1/*
2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013-2017 Milan Broz <gmazyland@gmail.com>
6 *
7 * This file is released under the GPL.
8 */
9
10#include <linux/completion.h>
11#include <linux/err.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/key.h>
16#include <linux/bio.h>
17#include <linux/blkdev.h>
18#include <linux/mempool.h>
19#include <linux/slab.h>
20#include <linux/crypto.h>
21#include <linux/workqueue.h>
22#include <linux/kthread.h>
23#include <linux/backing-dev.h>
24#include <linux/atomic.h>
25#include <linux/scatterlist.h>
26#include <linux/rbtree.h>
27#include <linux/ctype.h>
28#include <asm/page.h>
29#include <asm/unaligned.h>
30#include <crypto/hash.h>
31#include <crypto/md5.h>
32#include <crypto/algapi.h>
33#include <crypto/skcipher.h>
34#include <crypto/aead.h>
35#include <crypto/authenc.h>
36#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
37#include <keys/user-type.h>
38
39#include <linux/device-mapper.h>
40
41#define DM_MSG_PREFIX "crypt"
42
43/*
44 * context holding the current state of a multi-part conversion
45 */
46struct convert_context {
47 struct completion restart;
48 struct bio *bio_in;
49 struct bio *bio_out;
50 struct bvec_iter iter_in;
51 struct bvec_iter iter_out;
52 u64 cc_sector;
53 atomic_t cc_pending;
54 union {
55 struct skcipher_request *req;
56 struct aead_request *req_aead;
57 } r;
58
59};
60
61/*
62 * per bio private data
63 */
64struct dm_crypt_io {
65 struct crypt_config *cc;
66 struct bio *base_bio;
67 u8 *integrity_metadata;
68 bool integrity_metadata_from_pool;
69 struct work_struct work;
70
71 struct convert_context ctx;
72
73 atomic_t io_pending;
74 blk_status_t error;
75 sector_t sector;
76
77 struct rb_node rb_node;
78} CRYPTO_MINALIGN_ATTR;
79
80struct dm_crypt_request {
81 struct convert_context *ctx;
82 struct scatterlist sg_in[4];
83 struct scatterlist sg_out[4];
84 u64 iv_sector;
85};
86
87struct crypt_config;
88
89struct crypt_iv_operations {
90 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
91 const char *opts);
92 void (*dtr)(struct crypt_config *cc);
93 int (*init)(struct crypt_config *cc);
94 int (*wipe)(struct crypt_config *cc);
95 int (*generator)(struct crypt_config *cc, u8 *iv,
96 struct dm_crypt_request *dmreq);
97 int (*post)(struct crypt_config *cc, u8 *iv,
98 struct dm_crypt_request *dmreq);
99};
100
101struct iv_essiv_private {
102 struct crypto_shash *hash_tfm;
103 u8 *salt;
104};
105
106struct iv_benbi_private {
107 int shift;
108};
109
110#define LMK_SEED_SIZE 64 /* hash + 0 */
111struct iv_lmk_private {
112 struct crypto_shash *hash_tfm;
113 u8 *seed;
114};
115
116#define TCW_WHITENING_SIZE 16
117struct iv_tcw_private {
118 struct crypto_shash *crc32_tfm;
119 u8 *iv_seed;
120 u8 *whitening;
121};
122
123/*
124 * Crypt: maps a linear range of a block device
125 * and encrypts / decrypts at the same time.
126 */
127enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
128 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
129
130enum cipher_flags {
131 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */
132 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */
133};
134
135/*
136 * The fields in here must be read only after initialization.
137 */
138struct crypt_config {
139 struct dm_dev *dev;
140 sector_t start;
141
142 struct percpu_counter n_allocated_pages;
143
144 struct workqueue_struct *io_queue;
145 struct workqueue_struct *crypt_queue;
146
147 spinlock_t write_thread_lock;
148 struct task_struct *write_thread;
149 struct rb_root write_tree;
150
151 char *cipher;
152 char *cipher_string;
153 char *cipher_auth;
154 char *key_string;
155
156 const struct crypt_iv_operations *iv_gen_ops;
157 union {
158 struct iv_essiv_private essiv;
159 struct iv_benbi_private benbi;
160 struct iv_lmk_private lmk;
161 struct iv_tcw_private tcw;
162 } iv_gen_private;
163 u64 iv_offset;
164 unsigned int iv_size;
165 unsigned short int sector_size;
166 unsigned char sector_shift;
167
168 /* ESSIV: struct crypto_cipher *essiv_tfm */
169 void *iv_private;
170 union {
171 struct crypto_skcipher **tfms;
172 struct crypto_aead **tfms_aead;
173 } cipher_tfm;
174 unsigned tfms_count;
175 unsigned long cipher_flags;
176
177 /*
178 * Layout of each crypto request:
179 *
180 * struct skcipher_request
181 * context
182 * padding
183 * struct dm_crypt_request
184 * padding
185 * IV
186 *
187 * The padding is added so that dm_crypt_request and the IV are
188 * correctly aligned.
189 */
190 unsigned int dmreq_start;
191
192 unsigned int per_bio_data_size;
193
194 unsigned long flags;
195 unsigned int key_size;
196 unsigned int key_parts; /* independent parts in key buffer */
197 unsigned int key_extra_size; /* additional keys length */
198 unsigned int key_mac_size; /* MAC key size for authenc(...) */
199
200 unsigned int integrity_tag_size;
201 unsigned int integrity_iv_size;
202 unsigned int on_disk_tag_size;
203
204 /*
205 * pool for per bio private data, crypto requests,
206 * encryption requeusts/buffer pages and integrity tags
207 */
208 unsigned tag_pool_max_sectors;
209 mempool_t tag_pool;
210 mempool_t req_pool;
211 mempool_t page_pool;
212
213 struct bio_set bs;
214 struct mutex bio_alloc_lock;
215
216 u8 *authenc_key; /* space for keys in authenc() format (if used) */
217 u8 key[0];
218};
219
220#define MIN_IOS 64
221#define MAX_TAG_SIZE 480
222#define POOL_ENTRY_SIZE 512
223
224static DEFINE_SPINLOCK(dm_crypt_clients_lock);
225static unsigned dm_crypt_clients_n = 0;
226static volatile unsigned long dm_crypt_pages_per_client;
227#define DM_CRYPT_MEMORY_PERCENT 2
228#define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_PAGES * 16)
229
230static void clone_init(struct dm_crypt_io *, struct bio *);
231static void kcryptd_queue_crypt(struct dm_crypt_io *io);
232static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
233 struct scatterlist *sg);
234
235/*
236 * Use this to access cipher attributes that are independent of the key.
237 */
238static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
239{
240 return cc->cipher_tfm.tfms[0];
241}
242
243static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
244{
245 return cc->cipher_tfm.tfms_aead[0];
246}
247
248/*
249 * Different IV generation algorithms:
250 *
251 * plain: the initial vector is the 32-bit little-endian version of the sector
252 * number, padded with zeros if necessary.
253 *
254 * plain64: the initial vector is the 64-bit little-endian version of the sector
255 * number, padded with zeros if necessary.
256 *
257 * plain64be: the initial vector is the 64-bit big-endian version of the sector
258 * number, padded with zeros if necessary.
259 *
260 * essiv: "encrypted sector|salt initial vector", the sector number is
261 * encrypted with the bulk cipher using a salt as key. The salt
262 * should be derived from the bulk cipher's key via hashing.
263 *
264 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
265 * (needed for LRW-32-AES and possible other narrow block modes)
266 *
267 * null: the initial vector is always zero. Provides compatibility with
268 * obsolete loop_fish2 devices. Do not use for new devices.
269 *
270 * lmk: Compatible implementation of the block chaining mode used
271 * by the Loop-AES block device encryption system
272 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
273 * It operates on full 512 byte sectors and uses CBC
274 * with an IV derived from the sector number, the data and
275 * optionally extra IV seed.
276 * This means that after decryption the first block
277 * of sector must be tweaked according to decrypted data.
278 * Loop-AES can use three encryption schemes:
279 * version 1: is plain aes-cbc mode
280 * version 2: uses 64 multikey scheme with lmk IV generator
281 * version 3: the same as version 2 with additional IV seed
282 * (it uses 65 keys, last key is used as IV seed)
283 *
284 * tcw: Compatible implementation of the block chaining mode used
285 * by the TrueCrypt device encryption system (prior to version 4.1).
286 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
287 * It operates on full 512 byte sectors and uses CBC
288 * with an IV derived from initial key and the sector number.
289 * In addition, whitening value is applied on every sector, whitening
290 * is calculated from initial key, sector number and mixed using CRC32.
291 * Note that this encryption scheme is vulnerable to watermarking attacks
292 * and should be used for old compatible containers access only.
293 *
294 * plumb: unimplemented, see:
295 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
296 */
297
298static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
299 struct dm_crypt_request *dmreq)
300{
301 memset(iv, 0, cc->iv_size);
302 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
303
304 return 0;
305}
306
307static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
308 struct dm_crypt_request *dmreq)
309{
310 memset(iv, 0, cc->iv_size);
311 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
312
313 return 0;
314}
315
316static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
317 struct dm_crypt_request *dmreq)
318{
319 memset(iv, 0, cc->iv_size);
320 /* iv_size is at least of size u64; usually it is 16 bytes */
321 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
322
323 return 0;
324}
325
326/* Initialise ESSIV - compute salt but no local memory allocations */
327static int crypt_iv_essiv_init(struct crypt_config *cc)
328{
329 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
330 SHASH_DESC_ON_STACK(desc, essiv->hash_tfm);
331 struct crypto_cipher *essiv_tfm;
332 int err;
333
334 desc->tfm = essiv->hash_tfm;
335 desc->flags = 0;
336
337 err = crypto_shash_digest(desc, cc->key, cc->key_size, essiv->salt);
338 shash_desc_zero(desc);
339 if (err)
340 return err;
341
342 essiv_tfm = cc->iv_private;
343
344 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
345 crypto_shash_digestsize(essiv->hash_tfm));
346 if (err)
347 return err;
348
349 return 0;
350}
351
352/* Wipe salt and reset key derived from volume key */
353static int crypt_iv_essiv_wipe(struct crypt_config *cc)
354{
355 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
356 unsigned salt_size = crypto_shash_digestsize(essiv->hash_tfm);
357 struct crypto_cipher *essiv_tfm;
358 int r, err = 0;
359
360 memset(essiv->salt, 0, salt_size);
361
362 essiv_tfm = cc->iv_private;
363 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
364 if (r)
365 err = r;
366
367 return err;
368}
369
370/* Allocate the cipher for ESSIV */
371static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc,
372 struct dm_target *ti,
373 const u8 *salt,
374 unsigned int saltsize)
375{
376 struct crypto_cipher *essiv_tfm;
377 int err;
378
379 /* Setup the essiv_tfm with the given salt */
380 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, 0);
381 if (IS_ERR(essiv_tfm)) {
382 ti->error = "Error allocating crypto tfm for ESSIV";
383 return essiv_tfm;
384 }
385
386 if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) {
387 ti->error = "Block size of ESSIV cipher does "
388 "not match IV size of block cipher";
389 crypto_free_cipher(essiv_tfm);
390 return ERR_PTR(-EINVAL);
391 }
392
393 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
394 if (err) {
395 ti->error = "Failed to set key for ESSIV cipher";
396 crypto_free_cipher(essiv_tfm);
397 return ERR_PTR(err);
398 }
399
400 return essiv_tfm;
401}
402
403static void crypt_iv_essiv_dtr(struct crypt_config *cc)
404{
405 struct crypto_cipher *essiv_tfm;
406 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
407
408 crypto_free_shash(essiv->hash_tfm);
409 essiv->hash_tfm = NULL;
410
411 kzfree(essiv->salt);
412 essiv->salt = NULL;
413
414 essiv_tfm = cc->iv_private;
415
416 if (essiv_tfm)
417 crypto_free_cipher(essiv_tfm);
418
419 cc->iv_private = NULL;
420}
421
422static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
423 const char *opts)
424{
425 struct crypto_cipher *essiv_tfm = NULL;
426 struct crypto_shash *hash_tfm = NULL;
427 u8 *salt = NULL;
428 int err;
429
430 if (!opts) {
431 ti->error = "Digest algorithm missing for ESSIV mode";
432 return -EINVAL;
433 }
434
435 /* Allocate hash algorithm */
436 hash_tfm = crypto_alloc_shash(opts, 0, 0);
437 if (IS_ERR(hash_tfm)) {
438 ti->error = "Error initializing ESSIV hash";
439 err = PTR_ERR(hash_tfm);
440 goto bad;
441 }
442
443 salt = kzalloc(crypto_shash_digestsize(hash_tfm), GFP_KERNEL);
444 if (!salt) {
445 ti->error = "Error kmallocing salt storage in ESSIV";
446 err = -ENOMEM;
447 goto bad;
448 }
449
450 cc->iv_gen_private.essiv.salt = salt;
451 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
452
453 essiv_tfm = alloc_essiv_cipher(cc, ti, salt,
454 crypto_shash_digestsize(hash_tfm));
455 if (IS_ERR(essiv_tfm)) {
456 crypt_iv_essiv_dtr(cc);
457 return PTR_ERR(essiv_tfm);
458 }
459 cc->iv_private = essiv_tfm;
460
461 return 0;
462
463bad:
464 if (hash_tfm && !IS_ERR(hash_tfm))
465 crypto_free_shash(hash_tfm);
466 kfree(salt);
467 return err;
468}
469
470static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
471 struct dm_crypt_request *dmreq)
472{
473 struct crypto_cipher *essiv_tfm = cc->iv_private;
474
475 memset(iv, 0, cc->iv_size);
476 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
477 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
478
479 return 0;
480}
481
482static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
483 const char *opts)
484{
485 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
486 int log = ilog2(bs);
487
488 /* we need to calculate how far we must shift the sector count
489 * to get the cipher block count, we use this shift in _gen */
490
491 if (1 << log != bs) {
492 ti->error = "cypher blocksize is not a power of 2";
493 return -EINVAL;
494 }
495
496 if (log > 9) {
497 ti->error = "cypher blocksize is > 512";
498 return -EINVAL;
499 }
500
501 cc->iv_gen_private.benbi.shift = 9 - log;
502
503 return 0;
504}
505
506static void crypt_iv_benbi_dtr(struct crypt_config *cc)
507{
508}
509
510static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
511 struct dm_crypt_request *dmreq)
512{
513 __be64 val;
514
515 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
516
517 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
518 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
519
520 return 0;
521}
522
523static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
524 struct dm_crypt_request *dmreq)
525{
526 memset(iv, 0, cc->iv_size);
527
528 return 0;
529}
530
531static void crypt_iv_lmk_dtr(struct crypt_config *cc)
532{
533 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
534
535 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
536 crypto_free_shash(lmk->hash_tfm);
537 lmk->hash_tfm = NULL;
538
539 kzfree(lmk->seed);
540 lmk->seed = NULL;
541}
542
543static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
544 const char *opts)
545{
546 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
547
548 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
549 ti->error = "Unsupported sector size for LMK";
550 return -EINVAL;
551 }
552
553 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
554 if (IS_ERR(lmk->hash_tfm)) {
555 ti->error = "Error initializing LMK hash";
556 return PTR_ERR(lmk->hash_tfm);
557 }
558
559 /* No seed in LMK version 2 */
560 if (cc->key_parts == cc->tfms_count) {
561 lmk->seed = NULL;
562 return 0;
563 }
564
565 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
566 if (!lmk->seed) {
567 crypt_iv_lmk_dtr(cc);
568 ti->error = "Error kmallocing seed storage in LMK";
569 return -ENOMEM;
570 }
571
572 return 0;
573}
574
575static int crypt_iv_lmk_init(struct crypt_config *cc)
576{
577 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
578 int subkey_size = cc->key_size / cc->key_parts;
579
580 /* LMK seed is on the position of LMK_KEYS + 1 key */
581 if (lmk->seed)
582 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
583 crypto_shash_digestsize(lmk->hash_tfm));
584
585 return 0;
586}
587
588static int crypt_iv_lmk_wipe(struct crypt_config *cc)
589{
590 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
591
592 if (lmk->seed)
593 memset(lmk->seed, 0, LMK_SEED_SIZE);
594
595 return 0;
596}
597
598static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
599 struct dm_crypt_request *dmreq,
600 u8 *data)
601{
602 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
603 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
604 struct md5_state md5state;
605 __le32 buf[4];
606 int i, r;
607
608 desc->tfm = lmk->hash_tfm;
609 desc->flags = 0;
610
611 r = crypto_shash_init(desc);
612 if (r)
613 return r;
614
615 if (lmk->seed) {
616 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
617 if (r)
618 return r;
619 }
620
621 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
622 r = crypto_shash_update(desc, data + 16, 16 * 31);
623 if (r)
624 return r;
625
626 /* Sector is cropped to 56 bits here */
627 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
628 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
629 buf[2] = cpu_to_le32(4024);
630 buf[3] = 0;
631 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
632 if (r)
633 return r;
634
635 /* No MD5 padding here */
636 r = crypto_shash_export(desc, &md5state);
637 if (r)
638 return r;
639
640 for (i = 0; i < MD5_HASH_WORDS; i++)
641 __cpu_to_le32s(&md5state.hash[i]);
642 memcpy(iv, &md5state.hash, cc->iv_size);
643
644 return 0;
645}
646
647static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
648 struct dm_crypt_request *dmreq)
649{
650 struct scatterlist *sg;
651 u8 *src;
652 int r = 0;
653
654 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
655 sg = crypt_get_sg_data(cc, dmreq->sg_in);
656 src = kmap_atomic(sg_page(sg));
657 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
658 kunmap_atomic(src);
659 } else
660 memset(iv, 0, cc->iv_size);
661
662 return r;
663}
664
665static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
666 struct dm_crypt_request *dmreq)
667{
668 struct scatterlist *sg;
669 u8 *dst;
670 int r;
671
672 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
673 return 0;
674
675 sg = crypt_get_sg_data(cc, dmreq->sg_out);
676 dst = kmap_atomic(sg_page(sg));
677 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
678
679 /* Tweak the first block of plaintext sector */
680 if (!r)
681 crypto_xor(dst + sg->offset, iv, cc->iv_size);
682
683 kunmap_atomic(dst);
684 return r;
685}
686
687static void crypt_iv_tcw_dtr(struct crypt_config *cc)
688{
689 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
690
691 kzfree(tcw->iv_seed);
692 tcw->iv_seed = NULL;
693 kzfree(tcw->whitening);
694 tcw->whitening = NULL;
695
696 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
697 crypto_free_shash(tcw->crc32_tfm);
698 tcw->crc32_tfm = NULL;
699}
700
701static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
702 const char *opts)
703{
704 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
705
706 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
707 ti->error = "Unsupported sector size for TCW";
708 return -EINVAL;
709 }
710
711 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
712 ti->error = "Wrong key size for TCW";
713 return -EINVAL;
714 }
715
716 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
717 if (IS_ERR(tcw->crc32_tfm)) {
718 ti->error = "Error initializing CRC32 in TCW";
719 return PTR_ERR(tcw->crc32_tfm);
720 }
721
722 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
723 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
724 if (!tcw->iv_seed || !tcw->whitening) {
725 crypt_iv_tcw_dtr(cc);
726 ti->error = "Error allocating seed storage in TCW";
727 return -ENOMEM;
728 }
729
730 return 0;
731}
732
733static int crypt_iv_tcw_init(struct crypt_config *cc)
734{
735 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
736 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
737
738 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
739 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
740 TCW_WHITENING_SIZE);
741
742 return 0;
743}
744
745static int crypt_iv_tcw_wipe(struct crypt_config *cc)
746{
747 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
748
749 memset(tcw->iv_seed, 0, cc->iv_size);
750 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
751
752 return 0;
753}
754
755static int crypt_iv_tcw_whitening(struct crypt_config *cc,
756 struct dm_crypt_request *dmreq,
757 u8 *data)
758{
759 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
760 __le64 sector = cpu_to_le64(dmreq->iv_sector);
761 u8 buf[TCW_WHITENING_SIZE];
762 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
763 int i, r;
764
765 /* xor whitening with sector number */
766 crypto_xor_cpy(buf, tcw->whitening, (u8 *)&sector, 8);
767 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)&sector, 8);
768
769 /* calculate crc32 for every 32bit part and xor it */
770 desc->tfm = tcw->crc32_tfm;
771 desc->flags = 0;
772 for (i = 0; i < 4; i++) {
773 r = crypto_shash_init(desc);
774 if (r)
775 goto out;
776 r = crypto_shash_update(desc, &buf[i * 4], 4);
777 if (r)
778 goto out;
779 r = crypto_shash_final(desc, &buf[i * 4]);
780 if (r)
781 goto out;
782 }
783 crypto_xor(&buf[0], &buf[12], 4);
784 crypto_xor(&buf[4], &buf[8], 4);
785
786 /* apply whitening (8 bytes) to whole sector */
787 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
788 crypto_xor(data + i * 8, buf, 8);
789out:
790 memzero_explicit(buf, sizeof(buf));
791 return r;
792}
793
794static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
795 struct dm_crypt_request *dmreq)
796{
797 struct scatterlist *sg;
798 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
799 __le64 sector = cpu_to_le64(dmreq->iv_sector);
800 u8 *src;
801 int r = 0;
802
803 /* Remove whitening from ciphertext */
804 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
805 sg = crypt_get_sg_data(cc, dmreq->sg_in);
806 src = kmap_atomic(sg_page(sg));
807 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
808 kunmap_atomic(src);
809 }
810
811 /* Calculate IV */
