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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-31 16:21:11 +03:00
systemd-stable/udev/udevd.c
Kay Sievers 00f98bd2b3 skip entire rule containing device naming keys, if no device can be named
If rules set NAME, SYMLINK, OWNER, GROUP, MODE, events without a device node
and remove events will skip the entire rule. The old parser did the same.
2008-11-01 19:12:20 +01:00

963 lines
25 KiB
C

/*
* Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, 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 <string.h>
#include <ctype.h>
#include <fcntl.h>
#include <time.h>
#include <getopt.h>
#include <sys/select.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/ioctl.h>
#ifdef HAVE_INOTIFY
#include <sys/inotify.h>
#endif
#include "udev.h"
#define UDEVD_PRIORITY -4
#define UDEV_PRIORITY -2
/* maximum limit of forked childs */
#define UDEVD_MAX_CHILDS 256
static int 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) {
fprintf(stderr, "[%d] %s: ", (int) getpid(), fn);
vfprintf(stderr, format, args);
} else {
vsyslog(priority, format, args);
}
}
static int debug_trace;
static struct udev_rules *rules;
static struct udev_ctrl *udev_ctrl;
static struct udev_monitor *kernel_monitor;
static int inotify_fd = -1;
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 childs;
static struct udev_list_node event_list;
enum event_state {
EVENT_QUEUED,
EVENT_FINISHED,
EVENT_FAILED,
};
static struct udev_event *node_to_event(struct udev_list_node *node)
{
char *event;
event = (char *)node;
event -= offsetof(struct udev_event, node);
return (struct udev_event *)event;
}
static void export_event_state(struct udev_event *event, enum event_state state)
{
char filename[UTIL_PATH_SIZE];
char filename_failed[UTIL_PATH_SIZE];
size_t start;
/* location of queue file */
snprintf(filename, sizeof(filename), "%s/.udev/queue/%llu",
udev_get_dev_path(event->udev), udev_device_get_seqnum(event->dev));
/* location of failed file */
util_strlcpy(filename_failed, udev_get_dev_path(event->udev), sizeof(filename_failed));
util_strlcat(filename_failed, "/", sizeof(filename_failed));
start = util_strlcat(filename_failed, ".udev/failed/", sizeof(filename_failed));
util_strlcat(filename_failed, udev_device_get_devpath(event->dev), sizeof(filename_failed));
util_path_encode(&filename_failed[start], sizeof(filename_failed) - start);
switch (state) {
case EVENT_QUEUED:
if(unlink(filename_failed) == 0)
util_delete_path(event->udev, filename_failed);
util_create_path(event->udev, filename);
udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
symlink(udev_device_get_devpath(event->dev), filename);
udev_selinux_resetfscreatecon(event->udev);
break;
case EVENT_FINISHED:
if (udev_device_get_devpath_old(event->dev) != NULL) {
/* "move" event - rename failed file to current name, do not delete failed */
char filename_failed_old[UTIL_PATH_SIZE];
util_strlcpy(filename_failed_old, udev_get_dev_path(event->udev), sizeof(filename_failed_old));
util_strlcat(filename_failed_old, "/", sizeof(filename_failed_old));
start = util_strlcat(filename_failed_old, ".udev/failed/", sizeof(filename_failed_old));
util_strlcat(filename_failed_old, udev_device_get_devpath_old(event->dev), sizeof(filename_failed_old));
util_path_encode(&filename_failed_old[start], sizeof(filename) - start);
if (rename(filename_failed_old, filename_failed) == 0)
info(event->udev, "renamed devpath, moved failed state of '%s' to %s'\n",
udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
} else {
if (unlink(filename_failed) == 0)
util_delete_path(event->udev, filename_failed);
}
unlink(filename);
/* clean up possibly empty queue directory */
if (udev_list_is_empty(&event_list))
util_delete_path(event->udev, filename);
break;
case EVENT_FAILED:
/* move failed event to the failed directory */
util_create_path(event->udev, filename_failed);
rename(filename, filename_failed);
/* clean up possibly empty queue directory */
if (udev_list_is_empty(&event_list))
util_delete_path(event->udev, filename);
break;
}
return;
}
static void event_queue_delete(struct udev_event *event)
{
udev_list_node_remove(&event->node);
/* mark as failed, if "add" event returns non-zero */
if (event->exitstatus && strcmp(udev_device_get_action(event->dev), "add") == 0)
export_event_state(event, EVENT_FAILED);
else
export_event_state(event, EVENT_FINISHED);
udev_device_unref(event->dev);
udev_event_unref(event);
}
static void asmlinkage event_sig_handler(int signum)
{
if (signum == SIGALRM)
exit(1);
}
static void event_fork(struct udev_event *event)
{
pid_t pid;
