2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
7 * This file is released under the GPL.
10 #include <linux/completion.h>
11 #include <linux/err.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/bio.h>
16 #include <linux/blkdev.h>
17 #include <linux/mempool.h>
18 #include <linux/slab.h>
19 #include <linux/crypto.h>
20 #include <linux/workqueue.h>
21 #include <linux/backing-dev.h>
22 #include <linux/atomic.h>
23 #include <linux/scatterlist.h>
25 #include <asm/unaligned.h>
26 #include <crypto/hash.h>
27 #include <crypto/md5.h>
28 #include <crypto/algapi.h>
30 #include <linux/device-mapper.h>
32 #define DM_MSG_PREFIX "crypt"
35 * context holding the current state of a multi-part conversion
37 struct convert_context
{
38 struct completion restart
;
41 struct bvec_iter iter_in
;
42 struct bvec_iter iter_out
;
45 struct ablkcipher_request
*req
;
49 * per bio private data
52 struct crypt_config
*cc
;
54 struct work_struct work
;
56 struct convert_context ctx
;
61 struct dm_crypt_io
*base_io
;
64 struct dm_crypt_request
{
65 struct convert_context
*ctx
;
66 struct scatterlist sg_in
;
67 struct scatterlist sg_out
;
73 struct crypt_iv_operations
{
74 int (*ctr
)(struct crypt_config
*cc
, struct dm_target
*ti
,
76 void (*dtr
)(struct crypt_config
*cc
);
77 int (*init
)(struct crypt_config
*cc
);
78 int (*wipe
)(struct crypt_config
*cc
);
79 int (*generator
)(struct crypt_config
*cc
, u8
*iv
,
80 struct dm_crypt_request
*dmreq
);
81 int (*post
)(struct crypt_config
*cc
, u8
*iv
,
82 struct dm_crypt_request
*dmreq
);
85 struct iv_essiv_private
{
86 struct crypto_hash
*hash_tfm
;
90 struct iv_benbi_private
{
94 #define LMK_SEED_SIZE 64 /* hash + 0 */
95 struct iv_lmk_private
{
96 struct crypto_shash
*hash_tfm
;
100 #define TCW_WHITENING_SIZE 16
101 struct iv_tcw_private
{
102 struct crypto_shash
*crc32_tfm
;
108 * Crypt: maps a linear range of a block device
109 * and encrypts / decrypts at the same time.
111 enum flags
{ DM_CRYPT_SUSPENDED
, DM_CRYPT_KEY_VALID
};
114 * The fields in here must be read only after initialization.
116 struct crypt_config
{
121 * pool for per bio private data, crypto requests and
122 * encryption requeusts/buffer pages
126 mempool_t
*page_pool
;
129 struct workqueue_struct
*io_queue
;
130 struct workqueue_struct
*crypt_queue
;
135 struct crypt_iv_operations
*iv_gen_ops
;
137 struct iv_essiv_private essiv
;
138 struct iv_benbi_private benbi
;
139 struct iv_lmk_private lmk
;
140 struct iv_tcw_private tcw
;
143 unsigned int iv_size
;
145 /* ESSIV: struct crypto_cipher *essiv_tfm */
147 struct crypto_ablkcipher
**tfms
;
151 * Layout of each crypto request:
153 * struct ablkcipher_request
156 * struct dm_crypt_request
160 * The padding is added so that dm_crypt_request and the IV are
163 unsigned int dmreq_start
;
166 unsigned int key_size
;
167 unsigned int key_parts
; /* independent parts in key buffer */
168 unsigned int key_extra_size
; /* additional keys length */
173 #define MIN_POOL_PAGES 32
175 static struct kmem_cache
*_crypt_io_pool
;
177 static void clone_init(struct dm_crypt_io
*, struct bio
*);
178 static void kcryptd_queue_crypt(struct dm_crypt_io
*io
);
179 static u8
*iv_of_dmreq(struct crypt_config
*cc
, struct dm_crypt_request
*dmreq
);
182 * Use this to access cipher attributes that are the same for each CPU.
184 static struct crypto_ablkcipher
*any_tfm(struct crypt_config
*cc
)
190 * Different IV generation algorithms:
192 * plain: the initial vector is the 32-bit little-endian version of the sector
193 * number, padded with zeros if necessary.
195 * plain64: the initial vector is the 64-bit little-endian version of the sector
196 * number, padded with zeros if necessary.
198 * essiv: "encrypted sector|salt initial vector", the sector number is
199 * encrypted with the bulk cipher using a salt as key. The salt
200 * should be derived from the bulk cipher's key via hashing.
202 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
203 * (needed for LRW-32-AES and possible other narrow block modes)
205 * null: the initial vector is always zero. Provides compatibility with
206 * obsolete loop_fish2 devices. Do not use for new devices.
208 * lmk: Compatible implementation of the block chaining mode used
209 * by the Loop-AES block device encryption system
210 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
211 * It operates on full 512 byte sectors and uses CBC
212 * with an IV derived from the sector number, the data and
213 * optionally extra IV seed.
214 * This means that after decryption the first block
215 * of sector must be tweaked according to decrypted data.
216 * Loop-AES can use three encryption schemes:
217 * version 1: is plain aes-cbc mode
218 * version 2: uses 64 multikey scheme with lmk IV generator
219 * version 3: the same as version 2 with additional IV seed
220 * (it uses 65 keys, last key is used as IV seed)
222 * tcw: Compatible implementation of the block chaining mode used
223 * by the TrueCrypt device encryption system (prior to version 4.1).
224 * For more info see: http://www.truecrypt.org
225 * It operates on full 512 byte sectors and uses CBC
226 * with an IV derived from initial key and the sector number.
227 * In addition, whitening value is applied on every sector, whitening
228 * is calculated from initial key, sector number and mixed using CRC32.
229 * Note that this encryption scheme is vulnerable to watermarking attacks
230 * and should be used for old compatible containers access only.
