X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=udevd.c;h=14616b9824e16dd509f74ce00c0996b2624c0119;hp=08dede36ee335c597c2616709c24643195b9ec1a;hb=82de5983ab395df7f59ed53a51517a6066be3a57;hpb=7fafc0324272731c5666047715b9f58f56761534 diff --git a/udevd.c b/udevd.c index 08dede36e..7978bdb08 100644 --- a/udevd.c +++ b/udevd.c @@ -1,10 +1,8 @@ /* - * udevd.c + * udevd.c - event listener and serializer * - * Userspace devfs - * - * Copyright (C) 2004 Ling, Xiaofeng - * Copyright (C) 2004 Kay Sievers + * Copyright (C) 2004-2005 Kay Sievers + * Copyright (C) 2004 Chris Friesen * * * This program is free software; you can redistribute it and/or modify it @@ -22,234 +20,1033 @@ * */ -#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 "list.h" +#include "udev_libc_wrapper.h" #include "udev.h" +#include "udev_version.h" +#include "udev_rules.h" +#include "udev_utils.h" #include "udevd.h" #include "logging.h" -#define BUFFER_SIZE 1024 -#define TIMEOUT_SECONDS 10 +struct udev_rules rules; +static int udevd_sock; +static int uevent_netlink_sock; +static int inotify_fd; +static pid_t sid; -static void reset_timer(void); -static void reset_queue(void); +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); -static int expect_seqnum = 0; -static int timeout_value = TIMEOUT_SECONDS; -static int timeout = 0; -static struct hotplug_msg *head = NULL; -static char exec_program[100]; -static void sig_handler(int signum) +#ifdef USE_LOG +void log_message(int priority, const char *format, ...) { - dbg("caught signal %d", signum); - switch (signum) { - case SIGHUP: - dbg("reset requested, all waiting events killed"); - reset_timer(); - reset_queue(); - timeout = 0; - expect_seqnum = 0; + va_list args; + + if (priority > udev_log_priority) + return; + + 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 uevent_msg *msg) +{ + struct sigaction act; + struct udevice udev; + struct name_entry *name_loop; + 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); + + /* trigger timeout to prevent hanging processes */ + alarm(UDEV_ALARM_TIMEOUT); + + /* reconstruct env from message */ + for (i = 0; msg->envp[i]; i++) + putenv(msg->envp[i]); + + udev_init_device(&udev, msg->devpath, msg->subsystem, msg->action); + retval = udev_process_event(&rules, &udev); + + /* run programs collected by RUN-key*/ + if (!retval) { + 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:")], msg->devpath, msg->action); + else + if (run_program(name_loop->name, udev.subsystem, NULL, 0, NULL, + (udev_log_priority >= LOG_INFO))) + retval = -1; + } + } + + udev_cleanup_device(&udev); + + return retval; +} + +enum event_state { + EVENT_QUEUED, + EVENT_FINISHED, + EVENT_FAILED, +}; + +static void export_event_state(struct uevent_msg *msg, enum event_state state) +{ + char filename[PATH_SIZE]; + char filename_failed[PATH_SIZE]; + char target[PATH_SIZE]; + size_t start, end, i; + struct uevent_msg *loop_msg; + + /* add location of queue files */ + strlcpy(filename, udev_root, sizeof(filename)); + strlcat(filename, "/", sizeof(filename)); + start = strlcat(filename, EVENT_QUEUE_DIR, sizeof(filename)); + end = strlcat(filename, msg->devpath, sizeof(filename)); + if (end > sizeof(filename)) + end = sizeof(filename); + + /* replace '/' to transform path into a filename */ + for (i = start+1; i < end; i++) + if (filename[i] == '/') + filename[i] = PATH_TO_NAME_CHAR; + + /* 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)); + end = strlcat(filename_failed, msg->devpath, sizeof(filename_failed)); + if (end > sizeof(filename_failed)) + end = sizeof(filename_failed); + + /* replace '/' to transform path into a filename */ + for (i = start+1; i < end; i++) + if (filename_failed[i] == '/') + filename_failed[i] = PATH_TO_NAME_CHAR; + + switch (state) { + case EVENT_QUEUED: + unlink(filename_failed); + + strlcpy(target, sysfs_path, sizeof(target)); + strlcat(target, msg->devpath, sizeof(target)); + create_path(filename); + symlink(target, filename); + return; + case EVENT_FINISHED: + unlink(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; + unlink(filename); + case EVENT_FAILED: + create_path(filename_failed); + rename(filename, filename_failed); + return; + } +} + +static void msg_queue_delete(struct 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 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", msg->seqnum); + + 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 uevent_msg *msg) +{ + msg->queue_time = time(NULL); + + export_event_state(msg, EVENT_QUEUED); + + /* 