struct sigaction act;
int err;
if (debug_trace) {
event->trace = 1;
fprintf(stderr, "fork %s (%llu)\n",
udev_device_get_syspath(event->dev),
udev_device_get_seqnum(event->dev));
}
pid = fork();
switch (pid) {
case 0:
/* child */
udev_monitor_unref(kernel_monitor);
udev_ctrl_unref(udev_ctrl);
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);
/* set signal handlers */
memset(&act, 0x00, sizeof(act));
act.sa_handler = (void (*)(int)) event_sig_handler;
sigemptyset (&act.sa_mask);
act.sa_flags = 0;
sigaction(SIGALRM, &act, NULL);
/* reset to default */
act.sa_handler = SIG_DFL;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
sigaction(SIGCHLD, &act, NULL);
sigaction(SIGHUP, &act, NULL);
/* set timeout to prevent hanging processes */
alarm(UDEV_EVENT_TIMEOUT);
/* apply rules, create node, symlinks */
err = udev_event_execute_rules(event, rules);
/* rules may change/disable the timeout */
if (udev_device_get_event_timeout(event->dev) >= 0)
alarm(udev_device_get_event_timeout(event->dev));
/* execute RUN= */
if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
udev_event_execute_run(event);
info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
logging_close();
if (err != 0)
exit(1);
exit(0);
case -1:
err(event->udev, "fork of child failed: %m\n");
event_queue_delete(event);
break;
default:
/* get SIGCHLD in main loop */
info(event->udev, "seq %llu forked, pid [%d], '%s' '%s', %ld seconds old\n",
udev_device_get_seqnum(event->dev),
pid,
udev_device_get_action(event->dev),
udev_device_get_subsystem(event->dev),
time(NULL) - event->queue_time);
event->pid = pid;
childs++;
}
}
static void event_queue_insert(struct udev_event *event)
{
char filename[UTIL_PATH_SIZE];
int fd;
event->queue_time = time(NULL);
export_event_state(event, EVENT_QUEUED);
info(event->udev, "seq %llu queued, '%s' '%s'\n", udev_device_get_seqnum(event->dev),
udev_device_get_action(event->dev), udev_device_get_subsystem(event->dev));
util_strlcpy(filename, udev_get_dev_path(event->udev), sizeof(filename));
util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd >= 0) {
char str[32];
int len;
len = sprintf(str, "%llu\n", udev_device_get_seqnum(event->dev));
write(fd, str, len);
close(fd);
}
udev_list_node_append(&event->node, &event_list);
run_exec_q = 1;
/* run all events with a timeout set immediately */
if (udev_device_get_timeout(event->dev) > 0) {
event_fork(event);
return;
}
}
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 compare_devpath(const char *running, const char *waiting)
{
int i = 0;
while (running[i] != '\0' && running[i] == waiting[i])
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 */
return 0;
}
/* lookup event for identical, parent, child, or physical device */
static int devpath_busy(struct udev_event *event)
{
struct udev_list_node *loop;
if (event->delaying_seqnum > 0) {
}
/* check if queue contains events we depend on */
udev_list_node_foreach(loop, &event_list) {
struct udev_event *loop_event = node_to_event(loop);
/* we already found a later event, earlier can not block us, no need to check again */
if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
continue;
/* event we checked earlier still exists, no need to check again */
if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
return 2;
/* found ourself, no later event can block us */
if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
break;
/* check our old name */
if (udev_device_get_devpath_old(event->dev) != NULL)
if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
return 3;
}
/* check identical, parent, or child device event */
if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
dbg(event->udev, "%llu, device event still pending %llu (%s)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
return 4;
}
/* check for our major:minor number */
if (major(udev_device_get_devnum(event->dev)) > 0 &&
udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
return 5;
}
/* check physical device event (special case of parent) */
if (udev_device_get_physdevpath(event->dev) != NULL &&
strcmp(udev_device_get_action(event->dev), "add") == 0)
if (compare_devpath(udev_device_get_devpath(loop_event->dev),
udev_device_get_physdevpath(event->dev)) != 0) {
dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
udev_device_get_seqnum(event->dev),
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
return 6;
}
}
return 0;
}
/* serializes events for the identical and parent and child devices */
static void event_queue_manager(struct udev *udev)
{
struct udev_list_node *loop;
struct udev_list_node *tmp;
if (udev_list_is_empty(&event_list)) {
