dm rq: cope with DM device destruction while in dm_old_request_fn()
[linux-2.6-block.git] / drivers / md / dm-crypt.c
CommitLineData
1da177e4 1/*
bf14299f 2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
1da177e4 3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
54cea3f6 4 * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved.
ed04d981 5 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
1da177e4
LT
6 *
7 * This file is released under the GPL.
8 */
9
43d69034 10#include <linux/completion.h>
d1806f6a 11#include <linux/err.h>
1da177e4
LT
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
c538f6ec 15#include <linux/key.h>
1da177e4
LT
16#include <linux/bio.h>
17#include <linux/blkdev.h>
18#include <linux/mempool.h>
19#include <linux/slab.h>
20#include <linux/crypto.h>
21#include <linux/workqueue.h>
dc267621 22#include <linux/kthread.h>
3fcfab16 23#include <linux/backing-dev.h>
60063497 24#include <linux/atomic.h>
378f058c 25#include <linux/scatterlist.h>
b3c5fd30 26#include <linux/rbtree.h>
027c431c 27#include <linux/ctype.h>
1da177e4 28#include <asm/page.h>
48527fa7 29#include <asm/unaligned.h>
34745785
MB
30#include <crypto/hash.h>
31#include <crypto/md5.h>
32#include <crypto/algapi.h>
bbdb23b5 33#include <crypto/skcipher.h>
c538f6ec 34#include <keys/user-type.h>
1da177e4 35
586e80e6 36#include <linux/device-mapper.h>
1da177e4 37
72d94861 38#define DM_MSG_PREFIX "crypt"
1da177e4 39
1da177e4
LT
40/*
41 * context holding the current state of a multi-part conversion
42 */
43struct convert_context {
43d69034 44 struct completion restart;
1da177e4
LT
45 struct bio *bio_in;
46 struct bio *bio_out;
003b5c57
KO
47 struct bvec_iter iter_in;
48 struct bvec_iter iter_out;
c66029f4 49 sector_t cc_sector;
40b6229b 50 atomic_t cc_pending;
bbdb23b5 51 struct skcipher_request *req;
1da177e4
LT
52};
53
53017030
MB
54/*
55 * per bio private data
56 */
57struct dm_crypt_io {
49a8a920 58 struct crypt_config *cc;
53017030
MB
59 struct bio *base_bio;
60 struct work_struct work;
61
62 struct convert_context ctx;
63
40b6229b 64 atomic_t io_pending;
53017030 65 int error;
0c395b0f 66 sector_t sector;
dc267621 67
b3c5fd30 68 struct rb_node rb_node;
298a9fa0 69} CRYPTO_MINALIGN_ATTR;
53017030 70
01482b76 71struct dm_crypt_request {
b2174eeb 72 struct convert_context *ctx;
01482b76
MB
73 struct scatterlist sg_in;
74 struct scatterlist sg_out;
2dc5327d 75 sector_t iv_sector;
01482b76
MB
76};
77
1da177e4
LT
78struct crypt_config;
79
80struct crypt_iv_operations {
81 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
d469f841 82 const char *opts);
1da177e4 83 void (*dtr)(struct crypt_config *cc);
b95bf2d3 84 int (*init)(struct crypt_config *cc);
542da317 85 int (*wipe)(struct crypt_config *cc);
2dc5327d
MB
86 int (*generator)(struct crypt_config *cc, u8 *iv,
87 struct dm_crypt_request *dmreq);
88 int (*post)(struct crypt_config *cc, u8 *iv,
89 struct dm_crypt_request *dmreq);
1da177e4
LT
90};
91
60473592 92struct iv_essiv_private {
bbdb23b5 93 struct crypto_ahash *hash_tfm;
b95bf2d3 94 u8 *salt;
60473592
MB
95};
96
97struct iv_benbi_private {
98 int shift;
99};
100
34745785
MB
101#define LMK_SEED_SIZE 64 /* hash + 0 */
102struct iv_lmk_private {
103 struct crypto_shash *hash_tfm;
104 u8 *seed;
105};
106
ed04d981
MB
107#define TCW_WHITENING_SIZE 16
108struct iv_tcw_private {
109 struct crypto_shash *crc32_tfm;
110 u8 *iv_seed;
111 u8 *whitening;
112};
113
1da177e4
LT
114/*
115 * Crypt: maps a linear range of a block device
116 * and encrypts / decrypts at the same time.
117 */
0f5d8e6e 118enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
f659b100 119 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
c0297721
AK
120
121/*
610f2de3 122 * The fields in here must be read only after initialization.
c0297721 123 */
1da177e4
LT
124struct crypt_config {
125 struct dm_dev *dev;
126 sector_t start;
127
128 /*
ddd42edf
MB
129 * pool for per bio private data, crypto requests and
130 * encryption requeusts/buffer pages
1da177e4 131 */
ddd42edf 132 mempool_t *req_pool;
1da177e4 133 mempool_t *page_pool;
6a24c718 134 struct bio_set *bs;
7145c241 135 struct mutex bio_alloc_lock;
1da177e4 136
cabf08e4
MB
137 struct workqueue_struct *io_queue;
138 struct workqueue_struct *crypt_queue;
3f1e9070 139
dc267621
MP
140 struct task_struct *write_thread;
141 wait_queue_head_t write_thread_wait;
b3c5fd30 142 struct rb_root write_tree;
dc267621 143
5ebaee6d 144 char *cipher;
7dbcd137 145 char *cipher_string;
c538f6ec 146 char *key_string;
5ebaee6d 147
1b1b58f5 148 const struct crypt_iv_operations *iv_gen_ops;
79066ad3 149 union {
60473592
MB
150 struct iv_essiv_private essiv;
151 struct iv_benbi_private benbi;
34745785 152 struct iv_lmk_private lmk;
ed04d981 153 struct iv_tcw_private tcw;
79066ad3 154 } iv_gen_private;
1da177e4
LT
155 sector_t iv_offset;
156 unsigned int iv_size;
157
fd2d231f
MP
158 /* ESSIV: struct crypto_cipher *essiv_tfm */
159 void *iv_private;
bbdb23b5 160 struct crypto_skcipher **tfms;
d1f96423 161 unsigned tfms_count;
c0297721 162
ddd42edf
MB
163 /*
164 * Layout of each crypto request:
165 *
bbdb23b5 166 * struct skcipher_request
ddd42edf
MB
167 * context
168 * padding
169 * struct dm_crypt_request
170 * padding
171 * IV
172 *
173 * The padding is added so that dm_crypt_request and the IV are
174 * correctly aligned.
175 */
176 unsigned int dmreq_start;
ddd42edf 177
298a9fa0
MP
178 unsigned int per_bio_data_size;
179
e48d4bbf 180 unsigned long flags;
1da177e4 181 unsigned int key_size;
da31a078
MB
182 unsigned int key_parts; /* independent parts in key buffer */
183 unsigned int key_extra_size; /* additional keys length */
1da177e4
LT
184 u8 key[0];
185};
186
0a83df6c 187#define MIN_IOS 64
1da177e4 188
028867ac 189static void clone_init(struct dm_crypt_io *, struct bio *);
395b167c 190static void kcryptd_queue_crypt(struct dm_crypt_io *io);
2dc5327d 191static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
027581f3 192
c0297721
AK
193/*
194 * Use this to access cipher attributes that are the same for each CPU.
195 */
bbdb23b5 196static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
c0297721 197{
fd2d231f 198 return cc->tfms[0];
c0297721
AK
199}
200
1da177e4
LT
201/*
202 * Different IV generation algorithms:
203 *
3c164bd8 204 * plain: the initial vector is the 32-bit little-endian version of the sector
3a4fa0a2 205 * number, padded with zeros if necessary.
1da177e4 206 *
61afef61
MB
207 * plain64: the initial vector is the 64-bit little-endian version of the sector
208 * number, padded with zeros if necessary.
209 *
3c164bd8
RS
210 * essiv: "encrypted sector|salt initial vector", the sector number is
211 * encrypted with the bulk cipher using a salt as key. The salt
212 * should be derived from the bulk cipher's key via hashing.
1da177e4 213 *
48527fa7
RS
214 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
215 * (needed for LRW-32-AES and possible other narrow block modes)
216 *
46b47730
LN
217 * null: the initial vector is always zero. Provides compatibility with
218 * obsolete loop_fish2 devices. Do not use for new devices.
219 *
34745785
MB
220 * lmk: Compatible implementation of the block chaining mode used
221 * by the Loop-AES block device encryption system
222 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
223 * It operates on full 512 byte sectors and uses CBC
224 * with an IV derived from the sector number, the data and
225 * optionally extra IV seed.
226 * This means that after decryption the first block
227 * of sector must be tweaked according to decrypted data.
228 * Loop-AES can use three encryption schemes:
229 * version 1: is plain aes-cbc mode
230 * version 2: uses 64 multikey scheme with lmk IV generator
231 * version 3: the same as version 2 with additional IV seed
232 * (it uses 65 keys, last key is used as IV seed)
233 *
ed04d981
MB
234 * tcw: Compatible implementation of the block chaining mode used
235 * by the TrueCrypt device encryption system (prior to version 4.1).
e44f23b3 236 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
ed04d981
MB
237 * It operates on full 512 byte sectors and uses CBC
238 * with an IV derived from initial key and the sector number.
239 * In addition, whitening value is applied on every sector, whitening
240 * is calculated from initial key, sector number and mixed using CRC32.
241 * Note that this encryption scheme is vulnerable to watermarking attacks
242 * and should be used for old compatible containers access only.
