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_shash *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 {
142 struct percpu_counter n_allocated_pages;
144 struct workqueue_struct *io_queue;
145 struct workqueue_struct *crypt_queue;
147 spinlock_t write_thread_lock;
148 struct task_struct *write_thread;
149 struct rb_root write_tree;
156 const struct crypt_iv_operations *iv_gen_ops;
158 struct iv_essiv_private essiv;
159 struct iv_benbi_private benbi;
160 struct iv_lmk_private lmk;
161 struct iv_tcw_private tcw;
164 unsigned int iv_size;
165 unsigned short int sector_size;
166 unsigned char sector_shift;
168 /* ESSIV: struct crypto_cipher *essiv_tfm */
171 struct crypto_skcipher **tfms;
172 struct crypto_aead **tfms_aead;
175 unsigned long cipher_flags;
178 * Layout of each crypto request:
180 * struct skcipher_request
183 * struct dm_crypt_request
187 * The padding is added so that dm_crypt_request and the IV are
190 unsigned int dmreq_start;
192 unsigned int per_bio_data_size;
195 unsigned int key_size;
196 unsigned int key_parts; /* independent parts in key buffer */
197 unsigned int key_extra_size; /* additional keys length */
198 unsigned int key_mac_size; /* MAC key size for authenc(...) */
200 unsigned int integrity_tag_size;
201 unsigned int integrity_iv_size;
202 unsigned int on_disk_tag_size;
205 * pool for per bio private data, crypto requests,
206 * encryption requeusts/buffer pages and integrity tags
208 unsigned tag_pool_max_sectors;
214 struct mutex bio_alloc_lock;
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 SHASH_DESC_ON_STACK(desc, essiv->hash_tfm);
331 struct crypto_cipher *essiv_tfm;
334 desc->tfm = essiv->hash_tfm;
337 err = crypto_shash_digest(desc, cc->key, cc->key_size, essiv->salt);
338 shash_desc_zero(desc);
342 essiv_tfm = cc->iv_private;
344 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
345 crypto_shash_digestsize(essiv->hash_tfm));
352 /* Wipe salt and reset key derived from volume key */
353 static int crypt_iv_essiv_wipe(struct crypt_config *cc)
355 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
356 unsigned salt_size = crypto_shash_digestsize(essiv->hash_tfm);
357 struct crypto_cipher *essiv_tfm;
360 memset(essiv->salt, 0, salt_size);
362 essiv_tfm = cc->iv_private;
363 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
370 /* Allocate the cipher for ESSIV */
371 static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
372 struct dm_target *ti,
374 unsigned int saltsize)
376 struct crypto_cipher *essiv_tfm;
379 /* Setup the essiv_tfm with the given salt */
380 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
381 if (IS_ERR(essiv_tfm)) {
382 ti->error = "Error allocating crypto tfm for ESSIV";
386 if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) {
387 ti->error = "Block size of ESSIV cipher does "
388 "not match IV size of block cipher";
389 crypto_free_cipher(essiv_tfm);
390 return ERR_PTR(-EINVAL);
393 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
395 ti->error = "Failed to set key for ESSIV cipher";
396 crypto_free_cipher(essiv_tfm);
403 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
405 struct crypto_cipher *essiv_tfm;
406 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
408 crypto_free_shash(essiv->hash_tfm);
409 essiv->hash_tfm = NULL;
414 essiv_tfm = cc->iv_private;
417 crypto_free_cipher(essiv_tfm);
419 cc->iv_private = NULL;
422 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
425 struct crypto_cipher *essiv_tfm = NULL;
426 struct crypto_shash *hash_tfm = NULL;
431 ti->error = "Digest algorithm missing for ESSIV mode";
435 /* Allocate hash algorithm */
436 hash_tfm = crypto_alloc_shash(opts, 0, 0);
437 if (IS_ERR(hash_tfm)) {
438 ti->error = "Error initializing ESSIV hash";
439 err = PTR_ERR(hash_tfm);
443 salt = kzalloc(crypto_shash_digestsize(hash_tfm), GFP_KERNEL);
445 ti->error = "Error kmallocing salt storage in ESSIV";
450 cc->iv_gen_private.essiv.salt = salt;
451 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
453 essiv_tfm = alloc_essiv_cipher(cc, ti, salt,
454 crypto_shash_digestsize(hash_tfm));
455 if (IS_ERR(essiv_tfm)) {
456 crypt_iv_essiv_dtr(cc);
457 return PTR_ERR(essiv_tfm);
459 cc->iv_private = essiv_tfm;
464 if (hash_tfm && !IS_ERR(hash_tfm))
465 crypto_free_shash(hash_tfm);
470 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
471 struct dm_crypt_request *dmreq)
473 struct crypto_cipher *essiv_tfm = cc->iv_private;
475 memset(iv, 0, cc->iv_size);
476 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
477 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
482 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
488 if (test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags))
489 bs = crypto_aead_blocksize(any_tfm_aead(cc));
491 bs = crypto_skcipher_blocksize(any_tfm(cc));
494 /* we need to calculate how far we must shift the sector count
495 * to get the cipher block count, we use this shift in _gen */
497 if (1 << log != bs) {
498 ti->error = "cypher blocksize is not a power of 2";
503 ti->error = "cypher blocksize is > 512";
507 cc->iv_gen_private.benbi.shift = 9 - log;
512 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
516 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
517 struct dm_crypt_request *dmreq)
521 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
523 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
524 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
529 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
530 struct dm_crypt_request *dmreq)
532 memset(iv, 0, cc->iv_size);
537 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
539 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
541 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
542 crypto_free_shash(lmk->hash_tfm);
543 lmk->hash_tfm = NULL;
549 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
552 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
554 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
555 ti->error = "Unsupported sector size for LMK";
559 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
560 if (IS_ERR(lmk->hash_tfm)) {
561 ti->error = "Error initializing LMK hash";
562 return PTR_ERR(lmk->hash_tfm);
565 /* No seed in LMK version 2 */
566 if (cc->key_parts == cc->tfms_count) {
571 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
573 crypt_iv_lmk_dtr(cc);
574 ti->error = "Error kmallocing seed storage in LMK";
581 static int crypt_iv_lmk_init(struct crypt_config *cc)
583 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
584 int subkey_size = cc->key_size / cc->key_parts;
586 /* LMK seed is on the position of LMK_KEYS + 1 key */
588 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
589 crypto_shash_digestsize(lmk->hash_tfm));
594 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
596 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
599 memset(lmk->seed, 0, LMK_SEED_SIZE);
604 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
605 struct dm_crypt_request *dmreq,
608 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
609 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
610 struct md5_state md5state;
614 desc->tfm = lmk->hash_tfm;
617 r = crypto_shash_init(desc);
622 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
627 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
628 r = crypto_shash_update(desc, data + 16, 16 * 31);
632 /* Sector is cropped to 56 bits here */
633 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
634 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
635 buf[2] = cpu_to_le32(4024);
637 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
641 /* No MD5 padding here */
642 r = crypto_shash_export(desc, &md5state);
646 for (i = 0; i < MD5_HASH_WORDS; i++)
647 __cpu_to_le32s(&md5state.hash[i]);
648 memcpy(iv, &md5state.hash, cc->iv_size);
653 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
654 struct dm_crypt_request *dmreq)
656 struct scatterlist *sg;
660 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
661 sg = crypt_get_sg_data(cc, dmreq->sg_in);
662 src = kmap_atomic(sg_page(sg));
663 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
666 memset(iv, 0, cc->iv_size);
671 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
672 struct dm_crypt_request *dmreq)
674 struct scatterlist *sg;
678 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
681 sg = crypt_get_sg_data(cc, dmreq->sg_out);
682 dst = kmap_atomic(sg_page(sg));
683 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
685 /* Tweak the first block of plaintext sector */
687 crypto_xor(dst + sg->offset, iv, cc->iv_size);
693 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
695 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
697 kzfree(tcw->iv_seed);
699 kzfree(tcw->whitening);
700 tcw->whitening = NULL;
702 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
703 crypto_free_shash(tcw->crc32_tfm);
