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1/*
2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013-2020 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/blk-integrity.h>
19#include <linux/mempool.h>
20#include <linux/slab.h>
21#include <linux/crypto.h>
22#include <linux/workqueue.h>
23#include <linux/kthread.h>
24#include <linux/backing-dev.h>
25#include <linux/atomic.h>
26#include <linux/scatterlist.h>
27#include <linux/rbtree.h>
28#include <linux/ctype.h>
29#include <asm/page.h>
30#include <asm/unaligned.h>
31#include <crypto/hash.h>
32#include <crypto/md5.h>
33#include <crypto/algapi.h>
34#include <crypto/skcipher.h>
35#include <crypto/aead.h>
36#include <crypto/authenc.h>
37#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
38#include <linux/key-type.h>
39#include <keys/user-type.h>
40#include <keys/encrypted-type.h>
41#include <keys/trusted-type.h>
42
43#include <linux/device-mapper.h>
44
45#include "dm-audit.h"
46
47#define DM_MSG_PREFIX "crypt"
48
49/*
50 * context holding the current state of a multi-part conversion
51 */
52struct convert_context {
53 struct completion restart;
54 struct bio *bio_in;
55 struct bio *bio_out;
56 struct bvec_iter iter_in;
57 struct bvec_iter iter_out;
58 u64 cc_sector;
59 atomic_t cc_pending;
60 union {
61 struct skcipher_request *req;
62 struct aead_request *req_aead;
63 } r;
64
65};
66
67/*
68 * per bio private data
69 */
70struct dm_crypt_io {
71 struct crypt_config *cc;
72 struct bio *base_bio;
73 u8 *integrity_metadata;
74 bool integrity_metadata_from_pool;
75 struct work_struct work;
76 struct tasklet_struct tasklet;
77
78 struct convert_context ctx;
79
80 atomic_t io_pending;
81 blk_status_t error;
82 sector_t sector;
83
84 struct rb_node rb_node;
85} CRYPTO_MINALIGN_ATTR;
86
87struct dm_crypt_request {
88 struct convert_context *ctx;
89 struct scatterlist sg_in[4];
90 struct scatterlist sg_out[4];
91 u64 iv_sector;
92};
93
94struct crypt_config;
95
96struct crypt_iv_operations {
97 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
98 const char *opts);
99 void (*dtr)(struct crypt_config *cc);
100 int (*init)(struct crypt_config *cc);
101 int (*wipe)(struct crypt_config *cc);
102 int (*generator)(struct crypt_config *cc, u8 *iv,
103 struct dm_crypt_request *dmreq);
104 int (*post)(struct crypt_config *cc, u8 *iv,
105 struct dm_crypt_request *dmreq);
106};
107
108struct iv_benbi_private {
109 int shift;
110};
111
112#define LMK_SEED_SIZE 64 /* hash + 0 */
113struct iv_lmk_private {
114 struct crypto_shash *hash_tfm;
115 u8 *seed;
116};
117
118#define TCW_WHITENING_SIZE 16
119struct iv_tcw_private {
120 struct crypto_shash *crc32_tfm;
121 u8 *iv_seed;
122 u8 *whitening;
123};
124
125#define ELEPHANT_MAX_KEY_SIZE 32
126struct iv_elephant_private {
127 struct crypto_skcipher *tfm;
128};
129
130/*
131 * Crypt: maps a linear range of a block device
132 * and encrypts / decrypts at the same time.
133 */
134enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
135 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
136 DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE,
137 DM_CRYPT_WRITE_INLINE };
138
139enum cipher_flags {
140 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cipher */
141 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */
142 CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */
143};
144
145/*
146 * The fields in here must be read only after initialization.
147 */
148struct crypt_config {
149 struct dm_dev *dev;
150 sector_t start;
151
152 struct percpu_counter n_allocated_pages;
153
154 struct workqueue_struct *io_queue;
155 struct workqueue_struct *crypt_queue;
156
157 spinlock_t write_thread_lock;
158 struct task_struct *write_thread;
159 struct rb_root write_tree;
160
161 char *cipher_string;
162 char *cipher_auth;
163 char *key_string;
164
165 const struct crypt_iv_operations *iv_gen_ops;
166 union {
167 struct iv_benbi_private benbi;
168 struct iv_lmk_private lmk;
169 struct iv_tcw_private tcw;
170 struct iv_elephant_private elephant;
171 } iv_gen_private;
172 u64 iv_offset;
173 unsigned int iv_size;
174 unsigned short int sector_size;
175 unsigned char sector_shift;
176
177 union {
178 struct crypto_skcipher **tfms;
179 struct crypto_aead **tfms_aead;
180 } cipher_tfm;
181 unsigned tfms_count;
182 unsigned long cipher_flags;
183
184 /*
185 * Layout of each crypto request:
186 *
187 * struct skcipher_request
188 * context
189 * padding
190 * struct dm_crypt_request
191 * padding
192 * IV
193 *
194 * The padding is added so that dm_crypt_request and the IV are
195 * correctly aligned.
196 */
197 unsigned int dmreq_start;
198
199 unsigned int per_bio_data_size;
200
201 unsigned long flags;
202 unsigned int key_size;
203 unsigned int key_parts; /* independent parts in key buffer */
204 unsigned int key_extra_size; /* additional keys length */
205 unsigned int key_mac_size; /* MAC key size for authenc(...) */
206
207 unsigned int integrity_tag_size;
208 unsigned int integrity_iv_size;
209 unsigned int on_disk_tag_size;
210
211 /*
212 * pool for per bio private data, crypto requests,
213 * encryption requeusts/buffer pages and integrity tags
214 */
215 unsigned tag_pool_max_sectors;
216 mempool_t tag_pool;
217 mempool_t req_pool;
218 mempool_t page_pool;
219
220 struct bio_set bs;
221 struct mutex bio_alloc_lock;
222
223 u8 *authenc_key; /* space for keys in authenc() format (if used) */
224 u8 key[];
225};
226
227#define MIN_IOS 64
228#define MAX_TAG_SIZE 480
229#define POOL_ENTRY_SIZE 512
230
231static DEFINE_SPINLOCK(dm_crypt_clients_lock);
232static unsigned dm_crypt_clients_n = 0;
233static volatile unsigned long dm_crypt_pages_per_client;
234#define DM_CRYPT_MEMORY_PERCENT 2
235#define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16)
236
237static void crypt_endio(struct bio *clone);
238static void kcryptd_queue_crypt(struct dm_crypt_io *io);
239static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
240 struct scatterlist *sg);
241
242static bool crypt_integrity_aead(struct crypt_config *cc);
243
244/*
245 * Use this to access cipher attributes that are independent of the key.
246 */
247static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
248{
249 return cc->cipher_tfm.tfms[0];
250}
251
252static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
253{
254 return cc->cipher_tfm.tfms_aead[0];
255}
256
257/*
258 * Different IV generation algorithms:
259 *
260 * plain: the initial vector is the 32-bit little-endian version of the sector
261 * number, padded with zeros if necessary.
262 *
263 * plain64: the initial vector is the 64-bit little-endian version of the sector
264 * number, padded with zeros if necessary.
265 *
266 * plain64be: the initial vector is the 64-bit big-endian version of the sector
267 * number, padded with zeros if necessary.
268 *
269 * essiv: "encrypted sector|salt initial vector", the sector number is
270 * encrypted with the bulk cipher using a salt as key. The salt
271 * should be derived from the bulk cipher's key via hashing.
272 *
273 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
274 * (needed for LRW-32-AES and possible other narrow block modes)
275 *
276 * null: the initial vector is always zero. Provides compatibility with
277 * obsolete loop_fish2 devices. Do not use for new devices.
278 *
279 * lmk: Compatible implementation of the block chaining mode used
280 * by the Loop-AES block device encryption system
281 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
282 * It operates on full 512 byte sectors and uses CBC
283 * with an IV derived from the sector number, the data and
284 * optionally extra IV seed.
285 * This means that after decryption the first block
286 * of sector must be tweaked according to decrypted data.
287 * Loop-AES can use three encryption schemes:
288 * version 1: is plain aes-cbc mode
289 * version 2: uses 64 multikey scheme with lmk IV generator
290 * version 3: the same as version 2 with additional IV seed
291 * (it uses 65 keys, last key is used as IV seed)
292 *
293 * tcw: Compatible implementation of the block chaining mode used
294 * by the TrueCrypt device encryption system (prior to version 4.1).
295 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
296 * It operates on full 512 byte sectors and uses CBC
297 * with an IV derived from initial key and the sector number.
298 * In addition, whitening value is applied on every sector, whitening
299 * is calculated from initial key, sector number and mixed using CRC32.
300 * Note that this encryption scheme is vulnerable to watermarking attacks
301 * and should be used for old compatible containers access only.
302 *
303 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
304 * The IV is encrypted little-endian byte-offset (with the same key
305 * and cipher as the volume).
306 *
307 * elephant: The extended version of eboiv with additional Elephant diffuser
308 * used with Bitlocker CBC mode.
309 * This mode was used in older Windows systems
310 * https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
311 */
312
313static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
314 struct dm_crypt_request *dmreq)
315{
316 memset(iv, 0, cc->iv_size);
317 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
318
319 return 0;
320}
321
322static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
323 struct dm_crypt_request *dmreq)
324{
325 memset(iv, 0, cc->iv_size);
326 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
327
328 return 0;
329}
330
331static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
332 struct dm_crypt_request *dmreq)
333{
334 memset(iv, 0, cc->iv_size);
335 /* iv_size is at least of size u64; usually it is 16 bytes */
336 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
337
338 return 0;
339}
340
341static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
342 struct dm_crypt_request *dmreq)
343{
344 /*
345 * ESSIV encryption of the IV is now handled by the crypto API,
346 * so just pass the plain sector number here.
347 */
348 memset(iv, 0, cc->iv_size);
349 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
350
351 return 0;
352}
353
354static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
355 const char *opts)
356{
357 unsigned bs;
358 int log;
359
360 if (crypt_integrity_aead(cc))
361 bs = crypto_aead_blocksize(any_tfm_aead(cc));
362 else
363 bs = crypto_skcipher_blocksize(any_tfm(cc));
364 log = ilog2(bs);
365
366 /* we need to calculate how far we must shift the sector count
367 * to get the cipher block count, we use this shift in _gen */
368
369 if (1 << log != bs) {
370 ti->error = "cypher blocksize is not a power of 2";
371 return -EINVAL;
372 }
373
374 if (log > 9) {
375 ti->error = "cypher blocksize is > 512";
376 return -EINVAL;
377 }
378
379 cc->iv_gen_private.benbi.shift = 9 - log;
380
381 return 0;
382}
383
384static void crypt_iv_benbi_dtr(struct crypt_config *cc)
385{
386}
387
388static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
389 struct dm_crypt_request *dmreq)
390{
391 __be64 val;
392
393 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
394
395 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
396 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
397
398 return 0;
399}
400
401static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
402 struct dm_crypt_request *dmreq)
403{
404 memset(iv, 0, cc->iv_size);
405
406 return 0;
407}
408
409static void crypt_iv_lmk_dtr(struct crypt_config *cc)
410{
411 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
412
413 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
414 crypto_free_shash(lmk->hash_tfm);
415 lmk->hash_tfm = NULL;
416
417 kfree_sensitive(lmk->seed);
418 lmk->seed = NULL;
419}
420
421static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
422 const char *opts)
423{
424 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
425
426 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
427 ti->error = "Unsupported sector size for LMK";
428 return -EINVAL;
429 }
430
431 lmk->hash_tfm = crypto_alloc_shash("md5", 0,
432 CRYPTO_ALG_ALLOCATES_MEMORY);
433 if (IS_ERR(lmk->hash_tfm)) {
434 ti->error = "Error initializing LMK hash";
435 return PTR_ERR(lmk->hash_tfm);
436 }
437
438 /* No seed in LMK version 2 */
439 if (cc->key_parts == cc->tfms_count) {
440 lmk->seed = NULL;
441 return 0;
442 }
443
444 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
445 if (!lmk->seed) {
446 crypt_iv_lmk_dtr(cc);
447 ti->error = "Error kmallocing seed storage in LMK";
448 return -ENOMEM;
449 }
450
451 return 0;
452}
453
454static int crypt_iv_lmk_init(struct crypt_config *cc)
455{
456 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
457 int subkey_size = cc->key_size / cc->key_parts;
458
459 /* LMK seed is on the position of LMK_KEYS + 1 key */
460 if (lmk->seed)
461 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
462 crypto_shash_digestsize(lmk->hash_tfm));
463
464 return 0;
465}
466
467static int crypt_iv_lmk_wipe(struct crypt_config *cc)
468{
469 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
470
471 if (lmk->seed)
472 memset(lmk->seed, 0, LMK_SEED_SIZE);
473
474 return 0;
475}
476
477static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
478 struct dm_crypt_request *dmreq,
479 u8 *data)
480{
481 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
482 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
483 struct md5_state md5state;
484 __le32 buf[4];
485 int i, r;
486
487 desc->tfm = lmk->hash_tfm;
488
489 r = crypto_shash_init(desc);
490 if (r)
491 return r;
492
493 if (lmk->seed) {
494 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
495 if (r)
496 return r;
497 }
498
499 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
500 r = crypto_shash_update(desc, data + 16, 16 * 31);
501 if (r)
502 return r;
503
504 /* Sector is cropped to 56 bits here */
505 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
506 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
507 buf[2] = cpu_to_le32(4024);
508 buf[3] = 0;
509 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
510 if (r)
511 return r;
512
513 /* No MD5 padding here */
514 r = crypto_shash_export(desc, &md5state);
515 if (r)
516 return r;
517
518 for (i = 0; i < MD5_HASH_WORDS; i++)
519 __cpu_to_le32s(&md5state.hash[i]);
520 memcpy(iv, &md5state.hash, cc->iv_size);
521
522 return 0;
523}
524
525static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
526 struct dm_crypt_request *dmreq)
527{
528 struct scatterlist *sg;
529 u8 *src;
530 int r = 0;
531
532 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
533 sg = crypt_get_sg_data(cc, dmreq->sg_in);
534 src = kmap_atomic(sg_page(sg));
535 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
536 kunmap_atomic(src);
537 } else
538 memset(iv, 0, cc->iv_size);
539
540 return r;
541}
542
543static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
544 struct dm_crypt_request *dmreq)
545{
546 struct scatterlist *sg;
547 u8 *dst;
548 int r;
549
550 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
551 return 0;
552
553 sg = crypt_get_sg_data(cc, dmreq->sg_out);
554 dst = kmap_atomic(sg_page(sg));
555 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
556
557 /* Tweak the first block of plaintext sector */
558 if (!r)
559 crypto_xor(dst + sg->offset, iv, cc->iv_size);
560
561 kunmap_atomic(dst);
562 return r;
563}
564
565static void crypt_iv_tcw_dtr(struct crypt_config *cc)
566{
567 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
568
569 kfree_sensitive(tcw->iv_seed);
570 tcw->iv_seed = NULL;
571 kfree_sensitive(tcw->whitening);
572 tcw->whitening = NULL;
