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/blk-mq.h>
11
12/* Represents a crypto mode supported by blk-crypto  */
13struct blk_crypto_mode {
14	const char *name; /* name of this mode, shown in sysfs */
15	const char *cipher_str; /* crypto API name (for fallback case) */
16	unsigned int keysize; /* key size in bytes */
17	unsigned int ivsize; /* iv size in bytes */
18};
19
20extern const struct blk_crypto_mode blk_crypto_modes[];
21
22#ifdef CONFIG_BLK_INLINE_ENCRYPTION
23
24int blk_crypto_sysfs_register(struct gendisk *disk);
25
26void blk_crypto_sysfs_unregister(struct gendisk *disk);
27
28void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
29			     unsigned int inc);
30
31bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
32
33bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
34			     struct bio_crypt_ctx *bc2);
35
36static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
37						struct bio *bio)
38{
39	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
40				       bio->bi_crypt_context);
41}
42
43static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
44						 struct bio *bio)
45{
46	return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
47				       bio->bi_iter.bi_size, req->crypt_ctx);
48}
49
50static inline bool bio_crypt_ctx_merge_rq(struct request *req,
51					  struct request *next)
52{
53	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
54				       next->crypt_ctx);
55}
56
57static inline void blk_crypto_rq_set_defaults(struct request *rq)
58{
59	rq->crypt_ctx = NULL;
60	rq->crypt_keyslot = NULL;
61}
62
63static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
64{
65	return rq->crypt_ctx;
66}
67
68static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
69{
70	return rq->crypt_keyslot;
71}
72
73blk_status_t blk_crypto_get_keyslot(struct blk_crypto_profile *profile,
74				    const struct blk_crypto_key *key,
75				    struct blk_crypto_keyslot **slot_ptr);
76
77void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot);
78
79int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
80			   const struct blk_crypto_key *key);
81
82bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile,
83				const struct blk_crypto_config *cfg);
84
85#else /* CONFIG_BLK_INLINE_ENCRYPTION */
86
87static inline int blk_crypto_sysfs_register(struct gendisk *disk)
88{
89	return 0;
90}
91
92static inline void blk_crypto_sysfs_unregister(struct gendisk *disk)
93{
94}
95
96static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
97					       struct bio *bio)
98{
99	return true;
100}
101
102static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
103						 struct bio *bio)
104{
105	return true;
106}
107
108static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
109						struct bio *bio)
110{
111	return true;
112}
113
114static inline bool bio_crypt_ctx_merge_rq(struct request *req,
115					  struct request *next)
116{
117	return true;
118}
119
120static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
121
122static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
123{
124	return false;
125}
126
127static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
128{
129	return false;
130}
131
132#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
133
134void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
135static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
136{
137	if (bio_has_crypt_ctx(bio))
138		__bio_crypt_advance(bio, bytes);
139}
140
141void __bio_crypt_free_ctx(struct bio *bio);
142static inline void bio_crypt_free_ctx(struct bio *bio)
143{
144	if (bio_has_crypt_ctx(bio))
145		__bio_crypt_free_ctx(bio);
146}
147
148static inline void bio_crypt_do_front_merge(struct request *rq,
149					    struct bio *bio)
150{
151#ifdef CONFIG_BLK_INLINE_ENCRYPTION
152	if (bio_has_crypt_ctx(bio))
153		memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
154		       sizeof(rq->crypt_ctx->bc_dun));
155#endif
156}
157
158bool __blk_crypto_bio_prep(struct bio **bio_ptr);
159static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
160{
161	if (bio_has_crypt_ctx(*bio_ptr))
162		return __blk_crypto_bio_prep(bio_ptr);
163	return true;
164}
165
166blk_status_t __blk_crypto_rq_get_keyslot(struct request *rq);
167static inline blk_status_t blk_crypto_rq_get_keyslot(struct request *rq)
168{
169	if (blk_crypto_rq_is_encrypted(rq))
170		return __blk_crypto_rq_get_keyslot(rq);
171	return BLK_STS_OK;
172}
173
174void __blk_crypto_rq_put_keyslot(struct request *rq);
175static inline void blk_crypto_rq_put_keyslot(struct request *rq)
176{
177	if (blk_crypto_rq_has_keyslot(rq))
178		__blk_crypto_rq_put_keyslot(rq);
179}
180
181void __blk_crypto_free_request(struct request *rq);
182static inline void blk_crypto_free_request(struct request *rq)
183{
184	if (blk_crypto_rq_is_encrypted(rq))
185		__blk_crypto_free_request(rq);
186}
187
188int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
189			     gfp_t gfp_mask);
190/**
191 * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
192 *			    is inserted
193 * @rq: The request to prepare
194 * @bio: The first bio being inserted into the request
195 * @gfp_mask: Memory allocation flags
196 *
197 * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
198 *	   @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
199 */
200static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
201					 gfp_t gfp_mask)
202{
203	if (bio_has_crypt_ctx(bio))
204		return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
205	return 0;
206}
207
208#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
209
210int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
211
212bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
213
214int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
215
216#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
217
218static inline int
219blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
220{
221	pr_warn_once("crypto API fallback is disabled\n");
222	return -ENOPKG;
223}
224
225static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
226{
227	pr_warn_once("crypto API fallback disabled; failing request.\n");
228	(*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
229	return false;
230}
231
232static inline int
233blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
234{
235	return 0;
236}
237
238#endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
239
240#endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */
241