704 tcw->crc32_tfm = NULL;
707 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
710 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
712 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
713 ti->error = "Unsupported sector size for TCW";
717 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
718 ti->error = "Wrong key size for TCW";
722 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
723 if (IS_ERR(tcw->crc32_tfm)) {
724 ti->error = "Error initializing CRC32 in TCW";
725 return PTR_ERR(tcw->crc32_tfm);
728 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
729 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
730 if (!tcw->iv_seed || !tcw->whitening) {
731 crypt_iv_tcw_dtr(cc);
732 ti->error = "Error allocating seed storage in TCW";
739 static int crypt_iv_tcw_init(struct crypt_config *cc)
741 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
742 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
744 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
745 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
751 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
753 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
755 memset(tcw->iv_seed, 0, cc->iv_size);
756 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
761 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
762 struct dm_crypt_request *dmreq,
765 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
766 __le64 sector = cpu_to_le64(dmreq->iv_sector);
767 u8 buf[TCW_WHITENING_SIZE];
768 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
771 /* xor whitening with sector number */
772 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8);
773 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8);
775 /* calculate crc32 for every 32bit part and xor it */
776 desc->tfm = tcw->crc32_tfm;
778 for (i = 0; i < 4; i++) {
779 r = crypto_shash_init(desc);
782 r = crypto_shash_update(desc, &buf[i * 4], 4);
785 r = crypto_shash_final(desc, &buf[i * 4]);
789 crypto_xor(&buf[0], &buf[12], 4);
790 crypto_xor(&buf[4], &buf[8], 4);
792 /* apply whitening (8 bytes) to whole sector */
793 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
794 crypto_xor(data + i * 8, buf, 8);
796 memzero_explicit(buf, sizeof(buf));
800 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
801 struct dm_crypt_request *dmreq)
803 struct scatterlist *sg;
804 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
805 __le64 sector = cpu_to_le64(dmreq->iv_sector);
809 /* Remove whitening from ciphertext */
810 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
811 sg = crypt_get_sg_data(cc, dmreq->sg_in);
812 src = kmap_atomic(sg_page(sg));
813 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
818 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8);
820 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or,
826 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
827 struct dm_crypt_request *dmreq)
829 struct scatterlist *sg;
833 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
836 /* Apply whitening on ciphertext */
837 sg = crypt_get_sg_data(cc, dmreq->sg_out);
838 dst = kmap_atomic(sg_page(sg));
839 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
845 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
846 struct dm_crypt_request *dmreq)
848 /* Used only for writes, there must be an additional space to store IV */
849 get_random_bytes(iv, cc->iv_size);
853 static const struct crypt_iv_operations crypt_iv_plain_ops = {
854 .generator = crypt_iv_plain_gen
857 static const struct crypt_iv_operations crypt_iv_plain64_ops = {
858 .generator = crypt_iv_plain64_gen
861 static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
862 .generator = crypt_iv_plain64be_gen
865 static const struct crypt_iv_operations crypt_iv_essiv_ops = {
866 .ctr = crypt_iv_essiv_ctr,
867 .dtr = crypt_iv_essiv_dtr,
868 .init = crypt_iv_essiv_init,
869 .wipe = crypt_iv_essiv_wipe,
870 .generator = crypt_iv_essiv_gen
873 static const struct crypt_iv_operations crypt_iv_benbi_ops = {
874 .ctr = crypt_iv_benbi_ctr,
875 .dtr = crypt_iv_benbi_dtr,
876 .generator = crypt_iv_benbi_gen
879 static const struct crypt_iv_operations crypt_iv_null_ops = {
880 .generator = crypt_iv_null_gen
883 static const struct crypt_iv_operations crypt_iv_lmk_ops = {
884 .ctr = crypt_iv_lmk_ctr,
885 .dtr = crypt_iv_lmk_dtr,
886 .init = crypt_iv_lmk_init,
887 .wipe = crypt_iv_lmk_wipe,
888 .generator = crypt_iv_lmk_gen,
889 .post = crypt_iv_lmk_post
892 static const struct crypt_iv_operations crypt_iv_tcw_ops = {
893 .ctr = crypt_iv_tcw_ctr,
894 .dtr = crypt_iv_tcw_dtr,
895 .init = crypt_iv_tcw_init,
896 .wipe = crypt_iv_tcw_wipe,
897 .generator = crypt_iv_tcw_gen,
898 .post = crypt_iv_tcw_post
901 static struct crypt_iv_operations crypt_iv_random_ops = {
902 .generator = crypt_iv_random_gen
906 * Integrity extensions
908 static bool crypt_integrity_aead(struct crypt_config *cc)
910 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
913 static bool crypt_integrity_hmac(struct crypt_config *cc)
915 return crypt_integrity_aead(cc) && cc->key_mac_size;
918 /* Get sg containing data */
919 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
920 struct scatterlist *sg)
922 if (unlikely(crypt_integrity_aead(cc)))
928 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
930 struct bio_integrity_payload *bip;
931 unsigned int tag_len;
934 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
937 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
941 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
943 bip->bip_iter.bi_size = tag_len;
944 bip->bip_iter.bi_sector = io->cc->start + io->sector;
946 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
947 tag_len, offset_in_page(io->integrity_metadata));
948 if (unlikely(ret != tag_len))
954 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
956 #ifdef CONFIG_BLK_DEV_INTEGRITY
957 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
958 struct mapped_device *md = dm_table_get_md(ti->table);
960 /* From now we require underlying device with our integrity profile */
961 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
962 ti->error = "Integrity profile not supported.";
966 if (bi->tag_size != cc->on_disk_tag_size ||
967 bi->tuple_size != cc->on_disk_tag_size) {
968 ti->error = "Integrity profile tag size mismatch.";
971 if (1 << bi->interval_exp != cc->sector_size) {
972 ti->error = "Integrity profile sector size mismatch.";
976 if (crypt_integrity_aead(cc)) {
977 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
978 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
979 cc->integrity_tag_size, cc->integrity_iv_size);
981 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
982 ti->error = "Integrity AEAD auth tag size is not supported.";
985 } else if (cc->integrity_iv_size)
986 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
987 cc->integrity_iv_size);
989 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
990 ti->error = "Not enough space for integrity tag in the profile.";
996 ti->error = "Integrity profile not supported.";
1001 static void crypt_convert_init(struct crypt_config *cc,
1002 struct convert_context *ctx,
1003 struct bio *bio_out, struct bio *bio_in,
1006 ctx->bio_in = bio_in;
1007 ctx->bio_out = bio_out;
1009 ctx->iter_in = bio_in->bi_iter;
1011 ctx->iter_out = bio_out->bi_iter;
1012 ctx->cc_sector = sector + cc->iv_offset;
1013 init_completion(&ctx->restart);
1016 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1019 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1022 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1024 return (void *)((char *)dmreq - cc->dmreq_start);
1027 static u8 *iv_of_dmreq(struct crypt_config *cc,
1028 struct dm_crypt_request *dmreq)
1030 if (crypt_integrity_aead(cc))
1031 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1032 crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1034 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1035 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1038 static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1039 struct dm_crypt_request *dmreq)
1041 return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1044 static uint64_t *org_sector_of_dmreq(struct crypt_config *cc,
1045 struct dm_crypt_request *dmreq)
1047 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1048 return (uint64_t*) ptr;
1051 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1052 struct dm_crypt_request *dmreq)
1054 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1055 cc->iv_size + sizeof(uint64_t);
1056 return (unsigned int*)ptr;
1059 static void *tag_from_dmreq(struct crypt_config *cc,
1060 struct dm_crypt_request *dmreq)
1062 struct convert_context *ctx = dmreq->ctx;
1063 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1065 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1066 cc->on_disk_tag_size];
1069 static void *iv_tag_from_dmreq(struct crypt_config *cc,
