xref: /openbmc/linux/drivers/md/dm-crypt.c (revision 4da722ca)
1 /*
2  * Copyright (C) 2003 Jana Saout <jana@saout.de>
3  * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4  * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved.
5  * Copyright (C) 2013-2017 Milan Broz <gmazyland@gmail.com>
6  *
7  * This file is released under the GPL.
8  */
9 
10 #include <linux/completion.h>
11 #include <linux/err.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/key.h>
16 #include <linux/bio.h>
17 #include <linux/blkdev.h>
18 #include <linux/mempool.h>
19 #include <linux/slab.h>
20 #include <linux/crypto.h>
21 #include <linux/workqueue.h>
22 #include <linux/kthread.h>
23 #include <linux/backing-dev.h>
24 #include <linux/atomic.h>
25 #include <linux/scatterlist.h>
26 #include <linux/rbtree.h>
27 #include <linux/ctype.h>
28 #include <asm/page.h>
29 #include <asm/unaligned.h>
30 #include <crypto/hash.h>
31 #include <crypto/md5.h>
32 #include <crypto/algapi.h>
33 #include <crypto/skcipher.h>
34 #include <crypto/aead.h>
35 #include <crypto/authenc.h>
36 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
37 #include <keys/user-type.h>
38 
39 #include <linux/device-mapper.h>
40 
41 #define DM_MSG_PREFIX "crypt"
42 
43 /*
44  * context holding the current state of a multi-part conversion
45  */
46 struct convert_context {
47 	struct completion restart;
48 	struct bio *bio_in;
49 	struct bio *bio_out;
50 	struct bvec_iter iter_in;
51 	struct bvec_iter iter_out;
52 	sector_t cc_sector;
53 	atomic_t cc_pending;
54 	union {
55 		struct skcipher_request *req;
56 		struct aead_request *req_aead;
57 	} r;
58 
59 };
60 
61 /*
62  * per bio private data
63  */
64 struct dm_crypt_io {
65 	struct crypt_config *cc;
66 	struct bio *base_bio;
67 	u8 *integrity_metadata;
68 	bool integrity_metadata_from_pool;
69 	struct work_struct work;
70 
71 	struct convert_context ctx;
72 
73 	atomic_t io_pending;
74 	blk_status_t error;
75 	sector_t sector;
76 
77 	struct rb_node rb_node;
78 } CRYPTO_MINALIGN_ATTR;
79 
80 struct dm_crypt_request {
81 	struct convert_context *ctx;
82 	struct scatterlist sg_in[4];
83 	struct scatterlist sg_out[4];
84 	sector_t iv_sector;
85 };
86 
87 struct crypt_config;
88 
89 struct crypt_iv_operations {
90 	int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
91 		   const char *opts);
92 	void (*dtr)(struct crypt_config *cc);
93 	int (*init)(struct crypt_config *cc);
94 	int (*wipe)(struct crypt_config *cc);
95 	int (*generator)(struct crypt_config *cc, u8 *iv,
96 			 struct dm_crypt_request *dmreq);
97 	int (*post)(struct crypt_config *cc, u8 *iv,
98 		    struct dm_crypt_request *dmreq);
99 };
100 
101 struct iv_essiv_private {
102 	struct crypto_ahash *hash_tfm;
103 	u8 *salt;
104 };
105 
106 struct iv_benbi_private {
107 	int shift;
108 };
109 
110 #define LMK_SEED_SIZE 64 /* hash + 0 */
111 struct iv_lmk_private {
112 	struct crypto_shash *hash_tfm;
113 	u8 *seed;
114 };
115 
116 #define TCW_WHITENING_SIZE 16
117 struct iv_tcw_private {
118 	struct crypto_shash *crc32_tfm;
119 	u8 *iv_seed;
120 	u8 *whitening;
121 };
122 
123 /*
124  * Crypt: maps a linear range of a block device
125  * and encrypts / decrypts at the same time.
126  */
127 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
128 	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
129 
130 enum cipher_flags {
131 	CRYPT_MODE_INTEGRITY_AEAD,	/* Use authenticated mode for cihper */
132 	CRYPT_IV_LARGE_SECTORS,		/* Calculate IV from sector_size, not 512B sectors */
133 };
134 
135 /*
136  * The fields in here must be read only after initialization.
137  */
138 struct crypt_config {
139 	struct dm_dev *dev;
140 	sector_t start;
141 
142 	/*
143 	 * pool for per bio private data, crypto requests,
144 	 * encryption requeusts/buffer pages and integrity tags
145 	 */
146 	mempool_t *req_pool;
147 	mempool_t *page_pool;
148 	mempool_t *tag_pool;
149 	unsigned tag_pool_max_sectors;
150 
151 	struct bio_set *bs;
152 	struct mutex bio_alloc_lock;
153 
154 	struct workqueue_struct *io_queue;
155 	struct workqueue_struct *crypt_queue;
156 
157 	struct task_struct *write_thread;
158 	wait_queue_head_t write_thread_wait;
159 	struct rb_root write_tree;
160 
161 	char *cipher;
162 	char *cipher_string;
163 	char *cipher_auth;
164 	char *key_string;
165 
166 	const struct crypt_iv_operations *iv_gen_ops;
167 	union {
168 		struct iv_essiv_private essiv;
169 		struct iv_benbi_private benbi;
170 		struct iv_lmk_private lmk;
171 		struct iv_tcw_private tcw;
172 	} iv_gen_private;
173 	sector_t iv_offset;
174 	unsigned int iv_size;
175 	unsigned short int sector_size;
176 	unsigned char sector_shift;
177 
178 	/* ESSIV: struct crypto_cipher *essiv_tfm */
179 	void *iv_private;
180 	union {
181 		struct crypto_skcipher **tfms;
182 		struct crypto_aead **tfms_aead;
183 	} cipher_tfm;
184 	unsigned tfms_count;
185 	unsigned long cipher_flags;
186 
187 	/*
188 	 * Layout of each crypto request:
189 	 *
190 	 *   struct skcipher_request
191 	 *      context
192 	 *      padding
193 	 *   struct dm_crypt_request
194 	 *      padding
195 	 *   IV
196 	 *
197 	 * The padding is added so that dm_crypt_request and the IV are
198 	 * correctly aligned.
199 	 */
200 	unsigned int dmreq_start;
201 
202 	unsigned int per_bio_data_size;
203 
204 	unsigned long flags;
205 	unsigned int key_size;
206 	unsigned int key_parts;      /* independent parts in key buffer */
207 	unsigned int key_extra_size; /* additional keys length */
208 	unsigned int key_mac_size;   /* MAC key size for authenc(...) */
209 
210 	unsigned int integrity_tag_size;
211 	unsigned int integrity_iv_size;
212 	unsigned int on_disk_tag_size;
213 
214 	u8 *authenc_key; /* space for keys in authenc() format (if used) */
215 	u8 key[0];
216 };
217 
218 #define MIN_IOS		64
219 #define MAX_TAG_SIZE	480
220 #define POOL_ENTRY_SIZE	512
221 
222 static void clone_init(struct dm_crypt_io *, struct bio *);
223 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
224 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
225 					     struct scatterlist *sg);
226 
227 /*
228  * Use this to access cipher attributes that are independent of the key.
229  */
230 static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
231 {
232 	return cc->cipher_tfm.tfms[0];
233 }
234 
235 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
236 {
237 	return cc->cipher_tfm.tfms_aead[0];
238 }
239 
240 /*
241  * Different IV generation algorithms:
242  *
243  * plain: the initial vector is the 32-bit little-endian version of the sector
244  *        number, padded with zeros if necessary.
245  *
246  * plain64: the initial vector is the 64-bit little-endian version of the sector
247  *        number, padded with zeros if necessary.
248  *
249  * plain64be: the initial vector is the 64-bit big-endian version of the sector
250  *        number, padded with zeros if necessary.
251  *
252  * essiv: "encrypted sector|salt initial vector", the sector number is
253  *        encrypted with the bulk cipher using a salt as key. The salt
254  *        should be derived from the bulk cipher's key via hashing.
255  *
256  * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
257  *        (needed for LRW-32-AES and possible other narrow block modes)
258  *
259  * null: the initial vector is always zero.  Provides compatibility with
260  *       obsolete loop_fish2 devices.  Do not use for new devices.
261  *
262  * lmk:  Compatible implementation of the block chaining mode used
263  *       by the Loop-AES block device encryption system
264  *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
265  *       It operates on full 512 byte sectors and uses CBC
266  *       with an IV derived from the sector number, the data and
267  *       optionally extra IV seed.
268  *       This means that after decryption the first block
269  *       of sector must be tweaked according to decrypted data.
270  *       Loop-AES can use three encryption schemes:
271  *         version 1: is plain aes-cbc mode
272  *         version 2: uses 64 multikey scheme with lmk IV generator
273  *         version 3: the same as version 2 with additional IV seed
274  *                   (it uses 65 keys, last key is used as IV seed)
275  *
276  * tcw:  Compatible implementation of the block chaining mode used
277  *       by the TrueCrypt device encryption system (prior to version 4.1).
278  *       For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
279  *       It operates on full 512 byte sectors and uses CBC
280  *       with an IV derived from initial key and the sector number.
281  *       In addition, whitening value is applied on every sector, whitening
282  *       is calculated from initial key, sector number and mixed using CRC32.
283  *       Note that this encryption scheme is vulnerable to watermarking attacks
284  *       and should be used for old compatible containers access only.
