xref: /linux/block/blk-crypto-internal.h (revision 84b9b44b) 
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  */
13 struct 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 
20 extern const struct blk_crypto_mode blk_crypto_modes[];
21 
22 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
23 
24 int blk_crypto_sysfs_register(struct gendisk *disk);
25 
26 void blk_crypto_sysfs_unregister(struct gendisk *disk);
27 
28 void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
29 			     unsigned int inc);
30 
31 bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
32 
33 bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
34 			     struct bio_crypt_ctx *bc2);
35 
36 static 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 
43 static 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 
50 static 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 
57 static inline void blk_crypto_rq_set_defaults(struct request *rq)
58 {
59 	rq->crypt_ctx = NULL;
60 	rq->crypt_keyslot = NULL;
61 }
62 
63 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
64 {
65 	return rq->crypt_ctx;
66 }
67 
68 static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
69 {
70 	return rq->crypt_keyslot;
71 }
72 
73 blk_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 
77 void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot);
78 
79 int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
80 			   const struct blk_crypto_key *key);
81 
82 bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile,
83 				const struct blk_crypto_config *cfg);
84 
85 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
86 
87 static inline int blk_crypto_sysfs_register(struct gendisk *disk)
88 {
89 	return 0;
90 }
91 
92 static inline void blk_crypto_sysfs_unregister(struct gendisk *disk)
93 {
94 }
95 
96 static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
97 					       struct bio *bio)
98 {
99 	return true;
100 }
101 
102 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
103 						 struct bio *bio)
104 {
105 	return true;
106 }
107 
108 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
109 						struct bio *bio)
110 {
111 	return true;
112 }
113 
114 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
115 					  struct request *next)
116 {
117 	return true;
118 }
119 
120 static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
121 
122 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
123 {
124 	return false;
125 }
126 
127 static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
128 {
129 	return false;
130 }
131 
132 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
133 
134 void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
135 static 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 
141 void __bio_crypt_free_ctx(struct bio *bio);
142 static 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 
148 static 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 
158 bool __blk_crypto_bio_prep(struct bio **bio_ptr);
159 static 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 
166 blk_status_t __blk_crypto_rq_get_keyslot(struct request *rq);
167 static 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 
174 void __blk_crypto_rq_put_keyslot(struct request *rq);
175 static 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 
181 void __blk_crypto_free_request(struct request *rq);
182 static 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 
188 int __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  */
200 static 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 
210 int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
211 
212 bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
213 
214 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
215 
216 #else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
217 
218 static inline int
219 blk_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 
225 static 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 
232 static inline int
233 blk_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