the-tree/block/blk-crypto-internal.h

0001 /* SPDX-License-Identifier: GPL-2.0 */
0002 /*
0003  * Copyright 2019 Google LLC
0004  */
0005
0006 #ifndef __LINUX_BLK_CRYPTO_INTERNAL_H
0007 #define __LINUX_BLK_CRYPTO_INTERNAL_H
0008
0009 #include <linux/bio.h>
0010 #include <linux/blk-mq.h>
0011
0012 /* Represents a crypto mode supported by blk-crypto  */
0013 struct blk_crypto_mode {
0014     const char *name; /* name of this mode, shown in sysfs */
0015     const char *cipher_str; /* crypto API name (for fallback case) */
0016     unsigned int keysize; /* key size in bytes */
0017     unsigned int ivsize; /* iv size in bytes */
0018 };
0019
0020 extern const struct blk_crypto_mode blk_crypto_modes[];
0021
0022 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
0023
0024 int blk_crypto_sysfs_register(struct request_queue *q);
0025
0026 void blk_crypto_sysfs_unregister(struct request_queue *q);
0027
0028 void bio_crypt_dun_increment(u64 dun[BLK_CRYPTO_DUN_ARRAY_SIZE],
0029                  unsigned int inc);
0030
0031 bool bio_crypt_rq_ctx_compatible(struct request *rq, struct bio *bio);
0032
0033 bool bio_crypt_ctx_mergeable(struct bio_crypt_ctx *bc1, unsigned int bc1_bytes,
0034                  struct bio_crypt_ctx *bc2);
0035
0036 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
0037                         struct bio *bio)
0038 {
0039     return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
0040                        bio->bi_crypt_context);
0041 }
0042
0043 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
0044                          struct bio *bio)
0045 {
0046     return bio_crypt_ctx_mergeable(bio->bi_crypt_context,
0047                        bio->bi_iter.bi_size, req->crypt_ctx);
0048 }
0049
0050 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
0051                       struct request *next)
0052 {
0053     return bio_crypt_ctx_mergeable(req->crypt_ctx, blk_rq_bytes(req),
0054                        next->crypt_ctx);
0055 }
0056
0057 static inline void blk_crypto_rq_set_defaults(struct request *rq)
0058 {
0059     rq->crypt_ctx = NULL;
0060     rq->crypt_keyslot = NULL;
0061 }
0062
0063 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
0064 {
0065     return rq->crypt_ctx;
0066 }
0067
0068 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
0069
0070 static inline int blk_crypto_sysfs_register(struct request_queue *q)
0071 {
0072     return 0;
0073 }
0074
0075 static inline void blk_crypto_sysfs_unregister(struct request_queue *q) { }
0076
0077 static inline bool bio_crypt_rq_ctx_compatible(struct request *rq,
0078                            struct bio *bio)
0079 {
0080     return true;
0081 }
0082
0083 static inline bool bio_crypt_ctx_front_mergeable(struct request *req,
0084                          struct bio *bio)
0085 {
0086     return true;
0087 }
0088
0089 static inline bool bio_crypt_ctx_back_mergeable(struct request *req,
0090                         struct bio *bio)
0091 {
0092     return true;
0093 }
0094
0095 static inline bool bio_crypt_ctx_merge_rq(struct request *req,
0096                       struct request *next)
0097 {
0098     return true;
0099 }
0100
0101 static inline void blk_crypto_rq_set_defaults(struct request *rq) { }
0102
0103 static inline bool blk_crypto_rq_is_encrypted(struct request *rq)
0104 {
0105     return false;
0106 }
0107
0108 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */
0109
0110 void __bio_crypt_advance(struct bio *bio, unsigned int bytes);
0111 static inline void bio_crypt_advance(struct bio *bio, unsigned int bytes)
0112 {
0113     if (bio_has_crypt_ctx(bio))
0114         __bio_crypt_advance(bio, bytes);
0115 }
0116
