/* * 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 verbose; 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; if (verbose) { printf("[%d] ", (int) getpid()); va_start(args, format); vprintf(format, args); va_end(args); printf("\n"); } else { va_start(args, format); 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_ALARM_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->devt = msg->devt; retval = udev_device_event(&rules, udev); /* run programs collected by RUN-key*/ if (retval == 0 && !udev->ignore_device && udev_run) { struct name_entry *name_loop; dbg("executing run list"); list_for_each_entry(name_loop, &udev->run_list, node) { if (strncmp(name_loop->name, "socket:", strlen("socket:")) == 0) pass_env_to_socket(&name_loop->name[strlen("socket:")], udev->dev->devpath, udev->action); else { char program[PATH_SIZE]; strlcpy(program, name_loop->name, sizeof(program)); udev_rules_apply_format(udev, program, sizeof(program)); if (run_program(program, udev->dev->subsystem, NULL, 0, NULL) != 0) if (!name_loop->ignore_error) retval = -1; } } } 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; struct udevd_uevent_msg *loop_msg; int fd; /* add location of queue files */ strlcpy(filename, udev_root, sizeof(filename)); strlcat(filename, "/", sizeof(filename)); start = strlcat(filename, EVENT_QUEUE_DIR"/", sizeof(filename)); strlcat(filename, msg->devpath, sizeof(filename)); path_encode(&filename[start], sizeof(filename) - start); /* add location of failed files */ 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) - start); switch (state) { case EVENT_QUEUED: unlink(filename_failed); delete_path(filename_failed); create_path(filename); fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644); if (fd > 0) close(fd); return; case EVENT_FINISHED: case EVENT_FAILED: unlink(filename_failed); delete_path(filename_failed); /* don't remove, if events for the same path are still pending */ list_for_each_entry(loop_msg, &running_list, node) if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0) return; list_for_each_entry(loop_msg, &exec_list, node) if (loop_msg->devpath && strcmp(loop_msg->devpath, msg->devpath) == 0) return; /* move failed events to the failed directory */ if (state == EVENT_FAILED) { create_path(filename_failed); rename(filename, filename_failed); } else { unlink(filename); } /* clean up the queue directory */ delete_path(filename); 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", msg->seqnum, retval); logging_close(); if (retval) exit(1); exit(0); case -1: err("fork of child failed: %s", strerror(errno)); msg_queue_delete(msg); break; default: /* get SIGCHLD in main loop */ info("seq %llu forked, pid [%d], '%s' '%s', %ld seconds old", 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); 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); } export_event_state(msg, EVENT_QUEUED); /* 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 identical, parent, or child device event */ if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) { dbg("%llu, device event still pending %llu (%s)", msg->seqnum, loop_msg->seqnum, loop_msg->devpath); return 2; } /* 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)", msg->seqnum, loop_msg->seqnum, loop_msg->devpath); return 3; } } /* check runing-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", msg->seqnum, childs_count); return 1; } /* check identical, parent, or child device event */ if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) { dbg("%llu, device event still running %llu (%s)", msg->seqnum, loop_msg->seqnum, loop_msg->devpath); return 2; } /* 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)", msg->seqnum, loop_msg->seqnum, loop_msg->devpath); return 3; } } 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", 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", running); if (running >= max_childs_running) { dbg("delay seq %llu, too many processes already running", 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)", 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", 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]", 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, "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"); 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", 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"); return; } if (cred->uid != 0) { err("sender uid=%i, message ignored", 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", 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'", ctrl_msg.buf); break; } pos[0] = '\0'; if (pos[1] == '\0') { info("udevd message (ENV) received, unset '%s'", ctrl_msg.buf); unsetenv(ctrl_msg.buf); } else { info("udevd message (ENV) received, set '%s=%s'", 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"); stop_exec_q = 1; break; case UDEVD_CTRL_START_EXEC_QUEUE: info("udevd message (START_EXEC_QUEUE) received"); 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", *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", *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", *intval); max_childs_running = *intval; break; case UDEVD_CTRL_RELOAD_RULES: info("udevd message (RELOAD_RULES) received"); reload_config = 1; break; default: err("unknown control message type"); } } /* 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", strerror(errno)); return NULL; } if ((size_t)size > sizeof(buffer)-1) size = sizeof(buffer)-1; buffer[size] = '\0'; dbg("uevent_size=%zi", 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'", buffer); free(msg); return NULL; } pos[0] = '\0'; if (msg->action == NULL) { info("no ACTION in payload found, skip event '%s'", buffer); free(msg); return NULL; } if (strcmp(msg->action, buffer) != 0) { err("ACTION in payload does not match uevent, skip event '%s'", 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", 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) + strlen(saddr.sun_path+1) + 1; udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0); if (udevd_sock == -1) { err("error getting socket: %s", 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", 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", 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", 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' }, { "verbose", 0, NULL, 'v' }, { "help", 0, NULL, 'h' }, { "version", 0, NULL, 'V' }, {} }; int rc = 1; int maxfd; logging_init("udevd"); udev_config_init(); selinux_init(); dbg("version %s", UDEV_VERSION); while (1) { option = getopt_long(argc, argv, "dtvhV", options, NULL); if (option == -1) break; switch (option) { case 'd': daemonize = 1; break; case 't': debug_trace = 1; break; case 'v': verbose = 1; if (udev_log_priority < LOG_INFO) udev_log_priority = LOG_INFO; break; case 'h': printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--verbose] [--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"); 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"); } 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"); rc = 1; } else { fprintf(stderr, "error initializing udevd socket\n"); err("error initializing udevd socket"); rc = 2; } goto exit; } if (init_uevent_netlink_sock() < 0) { fprintf(stderr, "error initializing netlink socket\n"); err("error initializing netlink socket"); rc = 3; goto exit; } /* setup signal handler pipe */ retval = pipe(signal_pipe); if (retval < 0) { err("error getting pipes: %s", strerror(errno)); goto exit; } retval = fcntl(signal_pipe[READ_END], F_GETFL, 0); if (retval < 0) { err("error fcntl on read pipe: %s", 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", strerror(errno)); goto exit; } retval = fcntl(signal_pipe[WRITE_END], F_GETFL, 0); if (retval < 0) { err("error fcntl on write pipe: %s", 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", 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"); break; case -1: err("fork of daemon failed: %s", strerror(errno)); rc = 4; goto exit; default: dbg("child [%u] running, parent exits", pid); rc = 0; goto exit; } } /* redirect std{out,err} fd's */ if (!verbose) 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", sid); /* OOM_DISABLE == -17 */ fd = open("/proc/self/oom_adj", O_RDWR); if (fd < 0) err("error disabling OOM: %s", strerror(errno)); else { write(fd, "-17", 3); 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) inotify_add_watch(inotify_fd, udev_rules_dir, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); else if (errno == ENOSYS) err("the kernel does not support inotify, udevd can't monitor configuration file changes"); else err("inotify_init failed: %s", 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", 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", 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", 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) { char *buf; reload_config = 1; buf = malloc(nbytes); if (!buf) { err("error getting buffer for inotify, disable watching"); 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; }