1070 struct dm_crypt_request *dmreq)
1072 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1075 static int crypt_convert_block_aead(struct crypt_config *cc,
1076 struct convert_context *ctx,
1077 struct aead_request *req,
1078 unsigned int tag_offset)
1080 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1081 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1082 struct dm_crypt_request *dmreq;
1083 u8 *iv, *org_iv, *tag_iv, *tag;
1087 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1089 /* Reject unexpected unaligned bio. */
1090 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1093 dmreq = dmreq_of_req(cc, req);
1094 dmreq->iv_sector = ctx->cc_sector;
1095 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1096 dmreq->iv_sector >>= cc->sector_shift;
1099 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1101 sector = org_sector_of_dmreq(cc, dmreq);
1102 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1104 iv = iv_of_dmreq(cc, dmreq);
1105 org_iv = org_iv_of_dmreq(cc, dmreq);
1106 tag = tag_from_dmreq(cc, dmreq);
1107 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1110 * |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1111 * | (authenticated) | (auth+encryption) | |
1112 * | sector_LE | IV | sector in/out | tag in/out |
1114 sg_init_table(dmreq->sg_in, 4);
1115 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1116 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1117 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1118 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1120 sg_init_table(dmreq->sg_out, 4);
1121 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1122 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1123 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1124 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1126 if (cc->iv_gen_ops) {
1127 /* For READs use IV stored in integrity metadata */
1128 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1129 memcpy(org_iv, tag_iv, cc->iv_size);
1131 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1134 /* Store generated IV in integrity metadata */
1135 if (cc->integrity_iv_size)
1136 memcpy(tag_iv, org_iv, cc->iv_size);
1138 /* Working copy of IV, to be modified in crypto API */
1139 memcpy(iv, org_iv, cc->iv_size);
1142 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1143 if (bio_data_dir(ctx->bio_in) == WRITE) {
1144 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1145 cc->sector_size, iv);
1146 r = crypto_aead_encrypt(req);
1147 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1148 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1149 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1151 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1152 cc->sector_size + cc->integrity_tag_size, iv);
1153 r = crypto_aead_decrypt(req);
1157 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1158 (unsigned long long)le64_to_cpu(*sector));
1160 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1161 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1163 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1164 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1169 static int crypt_convert_block_skcipher(struct crypt_config *cc,
1170 struct convert_context *ctx,
1171 struct skcipher_request *req,
1172 unsigned int tag_offset)
1174 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1175 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1176 struct scatterlist *sg_in, *sg_out;
1177 struct dm_crypt_request *dmreq;
1178 u8 *iv, *org_iv, *tag_iv;
1182 /* Reject unexpected unaligned bio. */
1183 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1186 dmreq = dmreq_of_req(cc, req);
1187 dmreq->iv_sector = ctx->cc_sector;
1188 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1189 dmreq->iv_sector >>= cc->sector_shift;
1192 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1194 iv = iv_of_dmreq(cc, dmreq);
1195 org_iv = org_iv_of_dmreq(cc, dmreq);
1196 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1198 sector = org_sector_of_dmreq(cc, dmreq);
1199 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1201 /* For skcipher we use only the first sg item */
1202 sg_in = &dmreq->sg_in[0];
1203 sg_out = &dmreq->sg_out[0];
1205 sg_init_table(sg_in, 1);
1206 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1208 sg_init_table(sg_out, 1);
1209 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1211 if (cc->iv_gen_ops) {
1212 /* For READs use IV stored in integrity metadata */
1213 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1214 memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1216 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1219 /* Store generated IV in integrity metadata */
1220 if (cc->integrity_iv_size)
1221 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1223 /* Working copy of IV, to be modified in crypto API */
1224 memcpy(iv, org_iv, cc->iv_size);
1227 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1229 if (bio_data_dir(ctx->bio_in) == WRITE)
1230 r = crypto_skcipher_encrypt(req);
1232 r = crypto_skcipher_decrypt(req);
1234 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1235 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1237 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1238 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1243 static void kcryptd_async_done(struct crypto_async_request *async_req,
1246 static void crypt_alloc_req_skcipher(struct crypt_config *cc,
1247 struct convert_context *ctx)
1249 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1252 ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO);
1254 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1257 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1258 * requests if driver request queue is full.
1260 skcipher_request_set_callback(ctx->r.req,
1261 CRYPTO_TFM_REQ_MAY_BACKLOG,
1262 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1265 static void crypt_alloc_req_aead(struct crypt_config *cc,
1266 struct convert_context *ctx)
1268 if (!ctx->r.req_aead)
1269 ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO);
1271 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1274 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1275 * requests if driver request queue is full.
1277 aead_request_set_callback(ctx->r.req_aead,
1278 CRYPTO_TFM_REQ_MAY_BACKLOG,
1279 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1282 static void crypt_alloc_req(struct crypt_config *cc,
1283 struct convert_context *ctx)
1285 if (crypt_integrity_aead(cc))
1286 crypt_alloc_req_aead(cc, ctx);
1288 crypt_alloc_req_skcipher(cc, ctx);
1291 static void crypt_free_req_skcipher(struct crypt_config *cc,
1292 struct skcipher_request *req, struct bio *base_bio)
1294 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1296 if ((struct skcipher_request *)(io + 1) != req)
1297 mempool_free(req, &cc->req_pool);
1300 static void crypt_free_req_aead(struct crypt_config *cc,
1301 struct aead_request *req, struct bio *base_bio)
1303 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1305 if ((struct aead_request *)(io + 1) != req)
1306 mempool_free(req, &cc->req_pool);
1309 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1311 if (crypt_integrity_aead(cc))
1312 crypt_free_req_aead(cc, req, base_bio);
1314 crypt_free_req_skcipher(cc, req, base_bio);
1318 * Encrypt / decrypt data from one bio to another one (can be the same one)
1320 static blk_status_t crypt_convert(struct crypt_config *cc,
1321 struct convert_context *ctx)
1323 unsigned int tag_offset = 0;
1324 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1327 atomic_set(&ctx->cc_pending, 1);
1329 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1331 crypt_alloc_req(cc, ctx);
1332 atomic_inc(&ctx->cc_pending);
1334 if (crypt_integrity_aead(cc))
1335 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1337 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1341 * The request was queued by a crypto driver
1342 * but the driver request queue is full, let's wait.
1345 wait_for_completion(&ctx->restart);
1346 reinit_completion(&ctx->restart);
1349 * The request is queued and processed asynchronously,
1350 * completion function kcryptd_async_done() will be called.
1354 ctx->cc_sector += sector_step;
1358 * The request was already processed (synchronously).
1361 atomic_dec(&ctx->cc_pending);
1362 ctx->cc_sector += sector_step;
1367 * There was a data integrity error.
1370 atomic_dec(&ctx->cc_pending);
1371 return BLK_STS_PROTECTION;
1373 * There was an error while processing the request.
1376 atomic_dec(&ctx->cc_pending);
1377 return BLK_STS_IOERR;
1384 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1387 * Generate a new unfragmented bio with the given size
1388 * This should never violate the device limitations (but only because
1389 * max_segment_size is being constrained to PAGE_SIZE).