0117 void __bio_crypt_free_ctx(struct bio *bio);
0118 static inline void bio_crypt_free_ctx(struct bio *bio)
0119 {
0120     if (bio_has_crypt_ctx(bio))
0121         __bio_crypt_free_ctx(bio);
0122 }
0123
0124 static inline void bio_crypt_do_front_merge(struct request *rq,
0125                         struct bio *bio)
0126 {
0127 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
0128     if (bio_has_crypt_ctx(bio))
0129         memcpy(rq->crypt_ctx->bc_dun, bio->bi_crypt_context->bc_dun,
0130                sizeof(rq->crypt_ctx->bc_dun));
0131 #endif
0132 }
0133
0134 bool __blk_crypto_bio_prep(struct bio **bio_ptr);
0135 static inline bool blk_crypto_bio_prep(struct bio **bio_ptr)
0136 {
0137     if (bio_has_crypt_ctx(*bio_ptr))
0138         return __blk_crypto_bio_prep(bio_ptr);
0139     return true;
0140 }
0141
0142 blk_status_t __blk_crypto_init_request(struct request *rq);
0143 static inline blk_status_t blk_crypto_init_request(struct request *rq)
0144 {
0145     if (blk_crypto_rq_is_encrypted(rq))
0146         return __blk_crypto_init_request(rq);
0147     return BLK_STS_OK;
0148 }
0149
0150 void __blk_crypto_free_request(struct request *rq);
0151 static inline void blk_crypto_free_request(struct request *rq)
0152 {
0153     if (blk_crypto_rq_is_encrypted(rq))
0154         __blk_crypto_free_request(rq);
0155 }
0156
0157 int __blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
0158                  gfp_t gfp_mask);
0159 /**
0160  * blk_crypto_rq_bio_prep - Prepare a request's crypt_ctx when its first bio
0161  *              is inserted
0162  * @rq: The request to prepare
0163  * @bio: The first bio being inserted into the request
0164  * @gfp_mask: Memory allocation flags
0165  *
0166  * Return: 0 on success, -ENOMEM if out of memory.  -ENOMEM is only possible if
0167  *     @gfp_mask doesn't include %__GFP_DIRECT_RECLAIM.
0168  */
0169 static inline int blk_crypto_rq_bio_prep(struct request *rq, struct bio *bio,
0170                      gfp_t gfp_mask)
0171 {
0172     if (bio_has_crypt_ctx(bio))
0173         return __blk_crypto_rq_bio_prep(rq, bio, gfp_mask);
0174     return 0;
0175 }
0176
0177 /**
0178  * blk_crypto_insert_cloned_request - Prepare a cloned request to be inserted
0179  *                    into a request queue.
0180  * @rq: the request being queued
0181  *
0182  * Return: BLK_STS_OK on success, nonzero on error.
0183  */
0184 static inline blk_status_t blk_crypto_insert_cloned_request(struct request *rq)
0185 {
0186
0187     if (blk_crypto_rq_is_encrypted(rq))
0188         return blk_crypto_init_request(rq);
0189     return BLK_STS_OK;
0190 }
0191
0192 #ifdef CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK
0193
0194 int blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num);
0195
0196 bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr);
0197
0198 int blk_crypto_fallback_evict_key(const struct blk_crypto_key *key);
0199
0200 #else /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
0201
0202 static inline int
0203 blk_crypto_fallback_start_using_mode(enum blk_crypto_mode_num mode_num)
0204 {
0205     pr_warn_once("crypto API fallback is disabled\n");
0206     return -ENOPKG;
0207 }
0208
0209 static inline bool blk_crypto_fallback_bio_prep(struct bio **bio_ptr)
0210 {
0211     pr_warn_once("crypto API fallback disabled; failing request.\n");
0212     (*bio_ptr)->bi_status = BLK_STS_NOTSUPP;
0213     return false;
0214 }
0215
0216 static inline int
0217 blk_crypto_fallback_evict_key(const struct blk_crypto_key *key)
0218 {
0219     return 0;
0220 }
0221
0222 #endif /* CONFIG_BLK_INLINE_ENCRYPTION_FALLBACK */
0223
0224 #endif /* __LINUX_BLK_CRYPTO_INTERNAL_H */