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1/*
2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
6 *
7 * This file is released under the GPL.
8 */
9
10#include <linux/completion.h>
11#include <linux/err.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/bio.h>
16#include <linux/blkdev.h>
17#include <linux/mempool.h>
18#include <linux/slab.h>
19#include <linux/crypto.h>
20#include <linux/workqueue.h>
21#include <linux/kthread.h>
22#include <linux/backing-dev.h>
23#include <linux/atomic.h>
24#include <linux/scatterlist.h>
25#include <linux/rbtree.h>
26#include <asm/page.h>
27#include <asm/unaligned.h>
28#include <crypto/hash.h>
29#include <crypto/md5.h>
30#include <crypto/algapi.h>
31#include <crypto/skcipher.h>
32
33#include <linux/device-mapper.h>
34
35#define DM_MSG_PREFIX "crypt"
36
37/*
38 * context holding the current state of a multi-part conversion
39 */
40struct convert_context {
41 struct completion restart;
42 struct bio *bio_in;
43 struct bio *bio_out;
44 struct bvec_iter iter_in;
45 struct bvec_iter iter_out;
46 sector_t cc_sector;
47 atomic_t cc_pending;
48 struct skcipher_request *req;
49};
50
51/*
52 * per bio private data
53 */
54struct dm_crypt_io {
55 struct crypt_config *cc;
56 struct bio *base_bio;
57 struct work_struct work;
58
59 struct convert_context ctx;
60
61 atomic_t io_pending;
62 int error;
63 sector_t sector;
64
65 struct rb_node rb_node;
66} CRYPTO_MINALIGN_ATTR;
67
68struct dm_crypt_request {
69 struct convert_context *ctx;
70 struct scatterlist sg_in;
71 struct scatterlist sg_out;
72 sector_t iv_sector;
73};
74
75struct crypt_config;
76
77struct crypt_iv_operations {
78 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
79 const char *opts);
80 void (*dtr)(struct crypt_config *cc);
81 int (*init)(struct crypt_config *cc);
82 int (*wipe)(struct crypt_config *cc);
83 int (*generator)(struct crypt_config *cc, u8 *iv,
84 struct dm_crypt_request *dmreq);
85 int (*post)(struct crypt_config *cc, u8 *iv,
86 struct dm_crypt_request *dmreq);
87};
88
89struct iv_essiv_private {
90 struct crypto_ahash *hash_tfm;
91 u8 *salt;
92};
93
94struct iv_benbi_private {
95 int shift;
96};
97
98#define LMK_SEED_SIZE 64 /* hash + 0 */
99struct iv_lmk_private {
100 struct crypto_shash *hash_tfm;
101 u8 *seed;
102};
103
104#define TCW_WHITENING_SIZE 16
105struct iv_tcw_private {
106 struct crypto_shash *crc32_tfm;
107 u8 *iv_seed;
108 u8 *whitening;
109};
110
111/*
112 * Crypt: maps a linear range of a block device
113 * and encrypts / decrypts at the same time.
114 */
115enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
116 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
117 DM_CRYPT_EXIT_THREAD};
118
119/*
120 * The fields in here must be read only after initialization.
121 */
122struct crypt_config {
123 struct dm_dev *dev;
124 sector_t start;
125
126 /*
127 * pool for per bio private data, crypto requests and
128 * encryption requeusts/buffer pages
129 */
130 mempool_t *req_pool;
131 mempool_t *page_pool;
132 struct bio_set *bs;
133 struct mutex bio_alloc_lock;
134
135 struct workqueue_struct *io_queue;
136 struct workqueue_struct *crypt_queue;
137
138 struct task_struct *write_thread;
139 wait_queue_head_t write_thread_wait;
140 struct rb_root write_tree;
141
142 char *cipher;
143 char *cipher_string;
144
145 struct crypt_iv_operations *iv_gen_ops;
146 union {
147 struct iv_essiv_private essiv;
148 struct iv_benbi_private benbi;
149 struct iv_lmk_private lmk;
150 struct iv_tcw_private tcw;
151 } iv_gen_private;
152 sector_t iv_offset;
153 unsigned int iv_size;
154
155 /* ESSIV: struct crypto_cipher *essiv_tfm */
156 void *iv_private;
157 struct crypto_skcipher **tfms;
158 unsigned tfms_count;
159
160 /*
161 * Layout of each crypto request:
162 *
163 * struct skcipher_request
164 * context
165 * padding
166 * struct dm_crypt_request
167 * padding
168 * IV
169 *
170 * The padding is added so that dm_crypt_request and the IV are
171 * correctly aligned.
172 */
173 unsigned int dmreq_start;
174
175 unsigned int per_bio_data_size;
176
177 unsigned long flags;
178 unsigned int key_size;
179 unsigned int key_parts; /* independent parts in key buffer */
180 unsigned int key_extra_size; /* additional keys length */
181 u8 key[0];
182};
183
184#define MIN_IOS 16
185
186static void clone_init(struct dm_crypt_io *, struct bio *);
187static void kcryptd_queue_crypt(struct dm_crypt_io *io);
188static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
189
190/*
191 * Use this to access cipher attributes that are the same for each CPU.
192 */
193static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
194{
195 return cc->tfms[0];
196}
197
198/*
199 * Different IV generation algorithms:
200 *
201 * plain: the initial vector is the 32-bit little-endian version of the sector
202 * number, padded with zeros if necessary.
203 *
204 * plain64: the initial vector is the 64-bit little-endian version of the sector
205 * number, padded with zeros if necessary.
206 *
207 * essiv: "encrypted sector|salt initial vector", the sector number is
208 * encrypted with the bulk cipher using a salt as key. The salt
209 * should be derived from the bulk cipher's key via hashing.
210 *
211 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
212 * (needed for LRW-32-AES and possible other narrow block modes)
213 *
214 * null: the initial vector is always zero. Provides compatibility with
215 * obsolete loop_fish2 devices. Do not use for new devices.
216 *
217 * lmk: Compatible implementation of the block chaining mode used
218 * by the Loop-AES block device encryption system
219 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
220 * It operates on full 512 byte sectors and uses CBC
221 * with an IV derived from the sector number, the data and
222 * optionally extra IV seed.
223 * This means that after decryption the first block
224 * of sector must be tweaked according to decrypted data.
225 * Loop-AES can use three encryption schemes:
226 * version 1: is plain aes-cbc mode
227 * version 2: uses 64 multikey scheme with lmk IV generator
228 * version 3: the same as version 2 with additional IV seed
229 * (it uses 65 keys, last key is used as IV seed)
230 *
231 * tcw: Compatible implementation of the block chaining mode used
232 * by the TrueCrypt device encryption system (prior to version 4.1).
233 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
234 * It operates on full 512 byte sectors and uses CBC
235 * with an IV derived from initial key and the sector number.
236 * In addition, whitening value is applied on every sector, whitening
237 * is calculated from initial key, sector number and mixed using CRC32.
238 * Note that this encryption scheme is vulnerable to watermarking attacks
239 * and should be used for old compatible containers access only.
240 *
241 * plumb: unimplemented, see:
242 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
243 */
244
245static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
246 struct dm_crypt_request *dmreq)
247{
248 memset(iv, 0, cc->iv_size);
249 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
250
251 return 0;
252}
253
254static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
255 struct dm_crypt_request *dmreq)
256{
257 memset(iv, 0, cc->iv_size);
258 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
259
260 return 0;
261}
262
263/* Initialise ESSIV - compute salt but no local memory allocations */
264static int crypt_iv_essiv_init(struct crypt_config *cc)
265{
266 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
267 AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
268 struct scatterlist sg;
269 struct crypto_cipher *essiv_tfm;
270 int err;
271
272 sg_init_one(&sg, cc->key, cc->key_size);
273 ahash_request_set_tfm(req, essiv->hash_tfm);
274 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
275 ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
276
277 err = crypto_ahash_digest(req);
278 ahash_request_zero(req);
279 if (err)
280 return err;
281
282 essiv_tfm = cc->iv_private;
283
284 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
285 crypto_ahash_digestsize(essiv->hash_tfm));
286 if (err)
287 return err;
288
289 return 0;
290}
291
292/* Wipe salt and reset key derived from volume key */
293static int crypt_iv_essiv_wipe(struct crypt_config *cc)
294{
295 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
296 unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
297 struct crypto_cipher *essiv_tfm;
298 int r, err = 0;
299
300 memset(essiv->salt, 0, salt_size);
301
302 essiv_tfm = cc->iv_private;
303 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
304 if (r)
305 err = r;
306
307 return err;
308}
309
310/* Set up per cpu cipher state */
311static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
312 struct dm_target *ti,
313 u8 *salt, unsigned saltsize)
314{
315 struct crypto_cipher *essiv_tfm;
316 int err;
317
318 /* Setup the essiv_tfm with the given salt */
319 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
320 if (IS_ERR(essiv_tfm)) {
321 ti->error = "Error allocating crypto tfm for ESSIV";
322 return essiv_tfm;
323 }
324
325 if (crypto_cipher_blocksize(essiv_tfm) !=
326 crypto_skcipher_ivsize(any_tfm(cc))) {
327 ti->error = "Block size of ESSIV cipher does "
328 "not match IV size of block cipher";
329 crypto_free_cipher(essiv_tfm);
330 return ERR_PTR(-EINVAL);
331 }
332
333 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
334 if (err) {
335 ti->error = "Failed to set key for ESSIV cipher";
336 crypto_free_cipher(essiv_tfm);
337 return ERR_PTR(err);
338 }
339
340 return essiv_tfm;
341}
342
343static void crypt_iv_essiv_dtr(struct crypt_config *cc)
344{
345 struct crypto_cipher *essiv_tfm;
346 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
347
348 crypto_free_ahash(essiv->hash_tfm);
349 essiv->hash_tfm = NULL;
350
351 kzfree(essiv->salt);
352 essiv->salt = NULL;
353
354 essiv_tfm = cc->iv_private;
355
356 if (essiv_tfm)
357 crypto_free_cipher(essiv_tfm);
358
359 cc->iv_private = NULL;
360}
361
362static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
363 const char *opts)
364{
365 struct crypto_cipher *essiv_tfm = NULL;
366 struct crypto_ahash *hash_tfm = NULL;
367 u8 *salt = NULL;
368 int err;
369
370 if (!opts) {
371 ti->error = "Digest algorithm missing for ESSIV mode";
372 return -EINVAL;
373 }
374
375 /* Allocate hash algorithm */
376 hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
377 if (IS_ERR(hash_tfm)) {
378 ti->error = "Error initializing ESSIV hash";
379 err = PTR_ERR(hash_tfm);
380 goto bad;
381 }
382
383 salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
384 if (!salt) {
385 ti->error = "Error kmallocing salt storage in ESSIV";
386 err = -ENOMEM;
387 goto bad;
388 }
389
390 cc->iv_gen_private.essiv.salt = salt;
391 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
392
393 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
394 crypto_ahash_digestsize(hash_tfm));
395 if (IS_ERR(essiv_tfm)) {
396 crypt_iv_essiv_dtr(cc);
397 return PTR_ERR(essiv_tfm);
398 }
399 cc->iv_private = essiv_tfm;
400
401 return 0;
402
403bad:
404 if (hash_tfm && !IS_ERR(hash_tfm))
405 crypto_free_ahash(hash_tfm);
406 kfree(salt);
407 return err;
408}
409
410static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
411 struct dm_crypt_request *dmreq)
412{
413 struct crypto_cipher *essiv_tfm = cc->iv_private;
414
415 memset(iv, 0, cc->iv_size);
416 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
417 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
418
419 return 0;
420}
421
422static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
423 const char *opts)
424{
425 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
426 int log = ilog2(bs);
427
428 /* we need to calculate how far we must shift the sector count
429 * to get the cipher block count, we use this shift in _gen */
430
431 if (1 << log != bs) {
432 ti->error = "cypher blocksize is not a power of 2";
433 return -EINVAL;
434 }
435
436 if (log > 9) {
437 ti->error = "cypher blocksize is > 512";
438 return -EINVAL;
439 }
440
441 cc->iv_gen_private.benbi.shift = 9 - log;
442
443 return 0;
444}
445
446static void crypt_iv_benbi_dtr(struct crypt_config *cc)
447{
448}
449
450static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
451 struct dm_crypt_request *dmreq)
452{
453 __be64 val;
454
455 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
456
457 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
458 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
459
460 return 0;
461}
462
463static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
464 struct dm_crypt_request *dmreq)
465{
466 memset(iv, 0, cc->iv_size);
467
468 return 0;
469}
470
471static void crypt_iv_lmk_dtr(struct crypt_config *cc)
472{
473 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
474
475 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
476 crypto_free_shash(lmk->hash_tfm);
477 lmk->hash_tfm = NULL;
478
479 kzfree(lmk->seed);
480 lmk->seed = NULL;
481}
482
483static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
484 const char *opts)
485{
486 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
487
488 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
489 if (IS_ERR(lmk->hash_tfm)) {
490 ti->error = "Error initializing LMK hash";
491 return PTR_ERR(lmk->hash_tfm);
492 }
493
494 /* No seed in LMK version 2 */
495 if (cc->key_parts == cc->tfms_count) {
496 lmk->seed = NULL;
497 return 0;
498 }
499
500 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
501 if (!lmk->seed) {
502 crypt_iv_lmk_dtr(cc);
503 ti->error = "Error kmallocing seed storage in LMK";
504 return -ENOMEM;
505 }
506
507 return 0;
508}
509
510static int crypt_iv_lmk_init(struct crypt_config *cc)
511{
512 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
513 int subkey_size = cc->key_size / cc->key_parts;
514
515 /* LMK seed is on the position of LMK_KEYS + 1 key */
516 if (lmk->seed)
517 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
518 crypto_shash_digestsize(lmk->hash_tfm));
519
520 return 0;
521}
522
523static int crypt_iv_lmk_wipe(struct crypt_config *cc)
524{
525 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
526
527 if (lmk->seed)
528 memset(lmk->seed, 0, LMK_SEED_SIZE);
529
530 return 0;
531}
532
533static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
534 struct dm_crypt_request *dmreq,
535 u8 *data)
536{
537 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
538 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
539 struct md5_state md5state;
540 __le32 buf[4];
541 int i, r;
542
543 desc->tfm = lmk->hash_tfm;
544 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
545
546 r = crypto_shash_init(desc);
547 if (r)
548 return r;
549
550 if (lmk->seed) {
551 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
552 if (r)
553 return r;
554 }
555
556 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
557 r = crypto_shash_update(desc, data + 16, 16 * 31);
558 if (r)
559 return r;
560
561 /* Sector is cropped to 56 bits here */
562 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
563 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
564 buf[2] = cpu_to_le32(4024);
565 buf[3] = 0;
566 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
567 if (r)
568 return r;
569
570 /* No MD5 padding here */
571 r = crypto_shash_export(desc, &md5state);
572 if (r)
573 return r;
574
575 for (i = 0; i < MD5_HASH_WORDS; i++)
576 __cpu_to_le32s(&md5state.hash[i]);
577 memcpy(iv, &md5state.hash, cc->iv_size);
578
579 return 0;
580}
581
582static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
583 struct dm_crypt_request *dmreq)
584{
585 u8 *src;
586 int r = 0;
587
588 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
589 src = kmap_atomic(sg_page(&dmreq->sg_in));
590 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
591 kunmap_atomic(src);
592 } else
593 memset(iv, 0, cc->iv_size);
594
595 return r;
596}
597
598static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
599 struct dm_crypt_request *dmreq)
600{
601 u8 *dst;
602 int r;
603
604 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
605 return 0;
606
607 dst = kmap_atomic(sg_page(&dmreq->sg_out));
608 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
609
610 /* Tweak the first block of plaintext sector */
611 if (!r)
612 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
613
614 kunmap_atomic(dst);
615 return r;
616}
617
618static void crypt_iv_tcw_dtr(struct crypt_config *cc)
619{
620 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
621
622 kzfree(tcw->iv_seed);
623 tcw->iv_seed = NULL;
624 kzfree(tcw->whitening);
625 tcw->whitening = NULL;
626
627 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
628 crypto_free_shash(tcw->crc32_tfm);
629 tcw->crc32_tfm = NULL;
630}
631
632static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
633 const char *opts)
634{
635 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
636
637 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
638 ti->error = "Wrong key size for TCW";
639 return -EINVAL;
640 }
641
642 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
643 if (IS_ERR(tcw->crc32_tfm)) {
644 ti->error = "Error initializing CRC32 in TCW";
645 return PTR_ERR(tcw->crc32_tfm);
646 }
647
648 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
649 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
650 if (!tcw->iv_seed || !tcw->whitening) {
651 crypt_iv_tcw_dtr(cc);
652 ti->error = "Error allocating seed storage in TCW";
653 return -ENOMEM;
654 }
655
656 return 0;
657}
658
659static int crypt_iv_tcw_init(struct crypt_config *cc)
660{