232 * plumb: unimplemented, see:
233 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
236 static int crypt_iv_plain_gen(struct crypt_config
*cc
, u8
*iv
,
237 struct dm_crypt_request
*dmreq
)
239 memset(iv
, 0, cc
->iv_size
);
240 *(__le32
*)iv
= cpu_to_le32(dmreq
->iv_sector
& 0xffffffff);
245 static int crypt_iv_plain64_gen(struct crypt_config
*cc
, u8
*iv
,
246 struct dm_crypt_request
*dmreq
)
248 memset(iv
, 0, cc
->iv_size
);
249 *(__le64
*)iv
= cpu_to_le64(dmreq
->iv_sector
);
254 /* Initialise ESSIV - compute salt but no local memory allocations */
255 static int crypt_iv_essiv_init(struct crypt_config
*cc
)
257 struct iv_essiv_private
*essiv
= &cc
->iv_gen_private
.essiv
;
258 struct hash_desc desc
;
259 struct scatterlist sg
;
260 struct crypto_cipher
*essiv_tfm
;
263 sg_init_one(&sg
, cc
->key
, cc
->key_size
);
264 desc
.tfm
= essiv
->hash_tfm
;
265 desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
267 err
= crypto_hash_digest(&desc
, &sg
, cc
->key_size
, essiv
->salt
);
271 essiv_tfm
= cc
->iv_private
;
273 err
= crypto_cipher_setkey(essiv_tfm
, essiv
->salt
,
274 crypto_hash_digestsize(essiv
->hash_tfm
));
281 /* Wipe salt and reset key derived from volume key */
282 static int crypt_iv_essiv_wipe(struct crypt_config
*cc
)
284 struct iv_essiv_private
*essiv
= &cc
->iv_gen_private
.essiv
;
285 unsigned salt_size
= crypto_hash_digestsize(essiv
->hash_tfm
);
286 struct crypto_cipher
*essiv_tfm
;
289 memset(essiv
->salt
, 0, salt_size
);
291 essiv_tfm
= cc
->iv_private
;
292 r
= crypto_cipher_setkey(essiv_tfm
, essiv
->salt
, salt_size
);
299 /* Set up per cpu cipher state */
300 static struct crypto_cipher
*setup_essiv_cpu(struct crypt_config
*cc
,
301 struct dm_target
*ti
,
302 u8
*salt
, unsigned saltsize
)
304 struct crypto_cipher
*essiv_tfm
;
307 /* Setup the essiv_tfm with the given salt */
308 essiv_tfm
= crypto_alloc_cipher(cc
->cipher
, 0, CRYPTO_ALG_ASYNC
);
309 if (IS_ERR(essiv_tfm
)) {
310 ti
->error
= "Error allocating crypto tfm for ESSIV";
314 if (crypto_cipher_blocksize(essiv_tfm
) !=
315 crypto_ablkcipher_ivsize(any_tfm(cc
))) {
316 ti
->error
= "Block size of ESSIV cipher does "
317 "not match IV size of block cipher";
318 crypto_free_cipher(essiv_tfm
);
319 return ERR_PTR(-EINVAL
);
322 err
= crypto_cipher_setkey(essiv_tfm
, salt
, saltsize
);
324 ti
->error
= "Failed to set key for ESSIV cipher";
325 crypto_free_cipher(essiv_tfm
);
332 static void crypt_iv_essiv_dtr(struct crypt_config
*cc
)
334 struct crypto_cipher
*essiv_tfm
;
335 struct iv_essiv_private
*essiv
= &cc
->iv_gen_private
.essiv
;
337 crypto_free_hash(essiv
->hash_tfm
);
338 essiv
->hash_tfm
= NULL
;
343 essiv_tfm
= cc
->iv_private
;
346 crypto_free_cipher(essiv_tfm
);
348 cc
->iv_private
= NULL
;
351 static int crypt_iv_essiv_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
354 struct crypto_cipher
*essiv_tfm
= NULL
;
355 struct crypto_hash
*hash_tfm
= NULL
;
360 ti
->error
= "Digest algorithm missing for ESSIV mode";
364 /* Allocate hash algorithm */
365 hash_tfm
= crypto_alloc_hash(opts
, 0, CRYPTO_ALG_ASYNC
);
366 if (IS_ERR(hash_tfm
)) {
367 ti
->error
= "Error initializing ESSIV hash";
368 err
= PTR_ERR(hash_tfm
);
372 salt
= kzalloc(crypto_hash_digestsize(hash_tfm
), GFP_KERNEL
);
374 ti
->error
= "Error kmallocing salt storage in ESSIV";
379 cc
->iv_gen_private
.essiv
.salt
= salt
;
380 cc
->iv_gen_private
.essiv
.hash_tfm
= hash_tfm
;
382 essiv_tfm
= setup_essiv_cpu(cc
, ti
, salt
,
383 crypto_hash_digestsize(hash_tfm
));
384 if (IS_ERR(essiv_tfm
)) {
385 crypt_iv_essiv_dtr(cc
);
386 return PTR_ERR(essiv_tfm
);
388 cc
->iv_private
= essiv_tfm
;
393 if (hash_tfm
&& !IS_ERR(hash_tfm
))
394 crypto_free_hash(hash_tfm
);
399 static int crypt_iv_essiv_gen(struct crypt_config
*cc
, u8
*iv
,
400 struct dm_crypt_request
*dmreq
)
402 struct crypto_cipher
*essiv_tfm
= cc
->iv_private
;
404 memset(iv
, 0, cc
->iv_size
);
405 *(__le64
*)iv
= cpu_to_le64(dmreq
->iv_sector
);
406 crypto_cipher_encrypt_one(essiv_tfm
, iv
, iv
);
411 static int crypt_iv_benbi_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
414 unsigned bs
= crypto_ablkcipher_blocksize(any_tfm(cc
));
417 /* we need to calculate how far we must shift the sector count
418 * to get the cipher block count, we use this shift in _gen */
420 if (1 << log
!= bs
) {
421 ti
->error
= "cypher blocksize is not a power of 2";
426 ti
->error
= "cypher blocksize is > 512";
430 cc
->iv_gen_private
.benbi
.shift
= 9 - log
;
435 static void crypt_iv_benbi_dtr(struct crypt_config
*cc
)
439 static int crypt_iv_benbi_gen(struct crypt_config
*cc
, u8
*iv
,
440 struct dm_crypt_request
*dmreq
)
444 memset(iv
, 0, cc
->iv_size
- sizeof(u64
)); /* rest is cleared below */
446 val
= cpu_to_be64(((u64
)dmreq
->iv_sector
<< cc
->iv_gen_private
.benbi
.shift
) + 1);
447 put_unaligned(val
, (__be64
*)(iv
+ cc
->iv_size
- sizeof(u64
)));
452 static int crypt_iv_null_gen(struct crypt_config
*cc
, u8
*iv
,
453 struct dm_crypt_request
*dmreq
)
455 memset(iv
, 0, cc
->iv_size
);
460 static void crypt_iv_lmk_dtr(struct crypt_config
*cc
)
462 struct iv_lmk_private
*lmk
= &cc
->iv_gen_private
.lmk
;
464 if (lmk
->hash_tfm
&& !IS_ERR(lmk
->hash_tfm
))
465 crypto_free_shash(lmk
->hash_tfm
);
466 lmk
->hash_tfm
= NULL
;
472 static int crypt_iv_lmk_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
475 struct iv_lmk_private
*lmk
= &cc
->iv_gen_private
.lmk
;
477 lmk
->hash_tfm
= crypto_alloc_shash("md5", 0, 0);
478 if (IS_ERR(lmk
