extras/volume_id/lib/linux_raid.c

   1 /*
   2  * volume_id - reads filesystem label and uuid
   3  *
   4  * Copyright (C) 2004 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 #include <byteswap.h>
  31
  32 #include "libvolume_id.h"
  33 #include "libvolume_id-private.h"
  34
  35 struct mdp0_super_block {
  36         uint32_t        md_magic;
  37         uint32_t        major_version;
  38         uint32_t        minor_version;
  39         uint32_t        patch_version;
  40         uint32_t        gvalid_words;
  41         uint32_t        set_uuid0;
  42         uint32_t        ctime;
  43         uint32_t        level;
  44         uint32_t        size;
  45         uint32_t        nr_disks;
  46         uint32_t        raid_disks;
  47         uint32_t        md_minor;
  48         uint32_t        not_persistent;
  49         uint32_t        set_uuid1;
  50         uint32_t        set_uuid2;
  51         uint32_t        set_uuid3;
  52 } PACKED;
  53
  54 struct mdp1_super_block {
  55         uint32_t        magic;
  56         uint32_t        major_version;
  57         uint32_t        feature_map;
  58         uint32_t        pad0;
  59         uint8_t         set_uuid[16];
  60         uint8_t         set_name[32];
  61 } PACKED;
  62
  63 #define MD_RESERVED_BYTES               0x10000
  64 #define MD_SB_MAGIC                     0xa92b4efc
  65
  66 static int volume_id_probe_linux_raid0(struct volume_id *id, uint64_t off, uint64_t size)
  67 {
  68         const uint8_t *buf;
  69         struct mdp0_super_block *mdp0;
  70         union {
  71                 uint32_t ints[4];
  72                 uint8_t bytes[16];
  73         } uuid;
  74
  75         info("probing at offset 0x%" PRIx64 ", size 0x%" PRIx64 "\n", off, size);
  76         if (size < 0x10000)
  77                 return -1;
  78
  79         buf = volume_id_get_buffer(id, off, 0x800);
  80         if (buf == NULL)
  81                 return -1;
  82         mdp0 = (struct mdp0_super_block *) buf;
  83
  84         if (le32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
  85                 uuid.ints[0] = bswap_32(mdp0->set_uuid0);
  86                 if (le32_to_cpu(mdp0->minor_version >= 90)) {
  87                         uuid.ints[1] = bswap_32(mdp0->set_uuid1);
  88                         uuid.ints[2] = bswap_32(mdp0->set_uuid2);
  89                         uuid.ints[3] = bswap_32(mdp0->set_uuid3);
  90                 } else {
  91                         uuid.ints[1] = 0;
  92                         uuid.ints[2] = 0;
  93                         uuid.ints[3] = 0;
  94                 }
  95                 volume_id_set_uuid(id, uuid.bytes, 0, UUID_MD);
  96                 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u.%u",
  97                          le32_to_cpu(mdp0->major_version),
  98                          le32_to_cpu(mdp0->minor_version),
  99                          le32_to_cpu(mdp0->patch_version));
 100         } else if (be32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
 101                 uuid.ints[0] = mdp0->set_uuid0;
 102                 if (be32_to_cpu(mdp0->minor_version >= 90)) {
 103                         uuid.ints[1] = mdp0->set_uuid1;
 104                         uuid.ints[2] = mdp0->set_uuid2;
 105                         uuid.ints[3] = mdp0->set_uuid3;
 106                 } else {
 107                         uuid.ints[1] = 0;
 108                         uuid.ints[2] = 0;
 109                         uuid.ints[3] = 0;
 110                 }
 111                 volume_id_set_uuid(id, uuid.bytes, 0, UUID_MD);
 112                 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u.%u",
 113                          be32_to_cpu(mdp0->major_version),
 114                          be32_to_cpu(mdp0->minor_version),
 115                          be32_to_cpu(mdp0->patch_version));
 116         } else
 117                 return -1;
 118
 119         volume_id_set_usage(id, VOLUME_ID_RAID);
 120         id->type = "linux_raid_member";
 121         return 0;
 122 }
 123
 124 static int volume_id_probe_linux_raid1(struct volume_id *id, uint64_t off, uint64_t size)
 125 {
 126         const uint8_t *buf;
 127         struct mdp1_super_block *mdp1;
 128
 129         info("probing at offset 0x%" PRIx64 ", size 0x%" PRIx64 "\n", off, size);
 130
 131         buf = volume_id_get_buffer(id, off, 0x800);
 132         if (buf == NULL)
 133                 return -1;
 134         mdp1 = (struct mdp1_super_block *) buf;
 135
 136         if (le32_to_cpu(mdp1->magic) != MD_SB_MAGIC)
 137                 return -1;
 138
 139         if (le32_to_cpu(mdp1->major_version) != 1)
 140                 return -1;
 141
 142         volume_id_set_uuid(id, mdp1->set_uuid, 0, UUID_MD);
 143         volume_id_set_label_raw(id, mdp1->set_name, 32);
 144         volume_id_set_label_string(id, mdp1->set_name, 32);
 145         volume_id_set_usage(id, VOLUME_ID_RAID);
 146         id->type = "linux_raid_member";
 147         return 0;
 148 }
 149
 150 int volume_id_probe_linux_raid(struct volume_id *id, uint64_t off, uint64_t size)
 151 {
 152         uint64_t sboff;
 153
 154         if (size > MD_RESERVED_BYTES) {
 155                 /* version 0 at the end of the device */
 156                 sboff = (size & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES;
 157                 if (volume_id_probe_linux_raid0(id, off + sboff, size) == 0)
 158                         return 0;
 159
 160                 /* version 1.0 at the end of the device */
 161                 sboff = (size & ~(0x1000 - 1)) - 0x2000;
 162                 if (volume_id_probe_linux_raid1(id, off + sboff, size) == 0) {
 163                         strcpy(id->type_version, "1.0");
 164                         return 0;
 165                 }
 166         }
 167
 168         /* version 1.1 at the start of the device */
 169         if (volume_id_probe_linux_raid1(id, off, size) == 0) {
 170                 strcpy(id->type_version, "1.1");
 171                 return 0;
 172         }
 173
 174         /* version 1.2 at 4k offset from the start */
 175         if (volume_id_probe_linux_raid1(id, off + 0x1000, size) == 0) {
 176                 strcpy(id->type_version, "1.2");
 177                 return 0;
 178         }
 179
 180         return -1;
 181 }