573
574 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
575 crypto_free_shash(tcw->crc32_tfm);
576 tcw->crc32_tfm = NULL;
577}
578
579static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
580 const char *opts)
581{
582 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
583
584 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
585 ti->error = "Unsupported sector size for TCW";
586 return -EINVAL;
587 }
588
589 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
590 ti->error = "Wrong key size for TCW";
591 return -EINVAL;
592 }
593
594 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0,
595 CRYPTO_ALG_ALLOCATES_MEMORY);
596 if (IS_ERR(tcw->crc32_tfm)) {
597 ti->error = "Error initializing CRC32 in TCW";
598 return PTR_ERR(tcw->crc32_tfm);
599 }
600
601 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
602 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
603 if (!tcw->iv_seed || !tcw->whitening) {
604 crypt_iv_tcw_dtr(cc);
605 ti->error = "Error allocating seed storage in TCW";
606 return -ENOMEM;
607 }
608
609 return 0;
610}
611
612static int crypt_iv_tcw_init(struct crypt_config *cc)
613{
614 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
615 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
616
617 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
618 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
619 TCW_WHITENING_SIZE);
620
621 return 0;
622}
623
624static int crypt_iv_tcw_wipe(struct crypt_config *cc)
625{
626 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
627
628 memset(tcw->iv_seed, 0, cc->iv_size);
629 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
630
631 return 0;
632}
633
634static int crypt_iv_tcw_whitening(struct crypt_config *cc,
635 struct dm_crypt_request *dmreq,
636 u8 *data)
637{
638 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
639 __le64 sector = cpu_to_le64(dmreq->iv_sector);
640 u8 buf[TCW_WHITENING_SIZE];
641 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
642 int i, r;
643
644 /* xor whitening with sector number */
645 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8);
646 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8);
647
648 /* calculate crc32 for every 32bit part and xor it */
649 desc->tfm = tcw->crc32_tfm;
650 for (i = 0; i < 4; i++) {
651 r = crypto_shash_init(desc);
652 if (r)
653 goto out;
654 r = crypto_shash_update(desc, &buf[i * 4], 4);
655 if (r)
656 goto out;
657 r = crypto_shash_final(desc, &buf[i * 4]);
658 if (r)
659 goto out;
660 }
661 crypto_xor(&buf[0], &buf[12], 4);
662 crypto_xor(&buf[4], &buf[8], 4);
663
664 /* apply whitening (8 bytes) to whole sector */
665 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
666 crypto_xor(data + i * 8, buf, 8);
667out:
668 memzero_explicit(buf, sizeof(buf));
669 return r;
670}
671
672static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
673 struct dm_crypt_request *dmreq)
674{
675 struct scatterlist *sg;
676 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
677 __le64 sector = cpu_to_le64(dmreq->iv_sector);
678 u8 *src;
679 int r = 0;
680
681 /* Remove whitening from ciphertext */
682 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
683 sg = crypt_get_sg_data(cc, dmreq->sg_in);
684 src = kmap_atomic(sg_page(sg));
685 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
686 kunmap_atomic(src);
687 }
688
689 /* Calculate IV */
690 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8);
691 if (cc->iv_size > 8)
692 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or,
693 cc->iv_size - 8);
694
695 return r;
696}
697
698static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
699 struct dm_crypt_request *dmreq)
700{
701 struct scatterlist *sg;
702 u8 *dst;
703 int r;
704
705 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
706 return 0;
707
708 /* Apply whitening on ciphertext */
709 sg = crypt_get_sg_data(cc, dmreq->sg_out);
710 dst = kmap_atomic(sg_page(sg));
711 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
712 kunmap_atomic(dst);
713
714 return r;
715}
716
717static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
718 struct dm_crypt_request *dmreq)
719{
720 /* Used only for writes, there must be an additional space to store IV */
721 get_random_bytes(iv, cc->iv_size);
722 return 0;
723}
724
725static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti,
726 const char *opts)
727{
728 if (crypt_integrity_aead(cc)) {
729 ti->error = "AEAD transforms not supported for EBOIV";
730 return -EINVAL;
731 }
732
733 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
734 ti->error = "Block size of EBOIV cipher does "
735 "not match IV size of block cipher";
736 return -EINVAL;
737 }
738
739 return 0;
740}
741
742static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
743 struct dm_crypt_request *dmreq)
744{
745 u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64));
746 struct skcipher_request *req;
747 struct scatterlist src, dst;
748 DECLARE_CRYPTO_WAIT(wait);
749 int err;
750
751 req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO);
752 if (!req)
753 return -ENOMEM;
754
755 memset(buf, 0, cc->iv_size);
756 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
757
758 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
759 sg_init_one(&dst, iv, cc->iv_size);
760 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
761 skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
762 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
763 skcipher_request_free(req);
764
765 return err;
766}
767
768static void crypt_iv_elephant_dtr(struct crypt_config *cc)
769{
770 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
771
772 crypto_free_skcipher(elephant->tfm);
773 elephant->tfm = NULL;
774}
775
776static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti,
777 const char *opts)
778{
779 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
780 int r;
781
782 elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0,
783 CRYPTO_ALG_ALLOCATES_MEMORY);
784 if (IS_ERR(elephant->tfm)) {
785 r = PTR_ERR(elephant->tfm);
786 elephant->tfm = NULL;
787 return r;
788 }
789
790 r = crypt_iv_eboiv_ctr(cc, ti, NULL);
791 if (r)
792 crypt_iv_elephant_dtr(cc);
793 return r;
794}
795
796static void diffuser_disk_to_cpu(u32 *d, size_t n)
797{
798#ifndef __LITTLE_ENDIAN
799 int i;
800
801 for (i = 0; i < n; i++)
802 d[i] = le32_to_cpu((__le32)d[i]);
803#endif
804}
805
806static void diffuser_cpu_to_disk(__le32 *d, size_t n)
807{
808#ifndef __LITTLE_ENDIAN
809 int i;
810
811 for (i = 0; i < n; i++)
812 d[i] = cpu_to_le32((u32)d[i]);
813#endif
814}
815
816static void diffuser_a_decrypt(u32 *d, size_t n)
817{
818 int i, i1, i2, i3;
819
820 for (i = 0; i < 5; i++) {
821 i1 = 0;
822 i2 = n - 2;
823 i3 = n - 5;
824
825 while (i1 < (n - 1)) {
826 d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
827 i1++; i2++; i3++;
828
829 if (i3 >= n)
830 i3 -= n;
831
832 d[i1] += d[i2] ^ d[i3];
833 i1++; i2++; i3++;
834
835 if (i2 >= n)
836 i2 -= n;
837
838 d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
839 i1++; i2++; i3++;
840
841 d[i1] += d[i2] ^ d[i3];
842 i1++; i2++; i3++;
843 }
844 }
845}
846
847static void diffuser_a_encrypt(u32 *d, size_t n)
848{
849 int i, i1, i2, i3;
850
851 for (i = 0; i < 5; i++) {
852 i1 = n - 1;
853 i2 = n - 2 - 1;
854 i3 = n - 5 - 1;
855
856 while (i1 > 0) {
857 d[i1] -= d[i2] ^ d[i3];
858 i1--; i2--; i3--;
859
860 d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
861 i1--; i2--; i3--;
862
863 if (i2 < 0)
864 i2 += n;
865
866 d[i1] -= d[i2] ^ d[i3];
867 i1--; i2--; i3--;
868
869 if (i3 < 0)
870 i3 += n;
871
872 d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
873 i1--; i2--; i3--;
874 }
875 }
876}
877
878static void diffuser_b_decrypt(u32 *d, size_t n)
879{
880 int i, i1, i2, i3;
881
882 for (i = 0; i < 3; i++) {
883 i1 = 0;
884 i2 = 2;
885 i3 = 5;
886
887 while (i1 < (n - 1)) {
888 d[i1] += d[i2] ^ d[i3];
889 i1++; i2++; i3++;
890
891 d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
892 i1++; i2++; i3++;
893
894 if (i2 >= n)
895 i2 -= n;
896
897 d[i1] += d[i2] ^ d[i3];
898 i1++; i2++; i3++;
899
900 if (i3 >= n)
901 i3 -= n;
902
903 d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
904 i1++; i2++; i3++;
905 }
906 }
907}
908
909static void diffuser_b_encrypt(u32 *d, size_t n)
910{
911 int i, i1, i2, i3;
912
913 for (i = 0; i < 3; i++) {
914 i1 = n - 1;
915 i2 = 2 - 1;
916 i3 = 5 - 1;
917
918 while (i1 > 0) {
919 d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
920 i1--; i2--; i3--;
921
922 if (i3 < 0)
923 i3 += n;
924
925 d[i1] -= d[i2] ^ d[i3];
926 i1--; i2--; i3--;
927
928 if (i2 < 0)
929 i2 += n;
930
931 d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
932 i1--; i2--; i3--;
933
934 d[i1] -= d[i2] ^ d[i3];
935 i1--; i2--; i3--;
936 }
937 }
938}
939
940static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq)
941{
942 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
943 u8 *es, *ks, *data, *data2, *data_offset;
944 struct skcipher_request *req;
945 struct scatterlist *sg, *sg2, src, dst;
946 DECLARE_CRYPTO_WAIT(wait);
947 int i, r;
948
949 req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
950 es = kzalloc(16, GFP_NOIO); /* Key for AES */
951 ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */
952
953 if (!req || !es || !ks) {
954 r = -ENOMEM;
955 goto out;
956 }
957
958 *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
959
960 /* E(Ks, e(s)) */
961 sg_init_one(&src, es, 16);
962 sg_init_one(&dst, ks, 16);
963 skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
964 skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
965 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
966 if (r)
967 goto out;
968
969 /* E(Ks, e'(s)) */
970 es[15] = 0x80;
971 sg_init_one(&dst, &ks[16], 16);
972 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
973 if (r)
974 goto out;
975
976 sg = crypt_get_sg_data(cc, dmreq->sg_out);
977 data = kmap_atomic(sg_page(sg));
978 data_offset = data + sg->offset;
979
980 /* Cannot modify original bio, copy to sg_out and apply Elephant to it */
981 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
982 sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
983 data2 = kmap_atomic(sg_page(sg2));
984 memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
985 kunmap_atomic(data2);
986 }
987
988 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
989 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32));
990 diffuser_b_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
991 diffuser_a_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
992 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32));
993 }
994
995 for (i = 0; i < (cc->sector_size / 32); i++)
996 crypto_xor(data_offset + i * 32, ks, 32);
997
998 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
999 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32));
1000 diffuser_a_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
1001 diffuser_b_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
1002 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32));
1003 }
1004
1005 kunmap_atomic(data);
1006out:
1007 kfree_sensitive(ks);
1008 kfree_sensitive(es);
1009 skcipher_request_free(req);
1010 return r;
1011}
1012
1013static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv,
1014 struct dm_crypt_request *dmreq)
1015{
1016 int r;
1017
1018 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1019 r = crypt_iv_elephant(cc, dmreq);
1020 if (r)
1021 return r;
1022 }
1023
1024 return crypt_iv_eboiv_gen(cc, iv, dmreq);
1025}
1026
1027static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv,
1028 struct dm_crypt_request *dmreq)
1029{
1030 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
1031 return crypt_iv_elephant(cc, dmreq);
1032
1033 return 0;
1034}
1035
1036static int crypt_iv_elephant_init(struct crypt_config *cc)
1037{
1038 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1039 int key_offset = cc->key_size - cc->key_extra_size;
1040
1041 return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
1042}
1043
1044static int crypt_iv_elephant_wipe(struct crypt_config *cc)
1045{
1046 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1047 u8 key[ELEPHANT_MAX_KEY_SIZE];
1048
1049 memset(key, 0, cc->key_extra_size);
1050 return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
1051}
1052
1053static const struct crypt_iv_operations crypt_iv_plain_ops = {
1054 .generator = crypt_iv_plain_gen
1055};
1056
1057static const struct crypt_iv_operations crypt_iv_plain64_ops = {
1058 .generator = crypt_iv_plain64_gen
1059};
1060
1061static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
1062 .generator = crypt_iv_plain64be_gen
1063};
1064
1065static const struct crypt_iv_operations crypt_iv_essiv_ops = {
1066 .generator = crypt_iv_essiv_gen
1067};
1068
1069static const struct crypt_iv_operations crypt_iv_benbi_ops = {
1070 .ctr = crypt_iv_benbi_ctr,
1071 .dtr = crypt_iv_benbi_dtr,
1072 .generator = crypt_iv_benbi_gen
1073};
1074
1075static const struct crypt_iv_operations crypt_iv_null_ops = {
1076 .generator = crypt_iv_null_gen
1077};
1078
1079static const struct crypt_iv_operations crypt_iv_lmk_ops = {
1080 .ctr = crypt_iv_lmk_ctr,
1081 .dtr = crypt_iv_lmk_dtr,
1082 .init = crypt_iv_lmk_init,
1083 .wipe = crypt_iv_lmk_wipe,
1084 .generator = crypt_iv_lmk_gen,
1085 .post = crypt_iv_lmk_post
1086};
1087
1088static const struct crypt_iv_operations crypt_iv_tcw_ops = {
1089 .ctr = crypt_iv_tcw_ctr,
1090 .dtr = crypt_iv_tcw_dtr,
1091 .init = crypt_iv_tcw_init,
1092 .wipe = crypt_iv_tcw_wipe,
1093 .generator = crypt_iv_tcw_gen,
1094 .post = crypt_iv_tcw_post
1095};
1096
1097static const struct crypt_iv_operations crypt_iv_random_ops = {
1098 .generator = crypt_iv_random_gen
1099};
1100
1101static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
1102 .ctr = crypt_iv_eboiv_ctr,
1103 .generator = crypt_iv_eboiv_gen
1104};
1105
1106static const struct crypt_iv_operations crypt_iv_elephant_ops = {
1107 .ctr = crypt_iv_elephant_ctr,
1108 .dtr = crypt_iv_elephant_dtr,
1109 .init = crypt_iv_elephant_init,
1110 .wipe = crypt_iv_elephant_wipe,
1111 .generator = crypt_iv_elephant_gen,
1112 .post = crypt_iv_elephant_post
1113};
1114
1115/*
1116 * Integrity extensions
1117 */
1118static bool crypt_integrity_aead(struct crypt_config *cc)
1119{
1120 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
1121}
1122
1123static bool crypt_integrity_hmac(struct crypt_config *cc)
1124{
1125 return crypt_integrity_aead(cc) && cc->key_mac_size;
1126}
1127
1128/* Get sg containing data */
1129static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
1130 struct scatterlist *sg)
1131{
1132 if (unlikely(crypt_integrity_aead(cc)))
1133 return &sg[2];
1134
1135 return sg;
1136}
1137
1138static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
1139{
1140 struct bio_integrity_payload *bip;
1141 unsigned int tag_len;
1142 int ret;
1143
1144 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
1145 return 0;
1146
1147 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
1148 if (IS_ERR(bip))
1149 return PTR_ERR(bip);
1150
1151 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
1152
1153 bip->bip_iter.bi_size = tag_len;
1154 bip->bip_iter.bi_sector = io->cc->start + io->sector;
1155
1156 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
1157 tag_len, offset_in_page(io->integrity_metadata));
1158 if (unlikely(ret != tag_len))
1159 return -ENOMEM;
1160
1161 return 0;
1162}
1163
1164static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
1165{
1166#ifdef CONFIG_BLK_DEV_INTEGRITY
