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 } CRYPTO_MINALIGN_ATTR;
63 struct dm_crypt_request {
64 struct convert_context *ctx;
65 struct scatterlist sg_in;
66 struct scatterlist sg_out;
72 struct crypt_iv_operations {
73 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
75 void (*dtr)(struct crypt_config *cc);
76 int (*init)(struct crypt_config *cc);
77 int (*wipe)(struct crypt_config *cc);
78 int (*generator)(struct crypt_config *cc, u8 *iv,
79 struct dm_crypt_request *dmreq);
80 int (*post)(struct crypt_config *cc, u8 *iv,
81 struct dm_crypt_request *dmreq);
84 struct iv_essiv_private {
85 struct crypto_hash *hash_tfm;
89 struct iv_benbi_private {
93 #define LMK_SEED_SIZE 64 /* hash + 0 */
94 struct iv_lmk_private {
95 struct crypto_shash *hash_tfm;
99 #define TCW_WHITENING_SIZE 16
100 struct iv_tcw_private {
101 struct crypto_shash *crc32_tfm;
107 * Crypt: maps a linear range of a block device
108 * and encrypts / decrypts at the same time.
110 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, DM_CRYPT_SAME_CPU };
113 * The fields in here must be read only after initialization.
115 struct crypt_config {
120 * pool for per bio private data, crypto requests and
121 * encryption requeusts/buffer pages
125 mempool_t *page_pool;
128 struct workqueue_struct *io_queue;
129 struct workqueue_struct *crypt_queue;
134 struct crypt_iv_operations *iv_gen_ops;
136 struct iv_essiv_private essiv;
137 struct iv_benbi_private benbi;
138 struct iv_lmk_private lmk;
139 struct iv_tcw_private tcw;
142 unsigned int iv_size;
144 /* ESSIV: struct crypto_cipher *essiv_tfm */
146 struct crypto_ablkcipher **tfms;
150 * Layout of each crypto request:
152 * struct ablkcipher_request
155 * struct dm_crypt_request
159 * The padding is added so that dm_crypt_request and the IV are
162 unsigned int dmreq_start;
164 unsigned int per_bio_data_size;
167 unsigned int key_size;
168 unsigned int key_parts; /* independent parts in key buffer */
169 unsigned int key_extra_size; /* additional keys length */
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;
527 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
528 struct md5_state md5state;
532 desc->tfm = lmk->hash_tfm;
533 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
535 r = crypto_shash_init(desc);
540 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
545 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
546 r = crypto_shash_update(desc, data + 16, 16 * 31);
550 /* Sector is cropped to 56 bits here */
551 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
552 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
553 buf[2] = cpu_to_le32(4024);
555 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
559 /* No MD5 padding here */
560 r = crypto_shash_export(desc, &md5state);
564 for (i = 0; i < MD5_HASH_WORDS; i++)
565 __cpu_to_le32s(&md5state.hash[i]);
566 memcpy(iv, &md5state.hash, cc->iv_size);
571 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
572 struct dm_crypt_request *dmreq)
577 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
578 src = kmap_atomic(sg_page(&dmreq->sg_in));
579 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
582 memset(iv, 0, cc->iv_size);
587 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
588 struct dm_crypt_request *dmreq)
593 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
596 dst = kmap_atomic(sg_page(&dmreq->sg_out));
597 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
599 /* Tweak the first block of plaintext sector */
601 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
607 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
609 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
611 kzfree(tcw->iv_seed);
613 kzfree(tcw->whitening);
614 tcw->whitening = NULL;
616 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
617 crypto_free_shash(tcw->crc32_tfm);
618 tcw->crc32_tfm = NULL;
621 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
624 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
626 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
627 ti->error = "Wrong key size for TCW";
631 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
632 if (IS_ERR(tcw->crc32_tfm)) {
633 ti->error = "Error initializing CRC32 in TCW";
634 return PTR_ERR(tcw->crc32_tfm);
637 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
638 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
639 if (!tcw->iv_seed || !tcw->whitening) {
640 crypt_iv_tcw_dtr(cc);
641 ti->error = "Error allocating seed storage in TCW";
