2 * Copyright (C) 2003 Christophe Saout <christophe@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 unsigned int offset_in;
42 unsigned int offset_out;
47 struct ablkcipher_request *req;
51 * per bio private data
54 struct crypt_config *cc;
56 struct work_struct work;
58 struct convert_context ctx;
63 struct dm_crypt_io *base_io;
64 } CRYPTO_MINALIGN_ATTR;
66 struct dm_crypt_request {
67 struct convert_context *ctx;
68 struct scatterlist sg_in;
69 struct scatterlist sg_out;
75 struct crypt_iv_operations {
76 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
78 void (*dtr)(struct crypt_config *cc);
79 int (*init)(struct crypt_config *cc);
80 int (*wipe)(struct crypt_config *cc);
81 int (*generator)(struct crypt_config *cc, u8 *iv,
82 struct dm_crypt_request *dmreq);
83 int (*post)(struct crypt_config *cc, u8 *iv,
84 struct dm_crypt_request *dmreq);
87 struct iv_essiv_private {
88 struct crypto_hash *hash_tfm;
92 struct iv_benbi_private {
96 #define LMK_SEED_SIZE 64 /* hash + 0 */
97 struct iv_lmk_private {
98 struct crypto_shash *hash_tfm;
102 #define TCW_WHITENING_SIZE 16
103 struct iv_tcw_private {
104 struct crypto_shash *crc32_tfm;
110 * Crypt: maps a linear range of a block device
111 * and encrypts / decrypts at the same time.
113 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, DM_CRYPT_SAME_CPU };
116 * The fields in here must be read only after initialization.
118 struct crypt_config {
123 * pool for per bio private data, crypto requests and
124 * encryption requeusts/buffer pages
128 mempool_t *page_pool;
131 struct workqueue_struct *io_queue;
132 struct workqueue_struct *crypt_queue;
137 struct crypt_iv_operations *iv_gen_ops;
139 struct iv_essiv_private essiv;
140 struct iv_benbi_private benbi;
141 struct iv_lmk_private lmk;
142 struct iv_tcw_private tcw;
145 unsigned int iv_size;
147 /* ESSIV: struct crypto_cipher *essiv_tfm */
149 struct crypto_ablkcipher **tfms;
153 * Layout of each crypto request:
155 * struct ablkcipher_request
158 * struct dm_crypt_request
162 * The padding is added so that dm_crypt_request and the IV are
165 unsigned int dmreq_start;
167 unsigned int per_bio_data_size;
170 unsigned int key_size;
171 unsigned int key_parts; /* independent parts in key buffer */
172 unsigned int key_extra_size; /* additional keys length */
177 #define MIN_POOL_PAGES 32
179 static struct kmem_cache *_crypt_io_pool;
181 static void clone_init(struct dm_crypt_io *, struct bio *);
182 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
183 static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
186 * Use this to access cipher attributes that are the same for each CPU.
188 static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
194 * Different IV generation algorithms:
196 * plain: the initial vector is the 32-bit little-endian version of the sector
197 * number, padded with zeros if necessary.
199 * plain64: the initial vector is the 64-bit little-endian version of the sector
200 * number, padded with zeros if necessary.
202 * essiv: "encrypted sector|salt initial vector", the sector number is
203 * encrypted with the bulk cipher using a salt as key. The salt
204 * should be derived from the bulk cipher's key via hashing.
206 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
207 * (needed for LRW-32-AES and possible other narrow block modes)
209 * null: the initial vector is always zero. Provides compatibility with
210 * obsolete loop_fish2 devices. Do not use for new devices.
212 * lmk: Compatible implementation of the block chaining mode used
213 * by the Loop-AES block device encryption system
214 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
215 * It operates on full 512 byte sectors and uses CBC
216 * with an IV derived from the sector number, the data and
217 * optionally extra IV seed.
218 * This means that after decryption the first block
219 * of sector must be tweaked according to decrypted data.
220 * Loop-AES can use three encryption schemes:
221 * version 1: is plain aes-cbc mode
222 * version 2: uses 64 multikey scheme with lmk IV generator
223 * version 3: the same as version 2 with additional IV seed
224 * (it uses 65 keys, last key is used as IV seed)
226 * tcw: Compatible implementation of the block chaining mode used
227 * by the TrueCrypt device encryption system (prior to version 4.1).
228 * For more info see: http://www.truecrypt.org
229 * It operates on full 512 byte sectors and uses CBC
230 * with an IV derived from initial key and the sector number.
231 * In addition, whitening value is applied on every sector, whitening
232 * is calculated from initial key, sector number and mixed using CRC32.
233 * Note that this encryption scheme is vulnerable to watermarking attacks
234 * and should be used for old compatible containers access only.
