udev.c revision 2b41e68a08548ce44b4d145900dab2bb04cd34f7
/*
* udev.c
*
* Userspace devfs
*
* Copyright (C) 2003,2004 Greg Kroah-Hartman <greg@kroah.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 version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <signal.h>
#include <unistd.h>
#include "libsysfs/sysfs/libsysfs.h"
#include "udev.h"
#include "udev_lib.h"
#include "udev_sysfs.h"
#include "udev_version.h"
#include "logging.h"
#include "namedev.h"
#include "udevdb.h"
/* global variables */
char **main_argv;
char **main_envp;
#ifdef LOG
unsigned char logname[LOGNAME_SIZE];
void log_message(int level, const char *format, ...)
{
va_list args;
if (!udev_log)
return;
va_start(args, format);
vsyslog(level, format, args);
va_end(args);
}
#endif
static void asmlinkage sig_handler(int signum)
{
switch (signum) {
case SIGALRM:
exit(1);
case SIGINT:
case SIGTERM:
exit(20 + signum);
}
}
int main(int argc, char *argv[], char *envp[])
{
struct sigaction act;
struct sysfs_class_device *class_dev;
struct udevice udev;
char path[SYSFS_PATH_MAX];
int retval = -EINVAL;
enum {
ADD,
REMOVE,
UDEVSTART,
} act_type;
dbg("version %s", UDEV_VERSION);
main_argv = argv;
main_envp = envp;
logging_init("udev");
udev_init_config();
if (strstr(argv[0], "udevstart")) {
act_type = UDEVSTART;
} else {
const char *action = get_action();
const char *devpath = get_devpath();
const char *subsystem = get_subsystem(main_argv[1]);
if (!action) {
dbg("no action?");
goto exit;
}
if (strcmp(action, "add") == 0) {
act_type = ADD;
} else if (strcmp(action, "remove") == 0) {
act_type = REMOVE;
} else {
dbg("no action '%s' for us", action);
goto exit;
}
if (!devpath) {
dbg("no devpath?");
goto exit;
}
dbg("looking at '%s'", devpath);
/* we only care about class devices and block stuff */
if (!strstr(devpath, "class") && !strstr(devpath, "block")) {
dbg("not a block or class device");
goto exit;
}
if (!subsystem) {
dbg("no subsystem");
goto exit;
}
udev_set_values(&udev, devpath, subsystem);
/* skip blacklisted subsystems */
if (udev.type != 'n' && subsystem_expect_no_dev(subsystem)) {
dbg("don't care about '%s' devices", subsystem);
goto exit;
};
}
/* set signal handlers */
act.sa_handler = (void (*) (int))sig_handler;
sigemptyset (&act.sa_mask);
act.sa_flags = 0;
/* alarm must not restart syscalls*/
sigaction(SIGALRM, &act, NULL);
sigaction(SIGINT, &act, NULL);
sigaction(SIGTERM, &act, NULL);
/* trigger timout to interrupt blocking syscalls */
alarm(ALARM_TIMEOUT);
switch(act_type) {
case UDEVSTART:
dbg("udevstart");
namedev_init();
retval = udev_start();
break;
case ADD:
dbg("udev add");
/* open the device */
snprintf(path, SYSFS_PATH_MAX, "%s%s", sysfs_path, udev.devpath);
class_dev = sysfs_open_class_device_path(path);
if (class_dev == NULL) {
dbg ("sysfs_open_class_device_path failed");
break;
}
dbg("opened class_dev->name='%s'", class_dev->name);
/* init rules */
namedev_init();
/* name, create node, store in db */
retval = udev_add_device(&udev, class_dev);
/* run scripts */
dev_d_execute(&udev);
sysfs_close_class_device(class_dev);
break;
case REMOVE:
dbg("udev remove");
/* get node from db, delete it*/
retval = udev_remove_device(&udev);
/* run scripts */
dev_d_execute(&udev);
}
exit:
logging_close();
return retval;
}