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; +} + +/* runs event and removes event from run queue when finished */ +static int running_processes(void) +{ + int f; + static char buf[4096]; + int len; + int running; + const char *pos; + + f = open("/proc/stat", O_RDONLY); + if (f == -1) + return -1; + + len = read(f, buf, sizeof(buf)-1); + close(f); + + if (len <= 0) + return -1; + else + buf[len] = '\0'; + + pos = strstr(buf, "procs_running "); + if (pos == NULL) + return -1; + + if (sscanf(pos, "procs_running %u", &running) != 1) + return -1; + + 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); - case SIGINT: - case SIGTERM: - case SIGKILL: - exit(20 + signum); + 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; + } - default: - dbg("unhandled signal"); + return 0; +} + +/* returns still running task for the same device, its parent or its physical device */ +static int running_with_devpath(struct uevent_msg *msg, int limit) +{ + struct uevent_msg *loop_msg; + int childs_count = 0; + + list_for_each_entry(loop_msg, &running_list, node) { + if (limit && childs_count++ > limit) { + dbg("%llu, maximum number (%i) of child reached", msg->seqnum, childs_count); + return 1; + } + + /* return running parent/child device event */ + if (compare_devpath(loop_msg->devpath, msg->devpath) != 0) { + dbg("%llu, child device event still running %llu (%s)", + msg->seqnum, loop_msg->seqnum, loop_msg->devpath); + return 2; + } + + /* return running physical device event */ + 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; } -static void sig_alarmhandler(int signum) +/* exec queue management routine executes the events and serializes events in the same sequence */ +static void msg_queue_manager(void) { - dbg("caught signal %d", signum); - switch (signum) { - case SIGALRM: - timeout = 1; - dbg("event timeout reached"); - break; + struct uevent_msg *loop_msg; + struct uevent_msg *tmp_msg; + int running; - default: - dbg("unhandled signal"); + 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; + } + } + + /* don't run two processes for the same devpath and wait for the parent*/ + if (running_with_devpath(loop_msg, max_childs)) { + 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 void dump_queue(void) +static struct uevent_msg *get_msg_from_envbuf(const char *buf, int buf_size) { - struct hotplug_msg *p; - p = head; + int bufpos; + int i; + struct uevent_msg *msg; + int major = 0; + int minor = 0; + + msg = malloc(sizeof(struct uevent_msg) + buf_size); + if (msg == NULL) + return NULL; + memset(msg, 0x00, sizeof(struct 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); - dbg("next expected sequence is %d", expect_seqnum); - while(p) { - dbg("sequence %d in queue", p->seqnum); - p=p->next; + /* 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, "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, "MAJOR=", 6) == 0) + major = strtoull(&key[6], NULL, 10); + else if (strncmp(key, "MINOR=", 6) == 0) + minor = strtoull(&key[6], NULL, 10); + else if (strncmp(key, "TIMEOUT=", 8) == 0) + msg->timeout = strtoull(&key[8], NULL, 10); } + msg->devt = makedev(major, minor); + msg->envp[i++] = "UDEVD_EVENT=1"; + msg->envp[i] = NULL; + + if (!msg->devpath) { + info("DEVPATH missing, ignore message"); + free(msg); + return NULL; + } + + return msg; } -static void dump_msg(struct hotplug_msg *pmsg) +/* receive the udevd message from userspace */ +static struct uevent_msg *get_udevd_msg(void) { - dbg("sequence %d, '%s', '%s', '%s'", - pmsg->seqnum, pmsg->action, pmsg->devpath, pmsg->subsystem); + static struct udevd_msg usend_msg; + struct uevent_msg *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 envbuf_size; + int *intval; + + memset(&usend_msg, 0x00, sizeof(struct udevd_msg)); + iov.iov_base = &usend_msg; + iov.iov_len = sizeof(struct udevd_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 udevd message: %s", strerror(errno)); + return NULL; + } + 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 NULL; + } + + if (cred->uid != 0) { + err("sender uid=%i, message ignored", cred->uid); + return NULL; + } + + if (strncmp(usend_msg.magic, UDEV_MAGIC, sizeof(UDEV_MAGIC)) != 0 ) { + err("message magic '%s' doesn't match, ignore it", usend_msg.magic); + return NULL; + } + + switch (usend_msg.type) { + case UDEVD_UEVENT_UDEVSEND: + case UDEVD_UEVENT_INITSEND: + info("udevd event message received"); + envbuf_size = size - offsetof(struct udevd_msg, envbuf); + dbg("envbuf_size=%i", envbuf_size); + msg = get_msg_from_envbuf(usend_msg.envbuf, envbuf_size); + if (msg == NULL) + return NULL; + msg->type = usend_msg.type; + return msg; + case UDEVD_STOP_EXEC_QUEUE: + info("udevd message (STOP_EXEC_QUEUE) received"); + stop_exec_q = 1; + break; + case UDEVD_START_EXEC_QUEUE: + info("udevd message (START_EXEC_QUEUE) received"); + stop_exec_q = 0; + msg_queue_manager(); + break; + case UDEVD_SET_LOG_LEVEL: + intval = (int *) usend_msg.envbuf; + 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_SET_MAX_CHILDS: + intval = (int *) usend_msg.envbuf; + info("udevd message (UDEVD_SET_MAX_CHILDS) received, max_childs=%i", *intval); + max_childs = *intval; + break; + case UDEVD_RELOAD_RULES: + info("udevd message (RELOAD_RULES) received"); + reload_config = 1; + break; + default: + dbg("unknown message type"); + } + return NULL; } -static void dispatch_msg(struct hotplug_msg *pmsg) +/* receive the kernel user event message and do some sanity checks */ +static struct uevent_msg *get_netlink_msg(void) { - dump_msg(pmsg); - dbg("exec '%s'", exec_program); - setenv("ACTION", pmsg->action, 1); - setenv("DEVPATH", pmsg->devpath, 1); - execl(exec_program, pmsg->subsystem); + struct 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 udevd 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; + msg->type = UDEVD_UEVENT_NETLINK; + + /* 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 reset_timer(void) +static void asmlinkage sig_handler(int signum) { - alarm(0); + 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 set_timer(void) +static void udev_done(int pid, int exitstatus) { - signal(SIGALRM, sig_alarmhandler); - alarm(timeout_value); + /* find msg associated with pid and delete it */ + struct 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 reset_queue(void) +static void reap_sigchilds(void) { - struct hotplug_msg *p; - p = head; + pid_t pid; + int status; - while(head) { - p = head; - head = head->next; - free(p); + 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 void check_queue(void) +static int init_udevd_socket(void) { - struct hotplug_msg *p; - p = head; + struct sockaddr_un saddr; + const int buffersize = 16 * 1024 * 1024; + 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_SOCK_PATH); + addrlen = offsetof(struct sockaddr_un, sun_path) + strlen(saddr.sun_path+1) + 1; - dump_queue(); - while(head && head->seqnum == expect_seqnum) { - dispatch_msg(head); - expect_seqnum++; - p = head; - head = head->next; - free(p); + udevd_sock = socket(AF_LOCAL, SOCK_DGRAM, 0); + if (udevd_sock == -1) { + err("error getting socket: %s", strerror(errno)); + return -1; } - if (head != NULL) - set_timer(); - else - reset_timer(); + + /* set receive buffersize */ + setsockopt(udevd_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize)); + + /* 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)); + return -1; + } + + /* enable receiving of the sender credentials */ + setsockopt(udevd_sock, SOL_SOCKET, SO_PASSCRED, &feature_on, sizeof(feature_on)); + + return 0; } -static void add_queue(struct hotplug_msg *pmsg) +static int init_uevent_netlink_sock(void) { - struct hotplug_msg *pnewmsg; - struct hotplug_msg *p; - struct hotplug_msg *p1; + struct sockaddr_nl snl; + const int buffersize = 16 * 1024 * 1024; + int retval; - p = head; - p1 = NULL; - pnewmsg = malloc(sizeof(struct hotplug_msg)); - *pnewmsg = *pmsg; - pnewmsg->next = NULL; - while(p && pmsg->seqnum > p->seqnum) { - p1 = p; - p = p->next; + memset(&snl, 0x00, sizeof(struct sockaddr_nl)); + snl.nl_family = AF_NETLINK; + snl.nl_pid = getpid(); + snl.nl_groups = 0xffffffff; + + 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; } - pnewmsg->next = p; - if (p1 == NULL) { - head = pnewmsg; - } else { - p1->next = pnewmsg; + + /* 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; } - dump_queue(); + return 0; } -static int process_queue(void) +int main(int argc, char *argv[], char *envp[]) { - int msgid; - key_t key; - struct hotplug_msg *pmsg; - char buf[BUFFER_SIZE]; - int ret; + int retval; + int fd; + struct sigaction act; + fd_set readfds; + const char *value; + int daemonize = 0; + int i; + int rc = 0; + int maxfd; + + /* redirect std fd's, if the kernel forks us, we don't have them at all */ + fd = open("/dev/null", O_RDWR); + if (fd >= 0) { + if (fd != STDIN_FILENO) + dup2(fd, STDIN_FILENO); + if (fd != STDOUT_FILENO) + dup2(fd, STDOUT_FILENO); + if (fd != STDERR_FILENO) + dup2(fd, STDERR_FILENO); + if (fd > STDERR_FILENO) + close(fd); + } + + logging_init("udevd"); + if (fd < 0) + err("fatal, could not open /dev/null: %s", strerror(errno)); - key = ftok(DEFAULT_EXEC_PROGRAM, IPC_KEY_ID); - pmsg = (struct hotplug_msg *) buf; - msgid = msgget(key, IPC_CREAT); - if (msgid == -1) { - dbg("open message queue error"); + udev_init_config(); + dbg("version %s", UDEV_VERSION); + + if (getuid() != 0) { + err("need to be root, exit"); goto exit; } - while (1) { - ret = msgrcv(msgid, (struct msgbuf *) buf, BUFFER_SIZE-4, HOTPLUGMSGTYPE, 0); - if (ret != -1) { - dbg("current sequence %d, expected sequence %d", pmsg->seqnum, expect_seqnum); - - /* init expected sequence with value from first call */ - if (expect_seqnum == 0) { - expect_seqnum = pmsg->seqnum; - dbg("init next expected sequence number to %d", expect_seqnum); - } - if (pmsg->seqnum > expect_seqnum) { - add_queue(pmsg); - set_timer(); - } else { - if (pmsg->seqnum == expect_seqnum) { - dispatch_msg(pmsg); - expect_seqnum++; - check_queue(); - } else { - dbg("timeout event for unexpected sequence number %d", pmsg->seqnum); - } + /* parse commandline options */ + for (i = 1 ; i < argc; i++) { + char *arg = argv[i]; + if (strcmp(arg, "--daemon") == 0 || strcmp(arg, "-d") == 0) { + info("will daemonize"); + daemonize = 1; + } + if (strcmp(arg, "--stop-exec-queue") == 0) { + info("will not execute events until START_EXEC_QUEUE is received"); + stop_exec_q = 1; + } + } + + /* init sockets to receive events */ + if (init_udevd_socket() < 0) { + if (errno == EADDRINUSE) { + err("another udevd running, exit"); + rc = 1; + } else { + err("error initializing udevd socket: %s", strerror(errno)); + rc = 2; + } + goto exit; + } + + if (init_uevent_netlink_sock() < 0) { + err("uevent socket not available"); + rc = 3; + goto exit; + } + + /* parse the rules and keep it in memory */ + udev_rules_init(&rules, 1); + + 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); + goto exit; + } + } + + /* 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); + } + + /* 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_SETFL, O_NONBLOCK); + if (retval < 0) { + err("error fcntl on read pipe: %s", strerror(errno)); + goto exit; + } + retval = fcntl(signal_pipe[WRITE_END], F_SETFL, O_NONBLOCK); + if (retval < 0) { + err("error fcntl on write pipe: %s", strerror(errno)); + goto exit; + } + + /* 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_filename, IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE); + + /* maximum limit of forked childs */ + value = getenv("UDEVD_MAX_CHILDS"); + if (value) + max_childs = strtoul(value, NULL, 10); + 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 + 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); + + 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 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 user socket message */ + if (FD_ISSET(udevd_sock, &readfds)) { + msg = get_udevd_msg(); + if (msg) { + if (msg->type == UDEVD_UEVENT_UDEVSEND && msg->seqnum != 0) { + info("skip non-kernel message with SEQNUM"); + free(msg); + } else + msg_queue_insert(msg); } - } else - if (errno == EINTR) { - if (head != NULL) { - /* timeout, skip all missing, proceed with next queued event */ - dbg("timeout reached, skip events %d - %d", expect_seqnum, head->seqnum-1); - expect_seqnum = head->seqnum; + } + + /* get kernel 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; } - check_queue(); - timeout = 0; - } else { - dbg("ipc message receive error '%s'", strerror(errno)); + read(inotify_fd, buf, nbytes); + free(buf); } + } + + /* rules changed, set by inotify or a signal*/ + if (reload_config) { + reload_config = 0; + udev_rules_close(&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(); + } } - return 0; + exit: - return -1; -} + udev_rules_close(&rules); -int main(int argc, char *argv[]) -{ - /* get program to exec on events */ - if (argc == 2) - strncpy(exec_program, argv[1], sizeof(exec_program)); - else - strcpy(exec_program, DEFAULT_EXEC_PROGRAM); + if (signal_pipe[READ_END] > 0) + close(signal_pipe[READ_END]); + if (signal_pipe[WRITE_END] > 0) + close(signal_pipe[WRITE_END]); - /* set up signal handler */ - signal(SIGINT, sig_handler); - signal(SIGTERM, sig_handler); - signal(SIGKILL, sig_handler); - signal(SIGHUP, sig_handler); + if (udevd_sock > 0) + close(udevd_sock); + if (inotify_fd > 0) + close(inotify_fd); + if (uevent_netlink_sock > 0) + close(uevent_netlink_sock); - /* main loop */ - process_queue(); - return 0; + logging_close(); + + return rc; }