1  /*
       2   * Copyright (C) 2008 Karel Zak <kzak@redhat.com>
       3   *
       4   * This is written from scratch according to Linux kernel fs/sysv/super.c file.
       5   * It seems that sysv probing code in libvolume_id and also in the original
       6   * blkid is useless.
       7   *
       8   * This file may be redistributed under the terms of the
       9   * GNU Lesser General Public License.
      10   */
      11  #include <stdio.h>
      12  #include <stdlib.h>
      13  #include <unistd.h>
      14  #include <stdint.h>
      15  #include <stddef.h>
      16  
      17  #include "superblocks.h"
      18  
      19  #define XENIX_NICINOD				100
      20  #define XENIX_NICFREE				100
      21  
      22  struct xenix_super_block {
      23  	uint16_t	s_isize;
      24  	uint32_t	s_fsize;
      25  	uint16_t	s_nfree;
      26  	uint32_t	s_free[XENIX_NICFREE];
      27  	uint16_t	s_ninode;
      28  	uint16_t	s_inode[XENIX_NICINOD];
      29  	uint8_t		s_flock;
      30  	uint8_t		s_ilock;
      31  	uint8_t		s_fmod;
      32  	uint8_t		s_ronly;
      33  	uint32_t	s_time;
      34  	uint32_t	s_tfree;
      35  	uint16_t	s_tinode;
      36  	uint16_t	s_dinfo[4];
      37  	uint8_t		s_fname[6];
      38  	uint8_t		s_fpack[6];
      39  	uint8_t		s_clean;
      40  	uint8_t		s_fill[371];
      41  	uint32_t	s_magic;
      42  	uint32_t	s_type;
      43  } __attribute__((packed));
      44  
      45  
      46  #define SYSV_NICINOD			100
      47  #define SYSV_NICFREE			50
      48  
      49  struct sysv_super_block
      50  {
      51  	uint16_t	s_isize;
      52  	uint16_t	s_pad0;
      53  	uint32_t	s_fsize;
      54  	uint16_t	s_nfree;
      55  	uint16_t	s_pad1;
      56  	uint32_t	s_free[SYSV_NICFREE];
      57  	uint16_t	s_ninode;
      58  	uint16_t	s_pad2;
      59  	uint16_t	s_inode[SYSV_NICINOD];
      60  	uint8_t		s_flock;
      61  	uint8_t		s_ilock;
      62  	uint8_t		s_fmod;
      63  	uint8_t		s_ronly;
      64  	uint32_t	s_time;
      65  	uint16_t	s_dinfo[4];
      66  	uint32_t	s_tfree;
      67  	uint16_t	s_tinode;
      68  	uint16_t	s_pad3;
      69  	uint8_t		s_fname[6];
      70  	uint8_t		s_fpack[6];
      71  	uint32_t	s_fill[12];
      72  	uint32_t	s_state;
      73  	uint32_t	s_magic;
      74  	uint32_t	s_type;
      75  };
      76  
      77  static int probe_xenix(blkid_probe pr, const struct blkid_idmag *mag)
      78  {
      79  	struct xenix_super_block *sb;
      80  
      81  	sb = blkid_probe_get_sb(pr, mag, struct xenix_super_block);
      82  	if (!sb)
      83  		return errno ? -errno : 1;
      84  	blkid_probe_set_label(pr, sb->s_fname, sizeof(sb->s_fname));
      85  	return 0;
      86  }
      87  
      88  #define SYSV_BLOCK_SIZE	1024
      89  
      90  /* Note that we don't probe for Coherent FS, this FS does not have
      91   * magic string. (It requires to probe fname/fpack field..)
      92   */
      93  static int probe_sysv(blkid_probe pr,
      94  		const struct blkid_idmag *mag __attribute__((__unused__)))
      95  {
      96  	struct sysv_super_block *sb;
      97  	int blocks[] = {0, 9, 15, 18};
      98  	size_t i;
      99  
     100  	for (i = 0; i < ARRAY_SIZE(blocks); i++) {
     101  		int off = blocks[i] * SYSV_BLOCK_SIZE + SYSV_BLOCK_SIZE/2;
     102  
     103  		sb = (struct sysv_super_block *)
     104  			blkid_probe_get_buffer(pr,
     105  					off,
     106  					sizeof(struct sysv_super_block));
     107  		if (!sb)
     108  			return errno ? -errno : 1;
     109  
     110  		if (sb->s_magic == cpu_to_le32(0xfd187e20) ||
     111  		    sb->s_magic == cpu_to_be32(0xfd187e20)) {
     112  
     113  			if (blkid_probe_set_label(pr, sb->s_fname,
     114  						sizeof(sb->s_fname)))
     115  				return 1;
     116  
     117  			if (blkid_probe_set_magic(pr,
     118  					off + offsetof(struct sysv_super_block,
     119  								s_magic),
     120  					sizeof(sb->s_magic),
     121  					(unsigned char *) &sb->s_magic))
     122  				return 1;
     123  
     124  			return 0;
     125  		}
     126  	}
     127  	return 1;
     128  }
     129  
     130  const struct blkid_idinfo xenix_idinfo =
     131  {
     132  	.name		= "xenix",
     133  	.usage		= BLKID_USAGE_FILESYSTEM,
     134  	.probefunc	= probe_xenix,
     135  	.magics		=
     136  	{
     137  		{ .magic = "\x2b\x55\x44", .len = 3, .kboff = 1, .sboff = 0x400 },
     138  		{ .magic = "\x44\x55\x2b", .len = 3, .kboff = 1, .sboff = 0x400 },
     139  		{ NULL }
     140  	}
     141  };
     142  
     143  const struct blkid_idinfo sysv_idinfo =
     144  {
     145  	.name		= "sysv",
     146  	.usage		= BLKID_USAGE_FILESYSTEM,
     147  	.probefunc	= probe_sysv,
     148  
     149  	/* SYSV is BE and LE and superblock could be on four positions. It's
     150  	 * simpler to probe for the magic string by .probefunc().
     151  	 */
     152  	.magics		= BLKID_NONE_MAGIC
     153  };
     154