diff options
Diffstat (limited to 'udev/udevd.c')
| -rw-r--r-- | udev/udevd.c | 1304 |
1 files changed, 1304 insertions, 0 deletions
diff --git a/udev/udevd.c b/udev/udevd.c new file mode 100644 index 0000000000..0827a5ceb3 --- /dev/null +++ b/udev/udevd.c @@ -0,0 +1,1304 @@ +/* + * Copyright (C) 2004-2006 Kay Sievers <kay.sievers@vrfy.org> + * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca> + * + * 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 version 2 of the License. + * + * 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, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + * + */ + +#include <stddef.h> +#include <signal.h> +#include <unistd.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <ctype.h> +#include <dirent.h> +#include <fcntl.h> +#include <syslog.h> +#include <time.h> +#include <getopt.h> +#include <sys/select.h> +#include <sys/wait.h> +#include <sys/types.h> +#include <sys/socket.h> +#include <sys/un.h> +#include <sys/stat.h> +#include <sys/ioctl.h> +#include <linux/types.h> +#include <linux/netlink.h> + +#include "udev.h" +#include "udev_rules.h" +#include "udevd.h" +#include "udev_selinux.h" + +static int debug_trace; +static int debug; + +static struct udev_rules rules; +static int udevd_sock = -1; +static int uevent_netlink_sock = -1; +static int inotify_fd = -1; +static pid_t sid; + +static int signal_pipe[2] = {-1, -1}; +static volatile int sigchilds_waiting; +static volatile int udev_exit; +static volatile int reload_config; +static int run_exec_q; +static int stop_exec_q; +static int max_childs; +static int max_childs_running; +static char udev_log[32]; + +static LIST_HEAD(exec_list); +static LIST_HEAD(running_list); + + +#ifdef USE_LOG +void log_message(int priority, const char *format, ...) +{ + va_list args; + + if (priority > udev_log_priority) + return; + + va_start(args, format); + if (debug) { + printf("[%d] ", (int) getpid()); + vprintf(format, args); + } else + vsyslog(priority, format, args); + va_end(args); +} + +#endif + +static void asmlinkage udev_event_sig_handler(int signum) +{ + if (signum == SIGALRM) + exit(1); +} + +static int udev_event_process(struct udevd_uevent_msg *msg) +{ + struct sigaction act; + struct udevice *udev; + int i; + int retval; + + /* set signal handlers */ + memset(&act, 0x00, sizeof(act)); + act.sa_handler = (void (*)(int)) udev_event_sig_handler; + sigemptyset (&act.sa_mask); + act.sa_flags = 0; + sigaction(SIGALRM, &act, NULL); + + /* reset to default */ + act.sa_handler = SIG_DFL; + sigaction(SIGINT, &act, NULL); + sigaction(SIGTERM, &act, NULL); + sigaction(SIGCHLD, &act, NULL); + sigaction(SIGHUP, &act, NULL); + + /* trigger timeout to prevent hanging processes */ + alarm(UDEV_EVENT_TIMEOUT); + + /* reconstruct event environment from message */ + for (i = 0; msg->envp[i]; i++) + putenv(msg->envp[i]); + + udev = udev_device_init(NULL); + if (udev == NULL) + return -1; + strlcpy(udev->action, msg->action, sizeof(udev->action)); + sysfs_device_set_values(udev->dev, msg->devpath, msg->subsystem, msg->driver); + udev->devpath_old = msg->devpath_old; + udev->devt = msg->devt; + + retval = udev_device_event(&rules, udev); + + /* rules may change/disable the timeout */ + if (udev->event_timeout >= 0) + alarm(udev->event_timeout); + + /* run programs collected by RUN-key*/ + if (retval == 0 && !udev->ignore_device && udev_run) + retval = udev_rules_run(udev); + + udev_device_cleanup(udev); + return retval; +} + +enum event_state { + EVENT_QUEUED, + EVENT_FINISHED, + EVENT_FAILED, +}; + +static void export_event_state(struct udevd_uevent_msg *msg, enum event_state state) +{ + char filename[PATH_SIZE]; + char filename_failed[PATH_SIZE]; + size_t start; + + /* location of queue file */ + snprintf(filename, sizeof(filename), "%s/"EVENT_QUEUE_DIR"/%llu", udev_root, msg->seqnum); + + /* location of failed file */ + strlcpy(filename_failed, udev_root, sizeof(filename_failed)); + strlcat(filename_failed, "/", sizeof(filename_failed)); + start = strlcat(filename_failed, EVENT_FAILED_DIR"/", sizeof(filename_failed)); + strlcat(filename_failed, msg->devpath, sizeof(filename_failed)); + path_encode(&filename_failed[start], sizeof(filename_failed) - start); + + switch (state) { + case EVENT_QUEUED: + unlink(filename_failed); + delete_path(filename_failed); + + create_path(filename); + selinux_setfscreatecon(filename, NULL, S_IFLNK); + symlink(msg->devpath, filename); + selinux_resetfscreatecon(); + break; + case EVENT_FINISHED: + if (msg->devpath_old != NULL) { + /* "move" event - rename failed file to current name, do not delete failed */ + char filename_failed_old[PATH_SIZE]; + + strlcpy(filename_failed_old, udev_root, sizeof(filename_failed_old)); + strlcat(filename_failed_old, "/", sizeof(filename_failed_old)); + start = strlcat(filename_failed_old, EVENT_FAILED_DIR"/", sizeof(filename_failed_old)); + strlcat(filename_failed_old, msg->devpath_old, sizeof(filename_failed_old)); + path_encode(&filename_failed_old[start], sizeof(filename) - start); + + if (rename(filename_failed_old, filename_failed) == 0) + info("renamed devpath, moved failed state of '%s' to %s'\n", + msg->devpath_old, msg->devpath); + } else { + unlink(filename_failed); + delete_path(filename_failed); + } + + unlink(filename); + delete_path(filename); + break; + case EVENT_FAILED: + /* move failed event to the failed directory */ + create_path(filename_failed); + rename(filename, filename_failed); + + /* clean up possibly empty queue directory */ + delete_path(filename); + break; + } + + return; +} + +static void msg_queue_delete(struct udevd_uevent_msg *msg) +{ + list_del(&msg->node); + + /* mark as failed, if "add" event returns non-zero */ + if (msg->exitstatus && strcmp(msg->action, "add") == 0) + export_event_state(msg, EVENT_FAILED); + else + export_event_state(msg, EVENT_FINISHED); + + free(msg); +} + +static void udev_event_run(struct udevd_uevent_msg *msg) +{ + pid_t pid; + int retval; + + pid = fork(); + switch (pid) { + case 0: + /* child */ + close(uevent_netlink_sock); + close(udevd_sock); + if (inotify_fd >= 0) + close(inotify_fd); + close(signal_pipe[READ_END]); + close(signal_pipe[WRITE_END]); + logging_close(); + + logging_init("udevd-event"); + setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY); + + retval = udev_event_process(msg); + info("seq %llu finished with %i\n", msg->seqnum, retval); + + logging_close(); + if (retval) + exit(1); + exit(0); + case -1: + err("fork of child failed: %s\n", strerror(errno)); + msg_queue_delete(msg); + break; + default: + /* get SIGCHLD in main loop */ + info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n", + msg->seqnum, pid, msg->action, msg->subsystem, time(NULL) - msg->queue_time); + msg->pid = pid; + } +} + +static void msg_queue_insert(struct udevd_uevent_msg *msg) +{ + char filename[PATH_SIZE]; + int fd; + + msg->queue_time = time(NULL); + + export_event_state(msg, EVENT_QUEUED); + info("seq %llu queued, '%s' '%s'\n", msg->seqnum, msg->action, msg->subsystem); + + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename)); + fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644); + if (fd >= 0) { + char str[32]; + int len; + + len = sprintf(str, "%llu\n", msg->seqnum); + write(fd, str, len); + close(fd); + } + + /* run one event after the other in debug mode */ + if (debug_trace) { + list_add_tail(&msg->node, &running_list); + udev_event_run(msg); + waitpid(msg->pid, NULL, 0); + msg_queue_delete(msg); + return; + } + + /* run all events with a timeout set immediately */ + if (msg->timeout != 0) { + list_add_tail(&msg->node, &running_list); + udev_event_run(msg); + return; + } + + list_add_tail(&msg->node, &exec_list); + run_exec_q = 1; +} + +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 cpu_count(void) +{ + FILE* f; + char buf[4096]; + int count = 0; + + f = fopen("/proc/stat", "r"); + if (f == NULL) + return -1; + + while (fgets(buf, sizeof(buf), f) != NULL) { + if (strncmp(buf, "cpu", 3) == 0 && isdigit(buf[3])) + count++; + } + + fclose(f); + if (count == 0) + return -1; + return