1  /*
       2   * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
       3   *
       4   * Inspired by libvolume_id by
       5   *     Kay Sievers <kay.sievers@vrfy.org>
       6   *
       7   * This file may be redistributed under the terms of the
       8   * GNU Lesser General Public License.
       9   */
      10  #include <stdio.h>
      11  #include <stdlib.h>
      12  #include <unistd.h>
      13  #include <string.h>
      14  #include <stdint.h>
      15  
      16  #include "bitops.h"	/* swab16() */
      17  #include "superblocks.h"
      18  
      19  struct sqsh_super_block {
      20  	uint32_t	magic;
      21  	uint32_t	inode_count;
      22  	uint32_t	mod_time;
      23  	uint32_t	block_size;
      24  	uint32_t	frag_count;
      25  	uint16_t	compressor;
      26  	uint16_t	block_log;
      27  	uint16_t	flags;
      28  	uint16_t	id_count;
      29  	uint16_t	version_major;
      30  	uint16_t	version_minor;
      31  	uint64_t	root_inode;
      32  	uint64_t	bytes_used;
      33  	uint64_t	id_table;
      34  	uint64_t	xattr_table;
      35  	uint64_t	inode_table;
      36  	uint64_t	dir_table;
      37  	uint64_t	frag_table;
      38  	uint64_t	export_table;
      39  } __attribute__((packed));
      40  
      41  static int probe_squashfs(blkid_probe pr, const struct blkid_idmag *mag)
      42  {
      43  	struct sqsh_super_block *sq;
      44  	uint16_t vermaj;
      45  	uint16_t vermin;
      46  
      47  	sq = blkid_probe_get_sb(pr, mag, struct sqsh_super_block);
      48  	if (!sq)
      49  		return errno ? -errno : 1;
      50  
      51  	vermaj = le16_to_cpu(sq->version_major);
      52  	vermin = le16_to_cpu(sq->version_minor);
      53  	if (vermaj < 4)
      54  		return 1;
      55  
      56  	blkid_probe_sprintf_version(pr, "%u.%u", vermaj, vermin);
      57  	blkid_probe_set_fsblocksize(pr, le32_to_cpu(sq->block_size));
      58  	blkid_probe_set_block_size(pr, le32_to_cpu(sq->block_size));
      59  	blkid_probe_set_fssize(pr, le64_to_cpu(sq->bytes_used));
      60  
      61  	return 0;
      62  }
      63  
      64  static int probe_squashfs3(blkid_probe pr, const struct blkid_idmag *mag)
      65  {
      66  	struct sqsh_super_block *sq;
      67  	uint16_t vermaj;
      68  	uint16_t vermin;
      69  	enum BLKID_ENDIANNESS endianness;
      70  
      71  	sq = blkid_probe_get_sb(pr, mag, struct sqsh_super_block);
      72  	if (!sq)
      73  		return errno ? -errno : 1;
      74  
      75  	if (strcmp(mag->magic, "sqsh") == 0) {
      76  		vermaj = be16_to_cpu(sq->version_major);
      77  		vermin = be16_to_cpu(sq->version_minor);
      78  		endianness = BLKID_ENDIANNESS_BIG;
      79  	} else {
      80  		vermaj = le16_to_cpu(sq->version_major);
      81  		vermin = le16_to_cpu(sq->version_minor);
      82  		endianness = BLKID_ENDIANNESS_LITTLE;
      83  	}
      84  
      85  	if (vermaj > 3)
      86  		return 1;
      87  
      88  	blkid_probe_sprintf_version(pr, "%u.%u", vermaj, vermin);
      89  
      90  	blkid_probe_set_fsblocksize(pr, 1024);
      91  	blkid_probe_set_block_size(pr, 1024);
      92  	blkid_probe_set_fsendianness(pr, endianness);
      93  
      94  	return 0;
      95  }
      96  
      97  const struct blkid_idinfo squashfs_idinfo =
      98  {
      99  	.name		= "squashfs",
     100  	.usage		= BLKID_USAGE_FILESYSTEM,
     101  	.probefunc	= probe_squashfs,
     102  	.magics		=
     103  	{
     104  		{ .magic = "hsqs", .len = 4 },
     105  		{ NULL }
     106  	}
     107  };
     108  
     109  const struct blkid_idinfo squashfs3_idinfo =
     110  {
     111  	.name		= "squashfs3",
     112  	.usage		= BLKID_USAGE_FILESYSTEM,
     113  	.probefunc	= probe_squashfs3,
     114  	.magics		=
     115  	{
     116  		{ .magic = "sqsh", .len = 4 }, /* big endian */
     117  		{ .magic = "hsqs", .len = 4 }, /* little endian */
     118  		{ NULL }
     119  	}
     120  };
     121