diff options
Diffstat (limited to 'src/udev/udevd.c')
-rw-r--r-- | src/udev/udevd.c | 1578 |
1 files changed, 1578 insertions, 0 deletions
diff --git a/src/udev/udevd.c b/src/udev/udevd.c new file mode 100644 index 0000000000..ebd601e262 --- /dev/null +++ b/src/udev/udevd.c @@ -0,0 +1,1578 @@ +/* + * Copyright (C) 2004-2012 Kay Sievers <kay@vrfy.org> + * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca> + * Copyright (C) 2009 Canonical Ltd. + * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com> + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <stddef.h> +#include <signal.h> +#include <unistd.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <stdbool.h> +#include <string.h> +#include <ctype.h> +#include <fcntl.h> +#include <time.h> +#include <getopt.h> +#include <dirent.h> +#include <sys/time.h> +#include <sys/prctl.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <sys/signalfd.h> +#include <sys/epoll.h> +#include <sys/poll.h> +#include <sys/wait.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <sys/inotify.h> +#include <sys/utsname.h> + +#include "udev.h" +#include "sd-daemon.h" +#include "cgroup-util.h" +#include "dev-setup.h" + +static bool debug; + +void udev_main_log(struct udev *udev, int priority, + const char *file, int line, const char *fn, + const char *format, va_list args) +{ + log_metav(priority, file, line, fn, format, args); +} + +static struct udev_rules *rules; +static struct udev_queue_export *udev_queue_export; +static struct udev_ctrl *udev_ctrl; +static struct udev_monitor *monitor; +static int worker_watch[2] = { -1, -1 }; +static int fd_signal = -1; +static int fd_ep = -1; +static int fd_inotify = -1; +static bool stop_exec_queue; +static bool reload; +static int children; +static int children_max; +static int exec_delay; +static sigset_t sigmask_orig; +static UDEV_LIST(event_list); +static UDEV_LIST(worker_list); +char *udev_cgroup; +static bool udev_exit; + +enum event_state { + EVENT_UNDEF, + EVENT_QUEUED, + EVENT_RUNNING, +}; + +struct event { + struct udev_list_node node; + struct udev *udev; + struct udev_device *dev; + enum event_state state; + int exitcode; + unsigned long long int delaying_seqnum; + unsigned long long int seqnum; + const char *devpath; + size_t devpath_len; + const char *devpath_old; + dev_t devnum; + int ifindex; + bool is_block; + bool nodelay; +}; + +static inline struct event *node_to_event(struct udev_list_node *node) +{ + return container_of(node, struct event, node); +} + +static void event_queue_cleanup(struct udev *udev, enum event_state type); + +enum worker_state { + WORKER_UNDEF, + WORKER_RUNNING, + WORKER_IDLE, + WORKER_KILLED, +}; + +struct worker { + struct udev_list_node node; + struct udev *udev; + int refcount; + pid_t pid; + struct udev_monitor *monitor; + enum worker_state state; + struct event *event; + usec_t event_start_usec; +}; + +/* passed from worker to main process */ +struct worker_message { + pid_t pid; + int exitcode; +}; + +static inline struct worker *node_to_worker(struct udev_list_node *node) +{ + return container_of(node, struct worker, node); +} + +static void event_queue_delete(struct event *event, bool export) +{ + udev_list_node_remove(&event->node); + + if (export) { + udev_queue_export_device_finished(udev_queue_export, event->dev); + log_debug("seq %llu done with %i\n", udev_device_get_seqnum(event->dev), event->exitcode); + } + udev_device_unref(event->dev); + free(event); +} + +static struct worker *worker_ref(struct worker *worker) +{ + worker->refcount++; + return worker; +} + +static void worker_cleanup(struct worker *worker) +{ + udev_list_node_remove(&worker->node); + udev_monitor_unref(worker->monitor); + children--; + free(worker); +} + +static void worker_unref(struct worker *worker) +{ + worker->refcount--; + if (worker->refcount > 0) + return; + log_debug("worker [%u] cleaned up\n", worker->pid); + worker_cleanup(worker); +} + +static void worker_list_cleanup(struct udev *udev) +{ + struct udev_list_node *loop, *tmp; + + udev_list_node_foreach_safe(loop, tmp, &worker_list) { + struct worker *worker = node_to_worker(loop); + + worker_cleanup(worker); + } +} + +static void worker_new(struct event *event) +{ + struct udev *udev = event->udev; + struct worker *worker; + struct udev_monitor *worker_monitor; + pid_t pid; + + /* listen for new events */ + worker_monitor = udev_monitor_new_from_netlink(udev, NULL); + if (worker_monitor == NULL) + return; + /* allow the main daemon netlink address to send devices to the worker */ + udev_monitor_allow_unicast_sender(worker_monitor, monitor); + udev_monitor_enable_receiving(worker_monitor); + + worker = calloc(1, sizeof(struct worker)); + if (worker == NULL) { + udev_monitor_unref(worker_monitor); + return; + } + /* worker + event reference */ + worker->refcount = 2; + worker->udev = udev; + + pid = fork(); + switch (pid) { + case 0: { + struct udev_device *dev = NULL; + int fd_monitor; + struct epoll_event ep_signal, ep_monitor; + sigset_t mask; + int rc = EXIT_SUCCESS; + + /* take initial device from queue */ + dev = event->dev; + event->dev = NULL; + + free(worker); + worker_list_cleanup(udev); + event_queue_cleanup(udev, EVENT_UNDEF); + udev_queue_export_unref(udev_queue_export); + udev_monitor_unref(monitor); + udev_ctrl_unref(udev_ctrl); + close(fd_signal); + close(fd_ep); + close(worker_watch[READ_END]); + + sigfillset(&mask); + fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC); + if (fd_signal < 0) { + log_error("error creating signalfd %m\n"); + rc = 2; + goto out; + } + + fd_ep = epoll_create1(EPOLL_CLOEXEC); + if (fd_ep < 0) { + log_error("error creating epoll fd: %m\n"); + rc = 3; + goto out; + } + + memset(&ep_signal, 0, sizeof(struct epoll_event)); + ep_signal.events = EPOLLIN; + ep_signal.data.fd = fd_signal; + + fd_monitor = udev_monitor_get_fd(worker_monitor); + memset(&ep_monitor, 0, sizeof(struct epoll_event)); + ep_monitor.events = EPOLLIN; + ep_monitor.data.fd = fd_monitor; + + if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 || + epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) { + log_error("fail to add fds to epoll: %m\n"); + rc = 4; + goto out; + } + + /* request TERM signal if parent exits */ + prctl(PR_SET_PDEATHSIG, SIGTERM); + + /* reset OOM score, we only protect the main daemon */ + write_one_line_file("/proc/self/oom_score_adj", "0"); + + for (;;) { + struct udev_event *udev_event; + struct worker_message msg; + int err; + + log_debug("seq %llu running\n", udev_device_get_seqnum(dev)); + udev_event = udev_event_new(dev); + if (udev_event == NULL) { + rc = 5; + goto out; + } + + /* needed for SIGCHLD/SIGTERM in spawn() */ + udev_event->fd_signal = fd_signal; + + if (exec_delay > 0) + udev_event->exec_delay = exec_delay; + + /* apply rules, create node, symlinks */ + err = udev_event_execute_rules(udev_event, rules, &sigmask_orig); + + if (err == 0) + udev_event_execute_run(udev_event, &sigmask_orig); + + /* apply/restore inotify watch */ + if (err == 0 && udev_event->inotify_watch) { + udev_watch_begin(udev, dev); + udev_device_update_db(dev); + } + + /* send processed event back to libudev listeners */ + udev_monitor_send_device(worker_monitor, NULL, dev); + + /* send udevd the result of the event execution */ + memset(&msg, 0, sizeof(struct worker_message)); + if (err != 0) + msg.exitcode = err; + msg.pid = getpid(); + send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0); + + log_debug("seq %llu processed with %i\n", udev_device_get_seqnum(dev), err); + + udev_device_unref(dev); + dev = NULL; + + if (udev_event->sigterm) { + udev_event_unref(udev_event); + goto out; + } + + udev_event_unref(udev_event); + + /* wait for more device messages from main udevd, or term signal */ + while (dev == NULL) { + struct epoll_event ev[4]; + int fdcount; + int i; + + fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), -1); + if (fdcount < 0) { + if (errno == EINTR) + continue; + log_error("failed to poll: %m\n"); + goto out; + } + + for (i = 0; i < fdcount; i++) { + if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) { + dev = udev_monitor_receive_device(worker_monitor); + break; + } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) { + struct signalfd_siginfo fdsi; + ssize_t size; + + size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo)); + if (size != sizeof(struct signalfd_siginfo)) + continue; + switch (fdsi.ssi_signo) { + case SIGTERM: + goto out; + } + } + } + } + } +out: + udev_device_unref(dev); + if (fd_signal >= 0) + close(fd_signal); + if (fd_ep >= 0) + close(fd_ep); + close(fd_inotify); + close(worker_watch[WRITE_END]); + udev_rules_unref(rules); + udev_builtin_exit(udev); + udev_monitor_unref(worker_monitor); + udev_unref(udev); + log_close(); + exit(rc); + } + case -1: + udev_monitor_unref(worker_monitor); + event->state = EVENT_QUEUED; + free(worker); + log_error("fork of child failed: %m\n"); + break; + default: + /* close monitor, but keep address around */ + udev_monitor_disconnect(worker_monitor); + worker->monitor = worker_monitor; + worker->pid = pid; + worker->state = WORKER_RUNNING; + worker->event_start_usec = now(CLOCK_MONOTONIC); + worker->event = event; + event->state = EVENT_RUNNING; + udev_list_node_append(&worker->node, &worker_list); + children++; + log_debug("seq %llu forked new worker [%u]\n", udev_device_get_seqnum(event->dev), pid); + break; + } +} + +static void event_run(struct event *event) +{ + struct udev_list_node *loop; + + udev_list_node_foreach(loop, &worker_list) { + struct worker *worker = node_to_worker(loop); + ssize_t count; + + if (worker->state != WORKER_IDLE) + continue; + + count = udev_monitor_send_device(monitor, worker->monitor, event->dev); + if (count < 0) { + log_error("worker [%u] did not accept message %zi (%m), kill it\n", worker->pid, count); + kill(worker->pid, SIGKILL); + worker->state = WORKER_KILLED; + continue; + } + worker_ref(worker); + worker->event = event; + worker->state = WORKER_RUNNING; + worker->event_start_usec = now(CLOCK_MONOTONIC); + event->state = EVENT_RUNNING; + return; + } + + if (children >= children_max) { + if (children_max > 1) + log_debug("maximum number (%i) of children reached\n", children); + return; + } + + /* start new worker and pass initial device */ + worker_new(event); +} + +static int event_queue_insert(struct udev_device *dev) +{ + struct event *event; + + event = calloc(1, sizeof(struct event)); + if (event == NULL) + return -1; + + event->udev = udev_device_get_udev(dev); + event->dev = dev; + event->seqnum = udev_device_get_seqnum(dev); + event->devpath = udev_device_get_devpath(dev); + event->devpath_len = strlen(event->devpath); + event->devpath_old = udev_device_get_devpath_old(dev); + event->devnum = udev_device_get_devnum(dev); + event->is_block = streq("block", udev_device_get_subsystem(dev)); + event->ifindex = udev_device_get_ifindex(dev); + if (streq(udev_device_get_subsystem(dev), "firmware")) + event->nodelay = true; + + udev_queue_export_device_queued(udev_queue_export, dev); + log_debug("seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev), + udev_device_get_action(dev), udev_device_get_subsystem(dev)); + + event->state = EVENT_QUEUED; + udev_list_node_append(&event->node, &event_list); + return 0; +} + +static void worker_kill(struct udev *udev) +{ + struct udev_list_node *loop; + + udev_list_node_foreach(loop, &worker_list) { + struct worker *worker = node_to_worker(loop); + + if (worker->state == WORKER_KILLED) + continue; + + worker->state = WORKER_KILLED; + kill(worker->pid, SIGTERM); + } +} + +/* lookup event for identical, parent, child device */ +static bool is_devpath_busy(struct event *event) +{ + struct udev_list_node *loop; + size_t common; + + /* check if queue contains events we depend on */ + udev_list_node_foreach(loop, &event_list) { + struct event *loop_event = node_to_event(loop); + + /* we already found a later event, earlier can not block us, no need to check again */ + if (loop_event->seqnum < event->delaying_seqnum) + continue; + + /* event we checked earlier still exists, no need to check again */ + if (loop_event->seqnum == event->delaying_seqnum) + return true; + + /* found ourself, no later event can block us */ + if (loop_event->seqnum >= event->seqnum) + break; + + /* check major/minor */ + if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block) + return true; + + /* check network device ifindex */ + if (event->ifindex != 0 && event->ifindex == loop_event->ifindex) + return true; + + /* check our old name */ + if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) { + event->delaying_seqnum = loop_event->seqnum; + return true; + } + + /* compare devpath */ + common = MIN(loop_event->devpath_len, event->devpath_len); + + /* one devpath is contained in the other? */ + if (memcmp(loop_event->devpath, event->devpath, common) != 0) + continue; + + /* identical device event found */ + if (loop_event->devpath_len == event->devpath_len) { + /* devices names might have changed/swapped in the meantime */ + if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block)) + continue; + if (event->ifindex != 0 && event->ifindex != loop_event->ifindex) + continue; + event->delaying_seqnum = loop_event->seqnum; + return true; + } + + /* allow to bypass the dependency tracking */ + if (event->nodelay) + continue; + + /* parent device event found */ + if (event->devpath[common] == '/') { + event->delaying_seqnum = loop_event->seqnum; + return true; + } + + /* child device event found */ + if (loop_event->devpath[common] == '/') { + event->delaying_seqnum = loop_event->seqnum; + return true; + } + + /* no matching device */ + continue; + } + + return false; +} + +static void event_queue_start(struct udev *udev) +{ + struct udev_list_node *loop; + + udev_list_node_foreach(loop, &event_list) { + struct event *event = node_to_event(loop); + + if (event->state != EVENT_QUEUED) + continue; + + /* do not start event if parent or child event is still running */ + if (is_devpath_busy(event)) + continue; + + event_run(event); + } +} + +static void event_queue_cleanup(struct udev *udev, enum event_state match_type) +{ + struct udev_list_node *loop, *tmp; + + udev_list_node_foreach_safe(loop, tmp, &event_list) { + struct event *event = node_to_event(loop); + + if (match_type != EVENT_UNDEF && match_type != event->state) + continue; + + event_queue_delete(event, false); + } +} + +static void worker_returned(int fd_worker) +{ + for (;;) { + struct worker_message msg; + ssize_t size; + struct udev_list_node *loop; + + size = recv(fd_worker, &msg, sizeof(struct worker_message), MSG_DONTWAIT); + if (size != sizeof(struct worker_message)) + break; + + /* lookup worker who sent the signal */ + udev_list_node_foreach(loop, &worker_list) { + struct worker *worker = node_to_worker(loop); + + if (worker->pid != msg.pid) + continue; + + /* worker returned */ + if (worker->event) { + worker->event->exitcode = msg.exitcode; + event_queue_delete(worker->event, true); + worker->event = NULL; + } + if (worker->state != WORKER_KILLED) + worker->state = WORKER_IDLE; + worker_unref(worker); + break; + } + } +} + +/* receive the udevd message from userspace */ +static struct udev_ctrl_connection *handle_ctrl_msg(struct udev_ctrl *uctrl) +{ + struct udev *udev = udev_ctrl_get_udev(uctrl); + struct udev_ctrl_connection *ctrl_conn; + struct udev_ctrl_msg *ctrl_msg = NULL; + const char *str; + int i; + + ctrl_conn = udev_ctrl_get_connection(uctrl); + if (ctrl_conn == NULL) + goto out; + + ctrl_msg = udev_ctrl_receive_msg(ctrl_conn); + if (ctrl_msg == NULL) + goto out; + + i = udev_ctrl_get_set_log_level(ctrl_msg); + if (i >= 0) { + log_debug("udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i); + log_set_max_level(i); + udev_set_log_priority(udev, i); + worker_kill(udev); + } + + if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) { + log_debug("udevd message (STOP_EXEC_QUEUE) received\n"); + stop_exec_queue = true; + } + + if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) { + log_debug("udevd message (START_EXEC_QUEUE) received\n"); + stop_exec_queue = false; + } + + if (udev_ctrl_get_reload(ctrl_msg) > 0) { + log_debug("udevd message (RELOAD) received\n"); + reload = true; + } + + str = udev_ctrl_get_set_env(ctrl_msg); + if (str != NULL) { + char *key; + + key = strdup(str); + if (key != NULL) { + char *val; + + val = strchr(key, '='); + if (val != NULL) { + val[0] = '\0'; + val = &val[1]; + if (val[0] == '\0') { + log_debug("udevd message (ENV) received, unset '%s'\n", key); + udev_add_property(udev, key, NULL); + } else { + log_debug("udevd message (ENV) received, set '%s=%s'\n", key, val); + udev_add_property(udev, key, val); + } + } else { + log_error("wrong key format '%s'\n", key); + } + free(key); + } + worker_kill(udev); + } + + i = udev_ctrl_get_set_children_max(ctrl_msg); + if (i >= 0) { + log_debug("udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i); + children_max = i; + } + + if (udev_ctrl_get_ping(ctrl_msg) > 0) + log_debug("udevd message (SYNC) received\n"); + + if (udev_ctrl_get_exit(ctrl_msg) > 0) { + log_debug("udevd message (EXIT) received\n"); + udev_exit = true; + /* keep reference to block the client until we exit */ + udev_ctrl_connection_ref(ctrl_conn); + } +out: + udev_ctrl_msg_unref(ctrl_msg); + return udev_ctrl_connection_unref(ctrl_conn); +} + +/* read inotify messages */ +static int handle_inotify(struct udev *udev) +{ + int nbytes, pos; + char *buf; + struct inotify_event *ev; + + if ((ioctl(fd_inotify, FIONREAD, &nbytes) < 0) || (nbytes <= 0)) + return 0; + + buf = malloc(nbytes); + if (buf == NULL) { + log_error("error getting buffer for inotify\n"); + return -1; + } + + nbytes = read(fd_inotify, buf, nbytes); + + for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) { + struct udev_device *dev; + + ev = (struct inotify_event *)(buf + pos); + dev = udev_watch_lookup(udev, ev->wd); + if (dev != NULL) { + log_debug("inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev)); + if (ev->mask & IN_CLOSE_WRITE) { + char filename[UTIL_PATH_SIZE]; + int fd; + + log_debug("device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev)); + util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL); + fd = open(filename, O_WRONLY); + if (fd >= 0) { + if (write(fd, "change", 6) < 0) + log_debug("error writing uevent: %m\n"); + close(fd); + } + } + if (ev->mask & IN_IGNORED) + udev_watch_end(udev, dev); + + udev_device_unref(dev); + } + + } + + free(buf); + return 0; +} + +static void handle_signal(struct udev *udev, int signo) +{ + switch (signo) { + case SIGINT: + case SIGTERM: + udev_exit = true; + break; + case SIGCHLD: + for (;;) { + pid_t pid; + int status; + struct udev_list_node *loop, *tmp; + + pid = waitpid(-1, &status, WNOHANG); + if (pid <= 0) + break; + + udev_list_node_foreach_safe(loop, tmp, &worker_list) { + struct worker *worker = node_to_worker(loop); + + if (worker->pid != pid) + continue; + log_debug("worker [%u] exit\n", pid); + + if (WIFEXITED(status)) { + if (WEXITSTATUS(status) != 0) + log_error("worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status)); + } else if (WIFSIGNALED(status)) { + log_error("worker [%u] terminated by signal %i (%s)\n", + pid, WTERMSIG(status), strsignal(WTERMSIG(status))); + } else if (WIFSTOPPED(status)) { + log_error("worker [%u] stopped\n", pid); + } else if (WIFCONTINUED(status)) { + log_error("worker [%u] continued\n", pid); + } else { + log_error("worker [%u] exit with status 0x%04x\n", pid, status); + } + + if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { + if (worker->event) { + log_error("worker [%u] failed while handling '%s'\n", + pid, worker->event->devpath); + worker->event->exitcode = -32; + event_queue_delete(worker->event, true); + /* drop reference taken for state 'running' */ + worker_unref(worker); + } + } + worker_unref(worker); + break; + } + } + break; + case SIGHUP: + reload = true; + break; + } +} + +static void static_dev_create_from_modules(struct udev *udev) +{ + struct utsname kernel; + char modules[UTIL_PATH_SIZE]; + char buf[4096]; + FILE *f; + + uname(&kernel); + util_strscpyl(modules, sizeof(modules), ROOTPREFIX "/lib/modules/", kernel.release, "/modules.devname", NULL); + f = fopen(modules, "re"); + if (f == NULL) + return; + + while (fgets(buf, sizeof(buf), f) != NULL) { + char *s; + const char *modname; + const char *devname; + const char *devno; + int maj, min; + char type; + mode_t mode; + char filename[UTIL_PATH_SIZE]; + + if (buf[0] == '#') + continue; + + modname = buf; + s = strchr(modname, ' '); + if (s == NULL) + continue; + s[0] = '\0'; + + devname = &s[1]; + s = strchr(devname, ' '); + if (s == NULL) + continue; + s[0] = '\0'; + + devno = &s[1]; + s = strchr(devno, ' '); + if (s == NULL) + s = strchr(devno, '\n'); + if (s != NULL) + s[0] = '\0'; + if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3) + continue; + + mode = 0600; + if (type == 'c') + mode |= S_IFCHR; + else if (type == 'b') + mode |= S_IFBLK; + else + continue; + + util_strscpyl(filename, sizeof(filename), "/dev/", devname, NULL); + mkdir_parents_label(filename, 0755); + label_context_set(filename, mode); + log_debug("mknod '%s' %c%u:%u\n", filename, type, maj, min); + if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST) + utimensat(AT_FDCWD, filename, NULL, 0); + label_context_clear(); + } + + fclose(f); +} + +static int mem_size_mb(void) +{ + FILE *f; + char buf[4096]; + long int memsize = -1; + + f = fopen("/proc/meminfo", "re"); + if (f == NULL) + return -1; + + while (fgets(buf, sizeof(buf), f) != NULL) { + long int value; + + if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) { + memsize = value / 1024; + break; + } + } + + fclose(f); + return memsize; +} + +static int convert_db(struct udev *udev) +{ + char filename[UTIL_PATH_SIZE]; + struct udev_enumerate *udev_enumerate; + struct udev_list_entry *list_entry; + + /* current database */ + if (access("/run/udev/data", F_OK) >= 0) + return 0; + + /* make sure we do not get here again */ + mkdir_p("/run/udev/data", 0755); + + /* old database */ + util_strscpyl(filename, sizeof(filename), "/dev/.udev/db", NULL); + if (access(filename, F_OK) < 0) + return 0; + + print_kmsg("converting old udev database\n"); + + udev_enumerate = udev_enumerate_new(udev); + if (udev_enumerate == NULL) + return -1; + udev_enumerate_scan_devices(udev_enumerate); + udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) { + struct udev_device *device; + + device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry)); + if (device == NULL) + continue; + + /* try to find the old database for devices without a current one */ + if (udev_device_read_db(device, NULL) < 0) { + bool have_db; + const char *id; + struct stat stats; + char devpath[UTIL_PATH_SIZE]; + char from[UTIL_PATH_SIZE]; + + have_db = false; + + /* find database in old location */ + id = udev_device_get_id_filename(device); + util_strscpyl(from, sizeof(from), "/dev/.udev/db/", id, NULL); + if (lstat(from, &stats) == 0) { + if (!have_db) { + udev_device_read_db(device, from); + have_db = true; + } + unlink(from); + } + + /* find old database with $subsys:$sysname name */ + util_strscpyl(from, sizeof(from), "/dev/.udev/db/", + udev_device_get_subsystem(device), ":", udev_device_get_sysname(device), NULL); + if (lstat(from, &stats) == 0) { + if (!have_db) { + udev_device_read_db(device, from); + have_db = true; + } + unlink(from); + } + + /* find old database with the encoded devpath name */ + util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath)); + util_strscpyl(from, sizeof(from), "/dev/.udev/db/", devpath, NULL); + if (lstat(from, &stats) == 0) { + if (!have_db) { + udev_device_read_db(device, from); + have_db = true; + } + unlink(from); + } + + /* write out new database */ + if (have_db) + udev_device_update_db(device); + } + udev_device_unref(device); + } + udev_enumerate_unref(udev_enumerate); + return 0; +} + +static int systemd_fds(struct udev *udev, int *rctrl, int *rnetlink) +{ + int ctrl = -1, netlink = -1; + int fd, n; + + n = sd_listen_fds(true); + if (n <= 0) + return -1; + + for (fd = SD_LISTEN_FDS_START; fd < n + SD_LISTEN_FDS_START; fd++) { + if (sd_is_socket(fd, AF_LOCAL, SOCK_SEQPACKET, -1)) { + if (ctrl >= 