661 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
662 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
663
664 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
665 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
666 TCW_WHITENING_SIZE);
667
668 return 0;
669}
670
671static int crypt_iv_tcw_wipe(struct crypt_config *cc)
672{
673 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
674
675 memset(tcw->iv_seed, 0, cc->iv_size);
676 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
677
678 return 0;
679}
680
681static int crypt_iv_tcw_whitening(struct crypt_config *cc,
682 struct dm_crypt_request *dmreq,
683 u8 *data)
684{
685 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
686 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
687 u8 buf[TCW_WHITENING_SIZE];
688 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
689 int i, r;
690
691 /* xor whitening with sector number */
692 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
693 crypto_xor(buf, (u8 *)§or, 8);
694 crypto_xor(&buf[8], (u8 *)§or, 8);
695
696 /* calculate crc32 for every 32bit part and xor it */
697 desc->tfm = tcw->crc32_tfm;
698 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
699 for (i = 0; i < 4; i++) {
700 r = crypto_shash_init(desc);
701 if (r)
702 goto out;
703 r = crypto_shash_update(desc, &buf[i * 4], 4);
704 if (r)
705 goto out;
706 r = crypto_shash_final(desc, &buf[i * 4]);
707 if (r)
708 goto out;
709 }
710 crypto_xor(&buf[0], &buf[12], 4);
711 crypto_xor(&buf[4], &buf[8], 4);
712
713 /* apply whitening (8 bytes) to whole sector */
714 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
715 crypto_xor(data + i * 8, buf, 8);
716out:
717 memzero_explicit(buf, sizeof(buf));
718 return r;
719}
720
721static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
722 struct dm_crypt_request *dmreq)
723{
724 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
725 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
726 u8 *src;
727 int r = 0;
728
729 /* Remove whitening from ciphertext */
730 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
731 src = kmap_atomic(sg_page(&dmreq->sg_in));
732 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
733 kunmap_atomic(src);
734 }
735
736 /* Calculate IV */
737 memcpy(iv, tcw->iv_seed, cc->iv_size);
738 crypto_xor(iv, (u8 *)§or, 8);
739 if (cc->iv_size > 8)
740 crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
741
742 return r;
743}
744
745static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
746 struct dm_crypt_request *dmreq)
747{
748 u8 *dst;
749 int r;
750
751 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
752 return 0;
753
754 /* Apply whitening on ciphertext */
755 dst = kmap_atomic(sg_page(&dmreq->sg_out));
756 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
757 kunmap_atomic(dst);
758
759 return r;
760}
761
762static struct crypt_iv_operations crypt_iv_plain_ops = {
763 .generator = crypt_iv_plain_gen
764};
765
766static struct crypt_iv_operations crypt_iv_plain64_ops = {
767 .generator = crypt_iv_plain64_gen
768};
769
770static struct crypt_iv_operations crypt_iv_essiv_ops = {
771 .ctr = crypt_iv_essiv_ctr,
772 .dtr = crypt_iv_essiv_dtr,
773 .init = crypt_iv_essiv_init,
774 .wipe = crypt_iv_essiv_wipe,
775 .generator = crypt_iv_essiv_gen
776};
777
778static struct crypt_iv_operations crypt_iv_benbi_ops = {
779 .ctr = crypt_iv_benbi_ctr,
780 .dtr = crypt_iv_benbi_dtr,
781 .generator = crypt_iv_benbi_gen
782};
783
784static struct crypt_iv_operations crypt_iv_null_ops = {
785 .generator = crypt_iv_null_gen
786};
787
788static struct crypt_iv_operations crypt_iv_lmk_ops = {
789 .ctr = crypt_iv_lmk_ctr,
790 .dtr = crypt_iv_lmk_dtr,
791 .init = crypt_iv_lmk_init,
792 .wipe = crypt_iv_lmk_wipe,
793 .generator = crypt_iv_lmk_gen,
794 .post = crypt_iv_lmk_post
795};
796
797static struct crypt_iv_operations crypt_iv_tcw_ops = {
798 .ctr = crypt_iv_tcw_ctr,
799 .dtr = crypt_iv_tcw_dtr,
800 .init = crypt_iv_tcw_init,
801 .wipe = crypt_iv_tcw_wipe,
802 .generator = crypt_iv_tcw_gen,
803 .post = crypt_iv_tcw_post
804};
805
806static void crypt_convert_init(struct crypt_config *cc,
807 struct convert_context *ctx,
808 struct bio *bio_out, struct bio *bio_in,
809 sector_t sector)
810{
811 ctx->bio_in = bio_in;
812 ctx->bio_out = bio_out;
813 if (bio_in)
814 ctx->iter_in = bio_in->bi_iter;
815 if (bio_out)
816 ctx->iter_out = bio_out->bi_iter;
817 ctx->cc_sector = sector + cc->iv_offset;
818 init_completion(&ctx->restart);
819}
820
821static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
822 struct skcipher_request *req)
823{
824 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
825}
826
827static struct skcipher_request *req_of_dmreq(struct crypt_config *cc,
828 struct dm_crypt_request *dmreq)
829{
830 return (struct skcipher_request *)((char *)dmreq - cc->dmreq_start);
831}
832
833static u8 *iv_of_dmreq(struct crypt_config *cc,
834 struct dm_crypt_request *dmreq)
835{
836 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
837 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
838}
839
840static int crypt_convert_block(struct crypt_config *cc,
841 struct convert_context *ctx,
842 struct skcipher_request *req)
843{
844 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
845 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
846 struct dm_crypt_request *dmreq;
847 u8 *iv;
848 int r;
849
850 dmreq = dmreq_of_req(cc, req);
851 iv = iv_of_dmreq(cc, dmreq);
852
853 dmreq->iv_sector = ctx->cc_sector;
854 dmreq->ctx = ctx;
855 sg_init_table(&dmreq->sg_in, 1);
856 sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
857 bv_in.bv_offset);
858
859 sg_init_table(&dmreq->sg_out, 1);
860 sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
861 bv_out.bv_offset);
862
863 bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
864 bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
865
866 if (cc->iv_gen_ops) {
867 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
868 if (r < 0)
869 return r;
870 }
871
872 skcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
873 1 << SECTOR_SHIFT, iv);
874
875 if (bio_data_dir(ctx->bio_in) == WRITE)
876 r = crypto_skcipher_encrypt(req);
877 else
878 r = crypto_skcipher_decrypt(req);
879
880 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
881 r = cc->iv_gen_ops->post(cc, iv, dmreq);
882
883 return r;
884}
885
886static void kcryptd_async_done(struct crypto_async_request *async_req,
887 int error);
888
889static void crypt_alloc_req(struct crypt_config *cc,
890 struct convert_context *ctx)
891{
892 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
893
894 if (!ctx->req)
895 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
896
897 skcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
898
899 /*
900 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
901 * requests if driver request queue is full.
902 */
903 skcipher_request_set_callback(ctx->req,
904 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
905 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
906}
907
908static void crypt_free_req(struct crypt_config *cc,
909 struct skcipher_request *req, struct bio *base_bio)
910{
911 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
912
913 if ((struct skcipher_request *)(io + 1) != req)
914 mempool_free(req, cc->req_pool);
915}
916
917/*
918 * Encrypt / decrypt data from one bio to another one (can be the same one)
919 */
920static int crypt_convert(struct crypt_config *cc,
921 struct convert_context *ctx)
922{
923 int r;
924
925 atomic_set(&ctx->cc_pending, 1);
926
927 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
928
929 crypt_alloc_req(cc, ctx);
930
931 atomic_inc(&ctx->cc_pending);
932
933 r = crypt_convert_block(cc, ctx, ctx->req);
934
935 switch (r) {
936 /*
937 * The request was queued by a crypto driver
938 * but the driver request queue is full, let's wait.
939 */
940 case -EBUSY:
941 wait_for_completion(&ctx->restart);
942 reinit_completion(&ctx->restart);
943 /* fall through */
944 /*
945 * The request is queued and processed asynchronously,
946 * completion function kcryptd_async_done() will be called.
947 */
948 case -EINPROGRESS:
949 ctx->req = NULL;
950 ctx->cc_sector++;
951 continue;
952 /*
953 * The request was already processed (synchronously).
954 */
955 case 0:
956 atomic_dec(&ctx->cc_pending);
957 ctx->cc_sector++;
958 cond_resched();
959 continue;
960
961 /* There was an error while processing the request. */
962 default:
963 atomic_dec(&ctx->cc_pending);
964 return r;
965 }
966 }
967
968 return 0;
969}
970
971static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
972
973/*
974 * Generate a new unfragmented bio with the given size
975 * This should never violate the device limitations (but only because
976 * max_segment_size is being constrained to PAGE_SIZE).
977 *
978 * This function may be called concurrently. If we allocate from the mempool
979 * concurrently, there is a possibility of deadlock. For example, if we have
980 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
981 * the mempool concurrently, it may deadlock in a situation where both processes
982 * have allocated 128 pages and the mempool is exhausted.
983 *
984 * In order to avoid this scenario we allocate the pages under a mutex.
985 *
986 * In order to not degrade performance with excessive locking, we try
987 * non-blocking allocations without a mutex first but on failure we fallback
988 * to blocking allocations with a mutex.
989 */
990static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
991{
992 struct crypt_config *cc = io->cc;
993 struct bio *clone;
994 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
995 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
996 unsigned i, len, remaining_size;
997 struct page *page;
998 struct bio_vec *bvec;
999
1000retry:
1001 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1002 mutex_lock(&cc->bio_alloc_lock);
1003
1004 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1005 if (!clone)
1006 goto return_clone;
1007
1008 clone_init(io, clone);
1009
1010 remaining_size = size;
1011
1012 for (i = 0; i < nr_iovecs; i++) {
1013 page = mempool_alloc(cc->page_pool, gfp_mask);
1014 if (!page) {
1015 crypt_free_buffer_pages(cc, clone);
1016 bio_put(clone);
1017 gfp_mask |= __GFP_DIRECT_RECLAIM;
1018 goto retry;
1019 }
1020
1021 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1022
1023 bvec = &clone->bi_io_vec[clone->bi_vcnt++];
1024 bvec->bv_page = page;
1025 bvec->bv_len = len;
1026 bvec->bv_offset = 0;
1027
1028 clone->bi_iter.bi_size += len;
1029
1030 remaining_size -= len;
1031 }
1032
1033return_clone:
1034 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1035 mutex_unlock(&cc->bio_alloc_lock);
1036
1037 return clone;
1038}
1039
1040static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1041{
1042 unsigned int i;
1043 struct bio_vec *bv;
1044
1045 bio_for_each_segment_all(bv, clone, i) {
1046 BUG_ON(!bv->bv_page);
1047 mempool_free(bv->bv_page, cc->page_pool);
1048 bv->bv_page = NULL;
1049 }
1050}
1051
1052static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1053 struct bio *bio, sector_t sector)
1054{
1055 io->cc = cc;
1056 io->base_bio = bio;
1057 io->sector = sector;
1058 io->error = 0;
1059 io->ctx.req = NULL;
1060 atomic_set(&io->io_pending, 0);
1061}
1062
1063static void crypt_inc_pending(struct dm_crypt_io *io)
1064{
1065 atomic_inc(&io->io_pending);
1066}
1067
1068/*
1069 * One of the bios was finished. Check for completion of
1070 * the whole request and correctly clean up the buffer.
1071 */
1072static void crypt_dec_pending(struct dm_crypt_io *io)
1073{
1074 struct crypt_config *cc = io->cc;
1075 struct bio *base_bio = io->base_bio;
1076 int error = io->error;
1077
1078 if (!atomic_dec_and_test(&io->io_pending))
1079 return;
1080
1081 if (io->ctx.req)
1082 crypt_free_req(cc, io->ctx.req, base_bio);
1083
1084 base_bio->bi_error = error;
1085 bio_endio(base_bio);
1086}
1087
1088/*
1089 * kcryptd/kcryptd_io:
1090 *
1091 * Needed because it would be very unwise to do decryption in an
1092 * interrupt context.
1093 *
1094 * kcryptd performs the actual encryption or decryption.
1095 *
1096 * kcryptd_io performs the IO submission.
1097 *
1098 * They must be separated as otherwise the final stages could be
1099 * starved by new requests which can block in the first stages due
1100 * to memory allocation.
1101 *
1102 * The work is done per CPU global for all dm-crypt instances.
1103 * They should not depend on each other and do not block.
1104 */
1105static void crypt_endio(struct bio *clone)
1106{
1107 struct dm_crypt_io *io = clone->bi_private;
1108 struct crypt_config *cc = io->cc;
1109 unsigned rw = bio_data_dir(clone);
1110 int error;
1111
1112 /*
1113 * free the processed pages
1114 */
1115 if (rw == WRITE)
1116 crypt_free_buffer_pages(cc, clone);
1117
1118 error = clone->bi_error;
1119 bio_put(clone);
1120
1121 if (rw == READ && !error) {
1122 kcryptd_queue_crypt(io);
1123 return;
1124 }
1125
1126 if (unlikely(error))
1127 io->error = error;
1128
1129 crypt_dec_pending(io);
1130}
1131
1132static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1133{
1134 struct crypt_config *cc = io->cc;
1135
1136 clone->bi_private = io;
1137 clone->bi_end_io = crypt_endio;
1138 clone->bi_bdev = cc->dev->bdev;
1139 clone->bi_rw = io->base_bio->bi_rw;
1140}
1141
1142static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1143{
1144 struct crypt_config *cc = io->cc;
1145 struct bio *clone;
1146
1147 /*
1148 * We need the original biovec array in order to decrypt
1149 * the whole bio data *afterwards* -- thanks to immutable
1150 * biovecs we don't need to worry about the block layer
1151 * modifying the biovec array; so leverage bio_clone_fast().
1152 */
1153 clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1154 if (!clone)
1155 return 1;
1156
1157 crypt_inc_pending(io);
1158
1159 clone_init(io, clone);
1160 clone->bi_iter.bi_sector = cc->start + io->sector;
1161
1162 generic_make_request(clone);
1163 return 0;
1164}
1165
1166static void kcryptd_io_read_work(struct work_struct *work)
1167{
1168 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1169
1170 crypt_inc_pending(io);
1171 if (kcryptd_io_read(io, GFP_NOIO))
1172 io->error = -ENOMEM;
1173 crypt_dec_pending(io);
1174}
1175
1176static void kcryptd_queue_read(struct dm_crypt_io *io)
1177{
1178 struct crypt_config *cc = io->cc;
1179
1180 INIT_WORK(&io->work, kcryptd_io_read_work);
1181 queue_work(cc->io_queue, &io->work);
1182}
1183
1184static void kcryptd_io_write(struct dm_crypt_io *io)
1185{
1186 struct bio *clone = io->ctx.bio_out;
1187
1188 generic_make_request(clone);
1189}
1190
1191#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1192
1193static int dmcrypt_write(void *data)
1194{
1195 struct crypt_config *cc = data;
1196 struct dm_crypt_io *io;
1197
1198 while (1) {
1199 struct rb_root write_tree;
1200 struct blk_plug plug;
1201
1202 DECLARE_WAITQUEUE(wait, current);
1203
1204 spin_lock_irq(&cc->write_thread_wait.lock);
1205continue_locked:
1206
1207 if (!RB_EMPTY_ROOT(&cc->write_tree))
1208 goto pop_from_list;
1209
1210 if (unlikely(test_bit(DM_CRYPT_EXIT_THREAD, &cc->flags))) {
1211 spin_unlock_irq(&cc->write_thread_wait.lock);
1212 break;
1213 }
1214
1215 __set_current_state(TASK_INTERRUPTIBLE);
1216 __add_wait_queue(&cc->write_thread_wait, &wait);
1217
1218 spin_unlock_irq(&cc->write_thread_wait.lock);
1219
1220 schedule();
1221
1222 spin_lock_irq(&cc->write_thread_wait.lock);
1223 __remove_wait_queue(&cc->write_thread_wait, &wait);
1224 goto continue_locked;
1225
1226pop_from_list:
1227 write_tree = cc->write_tree;
1228 cc->write_tree = RB_ROOT;
1229 spin_unlock_irq(&cc->write_thread_wait.lock);
1230
1231 BUG_ON(rb_parent(write_tree.rb_node));
1232
1233 /*
1234 * Note: we cannot walk the tree here with rb_next because
1235 * the structures may be freed when kcryptd_io_write is called.
1236 */
1237 blk_start_plug(&plug);
1238 do {
1239 io = crypt_io_from_node(rb_first(&write_tree));
1240 rb_erase(&io->rb_node, &write_tree);
1241 kcryptd_io_write(io);
1242 } while (!RB_EMPTY_ROOT(&write_tree));
1243 blk_finish_plug(&plug);
1244 }
1245 return 0;
1246}
1247
1248static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1249{
1250 struct bio *clone = io->ctx.bio_out;
1251 struct crypt_config *cc = io->cc;
1252 unsigned long flags;
1253 sector_t sector;
1254 struct rb_node **rbp, *parent;
1255
1256 if (unlikely(io->error < 0)) {
1257 crypt_free_buffer_pages(cc, clone);
1258 bio_put(clone);
1259 crypt_dec_pending(io);
1260 return;
1261 }
1262
1263 /* crypt_convert should have filled the clone bio */
1264 BUG_ON(io->ctx.iter_out.bi_size);
1265
1266 clone->bi_iter.bi_sector = cc->start + io->sector;
1267
1268 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1269 generic_make_request(clone);
1270 return;
1271 }
1272
1273 spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1274 rbp = &cc->write_tree.rb_node;
1275 parent = NULL;
1276 sector = io->sector;
1277 while (*rbp) {
1278 parent = *rbp;
1279 if (sector < crypt_io_from_node(parent)->sector)
1280 rbp = &(*rbp)->rb_left;
1281 else
1282 rbp = &(*rbp)->rb_right;
1283 }
1284 rb_link_node(&io->rb_node, parent, rbp);
1285 rb_insert_color(&io->rb_node, &cc->write_tree);
1286
1287 wake_up_locked(&cc->write_thread_wait);
1288 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1289}
1290
1291static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1292{
1293 struct crypt_config *cc = io->cc;
1294 struct bio *clone;
1295 int crypt_finished;
1296 sector_t sector = io->sector;
1297 int r;
1298
1299 /*
1300 * Prevent io from disappearing until this function completes.