236 * plumb: unimplemented, see:
237 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
240 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
241 struct dm_crypt_request *dmreq)
243 memset(iv, 0, cc->iv_size);
244 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
249 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
250 struct dm_crypt_request *dmreq)
252 memset(iv, 0, cc->iv_size);
253 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
258 /* Initialise ESSIV - compute salt but no local memory allocations */
259 static int crypt_iv_essiv_init(struct crypt_config *cc)
261 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
262 struct hash_desc desc;
263 struct scatterlist sg;
264 struct crypto_cipher *essiv_tfm;
267 sg_init_one(&sg, cc->key, cc->key_size);
268 desc.tfm = essiv->hash_tfm;
269 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
271 err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
275 essiv_tfm = cc->iv_private;
277 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
278 crypto_hash_digestsize(essiv->hash_tfm));
285 /* Wipe salt and reset key derived from volume key */
286 static int crypt_iv_essiv_wipe(struct crypt_config *cc)
288 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
289 unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
290 struct crypto_cipher *essiv_tfm;
293 memset(essiv->salt, 0, salt_size);
295 essiv_tfm = cc->iv_private;
296 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
303 /* Set up per cpu cipher state */
304 static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
305 struct dm_target *ti,
306 u8 *salt, unsigned saltsize)
308 struct crypto_cipher *essiv_tfm;
311 /* Setup the essiv_tfm with the given salt */
312 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
313 if (IS_ERR(essiv_tfm)) {
314 ti->error = "Error allocating crypto tfm for ESSIV";
318 if (crypto_cipher_blocksize(essiv_tfm) !=
319 crypto_ablkcipher_ivsize(any_tfm(cc))) {
320 ti->error = "Block size of ESSIV cipher does "
321 "not match IV size of block cipher";
322 crypto_free_cipher(essiv_tfm);
323 return ERR_PTR(-EINVAL);
326 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
328 ti->error = "Failed to set key for ESSIV cipher";
329 crypto_free_cipher(essiv_tfm);
336 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
338 struct crypto_cipher *essiv_tfm;
339 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
341 crypto_free_hash(essiv->hash_tfm);
342 essiv->hash_tfm = NULL;
347 essiv_tfm = cc->iv_private;
350 crypto_free_cipher(essiv_tfm);
352 cc->iv_private = NULL;
355 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
358 struct crypto_cipher *essiv_tfm = NULL;
359 struct crypto_hash *hash_tfm = NULL;
364 ti->error = "Digest algorithm missing for ESSIV mode";
368 /* Allocate hash algorithm */
369 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
370 if (IS_ERR(hash_tfm)) {
371 ti->error = "Error initializing ESSIV hash";
372 err = PTR_ERR(hash_tfm);
376 salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
378 ti->error = "Error kmallocing salt storage in ESSIV";
383 cc->iv_gen_private.essiv.salt = salt;
384 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
386 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
387 crypto_hash_digestsize(hash_tfm));
388 if (IS_ERR(essiv_tfm)) {
389 crypt_iv_essiv_dtr(cc);
390 return PTR_ERR(essiv_tfm);
392 cc->iv_private = essiv_tfm;
397 if (hash_tfm && !IS_ERR(hash_tfm))
398 crypto_free_hash(hash_tfm);
403 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
404 struct dm_crypt_request *dmreq)
406 struct crypto_cipher *essiv_tfm = cc->iv_private;
408 memset(iv, 0, cc->iv_size);
409 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
410 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
415 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
418 unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
421 /* we need to calculate how far we must shift the sector count
422 * to get the cipher block count, we use this shift in _gen */
424 if (1 << log != bs) {
425 ti->error = "cypher blocksize is not a power of 2";
430 ti->error = "cypher blocksize is > 512";
434 cc->iv_gen_private.benbi.shift = 9 - log;
439 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
443 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
444 struct dm_crypt_request *dmreq)
448 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
450 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
451 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
456 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
457 struct dm_crypt_request *dmreq)
459 memset(iv, 0, cc->iv_size);
464 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
466 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
468 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
469 crypto_free_shash(lmk->hash_tfm);
470 lmk->hash_tfm = NULL;
476 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
479 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
481 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
482 if (IS_ERR(lmk->hash_tfm)) {
483 ti->error = "Error initializing LMK hash";
484 return PTR_ERR(lmk->hash_tfm);
487 /* No seed in LMK version 2 */
488 if (cc->key_parts == cc->tfms_count) {
493 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
495 crypt_iv_lmk_dtr(cc);
496 ti->error = "Error kmallocing seed storage in LMK";
503 static int crypt_iv_lmk_init(struct crypt_config *cc)
505 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
506 int subkey_size = cc->key_size / cc->key_parts;
508 /* LMK seed is on the position of LMK_KEYS + 1 key */
510 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
511 crypto_shash_digestsize(lmk->hash_tfm));
516 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