0) + return -1; + ctrl = fd; + continue; + } + + if (sd_is_socket(fd, AF_NETLINK, SOCK_RAW, -1)) { + if (netlink >= 0) + return -1; + netlink = fd; + continue; + } + + return -1; + } + + if (ctrl < 0 || netlink < 0) + return -1; + + log_debug("ctrl=%i netlink=%i\n", ctrl, netlink); + *rctrl = ctrl; + *rnetlink = netlink; + return 0; +} + +/* + * read the kernel commandline, in case we need to get into debug mode + * udev.log-priority=<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 + */ +static void kernel_cmdline_options(struct udev *udev) +{ + char *line, *w, *state; + size_t l; + + if (read_one_line_file("/proc/cmdline", &line) < 0) + return; + + FOREACH_WORD_QUOTED(w, l, line, state) { + char *s, *opt; + + s = strndup(w, l); + if (!s) + break; + + /* accept the same options for the initrd, prefixed with "rd." */ + if (in_initrd() && startswith(s, "rd.")) + opt = s + 3; + else + opt = s; + + if (startswith(opt, "udev.log-priority=")) { + int prio; + + prio = util_log_priority(opt + 18); + log_set_max_level(prio); + udev_set_log_priority(udev, prio); + } else if (startswith(opt, "udev.children-max=")) { + children_max = strtoul(opt + 18, NULL, 0); + } else if (startswith(opt, "udev.exec-delay=")) { + exec_delay = strtoul(opt + 16, NULL, 0); + } + + free(s); + } + + free(line); +} + +int main(int argc, char *argv[]) +{ + struct udev *udev; + sigset_t mask; + int daemonize = false; + int resolve_names = 1; + 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' }, + { "resolve-names", required_argument, NULL, 'N' }, + { "help", no_argument, NULL, 'h' }, + { "version", no_argument, NULL, 'V' }, + {} + }; + int fd_ctrl = -1; + int fd_netlink = -1; + int fd_worker = -1; + struct epoll_event ep_ctrl, ep_inotify, ep_signal, ep_netlink, ep_worker; + struct udev_ctrl_connection *ctrl_conn = NULL; + int rc = 1; + + udev = udev_new(); + if (udev == NULL) + goto exit; + + log_set_target(LOG_TARGET_AUTO); + log_parse_environment(); + log_open(); + udev_set_log_fn(udev, udev_main_log); + log_debug("version %s\n", VERSION); + label_init("/dev"); + + for (;;) { + int option; + + option = getopt_long(argc, argv, "c:deDtN:hV", options, NULL); + if (option == -1) + break; + + switch (option) { + case 'd': + daemonize = true; + break; + case 'c': + children_max = strtoul(optarg, NULL, 0); + break; + case 'e': + exec_delay = strtoul(optarg, NULL, 0); + break; + case 'D': + debug = true; + log_set_max_level(LOG_DEBUG); + udev_set_log_priority(udev, LOG_DEBUG); + break; + case 'N': + if (strcmp (optarg, "early") == 0) { + resolve_names = 1; + } else if (strcmp (optarg, "late") == 0) { + resolve_names = 0; + } else if (strcmp (optarg, "never") == 0) { + resolve_names = -1; + } else { + fprintf(stderr, "resolve-names must be early, late or never\n"); + log_error("resolve-names must be early, late or never\n"); + goto exit; + } + break; + case 'h': + printf("Usage: udevd OPTIONS\n" + " --daemon\n" + " --debug\n" + " --children-max=<maximum number of workers>\n" + " --exec-delay=<seconds to wait before executing RUN=>\n" + " --resolve-names=early|late|never\n" + " --version\n" + " --help\n" + "\n"); + goto exit; + case 'V': + printf("%s\n", VERSION); + goto exit; + default: + goto exit; + } + } + + kernel_cmdline_options(udev); + + if (getuid() != 0) { + fprintf(stderr, "root privileges required\n"); + log_error("root privileges required\n"); + goto exit; + } + + /* set umask before creating any file/directory */ + chdir("/"); + umask(022); + + mkdir("/run/udev", 0755); + + dev_setup(NULL); + static_dev_create_from_modules(udev); + + /* before opening new files, make sure std{in,out,err} fds are in a sane state */ + if (daemonize) { + int fd; + + fd = open("/dev/null", O_RDWR); + if (fd >= 0) { + if (write(STDOUT_FILENO, 0, 0) < 0) + dup2(fd, STDOUT_FILENO); + if (write(STDERR_FILENO, 0, 0) < 0) + dup2(fd, STDERR_FILENO); + if (fd > STDERR_FILENO) + close(fd); + } else { + fprintf(stderr, "cannot open /dev/null\n"); + log_error("cannot open /dev/null\n"); + } + } + + if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) { + /* get control and netlink socket from systemd */ + udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl); + if (udev_ctrl == NULL) { + log_error("error taking over udev control socket"); + rc = 1; + goto exit; + } + + monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink); + if (monitor == NULL) { + log_error("error taking over netlink socket\n"); + rc = 3; + goto exit; + } + + /* get our own cgroup, we regularly kill everything udev has left behind */ + if (cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, 0, &udev_cgroup) < 0) + udev_cgroup = NULL; + } else { + /* open control and netlink socket */ + udev_ctrl = udev_ctrl_new(udev); + if (udev_ctrl == NULL) { + fprintf(stderr, "error initializing udev control socket"); + log_error("error initializing