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
63static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
64{
65	return rq->crypt_keyslot;
66}
67
68#else /* CONFIG_BLK_INLINE_ENCRYPTION */
69
70static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
71					       struct bio *bio)
72{
73	return true;
74}
75
76static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
77						 struct bio *bio)
78{
79	return true;
80}
81
82static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
83						struct bio *bio)
84{
85	return true;
86}
87
88static inline bool bio_crypt_ctx_merge_rq(struct request *req,
89					  struct request *next)
90{
91	return true;
92}
93
94static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
95
96static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
97{
98	return false;
99}
100
101static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
102{
103	return false;
104}
105
106#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
107
108void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
109static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
110{
111	if (bio_has_crypt_ctx(bio))
112		__bio_crypt_advance(bio, bytes);
113}
114
115void __bio_crypt_free_ctx(struct bio *bio);
116static inline void bio_crypt_free_ctx(struct bio *bio)
117{
118	if (bio_has_crypt_ctx(bio))
119		__bio_crypt_free_ctx(bio);
120}
121
122static inline void bio_crypt_do_front_merge(struct request *rq,
123					    struct bio *bio)
124{
125#ifdef CONFIG_BLK_INLINE_ENCRYPTION
126	if (bio_has_crypt_ctx(bio))
127		memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
128		       sizeof(rq->crypt_ctx->bc_dun));
129#endif
130}
131
132bool __blk_crypto_bio_prep(struct bio **bio_ptr);
133static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
134{
135	if (bio_has_crypt_ctx(*bio_ptr))
136		return __blk_crypto_bio_prep(bio_ptr);
137	return true;
138}
139
140blk_status_t __blk_crypto_rq_get_keyslot(struct request *rq);
141static inline blk_status_t blk_crypto_rq_get_keyslot(struct request *rq)
142{
143	if (blk_crypto_rq_is_encrypted(rq))
144		return __blk_crypto_rq_get_keyslot(rq);
145	return BLK_STS_OK;
146}
147
148void __blk_crypto_rq_put_keyslot(struct request *rq);
149static inline void blk_crypto_rq_put_keyslot(struct request *rq)
150{
151	if (blk_crypto_rq_has_keyslot(rq))
152		__blk_crypto_rq_put_keyslot(rq);
153}
154
155void __blk_crypto_free_request(struct request *rq);
156static inline void blk_crypto_free_request(struct request *rq)
157{
158	if (blk_crypto_rq_is_encrypted(rq))
159		__blk_crypto_free_request(rq);
160}
161
162int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
163			     gfp_t gfp_mask);
164/**
165 * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
166 *			    is inserted
167 * @rq: The request to prepare
168 * @bio: The first bio being inserted into the request
169 * @gfp_mask: Memory allocation flags
170 *
171 * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
172 *	   @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
173 */
174static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
175					 gfp_t gfp_mask)
176{
177	if (bio_has_crypt_ctx(bio))
178		return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
179	return 0;
180}
181
182/**
183 * blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted
184 *				      into a request queue.
185 * @rq: the request being queued
186 *
187 * Return: BLK_STS_OK on success, nonzero on error.
188 */
189static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
190{
191
192	if (blk_crypto_rq_is_encrypted(rq))
193		return blk_crypto_rq_get_keyslot(rq);
194	return BLK_STS_OK;
195}
196
197#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
198
199int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
200
201bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
202
203int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
204
205#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
206
207static inline int
208blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
209{
210	pr_warn_once("crypto API fallback is disabled\n");
211	return -ENOPKG;
212}
213
214static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
215{
216	pr_warn_once("crypto API fallback disabled; failing request.\n");
217	(*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
218	return false;
219}
220
221static inline int
222blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
223{
224	return 0;
225}
226
227#endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
228
229#endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */
230