1391 * This function may be called concurrently. If we allocate from the mempool
1392 * concurrently, there is a possibility of deadlock. For example, if we have
1393 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1394 * the mempool concurrently, it may deadlock in a situation where both processes
1395 * have allocated 128 pages and the mempool is exhausted.
1397 * In order to avoid this scenario we allocate the pages under a mutex.
1399 * In order to not degrade performance with excessive locking, we try
1400 * non-blocking allocations without a mutex first but on failure we fallback
1401 * to blocking allocations with a mutex.
1403 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1405 struct crypt_config *cc = io->cc;
1407 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1408 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1409 unsigned i, len, remaining_size;
1413 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1414 mutex_lock(&cc->bio_alloc_lock);
1416 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs);
1420 clone_init(io, clone);
1422 remaining_size = size;
1424 for (i = 0; i < nr_iovecs; i++) {
1425 page = mempool_alloc(&cc->page_pool, gfp_mask);
1427 crypt_free_buffer_pages(cc, clone);
1429 gfp_mask |= __GFP_DIRECT_RECLAIM;
1433 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1435 bio_add_page(clone, page, len, 0);
1437 remaining_size -= len;
1440 /* Allocate space for integrity tags */
1441 if (dm_crypt_integrity_io_alloc(io, clone)) {
1442 crypt_free_buffer_pages(cc, clone);
1447 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1448 mutex_unlock(&cc->bio_alloc_lock);
1453 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1458 bio_for_each_segment_all(bv, clone, i) {
1459 BUG_ON(!bv->bv_page);
1460 mempool_free(bv->bv_page, &cc->page_pool);
1464 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1465 struct bio *bio, sector_t sector)
1469 io->sector = sector;
1471 io->ctx.r.req = NULL;
1472 io->integrity_metadata = NULL;
1473 io->integrity_metadata_from_pool = false;
1474 atomic_set(&io->io_pending, 0);
1477 static void crypt_inc_pending(struct dm_crypt_io *io)
1479 atomic_inc(&io->io_pending);
1483 * One of the bios was finished. Check for completion of
1484 * the whole request and correctly clean up the buffer.
1486 static void crypt_dec_pending(struct dm_crypt_io *io)
1488 struct crypt_config *cc = io->cc;
1489 struct bio *base_bio = io->base_bio;
1490 blk_status_t error = io->error;
1492 if (!atomic_dec_and_test(&io->io_pending))
1496 crypt_free_req(cc, io->ctx.r.req, base_bio);
1498 if (unlikely(io->integrity_metadata_from_pool))
1499 mempool_free(io->integrity_metadata, &io->cc->tag_pool);
1501 kfree(io->integrity_metadata);
1503 base_bio->bi_status = error;
1504 bio_endio(base_bio);
1508 * kcryptd/kcryptd_io:
1510 * Needed because it would be very unwise to do decryption in an
1511 * interrupt context.
1513 * kcryptd performs the actual encryption or decryption.
1515 * kcryptd_io performs the IO submission.
1517 * They must be separated as otherwise the final stages could be
1518 * starved by new requests which can block in the first stages due
1519 * to memory allocation.
1521 * The work is done per CPU global for all dm-crypt instances.
1522 * They should not depend on each other and do not block.
1524 static void crypt_endio(struct bio *clone)
1526 struct dm_crypt_io *io = clone->bi_private;
1527 struct crypt_config *cc = io->cc;
1528 unsigned rw = bio_data_dir(clone);
1532 * free the processed pages
1535 crypt_free_buffer_pages(cc, clone);
1537 error = clone->bi_status;
1540 if (rw == READ && !error) {
1541 kcryptd_queue_crypt(io);
1545 if (unlikely(error))
1548 crypt_dec_pending(io);
1551 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1553 struct crypt_config *cc = io->cc;
1555 clone->bi_private = io;
1556 clone->bi_end_io = crypt_endio;
1557 bio_set_dev(clone, cc->dev->bdev);
1558 clone->bi_opf = io->base_bio->bi_opf;
1561 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1563 struct crypt_config *cc = io->cc;
1567 * We need the original biovec array in order to decrypt
1568 * the whole bio data *afterwards* -- thanks to immutable
1569 * biovecs we don't need to worry about the block layer
1570 * modifying the biovec array; so leverage bio_clone_fast().
1572 clone = bio_clone_fast(io->base_bio, gfp, &cc->bs);
1576 crypt_inc_pending(io);
1578 clone_init(io, clone);
1579 clone->bi_iter.bi_sector = cc->start + io->sector;
1581 if (dm_crypt_integrity_io_alloc(io, clone)) {
1582 crypt_dec_pending(io);
1587 generic_make_request(clone);
1591 static void kcryptd_io_read_work(struct work_struct *work)
1593 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1595 crypt_inc_pending(io);
1596 if (kcryptd_io_read(io, GFP_NOIO))
1597 io->error = BLK_STS_RESOURCE;
1598 crypt_dec_pending(io);
1601 static void kcryptd_queue_read(struct dm_crypt_io *io)
1603 struct crypt_config *cc = io->cc;
1605 INIT_WORK(&io->work, kcryptd_io_read_work);
1606 queue_work(cc->io_queue, &io->work);
1609 static void kcryptd_io_write(struct dm_crypt_io *io)
1611 struct bio *clone = io->ctx.bio_out;
1613 generic_make_request(clone);
1616 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1618 static int dmcrypt_write(void *data)
1620 struct crypt_config *cc = data;
1621 struct dm_crypt_io *io;
1624 struct rb_root write_tree;
1625 struct blk_plug plug;
1627 spin_lock_irq(&cc->write_thread_lock);
1630 if (!RB_EMPTY_ROOT(&cc->write_tree))
1633 set_current_state(TASK_INTERRUPTIBLE);
1635 spin_unlock_irq(&cc->write_thread_lock);
1637 if (unlikely(kthread_should_stop())) {
1638 set_current_state(TASK_RUNNING);
1644 set_current_state(TASK_RUNNING);
1645 spin_lock_irq(&cc->write_thread_lock);
1646 goto continue_locked;
1649 write_tree = cc->write_tree;
1650 cc->write_tree = RB_ROOT;
1651 spin_unlock_irq(&cc->write_thread_lock);
1653 BUG_ON(rb_parent(write_tree.rb_node));
1656 * Note: we cannot walk the tree here with rb_next because
1657 * the structures may be freed when kcryptd_io_write is called.
1659 blk_start_plug(&plug);
1661 io = crypt_io_from_node(rb_first(&write_tree));
1662 rb_erase(&io->rb_node, &write_tree);
1663 kcryptd_io_write(io);
1665 } while (!RB_EMPTY_ROOT(&write_tree));
1666 blk_finish_plug(&plug);
1671 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1673 struct bio *clone = io->ctx.bio_out;
1674 struct crypt_config *cc = io->cc;
1675 unsigned long flags;
1677 struct rb_node **rbp, *parent;
1679 if (unlikely(io->error)) {
1680 crypt_free_buffer_pages(cc, clone);
1682 crypt_dec_pending(io);
1686 /* crypt_convert should have filled the clone bio */
1687 BUG_ON(io->ctx.iter_out.bi_size);
1689 clone->bi_iter.bi_sector = cc->start + io->sector;
1691 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1692 generic_make_request(clone);
1696 spin_lock_irqsave(&cc->write_thread_lock, flags);
1697 if (RB_EMPTY_ROOT(&cc->write_tree))
1698 wake_up_process(cc->write_thread);
1699 rbp = &cc->write_tree.rb_node;
1701 sector = io->sector;
1704 if (sector < crypt_io_from_node(parent)->sector)
1705 rbp = &(*rbp)->rb_left;
1707 rbp = &(*rbp)->rb_right;
1709 rb_link_node(&io->rb_node, parent, rbp);
1710 rb_insert_color(&io->rb_node, &cc->write_tree);
1711 spin_unlock_irqrestore(&cc->write_thread_lock, flags);
1714 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1716 struct crypt_config *cc = io->cc;
1719 sector_t sector = io->sector;
1723 * Prevent io from disappearing until this function completes.