->hash_tfm
)) {
479 ti
->error
= "Error initializing LMK hash";
480 return PTR_ERR(lmk
->hash_tfm
);
483 /* No seed in LMK version 2 */
484 if (cc
->key_parts
== cc
->tfms_count
) {
489 lmk
->seed
= kzalloc(LMK_SEED_SIZE
, GFP_KERNEL
);
491 crypt_iv_lmk_dtr(cc
);
492 ti
->error
= "Error kmallocing seed storage in LMK";
499 static int crypt_iv_lmk_init(struct crypt_config
*cc
)
501 struct iv_lmk_private
*lmk
= &cc
->iv_gen_private
.lmk
;
502 int subkey_size
= cc
->key_size
/ cc
->key_parts
;
504 /* LMK seed is on the position of LMK_KEYS + 1 key */
506 memcpy(lmk
->seed
, cc
->key
+ (cc
->tfms_count
* subkey_size
),
507 crypto_shash_digestsize(lmk
->hash_tfm
));
512 static int crypt_iv_lmk_wipe(struct crypt_config
*cc
)
514 struct iv_lmk_private
*lmk
= &cc
->iv_gen_private
.lmk
;
517 memset(lmk
->seed
, 0, LMK_SEED_SIZE
);
522 static int crypt_iv_lmk_one(struct crypt_config
*cc
, u8
*iv
,
523 struct dm_crypt_request
*dmreq
,
526 struct iv_lmk_private
*lmk
= &cc
->iv_gen_private
.lmk
;
528 struct shash_desc desc
;
529 char ctx
[crypto_shash_descsize(lmk
->hash_tfm
)];
531 struct md5_state md5state
;
535 sdesc
.desc
.tfm
= lmk
->hash_tfm
;
536 sdesc
.desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
538 r
= crypto_shash_init(&sdesc
.desc
);
543 r
= crypto_shash_update(&sdesc
.desc
, lmk
->seed
, LMK_SEED_SIZE
);
548 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
549 r
= crypto_shash_update(&sdesc
.desc
, data
+ 16, 16 * 31);
553 /* Sector is cropped to 56 bits here */
554 buf
[0] = cpu_to_le32(dmreq
->iv_sector
& 0xFFFFFFFF);
555 buf
[1] = cpu_to_le32((((u64
)dmreq
->iv_sector
>> 32) & 0x00FFFFFF) | 0x80000000);
556 buf
[2] = cpu_to_le32(4024);
558 r
= crypto_shash_update(&sdesc
.desc
, (u8
*)buf
, sizeof(buf
));
562 /* No MD5 padding here */
563 r
= crypto_shash_export(&sdesc
.desc
, &md5state
);
567 for (i
= 0; i
< MD5_HASH_WORDS
; i
++)
568 __cpu_to_le32s(&md5state
.hash
[i
]);
569 memcpy(iv
, &md5state
.hash
, cc
->iv_size
);
574 static int crypt_iv_lmk_gen(struct crypt_config
*cc
, u8
*iv
,
575 struct dm_crypt_request
*dmreq
)
580 if (bio_data_dir(dmreq
->ctx
->bio_in
) == WRITE
) {
581 src
= kmap_atomic(sg_page(&dmreq
->sg_in
));
582 r
= crypt_iv_lmk_one(cc
, iv
, dmreq
, src
+ dmreq
->sg_in
.offset
);
585 memset(iv
, 0, cc
->iv_size
);
590 static int crypt_iv_lmk_post(struct crypt_config
*cc
, u8
*iv
,
591 struct dm_crypt_request
*dmreq
)
596 if (bio_data_dir(dmreq
->ctx
->bio_in
) == WRITE
)
599 dst
= kmap_atomic(sg_page(&dmreq
->sg_out
));
600 r
= crypt_iv_lmk_one(cc
, iv
, dmreq
, dst
+ dmreq
->sg_out
.offset
);
602 /* Tweak the first block of plaintext sector */
604 crypto_xor(dst
+ dmreq
->sg_out
.offset
, iv
, cc
->iv_size
);
610 static void crypt_iv_tcw_dtr(struct crypt_config
*cc
)
612 struct iv_tcw_private
*tcw
= &cc
->iv_gen_private
.tcw
;
614 kzfree(tcw
->iv_seed
);
616 kzfree(tcw
->whitening
);
617 tcw
->whitening
= NULL
;
619 if (tcw
->crc32_tfm
&& !IS_ERR(tcw
->crc32_tfm
))
620 crypto_free_shash(tcw
->crc32_tfm
);
621 tcw
->crc32_tfm
= NULL
;
624 static int crypt_iv_tcw_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
627 struct iv_tcw_private
*tcw
= &cc
->iv_gen_private
.tcw
;
629 if (cc
->key_size
<= (cc
->iv_size
+ TCW_WHITENING_SIZE
)) {
630 ti
->error
= "Wrong key size for TCW";
634 tcw
->crc32_tfm
= crypto_alloc_shash("crc32", 0, 0);
635 if (IS_ERR(tcw
->crc32_tfm
)) {
636 ti
->error
= "Error initializing CRC32 in TCW";
637 return PTR_ERR(tcw
->crc32_tfm
);
640 tcw
->iv_seed
= kzalloc(cc
->iv_size
, GFP_KERNEL
);
641 tcw
->whitening
= kzalloc(TCW_WHITENING_SIZE
, GFP_KERNEL
);
642 if (!tcw
->iv_seed
|| !tcw
->whitening
) {
643 crypt_iv_tcw_dtr(cc
);
644 ti
->error
= "Error allocating seed storage in TCW";
651 static int crypt_iv_tcw_init(struct crypt_config
*cc
)
653 struct iv_tcw_private
*tcw
= &cc
->iv_gen_private
.tcw
;
654 int key_offset
= cc
->key_size
- cc
->iv_size
- TCW_WHITENING_SIZE
;
656 memcpy(tcw
->iv_seed
, &cc
->key
[key_offset
], cc
->iv_size
);
657 memcpy(tcw
->whitening
, &cc
->key
[key_offset
+ cc
->iv_size
],
663 static int crypt_iv_tcw_wipe(struct crypt_config
*cc
)
665 struct iv_tcw_private
*tcw
= &cc
->iv_gen_private
.tcw
;
667 memset(tcw
->iv_seed
, 0, cc
->iv_size
);
668 memset(tcw
->whitening
, 0, TCW_WHITENING_SIZE
);
673 static int crypt_iv_tcw_whitening(struct crypt_config
*cc
,
674 struct dm_crypt_request
*dmreq
,
677 struct iv_tcw_private
*tcw
= &cc
->iv_gen_private
.tcw
;
678 u64 sector
= cpu_to_le64((u64
)dmreq
->iv_sector
);
679 u8 buf
[TCW_WHITENING_SIZE
];
681 struct shash_desc desc
;
682 char ctx
[crypto_shash_descsize(tcw
->crc32_tfm
)];
686 /* xor whitening with sector number */
687 memcpy(buf
, tcw
->whitening
, TCW_WHITENING_SIZE
);
688 crypto_xor(buf
, (u8
*)§or
, 8);
689 crypto_xor(&buf
[8], (u8
*)§or
, 8);
691 /* calculate crc32 for every 32bit part and xor it */
692 sdesc
.desc
.tfm
= tcw
->crc32_tfm
;
693 sdesc
.desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
694 for (i
= 0; i
< 4; i
++) {
695 r
= crypto_shash_init(&sdesc
.desc
);
698 r
= crypto_shash_update(&sdesc
.desc
, &buf
[i
* 4], 4);
701 r
= crypto_shash_final(&sdesc
.desc
, &buf
[i
* 4]);
705 crypto_xor(&buf
[0], &buf
[12], 4);
706 crypto_xor(&buf
[4], &buf
[8], 4);
708 /* apply whitening (8 bytes) to whole sector */
709 for (i
= 0; i
< ((1 << SECTOR_SHIFT
) / 8); i
++)
710 crypto_xor(data
+ i
* 8, buf
, 8);
712 memset(buf
, 0, sizeof(buf
));
716 static int crypt_iv_tcw_gen(struct crypt_config
*cc
, u8
*iv
,