1301 */
1302 crypt_inc_pending(io);
1303 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1304
1305 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1306 if (unlikely(!clone)) {
1307 io->error = -EIO;
1308 goto dec;
1309 }
1310
1311 io->ctx.bio_out = clone;
1312 io->ctx.iter_out = clone->bi_iter;
1313
1314 sector += bio_sectors(clone);
1315
1316 crypt_inc_pending(io);
1317 r = crypt_convert(cc, &io->ctx);
1318 if (r)
1319 io->error = -EIO;
1320 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1321
1322 /* Encryption was already finished, submit io now */
1323 if (crypt_finished) {
1324 kcryptd_crypt_write_io_submit(io, 0);
1325 io->sector = sector;
1326 }
1327
1328dec:
1329 crypt_dec_pending(io);
1330}
1331
1332static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1333{
1334 crypt_dec_pending(io);
1335}
1336
1337static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1338{
1339 struct crypt_config *cc = io->cc;
1340 int r = 0;
1341
1342 crypt_inc_pending(io);
1343
1344 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1345 io->sector);
1346
1347 r = crypt_convert(cc, &io->ctx);
1348 if (r < 0)
1349 io->error = -EIO;
1350
1351 if (atomic_dec_and_test(&io->ctx.cc_pending))
1352 kcryptd_crypt_read_done(io);
1353
1354 crypt_dec_pending(io);
1355}
1356
1357static void kcryptd_async_done(struct crypto_async_request *async_req,
1358 int error)
1359{
1360 struct dm_crypt_request *dmreq = async_req->data;
1361 struct convert_context *ctx = dmreq->ctx;
1362 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1363 struct crypt_config *cc = io->cc;
1364
1365 /*
1366 * A request from crypto driver backlog is going to be processed now,
1367 * finish the completion and continue in crypt_convert().
1368 * (Callback will be called for the second time for this request.)
1369 */
1370 if (error == -EINPROGRESS) {
1371 complete(&ctx->restart);
1372 return;
1373 }
1374
1375 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1376 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1377
1378 if (error < 0)
1379 io->error = -EIO;
1380
1381 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1382
1383 if (!atomic_dec_and_test(&ctx->cc_pending))
1384 return;
1385
1386 if (bio_data_dir(io->base_bio) == READ)
1387 kcryptd_crypt_read_done(io);
1388 else
1389 kcryptd_crypt_write_io_submit(io, 1);
1390}
1391
1392static void kcryptd_crypt(struct work_struct *work)
1393{
1394 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1395
1396 if (bio_data_dir(io->base_bio) == READ)
1397 kcryptd_crypt_read_convert(io);
1398 else
1399 kcryptd_crypt_write_convert(io);
1400}
1401
1402static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1403{
1404 struct crypt_config *cc = io->cc;
1405
1406 INIT_WORK(&io->work, kcryptd_crypt);
1407 queue_work(cc->crypt_queue, &io->work);
1408}
1409
1410/*
1411 * Decode key from its hex representation
1412 */
1413static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1414{
1415 char buffer[3];
1416 unsigned int i;
1417
1418 buffer[2] = '\0';
1419
1420 for (i = 0; i < size; i++) {
1421 buffer[0] = *hex++;
1422 buffer[1] = *hex++;
1423
1424 if (kstrtou8(buffer, 16, &key[i]))
1425 return -EINVAL;
1426 }
1427
1428 if (*hex != '\0')
1429 return -EINVAL;
1430
1431 return 0;
1432}
1433
1434static void crypt_free_tfms(struct crypt_config *cc)
1435{
1436 unsigned i;
1437
1438 if (!cc->tfms)
1439 return;
1440
1441 for (i = 0; i < cc->tfms_count; i++)
1442 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1443 crypto_free_skcipher(cc->tfms[i]);
1444 cc->tfms[i] = NULL;
1445 }
1446
1447 kfree(cc->tfms);
1448 cc->tfms = NULL;
1449}
1450
1451static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1452{
1453 unsigned i;
1454 int err;
1455
1456 cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
1457 GFP_KERNEL);
1458 if (!cc->tfms)
1459 return -ENOMEM;
1460
1461 for (i = 0; i < cc->tfms_count; i++) {
1462 cc->tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1463 if (IS_ERR(cc->tfms[i])) {
1464 err = PTR_ERR(cc->tfms[i]);
1465 crypt_free_tfms(cc);
1466 return err;
1467 }
1468 }
1469
1470 return 0;
1471}
1472
1473static int crypt_setkey_allcpus(struct crypt_config *cc)
1474{
1475 unsigned subkey_size;
1476 int err = 0, i, r;
1477
1478 /* Ignore extra keys (which are used for IV etc) */
1479 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1480
1481 for (i = 0; i < cc->tfms_count; i++) {
1482 r = crypto_skcipher_setkey(cc->tfms[i],
1483 cc->key + (i * subkey_size),
1484 subkey_size);
1485 if (r)
1486 err = r;
1487 }
1488
1489 return err;
1490}
1491
1492static int crypt_set_key(struct crypt_config *cc, char *key)
1493{
1494 int r = -EINVAL;
1495 int key_string_len = strlen(key);
1496
1497 /* The key size may not be changed. */
1498 if (cc->key_size != (key_string_len >> 1))
1499 goto out;
1500
1501 /* Hyphen (which gives a key_size of zero) means there is no key. */
1502 if (!cc->key_size && strcmp(key, "-"))
1503 goto out;
1504
1505 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1506 goto out;
1507
1508 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1509
1510 r = crypt_setkey_allcpus(cc);
1511
1512out:
1513 /* Hex key string not needed after here, so wipe it. */
1514 memset(key, '0', key_string_len);
1515
1516 return r;
1517}
1518
1519static int crypt_wipe_key(struct crypt_config *cc)
1520{
1521 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1522 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1523
1524 return crypt_setkey_allcpus(cc);
1525}
1526
1527static void crypt_dtr(struct dm_target *ti)
1528{
1529 struct crypt_config *cc = ti->private;
1530
1531 ti->private = NULL;
1532
1533 if (!cc)
1534 return;
1535
1536 if (cc->write_thread) {
1537 spin_lock_irq(&cc->write_thread_wait.lock);
1538 set_bit(DM_CRYPT_EXIT_THREAD, &cc->flags);
1539 wake_up_locked(&cc->write_thread_wait);
1540 spin_unlock_irq(&cc->write_thread_wait.lock);
1541 kthread_stop(cc->write_thread);
1542 }
1543
1544 if (cc->io_queue)
1545 destroy_workqueue(cc->io_queue);
1546 if (cc->crypt_queue)
1547 destroy_workqueue(cc->crypt_queue);
1548
1549 crypt_free_tfms(cc);
1550
1551 if (cc->bs)
1552 bioset_free(cc->bs);
1553
1554 mempool_destroy(cc->page_pool);
1555 mempool_destroy(cc->req_pool);
1556
1557 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1558 cc->iv_gen_ops->dtr(cc);
1559
1560 if (cc->dev)
1561 dm_put_device(ti, cc->dev);
1562
1563 kzfree(cc->cipher);
1564 kzfree(cc->cipher_string);
1565
1566 /* Must zero key material before freeing */
1567 kzfree(cc);
1568}
1569
1570static int crypt_ctr_cipher(struct dm_target *ti,
1571 char *cipher_in, char *key)
1572{
1573 struct crypt_config *cc = ti->private;
1574 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1575 char *cipher_api = NULL;
1576 int ret = -EINVAL;
1577 char dummy;
1578
1579 /* Convert to crypto api definition? */
1580 if (strchr(cipher_in, '(')) {
1581 ti->error = "Bad cipher specification";
1582 return -EINVAL;
1583 }
1584
1585 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1586 if (!cc->cipher_string)
1587 goto bad_mem;
1588
1589 /*
1590 * Legacy dm-crypt cipher specification
1591 * cipher[:keycount]-mode-iv:ivopts
1592 */
1593 tmp = cipher_in;
1594 keycount = strsep(&tmp, "-");
1595 cipher = strsep(&keycount, ":");
1596
1597 if (!keycount)
1598 cc->tfms_count = 1;
1599 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1600 !is_power_of_2(cc->tfms_count)) {
1601 ti->error = "Bad cipher key count specification";
1602 return -EINVAL;
1603 }
1604 cc->key_parts = cc->tfms_count;
1605 cc->key_extra_size = 0;
1606
1607 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1608 if (!cc->cipher)
1609 goto bad_mem;
1610
1611 chainmode = strsep(&tmp, "-");
1612 ivopts = strsep(&tmp, "-");
1613 ivmode = strsep(&ivopts, ":");
1614
1615 if (tmp)
1616 DMWARN("Ignoring unexpected additional cipher options");
1617
1618 /*
1619 * For compatibility with the original dm-crypt mapping format, if
1620 * only the cipher name is supplied, use cbc-plain.
1621 */
1622 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1623 chainmode = "cbc";
1624 ivmode = "plain";
1625 }
1626
1627 if (strcmp(chainmode, "ecb") && !ivmode) {
1628 ti->error = "IV mechanism required";
1629 return -EINVAL;
1630 }
1631
1632 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1633 if (!cipher_api)
1634 goto bad_mem;
1635
1636 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1637 "%s(%s)", chainmode, cipher);
1638 if (ret < 0) {
1639 kfree(cipher_api);
1640 goto bad_mem;
1641 }
1642
1643 /* Allocate cipher */
1644 ret = crypt_alloc_tfms(cc, cipher_api);
1645 if (ret < 0) {
1646 ti->error = "Error allocating crypto tfm";
1647 goto bad;
1648 }
1649
1650 /* Initialize IV */
1651 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
1652 if (cc->iv_size)
1653 /* at least a 64 bit sector number should fit in our buffer */
1654 cc->iv_size = max(cc->iv_size,
1655 (unsigned int)(sizeof(u64) / sizeof(u8)));
1656 else if (ivmode) {
1657 DMWARN("Selected cipher does not support IVs");
1658 ivmode = NULL;
1659 }
1660
1661 /* Choose ivmode, see comments at iv code. */
1662 if (ivmode == NULL)
1663 cc->iv_gen_ops = NULL;
1664 else if (strcmp(ivmode, "plain") == 0)
1665 cc->iv_gen_ops = &crypt_iv_plain_ops;
1666 else if (strcmp(ivmode, "plain64") == 0)
1667 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1668 else if (strcmp(ivmode, "essiv") == 0)
1669 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1670 else if (strcmp(ivmode, "benbi") == 0)
1671 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1672 else if (strcmp(ivmode, "null") == 0)
1673 cc->iv_gen_ops = &crypt_iv_null_ops;
1674 else if (strcmp(ivmode, "lmk") == 0) {
1675 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1676 /*
1677 * Version 2 and 3 is recognised according
1678 * to length of provided multi-key string.
1679 * If present (version 3), last key is used as IV seed.
1680 * All keys (including IV seed) are always the same size.
1681 */
1682 if (cc->key_size % cc->key_parts) {
1683 cc->key_parts++;
1684 cc->key_extra_size = cc->key_size / cc->key_parts;
1685 }
1686 } else if (strcmp(ivmode, "tcw") == 0) {
1687 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1688 cc->key_parts += 2; /* IV + whitening */
1689 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1690 } else {
1691 ret = -EINVAL;
1692 ti->error = "Invalid IV mode";
1693 goto bad;
1694 }
1695
1696 /* Initialize and set key */
1697 ret = crypt_set_key(cc, key);
1698 if (ret < 0) {
1699 ti->error = "Error decoding and setting key";
1700 goto bad;
1701 }
1702
1703 /* Allocate IV */
1704 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1705 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1706 if (ret < 0) {
1707 ti->error = "Error creating IV";
1708 goto bad;
1709 }
1710 }
1711
1712 /* Initialize IV (set keys for ESSIV etc) */
1713 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1714 ret = cc->iv_gen_ops->init(cc);
1715 if (ret < 0) {
1716 ti->error = "Error initialising IV";
1717 goto bad;
1718 }
1719 }
1720
1721 ret = 0;
1722bad:
1723 kfree(cipher_api);
1724 return ret;
1725
1726bad_mem:
1727 ti->error = "Cannot allocate cipher strings";
1728 return -ENOMEM;
1729}
1730
1731/*
1732 * Construct an encryption mapping:
1733 * <cipher> <key> <iv_offset> <dev_path> <start>
1734 */
1735static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1736{
1737 struct crypt_config *cc;
1738 unsigned int key_size, opt_params;
1739 unsigned long long tmpll;
1740 int ret;
1741 size_t iv_size_padding;
1742 struct dm_arg_set as;
1743 const char *opt_string;
1744 char dummy;
1745
1746 static struct dm_arg _args[] = {
1747 {0, 3, "Invalid number of feature args"},
1748 };
1749
1750 if (argc < 5) {
1751 ti->error = "Not enough arguments";
1752 return -EINVAL;
1753 }
1754
1755 key_size = strlen(argv[1]) >> 1;
1756
1757 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1758 if (!cc) {
1759 ti->error = "Cannot allocate encryption context";
1760 return -ENOMEM;
1761 }
1762 cc->key_size = key_size;
1763
1764 ti->private = cc;
1765 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1766 if (ret < 0)
1767 goto bad;
1768
1769 cc->dmreq_start = sizeof(struct skcipher_request);
1770 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
1771 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1772
1773 if (crypto_skcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1774 /* Allocate the padding exactly */
1775 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1776 & crypto_skcipher_alignmask(any_tfm(cc));
1777 } else {
1778 /*
1779 * If the cipher requires greater alignment than kmalloc
1780 * alignment, we don't know the exact position of the
1781 * initialization vector. We must assume worst case.
1782 */
1783 iv_size_padding = crypto_skcipher_alignmask(any_tfm(cc));
1784 }
1785
1786 ret = -ENOMEM;
1787 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1788 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1789 if (!cc->req_pool) {
1790 ti->error = "Cannot allocate crypt request mempool";
1791 goto bad;
1792 }
1793
1794 cc->per_bio_data_size = ti->per_io_data_size =
1795 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1796 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1797 ARCH_KMALLOC_MINALIGN);
1798
1799 cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1800 if (!cc->page_pool) {
1801 ti->error = "Cannot allocate page mempool";
1802 goto bad;
1803 }
1804
1805 cc->bs = bioset_create(MIN_IOS, 0);
1806 if (!cc->bs) {
1807 ti->error = "Cannot allocate crypt bioset";
1808 goto bad;
1809 }
1810
1811 mutex_init(&cc->bio_alloc_lock);
1812
1813 ret = -EINVAL;
1814 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1815 ti->error = "Invalid iv_offset sector";
1816 goto bad;
1817 }
1818 cc->iv_offset = tmpll;
1819
1820 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
1821 if (ret) {
1822 ti->error = "Device lookup failed";
1823 goto bad;
1824 }
1825
1826 ret = -EINVAL;
1827 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1828 ti->error = "Invalid device sector";
1829 goto bad;
1830 }
1831 cc->start = tmpll;
1832
1833 argv += 5;
1834 argc -= 5;
1835
1836 /* Optional parameters */
1837 if (argc) {
1838 as.argc = argc;
1839 as.argv = argv;
1840
1841 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1842 if (ret)
1843 goto bad;
1844
1845 ret = -EINVAL;
1846 while (opt_params--) {
1847 opt_string = dm_shift_arg(&as);
1848 if (!opt_string) {
1849 ti->error = "Not enough feature arguments";
1850 goto bad;
1851 }
1852
1853 if (!strcasecmp(opt_string, "allow_discards"))
1854 ti->num_discard_bios = 1;
1855
1856 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1857 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1858
1859 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
1860 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1861
1862 else {
1863 ti->error = "Invalid feature arguments";
1864 goto bad;
1865 }
1866 }
1867 }
1868
1869 ret = -ENOMEM;
1870 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1871 if (!cc->io_queue) {
1872 ti->error = "Couldn't create kcryptd io queue";
1873 goto bad;
1874 }
1875
1876 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1877 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1878 else
1879 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
1880 num_online_cpus());
1881 if (!cc->crypt_queue) {
1882 ti->error = "Couldn't create kcryptd queue";
1883 goto bad;
1884 }
1885
1886 init_waitqueue_head(&cc->write_thread_wait);
1887 cc->write_tree = RB_ROOT;
1888
1889 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
1890 if (IS_ERR(cc->write_thread)) {
1891 ret = PTR_ERR(cc->write_thread);
1892 cc->write_thread = NULL;
1893 ti->error = "Couldn't spawn write thread";
1894 goto bad;
1895 }
1896 wake_up_process(cc->write_thread);
1897
1898 ti->num_flush_bios = 1;
1899 ti->discard_zeroes_data_unsupported = true;
1900
1901 return 0;
1902
1903bad:
1904 crypt_dtr(ti);
1905 return ret;
1906}
1907
1908static int crypt_map(struct dm_target *ti, struct bio *bio)
1909{
1910 struct dm_crypt_io *io;
1911 struct crypt_config *cc = ti->private;
1912
1913 /*
1914 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1915 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1916 * - for REQ_DISCARD caller must use flush if IO ordering matters
1917 */
1918 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1919 bio->bi_bdev = cc->dev->bdev;
1920 if (bio_sectors(bio))
1921 bio->bi_iter.bi_sector = cc->start +
1922 dm_target_offset(ti, bio->bi_iter.bi_sector);
1923 return DM_MAPIO_REMAPPED;
1924 }
1925
1926 io = dm_per_bio_data(bio, cc->per_bio_data_size);
1927 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
1928 io->ctx.req = (struct skcipher_request *)(io + 1);
1929
1930 if (bio_data_dir(io->base_bio) == READ) {
1931 if (kcryptd_io_read(io, GFP_NOWAIT))
1932 kcryptd_queue_read(io);
1933 } else
1934 kcryptd_queue_crypt(io);
1935
1936 return DM_MAPIO_SUBMITTED;
1937}
1938
1939static void crypt_status(struct dm_target *ti, status_type_t type,
1940 unsigned status_flags, char *result, unsigned maxlen)
1941{
1942 struct crypt_config *cc = ti->private;
1943 unsigned i, sz = 0;
1944 int num_feature_args = 0;
1945
1946 switch (type) {
1947 case STATUSTYPE_INFO:
1948 result[0] = '\0';
1949 break;
1950
1951 case STATUSTYPE_TABLE:
1952 DMEMIT("%s ", cc->cipher_string);
1953
1954 if (cc->key_size > 0)
1955 for (i = 0; i < cc->key_size; i++)
1956 DMEMIT("%02x", cc->key[i]);
1957 else
1958 DMEMIT("-");
1959
1960 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1961 cc->dev->name, (unsigned long long)cc->start);
1962
1963 num_feature_args += !!ti->num_discard_bios;
1964 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1965 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1966 if (num_feature_args) {
1967 DMEMIT(" %d", num_feature_args);
1968 if (ti->num_discard_bios)
1969 DMEMIT(" allow_discards");
1970 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1971 DMEMIT(" same_cpu_crypt");
1972 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
1973 DMEMIT(" submit_from_crypt_cpus");
1974 }
1975
1976 break;
1977 }
1978}
1979
1980static void crypt_postsuspend(struct dm_target *ti)
1981{
1982 struct crypt_config *cc = ti->private;
1983
1984 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1985}
1986
1987static int crypt_preresume(struct dm_target *ti)
1988{
1989 struct crypt_config *cc = ti->private;
1990
1991 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1992 DMERR("aborting resume - crypt key is not set.");
1993 return -EAGAIN;
1994 }
1995
1996 return 0;
1997}
1998
1999static void crypt_resume(struct dm_target *ti)
2000{
2001 struct crypt_config *cc = ti->private;
2002
2003 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2004}
2005
2006/* Message interface
2007 * key set <key>
2008 * key wipe
2009 */
2010static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
2011{
2012 struct crypt_config *cc = ti->private;
2013 int ret = -EINVAL;
2014
2015 if (argc < 2)
2016 goto error;
2017
2018 if (!strcasecmp(argv[0], "key")) {
2019 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2020 DMWARN("not suspended during key manipulation.");
2021 return -EINVAL;
2022 }
2023 if (argc == 3 && !strcasecmp(argv[1], "set")) {
2024 ret = crypt_set_key(cc, argv[2]);
2025 if (ret)
2026 return ret;
2027 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2028 ret = cc->iv_gen_ops->init(cc);
2029 return ret;
2030 }
2031 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
2032 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2033 ret = cc->iv_gen_ops->wipe(cc);
2034 if (ret)
2035 return ret;
2036 }
2037 return crypt_wipe_key(cc);
2038 }
2039 }
2040
2041error:
2042 DMWARN("unrecognised message received.");
2043 return -EINVAL;
2044}
2045
2046static int crypt_iterate_devices(struct dm_target *ti,
2047 iterate_devices_callout_fn fn, void *data)
2048{
2049 struct crypt_config *cc = ti->private;
2050
2051 return fn(ti, cc->dev, cc->start, ti->len, data);
2052}
2053
2054static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
2055{
2056 /*
2057 * Unfortunate constraint that is required to avoid the potential
2058 * for exceeding underlying device's max_segments limits -- due to
2059 * crypt_alloc_buffer() possibly allocating pages for the encryption
2060 * bio that are not as physically contiguous as the original bio.
