udev-add.c revision 4763256c65859b94ac7a309cbb8f772d5426a08d
/*
* 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 <sys/stat.h>
#include <sys/types.h>
#include <grp.h>
#ifndef __KLIBC__
#include <pwd.h>
#endif
#include "udev.h"
#include "udev_version.h"
#include "udev_dbus.h"
#include "namedev.h"
#include "udevdb.h"
#include "libsysfs/libsysfs.h"
#include "klibc_fixups.h"
/*
* Right now the major/minor of a device is stored in a file called
* "dev" in sysfs.
* The number is stored as:
* MM:mm
* MM is the major
* mm is the minor
* The value is in decimal.
*/
static int get_major_minor(struct sysfs_class_device *class_dev, struct udevice *udev)
{
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", &udev->major, &udev->minor) != 2)
goto exit;
dbg("found major=%d, minor=%d", udev->major, udev->minor);
retval = 0;
exit:
return retval;
}
static int create_path(char *file)
{
char p[NAME_SIZE];
char *pos;
int retval;
struct stat stats;
strncpy(p, file, sizeof(p));
pos = strchr(p+1, '/');
while (1) {
pos = strchr(pos+1, '/');
if (pos == NULL)
break;
*pos = 0x00;
if (stat(p, &stats)) {
retval = mkdir(p, 0755);
if (retval) {
dbg("mkdir(%s) failed with error '%s'",
p, strerror(errno));
return retval;
}
dbg("created '%s'", p);
}
*pos = '/';
}
return 0;
}
static int create_node(struct udevice *dev)
{
char filename[255];
char linktarget[255];
char *linkname;
char *symlinks;
int retval = 0;
uid_t uid = 0;
gid_t gid = 0;
dev_t res;
int i;
int tail;
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, dev->name, sizeof(filename));
#ifdef __KLIBC__
res = (dev->major << 8) | (dev->minor);
#else
res = makedev(dev->major, dev->minor);
#endif
switch (dev->type) {
case 'b':
dev->mode |= S_IFBLK;
break;
case 'c':
case 'u':
dev->mode |= S_IFCHR;
break;
case 'p':
dev->mode |= S_IFIFO;
break;
default:
dbg("unknown node type %c\n", dev->type);
return -EINVAL;
}
/* create parent directories if needed */
if (strrchr(dev->name, '/'))
create_path(filename);
dbg("mknod(%s, %#o, %u, %u)", filename, dev->mode, dev->major, dev->minor);
retval = mknod(filename, dev->mode, res);
if (retval)
dbg("mknod(%s, %#o, %u, %u) failed with error '%s'",
filename, dev->mode, dev->major, dev->minor, strerror(errno));
dbg("chmod(%s, %#o)", filename, dev->mode);
retval = chmod(filename, dev->mode);
if (retval)
dbg("chmod(%s, %#o) failed with error '%s'",
filename, dev->mode, strerror(errno));
if (*dev->owner) {
char *endptr;
unsigned long id = strtoul(dev->owner, &endptr, 10);
if (*endptr == 0x00)
uid = (uid_t) id;
else {
struct passwd *pw = getpwnam(dev->owner);
if (!pw)
dbg("user unknown '%s'", dev->owner);
else
uid = pw->pw_uid;
}
}
if (*dev->group) {
char *endptr;
unsigned long id = strtoul(dev->group, &endptr, 10);
if (*endptr == 0x00)
gid = (gid_t) id;
else {
struct group *gr = getgrnam(dev->group);
if (!gr)
dbg("group unknown '%s'", dev->group);
else
gid = gr->gr_gid;
}
}
if (uid || gid) {
dbg("chown(%s, %u, %u)", filename, uid, gid);
retval = chown(filename, uid, gid);
if (retval)
dbg("chown(%s, %u, %u) failed with error '%s'",
filename, uid, gid, strerror(errno));
}
/* create symlink if requested */
if (*dev->symlink) {
symlinks = dev->symlink;
while (1) {
linkname = strsep(&symlinks, " ");
if (linkname == NULL)
break;
strncpy(filename, udev_root, sizeof(filename));
strncat(filename, linkname, sizeof(filename));
dbg("symlink '%s' to node '%s' requested", filename, dev->name);
if (strrchr(linkname, '/'))
create_path(filename);
/* optimize relative link */
linktarget[0] = '\0';
i = 0;
tail = 0;
while ((dev->name[i] == linkname[i]) && dev->name[i]) {
if (dev->name[i] == '/')
tail = i+1;
i++;
}
while (linkname[i]) {
if (linkname[i] == '/')
strcat(linktarget, "../");
i++;
}
if (*linktarget == '\0')
strcpy(linktarget, "./");
strcat(linktarget, &dev->name[tail]);
dbg("symlink(%s, %s)", linktarget, filename);
retval = symlink(linktarget, filename);
if (retval)
dbg("symlink(%s, %s) failed with error '%s'",
linktarget, filename, strerror(errno));
}
}
return retval;
}
static struct sysfs_class_device *get_class_dev(char *device_name)
{
char dev_path[SYSFS_PATH_MAX];
struct sysfs_class_device *class_dev = NULL;
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;
}
/* wait for the "dev" file to show up in the directory in sysfs.
* If it doesn't happen in about 10 seconds, give up.
*/
#define SECONDS_TO_WAIT_FOR_DEV 10
static int sleep_for_dev(char *path)
{
char filename[SYSFS_PATH_MAX + 6];
int loop = SECONDS_TO_WAIT_FOR_DEV;
int retval;
strcpy(filename, sysfs_path);
strcat(filename, path);
strcat(filename, "/dev");
while (loop--) {
struct stat buf;
dbg("looking for '%s'", filename);
retval = stat(filename, &buf);
if (!retval)
goto exit;
/* sleep to give the kernel a chance to create the dev file */
sleep(1);
}
retval = -ENODEV;
exit:
return retval;
}
int udev_add_device(char *path, char *subsystem)
{
struct sysfs_class_device *class_dev = NULL;
struct udevice dev;
int retval = -EINVAL;
memset(&dev, 0x00, sizeof(dev));
/* for now, the block layer is the only place where block devices are */
if (strcmp(subsystem, "block") == 0)
dev.type = 'b';
else
dev.type = 'c';
retval = sleep_for_dev(path);
if (retval)
goto exit;
class_dev = get_class_dev(path);
if (class_dev == NULL)
goto exit;
retval = get_major_minor(class_dev, &dev);
if (retval) {
dbg("get_major_minor failed");
goto exit;
}
retval = namedev_name_device(class_dev, &dev);
if (retval)
goto exit;
retval = udevdb_add_dev(path, &dev);
if (retval != 0)
dbg("udevdb_add_dev failed, but we are going to try to create the node anyway. "
"But remove might not work properly for this device.");
dbg("name='%s'", dev.name);
retval = create_node(&dev);
if (retval == 0)
sysbus_send_create(&dev, path);
exit:
if (class_dev)
sysfs_close_class_device(class_dev);
return retval;
}