648 static int crypt_iv_tcw_init(struct crypt_config *cc)
650 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
651 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
653 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
654 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
660 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
662 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
664 memset(tcw->iv_seed, 0, cc->iv_size);
665 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
670 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
671 struct dm_crypt_request *dmreq,
674 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
675 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
676 u8 buf[TCW_WHITENING_SIZE];
677 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
680 /* xor whitening with sector number */
681 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
682 crypto_xor(buf, (u8 *)§or, 8);
683 crypto_xor(&buf[8], (u8 *)§or, 8);
685 /* calculate crc32 for every 32bit part and xor it */
686 desc->tfm = tcw->crc32_tfm;
687 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
688 for (i = 0; i < 4; i++) {
689 r = crypto_shash_init(desc);
692 r = crypto_shash_update(desc, &buf[i * 4], 4);
695 r = crypto_shash_final(desc, &buf[i * 4]);
699 crypto_xor(&buf[0], &buf[12], 4);
700 crypto_xor(&buf[4], &buf[8], 4);
702 /* apply whitening (8 bytes) to whole sector */
703 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
704 crypto_xor(data + i * 8, buf, 8);
706 memzero_explicit(buf, sizeof(buf));
710 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
711 struct dm_crypt_request *dmreq)
713 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
714 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
718 /* Remove whitening from ciphertext */
719 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
720 src = kmap_atomic(sg_page(&dmreq->sg_in));
721 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
726 memcpy(iv, tcw->iv_seed, cc->iv_size);
727 crypto_xor(iv, (u8 *)§or, 8);
729 crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
734 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
735 struct dm_crypt_request *dmreq)
740 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
743 /* Apply whitening on ciphertext */
744 dst = kmap_atomic(sg_page(&dmreq->sg_out));
745 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
751 static struct crypt_iv_operations crypt_iv_plain_ops = {
752 .generator = crypt_iv_plain_gen
755 static struct crypt_iv_operations crypt_iv_plain64_ops = {
756 .generator = crypt_iv_plain64_gen
759 static struct crypt_iv_operations crypt_iv_essiv_ops = {
760 .ctr = crypt_iv_essiv_ctr,
761 .dtr = crypt_iv_essiv_dtr,
762 .init = crypt_iv_essiv_init,
763 .wipe = crypt_iv_essiv_wipe,
764 .generator = crypt_iv_essiv_gen
767 static struct crypt_iv_operations crypt_iv_benbi_ops = {
768 .ctr = crypt_iv_benbi_ctr,
769 .dtr = crypt_iv_benbi_dtr,
770 .generator = crypt_iv_benbi_gen
773 static struct crypt_iv_operations crypt_iv_null_ops = {
774 .generator = crypt_iv_null_gen
777 static struct crypt_iv_operations crypt_iv_lmk_ops = {
778 .ctr = crypt_iv_lmk_ctr,
779 .dtr = crypt_iv_lmk_dtr,
780 .init = crypt_iv_lmk_init,
781 .wipe = crypt_iv_lmk_wipe,
782 .generator = crypt_iv_lmk_gen,
783 .post = crypt_iv_lmk_post
786 static struct crypt_iv_operations crypt_iv_tcw_ops = {
787 .ctr = crypt_iv_tcw_ctr,
788 .dtr = crypt_iv_tcw_dtr,
789 .init = crypt_iv_tcw_init,
790 .wipe = crypt_iv_tcw_wipe,
791 .generator = crypt_iv_tcw_gen,
792 .post = crypt_iv_tcw_post
795 static void crypt_convert_init(struct crypt_config *cc,
796 struct convert_context *ctx,
797 struct bio *bio_out, struct bio *bio_in,
800 ctx->bio_in = bio_in;
801 ctx->bio_out = bio_out;
803 ctx->iter_in = bio_in->bi_iter;
805 ctx->iter_out = bio_out->bi_iter;
806 ctx->cc_sector = sector + cc->iv_offset;
807 init_completion(&ctx->restart);
810 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
811 struct ablkcipher_request *req)
813 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
816 static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
817 struct dm_crypt_request *dmreq)
819 return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
822 static u8 *iv_of_dmreq(struct crypt_config *cc,
823 struct dm_crypt_request *dmreq)
825 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
826 crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
829 static int crypt_convert_block(struct crypt_config *cc,
830 struct convert_context *ctx,
