2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013-2017 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/key.h>
16 #include <linux/bio.h>
17 #include <linux/blkdev.h>
18 #include <linux/mempool.h>
19 #include <linux/slab.h>
20 #include <linux/crypto.h>
21 #include <linux/workqueue.h>
22 #include <linux/kthread.h>
23 #include <linux/backing-dev.h>
24 #include <linux/atomic.h>
25 #include <linux/scatterlist.h>
26 #include <linux/rbtree.h>
27 #include <linux/ctype.h>
29 #include <asm/unaligned.h>
30 #include <crypto/hash.h>
31 #include <crypto/md5.h>
32 #include <crypto/algapi.h>
33 #include <crypto/skcipher.h>
34 #include <crypto/aead.h>
35 #include <crypto/authenc.h>
36 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
37 #include <keys/user-type.h>
39 #include <linux/device-mapper.h>
41 #define DM_MSG_PREFIX "crypt"
44 * context holding the current state of a multi-part conversion
46 struct convert_context {
47 struct completion restart;
50 struct bvec_iter iter_in;
51 struct bvec_iter iter_out;
55 struct skcipher_request *req;
56 struct aead_request *req_aead;
62 * per bio private data
65 struct crypt_config *cc;
67 u8 *integrity_metadata;
68 bool integrity_metadata_from_pool;
69 struct work_struct work;
71 struct convert_context ctx;
77 struct rb_node rb_node;
78 } CRYPTO_MINALIGN_ATTR;
80 struct dm_crypt_request {
81 struct convert_context *ctx;
82 struct scatterlist sg_in[4];
83 struct scatterlist sg_out[4];
89 struct crypt_iv_operations {
90 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
92 void (*dtr)(struct crypt_config *cc);
93 int (*init)(struct crypt_config *cc);
94 int (*wipe)(struct crypt_config *cc);
95 int (*generator)(struct crypt_config *cc, u8 *iv,
96 struct dm_crypt_request *dmreq);
97 int (*post)(struct crypt_config *cc, u8 *iv,
98 struct dm_crypt_request *dmreq);
101 struct iv_essiv_private {
102 struct crypto_ahash *hash_tfm;
106 struct iv_benbi_private {
110 #define LMK_SEED_SIZE 64 /* hash + 0 */
111 struct iv_lmk_private {
112 struct crypto_shash *hash_tfm;
116 #define TCW_WHITENING_SIZE 16
117 struct iv_tcw_private {
118 struct crypto_shash *crc32_tfm;
124 * Crypt: maps a linear range of a block device
125 * and encrypts / decrypts at the same time.
127 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
128 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
131 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */
132 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */
136 * The fields in here must be read only after initialization.
138 struct crypt_config {
143 * pool for per bio private data, crypto requests,
144 * encryption requeusts/buffer pages and integrity tags
147 mempool_t *page_pool;
149 unsigned tag_pool_max_sectors;
151 struct percpu_counter n_allocated_pages;
154 struct mutex bio_alloc_lock;
156 struct workqueue_struct *io_queue;
157 struct workqueue_struct *crypt_queue;
159 struct task_struct *write_thread;
160 wait_queue_head_t write_thread_wait;
161 struct rb_root write_tree;
168 const struct crypt_iv_operations *iv_gen_ops;
170 struct iv_essiv_private essiv;
171 struct iv_benbi_private benbi;
172 struct iv_lmk_private lmk;
173 struct iv_tcw_private tcw;
176 unsigned int iv_size;
177 unsigned short int sector_size;
178 unsigned char sector_shift;
180 /* ESSIV: struct crypto_cipher *essiv_tfm */
183 struct crypto_skcipher **tfms;
184 struct crypto_aead **tfms_aead;
187 unsigned long cipher_flags;
190 * Layout of each crypto request:
192 * struct skcipher_request
195 * struct dm_crypt_request
199 * The padding is added so that dm_crypt_request and the IV are
202 unsigned int dmreq_start;
204 unsigned int per_bio_data_size;
207 unsigned int key_size;
208 unsigned int key_parts; /* independent parts in key buffer */
209 unsigned int key_extra_size; /* additional keys length */
210 unsigned int key_mac_size; /* MAC key size for authenc(...) */
212 unsigned int integrity_tag_size;
213 unsigned int integrity_iv_size;
214 unsigned int on_disk_tag_size;
216 u8 *authenc_key; /* space for keys in authenc() format (if used) */
221 #define MAX_TAG_SIZE 480
222 #define POOL_ENTRY_SIZE 512
224 static DEFINE_SPINLOCK(dm_crypt_clients_lock);
225 static unsigned dm_crypt_clients_n = 0;
226 static volatile unsigned long dm_crypt_pages_per_client;
227 #define DM_CRYPT_MEMORY_PERCENT 2
228 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_PAGES * 16)
230 static void clone_init(struct dm_crypt_io *, struct bio *);
231 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
232 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
233 struct scatterlist *sg);
236 * Use this to access cipher attributes that are independent of the key.
238 static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
240 return cc->cipher_tfm.tfms[0];
243 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
245 return cc->cipher_tfm.tfms_aead[0];
249 * Different IV generation algorithms:
251 * plain: the initial vector is the 32-bit little-endian version of the sector
252 * number, padded with zeros if necessary.
254 * plain64: the initial vector is the 64-bit little-endian version of the sector
255 * number, padded with zeros if necessary.
257 * plain64be: the initial vector is the 64-bit big-endian version of the sector
258 * number, padded with zeros if necessary.
260 * essiv: "encrypted sector|salt initial vector", the sector number is
261 * encrypted with the bulk cipher using a salt as key. The salt
262 * should be derived from the bulk cipher's key via hashing.
264 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
265 * (needed for LRW-32-AES and possible other narrow block modes)
267 * null: the initial vector is always zero. Provides compatibility with
268 * obsolete loop_fish2 devices. Do not use for new devices.
270 * lmk: Compatible implementation of the block chaining mode used
271 * by the Loop-AES block device encryption system
272 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
273 * It operates on full 512 byte sectors and uses CBC
274 * with an IV derived from the sector number, the data and
275 * optionally extra IV seed.
276 * This means that after decryption the first block
277 * of sector must be tweaked according to decrypted data.
278 * Loop-AES can use three encryption schemes:
279 * version 1: is plain aes-cbc mode
280 * version 2: uses 64 multikey scheme with lmk IV generator
281 * version 3: the same as version 2 with additional IV seed
282 * (it uses 65 keys, last key is used as IV seed)
284 * tcw: Compatible implementation of the block chaining mode used
285 * by the TrueCrypt device encryption system (prior to version 4.1).
286 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
287 * It operates on full 512 byte sectors and uses CBC
288 * with an IV derived from initial key and the sector number.
289 * In addition, whitening value is applied on every sector, whitening
290 * is calculated from initial key, sector number and mixed using CRC32.
291 * Note that this encryption scheme is vulnerable to watermarking attacks
292 * and should be used for old compatible containers access only.