udev control socket"); + rc = 1; + goto exit; + } + fd_ctrl = udev_ctrl_get_fd(udev_ctrl); + + monitor = udev_monitor_new_from_netlink(udev, "kernel"); + if (monitor == NULL) { + fprintf(stderr, "error initializing netlink socket\n"); + log_error("error initializing netlink socket\n"); + rc = 3; + goto exit; + } + fd_netlink = udev_monitor_get_fd(monitor); + } + + if (udev_monitor_enable_receiving(monitor) < 0) { + fprintf(stderr, "error binding netlink socket\n"); + log_error("error binding netlink socket\n"); + rc = 3; + goto exit; + } + + if (udev_ctrl_enable_receiving(udev_ctrl) < 0) { + fprintf(stderr, "error binding udev control socket\n"); + log_error("error binding udev control socket\n"); + rc = 1; + goto exit; + } + + udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024); + + /* create queue file before signalling 'ready', to make sure we block 'settle' */ + udev_queue_export = udev_queue_export_new(udev); + if (udev_queue_export == NULL) { + log_error("error creating queue file\n"); + goto exit; + } + + if (daemonize) { + pid_t pid; + + pid = fork(); + switch (pid) { + case 0: + break; + case -1: + log_error("fork of daemon failed: %m\n"); + rc = 4; + goto exit; + default: + rc = EXIT_SUCCESS; + goto exit_daemonize; + } + + setsid(); + + write_one_line_file("/proc/self/oom_score_adj", "-1000"); + } else { + sd_notify(1, "READY=1"); + } + + print_kmsg("starting version " VERSION "\n"); + + if (!debug) { + int fd; + + fd = open("/dev/null", O_RDWR); + if (fd >= 0) { + dup2(fd, STDIN_FILENO); + dup2(fd, STDOUT_FILENO); + dup2(fd, STDERR_FILENO); + close(fd); + } + } + + fd_inotify = udev_watch_init(udev); + if (fd_inotify < 0) { + fprintf(stderr, "error initializing inotify\n"); + log_error("error initializing inotify\n"); + rc = 4; + goto exit; + } + udev_watch_restore(udev); + + /* block and listen to all signals on signalfd */ + sigfillset(&mask); + sigprocmask(SIG_SETMASK, &mask, &sigmask_orig); + fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC); + if (fd_signal < 0) { + fprintf(stderr, "error creating signalfd\n"); + log_error("error creating signalfd\n"); + rc = 5; + goto exit; + } + + /* unnamed socket from workers to the main daemon */ + if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) { + fprintf(stderr, "error creating socketpair\n"); + log_error("error creating socketpair\n"); + rc = 6; + goto exit; + } + fd_worker = worker_watch[READ_END]; + + udev_builtin_init(udev); + + rules = udev_rules_new(udev, resolve_names); + if (rules == NULL) { + log_error("error reading rules\n"); + goto exit; + } + + memset(&ep_ctrl, 0, sizeof(struct epoll_event)); + ep_ctrl.events = EPOLLIN; + ep_ctrl.data.fd = fd_ctrl; + + memset(&ep_inotify, 0, sizeof(struct epoll_event)); + ep_inotify.events = EPOLLIN; + ep_inotify.data.fd = fd_inotify; + + memset(&ep_signal, 0, sizeof(struct epoll_event)); + ep_signal.events = EPOLLIN; + ep_signal.data.fd = fd_signal; + + memset(&ep_netlink, 0, sizeof(struct epoll_event)); + ep_netlink.events = EPOLLIN; + ep_netlink.data.fd = fd_netlink; + + memset(&ep_worker, 0, sizeof(struct epoll_event)); + ep_worker.events = EPOLLIN; + ep_worker.data.fd = fd_worker; + + fd_ep = epoll_create1(EPOLL_CLOEXEC); + if (fd_ep < 0) { + log_error("error creating epoll fd: %m\n"); + goto exit; + } + if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_ctrl, &ep_ctrl) < 0 || + epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_inotify, &ep_inotify) < 0 || + epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 || + epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_netlink, &ep_netlink) < 0 || + epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_worker, &ep_worker) < 0) { + log_error("fail to add fds to epoll: %m\n"); + goto exit; + } + + /* if needed, convert old database from earlier udev version */ + convert_db(udev); + + if (children_max <= 0) { + int memsize = mem_size_mb(); + + /* set value depending on the amount of RAM */ + if (memsize > 0) + children_max = 16 + (memsize / 8); + else + children_max = 16; + } + log_debug("set children_max to %u\n", children_max); + + udev_rules_apply_static_dev_perms(rules); + + udev_list_node_init(&event_list); + udev_list_node_init(&worker_list); + + for (;;) { + static usec_t last_usec; + struct epoll_event ev[8]; + int fdcount; + int timeout; + bool is_worker, is_signal, is_inotify, is_netlink, is_ctrl; + int i; + + if (udev_exit) { + /* close sources of new events and discard buffered events */ + if (fd_ctrl >= 0) { + epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_ctrl, NULL); + fd_ctrl = -1; + } + if (monitor != NULL) { + epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_netlink, NULL); + udev_monitor_unref(monitor); + monitor = NULL; + } + if (fd_inotify >= 0) { + epoll_ctl(fd_ep, EPOLL_CTL_DEL, fd_inotify, NULL); + close(fd_inotify); + fd_inotify = -1; + } + + /* discard queued events and kill workers */ + event_queue_cleanup(udev, EVENT_QUEUED); + worker_kill(udev); + + /* exit after all has cleaned up */ + if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list)) + break; + + /* timeout at exit for workers to finish */ + timeout = 30 * 1000; + } else if (udev_list_node_is_empty(&event_list) && !children) { + /* we are idle */ + timeout = -1; + + /* cleanup possible left-over processes in our cgroup */ + if (udev_cgroup) + cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL); + } else { + /* kill idle or hanging workers */ + timeout = 3 * 1000; + } + fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout); + if (fdcount < 0) + continue; + + if (fdcount == 0) { + struct udev_list_node *loop; + + /* timeout */ + if (udev_exit) { + log_error("timeout, giving up waiting for workers to finish\n"); + break; + } + + /* kill idle workers */ + if (udev_list_node_is_empty(&event_list)) { + log_debug("cleanup idle workers\n"); + worker_kill(udev); + } + + /* check for hanging events */ + udev_list_node_foreach(loop, &worker_list) { + struct worker *worker = node_to_worker(loop); + + if (worker->state != WORKER_RUNNING) + continue; + + if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * 1000 * 1000) { + log_error("worker [%u] %s timeout; kill it\n", worker->pid, + worker->event ? worker->event->devpath : "<idle>"); + kill(worker->pid, SIGKILL); + worker->state = WORKER_KILLED; + /* drop reference taken for state 'running' */ + worker_unref(worker); + if (worker->event) { + log_error("seq %llu '%s' killed\n", + udev_device_get_seqnum(worker->event->dev), worker->event->devpath); + worker->event->exitcode = -64; + event_queue_delete(worker->event, true); + worker->event = NULL; + } + } + } + + } + + is_worker = is_signal = is_inotify = is_netlink = is_ctrl = false; + for (i = 0; i < fdcount; i++) { + if (ev[i].data.fd == fd_worker && ev[i].events & EPOLLIN) + is_worker = true; + else if (ev[i].data.fd == fd_netlink && ev[i].events & EPOLLIN) + is_netlink = true; + else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) + is_signal = true; + else if (ev[i].data.fd == fd_inotify && ev[i].events & EPOLLIN) + is_inotify = true; + else if (ev[i].data.fd == fd_ctrl && ev[i].events & EPOLLIN) + is_ctrl = true; + } + + /* check for changed config, every 3 seconds at most */ + if ((now(CLOCK_MONOTONIC) - last_usec) > 3 * 1000 * 1000) { + if (udev_rules_check_timestamp(rules)) + reload = true; + if (udev_builtin_validate(udev)) + reload = true; + + last_usec = now(CLOCK_MONOTONIC); + } + + /* reload requested, HUP signal received, rules changed, builtin changed */ + if (reload) { + worker_kill(udev); + rules = udev_rules_unref(rules); + udev_builtin_exit(udev); + reload = false; + } + + /* event has finished */ + if (is_worker) + worker_returned(fd_worker); + + if (is_netlink) { + struct udev_device *dev; + + dev = udev_monitor_receive_device(monitor); + if (dev != NULL) { + udev_device_set_usec_initialized(dev, now(CLOCK_MONOTONIC)); + if (event_queue_insert(dev) < 0) + udev_device_unref(dev); + } + } + + /* start new events */ + if (!udev_list_node_is_empty(&event_list) && !udev_exit && !stop_exec_queue) { + udev_builtin_init(udev); + if (rules == NULL) + rules = udev_rules_new(udev, resolve_names); + if (rules != NULL) + event_queue_start(udev); + } + + if (is_signal) { + struct signalfd_siginfo fdsi; + ssize_t size; + + size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo)); + if (size == sizeof(struct signalfd_siginfo)) + handle_signal(udev, fdsi.ssi_signo); + } + + /* we are shutting down, the events below are not handled anymore */ + if (udev_exit) + continue; + + /* device node watch */ + if (is_inotify) + handle_inotify(udev); + + /* + * This needs to be after the inotify handling, to make sure, + * that the ping is send back after the possibly generated + * "change" events by the inotify device node watch. + * + * A single time we may receive a client connection which we need to + * keep open to block the client. It will be closed right before we + * exit. + */ + if (is_ctrl) + ctrl_conn = handle_ctrl_msg(udev_ctrl); + } + + rc = EXIT_SUCCESS; +exit: + udev_queue_export_cleanup(udev_queue_export); + udev_ctrl_cleanup(udev_ctrl); +exit_daemonize: + if (fd_ep >= 0) + close(fd_ep); + worker_list_cleanup(udev); + event_queue_cleanup(udev, EVENT_UNDEF); + udev_rules_unref(rules); + udev_builtin_exit(udev); + if (fd_signal >= 0) + close(fd_signal); + if (worker_watch[READ_END] >= 0) + close(worker_watch[READ_END]); + if (worker_watch[WRITE_END] >= 0) + close(worker_watch[WRITE_END]); + udev_monitor_unref(monitor); + udev_queue_export_unref(udev_queue_export); + udev_ctrl_connection_unref(ctrl_conn); + udev_ctrl_unref(udev_ctrl); + label_finish(); + udev_unref(udev); + log_close(); + return rc; +} |