717 struct dm_crypt_request
*dmreq
)
719 struct iv_tcw_private
*tcw
= &cc
->iv_gen_private
.tcw
;
720 u64 sector
= cpu_to_le64((u64
)dmreq
->iv_sector
);
724 /* Remove whitening from ciphertext */
725 if (bio_data_dir(dmreq
->ctx
->bio_in
) != WRITE
) {
726 src
= kmap_atomic(sg_page(&dmreq
->sg_in
));
727 r
= crypt_iv_tcw_whitening(cc
, dmreq
, src
+ dmreq
->sg_in
.offset
);
732 memcpy(iv
, tcw
->iv_seed
, cc
->iv_size
);
733 crypto_xor(iv
, (u8
*)§or
, 8);
735 crypto_xor(&iv
[8], (u8
*)§or
, cc
->iv_size
- 8);
740 static int crypt_iv_tcw_post(struct crypt_config
*cc
, u8
*iv
,
741 struct dm_crypt_request
*dmreq
)
746 if (bio_data_dir(dmreq
->ctx
->bio_in
) != WRITE
)
749 /* Apply whitening on ciphertext */
750 dst
= kmap_atomic(sg_page(&dmreq
->sg_out
));
751 r
= crypt_iv_tcw_whitening(cc
, dmreq
, dst
+ dmreq
->sg_out
.offset
);
757 static struct crypt_iv_operations crypt_iv_plain_ops
= {
758 .generator
= crypt_iv_plain_gen
761 static struct crypt_iv_operations crypt_iv_plain64_ops
= {
762 .generator
= crypt_iv_plain64_gen
765 static struct crypt_iv_operations crypt_iv_essiv_ops
= {
766 .ctr
= crypt_iv_essiv_ctr
,
767 .dtr
= crypt_iv_essiv_dtr
,
768 .init
= crypt_iv_essiv_init
,
769 .wipe
= crypt_iv_essiv_wipe
,
770 .generator
= crypt_iv_essiv_gen
773 static struct crypt_iv_operations crypt_iv_benbi_ops
= {
774 .ctr
= crypt_iv_benbi_ctr
,
775 .dtr
= crypt_iv_benbi_dtr
,
776 .generator
= crypt_iv_benbi_gen
779 static struct crypt_iv_operations crypt_iv_null_ops
= {
780 .generator
= crypt_iv_null_gen
783 static struct crypt_iv_operations crypt_iv_lmk_ops
= {
784 .ctr
= crypt_iv_lmk_ctr
,
785 .dtr
= crypt_iv_lmk_dtr
,
786 .init
= crypt_iv_lmk_init
,
787 .wipe
= crypt_iv_lmk_wipe
,
788 .generator
= crypt_iv_lmk_gen
,
789 .post
= crypt_iv_lmk_post
792 static struct crypt_iv_operations crypt_iv_tcw_ops
= {
793 .ctr
= crypt_iv_tcw_ctr
,
794 .dtr
= crypt_iv_tcw_dtr
,
795 .init
= crypt_iv_tcw_init
,
796 .wipe
= crypt_iv_tcw_wipe
,
797 .generator
= crypt_iv_tcw_gen
,
798 .post
= crypt_iv_tcw_post
801 static void crypt_convert_init(struct crypt_config
*cc
,
802 struct convert_context
*ctx
,
803 struct bio
*bio_out
, struct bio
*bio_in
,
806 ctx
->bio_in
= bio_in
;
807 ctx
->bio_out
= bio_out
;
809 ctx
->iter_in
= bio_in
->bi_iter
;
811 ctx
->iter_out
= bio_out
->bi_iter
;
812 ctx
->cc_sector
= sector
+ cc
->iv_offset
;
813 init_completion(&ctx
->restart
);
816 static struct dm_crypt_request
*dmreq_of_req(struct crypt_config
*cc
,
817 struct ablkcipher_request
*req
)
819 return (struct dm_crypt_request
*)((char *)req
+ cc
->dmreq_start
);
822 static struct ablkcipher_request
*req_of_dmreq(struct crypt_config
*cc
,
823 struct dm_crypt_request
*dmreq
)
825 return (struct ablkcipher_request
*)((char *)dmreq
- cc
->dmreq_start
);
828 static u8
*iv_of_dmreq(struct crypt_config
*cc
,
829 struct dm_crypt_request
*dmreq
)
831 return (u8
*)ALIGN((unsigned long)(dmreq
+ 1),
832 crypto_ablkcipher_alignmask(any_tfm(cc
)) + 1);
835 static int crypt_convert_block(struct crypt_config
*cc
,
836 struct convert_context
*ctx
,
837 struct ablkcipher_request
*req
)
839 struct bio_vec bv_in
= bio_iter_iovec(ctx
->bio_in
, ctx
->iter_in
);
840 struct bio_vec bv_out
= bio_iter_iovec(ctx
->bio_out
, ctx
->iter_out
);
841 struct dm_crypt_request
*dmreq
;
845 dmreq
= dmreq_of_req(cc
, req
);
846 iv
= iv_of_dmreq(cc
, dmreq
);
848 dmreq
->iv_sector
= ctx
->cc_sector
;
850 sg_init_table(&dmreq
->sg_in
, 1);
851 sg_set_page(&dmreq
->sg_in
, bv_in
.bv_page
, 1 << SECTOR_SHIFT
,
854 sg_init_table(&dmreq
->sg_out
, 1);
855 sg_set_page(&dmreq
->sg_out
, bv_out
.bv_page
, 1 << SECTOR_SHIFT
,
858 bio_advance_iter(ctx
->bio_in
, &ctx
->iter_in
, 1 << SECTOR_SHIFT
);
859 bio_advance_iter(ctx
->bio_out
, &ctx
->iter_out
, 1 << SECTOR_SHIFT
);
861 if (cc
->iv_gen_ops
) {
862 r
= cc
->iv_gen_ops
->generator(cc
, iv
, dmreq
);
867 ablkcipher_request_set_crypt(req
, &dmreq
->sg_in
, &dmreq
->sg_out
,
868 1 << SECTOR_SHIFT
, iv
);
870 if (bio_data_dir(ctx
->bio_in
) == WRITE
)
871 r
= crypto_ablkcipher_encrypt(req
);
873 r
= crypto_ablkcipher_decrypt(req
);
875 if (!r
&& cc
->iv_gen_ops
&& cc
->iv_gen_ops
->post
)
876 r
= cc
->iv_gen_ops
->post(cc
, iv
, dmreq
);
881 static void kcryptd_async_done(struct crypto_async_request
*async_req
,
884 static void crypt_alloc_req(struct crypt_config
*cc
,
885 struct convert_context
*ctx
)
887 unsigned key_index
= ctx
->cc_sector
& (cc
->tfms_count
- 1);
890 ctx
->req
= mempool_alloc(cc
->req_pool
, GFP_NOIO
);
892 ablkcipher_request_set_tfm(ctx
->req
, cc
->tfms
[key_index
]);
893 ablkcipher_request_set_callback(ctx
->req
,
894 CRYPTO_TFM_REQ_MAY_BACKLOG
| CRYPTO_TFM_REQ_MAY_SLEEP
,
895 kcryptd_async_done
, dmreq_of_req(cc
, ctx
->req
));
899 * Encrypt / decrypt data from one bio to another one (can be the same one)
901 static int crypt_convert(struct crypt_config
*cc
,
902 struct convert_context
*ctx
)
906 atomic_set(&ctx
->cc_pending
, 1);
908 while (ctx
->iter_in
.bi_size
&& ctx
->iter_out
.bi_size
) {
910 crypt_alloc_req(cc
, ctx
);
912 atomic_inc(&ctx
->cc_pending
);
914 r
= crypt_convert_block(cc
, ctx
, ctx
->req
);
919 wait_for_completion(&ctx
->restart
);
920 reinit_completion(&ctx
->restart
);
929 atomic_dec(&ctx
->cc_pending
);
936 atomic_dec(&ctx
->cc_pending
);
945 * Generate a new unfragmented bio with the given size
946 * This should never violate the device limitations
947 * May return a smaller bio when running out of pages, indicated by
948 * *out_of_pages set to 1.