1167 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
1168 struct mapped_device *md = dm_table_get_md(ti->table);
1169
1170 /* From now we require underlying device with our integrity profile */
1171 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
1172 ti->error = "Integrity profile not supported.";
1173 return -EINVAL;
1174 }
1175
1176 if (bi->tag_size != cc->on_disk_tag_size ||
1177 bi->tuple_size != cc->on_disk_tag_size) {
1178 ti->error = "Integrity profile tag size mismatch.";
1179 return -EINVAL;
1180 }
1181 if (1 << bi->interval_exp != cc->sector_size) {
1182 ti->error = "Integrity profile sector size mismatch.";
1183 return -EINVAL;
1184 }
1185
1186 if (crypt_integrity_aead(cc)) {
1187 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
1188 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
1189 cc->integrity_tag_size, cc->integrity_iv_size);
1190
1191 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
1192 ti->error = "Integrity AEAD auth tag size is not supported.";
1193 return -EINVAL;
1194 }
1195 } else if (cc->integrity_iv_size)
1196 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
1197 cc->integrity_iv_size);
1198
1199 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
1200 ti->error = "Not enough space for integrity tag in the profile.";
1201 return -EINVAL;
1202 }
1203
1204 return 0;
1205#else
1206 ti->error = "Integrity profile not supported.";
1207 return -EINVAL;
1208#endif
1209}
1210
1211static void crypt_convert_init(struct crypt_config *cc,
1212 struct convert_context *ctx,
1213 struct bio *bio_out, struct bio *bio_in,
1214 sector_t sector)
1215{
1216 ctx->bio_in = bio_in;
1217 ctx->bio_out = bio_out;
1218 if (bio_in)
1219 ctx->iter_in = bio_in->bi_iter;
1220 if (bio_out)
1221 ctx->iter_out = bio_out->bi_iter;
1222 ctx->cc_sector = sector + cc->iv_offset;
1223 init_completion(&ctx->restart);
1224}
1225
1226static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1227 void *req)
1228{
1229 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1230}
1231
1232static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1233{
1234 return (void *)((char *)dmreq - cc->dmreq_start);
1235}
1236
1237static u8 *iv_of_dmreq(struct crypt_config *cc,
1238 struct dm_crypt_request *dmreq)
1239{
1240 if (crypt_integrity_aead(cc))
1241 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1242 crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1243 else
1244 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1245 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1246}
1247
1248static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1249 struct dm_crypt_request *dmreq)
1250{
1251 return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1252}
1253
1254static __le64 *org_sector_of_dmreq(struct crypt_config *cc,
1255 struct dm_crypt_request *dmreq)
1256{
1257 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1258 return (__le64 *) ptr;
1259}
1260
1261static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1262 struct dm_crypt_request *dmreq)
1263{
1264 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1265 cc->iv_size + sizeof(uint64_t);
1266 return (unsigned int*)ptr;
1267}
1268
1269static void *tag_from_dmreq(struct crypt_config *cc,
1270 struct dm_crypt_request *dmreq)
1271{
1272 struct convert_context *ctx = dmreq->ctx;
1273 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1274
1275 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1276 cc->on_disk_tag_size];
1277}
1278
1279static void *iv_tag_from_dmreq(struct crypt_config *cc,
1280 struct dm_crypt_request *dmreq)
1281{
1282 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1283}
1284
1285static int crypt_convert_block_aead(struct crypt_config *cc,
1286 struct convert_context *ctx,
1287 struct aead_request *req,
1288 unsigned int tag_offset)
1289{
1290 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1291 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1292 struct dm_crypt_request *dmreq;
1293 u8 *iv, *org_iv, *tag_iv, *tag;
1294 __le64 *sector;
1295 int r = 0;
1296
1297 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1298
1299 /* Reject unexpected unaligned bio. */
1300 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1301 return -EIO;
1302
1303 dmreq = dmreq_of_req(cc, req);
1304 dmreq->iv_sector = ctx->cc_sector;
1305 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1306 dmreq->iv_sector >>= cc->sector_shift;
1307 dmreq->ctx = ctx;
1308
1309 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1310
1311 sector = org_sector_of_dmreq(cc, dmreq);
1312 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1313
1314 iv = iv_of_dmreq(cc, dmreq);
1315 org_iv = org_iv_of_dmreq(cc, dmreq);
1316 tag = tag_from_dmreq(cc, dmreq);
1317 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1318
1319 /* AEAD request:
1320 * |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1321 * | (authenticated) | (auth+encryption) | |
1322 * | sector_LE | IV | sector in/out | tag in/out |
1323 */
1324 sg_init_table(dmreq->sg_in, 4);
1325 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1326 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1327 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1328 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1329
1330 sg_init_table(dmreq->sg_out, 4);
1331 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1332 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1333 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1334 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1335
1336 if (cc->iv_gen_ops) {
1337 /* For READs use IV stored in integrity metadata */
1338 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1339 memcpy(org_iv, tag_iv, cc->iv_size);
1340 } else {
1341 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1342 if (r < 0)
1343 return r;
1344 /* Store generated IV in integrity metadata */
1345 if (cc->integrity_iv_size)
1346 memcpy(tag_iv, org_iv, cc->iv_size);
1347 }
1348 /* Working copy of IV, to be modified in crypto API */
1349 memcpy(iv, org_iv, cc->iv_size);
1350 }
1351
1352 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1353 if (bio_data_dir(ctx->bio_in) == WRITE) {
1354 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1355 cc->sector_size, iv);
1356 r = crypto_aead_encrypt(req);
1357 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1358 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1359 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1360 } else {
1361 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1362 cc->sector_size + cc->integrity_tag_size, iv);
1363 r = crypto_aead_decrypt(req);
1364 }
1365
1366 if (r == -EBADMSG) {
1367 sector_t s = le64_to_cpu(*sector);
1368
1369 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
1370 ctx->bio_in->bi_bdev, s);
1371 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
1372 ctx->bio_in, s, 0);
1373 }
1374
1375 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1376 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1377
1378 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1379 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1380
1381 return r;
1382}
1383
1384static int crypt_convert_block_skcipher(struct crypt_config *cc,
1385 struct convert_context *ctx,
1386 struct skcipher_request *req,
1387 unsigned int tag_offset)
1388{
1389 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1390 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1391 struct scatterlist *sg_in, *sg_out;
1392 struct dm_crypt_request *dmreq;
1393 u8 *iv, *org_iv, *tag_iv;
1394 __le64 *sector;
1395 int r = 0;
1396
1397 /* Reject unexpected unaligned bio. */
1398 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1399 return -EIO;
1400
1401 dmreq = dmreq_of_req(cc, req);
1402 dmreq->iv_sector = ctx->cc_sector;
1403 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1404 dmreq->iv_sector >>= cc->sector_shift;
1405 dmreq->ctx = ctx;
1406
1407 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1408
1409 iv = iv_of_dmreq(cc, dmreq);
1410 org_iv = org_iv_of_dmreq(cc, dmreq);
1411 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1412
1413 sector = org_sector_of_dmreq(cc, dmreq);
1414 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1415
1416 /* For skcipher we use only the first sg item */
1417 sg_in = &dmreq->sg_in[0];
1418 sg_out = &dmreq->sg_out[0];
1419
1420 sg_init_table(sg_in, 1);
1421 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1422
1423 sg_init_table(sg_out, 1);
1424 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1425
1426 if (cc->iv_gen_ops) {
1427 /* For READs use IV stored in integrity metadata */
1428 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1429 memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1430 } else {
1431 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1432 if (r < 0)
1433 return r;
1434 /* Data can be already preprocessed in generator */
1435 if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
1436 sg_in = sg_out;
1437 /* Store generated IV in integrity metadata */
1438 if (cc->integrity_iv_size)
1439 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1440 }
1441 /* Working copy of IV, to be modified in crypto API */
1442 memcpy(iv, org_iv, cc->iv_size);
1443 }
1444
1445 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1446
1447 if (bio_data_dir(ctx->bio_in) == WRITE)
1448 r = crypto_skcipher_encrypt(req);
1449 else
1450 r = crypto_skcipher_decrypt(req);
1451
1452 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1453 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1454
1455 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1456 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1457
1458 return r;
1459}
1460
1461static void kcryptd_async_done(struct crypto_async_request *async_req,
1462 int error);
1463
1464static int crypt_alloc_req_skcipher(struct crypt_config *cc,
1465 struct convert_context *ctx)
1466{
1467 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1468
1469 if (!ctx->r.req) {
1470 ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1471 if (!ctx->r.req)
1472 return -ENOMEM;
1473 }
1474
1475 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1476
1477 /*
1478 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1479 * requests if driver request queue is full.
1480 */
1481 skcipher_request_set_callback(ctx->r.req,
1482 CRYPTO_TFM_REQ_MAY_BACKLOG,
1483 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1484
1485 return 0;
1486}
1487
1488static int crypt_alloc_req_aead(struct crypt_config *cc,
1489 struct convert_context *ctx)
1490{
1491 if (!ctx->r.req_aead) {
1492 ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1493 if (!ctx->r.req_aead)
1494 return -ENOMEM;
1495 }
1496
1497 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1498
1499 /*
1500 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1501 * requests if driver request queue is full.
1502 */
1503 aead_request_set_callback(ctx->r.req_aead,
1504 CRYPTO_TFM_REQ_MAY_BACKLOG,
1505 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1506
1507 return 0;
1508}
1509
1510static int crypt_alloc_req(struct crypt_config *cc,
1511 struct convert_context *ctx)
1512{
1513 if (crypt_integrity_aead(cc))
1514 return crypt_alloc_req_aead(cc, ctx);
1515 else
1516 return crypt_alloc_req_skcipher(cc, ctx);
1517}
1518
1519static void crypt_free_req_skcipher(struct crypt_config *cc,
1520 struct skcipher_request *req, struct bio *base_bio)
1521{
1522 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1523
1524 if ((struct skcipher_request *)(io + 1) != req)
1525 mempool_free(req, &cc->req_pool);
1526}
1527
1528static void crypt_free_req_aead(struct crypt_config *cc,
1529 struct aead_request *req, struct bio *base_bio)
1530{
1531 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1532
1533 if ((struct aead_request *)(io + 1) != req)
1534 mempool_free(req, &cc->req_pool);
1535}
1536
1537static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1538{
1539 if (crypt_integrity_aead(cc))
1540 crypt_free_req_aead(cc, req, base_bio);
1541 else
1542 crypt_free_req_skcipher(cc, req, base_bio);
1543}
1544
1545/*
1546 * Encrypt / decrypt data from one bio to another one (can be the same one)
1547 */
1548static blk_status_t crypt_convert(struct crypt_config *cc,
1549 struct convert_context *ctx, bool atomic, bool reset_pending)
1550{
1551 unsigned int tag_offset = 0;
1552 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1553 int r;
1554
1555 /*
1556 * if reset_pending is set we are dealing with the bio for the first time,
1557 * else we're continuing to work on the previous bio, so don't mess with
1558 * the cc_pending counter
1559 */
1560 if (reset_pending)
1561 atomic_set(&ctx->cc_pending, 1);
1562
1563 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1564
1565 r = crypt_alloc_req(cc, ctx);
1566 if (r) {
1567 complete(&ctx->restart);
1568 return BLK_STS_DEV_RESOURCE;
1569 }
1570
1571 atomic_inc(&ctx->cc_pending);
1572
1573 if (crypt_integrity_aead(cc))
1574 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1575 else
1576 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1577
1578 switch (r) {
1579 /*
1580 * The request was queued by a crypto driver
1581 * but the driver request queue is full, let's wait.
1582 */
1583 case -EBUSY:
1584 if (in_interrupt()) {
1585 if (try_wait_for_completion(&ctx->restart)) {
1586 /*
1587 * we don't have to block to wait for completion,
1588 * so proceed
1589 */
1590 } else {
1591 /*
1592 * we can't wait for completion without blocking
1593 * exit and continue processing in a workqueue
1594 */
1595 ctx->r.req = NULL;
1596 ctx->cc_sector += sector_step;
1597 tag_offset++;
1598 return BLK_STS_DEV_RESOURCE;
1599 }
1600 } else {
1601 wait_for_completion(&ctx->restart);
1602 }
1603 reinit_completion(&ctx->restart);
1604 fallthrough;
1605 /*
1606 * The request is queued and processed asynchronously,
1607 * completion function kcryptd_async_done() will be called.
1608 */
1609 case -EINPROGRESS:
1610 ctx->r.req = NULL;
1611 ctx->cc_sector += sector_step;
1612 tag_offset++;
1613 continue;
1614 /*
1615 * The request was already processed (synchronously).
1616 */
1617 case 0:
1618 atomic_dec(&ctx->cc_pending);
1619 ctx->cc_sector += sector_step;
1620 tag_offset++;
1621 if (!atomic)
1622 cond_resched();
1623 continue;
1624 /*
1625 * There was a data integrity error.
1626 */
1627 case -EBADMSG:
1628 atomic_dec(&ctx->cc_pending);
1629 return BLK_STS_PROTECTION;
1630 /*
1631 * There was an error while processing the request.
1632 */
1633 default:
1634 atomic_dec(&ctx->cc_pending);
1635 return BLK_STS_IOERR;
1636 }
1637 }
1638
1639 return 0;
1640}
1641
1642static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1643
1644/*
1645 * Generate a new unfragmented bio with the given size
1646 * This should never violate the device limitations (but only because
1647 * max_segment_size is being constrained to PAGE_SIZE).
1648 *
1649 * This function may be called concurrently. If we allocate from the mempool
1650 * concurrently, there is a possibility of deadlock. For example, if we have
1651 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1652 * the mempool concurrently, it may deadlock in a situation where both processes
1653 * have allocated 128 pages and the mempool is exhausted.
1654 *
1655 * In order to avoid this scenario we allocate the pages under a mutex.
1656 *
1657 * In order to not degrade performance with excessive locking, we try
1658 * non-blocking allocations without a mutex first but on failure we fallback
1659 * to blocking allocations with a mutex.