518 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
521 memset(lmk->seed, 0, LMK_SEED_SIZE);
526 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
527 struct dm_crypt_request *dmreq,
530 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
532 struct shash_desc desc;
533 char ctx[crypto_shash_descsize(lmk->hash_tfm)];
535 struct md5_state md5state;
539 sdesc.desc.tfm = lmk->hash_tfm;
540 sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
542 r = crypto_shash_init(&sdesc.desc);
547 r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
552 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
553 r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
557 /* Sector is cropped to 56 bits here */
558 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
559 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
560 buf[2] = cpu_to_le32(4024);
562 r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
566 /* No MD5 padding here */
567 r = crypto_shash_export(&sdesc.desc, &md5state);
571 for (i = 0; i < MD5_HASH_WORDS; i++)
572 __cpu_to_le32s(&md5state.hash[i]);
573 memcpy(iv, &md5state.hash, cc->iv_size);
578 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
579 struct dm_crypt_request *dmreq)
584 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
585 src = kmap_atomic(sg_page(&dmreq->sg_in));
586 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
589 memset(iv, 0, cc->iv_size);
594 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
595 struct dm_crypt_request *dmreq)
600 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
603 dst = kmap_atomic(sg_page(&dmreq->sg_out));
604 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
606 /* Tweak the first block of plaintext sector */
608 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
614 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
616 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
618 kzfree(tcw->iv_seed);
620 kzfree(tcw->whitening);
621 tcw->whitening = NULL;
623 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
624 crypto_free_shash(tcw->crc32_tfm);
625 tcw->crc32_tfm = NULL;
628 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
631 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
633 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
634 ti->error = "Wrong key size for TCW";
638 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
639 if (IS_ERR(tcw->crc32_tfm)) {
640 ti->error = "Error initializing CRC32 in TCW";
641 return PTR_ERR(tcw->crc32_tfm);
644 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
645 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
646 if (!tcw->iv_seed || !tcw->whitening) {
647 crypt_iv_tcw_dtr(cc);
648 ti->error = "Error allocating seed storage in TCW";
655 static int crypt_iv_tcw_init(struct crypt_config *cc)
657 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
658 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
660 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
661 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
667 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
669 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
671 memset(tcw->iv_seed, 0, cc->iv_size);
672 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
677 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
678 struct dm_crypt_request *dmreq,
681 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
682 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
683 u8 buf[TCW_WHITENING_SIZE];
685 struct shash_desc desc;
686 char ctx[crypto_shash_descsize(tcw->crc32_tfm)];
690 /* xor whitening with sector number */
691 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
692 crypto_xor(buf, (u8 *)§or, 8);
693 crypto_xor(&buf[8], (u8 *)§or, 8);
695 /* calculate crc32 for every 32bit part and xor it */
696 sdesc.desc.tfm = tcw->crc32_tfm;
697 sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
698 for (i = 0; i < 4; i++) {
699 r = crypto_shash_init(&sdesc.desc);
702 r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4);
705 r = crypto_shash_final(&sdesc.desc, &buf[i * 4]);
709 crypto_xor(&buf[0], &buf[12], 4);
710 crypto_xor(&buf[4], &buf[8], 4);
712 /* apply whitening (8 bytes) to whole sector */
713 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
714 crypto_xor(data + i * 8, buf, 8);
716 memzero_explicit(buf, sizeof(buf));
720 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
721 struct dm_crypt_request *dmreq)
723 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
724 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
728 /* Remove whitening from ciphertext */
729 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
730 src = kmap_atomic(sg_page(&dmreq->sg_in));
731 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
736 memcpy(iv, tcw->iv_seed, cc->iv_size);
737 crypto_xor(iv, (u8 *)§or, 8);
739 crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
744 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
745 struct dm_crypt_request *dmreq)
750 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
753 /* Apply whitening on ciphertext */
754 dst = kmap_atomic(sg_page(&dmreq->sg_out));
755 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
761 static struct crypt_iv_operations crypt_iv_plain_ops = {
762 .generator = crypt_iv_plain_gen
765 static struct crypt_iv_operations crypt_iv_plain64_ops = {
766 .generator = crypt_iv_plain64_gen
769 static struct crypt_iv_operations crypt_iv_essiv_ops = {
770 .ctr = crypt_iv_essiv_ctr,
771 .dtr = crypt_iv_essiv_dtr,
772 .init = crypt_iv_essiv_init,
773 .wipe = crypt_iv_essiv_wipe,
774 .generator = crypt_iv_essiv_gen
777 static struct crypt_iv_operations crypt_iv_benbi_ops = {
778 .ctr = crypt_iv_benbi_ctr,
779 .dtr = crypt_iv_benbi_dtr,