950 static struct bio
*crypt_alloc_buffer(struct dm_crypt_io
*io
, unsigned size
,
951 unsigned *out_of_pages
)
953 struct crypt_config
*cc
= io
->cc
;
955 unsigned int nr_iovecs
= (size
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
956 gfp_t gfp_mask
= GFP_NOIO
| __GFP_HIGHMEM
;
960 clone
= bio_alloc_bioset(GFP_NOIO
, nr_iovecs
, cc
->bs
);
964 clone_init(io
, clone
);
967 for (i
= 0; i
< nr_iovecs
; i
++) {
968 page
= mempool_alloc(cc
->page_pool
, gfp_mask
);
975 * If additional pages cannot be allocated without waiting,
976 * return a partially-allocated bio. The caller will then try
977 * to allocate more bios while submitting this partial bio.
979 gfp_mask
= (gfp_mask
| __GFP_NOWARN
) & ~__GFP_WAIT
;
981 len
= (size
> PAGE_SIZE
) ? PAGE_SIZE
: size
;
983 if (!bio_add_page(clone
, page
, len
, 0)) {
984 mempool_free(page
, cc
->page_pool
);
991 if (!clone
->bi_iter
.bi_size
) {
999 static void crypt_free_buffer_pages(struct crypt_config
*cc
, struct bio
*clone
)
1004 bio_for_each_segment_all(bv
, clone
, i
) {
1005 BUG_ON(!bv
->bv_page
);
1006 mempool_free(bv
->bv_page
, cc
->page_pool
);
1011 static struct dm_crypt_io
*crypt_io_alloc(struct crypt_config
*cc
,
1012 struct bio
*bio
, sector_t sector
)
1014 struct dm_crypt_io
*io
;
1016 io
= mempool_alloc(cc
->io_pool
, GFP_NOIO
);
1019 io
->sector
= sector
;
1023 atomic_set(&io
->io_pending
, 0);
1028 static void crypt_inc_pending(struct dm_crypt_io
*io
)
1030 atomic_inc(&io
->io_pending
);
1034 * One of the bios was finished. Check for completion of
1035 * the whole request and correctly clean up the buffer.
1036 * If base_io is set, wait for the last fragment to complete.
1038 static void crypt_dec_pending(struct dm_crypt_io
*io
)
1040 struct crypt_config
*cc
= io
->cc
;
1041 struct bio
*base_bio
= io
->base_bio
;
1042 struct dm_crypt_io
*base_io
= io
->base_io
;
1043 int error
= io
->error
;
1045 if (!atomic_dec_and_test(&io
->io_pending
))
1049 mempool_free(io
->ctx
.req
, cc
->req_pool
);
1050 mempool_free(io
, cc
->io_pool
);
1052 if (likely(!base_io
))
1053 bio_endio(base_bio
, error
);
1055 if (error
&& !base_io
->error
)
1056 base_io
->error
= error
;
1057 crypt_dec_pending(base_io
);
1062 * kcryptd/kcryptd_io:
1064 * Needed because it would be very unwise to do decryption in an
1065 * interrupt context.
1067 * kcryptd performs the actual encryption or decryption.
1069 * kcryptd_io performs the IO submission.
1071 * They must be separated as otherwise the final stages could be
1072 * starved by new requests which can block in the first stages due
1073 * to memory allocation.
1075 * The work is done per CPU global for all dm-crypt instances.
1076 * They should not depend on each other and do not block.
1078 static void crypt_endio(struct bio
*clone
, int error
)
1080 struct dm_crypt_io
*io
= clone
->bi_private
;
1081 struct crypt_config
*cc
= io
->cc
;
1082 unsigned rw
= bio_data_dir(clone
);
1084 if (unlikely(!bio_flagged(clone
, BIO_UPTODATE
) && !error
))
1088 * free the processed pages
1091 crypt_free_buffer_pages(cc
, clone
);
1095 if (rw
== READ
&& !error
) {
1096 kcryptd_queue_crypt(io
);
1100 if (unlikely(error
))
1103 crypt_dec_pending(io
);
1106 static void clone_init(struct dm_crypt_io
*io
, struct bio
*clone
)
1108 struct crypt_config
*cc
= io
->cc
;
1110 clone
->bi_private
= io
;
1111 clone
->bi_end_io
= crypt_endio
;
1112 clone
->bi_bdev
= cc
->dev
->bdev
;
1113 clone
->bi_rw
= io
->base_bio
->bi_rw
;
1116 static int kcryptd_io_read(struct dm_crypt_io
*io
, gfp_t gfp
)
1118 struct crypt_config
*cc
= io
->cc
;
1119 struct bio
*base_bio
= io
->base_bio
;
1123 * The block layer might modify the bvec array, so always
1124 * copy the required bvecs because we need the original
1125 * one in order to decrypt the whole bio data *afterwards*.
1127 clone
= bio_clone_bioset(base_bio
, gfp
, cc
->bs
);
1131 crypt_inc_pending(io
);
1133 clone_init(io
, clone
);
1134 clone
->bi_iter
.bi_sector
= cc
->start
+ io
->sector
;
1136 generic_make_request(clone
);
1140 static void kcryptd_io_write(struct dm_crypt_io
*io
)
1142 struct bio
*clone
= io
->ctx
.bio_out
;
1143 generic_make_request(clone
);
1146 static void kcryptd_io(struct work_struct
*work
)
1148 struct dm_crypt_io
*io
= container_of(work
, struct dm_crypt_io
, work
);
1150 if (bio_data_dir(io
->base_bio
) == READ
) {
1151 crypt_inc_pending(io
);
1152 if (kcryptd_io_read(io
, GFP_NOIO
))
1153 io
->error
= -ENOMEM
;
1154 crypt_dec_pending(io
);
1156 kcryptd_io_write(io
);
1159 static void kcryptd_queue_io(struct dm_crypt_io
*io
)
1161 struct crypt_config
*cc
= io
->cc
;
1163 INIT_WORK(&io
->work
, kcryptd_io
);
1164 queue_work(cc
->io_queue
, &io
->work
);
1167 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io
*io
, int async
)
1169 struct bio
*clone
= io
->ctx
.bio_out
;
1170 struct crypt_config
*cc
= io
->cc
;
1172 if (unlikely(io
->error
< 0)) {
1173 crypt_free_buffer_pages(cc
, clone
);
1175 crypt_dec_pending(io
);
1179 /* crypt_convert should have filled the clone bio */
1180 BUG_ON(io
->ctx
.iter_out
.bi_size
);
1182 clone
->bi_iter
.bi_sector
= cc
->start
+ io
->sector
;
1185 kcryptd_queue_io(io
);
1187 generic_make_request(clone
);
1190 static void kcryptd_crypt_write_convert(struct dm_crypt_io
*io
)
1192 struct crypt_config
*cc
= io
->cc
;
1194 struct dm_crypt_io
*new_io
;
1196 unsigned out_of_pages
= 0;
1197 unsigned remaining
= io
->base_bio
->bi_iter
.bi_size
;
1198 sector_t sector
= io
->sector
;
1202 * Prevent io from disappearing until this function completes.
1204 crypt_inc_pending(io
);
1205 crypt_convert_init(cc
, &io
->ctx
, NULL
, io
->base_bio
, sector
);
1208 * The allocated buffers can be smaller than the whole bio,
1209 * so repeat the whole process until all the data can be handled.