2061 */
2062 limits->max_segment_size = PAGE_SIZE;
2063}
2064
2065static struct target_type crypt_target = {
2066 .name = "crypt",
2067 .version = {1, 14, 1},
2068 .module = THIS_MODULE,
2069 .ctr = crypt_ctr,
2070 .dtr = crypt_dtr,
2071 .map = crypt_map,
2072 .status = crypt_status,
2073 .postsuspend = crypt_postsuspend,
2074 .preresume = crypt_preresume,
2075 .resume = crypt_resume,
2076 .message = crypt_message,
2077 .iterate_devices = crypt_iterate_devices,
2078 .io_hints = crypt_io_hints,
2079};
2080
2081static int __init dm_crypt_init(void)
2082{
2083 int r;
2084
2085 r = dm_register_target(&crypt_target);
2086 if (r < 0)
2087 DMERR("register failed %d", r);
2088
2089 return r;
2090}
2091
2092static void __exit dm_crypt_exit(void)
2093{
2094 dm_unregister_target(&crypt_target);
2095}
2096
2097module_init(dm_crypt_init);
2098module_exit(dm_crypt_exit);
2099
2100MODULE_AUTHOR("Jana Saout <jana@saout.de>");
2101MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2102MODULE_LICENSE("GPL");
1/*
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>
6 *
7 * This file is released under the GPL.
8 */
9
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>
28#include <asm/page.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>
38
39#include <linux/device-mapper.h>
40
41#define DM_MSG_PREFIX "crypt"
42
43/*
44 * context holding the current state of a multi-part conversion
45 */
46struct convert_context {
47 struct completion restart;
48 struct bio *bio_in;
49 struct bio *bio_out;
50 struct bvec_iter iter_in;
51 struct bvec_iter iter_out;
52 sector_t cc_sector;
53 atomic_t cc_pending;
54 union {
55 struct skcipher_request *req;
56 struct aead_request *req_aead;
57 } r;
58
59};
60
61/*
62 * per bio private data
63 */
64struct dm_crypt_io {
65 struct crypt_config *cc;
66 struct bio *base_bio;
67 u8 *integrity_metadata;
68 bool integrity_metadata_from_pool;
69 struct work_struct work;
70
71 struct convert_context ctx;
72
73 atomic_t io_pending;
74 blk_status_t error;
75 sector_t sector;
76
77 struct rb_node rb_node;
78} CRYPTO_MINALIGN_ATTR;
79
80struct dm_crypt_request {
81 struct convert_context *ctx;
82 struct scatterlist sg_in[4];
83 struct scatterlist sg_out[4];
84 sector_t iv_sector;
85};
86
87struct crypt_config;
88
89struct crypt_iv_operations {
90 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
91 const char *opts);
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);
99};
100
101struct iv_essiv_private {
102 struct crypto_ahash *hash_tfm;
103 u8 *salt;
104};
105
106struct iv_benbi_private {
107 int shift;
108};
109
110#define LMK_SEED_SIZE 64 /* hash + 0 */
111struct iv_lmk_private {
112 struct crypto_shash *hash_tfm;
113 u8 *seed;
114};
115
116#define TCW_WHITENING_SIZE 16
117struct iv_tcw_private {
118 struct crypto_shash *crc32_tfm;
119 u8 *iv_seed;
120 u8 *whitening;
121};
122
123/*
124 * Crypt: maps a linear range of a block device
125 * and encrypts / decrypts at the same time.
126 */
127enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
128 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
129
130enum cipher_flags {
131 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */
132 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */
133};
134
135/*
136 * The fields in here must be read only after initialization.
137 */
138struct crypt_config {
139 struct dm_dev *dev;
140 sector_t start;
141
142 /*
143 * pool for per bio private data, crypto requests,
144 * encryption requeusts/buffer pages and integrity tags
145 */
146 mempool_t *req_pool;
147 mempool_t *page_pool;
148 mempool_t *tag_pool;
149 unsigned tag_pool_max_sectors;
150
151 struct percpu_counter n_allocated_pages;
152
153 struct bio_set *bs;
154 struct mutex bio_alloc_lock;
155
156 struct workqueue_struct *io_queue;
157 struct workqueue_struct *crypt_queue;
158
159 struct task_struct *write_thread;
160 wait_queue_head_t write_thread_wait;
161 struct rb_root write_tree;
162
163 char *cipher;
164 char *cipher_string;
165 char *cipher_auth;
166 char *key_string;
167
168 const struct crypt_iv_operations *iv_gen_ops;
169 union {
170 struct iv_essiv_private essiv;
171 struct iv_benbi_private benbi;
172 struct iv_lmk_private lmk;
173 struct iv_tcw_private tcw;
174 } iv_gen_private;
175 sector_t iv_offset;
176 unsigned int iv_size;
177 unsigned short int sector_size;
178 unsigned char sector_shift;
179
180 /* ESSIV: struct crypto_cipher *essiv_tfm */
181 void *iv_private;
182 union {
183 struct crypto_skcipher **tfms;
184 struct crypto_aead **tfms_aead;
185 } cipher_tfm;
186 unsigned tfms_count;
187 unsigned long cipher_flags;
188
189 /*
190 * Layout of each crypto request:
191 *
192 * struct skcipher_request
193 * context
194 * padding
195 * struct dm_crypt_request
196 * padding
197 * IV
198 *
199 * The padding is added so that dm_crypt_request and the IV are
200 * correctly aligned.
201 */
202 unsigned int dmreq_start;
203
204 unsigned int per_bio_data_size;
205
206 unsigned long flags;
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(...) */
211
212 unsigned int integrity_tag_size;
213 unsigned int integrity_iv_size;
214 unsigned int on_disk_tag_size;
215
216 u8 *authenc_key; /* space for keys in authenc() format (if used) */
217 u8 key[0];
218};
219
220#define MIN_IOS 64
221#define MAX_TAG_SIZE 480
222#define POOL_ENTRY_SIZE 512
223
224static DEFINE_SPINLOCK(dm_crypt_clients_lock);
225static unsigned dm_crypt_clients_n = 0;
226static 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)
229
230static void clone_init(struct dm_crypt_io *, struct bio *);
231static void kcryptd_queue_crypt(struct dm_crypt_io *io);
232static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
233 struct scatterlist *sg);
234
235/*
236 * Use this to access cipher attributes that are independent of the key.
237 */
238static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
239{
240 return cc->cipher_tfm.tfms[0];
241}
242
243static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
244{
245 return cc->cipher_tfm.tfms_aead[0];
246}
247
248/*
249 * Different IV generation algorithms:
250 *
251 * plain: the initial vector is the 32-bit little-endian version of the sector
252 * number, padded with zeros if necessary.
253 *
254 * plain64: the initial vector is the 64-bit little-endian version of the sector
255 * number, padded with zeros if necessary.
256 *
257 * plain64be: the initial vector is the 64-bit big-endian version of the sector
258 * number, padded with zeros if necessary.
259 *
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.
263 *
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)
266 *
267 * null: the initial vector is always zero. Provides compatibility with
268 * obsolete loop_fish2 devices. Do not use for new devices.
269 *
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)
283 *
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.
293 *
294 * plumb: unimplemented, see:
295 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
296 */
297
298static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
299 struct dm_crypt_request *dmreq)
300{
301 memset(iv, 0, cc->iv_size);
302 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
303
304 return 0;
305}
306
307static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
308 struct dm_crypt_request *dmreq)
309{
310 memset(iv, 0, cc->iv_size);
311 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
312
313 return 0;
314}
315
316static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
317 struct dm_crypt_request *dmreq)
318{
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);
322
323 return 0;
324}
325
326/* Initialise ESSIV - compute salt but no local memory allocations */
327static int crypt_iv_essiv_init(struct crypt_config *cc)
328{
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;
333 int err;
334
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, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
338 ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
339
340 err = crypto_ahash_digest(req);
341 ahash_request_zero(req);
342 if (err)
343 return err;
344
345 essiv_tfm = cc->iv_private;
346
347 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
348 crypto_ahash_digestsize(essiv->hash_tfm));
349 if (err)
350 return err;
351
352 return 0;
353}
354
355/* Wipe salt and reset key derived from volume key */
356static int crypt_iv_essiv_wipe(struct crypt_config *cc)
357{
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;
361 int r, err = 0;
362
363 memset(essiv->salt, 0, salt_size);
364
365 essiv_tfm = cc->iv_private;
366 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
367 if (r)
368 err = r;
369
370 return err;
371}
372
373/* Allocate the cipher for ESSIV */
374static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
375 struct dm_target *ti,
376 const u8 *salt,
377 unsigned int saltsize)
378{
379 struct crypto_cipher *essiv_tfm;
380 int err;
381
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";
386 return essiv_tfm;
387 }
388
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);
394 }
395
396 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
397 if (err) {
398 ti->error = "Failed to set key for ESSIV cipher";
399 crypto_free_cipher(essiv_tfm);
400 return ERR_PTR(err);
401 }
402
403 return essiv_tfm;
404}
405
406static void crypt_iv_essiv_dtr(struct crypt_config *cc)
407{
408 struct crypto_cipher *essiv_tfm;
409 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
410
411 crypto_free_ahash(essiv->hash_tfm);
412 essiv->hash_tfm = NULL;
413
414 kzfree(essiv->salt);
415 essiv->salt = NULL;
416
417 essiv_tfm = cc->iv_private;
418
419 if (essiv_tfm)
420 crypto_free_cipher(essiv_tfm);
421
422 cc->iv_private = NULL;
423}
424
425static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
426 const char *opts)
427{
428 struct crypto_cipher *essiv_tfm = NULL;
429 struct crypto_ahash *hash_tfm = NULL;
430 u8 *salt = NULL;
431 int err;
432
433 if (!opts) {
434 ti->error = "Digest algorithm missing for ESSIV mode";
435 return -EINVAL;
436 }
437
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);
443 goto bad;
444 }
445
446 salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
447 if (!salt) {
448 ti->error = "Error kmallocing salt storage in ESSIV";
449 err = -ENOMEM;
450 goto bad;
451 }
452
453 cc->iv_gen_private.essiv.salt = salt;
454 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
455
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);
461 }
462 cc->iv_private = essiv_tfm;
463
464 return 0;
465
466bad:
467 if (hash_tfm && !IS_ERR(hash_tfm))
468 crypto_free_ahash(hash_tfm);
469 kfree(salt);
470 return err;
471}
472
473static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
474 struct dm_crypt_request *dmreq)
475{
476 struct crypto_cipher *essiv_tfm = cc->iv_private;
477
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);
481
482 return 0;
483}
484
485static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
486 const char *opts)
487{
488 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
489 int log = ilog2(bs);
490
491 /* we need to calculate how far we must shift the sector count
492 * to get the cipher block count, we use this shift in _gen */
493
494 if (1 << log != bs) {
495 ti->error = "cypher blocksize is not a power of 2";
496 return -EINVAL;
497 }
498
499 if (log > 9) {
500 ti->error = "cypher blocksize is > 512";
501 return -EINVAL;
502 }
503
504 cc->iv_gen_private.benbi.shift = 9 - log;
505
506 return 0;
507}
508
509static void crypt_iv_benbi_dtr(struct crypt_config *cc)
510{
511}
512
513static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
514 struct dm_crypt_request *dmreq)
515{
516 __be64 val;
517
518 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
519
520 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
521 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
522
523 return 0;
524}
525
526static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
527 struct dm_crypt_request *dmreq)
528{
529 memset(iv, 0, cc->iv_size);
530
531 return 0;
532}
533
534static void crypt_iv_lmk_dtr(struct crypt_config *cc)
535{
536 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
537
538 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
539 crypto_free_shash(lmk->hash_tfm);
540 lmk->hash_tfm = NULL;
541
542 kzfree(lmk->seed);
543 lmk->seed = NULL;
544}
545
546static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
547 const char *opts)
548{
549 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
550
551 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
552 ti->error = "Unsupported sector size for LMK";
553 return -EINVAL;
554 }
555
556 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
557 if (IS_ERR(lmk->hash_tfm)) {
558 ti->error = "Error initializing LMK hash";
559 return PTR_ERR(lmk->hash_tfm);
560 }
561
562 /* No seed in LMK version 2 */
563 if (cc->key_parts == cc->tfms_count) {
564 lmk->seed = NULL;
565 return 0;
566 }
567
568 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
569 if (!lmk->seed) {
570 crypt_iv_lmk_dtr(cc);
571 ti->error = "Error kmallocing seed storage in LMK";
572 return -ENOMEM;
573 }
574
575 return 0;
576}
577
578static int crypt_iv_lmk_init(struct crypt_config *cc)
579{
580 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
581 int subkey_size = cc->key_size / cc->key_parts;
582
583 /* LMK seed is on the position of LMK_KEYS + 1 key */
584 if (lmk->seed)
585 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
586 crypto_shash_digestsize(lmk->hash_tfm));
587
588 return 0;
589}
590
591static int crypt_iv_lmk_wipe(struct crypt_config *cc)
592{
593 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
594
595 if (lmk->seed)
596 memset(lmk->seed, 0, LMK_SEED_SIZE);
597
598 return 0;
599}
600
601static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
602 struct dm_crypt_request *dmreq,
603 u8 *data)
604{
605 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
606 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
607 struct md5_state md5state;
608 __le32 buf[4];
609 int i, r;
610
611 desc->tfm = lmk->hash_tfm;
612 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
613
614 r = crypto_shash_init(desc);
615 if (r)
616 return r;
617
618 if (lmk->seed) {
619 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
620 if (r)
621 return r;
622 }
623
624 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
625 r = crypto_shash_update(desc, data + 16, 16 * 31);
626 if (r)
627 return r;
628
629 /* Sector is cropped to 56 bits here */
630 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
631 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
632 buf[2] = cpu_to_le32(4024);
633 buf[3] = 0;
634 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
635 if (r)
636 return r;
637
638 /* No MD5 padding here */
639 r = crypto_shash_export(desc, &md5state);
640 if (r)
641 return r;
642
643 for (i = 0; i < MD5_HASH_WORDS; i++)
644 __cpu_to_le32s(&md5state.hash[i]);
645 memcpy(iv, &md5state.hash, cc->iv_size);
646
647 return 0;
648}
649
650static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
651 struct dm_crypt_request *dmreq)
652{
653 struct scatterlist *sg;
654 u8 *src;
655 int r = 0;
656
657 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
658 sg = crypt_get_sg_data(cc, dmreq->sg_in);
659 src = kmap_atomic(sg_page(sg));
660 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
661 kunmap_atomic(src);
662 } else
663 memset(iv, 0, cc->iv_size);
664
665 return r;
666}
667
668static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
669 struct dm_crypt_request *dmreq)
670{
671 struct scatterlist *sg;
672 u8 *dst;
673 int r;
674
675 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
676 return 0;
677
678 sg = crypt_get_sg_data(cc, dmreq->sg_out);
679 dst = kmap_atomic(sg_page(sg));
680 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
681
682 /* Tweak the first block of plaintext sector */
683 if (!r)
684 crypto_xor(dst + sg->offset, iv, cc->iv_size);
685
686 kunmap_atomic(dst);
687 return r;
688}
689
690static void crypt_iv_tcw_dtr(struct crypt_config *cc)
691{
692 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
693
694 kzfree(tcw->iv_seed);
695 tcw->iv_seed = NULL;
696 kzfree(tcw->whitening);
697 tcw->whitening = NULL;
698
699 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
700 crypto_free_shash(tcw->crc32_tfm);
701 tcw->crc32_tfm = NULL;
702}
703
704static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
705 const char *opts)
706{
707 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
708
709 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
710 ti->error = "Unsupported sector size for TCW";
711 return -EINVAL;
712 }
713
714 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
715 ti->error = "Wrong key size for TCW";
716 return -EINVAL;
717 }
718
719 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
720 if (IS_ERR(tcw->crc32_tfm)) {
721 ti->error = "Error initializing CRC32 in TCW";
