udevd.c revision 4ec9c3e79771aa95586390cecff4218cc8938160
/*
* Copyright (C) 2004-2009 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
* Copyright (C) 2009 Canonical Ltd.
* Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stddef.h>
#include <signal.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <time.h>
#include <getopt.h>
#include <dirent.h>
#include <sys/time.h>
#include <sys/prctl.h>
#include <sys/socket.h>
#include <sys/un.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 <sys/utsname.h>
#include "udev.h"
#include "sd-daemon.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 struct udev_rules *rules;
static struct udev_queue_export *udev_queue_export;
static struct udev_ctrl *udev_ctrl;
static struct udev_monitor *monitor;
static int worker_watch[2] = { -1, -1 };
static pid_t settle_pid;
static bool stop_exec_queue;
static bool reload_config;
static int children;
static int children_max;
static int exec_delay;
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 = -1 },
[FD_WORKER] = { .events = POLLIN, .fd = -1 },
[FD_SIGNAL] = { .events = POLLIN, .fd = -1 },
[FD_INOTIFY] = { .events = POLLIN, .fd = -1 },
[FD_CONTROL] = { .events = POLLIN, .fd = -1 },
};
enum event_state {
EVENT_UNDEF,
EVENT_QUEUED,
EVENT_RUNNING,
};
struct event {
struct udev_list_node node;
struct udev *udev;
struct udev_device *dev;
enum event_state state;
int exitcode;
unsigned long long int delaying_seqnum;
unsigned long long int seqnum;
const char *devpath;
size_t devpath_len;
const char *devpath_old;
dev_t devnum;
bool is_block;
int ifindex;
};
static struct event *node_to_event(struct udev_list_node *node)
{
char *event;
event = (char *)node;
event -= offsetof(struct event, node);
return (struct event *)event;
}
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), "remove") != 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);
children--;
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) {
udev_monitor_unref(worker_monitor);
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);
if (exec_delay > 0)
udev_event->exec_delay = exec_delay;
/* 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));
if (err == 0)
failed = udev_event_execute_run(udev_event, &orig_sigmask);
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 udevd 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);
children++;
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, bool force)
{
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 (!force && children >= children_max) {
if (children_max > 1)
info(event->udev, "maximum number (%i) of children reached\n", children);
return;
}
/* start new worker and pass initial device */
worker_new(event);
}
static int event_queue_insert(struct udev_device *dev)
{
struct event *event;
event = calloc(1, sizeof(struct event));
if (event == NULL)
return -1;
event->udev = udev_device_get_udev(dev);
event->dev = dev;
event->seqnum = udev_device_get_seqnum(dev);
event->devpath = udev_device_get_devpath(dev);
event->devpath_len = strlen(event->devpath);
event->devpath_old = udev_device_get_devpath_old(dev);
event->devnum = udev_device_get_devnum(dev);
event->is_block = (strcmp("block", udev_device_get_subsystem(dev)) == 0);
event->ifindex = udev_device_get_ifindex(dev);
udev_queue_export_device_queued(udev_queue_export, dev);
info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(dev),
udev_device_get_action(dev), udev_device_get_subsystem(dev));
event->state = EVENT_QUEUED;
udev_list_node_append(&event->node, &event_list);
/* run all events with a timeout set immediately */
if (udev_device_get_timeout(dev) > 0) {
event_run(event, true);
return 0;
}
return 0;
}
static void worker_kill(struct udev *udev, int retain)
{
struct udev_list_node *loop;
int max;
if (children <= retain)
return;
max = children - retain;
udev_list_node_foreach(loop, &worker_list) {
struct worker *worker = node_to_worker(loop);
if (max-- <= 0)
break;
if (worker->state == WORKER_KILLED)
continue;
worker->state = WORKER_KILLED;
kill(worker->pid, SIGTERM);
}
}
/* lookup event for identical, parent, child device */
static bool is_devpath_busy(struct event *event)
{
struct udev_list_node *loop;
size_t common;
/* check if queue contains events we depend on */
udev_list_node_foreach(loop, &event_list) {
struct event *loop_event = node_to_event(loop);
/* we already found a later event, earlier can not block us, no need to check again */
if (loop_event->seqnum < event->delaying_seqnum)
continue;
/* event we checked earlier still exists, no need to check again */
if (loop_event->seqnum == event->delaying_seqnum)
return true;