294 * plumb: unimplemented, see:
295 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
298 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
299 struct dm_crypt_request *dmreq)
301 memset(iv, 0, cc->iv_size);
302 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
307 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
308 struct dm_crypt_request *dmreq)
310 memset(iv, 0, cc->iv_size);
311 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
316 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
317 struct dm_crypt_request *dmreq)
319 memset(iv, 0, cc->iv_size);
320 /* iv_size is at least of size u64; usually it is 16 bytes */
321 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
326 /* Initialise ESSIV - compute salt but no local memory allocations */
327 static int crypt_iv_essiv_init(struct crypt_config *cc)
329 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
330 AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
331 struct scatterlist sg;
332 struct crypto_cipher *essiv_tfm;
335 sg_init_one(&sg, cc->key, cc->key_size);
336 ahash_request_set_tfm(req, essiv->hash_tfm);
337 ahash_request_set_callback(req, 0, NULL, NULL);
338 ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
340 err = crypto_ahash_digest(req);
341 ahash_request_zero(req);
345 essiv_tfm = cc->iv_private;
347 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
348 crypto_ahash_digestsize(essiv->hash_tfm));
355 /* Wipe salt and reset key derived from volume key */
356 static int crypt_iv_essiv_wipe(struct crypt_config *cc)
358 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
359 unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
360 struct crypto_cipher *essiv_tfm;
363 memset(essiv->salt, 0, salt_size);
365 essiv_tfm = cc->iv_private;
366 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
373 /* Allocate the cipher for ESSIV */
374 static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
375 struct dm_target *ti,
377 unsigned int saltsize)
379 struct crypto_cipher *essiv_tfm;
382 /* Setup the essiv_tfm with the given salt */
383 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
384 if (IS_ERR(essiv_tfm)) {
385 ti->error = "Error allocating crypto tfm for ESSIV";
389 if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) {
390 ti->error = "Block size of ESSIV cipher does "
391 "not match IV size of block cipher";
392 crypto_free_cipher(essiv_tfm);
393 return ERR_PTR(-EINVAL);
396 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
398 ti->error = "Failed to set key for ESSIV cipher";
399 crypto_free_cipher(essiv_tfm);
406 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
408 struct crypto_cipher *essiv_tfm;
409 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
411 crypto_free_ahash(essiv->hash_tfm);
412 essiv->hash_tfm = NULL;
417 essiv_tfm = cc->iv_private;
420 crypto_free_cipher(essiv_tfm);
422 cc->iv_private = NULL;
425 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
428 struct crypto_cipher *essiv_tfm = NULL;
429 struct crypto_ahash *hash_tfm = NULL;
434 ti->error = "Digest algorithm missing for ESSIV mode";
438 /* Allocate hash algorithm */
439 hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
440 if (IS_ERR(hash_tfm)) {
441 ti->error = "Error initializing ESSIV hash";
442 err = PTR_ERR(hash_tfm);
446 salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
448 ti->error = "Error kmallocing salt storage in ESSIV";
453 cc->iv_gen_private.essiv.salt = salt;
454 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
456 essiv_tfm = alloc_essiv_cipher(cc, ti, salt,
457 crypto_ahash_digestsize(hash_tfm));
458 if (IS_ERR(essiv_tfm)) {
459 crypt_iv_essiv_dtr(cc);
460 return PTR_ERR(essiv_tfm);
462 cc->iv_private = essiv_tfm;
467 if (hash_tfm && !IS_ERR(hash_tfm))
468 crypto_free_ahash(hash_tfm);
473 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
474 struct dm_crypt_request *dmreq)
476 struct crypto_cipher *essiv_tfm = cc->iv_private;
478 memset(iv, 0, cc->iv_size);
479 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
480 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
485 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
491 if (test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags))
492 bs = crypto_aead_blocksize(any_tfm_aead(cc));
494 bs = crypto_skcipher_blocksize(any_tfm(cc));
497 /* we need to calculate how far we must shift the sector count
498 * to get the cipher block count, we use this shift in _gen */
500 if (1 << log != bs) {
501 ti->error = "cypher blocksize is not a power of 2";
506 ti->error = "cypher blocksize is > 512";
510 cc->iv_gen_private.benbi.shift = 9 - log;
515 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
519 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
520 struct dm_crypt_request *dmreq)
524 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
526 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
527 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
532 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
533 struct dm_crypt_request *dmreq)
535 memset(iv, 0, cc->iv_size);
540 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
542 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
544 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
545 crypto_free_shash(lmk->hash_tfm);
546 lmk->hash_tfm = NULL;
552 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
555 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
557 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
558 ti->error = "Unsupported sector size for LMK";
562 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
563 if (IS_ERR(lmk->hash_tfm)) {
564 ti->error = "Error initializing LMK hash";
565 return PTR_ERR(lmk->hash_tfm);
568 /* No seed in LMK version 2 */
569 if (cc->key_parts == cc->tfms_count) {
574 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
576 crypt_iv_lmk_dtr(cc);
577 ti->error = "Error kmallocing seed storage in LMK";
584 static int crypt_iv_lmk_init(struct crypt_config *cc)
586 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
587 int subkey_size = cc->key_size / cc->key_parts;
589 /* LMK seed is on the position of LMK_KEYS + 1 key */
591 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
592 crypto_shash_digestsize(lmk->hash_tfm));
597 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
599 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
602 memset(lmk->seed, 0, LMK_SEED_SIZE);
607 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
608 struct dm_crypt_request *dmreq,
611 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
612 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
613 struct md5_state md5state;
617 desc->tfm = lmk->hash_tfm;
620 r = crypto_shash_init(desc);
625 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
630 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
631 r = crypto_shash_update(desc, data + 16, 16 * 31);
635 /* Sector is cropped to 56 bits here */
636 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
637 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
638 buf[2] = cpu_to_le32(4024);
640 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
644 /* No MD5 padding here */
645 r = crypto_shash_export(desc, &md5state);
649 for (i = 0; i < MD5_HASH_WORDS; i++)
650 __cpu_to_le32s(&md5state.hash[i]);
651 memcpy(iv, &md5state.hash, cc->iv_size);
656 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
657 struct dm_crypt_request *dmreq)
659 struct scatterlist *sg;
663 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
664 sg = crypt_get_sg_data(cc, dmreq->sg_in);
665 src = kmap_atomic(sg_page(sg));
666 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
669 memset(iv, 0, cc->iv_size);
674 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
675 struct dm_crypt_request *dmreq)
677 struct scatterlist *sg;
681 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
684 sg = crypt_get_sg_data(cc, dmreq->sg_out);
685 dst = kmap_atomic(sg_page(sg));
686 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
688 /* Tweak the first block of plaintext sector */
690 crypto_xor(dst + sg->offset, iv, cc->iv_size);
696 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
698 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
700 kzfree(tcw->iv_seed);
702 kzfree(tcw->whitening);
703 tcw->whitening = NULL;
705 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
706 crypto_free_shash(tcw->crc32_tfm);
707 tcw->crc32_tfm = NULL;
710 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
713 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
715 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
716 ti->error = "Unsupported sector size for TCW";
720 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
721 ti->error = "Wrong key size for TCW";
725 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
726 if (IS_ERR(tcw->crc32_tfm)) {
727 ti->error = "Error initializing CRC32 in TCW";
728 return PTR_ERR(tcw->crc32_tfm);
731 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
732 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
733 if (!tcw->iv_seed || !tcw->whitening) {
734 crypt_iv_tcw_dtr(cc);
735 ti->error = "Error allocating seed storage in TCW";
742 static int crypt_iv_tcw_init(struct crypt_config *cc)
744 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
745 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
747 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
748 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
754 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
756 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
758 memset(tcw->iv_seed, 0, cc->iv_size);
759 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
764 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
765 struct dm_crypt_request *dmreq,
768 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
769 __le64 sector = cpu_to_le64(dmreq->iv_sector);
770 u8 buf[TCW_WHITENING_SIZE];
771 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
774 /* xor whitening with sector number */
775 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8);
776 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8);
778 /* calculate crc32 for every 32bit part and xor it */
779 desc->tfm = tcw->crc32_tfm;
781 for (i = 0; i < 4; i++) {
782 r = crypto_shash_init(desc);
785 r = crypto_shash_update(desc, &buf[i * 4], 4);
788 r = crypto_shash_final(desc, &buf[i * 4]);
792 crypto_xor(&buf[0], &buf[12], 4);
793 crypto_xor(&buf[4], &buf[8], 4);
795 /* apply whitening (8 bytes) to whole sector */
796 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
797 crypto_xor(data + i * 8, buf, 8);
799 memzero_explicit(buf, sizeof(buf));
803 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
804 struct dm_crypt_request *dmreq)
806 struct scatterlist *sg;
807 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
808 __le64 sector = cpu_to_le64(dmreq->iv_sector);
812 /* Remove whitening from ciphertext */
813 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
814 sg = crypt_get_sg_data(cc, dmreq->sg_in);
815 src = kmap_atomic(sg_page(sg));
816 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
821 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8);
823 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or,
829 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
830 struct dm_crypt_request *dmreq)
832 struct scatterlist *sg;
836 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
839 /* Apply whitening on ciphertext */
840 sg = crypt_get_sg_data(cc, dmreq->sg_out);
841 dst = kmap_atomic(sg_page(sg));