722 return PTR_ERR(tcw->crc32_tfm);
723 }
724
725 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
726 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
727 if (!tcw->iv_seed || !tcw->whitening) {
728 crypt_iv_tcw_dtr(cc);
729 ti->error = "Error allocating seed storage in TCW";
730 return -ENOMEM;
731 }
732
733 return 0;
734}
735
736static int crypt_iv_tcw_init(struct crypt_config *cc)
737{
738 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
739 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
740
741 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
742 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
743 TCW_WHITENING_SIZE);
744
745 return 0;
746}
747
748static int crypt_iv_tcw_wipe(struct crypt_config *cc)
749{
750 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
751
752 memset(tcw->iv_seed, 0, cc->iv_size);
753 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
754
755 return 0;
756}
757
758static int crypt_iv_tcw_whitening(struct crypt_config *cc,
759 struct dm_crypt_request *dmreq,
760 u8 *data)
761{
762 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
763 __le64 sector = cpu_to_le64(dmreq->iv_sector);
764 u8 buf[TCW_WHITENING_SIZE];
765 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
766 int i, r;
767
768 /* xor whitening with sector number */
769 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8);
770 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8);
771
772 /* calculate crc32 for every 32bit part and xor it */
773 desc->tfm = tcw->crc32_tfm;
774 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
775 for (i = 0; i < 4; i++) {
776 r = crypto_shash_init(desc);
777 if (r)
778 goto out;
779 r = crypto_shash_update(desc, &buf[i * 4], 4);
780 if (r)
781 goto out;
782 r = crypto_shash_final(desc, &buf[i * 4]);
783 if (r)
784 goto out;
785 }
786 crypto_xor(&buf[0], &buf[12], 4);
787 crypto_xor(&buf[4], &buf[8], 4);
788
789 /* apply whitening (8 bytes) to whole sector */
790 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
791 crypto_xor(data + i * 8, buf, 8);
792out:
793 memzero_explicit(buf, sizeof(buf));
794 return r;
795}
796
797static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
798 struct dm_crypt_request *dmreq)
799{
800 struct scatterlist *sg;
801 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
802 __le64 sector = cpu_to_le64(dmreq->iv_sector);
803 u8 *src;
804 int r = 0;
805
806 /* Remove whitening from ciphertext */
807 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
808 sg = crypt_get_sg_data(cc, dmreq->sg_in);
809 src = kmap_atomic(sg_page(sg));
810 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
811 kunmap_atomic(src);
812 }
813
814 /* Calculate IV */
815 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8);
816 if (cc->iv_size > 8)
817 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or,
818 cc->iv_size - 8);
819
820 return r;
821}
822
823static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
824 struct dm_crypt_request *dmreq)
825{
826 struct scatterlist *sg;
827 u8 *dst;
828 int r;
829
830 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
831 return 0;
832
833 /* Apply whitening on ciphertext */
834 sg = crypt_get_sg_data(cc, dmreq->sg_out);
835 dst = kmap_atomic(sg_page(sg));
836 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
837 kunmap_atomic(dst);
838
839 return r;
840}
841
842static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
843 struct dm_crypt_request *dmreq)
844{
845 /* Used only for writes, there must be an additional space to store IV */
846 get_random_bytes(iv, cc->iv_size);
847 return 0;
848}
849
850static const struct crypt_iv_operations crypt_iv_plain_ops = {
851 .generator = crypt_iv_plain_gen
852};
853
854static const struct crypt_iv_operations crypt_iv_plain64_ops = {
855 .generator = crypt_iv_plain64_gen
856};
857
858static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
859 .generator = crypt_iv_plain64be_gen
860};
861
862static const struct crypt_iv_operations crypt_iv_essiv_ops = {
863 .ctr = crypt_iv_essiv_ctr,
864 .dtr = crypt_iv_essiv_dtr,
865 .init = crypt_iv_essiv_init,
866 .wipe = crypt_iv_essiv_wipe,
867 .generator = crypt_iv_essiv_gen
868};
869
870static const struct crypt_iv_operations crypt_iv_benbi_ops = {
871 .ctr = crypt_iv_benbi_ctr,
872 .dtr = crypt_iv_benbi_dtr,
873 .generator = crypt_iv_benbi_gen
874};
875
876static const struct crypt_iv_operations crypt_iv_null_ops = {
877 .generator = crypt_iv_null_gen
878};
879
880static const struct crypt_iv_operations crypt_iv_lmk_ops = {
881 .ctr = crypt_iv_lmk_ctr,
882 .dtr = crypt_iv_lmk_dtr,
883 .init = crypt_iv_lmk_init,
884 .wipe = crypt_iv_lmk_wipe,
885 .generator = crypt_iv_lmk_gen,
886 .post = crypt_iv_lmk_post
887};
888
889static const struct crypt_iv_operations crypt_iv_tcw_ops = {
890 .ctr = crypt_iv_tcw_ctr,
891 .dtr = crypt_iv_tcw_dtr,
892 .init = crypt_iv_tcw_init,
893 .wipe = crypt_iv_tcw_wipe,
894 .generator = crypt_iv_tcw_gen,
895 .post = crypt_iv_tcw_post
896};
897
898static struct crypt_iv_operations crypt_iv_random_ops = {
899 .generator = crypt_iv_random_gen
900};
901
902/*
903 * Integrity extensions
904 */
905static bool crypt_integrity_aead(struct crypt_config *cc)
906{
907 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
908}
909
910static bool crypt_integrity_hmac(struct crypt_config *cc)
911{
912 return crypt_integrity_aead(cc) && cc->key_mac_size;
913}
914
915/* Get sg containing data */
916static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
917 struct scatterlist *sg)
918{
919 if (unlikely(crypt_integrity_aead(cc)))
920 return &sg[2];
921
922 return sg;
923}
924
925static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
926{
927 struct bio_integrity_payload *bip;
928 unsigned int tag_len;
929 int ret;
930
931 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
932 return 0;
933
934 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
935 if (IS_ERR(bip))
936 return PTR_ERR(bip);
937
938 tag_len = io->cc->on_disk_tag_size * bio_sectors(bio);
939
940 bip->bip_iter.bi_size = tag_len;
941 bip->bip_iter.bi_sector = io->cc->start + io->sector;
942
943 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
944 tag_len, offset_in_page(io->integrity_metadata));
945 if (unlikely(ret != tag_len))
946 return -ENOMEM;
947
948 return 0;
949}
950
951static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
952{
953#ifdef CONFIG_BLK_DEV_INTEGRITY
954 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
955
956 /* From now we require underlying device with our integrity profile */
957 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
958 ti->error = "Integrity profile not supported.";
959 return -EINVAL;
960 }
961
962 if (bi->tag_size != cc->on_disk_tag_size ||
963 bi->tuple_size != cc->on_disk_tag_size) {
964 ti->error = "Integrity profile tag size mismatch.";
965 return -EINVAL;
966 }
967 if (1 << bi->interval_exp != cc->sector_size) {
968 ti->error = "Integrity profile sector size mismatch.";
969 return -EINVAL;
970 }
971
972 if (crypt_integrity_aead(cc)) {
973 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
974 DMINFO("Integrity AEAD, tag size %u, IV size %u.",
975 cc->integrity_tag_size, cc->integrity_iv_size);
976
977 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
978 ti->error = "Integrity AEAD auth tag size is not supported.";
979 return -EINVAL;
980 }
981 } else if (cc->integrity_iv_size)
982 DMINFO("Additional per-sector space %u bytes for IV.",
983 cc->integrity_iv_size);
984
985 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
986 ti->error = "Not enough space for integrity tag in the profile.";
987 return -EINVAL;
988 }
989
990 return 0;
991#else
992 ti->error = "Integrity profile not supported.";
993 return -EINVAL;
994#endif
995}
996
997static void crypt_convert_init(struct crypt_config *cc,
998 struct convert_context *ctx,
999 struct bio *bio_out, struct bio *bio_in,
1000 sector_t sector)
1001{
1002 ctx->bio_in = bio_in;
1003 ctx->bio_out = bio_out;
1004 if (bio_in)
1005 ctx->iter_in = bio_in->bi_iter;
1006 if (bio_out)
1007 ctx->iter_out = bio_out->bi_iter;
1008 ctx->cc_sector = sector + cc->iv_offset;
1009 init_completion(&ctx->restart);
1010}
1011
1012static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1013 void *req)
1014{
1015 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1016}
1017
1018static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1019{
1020 return (void *)((char *)dmreq - cc->dmreq_start);
1021}
1022
1023static u8 *iv_of_dmreq(struct crypt_config *cc,
1024 struct dm_crypt_request *dmreq)
1025{
1026 if (crypt_integrity_aead(cc))
1027 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1028 crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1029 else
1030 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1031 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1032}
1033
1034static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1035 struct dm_crypt_request *dmreq)
1036{
1037 return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1038}
1039
1040static uint64_t *org_sector_of_dmreq(struct crypt_config *cc,
1041 struct dm_crypt_request *dmreq)
1042{
1043 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1044 return (uint64_t*) ptr;
1045}
1046
1047static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1048 struct dm_crypt_request *dmreq)
1049{
1050 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1051 cc->iv_size + sizeof(uint64_t);
1052 return (unsigned int*)ptr;
1053}
1054
1055static void *tag_from_dmreq(struct crypt_config *cc,
1056 struct dm_crypt_request *dmreq)
1057{
1058 struct convert_context *ctx = dmreq->ctx;
1059 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1060
1061 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1062 cc->on_disk_tag_size];
1063}
1064
1065static void *iv_tag_from_dmreq(struct crypt_config *cc,
1066 struct dm_crypt_request *dmreq)
1067{
1068 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1069}
1070
1071static int crypt_convert_block_aead(struct crypt_config *cc,
1072 struct convert_context *ctx,
1073 struct aead_request *req,
1074 unsigned int tag_offset)
1075{
1076 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1077 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1078 struct dm_crypt_request *dmreq;
1079 u8 *iv, *org_iv, *tag_iv, *tag;
1080 uint64_t *sector;
1081 int r = 0;
1082
1083 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1084
1085 /* Reject unexpected unaligned bio. */
1086 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1087 return -EIO;
1088
1089 dmreq = dmreq_of_req(cc, req);
1090 dmreq->iv_sector = ctx->cc_sector;
1091 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1092 dmreq->iv_sector >>= cc->sector_shift;
1093 dmreq->ctx = ctx;
1094
1095 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1096
1097 sector = org_sector_of_dmreq(cc, dmreq);
1098 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1099
1100 iv = iv_of_dmreq(cc, dmreq);
1101 org_iv = org_iv_of_dmreq(cc, dmreq);
1102 tag = tag_from_dmreq(cc, dmreq);
1103 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1104
1105 /* AEAD request:
1106 * |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1107 * | (authenticated) | (auth+encryption) | |
1108 * | sector_LE | IV | sector in/out | tag in/out |
1109 */
1110 sg_init_table(dmreq->sg_in, 4);
1111 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1112 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1113 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1114 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1115
1116 sg_init_table(dmreq->sg_out, 4);
1117 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1118 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1119 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1120 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1121
1122 if (cc->iv_gen_ops) {
1123 /* For READs use IV stored in integrity metadata */
1124 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1125 memcpy(org_iv, tag_iv, cc->iv_size);
1126 } else {
1127 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1128 if (r < 0)
1129 return r;
1130 /* Store generated IV in integrity metadata */
1131 if (cc->integrity_iv_size)
1132 memcpy(tag_iv, org_iv, cc->iv_size);
1133 }
1134 /* Working copy of IV, to be modified in crypto API */
1135 memcpy(iv, org_iv, cc->iv_size);
1136 }
1137
1138 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1139 if (bio_data_dir(ctx->bio_in) == WRITE) {
1140 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1141 cc->sector_size, iv);
1142 r = crypto_aead_encrypt(req);
1143 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1144 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1145 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1146 } else {
1147 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1148 cc->sector_size + cc->integrity_tag_size, iv);
1149 r = crypto_aead_decrypt(req);
1150 }
1151
1152 if (r == -EBADMSG)
1153 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1154 (unsigned long long)le64_to_cpu(*sector));
1155
1156 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1157 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1158
1159 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1160 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1161
1162 return r;
1163}
1164
1165static int crypt_convert_block_skcipher(struct crypt_config *cc,
1166 struct convert_context *ctx,
1167 struct skcipher_request *req,
1168 unsigned int tag_offset)
1169{
1170 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1171 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1172 struct scatterlist *sg_in, *sg_out;
1173 struct dm_crypt_request *dmreq;
1174 u8 *iv, *org_iv, *tag_iv;
1175 uint64_t *sector;
1176 int r = 0;
1177
1178 /* Reject unexpected unaligned bio. */
1179 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1180 return -EIO;
1181
1182 dmreq = dmreq_of_req(cc, req);
1183 dmreq->iv_sector = ctx->cc_sector;
1184 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1185 dmreq->iv_sector >>= cc->sector_shift;
1186 dmreq->ctx = ctx;
1187
1188 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1189
1190 iv = iv_of_dmreq(cc, dmreq);
1191 org_iv = org_iv_of_dmreq(cc, dmreq);
1192 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1193
1194 sector = org_sector_of_dmreq(cc, dmreq);
1195 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1196
1197 /* For skcipher we use only the first sg item */
1198 sg_in = &dmreq->sg_in[0];
1199 sg_out = &dmreq->sg_out[0];
1200
1201 sg_init_table(sg_in, 1);
1202 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1203
1204 sg_init_table(sg_out, 1);
1205 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1206
1207 if (cc->iv_gen_ops) {
1208 /* For READs use IV stored in integrity metadata */
1209 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1210 memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1211 } else {
1212 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1213 if (r < 0)
1214 return r;
1215 /* Store generated IV in integrity metadata */
1216 if (cc->integrity_iv_size)
1217 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1218 }
1219 /* Working copy of IV, to be modified in crypto API */
1220 memcpy(iv, org_iv, cc->iv_size);
1221 }
1222
1223 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1224
1225 if (bio_data_dir(ctx->bio_in) == WRITE)
1226 r = crypto_skcipher_encrypt(req);
1227 else
1228 r = crypto_skcipher_decrypt(req);
1229
1230 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1231 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1232
1233 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1234 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1235
1236 return r;
1237}
1238
1239static void kcryptd_async_done(struct crypto_async_request *async_req,
1240 int error);
1241
1242static void crypt_alloc_req_skcipher(struct crypt_config *cc,
1243 struct convert_context *ctx)
1244{
1245 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1246
1247 if (!ctx->r.req)
1248 ctx->r.req = mempool_alloc(cc->req_pool, GFP_NOIO);
1249
1250 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1251
1252 /*
1253 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1254 * requests if driver request queue is full.
1255 */
1256 skcipher_request_set_callback(ctx->r.req,
1257 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
1258 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1259}
1260
1261static void crypt_alloc_req_aead(struct crypt_config *cc,
1262 struct convert_context *ctx)
1263{
1264 if (!ctx->r.req_aead)
1265 ctx->r.req_aead = mempool_alloc(cc->req_pool, GFP_NOIO);
1266
1267 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1268
1269 /*
1270 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1271 * requests if driver request queue is full.