1725 crypt_inc_pending(io);
1726 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1728 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1729 if (unlikely(!clone)) {
1730 io->error = BLK_STS_IOERR;
1734 io->ctx.bio_out = clone;
1735 io->ctx.iter_out = clone->bi_iter;
1737 sector += bio_sectors(clone);
1739 crypt_inc_pending(io);
1740 r = crypt_convert(cc, &io->ctx);
1743 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1745 /* Encryption was already finished, submit io now */
1746 if (crypt_finished) {
1747 kcryptd_crypt_write_io_submit(io, 0);
1748 io->sector = sector;
1752 crypt_dec_pending(io);
1755 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1757 crypt_dec_pending(io);
1760 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1762 struct crypt_config *cc = io->cc;
1765 crypt_inc_pending(io);
1767 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1770 r = crypt_convert(cc, &io->ctx);
1774 if (atomic_dec_and_test(&io->ctx.cc_pending))
1775 kcryptd_crypt_read_done(io);
1777 crypt_dec_pending(io);
1780 static void kcryptd_async_done(struct crypto_async_request *async_req,
1783 struct dm_crypt_request *dmreq = async_req->data;
1784 struct convert_context *ctx = dmreq->ctx;
1785 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1786 struct crypt_config *cc = io->cc;
1789 * A request from crypto driver backlog is going to be processed now,
1790 * finish the completion and continue in crypt_convert().
1791 * (Callback will be called for the second time for this request.)
1793 if (error == -EINPROGRESS) {
1794 complete(&ctx->restart);
1798 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1799 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
1801 if (error == -EBADMSG) {
1802 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1803 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
1804 io->error = BLK_STS_PROTECTION;
1805 } else if (error < 0)
1806 io->error = BLK_STS_IOERR;
1808 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1810 if (!atomic_dec_and_test(&ctx->cc_pending))
1813 if (bio_data_dir(io->base_bio) == READ)
1814 kcryptd_crypt_read_done(io);
1816 kcryptd_crypt_write_io_submit(io, 1);
1819 static void kcryptd_crypt(struct work_struct *work)
1821 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1823 if (bio_data_dir(io->base_bio) == READ)
1824 kcryptd_crypt_read_convert(io);
1826 kcryptd_crypt_write_convert(io);
1829 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1831 struct crypt_config *cc = io->cc;
1833 INIT_WORK(&io->work, kcryptd_crypt);
1834 queue_work(cc->crypt_queue, &io->work);
1837 static void crypt_free_tfms_aead(struct crypt_config *cc)
1839 if (!cc->cipher_tfm.tfms_aead)
1842 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1843 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
1844 cc->cipher_tfm.tfms_aead[0] = NULL;
1847 kfree(cc->cipher_tfm.tfms_aead);
1848 cc->cipher_tfm.tfms_aead = NULL;
1851 static void crypt_free_tfms_skcipher(struct crypt_config *cc)
1855 if (!cc->cipher_tfm.tfms)
1858 for (i = 0; i < cc->tfms_count; i++)
1859 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
1860 crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
1861 cc->cipher_tfm.tfms[i] = NULL;
1864 kfree(cc->cipher_tfm.tfms);
1865 cc->cipher_tfm.tfms = NULL;
1868 static void crypt_free_tfms(struct crypt_config *cc)
1870 if (crypt_integrity_aead(cc))
1871 crypt_free_tfms_aead(cc);
1873 crypt_free_tfms_skcipher(cc);
1876 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
1881 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
1882 sizeof(struct crypto_skcipher *),
1884 if (!cc->cipher_tfm.tfms)
1887 for (i = 0; i < cc->tfms_count; i++) {
1888 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1889 if (IS_ERR(cc->cipher_tfm.tfms[i])) {
1890 err = PTR_ERR(cc->cipher_tfm.tfms[i]);
1891 crypt_free_tfms(cc);
1899 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
1903 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
1904 if (!cc->cipher_tfm.tfms)
1907 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0);
1908 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1909 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
1910 crypt_free_tfms(cc);
1917 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1919 if (crypt_integrity_aead(cc))
1920 return crypt_alloc_tfms_aead(cc, ciphermode);
1922 return crypt_alloc_tfms_skcipher(cc, ciphermode);
1925 static unsigned crypt_subkey_size(struct crypt_config *cc)
1927 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1930 static unsigned crypt_authenckey_size(struct crypt_config *cc)
1932 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
1936 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
1937 * the key must be for some reason in special format.
1938 * This funcion converts cc->key to this special format.
1940 static void crypt_copy_authenckey(char *p, const void *key,
1941 unsigned enckeylen, unsigned authkeylen)
1943 struct crypto_authenc_key_param *param;
1946 rta = (struct rtattr *)p;
1947 param = RTA_DATA(rta);
1948 param->enckeylen = cpu_to_be32(enckeylen);
1949 rta->rta_len = RTA_LENGTH(sizeof(*param));
1950 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1951 p += RTA_SPACE(sizeof(*param));
1952 memcpy(p, key + enckeylen, authkeylen);
1954 memcpy(p, key, enckeylen);
1957 static int crypt_setkey(struct crypt_config *cc)
1959 unsigned subkey_size;
1962 /* Ignore extra keys (which are used for IV etc) */
1963 subkey_size = crypt_subkey_size(cc);
1965 if (crypt_integrity_hmac(cc)) {
1966 if (subkey_size < cc->key_mac_size)
1969 crypt_copy_authenckey(cc->authenc_key, cc->key,
1970 subkey_size - cc->key_mac_size,
1974 for (i = 0; i < cc->tfms_count; i++) {
1975 if (crypt_integrity_hmac(cc))
1976 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1977 cc->authenc_key, crypt_authenckey_size(cc));
1978 else if (crypt_integrity_aead(cc))
1979 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1980 cc->key + (i * subkey_size),
1983 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
1984 cc->key + (i * subkey_size),
1990 if (crypt_integrity_hmac(cc))
1991 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
1998 static bool contains_whitespace(const char *str)
2001 if (isspace(*str++))
2006 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2008 char *new_key_string, *key_desc;
2011 const struct user_key_payload *ukp;
2014 * Reject key_string with whitespace. dm core currently lacks code for
2015 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2017 if (contains_whitespace(key_string)) {
2018 DMERR("whitespace chars not allowed in key string");
2022 /* look for next ':' separating key_type from key_description */
2023 key_desc = strpbrk(key_string, ":");
2024 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2027 if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
2028 strncmp(key_string, "user:", key_desc - key_string + 1))
2031 new_key_string = kstrdup(key_string, GFP_KERNEL);
2032 if (!new_key_string)
2035 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
2036 key_desc + 1, NULL);
2038 kzfree(new_key_string);
2039 return PTR_ERR(key);
2042 down_read(&key->sem);
2044 ukp = user_key_payload_locked(key);
2048 kzfree(new_key_string);
2049 return -EKEYREVOKED;