831 struct ablkcipher_request *req)
833 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
834 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
835 struct dm_crypt_request *dmreq;
839 dmreq = dmreq_of_req(cc, req);
840 iv = iv_of_dmreq(cc, dmreq);
842 dmreq->iv_sector = ctx->cc_sector;
844 sg_init_table(&dmreq->sg_in, 1);
845 sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
848 sg_init_table(&dmreq->sg_out, 1);
849 sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
852 bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
853 bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
855 if (cc->iv_gen_ops) {
856 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
861 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
862 1 << SECTOR_SHIFT, iv);
864 if (bio_data_dir(ctx->bio_in) == WRITE)
865 r = crypto_ablkcipher_encrypt(req);
867 r = crypto_ablkcipher_decrypt(req);
869 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
870 r = cc->iv_gen_ops->post(cc, iv, dmreq);
875 static void kcryptd_async_done(struct crypto_async_request *async_req,
878 static void crypt_alloc_req(struct crypt_config *cc,
879 struct convert_context *ctx)
881 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
884 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
886 ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
887 ablkcipher_request_set_callback(ctx->req,
888 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
889 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
892 static void crypt_free_req(struct crypt_config *cc,
893 struct ablkcipher_request *req, struct bio *base_bio)
895 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
897 if ((struct ablkcipher_request *)(io + 1) != req)
898 mempool_free(req, cc->req_pool);
902 * Encrypt / decrypt data from one bio to another one (can be the same one)
904 static int crypt_convert(struct crypt_config *cc,
905 struct convert_context *ctx)
909 atomic_set(&ctx->cc_pending, 1);
911 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
913 crypt_alloc_req(cc, ctx);
915 atomic_inc(&ctx->cc_pending);
917 r = crypt_convert_block(cc, ctx, ctx->req);
922 wait_for_completion(&ctx->restart);
923 reinit_completion(&ctx->restart);
932 atomic_dec(&ctx->cc_pending);
939 atomic_dec(&ctx->cc_pending);
947 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
950 * Generate a new unfragmented bio with the given size
951 * This should never violate the device limitations
953 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
955 struct crypt_config *cc = io->cc;
957 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
958 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
961 struct bio_vec *bvec;
963 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
967 clone_init(io, clone);
969 for (i = 0; i < nr_iovecs; i++) {
970 page = mempool_alloc(cc->page_pool, gfp_mask);
972 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
974 bvec = &clone->bi_io_vec[clone->bi_vcnt++];
975 bvec->bv_page = page;
979 clone->bi_iter.bi_size += len;
987 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
992 bio_for_each_segment_all(bv, clone, i) {
993 BUG_ON(!bv->bv_page);
994 mempool_free(bv->bv_page, cc->page_pool);
999 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1000 struct bio *bio, sector_t sector)
1004 io->sector = sector;
1007 atomic_set(&io->io_pending, 0);
1010 static void crypt_inc_pending(struct dm_crypt_io *io)
1012 atomic_inc(&io->io_pending);
1016 * One of the bios was finished. Check for completion of
1017 * the whole request and correctly clean up the buffer.
1019 static void crypt_dec_pending(struct dm_crypt_io *io)
1021 struct crypt_config *cc = io->cc;
1022 struct bio *base_bio = io->base_bio;
1023 int error = io->error;
1025 if (!atomic_dec_and_test(&io->io_pending))
1029 crypt_free_req(cc, io->ctx.req, base_bio);
1030 if (io != dm_per_bio_data(base_bio, cc->per_bio_data_size))
1031 mempool_free(io, cc->io_pool);
1033 bio_endio(base_bio, error);
1037 * kcryptd/kcryptd_io:
1039 * Needed because it would be very unwise to do decryption in an
1040 * interrupt context.
1042 * kcryptd performs the actual encryption or decryption.
1044 * kcryptd_io performs the IO submission.
1046 * They must be separated as otherwise the final stages could be
1047 * starved by new requests which can block in the first stages due
1048 * to memory allocation.
1050 * The work is done per CPU global for all dm-crypt instances.
1051 * They should not depend on each other and do not block.