842 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
848 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
849 struct dm_crypt_request *dmreq)
851 /* Used only for writes, there must be an additional space to store IV */
852 get_random_bytes(iv, cc->iv_size);
856 static const struct crypt_iv_operations crypt_iv_plain_ops = {
857 .generator = crypt_iv_plain_gen
860 static const struct crypt_iv_operations crypt_iv_plain64_ops = {
861 .generator = crypt_iv_plain64_gen
864 static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
865 .generator = crypt_iv_plain64be_gen
868 static const struct crypt_iv_operations crypt_iv_essiv_ops = {
869 .ctr = crypt_iv_essiv_ctr,
870 .dtr = crypt_iv_essiv_dtr,
871 .init = crypt_iv_essiv_init,
872 .wipe = crypt_iv_essiv_wipe,
873 .generator = crypt_iv_essiv_gen
876 static const struct crypt_iv_operations crypt_iv_benbi_ops = {
877 .ctr = crypt_iv_benbi_ctr,
878 .dtr = crypt_iv_benbi_dtr,
879 .generator = crypt_iv_benbi_gen
882 static const struct crypt_iv_operations crypt_iv_null_ops = {
883 .generator = crypt_iv_null_gen
886 static const struct crypt_iv_operations crypt_iv_lmk_ops = {
887 .ctr = crypt_iv_lmk_ctr,
888 .dtr = crypt_iv_lmk_dtr,
889 .init = crypt_iv_lmk_init,
890 .wipe = crypt_iv_lmk_wipe,
891 .generator = crypt_iv_lmk_gen,
892 .post = crypt_iv_lmk_post
895 static const struct crypt_iv_operations crypt_iv_tcw_ops = {
896 .ctr = crypt_iv_tcw_ctr,
897 .dtr = crypt_iv_tcw_dtr,
898 .init = crypt_iv_tcw_init,
899 .wipe = crypt_iv_tcw_wipe,
900 .generator = crypt_iv_tcw_gen,
901 .post = crypt_iv_tcw_post
904 static struct crypt_iv_operations crypt_iv_random_ops = {
905 .generator = crypt_iv_random_gen
909 * Integrity extensions
911 static bool crypt_integrity_aead(struct crypt_config *cc)
913 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
916 static bool crypt_integrity_hmac(struct crypt_config *cc)
918 return crypt_integrity_aead(cc) && cc->key_mac_size;
921 /* Get sg containing data */
922 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
923 struct scatterlist *sg)
925 if (unlikely(crypt_integrity_aead(cc)))
931 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
933 struct bio_integrity_payload *bip;
934 unsigned int tag_len;
937 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
940 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
944 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
946 bip->bip_iter.bi_size = tag_len;
947 bip->bip_iter.bi_sector = io->cc->start + io->sector;
949 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
950 tag_len, offset_in_page(io->integrity_metadata));
951 if (unlikely(ret != tag_len))
957 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
959 #ifdef CONFIG_BLK_DEV_INTEGRITY
960 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
962 /* From now we require underlying device with our integrity profile */
963 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
964 ti->error = "Integrity profile not supported.";
968 if (bi->tag_size != cc->on_disk_tag_size ||
969 bi->tuple_size != cc->on_disk_tag_size) {
970 ti->error = "Integrity profile tag size mismatch.";
973 if (1 << bi->interval_exp != cc->sector_size) {
974 ti->error = "Integrity profile sector size mismatch.";
978 if (crypt_integrity_aead(cc)) {
979 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
980 DMINFO("Integrity AEAD, tag size %u, IV size %u.",
981 cc->integrity_tag_size, cc->integrity_iv_size);
983 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
984 ti->error = "Integrity AEAD auth tag size is not supported.";
987 } else if (cc->integrity_iv_size)
988 DMINFO("Additional per-sector space %u bytes for IV.",
989 cc->integrity_iv_size);
991 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
992 ti->error = "Not enough space for integrity tag in the profile.";
998 ti->error = "Integrity profile not supported.";
1003 static void crypt_convert_init(struct crypt_config *cc,
1004 struct convert_context *ctx,
1005 struct bio *bio_out, struct bio *bio_in,
1008 ctx->bio_in = bio_in;
1009 ctx->bio_out = bio_out;
1011 ctx->iter_in = bio_in->bi_iter;
1013 ctx->iter_out = bio_out->bi_iter;
1014 ctx->cc_sector = sector + cc->iv_offset;
1015 init_completion(&ctx->restart);
1018 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1021 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1024 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1026 return (void *)((char *)dmreq - cc->dmreq_start);
1029 static u8 *iv_of_dmreq(struct crypt_config *cc,
1030 struct dm_crypt_request *dmreq)
1032 if (crypt_integrity_aead(cc))
1033 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1034 crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1036 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1037 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1040 static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1041 struct dm_crypt_request *dmreq)
1043 return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1046 static uint64_t *org_sector_of_dmreq(struct crypt_config *cc,
1047 struct dm_crypt_request *dmreq)
1049 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1050 return (uint64_t*) ptr;
1053 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1054 struct dm_crypt_request *dmreq)
1056 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1057 cc->iv_size + sizeof(uint64_t);
1058 return (unsigned int*)ptr;
1061 static void *tag_from_dmreq(struct crypt_config *cc,
1062 struct dm_crypt_request *dmreq)
1064 struct convert_context *ctx = dmreq->ctx;
1065 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1067 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1068 cc->on_disk_tag_size];
1071 static void *iv_tag_from_dmreq(struct crypt_config *cc,
1072 struct dm_crypt_request *dmreq)
1074 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1077 static int crypt_convert_block_aead(struct crypt_config *cc,
1078 struct convert_context *ctx,
1079 struct aead_request *req,
1080 unsigned int tag_offset)
1082 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1083 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1084 struct dm_crypt_request *dmreq;
1085 u8 *iv, *org_iv, *tag_iv, *tag;
1089 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1091 /* Reject unexpected unaligned bio. */
1092 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1095 dmreq = dmreq_of_req(cc, req);
1096 dmreq->iv_sector = ctx->cc_sector;
1097 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1098 dmreq->iv_sector >>= cc->sector_shift;
1101 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1103 sector = org_sector_of_dmreq(cc, dmreq);
1104 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1106 iv = iv_of_dmreq(cc, dmreq);
1107 org_iv = org_iv_of_dmreq(cc, dmreq);
1108 tag = tag_from_dmreq(cc, dmreq);
1109 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1112 * |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1113 * | (authenticated) | (auth+encryption) | |
1114 * | sector_LE | IV | sector in/out | tag in/out |
1116 sg_init_table(dmreq->sg_in, 4);
1117 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1118 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1119 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1120 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1122 sg_init_table(dmreq->sg_out, 4);
1123 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1124 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1125 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1126 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1128 if (cc->iv_gen_ops) {
1129 /* For READs use IV stored in integrity metadata */
1130 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1131 memcpy(org_iv, tag_iv, cc->iv_size);
1133 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1136 /* Store generated IV in integrity metadata */
1137 if (cc->integrity_iv_size)
1138 memcpy(tag_iv, org_iv, cc->iv_size);
1140 /* Working copy of IV, to be modified in crypto API */
1141 memcpy(iv, org_iv, cc->iv_size);
1144 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1145 if (bio_data_dir(ctx->bio_in) == WRITE) {
1146 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1147 cc->sector_size, iv);
1148 r = crypto_aead_encrypt(req);
1149 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1150 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1151 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1153 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1154 cc->sector_size + cc->integrity_tag_size, iv);
1155 r = crypto_aead_decrypt(req);
1159 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1160 (unsigned long long)le64_to_cpu(*sector));
1162 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1163 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1165 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1166 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1171 static int crypt_convert_block_skcipher(struct crypt_config *cc,
1172 struct convert_context *ctx,
1173 struct skcipher_request *req,
1174 unsigned int tag_offset)
1176 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1177 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1178 struct scatterlist *sg_in, *sg_out;
1179 struct dm_crypt_request *dmreq;
1180 u8 *iv, *org_iv, *tag_iv;
1184 /* Reject unexpected unaligned bio. */
1185 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1188 dmreq = dmreq_of_req(cc, req);
1189 dmreq->iv_sector = ctx->cc_sector;
1190 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1191 dmreq->iv_sector >>= cc->sector_shift;
1194 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1196 iv = iv_of_dmreq(cc, dmreq);
1197 org_iv = org_iv_of_dmreq(cc, dmreq);
1198 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1200 sector = org_sector_of_dmreq(cc, dmreq);
1201 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1203 /* For skcipher we use only the first sg item */
1204 sg_in = &dmreq->sg_in[0];
1205 sg_out = &dmreq->sg_out[0];
1207 sg_init_table(sg_in, 1);
1208 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1210 sg_init_table(sg_out, 1);
1211 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1213 if (cc->iv_gen_ops) {
1214 /* For READs use IV stored in integrity metadata */
1215 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1216 memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1218 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1221 /* Store generated IV in integrity metadata */
1222 if (cc->integrity_iv_size)
1223 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1225 /* Working copy of IV, to be modified in crypto API */
1226 memcpy(iv, org_iv, cc->iv_size);
1229 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1231 if (bio_data_dir(ctx->bio_in) == WRITE)
1232 r = crypto_skcipher_encrypt(req);
1234 r = crypto_skcipher_decrypt(req);
1236 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1237 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1239 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1240 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1245 static void kcryptd_async_done(struct crypto_async_request *async_req,
1248 static void crypt_alloc_req_skcipher(struct crypt_config *cc,
1249 struct convert_context *ctx)
1251 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1254 ctx->r.req = mempool_alloc(cc->req_pool, GFP_NOIO);
1256 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1259 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1260 * requests if driver request queue is full.
