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  */
 13struct 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
 19extern const struct blk_crypto_mode blk_crypto_modes[];
 20
 21#ifdef CONFIG_BLK_INLINE_ENCRYPTION
 22
 23void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
 24			     unsigned int inc);
 25
 26bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
 27
 28bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
 29			     struct bio_crypt_ctx *bc2);
 30
 31static 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
 38static 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
 45static 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
 52static inline void blk_crypto_rq_set_defaults(struct request *rq)
 53{
 54	rq->crypt_ctx = NULL;
 55	rq->crypt_keyslot = NULL;
 56}
 57
 58static 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
 65static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
 66					       struct bio *bio)
 67{
 68	return true;
 69}
 70
 71static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
 72						 struct bio *bio)
 73{
 74	return true;
 75}
 76
 77static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
 78						struct bio *bio)
 79{
 80	return true;
 81}
 82
 83static inline bool bio_crypt_ctx_merge_rq(struct request *req,
 84					  struct request *next)
 85{
 86	return true;
 87}
 88
 89static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
 90
 91static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
 92{
 93	return false;
 94}
 95
 96#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
 97
 98void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
 99static 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
105void __bio_crypt_free_ctx(struct bio *bio);
106static 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
112static 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
122bool __blk_crypto_bio_prep(struct bio **bio_ptr);
123static 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
130blk_status_t __blk_crypto_init_request(struct request *rq);
131static 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
138void __blk_crypto_free_request(struct request *rq);
139static 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
145int __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 */
157static 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 */
172static 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
182int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
183
184bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
185
186int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
187
188#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
189
190static inline int
191blk_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
197static 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
204static inline int
205blk_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 */