285  *
286  * plumb: unimplemented, see:
287  * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
288  */
289 
290 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
291 			      struct dm_crypt_request *dmreq)
292 {
293 	memset(iv, 0, cc->iv_size);
294 	*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
295 
296 	return 0;
297 }
298 
299 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
300 				struct dm_crypt_request *dmreq)
301 {
302 	memset(iv, 0, cc->iv_size);
303 	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
304 
305 	return 0;
306 }
307 
308 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
309 				  struct dm_crypt_request *dmreq)
310 {
311 	memset(iv, 0, cc->iv_size);
312 	/* iv_size is at least of size u64; usually it is 16 bytes */
313 	*(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
314 
315 	return 0;
316 }
317 
318 /* Initialise ESSIV - compute salt but no local memory allocations */
319 static int crypt_iv_essiv_init(struct crypt_config *cc)
320 {
321 	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
322 	AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
323 	struct scatterlist sg;
324 	struct crypto_cipher *essiv_tfm;
325 	int err;
326 
327 	sg_init_one(&sg, cc->key, cc->key_size);
328 	ahash_request_set_tfm(req, essiv->hash_tfm);
329 	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
330 	ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
331 
332 	err = crypto_ahash_digest(req);
333 	ahash_request_zero(req);
334 	if (err)
335 		return err;
336 
337 	essiv_tfm = cc->iv_private;
338 
339 	err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
340 			    crypto_ahash_digestsize(essiv->hash_tfm));
341 	if (err)
342 		return err;
343 
344 	return 0;
345 }
346 
347 /* Wipe salt and reset key derived from volume key */
348 static int crypt_iv_essiv_wipe(struct crypt_config *cc)
349 {
350 	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
351 	unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
352 	struct crypto_cipher *essiv_tfm;
353 	int r, err = 0;
354 
355 	memset(essiv->salt, 0, salt_size);
356 
357 	essiv_tfm = cc->iv_private;
358 	r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
359 	if (r)
360 		err = r;
361 
362 	return err;
363 }
364 
365 /* Allocate the cipher for ESSIV */
366 static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
367 						struct dm_target *ti,
368 						const u8 *salt,
369 						unsigned int saltsize)
370 {
371 	struct crypto_cipher *essiv_tfm;
372 	int err;
373 
374 	/* Setup the essiv_tfm with the given salt */
375 	essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
376 	if (IS_ERR(essiv_tfm)) {
377 		ti->error = "Error allocating crypto tfm for ESSIV";
378 		return essiv_tfm;
379 	}
380 
381 	if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) {
382 		ti->error = "Block size of ESSIV cipher does "
383 			    "not match IV size of block cipher";
384 		crypto_free_cipher(essiv_tfm);
385 		return ERR_PTR(-EINVAL);
386 	}
387 
388 	err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
389 	if (err) {
390 		ti->error = "Failed to set key for ESSIV cipher";
391 		crypto_free_cipher(essiv_tfm);
392 		return ERR_PTR(err);
393 	}
394 
395 	return essiv_tfm;
396 }
397 
398 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
399 {
400 	struct crypto_cipher *essiv_tfm;
401 	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
402 
403 	crypto_free_ahash(essiv->hash_tfm);
404 	essiv->hash_tfm = NULL;
405 
406 	kzfree(essiv->salt);
407 	essiv->salt = NULL;
408 
409 	essiv_tfm = cc->iv_private;
410 
411 	if (essiv_tfm)
412 		crypto_free_cipher(essiv_tfm);
413 
414 	cc->iv_private = NULL;
415 }
416 
417 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
418 			      const char *opts)
419 {
420 	struct crypto_cipher *essiv_tfm = NULL;
421 	struct crypto_ahash *hash_tfm = NULL;
422 	u8 *salt = NULL;
423 	int err;
424 
425 	if (!opts) {
426 		ti->error = "Digest algorithm missing for ESSIV mode";
427 		return -EINVAL;
428 	}
429 
430 	/* Allocate hash algorithm */
431 	hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
432 	if (IS_ERR(hash_tfm)) {
433 		ti->error = "Error initializing ESSIV hash";
434 		err = PTR_ERR(hash_tfm);
435 		goto bad;
436 	}
437 
438 	salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
439 	if (!salt) {
440 		ti->error = "Error kmallocing salt storage in ESSIV";
441 		err = -ENOMEM;
442 		goto bad;
443 	}
444 
445 	cc->iv_gen_private.essiv.salt = salt;
446 	cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
447 
448 	essiv_tfm = alloc_essiv_cipher(cc, ti, salt,
449 				       crypto_ahash_digestsize(hash_tfm));
450 	if (IS_ERR(essiv_tfm)) {
451 		crypt_iv_essiv_dtr(cc);
452 		return PTR_ERR(essiv_tfm);
453 	}
454 	cc->iv_private = essiv_tfm;
455 
456 	return 0;
457 
458 bad:
459 	if (hash_tfm && !IS_ERR(hash_tfm))
460 		crypto_free_ahash(hash_tfm);
461 	kfree(salt);
462 	return err;
463 }
464 
465 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
466 			      struct dm_crypt_request *dmreq)
467 {
468 	struct crypto_cipher *essiv_tfm = cc->iv_private;
469 
470 	memset(iv, 0, cc->iv_size);
471 	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
472 	crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
473 
474 	return 0;
475 }
476 
477 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
478 			      const char *opts)
479 {
480 	unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
481 	int log = ilog2(bs);
482 
483 	/* we need to calculate how far we must shift the sector count
484 	 * to get the cipher block count, we use this shift in _gen */
485 
486 	if (1 << log != bs) {
487 		ti->error = "cypher blocksize is not a power of 2";
488 		return -EINVAL;
489 	}
490 
491 	if (log > 9) {
492 		ti->error = "cypher blocksize is > 512";
493 		return -EINVAL;
494 	}
495 
496 	cc->iv_gen_private.benbi.shift = 9 - log;
497 
498 	return 0;
499 }
500 
501 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
502 {
503 }
504 
505 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
506 			      struct dm_crypt_request *dmreq)
507 {
508 	__be64 val;
509 
510 	memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
511 
512 	val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
513 	put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
514 
515 	return 0;
516 }
517 
518 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
519 			     struct dm_crypt_request *dmreq)
520 {
521 	memset(iv, 0, cc->iv_size);
522 
523 	return 0;
524 }
525 
526 static void crypt_iv_lmk_dtr(struct crypt_config *cc)
527 {
528 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
529 
530 	if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
531 		crypto_free_shash(lmk->hash_tfm);
532 	lmk->hash_tfm = NULL;
533 
534 	kzfree(lmk->seed);
535 	lmk->seed = NULL;
536 }
537 
538 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
539 			    const char *opts)
540 {
541 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
542 
543 	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
544 		ti->error = "Unsupported sector size for LMK";
545 		return -EINVAL;
546 	}
547 
548 	lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
549 	if (IS_ERR(lmk->hash_tfm)) {
550 		ti->error = "Error initializing LMK hash";
551 		return PTR_ERR(lmk->hash_tfm);
552 	}
553 
554 	/* No seed in LMK version 2 */
555 	if (cc->key_parts == cc->tfms_count) {
556 		lmk->seed = NULL;
557 		return 0;
558 	}
559 
560 	lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
561 	if (!lmk->seed) {
562 		crypt_iv_lmk_dtr(cc);
563 		ti->error = "Error kmallocing seed storage in LMK";
564 		return -ENOMEM;
565 	}
566 
567 	return 0;
568 }
569 
570 static int crypt_iv_lmk_init(struct crypt_config *cc)
571 {
572 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
573 	int subkey_size = cc->key_size / cc->key_parts;
574 
575 	/* LMK seed is on the position of LMK_KEYS + 1 key */
576 	if (lmk->seed)
577 		memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
578 		       crypto_shash_digestsize(lmk->hash_tfm));
579 
580 	return 0;
581 }
582 
583 static int crypt_iv_lmk_wipe(struct crypt_config *cc)
584 {
585 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
586 
587 	if (lmk->seed)
588 		memset(lmk->seed, 0, LMK_SEED_SIZE);
589 
590 	return 0;
591 }
592 
593 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
594 			    struct dm_crypt_request *dmreq,
595 			    u8 *data)
596 {
597 	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
598 	SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
599 	struct md5_state md5state;
600 	__le32 buf[4];
601 	int i, r;
602 
603 	desc->tfm = lmk->hash_tfm;
604 	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
605 
606 	r = crypto_shash_init(desc);
607 	if (r)
608 		return r;
609 
610 	if (lmk->seed) {
611 		r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
612 		if (r)
613 			return r;
614 	}
615 
616 	/* Sector is always 512B, block size 16, add data of blocks 1-31 */
617 	r = crypto_shash_update(desc, data + 16, 16 * 31);
618 	if (r)
619 		return r;
620 
621 	/* Sector is cropped to 56 bits here */
622 	buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
623 	buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
624 	buf[2] = cpu_to_le32(4024);
625 	buf[3] = 0;
626 	r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
627 	if (r)
628 		return r;
629 
630 	/* No MD5 padding here */
631 	r = crypto_shash_export(desc, &md5state);
632 	if (r)
633 		return r;
634 
635 	for (i = 0; i < MD5_HASH_WORDS; i++)
636 		__cpu_to_le32s(&md5state.hash[i]);
637 	memcpy(iv, &md5state.hash, cc->iv_size);
638 
639 	return 0;
640 }
641 
642 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
643 			    struct dm_crypt_request *dmreq)
644 {
645 	struct scatterlist *sg;
646 	u8 *src;
647 	int r = 0;
648 
649 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
650 		sg = crypt_get_sg_data(cc, dmreq->sg_in);
651 		src = kmap_atomic(sg_page(sg));
652 		r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
653 		kunmap_atomic(src);
654 	} else
655 		memset(iv, 0, cc->iv_size);
656 
657 	return r;
658 }
659 
660 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
661 			     struct dm_crypt_request *dmreq)
662 {
663 	struct scatterlist *sg;
664 	u8 *dst;
665 	int r;
666 
667 	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
668 		return 0;
669 
670 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
671 	dst = kmap_atomic(sg_page(sg));
672 	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
673 
674 	/* Tweak the first block of plaintext sector */
675 	if (!r)
676 		crypto_xor(dst + sg->offset, iv, cc->iv_size);
677 
678 	kunmap_atomic(dst);
679 	return r;
680 }
681 
682 static void crypt_iv_tcw_dtr(struct crypt_config *cc)
683 {
684 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
685 
686 	kzfree(tcw->iv_seed);
687 	tcw->iv_seed = NULL;
688 	kzfree(tcw->whitening);
689 	tcw->whitening = NULL;
690 
691 	if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
692 		crypto_free_shash(tcw->crc32_tfm);
693 	tcw->crc32_tfm = NULL;
694 }
695 
696 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
697 			    const char *opts)
698 {
699 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
700 
701 	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
702 		ti->error = "Unsupported sector size for TCW";
703 		return -EINVAL;
704 	}
705 
706 	if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
707 		ti->error = "Wrong key size for TCW";
708 		return -EINVAL;
709 	}
710 
711 	tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
712 	if (IS_ERR(tcw->crc32_tfm)) {
713 		ti->error = "Error initializing CRC32 in TCW";
714 		return PTR_ERR(tcw->crc32_tfm);
715 	}
716 
717 	tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
718 	tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
719 	if (!tcw->iv_seed || !tcw->whitening) {
720 		crypt_iv_tcw_dtr(cc);
721 		ti->error = "Error allocating seed storage in TCW";
722 		return -ENOMEM;
723 	}
724 
725 	return 0;
726 }
727 
728 static int crypt_iv_tcw_init(struct crypt_config *cc)
729 {
730 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
731 	int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
732 
733 	memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
734 	memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
735 	       TCW_WHITENING_SIZE);
736 
737 	return 0;
738 }
739 
740 static int crypt_iv_tcw_wipe(struct crypt_config *cc)
741 {
742 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
743 
744 	memset(tcw->iv_seed, 0, cc->iv_size);
745 	memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
746 
747 	return 0;
748 }
749 
750 static int crypt_iv_tcw_whitening(struct crypt_config *cc,
751 				  struct dm_crypt_request *dmreq,
752 				  u8 *data)
753 {
754 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
755 	__le64 sector = cpu_to_le64(dmreq->iv_sector);
756 	u8 buf[TCW_WHITENING_SIZE];
757 	SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
758 	int i, r;
759 
760 	/* xor whitening with sector number */
761 	memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
762 	crypto_xor(buf, (u8 *)&sector, 8);
763 	crypto_xor(&buf[8], (u8 *)&sector, 8);
764 
765 	/* calculate crc32 for every 32bit part and xor it */
766 	desc->tfm = tcw->crc32_tfm;
767 	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
768 	for (i = 0; i < 4; i++) {
769 		r = crypto_shash_init(desc);
770 		if (r)
771 			goto out;
772 		r = crypto_shash_update(desc, &buf[i * 4], 4);
773 		if (r)
774 			goto out;
775 		r = crypto_shash_final(desc, &buf[i * 4]);
776 		if (r)
777 			goto out;
778 	}
779 	crypto_xor(&buf[0], &buf[12], 4);
780 	crypto_xor(&buf[4], &buf[8], 4);
781 
782 	/* apply whitening (8 bytes) to whole sector */
783 	for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
784 		crypto_xor(data + i * 8, buf, 8);
785 out:
786 	memzero_explicit(buf, sizeof(buf));
787 	return r;
788 }
789 
790 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
791 			    struct dm_crypt_request *dmreq)
792 {
793 	struct scatterlist *sg;
794 	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
795 	__le64 sector = cpu_to_le64(dmreq->iv_sector);
796 	u8 *src;
797 	int r = 0;
798 
799 	/* Remove whitening from ciphertext */
800 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
801 		sg = crypt_get_sg_data(cc, dmreq->sg_in);
802 		src = kmap_atomic(sg_page(sg));
803 		r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
804 		kunmap_atomic(src);
805 	}
806 
807 	/* Calculate IV */