1262 skcipher_request_set_callback(ctx->r.req,
1263 CRYPTO_TFM_REQ_MAY_BACKLOG,
1264 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1267 static void crypt_alloc_req_aead(struct crypt_config *cc,
1268 struct convert_context *ctx)
1270 if (!ctx->r.req_aead)
1271 ctx->r.req_aead = mempool_alloc(cc->req_pool, GFP_NOIO);
1273 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1276 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1277 * requests if driver request queue is full.
1279 aead_request_set_callback(ctx->r.req_aead,
1280 CRYPTO_TFM_REQ_MAY_BACKLOG,
1281 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1284 static void crypt_alloc_req(struct crypt_config *cc,
1285 struct convert_context *ctx)
1287 if (crypt_integrity_aead(cc))
1288 crypt_alloc_req_aead(cc, ctx);
1290 crypt_alloc_req_skcipher(cc, ctx);
1293 static void crypt_free_req_skcipher(struct crypt_config *cc,
1294 struct skcipher_request *req, struct bio *base_bio)
1296 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1298 if ((struct skcipher_request *)(io + 1) != req)
1299 mempool_free(req, cc->req_pool);
1302 static void crypt_free_req_aead(struct crypt_config *cc,
1303 struct aead_request *req, struct bio *base_bio)
1305 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1307 if ((struct aead_request *)(io + 1) != req)
1308 mempool_free(req, cc->req_pool);
1311 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1313 if (crypt_integrity_aead(cc))
1314 crypt_free_req_aead(cc, req, base_bio);
1316 crypt_free_req_skcipher(cc, req, base_bio);
1320 * Encrypt / decrypt data from one bio to another one (can be the same one)
1322 static blk_status_t crypt_convert(struct crypt_config *cc,
1323 struct convert_context *ctx)
1325 unsigned int tag_offset = 0;
1326 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1329 atomic_set(&ctx->cc_pending, 1);
1331 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1333 crypt_alloc_req(cc, ctx);
1334 atomic_inc(&ctx->cc_pending);
1336 if (crypt_integrity_aead(cc))
1337 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1339 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1343 * The request was queued by a crypto driver
1344 * but the driver request queue is full, let's wait.
1347 wait_for_completion(&ctx->restart);
1348 reinit_completion(&ctx->restart);
1351 * The request is queued and processed asynchronously,
1352 * completion function kcryptd_async_done() will be called.
1356 ctx->cc_sector += sector_step;
1360 * The request was already processed (synchronously).
1363 atomic_dec(&ctx->cc_pending);
1364 ctx->cc_sector += sector_step;
1369 * There was a data integrity error.
1372 atomic_dec(&ctx->cc_pending);
1373 return BLK_STS_PROTECTION;
1375 * There was an error while processing the request.
1378 atomic_dec(&ctx->cc_pending);
1379 return BLK_STS_IOERR;
1386 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1389 * Generate a new unfragmented bio with the given size
1390 * This should never violate the device limitations (but only because
1391 * max_segment_size is being constrained to PAGE_SIZE).
1393 * This function may be called concurrently. If we allocate from the mempool
1394 * concurrently, there is a possibility of deadlock. For example, if we have
1395 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1396 * the mempool concurrently, it may deadlock in a situation where both processes
1397 * have allocated 128 pages and the mempool is exhausted.
1399 * In order to avoid this scenario we allocate the pages under a mutex.
1401 * In order to not degrade performance with excessive locking, we try
1402 * non-blocking allocations without a mutex first but on failure we fallback
1403 * to blocking allocations with a mutex.
1405 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1407 struct crypt_config *cc = io->cc;
1409 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1410 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1411 unsigned i, len, remaining_size;
1415 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1416 mutex_lock(&cc->bio_alloc_lock);
1418 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1422 clone_init(io, clone);
1424 remaining_size = size;
1426 for (i = 0; i < nr_iovecs; i++) {
1427 page = mempool_alloc(cc->page_pool, gfp_mask);
1429 crypt_free_buffer_pages(cc, clone);
1431 gfp_mask |= __GFP_DIRECT_RECLAIM;
1435 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1437 bio_add_page(clone, page, len, 0);
1439 remaining_size -= len;
1442 /* Allocate space for integrity tags */
1443 if (dm_crypt_integrity_io_alloc(io, clone)) {
1444 crypt_free_buffer_pages(cc, clone);
1449 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1450 mutex_unlock(&cc->bio_alloc_lock);
1455 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1460 bio_for_each_segment_all(bv, clone, i) {
1461 BUG_ON(!bv->bv_page);
1462 mempool_free(bv->bv_page, cc->page_pool);
1467 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1468 struct bio *bio, sector_t sector)
1472 io->sector = sector;
1474 io->ctx.r.req = NULL;
1475 io->integrity_metadata = NULL;
1476 io->integrity_metadata_from_pool = false;
1477 atomic_set(&io->io_pending, 0);
1480 static void crypt_inc_pending(struct dm_crypt_io *io)
1482 atomic_inc(&io->io_pending);
1486 * One of the bios was finished. Check for completion of
1487 * the whole request and correctly clean up the buffer.
1489 static void crypt_dec_pending(struct dm_crypt_io *io)
1491 struct crypt_config *cc = io->cc;
1492 struct bio *base_bio = io->base_bio;
1493 blk_status_t error = io->error;
1495 if (!atomic_dec_and_test(&io->io_pending))
1499 crypt_free_req(cc, io->ctx.r.req, base_bio);
1501 if (unlikely(io->integrity_metadata_from_pool))
1502 mempool_free(io->integrity_metadata, io->cc->tag_pool);
1504 kfree(io->integrity_metadata);
1506 base_bio->bi_status = error;
1507 bio_endio(base_bio);
1511 * kcryptd/kcryptd_io:
1513 * Needed because it would be very unwise to do decryption in an
1514 * interrupt context.
1516 * kcryptd performs the actual encryption or decryption.
1518 * kcryptd_io performs the IO submission.
1520 * They must be separated as otherwise the final stages could be
1521 * starved by new requests which can block in the first stages due
1522 * to memory allocation.
1524 * The work is done per CPU global for all dm-crypt instances.
1525 * They should not depend on each other and do not block.
1527 static void crypt_endio(struct bio *clone)
1529 struct dm_crypt_io *io = clone->bi_private;
1530 struct crypt_config *cc = io->cc;
1531 unsigned rw = bio_data_dir(clone);
1535 * free the processed pages
1538 crypt_free_buffer_pages(cc, clone);
1540 error = clone->bi_status;
1543 if (rw == READ && !error) {
1544 kcryptd_queue_crypt(io);
1548 if (unlikely(error))
1551 crypt_dec_pending(io);
1554 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1556 struct crypt_config *cc = io->cc;
1558 clone->bi_private = io;
1559 clone->bi_end_io = crypt_endio;
1560 bio_set_dev(clone, cc->dev->bdev);
1561 clone->bi_opf = io->base_bio->bi_opf;
1564 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1566 struct crypt_config *cc = io->cc;
1570 * We need the original biovec array in order to decrypt
1571 * the whole bio data *afterwards* -- thanks to immutable
1572 * biovecs we don't need to worry about the block layer
1573 * modifying the biovec array; so leverage bio_clone_fast().