812 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)&sector, 8);
813 if (cc->iv_size > 8)
814 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)&sector,
815 cc->iv_size - 8);
816
817 return r;
818}
819
820static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
821 struct dm_crypt_request *dmreq)
822{
823 struct scatterlist *sg;
824 u8 *dst;
825 int r;
826
827 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
828 return 0;
829
830 /* Apply whitening on ciphertext */
831 sg = crypt_get_sg_data(cc, dmreq->sg_out);
832 dst = kmap_atomic(sg_page(sg));
833 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
834 kunmap_atomic(dst);
835
836 return r;
837}
838
839static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
840 struct dm_crypt_request *dmreq)
841{
842 /* Used only for writes, there must be an additional space to store IV */
843 get_random_bytes(iv, cc->iv_size);
844 return 0;
845}
846
847static const struct crypt_iv_operations crypt_iv_plain_ops = {
848 .generator = crypt_iv_plain_gen
849};
850
851static const struct crypt_iv_operations crypt_iv_plain64_ops = {
852 .generator = crypt_iv_plain64_gen
853};
854
855static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
856 .generator = crypt_iv_plain64be_gen
857};
858
859static const struct crypt_iv_operations crypt_iv_essiv_ops = {
860 .ctr = crypt_iv_essiv_ctr,
861 .dtr = crypt_iv_essiv_dtr,
862 .init = crypt_iv_essiv_init,
863 .wipe = crypt_iv_essiv_wipe,
864 .generator = crypt_iv_essiv_gen
865};
866
867static const struct crypt_iv_operations crypt_iv_benbi_ops = {
868 .ctr = crypt_iv_benbi_ctr,
869 .dtr = crypt_iv_benbi_dtr,
870 .generator = crypt_iv_benbi_gen
871};
872
873static const struct crypt_iv_operations crypt_iv_null_ops = {
874 .generator = crypt_iv_null_gen
875};
876
877static const struct crypt_iv_operations crypt_iv_lmk_ops = {
878 .ctr = crypt_iv_lmk_ctr,
879 .dtr = crypt_iv_lmk_dtr,
880 .init = crypt_iv_lmk_init,
881 .wipe = crypt_iv_lmk_wipe,
882 .generator = crypt_iv_lmk_gen,
883 .post = crypt_iv_lmk_post
884};
885
886static const struct crypt_iv_operations crypt_iv_tcw_ops = {
887 .ctr = crypt_iv_tcw_ctr,
888 .dtr = crypt_iv_tcw_dtr,
889 .init = crypt_iv_tcw_init,
890 .wipe = crypt_iv_tcw_wipe,
891 .generator = crypt_iv_tcw_gen,
892 .post = crypt_iv_tcw_post
893};
894
895static struct crypt_iv_operations crypt_iv_random_ops = {
896 .generator = crypt_iv_random_gen
897};
898
899/*
900 * Integrity extensions
901 */
902static bool crypt_integrity_aead(struct crypt_config *cc)
903{
904 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
905}
906
907static bool crypt_integrity_hmac(struct crypt_config *cc)
908{
909 return crypt_integrity_aead(cc) && cc->key_mac_size;
910}
911
912/* Get sg containing data */
913static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
914 struct scatterlist *sg)
915{
916 if (unlikely(crypt_integrity_aead(cc)))
917 return &sg[2];
918
919 return sg;
920}
921
922static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
923{
924 struct bio_integrity_payload *bip;
925 unsigned int tag_len;
926 int ret;
927
928 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
929 return 0;
930
931 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
932 if (IS_ERR(bip))
933 return PTR_ERR(bip);
934
935 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
936
937 bip->bip_iter.bi_size = tag_len;
938 bip->bip_iter.bi_sector = io->cc->start + io->sector;
939
940 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
941 tag_len, offset_in_page(io->integrity_metadata));
942 if (unlikely(ret != tag_len))
943 return -ENOMEM;
944
945 return 0;
946}
947
948static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
949{
950#ifdef CONFIG_BLK_DEV_INTEGRITY
951 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
952
953 /* From now we require underlying device with our integrity profile */
954 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
955 ti->error = "Integrity profile not supported.";
956 return -EINVAL;
957 }
958
959 if (bi->tag_size != cc->on_disk_tag_size ||
960 bi->tuple_size != cc->on_disk_tag_size) {
961 ti->error = "Integrity profile tag size mismatch.";
962 return -EINVAL;
963 }
964 if (1 << bi->interval_exp != cc->sector_size) {
965 ti->error = "Integrity profile sector size mismatch.";
966 return -EINVAL;
967 }
968
969 if (crypt_integrity_aead(cc)) {
970 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
971 DMINFO("Integrity AEAD, tag size %u, IV size %u.",
972 cc->integrity_tag_size, cc->integrity_iv_size);
973
974 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
975 ti->error = "Integrity AEAD auth tag size is not supported.";
976 return -EINVAL;
977 }
978 } else if (cc->integrity_iv_size)
979 DMINFO("Additional per-sector space %u bytes for IV.",
980 cc->integrity_iv_size);
981
982 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
983 ti->error = "Not enough space for integrity tag in the profile.";
984 return -EINVAL;
985 }
986
987 return 0;
988#else
989 ti->error = "Integrity profile not supported.";
990 return -EINVAL;
991#endif
992}
993
994static void crypt_convert_init(struct crypt_config *cc,
995 struct convert_context *ctx,
996 struct bio *bio_out, struct bio *bio_in,
997 sector_t sector)
998{
999 ctx->bio_in = bio_in;
1000 ctx->bio_out = bio_out;
1001 if (bio_in)
1002 ctx->iter_in = bio_in->bi_iter;
1003 if (bio_out)
1004 ctx->iter_out = bio_out->bi_iter;
1005 ctx->cc_sector = sector + cc->iv_offset;
1006 init_completion(&ctx->restart);
1007}
1008
1009static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1010 void *req)
1011{
1012 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1013}
1014
1015static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1016{
1017 return (void *)((char *)dmreq - cc->dmreq_start);
1018}
1019
1020static u8 *iv_of_dmreq(struct crypt_config *cc,
1021 struct dm_crypt_request *dmreq)
1022{
1023 if (crypt_integrity_aead(cc))
1024 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1025 crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1026 else
1027 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1028 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1029}
1030
1031static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1032 struct dm_crypt_request *dmreq)
1033{
1034 return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1035}
1036
1037static uint64_t *org_sector_of_dmreq(struct crypt_config *cc,
1038 struct dm_crypt_request *dmreq)
1039{
1040 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1041 return (uint64_t*) ptr;
1042}
1043
1044static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1045 struct dm_crypt_request *dmreq)
1046{
1047 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1048 cc->iv_size + sizeof(uint64_t);
1049 return (unsigned int*)ptr;
1050}
1051
1052static void *tag_from_dmreq(struct crypt_config *cc,
1053 struct dm_crypt_request *dmreq)
1054{
1055 struct convert_context *ctx = dmreq->ctx;
1056 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1057
1058 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1059 cc->on_disk_tag_size];
1060}
1061
1062static void *iv_tag_from_dmreq(struct crypt_config *cc,
1063 struct dm_crypt_request *dmreq)
1064{
1065 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1066}
1067
1068static int crypt_convert_block_aead(struct crypt_config *cc,
1069 struct convert_context *ctx,
1070 struct aead_request *req,
1071 unsigned int tag_offset)
1072{
1073 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1074 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1075 struct dm_crypt_request *dmreq;
1076 u8 *iv, *org_iv, *tag_iv, *tag;
1077 uint64_t *sector;
1078 int r = 0;
1079
1080 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1081
1082 /* Reject unexpected unaligned bio. */
1083 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1084 return -EIO;
1085
1086 dmreq = dmreq_of_req(cc, req);
1087 dmreq->iv_sector = ctx->cc_sector;
1088 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1089 dmreq->iv_sector >>= cc->sector_shift;
1090 dmreq->ctx = ctx;
1091
1092 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1093
1094 sector = org_sector_of_dmreq(cc, dmreq);
1095 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1096
1097 iv = iv_of_dmreq(cc, dmreq);
1098 org_iv = org_iv_of_dmreq(cc, dmreq);
1099 tag = tag_from_dmreq(cc, dmreq);
1100 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1101
1102 /* AEAD request:
1103 * |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1104 * | (authenticated) | (auth+encryption) | |
1105 * | sector_LE | IV | sector in/out | tag in/out |
1106 */
1107 sg_init_table(dmreq->sg_in, 4);
1108 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1109 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1110 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1111 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1112
1113 sg_init_table(dmreq->sg_out, 4);
1114 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1115 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1116 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1117 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1118
1119 if (cc->iv_gen_ops) {
1120 /* For READs use IV stored in integrity metadata */
1121 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1122 memcpy(org_iv, tag_iv, cc->iv_size);
1123 } else {
1124 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1125 if (r < 0)
1126 return r;
1127 /* Store generated IV in integrity metadata */
1128 if (cc->integrity_iv_size)
1129 memcpy(tag_iv, org_iv, cc->iv_size);
1130 }
1131 /* Working copy of IV, to be modified in crypto API */
1132 memcpy(iv, org_iv, cc->iv_size);
1133 }
1134
1135 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1136 if (bio_data_dir(ctx->bio_in) == WRITE) {
1137 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1138 cc->sector_size, iv);
1139 r = crypto_aead_encrypt(req);
1140 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1141 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1142 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1143 } else {
1144 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1145 cc->sector_size + cc->integrity_tag_size, iv);
1146 r = crypto_aead_decrypt(req);
1147 }
1148
1149 if (r == -EBADMSG)
1150 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1151 (unsigned long long)le64_to_cpu(*sector));
1152
1153 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1154 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1155
1156 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1157 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1158
1159 return r;
1160}
1161
1162static int crypt_convert_block_skcipher(struct crypt_config *cc,
1163 struct convert_context *ctx,
1164 struct skcipher_request *req,
1165 unsigned int tag_offset)
1166{
1167 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1168 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1169 struct scatterlist *sg_in, *sg_out;
1170 struct dm_crypt_request *dmreq;
1171 u8 *iv, *org_iv, *tag_iv;
1172 uint64_t *sector;
1173 int r = 0;
1174
1175 /* Reject unexpected unaligned bio. */
1176 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1177 return -EIO;
1178
1179 dmreq = dmreq_of_req(cc, req);
1180 dmreq->iv_sector = ctx->cc_sector;
1181 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1182 dmreq->iv_sector >>= cc->sector_shift;
1183 dmreq->ctx = ctx;
1184
1185 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1186
1187 iv = iv_of_dmreq(cc, dmreq);
1188 org_iv = org_iv_of_dmreq(cc, dmreq);
1189 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1190
1191 sector = org_sector_of_dmreq(cc, dmreq);
1192 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1193
1194 /* For skcipher we use only the first sg item */
1195 sg_in = &dmreq->sg_in[0];
1196 sg_out = &dmreq->sg_out[0];
1197
1198 sg_init_table(sg_in, 1);
1199 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1200
1201 sg_init_table(sg_out, 1);
1202 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1203
1204 if (cc->iv_gen_ops) {
1205 /* For READs use IV stored in integrity metadata */
1206 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1207 memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1208 } else {
1209 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1210 if (r < 0)
1211 return r;
1212 /* Store generated IV in integrity metadata */
1213 if (cc->integrity_iv_size)
1214 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1215 }
1216 /* Working copy of IV, to be modified in crypto API */
1217 memcpy(iv, org_iv, cc->iv_size);
1218 }
1219
1220 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1221
1222 if (bio_data_dir(ctx->bio_in) == WRITE)
1223 r = crypto_skcipher_encrypt(req);
1224 else
1225 r = crypto_skcipher_decrypt(req);
1226
1227 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1228 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1229
1230 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1231 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1232
1233 return r;
1234}
1235
1236static void kcryptd_async_done(struct crypto_async_request *async_req,
1237 int error);
1238
1239static void crypt_alloc_req_skcipher(struct crypt_config *cc,
1240 struct convert_context *ctx)
1241{
1242 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1243
1244 if (!ctx->r.req)
1245 ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO);
1246
1247 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1248
1249 /*
1250 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1251 * requests if driver request queue is full.
