udevd.c revision 3c1898863fbf9c94cfb0258ae380b67b44c4b466
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering/*
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering * Copyright (C) 2004-2009 Kay Sievers <kay.sievers@vrfy.org>
1486dbe1c6510376a900c8c99f8bc032c8fa9cdbLennart Poettering * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering * Copyright (C) 2009 Canonical Ltd.
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering *
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * This program is free software: you can redistribute it and/or modify
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * it under the terms of the GNU General Public License as published by
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * the Free Software Foundation, either version 2 of the License, or
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * (at your option) any later version.
dee4c244254bb49d1ffa8bd7171ae9cce596d2d0Lennart Poettering *
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * This program is distributed in the hope that it will be useful,
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * but WITHOUT ANY WARRANTY; without even the implied warranty of
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * GNU General Public License for more details.
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering *
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * You should have received a copy of the GNU General Public License
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering * along with this program. If not, see <http://www.gnu.org/licenses/>.
edb9aaa8b27adf89cc712000318b1e9cf40ea296Lennart Poettering */
edb9aaa8b27adf89cc712000318b1e9cf40ea296Lennart Poettering
edb9aaa8b27adf89cc712000318b1e9cf40ea296Lennart Poettering#include <stddef.h>
edb9aaa8b27adf89cc712000318b1e9cf40ea296Lennart Poettering#include <signal.h>
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering#include <unistd.h>
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering#include <errno.h>
eb10a76494542fb560efd09c16b40826fc37bc5fLennart Poettering#include <stdio.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <stdlib.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <stdbool.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <string.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <ctype.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <fcntl.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <time.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <getopt.h>
1486dbe1c6510376a900c8c99f8bc032c8fa9cdbLennart Poettering#include <dirent.h>
bc2708414babc5c99bb8000e63c84e87606cc15dLennart Poettering#include <sys/time.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/signalfd.h>
#include <sys/select.h>
#include <sys/poll.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#include <sys/inotify.h>
#include "udev.h"
#define UDEVD_PRIORITY -4
#define UDEV_PRIORITY -2
static bool debug;
static void log_fn(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 timeval tv;
struct timezone tz;
vsnprintf(buf, sizeof(buf), format, args);
gettimeofday(&tv, &tz);
fprintf(stderr, "%llu.%06u [%u] %s: %s",
(unsigned long long) tv.tv_sec, (unsigned int) tv.tv_usec,
(int) getpid(), fn, buf);
} else {
vsyslog(priority, format, args);
}
}
static bool debug_trace;
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];
static pid_t settle_pid;
static bool stop_exec_queue;
static bool reload_config;
static int max_childs;
static int childs;
static sigset_t orig_sigmask;
static struct udev_list_node event_list;
static struct udev_list_node worker_list;
static bool udev_exit;
static volatile sig_atomic_t worker_exit;
enum poll_fd {
FD_CONTROL,
FD_NETLINK,
FD_INOTIFY,
FD_SIGNAL,
FD_WORKER,
};
static struct pollfd pfd[] = {
[FD_NETLINK] = { .events = POLLIN },
[FD_WORKER] = { .events = POLLIN },
[FD_SIGNAL] = { .events = POLLIN },
[FD_INOTIFY] = { .events = POLLIN },
[FD_CONTROL] = { .events = POLLIN },
};
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;
};
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;
}
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;
};
/* 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)
{
udev_list_node_remove(&event->node);
/* mark as failed, if "add" event returns non-zero */
if (event->exitcode != 0 && strcmp(udev_device_get_action(event->dev), "add") == 0)
udev_queue_export_device_failed(udev_queue_export, event->dev);
else
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 void event_sig_handler(int signum)
{
switch (signum) {
case SIGALRM:
_exit(1);
break;