count; +} + +static int running_processes(void) +{ + FILE* f; + char buf[4096]; + int running = -1; + + f = fopen("/proc/stat", "r"); + if (f == NULL) + return -1; + + while (fgets(buf, sizeof(buf), f) != NULL) { + int value; + + if (sscanf(buf, "procs_running %u", &value) == 1) { + running = value; + break; + } + } + + fclose(f); + return running; +} + +/* return the number of process es in our session, count only until limit */ +static int running_processes_in_session(pid_t session, int limit) +{ + DIR *dir; + struct dirent *dent; + int running = 0; + + dir = opendir("/proc"); + if (!dir) + return -1; + + /* read process info from /proc */ + for (dent = readdir(dir); dent != NULL; dent = readdir(dir)) { + int f; + char procdir[64]; + char line[256]; + const char *pos; + char state; + pid_t ppid, pgrp, sess; + int len; + + if (!isdigit(dent->d_name[0])) + continue; + + snprintf(procdir, sizeof(procdir), "/proc/%s/stat", dent->d_name); + procdir[sizeof(procdir)-1] = '\0'; + + f = open(procdir, O_RDONLY); + if (f == -1) + continue; + + len = read(f, line, sizeof(line)-1); + close(f); + + if (len <= 0) + continue; + else + line[len] = '\0'; + + /* skip ugly program name */ + pos = strrchr(line, ')') + 2; + if (pos == NULL) + continue; + + if (sscanf(pos, "%c %d %d %d ", &state, &ppid, &pgrp, &sess) != 4) + continue; + + /* count only processes in our session */ + if (sess != session) + continue; + + /* count only running, no sleeping processes */ + if (state != 'R') + continue; + + running++; + if (limit > 0 && running >= limit) + break; + } + closedir(dir); + + return running; +} + +static int compare_devpath(const char *running, const char *waiting) +{ + int i; + + for (i = 0; i < PATH_SIZE; i++) { + /* identical device event found */ + if (running[i] == '\0' && waiting[i] == '\0') + return 1; + + /* parent device event found */ + if (running[i] == '\0' && waiting[i] == '/') + return 2; + + /* child device event found */ + if (running[i] == '/' && waiting[i] == '\0') + return 3; + + /* no matching event */ + if (running[i] != waiting[i]) + break; + } + + return 0; +} + +/* lookup event for identical, parent, child, or physical device */ +static int devpath_busy(struct udevd_uevent_msg *msg, int limit) +{ + struct udevd_uevent_msg *loop_msg; + int childs_count = 0; + + /* check exec-queue which may still contain delayed events we depend on */ + list_for_each_entry(loop_msg, &exec_list, node) { + /* skip ourself and all later events */ + if (loop_msg->seqnum >= msg->seqnum) + break; + + /* check our old name */ + if (msg->devpath_old != NULL) + if (strcmp(loop_msg->devpath , msg->devpath_old) == 0) + return 2; + + /* check identical, parent, or child device event */ + if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) { + dbg("%llu, device event still pending %llu (%s)\n", + msg->seqnum, loop_msg->seqnum, loop_msg->devpath); + return 3; + } + + /* check for our major:minor number */ + if (msg->devt && loop_msg->devt == msg->devt && + strcmp(msg->subsystem, loop_msg->subsystem) == 0) { + dbg("%llu, device event still pending %llu (%d:%d)\n", msg->seqnum, + loop_msg->seqnum, major(loop_msg->devt), minor(loop_msg->devt)); + return 4; + } + + /* check physical device event (special case of parent) */ + if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0) + if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) { + dbg("%llu, physical device event still pending %llu (%s)\n", + msg->seqnum, loop_msg->seqnum, loop_msg->devpath); + return 5; + } + } + + /* check run queue for still running events */ + list_for_each_entry(loop_msg, &running_list, node) { + if (limit && childs_count++ > limit) { + dbg("%llu, maximum number (%i) of childs reached\n", msg->seqnum, childs_count); + return 1; + } + + /* check our old name */ + if (msg->devpath_old != NULL) + if (strcmp(loop_msg->devpath , msg->devpath_old) == 0) + return 2; + + /* check identical, parent, or child device event */ + if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) { + dbg("%llu, device event still running %llu (%s)\n", + msg->seqnum, loop_msg->seqnum, loop_msg->devpath); + return 3; + } + + /* check for our major:minor number */ + if (msg->devt && loop_msg->devt == msg->devt && + strcmp(msg->subsystem, loop_msg->subsystem) == 0) { + dbg("%llu, device event still running %llu (%d:%d)\n", msg->seqnum, + loop_msg->seqnum, major(loop_msg->devt), minor(loop_msg->devt)); + return 4; + } + + /* check physical device event (special case of parent) */ + if (msg->physdevpath && msg->action && strcmp(msg->action, "add") == 0) + if (compare_devpath(loop_msg->devpath, msg->physdevpath) != 0) { + dbg("%llu, physical device event still running %llu (%s)\n", + msg->seqnum, loop_msg->seqnum, loop_msg->devpath); + return 5; + } + } + return 0; +} + +/* serializes events for the identical and parent and child devices */ +static void msg_queue_manager(void) +{ + struct udevd_uevent_msg *loop_msg; + struct udevd_uevent_msg *tmp_msg; + int running; + + if (list_empty(&exec_list)) + return; + + running = running_processes(); + dbg("%d processes runnning on system\n", running); + if (running < 0) + running = max_childs_running; + + list_for_each_entry_safe(loop_msg, tmp_msg, &exec_list, node) { + /* check running processes in our session and possibly throttle */ + if (running >= max_childs_running) { + running = running_processes_in_session(sid, max_childs_running+10); + dbg("at least %d processes running in session\n", running); + if (running >= max_childs_running) { + dbg("delay seq %llu, too many processes already running\n", loop_msg->seqnum); + return; + } + } + + /* serialize and wait for parent or child events */ + if (devpath_busy(loop_msg, max_childs) != 0) { + dbg("delay seq %llu (%s)\n", loop_msg->seqnum, loop_msg->devpath); + continue; + } + + /* move event to run list */ + list_move_tail(&loop_msg->node, &running_list); + udev_event_run(loop_msg); + running++; + dbg("moved seq %llu to running list\n", loop_msg->seqnum); + } +} + +static struct udevd_uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size) +{ + int bufpos; + int i; + struct udevd_uevent_msg *msg; + char *physdevdriver_key = NULL; + int maj = 0; + int min = 0; + + msg = malloc(sizeof(struct udevd_uevent_msg) + buf_size); + if (msg == NULL) + return NULL; + memset(msg, 0x00, sizeof(struct udevd_uevent_msg) + buf_size); + + /* copy environment buffer and reconstruct envp */ + memcpy(msg->envbuf, buf, buf_size); + bufpos = 0; + for (i = 0; (bufpos < buf_size) && (i < UEVENT_NUM_ENVP-2); i++) { + int keylen; + char *key; + + key = &msg->envbuf[bufpos]; + keylen = strlen(key); + msg->envp[i] = key; + bufpos += keylen + 1; + dbg("add '%s' to msg.envp[%i]\n", msg->envp[i], i); + + /* remember some keys for further processing */ + if (strncmp(key, "ACTION=", 7) == 0) + msg->action = &key[7]; + else if (strncmp(key, "DEVPATH=", 8) == 0) + msg->devpath = &key[8]; + else if (strncmp(key, "SUBSYSTEM=", 10) == 0) + msg->subsystem = &key[10]; + else if (strncmp(key, "DRIVER=", 7) == 0) + msg->driver = &key[7]; + else if (strncmp(key, "SEQNUM=", 7) == 0) + msg->seqnum = strtoull(&key[7], NULL, 10); + else if (strncmp(key, "DEVPATH_OLD=", 12) == 0) + msg->devpath_old = &key[12]; + else if (strncmp(key, "PHYSDEVPATH=", 12) == 0) + msg->physdevpath = &key[12]; + else if (strncmp(key, "PHYSDEVDRIVER=", 14) == 0) + physdevdriver_key = key; + else if (strncmp(key, "MAJOR=", 6) == 0) + maj = strtoull(&key[6], NULL, 10); + else if (strncmp(key, "MINOR=", 6) == 0) + min = strtoull(&key[6], NULL, 10); + else if (strncmp(key, "TIMEOUT=", 8) == 0) + msg->timeout = strtoull(&key[8], NULL, 10); + } + msg->devt = makedev(maj, min); + msg->envp[i++] = "UDEVD_EVENT=1"; + + if (msg->driver == NULL && msg->physdevpath == NULL && physdevdriver_key != NULL) { + /* for older kernels DRIVER is empty for a bus device, export PHYSDEVDRIVER as DRIVER */ + msg->envp[i++] = &physdevdriver_key[7]; + msg->driver = &physdevdriver_key[14]; + } + + msg->envp[i] = NULL; + + if (msg->devpath == NULL || msg->action == NULL) { + info("DEVPATH or ACTION