/* found ourself, no later event can block us */
if (loop_event->seqnum >= event->seqnum)
break;
/* check major/minor */
if (major(event->devnum) != 0 && event->devnum == loop_event->devnum && event->is_block == loop_event->is_block)
return true;
/* check network device ifindex */
if (event->ifindex != 0 && event->ifindex == loop_event->ifindex)
return true;
/* check our old name */
if (event->devpath_old != NULL && strcmp(loop_event->devpath, event->devpath_old) == 0) {
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* compare devpath */
common = MIN(loop_event->devpath_len, event->devpath_len);
/* one devpath is contained in the other? */
if (memcmp(loop_event->devpath, event->devpath, common) != 0)
continue;
/* identical device event found */
if (loop_event->devpath_len == event->devpath_len) {
/* devices names might have changed/swapped in the meantime */
if (major(event->devnum) != 0 && (event->devnum != loop_event->devnum || event->is_block != loop_event->is_block))
continue;
if (event->ifindex != 0 && event->ifindex != loop_event->ifindex)
continue;
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* parent device event found */
if (event->devpath[common] == '/') {
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* child device event found */
if (loop_event->devpath[common] == '/') {
event->delaying_seqnum = loop_event->seqnum;
return true;
}
/* no matching device */
continue;
}
return false;
}
static void 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, false);
}
}
static void worker_returned(void)
{
for (;;) {
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_children_max(ctrl_msg);
if (i >= 0) {
info(udev, "udevd message (SET_MAX_CHILDREN) received, children_max=%i\n", i);
children_max = 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) {
const char *s;
info(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
s = strstr(ev->name, ".rules");
if (s == NULL)
continue;
if (strlen(s) != strlen(".rules"))
continue;
reload_config = true;
continue;
}
dev = udev_watch_lookup(udev, ev->wd);
if (dev != NULL) {
info(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
if (ev->mask & IN_CLOSE_WRITE) {
char filename[UTIL_PATH_SIZE];
int fd;
info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
util_strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL);
fd = open(filename, O_WRONLY);
if (fd < 0 || write(fd, "change", 6) < 0)
info(udev, "error writing uevent: %m\n");
close(fd);
}
if (ev->mask & IN_IGNORED)
udev_watch_end(udev, dev);
udev_device_unref(dev);
}
}
free(buf);
return 0;
}
static void handle_signal(struct udev *udev, int signo)
{
switch (signo) {
case SIGINT:
case SIGTERM:
udev_exit = true;
break;
case SIGCHLD:
for (;;) {
pid_t pid;
int status;
struct udev_list_node *loop, *tmp;
pid = waitpid(-1, &status, WNOHANG);
if (pid <= 0)
break;
udev_list_node_foreach_safe(loop, tmp, &worker_list) {
struct worker *worker = node_to_worker(loop);
if (worker->pid != pid)
continue;
info(udev, "worker [%u] exit\n", pid);
if (!WIFEXITED(status) || 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;
}
}
static void static_dev_create_from_modules(struct udev *udev)
{
struct utsname kernel;
char modules[UTIL_PATH_SIZE];
char buf[4096];
FILE *f;
uname(&kernel);
util_strscpyl(modules, sizeof(modules), "/lib/modules/", kernel.release, "/modules.devname", NULL);
f = fopen(modules, "r");
if (f == NULL)
return;
while (fgets(buf, sizeof(buf), f) != NULL) {
char *s;
const char *modname;
const char *devname;
const char *devno;
int maj, min;
char type;
mode_t mode;
char filename[UTIL_PATH_SIZE];
if (buf[0] == '#')
continue;
modname = buf;
s = strchr(modname, ' ');
if (s == NULL)
continue;
s[0] = '\0';
devname = &s[1];
s = strchr(devname, ' ');
if (s == NULL)
continue;
s[0] = '\0';
devno = &s[1];
s = strchr(devno, ' ');
if (s == NULL)
s = strchr(devno, '\n');
if (s != NULL)
s[0] = '\0';
if (sscanf(devno, "%c%u:%u", &type, &maj, &min) != 3)
continue;
if (type == 'c')
mode = 0600 | S_IFCHR;
else if (type == 'b')
mode = 0600 | S_IFBLK;
else
continue;
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/", devname, NULL);
util_create_path(udev, filename);
udev_selinux_setfscreatecon(udev, filename, mode);
info(udev, "mknod '%s' %c%u:%u\n", filename, type, maj, min);
if (mknod(filename, mode, makedev(maj, min)) < 0 && errno == EEXIST)
utimensat(AT_FDCWD, filename, NULL, 0);
udev_selinux_resetfscreatecon(udev);
}
fclose(f);
}
static int copy_dir(struct udev *udev, DIR *dir_from, DIR *dir_to, int maxdepth)
{
struct dirent *dent;
for (dent = readdir(dir_from); dent != NULL; dent = readdir(dir_from)) {
struct stat stats;
if (dent->d_name[0] == '.')