case SIGTERM:
worker_exit = true;
break;
}
}
static struct worker *worker_ref(struct worker *worker)
{
worker->refcount++;
return worker;
}
static void worker_unref(struct worker *worker)
{
worker->refcount--;
if (worker->refcount > 0)
return;
udev_list_node_remove(&worker->node);
udev_monitor_unref(worker->monitor);
childs--;
info(worker->udev, "worker [%u] cleaned up\n", worker->pid);
free(worker);
}
static void worker_new(struct event *event)
{
struct worker *worker;
struct udev_monitor *worker_monitor;
pid_t pid;
struct sigaction act;
/* listen for new events */
worker_monitor = udev_monitor_new_from_netlink(event->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)
return;
/* worker + event reference */
worker->refcount = 2;
worker->udev = event->udev;
pid = fork();
switch (pid) {
case 0: {
sigset_t sigmask;
struct udev_device *dev;
struct pollfd pmon = {
.fd = udev_monitor_get_fd(worker_monitor),
.events = POLLIN,
};
udev_queue_export_unref(udev_queue_export);
udev_monitor_unref(monitor);
udev_ctrl_unref(udev_ctrl);
close(pfd[FD_SIGNAL].fd);
close(worker_watch[READ_END]);
udev_log_close();
udev_log_init("udevd-work");
setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
/* set signal handlers */
memset(&act, 0x00, sizeof(act));
act.sa_handler = event_sig_handler;
sigemptyset (&act.sa_mask);
act.sa_flags = 0;
sigaction(SIGTERM, &act, NULL);
sigaction(SIGALRM, &act, NULL);
/* unblock SIGALRM */
sigfillset(&sigmask);
sigdelset(&sigmask, SIGALRM);
sigprocmask(SIG_SETMASK, &sigmask, NULL);
/* SIGTERM is unblocked in ppoll() */
sigdelset(&sigmask, SIGTERM);
/* request TERM signal if parent exits */
prctl(PR_SET_PDEATHSIG, SIGTERM);
/* initial device */
dev = event->dev;
do {
struct udev_event *udev_event;
struct worker_message msg = {};
int err;
int failed = 0;
info(event->udev, "seq %llu running\n", udev_device_get_seqnum(dev));
udev_event = udev_event_new(dev);
if (udev_event == NULL)
_exit(3);
/* set timeout to prevent hanging processes */
alarm(UDEV_EVENT_TIMEOUT);
/* apply rules, create node, symlinks */
err = udev_event_execute_rules(udev_event, rules);
/* rules may change/disable the timeout */
if (udev_device_get_event_timeout(dev) >= 0)
alarm(udev_device_get_event_timeout(dev));
/* execute RUN= */
if (err == 0 && udev_get_run(udev_event->udev))
failed = udev_event_execute_run(udev_event,
&orig_sigmask);
/* reset alarm */
alarm(0);
/* apply/restore inotify watch */
if (err == 0 && udev_event->inotify_watch) {
udev_watch_begin(udev_event->udev, dev);
udev_device_update_db(dev);
}
/* send processed event back to libudev listeners */
udev_monitor_send_device(worker_monitor, NULL, dev);
/* send back the result of the event execution */
if (err != 0)
msg.exitcode = err;
else if (failed != 0)
msg.exitcode = failed;
msg.pid = getpid();
send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0);
info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err);
udev_event_unref(udev_event);
udev_device_unref(dev);
dev = NULL;
/* wait for more device messages or signal from udevd */
while (!worker_exit) {
int fdcount;
fdcount = ppoll(&pmon, 1, NULL, &sigmask);
if (fdcount < 0)
continue;
if (pmon.revents & POLLIN) {
dev = udev_monitor_receive_device(worker_monitor);
if (dev != NULL)
break;
}
}
} while (dev != NULL);
udev_monitor_unref(worker_monitor);
udev_log_close();
exit(0);
}
case -1:
udev_monitor_unref(worker_monitor);
event->state = EVENT_QUEUED;
free(worker);
err(event->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 = event;
event->state = EVENT_RUNNING;
udev_list_node_append(&worker->node, &worker_list);
childs++;
info(event->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;
event->state = EVENT_RUNNING;
return;
}
if (childs >= max_childs) {
info(event->udev, "maximum number (%i) of childs reached\n", childs);
return;
}
/* start new worker and pass initial device */
worker_new(event);
}
static void event_queue_insert(struct udev_device *dev)
{
struct event *event;
event = calloc(1, sizeof(struct event));
if (event == NULL)
return;
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);
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);
/* run all events with a timeout set immediately */
if (udev_device_get_timeout(dev) > 0) {
worker_new(event);
return;
}
}
static void worker_kill(struct udev *udev, int retain)
{
struct udev_list_node *loop;
int max;
if (childs <= retain)
return;
max = childs - 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);
}
}
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;
}
/* 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 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) {
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 events_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 worker_returned(void)
{
while (1) {
struct worker_message msg;
ssize_t size;
struct udev_list_node *loop;
size = recv(pfd[FD_WORKER].fd, &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 */
worker->event->exitcode = msg.exitcode;
event_queue_delete(worker->event);
worker->event = NULL;
if (worker->state != WORKER_KILLED)
worker->state = WORKER_IDLE;
worker_unref(worker);
break;
}
}
}
/* receive the udevd message from userspace */
static void handle_ctrl_msg(struct udev_ctrl *uctrl)
{
struct udev *udev = udev_ctrl_get_udev(uctrl);
struct udev_ctrl_msg *ctrl_msg;
const char *str;
int i;
ctrl_msg = udev_ctrl_receive_msg(uctrl);
if (ctrl_msg == NULL)
return;
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_rules(ctrl_msg) > 0) {
info(udev, "udevd message (RELOAD_RULES) received\n");
reload_config = 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_max_childs(ctrl_msg);
if (i >= 0) {
info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
max_childs = i;
}
settle_pid = udev_ctrl_get_settle(ctrl_msg);
if (settle_pid > 0) {
info(udev, "udevd message (SETTLE) received\n");
kill(settle_pid, SIGUSR1);
settle_pid = 0;
}
udev_ctrl_msg_unref(ctrl_msg);
}
/* read inotify messages */
static int handle_inotify(struct udev *udev)
{
int nbytes, pos;
char *buf;
struct inotify_event *ev;
if ((ioctl(pfd[FD_INOTIFY].fd, 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(pfd[FD_INOTIFY].fd, buf, nbytes);
for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
struct udev_device *dev;
ev = (struct inotify_event *)(buf + pos);
if (ev->len) {
dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
reload_config = true;
continue;
}
dev = udev_watch_lookup(udev, ev->wd);
if (dev != NULL) {
dbg(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 || 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:
while (1) {
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) || WEXITSTATUS(status) != 0) {
err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status);
if (worker->event != NULL) {
err(udev, "worker [%u] failed while handling '%s'\n", pid, worker->event->devpath);
worker->event->exitcode = -32;
event_queue_delete(worker->event);
/* drop reference from running event */
worker_unref(worker);
}
}
worker_unref(worker);
break;
}
}
break;
case SIGHUP:
reload_config = true;
break;
}
}
int main(int argc, char *argv[])
{
struct udev *udev;
int fd;
FILE *f;
sigset_t mask;
const char *value;
int daemonize = false;
int resolve_names = 1;
static const struct option options[] = {
{ "daemon", no_argument, NULL, 'd' },
{ "debug-trace", no_argument, NULL, 't' },
{ "debug", no_argument, NULL, 'D' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{ "resolve-names", required_argument, NULL, 'N' },
{}
};
int rc = 1;
udev = udev_new();
if (udev == NULL)
goto exit;
udev_log_init("udevd");
udev_set_log_fn(udev, log_fn);
info(udev, "version %s\n", VERSION);
udev_selinux_init(udev);
while (1) {
int option;
option = getopt_long(argc, argv, "dDthV", options, NULL);
if (option == -1)
break;
switch (option) {
case 'd':
daemonize = true;
break;
case 't':
debug_trace = true;
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 [--help] [--daemon] [--debug-trace] [--debug] "
"[--resolve-names=early|late|never] [--version]\n");
goto exit;
case 'V':
printf("%s\n", VERSION);
goto exit;
default:
goto exit;
}
}
if (getuid() != 0) {
fprintf(stderr, "root privileges required\n");
err(udev, "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(udev, "cannot open /dev/null\n");
}
if (write(STDOUT_FILENO, 0, 0) < 0)
dup2(fd, STDOUT_FILENO);
if (write(STDERR_FILENO, 0, 0) < 0)
dup2(fd, STDERR_FILENO);
/* init control socket, bind() ensures, that only one udevd instance is running */
udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
if (udev_ctrl == NULL) {
fprintf(stderr, "error initializing control socket");
err(udev, "error initializing udevd socket");
rc = 1;
goto exit;
}
if (udev_ctrl_enable_receiving(udev_ctrl) < 0) {
fprintf(stderr, "error binding control socket, seems udevd is already running\n");
err(udev, "error binding control socket, seems udevd is already running\n");
rc = 1;
goto exit;
}
pfd[FD_CONTROL].fd = udev_ctrl_get_fd(udev_ctrl);
monitor = udev_monitor_new_from_netlink(udev, "kernel");
if (monitor == NULL || udev_monitor_enable_receiving(monitor) < 0) {
fprintf(stderr, "error initializing netlink socket\n");
err(udev, "error initializing netlink socket\n");
rc = 3;
goto exit;
}
udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024);
