| /* |
| * Copyright (C) 2012 Red Hat, Inc. |
| * Copyright (C) 2015 Google, Inc. |
| * |
| * Author: Mikulas Patocka <mpatocka@redhat.com> |
| * |
| * Based on Chromium dm-verity driver (C) 2011 The Chromium OS Authors |
| * |
| * This file is released under the GPLv2. |
| */ |
| |
| #ifndef DM_VERITY_H |
| #define DM_VERITY_H |
| |
| #include "dm-bufio.h" |
| #include <linux/device-mapper.h> |
| #include <crypto/hash.h> |
| |
| #define DM_VERITY_MAX_LEVELS 63 |
| |
| enum verity_mode { |
| DM_VERITY_MODE_EIO, |
| DM_VERITY_MODE_LOGGING, |
| DM_VERITY_MODE_RESTART |
| }; |
| |
| enum verity_block_type { |
| DM_VERITY_BLOCK_TYPE_DATA, |
| DM_VERITY_BLOCK_TYPE_METADATA |
| }; |
| |
| struct dm_verity { |
| struct dm_dev *data_dev; |
| struct dm_dev *hash_dev; |
| struct dm_target *ti; |
| struct dm_bufio_client *bufio; |
| char *alg_name; |
| struct crypto_shash *tfm; |
| u8 *root_digest; /* digest of the root block */ |
| u8 *salt; /* salt: its size is salt_size */ |
| unsigned salt_size; |
| sector_t data_start; /* data offset in 512-byte sectors */ |
| sector_t hash_start; /* hash start in blocks */ |
| sector_t data_blocks; /* the number of data blocks */ |
| sector_t hash_blocks; /* the number of hash blocks */ |
| unsigned char data_dev_block_bits; /* log2(data blocksize) */ |
| unsigned char hash_dev_block_bits; /* log2(hash blocksize) */ |
| unsigned char hash_per_block_bits; /* log2(hashes in hash block) */ |
| unsigned char levels; /* the number of tree levels */ |
| unsigned char version; |
| unsigned digest_size; /* digest size for the current hash algorithm */ |
| unsigned shash_descsize;/* the size of temporary space for crypto */ |
| int hash_failed; /* set to 1 if hash of any block failed */ |
| enum verity_mode mode; /* mode for handling verification errors */ |
| unsigned corrupted_errs;/* Number of errors for corrupted blocks */ |
| |
| struct workqueue_struct *verify_wq; |
| |
| /* starting blocks for each tree level. 0 is the lowest level. */ |
| sector_t hash_level_block[DM_VERITY_MAX_LEVELS]; |
| }; |
| |
| struct dm_verity_io { |
| struct dm_verity *v; |
| |
| /* original value of bio->bi_end_io */ |
| bio_end_io_t *orig_bi_end_io; |
| |
| sector_t block; |
| unsigned n_blocks; |
| |
| struct bvec_iter iter; |
| |
| struct work_struct work; |
| |
| /* |
| * Three variably-size fields follow this struct: |
| * |
| * u8 hash_desc[v->shash_descsize]; |
| * u8 real_digest[v->digest_size]; |
| * u8 want_digest[v->digest_size]; |
| * |
| * To access them use: verity_io_hash_desc(), verity_io_real_digest() |
| * and verity_io_want_digest(). |
| */ |
| }; |
| |
| static inline struct shash_desc *verity_io_hash_desc(struct dm_verity *v, |
| struct dm_verity_io *io) |
| { |
| return (struct shash_desc *)(io + 1); |
| } |
| |
| static inline u8 *verity_io_real_digest(struct dm_verity *v, |
| struct dm_verity_io *io) |
| { |
| return (u8 *)(io + 1) + v->shash_descsize; |
| } |
| |
| static inline u8 *verity_io_want_digest(struct dm_verity *v, |
| struct dm_verity_io *io) |
| { |
| return (u8 *)(io + 1) + v->shash_descsize + v->digest_size; |
| } |
| |
| extern int verity_for_bv_block(struct dm_verity *v, struct dm_verity_io *io, |
| struct bvec_iter *iter, |
| int (*process)(struct dm_verity *v, |
| struct dm_verity_io *io, |
| u8 *data, size_t len)); |
| |
| extern int verity_hash(struct dm_verity *v, struct shash_desc *desc, |
| const u8 *data, size_t len, u8 *digest); |
| |
| extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, |
| sector_t block, u8 *digest); |
| |
| #endif /* DM_VERITY_H */ |