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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | /* 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-io.h> #include <linux/dm-bufio.h> #include <linux/device-mapper.h> #include <linux/interrupt.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, DM_VERITY_MODE_PANIC }; 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 int 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; bool hash_failed:1; /* set if hash of any block failed */ bool use_tasklet:1; /* try to verify in tasklet before work-queue */ unsigned int digest_size; /* digest size for the current hash algorithm */ unsigned int ahash_reqsize;/* the size of temporary space for crypto */ enum verity_mode mode; /* mode for handling verification errors */ unsigned int 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_io_client *io; mempool_t recheck_pool; }; struct dm_verity_io { struct dm_verity *v; /* original value of bio->bi_end_io */ bio_end_io_t *orig_bi_end_io; struct bvec_iter iter; sector_t block; unsigned int n_blocks; bool in_tasklet; struct work_struct work; char *recheck_buffer; /* * 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; } 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, bool may_sleep); extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io, sector_t block, u8 *digest, bool *is_zero); extern bool dm_is_verity_target(struct dm_target *ti); extern int dm_verity_get_mode(struct dm_target *ti); extern int dm_verity_get_root_digest(struct dm_target *ti, u8 **root_digest, unsigned int *digest_size); #endif /* DM_VERITY_H */ |