1053 static void crypt_endio(struct bio *clone, int error)
1055 struct dm_crypt_io *io = clone->bi_private;
1056 struct crypt_config *cc = io->cc;
1057 unsigned rw = bio_data_dir(clone);
1059 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
1063 * free the processed pages
1066 crypt_free_buffer_pages(cc, clone);
1070 if (rw == READ && !error) {
1071 kcryptd_queue_crypt(io);
1075 if (unlikely(error))
1078 crypt_dec_pending(io);
1081 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1083 struct crypt_config *cc = io->cc;
1085 clone->bi_private = io;
1086 clone->bi_end_io = crypt_endio;
1087 clone->bi_bdev = cc->dev->bdev;
1088 clone->bi_rw = io->base_bio->bi_rw;
1091 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1093 struct crypt_config *cc = io->cc;
1094 struct bio *base_bio = io->base_bio;
1098 * The block layer might modify the bvec array, so always
1099 * copy the required bvecs because we need the original
1100 * one in order to decrypt the whole bio data *afterwards*.
1102 clone = bio_clone_bioset(base_bio, gfp, cc->bs);
1106 crypt_inc_pending(io);
1108 clone_init(io, clone);
1109 clone->bi_iter.bi_sector = cc->start + io->sector;
1111 generic_make_request(clone);
1115 static void kcryptd_io_write(struct dm_crypt_io *io)
1117 struct bio *clone = io->ctx.bio_out;
1118 generic_make_request(clone);
1121 static void kcryptd_io(struct work_struct *work)
1123 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1125 if (bio_data_dir(io->base_bio) == READ) {
1126 crypt_inc_pending(io);
1127 if (kcryptd_io_read(io, GFP_NOIO))
1128 io->error = -ENOMEM;
1129 crypt_dec_pending(io);
1131 kcryptd_io_write(io);
1134 static void kcryptd_queue_io(struct dm_crypt_io *io)
1136 struct crypt_config *cc = io->cc;
1138 INIT_WORK(&io->work, kcryptd_io);
1139 queue_work(cc->io_queue, &io->work);
1142 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1144 struct bio *clone = io->ctx.bio_out;
1145 struct crypt_config *cc = io->cc;
1147 if (unlikely(io->error < 0)) {
1148 crypt_free_buffer_pages(cc, clone);
1150 crypt_dec_pending(io);
1154 /* crypt_convert should have filled the clone bio */
1155 BUG_ON(io->ctx.iter_out.bi_size);
1157 clone->bi_iter.bi_sector = cc->start + io->sector;
1160 kcryptd_queue_io(io);
1162 generic_make_request(clone);
1165 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1167 struct crypt_config *cc = io->cc;
1170 sector_t sector = io->sector;
1174 * Prevent io from disappearing until this function completes.
1176 crypt_inc_pending(io);
1177 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1179 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1180 if (unlikely(!clone)) {
1185 io->ctx.bio_out = clone;
1186 io->ctx.iter_out = clone->bi_iter;
1188 sector += bio_sectors(clone);
1190 crypt_inc_pending(io);
1191 r = crypt_convert(cc, &io->ctx);
1194 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1196 /* Encryption was already finished, submit io now */
1197 if (crypt_finished) {
1198 kcryptd_crypt_write_io_submit(io, 0);
1199 io->sector = sector;
1203 crypt_dec_pending(io);
1206 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1208 crypt_dec_pending(io);
1211 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1213 struct crypt_config *cc = io->cc;
1216 crypt_inc_pending(io);
1218 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1221 r = crypt_convert(cc, &io->ctx);
1225 if (atomic_dec_and_test(&io->ctx.cc_pending))
1226 kcryptd_crypt_read_done(io);
1228 crypt_dec_pending(io);
1231 static void kcryptd_async_done(struct crypto_async_request *async_req,
1234 struct dm_crypt_request *dmreq = async_req->data;
1235 struct convert_context *ctx = dmreq->ctx;
1236 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1237 struct crypt_config *cc = io->cc;
1239 if (error == -EINPROGRESS) {
1240 complete(&ctx->restart);
1244 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1245 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1250 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1252 if (!atomic_dec_and_test(&ctx->cc_pending))
1255 if (bio_data_dir(io->base_bio) == READ)
1256 kcryptd_crypt_read_done(io);
1258 kcryptd_crypt_write_io_submit(io, 1);
1261 static void kcryptd_crypt(struct work_struct *work)
1263 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1265 if (bio_data_dir(io->base_bio) == READ)
1266 kcryptd_crypt_read_convert(io);
1268 kcryptd_crypt_write_convert(io);
1271 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1273 struct crypt_config *cc = io->cc;
1275 INIT_WORK(&io->work, kcryptd_crypt);
1276 queue_work(cc->crypt_queue, &io->work);
1280 * Decode key from its hex representation
1282 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1289 for (i = 0; i < size; i++) {
1293 if (kstrtou8(buffer, 16, &key[i]))