2052 if (cc->key_size != ukp->datalen) {
2055 kzfree(new_key_string);
2059 memcpy(cc->key, ukp->data, cc->key_size);
2064 /* clear the flag since following operations may invalidate previously valid key */
2065 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2067 ret = crypt_setkey(cc);
2070 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2071 kzfree(cc->key_string);
2072 cc->key_string = new_key_string;
2074 kzfree(new_key_string);
2079 static int get_key_size(char **key_string)
2084 if (*key_string[0] != ':')
2085 return strlen(*key_string) >> 1;
2087 /* look for next ':' in key string */
2088 colon = strpbrk(*key_string + 1, ":");
2092 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2095 *key_string = colon;
2097 /* remaining key string should be :<logon|user>:<key_desc> */
2104 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2109 static int get_key_size(char **key_string)
2111 return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
2116 static int crypt_set_key(struct crypt_config *cc, char *key)
2119 int key_string_len = strlen(key);
2121 /* Hyphen (which gives a key_size of zero) means there is no key. */
2122 if (!cc->key_size && strcmp(key, "-"))
2125 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2126 if (key[0] == ':') {
2127 r = crypt_set_keyring_key(cc, key + 1);
2131 /* clear the flag since following operations may invalidate previously valid key */
2132 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2134 /* wipe references to any kernel keyring key */
2135 kzfree(cc->key_string);
2136 cc->key_string = NULL;
2138 /* Decode key from its hex representation. */
2139 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2142 r = crypt_setkey(cc);
2144 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2147 /* Hex key string not needed after here, so wipe it. */
2148 memset(key, '0', key_string_len);
2153 static int crypt_wipe_key(struct crypt_config *cc)
2157 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2158 get_random_bytes(&cc->key, cc->key_size);
2159 kzfree(cc->key_string);
2160 cc->key_string = NULL;
2161 r = crypt_setkey(cc);
2162 memset(&cc->key, 0, cc->key_size * sizeof(u8));
2167 static void crypt_calculate_pages_per_client(void)
2169 unsigned long pages = (totalram_pages - totalhigh_pages) * DM_CRYPT_MEMORY_PERCENT / 100;
2171 if (!dm_crypt_clients_n)
2174 pages /= dm_crypt_clients_n;
2175 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2176 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2177 dm_crypt_pages_per_client = pages;
2180 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2182 struct crypt_config *cc = pool_data;
2186 * Note, percpu_counter_read_positive() may over (and under) estimate
2187 * the current usage by at most (batch - 1) * num_online_cpus() pages,
2188 * but avoids potential spinlock contention of an exact result.
2190 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
2191 likely(gfp_mask & __GFP_NORETRY))
2194 page = alloc_page(gfp_mask);
2195 if (likely(page != NULL))
2196 percpu_counter_add(&cc->n_allocated_pages, 1);
2201 static void crypt_page_free(void *page, void *pool_data)
2203 struct crypt_config *cc = pool_data;
2206 percpu_counter_sub(&cc->n_allocated_pages, 1);
2209 static void crypt_dtr(struct dm_target *ti)
2211 struct crypt_config *cc = ti->private;
2218 if (cc->write_thread)
2219 kthread_stop(cc->write_thread);
2222 destroy_workqueue(cc->io_queue);
2223 if (cc->crypt_queue)
2224 destroy_workqueue(cc->crypt_queue);
2226 crypt_free_tfms(cc);
2228 bioset_exit(&cc->bs);
2230 mempool_exit(&cc->page_pool);
2231 mempool_exit(&cc->req_pool);
2232 mempool_exit(&cc->tag_pool);
2234 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2235 percpu_counter_destroy(&cc->n_allocated_pages);
2237 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2238 cc->iv_gen_ops->dtr(cc);
2241 dm_put_device(ti, cc->dev);
2244 kzfree(cc->cipher_string);
2245 kzfree(cc->key_string);
2246 kzfree(cc->cipher_auth);
2247 kzfree(cc->authenc_key);
2249 mutex_destroy(&cc->bio_alloc_lock);
2251 /* Must zero key material before freeing */
2254 spin_lock(&dm_crypt_clients_lock);
2255 WARN_ON(!dm_crypt_clients_n);
2256 dm_crypt_clients_n--;
2257 crypt_calculate_pages_per_client();
2258 spin_unlock(&dm_crypt_clients_lock);
2261 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2263 struct crypt_config *cc = ti->private;
2265 if (crypt_integrity_aead(cc))
2266 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2268 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2271 /* at least a 64 bit sector number should fit in our buffer */
2272 cc->iv_size = max(cc->iv_size,
2273 (unsigned int)(sizeof(u64) / sizeof(u8)));
2275 DMWARN("Selected cipher does not support IVs");
2279 /* Choose ivmode, see comments at iv code. */
2281 cc->iv_gen_ops = NULL;
2282 else if (strcmp(ivmode, "plain") == 0)
2283 cc->iv_gen_ops = &crypt_iv_plain_ops;
2284 else if (strcmp(ivmode, "plain64") == 0)
2285 cc->iv_gen_ops = &crypt_iv_plain64_ops;
2286 else if (strcmp(ivmode, "plain64be") == 0)
2287 cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2288 else if (strcmp(ivmode, "essiv") == 0)
2289 cc->iv_gen_ops = &crypt_iv_essiv_ops;
2290 else if (strcmp(ivmode, "benbi") == 0)
2291 cc->iv_gen_ops = &crypt_iv_benbi_ops;
2292 else if (strcmp(ivmode, "null") == 0)
2293 cc->iv_gen_ops = &crypt_iv_null_ops;
2294 else if (strcmp(ivmode, "lmk") == 0) {
2295 cc->iv_gen_ops = &crypt_iv_lmk_ops;
2297 * Version 2 and 3 is recognised according
2298 * to length of provided multi-key string.
2299 * If present (version 3), last key is used as IV seed.
2300 * All keys (including IV seed) are always the same size.
2302 if (cc->key_size % cc->key_parts) {
2304 cc->key_extra_size = cc->key_size / cc->key_parts;
2306 } else if (strcmp(ivmode, "tcw") == 0) {
2307 cc->iv_gen_ops = &crypt_iv_tcw_ops;
2308 cc->key_parts += 2; /* IV + whitening */
2309 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2310 } else if (strcmp(ivmode, "random") == 0) {
2311 cc->iv_gen_ops = &crypt_iv_random_ops;
2312 /* Need storage space in integrity fields. */
2313 cc->integrity_iv_size = cc->iv_size;
2315 ti->error = "Invalid IV mode";
2323 * Workaround to parse cipher algorithm from crypto API spec.
2324 * The cc->cipher is currently used only in ESSIV.
2325 * This should be probably done by crypto-api calls (once available...)
2327 static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)
2329 const char *alg_name = NULL;
2332 if (crypt_integrity_aead(cc)) {
2333 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));
2336 if (crypt_integrity_hmac(cc)) {
2337 alg_name = strchr(alg_name, ',');
2343 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));
2348 start = strchr(alg_name, '(');
2349 end = strchr(alg_name, ')');
2351 if (!start && !end) {
2352 cc->cipher = kstrdup(alg_name, GFP_KERNEL);
2353 return cc->cipher ? 0 : -ENOMEM;
2356 if (!start || !end || ++start >= end)
2359 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);
2363 strncpy(cc->cipher, start, end - start);
2369 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2370 * The HMAC is needed to calculate tag size (HMAC digest size).
2371 * This should be probably done by crypto-api calls (once available...)