1272 */
1273 aead_request_set_callback(ctx->r.req_aead,
1274 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
1275 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1276}
1277
1278static void crypt_alloc_req(struct crypt_config *cc,
1279 struct convert_context *ctx)
1280{
1281 if (crypt_integrity_aead(cc))
1282 crypt_alloc_req_aead(cc, ctx);
1283 else
1284 crypt_alloc_req_skcipher(cc, ctx);
1285}
1286
1287static void crypt_free_req_skcipher(struct crypt_config *cc,
1288 struct skcipher_request *req, struct bio *base_bio)
1289{
1290 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1291
1292 if ((struct skcipher_request *)(io + 1) != req)
1293 mempool_free(req, cc->req_pool);
1294}
1295
1296static void crypt_free_req_aead(struct crypt_config *cc,
1297 struct aead_request *req, struct bio *base_bio)
1298{
1299 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1300
1301 if ((struct aead_request *)(io + 1) != req)
1302 mempool_free(req, cc->req_pool);
1303}
1304
1305static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1306{
1307 if (crypt_integrity_aead(cc))
1308 crypt_free_req_aead(cc, req, base_bio);
1309 else
1310 crypt_free_req_skcipher(cc, req, base_bio);
1311}
1312
1313/*
1314 * Encrypt / decrypt data from one bio to another one (can be the same one)
1315 */
1316static blk_status_t crypt_convert(struct crypt_config *cc,
1317 struct convert_context *ctx)
1318{
1319 unsigned int tag_offset = 0;
1320 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1321 int r;
1322
1323 atomic_set(&ctx->cc_pending, 1);
1324
1325 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1326
1327 crypt_alloc_req(cc, ctx);
1328 atomic_inc(&ctx->cc_pending);
1329
1330 if (crypt_integrity_aead(cc))
1331 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1332 else
1333 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1334
1335 switch (r) {
1336 /*
1337 * The request was queued by a crypto driver
1338 * but the driver request queue is full, let's wait.
1339 */
1340 case -EBUSY:
1341 wait_for_completion(&ctx->restart);
1342 reinit_completion(&ctx->restart);
1343 /* fall through */
1344 /*
1345 * The request is queued and processed asynchronously,
1346 * completion function kcryptd_async_done() will be called.
1347 */
1348 case -EINPROGRESS:
1349 ctx->r.req = NULL;
1350 ctx->cc_sector += sector_step;
1351 tag_offset++;
1352 continue;
1353 /*
1354 * The request was already processed (synchronously).
1355 */
1356 case 0:
1357 atomic_dec(&ctx->cc_pending);
1358 ctx->cc_sector += sector_step;
1359 tag_offset++;
1360 cond_resched();
1361 continue;
1362 /*
1363 * There was a data integrity error.
1364 */
1365 case -EBADMSG:
1366 atomic_dec(&ctx->cc_pending);
1367 return BLK_STS_PROTECTION;
1368 /*
1369 * There was an error while processing the request.
1370 */
1371 default:
1372 atomic_dec(&ctx->cc_pending);
1373 return BLK_STS_IOERR;
1374 }
1375 }
1376
1377 return 0;
1378}
1379
1380static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1381
1382/*
1383 * Generate a new unfragmented bio with the given size
1384 * This should never violate the device limitations (but only because
1385 * max_segment_size is being constrained to PAGE_SIZE).
1386 *
1387 * This function may be called concurrently. If we allocate from the mempool
1388 * concurrently, there is a possibility of deadlock. For example, if we have
1389 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1390 * the mempool concurrently, it may deadlock in a situation where both processes
1391 * have allocated 128 pages and the mempool is exhausted.
1392 *
1393 * In order to avoid this scenario we allocate the pages under a mutex.
1394 *
1395 * In order to not degrade performance with excessive locking, we try
1396 * non-blocking allocations without a mutex first but on failure we fallback
1397 * to blocking allocations with a mutex.
1398 */
1399static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1400{
1401 struct crypt_config *cc = io->cc;
1402 struct bio *clone;
1403 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1404 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1405 unsigned i, len, remaining_size;
1406 struct page *page;
1407
1408retry:
1409 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1410 mutex_lock(&cc->bio_alloc_lock);
1411
1412 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1413 if (!clone)
1414 goto out;
1415
1416 clone_init(io, clone);
1417
1418 remaining_size = size;
1419
1420 for (i = 0; i < nr_iovecs; i++) {
1421 page = mempool_alloc(cc->page_pool, gfp_mask);
1422 if (!page) {
1423 crypt_free_buffer_pages(cc, clone);
1424 bio_put(clone);
1425 gfp_mask |= __GFP_DIRECT_RECLAIM;
1426 goto retry;
1427 }
1428
1429 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1430
1431 bio_add_page(clone, page, len, 0);
1432
1433 remaining_size -= len;
1434 }
1435
1436 /* Allocate space for integrity tags */
1437 if (dm_crypt_integrity_io_alloc(io, clone)) {
1438 crypt_free_buffer_pages(cc, clone);
1439 bio_put(clone);
1440 clone = NULL;
1441 }
1442out:
1443 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1444 mutex_unlock(&cc->bio_alloc_lock);
1445
1446 return clone;
1447}
1448
1449static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1450{
1451 unsigned int i;
1452 struct bio_vec *bv;
1453
1454 bio_for_each_segment_all(bv, clone, i) {
1455 BUG_ON(!bv->bv_page);
1456 mempool_free(bv->bv_page, cc->page_pool);
1457 }
1458}
1459
1460static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1461 struct bio *bio, sector_t sector)
1462{
1463 io->cc = cc;
1464 io->base_bio = bio;
1465 io->sector = sector;
1466 io->error = 0;
1467 io->ctx.r.req = NULL;
1468 io->integrity_metadata = NULL;
1469 io->integrity_metadata_from_pool = false;
1470 atomic_set(&io->io_pending, 0);
1471}
1472
1473static void crypt_inc_pending(struct dm_crypt_io *io)
1474{
1475 atomic_inc(&io->io_pending);
1476}
1477
1478/*
1479 * One of the bios was finished. Check for completion of
1480 * the whole request and correctly clean up the buffer.
1481 */
1482static void crypt_dec_pending(struct dm_crypt_io *io)
1483{
1484 struct crypt_config *cc = io->cc;
1485 struct bio *base_bio = io->base_bio;
1486 blk_status_t error = io->error;
1487
1488 if (!atomic_dec_and_test(&io->io_pending))
1489 return;
1490
1491 if (io->ctx.r.req)
1492 crypt_free_req(cc, io->ctx.r.req, base_bio);
1493
1494 if (unlikely(io->integrity_metadata_from_pool))
1495 mempool_free(io->integrity_metadata, io->cc->tag_pool);
1496 else
1497 kfree(io->integrity_metadata);
1498
1499 base_bio->bi_status = error;
1500 bio_endio(base_bio);
1501}
1502
1503/*
1504 * kcryptd/kcryptd_io:
1505 *
1506 * Needed because it would be very unwise to do decryption in an
1507 * interrupt context.
1508 *
1509 * kcryptd performs the actual encryption or decryption.
1510 *
1511 * kcryptd_io performs the IO submission.
1512 *
1513 * They must be separated as otherwise the final stages could be
1514 * starved by new requests which can block in the first stages due
1515 * to memory allocation.
1516 *
1517 * The work is done per CPU global for all dm-crypt instances.
1518 * They should not depend on each other and do not block.
1519 */
1520static void crypt_endio(struct bio *clone)
1521{
1522 struct dm_crypt_io *io = clone->bi_private;
1523 struct crypt_config *cc = io->cc;
1524 unsigned rw = bio_data_dir(clone);
1525 blk_status_t error;
1526
1527 /*
1528 * free the processed pages
1529 */
1530 if (rw == WRITE)
1531 crypt_free_buffer_pages(cc, clone);
1532
1533 error = clone->bi_status;
1534 bio_put(clone);
1535
1536 if (rw == READ && !error) {
1537 kcryptd_queue_crypt(io);
1538 return;
1539 }
1540
1541 if (unlikely(error))
1542 io->error = error;
1543
1544 crypt_dec_pending(io);
1545}
1546
1547static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1548{
1549 struct crypt_config *cc = io->cc;
1550
1551 clone->bi_private = io;
1552 clone->bi_end_io = crypt_endio;
1553 bio_set_dev(clone, cc->dev->bdev);
1554 clone->bi_opf = io->base_bio->bi_opf;
1555}
1556
1557static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1558{
1559 struct crypt_config *cc = io->cc;
1560 struct bio *clone;
1561
1562 /*
1563 * We need the original biovec array in order to decrypt
1564 * the whole bio data *afterwards* -- thanks to immutable
1565 * biovecs we don't need to worry about the block layer
1566 * modifying the biovec array; so leverage bio_clone_fast().
1567 */
1568 clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1569 if (!clone)
1570 return 1;
1571
1572 crypt_inc_pending(io);
1573
1574 clone_init(io, clone);
1575 clone->bi_iter.bi_sector = cc->start + io->sector;
1576
1577 if (dm_crypt_integrity_io_alloc(io, clone)) {
1578 crypt_dec_pending(io);
1579 bio_put(clone);
1580 return 1;
1581 }
1582
1583 generic_make_request(clone);
1584 return 0;
1585}
1586
1587static void kcryptd_io_read_work(struct work_struct *work)
1588{
1589 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1590
1591 crypt_inc_pending(io);
1592 if (kcryptd_io_read(io, GFP_NOIO))
1593 io->error = BLK_STS_RESOURCE;
1594 crypt_dec_pending(io);
1595}
1596
1597static void kcryptd_queue_read(struct dm_crypt_io *io)
1598{
1599 struct crypt_config *cc = io->cc;
1600
1601 INIT_WORK(&io->work, kcryptd_io_read_work);
1602 queue_work(cc->io_queue, &io->work);
1603}
1604
1605static void kcryptd_io_write(struct dm_crypt_io *io)
1606{
1607 struct bio *clone = io->ctx.bio_out;
1608
1609 generic_make_request(clone);
1610}
1611
1612#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1613
1614static int dmcrypt_write(void *data)
1615{
1616 struct crypt_config *cc = data;
1617 struct dm_crypt_io *io;
1618
1619 while (1) {
1620 struct rb_root write_tree;
1621 struct blk_plug plug;
1622
1623 DECLARE_WAITQUEUE(wait, current);
1624
1625 spin_lock_irq(&cc->write_thread_wait.lock);
1626continue_locked:
1627
1628 if (!RB_EMPTY_ROOT(&cc->write_tree))
1629 goto pop_from_list;
1630
1631 set_current_state(TASK_INTERRUPTIBLE);
1632 __add_wait_queue(&cc->write_thread_wait, &wait);
1633
1634 spin_unlock_irq(&cc->write_thread_wait.lock);
1635
1636 if (unlikely(kthread_should_stop())) {
1637 set_current_state(TASK_RUNNING);
1638 remove_wait_queue(&cc->write_thread_wait, &wait);
1639 break;
1640 }
1641
1642 schedule();
1643
1644 set_current_state(TASK_RUNNING);
1645 spin_lock_irq(&cc->write_thread_wait.lock);
1646 __remove_wait_queue(&cc->write_thread_wait, &wait);
1647 goto continue_locked;
1648
1649pop_from_list:
1650 write_tree = cc->write_tree;
1651 cc->write_tree = RB_ROOT;
1652 spin_unlock_irq(&cc->write_thread_wait.lock);
1653
1654 BUG_ON(rb_parent(write_tree.rb_node));
1655
1656 /*
1657 * Note: we cannot walk the tree here with rb_next because
1658 * the structures may be freed when kcryptd_io_write is called.
1659 */
1660 blk_start_plug(&plug);
1661 do {
1662 io = crypt_io_from_node(rb_first(&write_tree));
1663 rb_erase(&io->rb_node, &write_tree);
1664 kcryptd_io_write(io);
1665 } while (!RB_EMPTY_ROOT(&write_tree));
1666 blk_finish_plug(&plug);
1667 }
1668 return 0;
1669}
1670
1671static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1672{
1673 struct bio *clone = io->ctx.bio_out;
1674 struct crypt_config *cc = io->cc;
1675 unsigned long flags;
1676 sector_t sector;
1677 struct rb_node **rbp, *parent;
1678
1679 if (unlikely(io->error)) {
1680 crypt_free_buffer_pages(cc, clone);
1681 bio_put(clone);
1682 crypt_dec_pending(io);
1683 return;
1684 }
1685
1686 /* crypt_convert should have filled the clone bio */
1687 BUG_ON(io->ctx.iter_out.bi_size);
1688
1689 clone->bi_iter.bi_sector = cc->start + io->sector;
1690
1691 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1692 generic_make_request(clone);
1693 return;
1694 }
1695
1696 spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1697 rbp = &cc->write_tree.rb_node;
1698 parent = NULL;
1699 sector = io->sector;
1700 while (*rbp) {
1701 parent = *rbp;
1702 if (sector < crypt_io_from_node(parent)->sector)
1703 rbp = &(*rbp)->rb_left;
1704 else
1705 rbp = &(*rbp)->rb_right;
1706 }
1707 rb_link_node(&io->rb_node, parent, rbp);
1708 rb_insert_color(&io->rb_node, &cc->write_tree);
1709
1710 wake_up_locked(&cc->write_thread_wait);
1711 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1712}
1713
1714static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1715{
1716 struct crypt_config *cc = io->cc;
1717 struct bio *clone;
1718 int crypt_finished;
1719 sector_t sector = io->sector;
1720 blk_status_t r;
1721
1722 /*
1723 * Prevent io from disappearing until this function completes.
1724 */
1725 crypt_inc_pending(io);
1726 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1727
1728 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1729 if (unlikely(!clone)) {
1730 io->error = BLK_STS_IOERR;
1731 goto dec;
1732 }
1733
1734 io->ctx.bio_out = clone;
1735 io->ctx.iter_out = clone->bi_iter;
1736
1737 sector += bio_sectors(clone);
1738
1739 crypt_inc_pending(io);
1740 r = crypt_convert(cc, &io->ctx);
1741 if (r)
1742 io->error = r;
1743 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1744
1745 /* Encryption was already finished, submit io now */
1746 if (crypt_finished) {
1747 kcryptd_crypt_write_io_submit(io, 0);
1748 io->sector = sector;
1749 }
1750
1751dec:
1752 crypt_dec_pending(io);
1753}
1754
1755static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1756{
1757 crypt_dec_pending(io);
1758}
1759
1760static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1761{
1762 struct crypt_config *cc = io->cc;
1763 blk_status_t r;
1764
1765 crypt_inc_pending(io);
1766
1767 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1768 io->sector);
1769
1770 r = crypt_convert(cc, &io->ctx);
1771 if (r)
1772 io->error = r;
1773
1774 if (atomic_dec_and_test(&io->ctx.cc_pending))
1775 kcryptd_crypt_read_done(io);
1776
1777 crypt_dec_pending(io);
1778}
1779
1780static void kcryptd_async_done(struct crypto_async_request *async_req,
1781 int error)
1782{
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;
1787
1788 /*
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.)
1792 */
1793 if (error == -EINPROGRESS) {
1794 complete(&ctx->restart);
1795 return;
1796 }
1797
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);
1800
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;
1807
1808 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1809
1810 if (!atomic_dec_and_test(&ctx->cc_pending))
1811 return;
1812
1813 if (bio_data_dir(io->base_bio) == READ)
1814 kcryptd_crypt_read_done(io);
1815 else
1816 kcryptd_crypt_write_io_submit(io, 1);
1817}
1818
1819static void kcryptd_crypt(struct work_struct *work)
1820{
1821 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1822
1823 if (bio_data_dir(io->base_bio) == READ)
1824 kcryptd_crypt_read_convert(io);
1825 else
1826 kcryptd_crypt_write_convert(io);
1827}
1828
1829static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1830{
1831 struct crypt_config *cc = io->cc;
1832
1833 INIT_WORK(&io->work, kcryptd_crypt);
1834 queue_work(cc->crypt_queue, &io->work);
1835}
1836
1837static void crypt_free_tfms_aead(struct crypt_config *cc)
1838{
1839 if (!cc->cipher_tfm.tfms_aead)
1840 return;
1841
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;
1845 }
1846
1847 kfree(cc->cipher_tfm.tfms_aead);
1848 cc->cipher_tfm.tfms_aead = NULL;
1849}
1850
1851static void crypt_free_tfms_skcipher(struct crypt_config *cc)
1852{
1853 unsigned i;
1854
1855 if (!cc->cipher_tfm.tfms)
1856 return;
1857
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;
1862 }
1863
1864 kfree(cc->cipher_tfm.tfms);
1865 cc->cipher_tfm.tfms = NULL;
1866}
1867
1868static void crypt_free_tfms(struct crypt_config *cc)
1869{
1870 if (crypt_integrity_aead(cc))
1871 crypt_free_tfms_aead(cc);
1872 else
1873 crypt_free_tfms_skcipher(cc);
1874}
1875
1876static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
1877{
1878 unsigned i;
1879 int err;
1880
1881 cc->cipher_tfm.tfms = kzalloc(cc->tfms_count *
1882 sizeof(struct crypto_skcipher *), GFP_KERNEL);
1883 if (!cc->cipher_tfm.tfms)
1884 return -ENOMEM;
1885
1886 for (i = 0; i < cc->tfms_count; i++) {
1887 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1888 if (IS_ERR(cc->cipher_tfm.tfms[i])) {
1889 err = PTR_ERR(cc->cipher_tfm.tfms[i]);
1890 crypt_free_tfms(cc);
1891 return err;
1892 }
1893 }
1894
1895 return 0;
1896}
1897
1898static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
1899{
1900 int err;
1901
1902 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
1903 if (!cc->cipher_tfm.tfms)
1904 return -ENOMEM;
1905
1906 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0);
1907 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1908 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
1909 crypt_free_tfms(cc);
1910 return err;
1911 }
1912
1913 return 0;
1914}
1915
1916static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1917{
1918 if (crypt_integrity_aead(cc))
1919 return crypt_alloc_tfms_aead(cc, ciphermode);
1920 else
1921 return crypt_alloc_tfms_skcipher(cc, ciphermode);
1922}
1923
1924static unsigned crypt_subkey_size(struct crypt_config *cc)
1925{
1926 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1927}
1928
1929static unsigned crypt_authenckey_size(struct crypt_config *cc)
1930{
1931 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
1932}
1933
1934/*
1935 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
1936 * the key must be for some reason in special format.
1937 * This funcion converts cc->key to this special format.
1938 */
1939static void crypt_copy_authenckey(char *p, const void *key,
1940 unsigned enckeylen, unsigned authkeylen)
1941{
1942 struct crypto_authenc_key_param *param;
1943 struct rtattr *rta;
1944
1945 rta = (struct rtattr *)p;
1946 param = RTA_DATA(rta);
1947 param->enckeylen = cpu_to_be32(enckeylen);
1948 rta->rta_len = RTA_LENGTH(sizeof(*param));
1949 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1950 p += RTA_SPACE(sizeof(*param));
1951 memcpy(p, key + enckeylen, authkeylen);
1952 p += authkeylen;
1953 memcpy(p, key, enckeylen);
1954}
1955
1956static int crypt_setkey(struct crypt_config *cc)
1957{
1958 unsigned subkey_size;
1959 int err = 0, i, r;
1960
1961 /* Ignore extra keys (which are used for IV etc) */
1962 subkey_size = crypt_subkey_size(cc);
1963
1964 if (crypt_integrity_hmac(cc)) {
1965 if (subkey_size < cc->key_mac_size)
1966 return -EINVAL;
1967
1968 crypt_copy_authenckey(cc->authenc_key, cc->key,
1969 subkey_size - cc->key_mac_size,
1970 cc->key_mac_size);
1971 }
1972
1973 for (i = 0; i < cc->tfms_count; i++) {
1974 if (crypt_integrity_hmac(cc))
1975 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1976 cc->authenc_key, crypt_authenckey_size(cc));
1977 else if (crypt_integrity_aead(cc))
1978 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1979 cc->key + (i * subkey_size),
1980 subkey_size);
1981 else
1982 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
1983 cc->key + (i * subkey_size),
1984 subkey_size);
1985 if (r)
1986 err = r;
1987 }
1988
1989 if (crypt_integrity_hmac(cc))
1990 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
1991
1992 return err;
1993}
1994
1995#ifdef CONFIG_KEYS
1996
1997static bool contains_whitespace(const char *str)
1998{
1999 while (*str)
2000 if (isspace(*str++))
2001 return true;
2002 return false;
2003}
2004
2005static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2006{
2007 char *new_key_string, *key_desc;
2008 int ret;
2009 struct key *key;
2010 const struct user_key_payload *ukp;
2011
2012 /*
2013 * Reject key_string with whitespace. dm core currently lacks code for
2014 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2015 */
2016 if (contains_whitespace(key_string)) {
2017 DMERR("whitespace chars not allowed in key string");
2018 return -EINVAL;
2019 }
2020
2021 /* look for next ':' separating key_type from key_description */
2022 key_desc = strpbrk(key_string, ":");
2023 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2024 return -EINVAL;
2025
2026 if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
2027 strncmp(key_string, "user:", key_desc - key_string + 1))
2028 return -EINVAL;
2029
2030 new_key_string = kstrdup(key_string, GFP_KERNEL);
2031 if (!new_key_string)
2032 return -ENOMEM;
2033
2034 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
2035 key_desc + 1, NULL);
2036 if (IS_ERR(key)) {
2037 kzfree(new_key_string);
2038 return PTR_ERR(key);
2039 }
2040
2041 down_read(&key->sem);
2042
2043 ukp = user_key_payload_locked(key);
2044 if (!ukp) {
2045 up_read(&key->sem);
2046 key_put(key);
2047 kzfree(new_key_string);
2048 return -EKEYREVOKED;
2049 }
2050
2051 if (cc->key_size != ukp->datalen) {
2052 up_read(&key->sem);
2053 key_put(key);
2054 kzfree(new_key_string);
2055 return -EINVAL;
2056 }
2057
2058 memcpy(cc->key, ukp->data, cc->key_size);
2059
2060 up_read(&key->sem);
2061 key_put(key);
2062
2063 /* clear the flag since following operations may invalidate previously valid key */
2064 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2065
2066 ret = crypt_setkey(cc);
2067
2068 if (!ret) {
2069 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2070 kzfree(cc->key_string);
2071 cc->key_string = new_key_string;
2072 } else
2073 kzfree(new_key_string);
2074
2075 return ret;
2076}
2077
2078static int get_key_size(char **key_string)
2079{
2080 char *colon, dummy;
2081 int ret;
2082
2083 if (*key_string[0] != ':')
2084 return strlen(*key_string) >> 1;
2085
2086 /* look for next ':' in key string */
2087 colon = strpbrk(*key_string + 1, ":");
2088 if (!colon)
2089 return -EINVAL;
2090
2091 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2092 return -EINVAL;
2093
2094 *key_string = colon;
2095
2096 /* remaining key string should be :<logon|user>:<key_desc> */
2097
2098 return ret;
2099}
2100
2101#else
2102
2103static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2104{
2105 return -EINVAL;
2106}
2107
2108static int get_key_size(char **key_string)
2109{
2110 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
2111}
2112
2113#endif
2114
2115static int crypt_set_key(struct crypt_config *cc, char *key)
2116{
2117 int r = -EINVAL;
2118 int key_string_len = strlen(key);
2119
2120 /* Hyphen (which gives a key_size of zero) means there is no key. */
2121 if (!cc->key_size && strcmp(key, "-"))
2122 goto out;
2123
2124 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2125 if (key[0] == ':') {
2126 r = crypt_set_keyring_key(cc, key + 1);
2127 goto out;
2128 }
2129
2130 /* clear the flag since following operations may invalidate previously valid key */
2131 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2132
2133 /* wipe references to any kernel keyring key */
2134 kzfree(cc->key_string);
2135 cc->key_string = NULL;
2136
2137 /* Decode key from its hex representation. */
2138 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2139 goto out;
2140
2141 r = crypt_setkey(cc);
2142 if (!r)
2143 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2144
2145out:
2146 /* Hex key string not needed after here, so wipe it. */
2147 memset(key, '0', key_string_len);
2148
2149 return r;
2150}
2151
2152static int crypt_wipe_key(struct crypt_config *cc)
2153{
2154 int r;
2155
2156 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2157 get_random_bytes(&cc->key, cc->key_size);
2158 kzfree(cc->key_string);
2159 cc->key_string = NULL;
2160 r = crypt_setkey(cc);
2161 memset(&cc->key, 0, cc->key_size * sizeof(u8));
2162
2163 return r;
2164}
2165
2166static void crypt_calculate_pages_per_client(void)
2167{
2168 unsigned long pages = (totalram_pages - totalhigh_pages) * DM_CRYPT_MEMORY_PERCENT / 100;
2169
2170 if (!dm_crypt_clients_n)
2171 return;
2172
2173 pages /= dm_crypt_clients_n;
2174 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2175 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2176 dm_crypt_pages_per_client = pages;
2177}
2178
2179static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2180{
2181 struct crypt_config *cc = pool_data;
2182 struct page *page;
2183
2184 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) &&
2185 likely(gfp_mask & __GFP_NORETRY))
2186 return NULL;
2187
2188 page = alloc_page(gfp_mask);
2189 if (likely(page != NULL))
2190 percpu_counter_add(&cc->n_allocated_pages, 1);
2191
2192 return page;
2193}
2194
2195static void crypt_page_free(void *page, void *pool_data)
2196{
2197 struct crypt_config *cc = pool_data;
2198
2199 __free_page(page);
2200 percpu_counter_sub(&cc->n_allocated_pages, 1);
2201}
2202
2203static void crypt_dtr(struct dm_target *ti)
2204{
2205 struct crypt_config *cc = ti->private;
2206
2207 ti->private = NULL;
2208
2209 if (!cc)
2210 return;
2211
2212 if (cc->write_thread)
2213 kthread_stop(cc->write_thread);
2214
2215 if (cc->io_queue)
2216 destroy_workqueue(cc->io_queue);
2217 if (cc->crypt_queue)
2218 destroy_workqueue(cc->crypt_queue);
2219
2220 crypt_free_tfms(cc);
2221
2222 if (cc->bs)
2223 bioset_free(cc->bs);
2224
2225 mempool_destroy(cc->page_pool);
2226 mempool_destroy(cc->req_pool);
2227 mempool_destroy(cc->tag_pool);
2228
2229 if (cc->page_pool)
2230 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2231 percpu_counter_destroy(&cc->n_allocated_pages);
2232
2233 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2234 cc->iv_gen_ops->dtr(cc);
2235
2236 if (cc->dev)
2237 dm_put_device(ti, cc->dev);
2238
2239 kzfree(cc->cipher);
2240 kzfree(cc->cipher_string);
2241 kzfree(cc->key_string);
2242 kzfree(cc->cipher_auth);
2243 kzfree(cc->authenc_key);
2244
2245 mutex_destroy(&cc->bio_alloc_lock);
2246
2247 /* Must zero key material before freeing */
2248 kzfree(cc);
2249
2250 spin_lock(&dm_crypt_clients_lock);
2251 WARN_ON(!dm_crypt_clients_n);
2252 dm_crypt_clients_n--;
2253 crypt_calculate_pages_per_client();
2254 spin_unlock(&dm_crypt_clients_lock);
2255}
2256
2257static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2258{
2259 struct crypt_config *cc = ti->private;
2260
2261 if (crypt_integrity_aead(cc))
2262 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2263 else
2264 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2265
2266 if (cc->iv_size)
2267 /* at least a 64 bit sector number should fit in our buffer */
2268 cc->iv_size = max(cc->iv_size,
2269 (unsigned int)(sizeof(u64) / sizeof(u8)));
2270 else if (ivmode) {
2271 DMWARN("Selected cipher does not support IVs");
2272 ivmode = NULL;
2273 }
2274
2275 /* Choose ivmode, see comments at iv code. */
2276 if (ivmode == NULL)
2277 cc->iv_gen_ops = NULL;
2278 else if (strcmp(ivmode, "plain") == 0)
2279 cc->iv_gen_ops = &crypt_iv_plain_ops;
2280 else if (strcmp(ivmode, "plain64") == 0)
2281 cc->iv_gen_ops = &crypt_iv_plain64_ops;
2282 else if (strcmp(ivmode, "plain64be") == 0)
2283 cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2284 else if (strcmp(ivmode, "essiv") == 0)
2285 cc->iv_gen_ops = &crypt_iv_essiv_ops;
2286 else if (strcmp(ivmode, "benbi") == 0)
2287 cc->iv_gen_ops = &crypt_iv_benbi_ops;
2288 else if (strcmp(ivmode, "null") == 0)
2289 cc->iv_gen_ops = &crypt_iv_null_ops;
2290 else if (strcmp(ivmode, "lmk") == 0) {
2291 cc->iv_gen_ops = &crypt_iv_lmk_ops;
2292 /*
2293 * Version 2 and 3 is recognised according
2294 * to length of provided multi-key string.
2295 * If present (version 3), last key is used as IV seed.
2296 * All keys (including IV seed) are always the same size.
2297 */
2298 if (cc->key_size % cc->key_parts) {
2299 cc->key_parts++;
2300 cc->key_extra_size = cc->key_size / cc->key_parts;
2301 }
2302 } else if (strcmp(ivmode, "tcw") == 0) {
2303 cc->iv_gen_ops = &crypt_iv_tcw_ops;
2304 cc->key_parts += 2; /* IV + whitening */
2305 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2306 } else if (strcmp(ivmode, "random") == 0) {
2307 cc->iv_gen_ops = &crypt_iv_random_ops;
2308 /* Need storage space in integrity fields. */
2309 cc->integrity_iv_size = cc->iv_size;
2310 } else {
2311 ti->error = "Invalid IV mode";
2312 return -EINVAL;
2313 }
2314
2315 return 0;
2316}
2317
2318/*
2319 * Workaround to parse cipher algorithm from crypto API spec.
2320 * The cc->cipher is currently used only in ESSIV.
2321 * This should be probably done by crypto-api calls (once available...)
2322 */
2323static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)
2324{
2325 const char *alg_name = NULL;
2326 char *start, *end;
2327
2328 if (crypt_integrity_aead(cc)) {
2329 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));
2330 if (!alg_name)
2331 return -EINVAL;
2332 if (crypt_integrity_hmac(cc)) {
2333 alg_name = strchr(alg_name, ',');
2334 if (!alg_name)
2335 return -EINVAL;
2336 }
2337 alg_name++;
2338 } else {
2339 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));
2340 if (!alg_name)
2341 return -EINVAL;
2342 }
2343
2344 start = strchr(alg_name, '(');
2345 end = strchr(alg_name, ')');
2346
2347 if (!start && !end) {
2348 cc->cipher = kstrdup(alg_name, GFP_KERNEL);
2349 return cc->cipher ? 0 : -ENOMEM;
2350 }
2351
2352 if (!start || !end || ++start >= end)
2353 return -EINVAL;
2354
2355 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);
2356 if (!cc->cipher)
2357 return -ENOMEM;
2358
2359 strncpy(cc->cipher, start, end - start);
2360
2361 return 0;
2362}
2363
2364/*
2365 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2366 * The HMAC is needed to calculate tag size (HMAC digest size).
2367 * This should be probably done by crypto-api calls (once available...)
2368 */
2369static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2370{
2371 char *start, *end, *mac_alg = NULL;
2372 struct crypto_ahash *mac;
2373
2374 if (!strstarts(cipher_api, "authenc("))
2375 return 0;
2376
2377 start = strchr(cipher_api, '(');
2378 end = strchr(cipher_api, ',');
2379 if (!start || !end || ++start > end)
2380 return -EINVAL;
2381
2382 mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2383 if (!mac_alg)
2384 return -ENOMEM;
2385 strncpy(mac_alg, start, end - start);
2386
2387 mac = crypto_alloc_ahash(mac_alg, 0, 0);
2388 kfree(mac_alg);
2389
2390 if (IS_ERR(mac))
2391 return PTR_ERR(mac);
2392
2393 cc->key_mac_size = crypto_ahash_digestsize(mac);
2394 crypto_free_ahash(mac);
2395
2396 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2397 if (!cc->authenc_key)
2398 return -ENOMEM;
2399
2400 return 0;
2401}
2402
2403static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2404 char **ivmode, char **ivopts)
2405{
2406 struct crypt_config *cc = ti->private;
2407 char *tmp, *cipher_api;
2408 int ret = -EINVAL;
2409
2410 cc->tfms_count = 1;
2411
2412 /*
2413 * New format (capi: prefix)
2414 * capi:cipher_api_spec-iv:ivopts
2415 */
2416 tmp = &cipher_in[strlen("capi:")];
2417 cipher_api = strsep(&tmp, "-");
2418 *ivmode = strsep(&tmp, ":");
2419 *ivopts = tmp;
2420
2421 if (*ivmode && !strcmp(*ivmode, "lmk"))
2422 cc->tfms_count = 64;
2423
2424 cc->key_parts = cc->tfms_count;
2425
2426 /* Allocate cipher */
2427 ret = crypt_alloc_tfms(cc, cipher_api);
2428 if (ret < 0) {
2429 ti->error = "Error allocating crypto tfm";
2430 return ret;
2431 }
2432
2433 /* Alloc AEAD, can be used only in new format. */
2434 if (crypt_integrity_aead(cc)) {
2435 ret = crypt_ctr_auth_cipher(cc, cipher_api);
2436 if (ret < 0) {
2437 ti->error = "Invalid AEAD cipher spec";
2438 return -ENOMEM;
2439 }
2440 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2441 } else
2442 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2443
2444 ret = crypt_ctr_blkdev_cipher(cc);
2445 if (ret < 0) {
2446 ti->error = "Cannot allocate cipher string";
2447 return -ENOMEM;
2448 }
2449
2450 return 0;
2451}
2452
2453static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2454 char **ivmode, char **ivopts)
2455{
2456 struct crypt_config *cc = ti->private;
2457 char *tmp, *cipher, *chainmode, *keycount;
2458 char *cipher_api = NULL;
2459 int ret = -EINVAL;
2460 char dummy;
2461
2462 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2463 ti->error = "Bad cipher specification";
2464 return -EINVAL;
2465 }
2466
2467 /*
2468 * Legacy dm-crypt cipher specification
2469 * cipher[:keycount]-mode-iv:ivopts
2470 */
2471 tmp = cipher_in;
2472 keycount = strsep(&tmp, "-");
2473 cipher = strsep(&keycount, ":");
2474
2475 if (!keycount)
2476 cc->tfms_count = 1;
2477 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2478 !is_power_of_2(cc->tfms_count)) {
2479 ti->error = "Bad cipher key count specification";
2480 return -EINVAL;
2481 }
2482 cc->key_parts = cc->tfms_count;
2483
2484 cc->cipher = kstrdup(cipher, GFP_KERNEL);
2485 if (!cc->cipher)
2486 goto bad_mem;
2487
2488 chainmode = strsep(&tmp, "-");
2489 *ivopts = strsep(&tmp, "-");
2490 *ivmode = strsep(&*ivopts, ":");
2491
2492 if (tmp)
2493 DMWARN("Ignoring unexpected additional cipher options");
2494
2495 /*
2496 * For compatibility with the original dm-crypt mapping format, if
2497 * only the cipher name is supplied, use cbc-plain.