1660 */
1661static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1662{
1663 struct crypt_config *cc = io->cc;
1664 struct bio *clone;
1665 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1666 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1667 unsigned i, len, remaining_size;
1668 struct page *page;
1669
1670retry:
1671 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1672 mutex_lock(&cc->bio_alloc_lock);
1673
1674 clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf,
1675 GFP_NOIO, &cc->bs);
1676 clone->bi_private = io;
1677 clone->bi_end_io = crypt_endio;
1678
1679 remaining_size = size;
1680
1681 for (i = 0; i < nr_iovecs; i++) {
1682 page = mempool_alloc(&cc->page_pool, gfp_mask);
1683 if (!page) {
1684 crypt_free_buffer_pages(cc, clone);
1685 bio_put(clone);
1686 gfp_mask |= __GFP_DIRECT_RECLAIM;
1687 goto retry;
1688 }
1689
1690 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1691
1692 bio_add_page(clone, page, len, 0);
1693
1694 remaining_size -= len;
1695 }
1696
1697 /* Allocate space for integrity tags */
1698 if (dm_crypt_integrity_io_alloc(io, clone)) {
1699 crypt_free_buffer_pages(cc, clone);
1700 bio_put(clone);
1701 clone = NULL;
1702 }
1703
1704 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1705 mutex_unlock(&cc->bio_alloc_lock);
1706
1707 return clone;
1708}
1709
1710static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1711{
1712 struct bio_vec *bv;
1713 struct bvec_iter_all iter_all;
1714
1715 bio_for_each_segment_all(bv, clone, iter_all) {
1716 BUG_ON(!bv->bv_page);
1717 mempool_free(bv->bv_page, &cc->page_pool);
1718 }
1719}
1720
1721static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1722 struct bio *bio, sector_t sector)
1723{
1724 io->cc = cc;
1725 io->base_bio = bio;
1726 io->sector = sector;
1727 io->error = 0;
1728 io->ctx.r.req = NULL;
1729 io->integrity_metadata = NULL;
1730 io->integrity_metadata_from_pool = false;
1731 atomic_set(&io->io_pending, 0);
1732}
1733
1734static void crypt_inc_pending(struct dm_crypt_io *io)
1735{
1736 atomic_inc(&io->io_pending);
1737}
1738
1739static void kcryptd_io_bio_endio(struct work_struct *work)
1740{
1741 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1742 bio_endio(io->base_bio);
1743}
1744
1745/*
1746 * One of the bios was finished. Check for completion of
1747 * the whole request and correctly clean up the buffer.
1748 */
1749static void crypt_dec_pending(struct dm_crypt_io *io)
1750{
1751 struct crypt_config *cc = io->cc;
1752 struct bio *base_bio = io->base_bio;
1753 blk_status_t error = io->error;
1754
1755 if (!atomic_dec_and_test(&io->io_pending))
1756 return;
1757
1758 if (io->ctx.r.req)
1759 crypt_free_req(cc, io->ctx.r.req, base_bio);
1760
1761 if (unlikely(io->integrity_metadata_from_pool))
1762 mempool_free(io->integrity_metadata, &io->cc->tag_pool);
1763 else
1764 kfree(io->integrity_metadata);
1765
1766 base_bio->bi_status = error;
1767
1768 /*
1769 * If we are running this function from our tasklet,
1770 * we can't call bio_endio() here, because it will call
1771 * clone_endio() from dm.c, which in turn will
1772 * free the current struct dm_crypt_io structure with
1773 * our tasklet. In this case we need to delay bio_endio()
1774 * execution to after the tasklet is done and dequeued.
1775 */
1776 if (tasklet_trylock(&io->tasklet)) {
1777 tasklet_unlock(&io->tasklet);
1778 bio_endio(base_bio);
1779 return;
1780 }
1781
1782 INIT_WORK(&io->work, kcryptd_io_bio_endio);
1783 queue_work(cc->io_queue, &io->work);
1784}
1785
1786/*
1787 * kcryptd/kcryptd_io:
1788 *
1789 * Needed because it would be very unwise to do decryption in an
1790 * interrupt context.
1791 *
1792 * kcryptd performs the actual encryption or decryption.
1793 *
1794 * kcryptd_io performs the IO submission.
1795 *
1796 * They must be separated as otherwise the final stages could be
1797 * starved by new requests which can block in the first stages due
1798 * to memory allocation.
1799 *
1800 * The work is done per CPU global for all dm-crypt instances.
1801 * They should not depend on each other and do not block.
1802 */
1803static void crypt_endio(struct bio *clone)
1804{
1805 struct dm_crypt_io *io = clone->bi_private;
1806 struct crypt_config *cc = io->cc;
1807 unsigned rw = bio_data_dir(clone);
1808 blk_status_t error;
1809
1810 /*
1811 * free the processed pages
1812 */
1813 if (rw == WRITE)
1814 crypt_free_buffer_pages(cc, clone);
1815
1816 error = clone->bi_status;
1817 bio_put(clone);
1818
1819 if (rw == READ && !error) {
1820 kcryptd_queue_crypt(io);
1821 return;
1822 }
1823
1824 if (unlikely(error))
1825 io->error = error;
1826
1827 crypt_dec_pending(io);
1828}
1829
1830#define CRYPT_MAP_READ_GFP GFP_NOWAIT
1831
1832static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1833{
1834 struct crypt_config *cc = io->cc;
1835 struct bio *clone;
1836
1837 /*
1838 * We need the original biovec array in order to decrypt the whole bio
1839 * data *afterwards* -- thanks to immutable biovecs we don't need to
1840 * worry about the block layer modifying the biovec array; so leverage
1841 * bio_alloc_clone().
1842 */
1843 clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs);
1844 if (!clone)
1845 return 1;
1846 clone->bi_private = io;
1847 clone->bi_end_io = crypt_endio;
1848
1849 crypt_inc_pending(io);
1850
1851 clone->bi_iter.bi_sector = cc->start + io->sector;
1852
1853 if (dm_crypt_integrity_io_alloc(io, clone)) {
1854 crypt_dec_pending(io);
1855 bio_put(clone);
1856 return 1;
1857 }
1858
1859 dm_submit_bio_remap(io->base_bio, clone);
1860 return 0;
1861}
1862
1863static void kcryptd_io_read_work(struct work_struct *work)
1864{
1865 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1866
1867 crypt_inc_pending(io);
1868 if (kcryptd_io_read(io, GFP_NOIO))
1869 io->error = BLK_STS_RESOURCE;
1870 crypt_dec_pending(io);
1871}
1872
1873static void kcryptd_queue_read(struct dm_crypt_io *io)
1874{
1875 struct crypt_config *cc = io->cc;
1876
1877 INIT_WORK(&io->work, kcryptd_io_read_work);
1878 queue_work(cc->io_queue, &io->work);
1879}
1880
1881static void kcryptd_io_write(struct dm_crypt_io *io)
1882{
1883 struct bio *clone = io->ctx.bio_out;
1884
1885 dm_submit_bio_remap(io->base_bio, clone);
1886}
1887
1888#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1889
1890static int dmcrypt_write(void *data)
1891{
1892 struct crypt_config *cc = data;
1893 struct dm_crypt_io *io;
1894
1895 while (1) {
1896 struct rb_root write_tree;
1897 struct blk_plug plug;
1898
1899 spin_lock_irq(&cc->write_thread_lock);
1900continue_locked:
1901
1902 if (!RB_EMPTY_ROOT(&cc->write_tree))
1903 goto pop_from_list;
1904
1905 set_current_state(TASK_INTERRUPTIBLE);
1906
1907 spin_unlock_irq(&cc->write_thread_lock);
1908
1909 if (unlikely(kthread_should_stop())) {
1910 set_current_state(TASK_RUNNING);
1911 break;
1912 }
1913
1914 schedule();
1915
1916 set_current_state(TASK_RUNNING);
1917 spin_lock_irq(&cc->write_thread_lock);
1918 goto continue_locked;
1919
1920pop_from_list:
1921 write_tree = cc->write_tree;
1922 cc->write_tree = RB_ROOT;
1923 spin_unlock_irq(&cc->write_thread_lock);
1924
1925 BUG_ON(rb_parent(write_tree.rb_node));
1926
1927 /*
1928 * Note: we cannot walk the tree here with rb_next because
1929 * the structures may be freed when kcryptd_io_write is called.
1930 */
1931 blk_start_plug(&plug);
1932 do {
1933 io = crypt_io_from_node(rb_first(&write_tree));
1934 rb_erase(&io->rb_node, &write_tree);
1935 kcryptd_io_write(io);
1936 } while (!RB_EMPTY_ROOT(&write_tree));
1937 blk_finish_plug(&plug);
1938 }
1939 return 0;
1940}
1941
1942static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1943{
1944 struct bio *clone = io->ctx.bio_out;
1945 struct crypt_config *cc = io->cc;
1946 unsigned long flags;
1947 sector_t sector;
1948 struct rb_node **rbp, *parent;
1949
1950 if (unlikely(io->error)) {
1951 crypt_free_buffer_pages(cc, clone);
1952 bio_put(clone);
1953 crypt_dec_pending(io);
1954 return;
1955 }
1956
1957 /* crypt_convert should have filled the clone bio */
1958 BUG_ON(io->ctx.iter_out.bi_size);
1959
1960 clone->bi_iter.bi_sector = cc->start + io->sector;
1961
1962 if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
1963 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
1964 dm_submit_bio_remap(io->base_bio, clone);
1965 return;
1966 }
1967
1968 spin_lock_irqsave(&cc->write_thread_lock, flags);
1969 if (RB_EMPTY_ROOT(&cc->write_tree))
1970 wake_up_process(cc->write_thread);
1971 rbp = &cc->write_tree.rb_node;
1972 parent = NULL;
1973 sector = io->sector;
1974 while (*rbp) {
1975 parent = *rbp;
1976 if (sector < crypt_io_from_node(parent)->sector)
1977 rbp = &(*rbp)->rb_left;
1978 else
1979 rbp = &(*rbp)->rb_right;
1980 }
1981 rb_link_node(&io->rb_node, parent, rbp);
1982 rb_insert_color(&io->rb_node, &cc->write_tree);
1983 spin_unlock_irqrestore(&cc->write_thread_lock, flags);
1984}
1985
1986static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
1987 struct convert_context *ctx)
1988
1989{
1990 if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
1991 return false;
1992
1993 /*
1994 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
1995 * constraints so they do not need to be issued inline by
1996 * kcryptd_crypt_write_convert().
1997 */
1998 switch (bio_op(ctx->bio_in)) {
1999 case REQ_OP_WRITE:
2000 case REQ_OP_WRITE_ZEROES:
2001 return true;
2002 default:
2003 return false;
2004 }
2005}
2006
2007static void kcryptd_crypt_write_continue(struct work_struct *work)
2008{
2009 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2010 struct crypt_config *cc = io->cc;
2011 struct convert_context *ctx = &io->ctx;
2012 int crypt_finished;
2013 sector_t sector = io->sector;
2014 blk_status_t r;
2015
2016 wait_for_completion(&ctx->restart);
2017 reinit_completion(&ctx->restart);
2018
2019 r = crypt_convert(cc, &io->ctx, true, false);
2020 if (r)
2021 io->error = r;
2022 crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2023 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2024 /* Wait for completion signaled by kcryptd_async_done() */
2025 wait_for_completion(&ctx->restart);
2026 crypt_finished = 1;
2027 }
2028
2029 /* Encryption was already finished, submit io now */
2030 if (crypt_finished) {
2031 kcryptd_crypt_write_io_submit(io, 0);
2032 io->sector = sector;
2033 }
2034
2035 crypt_dec_pending(io);
2036}
2037
2038static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
2039{
2040 struct crypt_config *cc = io->cc;
2041 struct convert_context *ctx = &io->ctx;
2042 struct bio *clone;
2043 int crypt_finished;
2044 sector_t sector = io->sector;
2045 blk_status_t r;
2046
2047 /*
2048 * Prevent io from disappearing until this function completes.
2049 */
2050 crypt_inc_pending(io);
2051 crypt_convert_init(cc, ctx, NULL, io->base_bio, sector);
2052
2053 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
2054 if (unlikely(!clone)) {
2055 io->error = BLK_STS_IOERR;
2056 goto dec;
2057 }
2058
2059 io->ctx.bio_out = clone;
2060 io->ctx.iter_out = clone->bi_iter;
2061
2062 sector += bio_sectors(clone);
2063
2064 crypt_inc_pending(io);
2065 r = crypt_convert(cc, ctx,
2066 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
2067 /*
2068 * Crypto API backlogged the request, because its queue was full
2069 * and we're in softirq context, so continue from a workqueue
2070 * (TODO: is it actually possible to be in softirq in the write path?)
2071 */
2072 if (r == BLK_STS_DEV_RESOURCE) {
2073 INIT_WORK(&io->work, kcryptd_crypt_write_continue);
2074 queue_work(cc->crypt_queue, &io->work);
2075 return;
2076 }
2077 if (r)
2078 io->error = r;
2079 crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2080 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2081 /* Wait for completion signaled by kcryptd_async_done() */
2082 wait_for_completion(&ctx->restart);
2083 crypt_finished = 1;
2084 }
2085
2086 /* Encryption was already finished, submit io now */
2087 if (crypt_finished) {
2088 kcryptd_crypt_write_io_submit(io, 0);
2089 io->sector = sector;
2090 }
2091
2092dec:
2093 crypt_dec_pending(io);
2094}
2095
2096static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
2097{
2098 crypt_dec_pending(io);
2099}
2100
2101static void kcryptd_crypt_read_continue(struct work_struct *work)
2102{
2103 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2104 struct crypt_config *cc = io->cc;
2105 blk_status_t r;
2106
2107 wait_for_completion(&io->ctx.restart);
2108 reinit_completion(&io->ctx.restart);
2109
2110 r = crypt_convert(cc, &io->ctx, true, false);
2111 if (r)
2112 io->error = r;
2113
2114 if (atomic_dec_and_test(&io->ctx.cc_pending))
2115 kcryptd_crypt_read_done(io);
2116
2117 crypt_dec_pending(io);
2118}
2119
2120static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
2121{
2122 struct crypt_config *cc = io->cc;
2123 blk_status_t r;
2124
2125 crypt_inc_pending(io);
2126
2127 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
2128 io->sector);
2129
2130 r = crypt_convert(cc, &io->ctx,
2131 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
2132 /*
2133 * Crypto API backlogged the request, because its queue was full
2134 * and we're in softirq context, so continue from a workqueue
2135 */
2136 if (r == BLK_STS_DEV_RESOURCE) {
2137 INIT_WORK(&io->work, kcryptd_crypt_read_continue);
2138 queue_work(cc->crypt_queue, &io->work);
2139 return;
2140 }
2141 if (r)
2142 io->error = r;
2143
2144 if (atomic_dec_and_test(&io->ctx.cc_pending))
2145 kcryptd_crypt_read_done(io);
2146
2147 crypt_dec_pending(io);
2148}
2149
2150static void kcryptd_async_done(struct crypto_async_request *async_req,
2151 int error)
2152{
2153 struct dm_crypt_request *dmreq = async_req->data;
2154 struct convert_context *ctx = dmreq->ctx;
2155 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
2156 struct crypt_config *cc = io->cc;
2157
2158 /*
2159 * A request from crypto driver backlog is going to be processed now,
2160 * finish the completion and continue in crypt_convert().