2373 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2375 char *start, *end, *mac_alg = NULL;
2376 struct crypto_ahash *mac;
2378 if (!strstarts(cipher_api, "authenc("))
2381 start = strchr(cipher_api, '(');
2382 end = strchr(cipher_api, ',');
2383 if (!start || !end || ++start > end)
2386 mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2389 strncpy(mac_alg, start, end - start);
2391 mac = crypto_alloc_ahash(mac_alg, 0, 0);
2395 return PTR_ERR(mac);
2397 cc->key_mac_size = crypto_ahash_digestsize(mac);
2398 crypto_free_ahash(mac);
2400 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2401 if (!cc->authenc_key)
2407 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2408 char **ivmode, char **ivopts)
2410 struct crypt_config *cc = ti->private;
2411 char *tmp, *cipher_api;
2417 * New format (capi: prefix)
2418 * capi:cipher_api_spec-iv:ivopts
2420 tmp = &cipher_in[strlen("capi:")];
2422 /* Separate IV options if present, it can contain another '-' in hash name */
2423 *ivopts = strrchr(tmp, ':');
2429 *ivmode = strrchr(tmp, '-');
2434 /* The rest is crypto API spec */
2437 if (*ivmode && !strcmp(*ivmode, "lmk"))
2438 cc->tfms_count = 64;
2440 cc->key_parts = cc->tfms_count;
2442 /* Allocate cipher */
2443 ret = crypt_alloc_tfms(cc, cipher_api);
2445 ti->error = "Error allocating crypto tfm";
2449 /* Alloc AEAD, can be used only in new format. */
2450 if (crypt_integrity_aead(cc)) {
2451 ret = crypt_ctr_auth_cipher(cc, cipher_api);
2453 ti->error = "Invalid AEAD cipher spec";
2456 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2458 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2460 ret = crypt_ctr_blkdev_cipher(cc);
2462 ti->error = "Cannot allocate cipher string";
2469 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2470 char **ivmode, char **ivopts)
2472 struct crypt_config *cc = ti->private;
2473 char *tmp, *cipher, *chainmode, *keycount;
2474 char *cipher_api = NULL;
2478 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2479 ti->error = "Bad cipher specification";
2484 * Legacy dm-crypt cipher specification
2485 * cipher[:keycount]-mode-iv:ivopts
2488 keycount = strsep(&tmp, "-");
2489 cipher = strsep(&keycount, ":");
2493 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2494 !is_power_of_2(cc->tfms_count)) {
2495 ti->error = "Bad cipher key count specification";
2498 cc->key_parts = cc->tfms_count;
2500 cc->cipher = kstrdup(cipher, GFP_KERNEL);
2504 chainmode = strsep(&tmp, "-");
2505 *ivmode = strsep(&tmp, ":");
2509 * For compatibility with the original dm-crypt mapping format, if
2510 * only the cipher name is supplied, use cbc-plain.
2512 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2517 if (strcmp(chainmode, "ecb") && !*ivmode) {
2518 ti->error = "IV mechanism required";
2522 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2526 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2527 "%s(%s)", chainmode, cipher);
2533 /* Allocate cipher */
2534 ret = crypt_alloc_tfms(cc, cipher_api);
2536 ti->error = "Error allocating crypto tfm";
2544 ti->error = "Cannot allocate cipher strings";
2548 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
2550 struct crypt_config *cc = ti->private;
2551 char *ivmode = NULL, *ivopts = NULL;
2554 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
2555 if (!cc->cipher_string) {
2556 ti->error = "Cannot allocate cipher strings";
2560 if (strstarts(cipher_in, "capi:"))
2561 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
2563 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
2568 ret = crypt_ctr_ivmode(ti, ivmode);
2572 /* Initialize and set key */
2573 ret = crypt_set_key(cc, key);
2575 ti->error = "Error decoding and setting key";
2580 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
2581 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
2583 ti->error = "Error creating IV";
2588 /* Initialize IV (set keys for ESSIV etc) */
2589 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
2590 ret = cc->iv_gen_ops->init(cc);
2592 ti->error = "Error initialising IV";
2597 /* wipe the kernel key payload copy */
2599 memset(cc->key, 0, cc->key_size * sizeof(u8));
2604 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
2606 struct crypt_config *cc = ti->private;
2607 struct dm_arg_set as;
2608 static const struct dm_arg _args[] = {
2609 {0, 6, "Invalid number of feature args"},
2611 unsigned int opt_params, val;
2612 const char *opt_string, *sval;
2616 /* Optional parameters */
2620 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
2624 while (opt_params--) {
2625 opt_string = dm_shift_arg(&as);
2627 ti->error = "Not enough feature arguments";
2631 if (!strcasecmp(opt_string, "allow_discards"))
2632 ti->num_discard_bios = 1;
2634 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
2635 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2637 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
2638 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2639 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
2640 if (val == 0 || val > MAX_TAG_SIZE) {
2641 ti->error = "Invalid integrity arguments";
2644 cc->on_disk_tag_size = val;
2645 sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
2646 if (!strcasecmp(sval, "aead")) {
2647 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
2648 } else if (strcasecmp(sval, "none")) {
2649 ti->error = "Unknown integrity profile";
2653 cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
2654 if (!cc->cipher_auth)
2656 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
2657 if (cc->sector_size < (1 << SECTOR_SHIFT) ||
2658 cc->sector_size > 4096 ||
2659 (cc->sector_size & (cc->sector_size - 1))) {
2660 ti->error = "Invalid feature value for sector_size";
2663 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
2664 ti->error = "Device size is not multiple of sector_size feature";
2667 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
2668 } else if (!strcasecmp(opt_string, "iv_large_sectors"))
2669 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2671 ti->error = "Invalid feature arguments";
2680 * Construct an encryption mapping:
2681 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
2683 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2685 struct crypt_config *cc;
2687 unsigned int align_mask;
2688 unsigned long long tmpll;
2690 size_t iv_size_padding, additional_req_size;
2694 ti->error = "Not enough arguments";
2698 key_size = get_key_size(&argv[1]);
2700 ti->error = "Cannot parse key size";
2704 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
2706 ti->error = "Cannot allocate encryption context";
2709 cc->key_size = key_size;
2710 cc->sector_size = (1 << SECTOR_SHIFT);
2711 cc->sector_shift = 0;
2715 spin_lock(&dm_crypt_clients_lock);
2716 dm_crypt_clients_n++;
2717 crypt_calculate_pages_per_client();
2718 spin_unlock(&dm_crypt_clients_lock);
2720 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
2724 /* Optional parameters need to be read before cipher constructor */
2726 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
2731 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
2735 if (crypt_integrity_aead(cc)) {
2736 cc->dmreq_start = sizeof(struct aead_request);
2737 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
2738 align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
2740 cc->dmreq_start = sizeof(struct skcipher_request);
2741 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
2742 align_mask = crypto_skcipher_alignmask(any_tfm(cc));
2744 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
2746 if (align_mask < CRYPTO_MINALIGN) {
2747 /* Allocate the padding exactly */
2748 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
2752 * If the cipher requires greater alignment than kmalloc
2753 * alignment, we don't know the exact position of the
2754 * initialization vector. We must assume worst case.
