SOL_SOCKET, SO_PASSCRED, true); + if (r < 0) + return log_error_errno(r, "Failed to enable SO_PASSCRED: %m"); + + manager->inotify_fd = inotify_init1(IN_CLOEXEC); + if (manager->inotify_fd < 0) + return log_error_errno(errno, "Failed to create inotify descriptor: %m"); + + udev_watch_restore(manager->inotify_fd); + + /* block and listen to all signals on signalfd */ + assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGHUP, SIGCHLD, -1) >= 0); + + r = sd_event_default(&manager->event); + if (r < 0) + return log_error_errno(r, "Failed to allocate event loop: %m"); + + r = sd_event_add_signal(manager->event, NULL, SIGINT, on_sigterm, manager); + if (r < 0) + return log_error_errno(r, "Failed to create SIGINT event source: %m"); + + r = sd_event_add_signal(manager->event, NULL, SIGTERM, on_sigterm, manager); + if (r < 0) + return log_error_errno(r, "Failed to create SIGTERM event source: %m"); + + r = sd_event_add_signal(manager->event, NULL, SIGHUP, on_sighup, manager); + if (r < 0) + return log_error_errno(r, "Failed to create SIGHUP event source: %m"); + + r = sd_event_set_watchdog(manager->event, true); + if (r < 0) + return log_error_errno(r, "Failed to create watchdog event source: %m"); + + r = udev_ctrl_attach_event(manager->ctrl, manager->event); + if (r < 0) + return log_error_errno(r, "Failed to attach event to udev control: %m"); + + r = udev_ctrl_start(manager->ctrl, on_ctrl_msg, manager); + if (r < 0) + return log_error_errno(r, "Failed to start device monitor: %m"); + + /* This needs to be after the inotify and uevent handling, to make sure + * that the ping is send back after fully processing the pending uevents + * (including the synthetic ones we may create due to inotify events). + */ + r = sd_event_source_set_priority(udev_ctrl_get_event_source(manager->ctrl), SD_EVENT_PRIORITY_IDLE); + if (r < 0) + return log_error_errno(r, "Failed to set IDLE event priority for udev control event source: %m"); + + r = sd_event_add_io(manager->event, &manager->inotify_event, manager->inotify_fd, EPOLLIN, on_inotify, manager); + if (r < 0) + return log_error_errno(r, "Failed to create inotify event source: %m"); + + r = sd_device_monitor_attach_event(manager->monitor, manager->event); + if (r < 0) + return log_error_errno(r, "Failed to attach event to device monitor: %m"); + + r = sd_device_monitor_start(manager->monitor, on_uevent, manager); + if (r < 0) + return log_error_errno(r, "Failed to start device monitor: %m"); + + r = sd_event_add_io(manager->event, NULL, fd_worker, EPOLLIN, on_worker, manager); + if (r < 0) + return log_error_errno(r, "Failed to create worker event source: %m"); + + r = sd_event_add_post(manager->event, NULL, on_post, manager); + if (r < 0) + return log_error_errno(r, "Failed to create post event source: %m"); + + manager->last_usec = now(CLOCK_MONOTONIC); + + udev_builtin_init(); + + r = udev_rules_load(&manager->rules, arg_resolve_name_timing); + if (r < 0) + return log_error_errno(r, "Failed to read udev rules: %m"); + + r = udev_rules_apply_static_dev_perms(manager->rules); + if (r < 0) + log_warning_errno(r, "Failed to apply permissions on static device nodes, ignoring: %m"); + + notify_ready(); + + r = sd_event_loop(manager->event); + if (r < 0) + log_error_errno(r, "Event loop failed: %m"); + + sd_notify(false, + "STOPPING=1\n" + "STATUS=Shutting down..."); + return r; +} + +int run_udevd(int argc, char *argv[]) { + _cleanup_(manager_freep) Manager *manager = NULL; + int fd_ctrl = -1, fd_uevent = -1; + int r; + + log_set_target(LOG_TARGET_AUTO); + log_open(); + udev_parse_config_full(&arg_children_max, &arg_exec_delay_usec, &arg_event_timeout_usec, &arg_resolve_name_timing, &arg_timeout_signal); + log_parse_environment(); + log_open(); /* Done again to update after reading configuration. */ + + r = parse_argv(argc, argv); + if (r <= 0) + return r; + + r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX); + if (r < 0) + log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m"); + + if (arg_debug) { + log_set_target(LOG_TARGET_CONSOLE); + log_set_max_level(LOG_DEBUG); + } + + r = must_be_root(); + if (r < 0) + return r; + + if (arg_children_max == 0) { + unsigned long cpu_limit, mem_limit, cpu_count = 1; + + r = cpus_in_affinity_mask(); + if (r < 0) + log_warning_errno(r, "Failed to determine number of local CPUs, ignoring: %m"); + else + cpu_count = r; + + cpu_limit = cpu_count * 2 + 16; + mem_limit = MAX(physical_memory() / (128UL*1024*1024), 10U); + + arg_children_max = MIN(cpu_limit, mem_limit); + arg_children_max = MIN(WORKER_NUM_MAX, arg_children_max); + + log_debug("Set children_max to %u", arg_children_max); + } + + /* set umask before creating any file/directory */ + umask(022); + + r = mac_selinux_init(); + if (r < 0) + return r; + + /* Make sure we can have plenty fds (for example for pidfds) */ + (void) rlimit_nofile_bump(-1); + + r = RET_NERRNO(mkdir("/run/udev", 0755)); + if (r < 0 && r != -EEXIST) + return log_error_errno(r, "Failed to create /run/udev: %m"); + + r = listen_fds(&fd_ctrl, &fd_uevent); + if (r < 0) + return log_error_errno(r, "Failed to listen on fds: %m"); + + r = manager_new(&manager, fd_ctrl, fd_uevent); + if (r < 0) + return log_error_errno(r, "Failed to create manager: %m"); + + if (arg_daemonize) { + pid_t pid; + + log_info("Starting systemd-udevd version " GIT_VERSION); + + /* connect /dev/null to stdin, stdout, stderr */ + if (log_get_max_level() < LOG_DEBUG) { + r = make_null_stdio(); + if (r < 0) + log_warning_errno(r, "Failed to redirect standard streams to /dev/null: %m"); + } + + pid = fork(); + if (pid < 0) + return log_error_errno(errno, "Failed to fork daemon: %m"); + if (pid > 0) + /* parent */ + return 0; + + /* child */ + (void) setsid(); + } + + return main_loop(manager); +} |