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/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 security_strength; /* security strength in bytes */
 18	unsigned int ivsize; /* iv size in bytes */
 19};
 20
 21extern const struct blk_crypto_mode blk_crypto_modes[];
 22
 23#ifdef CONFIG_BLK_INLINE_ENCRYPTION
 24
 25int blk_crypto_sysfs_register(struct gendisk *disk);
 26
 27void blk_crypto_sysfs_unregister(struct gendisk *disk);
 28
 29void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
 30			     unsigned int inc);
 31
 32bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
 33
 34bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
 35			     struct bio_crypt_ctx *bc2);
 36
 37static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
 38						struct bio *bio)
 39{
 40	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
 41				       bio->bi_crypt_context);
 42}
 43
 44static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
 45						 struct bio *bio)
 46{
 47	return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
 48				       bio->bi_iter.bi_size, req->crypt_ctx);
 49}
 50
 51static inline bool bio_crypt_ctx_merge_rq(struct request *req,
 52					  struct request *next)
 53{
 54	return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
 55				       next->crypt_ctx);
 56}
 57
 58static inline void blk_crypto_rq_set_defaults(struct request *rq)
 59{
 60	rq->crypt_ctx = NULL;
 61	rq->crypt_keyslot = NULL;
 62}
 63
 64static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
 65{
 66	return rq->crypt_ctx;
 67}
 68
 69static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
 70{
 71	return rq->crypt_keyslot;
 72}
 73
 74blk_status_t blk_crypto_get_keyslot(struct blk_crypto_profile *profile,
 75				    const struct blk_crypto_key *key,
 76				    struct blk_crypto_keyslot **slot_ptr);
 77
 78void blk_crypto_put_keyslot(struct blk_crypto_keyslot *slot);
 79
 80int __blk_crypto_evict_key(struct blk_crypto_profile *profile,
 81			   const struct blk_crypto_key *key);
 82
 83bool __blk_crypto_cfg_supported(struct blk_crypto_profile *profile,
 84				const struct blk_crypto_config *cfg);
 85
 86int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd,
 87		     void __user *argp);
 88
 89#else /* CONFIG_BLK_INLINE_ENCRYPTION */
 90
 91static inline int blk_crypto_sysfs_register(struct gendisk *disk)
 92{
 93	return 0;
 94}
 95
 96static inline void blk_crypto_sysfs_unregister(struct gendisk *disk)
 97{
 98}
 99
100static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
101					       struct bio *bio)
102{
103	return true;
104}
105
106static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
107						 struct bio *bio)
108{
109	return true;
110}
111
112static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
113						struct bio *bio)
114{
115	return true;
116}
117
118static inline bool bio_crypt_ctx_merge_rq(struct request *req,
119					  struct request *next)
120{
121	return true;
122}
123
124static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
125
126static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
127{
128	return false;
129}
130
131static inline bool blk_crypto_rq_has_keyslot(struct request *rq)
132{
133	return false;
134}
135
136static inline int blk_crypto_ioctl(struct block_device *bdev, unsigned int cmd,
137				   void __user *argp)
138{
139	return -ENOTTY;
140}
141
142#endif /* CONFIG_BLK_INLINE_ENCRYPTION */
143
144void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
145static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
146{
147	if (bio_has_crypt_ctx(bio))
148		__bio_crypt_advance(bio, bytes);
149}
150
151void __bio_crypt_free_ctx(struct bio *bio);
152static inline void bio_crypt_free_ctx(struct bio *bio)
153{
154	if (bio_has_crypt_ctx(bio))
155		__bio_crypt_free_ctx(bio);
156}
157
158static inline void bio_crypt_do_front_merge(struct request *rq,
159					    struct bio *bio)
160{
161#ifdef CONFIG_BLK_INLINE_ENCRYPTION
162	if (bio_has_crypt_ctx(bio))
163		memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
164		       sizeof(rq->crypt_ctx->bc_dun));
165#endif
166}
167
168bool __blk_crypto_bio_prep(struct bio **bio_ptr);
169static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
170{
171	if (bio_has_crypt_ctx(*bio_ptr))
172		return __blk_crypto_bio_prep(bio_ptr);
173	return true;
174}
175
176blk_status_t __blk_crypto_rq_get_keyslot(struct request *rq);
177static inline blk_status_t blk_crypto_rq_get_keyslot(struct request *rq)
178{
179	if (blk_crypto_rq_is_encrypted(rq))
180		return __blk_crypto_rq_get_keyslot(rq);
181	return BLK_STS_OK;
182}
183
184void __blk_crypto_rq_put_keyslot(struct request *rq);
185static inline void blk_crypto_rq_put_keyslot(struct request *rq)
186{
187	if (blk_crypto_rq_has_keyslot(rq))
188		__blk_crypto_rq_put_keyslot(rq);
189}
190
191void __blk_crypto_free_request(struct request *rq);
192static inline void blk_crypto_free_request(struct request *rq)
193{
194	if (blk_crypto_rq_is_encrypted(rq))
195		__blk_crypto_free_request(rq);
196}
197
198int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
199			     gfp_t gfp_mask);
200/**
201 * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
202 *			    is inserted
203 * @rq: The request to prepare
204 * @bio: The first bio being inserted into the request
205 * @gfp_mask: Memory allocation flags
206 *
207 * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
208 *	   @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
209 */
210static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
211					 gfp_t gfp_mask)
212{
213	if (bio_has_crypt_ctx(bio))
214		return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
215	return 0;
216}
217
218#ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
219
220int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
221
222bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
223
224int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
225
226#else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
227
228static inline int
229blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
230{
231	pr_warn_once("crypto API fallback is disabled\n");
232	return -ENOPKG;
233}
234
235static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
236{
237	pr_warn_once("crypto API fallback disabled; failing request.\n");
238	(*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
239	return false;
240}
241
242static inline int
243blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
244{
245	return 0;
246}
247
248#endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
249
250#endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */