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/*
* udev-add.c
*
* Userspace devfs
*
* Copyright (C) 2003 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 <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>
#include "udev.h"
#include "udev_version.h"
#include "namedev.h"
#include "udevdb.h"
#include "libsysfs/libsysfs.h"
/*
* Right now the major/minor of a device is stored in a file called
* "dev" in sysfs.
* The number is stored as:
* MMmm
* MM is the major
* mm is the minor
* The value is in hex.
* Yes, this will probably change when we go to a bigger major/minor
* range, and will have to be changed at that time.
*/
static int get_major_minor(struct sysfs_class_device *class_dev, int *major, int *minor)
{
int retval = -ENODEV;
char *dev;
dev = sysfs_get_value_from_attributes(class_dev->directory->attributes, "dev");
if (dev == NULL)
goto exit;
dbg("dev = %s", dev);
if (sscanf(dev, "%u:%u", major, minor) != 2)
goto exit;
dbg("found major = %d, minor = %d", *major, *minor);
retval = 0;
exit:
return retval;
}
/*
* We also want to add some permissions here, and possibly some symlinks
*/
static int create_node(char *name, char type, int major, int minor, int mode)
{
char filename[255];
int retval = 0;
strncpy(filename, UDEV_ROOT, sizeof(filename));
strncat(filename, name, sizeof(filename));
switch (type) {
case 'b':
mode |= S_IFBLK;
break;
case 'c':
case 'u':
mode |= S_IFCHR;
break;
case 'p':
mode |= S_IFIFO;
break;
default:
dbg("unknown node type %c\n", type);
return -EINVAL;
}
dbg("mknod(%s, %#o, %u, %u)", filename, mode, major, minor);
retval = mknod(filename,mode,makedev(major,minor));
if (retval)
dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
filename, mode, major, minor, strerror(errno));
return retval;
}
static struct sysfs_class_device *get_class_dev(char *device_name)
{
char sysfs_path[SYSFS_PATH_MAX];
char dev_path[SYSFS_PATH_MAX];
int retval;
struct sysfs_class_device *class_dev = NULL;
retval = sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX);
dbg("sysfs_path = %s", sysfs_path);
if (retval) {
dbg("sysfs_get_mnt_path failed");
goto exit;
}
strcpy(dev_path, sysfs_path);
strcat(dev_path, device_name);
dbg("looking at %s", dev_path);
/* open up the sysfs class device for this thing... */
class_dev = sysfs_open_class_device(dev_path);
if (class_dev == NULL) {
dbg ("sysfs_open_class_device failed");
goto exit;
}
dbg("class_dev->name = %s", class_dev->name);
exit:
return class_dev;
}
int udev_add_device(char *device, char *subsystem)
{
struct sysfs_class_device *class_dev;
struct device_attr attr;
int major;
int minor;
char type;
int retval = -EINVAL;
/* for now, the block layer is the only place where block devices are */
if (strcmp(subsystem, "block") == 0)
type = 'b';
else
type = 'c';
/* sleep for a second or two to give the kernel a chance to
* create the dev file
*/
sleep(1);
class_dev = get_class_dev(device);
if (class_dev == NULL)
goto exit;
retval = namedev_name_device(class_dev, &attr);
if (retval)
return retval;
retval = get_major_minor(class_dev, &major, &minor);
if (retval) {
dbg("get_major_minor failed");
goto exit;
}
retval = udevdb_add_device(device, class_dev, attr.name, type, major, minor, attr.mode);
if (retval != 0)
dbg("udevdb_add_device failed, but we are going to try to create the node anyway. "
"But remove might not work properly for this device.");
sysfs_close_class_device(class_dev);
return create_node(attr.name, type, major, minor, attr.mode);
exit:
return retval;
}
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