2498 */
2499 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2500 chainmode = "cbc";
2501 *ivmode = "plain";
2502 }
2503
2504 if (strcmp(chainmode, "ecb") && !*ivmode) {
2505 ti->error = "IV mechanism required";
2506 return -EINVAL;
2507 }
2508
2509 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2510 if (!cipher_api)
2511 goto bad_mem;
2512
2513 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2514 "%s(%s)", chainmode, cipher);
2515 if (ret < 0) {
2516 kfree(cipher_api);
2517 goto bad_mem;
2518 }
2519
2520 /* Allocate cipher */
2521 ret = crypt_alloc_tfms(cc, cipher_api);
2522 if (ret < 0) {
2523 ti->error = "Error allocating crypto tfm";
2524 kfree(cipher_api);
2525 return ret;
2526 }
2527 kfree(cipher_api);
2528
2529 return 0;
2530bad_mem:
2531 ti->error = "Cannot allocate cipher strings";
2532 return -ENOMEM;
2533}
2534
2535static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
2536{
2537 struct crypt_config *cc = ti->private;
2538 char *ivmode = NULL, *ivopts = NULL;
2539 int ret;
2540
2541 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
2542 if (!cc->cipher_string) {
2543 ti->error = "Cannot allocate cipher strings";
2544 return -ENOMEM;
2545 }
2546
2547 if (strstarts(cipher_in, "capi:"))
2548 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
2549 else
2550 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
2551 if (ret)
2552 return ret;
2553
2554 /* Initialize IV */
2555 ret = crypt_ctr_ivmode(ti, ivmode);
2556 if (ret < 0)
2557 return ret;
2558
2559 /* Initialize and set key */
2560 ret = crypt_set_key(cc, key);
2561 if (ret < 0) {
2562 ti->error = "Error decoding and setting key";
2563 return ret;
2564 }
2565
2566 /* Allocate IV */
2567 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
2568 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
2569 if (ret < 0) {
2570 ti->error = "Error creating IV";
2571 return ret;
2572 }
2573 }
2574
2575 /* Initialize IV (set keys for ESSIV etc) */
2576 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
2577 ret = cc->iv_gen_ops->init(cc);
2578 if (ret < 0) {
2579 ti->error = "Error initialising IV";
2580 return ret;
2581 }
2582 }
2583
2584 /* wipe the kernel key payload copy */
2585 if (cc->key_string)
2586 memset(cc->key, 0, cc->key_size * sizeof(u8));
2587
2588 return ret;
2589}
2590
2591static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
2592{
2593 struct crypt_config *cc = ti->private;
2594 struct dm_arg_set as;
2595 static const struct dm_arg _args[] = {
2596 {0, 6, "Invalid number of feature args"},
2597 };
2598 unsigned int opt_params, val;
2599 const char *opt_string, *sval;
2600 char dummy;
2601 int ret;
2602
2603 /* Optional parameters */
2604 as.argc = argc;
2605 as.argv = argv;
2606
2607 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
2608 if (ret)
2609 return ret;
2610
2611 while (opt_params--) {
2612 opt_string = dm_shift_arg(&as);
2613 if (!opt_string) {
2614 ti->error = "Not enough feature arguments";
2615 return -EINVAL;
2616 }
2617
2618 if (!strcasecmp(opt_string, "allow_discards"))
2619 ti->num_discard_bios = 1;
2620
2621 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
2622 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2623
2624 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
2625 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2626 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
2627 if (val == 0 || val > MAX_TAG_SIZE) {
2628 ti->error = "Invalid integrity arguments";
2629 return -EINVAL;
2630 }
2631 cc->on_disk_tag_size = val;
2632 sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
2633 if (!strcasecmp(sval, "aead")) {
2634 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
2635 } else if (strcasecmp(sval, "none")) {
2636 ti->error = "Unknown integrity profile";
2637 return -EINVAL;
2638 }
2639
2640 cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
2641 if (!cc->cipher_auth)
2642 return -ENOMEM;
2643 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
2644 if (cc->sector_size < (1 << SECTOR_SHIFT) ||
2645 cc->sector_size > 4096 ||
2646 (cc->sector_size & (cc->sector_size - 1))) {
2647 ti->error = "Invalid feature value for sector_size";
2648 return -EINVAL;
2649 }
2650 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
2651 ti->error = "Device size is not multiple of sector_size feature";
2652 return -EINVAL;
2653 }
2654 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
2655 } else if (!strcasecmp(opt_string, "iv_large_sectors"))
2656 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2657 else {
2658 ti->error = "Invalid feature arguments";
2659 return -EINVAL;
2660 }
2661 }
2662
2663 return 0;
2664}
2665
2666/*
2667 * Construct an encryption mapping:
2668 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
2669 */
2670static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2671{
2672 struct crypt_config *cc;
2673 int key_size;
2674 unsigned int align_mask;
2675 unsigned long long tmpll;
2676 int ret;
2677 size_t iv_size_padding, additional_req_size;
2678 char dummy;
2679
2680 if (argc < 5) {
2681 ti->error = "Not enough arguments";
2682 return -EINVAL;
2683 }
2684
2685 key_size = get_key_size(&argv[1]);
2686 if (key_size < 0) {
2687 ti->error = "Cannot parse key size";
2688 return -EINVAL;
2689 }
2690
2691 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
2692 if (!cc) {
2693 ti->error = "Cannot allocate encryption context";
2694 return -ENOMEM;
2695 }
2696 cc->key_size = key_size;
2697 cc->sector_size = (1 << SECTOR_SHIFT);
2698 cc->sector_shift = 0;
2699
2700 ti->private = cc;
2701
2702 spin_lock(&dm_crypt_clients_lock);
2703 dm_crypt_clients_n++;
2704 crypt_calculate_pages_per_client();
2705 spin_unlock(&dm_crypt_clients_lock);
2706
2707 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
2708 if (ret < 0)
2709 goto bad;
2710
2711 /* Optional parameters need to be read before cipher constructor */
2712 if (argc > 5) {
2713 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
2714 if (ret)
2715 goto bad;
2716 }
2717
2718 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
2719 if (ret < 0)
2720 goto bad;
2721
2722 if (crypt_integrity_aead(cc)) {
2723 cc->dmreq_start = sizeof(struct aead_request);
2724 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
2725 align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
2726 } else {
2727 cc->dmreq_start = sizeof(struct skcipher_request);
2728 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
2729 align_mask = crypto_skcipher_alignmask(any_tfm(cc));
2730 }
2731 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
2732
2733 if (align_mask < CRYPTO_MINALIGN) {
2734 /* Allocate the padding exactly */
2735 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
2736 & align_mask;
2737 } else {
2738 /*
2739 * If the cipher requires greater alignment than kmalloc
2740 * alignment, we don't know the exact position of the
2741 * initialization vector. We must assume worst case.
2742 */
2743 iv_size_padding = align_mask;
2744 }
2745
2746 ret = -ENOMEM;
2747
2748 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */
2749 additional_req_size = sizeof(struct dm_crypt_request) +
2750 iv_size_padding + cc->iv_size +
2751 cc->iv_size +
2752 sizeof(uint64_t) +
2753 sizeof(unsigned int);
2754
2755 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + additional_req_size);
2756 if (!cc->req_pool) {
2757 ti->error = "Cannot allocate crypt request mempool";
2758 goto bad;
2759 }
2760
2761 cc->per_bio_data_size = ti->per_io_data_size =
2762 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
2763 ARCH_KMALLOC_MINALIGN);
2764
2765 cc->page_pool = mempool_create(BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc);
2766 if (!cc->page_pool) {
2767 ti->error = "Cannot allocate page mempool";
2768 goto bad;
2769 }
2770
2771 cc->bs = bioset_create(MIN_IOS, 0, BIOSET_NEED_BVECS);
2772 if (!cc->bs) {
2773 ti->error = "Cannot allocate crypt bioset";
2774 goto bad;
2775 }
2776
2777 mutex_init(&cc->bio_alloc_lock);
2778
2779 ret = -EINVAL;
2780 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
2781 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
2782 ti->error = "Invalid iv_offset sector";
2783 goto bad;
2784 }
2785 cc->iv_offset = tmpll;
2786
2787 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
2788 if (ret) {
2789 ti->error = "Device lookup failed";
2790 goto bad;
2791 }
2792
2793 ret = -EINVAL;
2794 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
2795 ti->error = "Invalid device sector";
2796 goto bad;
2797 }
2798 cc->start = tmpll;
2799
2800 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
2801 ret = crypt_integrity_ctr(cc, ti);
2802 if (ret)
2803 goto bad;
2804
2805 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
2806 if (!cc->tag_pool_max_sectors)
2807 cc->tag_pool_max_sectors = 1;
2808
2809 cc->tag_pool = mempool_create_kmalloc_pool(MIN_IOS,
2810 cc->tag_pool_max_sectors * cc->on_disk_tag_size);
2811 if (!cc->tag_pool) {
2812 ti->error = "Cannot allocate integrity tags mempool";
2813 ret = -ENOMEM;
2814 goto bad;
2815 }
2816
2817 cc->tag_pool_max_sectors <<= cc->sector_shift;
2818 }
2819
2820 ret = -ENOMEM;
2821 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2822 if (!cc->io_queue) {
2823 ti->error = "Couldn't create kcryptd io queue";
2824 goto bad;
2825 }
2826
2827 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2828 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2829 else
2830 cc->crypt_queue = alloc_workqueue("kcryptd",
2831 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2832 num_online_cpus());
2833 if (!cc->crypt_queue) {
2834 ti->error = "Couldn't create kcryptd queue";
2835 goto bad;
2836 }
2837
2838 init_waitqueue_head(&cc->write_thread_wait);
2839 cc->write_tree = RB_ROOT;
2840
2841 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
2842 if (IS_ERR(cc->write_thread)) {
2843 ret = PTR_ERR(cc->write_thread);
2844 cc->write_thread = NULL;
2845 ti->error = "Couldn't spawn write thread";
2846 goto bad;
2847 }
2848 wake_up_process(cc->write_thread);
2849
2850 ti->num_flush_bios = 1;
2851
2852 return 0;
2853
2854bad:
2855 crypt_dtr(ti);
2856 return ret;
2857}
2858
2859static int crypt_map(struct dm_target *ti, struct bio *bio)
2860{
2861 struct dm_crypt_io *io;
2862 struct crypt_config *cc = ti->private;
2863
2864 /*
2865 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2866 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
2867 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
2868 */
2869 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
2870 bio_op(bio) == REQ_OP_DISCARD)) {
2871 bio_set_dev(bio, cc->dev->bdev);
2872 if (bio_sectors(bio))
2873 bio->bi_iter.bi_sector = cc->start +
2874 dm_target_offset(ti, bio->bi_iter.bi_sector);
2875 return DM_MAPIO_REMAPPED;
2876 }
2877
2878 /*
2879 * Check if bio is too large, split as needed.
2880 */
2881 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2882 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
2883 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2884
2885 /*
2886 * Ensure that bio is a multiple of internal sector encryption size
2887 * and is aligned to this size as defined in IO hints.
2888 */
2889 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
2890 return DM_MAPIO_KILL;
2891
2892 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
2893 return DM_MAPIO_KILL;
2894
2895 io = dm_per_bio_data(bio, cc->per_bio_data_size);
2896 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
2897
2898 if (cc->on_disk_tag_size) {
2899 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
2900
2901 if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
2902 unlikely(!(io->integrity_metadata = kmalloc(tag_len,
2903 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
2904 if (bio_sectors(bio) > cc->tag_pool_max_sectors)
2905 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
2906 io->integrity_metadata = mempool_alloc(cc->tag_pool, GFP_NOIO);
2907 io->integrity_metadata_from_pool = true;
2908 }
2909 }
2910
2911 if (crypt_integrity_aead(cc))
2912 io->ctx.r.req_aead = (struct aead_request *)(io + 1);
2913 else
2914 io->ctx.r.req = (struct skcipher_request *)(io + 1);
2915
2916 if (bio_data_dir(io->base_bio) == READ) {
2917 if (kcryptd_io_read(io, GFP_NOWAIT))
2918 kcryptd_queue_read(io);
2919 } else
2920 kcryptd_queue_crypt(io);
2921
2922 return DM_MAPIO_SUBMITTED;
2923}
2924
2925static void crypt_status(struct dm_target *ti, status_type_t type,
2926 unsigned status_flags, char *result, unsigned maxlen)
2927{
2928 struct crypt_config *cc = ti->private;
2929 unsigned i, sz = 0;
2930 int num_feature_args = 0;
2931
2932 switch (type) {
2933 case STATUSTYPE_INFO:
2934 result[0] = '\0';
2935 break;
2936
2937 case STATUSTYPE_TABLE:
2938 DMEMIT("%s ", cc->cipher_string);
2939
2940 if (cc->key_size > 0) {
2941 if (cc->key_string)
2942 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2943 else
2944 for (i = 0; i < cc->key_size; i++)
2945 DMEMIT("%02x", cc->key[i]);
2946 } else
2947 DMEMIT("-");
2948
2949 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2950 cc->dev->name, (unsigned long long)cc->start);
2951
2952 num_feature_args += !!ti->num_discard_bios;
2953 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2954 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2955 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
2956 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2957 if (cc->on_disk_tag_size)
2958 num_feature_args++;
2959 if (num_feature_args) {
2960 DMEMIT(" %d", num_feature_args);
2961 if (ti->num_discard_bios)
2962 DMEMIT(" allow_discards");
2963 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2964 DMEMIT(" same_cpu_crypt");
2965 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2966 DMEMIT(" submit_from_crypt_cpus");
2967 if (cc->on_disk_tag_size)
2968 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
2969 if (cc->sector_size != (1 << SECTOR_SHIFT))
2970 DMEMIT(" sector_size:%d", cc->sector_size);
2971 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
2972 DMEMIT(" iv_large_sectors");
2973 }
2974
2975 break;
2976 }
2977}
2978
2979static void crypt_postsuspend(struct dm_target *ti)
2980{
2981 struct crypt_config *cc = ti->private;
2982
2983 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2984}
2985
2986static int crypt_preresume(struct dm_target *ti)
2987{
2988 struct crypt_config *cc = ti->private;
2989
2990 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
2991 DMERR("aborting resume - crypt key is not set.");
2992 return -EAGAIN;
2993 }
2994
2995 return 0;
2996}
2997
2998static void crypt_resume(struct dm_target *ti)
2999{
3000 struct crypt_config *cc = ti->private;
3001
3002 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3003}
3004
3005/* Message interface
3006 * key set <key>
3007 * key wipe
3008 */
3009static int crypt_message(struct dm_target *ti, unsigned argc, char **argv,
3010 char *result, unsigned maxlen)
3011{
3012 struct crypt_config *cc = ti->private;
3013 int key_size, ret = -EINVAL;
3014
3015 if (argc < 2)
3016 goto error;
3017
3018 if (!strcasecmp(argv[0], "key")) {
3019 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3020 DMWARN("not suspended during key manipulation.");
3021 return -EINVAL;
3022 }
3023 if (argc == 3 && !strcasecmp(argv[1], "set")) {
3024 /* The key size may not be changed. */
3025 key_size = get_key_size(&argv[2]);
3026 if (key_size < 0 || cc->key_size != key_size) {
3027 memset(argv[2], '0', strlen(argv[2]));
3028 return -EINVAL;
3029 }
3030
3031 ret = crypt_set_key(cc, argv[2]);
3032 if (ret)
3033 return ret;
3034 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3035 ret = cc->iv_gen_ops->init(cc);
3036 /* wipe the kernel key payload copy */
3037 if (cc->key_string)
3038 memset(cc->key, 0, cc->key_size * sizeof(u8));
3039 return ret;
3040 }
3041 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
3042 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
3043 ret = cc->iv_gen_ops->wipe(cc);
3044 if (ret)
3045 return ret;
3046 }
3047 return crypt_wipe_key(cc);
3048 }
3049 }
3050
3051error:
3052 DMWARN("unrecognised message received.");
3053 return -EINVAL;
3054}
3055
3056static int crypt_iterate_devices(struct dm_target *ti,
3057 iterate_devices_callout_fn fn, void *data)
3058{
3059 struct crypt_config *cc = ti->private;
3060
3061 return fn(ti, cc->dev, cc->start, ti->len, data);
3062}
3063
3064static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3065{
3066 struct crypt_config *cc = ti->private;
3067
3068 /*
3069 * Unfortunate constraint that is required to avoid the potential
3070 * for exceeding underlying device's max_segments limits -- due to
3071 * crypt_alloc_buffer() possibly allocating pages for the encryption
3072 * bio that are not as physically contiguous as the original bio.
3073 */
3074 limits->max_segment_size = PAGE_SIZE;
3075
3076 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
3077 limits->logical_block_size = cc->sector_size;
3078 limits->physical_block_size = cc->sector_size;
3079 blk_limits_io_min(limits, cc->sector_size);
3080 }
3081}
3082
3083static struct target_type crypt_target = {
3084 .name = "crypt",
3085 .version = {1, 18, 1},
3086 .module = THIS_MODULE,
3087 .ctr = crypt_ctr,
3088 .dtr = crypt_dtr,
3089 .map = crypt_map,
3090 .status = crypt_status,
3091 .postsuspend = crypt_postsuspend,
3092 .preresume = crypt_preresume,
3093 .resume = crypt_resume,
3094 .message = crypt_message,
3095 .iterate_devices = crypt_iterate_devices,
3096 .io_hints = crypt_io_hints,
3097};
3098
3099static int __init dm_crypt_init(void)
3100{
3101 int r;
3102
3103 r = dm_register_target(&crypt_target);
3104 if (r < 0)
3105 DMERR("register failed %d", r);
3106
3107 return r;
3108}
3109
3110static void __exit dm_crypt_exit(void)
3111{
3112 dm_unregister_target(&crypt_target);
3113}
3114
3115module_init(dm_crypt_init);
3116module_exit(dm_crypt_exit);
3117
3118MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3119MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3120MODULE_LICENSE("GPL");