pfd[FD_NETLINK].fd = udev_monitor_get_fd(monitor);
pfd[FD_INOTIFY].fd = udev_watch_init(udev);
if (pfd[FD_INOTIFY].fd < 0) {
fprintf(stderr, "error initializing inotify\n");
err(udev, "error initializing inotify\n");
rc = 4;
goto exit;
}
if (udev_get_rules_path(udev) != NULL) {
inotify_add_watch(pfd[FD_INOTIFY].fd, udev_get_rules_path(udev),
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
} else {
char filename[UTIL_PATH_SIZE];
struct stat statbuf;
inotify_add_watch(pfd[FD_INOTIFY].fd, LIBEXECDIR "/rules.d",
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
/* watch dynamic rules directory */
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/rules.d", NULL);
if (stat(filename, &statbuf) != 0) {
util_create_path(udev, filename);
udev_selinux_setfscreatecon(udev, filename, S_IFDIR|0755);
mkdir(filename, 0755);
udev_selinux_resetfscreatecon(udev);
}
inotify_add_watch(pfd[FD_INOTIFY].fd, filename,
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
}
udev_watch_restore(udev);
/* block and listen to all signals on signalfd */
sigfillset(&mask);
sigprocmask(SIG_SETMASK, &mask, &orig_sigmask);
pfd[FD_SIGNAL].fd = signalfd(-1, &mask, 0);
if (pfd[FD_SIGNAL].fd < 0) {
fprintf(stderr, "error getting signalfd\n");
err(udev, "error getting 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 getting socketpair\n");
err(udev, "error getting socketpair\n");
rc = 6;
goto exit;
}
pfd[FD_WORKER].fd = worker_watch[READ_END];
rules = udev_rules_new(udev, resolve_names);
if (rules == NULL) {
err(udev, "error reading rules\n");
goto exit;
}
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;
pid = fork();
switch (pid) {
case 0:
break;
case -1:
err(udev, "fork of daemon failed: %m\n");
rc = 4;
goto exit;
default:
rc = 0;
goto exit;
}
}
f = fopen("/dev/kmsg", "w");
if (f != NULL) {
fprintf(f, "<6>udev: starting version " VERSION "\n");
fclose(f);
}
/* redirect std{out,err} */
if (!debug && !debug_trace) {
dup2(fd, STDIN_FILENO);
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);
setsid();
/* OOM_DISABLE == -17 */
fd = open("/proc/self/oom_adj", O_RDWR);
if (fd < 0) {
err(udev, "error disabling OOM: %m\n");
} else {
write(fd, "-17", 3);
close(fd);
}
/* in trace mode run one event after the other */
if (debug_trace) {
max_childs = 1;
} else {
int memsize = mem_size_mb();
if (memsize > 0)
max_childs = 128 + (memsize / 8);
else
max_childs = 128;
}
/* possibly overwrite maximum limit of executed events */
value = getenv("UDEVD_MAX_CHILDS");
if (value)
max_childs = strtoul(value, NULL, 10);
info(udev, "initialize max_childs to %u\n", max_childs);
udev_list_init(&event_list);
udev_list_init(&worker_list);
while (!udev_exit) {
int fdcount;
int timeout;
/* set timeout to kill idle workers */
if (udev_list_is_empty(&event_list) && childs > 2)
timeout = 3 * 1000;
else
timeout = -1;
/* wait for events */
fdcount = poll(pfd, ARRAY_SIZE(pfd), timeout);
if (fdcount < 0)
continue;
/* timeout - kill idle workers */
if (fdcount == 0)
worker_kill(udev, 2);
/* event has finished */
if (pfd[FD_WORKER].revents & POLLIN)
worker_returned();
/* get kernel uevent */
if (pfd[FD_NETLINK].revents & POLLIN) {
struct udev_device *dev;
dev = udev_monitor_receive_device(monitor);
if (dev != NULL)
event_queue_insert(dev);
else
udev_device_unref(dev);
}
/* start new events */
if (!udev_list_is_empty(&event_list) && !stop_exec_queue)
events_start(udev);
/* get signal */
if (pfd[FD_SIGNAL].revents & POLLIN) {
struct signalfd_siginfo fdsi;
ssize_t size;
size = read(pfd[FD_SIGNAL].fd, &fdsi, sizeof(struct signalfd_siginfo));
if (size == sizeof(struct signalfd_siginfo))
handle_signal(udev, fdsi.ssi_signo);
}
/* device node and rules directory inotify watch */
if (pfd[FD_INOTIFY].revents & POLLIN)
handle_inotify(udev);
/*
* get control message
*
* This needs to be after the inotify handling, to make sure,
* that the settle signal is send back after the possibly generated
* "change" events by the inotify device node watch.
*/
if (pfd[FD_CONTROL].revents & POLLIN)
handle_ctrl_msg(udev_ctrl);
/* rules changed, set by inotify or a HUP signal */
if (reload_config) {
struct udev_rules *rules_new;
worker_kill(udev, 0);
rules_new = udev_rules_new(udev, resolve_names);
if (rules_new != NULL) {
udev_rules_unref(rules);
rules = rules_new;
}
reload_config = 0;
}
}
udev_queue_export_cleanup(udev_queue_export);
rc = 0;
exit:
udev_queue_export_unref(udev_queue_export);
udev_rules_unref(rules);
udev_ctrl_unref(udev_ctrl);
if (pfd[FD_SIGNAL].fd >= 0)
close(pfd[FD_SIGNAL].fd);
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_selinux_exit(udev);
udev_unref(udev);
udev_log_close();
return rc;
}