808 	memcpy(iv, tcw->iv_seed, cc->iv_size);
809 	crypto_xor(iv, (u8 *)&sector, 8);
810 	if (cc->iv_size > 8)
811 		crypto_xor(&iv[8], (u8 *)&sector, cc->iv_size - 8);
812 
813 	return r;
814 }
815 
816 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
817 			     struct dm_crypt_request *dmreq)
818 {
819 	struct scatterlist *sg;
820 	u8 *dst;
821 	int r;
822 
823 	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
824 		return 0;
825 
826 	/* Apply whitening on ciphertext */
827 	sg = crypt_get_sg_data(cc, dmreq->sg_out);
828 	dst = kmap_atomic(sg_page(sg));
829 	r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
830 	kunmap_atomic(dst);
831 
832 	return r;
833 }
834 
835 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
836 				struct dm_crypt_request *dmreq)
837 {
838 	/* Used only for writes, there must be an additional space to store IV */
839 	get_random_bytes(iv, cc->iv_size);
840 	return 0;
841 }
842 
843 static const struct crypt_iv_operations crypt_iv_plain_ops = {
844 	.generator = crypt_iv_plain_gen
845 };
846 
847 static const struct crypt_iv_operations crypt_iv_plain64_ops = {
848 	.generator = crypt_iv_plain64_gen
849 };
850 
851 static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
852 	.generator = crypt_iv_plain64be_gen
853 };
854 
855 static const struct crypt_iv_operations crypt_iv_essiv_ops = {
856 	.ctr       = crypt_iv_essiv_ctr,
857 	.dtr       = crypt_iv_essiv_dtr,
858 	.init      = crypt_iv_essiv_init,
859 	.wipe      = crypt_iv_essiv_wipe,
860 	.generator = crypt_iv_essiv_gen
861 };
862 
863 static const struct crypt_iv_operations crypt_iv_benbi_ops = {
864 	.ctr	   = crypt_iv_benbi_ctr,
865 	.dtr	   = crypt_iv_benbi_dtr,
866 	.generator = crypt_iv_benbi_gen
867 };
868 
869 static const struct crypt_iv_operations crypt_iv_null_ops = {
870 	.generator = crypt_iv_null_gen
871 };
872 
873 static const struct crypt_iv_operations crypt_iv_lmk_ops = {
874 	.ctr	   = crypt_iv_lmk_ctr,
875 	.dtr	   = crypt_iv_lmk_dtr,
876 	.init	   = crypt_iv_lmk_init,
877 	.wipe	   = crypt_iv_lmk_wipe,
878 	.generator = crypt_iv_lmk_gen,
879 	.post	   = crypt_iv_lmk_post
880 };
881 
882 static const struct crypt_iv_operations crypt_iv_tcw_ops = {
883 	.ctr	   = crypt_iv_tcw_ctr,
884 	.dtr	   = crypt_iv_tcw_dtr,
885 	.init	   = crypt_iv_tcw_init,
886 	.wipe	   = crypt_iv_tcw_wipe,
887 	.generator = crypt_iv_tcw_gen,
888 	.post	   = crypt_iv_tcw_post
889 };
890 
891 static struct crypt_iv_operations crypt_iv_random_ops = {
892 	.generator = crypt_iv_random_gen
893 };
894 
895 /*
896  * Integrity extensions
897  */
898 static bool crypt_integrity_aead(struct crypt_config *cc)
899 {
900 	return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
901 }
902 
903 static bool crypt_integrity_hmac(struct crypt_config *cc)
904 {
905 	return crypt_integrity_aead(cc) && cc->key_mac_size;
906 }
907 
908 /* Get sg containing data */
909 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
910 					     struct scatterlist *sg)
911 {
912 	if (unlikely(crypt_integrity_aead(cc)))
913 		return &sg[2];
914 
915 	return sg;
916 }
917 
918 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
919 {
920 	struct bio_integrity_payload *bip;
921 	unsigned int tag_len;
922 	int ret;
923 
924 	if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
925 		return 0;
926 
927 	bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
928 	if (IS_ERR(bip))
929 		return PTR_ERR(bip);
930 
931 	tag_len = io->cc->on_disk_tag_size * bio_sectors(bio);
932 
933 	bip->bip_iter.bi_size = tag_len;
934 	bip->bip_iter.bi_sector = io->cc->start + io->sector;
935 
936 	/* We own the metadata, do not let bio_free to release it */
937 	bip->bip_flags &= ~BIP_BLOCK_INTEGRITY;
938 
939 	ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
940 				     tag_len, offset_in_page(io->integrity_metadata));
941 	if (unlikely(ret != tag_len))
942 		return -ENOMEM;
943 
944 	return 0;
945 }
946 
947 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
948 {
949 #ifdef CONFIG_BLK_DEV_INTEGRITY
950 	struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
951 
952 	/* From now we require underlying device with our integrity profile */
953 	if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
954 		ti->error = "Integrity profile not supported.";
955 		return -EINVAL;
956 	}
957 
958 	if (bi->tag_size != cc->on_disk_tag_size ||
959 	    bi->tuple_size != cc->on_disk_tag_size) {
960 		ti->error = "Integrity profile tag size mismatch.";
961 		return -EINVAL;
962 	}
963 	if (1 << bi->interval_exp != cc->sector_size) {
964 		ti->error = "Integrity profile sector size mismatch.";
965 		return -EINVAL;
966 	}
967 
968 	if (crypt_integrity_aead(cc)) {
969 		cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
970 		DMINFO("Integrity AEAD, tag size %u, IV size %u.",
971 		       cc->integrity_tag_size, cc->integrity_iv_size);
972 
973 		if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
974 			ti->error = "Integrity AEAD auth tag size is not supported.";
975 			return -EINVAL;
976 		}
977 	} else if (cc->integrity_iv_size)
978 		DMINFO("Additional per-sector space %u bytes for IV.",
979 		       cc->integrity_iv_size);
980 
981 	if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
982 		ti->error = "Not enough space for integrity tag in the profile.";
983 		return -EINVAL;
984 	}
985 
986 	return 0;
987 #else
988 	ti->error = "Integrity profile not supported.";
989 	return -EINVAL;
990 #endif
991 }
992 
993 static void crypt_convert_init(struct crypt_config *cc,
994 			       struct convert_context *ctx,
995 			       struct bio *bio_out, struct bio *bio_in,
996 			       sector_t sector)
997 {
998 	ctx->bio_in = bio_in;
999 	ctx->bio_out = bio_out;
1000 	if (bio_in)
1001 		ctx->iter_in = bio_in->bi_iter;
1002 	if (bio_out)
1003 		ctx->iter_out = bio_out->bi_iter;
1004 	ctx->cc_sector = sector + cc->iv_offset;
1005 	init_completion(&ctx->restart);
1006 }
1007 
1008 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1009 					     void *req)
1010 {
1011 	return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1012 }
1013 
1014 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1015 {
1016 	return (void *)((char *)dmreq - cc->dmreq_start);
1017 }
1018 
1019 static u8 *iv_of_dmreq(struct crypt_config *cc,
1020 		       struct dm_crypt_request *dmreq)
1021 {
1022 	if (crypt_integrity_aead(cc))
1023 		return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1024 			crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1025 	else
1026 		return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1027 			crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1028 }
1029 
1030 static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1031 		       struct dm_crypt_request *dmreq)
1032 {
1033 	return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1034 }
1035 
1036 static uint64_t *org_sector_of_dmreq(struct crypt_config *cc,
1037 		       struct dm_crypt_request *dmreq)
1038 {
1039 	u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1040 	return (uint64_t*) ptr;
1041 }
1042 
1043 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1044 		       struct dm_crypt_request *dmreq)
1045 {
1046 	u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1047 		  cc->iv_size + sizeof(uint64_t);
1048 	return (unsigned int*)ptr;
1049 }
1050 
1051 static void *tag_from_dmreq(struct crypt_config *cc,
1052 				struct dm_crypt_request *dmreq)
1053 {
1054 	struct convert_context *ctx = dmreq->ctx;
1055 	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1056 
1057 	return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1058 		cc->on_disk_tag_size];
1059 }
1060 
1061 static void *iv_tag_from_dmreq(struct crypt_config *cc,
1062 			       struct dm_crypt_request *dmreq)
1063 {
1064 	return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1065 }
1066 
1067 static int crypt_convert_block_aead(struct crypt_config *cc,
1068 				     struct convert_context *ctx,
1069 				     struct aead_request *req,
1070 				     unsigned int tag_offset)
1071 {
1072 	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1073 	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1074 	struct dm_crypt_request *dmreq;
1075 	u8 *iv, *org_iv, *tag_iv, *tag;
1076 	uint64_t *sector;
1077 	int r = 0;
1078 
1079 	BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1080 
1081 	/* Reject unexpected unaligned bio. */
1082 	if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
1083 		return -EIO;
1084 
1085 	dmreq = dmreq_of_req(cc, req);
1086 	dmreq->iv_sector = ctx->cc_sector;
1087 	if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1088 		dmreq->iv_sector >>= cc->sector_shift;
1089 	dmreq->ctx = ctx;
1090 
1091 	*org_tag_of_dmreq(cc, dmreq) = tag_offset;
1092 
1093 	sector = org_sector_of_dmreq(cc, dmreq);
1094 	*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1095 
1096 	iv = iv_of_dmreq(cc, dmreq);
1097 	org_iv = org_iv_of_dmreq(cc, dmreq);
1098 	tag = tag_from_dmreq(cc, dmreq);
1099 	tag_iv = iv_tag_from_dmreq(cc, dmreq);
1100 
1101 	/* AEAD request:
1102 	 *  |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1103 	 *  | (authenticated) | (auth+encryption) |              |
1104 	 *  | sector_LE |  IV |  sector in/out    |  tag in/out  |
1105 	 */
1106 	sg_init_table(dmreq->sg_in, 4);
1107 	sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1108 	sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1109 	sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1110 	sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1111 
1112 	sg_init_table(dmreq->sg_out, 4);
1113 	sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1114 	sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1115 	sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1116 	sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1117 
1118 	if (cc->iv_gen_ops) {
1119 		/* For READs use IV stored in integrity metadata */
1120 		if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1121 			memcpy(org_iv, tag_iv, cc->iv_size);
1122 		} else {
1123 			r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1124 			if (r < 0)
1125 				return r;
1126 			/* Store generated IV in integrity metadata */
1127 			if (cc->integrity_iv_size)
1128 				memcpy(tag_iv, org_iv, cc->iv_size);
1129 		}
1130 		/* Working copy of IV, to be modified in crypto API */
1131 		memcpy(iv, org_iv, cc->iv_size);
1132 	}
1133 
1134 	aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1135 	if (bio_data_dir(ctx->bio_in) == WRITE) {
1136 		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1137 				       cc->sector_size, iv);
1138 		r = crypto_aead_encrypt(req);
1139 		if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1140 			memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1141 			       cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1142 	} else {
1143 		aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1144 				       cc->sector_size + cc->integrity_tag_size, iv);
1145 		r = crypto_aead_decrypt(req);
1146 	}
1147 
1148 	if (r == -EBADMSG)
1149 		DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1150 			    (unsigned long long)le64_to_cpu(*sector));
1151 
1152 	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1153 		r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1154 
1155 	bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1156 	bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1157 
1158 	return r;
1159 }
1160 
1161 static int crypt_convert_block_skcipher(struct crypt_config *cc,
1162 					struct convert_context *ctx,
1163 					struct skcipher_request *req,
1164 					unsigned int tag_offset)
1165 {
1166 	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1167 	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1168 	struct scatterlist *sg_in, *sg_out;
1169 	struct dm_crypt_request *dmreq;
1170 	u8 *iv, *org_iv, *tag_iv;
1171 	uint64_t *sector;
1172 	int r = 0;
1173 
1174 	/* Reject unexpected unaligned bio. */
1175 	if (unlikely(bv_in.bv_offset & (cc->sector_size - 1)))
1176 		return -EIO;
1177 
1178 	dmreq = dmreq_of_req(cc, req);
1179 	dmreq->iv_sector = ctx->cc_sector;
1180 	if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1181 		dmreq->iv_sector >>= cc->sector_shift;
1182 	dmreq->ctx = ctx;
1183 
1184 	*org_tag_of_dmreq(cc, dmreq) = tag_offset;
1185 
1186 	iv = iv_of_dmreq(cc, dmreq);
1187 	org_iv = org_iv_of_dmreq(cc, dmreq);
1188 	tag_iv = iv_tag_from_dmreq(cc, dmreq);
1189 
1190 	sector = org_sector_of_dmreq(cc, dmreq);
1191 	*sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1192 
1193 	/* For skcipher we use only the first sg item */
1194 	sg_in  = &dmreq->sg_in[0];
1195 	sg_out = &dmreq->sg_out[0];
1196 
1197 	sg_init_table(sg_in, 1);
1198 	sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1199 
1200 	sg_init_table(sg_out, 1);
1201 	sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1202 
1203 	if (cc->iv_gen_ops) {
1204 		/* For READs use IV stored in integrity metadata */
1205 		if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1206 			memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1207 		} else {
1208 			r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1209 			if (r < 0)
1210 				return r;
1211 			/* Store generated IV in integrity metadata */
1212 			if (cc->integrity_iv_size)
1213 				memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1214 		}
1215 		/* Working copy of IV, to be modified in crypto API */
1216 		memcpy(iv, org_iv, cc->iv_size);
1217 	}
1218 
1219 	skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1220 
1221 	if (bio_data_dir(ctx->bio_in) == WRITE)
1222 		r = crypto_skcipher_encrypt(req);
1223 	else
1224 		r = crypto_skcipher_decrypt(req);
1225 
1226 	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1227 		r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1228 
1229 	bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1230 	bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1231 
1232 	return r;
1233 }
1234 
1235 static void kcryptd_async_done(struct crypto_async_request *async_req,
1236 			       int error);
1237 
1238 static void crypt_alloc_req_skcipher(struct crypt_config *cc,
1239 				     struct convert_context *ctx)
1240 {
1241 	unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1242 
1243 	if (!ctx->r.req)
1244 		ctx->r.req = mempool_alloc(cc->req_pool, GFP_NOIO);
1245 
1246 	skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1247 
1248 	/*
1249 	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1250 	 * requests if driver request queue is full.