2161 * (Callback will be called for the second time for this request.)
2162 */
2163 if (error == -EINPROGRESS) {
2164 complete(&ctx->restart);
2165 return;
2166 }
2167
2168 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
2169 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
2170
2171 if (error == -EBADMSG) {
2172 sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
2173
2174 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
2175 ctx->bio_in->bi_bdev, s);
2176 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
2177 ctx->bio_in, s, 0);
2178 io->error = BLK_STS_PROTECTION;
2179 } else if (error < 0)
2180 io->error = BLK_STS_IOERR;
2181
2182 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
2183
2184 if (!atomic_dec_and_test(&ctx->cc_pending))
2185 return;
2186
2187 /*
2188 * The request is fully completed: for inline writes, let
2189 * kcryptd_crypt_write_convert() do the IO submission.
2190 */
2191 if (bio_data_dir(io->base_bio) == READ) {
2192 kcryptd_crypt_read_done(io);
2193 return;
2194 }
2195
2196 if (kcryptd_crypt_write_inline(cc, ctx)) {
2197 complete(&ctx->restart);
2198 return;
2199 }
2200
2201 kcryptd_crypt_write_io_submit(io, 1);
2202}
2203
2204static void kcryptd_crypt(struct work_struct *work)
2205{
2206 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2207
2208 if (bio_data_dir(io->base_bio) == READ)
2209 kcryptd_crypt_read_convert(io);
2210 else
2211 kcryptd_crypt_write_convert(io);
2212}
2213
2214static void kcryptd_crypt_tasklet(unsigned long work)
2215{
2216 kcryptd_crypt((struct work_struct *)work);
2217}
2218
2219static void kcryptd_queue_crypt(struct dm_crypt_io *io)
2220{
2221 struct crypt_config *cc = io->cc;
2222
2223 if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
2224 (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
2225 /*
2226 * in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
2227 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but
2228 * it is being executed with irqs disabled.
2229 */
2230 if (in_hardirq() || irqs_disabled()) {
2231 tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
2232 tasklet_schedule(&io->tasklet);
2233 return;
2234 }
2235
2236 kcryptd_crypt(&io->work);
2237 return;
2238 }
2239
2240 INIT_WORK(&io->work, kcryptd_crypt);
2241 queue_work(cc->crypt_queue, &io->work);
2242}
2243
2244static void crypt_free_tfms_aead(struct crypt_config *cc)
2245{
2246 if (!cc->cipher_tfm.tfms_aead)
2247 return;
2248
2249 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2250 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
2251 cc->cipher_tfm.tfms_aead[0] = NULL;
2252 }
2253
2254 kfree(cc->cipher_tfm.tfms_aead);
2255 cc->cipher_tfm.tfms_aead = NULL;
2256}
2257
2258static void crypt_free_tfms_skcipher(struct crypt_config *cc)
2259{
2260 unsigned i;
2261
2262 if (!cc->cipher_tfm.tfms)
2263 return;
2264
2265 for (i = 0; i < cc->tfms_count; i++)
2266 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
2267 crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
2268 cc->cipher_tfm.tfms[i] = NULL;
2269 }
2270
2271 kfree(cc->cipher_tfm.tfms);
2272 cc->cipher_tfm.tfms = NULL;
2273}
2274
2275static void crypt_free_tfms(struct crypt_config *cc)
2276{
2277 if (crypt_integrity_aead(cc))
2278 crypt_free_tfms_aead(cc);
2279 else
2280 crypt_free_tfms_skcipher(cc);
2281}
2282
2283static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
2284{
2285 unsigned i;
2286 int err;
2287
2288 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
2289 sizeof(struct crypto_skcipher *),
2290 GFP_KERNEL);
2291 if (!cc->cipher_tfm.tfms)
2292 return -ENOMEM;
2293
2294 for (i = 0; i < cc->tfms_count; i++) {
2295 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0,
2296 CRYPTO_ALG_ALLOCATES_MEMORY);
2297 if (IS_ERR(cc->cipher_tfm.tfms[i])) {
2298 err = PTR_ERR(cc->cipher_tfm.tfms[i]);
2299 crypt_free_tfms(cc);
2300 return err;
2301 }
2302 }
2303
2304 /*
2305 * dm-crypt performance can vary greatly depending on which crypto
2306 * algorithm implementation is used. Help people debug performance
2307 * problems by logging the ->cra_driver_name.
2308 */
2309 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2310 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
2311 return 0;
2312}
2313
2314static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
2315{
2316 int err;
2317
2318 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
2319 if (!cc->cipher_tfm.tfms)
2320 return -ENOMEM;
2321
2322 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0,
2323 CRYPTO_ALG_ALLOCATES_MEMORY);
2324 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2325 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
2326 crypt_free_tfms(cc);
2327 return err;
2328 }
2329
2330 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2331 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
2332 return 0;
2333}
2334
2335static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
2336{
2337 if (crypt_integrity_aead(cc))
2338 return crypt_alloc_tfms_aead(cc, ciphermode);
2339 else
2340 return crypt_alloc_tfms_skcipher(cc, ciphermode);
2341}
2342
2343static unsigned crypt_subkey_size(struct crypt_config *cc)
2344{
2345 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
2346}
2347
2348static unsigned crypt_authenckey_size(struct crypt_config *cc)
2349{
2350 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
2351}
2352
2353/*
2354 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
2355 * the key must be for some reason in special format.
2356 * This funcion converts cc->key to this special format.
2357 */
2358static void crypt_copy_authenckey(char *p, const void *key,
2359 unsigned enckeylen, unsigned authkeylen)
2360{
2361 struct crypto_authenc_key_param *param;
2362 struct rtattr *rta;
2363
2364 rta = (struct rtattr *)p;
2365 param = RTA_DATA(rta);
2366 param->enckeylen = cpu_to_be32(enckeylen);
2367 rta->rta_len = RTA_LENGTH(sizeof(*param));
2368 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
2369 p += RTA_SPACE(sizeof(*param));
2370 memcpy(p, key + enckeylen, authkeylen);
2371 p += authkeylen;
2372 memcpy(p, key, enckeylen);
2373}
2374
2375static int crypt_setkey(struct crypt_config *cc)
2376{
2377 unsigned subkey_size;
2378 int err = 0, i, r;
2379
2380 /* Ignore extra keys (which are used for IV etc) */
2381 subkey_size = crypt_subkey_size(cc);
2382
2383 if (crypt_integrity_hmac(cc)) {
2384 if (subkey_size < cc->key_mac_size)
2385 return -EINVAL;
2386
2387 crypt_copy_authenckey(cc->authenc_key, cc->key,
2388 subkey_size - cc->key_mac_size,
2389 cc->key_mac_size);
2390 }
2391
2392 for (i = 0; i < cc->tfms_count; i++) {
2393 if (crypt_integrity_hmac(cc))
2394 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2395 cc->authenc_key, crypt_authenckey_size(cc));
2396 else if (crypt_integrity_aead(cc))
2397 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2398 cc->key + (i * subkey_size),
2399 subkey_size);
2400 else
2401 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
2402 cc->key + (i * subkey_size),
2403 subkey_size);
2404 if (r)
2405 err = r;
2406 }
2407
2408 if (crypt_integrity_hmac(cc))
2409 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
2410
2411 return err;
2412}
2413
2414#ifdef CONFIG_KEYS
2415
2416static bool contains_whitespace(const char *str)
2417{
2418 while (*str)
2419 if (isspace(*str++))
2420 return true;
2421 return false;
2422}
2423
2424static int set_key_user(struct crypt_config *cc, struct key *key)
2425{
2426 const struct user_key_payload *ukp;
2427
2428 ukp = user_key_payload_locked(key);
2429 if (!ukp)
2430 return -EKEYREVOKED;
2431
2432 if (cc->key_size != ukp->datalen)
2433 return -EINVAL;
2434
2435 memcpy(cc->key, ukp->data, cc->key_size);
2436
2437 return 0;
2438}
2439
2440static int set_key_encrypted(struct crypt_config *cc, struct key *key)
2441{
2442 const struct encrypted_key_payload *ekp;
2443
2444 ekp = key->payload.data[0];
2445 if (!ekp)
2446 return -EKEYREVOKED;
2447
2448 if (cc->key_size != ekp->decrypted_datalen)
2449 return -EINVAL;
2450
2451 memcpy(cc->key, ekp->decrypted_data, cc->key_size);
2452
2453 return 0;
2454}
2455
2456static int set_key_trusted(struct crypt_config *cc, struct key *key)
2457{
2458 const struct trusted_key_payload *tkp;
2459
2460 tkp = key->payload.data[0];
2461 if (!tkp)
2462 return -EKEYREVOKED;
2463
2464 if (cc->key_size != tkp->key_len)
2465 return -EINVAL;
2466
2467 memcpy(cc->key, tkp->key, cc->key_size);
2468
2469 return 0;
2470}
2471
2472static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2473{
2474 char *new_key_string, *key_desc;
2475 int ret;
2476 struct key_type *type;
2477 struct key *key;
2478 int (*set_key)(struct crypt_config *cc, struct key *key);
2479
2480 /*
2481 * Reject key_string with whitespace. dm core currently lacks code for
2482 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2483 */
2484 if (contains_whitespace(key_string)) {
2485 DMERR("whitespace chars not allowed in key string");
2486 return -EINVAL;
2487 }
2488
2489 /* look for next ':' separating key_type from key_description */
2490 key_desc = strpbrk(key_string, ":");
2491 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2492 return -EINVAL;
2493
2494 if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
2495 type = &key_type_logon;
2496 set_key = set_key_user;
2497 } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
2498 type = &key_type_user;
2499 set_key = set_key_user;
2500 } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
2501 !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
2502 type = &key_type_encrypted;
2503 set_key = set_key_encrypted;
2504 } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
2505 !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
2506 type = &key_type_trusted;
2507 set_key = set_key_trusted;
2508 } else {
2509 return -EINVAL;
2510 }
2511
2512 new_key_string = kstrdup(key_string, GFP_KERNEL);
2513 if (!new_key_string)
2514 return -ENOMEM;
2515
2516 key = request_key(type, key_desc + 1, NULL);
2517 if (IS_ERR(key)) {
2518 kfree_sensitive(new_key_string);
2519 return PTR_ERR(key);
2520 }
2521
2522 down_read(&key->sem);
2523
2524 ret = set_key(cc, key);
2525 if (ret < 0) {
2526 up_read(&key->sem);
2527 key_put(key);
2528 kfree_sensitive(new_key_string);
2529 return ret;
2530 }
2531
2532 up_read(&key->sem);
2533 key_put(key);
2534
2535 /* clear the flag since following operations may invalidate previously valid key */
2536 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2537
2538 ret = crypt_setkey(cc);
2539
2540 if (!ret) {
2541 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2542 kfree_sensitive(cc->key_string);
2543 cc->key_string = new_key_string;
2544 } else
2545 kfree_sensitive(new_key_string);
2546
2547 return ret;
2548}
2549
2550static int get_key_size(char **key_string)
2551{
2552 char *colon, dummy;
2553 int ret;
2554
2555 if (*key_string[0] != ':')
2556 return strlen(*key_string) >> 1;
2557
2558 /* look for next ':' in key string */
2559 colon = strpbrk(*key_string + 1, ":");
2560 if (!colon)
2561 return -EINVAL;
2562
2563 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2564 return -EINVAL;
2565
2566 *key_string = colon;
2567
2568 /* remaining key string should be :<logon|user>:<key_desc> */
2569
2570 return ret;
2571}
2572
2573#else
2574
2575static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2576{
2577 return -EINVAL;
2578}
2579
2580static int get_key_size(char **key_string)
2581{
2582 return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
2583}
2584
2585#endif /* CONFIG_KEYS */
2586
2587static int crypt_set_key(struct crypt_config *cc, char *key)
2588{
2589 int r = -EINVAL;
2590 int key_string_len = strlen(key);
2591
2592 /* Hyphen (which gives a key_size of zero) means there is no key. */
2593 if (!cc->key_size && strcmp(key, "-"))
2594 goto out;
2595
2596 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2597 if (key[0] == ':') {
2598 r = crypt_set_keyring_key(cc, key + 1);
2599 goto out;
2600 }
2601
2602 /* clear the flag since following operations may invalidate previously valid key */
2603 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2604
2605 /* wipe references to any kernel keyring key */
2606 kfree_sensitive(cc->key_string);
2607 cc->key_string = NULL;
2608
2609 /* Decode key from its hex representation. */
2610 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2611 goto out;
2612
2613 r = crypt_setkey(cc);
2614 if (!r)
2615 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2616
2617out:
2618 /* Hex key string not needed after here, so wipe it. */
2619 memset(key, '0', key_string_len);
2620
2621 return r;
2622}
2623
2624static int crypt_wipe_key(struct crypt_config *cc)
2625{
2626 int r;
2627
2628 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2629 get_random_bytes(&cc->key, cc->key_size);
2630
2631 /* Wipe IV private keys */
2632 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2633 r = cc->iv_gen_ops->wipe(cc);
2634 if (r)
2635 return r;
2636 }
2637
2638 kfree_sensitive(cc->key_string);
2639 cc->key_string = NULL;
2640 r = crypt_setkey(cc);
2641 memset(&cc->key, 0, cc->key_size * sizeof(u8));
2642
2643 return r;
2644}
2645
2646static void crypt_calculate_pages_per_client(void)
2647{
2648 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
2649
2650 if (!dm_crypt_clients_n)
2651 return;
2652
2653 pages /= dm_crypt_clients_n;
2654 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2655 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2656 dm_crypt_pages_per_client = pages;
2657}
2658
2659static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2660{
2661 struct crypt_config *cc = pool_data;
2662 struct page *page;
2663
2664 /*
2665 * Note, percpu_counter_read_positive() may over (and under) estimate
2666 * the current usage by at most (batch - 1) * num_online_cpus() pages,
2667 * but avoids potential spinlock contention of an exact result.
2668 */
2669 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
2670 likely(gfp_mask & __GFP_NORETRY))
2671 return NULL;
2672
2673 page = alloc_page(gfp_mask);
2674 if (likely(page != NULL))
2675 percpu_counter_add(&cc->n_allocated_pages, 1);
2676
2677 return page;
2678}
2679
2680static void crypt_page_free(void *page, void *pool_data)
2681{
2682 struct crypt_config *cc = pool_data;
2683
2684 __free_page(page);
2685 percpu_counter_sub(&cc->n_allocated_pages, 1);
2686}
2687
2688static void crypt_dtr(struct dm_target *ti)
2689{
2690 struct crypt_config *cc = ti->private;
2691
2692 ti->private = NULL;
2693
2694 if (!cc)
2695 return;
2696
2697 if (cc->write_thread)
2698 kthread_stop(cc->write_thread);
2699
2700 if (cc->io_queue)
2701 destroy_workqueue(cc->io_queue);
2702 if (cc->crypt_queue)
2703 destroy_workqueue(cc->crypt_queue);
2704
2705 crypt_free_tfms(cc);
2706
2707 bioset_exit(&cc->bs);
2708
2709 mempool_exit(&cc->page_pool);
2710 mempool_exit(&cc->req_pool);
2711 mempool_exit(&cc->tag_pool);
2712
2713 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2714 percpu_counter_destroy(&cc->n_allocated_pages);
2715
2716 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2717 cc->iv_gen_ops->dtr(cc);
2718
2719 if (cc->dev)
2720 dm_put_device(ti, cc->dev);
2721
2722 kfree_sensitive(cc->cipher_string);
2723 kfree_sensitive(cc->key_string);
2724 kfree_sensitive(cc->cipher_auth);
2725 kfree_sensitive(cc->authenc_key);
2726
2727 mutex_destroy(&cc->bio_alloc_lock);
2728
2729 /* Must zero key material before freeing */
2730 kfree_sensitive(cc);
2731
2732 spin_lock(&dm_crypt_clients_lock);
2733 WARN_ON(!dm_crypt_clients_n);
2734 dm_crypt_clients_n--;
2735 crypt_calculate_pages_per_client();
2736 spin_unlock(&dm_crypt_clients_lock);
2737
2738 dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1);
2739}
2740
2741static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2742{
2743 struct crypt_config *cc = ti->private;
2744
2745 if (crypt_integrity_aead(cc))
2746 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2747 else
2748 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2749
2750 if (cc->iv_size)
2751 /* at least a 64 bit sector number should fit in our buffer */
2752 cc->iv_size = max(cc->iv_size,
2753 (unsigned int)(sizeof(u64) / sizeof(u8)));
2754 else if (ivmode) {
2755 DMWARN("Selected cipher does not support IVs");
2756 ivmode = NULL;
2757 }
2758
2759 /* Choose ivmode, see comments at iv code. */
2760 if (ivmode == NULL)
2761 cc->iv_gen_ops = NULL;
2762 else if (strcmp(ivmode, "plain") == 0)
2763 cc->iv_gen_ops = &crypt_iv_plain_ops;
2764 else if (strcmp(ivmode, "plain64") == 0)
2765 cc->iv_gen_ops = &crypt_iv_plain64_ops;
2766 else if (strcmp(ivmode, "plain64be") == 0)
2767 cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2768 else if (strcmp(ivmode, "essiv") == 0)
2769 cc->iv_gen_ops = &crypt_iv_essiv_ops;
2770 else if (strcmp(ivmode, "benbi") == 0)
2771 cc->iv_gen_ops = &crypt_iv_benbi_ops;
2772 else if (strcmp(ivmode, "null") == 0)
2773 cc->iv_gen_ops = &crypt_iv_null_ops;
2774 else if (strcmp(ivmode, "eboiv") == 0)
2775 cc->iv_gen_ops = &crypt_iv_eboiv_ops;
2776 else if (strcmp(ivmode, "elephant") == 0) {
2777 cc->iv_gen_ops = &crypt_iv_elephant_ops;
2778 cc->key_parts = 2;
2779 cc->key_extra_size = cc->key_size / 2;
2780 if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE)
2781 return -EINVAL;
2782 set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags);
2783 } else if (strcmp(ivmode, "lmk") == 0) {
2784 cc->iv_gen_ops = &crypt_iv_lmk_ops;
2785 /*
2786 * Version 2 and 3 is recognised according
2787 * to length of provided multi-key string.
2788 * If present (version 3), last key is used as IV seed.
2789 * All keys (including IV seed) are always the same size.
2790 */
2791 if (cc->key_size % cc->key_parts) {
2792 cc->key_parts++;
2793 cc->key_extra_size = cc->key_size / cc->key_parts;
2794 }
2795 } else if (strcmp(ivmode, "tcw") == 0) {
2796 cc->iv_gen_ops = &crypt_iv_tcw_ops;
2797 cc->key_parts += 2; /* IV + whitening */
2798 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2799 } else if (strcmp(ivmode, "random") == 0) {
2800 cc->iv_gen_ops = &crypt_iv_random_ops;
2801 /* Need storage space in integrity fields. */
2802 cc->integrity_iv_size = cc->iv_size;
2803 } else {
2804 ti->error = "Invalid IV mode";
2805 return -EINVAL;
2806 }
2807
2808 return 0;
2809}
2810
2811/*
2812 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2813 * The HMAC is needed to calculate tag size (HMAC digest size).
2814 * This should be probably done by crypto-api calls (once available...)
2815 */
2816static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2817{
2818 char *start, *end, *mac_alg = NULL;
2819 struct crypto_ahash *mac;
2820
2821 if (!strstarts(cipher_api, "authenc("))
2822 return 0;
2823
2824 start = strchr(cipher_api, '(');
2825 end = strchr(cipher_api, ',');
2826 if (!start || !end || ++start > end)
2827 return -EINVAL;
2828
2829 mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2830 if (!mac_alg)
2831 return -ENOMEM;
2832 strncpy(mac_alg, start, end - start);
2833
2834 mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
2835 kfree(mac_alg);
2836
2837 if (IS_ERR(mac))
2838 return PTR_ERR(mac);
2839
2840 cc->key_mac_size = crypto_ahash_digestsize(mac);
2841 crypto_free_ahash(mac);
2842
2843 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2844 if (!cc->authenc_key)
2845 return -ENOMEM;
2846
2847 return 0;
2848}
2849
2850static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2851 char **ivmode, char **ivopts)
2852{
2853 struct crypt_config *cc = ti->private;
2854 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME];
2855 int ret = -EINVAL;
2856
2857 cc->tfms_count = 1;
2858
2859 /*
2860 * New format (capi: prefix)
2861 * capi:cipher_api_spec-iv:ivopts
2862 */
2863 tmp = &cipher_in[strlen("capi:")];
2864
2865 /* Separate IV options if present, it can contain another '-' in hash name */
2866 *ivopts = strrchr(tmp, ':');
2867 if (*ivopts) {
2868 **ivopts = '\0';
2869 (*ivopts)++;
2870 }
2871 /* Parse IV mode */
2872 *ivmode = strrchr(tmp, '-');
2873 if (*ivmode) {
2874 **ivmode = '\0';
2875 (*ivmode)++;
2876 }
2877 /* The rest is crypto API spec */
2878 cipher_api = tmp;
2879
2880 /* Alloc AEAD, can be used only in new format. */
2881 if (crypt_integrity_aead(cc)) {
2882 ret = crypt_ctr_auth_cipher(cc, cipher_api);
2883 if (ret < 0) {
2884 ti->error = "Invalid AEAD cipher spec";
2885 return -ENOMEM;
2886 }
2887 }
2888
2889 if (*ivmode && !strcmp(*ivmode, "lmk"))
2890 cc->tfms_count = 64;
2891
2892 if (*ivmode && !strcmp(*ivmode, "essiv")) {
2893 if (!*ivopts) {
2894 ti->error = "Digest algorithm missing for ESSIV mode";
2895 return -EINVAL;
2896 }
2897 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)",
2898 cipher_api, *ivopts);
2899 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
2900 ti->error = "Cannot allocate cipher string";
2901 return -ENOMEM;
2902 }
2903 cipher_api = buf;
2904 }
2905
2906 cc->key_parts = cc->tfms_count;
2907
2908 /* Allocate cipher */
2909 ret = crypt_alloc_tfms(cc, cipher_api);
2910 if (ret < 0) {
2911 ti->error = "Error allocating crypto tfm";
2912 return ret;
2913 }
2914
2915 if (crypt_integrity_aead(cc))
2916 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2917 else
2918 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2919
2920 return 0;
2921}
2922
2923static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2924 char **ivmode, char **ivopts)
2925{
2926 struct crypt_config *cc = ti->private;
2927 char *tmp, *cipher, *chainmode, *keycount;
2928 char *cipher_api = NULL;
2929 int ret = -EINVAL;
2930 char dummy;
2931
2932 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2933 ti->error = "Bad cipher specification";
2934 return -EINVAL;
2935 }
2936
2937 /*
2938 * Legacy dm-crypt cipher specification
2939 * cipher[:keycount]-mode-iv:ivopts
2940 */
2941 tmp = cipher_in;
2942 keycount = strsep(&tmp, "-");
2943 cipher = strsep(&keycount, ":");
2944
2945 if (!keycount)
2946 cc->tfms_count = 1;
2947 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2948 !is_power_of_2(cc->tfms_count)) {
2949 ti->error = "Bad cipher key count specification";
2950 return -EINVAL;
2951 }
2952 cc->key_parts = cc->tfms_count;
2953
2954 chainmode = strsep(&tmp, "-");
2955 *ivmode = strsep(&tmp, ":");
2956 *ivopts = tmp;
2957
2958 /*
2959 * For compatibility with the original dm-crypt mapping format, if
2960 * only the cipher name is supplied, use cbc-plain.
2961 */
2962 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2963 chainmode = "cbc";
2964 *ivmode = "plain";
2965 }
2966
2967 if (strcmp(chainmode, "ecb") && !*ivmode) {
2968 ti->error = "IV mechanism required";
2969 return -EINVAL;
2970 }
2971
2972 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2973 if (!cipher_api)
2974 goto bad_mem;
2975
2976 if (*ivmode && !strcmp(*ivmode, "essiv")) {
2977 if (!*ivopts) {
2978 ti->error = "Digest algorithm missing for ESSIV mode";
2979 kfree(cipher_api);
2980 return -EINVAL;
2981 }
2982 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2983 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts);
2984 } else {
2985 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2986 "%s(%s)", chainmode, cipher);
2987 }
2988 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
2989 kfree(cipher_api);
2990 goto bad_mem;
2991 }
2992
2993 /* Allocate cipher */
2994 ret = crypt_alloc_tfms(cc, cipher_api);
2995 if (ret < 0) {
2996 ti->error = "Error allocating crypto tfm";
2997 kfree(cipher_api);
2998 return ret;
2999 }
3000 kfree(cipher_api);
3001
3002 return 0;
3003bad_mem:
3004 ti->error = "Cannot allocate cipher strings";
3005 return -ENOMEM;
3006}
3007
3008static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
3009{
3010 struct crypt_config *cc = ti->private;
3011 char *ivmode = NULL, *ivopts = NULL;
3012 int ret;
3013
3014 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
3015 if (!cc->cipher_string) {
3016 ti->error = "Cannot allocate cipher strings";
3017 return -ENOMEM;
3018 }
3019
3020 if (strstarts(cipher_in, "capi:"))
3021 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
3022 else
3023 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
3024 if (ret)
3025 return ret;
3026
3027 /* Initialize IV */
3028 ret = crypt_ctr_ivmode(ti, ivmode);
3029 if (ret < 0)
3030 return ret;
3031
3032 /* Initialize and set key */
3033 ret = crypt_set_key(cc, key);
3034 if (ret < 0) {
3035 ti->error = "Error decoding and setting key";
3036 return ret;
3037 }
3038
3039 /* Allocate IV */
3040 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
3041 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
3042 if (ret < 0) {
3043 ti->error = "Error creating IV";
3044 return ret;
3045 }
3046 }
3047
3048 /* Initialize IV (set keys for ESSIV etc) */
3049 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
3050 ret = cc->iv_gen_ops->init(cc);
3051 if (ret < 0) {
3052 ti->error = "Error initialising IV";
3053 return ret;
3054 }
3055 }
3056
3057 /* wipe the kernel key payload copy */
3058 if (cc->key_string)
3059 memset(cc->key, 0, cc->key_size * sizeof(u8));
3060
3061 return ret;
3062}
3063
3064static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
3065{
3066 struct crypt_config *cc = ti->private;
3067 struct dm_arg_set as;
3068 static const struct dm_arg _args[] = {
3069 {0, 8, "Invalid number of feature args"},
3070 };
3071 unsigned int opt_params, val;
3072 const char *opt_string, *sval;
3073 char dummy;
3074 int ret;
3075
3076 /* Optional parameters */
3077 as.argc = argc;
3078 as.argv = argv;
3079
3080 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
3081 if (ret)
3082 return ret;
3083
3084 while (opt_params--) {
3085 opt_string = dm_shift_arg(&as);
3086 if (!opt_string) {
3087 ti->error = "Not enough feature arguments";
3088 return -EINVAL;
3089 }
3090
3091 if (!strcasecmp(opt_string, "allow_discards"))
3092 ti->num_discard_bios = 1;
3093
3094 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
3095 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3096
3097 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
3098 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3099 else if (!strcasecmp(opt_string, "no_read_workqueue"))
3100 set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3101 else if (!strcasecmp(opt_string, "no_write_workqueue"))
3102 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3103 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
3104 if (val == 0 || val > MAX_TAG_SIZE) {
3105 ti->error = "Invalid integrity arguments";
3106 return -EINVAL;
3107 }
3108 cc->on_disk_tag_size = val;
3109 sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
3110 if (!strcasecmp(sval, "aead")) {
3111 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
3112 } else if (strcasecmp(sval, "none")) {
3113 ti->error = "Unknown integrity profile";
3114 return -EINVAL;
3115 }
3116
3117 cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
3118 if (!cc->cipher_auth)
3119 return -ENOMEM;
3120 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
3121 if (cc->sector_size < (1 << SECTOR_SHIFT) ||
3122 cc->sector_size > 4096 ||
3123 (cc->sector_size & (cc->sector_size - 1))) {
3124 ti->error = "Invalid feature value for sector_size";
3125 return -EINVAL;
3126 }
3127 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
3128 ti->error = "Device size is not multiple of sector_size feature";
3129 return -EINVAL;
3130 }
3131 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
3132 } else if (!strcasecmp(opt_string, "iv_large_sectors"))
3133 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3134 else {
3135 ti->error = "Invalid feature arguments";
3136 return -EINVAL;
3137 }
3138 }
3139
3140 return 0;
3141}
3142
3143#ifdef CONFIG_BLK_DEV_ZONED
3144static int crypt_report_zones(struct dm_target *ti,
3145 struct dm_report_zones_args *args, unsigned int nr_zones)
3146{
3147 struct crypt_config *cc = ti->private;
3148
3149 return dm_report_zones(cc->dev->bdev, cc->start,
3150 cc->start + dm_target_offset(ti, args->next_sector),
3151 args, nr_zones);
3152}
3153#else
3154#define crypt_report_zones NULL
3155#endif
3156
3157/*
3158 * Construct an encryption mapping:
3159 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
3160 */
3161static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3162{
3163 struct crypt_config *cc;
3164 const char *devname = dm_table_device_name(ti->table);
3165 int key_size;
3166 unsigned int align_mask;
3167 unsigned long long tmpll;
3168 int ret;
3169 size_t iv_size_padding, additional_req_size;
3170 char dummy;
3171
3172 if (argc < 5) {
3173 ti->error = "Not enough arguments";
3174 return -EINVAL;
3175 }
3176
3177 key_size = get_key_size(&argv[1]);
3178 if (key_size < 0) {
3179 ti->error = "Cannot parse key size";
3180 return -EINVAL;
3181 }
3182
3183 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
3184 if (!cc) {
3185 ti->error = "Cannot allocate encryption context";
3186 return -ENOMEM;
3187 }
3188 cc->key_size = key_size;
3189 cc->sector_size = (1 << SECTOR_SHIFT);
3190 cc->sector_shift = 0;
3191
3192 ti->private = cc;
3193
3194 spin_lock(&dm_crypt_clients_lock);
3195 dm_crypt_clients_n++;
3196 crypt_calculate_pages_per_client();
3197 spin_unlock(&dm_crypt_clients_lock);
3198
3199 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
3200 if (ret < 0)
3201 goto bad;
3202
3203 /* Optional parameters need to be read before cipher constructor */
3204 if (argc > 5) {
3205 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
3206 if (ret)
3207 goto bad;
3208 }
3209
3210 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
3211 if (ret < 0)
3212 goto bad;
3213
3214 if (crypt_integrity_aead(cc)) {
3215 cc->dmreq_start = sizeof(struct aead_request);
3216 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
3217 align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
3218 } else {
3219 cc->dmreq_start = sizeof(struct skcipher_request);
3220 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
3221 align_mask = crypto_skcipher_alignmask(any_tfm(cc));
3222 }
3223 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
3224
3225 if (align_mask < CRYPTO_MINALIGN) {
3226 /* Allocate the padding exactly */
3227 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
3228 & align_mask;
3229 } else {
3230 /*
3231 * If the cipher requires greater alignment than kmalloc
3232 * alignment, we don't know the exact position of the
3233 * initialization vector. We must assume worst case.