1303 static void crypt_free_tfms(struct crypt_config *cc)
1310 for (i = 0; i < cc->tfms_count; i++)
1311 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1312 crypto_free_ablkcipher(cc->tfms[i]);
1320 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1325 cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *),
1330 for (i = 0; i < cc->tfms_count; i++) {
1331 cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1332 if (IS_ERR(cc->tfms[i])) {
1333 err = PTR_ERR(cc->tfms[i]);
1334 crypt_free_tfms(cc);
1342 static int crypt_setkey_allcpus(struct crypt_config *cc)
1344 unsigned subkey_size;
1347 /* Ignore extra keys (which are used for IV etc) */
1348 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1350 for (i = 0; i < cc->tfms_count; i++) {
1351 r = crypto_ablkcipher_setkey(cc->tfms[i],
1352 cc->key + (i * subkey_size),
1361 static int crypt_set_key(struct crypt_config *cc, char *key)
1364 int key_string_len = strlen(key);
1366 /* The key size may not be changed. */
1367 if (cc->key_size != (key_string_len >> 1))
1370 /* Hyphen (which gives a key_size of zero) means there is no key. */
1371 if (!cc->key_size && strcmp(key, "-"))
1374 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1377 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1379 r = crypt_setkey_allcpus(cc);
1382 /* Hex key string not needed after here, so wipe it. */
1383 memset(key, '0', key_string_len);
1388 static int crypt_wipe_key(struct crypt_config *cc)
1390 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1391 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1393 return crypt_setkey_allcpus(cc);
1396 static void crypt_dtr(struct dm_target *ti)
1398 struct crypt_config *cc = ti->private;
1406 destroy_workqueue(cc->io_queue);
1407 if (cc->crypt_queue)
1408 destroy_workqueue(cc->crypt_queue);
1410 crypt_free_tfms(cc);
1413 bioset_free(cc->bs);
1416 mempool_destroy(cc->page_pool);
1418 mempool_destroy(cc->req_pool);
1420 mempool_destroy(cc->io_pool);
1422 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1423 cc->iv_gen_ops->dtr(cc);
1426 dm_put_device(ti, cc->dev);
1429 kzfree(cc->cipher_string);
1431 /* Must zero key material before freeing */
1435 static int crypt_ctr_cipher(struct dm_target *ti,
1436 char *cipher_in, char *key)
1438 struct crypt_config *cc = ti->private;
1439 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1440 char *cipher_api = NULL;
1444 /* Convert to crypto api definition? */
1445 if (strchr(cipher_in, '(')) {
1446 ti->error = "Bad cipher specification";
1450 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1451 if (!cc->cipher_string)
1455 * Legacy dm-crypt cipher specification
1456 * cipher[:keycount]-mode-iv:ivopts
1459 keycount = strsep(&tmp, "-");
1460 cipher = strsep(&keycount, ":");
1464 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1465 !is_power_of_2(cc->tfms_count)) {
1466 ti->error = "Bad cipher key count specification";
1469 cc->key_parts = cc->tfms_count;
1470 cc->key_extra_size = 0;
1472 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1476 chainmode = strsep(&tmp, "-");
1477 ivopts = strsep(&tmp, "-");
1478 ivmode = strsep(&ivopts, ":");
1481 DMWARN("Ignoring unexpected additional cipher options");
1484 * For compatibility with the original dm-crypt mapping format, if
1485 * only the cipher name is supplied, use cbc-plain.
1487 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1492 if (strcmp(chainmode, "ecb") && !ivmode) {
1493 ti->error = "IV mechanism required";
1497 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1501 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1502 "%s(%s)", chainmode, cipher);
1508 /* Allocate cipher */
1509 ret = crypt_alloc_tfms(cc, cipher_api);
1511 ti->error = "Error allocating crypto tfm";
1516 cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1518 /* at least a 64 bit sector number should fit in our buffer */
1519 cc->iv_size = max(cc->iv_size,
1520 (unsigned int)(sizeof(u64) / sizeof(u8)));
1522 DMWARN("Selected cipher does not support IVs");
1526 /* Choose ivmode, see comments at iv code. */
1528 cc->iv_gen_ops = NULL;
1529 else if (strcmp(ivmode, "plain") == 0)
1530 cc->iv_gen_ops = &crypt_iv_plain_ops;
1531 else if (strcmp(ivmode, "plain64") == 0)
1532 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1533 else if (strcmp(ivmode, "essiv") == 0)
1534 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1535 else if (strcmp(ivmode, "benbi") == 0)
1536 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1537 else if (strcmp(ivmode, "null") == 0)
1538 cc->iv_gen_ops = &crypt_iv_null_ops;
1539 else if (strcmp(ivmode, "lmk") == 0) {
1540 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1542 * Version 2 and 3 is recognised according
1543 * to length of provided multi-key string.