243 *
1da177e4
LT
244 * plumb: unimplemented, see:
245 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
246 */
247
2dc5327d
MB
248static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
249 struct dm_crypt_request *dmreq)
1da177e4
LT
250{
251 memset(iv, 0, cc->iv_size);
283a8328 252 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
1da177e4
LT
253
254 return 0;
255}
256
61afef61 257static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
2dc5327d 258 struct dm_crypt_request *dmreq)
61afef61
MB
259{
260 memset(iv, 0, cc->iv_size);
283a8328 261 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
61afef61
MB
262
263 return 0;
264}
265
b95bf2d3
MB
266/* Initialise ESSIV - compute salt but no local memory allocations */
267static int crypt_iv_essiv_init(struct crypt_config *cc)
268{
269 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
bbdb23b5 270 AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
b95bf2d3 271 struct scatterlist sg;
c0297721 272 struct crypto_cipher *essiv_tfm;
fd2d231f 273 int err;
b95bf2d3
MB
274
275 sg_init_one(&sg, cc->key, cc->key_size);
bbdb23b5
HX
276 ahash_request_set_tfm(req, essiv->hash_tfm);
277 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
278 ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
b95bf2d3 279
bbdb23b5
HX
280 err = crypto_ahash_digest(req);
281 ahash_request_zero(req);
b95bf2d3
MB
282 if (err)
283 return err;
284
fd2d231f 285 essiv_tfm = cc->iv_private;
c0297721 286
fd2d231f 287 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
bbdb23b5 288 crypto_ahash_digestsize(essiv->hash_tfm));
fd2d231f
MP
289 if (err)
290 return err;
c0297721
AK
291
292 return 0;
b95bf2d3
MB
293}
294
542da317
MB
295/* Wipe salt and reset key derived from volume key */
296static int crypt_iv_essiv_wipe(struct crypt_config *cc)
297{
298 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
bbdb23b5 299 unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
c0297721 300 struct crypto_cipher *essiv_tfm;
fd2d231f 301 int r, err = 0;
542da317
MB
302
303 memset(essiv->salt, 0, salt_size);
304
fd2d231f
MP
305 essiv_tfm = cc->iv_private;
306 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
307 if (r)
308 err = r;
c0297721
AK
309
310 return err;
311}
312
313/* Set up per cpu cipher state */
314static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
315 struct dm_target *ti,
316 u8 *salt, unsigned saltsize)
317{
318 struct crypto_cipher *essiv_tfm;
319 int err;
320
321 /* Setup the essiv_tfm with the given salt */
322 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
323 if (IS_ERR(essiv_tfm)) {
324 ti->error = "Error allocating crypto tfm for ESSIV";
325 return essiv_tfm;
326 }
327
328 if (crypto_cipher_blocksize(essiv_tfm) !=
bbdb23b5 329 crypto_skcipher_ivsize(any_tfm(cc))) {
c0297721
AK
330 ti->error = "Block size of ESSIV cipher does "
331 "not match IV size of block cipher";
332 crypto_free_cipher(essiv_tfm);
333 return ERR_PTR(-EINVAL);
334 }
335
336 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
337 if (err) {
338 ti->error = "Failed to set key for ESSIV cipher";
339 crypto_free_cipher(essiv_tfm);
340 return ERR_PTR(err);
341 }
342
343 return essiv_tfm;
542da317
MB
344}
345
60473592
MB
346static void crypt_iv_essiv_dtr(struct crypt_config *cc)
347{
c0297721 348 struct crypto_cipher *essiv_tfm;
60473592
MB
349 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
350
bbdb23b5 351 crypto_free_ahash(essiv->hash_tfm);
b95bf2d3
MB
352 essiv->hash_tfm = NULL;
353
354 kzfree(essiv->salt);
355 essiv->salt = NULL;
c0297721 356
fd2d231f 357 essiv_tfm = cc->iv_private;
c0297721 358
fd2d231f
MP
359 if (essiv_tfm)
360 crypto_free_cipher(essiv_tfm);
c0297721 361
fd2d231f 362 cc->iv_private = NULL;
60473592
MB
363}
364
1da177e4 365static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
d469f841 366 const char *opts)
1da177e4 367{
5861f1be 368 struct crypto_cipher *essiv_tfm = NULL;
bbdb23b5 369 struct crypto_ahash *hash_tfm = NULL;
5861f1be 370 u8 *salt = NULL;
fd2d231f 371 int err;
1da177e4 372
5861f1be 373 if (!opts) {
72d94861 374 ti->error = "Digest algorithm missing for ESSIV mode";
1da177e4
LT
375 return -EINVAL;
376 }
377
b95bf2d3 378 /* Allocate hash algorithm */
bbdb23b5 379 hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
35058687 380 if (IS_ERR(hash_tfm)) {
72d94861 381 ti->error = "Error initializing ESSIV hash";
5861f1be
MB
382 err = PTR_ERR(hash_tfm);
383 goto bad;
1da177e4
LT
384 }
385
bbdb23b5 386 salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
5861f1be 387 if (!salt) {
72d94861 388 ti->error = "Error kmallocing salt storage in ESSIV";
5861f1be
MB
389 err = -ENOMEM;
390 goto bad;
1da177e4
LT
391 }
392
b95bf2d3 393 cc->iv_gen_private.essiv.salt = salt;
b95bf2d3
MB
394 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
395
fd2d231f 396 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
bbdb23b5 397 crypto_ahash_digestsize(hash_tfm));
fd2d231f
MP
398 if (IS_ERR(essiv_tfm)) {
399 crypt_iv_essiv_dtr(cc);
400 return PTR_ERR(essiv_tfm);
c0297721 401 }
fd2d231f 402 cc->iv_private = essiv_tfm;
c0297721 403
1da177e4 404 return 0;
5861f1be
MB
405
406bad:
5861f1be 407 if (hash_tfm && !IS_ERR(hash_tfm))
bbdb23b5 408 crypto_free_ahash(hash_tfm);
b95bf2d3 409 kfree(salt);
5861f1be 410 return err;
1da177e4
LT
411}
412
2dc5327d
MB
413static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
414 struct dm_crypt_request *dmreq)
1da177e4 415{
fd2d231f 416 struct crypto_cipher *essiv_tfm = cc->iv_private;
c0297721 417
1da177e4 418 memset(iv, 0, cc->iv_size);
283a8328 419 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
c0297721
AK
420 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
421
1da177e4
LT
422 return 0;
423}
424
48527fa7
RS
425static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
426 const char *opts)
427{
bbdb23b5 428 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
f0d1b0b3 429 int log = ilog2(bs);
48527fa7
RS
430
431 /* we need to calculate how far we must shift the sector count
432 * to get the cipher block count, we use this shift in _gen */
433
434 if (1 << log != bs) {
435 ti->error = "cypher blocksize is not a power of 2";
436 return -EINVAL;
437 }
438
439 if (log > 9) {
440 ti->error = "cypher blocksize is > 512";
441 return -EINVAL;
442 }
443
60473592 444 cc->iv_gen_private.benbi.shift = 9 - log;
48527fa7
RS
445
446 return 0;
447}
448
449static void crypt_iv_benbi_dtr(struct crypt_config *cc)
450{
48527fa7
RS
451}
452
2dc5327d
MB
453static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
454 struct dm_crypt_request *dmreq)
48527fa7 455{
79066ad3
HX
456 __be64 val;
457
48527fa7 458 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
79066ad3 459
2dc5327d 460 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
79066ad3 461 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
48527fa7 462
1da177e4
LT
463 return 0;
464}
465
2dc5327d
MB
466static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
467 struct dm_crypt_request *dmreq)
46b47730
LN
468{
469 memset(iv, 0, cc->iv_size);
470
471 return 0;
472}
473
34745785
MB
474static void crypt_iv_lmk_dtr(struct crypt_config *cc)
475{
476 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
477
478 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
479 crypto_free_shash(lmk->hash_tfm);
480 lmk->hash_tfm = NULL;
481
482 kzfree(lmk->seed);
483 lmk->seed = NULL;
484}
485
486static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
487 const char *opts)
488{
489 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
490
491 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
492 if (IS_ERR(lmk->hash_tfm)) {
493 ti->error = "Error initializing LMK hash";
494 return PTR_ERR(lmk->hash_tfm);
495 }
496
497 /* No seed in LMK version 2 */
498 if (cc->key_parts == cc->tfms_count) {
499 lmk->seed = NULL;
500 return 0;
501 }
502
503 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
504 if (!lmk->seed) {
505 crypt_iv_lmk_dtr(cc);
506 ti->error = "Error kmallocing seed storage in LMK";
507 return -ENOMEM;
508 }
509
510 return 0;
511}
512
513static int crypt_iv_lmk_init(struct crypt_config *cc)
514{
515 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
516 int subkey_size = cc->key_size / cc->key_parts;
517
518 /* LMK seed is on the position of LMK_KEYS + 1 key */
519 if (lmk->seed)
520 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
521 crypto_shash_digestsize(lmk->hash_tfm));
522
523 return 0;
524}
525
526static int crypt_iv_lmk_wipe(struct crypt_config *cc)
527{
528 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
529
530 if (lmk->seed)
531 memset(lmk->seed, 0, LMK_SEED_SIZE);
532
533 return 0;
534}
535
536static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
537 struct dm_crypt_request *dmreq,
538 u8 *data)
539{
540 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
b6106265 541 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
34745785 542 struct md5_state md5state;
da31a078 543 __le32 buf[4];
34745785
MB
544 int i, r;
545
b6106265
JSM
546 desc->tfm = lmk->hash_tfm;
547 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
34745785 548
b6106265 549 r = crypto_shash_init(desc);
34745785
MB
550 if (r)
551 return r;
552
553 if (lmk->seed) {
b6106265 554 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
34745785
MB
555 if (r)
556 return r;
557 }
558
559 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
b6106265 560 r = crypto_shash_update(desc, data + 16, 16 * 31);
34745785
MB
561 if (r)
562 return r;
563
564 /* Sector is cropped to 56 bits here */
565 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
566 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
567 buf[2] = cpu_to_le32(4024);
568 buf[3] = 0;
b6106265 569 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
34745785
MB
570 if (r)
571 return r;
572
573 /* No MD5 padding here */
b6106265 574 r = crypto_shash_export(desc, &md5state);
34745785
MB
575 if (r)
576 return r;
577
578 for (i = 0; i < MD5_HASH_WORDS; i++)
579 __cpu_to_le32s(&md5state.hash[i]);
580 memcpy(iv, &md5state.hash, cc->iv_size);
581
582 return 0;
583}
584
585static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
586 struct dm_crypt_request *dmreq)
587{
588 u8 *src;
589 int r = 0;
590
591 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
c2e022cb 592 src = kmap_atomic(sg_page(&dmreq->sg_in));
34745785 593 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
c2e022cb 594 kunmap_atomic(src);
34745785
MB
595 } else
596 memset(iv, 0, cc->iv_size);
597
598 return r;
599}
600
601static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
602 struct dm_crypt_request *dmreq)
603{
604 u8 *dst;
605 int r;
606
607 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
608 return 0;
609
c2e022cb 610 dst = kmap_atomic(sg_page(&dmreq->sg_out));
34745785
MB
611 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
612
613 /* Tweak the first block of plaintext sector */
614 if (!r)
615 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
616
c2e022cb 617 kunmap_atomic(dst);
34745785
MB
618 return r;
619}
620
ed04d981
MB
621static void crypt_iv_tcw_dtr(struct crypt_config *cc)
622{
623 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
624
625 kzfree(tcw->iv_seed);
626 tcw->iv_seed = NULL;
627 kzfree(tcw->whitening);
628 tcw->whitening = NULL;
629
630 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
631 crypto_free_shash(tcw->crc32_tfm);
632 tcw->crc32_tfm = NULL;
633}
634
635static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
636 const char *opts)
637{
638 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
639
640 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
641 ti->error = "Wrong key size for TCW";
642 return -EINVAL;
643 }
644
645 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
646 if (IS_ERR(tcw->crc32_tfm)) {
647 ti->error = "Error initializing CRC32 in TCW";
648 return PTR_ERR(tcw->crc32_tfm);
649 }
650
651 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
652 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
653 if (!tcw->iv_seed || !tcw->whitening) {
654 crypt_iv_tcw_dtr(cc);
655 ti->error = "Error allocating seed storage in TCW";
656 return -ENOMEM;
657 }
658
659 return 0;
660}
661
662static int crypt_iv_tcw_init(struct crypt_config *cc)
663{
664 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
665 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
666
667 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
668 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
669 TCW_WHITENING_SIZE);
670
671 return 0;
672}
673
674static int crypt_iv_tcw_wipe(struct crypt_config *cc)
675{
676 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
677
678 memset(tcw->iv_seed, 0, cc->iv_size);
679 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
680
681 return 0;
682}
683
684static int crypt_iv_tcw_whitening(struct crypt_config *cc,
685 struct dm_crypt_request *dmreq,
686 u8 *data)
687{
688 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
350b5393 689 __le64 sector = cpu_to_le64(dmreq->iv_sector);
ed04d981 690 u8 buf[TCW_WHITENING_SIZE];
b6106265 691 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
ed04d981
MB
692 int i, r;
693
694 /* xor whitening with sector number */
695 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
696 crypto_xor(buf, (u8 *)&sector, 8);
697 crypto_xor(&buf[8], (u8 *)&sector, 8);
698
699 /* calculate crc32 for every 32bit part and xor it */
b6106265
JSM
700 desc->tfm = tcw->crc32_tfm;
701 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
ed04d981 702 for (i = 0; i < 4; i++) {
b6106265 703 r = crypto_shash_init(desc);
ed04d981
MB
704 if (r)
705 goto out;
b6106265 706 r = crypto_shash_update(desc, &buf[i * 4], 4);
ed04d981
MB
707 if (r)
708 goto out;
b6106265 709 r = crypto_shash_final(desc, &buf[i * 4]);
ed04d981
MB
710 if (r)
711 goto out;
712 }
713 crypto_xor(&buf[0], &buf[12], 4);
714 crypto_xor(&buf[4], &buf[8], 4);
715
716 /* apply whitening (8 bytes) to whole sector */
717 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
718 crypto_xor(data + i * 8, buf, 8);
719out:
1a71d6ff 720 memzero_explicit(buf, sizeof(buf));
ed04d981
MB
721 return r;
722}
723
724static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
725 struct dm_crypt_request *dmreq)
726{
727 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
350b5393 728 __le64 sector = cpu_to_le64(dmreq->iv_sector);
ed04d981
MB
729 u8 *src;
730 int r = 0;
731
732 /* Remove whitening from ciphertext */
733 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
734 src = kmap_atomic(sg_page(&dmreq->sg_in));
735 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
736 kunmap_atomic(src);
737 }
738
739 /* Calculate IV */
740 memcpy(iv, tcw->iv_seed, cc->iv_size);
741 crypto_xor(iv, (u8 *)&sector, 8);
742 if (cc->iv_size > 8)
743 crypto_xor(&iv[8], (u8 *)&sector, cc->iv_size - 8);
744
745 return r;
746}
747
748static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
749 struct dm_crypt_request *dmreq)
750{
751 u8 *dst;
752 int r;
753
754 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
755 return 0;
756
757 /* Apply whitening on ciphertext */
758 dst = kmap_atomic(sg_page(&dmreq->sg_out));
759 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
760 kunmap_atomic(dst);
761
762 return r;
763}
764
1b1b58f5 765static const struct crypt_iv_operations crypt_iv_plain_ops = {
1da177e4
LT
766 .generator = crypt_iv_plain_gen
767};
768
1b1b58f5 769static const struct crypt_iv_operations crypt_iv_plain64_ops = {
61afef61
MB
770 .generator = crypt_iv_plain64_gen
771};
772
1b1b58f5 773static const struct crypt_iv_operations crypt_iv_essiv_ops = {
1da177e4
LT
774 .ctr = crypt_iv_essiv_ctr,
775 .dtr = crypt_iv_essiv_dtr,
b95bf2d3 776 .init = crypt_iv_essiv_init,
542da317 777 .wipe = crypt_iv_essiv_wipe,
1da177e4
LT
778 .generator = crypt_iv_essiv_gen
779};
780
1b1b58f5 781static const struct crypt_iv_operations crypt_iv_benbi_ops = {
48527fa7
RS
782 .ctr = crypt_iv_benbi_ctr,
783 .dtr = crypt_iv_benbi_dtr,
784 .generator = crypt_iv_benbi_gen
785};
1da177e4 786
1b1b58f5 787static const struct crypt_iv_operations crypt_iv_null_ops = {
46b47730
LN
788 .generator = crypt_iv_null_gen
789};
790
1b1b58f5 791static const struct crypt_iv_operations crypt_iv_lmk_ops = {
34745785
MB
792 .ctr = crypt_iv_lmk_ctr,
793 .dtr = crypt_iv_lmk_dtr,
794 .init = crypt_iv_lmk_init,
795 .wipe = crypt_iv_lmk_wipe,
796 .generator = crypt_iv_lmk_gen,
797 .post = crypt_iv_lmk_post
798};
799
1b1b58f5 800static const struct crypt_iv_operations crypt_iv_tcw_ops = {
ed04d981
MB
801 .ctr = crypt_iv_tcw_ctr,
802 .dtr = crypt_iv_tcw_dtr,
803 .init = crypt_iv_tcw_init,
804 .wipe = crypt_iv_tcw_wipe,
805 .generator = crypt_iv_tcw_gen,
806 .post = crypt_iv_tcw_post
807};
808
d469f841
MB
809static void crypt_convert_init(struct crypt_config *cc,
810 struct convert_context *ctx,
811 struct bio *bio_out, struct bio *bio_in,
fcd369da 812 sector_t sector)
1da177e4
LT
813{
814 ctx->bio_in = bio_in;
815 ctx->bio_out = bio_out;
003b5c57
KO
816 if (bio_in)
817 ctx->iter_in = bio_in->bi_iter;
818 if (bio_out)
819 ctx->iter_out = bio_out->bi_iter;
c66029f4 820 ctx->cc_sector = sector + cc->iv_offset;
43d69034 821 init_completion(&ctx->restart);
1da177e4
LT
822}
823
b2174eeb 824static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
bbdb23b5 825 struct skcipher_request *req)
b2174eeb
HY
826{
827 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
828}
829
bbdb23b5 830static struct skcipher_request *req_of_dmreq(struct crypt_config *cc,
b2174eeb
HY
831 struct dm_crypt_request *dmreq)
832{
bbdb23b5 833 return (struct skcipher_request *)((char *)dmreq - cc->dmreq_start);
b2174eeb
HY
834}
835
2dc5327d
MB
836static u8 *iv_of_dmreq(struct crypt_config *cc,
837 struct dm_crypt_request *dmreq)
838{
839 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
bbdb23b5 840 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
2dc5327d
MB
841}
842
01482b76 843static int crypt_convert_block(struct crypt_config *cc,
3a7f6c99 844 struct convert_context *ctx,
bbdb23b5 845 struct skcipher_request *req)
01482b76 846{
003b5c57
KO
847 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
848 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
3a7f6c99
MB
849 struct dm_crypt_request *dmreq;
850 u8 *iv;
40b6229b 851 int r;
3a7f6c99 852
b2174eeb 853 dmreq = dmreq_of_req(cc, req);
2dc5327d 854 iv = iv_of_dmreq(cc, dmreq);
01482b76 855
c66029f4 856 dmreq->iv_sector = ctx->cc_sector;
b2174eeb 857 dmreq->ctx = ctx;
3a7f6c99 858 sg_init_table(&dmreq->sg_in, 1);
003b5c57
KO
859 sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
860 bv_in.bv_offset);
01482b76 861
3a7f6c99 862 sg_init_table(&dmreq->sg_out, 1);
003b5c57
KO
863 sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
864 bv_out.bv_offset);
01482b76 865
003b5c57
KO
866 bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
867 bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
01482b76 868
3a7f6c99 869 if (cc->iv_gen_ops) {
2dc5327d 870 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
3a7f6c99
MB
871 if (r < 0)
872 return r;
873 }
874
bbdb23b5
HX
875 skcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
876 1 << SECTOR_SHIFT, iv);
3a7f6c99
MB
877
878 if (bio_data_dir(ctx->bio_in) == WRITE)
bbdb23b5 879 r = crypto_skcipher_encrypt(req);
3a7f6c99 880 else
bbdb23b5 881 r = crypto_skcipher_decrypt(req);
3a7f6c99 882
2dc5327d
MB
883 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
884 r = cc->iv_gen_ops->post(cc, iv, dmreq);
885
3a7f6c99 886 return r;
01482b76
MB
887}
888
95497a96
MB
889static void kcryptd_async_done(struct crypto_async_request *async_req,
890 int error);
c0297721 891
ddd42edf
MB
892static void crypt_alloc_req(struct crypt_config *cc,
893 struct convert_context *ctx)
894{
c66029f4 895 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
c0297721 896
610f2de3
MP
897 if (!ctx->req)
898 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
c0297721 899
bbdb23b5 900 skcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
54cea3f6
MB
901
902 /*
903 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
904 * requests if driver request queue is full.
905 */
bbdb23b5 906 skcipher_request_set_callback(ctx->req,
c0297721 907 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
610f2de3 908 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
ddd42edf
MB
909}
910
298a9fa0 911static void crypt_free_req(struct crypt_config *cc,
bbdb23b5 912 struct skcipher_request *req, struct bio *base_bio)
298a9fa0
MP
913{
914 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
915
bbdb23b5 916 if ((struct skcipher_request *)(io + 1) != req)
298a9fa0
MP
917 mempool_free(req, cc->req_pool);
918}
919
1da177e4
LT
920/*
921 * Encrypt / decrypt data from one bio to another one (can be the same one)
922 */
923static int crypt_convert(struct crypt_config *cc,
d469f841 924 struct convert_context *ctx)
1da177e4 925{
3f1e9070 926 int r;
1da177e4 927
40b6229b 928 atomic_set(&ctx->cc_pending, 1);
c8081618 929
003b5c57 930 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1da177e4 931
3a7f6c99
MB
932 crypt_alloc_req(cc, ctx);
933
40b6229b 934 atomic_inc(&ctx->cc_pending);
3f1e9070 935
610f2de3 936 r = crypt_convert_block(cc, ctx, ctx->req);
3a7f6c99
MB
937
938 switch (r) {
54cea3f6
MB
939 /*
940 * The request was queued by a crypto driver
941 * but the driver request queue is full, let's wait.
942 */
3a7f6c99
MB
943 case -EBUSY:
944 wait_for_completion(&ctx->restart);
16735d02 945 reinit_completion(&ctx->restart);
54cea3f6
MB
946 /* fall through */
947 /*
948 * The request is queued and processed asynchronously,
949 * completion function kcryptd_async_done() will be called.
950 */
c0403ec0 951 case -EINPROGRESS:
610f2de3 952 ctx->req = NULL;
c66029f4 953 ctx->cc_sector++;
3f1e9070 954 continue;
54cea3f6
MB
955 /*
956 * The request was already processed (synchronously).
957 */
3a7f6c99 958 case 0:
40b6229b 959 atomic_dec(&ctx->cc_pending);
c66029f4 960 ctx->cc_sector++;
c7f1b204 961 cond_resched();
3a7f6c99 962 continue;
3a7f6c99 963
54cea3f6 964 /* There was an error while processing the request. */
3f1e9070 965 default:
40b6229b 966 atomic_dec(&ctx->cc_pending);
3f1e9070
MB
967 return r;
968 }
1da177e4
LT
969 }
970
3f1e9070 971 return 0;
1da177e4
LT
972}
973
cf2f1abf
MP
974static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
975
1da177e4
LT
976/*
977 * Generate a new unfragmented bio with the given size
586b286b
MS
978 * This should never violate the device limitations (but only because
979 * max_segment_size is being constrained to PAGE_SIZE).
7145c241
MP
980 *
981 * This function may be called concurrently. If we allocate from the mempool
982 * concurrently, there is a possibility of deadlock. For example, if we have
983 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
984 * the mempool concurrently, it may deadlock in a situation where both processes
985 * have allocated 128 pages and the mempool is exhausted.
986 *
987 * In order to avoid this scenario we allocate the pages under a mutex.
988 *
989 * In order to not degrade performance with excessive locking, we try
990 * non-blocking allocations without a mutex first but on failure we fallback
991 * to blocking allocations with a mutex.
1da177e4 992 */
cf2f1abf 993static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1da177e4 994{
49a8a920 995 struct crypt_config *cc = io->cc;
8b004457 996 struct bio *clone;
1da177e4 997 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
7145c241
MP
998 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
999 unsigned i, len, remaining_size;
91e10625 1000 struct page *page;
1da177e4 1001
7145c241 1002retry:
d0164adc 1003 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
7145c241
MP
1004 mutex_lock(&cc->bio_alloc_lock);
1005
2f9941b6 1006 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
8b004457 1007 if (!clone)
7145c241 1008 goto return_clone;
1da177e4 1009
027581f3 1010 clone_init(io, clone);
6a24c718 1011
7145c241
MP
1012 remaining_size = size;
1013
f97380bc 1014 for (i = 0; i < nr_iovecs; i++) {
91e10625 1015 page = mempool_alloc(cc->page_pool, gfp_mask);
7145c241
MP
1016 if (!page) {
1017 crypt_free_buffer_pages(cc, clone);
1018 bio_put(clone);
d0164adc 1019 gfp_mask |= __GFP_DIRECT_RECLAIM;
7145c241
MP
1020 goto retry;
1021 }
1da177e4 1022
7145c241 1023 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
91e10625 1024
0dae7fe5 1025 bio_add_page(clone, page, len, 0);
1da177e4 1026
7145c241 1027 remaining_size -= len;
1da177e4
LT
1028 }
1029
7145c241 1030return_clone:
d0164adc 1031 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
7145c241
MP
1032 mutex_unlock(&cc->bio_alloc_lock);
1033
8b004457 1034 return clone;
1da177e4
LT
1035}
1036
644bd2f0 1037static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1da177e4 1038{
644bd2f0 1039 unsigned int i;
1da177e4
LT
1040 struct bio_vec *bv;
1041
cb34e057 1042 bio_for_each_segment_all(bv, clone, i) {
1da177e4
LT
1043 BUG_ON(!bv->bv_page);
1044 mempool_free(bv->bv_page, cc->page_pool);
1045 bv->bv_page = NULL;
1046 }
1047}
1048
298a9fa0
MP
1049static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1050 struct bio *bio, sector_t sector)
dc440d1e 1051{
49a8a920 1052 io->cc = cc;
dc440d1e
MB
1053 io->base_bio = bio;
1054 io->sector = sector;
1055 io->error = 0;
610f2de3 1056 io->ctx.req = NULL;
40b6229b 1057 atomic_set(&io->io_pending, 0);
dc440d1e
MB
1058}
1059
3e1a8bdd
MB
1060static void crypt_inc_pending(struct dm_crypt_io *io)
1061{
40b6229b 1062 atomic_inc(&io->io_pending);
3e1a8bdd
MB
1063}
1064
1da177e4
LT
1065/*
1066 * One of the bios was finished. Check for completion of
1067 * the whole request and correctly clean up the buffer.
1068 */
5742fd77 1069static void crypt_dec_pending(struct dm_crypt_io *io)
1da177e4 1070{
49a8a920 1071 struct crypt_config *cc = io->cc;
b35f8caa 1072 struct bio *base_bio = io->base_bio;
b35f8caa 1073 int error = io->error;
1da177e4 1074
40b6229b 1075 if (!atomic_dec_and_test(&io->io_pending))
1da177e4
LT
1076 return;
1077
610f2de3 1078 if (io->ctx.req)
298a9fa0 1079 crypt_free_req(cc, io->ctx.req, base_bio);
b35f8caa 1080
4246a0b6
CH
1081 base_bio->bi_error = error;
1082 bio_endio(base_bio);
1da177e4
LT
1083}
1084
1085/*
cabf08e4 1086 * kcryptd/kcryptd_io:
1da177e4
LT
1087 *
1088 * Needed because it would be very unwise to do decryption in an
23541d2d 1089 * interrupt context.
cabf08e4
MB
1090 *
1091 * kcryptd performs the actual encryption or decryption.
1092 *
1093 * kcryptd_io performs the IO submission.
1094 *
1095 * They must be separated as otherwise the final stages could be
1096 * starved by new requests which can block in the first stages due
1097 * to memory allocation.
c0297721
AK
1098 *
1099 * The work is done per CPU global for all dm-crypt instances.
1100 * They should not depend on each other and do not block.
1da177e4 1101 */
4246a0b6 1102static void crypt_endio(struct bio *clone)
8b004457 1103{
028867ac 1104 struct dm_crypt_io *io = clone->bi_private;
49a8a920 1105 struct crypt_config *cc = io->cc;
ee7a491e 1106 unsigned rw = bio_data_dir(clone);
9b81c842 1107 int error;
8b004457
MB
1108
1109 /*
6712ecf8 1110 * free the processed pages
8b004457 1111 */
ee7a491e 1112 if (rw == WRITE)
644bd2f0 1113 crypt_free_buffer_pages(cc, clone);
8b004457 1114
9b81c842 1115 error = clone->bi_error;
8b004457 1116 bio_put(clone);
8b004457 1117
9b81c842 1118 if (rw == READ && !error) {
ee7a491e
MB
1119 kcryptd_queue_crypt(io);
1120 return;
1121 }
5742fd77 1122
9b81c842
SL
1123 if (unlikely(error))
1124 io->error = error;
5742fd77
MB
1125
1126 crypt_dec_pending(io);
8b004457
MB
1127}
1128
028867ac 1129static void clone_init(struct dm_crypt_io *io, struct bio *clone)
8b004457 1130{
49a8a920 1131 struct crypt_config *cc = io->cc;
8b004457
MB
1132
1133 clone->bi_private = io;
1134 clone->bi_end_io = crypt_endio;
1135 clone->bi_bdev = cc->dev->bdev;
ef295ecf 1136 clone->bi_opf = io->base_bio->bi_opf;
8b004457
MB
1137}
1138
20c82538 1139static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
8b004457 1140{
49a8a920 1141 struct crypt_config *cc = io->cc;
8b004457 1142 struct bio *clone;
93e605c2 1143
8b004457 1144 /*
59779079
MS
1145 * We need the original biovec array in order to decrypt
1146 * the whole bio data *afterwards* -- thanks to immutable
1147 * biovecs we don't need to worry about the block layer
1148 * modifying the biovec array; so leverage bio_clone_fast().
8b004457 1149 */
59779079 1150 clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
7eaceacc 1151 if (!clone)
20c82538 1152 return 1;
8b004457 1153
20c82538
MB
1154 crypt_inc_pending(io);
1155
8b004457 1156 clone_init(io, clone);
4f024f37 1157 clone->bi_iter.bi_sector = cc->start + io->sector;
8b004457 1158
93e605c2 1159 generic_make_request(clone);
20c82538 1160 return 0;
8b004457
MB
1161}
1162
dc267621
MP
1163static void kcryptd_io_read_work(struct work_struct *work)
1164{
1165 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1166
1167 crypt_inc_pending(io);
1168 if (kcryptd_io_read(io, GFP_NOIO))
1169 io->error = -ENOMEM;
1170 crypt_dec_pending(io);
1171}
1172
1173static void kcryptd_queue_read(struct dm_crypt_io *io)
1174{
1175 struct crypt_config *cc = io->cc;
1176
1177 INIT_WORK(&io->work, kcryptd_io_read_work);
1178 queue_work(cc->io_queue, &io->work);
1179}
1180
4e4eef64
MB
1181static void kcryptd_io_write(struct dm_crypt_io *io)
1182{
95497a96 1183 struct bio *clone = io->ctx.bio_out;
dc267621 1184
95497a96 1185 generic_make_request(clone);
4e4eef64
MB
1186}
1187
b3c5fd30
MP
1188#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1189
dc267621 1190static int dmcrypt_write(void *data)
395b167c 1191{
dc267621 1192 struct crypt_config *cc = data;
b3c5fd30
MP
1193 struct dm_crypt_io *io;
1194
dc267621 1195 while (1) {
b3c5fd30 1196 struct rb_root write_tree;
dc267621 1197 struct blk_plug plug;
395b167c 1198
dc267621 1199 DECLARE_WAITQUEUE(wait, current);
395b167c 1200
dc267621
MP
1201 spin_lock_irq(&cc->write_thread_wait.lock);
1202continue_locked:
395b167c 1203
b3c5fd30 1204 if (!RB_EMPTY_ROOT(&cc->write_tree))
dc267621
MP
1205 goto pop_from_list;
1206
f659b100 1207 set_current_state(TASK_INTERRUPTIBLE);
dc267621
MP
1208 __add_wait_queue(&cc->write_thread_wait, &wait);
1209
1210 spin_unlock_irq(&cc->write_thread_wait.lock);
1211
f659b100
RV
1212 if (unlikely(kthread_should_stop())) {
1213 set_task_state(current, TASK_RUNNING);
1214 remove_wait_queue(&cc->write_thread_wait, &wait);
1215 break;
1216 }
1217
dc267621
MP
1218 schedule();
1219
f659b100 1220 set_task_state(current, TASK_RUNNING);
dc267621
MP
1221 spin_lock_irq(&cc->write_thread_wait.lock);
1222 __remove_wait_queue(&cc->write_thread_wait, &wait);
1223 goto continue_locked;
1224
1225pop_from_list:
b3c5fd30
MP
1226 write_tree = cc->write_tree;
1227 cc->write_tree = RB_ROOT;
dc267621
MP
1228 spin_unlock_irq(&cc->write_thread_wait.lock);
1229
b3c5fd30
MP
1230 BUG_ON(rb_parent(write_tree.rb_node));
1231
1232 /*
1233 * Note: we cannot walk the tree here with rb_next because
1234 * the structures may be freed when kcryptd_io_write is called.
1235 */
dc267621
MP
1236 blk_start_plug(&plug);
1237 do {
b3c5fd30
MP
1238 io = crypt_io_from_node(rb_first(&write_tree));
1239 rb_erase(&io->rb_node, &write_tree);
dc267621 1240 kcryptd_io_write(io);
b3c5fd30 1241 } while (!RB_EMPTY_ROOT(&write_tree));
dc267621
MP
1242 blk_finish_plug(&plug);
1243 }
1244 return 0;
395b167c
AK
1245}
1246
72c6e7af 1247static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
4e4eef64 1248{
dec1cedf 1249 struct bio *clone = io->ctx.bio_out;
49a8a920 1250 struct crypt_config *cc = io->cc;
dc267621 1251 unsigned long flags;
b3c5fd30
MP
1252 sector_t sector;
1253 struct rb_node **rbp, *parent;
dec1cedf 1254
72c6e7af 1255 if (unlikely(io->error < 0)) {
dec1cedf
MB
1256 crypt_free_buffer_pages(cc, clone);
1257 bio_put(clone);
6c031f41 1258 crypt_dec_pending(io);
dec1cedf
MB
1259 return;
1260 }
1261
1262 /* crypt_convert should have filled the clone bio */
003b5c57 1263 BUG_ON(io->ctx.iter_out.bi_size);
dec1cedf 1264
4f024f37 1265 clone->bi_iter.bi_sector = cc->start + io->sector;
899c95d3 1266
0f5d8e6e
MP
1267 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1268 generic_make_request(clone);
1269 return;
1270 }
1271
dc267621 1272 spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
b3c5fd30
MP
1273 rbp = &cc->write_tree.rb_node;
1274 parent = NULL;
1275 sector = io->sector;
1276 while (*rbp) {
1277 parent = *rbp;
1278 if (sector < crypt_io_from_node(parent)->sector)
1279 rbp = &(*rbp)->rb_left;
1280 else
1281 rbp = &(*rbp)->rb_right;
1282 }
1283 rb_link_node(&io->rb_node, parent, rbp);
1284 rb_insert_color(&io->rb_node, &cc->write_tree);
1285
dc267621
MP
1286 wake_up_locked(&cc->write_thread_wait);
1287 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
4e4eef64
MB
1288}
1289
fc5a5e9a 1290static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
8b004457 1291{
49a8a920 1292 struct crypt_config *cc = io->cc;
8b004457 1293 struct bio *clone;
c8081618 1294 int crypt_finished;
b635b00e 1295 sector_t sector = io->sector;
dec1cedf 1296 int r;
8b004457 1297
fc5a5e9a
MB
1298 /*
1299 * Prevent io from disappearing until this function completes.
1300 */
1301 crypt_inc_pending(io);
b635b00e 1302 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
fc5a5e9a 1303
cf2f1abf
MP
1304 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1305 if (unlikely(!clone)) {
1306 io->error = -EIO;
1307 goto dec;
1308 }
c8081618 1309
cf2f1abf
MP
1310 io->ctx.bio_out = clone;
1311 io->ctx.iter_out = clone->bi_iter;
b635b00e 1312
cf2f1abf 1313 sector += bio_sectors(clone);
93e605c2 1314
cf2f1abf
MP
1315 crypt_inc_pending(io);
1316 r = crypt_convert(cc, &io->ctx);
1317 if (r)
1318 io->error = -EIO;
1319 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
933f01d4 1320
cf2f1abf
MP
1321 /* Encryption was already finished, submit io now */
1322 if (crypt_finished) {
1323 kcryptd_crypt_write_io_submit(io, 0);
1324 io->sector = sector;
93e605c2 1325 }
899c95d3 1326
cf2f1abf 1327dec:
899c95d3 1328 crypt_dec_pending(io);
84131db6
MB
1329}
1330
72c6e7af 1331static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
5742fd77 1332{
5742fd77
MB
1333 crypt_dec_pending(io);
1334}
1335
4e4eef64 1336static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
8b004457 1337{
49a8a920 1338 struct crypt_config *cc = io->cc;
5742fd77 1339 int r = 0;
1da177e4 1340
3e1a8bdd 1341 crypt_inc_pending(io);
3a7f6c99 1342
53017030 1343 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
0c395b0f 1344 io->sector);
1da177e4 1345
5742fd77 1346 r = crypt_convert(cc, &io->ctx);
72c6e7af
MP
1347 if (r < 0)
1348 io->error = -EIO;
5742fd77 1349
40b6229b 1350 if (atomic_dec_and_test(&io->ctx.cc_pending))
72c6e7af 1351 kcryptd_crypt_read_done(io);
3a7f6c99
MB
1352
1353 crypt_dec_pending(io);
1da177e4
LT
1354}
1355
95497a96
MB
1356static void kcryptd_async_done(struct crypto_async_request *async_req,
1357 int error)
1358{
b2174eeb
HY
1359 struct dm_crypt_request *dmreq = async_req->data;
1360 struct convert_context *ctx = dmreq->ctx;
95497a96 1361 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
49a8a920 1362 struct crypt_config *cc = io->cc;
95497a96 1363
54cea3f6
MB
1364 /*
1365 * A request from crypto driver backlog is going to be processed now,
1366 * finish the completion and continue in crypt_convert().
1367 * (Callback will be called for the second time for this request.)
1368 */
c0403ec0
RV
1369 if (error == -EINPROGRESS) {
1370 complete(&ctx->restart);
95497a96 1371 return;
c0403ec0 1372 }
95497a96 1373
2dc5327d
MB
1374 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1375 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1376
72c6e7af
MP
1377 if (error < 0)
1378 io->error = -EIO;
1379
298a9fa0 1380 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
95497a96 1381
40b6229b 1382 if (!atomic_dec_and_test(&ctx->cc_pending))
c0403ec0 1383 return;
95497a96
MB
1384
1385 if (bio_data_dir(io->base_bio) == READ)
72c6e7af 1386 kcryptd_crypt_read_done(io);
95497a96 1387 else
72c6e7af 1388 kcryptd_crypt_write_io_submit(io, 1);
95497a96
MB
1389}
1390
395b167c 1391static void kcryptd_crypt(struct work_struct *work)
1da177e4 1392{
028867ac 1393 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
8b004457 1394
cabf08e4 1395 if (bio_data_dir(io->base_bio) == READ)
395b167c 1396 kcryptd_crypt_read_convert(io);
4e4eef64 1397 else
395b167c 1398 kcryptd_crypt_write_convert(io);
cabf08e4
MB
1399}
1400
395b167c 1401static void kcryptd_queue_crypt(struct dm_crypt_io *io)
cabf08e4 1402{
49a8a920 1403 struct crypt_config *cc = io->cc;
cabf08e4 1404
395b167c
AK
1405 INIT_WORK(&io->work, kcryptd_crypt);
1406 queue_work(cc->crypt_queue, &io->work);
1da177e4
LT
1407}
1408
1409/*
1410 * Decode key from its hex representation
1411 */
1412static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1413{
1414 char buffer[3];
1da177e4
LT
1415 unsigned int i;
1416
1417 buffer[2] = '\0';
1418
8b004457 1419 for (i = 0; i < size; i++) {
1da177e4
LT
1420 buffer[0] = *hex++;
1421 buffer[1] = *hex++;
1422
1a66a08a 1423 if (kstrtou8(buffer, 16, &key[i]))
1da177e4
LT
1424 return -EINVAL;
1425 }
1426
1427 if (*hex != '\0')
1428 return -EINVAL;
1429
1430 return 0;
1431}
1432
fd2d231f 1433static void crypt_free_tfms(struct crypt_config *cc)
d1f96423 1434{
d1f96423
MB
1435 unsigned i;
1436
fd2d231f
MP
1437 if (!cc->tfms)
1438 return;
1439
d1f96423 1440 for (i = 0; i < cc->tfms_count; i++)
fd2d231f 1441 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
bbdb23b5 1442 crypto_free_skcipher(cc->tfms[i]);
fd2d231f 1443 cc->tfms[i] = NULL;
d1f96423 1444 }
fd2d231f
MP
1445
1446 kfree(cc->tfms);
1447 cc->tfms = NULL;
d1f96423
MB
1448}
1449
fd2d231f 1450static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
d1f96423 1451{
d1f96423
MB
1452 unsigned i;
1453 int err;
1454
5d0be84e 1455 cc->tfms = kzalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
fd2d231f
MP
1456 GFP_KERNEL);
1457 if (!cc->tfms)
1458 return -ENOMEM;
1459
d1f96423 1460 for (i = 0; i < cc->tfms_count; i++) {
bbdb23b5 1461 cc->tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
fd2d231f
MP
1462 if (IS_ERR(cc->tfms[i])) {
1463 err = PTR_ERR(cc->tfms[i]);
1464 crypt_free_tfms(cc);
d1f96423
MB
1465 return err;
1466 }
1467 }
1468
1469 return 0;
1470}
1471
671ea6b4 1472static int crypt_setkey(struct crypt_config *cc)
c0297721 1473{
da31a078 1474 unsigned subkey_size;
fd2d231f
MP
1475 int err = 0, i, r;
1476
da31a078
MB
1477 /* Ignore extra keys (which are used for IV etc) */
1478 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1479
fd2d231f 1480 for (i = 0; i < cc->tfms_count; i++) {
bbdb23b5
HX
1481 r = crypto_skcipher_setkey(cc->tfms[i],
1482 cc->key + (i * subkey_size),
1483 subkey_size);
fd2d231f
MP
1484 if (r)
1485 err = r;
c0297721
AK
1486 }
1487
1488 return err;
1489}
1490
c538f6ec
OK
1491#ifdef CONFIG_KEYS
1492
027c431c
OK
1493static bool contains_whitespace(const char *str)
1494{
1495 while (*str)
1496 if (isspace(*str++))
1497 return true;
1498 return false;
1499}
1500
c538f6ec
OK
1501static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
1502{
1503 char *new_key_string, *key_desc;
1504 int ret;
1505 struct key *key;
1506 const struct user_key_payload *ukp;
1507
027c431c
OK
1508 /*
1509 * Reject key_string with whitespace. dm core currently lacks code for
1510 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
1511 */
1512 if (contains_whitespace(key_string)) {
1513 DMERR("whitespace chars not allowed in key string");
1514 return -EINVAL;
1515 }
1516
c538f6ec
OK
1517 /* look for next ':' separating key_type from key_description */
1518 key_desc = strpbrk(key_string, ":");
1519 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
1520 return -EINVAL;
1521
1522 if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
1523 strncmp(key_string, "user:", key_desc - key_string + 1))
1524 return -EINVAL;
1525
1526 new_key_string = kstrdup(key_string, GFP_KERNEL);
1527 if (!new_key_string)
1528 return -ENOMEM;
1529
1530 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
1531 key_desc + 1, NULL);
1532 if (IS_ERR(key)) {
1533 kzfree(new_key_string);
1534 return PTR_ERR(key);
1535 }
1536
1537 rcu_read_lock();
1538
1539 ukp = user_key_payload(key);
1540 if (!ukp) {
1541 rcu_read_unlock();
1542 key_put(key);
1543 kzfree(new_key_string);
1544 return -EKEYREVOKED;
1545 }
1546
1547 if (cc->key_size != ukp->datalen) {
1548 rcu_read_unlock();
1549 key_put(key);
1550 kzfree(new_key_string);
1551 return -EINVAL;
1552 }
1553
1554 memcpy(cc->key, ukp->data, cc->key_size);
1555
1556 rcu_read_unlock();
1557 key_put(key);
1558
1559 /* clear the flag since following operations may invalidate previously valid key */
1560 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1561
1562 ret = crypt_setkey(cc);
1563
1564 /* wipe the kernel key payload copy in each case */
1565 memset(cc->key, 0, cc->key_size * sizeof(u8));
1566
1567 if (!ret) {
1568 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1569 kzfree(cc->key_string);
1570 cc->key_string = new_key_string;
1571 } else
1572 kzfree(new_key_string);
1573
1574 return ret;
1575}
1576
1577static int get_key_size(char **key_string)
1578{
1579 char *colon, dummy;
1580 int ret;
1581
1582 if (*key_string[0] != ':')
1583 return strlen(*key_string) >> 1;
1584
1585 /* look for next ':' in key string */
1586 colon = strpbrk(*key_string + 1, ":");
1587 if (!colon)
1588 return -EINVAL;
1589
1590 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
1591 return -EINVAL;
1592
1593 *key_string = colon;
1594
1595 /* remaining key string should be :<logon|user>:<key_desc> */
1596
1597 return ret;
1598}
1599
1600#else
1601
1602static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
1603{
1604 return -EINVAL;
1605}
1606
1607static int get_key_size(char **key_string)
1608{
1609 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
1610}
1611
1612#endif
1613
e48d4bbf
MB
1614static int crypt_set_key(struct crypt_config *cc, char *key)
1615{
de8be5ac
MB
1616 int r = -EINVAL;
1617 int key_string_len = strlen(key);
1618
69a8cfcd
MB
1619 /* Hyphen (which gives a key_size of zero) means there is no key. */
1620 if (!cc->key_size && strcmp(key, "-"))
de8be5ac 1621 goto out;
e48d4bbf 1622
c538f6ec
OK
1623 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
1624 if (key[0] == ':') {
1625 r = crypt_set_keyring_key(cc, key + 1);
de8be5ac 1626 goto out;
c538f6ec 1627 }
e48d4bbf 1628
265e9098
OK
1629 /* clear the flag since following operations may invalidate previously valid key */
1630 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
e48d4bbf 1631
c538f6ec
OK
1632 /* wipe references to any kernel keyring key */
1633 kzfree(cc->key_string);
1634 cc->key_string = NULL;
1635
69a8cfcd 1636 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
de8be5ac 1637 goto out;
e48d4bbf 1638
671ea6b4 1639 r = crypt_setkey(cc);
265e9098
OK
1640 if (!r)
1641 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
de8be5ac
MB
1642
1643out:
1644 /* Hex key string not needed after here, so wipe it. */
1645 memset(key, '0', key_string_len);
1646
1647 return r;
e48d4bbf
MB
1648}
1649
1650static int crypt_wipe_key(struct crypt_config *cc)
1651{
1652 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1653 memset(&cc->key, 0, cc->key_size * sizeof(u8));
c538f6ec
OK
1654 kzfree(cc->key_string);
1655 cc->key_string = NULL;
c0297721 1656
671ea6b4 1657 return crypt_setkey(cc);
e48d4bbf
MB
1658}
1659
28513fcc
MB
1660static void crypt_dtr(struct dm_target *ti)
1661{
1662 struct crypt_config *cc = ti->private;
1663
1664 ti->private = NULL;
1665
1666 if (!cc)
1667 return;
1668
f659b100 1669 if (cc->write_thread)
dc267621
MP
1670 kthread_stop(cc->write_thread);
1671
28513fcc
MB
1672 if (cc->io_queue)
1673 destroy_workqueue(cc->io_queue);
1674 if (cc->crypt_queue)
1675 destroy_workqueue(cc->crypt_queue);
1676
fd2d231f
MP
1677 crypt_free_tfms(cc);
1678
28513fcc
MB
1679 if (cc->bs)
1680 bioset_free(cc->bs);
1681
6f65985e
JL
1682 mempool_destroy(cc->page_pool);
1683 mempool_destroy(cc->req_pool);
28513fcc
MB
1684
1685 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1686 cc->iv_gen_ops->dtr(cc);
1687
28513fcc
MB
1688 if (cc->dev)
1689 dm_put_device(ti, cc->dev);
1690
5ebaee6d 1691 kzfree(cc->cipher);
7dbcd137 1692 kzfree(cc->cipher_string);
c538f6ec 1693 kzfree(cc->key_string);
28513fcc
MB
1694
1695 /* Must zero key material before freeing */
1696 kzfree(cc);
1697}
1698
5ebaee6d
MB
1699static int crypt_ctr_cipher(struct dm_target *ti,
1700 char *cipher_in, char *key)
1da177e4 1701{
5ebaee6d 1702 struct crypt_config *cc = ti->private;
d1f96423 1703 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
5ebaee6d 1704 char *cipher_api = NULL;
fd2d231f 1705 int ret = -EINVAL;
31998ef1 1706 char dummy;
1da177e4 1707
5ebaee6d
MB
1708 /* Convert to crypto api definition? */
1709 if (strchr(cipher_in, '(')) {
1710 ti->error = "Bad cipher specification";
1da177e4
LT
1711 return -EINVAL;
1712 }
1713
7dbcd137
MB
1714 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1715 if (!cc->cipher_string)
1716 goto bad_mem;
1717
5ebaee6d
MB
1718 /*
1719 * Legacy dm-crypt cipher specification
d1f96423 1720 * cipher[:keycount]-mode-iv:ivopts
5ebaee6d
MB
1721 */
1722 tmp = cipher_in;
d1f96423
MB
1723 keycount = strsep(&tmp, "-");
1724 cipher = strsep(&keycount, ":");
1725
1726 if (!keycount)
1727 cc->tfms_count = 1;
31998ef1 1728 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
d1f96423
MB
1729 !is_power_of_2(cc->tfms_count)) {
1730 ti->error = "Bad cipher key count specification";
1731 return -EINVAL;
1732 }
1733 cc->key_parts = cc->tfms_count;
da31a078 1734 cc->key_extra_size = 0;
5ebaee6d
MB
1735
1736 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1737 if (!cc->cipher)
1738 goto bad_mem;
1739
1da177e4
LT
1740 chainmode = strsep(&tmp, "-");
1741 ivopts = strsep(&tmp, "-");
1742 ivmode = strsep(&ivopts, ":");
1743
1744 if (tmp)
5ebaee6d 1745 DMWARN("Ignoring unexpected additional cipher options");
1da177e4 1746
7dbcd137
MB
1747 /*
1748 * For compatibility with the original dm-crypt mapping format, if
1749 * only the cipher name is supplied, use cbc-plain.
