2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2015 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/kthread.h>
22 #include <linux/backing-dev.h>
23 #include <linux/atomic.h>
24 #include <linux/scatterlist.h>
25 #include <linux/rbtree.h>
27 #include <asm/unaligned.h>
28 #include <crypto/hash.h>
29 #include <crypto/md5.h>
30 #include <crypto/algapi.h>
32 #include <linux/device-mapper.h>
34 #define DM_MSG_PREFIX "crypt"
37 * context holding the current state of a multi-part conversion
39 struct convert_context {
40 struct completion restart;
43 struct bvec_iter iter_in;
44 struct bvec_iter iter_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;
64 struct rb_node rb_node;
65 } CRYPTO_MINALIGN_ATTR;
67 struct dm_crypt_request {
68 struct convert_context *ctx;
69 struct scatterlist sg_in;
70 struct scatterlist sg_out;
76 struct crypt_iv_operations {
77 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
79 void (*dtr)(struct crypt_config *cc);
80 int (*init)(struct crypt_config *cc);
81 int (*wipe)(struct crypt_config *cc);
82 int (*generator)(struct crypt_config *cc, u8 *iv,
83 struct dm_crypt_request *dmreq);
84 int (*post)(struct crypt_config *cc, u8 *iv,
85 struct dm_crypt_request *dmreq);
88 struct iv_essiv_private {
89 struct crypto_hash *hash_tfm;
93 struct iv_benbi_private {
97 #define LMK_SEED_SIZE 64 /* hash + 0 */
98 struct iv_lmk_private {
99 struct crypto_shash *hash_tfm;
103 #define TCW_WHITENING_SIZE 16
104 struct iv_tcw_private {
105 struct crypto_shash *crc32_tfm;
111 * Crypt: maps a linear range of a block device
112 * and encrypts / decrypts at the same time.
114 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
115 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
118 * The fields in here must be read only after initialization.
120 struct crypt_config {
125 * pool for per bio private data, crypto requests and
126 * encryption requeusts/buffer pages
129 mempool_t *page_pool;
131 struct mutex bio_alloc_lock;
133 struct workqueue_struct *io_queue;
134 struct workqueue_struct *crypt_queue;
136 struct task_struct *write_thread;
137 wait_queue_head_t write_thread_wait;
138 struct rb_root write_tree;
143 struct crypt_iv_operations *iv_gen_ops;
145 struct iv_essiv_private essiv;
146 struct iv_benbi_private benbi;
147 struct iv_lmk_private lmk;
148 struct iv_tcw_private tcw;
151 unsigned int iv_size;
153 /* ESSIV: struct crypto_cipher *essiv_tfm */
155 struct crypto_ablkcipher **tfms;
159 * Layout of each crypto request:
161 * struct ablkcipher_request
164 * struct dm_crypt_request
168 * The padding is added so that dm_crypt_request and the IV are
171 unsigned int dmreq_start;
173 unsigned int per_bio_data_size;
176 unsigned int key_size;
177 unsigned int key_parts; /* independent parts in key buffer */
178 unsigned int key_extra_size; /* additional keys length */
184 static void clone_init(struct dm_crypt_io *, struct bio *);
185 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
186 static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
189 * Use this to access cipher attributes that are the same for each CPU.
191 static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
197 * Different IV generation algorithms:
199 * plain: the initial vector is the 32-bit little-endian version of the sector
200 * number, padded with zeros if necessary.
202 * plain64: the initial vector is the 64-bit little-endian version of the sector
203 * number, padded with zeros if necessary.
205 * essiv: "encrypted sector|salt initial vector", the sector number is
206 * encrypted with the bulk cipher using a salt as key. The salt
207 * should be derived from the bulk cipher's key via hashing.
209 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
210 * (needed for LRW-32-AES and possible other narrow block modes)
212 * null: the initial vector is always zero. Provides compatibility with
213 * obsolete loop_fish2 devices. Do not use for new devices.
215 * lmk: Compatible implementation of the block chaining mode used
216 * by the Loop-AES block device encryption system
217 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
218 * It operates on full 512 byte sectors and uses CBC
219 * with an IV derived from the sector number, the data and
220 * optionally extra IV seed.
221 * This means that after decryption the first block
222 * of sector must be tweaked according to decrypted data.
223 * Loop-AES can use three encryption schemes:
224 * version 1: is plain aes-cbc mode
225 * version 2: uses 64 multikey scheme with lmk IV generator
226 * version 3: the same as version 2 with additional IV seed
227 * (it uses 65 keys, last key is used as IV seed)
229 * tcw: Compatible implementation of the block chaining mode used
230 * by the TrueCrypt device encryption system (prior to version 4.1).
231 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
232 * It operates on full 512 byte sectors and uses CBC
233 * with an IV derived from initial key and the sector number.
234 * In addition, whitening value is applied on every sector, whitening
235 * is calculated from initial key, sector number and mixed using CRC32.
236 * Note that this encryption scheme is vulnerable to watermarking attacks
237 * and should be used for old compatible containers access only.