1544 * If present (version 3), last key is used as IV seed.
1545 * All keys (including IV seed) are always the same size.
1547 if (cc->key_size % cc->key_parts) {
1549 cc->key_extra_size = cc->key_size / cc->key_parts;
1551 } else if (strcmp(ivmode, "tcw") == 0) {
1552 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1553 cc->key_parts += 2; /* IV + whitening */
1554 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1557 ti->error = "Invalid IV mode";
1561 /* Initialize and set key */
1562 ret = crypt_set_key(cc, key);
1564 ti->error = "Error decoding and setting key";
1569 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1570 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1572 ti->error = "Error creating IV";
1577 /* Initialize IV (set keys for ESSIV etc) */
1578 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1579 ret = cc->iv_gen_ops->init(cc);
1581 ti->error = "Error initialising IV";
1592 ti->error = "Cannot allocate cipher strings";
1597 * Construct an encryption mapping:
1598 * <cipher> <key> <iv_offset> <dev_path> <start>
1600 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1602 struct crypt_config *cc;
1603 unsigned int key_size, opt_params;
1604 unsigned long long tmpll;
1606 size_t iv_size_padding;
1607 struct dm_arg_set as;
1608 const char *opt_string;
1611 static struct dm_arg _args[] = {
1612 {0, 2, "Invalid number of feature args"},
1616 ti->error = "Not enough arguments";
1620 key_size = strlen(argv[1]) >> 1;
1622 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1624 ti->error = "Cannot allocate encryption context";
1627 cc->key_size = key_size;
1630 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1635 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
1637 ti->error = "Cannot allocate crypt io mempool";
1641 cc->dmreq_start = sizeof(struct ablkcipher_request);
1642 cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1643 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1645 if (crypto_ablkcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1646 /* Allocate the padding exactly */
1647 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1648 & crypto_ablkcipher_alignmask(any_tfm(cc));
1651 * If the cipher requires greater alignment than kmalloc
1652 * alignment, we don't know the exact position of the
1653 * initialization vector. We must assume worst case.
1655 iv_size_padding = crypto_ablkcipher_alignmask(any_tfm(cc));
1658 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1659 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1660 if (!cc->req_pool) {
1661 ti->error = "Cannot allocate crypt request mempool";
1665 cc->per_bio_data_size = ti->per_bio_data_size =
1666 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1667 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1668 ARCH_KMALLOC_MINALIGN);
1670 cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1671 if (!cc->page_pool) {
1672 ti->error = "Cannot allocate page mempool";
1676 cc->bs = bioset_create(MIN_IOS, 0);
1678 ti->error = "Cannot allocate crypt bioset";
1683 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1684 ti->error = "Invalid iv_offset sector";
1687 cc->iv_offset = tmpll;
1689 if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
1690 ti->error = "Device lookup failed";
1694 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1695 ti->error = "Invalid device sector";
1703 /* Optional parameters */
1708 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1712 while (opt_params--) {
1713 opt_string = dm_shift_arg(&as);
1715 ti->error = "Not enough feature arguments";
1719 if (!strcasecmp(opt_string, "allow_discards"))
1720 ti->num_discard_bios = 1;
1722 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1723 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1726 ti->error = "Invalid feature arguments";
1733 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1734 if (!cc->io_queue) {
1735 ti->error = "Couldn't create kcryptd io queue";
1739 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1740 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1742 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
1744 if (!cc->crypt_queue) {
1745 ti->error = "Couldn't create kcryptd queue";
1749 ti->num_flush_bios = 1;
1750 ti->discard_zeroes_data_unsupported = true;
1759 static int crypt_map(struct dm_target *ti, struct bio *bio)
1761 struct dm_crypt_io *io;