3234 */
3235 iv_size_padding = align_mask;
3236 }
3237
3238 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */
3239 additional_req_size = sizeof(struct dm_crypt_request) +
3240 iv_size_padding + cc->iv_size +
3241 cc->iv_size +
3242 sizeof(uint64_t) +
3243 sizeof(unsigned int);
3244
3245 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
3246 if (ret) {
3247 ti->error = "Cannot allocate crypt request mempool";
3248 goto bad;
3249 }
3250
3251 cc->per_bio_data_size = ti->per_io_data_size =
3252 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
3253 ARCH_KMALLOC_MINALIGN);
3254
3255 ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc);
3256 if (ret) {
3257 ti->error = "Cannot allocate page mempool";
3258 goto bad;
3259 }
3260
3261 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
3262 if (ret) {
3263 ti->error = "Cannot allocate crypt bioset";
3264 goto bad;
3265 }
3266
3267 mutex_init(&cc->bio_alloc_lock);
3268
3269 ret = -EINVAL;
3270 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
3271 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
3272 ti->error = "Invalid iv_offset sector";
3273 goto bad;
3274 }
3275 cc->iv_offset = tmpll;
3276
3277 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
3278 if (ret) {
3279 ti->error = "Device lookup failed";
3280 goto bad;
3281 }
3282
3283 ret = -EINVAL;
3284 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
3285 ti->error = "Invalid device sector";
3286 goto bad;
3287 }
3288 cc->start = tmpll;
3289
3290 if (bdev_is_zoned(cc->dev->bdev)) {
3291 /*
3292 * For zoned block devices, we need to preserve the issuer write
3293 * ordering. To do so, disable write workqueues and force inline
3294 * encryption completion.
3295 */
3296 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3297 set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
3298
3299 /*
3300 * All zone append writes to a zone of a zoned block device will
3301 * have the same BIO sector, the start of the zone. When the
3302 * cypher IV mode uses sector values, all data targeting a
3303 * zone will be encrypted using the first sector numbers of the
3304 * zone. This will not result in write errors but will
3305 * cause most reads to fail as reads will use the sector values
3306 * for the actual data locations, resulting in IV mismatch.
3307 * To avoid this problem, ask DM core to emulate zone append
3308 * operations with regular writes.
3309 */
3310 DMDEBUG("Zone append operations will be emulated");
3311 ti->emulate_zone_append = true;
3312 }
3313
3314 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
3315 ret = crypt_integrity_ctr(cc, ti);
3316 if (ret)
3317 goto bad;
3318
3319 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
3320 if (!cc->tag_pool_max_sectors)
3321 cc->tag_pool_max_sectors = 1;
3322
3323 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
3324 cc->tag_pool_max_sectors * cc->on_disk_tag_size);
3325 if (ret) {
3326 ti->error = "Cannot allocate integrity tags mempool";
3327 goto bad;
3328 }
3329
3330 cc->tag_pool_max_sectors <<= cc->sector_shift;
3331 }
3332
3333 ret = -ENOMEM;
3334 cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname);
3335 if (!cc->io_queue) {
3336 ti->error = "Couldn't create kcryptd io queue";
3337 goto bad;
3338 }
3339
3340 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3341 cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
3342 1, devname);
3343 else
3344 cc->crypt_queue = alloc_workqueue("kcryptd/%s",
3345 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
3346 num_online_cpus(), devname);
3347 if (!cc->crypt_queue) {
3348 ti->error = "Couldn't create kcryptd queue";
3349 goto bad;
3350 }
3351
3352 spin_lock_init(&cc->write_thread_lock);
3353 cc->write_tree = RB_ROOT;
3354
3355 cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
3356 if (IS_ERR(cc->write_thread)) {
3357 ret = PTR_ERR(cc->write_thread);
3358 cc->write_thread = NULL;
3359 ti->error = "Couldn't spawn write thread";
3360 goto bad;
3361 }
3362
3363 ti->num_flush_bios = 1;
3364 ti->limit_swap_bios = true;
3365 ti->accounts_remapped_io = true;
3366
3367 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);
3368 return 0;
3369
3370bad:
3371 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0);
3372 crypt_dtr(ti);
3373 return ret;
3374}
3375
3376static int crypt_map(struct dm_target *ti, struct bio *bio)
3377{
3378 struct dm_crypt_io *io;
3379 struct crypt_config *cc = ti->private;
3380
3381 /*
3382 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
3383 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
3384 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
3385 */
3386 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
3387 bio_op(bio) == REQ_OP_DISCARD)) {
3388 bio_set_dev(bio, cc->dev->bdev);
3389 if (bio_sectors(bio))
3390 bio->bi_iter.bi_sector = cc->start +
3391 dm_target_offset(ti, bio->bi_iter.bi_sector);
3392 return DM_MAPIO_REMAPPED;
3393 }
3394
3395 /*
3396 * Check if bio is too large, split as needed.
3397 */
3398 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) &&
3399 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
3400 dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT));
3401
3402 /*
3403 * Ensure that bio is a multiple of internal sector encryption size
3404 * and is aligned to this size as defined in IO hints.
3405 */
3406 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
3407 return DM_MAPIO_KILL;
3408
3409 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
3410 return DM_MAPIO_KILL;
3411
3412 io = dm_per_bio_data(bio, cc->per_bio_data_size);
3413 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
3414
3415 if (cc->on_disk_tag_size) {
3416 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
3417
3418 if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
3419 unlikely(!(io->integrity_metadata = kmalloc(tag_len,
3420 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
3421 if (bio_sectors(bio) > cc->tag_pool_max_sectors)
3422 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
3423 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
3424 io->integrity_metadata_from_pool = true;
3425 }
3426 }
3427
3428 if (crypt_integrity_aead(cc))
3429 io->ctx.r.req_aead = (struct aead_request *)(io + 1);
3430 else
3431 io->ctx.r.req = (struct skcipher_request *)(io + 1);
3432
3433 if (bio_data_dir(io->base_bio) == READ) {
3434 if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP))
3435 kcryptd_queue_read(io);
3436 } else
3437 kcryptd_queue_crypt(io);
3438
3439 return DM_MAPIO_SUBMITTED;
3440}
3441
3442static char hex2asc(unsigned char c)
3443{
3444 return c + '0' + ((unsigned)(9 - c) >> 4 & 0x27);
3445}
3446
3447static void crypt_status(struct dm_target *ti, status_type_t type,
3448 unsigned status_flags, char *result, unsigned maxlen)
3449{
3450 struct crypt_config *cc = ti->private;
3451 unsigned i, sz = 0;
3452 int num_feature_args = 0;
3453
3454 switch (type) {
3455 case STATUSTYPE_INFO:
3456 result[0] = '\0';
3457 break;
3458
3459 case STATUSTYPE_TABLE:
3460 DMEMIT("%s ", cc->cipher_string);
3461
3462 if (cc->key_size > 0) {
3463 if (cc->key_string)
3464 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
3465 else {
3466 for (i = 0; i < cc->key_size; i++) {
3467 DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
3468 hex2asc(cc->key[i] & 0xf));
3469 }
3470 }
3471 } else
3472 DMEMIT("-");
3473
3474 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
3475 cc->dev->name, (unsigned long long)cc->start);
3476
3477 num_feature_args += !!ti->num_discard_bios;
3478 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3479 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3480 num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3481 num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3482 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
3483 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3484 if (cc->on_disk_tag_size)
3485 num_feature_args++;
3486 if (num_feature_args) {
3487 DMEMIT(" %d", num_feature_args);
3488 if (ti->num_discard_bios)
3489 DMEMIT(" allow_discards");
3490 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3491 DMEMIT(" same_cpu_crypt");
3492 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
3493 DMEMIT(" submit_from_crypt_cpus");
3494 if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags))
3495 DMEMIT(" no_read_workqueue");
3496 if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
3497 DMEMIT(" no_write_workqueue");
3498 if (cc->on_disk_tag_size)
3499 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
3500 if (cc->sector_size != (1 << SECTOR_SHIFT))
3501 DMEMIT(" sector_size:%d", cc->sector_size);
3502 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
3503 DMEMIT(" iv_large_sectors");
3504 }
3505 break;
3506
3507 case STATUSTYPE_IMA:
3508 DMEMIT_TARGET_NAME_VERSION(ti->type);
3509 DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n');
3510 DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n');
3511 DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ?
3512 'y' : 'n');
3513 DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ?
3514 'y' : 'n');
3515 DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ?
3516 'y' : 'n');
3517 DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ?
3518 'y' : 'n');
3519
3520 if (cc->on_disk_tag_size)
3521 DMEMIT(",integrity_tag_size=%u,cipher_auth=%s",
3522 cc->on_disk_tag_size, cc->cipher_auth);
3523 if (cc->sector_size != (1 << SECTOR_SHIFT))
3524 DMEMIT(",sector_size=%d", cc->sector_size);
3525 if (cc->cipher_string)
3526 DMEMIT(",cipher_string=%s", cc->cipher_string);
3527
3528 DMEMIT(",key_size=%u", cc->key_size);
3529 DMEMIT(",key_parts=%u", cc->key_parts);
3530 DMEMIT(",key_extra_size=%u", cc->key_extra_size);
3531 DMEMIT(",key_mac_size=%u", cc->key_mac_size);
3532 DMEMIT(";");
3533 break;
3534 }
3535}
3536
3537static void crypt_postsuspend(struct dm_target *ti)
3538{
3539 struct crypt_config *cc = ti->private;
3540
3541 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3542}
3543
3544static int crypt_preresume(struct dm_target *ti)
3545{
3546 struct crypt_config *cc = ti->private;
3547
3548 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3549 DMERR("aborting resume - crypt key is not set.");
3550 return -EAGAIN;
3551 }
3552
3553 return 0;
3554}
3555
3556static void crypt_resume(struct dm_target *ti)
3557{
3558 struct crypt_config *cc = ti->private;
3559
3560 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3561}
3562
3563/* Message interface
3564 * key set <key>
3565 * key wipe
3566 */
3567static int crypt_message(struct dm_target *ti, unsigned argc, char **argv,
3568 char *result, unsigned maxlen)
3569{
3570 struct crypt_config *cc = ti->private;
3571 int key_size, ret = -EINVAL;
3572
3573 if (argc < 2)
3574 goto error;
3575
3576 if (!strcasecmp(argv[0], "key")) {
3577 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3578 DMWARN("not suspended during key manipulation.");
3579 return -EINVAL;
3580 }
3581 if (argc == 3 && !strcasecmp(argv[1], "set")) {
3582 /* The key size may not be changed. */
3583 key_size = get_key_size(&argv[2]);
3584 if (key_size < 0 || cc->key_size != key_size) {
3585 memset(argv[2], '0', strlen(argv[2]));
3586 return -EINVAL;
3587 }
3588
3589 ret = crypt_set_key(cc, argv[2]);
3590 if (ret)
3591 return ret;
3592 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3593 ret = cc->iv_gen_ops->init(cc);
3594 /* wipe the kernel key payload copy */
3595 if (cc->key_string)
3596 memset(cc->key, 0, cc->key_size * sizeof(u8));
3597 return ret;
3598 }
3599 if (argc == 2 && !strcasecmp(argv[1], "wipe"))
3600 return crypt_wipe_key(cc);
3601 }
3602
3603error:
3604 DMWARN("unrecognised message received.");
3605 return -EINVAL;
3606}
3607
3608static int crypt_iterate_devices(struct dm_target *ti,
3609 iterate_devices_callout_fn fn, void *data)
3610{
3611 struct crypt_config *cc = ti->private;
3612
3613 return fn(ti, cc->dev, cc->start, ti->len, data);
3614}
3615
3616static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3617{
3618 struct crypt_config *cc = ti->private;
3619
3620 /*
3621 * Unfortunate constraint that is required to avoid the potential
3622 * for exceeding underlying device's max_segments limits -- due to
3623 * crypt_alloc_buffer() possibly allocating pages for the encryption
3624 * bio that are not as physically contiguous as the original bio.
3625 */
3626 limits->max_segment_size = PAGE_SIZE;
3627
3628 limits->logical_block_size =
3629 max_t(unsigned, limits->logical_block_size, cc->sector_size);
3630 limits->physical_block_size =
3631 max_t(unsigned, limits->physical_block_size, cc->sector_size);
3632 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
3633 limits->dma_alignment = limits->logical_block_size - 1;
3634}
3635
3636static struct target_type crypt_target = {
3637 .name = "crypt",
3638 .version = {1, 24, 0},
3639 .module = THIS_MODULE,
3640 .ctr = crypt_ctr,
3641 .dtr = crypt_dtr,
3642 .features = DM_TARGET_ZONED_HM,
3643 .report_zones = crypt_report_zones,
3644 .map = crypt_map,
3645 .status = crypt_status,
3646 .postsuspend = crypt_postsuspend,
3647 .preresume = crypt_preresume,
3648 .resume = crypt_resume,
3649 .message = crypt_message,
3650 .iterate_devices = crypt_iterate_devices,
3651 .io_hints = crypt_io_hints,
3652};
3653
3654static int __init dm_crypt_init(void)
3655{
3656 int r;
3657
3658 r = dm_register_target(&crypt_target);
3659 if (r < 0)
3660 DMERR("register failed %d", r);
3661
3662 return r;
3663}
3664
3665static void __exit dm_crypt_exit(void)
3666{
3667 dm_unregister_target(&crypt_target);
3668}
3669
3670module_init(dm_crypt_init);
3671module_exit(dm_crypt_exit);
3672
3673MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3674MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3675MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved.