continue;
if (fstatat(dirfd(dir_from), dent->d_name, &stats, AT_SYMLINK_NOFOLLOW) != 0)
continue;
if (S_ISBLK(stats.st_mode) || S_ISCHR(stats.st_mode)) {
udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, stats.st_mode & 0777);
if (mknodat(dirfd(dir_to), dent->d_name, stats.st_mode, stats.st_rdev) == 0) {
fchmodat(dirfd(dir_to), dent->d_name, stats.st_mode & 0777, 0);
fchownat(dirfd(dir_to), dent->d_name, stats.st_uid, stats.st_gid, 0);
} else {
utimensat(dirfd(dir_to), dent->d_name, NULL, 0);
}
udev_selinux_resetfscreatecon(udev);
} else if (S_ISLNK(stats.st_mode)) {
char target[UTIL_PATH_SIZE];
ssize_t len;
len = readlinkat(dirfd(dir_from), dent->d_name, target, sizeof(target));
if (len <= 0 || len == (ssize_t)sizeof(target))
continue;
target[len] = '\0';
udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFLNK);
if (symlinkat(target, dirfd(dir_to), dent->d_name) < 0 && errno == EEXIST)
utimensat(dirfd(dir_to), dent->d_name, NULL, AT_SYMLINK_NOFOLLOW);
udev_selinux_resetfscreatecon(udev);
} else if (S_ISDIR(stats.st_mode)) {
DIR *dir2_from, *dir2_to;
if (maxdepth == 0)
continue;
udev_selinux_setfscreateconat(udev, dirfd(dir_to), dent->d_name, S_IFDIR|0755);
mkdirat(dirfd(dir_to), dent->d_name, 0755);
udev_selinux_resetfscreatecon(udev);
dir2_to = fdopendir(openat(dirfd(dir_to), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
if (dir2_to == NULL)
continue;
dir2_from = fdopendir(openat(dirfd(dir_from), dent->d_name, O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC));
if (dir2_from == NULL) {
closedir(dir2_to);
continue;
}
copy_dir(udev, dir2_from, dir2_to, maxdepth-1);
closedir(dir2_to);
closedir(dir2_from);
}
}
return 0;
}
static void static_dev_create_links(struct udev *udev, DIR *dir)
{
struct stdlinks {
const char *link;
const char *target;
};
static const struct stdlinks stdlinks[] = {
{ "core", "/proc/kcore" },
{ "fd", "/proc/self/fd" },
{ "stdin", "/proc/self/fd/0" },
{ "stdout", "/proc/self/fd/1" },
{ "stderr", "/proc/self/fd/2" },
};
unsigned int i;
for (i = 0; i < ARRAY_SIZE(stdlinks); i++) {
struct stat sb;
if (stat(stdlinks[i].target, &sb) == 0) {
udev_selinux_setfscreateconat(udev, dirfd(dir), stdlinks[i].link, S_IFLNK);
if (symlinkat(stdlinks[i].target, dirfd(dir), stdlinks[i].link) < 0 && errno == EEXIST)
utimensat(dirfd(dir), stdlinks[i].link, NULL, AT_SYMLINK_NOFOLLOW);
udev_selinux_resetfscreatecon(udev);
}
}
}
static void static_dev_create_from_devices(struct udev *udev, DIR *dir)
{
DIR *dir_from;
dir_from = opendir(LIBEXECDIR "/devices");
if (dir_from == NULL)
return;
copy_dir(udev, dir_from, dir, 8);
closedir(dir_from);
}
static void static_dev_create(struct udev *udev)
{
DIR *dir;
dir = opendir(udev_get_dev_path(udev));
if (dir == NULL)
return;
static_dev_create_links(udev, dir);
static_dev_create_from_devices(udev, dir);
closedir(dir);
}
static int mem_size_mb(void)
{
FILE *f;
char buf[4096];
long int memsize = -1;
f = fopen("/proc/meminfo", "r");
if (f == NULL)
return -1;
while (fgets(buf, sizeof(buf), f) != NULL) {
long int value;
if (sscanf(buf, "MemTotal: %ld kB", &value) == 1) {
memsize = value / 1024;
break;
}
}
fclose(f);
return memsize;
}
static int convert_db(struct udev *udev)
{
char filename[UTIL_PATH_SIZE];
FILE *f;
struct udev_enumerate *udev_enumerate;
struct udev_list_entry *list_entry;
/* current database */
util_strscpyl(filename, sizeof(filename), udev_get_run_path(udev), "/data", NULL);
if (access(filename, F_OK) >= 0)
return 0;
/* make sure we do not get here again */
util_create_path(udev, filename);
udev_selinux_setfscreatecon(udev, udev_get_run_path(udev), S_IFDIR|0755);
mkdir(filename, 0755);
udev_selinux_resetfscreatecon(udev);
/* old database */
