/* * Copyright (C) 2004-2011 Kay Sievers * Copyright (C) 2004 Chris Friesen * Copyright (C) 2009 Canonical Ltd. * Copyright (C) 2009 Scott James Remnant * * 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 . */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "udev.h" #include "sd-daemon.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) { if (debug) { char buf[1024]; struct timespec ts; vsnprintf(buf, sizeof(buf), format, args); clock_gettime(CLOCK_MONOTONIC, &ts); fprintf(stderr, "[%llu.%06u] [%u] %s: %s", (unsigned long long) ts.tv_sec, (unsigned int) ts.tv_nsec/1000, (int) getpid(), fn, buf); } else { vsyslog(priority, 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); 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; bool is_block; int ifindex; }; static struct event *node_to_event(struct udev_list_node *node) { char *event; event = (char *)node; event -= offsetof(struct event, node); return (struct event *)event; } 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; unsigned long long event_start_usec; }; /* passed from worker to main process */ struct worker_message { pid_t pid; int exitcode; }; static struct worker *node_to_worker(struct udev_list_node *node) { char *worker; worker = (char *)node; worker -= offsetof(struct worker, node); return (struct worker *)worker; } 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); info(event->udev, "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; info(worker->udev, "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) { err(udev, "error creating signalfd %m\n"); rc = 2; goto out; } fd_ep = epoll_create1(EPOLL_CLOEXEC); if (fd_ep < 0) { err(udev, "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) { err(udev, "fail to add fds to epoll: %m\n"); rc = 4; goto out; } /* request TERM signal if parent exits */ prctl(PR_SET_PDEATHSIG, SIGTERM); for (;;) { struct udev_event *udev_event; struct worker_message msg; int err; info(udev, "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); info(udev, "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, ARRAY_SIZE(ev), -1); if (fdcount < 0) { if (errno == EINTR) continue; err = -errno; err(udev, "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); udev_log_close(); exit(rc); } case -1: udev_monitor_unref(worker_monitor); event->state = EVENT_QUEUED; free(worker); err(udev, "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_usec(); worker->event = event; event->state = EVENT_RUNNING; udev_list_node_append(&worker->node, &worker_list); children++; info(udev, "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) { err(event->udev, "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_usec(); event->state = EVENT_RUNNING; return; } if (children >= children_max) { if (children_max > 1) info(event->udev, "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 = (strcmp("block", udev_device_get_subsystem(dev)) == 0); event->ifindex = udev_device_get_ifindex(dev); udev_queue_export_device_queued(udev_queue_export, dev); info(event->udev, "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, int retain) { struct udev_list_node *loop; int max; if (children <= retain) return; max = children - retain; udev_list_node_foreach(loop, &worker_list) { struct worker *worker = node_to_worker(loop); if (max-- <= 0) break; 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; } /* 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)) { dbg(udev, "delay seq %llu (%s)\n", event->seqnum, event->devpath); 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) { info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i); udev_set_log_priority(udev, i); worker_kill(udev, 0); } if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) { info(udev, "udevd message (STOP_EXEC_QUEUE) received\n"); stop_exec_queue = true; } if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) { info(udev, "udevd message (START_EXEC_QUEUE) received\n"); stop_exec_queue = false; } if (udev_ctrl_get_reload(ctrl_msg) > 0) { info(udev, "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') { info(udev, "udevd message (ENV) received, unset '%s'\n", key); udev_add_property(udev, key, NULL); } else { info(udev, "udevd message (ENV) received, set '%s=%s'\n", key, val); udev_add_property(udev, key, val); } } else { err(udev, "wrong key format '%s'\n", key); } free(key); } worker_kill(udev, 0); } i = udev_ctrl_get_set_children_max(ctrl_msg); if (i >= 0) { info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i); children_max = i; } if (udev_ctrl_get_ping(ctrl_msg) > 0) info(udev, "udevd message (SYNC) received\n"); if (udev_ctrl_get_exit(ctrl_msg) > 0) { info(udev, "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) { err(udev, "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) { info(udev, "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; info(udev, "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) info(udev, "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; info(udev, "worker [%u] exit\n", pid); if (WIFEXITED(status)) { if (WEXITSTATUS(status) != 0) err(udev, "worker [%u] exit with return code %i\n", pid, WEXITSTATUS(status)); } else if (WIFSIGNALED(status)) { err(udev, "worker [%u] terminated by signal %i (%s)\n", pid, WTERMSIG(status), strsignal(WTERMSIG(status))); } else if (WIFSTOPPED(status)) { err(udev, "worker [%u] stopped\n", pid); } else if (WIFCONTINUED(status)) { err(udev, "worker [%u] continued\n", pid); } else { err(udev, "worker [%u] exit with status 0x%04x\n", pid, status); } if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) { if (worker->event) { err(udev, "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), "/lib/modules/", kernel.release, "/modules.devname", NULL); f = fopen(modules, "r"); 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; if (type == 'c') mode = S_IFCHR; else if (type == 'b') mode = S_IFBLK; else continue; util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL); util_create_path_selinux(udev, filename); udev_selinux_setfscreatecon(udev, filename, mode); info(udev, "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); udev_selinux_resetfscreatecon(udev); } fclose(f); } static int copy_dev_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth) { struct dirent *dent; for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) { struct stat stats; if (dent->d_name[0] == '.') continue; if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0) continue; if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) { udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777); if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) { fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0); fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0); } else { utimensat(dirfd(dir_to), dent->d_name, NULL, 0); } udev_selinux_resetfscreatecon(udev); } else if (S_ISLNK(stats.st_mode)) { char target[UTIL_PATH_SIZE]; ssize_t len; len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target)); if (len <= 0 || len == (ssize_t)sizeof(target)) continue; target[len] = '\0'; udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK); if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST) utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW); udev_selinux_resetfscreatecon(udev); } else if (S_ISDIR(stats.st_mode)) { DIR *dir2_from, *dir2_to; if (maxdepth == 0) continue; udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755); mkdirat(dirfd(dir_to), dent->d_name, 0755); udev_selinux_resetfscreatecon(udev); dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC)); if (dir2_to == NULL) continue; dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC)); if (dir2_from == NULL) { closedir(dir2_to); continue; } copy_dev_dir(udev, dir2_from, dir2_to, maxdepth-1); closedir(dir2_to); closedir(dir2_from); } } return 0; } static void static_dev_create_links(struct udev *udev, DIR *dir) { struct stdlinks { const char *link; const char *target; }; static const struct stdlinks stdlinks[] = { { "core", "/proc/kcore" }, { "fd", "/proc/self/fd" }, { "stdin", "/proc/self/fd/0" }, { "stdout", "/proc/self/fd/1" }, { "stderr", "/proc/self/fd/2" }, }; unsigned int i; for (i = 0; i < ARRAY_SIZE(stdlinks); i++) { struct stat sb; if (stat(stdlinks[i].target, &sb) == 0) { udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK); if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST) utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW); udev_selinux_resetfscreatecon(udev); } } } static void static_dev_create_from_devices(struct udev *udev, DIR *dir) { DIR *dir_from; dir_from = opendir(UDEVLIBEXECDIR "/devices"); if (dir_from == NULL) return; copy_dev_dir(udev, dir_from, dir, 8); closedir(dir_from); } static void static_dev_create(struct udev *udev) { DIR *dir; dir = opendir(udev_get_dev_path(udev)); if (dir == NULL) return; static_dev_create_links(udev, dir); static_dev_create_from_devices(udev, dir); closedir(dir); } static int mem_size_mb(void) { FILE *f; char buf[4096]; long int memsize = -1; f = fopen("/proc/meminfo", "r"); 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]; FILE *f; struct udev_enumerate *udev_enumerate; struct udev_list_entry *list_entry; /* current database */ util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL); if (access(filename, F_OK) >= 0) return 0; /* make sure we do not get here again */ util_create_path(udev, filename); mkdir(filename, 0755); /* old database */ util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL); if (access(filename, F_OK) < 0) return 0; f = fopen("/dev/kmsg", "w"); if (f != NULL) { fprintf(f, "<30>udevd[%u]: converting old udev database\n", getpid()); fclose(f); } 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), udev_get_dev_path(udev), "/.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), udev_get_dev_path(udev), "/.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), udev_get_dev_path(udev), "/.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; info(udev, "ctrl=%i netlink=%i\n", ctrl, netlink); *rctrl = ctrl; *rnetlink = netlink; return 0; } static bool check_rules_timestamp(struct udev *udev) { char **p; unsigned long long *stamp_usec; int i, n; bool changed = false; n = udev_get_rules_path(udev, &p, &stamp_usec); for (i = 0; i < n; i++) { struct stat stats; if (stat(p[i], &stats) < 0) continue; if (stamp_usec[i] == ts_usec(&stats.st_mtim)) continue; /* first check */ if (stamp_usec[i] != 0) { info(udev, "reload - timestamp of '%s' changed\n", p[i]); changed = true; } /* update timestamp */ stamp_usec[i] = ts_usec(&stats.st_mtim); } return changed; } int main(int argc, char *argv[]) { struct udev *udev; FILE *f; 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; char **s; int rc = 1; udev = udev_new(); if (udev == NULL) goto exit; udev_log_init("udevd"); udev_set_log_fn(udev, udev_main_log); info(udev, "version %s\n", VERSION); udev_selinux_init(udev); 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; if (udev_get_log_priority(udev) < LOG_INFO) udev_set_log_priority(udev, LOG_INFO); 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"); err(udev, "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=\n" " --exec-delay=\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; } } /* * read the kernel commandline, in case we need to get into debug mode * udev.log-priority= syslog priority * udev.children-max= events are fully serialized if set to 1 * */ f = fopen("/proc/cmdline", "r"); if (f != NULL) { char cmdline[4096]; if (fgets(cmdline, sizeof(cmdline), f) != NULL) { char *pos; pos = strstr(cmdline, "udev.log-priority="); if (pos != NULL) { pos += strlen("udev.log-priority="); udev_set_log_priority(udev, util_log_priority(pos)); } pos = strstr(cmdline, "udev.children-max="); if (pos != NULL) { pos += strlen("udev.children-max="); children_max = strtoul(pos, NULL, 0); } pos = strstr(cmdline, "udev.exec-delay="); if (pos != NULL) { pos += strlen("udev.exec-delay="); exec_delay = strtoul(pos, NULL, 0); } } fclose(f); } if (getuid() != 0) { fprintf(stderr, "root privileges required\n"); err(udev, "root privileges required\n"); goto exit; } /* set umask before creating any file/directory */ chdir("/"); umask(022); /* /run/udev */ mkdir(udev_get_run_path(udev), 0755); /* create standard links, copy static nodes, create nodes from modules */ static_dev_create(udev); 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"); err(udev, "cannot open /dev/null\n"); } } if (systemd_fds(udev, &fd_ctrl, &fd_netlink) >= 0) { /* get control and netlink socket from from systemd */ udev_ctrl = udev_ctrl_new_from_fd(udev, fd_ctrl); if (udev_ctrl == NULL) { err(udev, "error taking over udev control socket"); rc = 1; goto exit; } monitor = udev_monitor_new_from_netlink_fd(udev, "kernel", fd_netlink); if (monitor == NULL) { err(udev, "error taking over netlink socket\n"); rc = 3; goto exit; } } else { /* open control and netlink socket */ udev_ctrl = udev_ctrl_new(udev); if (udev_ctrl == NULL) { fprintf(stderr, "error initializing udev control socket"); err(udev, "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"); err(udev, "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"); err(udev, "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"); err(udev, "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) { err(udev, "error creating queue file\n"); goto exit; } if (daemonize) { pid_t pid; int fd; pid = fork(); switch (pid) { case 0: break; case -1: err(udev, "fork of daemon failed: %m\n"); rc = 4; goto exit; default: rc = EXIT_SUCCESS; goto exit_daemonize; } setsid(); fd = open("/proc/self/oom_score_adj", O_RDWR); if (fd < 0) { /* Fallback to old interface */ fd = open("/proc/self/oom_adj", O_RDWR); if (fd < 0) { err(udev, "error disabling OOM: %m\n"); } else { /* OOM_DISABLE == -17 */ write(fd, "-17", 3); close(fd); } } else { write(fd, "-1000", 5); close(fd); } } else { sd_notify(1, "READY=1"); } f = fopen("/dev/kmsg", "w"); if (f != NULL) { fprintf(f, "<30>udevd[%u]: starting version " VERSION "\n", getpid()); fclose(f); } 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"); err(udev, "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"); err(udev, "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"); err(udev, "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) { err(udev, "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) { err(udev, "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) { err(udev, "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 = 128 + (memsize / 8); else children_max = 128; } info(udev, "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 unsigned long long 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, 0); /* 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 <= 2) { /* we are idle */ timeout = -1; } else { /* kill idle or hanging workers */ timeout = 3 * 1000; } fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), timeout); if (fdcount < 0) continue; if (fdcount == 0) { struct udev_list_node *loop; /* timeout */ if (udev_exit) { err(udev, "timeout, giving up waiting for workers to finish\n"); break; } /* kill idle workers */ if (udev_list_node_is_empty(&event_list)) { info(udev, "cleanup idle workers\n"); worker_kill(udev, 2); } /* 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_usec() - worker->event_start_usec) > 30 * 1000 * 1000) { err(udev, "worker [%u] timeout, kill it\n", worker->pid, worker->event ? worker->event->devpath : ""); kill(worker->pid, SIGKILL); worker->state = WORKER_KILLED; /* drop reference taken for state 'running' */ worker_unref(worker); if (worker->event) { err(udev, "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_usec() - last_usec) > 3 * 1000 * 1000) { if (check_rules_timestamp(udev)) reload = true; if (udev_builtin_validate(udev)) reload = true; last_usec = now_usec(); } /* reload requested, HUP signal received, rules changed, builtin changed */ if (reload) { worker_kill(udev, 0); rules = udev_rules_unref(rules); udev_builtin_exit(udev); reload = 0; } /* 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_usec()); 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) { 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); udev_selinux_exit(udev); udev_unref(udev); udev_log_close(); return rc; }