1750 */
5ebaee6d 1751 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1da177e4
LT
1752 chainmode = "cbc";
1753 ivmode = "plain";
1754 }
1755
d1806f6a 1756 if (strcmp(chainmode, "ecb") && !ivmode) {
5ebaee6d
MB
1757 ti->error = "IV mechanism required";
1758 return -EINVAL;
1da177e4
LT
1759 }
1760
5ebaee6d
MB
1761 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1762 if (!cipher_api)
1763 goto bad_mem;
1764
1765 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1766 "%s(%s)", chainmode, cipher);
1767 if (ret < 0) {
1768 kfree(cipher_api);
1769 goto bad_mem;
1da177e4
LT
1770 }
1771
5ebaee6d 1772 /* Allocate cipher */
fd2d231f
MP
1773 ret = crypt_alloc_tfms(cc, cipher_api);
1774 if (ret < 0) {
1775 ti->error = "Error allocating crypto tfm";
1776 goto bad;
1da177e4 1777 }
1da177e4 1778
5ebaee6d 1779 /* Initialize IV */
bbdb23b5 1780 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
5ebaee6d
MB
1781 if (cc->iv_size)
1782 /* at least a 64 bit sector number should fit in our buffer */
1783 cc->iv_size = max(cc->iv_size,
1784 (unsigned int)(sizeof(u64) / sizeof(u8)));
1785 else if (ivmode) {
1786 DMWARN("Selected cipher does not support IVs");
1787 ivmode = NULL;
1788 }
1789
1790 /* Choose ivmode, see comments at iv code. */
1da177e4
LT
1791 if (ivmode == NULL)
1792 cc->iv_gen_ops = NULL;
1793 else if (strcmp(ivmode, "plain") == 0)
1794 cc->iv_gen_ops = &crypt_iv_plain_ops;
61afef61
MB
1795 else if (strcmp(ivmode, "plain64") == 0)
1796 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1da177e4
LT
1797 else if (strcmp(ivmode, "essiv") == 0)
1798 cc->iv_gen_ops = &crypt_iv_essiv_ops;
48527fa7
RS
1799 else if (strcmp(ivmode, "benbi") == 0)
1800 cc->iv_gen_ops = &crypt_iv_benbi_ops;
46b47730
LN
1801 else if (strcmp(ivmode, "null") == 0)
1802 cc->iv_gen_ops = &crypt_iv_null_ops;
34745785
MB
1803 else if (strcmp(ivmode, "lmk") == 0) {
1804 cc->iv_gen_ops = &crypt_iv_lmk_ops;
ed04d981
MB
1805 /*
1806 * Version 2 and 3 is recognised according
34745785
MB
1807 * to length of provided multi-key string.
1808 * If present (version 3), last key is used as IV seed.
ed04d981 1809 * All keys (including IV seed) are always the same size.
34745785 1810 */
da31a078 1811 if (cc->key_size % cc->key_parts) {
34745785 1812 cc->key_parts++;
da31a078
MB
1813 cc->key_extra_size = cc->key_size / cc->key_parts;
1814 }
ed04d981
MB
1815 } else if (strcmp(ivmode, "tcw") == 0) {
1816 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1817 cc->key_parts += 2; /* IV + whitening */
1818 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
34745785 1819 } else {
5ebaee6d 1820 ret = -EINVAL;
72d94861 1821 ti->error = "Invalid IV mode";
28513fcc 1822 goto bad;
1da177e4
LT
1823 }
1824
da31a078
MB
1825 /* Initialize and set key */
1826 ret = crypt_set_key(cc, key);
1827 if (ret < 0) {
1828 ti->error = "Error decoding and setting key";
1829 goto bad;
1830 }
1831
28513fcc
MB
1832 /* Allocate IV */
1833 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1834 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1835 if (ret < 0) {
1836 ti->error = "Error creating IV";
1837 goto bad;
1838 }
1839 }
1da177e4 1840
28513fcc
MB
1841 /* Initialize IV (set keys for ESSIV etc) */
1842 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1843 ret = cc->iv_gen_ops->init(cc);
1844 if (ret < 0) {
1845 ti->error = "Error initialising IV";
1846 goto bad;
1847 }
b95bf2d3
MB
1848 }
1849
5ebaee6d
MB
1850 ret = 0;
1851bad:
1852 kfree(cipher_api);
1853 return ret;
1854
1855bad_mem:
1856 ti->error = "Cannot allocate cipher strings";
1857 return -ENOMEM;
1858}
1859
1860/*
1861 * Construct an encryption mapping:
c538f6ec 1862 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
5ebaee6d
MB
1863 */
1864static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1865{
1866 struct crypt_config *cc;
c538f6ec
OK
1867 int key_size;
1868 unsigned int opt_params;
5ebaee6d
MB
1869 unsigned long long tmpll;
1870 int ret;
d49ec52f 1871 size_t iv_size_padding;
772ae5f5
MB
1872 struct dm_arg_set as;
1873 const char *opt_string;
31998ef1 1874 char dummy;
772ae5f5
MB
1875
1876 static struct dm_arg _args[] = {
0f5d8e6e 1877 {0, 3, "Invalid number of feature args"},
772ae5f5 1878 };
5ebaee6d 1879
772ae5f5 1880 if (argc < 5) {
5ebaee6d
MB
1881 ti->error = "Not enough arguments";
1882 return -EINVAL;
1da177e4
LT
1883 }
1884
c538f6ec
OK
1885 key_size = get_key_size(&argv[1]);
1886 if (key_size < 0) {
1887 ti->error = "Cannot parse key size";
1888 return -EINVAL;
1889 }
5ebaee6d
MB
1890
1891 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1892 if (!cc) {
1893 ti->error = "Cannot allocate encryption context";
1894 return -ENOMEM;
1895 }
69a8cfcd 1896 cc->key_size = key_size;
5ebaee6d
MB
1897
1898 ti->private = cc;
1899 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1900 if (ret < 0)
1901 goto bad;
1902
bbdb23b5
HX
1903 cc->dmreq_start = sizeof(struct skcipher_request);
1904 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
d49ec52f
MP
1905 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1906
bbdb23b5 1907 if (crypto_skcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
d49ec52f
MP
1908 /* Allocate the padding exactly */
1909 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
bbdb23b5 1910 & crypto_skcipher_alignmask(any_tfm(cc));
d49ec52f
MP
1911 } else {
1912 /*
1913 * If the cipher requires greater alignment than kmalloc
1914 * alignment, we don't know the exact position of the
1915 * initialization vector. We must assume worst case.
1916 */
bbdb23b5 1917 iv_size_padding = crypto_skcipher_alignmask(any_tfm(cc));
d49ec52f 1918 }
ddd42edf 1919
94f5e024 1920 ret = -ENOMEM;
ddd42edf 1921 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
d49ec52f 1922 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
ddd42edf
MB
1923 if (!cc->req_pool) {
1924 ti->error = "Cannot allocate crypt request mempool";
28513fcc 1925 goto bad;
ddd42edf 1926 }
ddd42edf 1927
30187e1d 1928 cc->per_bio_data_size = ti->per_io_data_size =
d49ec52f
MP
1929 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1930 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1931 ARCH_KMALLOC_MINALIGN);
298a9fa0 1932
cf2f1abf 1933 cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1da177e4 1934 if (!cc->page_pool) {
72d94861 1935 ti->error = "Cannot allocate page mempool";
28513fcc 1936 goto bad;
1da177e4
LT
1937 }
1938
bb799ca0 1939 cc->bs = bioset_create(MIN_IOS, 0);
6a24c718
MB
1940 if (!cc->bs) {
1941 ti->error = "Cannot allocate crypt bioset";
28513fcc 1942 goto bad;
6a24c718
MB
1943 }
1944
7145c241
MP
1945 mutex_init(&cc->bio_alloc_lock);
1946
28513fcc 1947 ret = -EINVAL;
31998ef1 1948 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
72d94861 1949 ti->error = "Invalid iv_offset sector";
28513fcc 1950 goto bad;
1da177e4 1951 }
4ee218cd 1952 cc->iv_offset = tmpll;
1da177e4 1953
e80d1c80
VG
1954 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
1955 if (ret) {
28513fcc
MB
1956 ti->error = "Device lookup failed";
1957 goto bad;
1958 }
1959
e80d1c80 1960 ret = -EINVAL;
31998ef1 1961 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
72d94861 1962 ti->error = "Invalid device sector";
28513fcc 1963 goto bad;
1da177e4 1964 }
4ee218cd 1965 cc->start = tmpll;
1da177e4 1966
772ae5f5
MB
1967 argv += 5;
1968 argc -= 5;
1969
1970 /* Optional parameters */
1971 if (argc) {
1972 as.argc = argc;
1973 as.argv = argv;
1974
1975 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1976 if (ret)
1977 goto bad;
1978
44c144f9 1979 ret = -EINVAL;
f3396c58
MP
1980 while (opt_params--) {
1981 opt_string = dm_shift_arg(&as);
1982 if (!opt_string) {
1983 ti->error = "Not enough feature arguments";
1984 goto bad;
1985 }
772ae5f5 1986
f3396c58
MP
1987 if (!strcasecmp(opt_string, "allow_discards"))
1988 ti->num_discard_bios = 1;
1989
1990 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1991 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1992
0f5d8e6e
MP
1993 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
1994 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1995
f3396c58
MP
1996 else {
1997 ti->error = "Invalid feature arguments";
1998 goto bad;
1999 }
772ae5f5
MB
2000 }
2001 }
2002
28513fcc 2003 ret = -ENOMEM;
670368a8 2004 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
cabf08e4
MB
2005 if (!cc->io_queue) {
2006 ti->error = "Couldn't create kcryptd io queue";
28513fcc 2007 goto bad;
cabf08e4
MB
2008 }
2009
f3396c58
MP
2010 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2011 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2012 else
2013 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2014 num_online_cpus());
cabf08e4 2015 if (!cc->crypt_queue) {
9934a8be 2016 ti->error = "Couldn't create kcryptd queue";
28513fcc 2017 goto bad;
9934a8be
MB
2018 }
2019
dc267621 2020 init_waitqueue_head(&cc->write_thread_wait);
b3c5fd30 2021 cc->write_tree = RB_ROOT;
dc267621
MP
2022
2023 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
2024 if (IS_ERR(cc->write_thread)) {
2025 ret = PTR_ERR(cc->write_thread);
2026 cc->write_thread = NULL;
2027 ti->error = "Couldn't spawn write thread";
2028 goto bad;
2029 }
2030 wake_up_process(cc->write_thread);
2031
55a62eef 2032 ti->num_flush_bios = 1;
0ac55489 2033 ti->discard_zeroes_data_unsupported = true;
983c7db3 2034
1da177e4
LT
2035 return 0;
2036
28513fcc
MB
2037bad:
2038 crypt_dtr(ti);
2039 return ret;
1da177e4
LT
2040}
2041
7de3ee57 2042static int crypt_map(struct dm_target *ti, struct bio *bio)
1da177e4 2043{
028867ac 2044 struct dm_crypt_io *io;
49a8a920 2045 struct crypt_config *cc = ti->private;
647c7db1 2046
772ae5f5 2047 /*
28a8f0d3
MC
2048 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2049 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
e6047149 2050 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
772ae5f5 2051 */
1eff9d32 2052 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
28a8f0d3 2053 bio_op(bio) == REQ_OP_DISCARD)) {
647c7db1 2054 bio->bi_bdev = cc->dev->bdev;
772ae5f5 2055 if (bio_sectors(bio))
4f024f37
KO
2056 bio->bi_iter.bi_sector = cc->start +
2057 dm_target_offset(ti, bio->bi_iter.bi_sector);
647c7db1
MP
2058 return DM_MAPIO_REMAPPED;
2059 }
1da177e4 2060
4e870e94
MP
2061 /*
2062 * Check if bio is too large, split as needed.
2063 */
2064 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2065 bio_data_dir(bio) == WRITE)
2066 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2067
298a9fa0
MP
2068 io = dm_per_bio_data(bio, cc->per_bio_data_size);
2069 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
bbdb23b5 2070 io->ctx.req = (struct skcipher_request *)(io + 1);
cabf08e4 2071
20c82538
MB
2072 if (bio_data_dir(io->base_bio) == READ) {
2073 if (kcryptd_io_read(io, GFP_NOWAIT))
dc267621 2074 kcryptd_queue_read(io);
20c82538 2075 } else
cabf08e4 2076 kcryptd_queue_crypt(io);
1da177e4 2077
d2a7ad29 2078 return DM_MAPIO_SUBMITTED;
1da177e4
LT
2079}
2080
fd7c092e
MP
2081static void crypt_status(struct dm_target *ti, status_type_t type,
2082 unsigned status_flags, char *result, unsigned maxlen)
1da177e4 2083{
5ebaee6d 2084 struct crypt_config *cc = ti->private;
fd7c092e 2085 unsigned i, sz = 0;
f3396c58 2086 int num_feature_args = 0;
1da177e4
LT
2087
2088 switch (type) {
2089 case STATUSTYPE_INFO:
2090 result[0] = '\0';
2091 break;
2092
2093 case STATUSTYPE_TABLE:
7dbcd137 2094 DMEMIT("%s ", cc->cipher_string);
1da177e4 2095
c538f6ec
OK
2096 if (cc->key_size > 0) {
2097 if (cc->key_string)
2098 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2099 else
2100 for (i = 0; i < cc->key_size; i++)
2101 DMEMIT("%02x", cc->key[i]);
2102 } else
fd7c092e 2103 DMEMIT("-");
1da177e4 2104
4ee218cd
AM
2105 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2106 cc->dev->name, (unsigned long long)cc->start);
772ae5f5 2107
f3396c58
MP
2108 num_feature_args += !!ti->num_discard_bios;
2109 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
0f5d8e6e 2110 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
f3396c58
MP
2111 if (num_feature_args) {
2112 DMEMIT(" %d", num_feature_args);
2113 if (ti->num_discard_bios)
2114 DMEMIT(" allow_discards");
2115 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2116 DMEMIT(" same_cpu_crypt");
0f5d8e6e
MP
2117 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2118 DMEMIT(" submit_from_crypt_cpus");
f3396c58 2119 }
772ae5f5 2120
1da177e4
LT
2121 break;
2122 }
1da177e4
LT
2123}
2124
e48d4bbf
MB
2125static void crypt_postsuspend(struct dm_target *ti)
2126{
2127 struct crypt_config *cc = ti->private;
2128
2129 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2130}
2131
2132static int crypt_preresume(struct dm_target *ti)
2133{
2134 struct crypt_config *cc = ti->private;
2135
2136 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
2137 DMERR("aborting resume - crypt key is not set.");
2138 return -EAGAIN;
2139 }
2140
2141 return 0;
2142}
2143
2144static void crypt_resume(struct dm_target *ti)
2145{
2146 struct crypt_config *cc = ti->private;
2147
2148 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2149}
2150
2151/* Message interface
2152 * key set <key>
2153 * key wipe
2154 */
2155static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
2156{
2157 struct crypt_config *cc = ti->private;
c538f6ec 2158 int key_size, ret = -EINVAL;
e48d4bbf
MB
2159
2160 if (argc < 2)
2161 goto error;
2162
498f0103 2163 if (!strcasecmp(argv[0], "key")) {
e48d4bbf
MB
2164 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2165 DMWARN("not suspended during key manipulation.");
2166 return -EINVAL;
2167 }
498f0103 2168 if (argc == 3 && !strcasecmp(argv[1], "set")) {
c538f6ec
OK
2169 /* The key size may not be changed. */
2170 key_size = get_key_size(&argv[2]);
2171 if (key_size < 0 || cc->key_size != key_size) {
2172 memset(argv[2], '0', strlen(argv[2]));
2173 return -EINVAL;
2174 }
2175
542da317
MB
2176 ret = crypt_set_key(cc, argv[2]);
2177 if (ret)
2178 return ret;
2179 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2180 ret = cc->iv_gen_ops->init(cc);
2181 return ret;
2182 }
498f0103 2183 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
542da317
MB
2184 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2185 ret = cc->iv_gen_ops->wipe(cc);
2186 if (ret)
2187 return ret;
2188 }
e48d4bbf 2189 return crypt_wipe_key(cc);
542da317 2190 }
e48d4bbf
MB
2191 }
2192
2193error:
2194 DMWARN("unrecognised message received.");
2195 return -EINVAL;
2196}
2197
af4874e0
MS
2198static int crypt_iterate_devices(struct dm_target *ti,
2199 iterate_devices_callout_fn fn, void *data)
2200{
2201 struct crypt_config *cc = ti->private;
2202
5dea271b 2203 return fn(ti, cc->dev, cc->start, ti->len, data);
af4874e0
MS
2204}
2205
586b286b
MS
2206static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
2207{
2208 /*
2209 * Unfortunate constraint that is required to avoid the potential
2210 * for exceeding underlying device's max_segments limits -- due to
2211 * crypt_alloc_buffer() possibly allocating pages for the encryption
2212 * bio that are not as physically contiguous as the original bio.
2213 */
2214 limits->max_segment_size = PAGE_SIZE;
2215}
2216
1da177e4
LT
2217static struct target_type crypt_target = {
2218 .name = "crypt",
c538f6ec 2219 .version = {1, 15, 0},
1da177e4
LT
2220 .module = THIS_MODULE,
2221 .ctr = crypt_ctr,
2222 .dtr = crypt_dtr,
2223 .map = crypt_map,
2224 .status = crypt_status,
e48d4bbf
MB
2225 .postsuspend = crypt_postsuspend,
2226 .preresume = crypt_preresume,
2227 .resume = crypt_resume,
2228 .message = crypt_message,
af4874e0 2229 .iterate_devices = crypt_iterate_devices,
586b286b 2230 .io_hints = crypt_io_hints,
1da177e4
LT
2231};
2232
2233static int __init dm_crypt_init(void)
2234{
2235 int r;
2236
1da177e4 2237 r = dm_register_target(&crypt_target);
94f5e024 2238 if (r < 0)
72d94861 2239 DMERR("register failed %d", r);
1da177e4 2240
1da177e4
LT
2241 return r;
2242}
2243
2244static void __exit dm_crypt_exit(void)
2245{
10d3bd09 2246 dm_unregister_target(&crypt_target);
1da177e4
LT
2247}
2248
2249module_init(dm_crypt_init);
2250module_exit(dm_crypt_exit);
2251
bf14299f 2252MODULE_AUTHOR("Jana Saout <jana@saout.de>");
1da177e4
LT
2253MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2254MODULE_LICENSE("GPL");