239 * plumb: unimplemented, see:
240 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
243 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
244 struct dm_crypt_request *dmreq)
246 memset(iv, 0, cc->iv_size);
247 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
252 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
253 struct dm_crypt_request *dmreq)
255 memset(iv, 0, cc->iv_size);
256 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
261 /* Initialise ESSIV - compute salt but no local memory allocations */
262 static int crypt_iv_essiv_init(struct crypt_config *cc)
264 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
265 struct hash_desc desc;
266 struct scatterlist sg;
267 struct crypto_cipher *essiv_tfm;
270 sg_init_one(&sg, cc->key, cc->key_size);
271 desc.tfm = essiv->hash_tfm;
272 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
274 err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
278 essiv_tfm = cc->iv_private;
280 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
281 crypto_hash_digestsize(essiv->hash_tfm));
288 /* Wipe salt and reset key derived from volume key */
289 static int crypt_iv_essiv_wipe(struct crypt_config *cc)
291 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
292 unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
293 struct crypto_cipher *essiv_tfm;
296 memset(essiv->salt, 0, salt_size);
298 essiv_tfm = cc->iv_private;
299 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
306 /* Set up per cpu cipher state */
307 static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
308 struct dm_target *ti,
309 u8 *salt, unsigned saltsize)
311 struct crypto_cipher *essiv_tfm;
314 /* Setup the essiv_tfm with the given salt */
315 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
316 if (IS_ERR(essiv_tfm)) {
317 ti->error = "Error allocating crypto tfm for ESSIV";
321 if (crypto_cipher_blocksize(essiv_tfm) !=
322 crypto_ablkcipher_ivsize(any_tfm(cc))) {
323 ti->error = "Block size of ESSIV cipher does "
324 "not match IV size of block cipher";
325 crypto_free_cipher(essiv_tfm);
326 return ERR_PTR(-EINVAL);
329 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
331 ti->error = "Failed to set key for ESSIV cipher";
332 crypto_free_cipher(essiv_tfm);
339 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
341 struct crypto_cipher *essiv_tfm;
342 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
344 crypto_free_hash(essiv->hash_tfm);
345 essiv->hash_tfm = NULL;
350 essiv_tfm = cc->iv_private;
353 crypto_free_cipher(essiv_tfm);
355 cc->iv_private = NULL;
358 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
361 struct crypto_cipher *essiv_tfm = NULL;
362 struct crypto_hash *hash_tfm = NULL;
367 ti->error = "Digest algorithm missing for ESSIV mode";
371 /* Allocate hash algorithm */
372 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
373 if (IS_ERR(hash_tfm)) {
374 ti->error = "Error initializing ESSIV hash";
375 err = PTR_ERR(hash_tfm);
379 salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
381 ti->error = "Error kmallocing salt storage in ESSIV";
386 cc->iv_gen_private.essiv.salt = salt;
387 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
389 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
390 crypto_hash_digestsize(hash_tfm));
391 if (IS_ERR(essiv_tfm)) {
392 crypt_iv_essiv_dtr(cc);
393 return PTR_ERR(essiv_tfm);
395 cc->iv_private = essiv_tfm;
400 if (hash_tfm && !IS_ERR(hash_tfm))
401 crypto_free_hash(hash_tfm);
406 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
407 struct dm_crypt_request *dmreq)
409 struct crypto_cipher *essiv_tfm = cc->iv_private;
411 memset(iv, 0, cc->iv_size);
412 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
413 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
418 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
421 unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
424 /* we need to calculate how far we must shift the sector count
425 * to get the cipher block count, we use this shift in _gen */
427 if (1 << log != bs) {
428 ti->error = "cypher blocksize is not a power of 2";
433 ti->error = "cypher blocksize is > 512";
437 cc->iv_gen_private.benbi.shift = 9 - log;
442 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
446 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
447 struct dm_crypt_request *dmreq)
451 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
453 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
454 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
459 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
460 struct dm_crypt_request *dmreq)
462 memset(iv, 0, cc->iv_size);
467 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
469 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
471 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
472 crypto_free_shash(lmk->hash_tfm);
473 lmk->hash_tfm = NULL;
479 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
482 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
484 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
485 if (IS_ERR(lmk->hash_tfm)) {
486 ti->error = "Error initializing LMK hash";
487 return PTR_ERR(lmk->hash_tfm);
490 /* No seed in LMK version 2 */
491 if (cc->key_parts == cc->tfms_count) {
496 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
498 crypt_iv_lmk_dtr(cc);
499 ti->error = "Error kmallocing seed storage in LMK";
506 static int crypt_iv_lmk_init(struct crypt_config *cc)
508 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
509 int subkey_size = cc->key_size / cc->key_parts;
511 /* LMK seed is on the position of LMK_KEYS + 1 key */
513 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
514 crypto_shash_digestsize(lmk->hash_tfm));
519 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
521 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
524 memset(lmk->seed, 0, LMK_SEED_SIZE);
