block/blk-crypto-internal.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright 2019 Google LLC
   4  */
   5
   6 #ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
   7 #define __LINUX_BLK_CRYPTO_INTERNAL_H
   8
   9 #include <linux/bio.h>
  10 #include <linux/blkdev.h>
  11
  12 /* Represents a crypto mode supported by blk-crypto  */
  13 struct blk_crypto_mode {
  14         const char *cipher_str; /* crypto API name (for fallback case) */
  15         unsigned int keysize; /* key size in bytes */
  16         unsigned int ivsize; /* iv size in bytes */
  17 };
  18
  19 extern const struct blk_crypto_mode blk_crypto_modes[];
  20
  21 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
  22
  23 void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
  24                              unsigned int inc);
  25
  26 bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
  27
  28 bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
  29                              struct bio_crypt_ctx *bc2);
  30
  31 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
  32                                                 struct bio *bio)
  33 {
  34         return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
  35                                        bio->bi_crypt_context);
  36 }
  37
  38 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
  39                                                  struct bio *bio)
  40 {
  41         return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
  42                                        bio->bi_iter.bi_size, req->crypt_ctx);
  43 }
  44
  45 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
  46                                           struct request *next)
  47 {
  48         return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
  49                                        next->crypt_ctx);
  50 }
  51
  52 static inline void blk_crypto_rq_set_defaults(struct request *rq)
  53 {
  54         rq->crypt_ctx = NULL;
  55         rq->crypt_keyslot = NULL;
  56 }
  57
  58 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
  59 {
  60         return rq->crypt_ctx;
  61 }
  62
  63 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
  64
  65 static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
  66                                                struct bio *bio)
  67 {
  68         return true;
  69 }
  70
  71 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
  72                                                  struct bio *bio)
  73 {
  74         return true;
  75 }
  76
  77 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
  78                                                 struct bio *bio)
  79 {
  80         return true;
  81 }
  82
  83 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
  84                                           struct request *next)
  85 {
  86         return true;
  87 }
  88
  89 static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
  90
  91 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
  92 {
  93         return false;
  94 }
  95
  96 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
  97
  98 void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
  99 static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
 100 {
 101         if (bio_has_crypt_ctx(bio))
 102                 __bio_crypt_advance(bio, bytes);
 103 }
 104
 105 void __bio_crypt_free_ctx(struct bio *bio);
 106 static inline void bio_crypt_free_ctx(struct bio *bio)
 107 {
 108         if (bio_has_crypt_ctx(bio))
 109                 __bio_crypt_free_ctx(bio);
 110 }
 111
 112 static inline void bio_crypt_do_front_merge(struct request *rq,
 113                                             struct bio *bio)
 114 {
 115 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
 116         if (bio_has_crypt_ctx(bio))
 117                 memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
 118                        sizeof(rq->crypt_ctx->bc_dun));
 119 #endif
 120 }
 121
 122 bool __blk_crypto_bio_prep(struct bio **bio_ptr);
 123 static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
 124 {
 125         if (bio_has_crypt_ctx(*bio_ptr))
 126                 return __blk_crypto_bio_prep(bio_ptr);
 127         return true;
 128 }
 129
 130 blk_status_t __blk_crypto_init_request(struct request *rq);
 131 static inline blk_status_t blk_crypto_init_request(struct request *rq)
 132 {
 133         if (blk_crypto_rq_is_encrypted(rq))
 134                 return __blk_crypto_init_request(rq);
 135         return BLK_STS_OK;
 136 }
 137
 138 void __blk_crypto_free_request(struct request *rq);
 139 static inline void blk_crypto_free_request(struct request *rq)
 140 {
 141         if (blk_crypto_rq_is_encrypted(rq))
 142                 __blk_crypto_free_request(rq);
 143 }
 144
 145 int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
 146                              gfp_t gfp_mask);
 147 /**
 148  * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
 149  *                          is inserted
 150  * @rq: The request to prepare
 151  * @bio: The first bio being inserted into the request
 152  * @gfp_mask: Memory allocation flags
 153  *
 154  * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
 155  *         @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
 156  */
 157 static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
 158                                          gfp_t gfp_mask)
 159 {
 160         if (bio_has_crypt_ctx(bio))
 161                 return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
 162         return 0;
 163 }
 164
 165 /**
 166  * blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted
 167  *                                    into a request queue.
 168  * @rq: the request being queued
 169  *
 170  * Return: BLK_STS_OK on success, nonzero on error.
 171  */
 172 static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
 173 {
 174
 175         if (blk_crypto_rq_is_encrypted(rq))
 176                 return blk_crypto_init_request(rq);
 177         return BLK_STS_OK;
 178 }
 179
 180 #ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
 181
 182 int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
 183
 184 bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
 185
 186 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
 187
 188 #else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
 189
 190 static inline int
 191 blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
 192 {
 193         pr_warn_once("crypto API fallback is disabled\n");
 194         return -ENOPKG;
 195 }
 196
 197 static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
 198 {
 199         pr_warn_once("crypto API fallback disabled; failing request.\n");
 200         (*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
 201         return false;
 202 }
 203
 204 static inline int
 205 blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
 206 {
 207         return 0;
 208 }
 209
 210 #endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
 211
 212 #endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */