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1/*
2 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the GPL.
7 */
8
9#include <linux/completion.h>
10#include <linux/err.h>
11#include <linux/module.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/bio.h>
15#include <linux/blkdev.h>
16#include <linux/mempool.h>
17#include <linux/slab.h>
18#include <linux/crypto.h>
19#include <linux/workqueue.h>
20#include <linux/backing-dev.h>
21#include <linux/percpu.h>
22#include <linux/atomic.h>
23#include <linux/scatterlist.h>
24#include <asm/page.h>
25#include <asm/unaligned.h>
26#include <crypto/hash.h>
27#include <crypto/md5.h>
28#include <crypto/algapi.h>
29
30#include <linux/device-mapper.h>
31
32#define DM_MSG_PREFIX "crypt"
33
34/*
35 * context holding the current state of a multi-part conversion
36 */
37struct convert_context {
38 struct completion restart;
39 struct bio *bio_in;
40 struct bio *bio_out;
41 unsigned int offset_in;
42 unsigned int offset_out;
43 unsigned int idx_in;
44 unsigned int idx_out;
45 sector_t sector;
46 atomic_t pending;
47};
48
49/*
50 * per bio private data
51 */
52struct dm_crypt_io {
53 struct dm_target *target;
54 struct bio *base_bio;
55 struct work_struct work;
56
57 struct convert_context ctx;
58
59 atomic_t pending;
60 int error;
61 sector_t sector;
62 struct dm_crypt_io *base_io;
63};
64
65struct dm_crypt_request {
66 struct convert_context *ctx;
67 struct scatterlist sg_in;
68 struct scatterlist sg_out;
69 sector_t iv_sector;
70};
71
72struct crypt_config;
73
74struct crypt_iv_operations {
75 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
76 const char *opts);
77 void (*dtr)(struct crypt_config *cc);
78 int (*init)(struct crypt_config *cc);
79 int (*wipe)(struct crypt_config *cc);
80 int (*generator)(struct crypt_config *cc, u8 *iv,
81 struct dm_crypt_request *dmreq);
82 int (*post)(struct crypt_config *cc, u8 *iv,
83 struct dm_crypt_request *dmreq);
84};
85
86struct iv_essiv_private {
87 struct crypto_hash *hash_tfm;
88 u8 *salt;
89};
90
91struct iv_benbi_private {
92 int shift;
93};
94
95#define LMK_SEED_SIZE 64 /* hash + 0 */
96struct iv_lmk_private {
97 struct crypto_shash *hash_tfm;
98 u8 *seed;
99};
100
101/*
102 * Crypt: maps a linear range of a block device
103 * and encrypts / decrypts at the same time.
104 */
105enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
106
107/*
108 * Duplicated per-CPU state for cipher.
109 */
110struct crypt_cpu {
111 struct ablkcipher_request *req;
112 /* ESSIV: struct crypto_cipher *essiv_tfm */
113 void *iv_private;
114 struct crypto_ablkcipher *tfms[0];
115};
116
117/*
118 * The fields in here must be read only after initialization,
119 * changing state should be in crypt_cpu.
120 */
121struct crypt_config {
122 struct dm_dev *dev;
123 sector_t start;
124
125 /*
126 * pool for per bio private data, crypto requests and
127 * encryption requeusts/buffer pages
128 */
129 mempool_t *io_pool;
130 mempool_t *req_pool;
131 mempool_t *page_pool;
132 struct bio_set *bs;
133
134 struct workqueue_struct *io_queue;
135 struct workqueue_struct *crypt_queue;
136
137 char *cipher;
138 char *cipher_string;
139
140 struct crypt_iv_operations *iv_gen_ops;
141 union {
142 struct iv_essiv_private essiv;
143 struct iv_benbi_private benbi;
144 struct iv_lmk_private lmk;
145 } iv_gen_private;
146 sector_t iv_offset;
147 unsigned int iv_size;
148
149 /*
150 * Duplicated per cpu state. Access through
151 * per_cpu_ptr() only.
152 */
153 struct crypt_cpu __percpu *cpu;
154 unsigned tfms_count;
155
156 /*
157 * Layout of each crypto request:
158 *
159 * struct ablkcipher_request
160 * context
161 * padding
162 * struct dm_crypt_request
163 * padding
164 * IV
165 *
166 * The padding is added so that dm_crypt_request and the IV are
167 * correctly aligned.
168 */
169 unsigned int dmreq_start;
170
171 unsigned long flags;
172 unsigned int key_size;
173 unsigned int key_parts;
174 u8 key[0];
175};
176
177#define MIN_IOS 16
178#define MIN_POOL_PAGES 32
179#define MIN_BIO_PAGES 8
180
181static struct kmem_cache *_crypt_io_pool;
182
183static void clone_init(struct dm_crypt_io *, struct bio *);
184static void kcryptd_queue_crypt(struct dm_crypt_io *io);
185static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
186
187static struct crypt_cpu *this_crypt_config(struct crypt_config *cc)
188{
189 return this_cpu_ptr(cc->cpu);
190}
191
192/*
193 * Use this to access cipher attributes that are the same for each CPU.
194 */
195static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
196{
197 return __this_cpu_ptr(cc->cpu)->tfms[0];
198}
199
200/*
201 * Different IV generation algorithms:
202 *
203 * plain: the initial vector is the 32-bit little-endian version of the sector
204 * number, padded with zeros if necessary.
205 *
206 * plain64: the initial vector is the 64-bit little-endian version of the sector
207 * number, padded with zeros if necessary.
208 *
209 * essiv: "encrypted sector|salt initial vector", the sector number is
210 * encrypted with the bulk cipher using a salt as key. The salt
211 * should be derived from the bulk cipher's key via hashing.
212 *
213 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
214 * (needed for LRW-32-AES and possible other narrow block modes)
215 *
216 * null: the initial vector is always zero. Provides compatibility with
217 * obsolete loop_fish2 devices. Do not use for new devices.
218 *
219 * lmk: Compatible implementation of the block chaining mode used
220 * by the Loop-AES block device encryption system
221 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
222 * It operates on full 512 byte sectors and uses CBC
223 * with an IV derived from the sector number, the data and
224 * optionally extra IV seed.
225 * This means that after decryption the first block
226 * of sector must be tweaked according to decrypted data.
227 * Loop-AES can use three encryption schemes:
228 * version 1: is plain aes-cbc mode
229 * version 2: uses 64 multikey scheme with lmk IV generator
230 * version 3: the same as version 2 with additional IV seed
231 * (it uses 65 keys, last key is used as IV seed)
232 *
233 * plumb: unimplemented, see:
234 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
235 */
236
237static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
238 struct dm_crypt_request *dmreq)
239{
240 memset(iv, 0, cc->iv_size);
241 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
242
243 return 0;
244}
245
246static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
247 struct dm_crypt_request *dmreq)
248{
249 memset(iv, 0, cc->iv_size);
250 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
251
252 return 0;
253}
254
255/* Initialise ESSIV - compute salt but no local memory allocations */
256static int crypt_iv_essiv_init(struct crypt_config *cc)
257{
258 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
259 struct hash_desc desc;
260 struct scatterlist sg;
261 struct crypto_cipher *essiv_tfm;
262 int err, cpu;
263
264 sg_init_one(&sg, cc->key, cc->key_size);
265 desc.tfm = essiv->hash_tfm;
266 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
267
268 err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
269 if (err)
270 return err;
271
272 for_each_possible_cpu(cpu) {
273 essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->iv_private,
274
275 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
276 crypto_hash_digestsize(essiv->hash_tfm));
277 if (err)
278 return err;
279 }
280
281 return 0;
282}
283
284/* Wipe salt and reset key derived from volume key */
285static int crypt_iv_essiv_wipe(struct crypt_config *cc)
286{
287 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
288 unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
289 struct crypto_cipher *essiv_tfm;
290 int cpu, r, err = 0;
291
292 memset(essiv->salt, 0, salt_size);
293
294 for_each_possible_cpu(cpu) {
295 essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->iv_private;
296 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
297 if (r)
298 err = r;
299 }
300
301 return err;
302}
303
304/* Set up per cpu cipher state */
305static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
306 struct dm_target *ti,
307 u8 *salt, unsigned saltsize)
308{
309 struct crypto_cipher *essiv_tfm;
310 int err;
311
312 /* Setup the essiv_tfm with the given salt */
313 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
314 if (IS_ERR(essiv_tfm)) {
315 ti->error = "Error allocating crypto tfm for ESSIV";
316 return essiv_tfm;
317 }
318
319 if (crypto_cipher_blocksize(essiv_tfm) !=
320 crypto_ablkcipher_ivsize(any_tfm(cc))) {
321 ti->error = "Block size of ESSIV cipher does "
322 "not match IV size of block cipher";
323 crypto_free_cipher(essiv_tfm);
324 return ERR_PTR(-EINVAL);
325 }
326
327 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
328 if (err) {
329 ti->error = "Failed to set key for ESSIV cipher";
330 crypto_free_cipher(essiv_tfm);
331 return ERR_PTR(err);
332 }
333
334 return essiv_tfm;
335}
336
337static void crypt_iv_essiv_dtr(struct crypt_config *cc)
338{
339 int cpu;
340 struct crypt_cpu *cpu_cc;
341 struct crypto_cipher *essiv_tfm;
342 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
343
344 crypto_free_hash(essiv->hash_tfm);
345 essiv->hash_tfm = NULL;
346
347 kzfree(essiv->salt);
348 essiv->salt = NULL;
349
350 for_each_possible_cpu(cpu) {
351 cpu_cc = per_cpu_ptr(cc->cpu, cpu);
352 essiv_tfm = cpu_cc->iv_private;
353
354 if (essiv_tfm)
355 crypto_free_cipher(essiv_tfm);
356
357 cpu_cc->iv_private = NULL;
358 }
359}
360
361static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
362 const char *opts)
363{
364 struct crypto_cipher *essiv_tfm = NULL;
365 struct crypto_hash *hash_tfm = NULL;
366 u8 *salt = NULL;
367 int err, cpu;
368
369 if (!opts) {
370 ti->error = "Digest algorithm missing for ESSIV mode";
371 return -EINVAL;
372 }
373
374 /* Allocate hash algorithm */
375 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
376 if (IS_ERR(hash_tfm)) {
377 ti->error = "Error initializing ESSIV hash";
378 err = PTR_ERR(hash_tfm);
379 goto bad;
380 }
381
382 salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
383 if (!salt) {
384 ti->error = "Error kmallocing salt storage in ESSIV";
385 err = -ENOMEM;
386 goto bad;
387 }
388
389 cc->iv_gen_private.essiv.salt = salt;
390 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
391
392 for_each_possible_cpu(cpu) {
393 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
394 crypto_hash_digestsize(hash_tfm));
395 if (IS_ERR(essiv_tfm)) {
396 crypt_iv_essiv_dtr(cc);
397 return PTR_ERR(essiv_tfm);
398 }
399 per_cpu_ptr(cc->cpu, cpu)->iv_private = essiv_tfm;
400 }
401
402 return 0;
403
404bad:
405 if (hash_tfm && !IS_ERR(hash_tfm))
406 crypto_free_hash(hash_tfm);
407 kfree(salt);
408 return err;
409}
410
411static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
412 struct dm_crypt_request *dmreq)
413{
414 struct crypto_cipher *essiv_tfm = this_crypt_config(cc)->iv_private;
415
416 memset(iv, 0, cc->iv_size);
417 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
418 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
419
420 return 0;
421}
422
423static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
424 const char *opts)
425{
426 unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
427 int log = ilog2(bs);
428
429 /* we need to calculate how far we must shift the sector count
430 * to get the cipher block count, we use this shift in _gen */
431
432 if (1 << log != bs) {
433 ti->error = "cypher blocksize is not a power of 2";
434 return -EINVAL;
435 }
436
437 if (log > 9) {
438 ti->error = "cypher blocksize is > 512";
439 return -EINVAL;
440 }
441
442 cc->iv_gen_private.benbi.shift = 9 - log;
443
444 return 0;
445}
446
447static void crypt_iv_benbi_dtr(struct crypt_config *cc)
448{
449}
450
451static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
452 struct dm_crypt_request *dmreq)
453{
454 __be64 val;
455
456 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
457
458 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
459 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
460
461 return 0;
462}
463
464static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
465 struct dm_crypt_request *dmreq)
466{
467 memset(iv, 0, cc->iv_size);
468
469 return 0;
470}
471
472static void crypt_iv_lmk_dtr(struct crypt_config *cc)
473{
474 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
475
476 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
477 crypto_free_shash(lmk->hash_tfm);
478 lmk->hash_tfm = NULL;
479
480 kzfree(lmk->seed);
481 lmk->seed = NULL;
482}
483
484static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
485 const char *opts)
486{
487 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
488
489 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
490 if (IS_ERR(lmk->hash_tfm)) {
491 ti->error = "Error initializing LMK hash";
492 return PTR_ERR(lmk->hash_tfm);
493 }
494
495 /* No seed in LMK version 2 */
496 if (cc->key_parts == cc->tfms_count) {
497 lmk->seed = NULL;
498 return 0;
499 }
500
501 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
502 if (!lmk->seed) {
503 crypt_iv_lmk_dtr(cc);
504 ti->error = "Error kmallocing seed storage in LMK";
505 return -ENOMEM;
506 }
507
508 return 0;
509}
510
511static int crypt_iv_lmk_init(struct crypt_config *cc)
512{
513 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
514 int subkey_size = cc->key_size / cc->key_parts;
515
516 /* LMK seed is on the position of LMK_KEYS + 1 key */
517 if (lmk->seed)
518 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
519 crypto_shash_digestsize(lmk->hash_tfm));
520
521 return 0;
522}
523
524static int crypt_iv_lmk_wipe(struct crypt_config *cc)
525{
526 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
527
528 if (lmk->seed)
529 memset(lmk->seed, 0, LMK_SEED_SIZE);
530
531 return 0;
532}
533
534static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
535 struct dm_crypt_request *dmreq,
536 u8 *data)
537{
538 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
539 struct {
540 struct shash_desc desc;
541 char ctx[crypto_shash_descsize(lmk->hash_tfm)];
542 } sdesc;
543 struct md5_state md5state;
544 u32 buf[4];
545 int i, r;
546
547 sdesc.desc.tfm = lmk->hash_tfm;
548 sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
549
550 r = crypto_shash_init(&sdesc.desc);
551 if (r)
552 return r;
553
554 if (lmk->seed) {
555 r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
556 if (r)
557 return r;
558 }
559
560 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
561 r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
562 if (r)
563 return r;
564
565 /* Sector is cropped to 56 bits here */
566 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
567 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
568 buf[2] = cpu_to_le32(4024);
569 buf[3] = 0;
570 r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
571 if (r)
572 return r;
573
574 /* No MD5 padding here */
575 r = crypto_shash_export(&sdesc.desc, &md5state);
576 if (r)
577 return r;
578
579 for (i = 0; i < MD5_HASH_WORDS; i++)
580 __cpu_to_le32s(&md5state.hash[i]);
581 memcpy(iv, &md5state.hash, cc->iv_size);
582
583 return 0;
584}
585
586static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
587 struct dm_crypt_request *dmreq)
588{
589 u8 *src;
590 int r = 0;
591
592 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
593 src = kmap_atomic(sg_page(&dmreq->sg_in), KM_USER0);
594 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
595 kunmap_atomic(src, KM_USER0);
596 } else
597 memset(iv, 0, cc->iv_size);
598
599 return r;
600}
601
602static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
603 struct dm_crypt_request *dmreq)
604{
605 u8 *dst;
606 int r;
607
608 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
609 return 0;
610
611 dst = kmap_atomic(sg_page(&dmreq->sg_out), KM_USER0);
612 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
613
614 /* Tweak the first block of plaintext sector */
615 if (!r)
616 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
617
618 kunmap_atomic(dst, KM_USER0);
619 return r;
620}
621
622static struct crypt_iv_operations crypt_iv_plain_ops = {
623 .generator = crypt_iv_plain_gen
624};
625
626static struct crypt_iv_operations crypt_iv_plain64_ops = {
627 .generator = crypt_iv_plain64_gen
628};
629
630static struct crypt_iv_operations crypt_iv_essiv_ops = {
631 .ctr = crypt_iv_essiv_ctr,
632 .dtr = crypt_iv_essiv_dtr,
633 .init = crypt_iv_essiv_init,
634 .wipe = crypt_iv_essiv_wipe,
635 .generator = crypt_iv_essiv_gen
636};
637
638static struct crypt_iv_operations crypt_iv_benbi_ops = {
639 .ctr = crypt_iv_benbi_ctr,
640 .dtr = crypt_iv_benbi_dtr,
641 .generator = crypt_iv_benbi_gen
642};
643
644static struct crypt_iv_operations crypt_iv_null_ops = {
645 .generator = crypt_iv_null_gen
646};
647
648static struct crypt_iv_operations crypt_iv_lmk_ops = {
649 .ctr = crypt_iv_lmk_ctr,
650 .dtr = crypt_iv_lmk_dtr,
651 .init = crypt_iv_lmk_init,
652 .wipe = crypt_iv_lmk_wipe,
653 .generator = crypt_iv_lmk_gen,
654 .post = crypt_iv_lmk_post
655};
656
657static void crypt_convert_init(struct crypt_config *cc,
658 struct convert_context *ctx,
659 struct bio *bio_out, struct bio *bio_in,
660 sector_t sector)
661{
662 ctx->bio_in = bio_in;
663 ctx->bio_out = bio_out;
664 ctx->offset_in = 0;
665 ctx->offset_out = 0;
666 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
667 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
668 ctx->sector = sector + cc->iv_offset;
669 init_completion(&ctx->restart);
670}
671
672static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
673 struct ablkcipher_request *req)
674{
675 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
676}
677
678static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
679 struct dm_crypt_request *dmreq)
680{
681 return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
682}
683
684static u8 *iv_of_dmreq(struct crypt_config *cc,
685 struct dm_crypt_request *dmreq)
686{
687 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
688 crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
689}
690
691static int crypt_convert_block(struct crypt_config *cc,
692 struct convert_context *ctx,
693 struct ablkcipher_request *req)
694{
695 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
696 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
697 struct dm_crypt_request *dmreq;
698 u8 *iv;
699 int r = 0;
700
701 dmreq = dmreq_of_req(cc, req);
702 iv = iv_of_dmreq(cc, dmreq);
703
704 dmreq->iv_sector = ctx->sector;
705 dmreq->ctx = ctx;
706 sg_init_table(&dmreq->sg_in, 1);
707 sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
708 bv_in->bv_offset + ctx->offset_in);
709
710 sg_init_table(&dmreq->sg_out, 1);
711 sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
712 bv_out->bv_offset + ctx->offset_out);
713
714 ctx->offset_in += 1 << SECTOR_SHIFT;
715 if (ctx->offset_in >= bv_in->bv_len) {
716 ctx->offset_in = 0;
717 ctx->idx_in++;
718 }
719
720 ctx->offset_out += 1 << SECTOR_SHIFT;
721 if (ctx->offset_out >= bv_out->bv_len) {
722 ctx->offset_out = 0;
723 ctx->idx_out++;
724 }
725
726 if (cc->iv_gen_ops) {
727 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
728 if (r < 0)
729 return r;
730 }
731
732 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
733 1 << SECTOR_SHIFT, iv);
734
735 if (bio_data_dir(ctx->bio_in) == WRITE)
736 r = crypto_ablkcipher_encrypt(req);
737 else
738 r = crypto_ablkcipher_decrypt(req);
739
740 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
741 r = cc->iv_gen_ops->post(cc, iv, dmreq);
742
743 return r;
744}
745
746static void kcryptd_async_done(struct crypto_async_request *async_req,
747 int error);
748
749static void crypt_alloc_req(struct crypt_config *cc,
750 struct convert_context *ctx)
751{
752 struct crypt_cpu *this_cc = this_crypt_config(cc);
753 unsigned key_index = ctx->sector & (cc->tfms_count - 1);
754
755 if (!this_cc->req)
756 this_cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
757
758 ablkcipher_request_set_tfm(this_cc->req, this_cc->tfms[key_index]);
759 ablkcipher_request_set_callback(this_cc->req,
760 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
761 kcryptd_async_done, dmreq_of_req(cc, this_cc->req));
762}
763
764/*
765 * Encrypt / decrypt data from one bio to another one (can be the same one)
766 */
767static int crypt_convert(struct crypt_config *cc,
768 struct convert_context *ctx)
769{
770 struct crypt_cpu *this_cc = this_crypt_config(cc);
771 int r;
772
773 atomic_set(&ctx->pending, 1);
774
775 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
776 ctx->idx_out < ctx->bio_out->bi_vcnt) {
777
778 crypt_alloc_req(cc, ctx);
779
780 atomic_inc(&ctx->pending);
781
782 r = crypt_convert_block(cc, ctx, this_cc->req);
783
784 switch (r) {
785 /* async */
786 case -EBUSY:
787 wait_for_completion(&ctx->restart);
788 INIT_COMPLETION(ctx->restart);
789 /* fall through*/
790 case -EINPROGRESS:
791 this_cc->req = NULL;
792 ctx->sector++;
793 continue;
794
795 /* sync */
796 case 0:
797 atomic_dec(&ctx->pending);
798 ctx->sector++;
799 cond_resched();
800 continue;
801
802 /* error */
803 default:
804 atomic_dec(&ctx->pending);
805 return r;
806 }
807 }
808
809 return 0;
810}
811
812static void dm_crypt_bio_destructor(struct bio *bio)
813{
814 struct dm_crypt_io *io = bio->bi_private;
815 struct crypt_config *cc = io->target->private;
816
817 bio_free(bio, cc->bs);
818}
819
820/*
821 * Generate a new unfragmented bio with the given size
822 * This should never violate the device limitations
823 * May return a smaller bio when running out of pages, indicated by
824 * *out_of_pages set to 1.
825 */
826static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
827 unsigned *out_of_pages)
828{
829 struct crypt_config *cc = io->target->private;
830 struct bio *clone;
831 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
832 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
833 unsigned i, len;
834 struct page *page;
835
836 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
837 if (!clone)
838 return NULL;
839
840 clone_init(io, clone);
841 *out_of_pages = 0;
842
843 for (i = 0; i < nr_iovecs; i++) {
844 page = mempool_alloc(cc->page_pool, gfp_mask);
845 if (!page) {
846 *out_of_pages = 1;
847 break;
848 }
849
850 /*
851 * if additional pages cannot be allocated without waiting,
852 * return a partially allocated bio, the caller will then try
853 * to allocate additional bios while submitting this partial bio
854 */
855 if (i == (MIN_BIO_PAGES - 1))
856 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
857
858 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
859
860 if (!bio_add_page(clone, page, len, 0)) {
861 mempool_free(page, cc->page_pool);
862 break;
863 }
864
865 size -= len;
866 }
867
868 if (!clone->bi_size) {
869 bio_put(clone);
870 return NULL;
871 }
872
873 return clone;
874}
875
876static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
877{
878 unsigned int i;
879 struct bio_vec *bv;
880
881 for (i = 0; i < clone->bi_vcnt; i++) {
882 bv = bio_iovec_idx(clone, i);
883 BUG_ON(!bv->bv_page);
884 mempool_free(bv->bv_page, cc->page_pool);
885 bv->bv_page = NULL;
886 }
887}
888
889static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
890 struct bio *bio, sector_t sector)
891{
892 struct crypt_config *cc = ti->private;
893 struct dm_crypt_io *io;
894
895 io = mempool_alloc(cc->io_pool, GFP_NOIO);
896 io->target = ti;
897 io->base_bio = bio;
898 io->sector = sector;
899 io->error = 0;
900 io->base_io = NULL;
901 atomic_set(&io->pending, 0);
902
903 return io;
904}
905
906static void crypt_inc_pending(struct dm_crypt_io *io)
907{
908 atomic_inc(&io->pending);
909}
910
911/*
912 * One of the bios was finished. Check for completion of
913 * the whole request and correctly clean up the buffer.
914 * If base_io is set, wait for the last fragment to complete.
915 */
916static void crypt_dec_pending(struct dm_crypt_io *io)
917{
918 struct crypt_config *cc = io->target->private;
919 struct bio *base_bio = io->base_bio;
920 struct dm_crypt_io *base_io = io->base_io;
921 int error = io->error;
922
923 if (!atomic_dec_and_test(&io->pending))
924 return;
925
926 mempool_free(io, cc->io_pool);
927
928 if (likely(!base_io))
929 bio_endio(base_bio, error);
930 else {
931 if (error && !base_io->error)
932 base_io->error = error;
933 crypt_dec_pending(base_io);
934 }
935}
936
937/*
938 * kcryptd/kcryptd_io:
939 *
940 * Needed because it would be very unwise to do decryption in an
941 * interrupt context.
942 *
943 * kcryptd performs the actual encryption or decryption.
944 *
945 * kcryptd_io performs the IO submission.
946 *
947 * They must be separated as otherwise the final stages could be
948 * starved by new requests which can block in the first stages due
949 * to memory allocation.
950 *
951 * The work is done per CPU global for all dm-crypt instances.
952 * They should not depend on each other and do not block.
953 */
954static void crypt_endio(struct bio *clone, int error)
955{
956 struct dm_crypt_io *io = clone->bi_private;
957 struct crypt_config *cc = io->target->private;
958 unsigned rw = bio_data_dir(clone);
959
960 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
961 error = -EIO;
962
963 /*
964 * free the processed pages
965 */
966 if (rw == WRITE)
967 crypt_free_buffer_pages(cc, clone);
968
969 bio_put(clone);
970
971 if (rw == READ && !error) {
972 kcryptd_queue_crypt(io);
973 return;
974 }
975
976 if (unlikely(error))
977 io->error = error;
978
979 crypt_dec_pending(io);
980}
981
982static void clone_init(struct dm_crypt_io *io, struct bio *clone)
983{
984 struct crypt_config *cc = io->target->private;
985
986 clone->bi_private = io;
987 clone->bi_end_io = crypt_endio;
988 clone->bi_bdev = cc->dev->bdev;
989 clone->bi_rw = io->base_bio->bi_rw;
990 clone->bi_destructor = dm_crypt_bio_destructor;
991}
992
993static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
994{
995 struct crypt_config *cc = io->target->private;
996 struct bio *base_bio = io->base_bio;
997 struct bio *clone;
998
999 /*
1000 * The block layer might modify the bvec array, so always
1001 * copy the required bvecs because we need the original
1002 * one in order to decrypt the whole bio data *afterwards*.
1003 */
1004 clone = bio_alloc_bioset(gfp, bio_segments(base_bio), cc->bs);
1005 if (!clone)
1006 return 1;
1007
1008 crypt_inc_pending(io);
1009
1010 clone_init(io, clone);
1011 clone->bi_idx = 0;
1012 clone->bi_vcnt = bio_segments(base_bio);
1013 clone->bi_size = base_bio->bi_size;
1014 clone->bi_sector = cc->start + io->sector;
1015 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
1016 sizeof(struct bio_vec) * clone->bi_vcnt);
1017
1018 generic_make_request(clone);
1019 return 0;
1020}
1021
1022static void kcryptd_io_write(struct dm_crypt_io *io)
1023{
1024 struct bio *clone = io->ctx.bio_out;
1025 generic_make_request(clone);
1026}
1027
1028static void kcryptd_io(struct work_struct *work)
1029{
1030 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1031
1032 if (bio_data_dir(io->base_bio) == READ) {
1033 crypt_inc_pending(io);
1034 if (kcryptd_io_read(io, GFP_NOIO))
1035 io->error = -ENOMEM;
1036 crypt_dec_pending(io);
1037 } else
1038 kcryptd_io_write(io);
1039}
1040
1041static void kcryptd_queue_io(struct dm_crypt_io *io)
1042{
1043 struct crypt_config *cc = io->target->private;
1044
1045 INIT_WORK(&io->work, kcryptd_io);
1046 queue_work(cc->io_queue, &io->work);
1047}
1048
1049static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
1050 int error, int async)
1051{
1052 struct bio *clone = io->ctx.bio_out;
1053 struct crypt_config *cc = io->target->private;
1054
1055 if (unlikely(error < 0)) {
1056 crypt_free_buffer_pages(cc, clone);
1057 bio_put(clone);
1058 io->error = -EIO;
1059 crypt_dec_pending(io);
1060 return;
1061 }
1062
1063 /* crypt_convert should have filled the clone bio */
1064 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
1065
1066 clone->bi_sector = cc->start + io->sector;
1067
1068 if (async)
1069 kcryptd_queue_io(io);
1070 else
1071 generic_make_request(clone);
1072}
1073
1074static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1075{
1076 struct crypt_config *cc = io->target->private;
1077 struct bio *clone;
1078 struct dm_crypt_io *new_io;
1079 int crypt_finished;
1080 unsigned out_of_pages = 0;
1081 unsigned remaining = io->base_bio->bi_size;
1082 sector_t sector = io->sector;
1083 int r;
1084
1085 /*
1086 * Prevent io from disappearing until this function completes.
1087 */
1088 crypt_inc_pending(io);
1089 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1090
1091 /*
1092 * The allocated buffers can be smaller than the whole bio,
1093 * so repeat the whole process until all the data can be handled.
1094 */
1095 while (remaining) {
1096 clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
1097 if (unlikely(!clone)) {
1098 io->error = -ENOMEM;
1099 break;
1100 }
1101
1102 io->ctx.bio_out = clone;
1103 io->ctx.idx_out = 0;
1104
1105 remaining -= clone->bi_size;
1106 sector += bio_sectors(clone);
1107
1108 crypt_inc_pending(io);
1109 r = crypt_convert(cc, &io->ctx);
1110 crypt_finished = atomic_dec_and_test(&io->ctx.pending);
1111
1112 /* Encryption was already finished, submit io now */
1113 if (crypt_finished) {
1114 kcryptd_crypt_write_io_submit(io, r, 0);
1115
1116 /*
1117 * If there was an error, do not try next fragments.
1118 * For async, error is processed in async handler.
1119 */
1120 if (unlikely(r < 0))
1121 break;
1122
1123 io->sector = sector;
1124 }
1125
1126 /*
1127 * Out of memory -> run queues
1128 * But don't wait if split was due to the io size restriction
1129 */
1130 if (unlikely(out_of_pages))
1131 congestion_wait(BLK_RW_ASYNC, HZ/100);
1132
1133 /*
1134 * With async crypto it is unsafe to share the crypto context
1135 * between fragments, so switch to a new dm_crypt_io structure.
1136 */
1137 if (unlikely(!crypt_finished && remaining)) {
1138 new_io = crypt_io_alloc(io->target, io->base_bio,
1139 sector);
1140 crypt_inc_pending(new_io);
1141 crypt_convert_init(cc, &new_io->ctx, NULL,
1142 io->base_bio, sector);
1143 new_io->ctx.idx_in = io->ctx.idx_in;
1144 new_io->ctx.offset_in = io->ctx.offset_in;
1145
1146 /*
1147 * Fragments after the first use the base_io
1148 * pending count.
1149 */
1150 if (!io->base_io)
1151 new_io->base_io = io;
1152 else {
1153 new_io->base_io = io->base_io;
1154 crypt_inc_pending(io->base_io);
1155 crypt_dec_pending(io);
1156 }
1157
1158 io = new_io;
1159 }
1160 }
1161
1162 crypt_dec_pending(io);
1163}
1164
1165static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
1166{
1167 if (unlikely(error < 0))
1168 io->error = -EIO;
1169
1170 crypt_dec_pending(io);
1171}
1172
1173static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1174{
1175 struct crypt_config *cc = io->target->private;
1176 int r = 0;
1177
1178 crypt_inc_pending(io);
1179
1180 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1181 io->sector);
1182
1183 r = crypt_convert(cc, &io->ctx);
1184
1185 if (atomic_dec_and_test(&io->ctx.pending))
1186 kcryptd_crypt_read_done(io, r);
1187
1188 crypt_dec_pending(io);
1189}
1190
1191static void kcryptd_async_done(struct crypto_async_request *async_req,
1192 int error)
1193{
1194 struct dm_crypt_request *dmreq = async_req->data;
1195 struct convert_context *ctx = dmreq->ctx;
1196 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1197 struct crypt_config *cc = io->target->private;
1198
1199 if (error == -EINPROGRESS) {
1200 complete(&ctx->restart);
1201 return;
1202 }
1203
1204 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1205 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1206
1207 mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
1208
1209 if (!atomic_dec_and_test(&ctx->pending))
1210 return;
1211
1212 if (bio_data_dir(io->base_bio) == READ)
1213 kcryptd_crypt_read_done(io, error);
1214 else
1215 kcryptd_crypt_write_io_submit(io, error, 1);
1216}
1217
1218static void kcryptd_crypt(struct work_struct *work)
1219{
1220 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1221
1222 if (bio_data_dir(io->base_bio) == READ)
1223 kcryptd_crypt_read_convert(io);
1224 else
1225 kcryptd_crypt_write_convert(io);
1226}
1227
1228static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1229{
1230 struct crypt_config *cc = io->target->private;
1231
1232 INIT_WORK(&io->work, kcryptd_crypt);
1233 queue_work(cc->crypt_queue, &io->work);
1234}
1235
1236/*
1237 * Decode key from its hex representation
1238 */
1239static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1240{
1241 char buffer[3];
1242 char *endp;
1243 unsigned int i;
1244
1245 buffer[2] = '\0';
1246
1247 for (i = 0; i < size; i++) {
1248 buffer[0] = *hex++;
1249 buffer[1] = *hex++;
1250
1251 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
1252
1253 if (endp != &buffer[2])
1254 return -EINVAL;
1255 }
1256
1257 if (*hex != '\0')
1258 return -EINVAL;
1259
1260 return 0;
1261}
1262
1263/*
1264 * Encode key into its hex representation
1265 */
1266static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
1267{
1268 unsigned int i;
1269
1270 for (i = 0; i < size; i++) {
1271 sprintf(hex, "%02x", *key);
1272 hex += 2;
1273 key++;
1274 }
1275}
1276
1277static void crypt_free_tfms(struct crypt_config *cc, int cpu)
1278{
1279 struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
1280 unsigned i;
1281
1282 for (i = 0; i < cc->tfms_count; i++)
1283 if (cpu_cc->tfms[i] && !IS_ERR(cpu_cc->tfms[i])) {
1284 crypto_free_ablkcipher(cpu_cc->tfms[i]);
1285 cpu_cc->tfms[i] = NULL;
1286 }
1287}
1288
1289static int crypt_alloc_tfms(struct crypt_config *cc, int cpu, char *ciphermode)
1290{
1291 struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
1292 unsigned i;
1293 int err;
1294
1295 for (i = 0; i < cc->tfms_count; i++) {
1296 cpu_cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1297 if (IS_ERR(cpu_cc->tfms[i])) {
1298 err = PTR_ERR(cpu_cc->tfms[i]);
1299 crypt_free_tfms(cc, cpu);
1300 return err;
1301 }
1302 }
1303
1304 return 0;
1305}
1306
1307static int crypt_setkey_allcpus(struct crypt_config *cc)
1308{
1309 unsigned subkey_size = cc->key_size >> ilog2(cc->tfms_count);
1310 int cpu, err = 0, i, r;
1311
1312 for_each_possible_cpu(cpu) {
1313 for (i = 0; i < cc->tfms_count; i++) {
1314 r = crypto_ablkcipher_setkey(per_cpu_ptr(cc->cpu, cpu)->tfms[i],
1315 cc->key + (i * subkey_size), subkey_size);
1316 if (r)
1317 err = r;
1318 }
1319 }
1320
1321 return err;
1322}
1323
1324static int crypt_set_key(struct crypt_config *cc, char *key)
1325{
1326 int r = -EINVAL;
1327 int key_string_len = strlen(key);
1328
1329 /* The key size may not be changed. */
1330 if (cc->key_size != (key_string_len >> 1))
1331 goto out;
1332
1333 /* Hyphen (which gives a key_size of zero) means there is no key. */
1334 if (!cc->key_size && strcmp(key, "-"))
1335 goto out;
1336
1337 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1338 goto out;
1339
1340 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1341
1342 r = crypt_setkey_allcpus(cc);
1343
1344out:
1345 /* Hex key string not needed after here, so wipe it. */
1346 memset(key, '0', key_string_len);
1347
1348 return r;
1349}
1350
1351static int crypt_wipe_key(struct crypt_config *cc)
1352{
1353 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1354 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1355
1356 return crypt_setkey_allcpus(cc);
1357}
1358
1359static void crypt_dtr(struct dm_target *ti)
1360{
1361 struct crypt_config *cc = ti->private;
1362 struct crypt_cpu *cpu_cc;
1363 int cpu;
1364
1365 ti->private = NULL;
1366
1367 if (!cc)
1368 return;
1369
1370 if (cc->io_queue)
1371 destroy_workqueue(cc->io_queue);
1372 if (cc->crypt_queue)
1373 destroy_workqueue(cc->crypt_queue);
1374
1375 if (cc->cpu)
1376 for_each_possible_cpu(cpu) {
1377 cpu_cc = per_cpu_ptr(cc->cpu, cpu);
1378 if (cpu_cc->req)
1379 mempool_free(cpu_cc->req, cc->req_pool);
1380 crypt_free_tfms(cc, cpu);
1381 }
1382
1383 if (cc->bs)
1384 bioset_free(cc->bs);
1385
1386 if (cc->page_pool)
1387 mempool_destroy(cc->page_pool);
1388 if (cc->req_pool)
1389 mempool_destroy(cc->req_pool);
1390 if (cc->io_pool)
1391 mempool_destroy(cc->io_pool);
1392
1393 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1394 cc->iv_gen_ops->dtr(cc);
1395
1396 if (cc->dev)
1397 dm_put_device(ti, cc->dev);
1398
1399 if (cc->cpu)
1400 free_percpu(cc->cpu);
1401
1402 kzfree(cc->cipher);
1403 kzfree(cc->cipher_string);
1404
1405 /* Must zero key material before freeing */
1406 kzfree(cc);
1407}
1408
1409static int crypt_ctr_cipher(struct dm_target *ti,
1410 char *cipher_in, char *key)
1411{
1412 struct crypt_config *cc = ti->private;
1413 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1414 char *cipher_api = NULL;
1415 int cpu, ret = -EINVAL;
1416
1417 /* Convert to crypto api definition? */
1418 if (strchr(cipher_in, '(')) {
1419 ti->error = "Bad cipher specification";
1420 return -EINVAL;
1421 }
1422
1423 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1424 if (!cc->cipher_string)
1425 goto bad_mem;
1426
1427 /*
1428 * Legacy dm-crypt cipher specification
1429 * cipher[:keycount]-mode-iv:ivopts
1430 */
1431 tmp = cipher_in;
1432 keycount = strsep(&tmp, "-");
1433 cipher = strsep(&keycount, ":");
1434
1435 if (!keycount)
1436 cc->tfms_count = 1;
1437 else if (sscanf(keycount, "%u", &cc->tfms_count) != 1 ||
1438 !is_power_of_2(cc->tfms_count)) {
1439 ti->error = "Bad cipher key count specification";
1440 return -EINVAL;
1441 }
1442 cc->key_parts = cc->tfms_count;
1443
1444 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1445 if (!cc->cipher)
1446 goto bad_mem;
1447
1448 chainmode = strsep(&tmp, "-");
1449 ivopts = strsep(&tmp, "-");
1450 ivmode = strsep(&ivopts, ":");
1451
1452 if (tmp)
1453 DMWARN("Ignoring unexpected additional cipher options");
1454
1455 cc->cpu = __alloc_percpu(sizeof(*(cc->cpu)) +
1456 cc->tfms_count * sizeof(*(cc->cpu->tfms)),
1457 __alignof__(struct crypt_cpu));
1458 if (!cc->cpu) {
1459 ti->error = "Cannot allocate per cpu state";
1460 goto bad_mem;
1461 }
1462
1463 /*
1464 * For compatibility with the original dm-crypt mapping format, if
1465 * only the cipher name is supplied, use cbc-plain.
1466 */
1467 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1468 chainmode = "cbc";
1469 ivmode = "plain";
1470 }
1471
1472 if (strcmp(chainmode, "ecb") && !ivmode) {
1473 ti->error = "IV mechanism required";
1474 return -EINVAL;
1475 }
1476
1477 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1478 if (!cipher_api)
1479 goto bad_mem;
1480
1481 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1482 "%s(%s)", chainmode, cipher);
1483 if (ret < 0) {
1484 kfree(cipher_api);
1485 goto bad_mem;
1486 }
1487
1488 /* Allocate cipher */
1489 for_each_possible_cpu(cpu) {
1490 ret = crypt_alloc_tfms(cc, cpu, cipher_api);
1491 if (ret < 0) {
1492 ti->error = "Error allocating crypto tfm";
1493 goto bad;
1494 }
1495 }
1496
1497 /* Initialize and set key */
1498 ret = crypt_set_key(cc, key);
1499 if (ret < 0) {
1500 ti->error = "Error decoding and setting key";
1501 goto bad;
1502 }
1503
1504 /* Initialize IV */
1505 cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1506 if (cc->iv_size)
1507 /* at least a 64 bit sector number should fit in our buffer */
1508 cc->iv_size = max(cc->iv_size,
1509 (unsigned int)(sizeof(u64) / sizeof(u8)));
1510 else if (ivmode) {
1511 DMWARN("Selected cipher does not support IVs");
1512 ivmode = NULL;
1513 }
1514
1515 /* Choose ivmode, see comments at iv code. */
1516 if (ivmode == NULL)
1517 cc->iv_gen_ops = NULL;
1518 else if (strcmp(ivmode, "plain") == 0)
1519 cc->iv_gen_ops = &crypt_iv_plain_ops;
1520 else if (strcmp(ivmode, "plain64") == 0)
1521 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1522 else if (strcmp(ivmode, "essiv") == 0)
1523 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1524 else if (strcmp(ivmode, "benbi") == 0)
1525 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1526 else if (strcmp(ivmode, "null") == 0)
1527 cc->iv_gen_ops = &crypt_iv_null_ops;
1528 else if (strcmp(ivmode, "lmk") == 0) {
1529 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1530 /* Version 2 and 3 is recognised according
1531 * to length of provided multi-key string.
1532 * If present (version 3), last key is used as IV seed.
1533 */
1534 if (cc->key_size % cc->key_parts)
1535 cc->key_parts++;
1536 } else {
1537 ret = -EINVAL;
1538 ti->error = "Invalid IV mode";
1539 goto bad;
1540 }
1541
1542 /* Allocate IV */
1543 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1544 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1545 if (ret < 0) {
1546 ti->error = "Error creating IV";
1547 goto bad;
1548 }
1549 }
1550
1551 /* Initialize IV (set keys for ESSIV etc) */
1552 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1553 ret = cc->iv_gen_ops->init(cc);
1554 if (ret < 0) {
1555 ti->error = "Error initialising IV";
1556 goto bad;
1557 }
1558 }
1559
1560 ret = 0;
1561bad:
1562 kfree(cipher_api);
1563 return ret;
1564
1565bad_mem:
1566 ti->error = "Cannot allocate cipher strings";
1567 return -ENOMEM;
1568}
1569
1570/*
1571 * Construct an encryption mapping:
1572 * <cipher> <key> <iv_offset> <dev_path> <start>
1573 */
1574static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1575{
1576 struct crypt_config *cc;
1577 unsigned int key_size, opt_params;
1578 unsigned long long tmpll;
1579 int ret;
1580 struct dm_arg_set as;
1581 const char *opt_string;
1582
1583 static struct dm_arg _args[] = {
1584 {0, 1, "Invalid number of feature args"},
1585 };
1586
1587 if (argc < 5) {
1588 ti->error = "Not enough arguments";
1589 return -EINVAL;
1590 }
1591
1592 key_size = strlen(argv[1]) >> 1;
1593
1594 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1595 if (!cc) {
1596 ti->error = "Cannot allocate encryption context";
1597 return -ENOMEM;
1598 }
1599 cc->key_size = key_size;
1600
1601 ti->private = cc;
1602 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1603 if (ret < 0)
1604 goto bad;
1605
1606 ret = -ENOMEM;
1607 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
1608 if (!cc->io_pool) {
1609 ti->error = "Cannot allocate crypt io mempool";
1610 goto bad;
1611 }
1612
1613 cc->dmreq_start = sizeof(struct ablkcipher_request);
1614 cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1615 cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
1616 cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) &
1617 ~(crypto_tfm_ctx_alignment() - 1);
1618
1619 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1620 sizeof(struct dm_crypt_request) + cc->iv_size);
1621 if (!cc->req_pool) {
1622 ti->error = "Cannot allocate crypt request mempool";
1623 goto bad;
1624 }
1625
1626 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
1627 if (!cc->page_pool) {
1628 ti->error = "Cannot allocate page mempool";
1629 goto bad;
1630 }
1631
1632 cc->bs = bioset_create(MIN_IOS, 0);
1633 if (!cc->bs) {
1634 ti->error = "Cannot allocate crypt bioset";
1635 goto bad;
1636 }
1637
1638 ret = -EINVAL;
1639 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
1640 ti->error = "Invalid iv_offset sector";
1641 goto bad;
1642 }
1643 cc->iv_offset = tmpll;
1644
1645 if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
1646 ti->error = "Device lookup failed";
1647 goto bad;
1648 }
1649
1650 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
1651 ti->error = "Invalid device sector";
1652 goto bad;
1653 }
1654 cc->start = tmpll;
1655
1656 argv += 5;
1657 argc -= 5;
1658
1659 /* Optional parameters */
1660 if (argc) {
1661 as.argc = argc;
1662 as.argv = argv;
1663
1664 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1665 if (ret)
1666 goto bad;
1667
1668 opt_string = dm_shift_arg(&as);
1669
1670 if (opt_params == 1 && opt_string &&
1671 !strcasecmp(opt_string, "allow_discards"))
1672 ti->num_discard_requests = 1;
1673 else if (opt_params) {
1674 ret = -EINVAL;
1675 ti->error = "Invalid feature arguments";
1676 goto bad;
1677 }
1678 }
1679
1680 ret = -ENOMEM;
1681 cc->io_queue = alloc_workqueue("kcryptd_io",
1682 WQ_NON_REENTRANT|
1683 WQ_MEM_RECLAIM,
1684 1);
1685 if (!cc->io_queue) {
1686 ti->error = "Couldn't create kcryptd io queue";
1687 goto bad;
1688 }
1689
1690 cc->crypt_queue = alloc_workqueue("kcryptd",
1691 WQ_NON_REENTRANT|
1692 WQ_CPU_INTENSIVE|
1693 WQ_MEM_RECLAIM,
1694 1);
1695 if (!cc->crypt_queue) {
1696 ti->error = "Couldn't create kcryptd queue";
1697 goto bad;
1698 }
1699
1700 ti->num_flush_requests = 1;
1701 ti->discard_zeroes_data_unsupported = 1;
1702
1703 return 0;
1704
1705bad:
1706 crypt_dtr(ti);
1707 return ret;
1708}
1709
1710static int crypt_map(struct dm_target *ti, struct bio *bio,
1711 union map_info *map_context)
1712{
1713 struct dm_crypt_io *io;
1714 struct crypt_config *cc;
1715
1716 /*
1717 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1718 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1719 * - for REQ_DISCARD caller must use flush if IO ordering matters
1720 */
1721 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1722 cc = ti->private;
1723 bio->bi_bdev = cc->dev->bdev;
1724 if (bio_sectors(bio))
1725 bio->bi_sector = cc->start + dm_target_offset(ti, bio->bi_sector);
1726 return DM_MAPIO_REMAPPED;
1727 }
1728
1729 io = crypt_io_alloc(ti, bio, dm_target_offset(ti, bio->bi_sector));
1730
1731 if (bio_data_dir(io->base_bio) == READ) {
1732 if (kcryptd_io_read(io, GFP_NOWAIT))
1733 kcryptd_queue_io(io);
1734 } else
1735 kcryptd_queue_crypt(io);
1736
1737 return DM_MAPIO_SUBMITTED;
1738}
1739
1740static int crypt_status(struct dm_target *ti, status_type_t type,
1741 char *result, unsigned int maxlen)
1742{
1743 struct crypt_config *cc = ti->private;
1744 unsigned int sz = 0;
1745
1746 switch (type) {
1747 case STATUSTYPE_INFO:
1748 result[0] = '\0';
1749 break;
1750
1751 case STATUSTYPE_TABLE:
1752 DMEMIT("%s ", cc->cipher_string);
1753
1754 if (cc->key_size > 0) {
1755 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1756 return -ENOMEM;
1757
1758 crypt_encode_key(result + sz, cc->key, cc->key_size);
1759 sz += cc->key_size << 1;
1760 } else {
1761 if (sz >= maxlen)
1762 return -ENOMEM;
1763 result[sz++] = '-';
1764 }
1765
1766 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1767 cc->dev->name, (unsigned long long)cc->start);
1768
1769 if (ti->num_discard_requests)
1770 DMEMIT(" 1 allow_discards");
1771
1772 break;
1773 }
1774 return 0;
1775}
1776
1777static void crypt_postsuspend(struct dm_target *ti)
1778{
1779 struct crypt_config *cc = ti->private;
1780
1781 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1782}
1783
1784static int crypt_preresume(struct dm_target *ti)
1785{
1786 struct crypt_config *cc = ti->private;
1787
1788 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1789 DMERR("aborting resume - crypt key is not set.");
1790 return -EAGAIN;
1791 }
1792
1793 return 0;
1794}
1795
1796static void crypt_resume(struct dm_target *ti)
1797{
1798 struct crypt_config *cc = ti->private;
1799
1800 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1801}
1802
1803/* Message interface
1804 * key set <key>
1805 * key wipe
1806 */
1807static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1808{
1809 struct crypt_config *cc = ti->private;
1810 int ret = -EINVAL;
1811
1812 if (argc < 2)
1813 goto error;
1814
1815 if (!strcasecmp(argv[0], "key")) {
1816 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1817 DMWARN("not suspended during key manipulation.");
1818 return -EINVAL;
1819 }
1820 if (argc == 3 && !strcasecmp(argv[1], "set")) {
1821 ret = crypt_set_key(cc, argv[2]);
1822 if (ret)
1823 return ret;
1824 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
1825 ret = cc->iv_gen_ops->init(cc);
1826 return ret;
1827 }
1828 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
1829 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
1830 ret = cc->iv_gen_ops->wipe(cc);
1831 if (ret)
1832 return ret;
1833 }
1834 return crypt_wipe_key(cc);
1835 }
1836 }
1837
1838error:
1839 DMWARN("unrecognised message received.");
1840 return -EINVAL;
1841}
1842
1843static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1844 struct bio_vec *biovec, int max_size)
1845{
1846 struct crypt_config *cc = ti->private;
1847 struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1848
1849 if (!q->merge_bvec_fn)
1850 return max_size;
1851
1852 bvm->bi_bdev = cc->dev->bdev;
1853 bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
1854
1855 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
1856}
1857
1858static int crypt_iterate_devices(struct dm_target *ti,
1859 iterate_devices_callout_fn fn, void *data)
1860{
1861 struct crypt_config *cc = ti->private;
1862
1863 return fn(ti, cc->dev, cc->start, ti->len, data);
1864}
1865
1866static struct target_type crypt_target = {
1867 .name = "crypt",
1868 .version = {1, 11, 0},
1869 .module = THIS_MODULE,
1870 .ctr = crypt_ctr,
1871 .dtr = crypt_dtr,
1872 .map = crypt_map,
1873 .status = crypt_status,
1874 .postsuspend = crypt_postsuspend,
1875 .preresume = crypt_preresume,
1876 .resume = crypt_resume,
1877 .message = crypt_message,
1878 .merge = crypt_merge,
1879 .iterate_devices = crypt_iterate_devices,
1880};
1881
1882static int __init dm_crypt_init(void)
1883{
1884 int r;
1885
1886 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1887 if (!_crypt_io_pool)
1888 return -ENOMEM;
1889
1890 r = dm_register_target(&crypt_target);
1891 if (r < 0) {
1892 DMERR("register failed %d", r);
1893 kmem_cache_destroy(_crypt_io_pool);
1894 }
1895
1896 return r;
1897}
1898
1899static void __exit dm_crypt_exit(void)
1900{
1901 dm_unregister_target(&crypt_target);
1902 kmem_cache_destroy(_crypt_io_pool);
1903}
1904
1905module_init(dm_crypt_init);
1906module_exit(dm_crypt_exit);
1907
1908MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1909MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1910MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
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/backing-dev.h>
22#include <linux/atomic.h>
23#include <linux/scatterlist.h>
24#include <asm/page.h>
25#include <asm/unaligned.h>
26#include <crypto/hash.h>
27#include <crypto/md5.h>
28#include <crypto/algapi.h>
29
30#include <linux/device-mapper.h>
31
32#define DM_MSG_PREFIX "crypt"
33
34/*
35 * context holding the current state of a multi-part conversion
36 */
37struct convert_context {
38 struct completion restart;
39 struct bio *bio_in;
40 struct bio *bio_out;
41 struct bvec_iter iter_in;
42 struct bvec_iter iter_out;
43 sector_t cc_sector;
44 atomic_t cc_pending;
45 struct ablkcipher_request *req;
46};
47
48/*
49 * per bio private data
50 */
51struct dm_crypt_io {
52 struct crypt_config *cc;
53 struct bio *base_bio;
54 struct work_struct work;
55
56 struct convert_context ctx;
57
58 atomic_t io_pending;
59 int error;
60 sector_t sector;
61 struct dm_crypt_io *base_io;
62};
63
64struct dm_crypt_request {
65 struct convert_context *ctx;
66 struct scatterlist sg_in;
67 struct scatterlist sg_out;
68 sector_t iv_sector;
69};
70
71struct crypt_config;
72
73struct crypt_iv_operations {
74 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
75 const char *opts);
76 void (*dtr)(struct crypt_config *cc);
77 int (*init)(struct crypt_config *cc);
78 int (*wipe)(struct crypt_config *cc);
79 int (*generator)(struct crypt_config *cc, u8 *iv,
80 struct dm_crypt_request *dmreq);
81 int (*post)(struct crypt_config *cc, u8 *iv,
82 struct dm_crypt_request *dmreq);
83};
84
85struct iv_essiv_private {
86 struct crypto_hash *hash_tfm;
87 u8 *salt;
88};
89
90struct iv_benbi_private {
91 int shift;
92};
93
94#define LMK_SEED_SIZE 64 /* hash + 0 */
95struct iv_lmk_private {
96 struct crypto_shash *hash_tfm;
97 u8 *seed;
98};
99
100#define TCW_WHITENING_SIZE 16
101struct iv_tcw_private {
102 struct crypto_shash *crc32_tfm;
103 u8 *iv_seed;
104 u8 *whitening;
105};
106
107/*
108 * Crypt: maps a linear range of a block device
109 * and encrypts / decrypts at the same time.
110 */
111enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
112
113/*
114 * The fields in here must be read only after initialization.
115 */
116struct crypt_config {
117 struct dm_dev *dev;
118 sector_t start;
119
120 /*
121 * pool for per bio private data, crypto requests and
122 * encryption requeusts/buffer pages
123 */
124 mempool_t *io_pool;
125 mempool_t *req_pool;
126 mempool_t *page_pool;
127 struct bio_set *bs;
128
129 struct workqueue_struct *io_queue;
130 struct workqueue_struct *crypt_queue;
131
132 char *cipher;
133 char *cipher_string;
134
135 struct crypt_iv_operations *iv_gen_ops;
136 union {
137 struct iv_essiv_private essiv;
138 struct iv_benbi_private benbi;
139 struct iv_lmk_private lmk;
140 struct iv_tcw_private tcw;
141 } iv_gen_private;
142 sector_t iv_offset;
143 unsigned int iv_size;
144
145 /* ESSIV: struct crypto_cipher *essiv_tfm */
146 void *iv_private;
147 struct crypto_ablkcipher **tfms;
148 unsigned tfms_count;
149
150 /*
151 * Layout of each crypto request:
152 *
153 * struct ablkcipher_request
154 * context
155 * padding
156 * struct dm_crypt_request
157 * padding
158 * IV
159 *
160 * The padding is added so that dm_crypt_request and the IV are
161 * correctly aligned.
162 */
163 unsigned int dmreq_start;
164
165 unsigned long flags;
166 unsigned int key_size;
167 unsigned int key_parts; /* independent parts in key buffer */
168 unsigned int key_extra_size; /* additional keys length */
169 u8 key[0];
170};
171
172#define MIN_IOS 16
173#define MIN_POOL_PAGES 32
174
175static struct kmem_cache *_crypt_io_pool;
176
177static void clone_init(struct dm_crypt_io *, struct bio *);
178static void kcryptd_queue_crypt(struct dm_crypt_io *io);
179static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
180
181/*
182 * Use this to access cipher attributes that are the same for each CPU.
183 */
184static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
185{
186 return cc->tfms[0];
187}
188
189/*
190 * Different IV generation algorithms:
191 *
192 * plain: the initial vector is the 32-bit little-endian version of the sector
193 * number, padded with zeros if necessary.
194 *
195 * plain64: the initial vector is the 64-bit little-endian version of the sector
196 * number, padded with zeros if necessary.
197 *
198 * essiv: "encrypted sector|salt initial vector", the sector number is
199 * encrypted with the bulk cipher using a salt as key. The salt
200 * should be derived from the bulk cipher's key via hashing.
201 *
202 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
203 * (needed for LRW-32-AES and possible other narrow block modes)
204 *
205 * null: the initial vector is always zero. Provides compatibility with
206 * obsolete loop_fish2 devices. Do not use for new devices.
207 *
208 * lmk: Compatible implementation of the block chaining mode used
209 * by the Loop-AES block device encryption system
210 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
211 * It operates on full 512 byte sectors and uses CBC
212 * with an IV derived from the sector number, the data and
213 * optionally extra IV seed.
214 * This means that after decryption the first block
215 * of sector must be tweaked according to decrypted data.
216 * Loop-AES can use three encryption schemes:
217 * version 1: is plain aes-cbc mode
218 * version 2: uses 64 multikey scheme with lmk IV generator
219 * version 3: the same as version 2 with additional IV seed
220 * (it uses 65 keys, last key is used as IV seed)
221 *
222 * tcw: Compatible implementation of the block chaining mode used
223 * by the TrueCrypt device encryption system (prior to version 4.1).
224 * For more info see: http://www.truecrypt.org
225 * It operates on full 512 byte sectors and uses CBC
226 * with an IV derived from initial key and the sector number.
227 * In addition, whitening value is applied on every sector, whitening
228 * is calculated from initial key, sector number and mixed using CRC32.
229 * Note that this encryption scheme is vulnerable to watermarking attacks
230 * and should be used for old compatible containers access only.
231 *
232 * plumb: unimplemented, see:
233 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
234 */
235
236static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
237 struct dm_crypt_request *dmreq)
238{
239 memset(iv, 0, cc->iv_size);
240 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
241
242 return 0;
243}
244
245static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
246 struct dm_crypt_request *dmreq)
247{
248 memset(iv, 0, cc->iv_size);
249 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
250
251 return 0;
252}
253
254/* Initialise ESSIV - compute salt but no local memory allocations */
255static int crypt_iv_essiv_init(struct crypt_config *cc)
256{
257 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
258 struct hash_desc desc;
259 struct scatterlist sg;
260 struct crypto_cipher *essiv_tfm;
261 int err;
262
263 sg_init_one(&sg, cc->key, cc->key_size);
264 desc.tfm = essiv->hash_tfm;
265 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
266
267 err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
268 if (err)
269 return err;
270
271 essiv_tfm = cc->iv_private;
272
273 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
274 crypto_hash_digestsize(essiv->hash_tfm));
275 if (err)
276 return err;
277
278 return 0;
279}
280
281/* Wipe salt and reset key derived from volume key */
282static int crypt_iv_essiv_wipe(struct crypt_config *cc)
283{
284 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
285 unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
286 struct crypto_cipher *essiv_tfm;
287 int r, err = 0;
288
289 memset(essiv->salt, 0, salt_size);
290
291 essiv_tfm = cc->iv_private;
292 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
293 if (r)
294 err = r;
295
296 return err;
297}
298
299/* Set up per cpu cipher state */
300static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
301 struct dm_target *ti,
302 u8 *salt, unsigned saltsize)
303{
304 struct crypto_cipher *essiv_tfm;
305 int err;
306
307 /* Setup the essiv_tfm with the given salt */
308 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
309 if (IS_ERR(essiv_tfm)) {
310 ti->error = "Error allocating crypto tfm for ESSIV";
311 return essiv_tfm;
312 }
313
314 if (crypto_cipher_blocksize(essiv_tfm) !=
315 crypto_ablkcipher_ivsize(any_tfm(cc))) {
316 ti->error = "Block size of ESSIV cipher does "
317 "not match IV size of block cipher";
318 crypto_free_cipher(essiv_tfm);
319 return ERR_PTR(-EINVAL);
320 }
321
322 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
323 if (err) {
324 ti->error = "Failed to set key for ESSIV cipher";
325 crypto_free_cipher(essiv_tfm);
326 return ERR_PTR(err);
327 }
328
329 return essiv_tfm;
330}
331
332static void crypt_iv_essiv_dtr(struct crypt_config *cc)
333{
334 struct crypto_cipher *essiv_tfm;
335 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
336
337 crypto_free_hash(essiv->hash_tfm);
338 essiv->hash_tfm = NULL;
339
340 kzfree(essiv->salt);
341 essiv->salt = NULL;
342
343 essiv_tfm = cc->iv_private;
344
345 if (essiv_tfm)
346 crypto_free_cipher(essiv_tfm);
347
348 cc->iv_private = NULL;
349}
350
351static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
352 const char *opts)
353{
354 struct crypto_cipher *essiv_tfm = NULL;
355 struct crypto_hash *hash_tfm = NULL;
356 u8 *salt = NULL;
357 int err;
358
359 if (!opts) {
360 ti->error = "Digest algorithm missing for ESSIV mode";
361 return -EINVAL;
362 }
363
364 /* Allocate hash algorithm */
365 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
366 if (IS_ERR(hash_tfm)) {
367 ti->error = "Error initializing ESSIV hash";
368 err = PTR_ERR(hash_tfm);
369 goto bad;
370 }
371
372 salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
373 if (!salt) {
374 ti->error = "Error kmallocing salt storage in ESSIV";
375 err = -ENOMEM;
376 goto bad;
377 }
378
379 cc->iv_gen_private.essiv.salt = salt;
380 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
381
382 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
383 crypto_hash_digestsize(hash_tfm));
384 if (IS_ERR(essiv_tfm)) {
385 crypt_iv_essiv_dtr(cc);
386 return PTR_ERR(essiv_tfm);
387 }
388 cc->iv_private = essiv_tfm;
389
390 return 0;
391
392bad:
393 if (hash_tfm && !IS_ERR(hash_tfm))
394 crypto_free_hash(hash_tfm);
395 kfree(salt);
396 return err;
397}
398
399static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
400 struct dm_crypt_request *dmreq)
401{
402 struct crypto_cipher *essiv_tfm = cc->iv_private;
403
404 memset(iv, 0, cc->iv_size);
405 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
406 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
407
408 return 0;
409}
410
411static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
412 const char *opts)
413{
414 unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
415 int log = ilog2(bs);
416
417 /* we need to calculate how far we must shift the sector count
418 * to get the cipher block count, we use this shift in _gen */
419
420 if (1 << log != bs) {
421 ti->error = "cypher blocksize is not a power of 2";
422 return -EINVAL;
423 }
424
425 if (log > 9) {
426 ti->error = "cypher blocksize is > 512";
427 return -EINVAL;
428 }
429
430 cc->iv_gen_private.benbi.shift = 9 - log;
431
432 return 0;
433}
434
435static void crypt_iv_benbi_dtr(struct crypt_config *cc)
436{
437}
438
439static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
440 struct dm_crypt_request *dmreq)
441{
442 __be64 val;
443
444 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
445
446 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
447 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
448
449 return 0;
450}
451
452static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
453 struct dm_crypt_request *dmreq)
454{
455 memset(iv, 0, cc->iv_size);
456
457 return 0;
458}
459
460static void crypt_iv_lmk_dtr(struct crypt_config *cc)
461{
462 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
463
464 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
465 crypto_free_shash(lmk->hash_tfm);
466 lmk->hash_tfm = NULL;
467
468 kzfree(lmk->seed);
469 lmk->seed = NULL;
470}
471
472static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
473 const char *opts)
474{
475 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
476
477 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
478 if (IS_ERR(lmk->hash_tfm)) {
479 ti->error = "Error initializing LMK hash";
480 return PTR_ERR(lmk->hash_tfm);
481 }
482
483 /* No seed in LMK version 2 */
484 if (cc->key_parts == cc->tfms_count) {
485 lmk->seed = NULL;
486 return 0;
487 }
488
489 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
490 if (!lmk->seed) {
491 crypt_iv_lmk_dtr(cc);
492 ti->error = "Error kmallocing seed storage in LMK";
493 return -ENOMEM;
494 }
495
496 return 0;
497}
498
499static int crypt_iv_lmk_init(struct crypt_config *cc)
500{
501 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
502 int subkey_size = cc->key_size / cc->key_parts;
503
504 /* LMK seed is on the position of LMK_KEYS + 1 key */
505 if (lmk->seed)
506 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
507 crypto_shash_digestsize(lmk->hash_tfm));
508
509 return 0;
510}
511
512static int crypt_iv_lmk_wipe(struct crypt_config *cc)
513{
514 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
515
516 if (lmk->seed)
517 memset(lmk->seed, 0, LMK_SEED_SIZE);
518
519 return 0;
520}
521
522static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
523 struct dm_crypt_request *dmreq,
524 u8 *data)
525{
526 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
527 struct {
528 struct shash_desc desc;
529 char ctx[crypto_shash_descsize(lmk->hash_tfm)];
530 } sdesc;
531 struct md5_state md5state;
532 __le32 buf[4];
533 int i, r;
534
535 sdesc.desc.tfm = lmk->hash_tfm;
536 sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
537
538 r = crypto_shash_init(&sdesc.desc);
539 if (r)
540 return r;
541
542 if (lmk->seed) {
543 r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
544 if (r)
545 return r;
546 }
547
548 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
549 r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
550 if (r)
551 return r;
552
553 /* Sector is cropped to 56 bits here */
554 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
555 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
556 buf[2] = cpu_to_le32(4024);
557 buf[3] = 0;
558 r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
559 if (r)
560 return r;
561
562 /* No MD5 padding here */
563 r = crypto_shash_export(&sdesc.desc, &md5state);
564 if (r)
565 return r;
566
567 for (i = 0; i < MD5_HASH_WORDS; i++)
568 __cpu_to_le32s(&md5state.hash[i]);
569 memcpy(iv, &md5state.hash, cc->iv_size);
570
571 return 0;
572}
573
574static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
575 struct dm_crypt_request *dmreq)
576{
577 u8 *src;
578 int r = 0;
579
580 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
581 src = kmap_atomic(sg_page(&dmreq->sg_in));
582 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
583 kunmap_atomic(src);
584 } else
585 memset(iv, 0, cc->iv_size);
586
587 return r;
588}
589
590static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
591 struct dm_crypt_request *dmreq)
592{
593 u8 *dst;
594 int r;
595
596 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
597 return 0;
598
599 dst = kmap_atomic(sg_page(&dmreq->sg_out));
600 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
601
602 /* Tweak the first block of plaintext sector */
603 if (!r)
604 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
605
606 kunmap_atomic(dst);
607 return r;
608}
609
610static void crypt_iv_tcw_dtr(struct crypt_config *cc)
611{
612 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
613
614 kzfree(tcw->iv_seed);
615 tcw->iv_seed = NULL;
616 kzfree(tcw->whitening);
617 tcw->whitening = NULL;
618
619 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
620 crypto_free_shash(tcw->crc32_tfm);
621 tcw->crc32_tfm = NULL;
622}
623
624static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
625 const char *opts)
626{
627 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
628
629 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
630 ti->error = "Wrong key size for TCW";
631 return -EINVAL;
632 }
633
634 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
635 if (IS_ERR(tcw->crc32_tfm)) {
636 ti->error = "Error initializing CRC32 in TCW";
637 return PTR_ERR(tcw->crc32_tfm);
638 }
639
640 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
641 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
642 if (!tcw->iv_seed || !tcw->whitening) {
643 crypt_iv_tcw_dtr(cc);
644 ti->error = "Error allocating seed storage in TCW";
645 return -ENOMEM;
646 }
647
648 return 0;
649}
650
651static int crypt_iv_tcw_init(struct crypt_config *cc)
652{
653 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
654 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
655
656 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
657 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
658 TCW_WHITENING_SIZE);
659
660 return 0;
661}
662
663static int crypt_iv_tcw_wipe(struct crypt_config *cc)
664{
665 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
666
667 memset(tcw->iv_seed, 0, cc->iv_size);
668 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
669
670 return 0;
671}
672
673static int crypt_iv_tcw_whitening(struct crypt_config *cc,
674 struct dm_crypt_request *dmreq,
675 u8 *data)
676{
677 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
678 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
679 u8 buf[TCW_WHITENING_SIZE];
680 struct {
681 struct shash_desc desc;
682 char ctx[crypto_shash_descsize(tcw->crc32_tfm)];
683 } sdesc;
684 int i, r;
685
686 /* xor whitening with sector number */
687 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
688 crypto_xor(buf, (u8 *)§or, 8);
689 crypto_xor(&buf[8], (u8 *)§or, 8);
690
691 /* calculate crc32 for every 32bit part and xor it */
692 sdesc.desc.tfm = tcw->crc32_tfm;
693 sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
694 for (i = 0; i < 4; i++) {
695 r = crypto_shash_init(&sdesc.desc);
696 if (r)
697 goto out;
698 r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4);
699 if (r)
700 goto out;
701 r = crypto_shash_final(&sdesc.desc, &buf[i * 4]);
702 if (r)
703 goto out;
704 }
705 crypto_xor(&buf[0], &buf[12], 4);
706 crypto_xor(&buf[4], &buf[8], 4);
707
708 /* apply whitening (8 bytes) to whole sector */
709 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
710 crypto_xor(data + i * 8, buf, 8);
711out:
712 memset(buf, 0, sizeof(buf));
713 return r;
714}
715
716static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
717 struct dm_crypt_request *dmreq)
718{
719 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
720 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
721 u8 *src;
722 int r = 0;
723
724 /* Remove whitening from ciphertext */
725 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
726 src = kmap_atomic(sg_page(&dmreq->sg_in));
727 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
728 kunmap_atomic(src);
729 }
730
731 /* Calculate IV */
732 memcpy(iv, tcw->iv_seed, cc->iv_size);
733 crypto_xor(iv, (u8 *)§or, 8);
734 if (cc->iv_size > 8)
735 crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
736
737 return r;
738}
739
740static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
741 struct dm_crypt_request *dmreq)
742{
743 u8 *dst;
744 int r;
745
746 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
747 return 0;
748
749 /* Apply whitening on ciphertext */
750 dst = kmap_atomic(sg_page(&dmreq->sg_out));
751 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
752 kunmap_atomic(dst);
753
754 return r;
755}
756
757static struct crypt_iv_operations crypt_iv_plain_ops = {
758 .generator = crypt_iv_plain_gen
759};
760
761static struct crypt_iv_operations crypt_iv_plain64_ops = {
762 .generator = crypt_iv_plain64_gen
763};
764
765static struct crypt_iv_operations crypt_iv_essiv_ops = {
766 .ctr = crypt_iv_essiv_ctr,
767 .dtr = crypt_iv_essiv_dtr,
768 .init = crypt_iv_essiv_init,
769 .wipe = crypt_iv_essiv_wipe,
770 .generator = crypt_iv_essiv_gen
771};
772
773static struct crypt_iv_operations crypt_iv_benbi_ops = {
774 .ctr = crypt_iv_benbi_ctr,
775 .dtr = crypt_iv_benbi_dtr,
776 .generator = crypt_iv_benbi_gen
777};
778
779static struct crypt_iv_operations crypt_iv_null_ops = {
780 .generator = crypt_iv_null_gen
781};
782
783static struct crypt_iv_operations crypt_iv_lmk_ops = {
784 .ctr = crypt_iv_lmk_ctr,
785 .dtr = crypt_iv_lmk_dtr,
786 .init = crypt_iv_lmk_init,
787 .wipe = crypt_iv_lmk_wipe,
788 .generator = crypt_iv_lmk_gen,
789 .post = crypt_iv_lmk_post
790};
791
792static struct crypt_iv_operations crypt_iv_tcw_ops = {
793 .ctr = crypt_iv_tcw_ctr,
794 .dtr = crypt_iv_tcw_dtr,
795 .init = crypt_iv_tcw_init,
796 .wipe = crypt_iv_tcw_wipe,
797 .generator = crypt_iv_tcw_gen,
798 .post = crypt_iv_tcw_post
799};
800
801static void crypt_convert_init(struct crypt_config *cc,
802 struct convert_context *ctx,
803 struct bio *bio_out, struct bio *bio_in,
804 sector_t sector)
805{
806 ctx->bio_in = bio_in;
807 ctx->bio_out = bio_out;
808 if (bio_in)
809 ctx->iter_in = bio_in->bi_iter;
810 if (bio_out)
811 ctx->iter_out = bio_out->bi_iter;
812 ctx->cc_sector = sector + cc->iv_offset;
813 init_completion(&ctx->restart);
814}
815
816static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
817 struct ablkcipher_request *req)
818{
819 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
820}
821
822static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
823 struct dm_crypt_request *dmreq)
824{
825 return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
826}
827
828static u8 *iv_of_dmreq(struct crypt_config *cc,
829 struct dm_crypt_request *dmreq)
830{
831 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
832 crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
833}
834
835static int crypt_convert_block(struct crypt_config *cc,
836 struct convert_context *ctx,
837 struct ablkcipher_request *req)
838{
839 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
840 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
841 struct dm_crypt_request *dmreq;
842 u8 *iv;
843 int r;
844
845 dmreq = dmreq_of_req(cc, req);
846 iv = iv_of_dmreq(cc, dmreq);
847
848 dmreq->iv_sector = ctx->cc_sector;
849 dmreq->ctx = ctx;
850 sg_init_table(&dmreq->sg_in, 1);
851 sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
852 bv_in.bv_offset);
853
854 sg_init_table(&dmreq->sg_out, 1);
855 sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
856 bv_out.bv_offset);
857
858 bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
859 bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
860
861 if (cc->iv_gen_ops) {
862 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
863 if (r < 0)
864 return r;
865 }
866
867 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
868 1 << SECTOR_SHIFT, iv);
869
870 if (bio_data_dir(ctx->bio_in) == WRITE)
871 r = crypto_ablkcipher_encrypt(req);
872 else
873 r = crypto_ablkcipher_decrypt(req);
874
875 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
876 r = cc->iv_gen_ops->post(cc, iv, dmreq);
877
878 return r;
879}
880
881static void kcryptd_async_done(struct crypto_async_request *async_req,
882 int error);
883
884static void crypt_alloc_req(struct crypt_config *cc,
885 struct convert_context *ctx)
886{
887 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
888
889 if (!ctx->req)
890 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
891
892 ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
893 ablkcipher_request_set_callback(ctx->req,
894 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
895 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
896}
897
898/*
899 * Encrypt / decrypt data from one bio to another one (can be the same one)
900 */
901static int crypt_convert(struct crypt_config *cc,
902 struct convert_context *ctx)
903{
904 int r;
905
906 atomic_set(&ctx->cc_pending, 1);
907
908 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
909
910 crypt_alloc_req(cc, ctx);
911
912 atomic_inc(&ctx->cc_pending);
913
914 r = crypt_convert_block(cc, ctx, ctx->req);
915
916 switch (r) {
917 /* async */
918 case -EBUSY:
919 wait_for_completion(&ctx->restart);
920 reinit_completion(&ctx->restart);
921 /* fall through*/
922 case -EINPROGRESS:
923 ctx->req = NULL;
924 ctx->cc_sector++;
925 continue;
926
927 /* sync */
928 case 0:
929 atomic_dec(&ctx->cc_pending);
930 ctx->cc_sector++;
931 cond_resched();
932 continue;
933
934 /* error */
935 default:
936 atomic_dec(&ctx->cc_pending);
937 return r;
938 }
939 }
940
941 return 0;
942}
943
944/*
945 * Generate a new unfragmented bio with the given size
946 * This should never violate the device limitations
947 * May return a smaller bio when running out of pages, indicated by
948 * *out_of_pages set to 1.
949 */
950static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
951 unsigned *out_of_pages)
952{
953 struct crypt_config *cc = io->cc;
954 struct bio *clone;
955 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
956 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
957 unsigned i, len;
958 struct page *page;
959
960 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
961 if (!clone)
962 return NULL;
963
964 clone_init(io, clone);
965 *out_of_pages = 0;
966
967 for (i = 0; i < nr_iovecs; i++) {
968 page = mempool_alloc(cc->page_pool, gfp_mask);
969 if (!page) {
970 *out_of_pages = 1;
971 break;
972 }
973
974 /*
975 * If additional pages cannot be allocated without waiting,
976 * return a partially-allocated bio. The caller will then try
977 * to allocate more bios while submitting this partial bio.
978 */
979 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
980
981 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
982
983 if (!bio_add_page(clone, page, len, 0)) {
984 mempool_free(page, cc->page_pool);
985 break;
986 }
987
988 size -= len;
989 }
990
991 if (!clone->bi_iter.bi_size) {
992 bio_put(clone);
993 return NULL;
994 }
995
996 return clone;
997}
998
999static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1000{
1001 unsigned int i;
1002 struct bio_vec *bv;
1003
1004 bio_for_each_segment_all(bv, clone, i) {
1005 BUG_ON(!bv->bv_page);
1006 mempool_free(bv->bv_page, cc->page_pool);
1007 bv->bv_page = NULL;
1008 }
1009}
1010
1011static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc,
1012 struct bio *bio, sector_t sector)
1013{
1014 struct dm_crypt_io *io;
1015
1016 io = mempool_alloc(cc->io_pool, GFP_NOIO);
1017 io->cc = cc;
1018 io->base_bio = bio;
1019 io->sector = sector;
1020 io->error = 0;
1021 io->base_io = NULL;
1022 io->ctx.req = NULL;
1023 atomic_set(&io->io_pending, 0);
1024
1025 return io;
1026}
1027
1028static void crypt_inc_pending(struct dm_crypt_io *io)
1029{
1030 atomic_inc(&io->io_pending);
1031}
1032
1033/*
1034 * One of the bios was finished. Check for completion of
1035 * the whole request and correctly clean up the buffer.
1036 * If base_io is set, wait for the last fragment to complete.
1037 */
1038static void crypt_dec_pending(struct dm_crypt_io *io)
1039{
1040 struct crypt_config *cc = io->cc;
1041 struct bio *base_bio = io->base_bio;
1042 struct dm_crypt_io *base_io = io->base_io;
1043 int error = io->error;
1044
1045 if (!atomic_dec_and_test(&io->io_pending))
1046 return;
1047
1048 if (io->ctx.req)
1049 mempool_free(io->ctx.req, cc->req_pool);
1050 mempool_free(io, cc->io_pool);
1051
1052 if (likely(!base_io))
1053 bio_endio(base_bio, error);
1054 else {
1055 if (error && !base_io->error)
1056 base_io->error = error;
1057 crypt_dec_pending(base_io);
1058 }
1059}
1060
1061/*
1062 * kcryptd/kcryptd_io:
1063 *
1064 * Needed because it would be very unwise to do decryption in an
1065 * interrupt context.
1066 *
1067 * kcryptd performs the actual encryption or decryption.
1068 *
1069 * kcryptd_io performs the IO submission.
1070 *
1071 * They must be separated as otherwise the final stages could be
1072 * starved by new requests which can block in the first stages due
1073 * to memory allocation.
1074 *
1075 * The work is done per CPU global for all dm-crypt instances.
1076 * They should not depend on each other and do not block.
1077 */
1078static void crypt_endio(struct bio *clone, int error)
1079{
1080 struct dm_crypt_io *io = clone->bi_private;
1081 struct crypt_config *cc = io->cc;
1082 unsigned rw = bio_data_dir(clone);
1083
1084 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
1085 error = -EIO;
1086
1087 /*
1088 * free the processed pages
1089 */
1090 if (rw == WRITE)
1091 crypt_free_buffer_pages(cc, clone);
1092
1093 bio_put(clone);
1094
1095 if (rw == READ && !error) {
1096 kcryptd_queue_crypt(io);
1097 return;
1098 }
1099
1100 if (unlikely(error))
1101 io->error = error;
1102
1103 crypt_dec_pending(io);
1104}
1105
1106static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1107{
1108 struct crypt_config *cc = io->cc;
1109
1110 clone->bi_private = io;
1111 clone->bi_end_io = crypt_endio;
1112 clone->bi_bdev = cc->dev->bdev;
1113 clone->bi_rw = io->base_bio->bi_rw;
1114}
1115
1116static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1117{
1118 struct crypt_config *cc = io->cc;
1119 struct bio *base_bio = io->base_bio;
1120 struct bio *clone;
1121
1122 /*
1123 * The block layer might modify the bvec array, so always
1124 * copy the required bvecs because we need the original
1125 * one in order to decrypt the whole bio data *afterwards*.
1126 */
1127 clone = bio_clone_bioset(base_bio, gfp, cc->bs);
1128 if (!clone)
1129 return 1;
1130
1131 crypt_inc_pending(io);
1132
1133 clone_init(io, clone);
1134 clone->bi_iter.bi_sector = cc->start + io->sector;
1135
1136 generic_make_request(clone);
1137 return 0;
1138}
1139
1140static void kcryptd_io_write(struct dm_crypt_io *io)
1141{
1142 struct bio *clone = io->ctx.bio_out;
1143 generic_make_request(clone);
1144}
1145
1146static void kcryptd_io(struct work_struct *work)
1147{
1148 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1149
1150 if (bio_data_dir(io->base_bio) == READ) {
1151 crypt_inc_pending(io);
1152 if (kcryptd_io_read(io, GFP_NOIO))
1153 io->error = -ENOMEM;
1154 crypt_dec_pending(io);
1155 } else
1156 kcryptd_io_write(io);
1157}
1158
1159static void kcryptd_queue_io(struct dm_crypt_io *io)
1160{
1161 struct crypt_config *cc = io->cc;
1162
1163 INIT_WORK(&io->work, kcryptd_io);
1164 queue_work(cc->io_queue, &io->work);
1165}
1166
1167static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1168{
1169 struct bio *clone = io->ctx.bio_out;
1170 struct crypt_config *cc = io->cc;
1171
1172 if (unlikely(io->error < 0)) {
1173 crypt_free_buffer_pages(cc, clone);
1174 bio_put(clone);
1175 crypt_dec_pending(io);
1176 return;
1177 }
1178
1179 /* crypt_convert should have filled the clone bio */
1180 BUG_ON(io->ctx.iter_out.bi_size);
1181
1182 clone->bi_iter.bi_sector = cc->start + io->sector;
1183
1184 if (async)
1185 kcryptd_queue_io(io);
1186 else
1187 generic_make_request(clone);
1188}
1189
1190static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1191{
1192 struct crypt_config *cc = io->cc;
1193 struct bio *clone;
1194 struct dm_crypt_io *new_io;
1195 int crypt_finished;
1196 unsigned out_of_pages = 0;
1197 unsigned remaining = io->base_bio->bi_iter.bi_size;
1198 sector_t sector = io->sector;
1199 int r;
1200
1201 /*
1202 * Prevent io from disappearing until this function completes.
1203 */
1204 crypt_inc_pending(io);
1205 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1206
1207 /*
1208 * The allocated buffers can be smaller than the whole bio,
1209 * so repeat the whole process until all the data can be handled.
1210 */
1211 while (remaining) {
1212 clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
1213 if (unlikely(!clone)) {
1214 io->error = -ENOMEM;
1215 break;
1216 }
1217
1218 io->ctx.bio_out = clone;
1219 io->ctx.iter_out = clone->bi_iter;
1220
1221 remaining -= clone->bi_iter.bi_size;
1222 sector += bio_sectors(clone);
1223
1224 crypt_inc_pending(io);
1225
1226 r = crypt_convert(cc, &io->ctx);
1227 if (r < 0)
1228 io->error = -EIO;
1229
1230 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1231
1232 /* Encryption was already finished, submit io now */
1233 if (crypt_finished) {
1234 kcryptd_crypt_write_io_submit(io, 0);
1235
1236 /*
1237 * If there was an error, do not try next fragments.
1238 * For async, error is processed in async handler.
1239 */
1240 if (unlikely(r < 0))
1241 break;
1242
1243 io->sector = sector;
1244 }
1245
1246 /*
1247 * Out of memory -> run queues
1248 * But don't wait if split was due to the io size restriction
1249 */
1250 if (unlikely(out_of_pages))
1251 congestion_wait(BLK_RW_ASYNC, HZ/100);
1252
1253 /*
1254 * With async crypto it is unsafe to share the crypto context
1255 * between fragments, so switch to a new dm_crypt_io structure.
1256 */
1257 if (unlikely(!crypt_finished && remaining)) {
1258 new_io = crypt_io_alloc(io->cc, io->base_bio,
1259 sector);
1260 crypt_inc_pending(new_io);
1261 crypt_convert_init(cc, &new_io->ctx, NULL,
1262 io->base_bio, sector);
1263 new_io->ctx.iter_in = io->ctx.iter_in;
1264
1265 /*
1266 * Fragments after the first use the base_io
1267 * pending count.
1268 */
1269 if (!io->base_io)
1270 new_io->base_io = io;
1271 else {
1272 new_io->base_io = io->base_io;
1273 crypt_inc_pending(io->base_io);
1274 crypt_dec_pending(io);
1275 }
1276
1277 io = new_io;
1278 }
1279 }
1280
1281 crypt_dec_pending(io);
1282}
1283
1284static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1285{
1286 crypt_dec_pending(io);
1287}
1288
1289static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1290{
1291 struct crypt_config *cc = io->cc;
1292 int r = 0;
1293
1294 crypt_inc_pending(io);
1295
1296 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1297 io->sector);
1298
1299 r = crypt_convert(cc, &io->ctx);
1300 if (r < 0)
1301 io->error = -EIO;
1302
1303 if (atomic_dec_and_test(&io->ctx.cc_pending))
1304 kcryptd_crypt_read_done(io);
1305
1306 crypt_dec_pending(io);
1307}
1308
1309static void kcryptd_async_done(struct crypto_async_request *async_req,
1310 int error)
1311{
1312 struct dm_crypt_request *dmreq = async_req->data;
1313 struct convert_context *ctx = dmreq->ctx;
1314 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1315 struct crypt_config *cc = io->cc;
1316
1317 if (error == -EINPROGRESS) {
1318 complete(&ctx->restart);
1319 return;
1320 }
1321
1322 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1323 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1324
1325 if (error < 0)
1326 io->error = -EIO;
1327
1328 mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
1329
1330 if (!atomic_dec_and_test(&ctx->cc_pending))
1331 return;
1332
1333 if (bio_data_dir(io->base_bio) == READ)
1334 kcryptd_crypt_read_done(io);
1335 else
1336 kcryptd_crypt_write_io_submit(io, 1);
1337}
1338
1339static void kcryptd_crypt(struct work_struct *work)
1340{
1341 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1342
1343 if (bio_data_dir(io->base_bio) == READ)
1344 kcryptd_crypt_read_convert(io);
1345 else
1346 kcryptd_crypt_write_convert(io);
1347}
1348
1349static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1350{
1351 struct crypt_config *cc = io->cc;
1352
1353 INIT_WORK(&io->work, kcryptd_crypt);
1354 queue_work(cc->crypt_queue, &io->work);
1355}
1356
1357/*
1358 * Decode key from its hex representation
1359 */
1360static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1361{
1362 char buffer[3];
1363 unsigned int i;
1364
1365 buffer[2] = '\0';
1366
1367 for (i = 0; i < size; i++) {
1368 buffer[0] = *hex++;
1369 buffer[1] = *hex++;
1370
1371 if (kstrtou8(buffer, 16, &key[i]))
1372 return -EINVAL;
1373 }
1374
1375 if (*hex != '\0')
1376 return -EINVAL;
1377
1378 return 0;
1379}
1380
1381static void crypt_free_tfms(struct crypt_config *cc)
1382{
1383 unsigned i;
1384
1385 if (!cc->tfms)
1386 return;
1387
1388 for (i = 0; i < cc->tfms_count; i++)
1389 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1390 crypto_free_ablkcipher(cc->tfms[i]);
1391 cc->tfms[i] = NULL;
1392 }
1393
1394 kfree(cc->tfms);
1395 cc->tfms = NULL;
1396}
1397
1398static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1399{
1400 unsigned i;
1401 int err;
1402
1403 cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *),
1404 GFP_KERNEL);
1405 if (!cc->tfms)
1406 return -ENOMEM;
1407
1408 for (i = 0; i < cc->tfms_count; i++) {
1409 cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1410 if (IS_ERR(cc->tfms[i])) {
1411 err = PTR_ERR(cc->tfms[i]);
1412 crypt_free_tfms(cc);
1413 return err;
1414 }
1415 }
1416
1417 return 0;
1418}
1419
1420static int crypt_setkey_allcpus(struct crypt_config *cc)
1421{
1422 unsigned subkey_size;
1423 int err = 0, i, r;
1424
1425 /* Ignore extra keys (which are used for IV etc) */
1426 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1427
1428 for (i = 0; i < cc->tfms_count; i++) {
1429 r = crypto_ablkcipher_setkey(cc->tfms[i],
1430 cc->key + (i * subkey_size),
1431 subkey_size);
1432 if (r)
1433 err = r;
1434 }
1435
1436 return err;
1437}
1438
1439static int crypt_set_key(struct crypt_config *cc, char *key)
1440{
1441 int r = -EINVAL;
1442 int key_string_len = strlen(key);
1443
1444 /* The key size may not be changed. */
1445 if (cc->key_size != (key_string_len >> 1))
1446 goto out;
1447
1448 /* Hyphen (which gives a key_size of zero) means there is no key. */
1449 if (!cc->key_size && strcmp(key, "-"))
1450 goto out;
1451
1452 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1453 goto out;
1454
1455 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1456
1457 r = crypt_setkey_allcpus(cc);
1458
1459out:
1460 /* Hex key string not needed after here, so wipe it. */
1461 memset(key, '0', key_string_len);
1462
1463 return r;
1464}
1465
1466static int crypt_wipe_key(struct crypt_config *cc)
1467{
1468 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1469 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1470
1471 return crypt_setkey_allcpus(cc);
1472}
1473
1474static void crypt_dtr(struct dm_target *ti)
1475{
1476 struct crypt_config *cc = ti->private;
1477
1478 ti->private = NULL;
1479
1480 if (!cc)
1481 return;
1482
1483 if (cc->io_queue)
1484 destroy_workqueue(cc->io_queue);
1485 if (cc->crypt_queue)
1486 destroy_workqueue(cc->crypt_queue);
1487
1488 crypt_free_tfms(cc);
1489
1490 if (cc->bs)
1491 bioset_free(cc->bs);
1492
1493 if (cc->page_pool)
1494 mempool_destroy(cc->page_pool);
1495 if (cc->req_pool)
1496 mempool_destroy(cc->req_pool);
1497 if (cc->io_pool)
1498 mempool_destroy(cc->io_pool);
1499
1500 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1501 cc->iv_gen_ops->dtr(cc);
1502
1503 if (cc->dev)
1504 dm_put_device(ti, cc->dev);
1505
1506 kzfree(cc->cipher);
1507 kzfree(cc->cipher_string);
1508
1509 /* Must zero key material before freeing */
1510 kzfree(cc);
1511}
1512
1513static int crypt_ctr_cipher(struct dm_target *ti,
1514 char *cipher_in, char *key)
1515{
1516 struct crypt_config *cc = ti->private;
1517 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1518 char *cipher_api = NULL;
1519 int ret = -EINVAL;
1520 char dummy;
1521
1522 /* Convert to crypto api definition? */
1523 if (strchr(cipher_in, '(')) {
1524 ti->error = "Bad cipher specification";
1525 return -EINVAL;
1526 }
1527
1528 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1529 if (!cc->cipher_string)
1530 goto bad_mem;
1531
1532 /*
1533 * Legacy dm-crypt cipher specification
1534 * cipher[:keycount]-mode-iv:ivopts
1535 */
1536 tmp = cipher_in;
1537 keycount = strsep(&tmp, "-");
1538 cipher = strsep(&keycount, ":");
1539
1540 if (!keycount)
1541 cc->tfms_count = 1;
1542 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1543 !is_power_of_2(cc->tfms_count)) {
1544 ti->error = "Bad cipher key count specification";
1545 return -EINVAL;
1546 }
1547 cc->key_parts = cc->tfms_count;
1548 cc->key_extra_size = 0;
1549
1550 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1551 if (!cc->cipher)
1552 goto bad_mem;
1553
1554 chainmode = strsep(&tmp, "-");
1555 ivopts = strsep(&tmp, "-");
1556 ivmode = strsep(&ivopts, ":");
1557
1558 if (tmp)
1559 DMWARN("Ignoring unexpected additional cipher options");
1560
1561 /*
1562 * For compatibility with the original dm-crypt mapping format, if
1563 * only the cipher name is supplied, use cbc-plain.
1564 */
1565 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1566 chainmode = "cbc";
1567 ivmode = "plain";
1568 }
1569
1570 if (strcmp(chainmode, "ecb") && !ivmode) {
1571 ti->error = "IV mechanism required";
1572 return -EINVAL;
1573 }
1574
1575 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1576 if (!cipher_api)
1577 goto bad_mem;
1578
1579 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1580 "%s(%s)", chainmode, cipher);
1581 if (ret < 0) {
1582 kfree(cipher_api);
1583 goto bad_mem;
1584 }
1585
1586 /* Allocate cipher */
1587 ret = crypt_alloc_tfms(cc, cipher_api);
1588 if (ret < 0) {
1589 ti->error = "Error allocating crypto tfm";
1590 goto bad;
1591 }
1592
1593 /* Initialize IV */
1594 cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1595 if (cc->iv_size)
1596 /* at least a 64 bit sector number should fit in our buffer */
1597 cc->iv_size = max(cc->iv_size,
1598 (unsigned int)(sizeof(u64) / sizeof(u8)));
1599 else if (ivmode) {
1600 DMWARN("Selected cipher does not support IVs");
1601 ivmode = NULL;
1602 }
1603
1604 /* Choose ivmode, see comments at iv code. */
1605 if (ivmode == NULL)
1606 cc->iv_gen_ops = NULL;
1607 else if (strcmp(ivmode, "plain") == 0)
1608 cc->iv_gen_ops = &crypt_iv_plain_ops;
1609 else if (strcmp(ivmode, "plain64") == 0)
1610 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1611 else if (strcmp(ivmode, "essiv") == 0)
1612 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1613 else if (strcmp(ivmode, "benbi") == 0)
1614 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1615 else if (strcmp(ivmode, "null") == 0)
1616 cc->iv_gen_ops = &crypt_iv_null_ops;
1617 else if (strcmp(ivmode, "lmk") == 0) {
1618 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1619 /*
1620 * Version 2 and 3 is recognised according
1621 * to length of provided multi-key string.
1622 * If present (version 3), last key is used as IV seed.
1623 * All keys (including IV seed) are always the same size.
1624 */
1625 if (cc->key_size % cc->key_parts) {
1626 cc->key_parts++;
1627 cc->key_extra_size = cc->key_size / cc->key_parts;
1628 }
1629 } else if (strcmp(ivmode, "tcw") == 0) {
1630 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1631 cc->key_parts += 2; /* IV + whitening */
1632 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1633 } else {
1634 ret = -EINVAL;
1635 ti->error = "Invalid IV mode";
1636 goto bad;
1637 }
1638
1639 /* Initialize and set key */
1640 ret = crypt_set_key(cc, key);
1641 if (ret < 0) {
1642 ti->error = "Error decoding and setting key";
1643 goto bad;
1644 }
1645
1646 /* Allocate IV */
1647 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1648 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1649 if (ret < 0) {
1650 ti->error = "Error creating IV";
1651 goto bad;
1652 }
1653 }
1654
1655 /* Initialize IV (set keys for ESSIV etc) */
1656 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1657 ret = cc->iv_gen_ops->init(cc);
1658 if (ret < 0) {
1659 ti->error = "Error initialising IV";
1660 goto bad;
1661 }
1662 }
1663
1664 ret = 0;
1665bad:
1666 kfree(cipher_api);
1667 return ret;
1668
1669bad_mem:
1670 ti->error = "Cannot allocate cipher strings";
1671 return -ENOMEM;
1672}
1673
1674/*
1675 * Construct an encryption mapping:
1676 * <cipher> <key> <iv_offset> <dev_path> <start>
1677 */
1678static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1679{
1680 struct crypt_config *cc;
1681 unsigned int key_size, opt_params;
1682 unsigned long long tmpll;
1683 int ret;
1684 struct dm_arg_set as;
1685 const char *opt_string;
1686 char dummy;
1687
1688 static struct dm_arg _args[] = {
1689 {0, 1, "Invalid number of feature args"},
1690 };
1691
1692 if (argc < 5) {
1693 ti->error = "Not enough arguments";
1694 return -EINVAL;
1695 }
1696
1697 key_size = strlen(argv[1]) >> 1;
1698
1699 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1700 if (!cc) {
1701 ti->error = "Cannot allocate encryption context";
1702 return -ENOMEM;
1703 }
1704 cc->key_size = key_size;
1705
1706 ti->private = cc;
1707 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1708 if (ret < 0)
1709 goto bad;
1710
1711 ret = -ENOMEM;
1712 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
1713 if (!cc->io_pool) {
1714 ti->error = "Cannot allocate crypt io mempool";
1715 goto bad;
1716 }
1717
1718 cc->dmreq_start = sizeof(struct ablkcipher_request);
1719 cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1720 cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
1721 cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) &
1722 ~(crypto_tfm_ctx_alignment() - 1);
1723
1724 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1725 sizeof(struct dm_crypt_request) + cc->iv_size);
1726 if (!cc->req_pool) {
1727 ti->error = "Cannot allocate crypt request mempool";
1728 goto bad;
1729 }
1730
1731 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
1732 if (!cc->page_pool) {
1733 ti->error = "Cannot allocate page mempool";
1734 goto bad;
1735 }
1736
1737 cc->bs = bioset_create(MIN_IOS, 0);
1738 if (!cc->bs) {
1739 ti->error = "Cannot allocate crypt bioset";
1740 goto bad;
1741 }
1742
1743 ret = -EINVAL;
1744 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1745 ti->error = "Invalid iv_offset sector";
1746 goto bad;
1747 }
1748 cc->iv_offset = tmpll;
1749
1750 if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
1751 ti->error = "Device lookup failed";
1752 goto bad;
1753 }
1754
1755 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1756 ti->error = "Invalid device sector";
1757 goto bad;
1758 }
1759 cc->start = tmpll;
1760
1761 argv += 5;
1762 argc -= 5;
1763
1764 /* Optional parameters */
1765 if (argc) {
1766 as.argc = argc;
1767 as.argv = argv;
1768
1769 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1770 if (ret)
1771 goto bad;
1772
1773 opt_string = dm_shift_arg(&as);
1774
1775 if (opt_params == 1 && opt_string &&
1776 !strcasecmp(opt_string, "allow_discards"))
1777 ti->num_discard_bios = 1;
1778 else if (opt_params) {
1779 ret = -EINVAL;
1780 ti->error = "Invalid feature arguments";
1781 goto bad;
1782 }
1783 }
1784
1785 ret = -ENOMEM;
1786 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1787 if (!cc->io_queue) {
1788 ti->error = "Couldn't create kcryptd io queue";
1789 goto bad;
1790 }
1791
1792 cc->crypt_queue = alloc_workqueue("kcryptd",
1793 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1794 if (!cc->crypt_queue) {
1795 ti->error = "Couldn't create kcryptd queue";
1796 goto bad;
1797 }
1798
1799 ti->num_flush_bios = 1;
1800 ti->discard_zeroes_data_unsupported = true;
1801
1802 return 0;
1803
1804bad:
1805 crypt_dtr(ti);
1806 return ret;
1807}
1808
1809static int crypt_map(struct dm_target *ti, struct bio *bio)
1810{
1811 struct dm_crypt_io *io;
1812 struct crypt_config *cc = ti->private;
1813
1814 /*
1815 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1816 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1817 * - for REQ_DISCARD caller must use flush if IO ordering matters
1818 */
1819 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1820 bio->bi_bdev = cc->dev->bdev;
1821 if (bio_sectors(bio))
1822 bio->bi_iter.bi_sector = cc->start +
1823 dm_target_offset(ti, bio->bi_iter.bi_sector);
1824 return DM_MAPIO_REMAPPED;
1825 }
1826
1827 io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
1828
1829 if (bio_data_dir(io->base_bio) == READ) {
1830 if (kcryptd_io_read(io, GFP_NOWAIT))
1831 kcryptd_queue_io(io);
1832 } else
1833 kcryptd_queue_crypt(io);
1834
1835 return DM_MAPIO_SUBMITTED;
1836}
1837
1838static void crypt_status(struct dm_target *ti, status_type_t type,
1839 unsigned status_flags, char *result, unsigned maxlen)
1840{
1841 struct crypt_config *cc = ti->private;
1842 unsigned i, sz = 0;
1843
1844 switch (type) {
1845 case STATUSTYPE_INFO:
1846 result[0] = '\0';
1847 break;
1848
1849 case STATUSTYPE_TABLE:
1850 DMEMIT("%s ", cc->cipher_string);
1851
1852 if (cc->key_size > 0)
1853 for (i = 0; i < cc->key_size; i++)
1854 DMEMIT("%02x", cc->key[i]);
1855 else
1856 DMEMIT("-");
1857
1858 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1859 cc->dev->name, (unsigned long long)cc->start);
1860
1861 if (ti->num_discard_bios)
1862 DMEMIT(" 1 allow_discards");
1863
1864 break;
1865 }
1866}
1867
1868static void crypt_postsuspend(struct dm_target *ti)
1869{
1870 struct crypt_config *cc = ti->private;
1871
1872 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1873}
1874
1875static int crypt_preresume(struct dm_target *ti)
1876{
1877 struct crypt_config *cc = ti->private;
1878
1879 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1880 DMERR("aborting resume - crypt key is not set.");
1881 return -EAGAIN;
1882 }
1883
1884 return 0;
1885}
1886
1887static void crypt_resume(struct dm_target *ti)
1888{
1889 struct crypt_config *cc = ti->private;
1890
1891 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1892}
1893
1894/* Message interface
1895 * key set <key>
1896 * key wipe
1897 */
1898static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1899{
1900 struct crypt_config *cc = ti->private;
1901 int ret = -EINVAL;
1902
1903 if (argc < 2)
1904 goto error;
1905
1906 if (!strcasecmp(argv[0], "key")) {
1907 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1908 DMWARN("not suspended during key manipulation.");
1909 return -EINVAL;
1910 }
1911 if (argc == 3 && !strcasecmp(argv[1], "set")) {
1912 ret = crypt_set_key(cc, argv[2]);
1913 if (ret)
1914 return ret;
1915 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
1916 ret = cc->iv_gen_ops->init(cc);
1917 return ret;
1918 }
1919 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
1920 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
1921 ret = cc->iv_gen_ops->wipe(cc);
1922 if (ret)
1923 return ret;
1924 }
1925 return crypt_wipe_key(cc);
1926 }
1927 }
1928
1929error:
1930 DMWARN("unrecognised message received.");
1931 return -EINVAL;
1932}
1933
1934static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1935 struct bio_vec *biovec, int max_size)
1936{
1937 struct crypt_config *cc = ti->private;
1938 struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1939
1940 if (!q->merge_bvec_fn)
1941 return max_size;
1942
1943 bvm->bi_bdev = cc->dev->bdev;
1944 bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
1945
1946 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
1947}
1948
1949static int crypt_iterate_devices(struct dm_target *ti,
1950 iterate_devices_callout_fn fn, void *data)
1951{
1952 struct crypt_config *cc = ti->private;
1953
1954 return fn(ti, cc->dev, cc->start, ti->len, data);
1955}
1956
1957static struct target_type crypt_target = {
1958 .name = "crypt",
1959 .version = {1, 13, 0},
1960 .module = THIS_MODULE,
1961 .ctr = crypt_ctr,
1962 .dtr = crypt_dtr,
1963 .map = crypt_map,
1964 .status = crypt_status,
1965 .postsuspend = crypt_postsuspend,
1966 .preresume = crypt_preresume,
1967 .resume = crypt_resume,
1968 .message = crypt_message,
1969 .merge = crypt_merge,
1970 .iterate_devices = crypt_iterate_devices,
1971};
1972
1973static int __init dm_crypt_init(void)
1974{
1975 int r;
1976
1977 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1978 if (!_crypt_io_pool)
1979 return -ENOMEM;
1980
1981 r = dm_register_target(&crypt_target);
1982 if (r < 0) {
1983 DMERR("register failed %d", r);
1984 kmem_cache_destroy(_crypt_io_pool);
1985 }
1986
1987 return r;
1988}
1989
1990static void __exit dm_crypt_exit(void)
1991{
1992 dm_unregister_target(&crypt_target);
1993 kmem_cache_destroy(_crypt_io_pool);
1994}
1995
1996module_init(dm_crypt_init);
1997module_exit(dm_crypt_exit);
1998
1999MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
2000MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2001MODULE_LICENSE("GPL");