1212 clone
= crypt_alloc_buffer(io
, remaining
, &out_of_pages
);
1213 if (unlikely(!clone
)) {
1214 io
->error
= -ENOMEM
;
1218 io
->ctx
.bio_out
= clone
;
1219 io
->ctx
.iter_out
= clone
->bi_iter
;
1221 remaining
-= clone
->bi_iter
.bi_size
;
1222 sector
+= bio_sectors(clone
);
1224 crypt_inc_pending(io
);
1226 r
= crypt_convert(cc
, &io
->ctx
);
1230 crypt_finished
= atomic_dec_and_test(&io
->ctx
.cc_pending
);
1232 /* Encryption was already finished, submit io now */
1233 if (crypt_finished
) {
1234 kcryptd_crypt_write_io_submit(io
, 0);
1237 * If there was an error, do not try next fragments.
1238 * For async, error is processed in async handler.
1240 if (unlikely(r
< 0))
1243 io
->sector
= sector
;
1247 * Out of memory -> run queues
1248 * But don't wait if split was due to the io size restriction
1250 if (unlikely(out_of_pages
))
1251 congestion_wait(BLK_RW_ASYNC
, HZ
/100);
1254 * With async crypto it is unsafe to share the crypto context
1255 * between fragments, so switch to a new dm_crypt_io structure.
1257 if (unlikely(!crypt_finished
&& remaining
)) {
1258 new_io
= crypt_io_alloc(io
->cc
, io
->base_bio
,
1260 crypt_inc_pending(new_io
);
1261 crypt_convert_init(cc
, &new_io
->ctx
, NULL
,
1262 io
->base_bio
, sector
);
1263 new_io
->ctx
.iter_in
= io
->ctx
.iter_in
;
1266 * Fragments after the first use the base_io
1270 new_io
->base_io
= io
;
1272 new_io
->base_io
= io
->base_io
;
1273 crypt_inc_pending(io
->base_io
);
1274 crypt_dec_pending(io
);
1281 crypt_dec_pending(io
);
1284 static void kcryptd_crypt_read_done(struct dm_crypt_io
*io
)
1286 crypt_dec_pending(io
);
1289 static void kcryptd_crypt_read_convert(struct dm_crypt_io
*io
)
1291 struct crypt_config
*cc
= io
->cc
;
1294 crypt_inc_pending(io
);
1296 crypt_convert_init(cc
, &io
->ctx
, io
->base_bio
, io
->base_bio
,
1299 r
= crypt_convert(cc
, &io
->ctx
);
1303 if (atomic_dec_and_test(&io
->ctx
.cc_pending
))
1304 kcryptd_crypt_read_done(io
);
1306 crypt_dec_pending(io
);
1309 static void kcryptd_async_done(struct crypto_async_request
*async_req
,
1312 struct dm_crypt_request
*dmreq
= async_req
->data
;
1313 struct convert_context
*ctx
= dmreq
->ctx
;
1314 struct dm_crypt_io
*io
= container_of(ctx
, struct dm_crypt_io
, ctx
);
1315 struct crypt_config
*cc
= io
->cc
;
1317 if (error
== -EINPROGRESS
) {
1318 complete(&ctx
->restart
);
1322 if (!error
&& cc
->iv_gen_ops
&& cc
->iv_gen_ops
->post
)
1323 error
= cc
->iv_gen_ops
->post(cc
, iv_of_dmreq(cc
, dmreq
), dmreq
);
1328 mempool_free(req_of_dmreq(cc
, dmreq
), cc
->req_pool
);
1330 if (!atomic_dec_and_test(&ctx
->cc_pending
))
1333 if (bio_data_dir(io
->base_bio
) == READ
)
1334 kcryptd_crypt_read_done(io
);
1336 kcryptd_crypt_write_io_submit(io
, 1);
1339 static void kcryptd_crypt(struct work_struct
*work
)
1341 struct dm_crypt_io
*io
= container_of(work
, struct dm_crypt_io
, work
);
1343 if (bio_data_dir(io
->base_bio
) == READ
)
1344 kcryptd_crypt_read_convert(io
);
1346 kcryptd_crypt_write_convert(io
);
1349 static void kcryptd_queue_crypt(struct dm_crypt_io
*io
)
1351 struct crypt_config
*cc
= io
->cc
;
1353 INIT_WORK(&io
->work
, kcryptd_crypt
);
1354 queue_work(cc
->crypt_queue
, &io
->work
);
1358 * Decode key from its hex representation
1360 static int crypt_decode_key(u8
*key
, char *hex
, unsigned int size
)
1367 for (i
= 0; i
< size
; i
++) {
1371 if (kstrtou8(buffer
, 16, &key
[i
]))
1381 static void crypt_free_tfms(struct crypt_config
*cc
)
1388 for (i
= 0; i
< cc
->tfms_count
; i
++)
1389 if (cc
->tfms
[i
] && !IS_ERR(cc
->tfms
[i
])) {
1390 crypto_free_ablkcipher(cc
->tfms
[i
]);
1398 static int crypt_alloc_tfms(struct crypt_config
*cc
, char *ciphermode
)
1403 cc
->tfms
= kmalloc(cc
->tfms_count
* sizeof(struct crypto_ablkcipher
*),
1408 for (i
= 0; i
< cc
->tfms_count
; i
++) {
1409 cc
->tfms
[i
] = crypto_alloc_ablkcipher(ciphermode
, 0, 0);
1410 if (IS_ERR(cc
->tfms
[i
])) {
1411 err
= PTR_ERR(cc
->tfms
[i
]);
1412 crypt_free_tfms(cc
);
1420 static int crypt_setkey_allcpus(struct crypt_config
*cc
)
1422 unsigned subkey_size
;
1425 /* Ignore extra keys (which are used for IV etc) */
1426 subkey_size
= (cc
->key_size
- cc
->key_extra_size
) >> ilog2(cc
->tfms_count
);
1428 for (i
= 0; i
< cc
->tfms_count
; i
++) {
1429 r
= crypto_ablkcipher_setkey(cc
->tfms
[i
],
1430 cc
->key
+ (i
* subkey_size
),
1439 static int crypt_set_key(struct crypt_config
*cc
, char *key
)
1442 int key_string_len
= strlen(key
);
1444 /* The key size may not be changed. */
1445 if (cc
->key_size
!= (key_string_len
>> 1))
1448 /* Hyphen (which gives a key_size of zero) means there is no key. */
1449 if (!cc
->key_size
&& strcmp(key
, "-"))
1452 if (cc
->key_size
&& crypt_decode_key(cc
->key
, key
, cc
->key_size
) < 0)
1455 set_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
);
1457 r
= crypt_setkey_allcpus(cc
);
1460 /* Hex key string not needed after here, so wipe it. */
1461 memset(key
, '0', key_string_len
);
1466 static int crypt_wipe_key(struct crypt_config
*cc
)
1468 clear_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
);
1469 memset(&cc
->key
, 0, cc
->key_size
* sizeof(u8
));
1471 return crypt_setkey_allcpus(cc
);
1474 static void crypt_dtr(struct dm_target
*ti
)
1476 struct crypt_config
*cc
= ti
->private;
1484 destroy_workqueue(cc
->io_queue
);
1485 if (cc
->crypt_queue
)
1486 destroy_workqueue(cc
->crypt_queue
);
1488 crypt_free_tfms(cc
);
1491 bioset_free(cc
->bs
);
1494 mempool_destroy(cc
->page_pool
);
1496 mempool_destroy(cc
->req_pool
);
1498 mempool_destroy(cc
->io_pool
);
1500 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->dtr
)
1501 cc
->iv_gen_ops
->dtr(cc
);
1504 dm_put_device(ti
, cc
->dev
);
1507 kzfree(cc
->cipher_string
);
1509 /* Must zero key material before freeing */
1513 static int crypt_ctr_cipher(struct dm_target
*ti
,
1514 char *cipher_in
, char *key
)
1516 struct crypt_config
*cc
= ti
->private;
1517 char *tmp
, *cipher
, *chainmode
, *ivmode
, *ivopts
, *keycount
;
1518 char *cipher_api
= NULL
;
1522 /* Convert to crypto api definition? */
1523 if (strchr(cipher_in
, '(')) {
1524 ti
->error
= "Bad cipher specification";
1528 cc
->cipher_string
= kstrdup(cipher_in
, GFP_KERNEL
);
1529 if (!cc
->cipher_string
)
1533 * Legacy dm-crypt cipher specification
1534 * cipher[:keycount]-mode-iv:ivopts
1537 keycount
= strsep(&tmp
, "-");
1538 cipher
= strsep(&keycount
, ":");
1542 else if (sscanf(keycount
, "%u%c", &cc
->tfms_count
, &dummy
) != 1 ||
1543 !is_power_of_2(cc
->tfms_count
)) {
1544 ti
->error
= "Bad cipher key count specification";
1547 cc
->key_parts
= cc
->tfms_count
;
1548 cc
->key_extra_size
= 0;
1550 cc
->cipher
= kstrdup(cipher
, GFP_KERNEL
);
1554 chainmode
= strsep(&tmp
, "-");
1555 ivopts
= strsep(&tmp
, "-");
1556 ivmode
= strsep(&ivopts
, ":");
1559 DMWARN("Ignoring unexpected additional cipher options");
1562 * For compatibility with the original dm-crypt mapping format, if
1563 * only the cipher name is supplied, use cbc-plain.
1565 if (!chainmode
|| (!strcmp(chainmode
, "plain") && !ivmode
)) {
1570 if (strcmp(chainmode
, "ecb") && !ivmode
) {
1571 ti
->error
= "IV mechanism required";
1575 cipher_api
= kmalloc(CRYPTO_MAX_ALG_NAME
, GFP_KERNEL
);
1579 ret
= snprintf(cipher_api
, CRYPTO_MAX_ALG_NAME
,
1580 "%s(%s)", chainmode
, cipher
);
1586 /* Allocate cipher */
1587 ret
= crypt_alloc_tfms(cc
, cipher_api
);
1589 ti
->error
= "Error allocating crypto tfm";
1594 cc
->iv_size
= crypto_ablkcipher_ivsize(any_tfm(cc
));
1596 /* at least a 64 bit sector number should fit in our buffer */
1597 cc
->iv_size
= max(cc
->iv_size
,
1598 (unsigned int)(sizeof(u64
) / sizeof(u8
)));
1600 DMWARN("Selected cipher does not support IVs");
1604 /* Choose ivmode, see comments at iv code. */
1606 cc
->iv_gen_ops
= NULL
;
1607 else if (strcmp(ivmode
, "plain") == 0)
1608 cc
->iv_gen_ops
= &crypt_iv_plain_ops
;
1609 else if (strcmp(ivmode
, "plain64") == 0)
1610 cc
->iv_gen_ops
= &crypt_iv_plain64_ops
;
1611 else if (strcmp(ivmode
, "essiv") == 0)
1612 cc
->iv_gen_ops
= &crypt_iv_essiv_ops
;
1613 else if (strcmp(ivmode
, "benbi") == 0)
1614 cc
->iv_gen_ops
= &crypt_iv_benbi_ops
;
1615 else if (strcmp(ivmode
, "null") == 0)
1616 cc
->iv_gen_ops
= &crypt_iv_null_ops
;
1617 else if (strcmp(ivmode
, "lmk") == 0) {
1618 cc
->iv_gen_ops
= &crypt_iv_lmk_ops
;
1620 * Version 2 and 3 is recognised according
1621 * to length of provided multi-key string.
1622 * If present (version 3), last key is used as IV seed.
1623 * All keys (including IV seed) are always the same size.
1625 if (cc
->key_size
% cc
->key_parts
) {
1627 cc
->key_extra_size
= cc
->key_size
/ cc
->key_parts
;
1629 } else if (strcmp(ivmode
, "tcw") == 0) {
1630 cc
->iv_gen_ops
= &crypt_iv_tcw_ops
;
1631 cc
->key_parts
+= 2; /* IV + whitening */
1632 cc
->key_extra_size
= cc
->iv_size
+ TCW_WHITENING_SIZE
;
1635 ti
->error
= "Invalid IV mode";
1639 /* Initialize and set key */
1640 ret
= crypt_set_key(cc
, key
);
1642 ti
->error
= "Error decoding and setting key";
1647 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->ctr
) {
1648 ret
= cc
->iv_gen_ops
->ctr(cc
, ti
, ivopts
);
1650 ti
->error
= "Error creating IV";
1655 /* Initialize IV (set keys for ESSIV etc) */
1656 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->init
) {
1657 ret
= cc
->iv_gen_ops
->init(cc
);
1659 ti
->error
= "Error initialising IV";
1670 ti
->error
= "Cannot allocate cipher strings";
1675 * Construct an encryption mapping:
1676 * <cipher> <key> <iv_offset> <dev_path> <start>
1678 static int crypt_ctr(struct dm_target
*ti
, unsigned int argc
, char **argv
)
1680 struct crypt_config
*cc
;
1681 unsigned int key_size
, opt_params
;
1682 unsigned long long tmpll
;
1684 struct dm_arg_set as
;
1685 const char *opt_string
;
1688 static struct dm_arg _args
[] = {
1689 {0, 1, "Invalid number of feature args"},
1693 ti
->error
= "Not enough arguments";
1697 key_size
= strlen(argv
[1]) >> 1;
1699 cc
= kzalloc(sizeof(*cc
) + key_size
* sizeof(u8
), GFP_KERNEL
);
1701 ti
->error
= "Cannot allocate encryption context";
1704 cc
->key_size
= key_size
;
1707 ret
= crypt_ctr_cipher(ti
, argv
[0], argv
[1]);
1712 cc
->io_pool
= mempool_create_slab_pool(MIN_IOS
, _crypt_io_pool
);
1714 ti
->error
= "Cannot allocate crypt io mempool";
1718 cc
->dmreq_start
= sizeof(struct ablkcipher_request
);
1719 cc
->dmreq_start
+= crypto_ablkcipher_reqsize(any_tfm(cc
));
1720 cc
->dmreq_start
= ALIGN(cc
->dmreq_start
, crypto_tfm_ctx_alignment());
1721 cc
->dmreq_start
+= crypto_ablkcipher_alignmask(any_tfm(cc
)) &
1722 ~(crypto_tfm_ctx_alignment() - 1);
1724 cc
->req_pool
= mempool_create_kmalloc_pool(MIN_IOS
, cc
->dmreq_start
+
1725 sizeof(struct dm_crypt_request
) + cc
->iv_size
);
1726 if (!cc
->req_pool
) {
1727 ti
->error
= "Cannot allocate crypt request mempool";
1731 cc
->page_pool
= mempool_create_page_pool(MIN_POOL_PAGES
, 0);
1732 if (!cc
->page_pool
) {
1733 ti
->error
= "Cannot allocate page mempool";
1737 cc
->bs
= bioset_create(MIN_IOS
, 0);
1739 ti
->error
= "Cannot allocate crypt bioset";
1744 if (sscanf(argv
[2], "%llu%c", &tmpll
, &dummy
) != 1) {
1745 ti
->error
= "Invalid iv_offset sector";
1748 cc
->iv_offset
= tmpll
;
1750 if (dm_get_device(ti
, argv
[3], dm_table_get_mode(ti
->table
), &cc
->dev
)) {
1751 ti
->error
= "Device lookup failed";
1755 if (sscanf(argv
[4], "%llu%c", &tmpll
, &dummy
) != 1) {
1756 ti
->error
= "Invalid device sector";
1764 /* Optional parameters */
1769 ret
= dm_read_arg_group(_args
, &as
, &opt_params
, &ti
->error
);
1773 opt_string
= dm_shift_arg(&as
);
1775 if (opt_params
== 1 && opt_string
&&
1776 !strcasecmp(opt_string
, "allow_discards"))
1777 ti
->num_discard_bios
= 1;
1778 else if (opt_params
) {
1780 ti
->error
= "Invalid feature arguments";
1786 cc
->io_queue
= alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM
, 1);
1787 if (!cc
->io_queue
) {
1788 ti
->error
= "Couldn't create kcryptd io queue";
1792 cc
->crypt_queue
= alloc_workqueue("kcryptd",
1793 WQ_CPU_INTENSIVE
| WQ_MEM_RECLAIM
, 1);
1794 if (!cc
->crypt_queue
) {
1795 ti
->error
= "Couldn't create kcryptd queue";
1799 ti
->num_flush_bios
= 1;
1800 ti
->discard_zeroes_data_unsupported
= true;
1809 static int crypt_map(struct dm_target
*ti
, struct bio
*bio
)
1811 struct dm_crypt_io
*io
;
1812 struct crypt_config
*cc
= ti
->private;
1815 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1816 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1817 * - for REQ_DISCARD caller must use flush if IO ordering matters
1819 if (unlikely(bio
->bi_rw
& (REQ_FLUSH
| REQ_DISCARD
))) {
1820 bio
->bi_bdev
= cc
->dev
->bdev
;
1821 if (bio_sectors(bio
))
1822 bio
->bi_iter
.bi_sector
= cc
->start
+
1823 dm_target_offset(ti
, bio
->bi_iter
.bi_sector
);
1824 return DM_MAPIO_REMAPPED
;
1827 io
= crypt_io_alloc(cc
, bio
, dm_target_offset(ti
, bio
->bi_iter
.bi_sector
));
1829 if (bio_data_dir(io
->base_bio
) == READ
) {
1830 if (kcryptd_io_read(io
, GFP_NOWAIT
))
1831 kcryptd_queue_io(io
);
1833 kcryptd_queue_crypt(io
);
1835 return DM_MAPIO_SUBMITTED
;
1838 static void crypt_status(struct dm_target
*ti
, status_type_t type
,
1839 unsigned status_flags
, char *result
, unsigned maxlen
)
1841 struct crypt_config
*cc
= ti
->private;
1845 case STATUSTYPE_INFO
:
1849 case STATUSTYPE_TABLE
:
1850 DMEMIT("%s ", cc
->cipher_string
);
1852 if (cc
->key_size
> 0)
1853 for (i
= 0; i
< cc
->key_size
; i
++)
1854 DMEMIT("%02x", cc
->key
[i
]);
1858 DMEMIT(" %llu %s %llu", (unsigned long long)cc
->iv_offset
,
1859 cc
->dev
->name
, (unsigned long long)cc
->start
);
1861 if (ti
->num_discard_bios
)
1862 DMEMIT(" 1 allow_discards");
1868 static void crypt_postsuspend(struct dm_target
*ti
)
1870 struct crypt_config
*cc
= ti
->private;
1872 set_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
);
1875 static int crypt_preresume(struct dm_target
*ti
)
1877 struct crypt_config
*cc
= ti
->private;
1879 if (!test_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
)) {
1880 DMERR("aborting resume - crypt key is not set.");
1887 static void crypt_resume(struct dm_target
*ti
)
1889 struct crypt_config
*cc
= ti
->private;
1891 clear_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
);
1894 /* Message interface
1898 static int crypt_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
1900 struct crypt_config
*cc
= ti
->private;
1906 if (!strcasecmp(argv
[0], "key")) {
1907 if (!test_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
)) {
1908 DMWARN("not suspended during key manipulation.");
1911 if (argc
== 3 && !strcasecmp(argv
[1], "set")) {
1912 ret
= crypt_set_key(cc
, argv
[2]);
1915 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->init
)
1916 ret
= cc
->iv_gen_ops
->init(cc
);
1919 if (argc
== 2 && !strcasecmp(argv
[1], "wipe")) {
1920 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->wipe
) {
1921 ret
= cc
->iv_gen_ops
->wipe(cc
);
1925 return crypt_wipe_key(cc
);
1930 DMWARN("unrecognised message received.");
1934 static int crypt_merge(struct dm_target
*ti
, struct bvec_merge_data
*bvm
,
1935 struct bio_vec
*biovec
, int max_size
)
1937 struct crypt_config
*cc
= ti
->private;
1938 struct request_queue
*q
= bdev_get_queue(cc
->dev
->bdev
);
1940 if (!q
->merge_bvec_fn
)
1943 bvm
->bi_bdev
= cc
->dev
->bdev
;
1944 bvm
->bi_sector
= cc
->start
+ dm_target_offset(ti
, bvm
->bi_sector
);
1946 return min(max_size
, q
->merge_bvec_fn(q
, bvm
, biovec
));
1949 static int crypt_iterate_devices(struct dm_target
*ti
,
1950 iterate_devices_callout_fn fn
, void *data
)
1952 struct crypt_config
*cc
= ti
->private;
1954 return fn(ti
, cc
->dev
, cc
->start
, ti
->len
, data
);
1957 static struct target_type crypt_target
= {
1959 .version
= {1, 13, 0},
1960 .module
= THIS_MODULE
,
1964 .status
= crypt_status
,
1965 .postsuspend
= crypt_postsuspend
,
1966 .preresume
= crypt_preresume
,
1967 .resume
= crypt_resume
,
1968 .message
= crypt_message
,
1969 .merge
= crypt_merge
,
1970 .iterate_devices
= crypt_iterate_devices
,
1973 static int __init
dm_crypt_init(void)
1977 _crypt_io_pool
= KMEM_CACHE(dm_crypt_io
, 0);
1978 if (!_crypt_io_pool
)
1981 r
= dm_register_target(&crypt_target
);
1983 DMERR("register failed %d", r
);
1984 kmem_cache_destroy(_crypt_io_pool
);
1990 static void __exit
dm_crypt_exit(void)
1992 dm_unregister_target(&crypt_target
);
1993 kmem_cache_destroy(_crypt_io_pool
);
1996 module_init(dm_crypt_init
);
1997 module_exit(dm_crypt_exit
);
1999 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
2000 MODULE_DESCRIPTION(DM_NAME
" target for transparent encryption / decryption");
2001 MODULE_LICENSE("GPL");