780 .generator = crypt_iv_benbi_gen
783 static struct crypt_iv_operations crypt_iv_null_ops = {
784 .generator = crypt_iv_null_gen
787 static struct crypt_iv_operations crypt_iv_lmk_ops = {
788 .ctr = crypt_iv_lmk_ctr,
789 .dtr = crypt_iv_lmk_dtr,
790 .init = crypt_iv_lmk_init,
791 .wipe = crypt_iv_lmk_wipe,
792 .generator = crypt_iv_lmk_gen,
793 .post = crypt_iv_lmk_post
796 static struct crypt_iv_operations crypt_iv_tcw_ops = {
797 .ctr = crypt_iv_tcw_ctr,
798 .dtr = crypt_iv_tcw_dtr,
799 .init = crypt_iv_tcw_init,
800 .wipe = crypt_iv_tcw_wipe,
801 .generator = crypt_iv_tcw_gen,
802 .post = crypt_iv_tcw_post
805 static void crypt_convert_init(struct crypt_config *cc,
806 struct convert_context *ctx,
807 struct bio *bio_out, struct bio *bio_in,
810 ctx->bio_in = bio_in;
811 ctx->bio_out = bio_out;
814 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
815 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
816 ctx->cc_sector = sector + cc->iv_offset;
817 init_completion(&ctx->restart);
820 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
821 struct ablkcipher_request *req)
823 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
826 static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
827 struct dm_crypt_request *dmreq)
829 return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
832 static u8 *iv_of_dmreq(struct crypt_config *cc,
833 struct dm_crypt_request *dmreq)
835 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
836 crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
839 static int crypt_convert_block(struct crypt_config *cc,
840 struct convert_context *ctx,
841 struct ablkcipher_request *req)
843 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
844 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
845 struct dm_crypt_request *dmreq;
849 dmreq = dmreq_of_req(cc, req);
850 iv = iv_of_dmreq(cc, dmreq);
852 dmreq->iv_sector = ctx->cc_sector;
854 sg_init_table(&dmreq->sg_in, 1);
855 sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
856 bv_in->bv_offset + ctx->offset_in);
858 sg_init_table(&dmreq->sg_out, 1);
859 sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
860 bv_out->bv_offset + ctx->offset_out);
862 ctx->offset_in += 1 << SECTOR_SHIFT;
863 if (ctx->offset_in >= bv_in->bv_len) {
868 ctx->offset_out += 1 << SECTOR_SHIFT;
869 if (ctx->offset_out >= bv_out->bv_len) {
874 if (cc->iv_gen_ops) {
875 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
880 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
881 1 << SECTOR_SHIFT, iv);
883 if (bio_data_dir(ctx->bio_in) == WRITE)
884 r = crypto_ablkcipher_encrypt(req);
886 r = crypto_ablkcipher_decrypt(req);
888 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
889 r = cc->iv_gen_ops->post(cc, iv, dmreq);
894 static void kcryptd_async_done(struct crypto_async_request *async_req,
897 static void crypt_alloc_req(struct crypt_config *cc,
898 struct convert_context *ctx)
900 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
903 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
905 ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
906 ablkcipher_request_set_callback(ctx->req,
907 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
908 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
911 static void crypt_free_req(struct crypt_config *cc,
912 struct ablkcipher_request *req, struct bio *base_bio)
914 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
916 if ((struct ablkcipher_request *)(io + 1) != req)
917 mempool_free(req, cc->req_pool);
921 * Encrypt / decrypt data from one bio to another one (can be the same one)
923 static int crypt_convert(struct crypt_config *cc,
924 struct convert_context *ctx)
928 atomic_set(&ctx->cc_pending, 1);
930 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
931 ctx->idx_out < ctx->bio_out->bi_vcnt) {
933 crypt_alloc_req(cc, ctx);
935 atomic_inc(&ctx->cc_pending);
937 r = crypt_convert_block(cc, ctx, ctx->req);
942 wait_for_completion(&ctx->restart);
943 INIT_COMPLETION(ctx->restart);
952 atomic_dec(&ctx->cc_pending);
959 atomic_dec(&ctx->cc_pending);
968 * Generate a new unfragmented bio with the given size
969 * This should never violate the device limitations
970 * May return a smaller bio when running out of pages, indicated by
971 * *out_of_pages set to 1.
973 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
974 unsigned *out_of_pages)
976 struct crypt_config *cc = io->cc;
978 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
979 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
983 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
987 clone_init(io, clone);
990 for (i = 0; i < nr_iovecs; i++) {
991 page = mempool_alloc(cc->page_pool, gfp_mask);
998 * If additional pages cannot be allocated without waiting,
999 * return a partially-allocated bio. The caller will then try
1000 * to allocate more bios while submitting this partial bio.
1002 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
1004 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
1006 if (!bio_add_page(clone, page, len, 0)) {
1007 mempool_free(page, cc->page_pool);
1014 if (!clone->bi_size) {
1022 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1027 bio_for_each_segment_all(bv, clone, i) {
1028 BUG_ON(!bv->bv_page);
1029 mempool_free(bv->bv_page, cc->page_pool);
1034 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1035 struct bio *bio, sector_t sector)
1039 io->sector = sector;
1043 atomic_set(&io->io_pending, 0);
1046 static void crypt_inc_pending(struct dm_crypt_io *io)
1048 atomic_inc(&io->io_pending);
1052 * One of the bios was finished. Check for completion of
1053 * the whole request and correctly clean up the buffer.
1054 * If base_io is set, wait for the last fragment to complete.