missing, ignore message\n"); + free(msg); + return NULL; + } + return msg; +} + +/* receive the udevd message from userspace */ +static void get_ctrl_msg(void) +{ + struct udevd_ctrl_msg ctrl_msg; + ssize_t size; + struct msghdr smsg; + struct cmsghdr *cmsg; + struct iovec iov; + struct ucred *cred; + char cred_msg[CMSG_SPACE(sizeof(struct ucred))]; + int *intval; + char *pos; + + memset(&ctrl_msg, 0x00, sizeof(struct udevd_ctrl_msg)); + iov.iov_base = &ctrl_msg; + iov.iov_len = sizeof(struct udevd_ctrl_msg); + + memset(&smsg, 0x00, sizeof(struct msghdr)); + smsg.msg_iov = &iov; + smsg.msg_iovlen = 1; + smsg.msg_control = cred_msg; + smsg.msg_controllen = sizeof(cred_msg); + + size = recvmsg(udevd_sock, &smsg, 0); + if (size < 0) { + if (errno != EINTR) + err("unable to receive user udevd message: %s\n", strerror(errno)); + return; + } + cmsg = CMSG_FIRSTHDR(&smsg); + cred = (struct ucred *) CMSG_DATA(cmsg); + + if (cmsg == NULL || cmsg->cmsg_type != SCM_CREDENTIALS) { + err("no sender credentials received, message ignored\n"); + return; + } + + if (cred->uid != 0) { + err("sender uid=%i, message ignored\n", cred->uid); + return; + } + + if (strncmp(ctrl_msg.magic, UDEVD_CTRL_MAGIC, sizeof(UDEVD_CTRL_MAGIC)) != 0 ) { + err("message magic '%s' doesn't match, ignore it\n", ctrl_msg.magic); + return; + } + + switch (ctrl_msg.type) { + case UDEVD_CTRL_ENV: + pos = strchr(ctrl_msg.buf, '='); + if (pos == NULL) { + err("wrong key format '%s'\n", ctrl_msg.buf); + break; + } + pos[0] = '\0'; + if (pos[1] == '\0') { + info("udevd message (ENV) received, unset '%s'\n", ctrl_msg.buf); + unsetenv(ctrl_msg.buf); + } else { + info("udevd message (ENV) received, set '%s=%s'\n", ctrl_msg.buf, &pos[1]); + setenv(ctrl_msg.buf, &pos[1], 1); + } + break; + case UDEVD_CTRL_STOP_EXEC_QUEUE: + info("udevd message (STOP_EXEC_QUEUE) received\n"); + stop_exec_q = 1; + break; + case UDEVD_CTRL_START_EXEC_QUEUE: + info("udevd message (START_EXEC_QUEUE) received\n"); + stop_exec_q = 0; + msg_queue_manager(); + break; + case UDEVD_CTRL_SET_LOG_LEVEL: + intval = (int *) ctrl_msg.buf; + info("udevd message (SET_LOG_PRIORITY) received, udev_log_priority=%i\n", *intval); + udev_log_priority = *intval; + sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority); + putenv(udev_log); + break; + case UDEVD_CTRL_SET_MAX_CHILDS: + intval = (int *) ctrl_msg.buf; + info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i\n", *intval); + max_childs = *intval; + break; + case UDEVD_CTRL_SET_MAX_CHILDS_RUNNING: + intval = (int *) ctrl_msg.buf; + info("udevd message (UDEVD_SET_MAX_CHILDS_RUNNING) received, max_childs=%i\n", *intval); + max_childs_running = *intval; + break; + case UDEVD_CTRL_RELOAD_RULES: + info("udevd message (RELOAD_RULES) received\n"); + reload_config = 1; + break; + default: + err("unknown control message type\n"); + } +} + +/* receive the kernel user event message and do some sanity checks */ +static struct udevd_uevent_msg *get_netlink_msg(void) +{ + struct udevd_uevent_msg *msg; + int bufpos; + ssize_t size; + static char buffer[UEVENT_BUFFER_SIZE+512]; + char *pos; + + size = recv(uevent_netlink_sock, &buffer, sizeof(buffer), 0); + if (size < 0) { + if (errno != EINTR) + err("unable to receive kernel netlink message: %s\n", strerror(errno)); + return NULL; + } + + if ((size_t)size > sizeof(buffer)-1) + size = sizeof(buffer)-1; + buffer[size] = '\0'; + dbg("uevent_size=%zi\n", size); + + /* start of event payload */ + bufpos = strlen(buffer)+1; + msg = get_msg_from_envbuf(&buffer[bufpos], size-bufpos); + if (msg == NULL) + return NULL; + + /* validate message */ + pos = strchr(buffer, '@'); + if (pos == NULL) { + err("invalid uevent '%s'\n", buffer); + free(msg); + return NULL; + } + pos[0] = '\0'; + + if (msg->action == NULL) { + info("no ACTION in payload found, skip event '%s'\n", buffer); + free(msg); + return NULL; + } + + if (strcmp(msg->action, buffer) != 0) { + err("ACTION in payload does not match uevent, skip event '%s'\n", buffer); + free(msg); + return NULL; + } + + return