diff options
Diffstat (limited to 'libblkid/lvm2.c')
| -rw-r--r-- | libblkid/lvm2.c | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/libblkid/lvm2.c b/libblkid/lvm2.c new file mode 100644 index 000000000..0afc77322 --- /dev/null +++ b/libblkid/lvm2.c @@ -0,0 +1,228 @@ +/* + * Copyright (C) 1999 by Andries Brouwer + * Copyright (C) 1999, 2000, 2003 by Theodore Ts'o + * Copyright (C) 2001 by Andreas Dilger + * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org> + * Copyright (C) 2008 Karel Zak <kzak@redhat.com> + * Copyright (C) 2012 Milan Broz <mbroz@redhat.com> + * + * This file may be redistributed under the terms of the + * GNU Lesser General Public License. + */ +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <string.h> +#include <stdint.h> + +#include "superblocks.h" + +#define LVM1_ID_LEN 128 +#define LVM2_ID_LEN 32 + +struct lvm2_pv_label_header { + /* label_header */ + uint8_t id[8]; /* LABELONE */ + uint64_t sector_xl; /* Sector number of this label */ + uint32_t crc_xl; /* From next field to end of sector */ + uint32_t offset_xl; /* Offset from start of struct to contents */ + uint8_t type[8]; /* LVM2 001 */ + /* pv_header */ + uint8_t pv_uuid[LVM2_ID_LEN]; +} __attribute__ ((packed)); + +struct lvm1_pv_label_header { + uint8_t id[2]; /* HM */ + uint16_t version; /* version 1 or 2 */ + uint32_t _notused[10]; /* lvm1 internals */ + uint8_t pv_uuid[LVM1_ID_LEN]; +} __attribute__ ((packed)); + +#define LVM2_LABEL_SIZE 512 +static unsigned int lvm2_calc_crc(const void *buf, unsigned int size) +{ + static const unsigned int crctab[] = { + 0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, + 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c, + 0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, + 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c + }; + unsigned int i, crc = 0xf597a6cf; + const uint8_t *data = (const uint8_t *) buf; + + for (i = 0; i < size; i++) { + crc ^= *data++; + crc = (crc >> 4) ^ crctab[crc & 0xf]; + crc = (crc >> 4) ^ crctab[crc & 0xf]; + } + return crc; +} + +/* Length of real UUID is always LVM2_ID_LEN */ +static void format_lvm_uuid(char *dst_uuid, char *src_uuid) +{ + unsigned int i, b; + + for (i = 0, b = 1; i < LVM2_ID_LEN; i++, b <<= 1) { + if (b & 0x4444440) + *dst_uuid++ = '-'; + *dst_uuid++ = *src_uuid++; + } + *dst_uuid = '\0'; +} + +static int probe_lvm2(blkid_probe pr, const struct blkid_idmag *mag) +{ + int sector = mag->kboff << 1; + struct lvm2_pv_label_header *label; + char uuid[LVM2_ID_LEN + 7]; + unsigned char *buf; + + buf = blkid_probe_get_buffer(pr, + mag->kboff << 10, + 512 + sizeof(struct lvm2_pv_label_header)); + if (!buf) + return -1; + + /* buf is at 0k or 1k offset; find label inside */ + if (memcmp(buf, "LABELONE", 8) == 0) { + label = (struct lvm2_pv_label_header *) buf; + } else if (memcmp(buf + 512, "LABELONE", 8) == 0) { + label = (struct lvm2_pv_label_header *)(buf + 512); + sector++; + } else { + return 1; + } + + if (le64_to_cpu(label->sector_xl) != (unsigned) sector) + return 1; + + if (lvm2_calc_crc(&label->offset_xl, LVM2_LABEL_SIZE - + ((char *) &label->offset_xl - (char *) label)) != + le32_to_cpu(label->crc_xl)) { + DBG(DEBUG_PROBE, + printf("LVM2: label checksum incorrect at sector %d\n", + sector)); + return 1; + } + + format_lvm_uuid(uuid, (char *) label->pv_uuid); + blkid_probe_sprintf_uuid(pr, label->pv_uuid, sizeof(label->pv_uuid), + "%s", uuid); + + /* the mag->magic is the same string as label->type, + * but zero terminated */ + blkid_probe_set_version(pr, mag->magic); + + /* LVM (pvcreate) wipes begin of the device -- let's remember this + * to resolve conflicts bettween LVM and partition tables, ... + */ + blkid_probe_set_wiper(pr, 0, 8 * 1024); + + return 0; +} + +static int probe_lvm1(blkid_probe pr, const struct blkid_idmag *mag) +{ + struct lvm1_pv_label_header *label; + char uuid[LVM2_ID_LEN + 7]; + unsigned int version; + + label = blkid_probe_get_sb(pr, mag, struct lvm1_pv_label_header); + if (!label) + return -1; + + version = le16_to_cpu(label->version); + if (version != 1 && version != 2) + return 1; + + format_lvm_uuid(uuid, (char *) label->pv_uuid); + blkid_probe_sprintf_uuid(pr, label->pv_uuid, sizeof(label->pv_uuid), + "%s", uuid); + + return 0; +} + +struct verity_sb { + uint8_t signature[8]; /* "verity\0\0" */ + uint32_t version; /* superblock version */ + uint32_t hash_type; /* 0 - Chrome OS, 1 - normal */ + uint8_t uuid[16]; /* UUID of hash device */ + uint8_t algorithm[32];/* hash algorithm name */ + uint32_t data_block_size; /* data block in bytes */ + uint32_t hash_block_size; /* hash block in bytes */ + uint64_t data_blocks; /* number of data blocks */ + uint16_t salt_size; /* salt size */ + uint8_t _pad1[6]; + uint8_t salt[256]; /* salt */ + uint8_t _pad2[168]; +} __attribute__((packed)); + +static int probe_verity(blkid_probe pr, const struct blkid_idmag *mag) +{ + struct verity_sb *sb; + unsigned int version; + + sb = blkid_probe_get_sb(pr, mag, struct verity_sb); + if (sb == NULL) + return -1; + + version = le32_to_cpu(sb->version); + if (version != 1) + return 1; + + blkid_probe_set_uuid(pr, sb->uuid); + blkid_probe_sprintf_version(pr, "%u", version); + return 0; +} + +/* NOTE: the original libblkid uses "lvm2pv" as a name */ +const struct blkid_idinfo lvm2_idinfo = +{ + .name = "LVM2_member", + .usage = BLKID_USAGE_RAID, + .probefunc = probe_lvm2, + .magics = + { + { .magic = "LVM2 001", .len = 8, .sboff = 0x218 }, + { .magic = "LVM2 001", .len = 8, .sboff = 0x018 }, + { .magic = "LVM2 001", .len = 8, .kboff = 1, .sboff = 0x018 }, + { .magic = "LVM2 001", .len = 8, .kboff = 1, .sboff = 0x218 }, + { NULL } + } +}; + +const struct blkid_idinfo lvm1_idinfo = +{ + .name = "LVM1_member", + .usage = BLKID_USAGE_RAID, + .probefunc = probe_lvm1, + .magics = + { + { .magic = "HM", .len = 2 }, + { NULL } + } +}; + +const struct blkid_idinfo snapcow_idinfo = +{ + .name = "DM_snapshot_cow", + .usage = BLKID_USAGE_OTHER, + .magics = + { + { .magic = "SnAp", .len = 4 }, + { NULL } + } +}; + +const struct blkid_idinfo verity_hash_idinfo = +{ + .name = "DM_verity_hash", + .usage = BLKID_USAGE_CRYPTO, + .probefunc = probe_verity, + .magics = + { + { .magic = "verity\0\0", .len = 8 }, + { NULL } + } +}; |