1056 static void crypt_dec_pending(struct dm_crypt_io *io)
1058 struct crypt_config *cc = io->cc;
1059 struct bio *base_bio = io->base_bio;
1060 struct dm_crypt_io *base_io = io->base_io;
1061 int error = io->error;
1063 if (!atomic_dec_and_test(&io->io_pending))
1067 crypt_free_req(cc, io->ctx.req, base_bio);
1068 if (io != dm_per_bio_data(base_bio, cc->per_bio_data_size))
1069 mempool_free(io, cc->io_pool);
1071 if (likely(!base_io))
1072 bio_endio(base_bio, error);
1074 if (error && !base_io->error)
1075 base_io->error = error;
1076 crypt_dec_pending(base_io);
1081 * kcryptd/kcryptd_io:
1083 * Needed because it would be very unwise to do decryption in an
1084 * interrupt context.
1086 * kcryptd performs the actual encryption or decryption.
1088 * kcryptd_io performs the IO submission.
1090 * They must be separated as otherwise the final stages could be
1091 * starved by new requests which can block in the first stages due
1092 * to memory allocation.
1094 * The work is done per CPU global for all dm-crypt instances.
1095 * They should not depend on each other and do not block.
1097 static void crypt_endio(struct bio *clone, int error)
1099 struct dm_crypt_io *io = clone->bi_private;
1100 struct crypt_config *cc = io->cc;
1101 unsigned rw = bio_data_dir(clone);
1103 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
1107 * free the processed pages
1110 crypt_free_buffer_pages(cc, clone);
1114 if (rw == READ && !error) {
1115 kcryptd_queue_crypt(io);
1119 if (unlikely(error))
1122 crypt_dec_pending(io);
1125 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1127 struct crypt_config *cc = io->cc;
1129 clone->bi_private = io;
1130 clone->bi_end_io = crypt_endio;
1131 clone->bi_bdev = cc->dev->bdev;
1132 clone->bi_rw = io->base_bio->bi_rw;
1135 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1137 struct crypt_config *cc = io->cc;
1138 struct bio *base_bio = io->base_bio;
1142 * The block layer might modify the bvec array, so always
1143 * copy the required bvecs because we need the original
1144 * one in order to decrypt the whole bio data *afterwards*.
1146 clone = bio_clone_bioset(base_bio, gfp, cc->bs);
1150 crypt_inc_pending(io);
1152 clone_init(io, clone);
1153 clone->bi_sector = cc->start + io->sector;
1155 generic_make_request(clone);
1159 static void kcryptd_io_write(struct dm_crypt_io *io)
1161 struct bio *clone = io->ctx.bio_out;
1162 generic_make_request(clone);
1165 static void kcryptd_io(struct work_struct *work)
1167 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1169 if (bio_data_dir(io->base_bio) == READ) {
1170 crypt_inc_pending(io);
1171 if (kcryptd_io_read(io, GFP_NOIO))
1172 io->error = -ENOMEM;
1173 crypt_dec_pending(io);
1175 kcryptd_io_write(io);
1178 static void kcryptd_queue_io(struct dm_crypt_io *io)
1180 struct crypt_config *cc = io->cc;
1182 INIT_WORK(&io->work, kcryptd_io);
1183 queue_work(cc->io_queue, &io->work);
1186 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1188 struct bio *clone = io->ctx.bio_out;
1189 struct crypt_config *cc = io->cc;
1191 if (unlikely(io->error < 0)) {
1192 crypt_free_buffer_pages(cc, clone);
1194 crypt_dec_pending(io);
1198 /* crypt_convert should have filled the clone bio */
1199 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
1201 clone->bi_sector = cc->start + io->sector;
1204 kcryptd_queue_io(io);
1206 generic_make_request(clone);
1209 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1211 struct crypt_config *cc = io->cc;
1213 struct dm_crypt_io *new_io;
1215 unsigned out_of_pages = 0;
1216 unsigned remaining = io->base_bio->bi_size;
1217 sector_t sector = io->sector;
1221 * Prevent io from disappearing until this function completes.
1223 crypt_inc_pending(io);
1224 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1227 * The allocated buffers can be smaller than the whole bio,
1228 * so repeat the whole process until all the data can be handled.
1231 clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
1232 if (unlikely(!clone)) {
1233 io->error = -ENOMEM;
1237 io->ctx.bio_out = clone;
1238 io->ctx.idx_out = 0;
1240 remaining -= clone->bi_size;
1241 sector += bio_sectors(clone);
1243 crypt_inc_pending(io);
1245 r = crypt_convert(cc, &io->ctx);
1249 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1251 /* Encryption was already finished, submit io now */
1252 if (crypt_finished) {
1253 kcryptd_crypt_write_io_submit(io, 0);
1256 * If there was an error, do not try next fragments.
1257 * For async, error is processed in async handler.
1259 if (unlikely(r < 0))
1262 io->sector = sector;
1266 * Out of memory -> run queues
1267 * But don't wait if split was due to the io size restriction
1269 if (unlikely(out_of_pages))
1270 congestion_wait(BLK_RW_ASYNC, HZ/100);
1273 * With async crypto it is unsafe to share the crypto context
1274 * between fragments, so switch to a new dm_crypt_io structure.
