extras/volume_id/lib/minix.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2005-2007 Kay Sievers <kay.sievers@vrfy.org>
   5  *
   6  * This program is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #ifndef _GNU_SOURCE
  21 #define _GNU_SOURCE 1
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <unistd.h>
  27 #include <string.h>
  28 #include <errno.h>
  29 #include <ctype.h>
  30
  31 #include "libvolume_id.h"
  32 #include "libvolume_id-private.h"
  33
  34 #define MINIX_SUPERBLOCK_OFFSET                 0x400
  35
  36 #define MINIX_SUPER_MAGIC                       0x137F
  37 #define MINIX_SUPER_MAGIC2                      0x138F
  38 #define MINIX2_SUPER_MAGIC                      0x2468
  39 #define MINIX2_SUPER_MAGIC2                     0x2478
  40 #define MINIX3_SUPER_MAGIC                      0x4d5a
  41
  42 struct minix_super_block
  43 {
  44         uint16_t        s_ninodes;
  45         uint16_t        s_nzones;
  46         uint16_t        s_imap_blocks;
  47         uint16_t        s_zmap_blocks;
  48         uint16_t        s_firstdatazone;
  49         uint16_t        s_log_zone_size;
  50         uint32_t        s_max_size;
  51         uint16_t        s_magic;
  52         uint16_t        s_state;
  53         uint32_t        s_zones;
  54 } PACKED;
  55
  56 struct minix3_super_block {
  57         uint32_t        s_ninodes;
  58         uint16_t        s_pad0;
  59         uint16_t        s_imap_blocks;
  60         uint16_t        s_zmap_blocks;
  61         uint16_t        s_firstdatazone;
  62         uint16_t        s_log_zone_size;
  63         uint16_t        s_pad1;
  64         uint32_t        s_max_size;
  65         uint32_t        s_zones;
  66         uint16_t        s_magic;
  67         uint16_t        s_pad2;
  68         uint16_t        s_blocksize;
  69         uint8_t         s_disk_version;
  70 } PACKED;
  71
  72 int volume_id_probe_minix(struct volume_id *id, uint64_t off, uint64_t size)
  73 {
  74         uint8_t *buf;
  75         struct minix_super_block *ms;
  76         struct minix3_super_block *m3s;
  77
  78         info("probing at offset 0x%llx\n", (unsigned long long) off);
  79
  80         buf = volume_id_get_buffer(id, off + MINIX_SUPERBLOCK_OFFSET, 0x200);
  81         if (buf == NULL)
  82                 return -1;
  83
  84         ms = (struct minix_super_block *) buf;
  85
  86         if (ms->s_magic == MINIX_SUPER_MAGIC ||
  87             ms->s_magic == bswap_16(MINIX_SUPER_MAGIC)) {
  88                 strcpy(id->type_version, "1");
  89                 goto found;
  90         }
  91         if (ms->s_magic == MINIX_SUPER_MAGIC2 ||
  92             ms->s_magic == bswap_16(MINIX_SUPER_MAGIC2)) {
  93                 strcpy(id->type_version, "1");
  94                 goto found;
  95         }
  96         if (ms->s_magic == MINIX2_SUPER_MAGIC ||
  97             ms->s_magic == bswap_16(MINIX2_SUPER_MAGIC)) {
  98                 strcpy(id->type_version, "2");
  99                 goto found;
 100         }
 101         if (ms->s_magic == MINIX2_SUPER_MAGIC2 ||
 102             ms->s_magic == bswap_16(MINIX2_SUPER_MAGIC2)) {
 103                 strcpy(id->type_version, "2");
 104                 goto found;
 105         }
 106
 107         m3s = (struct minix3_super_block *) buf;
 108         if (m3s->s_magic == MINIX3_SUPER_MAGIC ||
 109             m3s->s_magic == bswap_16(MINIX3_SUPER_MAGIC)) {
 110                 strcpy(id->type_version, "3");
 111                 goto found;
 112         }
 113         goto exit;
 114
 115 found:
 116         volume_id_set_usage(id, VOLUME_ID_FILESYSTEM);
 117         id->type = "minix";
 118         return 0;
 119
 120 exit:
 121         return -1;
 122 }