1575 clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1579 crypt_inc_pending(io);
1581 clone_init(io, clone);
1582 clone->bi_iter.bi_sector = cc->start + io->sector;
1584 if (dm_crypt_integrity_io_alloc(io, clone)) {
1585 crypt_dec_pending(io);
1590 generic_make_request(clone);
1594 static void kcryptd_io_read_work(struct work_struct *work)
1596 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1598 crypt_inc_pending(io);
1599 if (kcryptd_io_read(io, GFP_NOIO))
1600 io->error = BLK_STS_RESOURCE;
1601 crypt_dec_pending(io);
1604 static void kcryptd_queue_read(struct dm_crypt_io *io)
1606 struct crypt_config *cc = io->cc;
1608 INIT_WORK(&io->work, kcryptd_io_read_work);
1609 queue_work(cc->io_queue, &io->work);
1612 static void kcryptd_io_write(struct dm_crypt_io *io)
1614 struct bio *clone = io->ctx.bio_out;
1616 generic_make_request(clone);
1619 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1621 static int dmcrypt_write(void *data)
1623 struct crypt_config *cc = data;
1624 struct dm_crypt_io *io;
1627 struct rb_root write_tree;
1628 struct blk_plug plug;
1630 DECLARE_WAITQUEUE(wait, current);
1632 spin_lock_irq(&cc->write_thread_wait.lock);
1635 if (!RB_EMPTY_ROOT(&cc->write_tree))
1638 set_current_state(TASK_INTERRUPTIBLE);
1639 __add_wait_queue(&cc->write_thread_wait, &wait);
1641 spin_unlock_irq(&cc->write_thread_wait.lock);
1643 if (unlikely(kthread_should_stop())) {
1644 set_current_state(TASK_RUNNING);
1645 remove_wait_queue(&cc->write_thread_wait, &wait);
1651 set_current_state(TASK_RUNNING);
1652 spin_lock_irq(&cc->write_thread_wait.lock);
1653 __remove_wait_queue(&cc->write_thread_wait, &wait);
1654 goto continue_locked;
1657 write_tree = cc->write_tree;
1658 cc->write_tree = RB_ROOT;
1659 spin_unlock_irq(&cc->write_thread_wait.lock);
1661 BUG_ON(rb_parent(write_tree.rb_node));
1664 * Note: we cannot walk the tree here with rb_next because
1665 * the structures may be freed when kcryptd_io_write is called.
1667 blk_start_plug(&plug);
1669 io = crypt_io_from_node(rb_first(&write_tree));
1670 rb_erase(&io->rb_node, &write_tree);
1671 kcryptd_io_write(io);
1673 } while (!RB_EMPTY_ROOT(&write_tree));
1674 blk_finish_plug(&plug);
1679 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1681 struct bio *clone = io->ctx.bio_out;
1682 struct crypt_config *cc = io->cc;
1683 unsigned long flags;
1685 struct rb_node **rbp, *parent;
1687 if (unlikely(io->error)) {
1688 crypt_free_buffer_pages(cc, clone);
1690 crypt_dec_pending(io);
1694 /* crypt_convert should have filled the clone bio */
1695 BUG_ON(io->ctx.iter_out.bi_size);
1697 clone->bi_iter.bi_sector = cc->start + io->sector;
1699 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1700 generic_make_request(clone);
1704 spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1705 rbp = &cc->write_tree.rb_node;
1707 sector = io->sector;
1710 if (sector < crypt_io_from_node(parent)->sector)
1711 rbp = &(*rbp)->rb_left;
1713 rbp = &(*rbp)->rb_right;
1715 rb_link_node(&io->rb_node, parent, rbp);
1716 rb_insert_color(&io->rb_node, &cc->write_tree);
1718 wake_up_locked(&cc->write_thread_wait);
1719 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1722 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1724 struct crypt_config *cc = io->cc;
1727 sector_t sector = io->sector;
1731 * Prevent io from disappearing until this function completes.
1733 crypt_inc_pending(io);
1734 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1736 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1737 if (unlikely(!clone)) {
1738 io->error = BLK_STS_IOERR;
1742 io->ctx.bio_out = clone;
1743 io->ctx.iter_out = clone->bi_iter;
1745 sector += bio_sectors(clone);
1747 crypt_inc_pending(io);
1748 r = crypt_convert(cc, &io->ctx);
1751 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1753 /* Encryption was already finished, submit io now */
1754 if (crypt_finished) {
1755 kcryptd_crypt_write_io_submit(io, 0);
1756 io->sector = sector;
1760 crypt_dec_pending(io);
1763 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1765 crypt_dec_pending(io);
1768 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1770 struct crypt_config *cc = io->cc;
1773 crypt_inc_pending(io);
1775 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1778 r = crypt_convert(cc, &io->ctx);
1782 if (atomic_dec_and_test(&io->ctx.cc_pending))
1783 kcryptd_crypt_read_done(io);
1785 crypt_dec_pending(io);
1788 static void kcryptd_async_done(struct crypto_async_request *async_req,
1791 struct dm_crypt_request *dmreq = async_req->data;
1792 struct convert_context *ctx = dmreq->ctx;
1793 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1794 struct crypt_config *cc = io->cc;
1797 * A request from crypto driver backlog is going to be processed now,
1798 * finish the completion and continue in crypt_convert().
1799 * (Callback will be called for the second time for this request.)
1801 if (error == -EINPROGRESS) {
1802 complete(&ctx->restart);
1806 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1807 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
1809 if (error == -EBADMSG) {
1810 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1811 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
1812 io->error = BLK_STS_PROTECTION;
1813 } else if (error < 0)
1814 io->error = BLK_STS_IOERR;
1816 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1818 if (!atomic_dec_and_test(&ctx->cc_pending))
1821 if (bio_data_dir(io->base_bio) == READ)
1822 kcryptd_crypt_read_done(io);
1824 kcryptd_crypt_write_io_submit(io, 1);
1827 static void kcryptd_crypt(struct work_struct *work)
1829 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1831 if (bio_data_dir(io->base_bio) == READ)
1832 kcryptd_crypt_read_convert(io);
1834 kcryptd_crypt_write_convert(io);
1837 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1839 struct crypt_config *cc = io->cc;
1841 INIT_WORK(&io->work, kcryptd_crypt);
1842 queue_work(cc->crypt_queue, &io->work);
1845 static void crypt_free_tfms_aead(struct crypt_config *cc)
1847 if (!cc->cipher_tfm.tfms_aead)
1850 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1851 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
1852 cc->cipher_tfm.tfms_aead[0] = NULL;
1855 kfree(cc->cipher_tfm.tfms_aead);
1856 cc->cipher_tfm.tfms_aead = NULL;
1859 static void crypt_free_tfms_skcipher(struct crypt_config *cc)
1863 if (!cc->cipher_tfm.tfms)
1866 for (i = 0; i < cc->tfms_count; i++)
1867 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
1868 crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
1869 cc->cipher_tfm.tfms[i] = NULL;
1872 kfree(cc->cipher_tfm.tfms);
1873 cc->cipher_tfm.tfms = NULL;
1876 static void crypt_free_tfms(struct crypt_config *cc)
1878 if (crypt_integrity_aead(cc))
1879 crypt_free_tfms_aead(cc);
1881 crypt_free_tfms_skcipher(cc);
1884 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
1889 cc->cipher_tfm.tfms = kzalloc(cc->tfms_count *
1890 sizeof(struct crypto_skcipher *), GFP_KERNEL);
1891 if (!cc->cipher_tfm.tfms)
1894 for (i = 0; i < cc->tfms_count; i++) {
1895 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1896 if (IS_ERR(cc->cipher_tfm.tfms[i])) {
1897 err = PTR_ERR(cc->cipher_tfm.tfms[i]);
1898 crypt_free_tfms(cc);
1906 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
1910 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
1911 if (!cc->cipher_tfm.tfms)
1914 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0);
1915 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1916 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
1917 crypt_free_tfms(cc);
1924 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1926 if (crypt_integrity_aead(cc))
1927 return crypt_alloc_tfms_aead(cc, ciphermode);
1929 return crypt_alloc_tfms_skcipher(cc, ciphermode);
1932 static unsigned crypt_subkey_size(struct crypt_config *cc)
1934 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1937 static unsigned crypt_authenckey_size(struct crypt_config *cc)
1939 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
1943 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
1944 * the key must be for some reason in special format.
1945 * This funcion converts cc->key to this special format.
