132 lines
3.6 KiB
C
132 lines
3.6 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
|
|
/*
|
|
* 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
|
|
*/
|
|
|
|
#ifndef DM_VERITY_H
|
|
#define DM_VERITY_H
|
|
|
|
#include <linux/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_fec;
|
|
|
|
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_ahash *tfm;
|
|
u8 *root_digest; /* digest of the root block */
|
|
u8 *salt; /* salt: its size is salt_size */
|
|
u8 *zero_digest; /* digest for a zero block */
|
|
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 int ahash_reqsize;/* 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_fec *fec; /* forward error correction */
|
|
unsigned long *validated_blocks; /* bitset blocks validated */
|
|
|
|
char *signature_key_desc; /* signature keyring reference */
|
|
};
|
|
|
|
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_req[v->ahash_reqsize];
|
|
* u8 real_digest[v->digest_size];
|
|
* u8 want_digest[v->digest_size];
|
|
*
|
|
* To access them use: verity_io_hash_req(), verity_io_real_digest()
|
|
* and verity_io_want_digest().
|
|
*/
|
|
};
|
|
|
|
static inline struct ahash_request *verity_io_hash_req(struct dm_verity *v,
|
|
struct dm_verity_io *io)
|
|
{
|
|
return (struct ahash_request *)(io + 1);
|
|
}
|
|
|
|
static inline u8 *verity_io_real_digest(struct dm_verity *v,
|
|
struct dm_verity_io *io)
|
|
{
|
|
return (u8 *)(io + 1) + v->ahash_reqsize;
|
|
}
|
|
|
|
static inline u8 *verity_io_want_digest(struct dm_verity *v,
|
|
struct dm_verity_io *io)
|
|
{
|
|
return (u8 *)(io + 1) + v->ahash_reqsize + v->digest_size;
|
|
}
|
|
|
|
static inline u8 *verity_io_digest_end(struct dm_verity *v,
|
|
struct dm_verity_io *io)
|
|
{
|
|
return verity_io_want_digest(v, io) + 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 ahash_request *req,
|
|
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, bool *is_zero);
|
|
|
|
#endif /* DM_VERITY_H */
|