1252 */
1253 skcipher_request_set_callback(ctx->r.req,
1254 CRYPTO_TFM_REQ_MAY_BACKLOG,
1255 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1256}
1257
1258static void crypt_alloc_req_aead(struct crypt_config *cc,
1259 struct convert_context *ctx)
1260{
1261 if (!ctx->r.req_aead)
1262 ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO);
1263
1264 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1265
1266 /*
1267 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1268 * requests if driver request queue is full.
1269 */
1270 aead_request_set_callback(ctx->r.req_aead,
1271 CRYPTO_TFM_REQ_MAY_BACKLOG,
1272 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1273}
1274
1275static void crypt_alloc_req(struct crypt_config *cc,
1276 struct convert_context *ctx)
1277{
1278 if (crypt_integrity_aead(cc))
1279 crypt_alloc_req_aead(cc, ctx);
1280 else
1281 crypt_alloc_req_skcipher(cc, ctx);
1282}
1283
1284static void crypt_free_req_skcipher(struct crypt_config *cc,
1285 struct skcipher_request *req, struct bio *base_bio)
1286{
1287 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1288
1289 if ((struct skcipher_request *)(io + 1) != req)
1290 mempool_free(req, &cc->req_pool);
1291}
1292
1293static void crypt_free_req_aead(struct crypt_config *cc,
1294 struct aead_request *req, struct bio *base_bio)
1295{
1296 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1297
1298 if ((struct aead_request *)(io + 1) != req)
1299 mempool_free(req, &cc->req_pool);
1300}
1301
1302static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1303{
1304 if (crypt_integrity_aead(cc))
1305 crypt_free_req_aead(cc, req, base_bio);
1306 else
1307 crypt_free_req_skcipher(cc, req, base_bio);
1308}
1309
1310/*
1311 * Encrypt / decrypt data from one bio to another one (can be the same one)
1312 */
1313static blk_status_t crypt_convert(struct crypt_config *cc,
1314 struct convert_context *ctx)
1315{
1316 unsigned int tag_offset = 0;
1317 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1318 int r;
1319
1320 atomic_set(&ctx->cc_pending, 1);
1321
1322 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1323
1324 crypt_alloc_req(cc, ctx);
1325 atomic_inc(&ctx->cc_pending);
1326
1327 if (crypt_integrity_aead(cc))
1328 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1329 else
1330 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1331
1332 switch (r) {
1333 /*
1334 * The request was queued by a crypto driver
1335 * but the driver request queue is full, let's wait.
1336 */
1337 case -EBUSY:
1338 wait_for_completion(&ctx->restart);
1339 reinit_completion(&ctx->restart);
1340 /* fall through */
1341 /*
1342 * The request is queued and processed asynchronously,
1343 * completion function kcryptd_async_done() will be called.
1344 */
1345 case -EINPROGRESS:
1346 ctx->r.req = NULL;
1347 ctx->cc_sector += sector_step;
1348 tag_offset++;
1349 continue;
1350 /*
1351 * The request was already processed (synchronously).
1352 */
1353 case 0:
1354 atomic_dec(&ctx->cc_pending);
1355 ctx->cc_sector += sector_step;
1356 tag_offset++;
1357 cond_resched();
1358 continue;
1359 /*
1360 * There was a data integrity error.
1361 */
1362 case -EBADMSG:
1363 atomic_dec(&ctx->cc_pending);
1364 return BLK_STS_PROTECTION;
1365 /*
1366 * There was an error while processing the request.
1367 */
1368 default:
1369 atomic_dec(&ctx->cc_pending);
1370 return BLK_STS_IOERR;
1371 }
1372 }
1373
1374 return 0;
1375}
1376
1377static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1378
1379/*
1380 * Generate a new unfragmented bio with the given size
1381 * This should never violate the device limitations (but only because
1382 * max_segment_size is being constrained to PAGE_SIZE).
1383 *
1384 * This function may be called concurrently. If we allocate from the mempool
1385 * concurrently, there is a possibility of deadlock. For example, if we have
1386 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1387 * the mempool concurrently, it may deadlock in a situation where both processes
1388 * have allocated 128 pages and the mempool is exhausted.
1389 *
1390 * In order to avoid this scenario we allocate the pages under a mutex.
1391 *
1392 * In order to not degrade performance with excessive locking, we try
1393 * non-blocking allocations without a mutex first but on failure we fallback
1394 * to blocking allocations with a mutex.
1395 */
1396static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1397{
1398 struct crypt_config *cc = io->cc;
1399 struct bio *clone;
1400 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1401 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1402 unsigned i, len, remaining_size;
1403 struct page *page;
1404
1405retry:
1406 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1407 mutex_lock(&cc->bio_alloc_lock);
1408
1409 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs);
1410 if (!clone)
1411 goto out;
1412
1413 clone_init(io, clone);
1414
1415 remaining_size = size;
1416
1417 for (i = 0; i < nr_iovecs; i++) {
1418 page = mempool_alloc(&cc->page_pool, gfp_mask);
1419 if (!page) {
1420 crypt_free_buffer_pages(cc, clone);
1421 bio_put(clone);
1422 gfp_mask |= __GFP_DIRECT_RECLAIM;
1423 goto retry;
1424 }
1425
1426 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1427
1428 bio_add_page(clone, page, len, 0);
1429
1430 remaining_size -= len;
1431 }
1432
1433 /* Allocate space for integrity tags */
1434 if (dm_crypt_integrity_io_alloc(io, clone)) {
1435 crypt_free_buffer_pages(cc, clone);
1436 bio_put(clone);
1437 clone = NULL;
1438 }
1439out:
1440 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1441 mutex_unlock(&cc->bio_alloc_lock);
1442
1443 return clone;
1444}
1445
1446static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1447{
1448 unsigned int i;
1449 struct bio_vec *bv;
1450 struct bvec_iter_all iter_all;
1451
1452 bio_for_each_segment_all(bv, clone, i, iter_all) {
1453 BUG_ON(!bv->bv_page);
1454 mempool_free(bv->bv_page, &cc->page_pool);
1455 }
1456}
1457
1458static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1459 struct bio *bio, sector_t sector)
1460{
1461 io->cc = cc;
1462 io->base_bio = bio;
1463 io->sector = sector;
1464 io->error = 0;
1465 io->ctx.r.req = NULL;
1466 io->integrity_metadata = NULL;
1467 io->integrity_metadata_from_pool = false;
1468 atomic_set(&io->io_pending, 0);
1469}
1470
1471static void crypt_inc_pending(struct dm_crypt_io *io)
1472{
1473 atomic_inc(&io->io_pending);
1474}
1475
1476/*
1477 * One of the bios was finished. Check for completion of
1478 * the whole request and correctly clean up the buffer.
1479 */
1480static void crypt_dec_pending(struct dm_crypt_io *io)
1481{
1482 struct crypt_config *cc = io->cc;
1483 struct bio *base_bio = io->base_bio;
1484 blk_status_t error = io->error;
1485
1486 if (!atomic_dec_and_test(&io->io_pending))
1487 return;
1488
1489 if (io->ctx.r.req)
1490 crypt_free_req(cc, io->ctx.r.req, base_bio);
1491
1492 if (unlikely(io->integrity_metadata_from_pool))
1493 mempool_free(io->integrity_metadata, &io->cc->tag_pool);
1494 else
1495 kfree(io->integrity_metadata);
1496
1497 base_bio->bi_status = error;
1498 bio_endio(base_bio);
1499}
1500
1501/*
1502 * kcryptd/kcryptd_io:
1503 *
1504 * Needed because it would be very unwise to do decryption in an
1505 * interrupt context.
1506 *
1507 * kcryptd performs the actual encryption or decryption.
1508 *
1509 * kcryptd_io performs the IO submission.
1510 *
1511 * They must be separated as otherwise the final stages could be
1512 * starved by new requests which can block in the first stages due
1513 * to memory allocation.
1514 *
1515 * The work is done per CPU global for all dm-crypt instances.
1516 * They should not depend on each other and do not block.
1517 */
1518static void crypt_endio(struct bio *clone)
1519{
1520 struct dm_crypt_io *io = clone->bi_private;
1521 struct crypt_config *cc = io->cc;
1522 unsigned rw = bio_data_dir(clone);
1523 blk_status_t error;
1524
1525 /*
1526 * free the processed pages
1527 */
1528 if (rw == WRITE)
1529 crypt_free_buffer_pages(cc, clone);
1530
1531 error = clone->bi_status;
1532 bio_put(clone);
1533
1534 if (rw == READ && !error) {
1535 kcryptd_queue_crypt(io);
1536 return;
1537 }
1538
1539 if (unlikely(error))
1540 io->error = error;
1541
1542 crypt_dec_pending(io);
1543}
1544
1545static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1546{
1547 struct crypt_config *cc = io->cc;
1548
1549 clone->bi_private = io;
1550 clone->bi_end_io = crypt_endio;
1551 bio_set_dev(clone, cc->dev->bdev);
1552 clone->bi_opf = io->base_bio->bi_opf;
1553}
1554
1555static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1556{
1557 struct crypt_config *cc = io->cc;
1558 struct bio *clone;
1559
1560 /*
1561 * We need the original biovec array in order to decrypt
1562 * the whole bio data *afterwards* -- thanks to immutable
1563 * biovecs we don't need to worry about the block layer
1564 * modifying the biovec array; so leverage bio_clone_fast().
1565 */
1566 clone = bio_clone_fast(io->base_bio, gfp, &cc->bs);
1567 if (!clone)
1568 return 1;
1569
1570 crypt_inc_pending(io);
1571
1572 clone_init(io, clone);
1573 clone->bi_iter.bi_sector = cc->start + io->sector;
1574
1575 if (dm_crypt_integrity_io_alloc(io, clone)) {
1576 crypt_dec_pending(io);
1577 bio_put(clone);
1578 return 1;
1579 }
1580
1581 generic_make_request(clone);
1582 return 0;
1583}
1584
1585static void kcryptd_io_read_work(struct work_struct *work)
1586{
1587 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1588
1589 crypt_inc_pending(io);
1590 if (kcryptd_io_read(io, GFP_NOIO))
1591 io->error = BLK_STS_RESOURCE;
1592 crypt_dec_pending(io);
1593}
1594
1595static void kcryptd_queue_read(struct dm_crypt_io *io)
1596{
1597 struct crypt_config *cc = io->cc;
1598
1599 INIT_WORK(&io->work, kcryptd_io_read_work);
1600 queue_work(cc->io_queue, &io->work);
1601}
1602
1603static void kcryptd_io_write(struct dm_crypt_io *io)
1604{
1605 struct bio *clone = io->ctx.bio_out;
1606
1607 generic_make_request(clone);
1608}
1609
1610#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1611
1612static int dmcrypt_write(void *data)
1613{
1614 struct crypt_config *cc = data;
1615 struct dm_crypt_io *io;
1616
1617 while (1) {
1618 struct rb_root write_tree;
1619 struct blk_plug plug;
1620
1621 spin_lock_irq(&cc->write_thread_lock);
1622continue_locked:
1623
1624 if (!RB_EMPTY_ROOT(&cc->write_tree))
1625 goto pop_from_list;
1626
1627 set_current_state(TASK_INTERRUPTIBLE);
1628
1629 spin_unlock_irq(&cc->write_thread_lock);
1630
1631 if (unlikely(kthread_should_stop())) {
1632 set_current_state(TASK_RUNNING);
1633 break;
1634 }
1635
1636 schedule();
1637
1638 set_current_state(TASK_RUNNING);
1639 spin_lock_irq(&cc->write_thread_lock);
1640 goto continue_locked;
1641
1642pop_from_list:
1643 write_tree = cc->write_tree;
1644 cc->write_tree = RB_ROOT;
1645 spin_unlock_irq(&cc->write_thread_lock);
1646
1647 BUG_ON(rb_parent(write_tree.rb_node));
1648
1649 /*
1650 * Note: we cannot walk the tree here with rb_next because
1651 * the structures may be freed when kcryptd_io_write is called.
1652 */
1653 blk_start_plug(&plug);
1654 do {
1655 io = crypt_io_from_node(rb_first(&write_tree));
1656 rb_erase(&io->rb_node, &write_tree);
1657 kcryptd_io_write(io);
1658 } while (!RB_EMPTY_ROOT(&write_tree));
1659 blk_finish_plug(&plug);
1660 }
1661 return 0;
1662}
1663
1664static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1665{
1666 struct bio *clone = io->ctx.bio_out;
1667 struct crypt_config *cc = io->cc;
1668 unsigned long flags;
1669 sector_t sector;
1670 struct rb_node **rbp, *parent;
1671
1672 if (unlikely(io->error)) {
1673 crypt_free_buffer_pages(cc, clone);
1674 bio_put(clone);
1675 crypt_dec_pending(io);
1676 return;
1677 }
1678
1679 /* crypt_convert should have filled the clone bio */
1680 BUG_ON(io->ctx.iter_out.bi_size);
1681
1682 clone->bi_iter.bi_sector = cc->start + io->sector;
1683
1684 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1685 generic_make_request(clone);
1686 return;
1687 }
1688
1689 spin_lock_irqsave(&cc->write_thread_lock, flags);
1690 if (RB_EMPTY_ROOT(&cc->write_tree))
1691 wake_up_process(cc->write_thread);
1692 rbp = &cc->write_tree.rb_node;
1693 parent = NULL;
1694 sector = io->sector;
1695 while (*rbp) {
1696 parent = *rbp;
1697 if (sector < crypt_io_from_node(parent)->sector)
1698 rbp = &(*rbp)->rb_left;
1699 else
1700 rbp = &(*rbp)->rb_right;
1701 }
1702 rb_link_node(&io->rb_node, parent, rbp);
1703 rb_insert_color(&io->rb_node, &cc->write_tree);
1704 spin_unlock_irqrestore(&cc->write_thread_lock, flags);
1705}
1706
1707static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1708{
1709 struct crypt_config *cc = io->cc;
1710 struct bio *clone;
1711 int crypt_finished;
1712 sector_t sector = io->sector;
1713 blk_status_t r;
1714
1715 /*
1716 * Prevent io from disappearing until this function completes.
1717 */
1718 crypt_inc_pending(io);
1719 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1720
1721 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1722 if (unlikely(!clone)) {
1723 io->error = BLK_STS_IOERR;
1724 goto dec;
1725 }
1726
1727 io->ctx.bio_out = clone;
1728 io->ctx.iter_out = clone->bi_iter;
1729
1730 sector += bio_sectors(clone);
1731
1732 crypt_inc_pending(io);
1733 r = crypt_convert(cc, &io->ctx);
1734 if (r)
1735 io->error = r;
1736 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1737
1738 /* Encryption was already finished, submit io now */
1739 if (crypt_finished) {
1740 kcryptd_crypt_write_io_submit(io, 0);
1741 io->sector = sector;
1742 }
1743
1744dec:
1745 crypt_dec_pending(io);
1746}
1747
1748static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1749{
1750 crypt_dec_pending(io);
1751}
1752
1753static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1754{
1755 struct crypt_config *cc = io->cc;
1756 blk_status_t r;
1757
1758 crypt_inc_pending(io);
1759
1760 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1761 io->sector);
1762
1763 r = crypt_convert(cc, &io->ctx);
1764 if (r)
1765 io->error = r;
1766
1767 if (atomic_dec_and_test(&io->ctx.cc_pending))
1768 kcryptd_crypt_read_done(io);
1769
1770 crypt_dec_pending(io);
1771}
1772
1773static void kcryptd_async_done(struct crypto_async_request *async_req,
1774 int error)
1775{
1776 struct dm_crypt_request *dmreq = async_req->data;
1777 struct convert_context *ctx = dmreq->ctx;
1778 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1779 struct crypt_config *cc = io->cc;
1780
1781 /*
1782 * A request from crypto driver backlog is going to be processed now,
1783 * finish the completion and continue in crypt_convert().
1784 * (Callback will be called for the second time for this request.)
1785 */
1786 if (error == -EINPROGRESS) {
1787 complete(&ctx->restart);
1788 return;
1789 }
1790
1791 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1792 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
1793
1794 if (error == -EBADMSG) {
1795 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu",
1796 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
1797 io->error = BLK_STS_PROTECTION;
1798 } else if (error < 0)
1799 io->error = BLK_STS_IOERR;
1800
1801 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1802
1803 if (!atomic_dec_and_test(&ctx->cc_pending))
1804 return;
1805
1806 if (bio_data_dir(io->base_bio) == READ)
1807 kcryptd_crypt_read_done(io);
1808 else
1809 kcryptd_crypt_write_io_submit(io, 1);
1810}
1811
1812static void kcryptd_crypt(struct work_struct *work)
1813{
1814 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1815
1816 if (bio_data_dir(io->base_bio) == READ)
1817 kcryptd_crypt_read_convert(io);
1818 else
1819 kcryptd_crypt_write_convert(io);
1820}
1821
1822static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1823{
1824 struct crypt_config *cc = io->cc;
1825
1826 INIT_WORK(&io->work, kcryptd_crypt);
1827 queue_work(cc->crypt_queue, &io->work);
1828}
1829
1830static void crypt_free_tfms_aead(struct crypt_config *cc)
1831{
1832 if (!cc->cipher_tfm.tfms_aead)
1833 return;
1834
1835 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1836 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
1837 cc->cipher_tfm.tfms_aead[0] = NULL;
1838 }
1839
1840 kfree(cc->cipher_tfm.tfms_aead);
1841 cc->cipher_tfm.tfms_aead = NULL;
1842}
1843
1844static void crypt_free_tfms_skcipher(struct crypt_config *cc)
1845{
1846 unsigned i;
1847
1848 if (!cc->cipher_tfm.tfms)
1849 return;
1850
1851 for (i = 0; i < cc->tfms_count; i++)
1852 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
1853 crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
1854 cc->cipher_tfm.tfms[i] = NULL;
1855 }
1856
1857 kfree(cc->cipher_tfm.tfms);
1858 cc->cipher_tfm.tfms = NULL;
1859}
1860
1861static void crypt_free_tfms(struct crypt_config *cc)
1862{
1863 if (crypt_integrity_aead(cc))
1864 crypt_free_tfms_aead(cc);
1865 else
1866 crypt_free_tfms_skcipher(cc);
1867}
1868
1869static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
1870{
1871 unsigned i;
1872 int err;
1873
1874 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
1875 sizeof(struct crypto_skcipher *),
1876 GFP_KERNEL);
1877 if (!cc->cipher_tfm.tfms)
1878 return -ENOMEM;
1879
1880 for (i = 0; i < cc->tfms_count; i++) {
1881 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1882 if (IS_ERR(cc->cipher_tfm.tfms[i])) {
1883 err = PTR_ERR(cc->cipher_tfm.tfms[i]);
1884 crypt_free_tfms(cc);
1885 return err;
1886 }
1887 }
1888
1889 /*
1890 * dm-crypt performance can vary greatly depending on which crypto
1891 * algorithm implementation is used. Help people debug performance
1892 * problems by logging the ->cra_driver_name.
1893 */
1894 DMINFO("%s using implementation \"%s\"", ciphermode,
1895 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
1896 return 0;
1897}
1898
1899static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
1900{
1901 int err;
1902
1903 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
1904 if (!cc->cipher_tfm.tfms)
1905 return -ENOMEM;
1906
1907 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0);
1908 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
1909 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
1910 crypt_free_tfms(cc);
1911 return err;
1912 }
1913
1914 DMINFO("%s using implementation \"%s\"", ciphermode,
1915 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
1916 return 0;
1917}
1918
1919static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1920{
1921 if (crypt_integrity_aead(cc))
1922 return crypt_alloc_tfms_aead(cc, ciphermode);
1923 else
1924 return crypt_alloc_tfms_skcipher(cc, ciphermode);
1925}
1926
1927static unsigned crypt_subkey_size(struct crypt_config *cc)
1928{
1929 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1930}
1931
1932static unsigned crypt_authenckey_size(struct crypt_config *cc)
1933{
1934 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
1935}
1936
1937/*
1938 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
1939 * the key must be for some reason in special format.
1940 * This funcion converts cc->key to this special format.
1941 */
1942static void crypt_copy_authenckey(char *p, const void *key,
1943 unsigned enckeylen, unsigned authkeylen)
1944{
1945 struct crypto_authenc_key_param *param;
1946 struct rtattr *rta;
1947
1948 rta = (struct rtattr *)p;
1949 param = RTA_DATA(rta);
1950 param->enckeylen = cpu_to_be32(enckeylen);
1951 rta->rta_len = RTA_LENGTH(sizeof(*param));
1952 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
1953 p += RTA_SPACE(sizeof(*param));
1954 memcpy(p, key + enckeylen, authkeylen);
1955 p += authkeylen;
1956 memcpy(p, key, enckeylen);
1957}
1958
1959static int crypt_setkey(struct crypt_config *cc)
1960{
1961 unsigned subkey_size;
1962 int err = 0, i, r;
1963
1964 /* Ignore extra keys (which are used for IV etc) */
1965 subkey_size = crypt_subkey_size(cc);
1966
1967 if (crypt_integrity_hmac(cc)) {
1968 if (subkey_size < cc->key_mac_size)
1969 return -EINVAL;
1970
1971 crypt_copy_authenckey(cc->authenc_key, cc->key,
1972 subkey_size - cc->key_mac_size,
1973 cc->key_mac_size);
1974 }
1975
1976 for (i = 0; i < cc->tfms_count; i++) {
1977 if (crypt_integrity_hmac(cc))
1978 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1979 cc->authenc_key, crypt_authenckey_size(cc));
1980 else if (crypt_integrity_aead(cc))
1981 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
1982 cc->key + (i * subkey_size),
1983 subkey_size);
1984 else
1985 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
1986 cc->key + (i * subkey_size),
1987 subkey_size);
1988 if (r)
1989 err = r;
1990 }
1991
1992 if (crypt_integrity_hmac(cc))
1993 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
1994
1995 return err;
1996}
1997
1998#ifdef CONFIG_KEYS
1999
2000static bool contains_whitespace(const char *str)
2001{
2002 while (*str)
2003 if (isspace(*str++))
2004 return true;
2005 return false;
2006}
2007
2008static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2009{
2010 char *new_key_string, *key_desc;
2011 int ret;
2012 struct key *key;
2013 const struct user_key_payload *ukp;
2014
2015 /*
2016 * Reject key_string with whitespace. dm core currently lacks code for
2017 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2018 */
2019 if (contains_whitespace(key_string)) {
2020 DMERR("whitespace chars not allowed in key string");
2021 return -EINVAL;
2022 }
2023
2024 /* look for next ':' separating key_type from key_description */
2025 key_desc = strpbrk(key_string, ":");
2026 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2027 return -EINVAL;
2028
2029 if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
2030 strncmp(key_string, "user:", key_desc - key_string + 1))
2031 return -EINVAL;
2032
2033 new_key_string = kstrdup(key_string, GFP_KERNEL);
2034 if (!new_key_string)
2035 return -ENOMEM;
2036
2037 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
2038 key_desc + 1, NULL);
2039 if (IS_ERR(key)) {
2040 kzfree(new_key_string);
2041 return PTR_ERR(key);
2042 }
2043
2044 down_read(&key->sem);
2045
2046 ukp = user_key_payload_locked(key);
2047 if (!ukp) {
2048 up_read(&key->sem);
2049 key_put(key);
2050 kzfree(new_key_string);
2051 return -EKEYREVOKED;
2052 }
2053
2054 if (cc->key_size != ukp->datalen) {
2055 up_read(&key->sem);
2056 key_put(key);
2057 kzfree(new_key_string);
2058 return -EINVAL;
2059 }
2060
2061 memcpy(cc->key, ukp->data, cc->key_size);
2062
2063 up_read(&key->sem);
2064 key_put(key);
2065
2066 /* clear the flag since following operations may invalidate previously valid key */
2067 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2068
2069 ret = crypt_setkey(cc);
2070
2071 if (!ret) {
2072 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2073 kzfree(cc->key_string);
2074 cc->key_string = new_key_string;
2075 } else
2076 kzfree(new_key_string);
2077
2078 return ret;
2079}
2080
2081static int get_key_size(char **key_string)
2082{
2083 char *colon, dummy;
2084 int ret;
2085
2086 if (*key_string[0] != ':')
2087 return strlen(*key_string) >> 1;
2088
2089 /* look for next ':' in key string */
2090 colon = strpbrk(*key_string + 1, ":");
2091 if (!colon)
2092 return -EINVAL;
2093
2094 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2095 return -EINVAL;
2096
2097 *key_string = colon;
2098
2099 /* remaining key string should be :<logon|user>:<key_desc> */
2100
2101 return ret;
2102}
2103
2104#else
2105
2106static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2107{
2108 return -EINVAL;
2109}
2110
2111static int get_key_size(char **key_string)
2112{
2113 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
2114}
2115
2116#endif
2117
2118static int crypt_set_key(struct crypt_config *cc, char *key)
2119{
2120 int r = -EINVAL;
2121 int key_string_len = strlen(key);
2122
2123 /* Hyphen (which gives a key_size of zero) means there is no key. */
2124 if (!cc->key_size && strcmp(key, "-"))
2125 goto out;
2126
2127 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2128 if (key[0] == ':') {
2129 r = crypt_set_keyring_key(cc, key + 1);
2130 goto out;
2131 }
2132
2133 /* clear the flag since following operations may invalidate previously valid key */
2134 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2135
2136 /* wipe references to any kernel keyring key */
2137 kzfree(cc->key_string);
2138 cc->key_string = NULL;
2139
2140 /* Decode key from its hex representation. */
2141 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2142 goto out;
2143
2144 r = crypt_setkey(cc);
2145 if (!r)
2146 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2147
2148out:
2149 /* Hex key string not needed after here, so wipe it. */
2150 memset(key, '0', key_string_len);
2151
2152 return r;
2153}
2154
2155static int crypt_wipe_key(struct crypt_config *cc)
2156{
2157 int r;
2158
2159 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2160 get_random_bytes(&cc->key, cc->key_size);
2161 kzfree(cc->key_string);
2162 cc->key_string = NULL;
2163 r = crypt_setkey(cc);
2164 memset(&cc->key, 0, cc->key_size * sizeof(u8));
2165
2166 return r;
2167}
2168
2169static void crypt_calculate_pages_per_client(void)
2170{
2171 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
2172
2173 if (!dm_crypt_clients_n)
2174 return;
2175
2176 pages /= dm_crypt_clients_n;
2177 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2178 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2179 dm_crypt_pages_per_client = pages;
2180}
2181
2182static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2183{
2184 struct crypt_config *cc = pool_data;
2185 struct page *page;
2186
2187 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) &&
2188 likely(gfp_mask & __GFP_NORETRY))
2189 return NULL;
2190
2191 page = alloc_page(gfp_mask);
2192 if (likely(page != NULL))
2193 percpu_counter_add(&cc->n_allocated_pages, 1);
2194
2195 return page;
2196}
2197
2198static void crypt_page_free(void *page, void *pool_data)
2199{
2200 struct crypt_config *cc = pool_data;
2201
2202 __free_page(page);
2203 percpu_counter_sub(&cc->n_allocated_pages, 1);
2204}
2205
2206static void crypt_dtr(struct dm_target *ti)
2207{
2208 struct crypt_config *cc = ti->private;
2209
2210 ti->private = NULL;
2211
2212 if (!cc)
2213 return;
2214
2215 if (cc->write_thread)
2216 kthread_stop(cc->write_thread);
2217
2218 if (cc->io_queue)
2219 destroy_workqueue(cc->io_queue);
2220 if (cc->crypt_queue)
2221 destroy_workqueue(cc->crypt_queue);
2222
2223 crypt_free_tfms(cc);
2224
2225 bioset_exit(&cc->bs);
2226
2227 mempool_exit(&cc->page_pool);
2228 mempool_exit(&cc->req_pool);
2229 mempool_exit(&cc->tag_pool);
2230
2231 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2232 percpu_counter_destroy(&cc->n_allocated_pages);
2233
2234 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2235 cc->iv_gen_ops->dtr(cc);
2236
2237 if (cc->dev)
2238 dm_put_device(ti, cc->dev);
2239
2240 kzfree(cc->cipher);
2241 kzfree(cc->cipher_string);
2242 kzfree(cc->key_string);
2243 kzfree(cc->cipher_auth);
2244 kzfree(cc->authenc_key);
2245
2246 mutex_destroy(&cc->bio_alloc_lock);
2247
2248 /* Must zero key material before freeing */
2249 kzfree(cc);
2250
2251 spin_lock(&dm_crypt_clients_lock);
2252 WARN_ON(!dm_crypt_clients_n);
2253 dm_crypt_clients_n--;
2254 crypt_calculate_pages_per_client();
2255 spin_unlock(&dm_crypt_clients_lock);
2256}
2257
2258static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2259{
2260 struct crypt_config *cc = ti->private;
2261
2262 if (crypt_integrity_aead(cc))
2263 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2264 else
2265 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2266
2267 if (cc->iv_size)
2268 /* at least a 64 bit sector number should fit in our buffer */
2269 cc->iv_size = max(cc->iv_size,
2270 (unsigned int)(sizeof(u64) / sizeof(u8)));
2271 else if (ivmode) {
2272 DMWARN("Selected cipher does not support IVs");
2273 ivmode = NULL;
2274 }
2275
2276 /* Choose ivmode, see comments at iv code. */
2277 if (ivmode == NULL)
2278 cc->iv_gen_ops = NULL;
2279 else if (strcmp(ivmode, "plain") == 0)
2280 cc->iv_gen_ops = &crypt_iv_plain_ops;
2281 else if (strcmp(ivmode, "plain64") == 0)
2282 cc->iv_gen_ops = &crypt_iv_plain64_ops;
2283 else if (strcmp(ivmode, "plain64be") == 0)
2284 cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2285 else if (strcmp(ivmode, "essiv") == 0)
2286 cc->iv_gen_ops = &crypt_iv_essiv_ops;
2287 else if (strcmp(ivmode, "benbi") == 0)
2288 cc->iv_gen_ops = &crypt_iv_benbi_ops;
2289 else if (strcmp(ivmode, "null") == 0)
2290 cc->iv_gen_ops = &crypt_iv_null_ops;
2291 else if (strcmp(ivmode, "lmk") == 0) {
2292 cc->iv_gen_ops = &crypt_iv_lmk_ops;
2293 /*
2294 * Version 2 and 3 is recognised according
2295 * to length of provided multi-key string.
2296 * If present (version 3), last key is used as IV seed.
2297 * All keys (including IV seed) are always the same size.
2298 */
2299 if (cc->key_size % cc->key_parts) {
2300 cc->key_parts++;
2301 cc->key_extra_size = cc->key_size / cc->key_parts;
2302 }
2303 } else if (strcmp(ivmode, "tcw") == 0) {
2304 cc->iv_gen_ops = &crypt_iv_tcw_ops;
2305 cc->key_parts += 2; /* IV + whitening */
2306 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2307 } else if (strcmp(ivmode, "random") == 0) {
2308 cc->iv_gen_ops = &crypt_iv_random_ops;
2309 /* Need storage space in integrity fields. */
2310 cc->integrity_iv_size = cc->iv_size;
2311 } else {
2312 ti->error = "Invalid IV mode";
2313 return -EINVAL;
2314 }
2315
2316 return 0;
2317}
2318
2319/*
2320 * Workaround to parse cipher algorithm from crypto API spec.
2321 * The cc->cipher is currently used only in ESSIV.
2322 * This should be probably done by crypto-api calls (once available...)
2323 */
2324static int crypt_ctr_blkdev_cipher(struct crypt_config *cc)
2325{
2326 const char *alg_name = NULL;
2327 char *start, *end;
2328
2329 if (crypt_integrity_aead(cc)) {
2330 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc)));
2331 if (!alg_name)
2332 return -EINVAL;
2333 if (crypt_integrity_hmac(cc)) {
2334 alg_name = strchr(alg_name, ',');
2335 if (!alg_name)
2336 return -EINVAL;
2337 }
2338 alg_name++;
2339 } else {
2340 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc)));
2341 if (!alg_name)
2342 return -EINVAL;
2343 }
2344
2345 start = strchr(alg_name, '(');
2346 end = strchr(alg_name, ')');
2347
2348 if (!start && !end) {
2349 cc->cipher = kstrdup(alg_name, GFP_KERNEL);
2350 return cc->cipher ? 0 : -ENOMEM;
2351 }
2352
2353 if (!start || !end || ++start >= end)
2354 return -EINVAL;
2355
2356 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL);
2357 if (!cc->cipher)
2358 return -ENOMEM;
2359
2360 strncpy(cc->cipher, start, end - start);
2361
2362 return 0;
2363}
2364
2365/*
2366 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2367 * The HMAC is needed to calculate tag size (HMAC digest size).
2368 * This should be probably done by crypto-api calls (once available...)
2369 */
2370static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2371{
2372 char *start, *end, *mac_alg = NULL;
2373 struct crypto_ahash *mac;
2374
2375 if (!strstarts(cipher_api, "authenc("))
2376 return 0;
2377
2378 start = strchr(cipher_api, '(');
2379 end = strchr(cipher_api, ',');
2380 if (!start || !end || ++start > end)
2381 return -EINVAL;
2382
2383 mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2384 if (!mac_alg)
2385 return -ENOMEM;
2386 strncpy(mac_alg, start, end - start);
2387
2388 mac = crypto_alloc_ahash(mac_alg, 0, 0);
2389 kfree(mac_alg);
2390
2391 if (IS_ERR(mac))
2392 return PTR_ERR(mac);
2393
2394 cc->key_mac_size = crypto_ahash_digestsize(mac);
2395 crypto_free_ahash(mac);
2396
2397 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2398 if (!cc->authenc_key)
2399 return -ENOMEM;
2400
2401 return 0;
2402}
2403
2404static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2405 char **ivmode, char **ivopts)
2406{
2407 struct crypt_config *cc = ti->private;
2408 char *tmp, *cipher_api;
2409 int ret = -EINVAL;
2410
2411 cc->tfms_count = 1;
2412
2413 /*
2414 * New format (capi: prefix)
2415 * capi:cipher_api_spec-iv:ivopts
2416 */
2417 tmp = &cipher_in[strlen("capi:")];
2418
2419 /* Separate IV options if present, it can contain another '-' in hash name */
2420 *ivopts = strrchr(tmp, ':');
2421 if (*ivopts) {
2422 **ivopts = '\0';
2423 (*ivopts)++;
2424 }
2425 /* Parse IV mode */
2426 *ivmode = strrchr(tmp, '-');
2427 if (*ivmode) {
2428 **ivmode = '\0';
2429 (*ivmode)++;
2430 }
2431 /* The rest is crypto API spec */
2432 cipher_api = tmp;
2433
2434 if (*ivmode && !strcmp(*ivmode, "lmk"))
2435 cc->tfms_count = 64;
2436
2437 cc->key_parts = cc->tfms_count;
2438
2439 /* Allocate cipher */
2440 ret = crypt_alloc_tfms(cc, cipher_api);
2441 if (ret < 0) {
2442 ti->error = "Error allocating crypto tfm";
2443 return ret;
2444 }
2445
2446 /* Alloc AEAD, can be used only in new format. */
2447 if (crypt_integrity_aead(cc)) {
2448 ret = crypt_ctr_auth_cipher(cc, cipher_api);
2449 if (ret < 0) {
2450 ti->error = "Invalid AEAD cipher spec";
2451 return -ENOMEM;
2452 }
2453 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2454 } else
2455 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2456
2457 ret = crypt_ctr_blkdev_cipher(cc);
2458 if (ret < 0) {
2459 ti->error = "Cannot allocate cipher string";
2460 return -ENOMEM;
2461 }
2462
2463 return 0;
2464}
2465
2466static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2467 char **ivmode, char **ivopts)
2468{
2469 struct crypt_config *cc = ti->private;
2470 char *tmp, *cipher, *chainmode, *keycount;
2471 char *cipher_api = NULL;
2472 int ret = -EINVAL;
2473 char dummy;
2474
2475 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2476 ti->error = "Bad cipher specification";
2477 return -EINVAL;
2478 }
2479
2480 /*
2481 * Legacy dm-crypt cipher specification
2482 * cipher[:keycount]-mode-iv:ivopts
2483 */
2484 tmp = cipher_in;
2485 keycount = strsep(&tmp, "-");
2486 cipher = strsep(&keycount, ":");
2487
2488 if (!keycount)
2489 cc->tfms_count = 1;
2490 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2491 !is_power_of_2(cc->tfms_count)) {
2492 ti->error = "Bad cipher key count specification";
2493 return -EINVAL;
2494 }
2495 cc->key_parts = cc->tfms_count;
2496
2497 cc->cipher = kstrdup(cipher, GFP_KERNEL);
2498 if (!cc->cipher)
2499 goto bad_mem;
2500
2501 chainmode = strsep(&tmp, "-");
2502 *ivmode = strsep(&tmp, ":");
2503 *ivopts = tmp;
2504
2505 /*
2506 * For compatibility with the original dm-crypt mapping format, if
2507 * only the cipher name is supplied, use cbc-plain.
2508 */
2509 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2510 chainmode = "cbc";
2511 *ivmode = "plain";
2512 }
2513
2514 if (strcmp(chainmode, "ecb") && !*ivmode) {
2515 ti->error = "IV mechanism required";
2516 return -EINVAL;
2517 }
2518
2519 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2520 if (!cipher_api)
2521 goto bad_mem;
2522
2523 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2524 "%s(%s)", chainmode, cipher);
2525 if (ret < 0) {
2526 kfree(cipher_api);
2527 goto bad_mem;
2528 }
2529
2530 /* Allocate cipher */
2531 ret = crypt_alloc_tfms(cc, cipher_api);
2532 if (ret < 0) {
2533 ti->error = "Error allocating crypto tfm";
2534 kfree(cipher_api);
2535 return ret;
2536 }
2537 kfree(cipher_api);
2538
2539 return 0;
2540bad_mem:
2541 ti->error = "Cannot allocate cipher strings";
2542 return -ENOMEM;
2543}
2544
2545static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
2546{
2547 struct crypt_config *cc = ti->private;
2548 char *ivmode = NULL, *ivopts = NULL;
2549 int ret;
2550
2551 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
2552 if (!cc->cipher_string) {
2553 ti->error = "Cannot allocate cipher strings";
2554 return -ENOMEM;
2555 }
2556
2557 if (strstarts(cipher_in, "capi:"))
2558 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
2559 else
2560 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
2561 if (ret)
2562 return ret;
2563
2564 /* Initialize IV */
2565 ret = crypt_ctr_ivmode(ti, ivmode);
2566 if (ret < 0)
2567 return ret;
2568
2569 /* Initialize and set key */
2570 ret = crypt_set_key(cc, key);
2571 if (ret < 0) {
2572 ti->error = "Error decoding and setting key";
2573 return ret;
2574 }
2575
2576 /* Allocate IV */
2577 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
2578 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
2579 if (ret < 0) {
2580 ti->error = "Error creating IV";
2581 return ret;
2582 }
2583 }
2584
2585 /* Initialize IV (set keys for ESSIV etc) */
2586 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
2587 ret = cc->iv_gen_ops->init(cc);
2588 if (ret < 0) {
2589 ti->error = "Error initialising IV";
2590 return ret;
2591 }
2592 }
2593
2594 /* wipe the kernel key payload copy */
2595 if (cc->key_string)
2596 memset(cc->key, 0, cc->key_size * sizeof(u8));
2597
2598 return ret;
2599}
2600
2601static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
2602{
2603 struct crypt_config *cc = ti->private;
2604 struct dm_arg_set as;
2605 static const struct dm_arg _args[] = {
2606 {0, 6, "Invalid number of feature args"},
2607 };
2608 unsigned int opt_params, val;
2609 const char *opt_string, *sval;
2610 char dummy;
2611 int ret;
2612
2613 /* Optional parameters */
2614 as.argc = argc;
2615 as.argv = argv;
2616
2617 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
2618 if (ret)
2619 return ret;
2620
2621 while (opt_params--) {
2622 opt_string = dm_shift_arg(&as);
2623 if (!opt_string) {
2624 ti->error = "Not enough feature arguments";
2625 return -EINVAL;
2626 }
2627
2628 if (!strcasecmp(opt_string, "allow_discards"))
2629 ti->num_discard_bios = 1;
2630
2631 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
2632 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2633
2634 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
2635 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2636 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
2637 if (val == 0 || val > MAX_TAG_SIZE) {
2638 ti->error = "Invalid integrity arguments";
2639 return -EINVAL;
2640 }
2641 cc->on_disk_tag_size = val;
2642 sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
2643 if (!strcasecmp(sval, "aead")) {
2644 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
2645 } else if (strcasecmp(sval, "none")) {
2646 ti->error = "Unknown integrity profile";
2647 return -EINVAL;
2648 }
2649
2650 cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
2651 if (!cc->cipher_auth)
2652 return -ENOMEM;
2653 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
2654 if (cc->sector_size < (1 << SECTOR_SHIFT) ||
2655 cc->sector_size > 4096 ||
2656 (cc->sector_size & (cc->sector_size - 1))) {
2657 ti->error = "Invalid feature value for sector_size";
2658 return -EINVAL;
2659 }
2660 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
2661 ti->error = "Device size is not multiple of sector_size feature";
2662 return -EINVAL;
2663 }
2664 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
2665 } else if (!strcasecmp(opt_string, "iv_large_sectors"))
2666 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2667 else {
2668 ti->error = "Invalid feature arguments";
2669 return -EINVAL;
2670 }
2671 }
2672
2673 return 0;
2674}
2675
2676/*
2677 * Construct an encryption mapping:
2678 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
2679 */
2680static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2681{
2682 struct crypt_config *cc;
2683 const char *devname = dm_table_device_name(ti->table);
2684 int key_size;
2685 unsigned int align_mask;
2686 unsigned long long tmpll;
2687 int ret;
2688 size_t iv_size_padding, additional_req_size;
2689 char dummy;
2690
2691 if (argc < 5) {
2692 ti->error = "Not enough arguments";
2693 return -EINVAL;
2694 }
2695
2696 key_size = get_key_size(&argv[1]);
2697 if (key_size < 0) {
2698 ti->error = "Cannot parse key size";
2699 return -EINVAL;
2700 }
2701
2702 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
2703 if (!cc) {
2704 ti->error = "Cannot allocate encryption context";
2705 return -ENOMEM;
2706 }
2707 cc->key_size = key_size;
2708 cc->sector_size = (1 << SECTOR_SHIFT);
2709 cc->sector_shift = 0;
2710
2711 ti->private = cc;
2712
2713 spin_lock(&dm_crypt_clients_lock);
2714 dm_crypt_clients_n++;
2715 crypt_calculate_pages_per_client();
2716 spin_unlock(&dm_crypt_clients_lock);
2717
2718 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
2719 if (ret < 0)
2720 goto bad;
2721
2722 /* Optional parameters need to be read before cipher constructor */
2723 if (argc > 5) {
2724 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
2725 if (ret)
2726 goto bad;
2727 }
2728
2729 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
2730 if (ret < 0)
2731 goto bad;
2732
2733 if (crypt_integrity_aead(cc)) {
2734 cc->dmreq_start = sizeof(struct aead_request);
2735 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
2736 align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
2737 } else {
2738 cc->dmreq_start = sizeof(struct skcipher_request);
2739 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
2740 align_mask = crypto_skcipher_alignmask(any_tfm(cc));
2741 }
2742 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
2743
2744 if (align_mask < CRYPTO_MINALIGN) {
2745 /* Allocate the padding exactly */
2746 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
2747 & align_mask;
2748 } else {
2749 /*
2750 * If the cipher requires greater alignment than kmalloc
2751 * alignment, we don't know the exact position of the
2752 * initialization vector. We must assume worst case.
2753 */
2754 iv_size_padding = align_mask;
2755 }
2756
2757 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */
2758 additional_req_size = sizeof(struct dm_crypt_request) +
2759 iv_size_padding + cc->iv_size +
2760 cc->iv_size +
2761 sizeof(uint64_t) +
2762 sizeof(unsigned int);
2763
2764 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
2765 if (ret) {
2766 ti->error = "Cannot allocate crypt request mempool";
2767 goto bad;
2768 }
2769
2770 cc->per_bio_data_size = ti->per_io_data_size =
2771 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
2772 ARCH_KMALLOC_MINALIGN);
2773
2774 ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc);
2775 if (ret) {
2776 ti->error = "Cannot allocate page mempool";
2777 goto bad;
2778 }
2779
2780 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
2781 if (ret) {
2782 ti->error = "Cannot allocate crypt bioset";
2783 goto bad;
2784 }
2785
2786 mutex_init(&cc->bio_alloc_lock);
2787
2788 ret = -EINVAL;
2789 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
2790 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
2791 ti->error = "Invalid iv_offset sector";
2792 goto bad;
2793 }
2794 cc->iv_offset = tmpll;
2795
2796 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
2797 if (ret) {
2798 ti->error = "Device lookup failed";
2799 goto bad;
2800 }
2801
2802 ret = -EINVAL;
2803 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
2804 ti->error = "Invalid device sector";
2805 goto bad;
2806 }
2807 cc->start = tmpll;
2808
2809 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
2810 ret = crypt_integrity_ctr(cc, ti);
2811 if (ret)
2812 goto bad;
2813
2814 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
2815 if (!cc->tag_pool_max_sectors)
2816 cc->tag_pool_max_sectors = 1;
2817
2818 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
2819 cc->tag_pool_max_sectors * cc->on_disk_tag_size);
2820 if (ret) {
2821 ti->error = "Cannot allocate integrity tags mempool";
2822 goto bad;
2823 }
2824
2825 cc->tag_pool_max_sectors <<= cc->sector_shift;
2826 }
2827
2828 ret = -ENOMEM;
2829 cc->io_queue = alloc_workqueue("kcryptd_io/%s",
2830 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
2831 1, devname);
2832 if (!cc->io_queue) {
2833 ti->error = "Couldn't create kcryptd io queue";
2834 goto bad;
2835 }
2836
2837 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2838 cc->crypt_queue = alloc_workqueue("kcryptd/%s",
2839 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
2840 1, devname);
2841 else
2842 cc->crypt_queue = alloc_workqueue("kcryptd/%s",
2843 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2844 num_online_cpus(), devname);
2845 if (!cc->crypt_queue) {
2846 ti->error = "Couldn't create kcryptd queue";
2847 goto bad;
2848 }
2849
2850 spin_lock_init(&cc->write_thread_lock);
2851 cc->write_tree = RB_ROOT;
2852
2853 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
2854 if (IS_ERR(cc->write_thread)) {
2855 ret = PTR_ERR(cc->write_thread);
2856 cc->write_thread = NULL;
2857 ti->error = "Couldn't spawn write thread";
2858 goto bad;
2859 }
2860 wake_up_process(cc->write_thread);
2861
2862 ti->num_flush_bios = 1;
2863
2864 return 0;
2865
2866bad:
2867 crypt_dtr(ti);
2868 return ret;
2869}
2870
2871static int crypt_map(struct dm_target *ti, struct bio *bio)
2872{
2873 struct dm_crypt_io *io;
2874 struct crypt_config *cc = ti->private;
2875
2876 /*
2877 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2878 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
2879 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
2880 */
2881 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
2882 bio_op(bio) == REQ_OP_DISCARD)) {
2883 bio_set_dev(bio, cc->dev->bdev);
2884 if (bio_sectors(bio))
2885 bio->bi_iter.bi_sector = cc->start +
2886 dm_target_offset(ti, bio->bi_iter.bi_sector);
2887 return DM_MAPIO_REMAPPED;
2888 }
2889
2890 /*
2891 * Check if bio is too large, split as needed.
2892 */
2893 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2894 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
2895 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2896
2897 /*
2898 * Ensure that bio is a multiple of internal sector encryption size
2899 * and is aligned to this size as defined in IO hints.
2900 */
2901 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
2902 return DM_MAPIO_KILL;
2903
2904 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
2905 return DM_MAPIO_KILL;
2906
2907 io = dm_per_bio_data(bio, cc->per_bio_data_size);
2908 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
2909
2910 if (cc->on_disk_tag_size) {
2911 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
2912
2913 if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
2914 unlikely(!(io->integrity_metadata = kmalloc(tag_len,
2915 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
2916 if (bio_sectors(bio) > cc->tag_pool_max_sectors)
2917 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
2918 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
2919 io->integrity_metadata_from_pool = true;
2920 }
2921 }
2922
2923 if (crypt_integrity_aead(cc))
2924 io->ctx.r.req_aead = (struct aead_request *)(io + 1);
2925 else
2926 io->ctx.r.req = (struct skcipher_request *)(io + 1);
2927
2928 if (bio_data_dir(io->base_bio) == READ) {
2929 if (kcryptd_io_read(io, GFP_NOWAIT))
2930 kcryptd_queue_read(io);
2931 } else
2932 kcryptd_queue_crypt(io);
2933
2934 return DM_MAPIO_SUBMITTED;
2935}
2936
2937static void crypt_status(struct dm_target *ti, status_type_t type,
2938 unsigned status_flags, char *result, unsigned maxlen)
2939{
2940 struct crypt_config *cc = ti->private;
2941 unsigned i, sz = 0;
2942 int num_feature_args = 0;
2943
2944 switch (type) {
2945 case STATUSTYPE_INFO:
2946 result[0] = '\0';
2947 break;
2948
2949 case STATUSTYPE_TABLE:
2950 DMEMIT("%s ", cc->cipher_string);
2951
2952 if (cc->key_size > 0) {
2953 if (cc->key_string)
2954 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2955 else
2956 for (i = 0; i < cc->key_size; i++)
2957 DMEMIT("%02x", cc->key[i]);
2958 } else
2959 DMEMIT("-");
2960
2961 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2962 cc->dev->name, (unsigned long long)cc->start);
2963
2964 num_feature_args += !!ti->num_discard_bios;
2965 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2966 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
2967 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
2968 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
2969 if (cc->on_disk_tag_size)
2970 num_feature_args++;
2971 if (num_feature_args) {
2972 DMEMIT(" %d", num_feature_args);
2973 if (ti->num_discard_bios)
2974 DMEMIT(" allow_discards");
2975 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2976 DMEMIT(" same_cpu_crypt");
2977 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2978 DMEMIT(" submit_from_crypt_cpus");
2979 if (cc->on_disk_tag_size)
2980 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
2981 if (cc->sector_size != (1 << SECTOR_SHIFT))
2982 DMEMIT(" sector_size:%d", cc->sector_size);
2983 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
2984 DMEMIT(" iv_large_sectors");
2985 }
2986
2987 break;
2988 }
2989}
2990
2991static void crypt_postsuspend(struct dm_target *ti)
2992{
2993 struct crypt_config *cc = ti->private;
2994
2995 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2996}
2997
2998static int crypt_preresume(struct dm_target *ti)
2999{
3000 struct crypt_config *cc = ti->private;
3001
3002 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3003 DMERR("aborting resume - crypt key is not set.");
3004 return -EAGAIN;
3005 }
3006
3007 return 0;
3008}
3009
3010static void crypt_resume(struct dm_target *ti)
3011{
3012 struct crypt_config *cc = ti->private;
3013
3014 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3015}
3016
3017/* Message interface
3018 * key set <key>
3019 * key wipe
3020 */
3021static int crypt_message(struct dm_target *ti, unsigned argc, char **argv,
3022 char *result, unsigned maxlen)
3023{
3024 struct crypt_config *cc = ti->private;
3025 int key_size, ret = -EINVAL;
3026
3027 if (argc < 2)
3028 goto error;
3029
3030 if (!strcasecmp(argv[0], "key")) {
3031 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3032 DMWARN("not suspended during key manipulation.");
3033 return -EINVAL;
3034 }
3035 if (argc == 3 && !strcasecmp(argv[1], "set")) {
3036 /* The key size may not be changed. */
3037 key_size = get_key_size(&argv[2]);
3038 if (key_size < 0 || cc->key_size != key_size) {
3039 memset(argv[2], '0', strlen(argv[2]));
3040 return -EINVAL;
3041 }
3042
3043 ret = crypt_set_key(cc, argv[2]);
3044 if (ret)
3045 return ret;
3046 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3047 ret = cc->iv_gen_ops->init(cc);
3048 /* wipe the kernel key payload copy */
3049 if (cc->key_string)
3050 memset(cc->key, 0, cc->key_size * sizeof(u8));
3051 return ret;
3052 }
3053 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
3054 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
3055 ret = cc->iv_gen_ops->wipe(cc);
3056 if (ret)
3057 return ret;
3058 }
3059 return crypt_wipe_key(cc);
3060 }
3061 }
3062
3063error:
3064 DMWARN("unrecognised message received.");
3065 return -EINVAL;
3066}
3067
3068static int crypt_iterate_devices(struct dm_target *ti,
3069 iterate_devices_callout_fn fn, void *data)
3070{
3071 struct crypt_config *cc = ti->private;
3072
3073 return fn(ti, cc->dev, cc->start, ti->len, data);
3074}
3075
3076static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3077{
3078 struct crypt_config *cc = ti->private;
3079
3080 /*
3081 * Unfortunate constraint that is required to avoid the potential
3082 * for exceeding underlying device's max_segments limits -- due to
3083 * crypt_alloc_buffer() possibly allocating pages for the encryption
3084 * bio that are not as physically contiguous as the original bio.
3085 */
3086 limits->max_segment_size = PAGE_SIZE;
3087
3088 limits->logical_block_size =
3089 max_t(unsigned short, limits->logical_block_size, cc->sector_size);
3090 limits->physical_block_size =
3091 max_t(unsigned, limits->physical_block_size, cc->sector_size);
3092 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
3093}
3094
3095static struct target_type crypt_target = {
3096 .name = "crypt",
3097 .version = {1, 18, 1},
3098 .module = THIS_MODULE,
3099 .ctr = crypt_ctr,
3100 .dtr = crypt_dtr,
3101 .map = crypt_map,
3102 .status = crypt_status,
3103 .postsuspend = crypt_postsuspend,
3104 .preresume = crypt_preresume,
3105 .resume = crypt_resume,
3106 .message = crypt_message,
3107 .iterate_devices = crypt_iterate_devices,
3108 .io_hints = crypt_io_hints,
3109};
3110
3111static int __init dm_crypt_init(void)
3112{
3113 int r;
3114
3115 r = dm_register_target(&crypt_target);
3116 if (r < 0)
3117 DMERR("register failed %d", r);
3118
3119 return r;
3120}
3121
3122static void __exit dm_crypt_exit(void)
3123{
3124 dm_unregister_target(&crypt_target);
3125}
3126
3127module_init(dm_crypt_init);
3128module_exit(dm_crypt_exit);
3129
3130MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3131MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3132MODULE_LICENSE("GPL");
3133