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev/db", NULL);
if (access(filename, F_OK) < 0)
return 0;
f = fopen("/dev/kmsg", "w");
if (f != NULL) {
fprintf(f, "<30>udev[%u]: converting old udev database\n", getpid());
fclose(f);
}
udev_enumerate = udev_enumerate_new(udev);
if (udev_enumerate == NULL)
return -1;
udev_enumerate_scan_devices(udev_enumerate);
udev_list_entry_foreach(list_entry, udev_enumerate_get_list_entry(udev_enumerate)) {
struct udev_device *device;
device = udev_device_new_from_syspath(udev, udev_list_entry_get_name(list_entry));
if (device == NULL)
continue;
/* try to find the old database for devices without a current one */
if (udev_device_read_db(device, NULL) < 0) {
bool have_db;
const char *id;
struct stat stats;
char devpath[UTIL_PATH_SIZE];
char from[UTIL_PATH_SIZE];
have_db = false;
/* find database in old location */
id = udev_device_get_id_filename(device);
util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", id, NULL);
if (lstat(from, &stats) == 0) {
if (!have_db) {
udev_device_read_db(device, from);
have_db = true;
}
unlink(from);
}
/* find old database with $subsys:$sysname name */
util_strscpyl(from, sizeof(from), udev_get_dev_path(udev),
"/.udev/db/", udev_device_get_subsystem(device), ":",
udev_device_get_sysname(device), NULL);
if (lstat(from, &stats) == 0) {
if (!have_db) {
udev_device_read_db(device, from);
have_db = true;
}
unlink(from);
}
/* find old database with the encoded devpath name */
util_path_encode(udev_device_get_devpath(device), devpath, sizeof(devpath));
util_strscpyl(from, sizeof(from), udev_get_dev_path(udev), "/.udev/db/", devpath, NULL);
if (lstat(from, &stats) == 0) {
if (!have_db) {
udev_device_read_db(device, from);
have_db = true;
}
unlink(from);
}
/* write out new database */
if (have_db)
udev_device_update_db(device);
}
udev_device_unref(device);
}
udev_enumerate_unref(udev_enumerate);
return 0;
}
int main(int argc, char *argv[])
{
struct udev *udev;
int fd;
FILE *f;
sigset_t mask;
int daemonize = false;
int resolve_names = 1;
static const struct option options[] = {
{ "daemon", no_argument, NULL, 'd' },
{ "debug", no_argument, NULL, 'D' },
{ "children-max", required_argument, NULL, 'c' },
{ "exec-delay", required_argument, NULL, 'e' },
{ "resolve-names", required_argument, NULL, 'N' },
{ "help", no_argument, NULL, 'h' },
{ "version", no_argument, NULL, 'V' },
{}
};
int 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);
/* make sure, that our runtime dir exists and is writable */
if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) < 0) {
/* try to create our own subdirectory, do not create parent directories */
udev_selinux_setfscreatecon(udev, udev_get_run_config_path(udev), S_IFDIR|0755);
mkdir(udev_get_run_config_path(udev), 0755);
udev_selinux_resetfscreatecon(udev);
if (utimensat(AT_FDCWD, udev_get_run_config_path(udev), NULL, 0) >= 0) {
/* directory seems writable now */
udev_set_run_path(udev, udev_get_run_config_path(udev));
} else {
/* fall back to /dev/.udev */
char filename[UTIL_PATH_SIZE];
util_strscpyl(filename, sizeof(filename), udev_get_dev_path(udev), "/.udev", NULL);
if (udev_set_run_path(udev, filename) == NULL)
goto exit;
}
}
info(udev, "runtime dir '%s'\n", udev_get_run_path(udev));
for (;;) {
int option;
option = getopt_long(argc, argv, "c:deDthV", options, NULL);
if (option == -1)
break;
switch (option) {
case 'd':
daemonize = true;
break;
case 'c':
children_max = strtoul(optarg, NULL, 0);
break;
case 'e':
exec_delay = strtoul(optarg, NULL, 0);
break;
case 'D':
debug = true;
if (udev_get_log_priority(udev) < LOG_INFO)
udev_set_log_priority(udev, LOG_INFO);
break;
case 'N':
if (strcmp (optarg, "early") == 0) {
resolve_names = 1;