1762 struct crypt_config *cc = ti->private;
1765 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1766 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1767 * - for REQ_DISCARD caller must use flush if IO ordering matters
1769 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1770 bio->bi_bdev = cc->dev->bdev;
1771 if (bio_sectors(bio))
1772 bio->bi_iter.bi_sector = cc->start +
1773 dm_target_offset(ti, bio->bi_iter.bi_sector);
1774 return DM_MAPIO_REMAPPED;
1777 io = dm_per_bio_data(bio, cc->per_bio_data_size);
1778 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
1779 io->ctx.req = (struct ablkcipher_request *)(io + 1);
1781 if (bio_data_dir(io->base_bio) == READ) {
1782 if (kcryptd_io_read(io, GFP_NOWAIT))
1783 kcryptd_queue_io(io);
1785 kcryptd_queue_crypt(io);
1787 return DM_MAPIO_SUBMITTED;
1790 static void crypt_status(struct dm_target *ti, status_type_t type,
1791 unsigned status_flags, char *result, unsigned maxlen)
1793 struct crypt_config *cc = ti->private;
1795 int num_feature_args = 0;
1798 case STATUSTYPE_INFO:
1802 case STATUSTYPE_TABLE:
1803 DMEMIT("%s ", cc->cipher_string);
1805 if (cc->key_size > 0)
1806 for (i = 0; i < cc->key_size; i++)
1807 DMEMIT("%02x", cc->key[i]);
1811 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1812 cc->dev->name, (unsigned long long)cc->start);
1814 num_feature_args += !!ti->num_discard_bios;
1815 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1816 if (num_feature_args) {
1817 DMEMIT(" %d", num_feature_args);
1818 if (ti->num_discard_bios)
1819 DMEMIT(" allow_discards");
1820 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1821 DMEMIT(" same_cpu_crypt");
1828 static void crypt_postsuspend(struct dm_target *ti)
1830 struct crypt_config *cc = ti->private;
1832 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1835 static int crypt_preresume(struct dm_target *ti)
1837 struct crypt_config *cc = ti->private;
1839 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1840 DMERR("aborting resume - crypt key is not set.");
1847 static void crypt_resume(struct dm_target *ti)
1849 struct crypt_config *cc = ti->private;
1851 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1854 /* Message interface
1858 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1860 struct crypt_config *cc = ti->private;
1866 if (!strcasecmp(argv[0], "key")) {
1867 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1868 DMWARN("not suspended during key manipulation.");
1871 if (argc == 3 && !strcasecmp(argv[1], "set")) {
1872 ret = crypt_set_key(cc, argv[2]);
1875 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
1876 ret = cc->iv_gen_ops->init(cc);
1879 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
1880 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
1881 ret = cc->iv_gen_ops->wipe(cc);
1885 return crypt_wipe_key(cc);
1890 DMWARN("unrecognised message received.");
1894 static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1895 struct bio_vec *biovec, int max_size)
1897 struct crypt_config *cc = ti->private;
1898 struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1900 if (!q->merge_bvec_fn)
1903 bvm->bi_bdev = cc->dev->bdev;
1904 bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
1906 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
1909 static int crypt_iterate_devices(struct dm_target *ti,
1910 iterate_devices_callout_fn fn, void *data)
1912 struct crypt_config *cc = ti->private;
1914 return fn(ti, cc->dev, cc->start, ti->len, data);
1917 static struct target_type crypt_target = {
1919 .version = {1, 14, 0},
1920 .module = THIS_MODULE,
1924 .status = crypt_status,
1925 .postsuspend = crypt_postsuspend,
1926 .preresume = crypt_preresume,
1927 .resume = crypt_resume,
1928 .message = crypt_message,
1929 .merge = crypt_merge,
1930 .iterate_devices = crypt_iterate_devices,
1933 static int __init dm_crypt_init(void)
1937 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1938 if (!_crypt_io_pool)
1941 r = dm_register_target(&crypt_target);
1943 DMERR("register failed %d", r);
1944 kmem_cache_destroy(_crypt_io_pool);
1950 static void __exit dm_crypt_exit(void)
1952 dm_unregister_target(&crypt_target);
1953 kmem_cache_destroy(_crypt_io_pool);
1956 module_init(dm_crypt_init);
1957 module_exit(dm_crypt_exit);
1959 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
1960 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1961 MODULE_LICENSE("GPL");