1947 static void crypt_copy_authenckey(char *p, const void *key,
1948 unsigned enckeylen, unsigned authkeylen)
1950 struct crypto_authenc_key_param *param;
1953 rta = (struct rtattr *)p;
1954 param = RTA_DATA(rta);
1955 param->enckeylen = cpu_to_be32(enckeylen);
1956 rta->rta_len = RTA_LENGTH(sizeof(*param));
1957 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1958 p += RTA_SPACE(sizeof(*param));
1959 memcpy(p, key + enckeylen, authkeylen);
1961 memcpy(p, key, enckeylen);
1964 static int crypt_setkey(struct crypt_config *cc)
1966 unsigned subkey_size;
1969 /* Ignore extra keys (which are used for IV etc) */
1970 subkey_size = crypt_subkey_size(cc);
1972 if (crypt_integrity_hmac(cc)) {
1973 if (subkey_size < cc->key_mac_size)
1976 crypt_copy_authenckey(cc->authenc_key, cc->key,
1977 subkey_size - cc->key_mac_size,
1981 for (i = 0; i < cc->tfms_count; i++) {
1982 if (crypt_integrity_hmac(cc))
1983 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1984 cc->authenc_key, crypt_authenckey_size(cc));
1985 else if (crypt_integrity_aead(cc))
1986 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1987 cc->key + (i * subkey_size),
1990 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
1991 cc->key + (i * subkey_size),
1997 if (crypt_integrity_hmac(cc))
1998 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
2005 static bool contains_whitespace(const char *str)
2008 if (isspace(*str++))
2013 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2015 char *new_key_string, *key_desc;
2018 const struct user_key_payload *ukp;
2021 * Reject key_string with whitespace. dm core currently lacks code for
2022 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2024 if (contains_whitespace(key_string)) {
2025 DMERR("whitespace chars not allowed in key string");
2029 /* look for next ':' separating key_type from key_description */
2030 key_desc = strpbrk(key_string, ":");
2031 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2034 if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
2035 strncmp(key_string, "user:", key_desc - key_string + 1))
2038 new_key_string = kstrdup(key_string, GFP_KERNEL);
2039 if (!new_key_string)
2042 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
2043 key_desc + 1, NULL);
2045 kzfree(new_key_string);
2046 return PTR_ERR(key);
2049 down_read(&key->sem);
2051 ukp = user_key_payload_locked(key);
2055 kzfree(new_key_string);
2056 return -EKEYREVOKED;
2059 if (cc->key_size != ukp->datalen) {
2062 kzfree(new_key_string);
2066 memcpy(cc->key, ukp->data, cc->key_size);
2071 /* clear the flag since following operations may invalidate previously valid key */
2072 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2074 ret = crypt_setkey(cc);
2077 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2078 kzfree(cc->key_string);
2079 cc->key_string = new_key_string;
2081 kzfree(new_key_string);
2086 static int get_key_size(char **key_string)
2091 if (*key_string[0] != ':')
2092 return strlen(*key_string) >> 1;
2094 /* look for next ':' in key string */
2095 colon = strpbrk(*key_string + 1, ":");
2099 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2102 *key_string = colon;
2104 /* remaining key string should be :<logon|user>:<key_desc> */
2111 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2116 static int get_key_size(char **key_string)
2118 return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
2123 static int crypt_set_key(struct crypt_config *cc, char *key)
2126 int key_string_len = strlen(key);
2128 /* Hyphen (which gives a key_size of zero) means there is no key. */
2129 if (!cc->key_size && strcmp(key, "-"))
2132 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2133 if (key[0] == ':') {
2134 r = crypt_set_keyring_key(cc, key + 1);
2138 /* clear the flag since following operations may invalidate previously valid key */
2139 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2141 /* wipe references to any kernel keyring key */
2142 kzfree(cc->key_string);
2143 cc->key_string = NULL;
2145 /* Decode key from its hex representation. */
2146 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2149 r = crypt_setkey(cc);
2151 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2154 /* Hex key string not needed after here, so wipe it. */
2155 memset(key, '0', key_string_len);
2160 static int crypt_wipe_key(struct crypt_config *cc)
2164 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2165 get_random_bytes(&cc->key, cc->key_size);
2166 kzfree(cc->key_string);
2167 cc->key_string = NULL;
2168 r = crypt_setkey(cc);
2169 memset(&cc->key, 0, cc->key_size * sizeof(u8));
2174 static void crypt_calculate_pages_per_client(void)
2176 unsigned long pages = (totalram_pages - totalhigh_pages) * DM_CRYPT_MEMORY_PERCENT / 100;
2178 if (!dm_crypt_clients_n)
2181 pages /= dm_crypt_clients_n;
2182 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2183 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2184 dm_crypt_pages_per_client = pages;
2187 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2189 struct crypt_config *cc = pool_data;
2193 * Note, percpu_counter_read_positive() may over (and under) estimate
2194 * the current usage by at most (batch - 1) * num_online_cpus() pages,
2195 * but avoids potential spinlock contention of an exact result.
2197 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
2198 likely(gfp_mask & __GFP_NORETRY))
2201 page = alloc_page(gfp_mask);
2202 if (likely(page != NULL))
2203 percpu_counter_add(&cc->n_allocated_pages, 1);
2208 static void crypt_page_free(void *page, void *pool_data)
2210 struct crypt_config *cc = pool_data;
2213 percpu_counter_sub(&cc->n_allocated_pages, 1);
2216 static void crypt_dtr(struct dm_target *ti)
2218 struct crypt_config *cc = ti->private;
2225 if (cc->write_thread)
2226 kthread_stop(cc->write_thread);
2229 destroy_workqueue(cc->io_queue);
2230 if (cc->crypt_queue)
2231 destroy_workqueue(cc->crypt_queue);
2233 crypt_free_tfms(cc);
2236 bioset_free(cc->bs);
2238 mempool_destroy(cc->page_pool);
2239 mempool_destroy(cc->req_pool);
2240 mempool_destroy(cc->tag_pool);
2243 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2244 percpu_counter_destroy(&cc->n_allocated_pages);
2246 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2247 cc->iv_gen_ops->dtr(cc);
2250 dm_put_device(ti, cc->dev);
2253 kzfree(cc->cipher_string);
2254 kzfree(cc->key_string);
2255 kzfree(cc->cipher_auth);
2256 kzfree(cc->authenc_key);
2258 /* Must zero key material before freeing */
2261 spin_lock(&dm_crypt_clients_lock);
2262 WARN_ON(!dm_crypt_clients_n);
2263 dm_crypt_clients_n--;
2264 crypt_calculate_pages_per_client();
2265 spin_unlock(&dm_crypt_clients_lock);
2268 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2270 struct crypt_config *cc = ti->private;
2272 if (crypt_integrity_aead(cc))
2273 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2275 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2278 /* at least a 64 bit sector number should fit in our buffer */
2279 cc->iv_size = max(cc->iv_size,
2280 (unsigned int)(sizeof(u64) / sizeof(u8)));
2282 DMWARN("Selected cipher does not support IVs");
2286 /* Choose ivmode, see comments at iv code. */
2288 cc->iv_gen_ops = NULL;
2289 else if (strcmp(ivmode, "plain") == 0)
2290 cc->iv_gen_ops = &crypt_iv_plain_ops;
2291 else if (strcmp(ivmode, "plain64") == 0)
2292 cc->iv_gen_ops = &crypt_iv_plain64_ops;
2293 else if (strcmp(ivmode, "plain64be") == 0)
2294 cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2295 else if (strcmp(ivmode, "essiv") == 0)
2296 cc->iv_gen_ops = &crypt_iv_essiv_ops;
2297 else if (strcmp(ivmode, "benbi") == 0)
2298 cc->iv_gen_ops = &crypt_iv_benbi_ops;
2299 else if (strcmp(ivmode, "null") == 0)
2300 cc->iv_gen_ops = &crypt_iv_null_ops;
2301 else if (strcmp(ivmode, "lmk") == 0) {
2302 cc->iv_gen_ops = &crypt_iv_lmk_ops;
2304 * Version 2 and 3 is recognised according
2305 * to length of provided multi-key string.
2306 * If present (version 3), last key is used as IV seed.
2307 * All keys (including IV seed) are always the same size.
2309 if (cc->key_size % cc->key_parts) {
2311 cc->key_extra_size = cc->key_size / cc->key_parts;
2313 } else if (strcmp(ivmode, "tcw") == 0) {
2314 cc->iv_gen_ops = &crypt_iv_tcw_ops;
2315 cc->key_parts += 2; /* IV + whitening */
2316 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2317 } else if (strcmp(ivmode, "random") == 0) {
2318 cc->iv_gen_ops = &crypt_iv_random_ops;
2319 /* Need storage space in integrity fields. */
2320 cc->integrity_iv_size = cc->iv_size;
2322 ti->error = "Invalid IV mode";
2330 * Workaround to parse cipher algorithm from crypto API spec.
2331 * The cc->cipher is currently used only in ESSIV.
