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");