529 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
530 struct dm_crypt_request *dmreq,
533 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
534 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
535 struct md5_state md5state;
539 desc->tfm = lmk->hash_tfm;
540 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
542 r = crypto_shash_init(desc);
547 r = crypto_shash_update(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(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(desc, (u8 *)buf, sizeof(buf));
566 /* No MD5 padding here */
567 r = crypto_shash_export(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];
684 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
687 /* xor whitening with sector number */
688 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
689 crypto_xor(buf, (u8 *)§or, 8);
690 crypto_xor(&buf[8], (u8 *)§or, 8);
692 /* calculate crc32 for every 32bit part and xor it */
693 desc->tfm = tcw->crc32_tfm;
694 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
695 for (i = 0; i < 4; i++) {
696 r = crypto_shash_init(desc);
699 r = crypto_shash_update(desc, &buf[i * 4], 4);
702 r = crypto_shash_final(desc, &buf[i * 4]);
706 crypto_xor(&buf[0], &buf[12], 4);
707 crypto_xor(&buf[4], &buf[8], 4);
709 /* apply whitening (8 bytes) to whole sector */
710 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
711 crypto_xor(data + i * 8, buf, 8);
713 memzero_explicit(buf, sizeof(buf));
717 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
718 struct dm_crypt_request *dmreq)
720 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
721 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
725 /* Remove whitening from ciphertext */
726 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
727 src = kmap_atomic(sg_page(&dmreq->sg_in));
728 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
733 memcpy(iv, tcw->iv_seed, cc->iv_size);
734 crypto_xor(iv, (u8 *)§or, 8);
736 crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
741 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
742 struct dm_crypt_request *dmreq)
747 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
750 /* Apply whitening on ciphertext */
751 dst = kmap_atomic(sg_page(&dmreq->sg_out));
752 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
758 static struct crypt_iv_operations crypt_iv_plain_ops = {
759 .generator = crypt_iv_plain_gen
762 static struct crypt_iv_operations crypt_iv_plain64_ops = {
763 .generator = crypt_iv_plain64_gen
766 static struct crypt_iv_operations crypt_iv_essiv_ops = {
767 .ctr = crypt_iv_essiv_ctr,
768 .dtr = crypt_iv_essiv_dtr,
769 .init = crypt_iv_essiv_init,
770 .wipe = crypt_iv_essiv_wipe,
771 .generator = crypt_iv_essiv_gen
774 static struct crypt_iv_operations crypt_iv_benbi_ops = {
775 .ctr = crypt_iv_benbi_ctr,
776 .dtr = crypt_iv_benbi_dtr,
777 .generator = crypt_iv_benbi_gen
780 static struct crypt_iv_operations crypt_iv_null_ops = {
781 .generator = crypt_iv_null_gen
784 static struct crypt_iv_operations crypt_iv_lmk_ops = {
785 .ctr = crypt_iv_lmk_ctr,
786 .dtr = crypt_iv_lmk_dtr,
787 .init = crypt_iv_lmk_init,
788 .wipe = crypt_iv_lmk_wipe,
789 .generator = crypt_iv_lmk_gen,
790 .post = crypt_iv_lmk_post
793 static struct crypt_iv_operations crypt_iv_tcw_ops = {
794 .ctr = crypt_iv_tcw_ctr,
795 .dtr = crypt_iv_tcw_dtr,
796 .init = crypt_iv_tcw_init,
797 .wipe = crypt_iv_tcw_wipe,
798 .generator = crypt_iv_tcw_gen,
799 .post = crypt_iv_tcw_post
802 static void crypt_convert_init(struct crypt_config *cc,
803 struct convert_context *ctx,
804 struct bio *bio_out, struct bio *bio_in,
807 ctx->bio_in = bio_in;
808 ctx->bio_out = bio_out;
810 ctx->iter_in = bio_in->bi_iter;
812 ctx->iter_out = bio_out->bi_iter;
813 ctx->cc_sector = sector + cc->iv_offset;
814 init_completion(&ctx->restart);
817 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
818 struct ablkcipher_request *req)
820 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
823 static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
824 struct dm_crypt_request *dmreq)
826 return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
829 static u8 *iv_of_dmreq(struct crypt_config *cc,
830 struct dm_crypt_request *dmreq)
832 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
833 crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
836 static int crypt_convert_block(struct crypt_config *cc,
837 struct convert_context *ctx,
838 struct ablkcipher_request *req)
840 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
841 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
842 struct dm_crypt_request *dmreq;
846 dmreq = dmreq_of_req(cc, req);
847 iv = iv_of_dmreq(cc, dmreq);
849 dmreq->iv_sector = ctx->cc_sector;
851 sg_init_table(&dmreq->sg_in, 1);
852 sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
855 sg_init_table(&dmreq->sg_out, 1);
856 sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
859 bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
860 bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
862 if (cc->iv_gen_ops) {
863 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
868 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
869 1 << SECTOR_SHIFT, iv);
871 if (bio_data_dir(ctx->bio_in) == WRITE)
872 r = crypto_ablkcipher_encrypt(req);
874 r = crypto_ablkcipher_decrypt(req);
876 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
877 r = cc->iv_gen_ops->post(cc, iv, dmreq);
882 static void kcryptd_async_done(struct crypto_async_request *async_req,
885 static void crypt_alloc_req(struct crypt_config *cc,
886 struct convert_context *ctx)
888 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
891 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
893 ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
896 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
897 * requests if driver request queue is full.
899 ablkcipher_request_set_callback(ctx->req,
900 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
901 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
904 static void crypt_free_req(struct crypt_config *cc,
905 struct ablkcipher_request *req, struct bio *base_bio)
907 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
909 if ((struct ablkcipher_request *)(io + 1) != req)
910 mempool_free(req, cc->req_pool);
914 * Encrypt / decrypt data from one bio to another one (can be the same one)
916 static int crypt_convert(struct crypt_config *cc,
917 struct convert_context *ctx)
921 atomic_set(&ctx->cc_pending, 1);
923 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
925 crypt_alloc_req(cc, ctx);
927 atomic_inc(&ctx->cc_pending);
929 r = crypt_convert_block(cc, ctx, ctx->req);
933 * The request was queued by a crypto driver
934 * but the driver request queue is full, let's wait.
937 wait_for_completion(&ctx->restart);
938 reinit_completion(&ctx->restart);
941 * The request is queued and processed asynchronously,
942 * completion function kcryptd_async_done() will be called.
949 * The request was already processed (synchronously).
952 atomic_dec(&ctx->cc_pending);
957 /* There was an error while processing the request. */
959 atomic_dec(&ctx->cc_pending);
967 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
970 * Generate a new unfragmented bio with the given size
971 * This should never violate the device limitations (but only because
972 * max_segment_size is being constrained to PAGE_SIZE).
974 * This function may be called concurrently. If we allocate from the mempool
975 * concurrently, there is a possibility of deadlock. For example, if we have
976 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
977 * the mempool concurrently, it may deadlock in a situation where both processes
978 * have allocated 128 pages and the mempool is exhausted.
980 * In order to avoid this scenario we allocate the pages under a mutex.
982 * In order to not degrade performance with excessive locking, we try
983 * non-blocking allocations without a mutex first but on failure we fallback
984 * to blocking allocations with a mutex.
986 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
988 struct crypt_config *cc = io->cc;
990 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
991 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
992 unsigned i, len, remaining_size;
994 struct bio_vec *bvec;
997 if (unlikely(gfp_mask & __GFP_WAIT))
998 mutex_lock(&cc->bio_alloc_lock);
1000 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1004 clone_init(io, clone);
1006 remaining_size = size;
1008 for (i = 0; i < nr_iovecs; i++) {
1009 page = mempool_alloc(cc->page_pool, gfp_mask);
1011 crypt_free_buffer_pages(cc, clone);
1013 gfp_mask |= __GFP_WAIT;
1017 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1019 bvec = &clone->bi_io_vec[clone->bi_vcnt++];
1020 bvec->bv_page = page;
1022 bvec->bv_offset = 0;
1024 clone->bi_iter.bi_size += len;
1026 remaining_size -= len;
1030 if (unlikely(gfp_mask & __GFP_WAIT))
1031 mutex_unlock(&cc->bio_alloc_lock);
1036 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1041 bio_for_each_segment_all(bv, clone, i) {
1042 BUG_ON(!bv->bv_page);
1043 mempool_free(bv->bv_page, cc->page_pool);
1048 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1049 struct bio *bio, sector_t sector)
1053 io->sector = sector;
1056 atomic_set(&io->io_pending, 0);
1059 static void crypt_inc_pending(struct dm_crypt_io *io)
1061 atomic_inc(&io->io_pending);
1065 * One of the bios was finished. Check for completion of
1066 * the whole request and correctly clean up the buffer.
1068 static void crypt_dec_pending(struct dm_crypt_io *io)
1070 struct crypt_config *cc = io->cc;
1071 struct bio *base_bio = io->base_bio;
1072 int error = io->error;
1074 if (!atomic_dec_and_test(&io->io_pending))
1078 crypt_free_req(cc, io->ctx.req, base_bio);
1080 base_bio->bi_error = error;
1081 bio_endio(base_bio);
1085 * kcryptd/kcryptd_io:
1087 * Needed because it would be very unwise to do decryption in an
1088 * interrupt context.
1090 * kcryptd performs the actual encryption or decryption.
1092 * kcryptd_io performs the IO submission.
1094 * They must be separated as otherwise the final stages could be
1095 * starved by new requests which can block in the first stages due
1096 * to memory allocation.
1098 * The work is done per CPU global for all dm-crypt instances.
1099 * They should not depend on each other and do not block.
1101 static void crypt_endio(struct bio *clone)
1103 struct dm_crypt_io *io = clone->bi_private;
1104 struct crypt_config *cc = io->cc;
1105 unsigned rw = bio_data_dir(clone);
1109 * free the processed pages
1112 crypt_free_buffer_pages(cc, clone);
1114 error = clone->bi_error;
1117 if (rw == READ && !error) {
1118 kcryptd_queue_crypt(io);
1122 if (unlikely(error))
1125 crypt_dec_pending(io);
1128 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1130 struct crypt_config *cc = io->cc;
1132 clone->bi_private = io;
1133 clone->bi_end_io = crypt_endio;
1134 clone->bi_bdev = cc->dev->bdev;
1135 clone->bi_rw = io->base_bio->bi_rw;
1138 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1140 struct crypt_config *cc = io->cc;
1144 * We need the original biovec array in order to decrypt
1145 * the whole bio data *afterwards* -- thanks to immutable
1146 * biovecs we don't need to worry about the block layer
1147 * modifying the biovec array; so leverage bio_clone_fast().
1149 clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1153 crypt_inc_pending(io);
1155 clone_init(io, clone);
1156 clone->bi_iter.bi_sector = cc->start + io->sector;
1158 generic_make_request(clone);
1162 static void kcryptd_io_read_work(struct work_struct *work)
1164 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1166 crypt_inc_pending(io);
1167 if (kcryptd_io_read(io, GFP_NOIO))
1168 io->error = -ENOMEM;
1169 crypt_dec_pending(io);
1172 static void kcryptd_queue_read(struct dm_crypt_io *io)
1174 struct crypt_config *cc = io->cc;
1176 INIT_WORK(&io->work, kcryptd_io_read_work);
1177 queue_work(cc->io_queue, &io->work);
1180 static void kcryptd_io_write(struct dm_crypt_io *io)
1182 struct bio *clone = io->ctx.bio_out;
1184 generic_make_request(clone);
1187 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1189 static int dmcrypt_write(void *data)
1191 struct crypt_config *cc = data;
1192 struct dm_crypt_io *io;
1195 struct rb_root write_tree;
1196 struct blk_plug plug;
1198 DECLARE_WAITQUEUE(wait, current);
1200 spin_lock_irq(&cc->write_thread_wait.lock);
1203 if (!RB_EMPTY_ROOT(&cc->write_tree))
1206 __set_current_state(TASK_INTERRUPTIBLE);
1207 __add_wait_queue(&cc->write_thread_wait, &wait);
1209 spin_unlock_irq(&cc->write_thread_wait.lock);
1211 if (unlikely(kthread_should_stop())) {
1212 set_task_state(current, TASK_RUNNING);
1213 remove_wait_queue(&cc->write_thread_wait, &wait);
1219 set_task_state(current, TASK_RUNNING);
1220 spin_lock_irq(&cc->write_thread_wait.lock);
1221 __remove_wait_queue(&cc->write_thread_wait, &wait);
1222 goto continue_locked;
1225 write_tree = cc->write_tree;
1226 cc->write_tree = RB_ROOT;
1227 spin_unlock_irq(&cc->write_thread_wait.lock);
1229 BUG_ON(rb_parent(write_tree.rb_node));
1232 * Note: we cannot walk the tree here with rb_next because
1233 * the structures may be freed when kcryptd_io_write is called.
1235 blk_start_plug(&plug);
1237 io = crypt_io_from_node(rb_first(&write_tree));
1238 rb_erase(&io->rb_node, &write_tree);
1239 kcryptd_io_write(io);
1240 } while (!RB_EMPTY_ROOT(&write_tree));
1241 blk_finish_plug(&plug);
1246 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1248 struct bio *clone = io->ctx.bio_out;
1249 struct crypt_config *cc = io->cc;
1250 unsigned long flags;
1252 struct rb_node **rbp, *parent;
1254 if (unlikely(io->error < 0)) {
1255 crypt_free_buffer_pages(cc, clone);
1257 crypt_dec_pending(io);
1261 /* crypt_convert should have filled the clone bio */
1262 BUG_ON(io->ctx.iter_out.bi_size);
1264 clone->bi_iter.bi_sector = cc->start + io->sector;
1266 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1267 generic_make_request(clone);
1271 spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1272 rbp = &cc->write_tree.rb_node;
1274 sector = io->sector;
1277 if (sector < crypt_io_from_node(parent)->sector)
1278 rbp = &(*rbp)->rb_left;
1280 rbp = &(*rbp)->rb_right;
1282 rb_link_node(&io->rb_node, parent, rbp);
1283 rb_insert_color(&io->rb_node, &cc->write_tree);
1285 wake_up_locked(&cc->write_thread_wait);
1286 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1289 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1291 struct crypt_config *cc = io->cc;
1294 sector_t sector = io->sector;
1298 * Prevent io from disappearing until this function completes.
1300 crypt_inc_pending(io);
1301 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1303 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1304 if (unlikely(!clone)) {
1309 io->ctx.bio_out = clone;
1310 io->ctx.iter_out = clone->bi_iter;
1312 sector += bio_sectors(clone);
1314 crypt_inc_pending(io);
1315 r = crypt_convert(cc, &io->ctx);
1318 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1320 /* Encryption was already finished, submit io now */
1321 if (crypt_finished) {
1322 kcryptd_crypt_write_io_submit(io, 0);
1323 io->sector = sector;
1327 crypt_dec_pending(io);
1330 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1332 crypt_dec_pending(io);
1335 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1337 struct crypt_config *cc = io->cc;
1340 crypt_inc_pending(io);
1342 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1345 r = crypt_convert(cc, &io->ctx);
1349 if (atomic_dec_and_test(&io->ctx.cc_pending))
1350 kcryptd_crypt_read_done(io);
1352 crypt_dec_pending(io);
1355 static void kcryptd_async_done(struct crypto_async_request *async_req,
1358 struct dm_crypt_request *dmreq = async_req->data;
1359 struct convert_context *ctx = dmreq->ctx;
1360 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1361 struct crypt_config *cc = io->cc;
1364 * A request from crypto driver backlog is going to be processed now,
1365 * finish the completion and continue in crypt_convert().
1366 * (Callback will be called for the second time for this request.)
1368 if (error == -EINPROGRESS) {
1369 complete(&ctx->restart);
1373 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1374 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1379 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1381 if (!atomic_dec_and_test(&ctx->cc_pending))
1384 if (bio_data_dir(io->base_bio) == READ)
1385 kcryptd_crypt_read_done(io);
1387 kcryptd_crypt_write_io_submit(io, 1);
1390 static void kcryptd_crypt(struct work_struct *work)
1392 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1394 if (bio_data_dir(io->base_bio) == READ)
1395 kcryptd_crypt_read_convert(io);
1397 kcryptd_crypt_write_convert(io);
1400 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1402 struct crypt_config *cc = io->cc;
1404 INIT_WORK(&io->work, kcryptd_crypt);
1405 queue_work(cc->crypt_queue, &io->work);
1409 * Decode key from its hex representation
1411 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1418 for (i = 0; i < size; i++) {
1422 if (kstrtou8(buffer, 16, &key[i]))
1432 static void crypt_free_tfms(struct crypt_config *cc)
1439 for (i = 0; i < cc->tfms_count; i++)
1440 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1441 crypto_free_ablkcipher(cc->tfms[i]);
1449 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1454 cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *),
1459 for (i = 0; i < cc->tfms_count; i++) {
1460 cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1461 if (IS_ERR(cc->tfms[i])) {
1462 err = PTR_ERR(cc->tfms[i]);
1463 crypt_free_tfms(cc);
1471 static int crypt_setkey_allcpus(struct crypt_config *cc)
1473 unsigned subkey_size;
1476 /* Ignore extra keys (which are used for IV etc) */
1477 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1479 for (i = 0; i < cc->tfms_count; i++) {
1480 r = crypto_ablkcipher_setkey(cc->tfms[i],
1481 cc->key + (i * subkey_size),
1490 static int crypt_set_key(struct crypt_config *cc, char *key)
1493 int key_string_len = strlen(key);
1495 /* The key size may not be changed. */
1496 if (cc->key_size != (key_string_len >> 1))
1499 /* Hyphen (which gives a key_size of zero) means there is no key. */
1500 if (!cc->key_size && strcmp(key, "-"))
1503 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1506 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1508 r = crypt_setkey_allcpus(cc);
1511 /* Hex key string not needed after here, so wipe it. */
1512 memset(key, '0', key_string_len);
1517 static int crypt_wipe_key(struct crypt_config *cc)
1519 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1520 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1522 return crypt_setkey_allcpus(cc);
1525 static void crypt_dtr(struct dm_target *ti)
1527 struct crypt_config *cc = ti->private;
1534 if (cc->write_thread)
1535 kthread_stop(cc->write_thread);
1538 destroy_workqueue(cc->io_queue);
1539 if (cc->crypt_queue)
1540 destroy_workqueue(cc->crypt_queue);
1542 crypt_free_tfms(cc);
1545 bioset_free(cc->bs);
1548 mempool_destroy(cc->page_pool);
1550 mempool_destroy(cc->req_pool);
1552 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1553 cc->iv_gen_ops->dtr(cc);
1556 dm_put_device(ti, cc->dev);
1559 kzfree(cc->cipher_string);
1561 /* Must zero key material before freeing */
1565 static int crypt_ctr_cipher(struct dm_target *ti,
1566 char *cipher_in, char *key)
1568 struct crypt_config *cc = ti->private;
1569 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1570 char *cipher_api = NULL;
1574 /* Convert to crypto api definition? */
1575 if (strchr(cipher_in, '(')) {
1576 ti->error = "Bad cipher specification";
1580 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1581 if (!cc->cipher_string)
1585 * Legacy dm-crypt cipher specification
1586 * cipher[:keycount]-mode-iv:ivopts
1589 keycount = strsep(&tmp, "-");
1590 cipher = strsep(&keycount, ":");
1594 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1595 !is_power_of_2(cc->tfms_count)) {
1596 ti->error = "Bad cipher key count specification";
1599 cc->key_parts = cc->tfms_count;
1600 cc->key_extra_size = 0;
1602 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1606 chainmode = strsep(&tmp, "-");
1607 ivopts = strsep(&tmp, "-");
1608 ivmode = strsep(&ivopts, ":");
1611 DMWARN("Ignoring unexpected additional cipher options");
1614 * For compatibility with the original dm-crypt mapping format, if
1615 * only the cipher name is supplied, use cbc-plain.
1617 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1622 if (strcmp(chainmode, "ecb") && !ivmode) {
1623 ti->error = "IV mechanism required";
1627 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1631 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1632 "%s(%s)", chainmode, cipher);
1638 /* Allocate cipher */
1639 ret = crypt_alloc_tfms(cc, cipher_api);
1641 ti->error = "Error allocating crypto tfm";
1646 cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1648 /* at least a 64 bit sector number should fit in our buffer */
1649 cc->iv_size = max(cc->iv_size,
1650 (unsigned int)(sizeof(u64) / sizeof(u8)));
1652 DMWARN("Selected cipher does not support IVs");
1656 /* Choose ivmode, see comments at iv code. */
1658 cc->iv_gen_ops = NULL;
1659 else if (strcmp(ivmode, "plain") == 0)
1660 cc->iv_gen_ops = &crypt_iv_plain_ops;
1661 else if (strcmp(ivmode, "plain64") == 0)
1662 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1663 else if (strcmp(ivmode, "essiv") == 0)
1664 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1665 else if (strcmp(ivmode, "benbi") == 0)
1666 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1667 else if (strcmp(ivmode, "null") == 0)
1668 cc->iv_gen_ops = &crypt_iv_null_ops;
1669 else if (strcmp(ivmode, "lmk") == 0) {
1670 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1672 * Version 2 and 3 is recognised according
1673 * to length of provided multi-key string.
1674 * If present (version 3), last key is used as IV seed.
1675 * All keys (including IV seed) are always the same size.
1677 if (cc->key_size % cc->key_parts) {
1679 cc->key_extra_size = cc->key_size / cc->key_parts;
1681 } else if (strcmp(ivmode, "tcw") == 0) {
1682 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1683 cc->key_parts += 2; /* IV + whitening */
1684 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1687 ti->error = "Invalid IV mode";
1691 /* Initialize and set key */
1692 ret = crypt_set_key(cc, key);
1694 ti->error = "Error decoding and setting key";
1699 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1700 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1702 ti->error = "Error creating IV";
1707 /* Initialize IV (set keys for ESSIV etc) */
1708 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1709 ret = cc->iv_gen_ops->init(cc);
1711 ti->error = "Error initialising IV";
1722 ti->error = "Cannot allocate cipher strings";
1727 * Construct an encryption mapping:
1728 * <cipher> <key> <iv_offset> <dev_path> <start>
1730 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1732 struct crypt_config *cc;
1733 unsigned int key_size, opt_params;
1734 unsigned long long tmpll;
1736 size_t iv_size_padding;
1737 struct dm_arg_set as;
1738 const char *opt_string;
1741 static struct dm_arg _args[] = {
1742 {0, 3, "Invalid number of feature args"},
1746 ti->error = "Not enough arguments";
1750 key_size = strlen(argv[1]) >> 1;
1752 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1754 ti->error = "Cannot allocate encryption context";
1757 cc->key_size = key_size;
1760 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1764 cc->dmreq_start = sizeof(struct ablkcipher_request);
1765 cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1766 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1768 if (crypto_ablkcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1769 /* Allocate the padding exactly */
1770 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1771 & crypto_ablkcipher_alignmask(any_tfm(cc));
1774 * If the cipher requires greater alignment than kmalloc
1775 * alignment, we don't know the exact position of the
1776 * initialization vector. We must assume worst case.