1276 if (unlikely(!crypt_finished && remaining)) {
1277 new_io = mempool_alloc(cc->io_pool, GFP_NOIO);
1278 crypt_io_init(new_io, io->cc, io->base_bio, sector);
1279 crypt_inc_pending(new_io);
1280 crypt_convert_init(cc, &new_io->ctx, NULL,
1281 io->base_bio, sector);
1282 new_io->ctx.idx_in = io->ctx.idx_in;
1283 new_io->ctx.offset_in = io->ctx.offset_in;
1286 * Fragments after the first use the base_io
1290 new_io->base_io = io;
1292 new_io->base_io = io->base_io;
1293 crypt_inc_pending(io->base_io);
1294 crypt_dec_pending(io);
1301 crypt_dec_pending(io);
1304 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1306 crypt_dec_pending(io);
1309 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1311 struct crypt_config *cc = io->cc;
1314 crypt_inc_pending(io);
1316 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1319 r = crypt_convert(cc, &io->ctx);
1323 if (atomic_dec_and_test(&io->ctx.cc_pending))
1324 kcryptd_crypt_read_done(io);
1326 crypt_dec_pending(io);
1329 static void kcryptd_async_done(struct crypto_async_request *async_req,
1332 struct dm_crypt_request *dmreq = async_req->data;
1333 struct convert_context *ctx = dmreq->ctx;
1334 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1335 struct crypt_config *cc = io->cc;
1337 if (error == -EINPROGRESS) {
1338 complete(&ctx->restart);
1342 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1343 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1348 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1350 if (!atomic_dec_and_test(&ctx->cc_pending))
1353 if (bio_data_dir(io->base_bio) == READ)
1354 kcryptd_crypt_read_done(io);
1356 kcryptd_crypt_write_io_submit(io, 1);
1359 static void kcryptd_crypt(struct work_struct *work)
1361 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1363 if (bio_data_dir(io->base_bio) == READ)
1364 kcryptd_crypt_read_convert(io);
1366 kcryptd_crypt_write_convert(io);
1369 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1371 struct crypt_config *cc = io->cc;
1373 INIT_WORK(&io->work, kcryptd_crypt);
1374 queue_work(cc->crypt_queue, &io->work);
1378 * Decode key from its hex representation
1380 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1387 for (i = 0; i < size; i++) {
1391 if (kstrtou8(buffer, 16, &key[i]))
1401 static void crypt_free_tfms(struct crypt_config *cc)
1408 for (i = 0; i < cc->tfms_count; i++)
1409 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1410 crypto_free_ablkcipher(cc->tfms[i]);
1418 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1423 cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *),
1428 for (i = 0; i < cc->tfms_count; i++) {
1429 cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1430 if (IS_ERR(cc->tfms[i])) {
1431 err = PTR_ERR(cc->tfms[i]);
1432 crypt_free_tfms(cc);
1440 static int crypt_setkey_allcpus(struct crypt_config *cc)
1442 unsigned subkey_size;
1445 /* Ignore extra keys (which are used for IV etc) */
1446 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1448 for (i = 0; i < cc->tfms_count; i++) {
1449 r = crypto_ablkcipher_setkey(cc->tfms[i],
1450 cc->key + (i * subkey_size),
1459 static int crypt_set_key(struct crypt_config *cc, char *key)
1462 int key_string_len = strlen(key);
1464 /* The key size may not be changed. */
1465 if (cc->key_size != (key_string_len >> 1))
1468 /* Hyphen (which gives a key_size of zero) means there is no key. */
1469 if (!cc->key_size && strcmp(key, "-"))
1472 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1475 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1477 r = crypt_setkey_allcpus(cc);
1480 /* Hex key string not needed after here, so wipe it. */
1481 memset(key, '0', key_string_len);
1486 static int crypt_wipe_key(struct crypt_config *cc)
1488 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1489 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1491 return crypt_setkey_allcpus(cc);
1494 static void crypt_dtr(struct dm_target *ti)
1496 struct crypt_config *cc = ti->private;
1504 destroy_workqueue(cc->io_queue);
1505 if (cc->crypt_queue)
1506 destroy_workqueue(cc->crypt_queue);
1508 crypt_free_tfms(cc);
1511 bioset_free(cc->bs);
1514 mempool_destroy(cc->page_pool);
1516 mempool_destroy(cc->req_pool);
1518 mempool_destroy(cc->io_pool);
1520 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1521 cc->iv_gen_ops->dtr(cc);
1524 dm_put_device(ti, cc->dev);
1527 kzfree(cc->cipher_string);
1529 /* Must zero key material before freeing */
1533 static int crypt_ctr_cipher(struct dm_target *ti,
1534 char *cipher_in, char *key)
1536 struct crypt_config *cc = ti->private;
1537 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1538 char *cipher_api = NULL;
1542 /* Convert to crypto api definition? */
1543 if (strchr(cipher_in, '(')) {
1544 ti->error = "Bad cipher specification";
1548 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1549 if (!cc->cipher_string)
1553 * Legacy dm-crypt cipher specification
1554 * cipher[:keycount]-mode-iv:ivopts
1557 keycount = strsep(&tmp, "-");
1558 cipher = strsep(&keycount, ":");
1562 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1563 !is_power_of_2(cc->tfms_count)) {
1564 ti->error = "Bad cipher key count specification";
1567 cc->key_parts = cc->tfms_count;
1568 cc->key_extra_size = 0;
1570 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1574 chainmode = strsep(&tmp, "-");
1575 ivopts = strsep(&tmp, "-");
1576 ivmode = strsep(&ivopts, ":");
1579 DMWARN("Ignoring unexpected additional cipher options");
1582 * For compatibility with the original dm-crypt mapping format, if
1583 * only the cipher name is supplied, use cbc-plain.