} else if (strcmp (optarg, "late") == 0) {
resolve_names = 0;
} else if (strcmp (optarg, "never") == 0) {
resolve_names = -1;
} else {
fprintf(stderr, "resolve-names must be early, late or never\n");
err(udev, "resolve-names must be early, late or never\n");
goto exit;
}
break;
case 'h':
printf("Usage: udevd OPTIONS\n"
" --daemon\n"
" --debug\n"
" --children-max=<maximum number of workers>\n"
" --exec-delay=<seconds to wait before executing RUN=>\n"
" --resolve-names=early|late|never\n"
" --version\n"
" --help\n"
"\n");
goto exit;
case 'V':
printf("%s\n", VERSION);
goto exit;
default:
goto exit;
}
}
/*
* read the kernel commandline, in case we need to get into debug mode
* udev.log-priority=<level> syslog priority
* udev.children-max=<number of workers> events are fully serialized if set to 1
*
*/
f = fopen("/proc/cmdline", "r");
if (f != NULL) {
char cmdline[4096];
if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
char *pos;
pos = strstr(cmdline, "udev.log-priority=");
if (pos != NULL) {
pos += strlen("udev.log-priority=");
udev_set_log_priority(udev, util_log_priority(pos));
}
pos = strstr(cmdline, "udev.children-max=");
if (pos != NULL) {
pos += strlen("udev.children-max=");
children_max = strtoul(pos, NULL, 0);
}
pos = strstr(cmdline, "udev.exec-delay=");
if (pos != NULL) {
pos += strlen("udev.exec-delay=");
exec_delay = strtoul(pos, NULL, 0);
}
}
fclose(f);
}
if (getuid() != 0) {
fprintf(stderr, "root privileges required\n");
err(udev, "root privileges required\n");
goto exit;
}
/* set umask before creating any file/directory */
chdir("/");
umask(022);
/* create standard links, copy static nodes, create nodes from modules */
static_dev_create(udev);
static_dev_create_from_modules(udev);
/* before opening new files, make sure std{in,out,err} fds are in a sane state */
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);
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_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_DELETE | IN_MOVE | IN_CLOSE_WRITE);
inotify_add_watch(pfd[FD_INOTIFY].fd, SYSCONFDIR "/udev/rules.d",
IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
/* watch dynamic rules directory */
util_strscpyl(filename, sizeof(filename), udev_get_run_path(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_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 needed, convert old database from earlier udev version */
convert_db(udev);
if (!debug) {
dup2(fd, STDIN_FILENO);
dup2(fd, STDOUT_FILENO);
dup2(fd, STDERR_FILENO);
}
if (fd > STDERR_FILENO)
close(fd);
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;
}
} else {
sd_notify(1, "READY=1");
}
/* set scheduling priority for the main daemon process */
setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
setsid();
f = fopen("/dev/kmsg", "w");
if (f != NULL) {
fprintf(f, "<30>udev[%u]: starting version " VERSION "\n", getpid());
fclose(f);
}
fd = open("/proc/self/oom_score_adj", O_RDWR);
if (fd < 0) {
/* Fallback to old interface */
fd = open("/proc/self/oom_adj", O_RDWR);
if (fd < 0) {
err(udev, "error disabling OOM: %m\n");
} else {
/* OOM_DISABLE == -17 */
write(fd, "-17", 3);
close(fd);
}
} else {
write(fd, "-1000", 5);
close(fd);
}
if (children_max <= 0) {
int memsize = mem_size_mb();
/* set value depending on the amount of RAM */
if (memsize > 0)
children_max = 128 + (memsize / 8);
else
children_max = 128;
}
info(udev, "set children_max to %u\n", children_max);
udev_rules_apply_static_dev_perms(rules);
udev_list_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) && children > 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)
if (event_queue_insert(dev) < 0)
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;
}