msg; +} + +static void asmlinkage sig_handler(int signum) +{ + switch (signum) { + case SIGINT: + case SIGTERM: + udev_exit = 1; + break; + case SIGCHLD: + /* set flag, then write to pipe if needed */ + sigchilds_waiting = 1; + break; + case SIGHUP: + reload_config = 1; + break; + } + + /* write to pipe, which will wakeup select() in our mainloop */ + write(signal_pipe[WRITE_END], "", 1); +} + +static void udev_done(int pid, int exitstatus) +{ + /* find msg associated with pid and delete it */ + struct udevd_uevent_msg *msg; + + list_for_each_entry(msg, &running_list, node) { + if (msg->pid == pid) { + info("seq %llu, pid [%d] exit with %i, %ld seconds old\n", msg->seqnum, msg->pid, + exitstatus, time(NULL) - msg->queue_time); + msg->exitstatus = exitstatus; + msg_queue_delete(msg); + + /* there may be events waiting with the same devpath */ + run_exec_q = 1; + return; + } + } +} + +static void reap_sigchilds(void) +{ + pid_t pid; + int status; + + while (1) { + pid = waitpid(-1, &status, WNOHANG); + if (pid <= 0) + break; + if (WIFEXITED(status)) + status = WEXITSTATUS(status); + else if (WIFSIGNALED(status)) + status = WTERMSIG(status) + 128; + else + status = 0; + udev_done(pid, status); + } +} + +static int init_udevd_socket(void) +{ + struct sockaddr_un saddr; + socklen_t addrlen; + const int feature_on = 1; + int retval; + + memset(&saddr, 0x00, sizeof(saddr)); + saddr.sun_family = AF_LOCAL; + /* use abstract namespace for socket path */ + strcpy(&saddr.sun_path[1], UDEVD_CTRL_SOCK_PATH); + addrlen = offsetof(struct sockaddr_un, sun_path) + 1 + strlen(&saddr.sun_path[1]); + + udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0); + if (udevd_sock == -1) { + err("error getting socket: %s\n", strerror(errno)); + return -1; + } + + /* the bind takes care of ensuring only one copy running */ + retval = bind(udevd_sock, (struct sockaddr *) &saddr, addrlen); + if (retval < 0) { + err("bind failed: %s\n", strerror(errno)); + close(udevd_sock); + udevd_sock = -1; + return -1; + } + + /* enable receiving of the sender credentials */ + setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on)); + + return 0; +} + +static int init_uevent_netlink_sock(void) +{ + struct sockaddr_nl snl; + const int buffersize = 16 * 1024 * 1024; + int retval; + + memset(&snl, 0x00, sizeof(struct sockaddr_nl)); + snl.nl_family = AF_NETLINK; + snl.nl_pid = getpid(); + snl.nl_groups = 1; + + uevent_netlink_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT); + if (uevent_netlink_sock == -1) { + err("error getting socket: %s\n", strerror(errno)); + return -1; + } + + /* set receive buffersize */ + setsockopt(uevent_netlink_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize)); + + retval = bind(uevent_netlink_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl)); + if (retval < 0) { + err("bind failed: %s\n", strerror(errno)); + close(uevent_netlink_sock); + uevent_netlink_sock = -1; + return -1; + } + return 0; +} + +static void export_initial_seqnum(void) +{ + char filename[PATH_SIZE]; + int fd; + char seqnum[32]; + ssize_t len = 0; + + strlcpy(filename, sysfs_path, sizeof(filename)); + strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename)); + fd = open(filename, O_RDONLY); + if (fd >= 0) { + len = read(fd, seqnum, sizeof(seqnum)-1); + close(fd); + } + if (len <= 0) { + strcpy(seqnum, "0\n"); + len = 3; + } + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/" EVENT_SEQNUM, sizeof(filename)); + create_path(filename); + fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644); + if (fd >= 0) { + write(fd, seqnum, len); + close(fd); + } +} + +int main(int argc, char *argv[], char *envp[]) +{ + int retval; + int fd; + struct sigaction act; + fd_set readfds; + const char *value; + int daemonize = 0; + int option; + static const struct option options[] = { + { "daemon", 0, NULL, 'd' }, + { "debug-trace", 0, NULL, 't' }, + { "debug", 0, NULL, 'D' }, + { "help", 0, NULL, 'h' }, + { "version", 0, NULL, 'V' }, + {} + }; + int rc = 1; + int