1585 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1590 if (strcmp(chainmode, "ecb") && !ivmode) {
1591 ti->error = "IV mechanism required";
1595 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1599 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1600 "%s(%s)", chainmode, cipher);
1606 /* Allocate cipher */
1607 ret = crypt_alloc_tfms(cc, cipher_api);
1609 ti->error = "Error allocating crypto tfm";
1614 cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1616 /* at least a 64 bit sector number should fit in our buffer */
1617 cc->iv_size = max(cc->iv_size,
1618 (unsigned int)(sizeof(u64) / sizeof(u8)));
1620 DMWARN("Selected cipher does not support IVs");
1624 /* Choose ivmode, see comments at iv code. */
1626 cc->iv_gen_ops = NULL;
1627 else if (strcmp(ivmode, "plain") == 0)
1628 cc->iv_gen_ops = &crypt_iv_plain_ops;
1629 else if (strcmp(ivmode, "plain64") == 0)
1630 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1631 else if (strcmp(ivmode, "essiv") == 0)
1632 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1633 else if (strcmp(ivmode, "benbi") == 0)
1634 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1635 else if (strcmp(ivmode, "null") == 0)
1636 cc->iv_gen_ops = &crypt_iv_null_ops;
1637 else if (strcmp(ivmode, "lmk") == 0) {
1638 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1640 * Version 2 and 3 is recognised according
1641 * to length of provided multi-key string.
1642 * If present (version 3), last key is used as IV seed.
1643 * All keys (including IV seed) are always the same size.
1645 if (cc->key_size % cc->key_parts) {
1647 cc->key_extra_size = cc->key_size / cc->key_parts;
1649 } else if (strcmp(ivmode, "tcw") == 0) {
1650 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1651 cc->key_parts += 2; /* IV + whitening */
1652 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1655 ti->error = "Invalid IV mode";
1659 /* Initialize and set key */
1660 ret = crypt_set_key(cc, key);
1662 ti->error = "Error decoding and setting key";
1667 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1668 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1670 ti->error = "Error creating IV";
1675 /* Initialize IV (set keys for ESSIV etc) */
1676 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1677 ret = cc->iv_gen_ops->init(cc);
1679 ti->error = "Error initialising IV";
1690 ti->error = "Cannot allocate cipher strings";
1695 * Construct an encryption mapping:
1696 * <cipher> <key> <iv_offset> <dev_path> <start>
1698 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1700 struct crypt_config *cc;
1701 unsigned int key_size, opt_params;
1702 unsigned long long tmpll;
1704 size_t iv_size_padding;
1705 struct dm_arg_set as;
1706 const char *opt_string;
1709 static struct dm_arg _args[] = {
1710 {0, 2, "Invalid number of feature args"},
1714 ti->error = "Not enough arguments";
1718 key_size = strlen(argv[1]) >> 1;
1720 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1722 ti->error = "Cannot allocate encryption context";
1725 cc->key_size = key_size;
1728 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1733 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
1735 ti->error = "Cannot allocate crypt io mempool";
1739 cc->dmreq_start = sizeof(struct ablkcipher_request);
1740 cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1741 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1743 if (crypto_ablkcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1744 /* Allocate the padding exactly */
1745 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1746 & crypto_ablkcipher_alignmask(any_tfm(cc));
1749 * If the cipher requires greater alignment than kmalloc
1750 * alignment, we don't know the exact position of the
1751 * initialization vector. We must assume worst case.