1778 iv_size_padding = crypto_ablkcipher_alignmask(any_tfm(cc));
1782 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1783 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1784 if (!cc->req_pool) {
1785 ti->error = "Cannot allocate crypt request mempool";
1789 cc->per_bio_data_size = ti->per_bio_data_size =
1790 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1791 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1792 ARCH_KMALLOC_MINALIGN);
1794 cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1795 if (!cc->page_pool) {
1796 ti->error = "Cannot allocate page mempool";
1800 cc->bs = bioset_create(MIN_IOS, 0);
1802 ti->error = "Cannot allocate crypt bioset";
1806 mutex_init(&cc->bio_alloc_lock);
1809 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1810 ti->error = "Invalid iv_offset sector";
1813 cc->iv_offset = tmpll;
1815 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
1817 ti->error = "Device lookup failed";
1822 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1823 ti->error = "Invalid device sector";
1831 /* Optional parameters */
1836 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1841 while (opt_params--) {
1842 opt_string = dm_shift_arg(&as);
1844 ti->error = "Not enough feature arguments";
1848 if (!strcasecmp(opt_string, "allow_discards"))
1849 ti->num_discard_bios = 1;
1851 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1852 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1854 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
1855 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1858 ti->error = "Invalid feature arguments";
1865 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1866 if (!cc->io_queue) {
1867 ti->error = "Couldn't create kcryptd io queue";
1871 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1872 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1874 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
1876 if (!cc->crypt_queue) {
1877 ti->error = "Couldn't create kcryptd queue";
1881 init_waitqueue_head(&cc->write_thread_wait);
1882 cc->write_tree = RB_ROOT;
1884 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
1885 if (IS_ERR(cc->write_thread)) {
1886 ret = PTR_ERR(cc->write_thread);
1887 cc->write_thread = NULL;
1888 ti->error = "Couldn't spawn write thread";
1891 wake_up_process(cc->write_thread);
1893 ti->num_flush_bios = 1;
1894 ti->discard_zeroes_data_unsupported = true;
1903 static int crypt_map(struct dm_target *ti, struct bio *bio)
1905 struct dm_crypt_io *io;
1906 struct crypt_config *cc = ti->private;
1909 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1910 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1911 * - for REQ_DISCARD caller must use flush if IO ordering matters
1913 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1914 bio->bi_bdev = cc->dev->bdev;
1915 if (bio_sectors(bio))
1916 bio->bi_iter.bi_sector = cc->start +
1917 dm_target_offset(ti, bio->bi_iter.bi_sector);
1918 return DM_MAPIO_REMAPPED;
1921 io = dm_per_bio_data(bio, cc->per_bio_data_size);
1922 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
1923 io->ctx.req = (struct ablkcipher_request *)(io + 1);
1925 if (bio_data_dir(io->base_bio) == READ) {
1926 if (kcryptd_io_read(io, GFP_NOWAIT))
1927 kcryptd_queue_read(io);
1929 kcryptd_queue_crypt(io);
1931 return DM_MAPIO_SUBMITTED;
1934 static void crypt_status(struct dm_target *ti, status_type_t type,
1935 unsigned status_flags, char *result, unsigned maxlen)
1937 struct crypt_config *cc = ti->private;
1939 int num_feature_args = 0;
1942 case STATUSTYPE_INFO:
1946 case STATUSTYPE_TABLE:
1947 DMEMIT("%s ", cc->cipher_string);
1949 if (cc->key_size > 0)
1950 for (i = 0; i < cc->key_size; i++)
1951 DMEMIT("%02x", cc->key[i]);
1955 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1956 cc->dev->name, (unsigned long long)cc->start);
1958 num_feature_args += !!ti->num_discard_bios;
1959 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1960 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1961 if (num_feature_args) {
1962 DMEMIT(" %d", num_feature_args);
1963 if (ti->num_discard_bios)
1964 DMEMIT(" allow_discards");
1965 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1966 DMEMIT(" same_cpu_crypt");
1967 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
1968 DMEMIT(" submit_from_crypt_cpus");
1975 static void crypt_postsuspend(struct dm_target *ti)
1977 struct crypt_config *cc = ti->private;
1979 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1982 static int crypt_preresume(struct dm_target *ti)
1984 struct crypt_config *cc = ti->private;
1986 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1987 DMERR("aborting resume - crypt key is not set.");
1994 static void crypt_resume(struct dm_target *ti)
1996 struct crypt_config *cc = ti->private;
1998 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2001 /* Message interface
2005 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
2007 struct crypt_config *cc = ti->private;
2013 if (!strcasecmp(argv[0], "key")) {
2014 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2015 DMWARN("not suspended during key manipulation.");
2018 if (argc == 3 && !strcasecmp(argv[1], "set")) {
2019 ret = crypt_set_key(cc, argv[2]);
2022 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2023 ret = cc->iv_gen_ops->init(cc);
2026 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
2027 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2028 ret = cc->iv_gen_ops->wipe(cc);
2032 return crypt_wipe_key(cc);
2037 DMWARN("unrecognised message received.");
2041 static int crypt_iterate_devices(struct dm_target *ti,
2042 iterate_devices_callout_fn fn, void *data)
2044 struct crypt_config *cc = ti->private;
2046 return fn(ti, cc->dev, cc->start, ti->len, data);
2049 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
2052 * Unfortunate constraint that is required to avoid the potential
2053 * for exceeding underlying device's max_segments limits -- due to
2054 * crypt_alloc_buffer() possibly allocating pages for the encryption
2055 * bio that are not as physically contiguous as the original bio.
2057 limits->max_segment_size = PAGE_SIZE;
2060 static struct target_type crypt_target = {
2062 .version = {1, 14, 1},
2063 .module = THIS_MODULE,
2067 .status = crypt_status,
2068 .postsuspend = crypt_postsuspend,
2069 .preresume = crypt_preresume,
2070 .resume = crypt_resume,
2071 .message = crypt_message,
2072 .iterate_devices = crypt_iterate_devices,
2073 .io_hints = crypt_io_hints,
2076 static int __init dm_crypt_init(void)
2080 r = dm_register_target(&crypt_target);
2082 DMERR("register failed %d", r);
2087 static void __exit dm_crypt_exit(void)
2089 dm_unregister_target(&crypt_target);
2092 module_init(dm_crypt_init);
2093 module_exit(dm_crypt_exit);
2095 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
2096 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2097 MODULE_LICENSE("GPL");