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%llx, size 0x%llx\n",
  76             (unsigned long long) off, (unsigned long long) size);
  77         if (size < 0x10000)
  78                 return -1;
  79
  80         buf = volume_id_get_buffer(id, off, 0x800);
  81         if (buf == NULL)
  82                 return -1;
  83         mdp0 = (struct mdp0_super_block *) buf;
  84
  85         if (le32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
  86                 uuid.ints[0] = bswap_32(mdp0->set_uuid0);
  87                 if (le32_to_cpu(mdp0->minor_version >= 90)) {
  88                         uuid.ints[1] = bswap_32(mdp0->set_uuid1);
  89                         uuid.ints[2] = bswap_32(mdp0->set_uuid2);
  90                         uuid.ints[3] = bswap_32(mdp0->set_uuid3);
  91                 } else {
  92                         uuid.ints[1] = 0;
  93                         uuid.ints[2] = 0;
  94                         uuid.ints[3] = 0;
  95                 }
  96                 volume_id_set_uuid(id, uuid.bytes, 0, UUID_MD);
  97                 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u.%u",
  98                          le32_to_cpu(mdp0->major_version),
  99                          le32_to_cpu(mdp0->minor_version),
 100                          le32_to_cpu(mdp0->patch_version));
 101         } else if (be32_to_cpu(mdp0->md_magic) == MD_SB_MAGIC) {
 102                 uuid.ints[0] = mdp0->set_uuid0;
 103                 if (be32_to_cpu(mdp0->minor_version >= 90)) {
 104                         uuid.ints[1] = mdp0->set_uuid1;
 105                         uuid.ints[2] = mdp0->set_uuid2;
 106                         uuid.ints[3] = mdp0->set_uuid3;
 107                 } else {
 108                         uuid.ints[1] = 0;
 109                         uuid.ints[2] = 0;
 110                         uuid.ints[3] = 0;
 111                 }
 112                 volume_id_set_uuid(id, uuid.bytes, 0, UUID_MD);
 113                 snprintf(id->type_version, sizeof(id->type_version)-1, "%u.%u.%u",
 114                          be32_to_cpu(mdp0->major_version),
 115                          be32_to_cpu(mdp0->minor_version),
 116                          be32_to_cpu(mdp0->patch_version));
 117         } else
 118                 return -1;
 119
 120         volume_id_set_usage(id, VOLUME_ID_RAID);
 121         id->type = "linux_raid_member";
 122         return 0;
 123 }
 124
 125 static int volume_id_probe_linux_raid1(struct volume_id *id, uint64_t off, uint64_t size)
 126 {
 127         const uint8_t *buf;
 128         struct mdp1_super_block *mdp1;
 129
 130         info("probing at offset 0x%llx, size 0x%llx\n",
 131             (unsigned long long) off, (unsigned long long) size);
 132
 133         buf = volume_id_get_buffer(id, off, 0x800);
 134         if (buf == NULL)
 135                 return -1;
 136         mdp1 = (struct mdp1_super_block *) buf;
 137
 138         if (le32_to_cpu(mdp1->magic) != MD_SB_MAGIC)
 139                 return -1;
 140
 141         if (le32_to_cpu(mdp1->major_version) != 1)
 142                 return -1;
 143
 144         volume_id_set_uuid(id, mdp1->set_uuid, 0, UUID_MD);
 145         volume_id_set_label_raw(id, mdp1->set_name, 32);
 146         volume_id_set_label_string(id, mdp1->set_name, 32);
 147         volume_id_set_usage(id, VOLUME_ID_RAID);
 148         id->type = "linux_raid_member";
 149         return 0;
 150 }
 151
 152 int volume_id_probe_linux_raid(struct volume_id *id, uint64_t off, uint64_t size)
 153 {
 154         uint64_t sboff;
 155
 156         if (size > MD_RESERVED_BYTES) {
 157                 /* version 0 at the end of the device */
 158                 sboff = (size & ~(MD_RESERVED_BYTES - 1)) - MD_RESERVED_BYTES;
 159                 if (volume_id_probe_linux_raid0(id, off + sboff, size) == 0)
 160                         return 0;
 161
 162                 /* version 1.0 at the end of the device */
 163                 sboff = (size & ~(0x1000 - 1)) - 0x2000;
 164                 if (volume_id_probe_linux_raid1(id, off + sboff, size) == 0) {
 165                         strcpy(id->type_version, "1.0");
 166                         return 0;
 167                 }
 168         }
 169
 170         /* version 1.1 at the start of the device */
 171         if (volume_id_probe_linux_raid1(id, off, size) == 0) {
 172                 strcpy(id->type_version, "1.1");
 173                 return 0;
 174         }
 175
 176         /* version 1.2 at 4k offset from the start */
 177         if (volume_id_probe_linux_raid1(id, off + 0x1000, size) == 0) {
 178                 strcpy(id->type_version, "1.2");
 179                 return 0;
 180         }
 181
 182         return -1;
 183 }