1753 iv_size_padding = crypto_ablkcipher_alignmask(any_tfm(cc));
1756 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1757 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1758 if (!cc->req_pool) {
1759 ti->error = "Cannot allocate crypt request mempool";
1763 cc->per_bio_data_size = ti->per_bio_data_size =
1764 sizeof(struct dm_crypt_io) + cc->dmreq_start +
1765 sizeof(struct dm_crypt_request) + cc->iv_size;
1767 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
1768 if (!cc->page_pool) {
1769 ti->error = "Cannot allocate page mempool";
1773 cc->bs = bioset_create(MIN_IOS, 0);
1775 ti->error = "Cannot allocate crypt bioset";
1780 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1781 ti->error = "Invalid iv_offset sector";
1784 cc->iv_offset = tmpll;
1786 if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
1787 ti->error = "Device lookup failed";
1791 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1792 ti->error = "Invalid device sector";
1800 /* Optional parameters */
1805 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1809 while (opt_params--) {
1810 opt_string = dm_shift_arg(&as);
1812 ti->error = "Not enough feature arguments";
1816 if (!strcasecmp(opt_string, "allow_discards"))
1817 ti->num_discard_bios = 1;
1819 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1820 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1823 ti->error = "Invalid feature arguments";
1830 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1831 if (!cc->io_queue) {
1832 ti->error = "Couldn't create kcryptd io queue";
1836 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1837 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1839 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
1841 if (!cc->crypt_queue) {
1842 ti->error = "Couldn't create kcryptd queue";
1846 ti->num_flush_bios = 1;
1847 ti->discard_zeroes_data_unsupported = true;
1856 static int crypt_map(struct dm_target *ti, struct bio *bio)
1858 struct dm_crypt_io *io;
1859 struct crypt_config *cc = ti->private;
1862 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1863 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1864 * - for REQ_DISCARD caller must use flush if IO ordering matters
1866 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1867 bio->bi_bdev = cc->dev->bdev;
1868 if (bio_sectors(bio))
1869 bio->bi_sector = cc->start + dm_target_offset(ti, bio->bi_sector);
1870 return DM_MAPIO_REMAPPED;
1873 io = dm_per_bio_data(bio, cc->per_bio_data_size);
1874 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_sector));
1875 io->ctx.req = (struct ablkcipher_request *)(io + 1);
1877 if (bio_data_dir(io->base_bio) == READ) {
1878 if (kcryptd_io_read(io, GFP_NOWAIT))
1879 kcryptd_queue_io(io);
1881 kcryptd_queue_crypt(io);
1883 return DM_MAPIO_SUBMITTED;
1886 static void crypt_status(struct dm_target *ti, status_type_t type,
1887 unsigned status_flags, char *result, unsigned maxlen)
1889 struct crypt_config *cc = ti->private;
1891 int num_feature_args = 0;
1894 case STATUSTYPE_INFO:
1898 case STATUSTYPE_TABLE:
1899 DMEMIT("%s ", cc->cipher_string);
1901 if (cc->key_size > 0)
1902 for (i = 0; i < cc->key_size; i++)
1903 DMEMIT("%02x", cc->key[i]);
1907 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1908 cc->dev->name, (unsigned long long)cc->start);
1910 num_feature_args += !!ti->num_discard_bios;
1911 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1912 if (num_feature_args) {
1913 DMEMIT(" %d", num_feature_args);
1914 if (ti->num_discard_bios)
1915 DMEMIT(" allow_discards");
1916 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1917 DMEMIT(" same_cpu_crypt");
1924 static void crypt_postsuspend(struct dm_target *ti)
1926 struct crypt_config *cc = ti->private;
1928 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1931 static int crypt_preresume(struct dm_target *ti)
1933 struct crypt_config *cc = ti->private;
1935 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1936 DMERR("aborting resume - crypt key is not set.");
1943 static void crypt_resume(struct dm_target *ti)
1945 struct crypt_config *cc = ti->private;
1947 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1950 /* Message interface
1954 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1956 struct crypt_config *cc = ti->private;
1962 if (!strcasecmp(argv[0], "key")) {
1963 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1964 DMWARN("not suspended during key manipulation.");
1967 if (argc == 3 && !strcasecmp(argv[1], "set")) {
1968 ret = crypt_set_key(cc, argv[2]);
1971 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
1972 ret = cc->iv_gen_ops->init(cc);
1975 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
1976 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
1977 ret = cc->iv_gen_ops->wipe(cc);
1981 return crypt_wipe_key(cc);
1986 DMWARN("unrecognised message received.");
1990 static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1991 struct bio_vec *biovec, int max_size)
1993 struct crypt_config *cc = ti->private;
1994 struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1996 if (!q->merge_bvec_fn)
1999 bvm->bi_bdev = cc->dev->bdev;
2000 bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
2002 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
2005 static int crypt_iterate_devices(struct dm_target *ti,
2006 iterate_devices_callout_fn fn, void *data)
2008 struct crypt_config *cc = ti->private;
2010 return fn(ti, cc->dev, cc->start, ti->len, data);
2013 static struct target_type crypt_target = {
2015 .version = {1, 14, 0},
2016 .module = THIS_MODULE,
2020 .status = crypt_status,
2021 .postsuspend = crypt_postsuspend,
2022 .preresume = crypt_preresume,
2023 .resume = crypt_resume,
2024 .message = crypt_message,
2025 .merge = crypt_merge,
2026 .iterate_devices = crypt_iterate_devices,
2029 static int __init dm_crypt_init(void)
2033 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
2034 if (!_crypt_io_pool)
2037 r = dm_register_target(&crypt_target);
2039 DMERR("register failed %d", r);
2040 kmem_cache_destroy(_crypt_io_pool);
2046 static void __exit dm_crypt_exit(void)
2048 dm_unregister_target(&crypt_target);
2049 kmem_cache_destroy(_crypt_io_pool);
2052 module_init(dm_crypt_init);
2053 module_exit(dm_crypt_exit);
2055 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
2056 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2057 MODULE_LICENSE("GPL");