2332 * This should be probably done by crypto-api calls (once available...)
2334 static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)
2336 const char *alg_name = NULL;
2339 if (crypt_integrity_aead(cc)) {
2340 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));
2343 if (crypt_integrity_hmac(cc)) {
2344 alg_name = strchr(alg_name, ',');
2350 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));
2355 start = strchr(alg_name, '(');
2356 end = strchr(alg_name, ')');
2358 if (!start && !end) {
2359 cc->cipher = kstrdup(alg_name, GFP_KERNEL);
2360 return cc->cipher ? 0 : -ENOMEM;
2363 if (!start || !end || ++start >= end)
2366 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);
2370 strncpy(cc->cipher, start, end - start);
2376 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2377 * The HMAC is needed to calculate tag size (HMAC digest size).
2378 * This should be probably done by crypto-api calls (once available...)
2380 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2382 char *start, *end, *mac_alg = NULL;
2383 struct crypto_ahash *mac;
2385 if (!strstarts(cipher_api, "authenc("))
2388 start = strchr(cipher_api, '(');
2389 end = strchr(cipher_api, ',');
2390 if (!start || !end || ++start > end)
2393 mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2396 strncpy(mac_alg, start, end - start);
2398 mac = crypto_alloc_ahash(mac_alg, 0, 0);
2402 return PTR_ERR(mac);
2404 cc->key_mac_size = crypto_ahash_digestsize(mac);
2405 crypto_free_ahash(mac);
2407 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2408 if (!cc->authenc_key)
2414 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2415 char **ivmode, char **ivopts)
2417 struct crypt_config *cc = ti->private;
2418 char *tmp, *cipher_api;
2424 * New format (capi: prefix)
2425 * capi:cipher_api_spec-iv:ivopts
2427 tmp = &cipher_in[strlen("capi:")];
2429 /* Separate IV options if present, it can contain another '-' in hash name */
2430 *ivopts = strrchr(tmp, ':');
2436 *ivmode = strrchr(tmp, '-');
2441 /* The rest is crypto API spec */
2444 if (*ivmode && !strcmp(*ivmode, "lmk"))
2445 cc->tfms_count = 64;
2447 cc->key_parts = cc->tfms_count;
2449 /* Allocate cipher */
2450 ret = crypt_alloc_tfms(cc, cipher_api);
2452 ti->error = "Error allocating crypto tfm";
2456 /* Alloc AEAD, can be used only in new format. */
2457 if (crypt_integrity_aead(cc)) {
2458 ret = crypt_ctr_auth_cipher(cc, cipher_api);
2460 ti->error = "Invalid AEAD cipher spec";
2463 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2465 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2467 ret = crypt_ctr_blkdev_cipher(cc);
2469 ti->error = "Cannot allocate cipher string";
2476 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2477 char **ivmode, char **ivopts)
2479 struct crypt_config *cc = ti->private;
2480 char *tmp, *cipher, *chainmode, *keycount;
2481 char *cipher_api = NULL;
2485 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2486 ti->error = "Bad cipher specification";
2491 * Legacy dm-crypt cipher specification
2492 * cipher[:keycount]-mode-iv:ivopts
2495 keycount = strsep(&tmp, "-");
2496 cipher = strsep(&keycount, ":");
2500 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2501 !is_power_of_2(cc->tfms_count)) {
2502 ti->error = "Bad cipher key count specification";
2505 cc->key_parts = cc->tfms_count;
2507 cc->cipher = kstrdup(cipher, GFP_KERNEL);
2511 chainmode = strsep(&tmp, "-");
2512 *ivmode = strsep(&tmp, ":");
2516 * For compatibility with the original dm-crypt mapping format, if
2517 * only the cipher name is supplied, use cbc-plain.
2519 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2524 if (strcmp(chainmode, "ecb") && !*ivmode) {
2525 ti->error = "IV mechanism required";
2529 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2533 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2534 "%s(%s)", chainmode, cipher);
2540 /* Allocate cipher */
2541 ret = crypt_alloc_tfms(cc, cipher_api);
2543 ti->error = "Error allocating crypto tfm";
2551 ti->error = "Cannot allocate cipher strings";
2555 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
2557 struct crypt_config *cc = ti->private;
2558 char *ivmode = NULL, *ivopts = NULL;
2561 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
2562 if (!cc->cipher_string) {
2563 ti->error = "Cannot allocate cipher strings";
2567 if (strstarts(cipher_in, "capi:"))
2568 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
2570 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
2575 ret = crypt_ctr_ivmode(ti, ivmode);
2579 /* Initialize and set key */
2580 ret = crypt_set_key(cc, key);
2582 ti->error = "Error decoding and setting key";
2587 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
2588 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
2590 ti->error = "Error creating IV";
2595 /* Initialize IV (set keys for ESSIV etc) */
2596 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
2597 ret = cc->iv_gen_ops->init(cc);
2599 ti->error = "Error initialising IV";
2604 /* wipe the kernel key payload copy */
2606 memset(cc->key, 0, cc->key_size * sizeof(u8));
2611 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
2613 struct crypt_config *cc = ti->private;
2614 struct dm_arg_set as;
2615 static const struct dm_arg _args[] = {
2616 {0, 6, "Invalid number of feature args"},
2618 unsigned int opt_params, val;
2619 const char *opt_string, *sval;
2623 /* Optional parameters */
2627 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
2631 while (opt_params--) {
2632 opt_string = dm_shift_arg(&as);
2634 ti->error = "Not enough feature arguments";
2638 if (!strcasecmp(opt_string, "allow_discards"))
2639 ti->num_discard_bios = 1;
2641 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
2642 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2644 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
2645 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2646 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
2647 if (val == 0 || val > MAX_TAG_SIZE) {
2648 ti->error = "Invalid integrity arguments";
2651 cc->on_disk_tag_size = val;
2652 sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
2653 if (!strcasecmp(sval, "aead")) {
2654 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
2655 } else if (strcasecmp(sval, "none")) {
2656 ti->error = "Unknown integrity profile";
2660 cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
2661 if (!cc->cipher_auth)
2663 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
2664 if (cc->sector_size < (1 << SECTOR_SHIFT) ||
2665 cc->sector_size > 4096 ||
2666 (cc->sector_size & (cc->sector_size - 1))) {
2667 ti->error = "Invalid feature value for sector_size";
2670 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
2671 ti->error = "Device size is not multiple of sector_size feature";
2674 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
2675 } else if (!strcasecmp(opt_string, "iv_large_sectors"))
2676 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2678 ti->error = "Invalid feature arguments";
2687 * Construct an encryption mapping:
2688 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
2690 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2692 struct crypt_config *cc;
2694 unsigned int align_mask;
2695 unsigned long long tmpll;
2697 size_t iv_size_padding, additional_req_size;
2701 ti->error = "Not enough arguments";
2705 key_size = get_key_size(&argv[1]);
2707 ti->error = "Cannot parse key size";
2711 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
2713 ti->error = "Cannot allocate encryption context";
2716 cc->key_size = key_size;
2717 cc->sector_size = (1 << SECTOR_SHIFT);
2718 cc->sector_shift = 0;
2722 spin_lock(&dm_crypt_clients_lock);
2723 dm_crypt_clients_n++;
2724 crypt_calculate_pages_per_client();
2725 spin_unlock(&dm_crypt_clients_lock);
2727 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
2731 /* Optional parameters need to be read before cipher constructor */
2733 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
2738 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
2742 if (crypt_integrity_aead(cc)) {
2743 cc->dmreq_start = sizeof(struct aead_request);
2744 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
2745 align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
2747 cc->dmreq_start = sizeof(struct skcipher_request);
2748 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
2749 align_mask = crypto_skcipher_alignmask(any_tfm(cc));
2751 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
2753 if (align_mask < CRYPTO_MINALIGN) {
2754 /* Allocate the padding exactly */
2755 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
2759 * If the cipher requires greater alignment than kmalloc
2760 * alignment, we don't know the exact position of the
2761 * initialization vector. We must assume worst case.