if (childs > 0) {
err(udev, "event list empty, but childs count is %i", childs);
childs = 0;
}
return;
}
udev_list_node_foreach_safe(loop, tmp, &event_list) {
struct udev_event *loop_event = node_to_event(loop);
if (childs >= max_childs) {
info(udev, "maximum number (%i) of childs reached\n", childs);
break;
}
if (loop_event->pid != 0)
continue;
/* do not start event if parent or child event is still running */
if (devpath_busy(loop_event) != 0) {
dbg(udev, "delay seq %llu (%s)\n",
udev_device_get_seqnum(loop_event->dev),
udev_device_get_devpath(loop_event->dev));
continue;
}
event_fork(loop_event);
dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
}
}
/* 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);
}
if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) {
info(udev, "udevd message (STOP_EXEC_QUEUE) received\n");
stop_exec_q = 1;
}
if (udev_ctrl_get_start_exec_queue(ctrl_msg) > 0) {
info(udev, "udevd message (START_EXEC_QUEUE) received\n");
stop_exec_q = 0;
event_queue_manager(udev);
}
if (udev_ctrl_get_reload_rules(ctrl_msg) > 0) {
info(udev, "udevd message (RELOAD_RULES) received\n");
reload_config = 1;
}
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);
}
}
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;
}
udev_ctrl_msg_unref(ctrl_msg);
}
static void asmlinkage sig_handler(int signum)
{
switch (signum) {
case SIGINT:
case SIGTERM:
udev_exit = 1;
break;
case SIGCHLD:
/* set flag, then write to pipe if needed */
sigchilds_waiting = 1;
break;
case SIGHUP:
reload_config = 1;
break;
}
/* write to pipe, which will wakeup select() in our mainloop */
write(signal_pipe[WRITE_END], "", 1);
}
static void udev_done(int pid, int exitstatus)
{
struct udev_list_node *loop;
/* find event associated with pid and delete it */
udev_list_node_foreach(loop, &event_list) {
struct udev_event *loop_event = node_to_event(loop);
if (loop_event->pid == pid) {
info(loop_event->udev, "seq %llu cleanup, pid [%d], status %i, %ld seconds old\n",
udev_device_get_seqnum(loop_event->dev), loop_event->pid,
exitstatus, time(NULL) - loop_event->queue_time);
loop_event->exitstatus = exitstatus;
if (debug_trace)
fprintf(stderr, "exit %s (%llu)\n",
udev_device_get_syspath(loop_event->dev),
udev_device_get_seqnum(loop_event->dev));
event_queue_delete(loop_event);
childs--;
/* there may be dependent events waiting */
run_exec_q = 1;
return;
}
}
}
static void reap_sigchilds(void)
{
pid_t pid;
int status;
while (1) {
pid = waitpid(-1, &status, WNOHANG);
if (pid <= 0)
break;
if (WIFEXITED(status))
status = WEXITSTATUS(status);
else if (WIFSIGNALED(status))
status = WTERMSIG(status) + 128;
else
status = 0;
udev_done(pid, status);
}
}
static void export_initial_seqnum(struct udev *udev)
{
char filename[UTIL_PATH_SIZE];
int fd;
char seqnum[32];
ssize_t len = 0;
util_strlcpy(filename, udev_get_sys_path(udev), sizeof(filename));
util_strlcat(filename, "/kernel/uevent_seqnum", sizeof(filename));
fd = open(filename, O_RDONLY);
if (fd >= 0) {
len = read(fd, seqnum, sizeof(seqnum)-1);
close(fd);
}
if (len <= 0) {
strcpy(seqnum, "0\n");
len = 3;
}
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
util_create_path(udev, filename);
fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
if (fd >= 0) {
write(fd, seqnum, len);
close(fd);
}
}
int main(int argc, char *argv[])
{
struct udev *udev;
int err;
int fd;
struct sigaction act;
fd_set readfds;
const char *value;
int daemonize = 0;
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' },
{}
};
int rc = 1;
int maxfd;
udev = udev_new();
if (udev == NULL)
goto exit;
logging_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 = 1;
break;
case 't':
debug_trace = 1;
break;
case 'D':
debug = 1;
if (udev_get_log_priority(udev) < LOG_INFO)
udev_set_log_priority(udev, LOG_INFO);
break;
case 'h':
printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--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;
}
kernel_monitor = udev_monitor_new_from_netlink(udev);
if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_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(kernel_monitor, 128*1024*1024);
err = pipe(signal_pipe);
if (err < 0) {
err(udev, "error getting pipes: %m\n");
goto exit;
}
err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
if (err < 0) {
err(udev, "error fcntl on read pipe: %m\n");
goto exit;
}
err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
if (err < 0) {
err(udev, "error fcntl on read pipe: %m\n");
goto exit;
}
err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
if (err < 0) {
err(udev, "error fcntl on write pipe: %m\n");
goto exit;
}
