busybox

/* vi: set sw=4 ts=4: */

/*

 * probe.c - identify a block device by its contents, and return a dev

 *           struct with the details

 *

 * Copyright (C) 1999 by Andries Brouwer

 * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o

 * Copyright (C) 2001 by Andreas Dilger

 *

 * %Begin-Header%

 * This file may be redistributed under the terms of the

 * GNU Lesser General Public License.

 * %End-Header%

 */

​

#include <stdio.h>

#include <string.h>

#include <stdlib.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/types.h>

#ifdef HAVE_SYS_STAT_H

#include <sys/stat.h>

#endif

#ifdef HAVE_SYS_MKDEV_H

#include <sys/mkdev.h>

#endif

#ifdef HAVE_ERRNO_H

#include <errno.h>

#endif

#include "blkidP.h"

#include "../uuid/uuid.h"

#include "probe.h"

​

/*

 * This is a special case code to check for an MDRAID device.  We do

 * this special since it requires checking for a superblock at the end

 * of the device.

 */

static int check_mdraid(int fd, unsigned char *ret_uuid)

{

    struct mdp_superblock_s *md;

    blkid_loff_t        offset;

    char            buf[4096];

​

    if (fd < 0)

        return -BLKID_ERR_PARAM;

​

    offset = (blkid_get_dev_size(fd) & ~((blkid_loff_t)65535)) - 65536;

​

    if (blkid_llseek(fd, offset, 0) < 0 ||

        read(fd, buf, 4096) != 4096)

        return -BLKID_ERR_IO;

​

    /* Check for magic number */

    if (memcmp("\251+N\374", buf, 4))

        return -BLKID_ERR_PARAM;

​

    if (!ret_uuid)

        return 0;

    *ret_uuid = 0;

​

    /* The MD UUID is not contiguous in the superblock, make it so */

    md = (struct mdp_superblock_s *)buf;

    if (md->set_uuid0 || md->set_uuid1 || md->set_uuid2 || md->set_uuid3) {

        memcpy(ret_uuid, &md->set_uuid0, 4);

        memcpy(ret_uuid, &md->set_uuid1, 12);

    }

    return 0;

}

​

static void set_uuid(blkid_dev dev, uuid_t uuid)

{

    char    str[37];

​

    if (!uuid_is_null(uuid)) {

        uuid_unparse(uuid, str);

        blkid_set_tag(dev, "UUID", str, sizeof(str));

    }

}

​

static void get_ext2_info(blkid_dev dev, unsigned char *buf)

{

    struct ext2_super_block *es = (struct ext2_super_block *) buf;

    const char *label = NULL;

​

    DBG(DEBUG_PROBE, printf("ext2_sb.compat = %08X:%08X:%08X\n",

           blkid_le32(es->s_feature_compat),

           blkid_le32(es->s_feature_incompat),

           blkid_le32(es->s_feature_ro_compat)));

​

    if (strlen(es->s_volume_name))