2763 iv_size_padding = align_mask;
2768 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */
2769 additional_req_size = sizeof(struct dm_crypt_request) +
2770 iv_size_padding + cc->iv_size +
2773 sizeof(unsigned int);
2775 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + additional_req_size);
2776 if (!cc->req_pool) {
2777 ti->error = "Cannot allocate crypt request mempool";
2781 cc->per_bio_data_size = ti->per_io_data_size =
2782 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
2783 ARCH_KMALLOC_MINALIGN);
2785 cc->page_pool = mempool_create(BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc);
2786 if (!cc->page_pool) {
2787 ti->error = "Cannot allocate page mempool";
2791 cc->bs = bioset_create(MIN_IOS, 0, (BIOSET_NEED_BVECS |
2792 BIOSET_NEED_RESCUER));
2794 ti->error = "Cannot allocate crypt bioset";
2798 mutex_init(&cc->bio_alloc_lock);
2801 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
2802 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
2803 ti->error = "Invalid iv_offset sector";
2806 cc->iv_offset = tmpll;
2808 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
2810 ti->error = "Device lookup failed";
2815 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
2816 ti->error = "Invalid device sector";
2821 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
2822 ret = crypt_integrity_ctr(cc, ti);
2826 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
2827 if (!cc->tag_pool_max_sectors)
2828 cc->tag_pool_max_sectors = 1;
2830 cc->tag_pool = mempool_create_kmalloc_pool(MIN_IOS,
2831 cc->tag_pool_max_sectors * cc->on_disk_tag_size);
2832 if (!cc->tag_pool) {
2833 ti->error = "Cannot allocate integrity tags mempool";
2838 cc->tag_pool_max_sectors <<= cc->sector_shift;
2842 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2843 if (!cc->io_queue) {
2844 ti->error = "Couldn't create kcryptd io queue";
2848 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2849 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2851 cc->crypt_queue = alloc_workqueue("kcryptd",
2852 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2854 if (!cc->crypt_queue) {
2855 ti->error = "Couldn't create kcryptd queue";
2859 init_waitqueue_head(&cc->write_thread_wait);
2860 cc->write_tree = RB_ROOT;
2862 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
2863 if (IS_ERR(cc->write_thread)) {
2864 ret = PTR_ERR(cc->write_thread);
2865 cc->write_thread = NULL;
2866 ti->error = "Couldn't spawn write thread";
2869 wake_up_process(cc->write_thread);
2871 ti->num_flush_bios = 1;
2880 static int crypt_map(struct dm_target *ti, struct bio *bio)
2882 struct dm_crypt_io *io;
2883 struct crypt_config *cc = ti->private;
2886 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2887 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
2888 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
2890 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
2891 bio_op(bio) == REQ_OP_DISCARD)) {
2892 bio_set_dev(bio, cc->dev->bdev);
2893 if (bio_sectors(bio))
2894 bio->bi_iter.bi_sector = cc->start +
2895 dm_target_offset(ti, bio->bi_iter.bi_sector);
2896 return DM_MAPIO_REMAPPED;
2900 * Check if bio is too large, split as needed.
2902 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2903 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
2904 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2907 * Ensure that bio is a multiple of internal sector encryption size
2908 * and is aligned to this size as defined in IO hints.
2910 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
2911 return DM_MAPIO_KILL;
2913 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
2914 return DM_MAPIO_KILL;
2916 io = dm_per_bio_data(bio, cc->per_bio_data_size);
2917 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
2919 if (cc->on_disk_tag_size) {
2920 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
2922 if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
2923 unlikely(!(io->integrity_metadata = kmalloc(tag_len,
2924 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
2925 if (bio_sectors(bio) > cc->tag_pool_max_sectors)
2926 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
2927 io->integrity_metadata = mempool_alloc(cc->tag_pool, GFP_NOIO);
2928 io->integrity_metadata_from_pool = true;
2932 if (crypt_integrity_aead(cc))
2933 io->ctx.r.req_aead = (struct aead_request *)(io + 1);
2935 io->ctx.r.req = (struct skcipher_request *)(io + 1);
2937 if (bio_data_dir(io->base_bio) == READ) {
2938 if (kcryptd_io_read(io, GFP_NOWAIT))
2939 kcryptd_queue_read(io);
2941 kcryptd_queue_crypt(io);
2943 return DM_MAPIO_SUBMITTED;
2946 static char hex2asc(unsigned char c)
2948 return c + '0' + ((unsigned)(9 - c) >> 4 & 0x27);
2951 static void crypt_status(struct dm_target *ti, status_type_t type,
2952 unsigned status_flags, char *result, unsigned maxlen)
2954 struct crypt_config *cc = ti->private;
2956 int num_feature_args = 0;
2959 case STATUSTYPE_INFO:
2963 case STATUSTYPE_TABLE:
2964 DMEMIT("%s ", cc->cipher_string);
2966 if (cc->key_size > 0) {
2968 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2970 for (i = 0; i < cc->key_size; i++) {
2971 DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
2972 hex2asc(cc->key[i] & 0xf));
2978 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2979 cc->dev->name, (unsigned long long)cc->start);
2981 num_feature_args += !!ti->num_discard_bios;
2982 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2983 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2984 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
2985 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2986 if (cc->on_disk_tag_size)
2988 if (num_feature_args) {
2989 DMEMIT(" %d", num_feature_args);
2990 if (ti->num_discard_bios)
2991 DMEMIT(" allow_discards");
2992 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2993 DMEMIT(" same_cpu_crypt");
2994 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2995 DMEMIT(" submit_from_crypt_cpus");
2996 if (cc->on_disk_tag_size)
2997 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
2998 if (cc->sector_size != (1 << SECTOR_SHIFT))
2999 DMEMIT(" sector_size:%d", cc->sector_size);
3000 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
3001 DMEMIT(" iv_large_sectors");
3008 static void crypt_postsuspend(struct dm_target *ti)
3010 struct crypt_config *cc = ti->private;
3012 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3015 static int crypt_preresume(struct dm_target *ti)
3017 struct crypt_config *cc = ti->private;
3019 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3020 DMERR("aborting resume - crypt key is not set.");
3027 static void crypt_resume(struct dm_target *ti)
3029 struct crypt_config *cc = ti->private;
3031 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3034 /* Message interface
3038 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
3040 struct crypt_config *cc = ti->private;
3041 int key_size, ret = -EINVAL;
3046 if (!strcasecmp(argv[0], "key")) {
3047 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3048 DMWARN("not suspended during key manipulation.");
3051 if (argc == 3 && !strcasecmp(argv[1], "set")) {
3052 /* The key size may not be changed. */
3053 key_size = get_key_size(&argv[2]);
3054 if (key_size < 0 || cc->key_size != key_size) {
3055 memset(argv[2], '0', strlen(argv[2]));
3059 ret = crypt_set_key(cc, argv[2]);
3062 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3063 ret = cc->iv_gen_ops->init(cc);
3064 /* wipe the kernel key payload copy */
3066 memset(cc->key, 0, cc->key_size * sizeof(u8));
3069 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
3070 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
3071 ret = cc->iv_gen_ops->wipe(cc);
3075 return crypt_wipe_key(cc);
3080 DMWARN("unrecognised message received.");
3084 static int crypt_iterate_devices(struct dm_target *ti,
3085 iterate_devices_callout_fn fn, void *data)
3087 struct crypt_config *cc = ti->private;
3089 return fn(ti, cc->dev, cc->start, ti->len, data);
3092 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3094 struct crypt_config *cc = ti->private;
3097 * Unfortunate constraint that is required to avoid the potential
3098 * for exceeding underlying device's max_segments limits -- due to
3099 * crypt_alloc_buffer() possibly allocating pages for the encryption
3100 * bio that are not as physically contiguous as the original bio.
3102 limits->max_segment_size = PAGE_SIZE;
3104 limits->logical_block_size =
3105 max_t(unsigned, limits->logical_block_size, cc->sector_size);
3106 limits->physical_block_size =
3107 max_t(unsigned, limits->physical_block_size, cc->sector_size);
3108 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
3111 static struct target_type crypt_target = {
3113 .version = {1, 18, 1},
3114 .module = THIS_MODULE,
3118 .status = crypt_status,
3119 .postsuspend = crypt_postsuspend,
3120 .preresume = crypt_preresume,
3121 .resume = crypt_resume,
3122 .message = crypt_message,
3123 .iterate_devices = crypt_iterate_devices,
3124 .io_hints = crypt_io_hints,
3127 static int __init dm_crypt_init(void)
3131 r = dm_register_target(&crypt_target);
3133 DMERR("register failed %d", r);
3138 static void __exit dm_crypt_exit(void)
3140 dm_unregister_target(&crypt_target);
3143 module_init(dm_crypt_init);
3144 module_exit(dm_crypt_exit);
3146 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3147 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3148 MODULE_LICENSE("GPL");