1251 	 */
1252 	skcipher_request_set_callback(ctx->r.req,
1253 	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
1254 	    kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1255 }
1256 
1257 static void crypt_alloc_req_aead(struct crypt_config *cc,
1258 				 struct convert_context *ctx)
1259 {
1260 	if (!ctx->r.req_aead)
1261 		ctx->r.req_aead = mempool_alloc(cc->req_pool, GFP_NOIO);
1262 
1263 	aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1264 
1265 	/*
1266 	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1267 	 * requests if driver request queue is full.
1268 	 */
1269 	aead_request_set_callback(ctx->r.req_aead,
1270 	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
1271 	    kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1272 }
1273 
1274 static void crypt_alloc_req(struct crypt_config *cc,
1275 			    struct convert_context *ctx)
1276 {
1277 	if (crypt_integrity_aead(cc))
1278 		crypt_alloc_req_aead(cc, ctx);
1279 	else
1280 		crypt_alloc_req_skcipher(cc, ctx);
1281 }
1282 
1283 static void crypt_free_req_skcipher(struct crypt_config *cc,
1284 				    struct skcipher_request *req, struct bio *base_bio)
1285 {
1286 	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1287 
1288 	if ((struct skcipher_request *)(io + 1) != req)
1289 		mempool_free(req, cc->req_pool);
1290 }
1291 
1292 static void crypt_free_req_aead(struct crypt_config *cc,
1293 				struct aead_request *req, struct bio *base_bio)
1294 {
1295 	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1296 
1297 	if ((struct aead_request *)(io + 1) != req)
1298 		mempool_free(req, cc->req_pool);
1299 }
1300 
1301 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1302 {
1303 	if (crypt_integrity_aead(cc))
1304 		crypt_free_req_aead(cc, req, base_bio);
1305 	else
1306 		crypt_free_req_skcipher(cc, req, base_bio);
1307 }
1308 
1309 /*
1310  * Encrypt / decrypt data from one bio to another one (can be the same one)
1311  */
1312 static blk_status_t crypt_convert(struct crypt_config *cc,
1313 			 struct convert_context *ctx)
1314 {
1315 	unsigned int tag_offset = 0;
1316 	unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1317 	int r;
1318 
1319 	atomic_set(&ctx->cc_pending, 1);
1320 
1321 	while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1322 
1323 		crypt_alloc_req(cc, ctx);
1324 		atomic_inc(&ctx->cc_pending);
1325 
1326 		if (crypt_integrity_aead(cc))
1327 			r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1328 		else
1329 			r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1330 
1331 		switch (r) {
1332 		/*
1333 		 * The request was queued by a crypto driver
1334 		 * but the driver request queue is full, let's wait.
1335 		 */
1336 		case -EBUSY:
1337 			wait_for_completion(&ctx->restart);
1338 			reinit_completion(&ctx->restart);
1339 			/* fall through */
1340 		/*
1341 		 * The request is queued and processed asynchronously,
1342 		 * completion function kcryptd_async_done() will be called.
1343 		 */
1344 		case -EINPROGRESS:
1345 			ctx->r.req = NULL;
1346 			ctx->cc_sector += sector_step;
1347 			tag_offset++;
1348 			continue;
1349 		/*
1350 		 * The request was already processed (synchronously).
1351 		 */
1352 		case 0:
1353 			atomic_dec(&ctx->cc_pending);
1354 			ctx->cc_sector += sector_step;
1355 			tag_offset++;
1356 			cond_resched();
1357 			continue;
1358 		/*
1359 		 * There was a data integrity error.
1360 		 */
1361 		case -EBADMSG:
1362 			atomic_dec(&ctx->cc_pending);
1363 			return BLK_STS_PROTECTION;
1364 		/*
1365 		 * There was an error while processing the request.
1366 		 */
1367 		default:
1368 			atomic_dec(&ctx->cc_pending);
1369 			return BLK_STS_IOERR;
1370 		}
1371 	}
1372 
1373 	return 0;
1374 }
1375 
1376 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1377 
1378 /*
1379  * Generate a new unfragmented bio with the given size
1380  * This should never violate the device limitations (but only because
1381  * max_segment_size is being constrained to PAGE_SIZE).
1382  *
1383  * This function may be called concurrently. If we allocate from the mempool
1384  * concurrently, there is a possibility of deadlock. For example, if we have
1385  * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1386  * the mempool concurrently, it may deadlock in a situation where both processes
1387  * have allocated 128 pages and the mempool is exhausted.
1388  *
1389  * In order to avoid this scenario we allocate the pages under a mutex.
1390  *
1391  * In order to not degrade performance with excessive locking, we try
1392  * non-blocking allocations without a mutex first but on failure we fallback
1393  * to blocking allocations with a mutex.
1394  */
1395 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1396 {
1397 	struct crypt_config *cc = io->cc;
1398 	struct bio *clone;
1399 	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1400 	gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1401 	unsigned i, len, remaining_size;
1402 	struct page *page;
1403 
1404 retry:
1405 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1406 		mutex_lock(&cc->bio_alloc_lock);
1407 
1408 	clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1409 	if (!clone)
1410 		goto out;
1411 
1412 	clone_init(io, clone);
1413 
1414 	remaining_size = size;
1415 
1416 	for (i = 0; i < nr_iovecs; i++) {
1417 		page = mempool_alloc(cc->page_pool, gfp_mask);
1418 		if (!page) {
1419 			crypt_free_buffer_pages(cc, clone);
1420 			bio_put(clone);
1421 			gfp_mask |= __GFP_DIRECT_RECLAIM;
1422 			goto retry;
1423 		}
1424 
1425 		len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1426 
1427 		bio_add_page(clone, page, len, 0);
1428 
1429 		remaining_size -= len;
1430 	}
1431 
1432 	/* Allocate space for integrity tags */
1433 	if (dm_crypt_integrity_io_alloc(io, clone)) {
1434 		crypt_free_buffer_pages(cc, clone);
1435 		bio_put(clone);
1436 		clone = NULL;
1437 	}
1438 out:
1439 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1440 		mutex_unlock(&cc->bio_alloc_lock);
1441 
1442 	return clone;
1443 }
1444 
1445 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1446 {
1447 	unsigned int i;
1448 	struct bio_vec *bv;
1449 
1450 	bio_for_each_segment_all(bv, clone, i) {
1451 		BUG_ON(!bv->bv_page);
1452 		mempool_free(bv->bv_page, cc->page_pool);
1453 		bv->bv_page = NULL;
1454 	}
1455 }
1456 
1457 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1458 			  struct bio *bio, sector_t sector)
1459 {
1460 	io->cc = cc;
1461 	io->base_bio = bio;
1462 	io->sector = sector;
1463 	io->error = 0;
1464 	io->ctx.r.req = NULL;
1465 	io->integrity_metadata = NULL;
1466 	io->integrity_metadata_from_pool = false;
1467 	atomic_set(&io->io_pending, 0);
1468 }
1469 
1470 static void crypt_inc_pending(struct dm_crypt_io *io)
1471 {
1472 	atomic_inc(&io->io_pending);
1473 }
1474 
1475 /*
1476  * One of the bios was finished. Check for completion of
1477  * the whole request and correctly clean up the buffer.
1478  */
1479 static void crypt_dec_pending(struct dm_crypt_io *io)
1480 {
1481 	struct crypt_config *cc = io->cc;
1482 	struct bio *base_bio = io->base_bio;
1483 	blk_status_t error = io->error;
1484 
1485 	if (!atomic_dec_and_test(&io->io_pending))
1486 		return;
1487 
1488 	if (io->ctx.r.req)
1489 		crypt_free_req(cc, io->ctx.r.req, base_bio);
1490 
1491 	if (unlikely(io->integrity_metadata_from_pool))
1492 		mempool_free(io->integrity_metadata, io->cc->tag_pool);
1493 	else
1494 		kfree(io->integrity_metadata);
1495 
1496 	base_bio->bi_status = error;
1497 	bio_endio(base_bio);
1498 }
1499 
1500 /*
1501  * kcryptd/kcryptd_io:
1502  *
1503  * Needed because it would be very unwise to do decryption in an
1504  * interrupt context.
1505  *
1506  * kcryptd performs the actual encryption or decryption.
1507  *
1508  * kcryptd_io performs the IO submission.
1509  *
1510  * They must be separated as otherwise the final stages could be
1511  * starved by new requests which can block in the first stages due
1512  * to memory allocation.
1513  *
1514  * The work is done per CPU global for all dm-crypt instances.
1515  * They should not depend on each other and do not block.
1516  */
1517 static void crypt_endio(struct bio *clone)
1518 {
1519 	struct dm_crypt_io *io = clone->bi_private;
1520 	struct crypt_config *cc = io->cc;
1521 	unsigned rw = bio_data_dir(clone);
1522 	blk_status_t error;
1523 
1524 	/*
1525 	 * free the processed pages
1526 	 */
1527 	if (rw == WRITE)
1528 		crypt_free_buffer_pages(cc, clone);
1529 
1530 	error = clone->bi_status;
1531 	bio_put(clone);
1532 
1533 	if (rw == READ && !error) {
1534 		kcryptd_queue_crypt(io);
1535 		return;
1536 	}
1537 
1538 	if (unlikely(error))
1539 		io->error = error;
1540 
1541 	crypt_dec_pending(io);
1542 }
1543 
1544 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1545 {
1546 	struct crypt_config *cc = io->cc;
1547 
1548 	clone->bi_private = io;
1549 	clone->bi_end_io  = crypt_endio;
1550 	clone->bi_bdev    = cc->dev->bdev;
1551 	clone->bi_opf	  = io->base_bio->bi_opf;
1552 }
1553 
1554 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1555 {
1556 	struct crypt_config *cc = io->cc;
1557 	struct bio *clone;
1558 
1559 	/*
1560 	 * We need the original biovec array in order to decrypt
1561 	 * the whole bio data *afterwards* -- thanks to immutable
1562 	 * biovecs we don't need to worry about the block layer
1563 	 * modifying the biovec array; so leverage bio_clone_fast().