maxfd; + + logging_init("udevd"); + udev_config_init(); + selinux_init(); + dbg("version %s\n", UDEV_VERSION); + + while (1) { + option = getopt_long(argc, argv, "dDthV", options, NULL); + if (option == -1) + break; + + switch (option) { + case 'd': + daemonize = 1; + break; + case 't': + debug_trace = 1; + break; + case 'D': + debug = 1; + if (udev_log_priority < LOG_INFO) + udev_log_priority = LOG_INFO; + break; + case 'h': + printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n"); + goto exit; + case 'V': + printf("%s\n", UDEV_VERSION); + goto exit; + default: + goto exit; + } + } + + if (getuid() != 0) { + fprintf(stderr, "root privileges required\n"); + err("root privileges required\n"); + goto exit; + } + + /* make sure std{in,out,err} fd's are in a sane state */ + fd = open("/dev/null", O_RDWR); + if (fd < 0) { + fprintf(stderr, "cannot open /dev/null\n"); + err("cannot open /dev/null\n"); + } + if (fd > STDIN_FILENO) + dup2(fd, STDIN_FILENO); + if (write(STDOUT_FILENO, 0, 0) < 0) + dup2(fd, STDOUT_FILENO); + if (write(STDERR_FILENO, 0, 0) < 0) + dup2(fd, STDERR_FILENO); + + /* init sockets to receive events */ + if (init_udevd_socket() < 0) { + if (errno == EADDRINUSE) { + fprintf(stderr, "another udev daemon already running\n"); + err("another udev daemon already running\n"); + rc = 1; + } else { + fprintf(stderr, "error initializing udevd socket\n"); + err("error initializing udevd socket\n"); + rc = 2; + } + goto exit; + } + + if (init_uevent_netlink_sock() < 0) { + fprintf(stderr, "error initializing netlink socket\n"); + err("error initializing netlink socket\n"); + rc = 3; + goto exit; + } + + /* setup signal handler pipe */ + retval = pipe(signal_pipe); + if (retval < 0) { + err("error getting pipes: %s\n", strerror(errno)); + goto exit; + } + + retval = fcntl(signal_pipe[READ_END], F_GETFL, 0); + if (retval < 0) { + err("error fcntl on read pipe: %s\n", strerror(errno)); + goto exit; + } + retval = fcntl(signal_pipe[READ_END], F_SETFL, retval | O_NONBLOCK); + if (retval < 0) { + err("error fcntl on read pipe: %s\n", strerror(errno)); + goto exit; + } + + retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0); + if (retval < 0) { + err("error fcntl on write pipe: %s\n", strerror(errno)); + goto exit; + } + retval = fcntl(signal_pipe[WRITE_END], F_SETFL, retval | O_NONBLOCK); + if (retval < 0) { + err("error fcntl on write pipe: %s\n", strerror(errno)); + goto exit; + } + + /* parse the rules and keep them in memory */ + sysfs_init(); + udev_rules_init(&rules, 1); + + export_initial_seqnum(); + + if (daemonize) { + pid_t pid; + + pid = fork(); + switch (pid) { + case 0: + dbg("daemonized fork running\n"); + break; + case -1: + err("fork of daemon failed: %s\n", strerror(errno)); + rc = 4; + goto exit; + default: + dbg("child [%u] running, parent exits\n", pid); + rc = 0; + goto exit; + } + } + + /* redirect std{out,err} fd's */ + if (!debug) + dup2(fd, STDOUT_FILENO); + dup2(fd, STDERR_FILENO); + if (fd > STDERR_FILENO) + close(fd); + + /* set scheduling priority for the daemon */ + setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY); + + chdir("/"); + umask(022); + + /* become session leader */ + sid = setsid(); + dbg("our session is %d\n", sid); + + /* OOM_DISABLE == -17 */ + fd = open("/proc/self/oom_adj", O_RDWR); + if (fd < 0) + err("error disabling OOM: %s\n", strerror(errno)); + else { + write(fd, "-17", 3); + close(fd); + } + + fd = open("/dev/kmsg", O_WRONLY); + if (fd > 0) { + const char *str = "<6>udevd version " UDEV_VERSION " started\n"; + + write(fd, str, strlen(str)); + close(fd); + } + + /* set signal handlers */ + memset(&act, 0x00, sizeof(struct sigaction)); + act.sa_handler = (void (*)(int)) sig_handler; + sigemptyset(&act.sa_mask); + act.sa_flags = SA_RESTART; + sigaction(SIGINT, &act, NULL); + sigaction(SIGTERM, &act, NULL); + sigaction(SIGCHLD, &act, NULL); + sigaction(SIGHUP, &act, NULL); + + /* watch rules directory */ + inotify_fd = inotify_init(); + if (inotify_fd >= 0) { + if (udev_rules_dir[0] != '\0') { + inotify_add_watch(inotify_fd, udev_rules_dir, + IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); + } else { + char filename[PATH_MAX]; + + inotify_add_watch(inotify_fd, RULES_LIB_DIR, + IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); + inotify_add_watch(inotify_fd, RULES_ETC_DIR, + IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); + + /* watch dynamic rules directory */ + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/"RULES_DYN_DIR, sizeof(filename)); + inotify_add_watch(inotify_fd, filename, + IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); + } + } else if (errno == ENOSYS) + err("the kernel does not support inotify, udevd can't monitor rules file changes\n"); + else + err("inotify_init failed: %s\n", strerror(errno)); + + /* maximum limit of forked childs */ + value = getenv("UDEVD_MAX_CHILDS"); + if (value) + max_childs = strtoul(value, NULL, 10); + else { + int memsize = mem_size_mb(); + if (memsize > 0) + max_childs = 128 + (memsize / 4); + else + max_childs = UDEVD_MAX_CHILDS; + } + info("initialize max_childs to %u\n", max_childs); + + /* start to throttle forking if maximum number of _running_ childs is reached */ + value = getenv("UDEVD_MAX_CHILDS_RUNNING"); + if (value) + max_childs_running = strtoull(value, NULL, 10); + else { + int cpus = cpu_count(); + if (cpus > 0) + max_childs_running = 8 + (8 * cpus); + else + max_childs_running = UDEVD_MAX_CHILDS_RUNNING; + } + info("initialize max_childs_running to %u\n", max_childs_running); + + /* clear environment for forked event processes */ + clearenv(); + + /* export log_priority , as called programs may want to follow that setting */ + sprintf(udev_log, "UDEV_LOG=%i", udev_log_priority); + putenv(udev_log); + if (debug_trace) + putenv("DEBUG=1"); + + maxfd = udevd_sock; + maxfd = UDEV_MAX(maxfd, uevent_netlink_sock); + maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]); + maxfd = UDEV_MAX(maxfd, inotify_fd); + + while (!udev_exit) { + struct udevd_uevent_msg *msg; + int fdcount; + + FD_ZERO(&readfds); + FD_SET(signal_pipe[READ_END], &readfds); + FD_SET(udevd_sock, &readfds); + FD_SET(uevent_netlink_sock, &readfds); + if (inotify_fd >= 0) + FD_SET(inotify_fd, &readfds); + + fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL); + if (fdcount < 0) { + if (errno != EINTR) + err("error in select: %s\n", strerror(errno)); + continue; + } + + /* get control message */ + if (FD_ISSET(udevd_sock, &readfds)) + get_ctrl_msg(); + + /* get netlink message */ + if (FD_ISSET(uevent_netlink_sock, &readfds)) { + msg = get_netlink_msg(); + if (msg) + msg_queue_insert(msg); + } + + /* received a signal, clear our notification pipe */ + if (FD_ISSET(signal_pipe[READ_END], &readfds)) { + char buf[256]; + + read(signal_pipe[READ_END], &buf, sizeof(buf)); + } + + /* rules directory inotify watch */ + if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) { + int nbytes; + + /* discard all possible events, we can just reload the config */ + if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) { + char *buf; + + reload_config = 1; + buf = malloc(nbytes); + if (buf == NULL) { + err("error getting buffer for inotify, disable watching\n"); + close(inotify_fd); + inotify_fd = -1; + } + read(inotify_fd, buf, nbytes); + free(buf); + } + } + + /* rules changed, set by inotify or a HUP signal */ + if (reload_config) { + reload_config = 0; + udev_rules_cleanup(&rules); + udev_rules_init(&rules, 1); + } + + /* forked child has returned */ + if (sigchilds_waiting) { + sigchilds_waiting = 0; + reap_sigchilds(); + } + + if (run_exec_q) { + run_exec_q = 0; + if (!stop_exec_q) + msg_queue_manager(); + } + } + rc = 0; + +exit: + udev_rules_cleanup(&rules); + sysfs_cleanup(); + selinux_exit(); + + if (signal_pipe[READ_END] >= 0) + close(signal_pipe[READ_END]); + if (signal_pipe[WRITE_END] >= 0) + close(signal_pipe[WRITE_END]); + + if (udevd_sock >= 0) + close(udevd_sock); + if (inotify_fd >= 0) + close(inotify_fd); + if (uevent_netlink_sock >= 0) + close(uevent_netlink_sock); + + logging_close(); + + return rc; +} |