err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
if (err < 0) {
err(udev, "error fcntl on write pipe: %m\n");
goto exit;
}
rules = udev_rules_new(udev, 1);
if (rules == NULL) {
err(udev, "error reading rules\n");
goto exit;
}
udev_list_init(&event_list);
export_initial_seqnum(udev);
if (daemonize) {
pid_t pid;
pid = fork();
switch (pid) {
case 0:
dbg(udev, "daemonized fork running\n");
break;
case -1:
err(udev, "fork of daemon failed: %m\n");
rc = 4;
goto exit;
default:
dbg(udev, "child [%u] running, parent exits\n", pid);
rc = 0;
goto exit;
}
}
/* 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);
}
fd = open("/dev/kmsg", O_WRONLY);
if (fd > 0) {
const char *ver_str = "<6>udev: starting version " VERSION "\n";
char path[UTIL_PATH_SIZE];
struct stat statbuf;
write(fd, ver_str, strlen(ver_str));
util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
util_strlcat(path, "/class/mem/null", sizeof(path));
if (lstat(path, &statbuf) == 0) {
if (S_ISDIR(statbuf.st_mode)) {
const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
"or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
"udev features may fail\n";
write(fd, depr_str, strlen(depr_str));
}
}
close(fd);
}
/* set signal handlers */
memset(&act, 0x00, sizeof(struct sigaction));
act.sa_handler = (void (*)(int)) sig_handler;
sigemptyset(&act.sa_mask);
act.sa_flags = SA_RESTART;
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
sigaction(SIGCHLD, &act, NULL);
sigaction(SIGHUP, &act, NULL);
/* watch rules directory */
inotify_fd = inotify_init();
if (inotify_fd >= 0) {
if (udev_get_rules_path(udev) != NULL) {
inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
} else {
char filename[UTIL_PATH_SIZE];
inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
inotify_add_watch(inotify_fd, SYSCONFDIR "/udev/rules.d",
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
/* watch dynamic rules directory */
util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
util_strlcat(filename, "/.udev/rules.d", sizeof(filename));
inotify_add_watch(inotify_fd, filename,
IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
}
} else if (errno == ENOSYS)
err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
else
err(udev, "inotify_init failed: %m\n");
/* 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 / 4);
else
max_childs = UDEVD_MAX_CHILDS;
}
/* 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);
maxfd = udev_ctrl_get_fd(udev_ctrl);
maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
maxfd = UDEV_MAX(maxfd, inotify_fd);
while (!udev_exit) {
int fdcount;
FD_ZERO(&readfds);
FD_SET(signal_pipe[READ_END], &readfds);
FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
FD_SET(udev_monitor_get_fd(kernel_monitor), &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(udev, "error in select: %m\n");
continue;
}
/* get control message */
if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
handle_ctrl_msg(udev_ctrl);
/* get kernel uevent */
if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
struct udev_device *dev;
dev = udev_monitor_receive_device(kernel_monitor);
if (dev != NULL) {
struct udev_event *event;
event = udev_event_new(dev);
if (event != NULL)
event_queue_insert(event);
else
udev_device_unref(dev);
}
}
/* received a signal, clear our notification pipe */
if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
char buf[256];
read(signal_pipe[READ_END], &buf, sizeof(buf));
}
/* rules directory inotify watch */
if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
int nbytes;
/* discard all possible events, we can just reload the config */
if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
char *buf;
reload_config = 1;
buf = malloc(nbytes);
if (buf == NULL) {
err(udev, "error getting buffer for inotify, disable watching\n");
close(inotify_fd);
inotify_fd = -1;
}
read(inotify_fd, buf, nbytes);
free(buf);
}
}
/* rules changed, set by inotify or a HUP signal */
if (reload_config) {
struct udev_rules *rules_new;
reload_config = 0;
rules_new = udev_rules_new(udev, 1);
if (rules_new != NULL) {
udev_rules_unref(rules);
rules = rules_new;
}
}
if (sigchilds_waiting) {
sigchilds_waiting = 0;
reap_sigchilds();
}
if (run_exec_q) {
run_exec_q = 0;
if (!stop_exec_q)
event_queue_manager(udev);
}
}
rc = 0;
exit:
udev_rules_unref(rules);
if (signal_pipe[READ_END] >= 0)
close(signal_pipe[READ_END]);
if (signal_pipe[WRITE_END] >= 0)
close(signal_pipe[WRITE_END]);
udev_ctrl_unref(udev_ctrl);
if (inotify_fd >= 0)
close(inotify_fd);
udev_monitor_unref(kernel_monitor);
udev_selinux_exit(udev);
udev_unref(udev);
logging_close();
return rc;
}