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mirror of https://github.com/systemd/systemd-stable.git synced 2024-10-30 14:55:26 +03:00
systemd-stable/wait_for_sysfs.c

156 lines
4.1 KiB
C

/*
* wait_for_sysfs.c - small program to delay the execution
* of /etc/hotplug.d/ programs, until sysfs
* is fully populated by the kernel. Depending on
* the type of device, we wait for all expected
* directories and then just exit.
*
* Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
* Copyright (C) 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 <unistd.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <sys/stat.h>
#include "logging.h"
#include "udev_version.h"
#include "udev_sysfs.h"
#include "libsysfs/sysfs/libsysfs.h"
#ifdef LOG
unsigned char logname[LOGNAME_SIZE];
void log_message(int level, const char *format, ...)
{
va_list args;
va_start(args, format);
vsyslog(level, format, args);
va_end(args);
}
#endif
int main(int argc, char *argv[], char *envp[])
{
const char *devpath = "";
const char *action;
const char *subsystem;
char sysfs_mnt_path[SYSFS_PATH_MAX];
char filename[SYSFS_PATH_MAX];
struct sysfs_class_device *class_dev;
struct sysfs_device *devices_dev;
int rc = 0;
const char *error = NULL;
logging_init("wait_for_sysfs");
if (argc != 2) {
dbg("error: subsystem");
return 1;
}
subsystem = argv[1];
devpath = getenv ("DEVPATH");
if (!devpath) {
dbg("error: no DEVPATH");
rc = 1;
goto exit;
}
action = getenv ("ACTION");
if (!action) {
dbg("error: no ACTION");
rc = 1;
goto exit;
}
/* we only wait on an add event */
if (strcmp(action, "add") != 0) {
dbg("no add ACTION");
goto exit;
}
if (sysfs_get_mnt_path(sysfs_mnt_path, SYSFS_PATH_MAX) != 0) {
dbg("error: no sysfs path");
rc = 2;
goto exit;
}
if ((strncmp(devpath, "/block/", 7) == 0) || (strncmp(devpath, "/class/", 7) == 0)) {
snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_mnt_path, devpath);
filename[SYSFS_PATH_MAX-1] = '\0';
/* skip bad events where we get no device for the class */
if (strncmp(devpath, "/class/", 7) == 0 && strchr(&devpath[7], '/') == NULL) {
dbg("no device name for '%s', bad event", devpath);
goto exit;
}
/* open the class device we are called for */
class_dev = open_class_device_wait(filename);
if (!class_dev) {
dbg("error: class device unavailable (probably remove has beaten us)");
goto exit;
}
dbg("class device opened '%s'", filename);
/* wait for the class device with possible physical device and bus */
wait_for_class_device(class_dev, &error);
sysfs_close_class_device(class_dev);
} else if ((strncmp(devpath, "/devices/", 9) == 0)) {
snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_mnt_path, devpath);
filename[SYSFS_PATH_MAX-1] = '\0';
/* open the path we are called for */
devices_dev = open_devices_device_wait(filename);
if (!devices_dev) {
dbg("error: devices device unavailable (probably remove has beaten us)");
goto exit;
}
dbg("devices device opened '%s'", filename);
/* wait for the bus value */
wait_for_bus_device(devices_dev, &error);
sysfs_close_device(devices_dev);
} else {
dbg("unhandled sysfs path, no need to wait");
}
exit:
if (error) {
info("either wait_for_sysfs (udev %s) needs an update to handle the device '%s' "
"properly (%s) or the sysfs-support of your device's driver needs to be fixed, "
"please report to <linux-hotplug-devel@lists.sourceforge.net>",
UDEV_VERSION, devpath, error);
rc =3;
} else {
dbg("result: waiting for sysfs successful '%s'", devpath);
}
logging_close();
exit(rc);
}