1564 	 */
1565 	clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1566 	if (!clone)
1567 		return 1;
1568 
1569 	crypt_inc_pending(io);
1570 
1571 	clone_init(io, clone);
1572 	clone->bi_iter.bi_sector = cc->start + io->sector;
1573 
1574 	if (dm_crypt_integrity_io_alloc(io, clone)) {
1575 		crypt_dec_pending(io);
1576 		bio_put(clone);
1577 		return 1;
1578 	}
1579 
1580 	generic_make_request(clone);
1581 	return 0;
1582 }
1583 
1584 static void kcryptd_io_read_work(struct work_struct *work)
1585 {
1586 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1587 
1588 	crypt_inc_pending(io);
1589 	if (kcryptd_io_read(io, GFP_NOIO))
1590 		io->error = BLK_STS_RESOURCE;
1591 	crypt_dec_pending(io);
1592 }
1593 
1594 static void kcryptd_queue_read(struct dm_crypt_io *io)
1595 {
1596 	struct crypt_config *cc = io->cc;
1597 
1598 	INIT_WORK(&io->work, kcryptd_io_read_work);
1599 	queue_work(cc->io_queue, &io->work);
1600 }
1601 
1602 static void kcryptd_io_write(struct dm_crypt_io *io)
1603 {
1604 	struct bio *clone = io->ctx.bio_out;
1605 
1606 	generic_make_request(clone);
1607 }
1608 
1609 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1610 
1611 static int dmcrypt_write(void *data)
1612 {
1613 	struct crypt_config *cc = data;
1614 	struct dm_crypt_io *io;
1615 
1616 	while (1) {
1617 		struct rb_root write_tree;
1618 		struct blk_plug plug;
1619 
1620 		DECLARE_WAITQUEUE(wait, current);
1621 
1622 		spin_lock_irq(&cc->write_thread_wait.lock);
1623 continue_locked:
1624 
1625 		if (!RB_EMPTY_ROOT(&cc->write_tree))
1626 			goto pop_from_list;
1627 
1628 		set_current_state(TASK_INTERRUPTIBLE);
1629 		__add_wait_queue(&cc->write_thread_wait, &wait);
1630 
1631 		spin_unlock_irq(&cc->write_thread_wait.lock);
1632 
1633 		if (unlikely(kthread_should_stop())) {
1634 			set_current_state(TASK_RUNNING);
1635 			remove_wait_queue(&cc->write_thread_wait, &wait);
1636 			break;
1637 		}
1638 
1639 		schedule();
1640 
1641 		set_current_state(TASK_RUNNING);
1642 		spin_lock_irq(&cc->write_thread_wait.lock);
1643 		__remove_wait_queue(&cc->write_thread_wait, &wait);
1644 		goto continue_locked;
1645 
1646 pop_from_list:
1647 		write_tree = cc->write_tree;
1648 		cc->write_tree = RB_ROOT;
1649 		spin_unlock_irq(&cc->write_thread_wait.lock);
1650 
1651 		BUG_ON(rb_parent(write_tree.rb_node));
1652 
1653 		/*
1654 		 * Note: we cannot walk the tree here with rb_next because
1655 		 * the structures may be freed when kcryptd_io_write is called.
1656 		 */
1657 		blk_start_plug(&plug);
1658 		do {
1659 			io = crypt_io_from_node(rb_first(&write_tree));
1660 			rb_erase(&io->rb_node, &write_tree);
1661 			kcryptd_io_write(io);
1662 		} while (!RB_EMPTY_ROOT(&write_tree));
1663 		blk_finish_plug(&plug);
1664 	}
1665 	return 0;
1666 }
1667 
1668 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1669 {
1670 	struct bio *clone = io->ctx.bio_out;
1671 	struct crypt_config *cc = io->cc;
1672 	unsigned long flags;
1673 	sector_t sector;
1674 	struct rb_node **rbp, *parent;
1675 
1676 	if (unlikely(io->error)) {
1677 		crypt_free_buffer_pages(cc, clone);
1678 		bio_put(clone);
1679 		crypt_dec_pending(io);
1680 		return;
1681 	}
1682 
1683 	/* crypt_convert should have filled the clone bio */
1684 	BUG_ON(io->ctx.iter_out.bi_size);
1685 
1686 	clone->bi_iter.bi_sector = cc->start + io->sector;
1687 
1688 	if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1689 		generic_make_request(clone);
1690 		return;
1691 	}
1692 
1693 	spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1694 	rbp = &cc->write_tree.rb_node;
1695 	parent = NULL;
1696 	sector = io->sector;
1697 	while (*rbp) {
1698 		parent = *rbp;
1699 		if (sector < crypt_io_from_node(parent)->sector)
1700 			rbp = &(*rbp)->rb_left;
1701 		else
1702 			rbp = &(*rbp)->rb_right;
1703 	}
1704 	rb_link_node(&io->rb_node, parent, rbp);
1705 	rb_insert_color(&io->rb_node, &cc->write_tree);
1706 
1707 	wake_up_locked(&cc->write_thread_wait);
1708 	spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1709 }
1710 
1711 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1712 {
1713 	struct crypt_config *cc = io->cc;
1714 	struct bio *clone;
1715 	int crypt_finished;
1716 	sector_t sector = io->sector;
1717 	blk_status_t r;
1718 
1719 	/*
1720 	 * Prevent io from disappearing until this function completes.
1721 	 */
1722 	crypt_inc_pending(io);
1723 	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1724 
1725 	clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1726 	if (unlikely(!clone)) {
1727 		io->error = BLK_STS_IOERR;
1728 		goto dec;
1729 	}
1730 
1731 	io->ctx.bio_out = clone;
1732 	io->ctx.iter_out = clone->bi_iter;
1733 
1734 	sector += bio_sectors(clone);
1735 
1736 	crypt_inc_pending(io);
1737 	r = crypt_convert(cc, &io->ctx);
1738 	if (r)
1739 		io->error = r;
1740 	crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1741 
1742 	/* Encryption was already finished, submit io now */
1743 	if (crypt_finished) {
1744 		kcryptd_crypt_write_io_submit(io, 0);
1745 		io->sector = sector;
1746 	}
1747 
1748 dec:
1749 	crypt_dec_pending(io);
1750 }
1751 
1752 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1753 {
1754 	crypt_dec_pending(io);
1755 }
1756 
1757 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1758 {
1759 	struct crypt_config *cc = io->cc;
1760 	blk_status_t r;
1761 
1762 	crypt_inc_pending(io);
1763 
1764 	crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1765 			   io->sector);
1766 
1767 	r = crypt_convert(cc, &io->ctx);
1768 	if (r)
1769 		io->error = r;
1770 
1771 	if (atomic_dec_and_test(&io->ctx.cc_pending))
1772 		kcryptd_crypt_read_done(io);
1773 
1774 	crypt_dec_pending(io);
1775 }
1776 
1777 static void kcryptd_async_done(struct crypto_async_request *async_req,
1778 			       int error)
1779 {
1780 	struct dm_crypt_request *dmreq = async_req->data;
1781 	struct convert_context *ctx = dmreq->ctx;
1782 	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1783 	struct crypt_config *cc = io->cc;
1784 
1785 	/*
1786 	 * A request from crypto driver backlog is going to be processed now,
1787 	 * finish the completion and continue in crypt_convert().
1788 	 * (Callback will be called for the second time for this request.)
1789 	 */
1790 	if (error == -EINPROGRESS) {
1791 		complete(&ctx->restart);
1792 		return;
1793 	}
1794 
1795 	if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1796 		error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
1797 
1798 	if (error == -EBADMSG) {
1799 		DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1800 			    (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
1801 		io->error = BLK_STS_PROTECTION;
1802 	} else if (error < 0)
1803 		io->error = BLK_STS_IOERR;
1804 
1805 	crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1806 
1807 	if (!atomic_dec_and_test(&ctx->cc_pending))
1808 		return;
1809 
1810 	if (bio_data_dir(io->base_bio) == READ)
1811 		kcryptd_crypt_read_done(io);
1812 	else
1813 		kcryptd_crypt_write_io_submit(io, 1);
1814 }
1815 
1816 static void kcryptd_crypt(struct work_struct *work)
1817 {
1818 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1819 
1820 	if (bio_data_dir(io->base_bio) == READ)
1821 		kcryptd_crypt_read_convert(io);
1822 	else
1823 		kcryptd_crypt_write_convert(io);
1824 }
1825 
1826 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1827 {
1828 	struct crypt_config *cc = io->cc;
1829 
1830 	INIT_WORK(&io->work, kcryptd_crypt);
1831 	queue_work(cc->crypt_queue, &io->work);
1832 }
1833 
1834 static void crypt_free_tfms_aead(struct crypt_config *cc)
1835 {
1836 	if (!cc->cipher_tfm.tfms_aead)
1837 		return;
1838 
1839 	if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1840 		crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
1841 		cc->cipher_tfm.tfms_aead[0] = NULL;
1842 	}
1843 
1844 	kfree(cc->cipher_tfm.tfms_aead);
1845 	cc->cipher_tfm.tfms_aead = NULL;
1846 }
1847 
1848 static void crypt_free_tfms_skcipher(struct crypt_config *cc)
1849 {
1850 	unsigned i;
1851 
1852 	if (!cc->cipher_tfm.tfms)
1853 		return;
1854 
1855 	for (i = 0; i < cc->tfms_count; i++)
1856 		if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
1857 			crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
1858 			cc->cipher_tfm.tfms[i] = NULL;
1859 		}
1860 
1861 	kfree(cc->cipher_tfm.tfms);
1862 	cc->cipher_tfm.tfms = NULL;
1863 }
1864 
1865 static void crypt_free_tfms(struct crypt_config *cc)
1866 {
1867 	if (crypt_integrity_aead(cc))
1868 		crypt_free_tfms_aead(cc);
1869 	else
1870 		crypt_free_tfms_skcipher(cc);
1871 }
1872 
1873 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
1874 {
1875 	unsigned i;
1876 	int err;
1877 
1878 	cc->cipher_tfm.tfms = kzalloc(cc->tfms_count *
1879 				      sizeof(struct crypto_skcipher *), GFP_KERNEL);
1880 	if (!cc->cipher_tfm.tfms)
1881 		return -ENOMEM;
1882 
1883 	for (i = 0; i < cc->tfms_count; i++) {
1884 		cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1885 		if (IS_ERR(cc->cipher_tfm.tfms[i])) {
1886 			err = PTR_ERR(cc->cipher_tfm.tfms[i]);
1887 			crypt_free_tfms(cc);
1888 			return err;
1889 		}
1890 	}
1891 
1892 	return 0;
1893 }
1894 
1895 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
1896 {
1897 	int err;
1898 
1899 	cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
1900 	if (!cc->cipher_tfm.tfms)
1901 		return -ENOMEM;
1902 
1903 	cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0);
1904 	if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1905 		err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
1906 		crypt_free_tfms(cc);
1907 		return err;
1908 	}
1909 
1910 	return 0;
1911 }
1912 
1913 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1914 {
1915 	if (crypt_integrity_aead(cc))
1916 		return crypt_alloc_tfms_aead(cc, ciphermode);
1917 	else
1918 		return crypt_alloc_tfms_skcipher(cc, ciphermode);
1919 }
1920 
1921 static unsigned crypt_subkey_size(struct crypt_config *cc)
1922 {
1923 	return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1924 }
1925 
1926 static unsigned crypt_authenckey_size(struct crypt_config *cc)
1927 {
1928 	return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
1929 }
1930 
1931 /*
1932  * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
1933  * the key must be for some reason in special format.
1934  * This funcion converts cc->key to this special format.
1935  */
1936 static void crypt_copy_authenckey(char *p, const void *key,
1937 				  unsigned enckeylen, unsigned authkeylen)
1938 {
1939 	struct crypto_authenc_key_param *param;
1940 	struct rtattr *rta;
1941 
1942 	rta = (struct rtattr *)p;
1943 	param = RTA_DATA(rta);
1944 	param->enckeylen = cpu_to_be32(enckeylen);
1945 	rta->rta_len = RTA_LENGTH(sizeof(*param));
1946 	rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1947 	p += RTA_SPACE(sizeof(*param));
1948 	memcpy(p, key + enckeylen, authkeylen);
1949 	p += authkeylen;
1950 	memcpy(p, key, enckeylen);
1951 }
1952 
1953 static int crypt_setkey(struct crypt_config *cc)
1954 {
1955 	unsigned subkey_size;
1956 	int err = 0, i, r;
1957 
1958 	/* Ignore extra keys (which are used for IV etc) */
1959 	subkey_size = crypt_subkey_size(cc);
1960 
1961 	if (crypt_integrity_hmac(cc))
1962 		crypt_copy_authenckey(cc->authenc_key, cc->key,
1963 				      subkey_size - cc->key_mac_size,
1964 				      cc->key_mac_size);
1965 	for (i = 0; i < cc->tfms_count; i++) {
1966 		if (crypt_integrity_hmac(cc))
1967 			r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1968 				cc->authenc_key, crypt_authenckey_size(cc));
1969 		else if (crypt_integrity_aead(cc))
1970 			r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1971 					       cc->key + (i * subkey_size),
1972 					       subkey_size);
1973 		else
1974 			r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
1975 						   cc->key + (i * subkey_size),
1976 						   subkey_size);
1977 		if (r)
1978 			err = r;
1979 	}
1980 
1981 	if (crypt_integrity_hmac(cc))
1982 		memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
1983 
1984 	return err;
1985 }
1986 
1987 #ifdef CONFIG_KEYS
1988 
1989 static bool contains_whitespace(const char *str)
1990 {
1991 	while (*str)
1992 		if (isspace(*str++))
1993 			return true;
1994 	return false;
1995 }
1996 
1997 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
1998 {
1999 	char *new_key_string, *key_desc;
2000 	int ret;
2001 	struct key *key;
2002 	const struct user_key_payload *ukp;
2003 
2004 	/*
2005 	 * Reject key_string with whitespace. dm core currently lacks code for
2006 	 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2007 	 */
2008 	if (contains_whitespace(key_string)) {
2009 		DMERR("whitespace chars not allowed in key string");
2010 		return -EINVAL;
2011 	}
2012 
2013 	/* look for next ':' separating key_type from key_description */
2014 	key_desc = strpbrk(key_string, ":");
2015 	if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2016 		return -EINVAL;
2017 
2018 	if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
2019 	    strncmp(key_string, "user:", key_desc - key_string + 1))
2020 		return -EINVAL;
2021 
2022 	new_key_string = kstrdup(key_string, GFP_KERNEL);
2023 	if (!new_key_string)
2024 		return -ENOMEM;
2025 
2026 	key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
2027 			  key_desc + 1, NULL);
2028 	if (IS_ERR(key)) {
2029 		kzfree(new_key_string);
2030 		return PTR_ERR(key);
2031 	}
2032 
2033 	down_read(&key->sem);
2034 
2035 	ukp = user_key_payload_locked(key);
2036 	if (!ukp) {
2037 		up_read(&key->sem);
2038 		key_put(key);
2039 		kzfree(new_key_string);
2040 		return -EKEYREVOKED;
2041 	}
2042 
2043 	if (cc->key_size != ukp->datalen) {
2044 		up_read(&key->sem);
2045 		key_put(key);
2046 		kzfree(new_key_string);
2047 		return -EINVAL;
2048 	}
2049 
2050 	memcpy(cc->key, ukp->data, cc->key_size);
2051 
2052 	up_read(&key->sem);
2053 	key_put(key);
2054 
2055 	/* clear the flag since following operations may invalidate previously valid key */
2056 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2057 
2058 	ret = crypt_setkey(cc);
2059 
2060 	/* wipe the kernel key payload copy in each case */
2061 	memset(cc->key, 0, cc->key_size * sizeof(u8));
2062 
2063 	if (!ret) {
2064 		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2065 		kzfree(cc->key_string);
2066 		cc->key_string = new_key_string;
2067 	} else
2068 		kzfree(new_key_string);
2069 
2070 	return ret;
2071 }
2072 
2073 static int get_key_size(char **key_string)
2074 {
2075 	char *colon, dummy;
2076 	int ret;
2077 
2078 	if (*key_string[0] != ':')
2079 		return strlen(*key_string) >> 1;
2080 
2081 	/* look for next ':' in key string */
2082 	colon = strpbrk(*key_string + 1, ":");
2083 	if (!colon)
2084 		return -EINVAL;
2085 
2086 	if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2087 		return -EINVAL;
2088 
2089 	*key_string = colon;
2090 
2091 	/* remaining key string should be :<logon|user>:<key_desc> */
2092 
2093 	return ret;
2094 }
2095 
2096 #else
2097 
2098 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2099 {
2100 	return -EINVAL;
2101 }
2102 
2103 static int get_key_size(char **key_string)
2104 {
2105 	return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
2106 }
2107 
2108 #endif
2109 
2110 static int crypt_set_key(struct crypt_config *cc, char *key)
2111 {
2112 	int r = -EINVAL;
2113 	int key_string_len = strlen(key);
2114 
2115 	/* Hyphen (which gives a key_size of zero) means there is no key. */
2116 	if (!cc->key_size && strcmp(key, "-"))
2117 		goto out;
2118 
2119 	/* ':' means the key is in kernel keyring, short-circuit normal key processing */
2120 	if (key[0] == ':') {
2121 		r = crypt_set_keyring_key(cc, key + 1);
2122 		goto out;
2123 	}
2124 
2125 	/* clear the flag since following operations may invalidate previously valid key */
2126 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2127 
2128 	/* wipe references to any kernel keyring key */
2129 	kzfree(cc->key_string);
2130 	cc->key_string = NULL;
2131 
2132 	/* Decode key from its hex representation. */
2133 	if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2134 		goto out;
2135 
2136 	r = crypt_setkey(cc);
2137 	if (!r)
2138 		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2139 
2140 out:
2141 	/* Hex key string not needed after here, so wipe it. */
2142 	memset(key, '0', key_string_len);
2143 
2144 	return r;
2145 }
2146 
2147 static int crypt_wipe_key(struct crypt_config *cc)
2148 {
2149 	int r;
2150 
2151 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2152 	get_random_bytes(&cc->key, cc->key_size);
2153 	kzfree(cc->key_string);
2154 	cc->key_string = NULL;
2155 	r = crypt_setkey(cc);
2156 	memset(&cc->key, 0, cc->key_size * sizeof(u8));
2157 
2158 	return r;
2159 }
2160 
2161 static void crypt_dtr(struct dm_target *ti)
2162 {
2163 	struct crypt_config *cc = ti->private;
2164 
2165 	ti->private = NULL;
2166 
2167 	if (!cc)
2168 		return;
2169 
2170 	if (cc->write_thread)
2171 		kthread_stop(cc->write_thread);
2172 
2173 	if (cc->io_queue)
2174 		destroy_workqueue(cc->io_queue);
2175 	if (cc->crypt_queue)
2176 		destroy_workqueue(cc->crypt_queue);
2177 
2178 	crypt_free_tfms(cc);
2179 
2180 	if (cc->bs)
2181 		bioset_free(cc->bs);
2182 
2183 	mempool_destroy(cc->page_pool);
2184 	mempool_destroy(cc->req_pool);
2185 	mempool_destroy(cc->tag_pool);
2186 
2187 	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2188 		cc->iv_gen_ops->dtr(cc);
2189 
2190 	if (cc->dev)
2191 		dm_put_device(ti, cc->dev);
2192 
2193 	kzfree(cc->cipher);
2194 	kzfree(cc->cipher_string);
2195 	kzfree(cc->key_string);
2196 	kzfree(cc->cipher_auth);
2197 	kzfree(cc->authenc_key);
2198 
2199 	/* Must zero key material before freeing */
2200 	kzfree(cc);
2201 }
2202 
2203 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2204 {
2205 	struct crypt_config *cc = ti->private;
2206 
2207 	if (crypt_integrity_aead(cc))
2208 		cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2209 	else
2210 		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2211 
2212 	if (cc->iv_size)
2213 		/* at least a 64 bit sector number should fit in our buffer */
2214 		cc->iv_size = max(cc->iv_size,
2215 				  (unsigned int)(sizeof(u64) / sizeof(u8)));
2216 	else if (ivmode) {
2217 		DMWARN("Selected cipher does not support IVs");
2218 		ivmode = NULL;
2219 	}
2220 
2221 	/* Choose ivmode, see comments at iv code. */
2222 	if (ivmode == NULL)
2223 		cc->iv_gen_ops = NULL;
2224 	else if (strcmp(ivmode, "plain") == 0)
2225 		cc->iv_gen_ops = &crypt_iv_plain_ops;
2226 	else if (strcmp(ivmode, "plain64") == 0)
2227 		cc->iv_gen_ops = &crypt_iv_plain64_ops;
2228 	else if (strcmp(ivmode, "plain64be") == 0)
2229 		cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2230 	else if (strcmp(ivmode, "essiv") == 0)
2231 		cc->iv_gen_ops = &crypt_iv_essiv_ops;
2232 	else if (strcmp(ivmode, "benbi") == 0)
2233 		cc->iv_gen_ops = &crypt_iv_benbi_ops;
2234 	else if (strcmp(ivmode, "null") == 0)
2235 		cc->iv_gen_ops = &crypt_iv_null_ops;
2236 	else if (strcmp(ivmode, "lmk") == 0) {
2237 		cc->iv_gen_ops = &crypt_iv_lmk_ops;
2238 		/*
2239 		 * Version 2 and 3 is recognised according
2240 		 * to length of provided multi-key string.
2241 		 * If present (version 3), last key is used as IV seed.
2242 		 * All keys (including IV seed) are always the same size.
2243 		 */
2244 		if (cc->key_size % cc->key_parts) {
2245 			cc->key_parts++;
2246 			cc->key_extra_size = cc->key_size / cc->key_parts;
2247 		}
2248 	} else if (strcmp(ivmode, "tcw") == 0) {
2249 		cc->iv_gen_ops = &crypt_iv_tcw_ops;
2250 		cc->key_parts += 2; /* IV + whitening */
2251 		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2252 	} else if (strcmp(ivmode, "random") == 0) {
2253 		cc->iv_gen_ops = &crypt_iv_random_ops;
2254 		/* Need storage space in integrity fields. */
2255 		cc->integrity_iv_size = cc->iv_size;
2256 	} else {
2257 		ti->error = "Invalid IV mode";
2258 		return -EINVAL;
2259 	}
2260 
2261 	return 0;
2262 }
2263 
2264 /*
2265  * Workaround to parse cipher algorithm from crypto API spec.
2266  * The cc->cipher is currently used only in ESSIV.
2267  * This should be probably done by crypto-api calls (once available...)
2268  */
2269 static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)
2270 {
2271 	const char *alg_name = NULL;
2272 	char *start, *end;
2273 
2274 	if (crypt_integrity_aead(cc)) {
2275 		alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));
2276 		if (!alg_name)
2277 			return -EINVAL;
2278 		if (crypt_integrity_hmac(cc)) {
2279 			alg_name = strchr(alg_name, ',');
2280 			if (!alg_name)
2281 				return -EINVAL;
2282 		}
2283 		alg_name++;
2284 	} else {
2285 		alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));
2286 		if (!alg_name)
2287 			return -EINVAL;
2288 	}
2289 
2290 	start = strchr(alg_name, '(');
2291 	end = strchr(alg_name, ')');
2292 
2293 	if (!start && !end) {
2294 		cc->cipher = kstrdup(alg_name, GFP_KERNEL);
2295 		return cc->cipher ? 0 : -ENOMEM;
2296 	}
2297 
2298 	if (!start || !end || ++start >= end)
2299 		return -EINVAL;
2300 
2301 	cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);
2302 	if (!cc->cipher)
2303 		return -ENOMEM;
2304 
2305 	strncpy(cc->cipher, start, end - start);
2306 
2307 	return 0;
2308 }
2309 
2310 /*
2311  * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2312  * The HMAC is needed to calculate tag size (HMAC digest size).
2313  * This should be probably done by crypto-api calls (once available...)
2314  */
2315 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2316 {
2317 	char *start, *end, *mac_alg = NULL;
2318 	struct crypto_ahash *mac;
2319 
2320 	if (!strstarts(cipher_api, "authenc("))
2321 		return 0;
2322 
2323 	start = strchr(cipher_api, '(');
2324 	end = strchr(cipher_api, ',');
2325 	if (!start || !end || ++start > end)
2326 		return -EINVAL;
2327 
2328 	mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2329 	if (!mac_alg)
2330 		return -ENOMEM;
2331 	strncpy(mac_alg, start, end - start);
2332 
2333 	mac = crypto_alloc_ahash(mac_alg, 0, 0);
2334 	kfree(mac_alg);
2335 
2336 	if (IS_ERR(mac))
2337 		return PTR_ERR(mac);
2338 
2339 	cc->key_mac_size = crypto_ahash_digestsize(mac);
2340 	crypto_free_ahash(mac);
2341 
2342 	cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2343 	if (!cc->authenc_key)
2344 		return -ENOMEM;
2345 
2346 	return 0;
2347 }
2348 
2349 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2350 				char **ivmode, char **ivopts)
2351 {
2352 	struct crypt_config *cc = ti->private;
2353 	char *tmp, *cipher_api;
2354 	int ret = -EINVAL;
2355 
2356 	cc->tfms_count = 1;
2357 
2358 	/*
2359 	 * New format (capi: prefix)
2360 	 * capi:cipher_api_spec-iv:ivopts
2361 	 */
2362 	tmp = &cipher_in[strlen("capi:")];
2363 	cipher_api = strsep(&tmp, "-");
2364 	*ivmode = strsep(&tmp, ":");
2365 	*ivopts = tmp;
2366 
2367 	if (*ivmode && !strcmp(*ivmode, "lmk"))
2368 		cc->tfms_count = 64;
2369 
2370 	cc->key_parts = cc->tfms_count;
2371 
2372 	/* Allocate cipher */
2373 	ret = crypt_alloc_tfms(cc, cipher_api);
2374 	if (ret < 0) {
2375 		ti->error = "Error allocating crypto tfm";
2376 		return ret;
2377 	}
2378 
2379 	/* Alloc AEAD, can be used only in new format. */
2380 	if (crypt_integrity_aead(cc)) {
2381 		ret = crypt_ctr_auth_cipher(cc, cipher_api);
2382 		if (ret < 0) {
2383 			ti->error = "Invalid AEAD cipher spec";
2384 			return -ENOMEM;
2385 		}
2386 		cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2387 	} else
2388 		cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2389 
2390 	ret = crypt_ctr_blkdev_cipher(cc);
2391 	if (ret < 0) {
2392 		ti->error = "Cannot allocate cipher string";
2393 		return -ENOMEM;
2394 	}
2395 
2396 	return 0;
2397 }
2398 
2399 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2400 				char **ivmode, char **ivopts)
2401 {
2402 	struct crypt_config *cc = ti->private;
2403 	char *tmp, *cipher, *chainmode, *keycount;
2404 	char *cipher_api = NULL;
2405 	int ret = -EINVAL;
2406 	char dummy;
2407 
2408 	if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2409 		ti->error = "Bad cipher specification";
2410 		return -EINVAL;
2411 	}
2412 
2413 	/*
2414 	 * Legacy dm-crypt cipher specification
2415 	 * cipher[:keycount]-mode-iv:ivopts
2416 	 */
2417 	tmp = cipher_in;
2418 	keycount = strsep(&tmp, "-");
2419 	cipher = strsep(&keycount, ":");
2420 
2421 	if (!keycount)
2422 		cc->tfms_count = 1;
2423 	else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2424 		 !is_power_of_2(cc->tfms_count)) {
2425 		ti->error = "Bad cipher key count specification";
2426 		return -EINVAL;
2427 	}
2428 	cc->key_parts = cc->tfms_count;
2429 
2430 	cc->cipher = kstrdup(cipher, GFP_KERNEL);
2431 	if (!cc->cipher)
2432 		goto bad_mem;
2433 
2434 	chainmode = strsep(&tmp, "-");
2435 	*ivopts = strsep(&tmp, "-");
2436 	*ivmode = strsep(&*ivopts, ":");
2437 
2438 	if (tmp)
2439 		DMWARN("Ignoring unexpected additional cipher options");
2440 
2441 	/*
2442 	 * For compatibility with the original dm-crypt mapping format, if
2443 	 * only the cipher name is supplied, use cbc-plain.
2444 	 */
2445 	if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2446 		chainmode = "cbc";
2447 		*ivmode = "plain";
2448 	}
2449 
2450 	if (strcmp(chainmode, "ecb") && !*ivmode) {
2451 		ti->error = "IV mechanism required";
2452 		return -EINVAL;
2453 	}
2454 
2455 	cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2456 	if (!cipher_api)
2457 		goto bad_mem;
2458 
2459 	ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2460 		       "%s(%s)", chainmode, cipher);
2461 	if (ret < 0) {
2462 		kfree(cipher_api);
2463 		goto bad_mem;
2464 	}
2465 
2466 	/* Allocate cipher */
2467 	ret = crypt_alloc_tfms(cc, cipher_api);
2468 	if (ret < 0) {
2469 		ti->error = "Error allocating crypto tfm";
2470 		kfree(cipher_api);
2471 		return ret;
2472 	}
2473 
2474 	return 0;
2475 bad_mem:
2476 	ti->error = "Cannot allocate cipher strings";
2477 	return -ENOMEM;
2478 }
2479 
2480 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
2481 {
2482 	struct crypt_config *cc = ti->private;
2483 	char *ivmode = NULL, *ivopts = NULL;
2484 	int ret;
2485 
2486 	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
2487 	if (!cc->cipher_string) {
2488 		ti->error = "Cannot allocate cipher strings";
2489 		return -ENOMEM;
2490 	}
2491 
2492 	if (strstarts(cipher_in, "capi:"))
2493 		ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
2494 	else
2495 		ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
2496 	if (ret)
2497 		return ret;
2498 
2499 	/* Initialize IV */
2500 	ret = crypt_ctr_ivmode(ti, ivmode);
2501 	if (ret < 0)
2502 		return ret;
2503 
2504 	/* Initialize and set key */
2505 	ret = crypt_set_key(cc, key);
2506 	if (ret < 0) {
2507 		ti->error = "Error decoding and setting key";
2508 		return ret;
2509 	}
2510 
2511 	/* Allocate IV */
2512 	if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
2513 		ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
2514 		if (ret < 0) {
2515 			ti->error = "Error creating IV";
2516 			return ret;
2517 		}
2518 	}
2519 
2520 	/* Initialize IV (set keys for ESSIV etc) */
2521 	if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
2522 		ret = cc->iv_gen_ops->init(cc);
2523 		if (ret < 0) {
2524 			ti->error = "Error initialising IV";
2525 			return ret;
2526 		}
2527 	}
2528 
2529 	return ret;
2530 }
2531 
2532 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
2533 {
2534 	struct crypt_config *cc = ti->private;
2535 	struct dm_arg_set as;
2536 	static struct dm_arg _args[] = {
2537 		{0, 6, "Invalid number of feature args"},
2538 	};
2539 	unsigned int opt_params, val;
2540 	const char *opt_string, *sval;
2541 	char dummy;
2542 	int ret;
2543 
2544 	/* Optional parameters */
2545 	as.argc = argc;
2546 	as.argv = argv;
2547 
2548 	ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
2549 	if (ret)
2550 		return ret;
2551 
2552 	while (opt_params--) {
2553 		opt_string = dm_shift_arg(&as);
2554 		if (!opt_string) {
2555 			ti->error = "Not enough feature arguments";
2556 			return -EINVAL;
2557 		}
2558 
2559 		if (!strcasecmp(opt_string, "allow_discards"))
2560 			ti->num_discard_bios = 1;
2561 
2562 		else if (!strcasecmp(opt_string, "same_cpu_crypt"))
2563 			set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2564 
2565 		else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
2566 			set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2567 		else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
2568 			if (val == 0 || val > MAX_TAG_SIZE) {
2569 				ti->error = "Invalid integrity arguments";
2570 				return -EINVAL;
2571 			}
2572 			cc->on_disk_tag_size = val;
2573 			sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
2574 			if (!strcasecmp(sval, "aead")) {
2575 				set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
2576 			} else  if (strcasecmp(sval, "none")) {
2577 				ti->error = "Unknown integrity profile";
2578 				return -EINVAL;
2579 			}
2580 
2581 			cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
2582 			if (!cc->cipher_auth)
2583 				return -ENOMEM;
2584 		} else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
2585 			if (cc->sector_size < (1 << SECTOR_SHIFT) ||
2586 			    cc->sector_size > 4096 ||
2587 			    (cc->sector_size & (cc->sector_size - 1))) {
2588 				ti->error = "Invalid feature value for sector_size";
2589 				return -EINVAL;
2590 			}
2591 			cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
2592 		} else if (!strcasecmp(opt_string, "iv_large_sectors"))
2593 			set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2594 		else {
2595 			ti->error = "Invalid feature arguments";
2596 			return -EINVAL;
2597 		}
2598 	}
2599 
2600 	return 0;
2601 }
2602 
2603 /*
2604  * Construct an encryption mapping:
2605  * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
2606  */
2607 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2608 {
2609 	struct crypt_config *cc;
2610 	int key_size;
2611 	unsigned int align_mask;
2612 	unsigned long long tmpll;
2613 	int ret;
2614 	size_t iv_size_padding, additional_req_size;
2615 	char dummy;
2616 
2617 	if (argc < 5) {
2618 		ti->error = "Not enough arguments";
2619 		return -EINVAL;
2620 	}
2621 
2622 	key_size = get_key_size(&argv[1]);
2623 	if (key_size < 0) {
2624 		ti->error = "Cannot parse key size";
2625 		return -EINVAL;
2626 	}
2627 
2628 	cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
2629 	if (!cc) {
2630 		ti->error = "Cannot allocate encryption context";
2631 		return -ENOMEM;
2632 	}
2633 	cc->key_size = key_size;
2634 	cc->sector_size = (1 << SECTOR_SHIFT);
2635 	cc->sector_shift = 0;
2636 
2637 	ti->private = cc;
2638 
2639 	/* Optional parameters need to be read before cipher constructor */
2640 	if (argc > 5) {
2641 		ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
2642 		if (ret)
2643 			goto bad;
2644 	}
2645 
2646 	ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
2647 	if (ret < 0)
2648 		goto bad;
2649 
2650 	if (crypt_integrity_aead(cc)) {
2651 		cc->dmreq_start = sizeof(struct aead_request);
2652 		cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
2653 		align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
2654 	} else {
2655 		cc->dmreq_start = sizeof(struct skcipher_request);
2656 		cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
2657 		align_mask = crypto_skcipher_alignmask(any_tfm(cc));
2658 	}
2659 	cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
2660 
2661 	if (align_mask < CRYPTO_MINALIGN) {
2662 		/* Allocate the padding exactly */
2663 		iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
2664 				& align_mask;
2665 	} else {
2666 		/*
2667 		 * If the cipher requires greater alignment than kmalloc
2668 		 * alignment, we don't know the exact position of the
2669 		 * initialization vector. We must assume worst case.
2670 		 */
2671 		iv_size_padding = align_mask;
2672 	}
2673 
2674 	ret = -ENOMEM;
2675 
2676 	/*  ...| IV + padding | original IV | original sec. number | bio tag offset | */
2677 	additional_req_size = sizeof(struct dm_crypt_request) +
2678 		iv_size_padding + cc->iv_size +
2679 		cc->iv_size +
2680 		sizeof(uint64_t) +
2681 		sizeof(unsigned int);
2682 
2683 	cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + additional_req_size);
2684 	if (!cc->req_pool) {
2685 		ti->error = "Cannot allocate crypt request mempool";
2686 		goto bad;
2687 	}
2688 
2689 	cc->per_bio_data_size = ti->per_io_data_size =
2690 		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
2691 		      ARCH_KMALLOC_MINALIGN);
2692 
2693 	cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
2694 	if (!cc->page_pool) {
2695 		ti->error = "Cannot allocate page mempool";
2696 		goto bad;
2697 	}
2698 
2699 	cc->bs = bioset_create(MIN_IOS, 0, (BIOSET_NEED_BVECS |
2700 					    BIOSET_NEED_RESCUER));
2701 	if (!cc->bs) {
2702 		ti->error = "Cannot allocate crypt bioset";
2703 		goto bad;
2704 	}
2705 
2706 	mutex_init(&cc->bio_alloc_lock);
2707 
2708 	ret = -EINVAL;
2709 	if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
2710 	    (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
2711 		ti->error = "Invalid iv_offset sector";
2712 		goto bad;
2713 	}
2714 	cc->iv_offset = tmpll;
2715 
2716 	ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
2717 	if (ret) {
2718 		ti->error = "Device lookup failed";
2719 		goto bad;
2720 	}
2721 
2722 	ret = -EINVAL;
2723 	if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
2724 		ti->error = "Invalid device sector";
2725 		goto bad;
2726 	}
2727 	cc->start = tmpll;
2728 
2729 	if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
2730 		ret = crypt_integrity_ctr(cc, ti);
2731 		if (ret)
2732 			goto bad;
2733 
2734 		cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
2735 		if (!cc->tag_pool_max_sectors)
2736 			cc->tag_pool_max_sectors = 1;
2737 
2738 		cc->tag_pool = mempool_create_kmalloc_pool(MIN_IOS,
2739 			cc->tag_pool_max_sectors * cc->on_disk_tag_size);
2740 		if (!cc->tag_pool) {
2741 			ti->error = "Cannot allocate integrity tags mempool";
2742 			goto bad;
2743 		}
2744 
2745 		cc->tag_pool_max_sectors <<= cc->sector_shift;
2746 	}
2747 
2748 	ret = -ENOMEM;
2749 	cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2750 	if (!cc->io_queue) {
2751 		ti->error = "Couldn't create kcryptd io queue";
2752 		goto bad;
2753 	}
2754 
2755 	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2756 		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
2757 	else
2758 		cc->crypt_queue = alloc_workqueue("kcryptd",
2759 						  WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2760 						  num_online_cpus());
2761 	if (!cc->crypt_queue) {
2762 		ti->error = "Couldn't create kcryptd queue";
2763 		goto bad;
2764 	}
2765 
2766 	init_waitqueue_head(&cc->write_thread_wait);
2767 	cc->write_tree = RB_ROOT;
2768 
2769 	cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
2770 	if (IS_ERR(cc->write_thread)) {
2771 		ret = PTR_ERR(cc->write_thread);
2772 		cc->write_thread = NULL;
2773 		ti->error = "Couldn't spawn write thread";
2774 		goto bad;
2775 	}
2776 	wake_up_process(cc->write_thread);
2777 
2778 	ti->num_flush_bios = 1;
2779 
2780 	return 0;
2781 
2782 bad:
2783 	crypt_dtr(ti);
2784 	return ret;
2785 }
2786 
2787 static int crypt_map(struct dm_target *ti, struct bio *bio)
2788 {
2789 	struct dm_crypt_io *io;
2790 	struct crypt_config *cc = ti->private;
2791 
2792 	/*
2793 	 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2794 	 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
2795 	 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
2796 	 */
2797 	if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
2798 	    bio_op(bio) == REQ_OP_DISCARD)) {
2799 		bio->bi_bdev = cc->dev->bdev;
2800 		if (bio_sectors(bio))
2801 			bio->bi_iter.bi_sector = cc->start +
2802 				dm_target_offset(ti, bio->bi_iter.bi_sector);
2803 		return DM_MAPIO_REMAPPED;
2804 	}
2805 
2806 	/*
2807 	 * Check if bio is too large, split as needed.
2808 	 */
2809 	if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2810 	    (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
2811 		dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2812 
2813 	/*
2814 	 * Ensure that bio is a multiple of internal sector encryption size
2815 	 * and is aligned to this size as defined in IO hints.
2816 	 */
2817 	if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
2818 		return DM_MAPIO_KILL;
2819 
2820 	if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
2821 		return DM_MAPIO_KILL;
2822 
2823 	io = dm_per_bio_data(bio, cc->per_bio_data_size);
2824 	crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
2825 
2826 	if (cc->on_disk_tag_size) {
2827 		unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
2828 
2829 		if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
2830 		    unlikely(!(io->integrity_metadata = kmalloc(tag_len,
2831 				GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
2832 			if (bio_sectors(bio) > cc->tag_pool_max_sectors)
2833 				dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
2834 			io->integrity_metadata = mempool_alloc(cc->tag_pool, GFP_NOIO);
2835 			io->integrity_metadata_from_pool = true;
2836 		}
2837 	}
2838 
2839 	if (crypt_integrity_aead(cc))
2840 		io->ctx.r.req_aead = (struct aead_request *)(io + 1);
2841 	else
2842 		io->ctx.r.req = (struct skcipher_request *)(io + 1);
2843 
2844 	if (bio_data_dir(io->base_bio) == READ) {
2845 		if (kcryptd_io_read(io, GFP_NOWAIT))
2846 			kcryptd_queue_read(io);
2847 	} else
2848 		kcryptd_queue_crypt(io);
2849 
2850 	return DM_MAPIO_SUBMITTED;
2851 }
2852 
2853 static void crypt_status(struct dm_target *ti, status_type_t type,
2854 			 unsigned status_flags, char *result, unsigned maxlen)
2855 {
2856 	struct crypt_config *cc = ti->private;
2857 	unsigned i, sz = 0;
2858 	int num_feature_args = 0;
2859 
2860 	switch (type) {
2861 	case STATUSTYPE_INFO:
2862 		result[0] = '\0';
2863 		break;
2864 
2865 	case STATUSTYPE_TABLE:
2866 		DMEMIT("%s ", cc->cipher_string);
2867 
2868 		if (cc->key_size > 0) {
2869 			if (cc->key_string)
2870 				DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2871 			else
2872 				for (i = 0; i < cc->key_size; i++)
2873 					DMEMIT("%02x", cc->key[i]);
2874 		} else
2875 			DMEMIT("-");
2876 
2877 		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2878 				cc->dev->name, (unsigned long long)cc->start);
2879 
2880 		num_feature_args += !!ti->num_discard_bios;
2881 		num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2882 		num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2883 		num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
2884 		num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2885 		if (cc->on_disk_tag_size)
2886 			num_feature_args++;
2887 		if (num_feature_args) {
2888 			DMEMIT(" %d", num_feature_args);
2889 			if (ti->num_discard_bios)
2890 				DMEMIT(" allow_discards");
2891 			if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2892 				DMEMIT(" same_cpu_crypt");
2893 			if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2894 				DMEMIT(" submit_from_crypt_cpus");
2895 			if (cc->on_disk_tag_size)
2896 				DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
2897 			if (cc->sector_size != (1 << SECTOR_SHIFT))
2898 				DMEMIT(" sector_size:%d", cc->sector_size);
2899 			if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
2900 				DMEMIT(" iv_large_sectors");
2901 		}
2902 
2903 		break;
2904 	}
2905 }
2906 
2907 static void crypt_postsuspend(struct dm_target *ti)
2908 {
2909 	struct crypt_config *cc = ti->private;
2910 
2911 	set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2912 }
2913 
2914 static int crypt_preresume(struct dm_target *ti)
2915 {
2916 	struct crypt_config *cc = ti->private;
2917 
2918 	if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
2919 		DMERR("aborting resume - crypt key is not set.");
2920 		return -EAGAIN;
2921 	}
2922 
2923 	return 0;
2924 }
2925 
2926 static void crypt_resume(struct dm_target *ti)
2927 {
2928 	struct crypt_config *cc = ti->private;
2929 
2930 	clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2931 }
2932 
2933 /* Message interface
2934  *	key set <key>
2935  *	key wipe
2936  */
2937 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
2938 {
2939 	struct crypt_config *cc = ti->private;
2940 	int key_size, ret = -EINVAL;
2941 
2942 	if (argc < 2)
2943 		goto error;
2944 
2945 	if (!strcasecmp(argv[0], "key")) {
2946 		if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2947 			DMWARN("not suspended during key manipulation.");
2948 			return -EINVAL;
2949 		}
2950 		if (argc == 3 && !strcasecmp(argv[1], "set")) {
2951 			/* The key size may not be changed. */
2952 			key_size = get_key_size(&argv[2]);
2953 			if (key_size < 0 || cc->key_size != key_size) {
2954 				memset(argv[2], '0', strlen(argv[2]));
2955 				return -EINVAL;
2956 			}
2957 
2958 			ret = crypt_set_key(cc, argv[2]);
2959 			if (ret)
2960 				return ret;
2961 			if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2962 				ret = cc->iv_gen_ops->init(cc);
2963 			return ret;
2964 		}
2965 		if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
2966 			if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2967 				ret = cc->iv_gen_ops->wipe(cc);
2968 				if (ret)
2969 					return ret;
2970 			}
2971 			return crypt_wipe_key(cc);
2972 		}
2973 	}
2974 
2975 error:
2976 	DMWARN("unrecognised message received.");
2977 	return -EINVAL;
2978 }
2979 
2980 static int crypt_iterate_devices(struct dm_target *ti,
2981 				 iterate_devices_callout_fn fn, void *data)
2982 {
2983 	struct crypt_config *cc = ti->private;
2984 
2985 	return fn(ti, cc->dev, cc->start, ti->len, data);
2986 }
2987 
2988 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
2989 {
2990 	struct crypt_config *cc = ti->private;
2991 
2992 	/*
2993 	 * Unfortunate constraint that is required to avoid the potential
2994 	 * for exceeding underlying device's max_segments limits -- due to
2995 	 * crypt_alloc_buffer() possibly allocating pages for the encryption
2996 	 * bio that are not as physically contiguous as the original bio.
2997 	 */
2998 	limits->max_segment_size = PAGE_SIZE;
2999 
3000 	if (cc->sector_size != (1 << SECTOR_SHIFT)) {
3001 		limits->logical_block_size = cc->sector_size;
3002 		limits->physical_block_size = cc->sector_size;
3003 		blk_limits_io_min(limits, cc->sector_size);
3004 	}
3005 }
3006 
3007 static struct target_type crypt_target = {
3008 	.name   = "crypt",
3009 	.version = {1, 18, 0},
3010 	.module = THIS_MODULE,
3011 	.ctr    = crypt_ctr,
3012 	.dtr    = crypt_dtr,
3013 	.map    = crypt_map,
3014 	.status = crypt_status,
3015 	.postsuspend = crypt_postsuspend,
3016 	.preresume = crypt_preresume,
3017 	.resume = crypt_resume,
3018 	.message = crypt_message,
3019 	.iterate_devices = crypt_iterate_devices,
3020 	.io_hints = crypt_io_hints,
3021 };
3022 
3023 static int __init dm_crypt_init(void)
3024 {
3025 	int r;
3026 
3027 	r = dm_register_target(&crypt_target);
3028 	if (r < 0)
3029 		DMERR("register failed %d", r);
3030 
3031 	return r;
3032 }
3033 
3034 static void __exit dm_crypt_exit(void)
3035 {
3036 	dm_unregister_target(&crypt_target);
3037 }
3038 
3039 module_init(dm_crypt_init);
3040 module_exit(dm_crypt_exit);
3041 
3042 MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3043 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3044 MODULE_LICENSE("GPL");
3045