2756 iv_size_padding = align_mask;
2759 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */
2760 additional_req_size = sizeof(struct dm_crypt_request) +
2761 iv_size_padding + cc->iv_size +
2764 sizeof(unsigned int);
2766 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
2768 ti->error = "Cannot allocate crypt request mempool";
2772 cc->per_bio_data_size = ti->per_io_data_size =
2773 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
2774 ARCH_KMALLOC_MINALIGN);
2776 ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc);
2778 ti->error = "Cannot allocate page mempool";
2782 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
2784 ti->error = "Cannot allocate crypt bioset";
2788 mutex_init(&cc->bio_alloc_lock);
2791 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
2792 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
2793 ti->error = "Invalid iv_offset sector";
2796 cc->iv_offset = tmpll;
2798 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
2800 ti->error = "Device lookup failed";
2805 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
2806 ti->error = "Invalid device sector";
2811 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
2812 ret = crypt_integrity_ctr(cc, ti);
2816 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
2817 if (!cc->tag_pool_max_sectors)
2818 cc->tag_pool_max_sectors = 1;
2820 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
2821 cc->tag_pool_max_sectors * cc->on_disk_tag_size);
2823 ti->error = "Cannot allocate integrity tags mempool";
2827 cc->tag_pool_max_sectors <<= cc->sector_shift;
2831 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2832 if (!cc->io_queue) {
2833 ti->error = "Couldn't create kcryptd io queue";
2837 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2838 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2840 cc->crypt_queue = alloc_workqueue("kcryptd",
2841 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2843 if (!cc->crypt_queue) {
2844 ti->error = "Couldn't create kcryptd queue";
2848 spin_lock_init(&cc->write_thread_lock);
2849 cc->write_tree = RB_ROOT;
2851 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
2852 if (IS_ERR(cc->write_thread)) {
2853 ret = PTR_ERR(cc->write_thread);
2854 cc->write_thread = NULL;
2855 ti->error = "Couldn't spawn write thread";
2858 wake_up_process(cc->write_thread);
2860 ti->num_flush_bios = 1;
2861 ti->limit_swap_bios = true;
2870 static int crypt_map(struct dm_target *ti, struct bio *bio)
2872 struct dm_crypt_io *io;
2873 struct crypt_config *cc = ti->private;
2876 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2877 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
2878 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
2880 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
2881 bio_op(bio) == REQ_OP_DISCARD)) {
2882 bio_set_dev(bio, cc->dev->bdev);
2883 if (bio_sectors(bio))
2884 bio->bi_iter.bi_sector = cc->start +
2885 dm_target_offset(ti, bio->bi_iter.bi_sector);
2886 return DM_MAPIO_REMAPPED;
2890 * Check if bio is too large, split as needed.
2892 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2893 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
2894 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2897 * Ensure that bio is a multiple of internal sector encryption size
2898 * and is aligned to this size as defined in IO hints.
2900 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
2901 return DM_MAPIO_KILL;
2903 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
2904 return DM_MAPIO_KILL;
2906 io = dm_per_bio_data(bio, cc->per_bio_data_size);
2907 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
2909 if (cc->on_disk_tag_size) {
2910 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
2912 if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
2913 unlikely(!(io->integrity_metadata = kmalloc(tag_len,
2914 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
2915 if (bio_sectors(bio) > cc->tag_pool_max_sectors)
2916 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
2917 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
2918 io->integrity_metadata_from_pool = true;
2922 if (crypt_integrity_aead(cc))
2923 io->ctx.r.req_aead = (struct aead_request *)(io + 1);
2925 io->ctx.r.req = (struct skcipher_request *)(io + 1);
2927 if (bio_data_dir(io->base_bio) == READ) {
2928 if (kcryptd_io_read(io, GFP_NOWAIT))
2929 kcryptd_queue_read(io);
2931 kcryptd_queue_crypt(io);
2933 return DM_MAPIO_SUBMITTED;
2936 static char hex2asc(unsigned char c)
2938 return c + '0' + ((unsigned)(9 - c) >> 4 & 0x27);
2941 static void crypt_status(struct dm_target *ti, status_type_t type,
2942 unsigned status_flags, char *result, unsigned maxlen)
2944 struct crypt_config *cc = ti->private;
2946 int num_feature_args = 0;
2949 case STATUSTYPE_INFO:
2953 case STATUSTYPE_TABLE:
2954 DMEMIT("%s ", cc->cipher_string);
2956 if (cc->key_size > 0) {
2958 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2960 for (i = 0; i < cc->key_size; i++) {
2961 DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
2962 hex2asc(cc->key[i] & 0xf));
2968 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2969 cc->dev->name, (unsigned long long)cc->start);
2971 num_feature_args += !!ti->num_discard_bios;
2972 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2973 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2974 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
2975 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2976 if (cc->on_disk_tag_size)
2978 if (num_feature_args) {
2979 DMEMIT(" %d", num_feature_args);
2980 if (ti->num_discard_bios)
2981 DMEMIT(" allow_discards");
2982 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2983 DMEMIT(" same_cpu_crypt");
2984 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2985 DMEMIT(" submit_from_crypt_cpus");
2986 if (cc->on_disk_tag_size)
2987 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
2988 if (cc->sector_size != (1 << SECTOR_SHIFT))
2989 DMEMIT(" sector_size:%d", cc->sector_size);
2990 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
2991 DMEMIT(" iv_large_sectors");
2998 static void crypt_postsuspend(struct dm_target *ti)
3000 struct crypt_config *cc = ti->private;
3002 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3005 static int crypt_preresume(struct dm_target *ti)
3007 struct crypt_config *cc = ti->private;
3009 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3010 DMERR("aborting resume - crypt key is not set.");
3017 static void crypt_resume(struct dm_target *ti)
3019 struct crypt_config *cc = ti->private;
3021 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3024 /* Message interface
3028 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv,
3029 char *result, unsigned maxlen)
3031 struct crypt_config *cc = ti->private;
3032 int key_size, ret = -EINVAL;
3037 if (!strcasecmp(argv[0], "key")) {
3038 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3039 DMWARN("not suspended during key manipulation.");
3042 if (argc == 3 && !strcasecmp(argv[1], "set")) {
3043 /* The key size may not be changed. */
3044 key_size = get_key_size(&argv[2]);
3045 if (key_size < 0 || cc->key_size != key_size) {
3046 memset(argv[2], '0', strlen(argv[2]));
3050 ret = crypt_set_key(cc, argv[2]);
3053 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3054 ret = cc->iv_gen_ops->init(cc);
3055 /* wipe the kernel key payload copy */
3057 memset(cc->key, 0, cc->key_size * sizeof(u8));
3060 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
3061 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
3062 ret = cc->iv_gen_ops->wipe(cc);
3066 return crypt_wipe_key(cc);
3071 DMWARN("unrecognised message received.");
3075 static int crypt_iterate_devices(struct dm_target *ti,
3076 iterate_devices_callout_fn fn, void *data)
3078 struct crypt_config *cc = ti->private;
3080 return fn(ti, cc->dev, cc->start, ti->len, data);
3083 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3085 struct crypt_config *cc = ti->private;
3088 * Unfortunate constraint that is required to avoid the potential
3089 * for exceeding underlying device's max_segments limits -- due to
3090 * crypt_alloc_buffer() possibly allocating pages for the encryption
3091 * bio that are not as physically contiguous as the original bio.
3093 limits->max_segment_size = PAGE_SIZE;
3095 limits->logical_block_size =
3096 max_t(unsigned, limits->logical_block_size, cc->sector_size);
3097 limits->physical_block_size =
3098 max_t(unsigned, limits->physical_block_size, cc->sector_size);
3099 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
3102 static struct target_type crypt_target = {
3104 .version = {1, 18, 1},
3105 .module = THIS_MODULE,
3109 .status = crypt_status,
3110 .postsuspend = crypt_postsuspend,
3111 .preresume = crypt_preresume,
3112 .resume = crypt_resume,
3113 .message = crypt_message,
3114 .iterate_devices = crypt_iterate_devices,
3115 .io_hints = crypt_io_hints,
3118 static int __init dm_crypt_init(void)
3122 r = dm_register_target(&crypt_target);
3124 DMERR("register failed %d", r);
3129 static void __exit dm_crypt_exit(void)
3131 dm_unregister_target(&crypt_target);
3134 module_init(dm_crypt_init);
3135 module_exit(dm_crypt_exit);
3137 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3138 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3139 MODULE_LICENSE("GPL");