5 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
6 *
7 * This file is released under the GPL.
8 */
9
10#include <linux/completion.h>
11#include <linux/err.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/bio.h>
16#include <linux/blkdev.h>
17#include <linux/mempool.h>
18#include <linux/slab.h>
19#include <linux/crypto.h>
20#include <linux/workqueue.h>
21#include <linux/kthread.h>
22#include <linux/backing-dev.h>
23#include <linux/atomic.h>
24#include <linux/scatterlist.h>
25#include <linux/rbtree.h>
26#include <asm/page.h>
27#include <asm/unaligned.h>
28#include <crypto/hash.h>
29#include <crypto/md5.h>
30#include <crypto/algapi.h>
31#include <crypto/skcipher.h>
32
33#include <linux/device-mapper.h>
34
35#define DM_MSG_PREFIX "crypt"
36
37/*
38 * context holding the current state of a multi-part conversion
39 */
40struct convert_context {
41 struct completion restart;
42 struct bio *bio_in;
43 struct bio *bio_out;
44 struct bvec_iter iter_in;
45 struct bvec_iter iter_out;
46 sector_t cc_sector;
47 atomic_t cc_pending;
48 struct skcipher_request *req;
49};
50
51/*
52 * per bio private data
53 */
54struct dm_crypt_io {
55 struct crypt_config *cc;
56 struct bio *base_bio;
57 struct work_struct work;
58
59 struct convert_context ctx;
60
61 atomic_t io_pending;
62 int error;
63 sector_t sector;
64
65 struct rb_node rb_node;
66} CRYPTO_MINALIGN_ATTR;
67
68struct dm_crypt_request {
69 struct convert_context *ctx;
70 struct scatterlist sg_in;
71 struct scatterlist sg_out;
72 sector_t iv_sector;
73};
74
75struct crypt_config;
76
77struct crypt_iv_operations {
78 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
79 const char *opts);
80 void (*dtr)(struct crypt_config *cc);
81 int (*init)(struct crypt_config *cc);
82 int (*wipe)(struct crypt_config *cc);
83 int (*generator)(struct crypt_config *cc, u8 *iv,
84 struct dm_crypt_request *dmreq);
85 int (*post)(struct crypt_config *cc, u8 *iv,
86 struct dm_crypt_request *dmreq);
87};
88
89struct iv_essiv_private {
90 struct crypto_ahash *hash_tfm;
91 u8 *salt;
92};
93
94struct iv_benbi_private {
95 int shift;
96};
97
98#define LMK_SEED_SIZE 64 /* hash + 0 */
99struct iv_lmk_private {
100 struct crypto_shash *hash_tfm;
101 u8 *seed;
102};
103
104#define TCW_WHITENING_SIZE 16
105struct iv_tcw_private {
106 struct crypto_shash *crc32_tfm;
107 u8 *iv_seed;
108 u8 *whitening;
109};
110
111/*
112 * Crypt: maps a linear range of a block device
113 * and encrypts / decrypts at the same time.
114 */
115enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
116 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
117 DM_CRYPT_EXIT_THREAD};
118
119/*
120 * The fields in here must be read only after initialization.
121 */
122struct crypt_config {
123 struct dm_dev *dev;
124 sector_t start;
125
126 /*
127 * pool for per bio private data, crypto requests and
128 * encryption requeusts/buffer pages
129 */
130 mempool_t *req_pool;
131 mempool_t *page_pool;
132 struct bio_set *bs;
133 struct mutex bio_alloc_lock;
134
135 struct workqueue_struct *io_queue;
136 struct workqueue_struct *crypt_queue;
137
138 struct task_struct *write_thread;
139 wait_queue_head_t write_thread_wait;
140 struct rb_root write_tree;
141
142 char *cipher;
143 char *cipher_string;
144
145 struct crypt_iv_operations *iv_gen_ops;
146 union {
147 struct iv_essiv_private essiv;
148 struct iv_benbi_private benbi;
149 struct iv_lmk_private lmk;
150 struct iv_tcw_private tcw;
151 } iv_gen_private;
152 sector_t iv_offset;
153 unsigned int iv_size;
154
155 /* ESSIV: struct crypto_cipher *essiv_tfm */
156 void *iv_private;
157 struct crypto_skcipher **tfms;
158 unsigned tfms_count;
159
160 /*
161 * Layout of each crypto request:
162 *
163 * struct skcipher_request
164 * context
165 * padding
166 * struct dm_crypt_request
167 * padding
168 * IV
169 *
170 * The padding is added so that dm_crypt_request and the IV are
171 * correctly aligned.
172 */
173 unsigned int dmreq_start;
174
175 unsigned int per_bio_data_size;
176
177 unsigned long flags;
178 unsigned int key_size;
179 unsigned int key_parts; /* independent parts in key buffer */
180 unsigned int key_extra_size; /* additional keys length */
181 u8 key[0];
182};
183
184#define MIN_IOS 16
185
186static void clone_init(struct dm_crypt_io *, struct bio *);
187static void kcryptd_queue_crypt(struct dm_crypt_io *io);
188static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
189
190/*
191 * Use this to access cipher attributes that are the same for each CPU.
192 */
193static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
194{
195 return cc->tfms[0];
196}
197
198/*
199 * Different IV generation algorithms:
200 *
201 * plain: the initial vector is the 32-bit little-endian version of the sector
202 * number, padded with zeros if necessary.
203 *
204 * plain64: the initial vector is the 64-bit little-endian version of the sector
205 * number, padded with zeros if necessary.
206 *
207 * essiv: "encrypted sector|salt initial vector", the sector number is
208 * encrypted with the bulk cipher using a salt as key. The salt
209 * should be derived from the bulk cipher's key via hashing.
210 *
211 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
212 * (needed for LRW-32-AES and possible other narrow block modes)
213 *
214 * null: the initial vector is always zero. Provides compatibility with
215 * obsolete loop_fish2 devices. Do not use for new devices.
216 *
217 * lmk: Compatible implementation of the block chaining mode used
218 * by the Loop-AES block device encryption system
219 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
220 * It operates on full 512 byte sectors and uses CBC
221 * with an IV derived from the sector number, the data and
222 * optionally extra IV seed.
223 * This means that after decryption the first block
224 * of sector must be tweaked according to decrypted data.
225 * Loop-AES can use three encryption schemes:
226 * version 1: is plain aes-cbc mode
227 * version 2: uses 64 multikey scheme with lmk IV generator
228 * version 3: the same as version 2 with additional IV seed
229 * (it uses 65 keys, last key is used as IV seed)
230 *
231 * tcw: Compatible implementation of the block chaining mode used
232 * by the TrueCrypt device encryption system (prior to version 4.1).
233 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
234 * It operates on full 512 byte sectors and uses CBC
235 * with an IV derived from initial key and the sector number.
236 * In addition, whitening value is applied on every sector, whitening
237 * is calculated from initial key, sector number and mixed using CRC32.
238 * Note that this encryption scheme is vulnerable to watermarking attacks
239 * and should be used for old compatible containers access only.
240 *
241 * plumb: unimplemented, see:
242 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
243 */
244
245static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
246 struct dm_crypt_request *dmreq)
247{
248 memset(iv, 0, cc->iv_size);
249 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
250
251 return 0;
252}
253
254static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
255 struct dm_crypt_request *dmreq)
256{
257 memset(iv, 0, cc->iv_size);
258 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
259
260 return 0;
261}
262
263/* Initialise ESSIV - compute salt but no local memory allocations */
264static int crypt_iv_essiv_init(struct crypt_config *cc)
265{
266 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
267 AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
268 struct scatterlist sg;
269 struct crypto_cipher *essiv_tfm;
270 int err;
271
272 sg_init_one(&sg, cc->key, cc->key_size);
273 ahash_request_set_tfm(req, essiv->hash_tfm);
274 ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
275 ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
276
277 err = crypto_ahash_digest(req);
278 ahash_request_zero(req);
279 if (err)
280 return err;
281
282 essiv_tfm = cc->iv_private;
283
284 err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
285 crypto_ahash_digestsize(essiv->hash_tfm));
286 if (err)
287 return err;
288
289 return 0;
290}
291
292/* Wipe salt and reset key derived from volume key */
293static int crypt_iv_essiv_wipe(struct crypt_config *cc)
294{
295 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
296 unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
297 struct crypto_cipher *essiv_tfm;
298 int r, err = 0;
299
300 memset(essiv->salt, 0, salt_size);
301
302 essiv_tfm = cc->iv_private;
303 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
304 if (r)
305 err = r;
306
307 return err;
308}
309
310/* Set up per cpu cipher state */
311static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
312 struct dm_target *ti,
313 u8 *salt, unsigned saltsize)
314{
315 struct crypto_cipher *essiv_tfm;
316 int err;
317
318 /* Setup the essiv_tfm with the given salt */
319 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
320 if (IS_ERR(essiv_tfm)) {
321 ti->error = "Error allocating crypto tfm for ESSIV";
322 return essiv_tfm;
323 }
324
325 if (crypto_cipher_blocksize(essiv_tfm) !=
326 crypto_skcipher_ivsize(any_tfm(cc))) {
327 ti->error = "Block size of ESSIV cipher does "
328 "not match IV size of block cipher";
329 crypto_free_cipher(essiv_tfm);
330 return ERR_PTR(-EINVAL);
331 }
332
333 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
334 if (err) {
335 ti->error = "Failed to set key for ESSIV cipher";
336 crypto_free_cipher(essiv_tfm);
337 return ERR_PTR(err);
338 }
339
340 return essiv_tfm;
341}
342
343static void crypt_iv_essiv_dtr(struct crypt_config *cc)
344{
345 struct crypto_cipher *essiv_tfm;
346 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
347
348 crypto_free_ahash(essiv->hash_tfm);
349 essiv->hash_tfm = NULL;
350
351 kzfree(essiv->salt);
352 essiv->salt = NULL;
353
354 essiv_tfm = cc->iv_private;
355
356 if (essiv_tfm)
357 crypto_free_cipher(essiv_tfm);
358
359 cc->iv_private = NULL;
360}
361
362static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
363 const char *opts)
364{
365 struct crypto_cipher *essiv_tfm = NULL;
366 struct crypto_ahash *hash_tfm = NULL;
367 u8 *salt = NULL;
368 int err;
369
370 if (!opts) {
371 ti->error = "Digest algorithm missing for ESSIV mode";
372 return -EINVAL;
373 }
374
375 /* Allocate hash algorithm */
376 hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
377 if (IS_ERR(hash_tfm)) {
378 ti->error = "Error initializing ESSIV hash";
379 err = PTR_ERR(hash_tfm);
380 goto bad;
381 }
382
383 salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
384 if (!salt) {
385 ti->error = "Error kmallocing salt storage in ESSIV";
386 err = -ENOMEM;
387 goto bad;
388 }
389
390 cc->iv_gen_private.essiv.salt = salt;
391 cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
392
393 essiv_tfm = setup_essiv_cpu(cc, ti, salt,
394 crypto_ahash_digestsize(hash_tfm));
395 if (IS_ERR(essiv_tfm)) {
396 crypt_iv_essiv_dtr(cc);
397 return PTR_ERR(essiv_tfm);
398 }
399 cc->iv_private = essiv_tfm;
400
401 return 0;
402
403bad:
404 if (hash_tfm && !IS_ERR(hash_tfm))
405 crypto_free_ahash(hash_tfm);
406 kfree(salt);
407 return err;
408}
409
410static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
411 struct dm_crypt_request *dmreq)
412{
413 struct crypto_cipher *essiv_tfm = cc->iv_private;
414
415 memset(iv, 0, cc->iv_size);
416 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
417 crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
418
419 return 0;
420}
421
422static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
423 const char *opts)
424{
425 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
426 int log = ilog2(bs);
427
428 /* we need to calculate how far we must shift the sector count
429 * to get the cipher block count, we use this shift in _gen */
430
431 if (1 << log != bs) {
432 ti->error = "cypher blocksize is not a power of 2";
433 return -EINVAL;
434 }
435
436 if (log > 9) {
437 ti->error = "cypher blocksize is > 512";
438 return -EINVAL;
439 }
440
441 cc->iv_gen_private.benbi.shift = 9 - log;
442
443 return 0;
444}
445
446static void crypt_iv_benbi_dtr(struct crypt_config *cc)
447{
448}
449
450static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
451 struct dm_crypt_request *dmreq)
452{
453 __be64 val;
454
455 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
456
457 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
458 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
459
460 return 0;
461}
462
463static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
464 struct dm_crypt_request *dmreq)
465{
466 memset(iv, 0, cc->iv_size);
467
468 return 0;
469}
470
471static void crypt_iv_lmk_dtr(struct crypt_config *cc)
472{
473 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
474
475 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
476 crypto_free_shash(lmk->hash_tfm);
477 lmk->hash_tfm = NULL;
478
479 kzfree(lmk->seed);
480 lmk->seed = NULL;
481}
482
483static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
484 const char *opts)
485{
486 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
487
488 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
489 if (IS_ERR(lmk->hash_tfm)) {
490 ti->error = "Error initializing LMK hash";
491 return PTR_ERR(lmk->hash_tfm);
492 }
493
494 /* No seed in LMK version 2 */
495 if (cc->key_parts == cc->tfms_count) {
496 lmk->seed = NULL;
497 return 0;
498 }
499
500 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
501 if (!lmk->seed) {
502 crypt_iv_lmk_dtr(cc);
503 ti->error = "Error kmallocing seed storage in LMK";
504 return -ENOMEM;
505 }
506
507 return 0;
508}
509
510static int crypt_iv_lmk_init(struct crypt_config *cc)
511{
512 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
513 int subkey_size = cc->key_size / cc->key_parts;
514
515 /* LMK seed is on the position of LMK_KEYS + 1 key */
516 if (lmk->seed)
517 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
518 crypto_shash_digestsize(lmk->hash_tfm));
519
520 return 0;
521}
522
523static int crypt_iv_lmk_wipe(struct crypt_config *cc)
524{
525 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
526
527 if (lmk->seed)
528 memset(lmk->seed, 0, LMK_SEED_SIZE);
529
530 return 0;
531}
532
533static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
534 struct dm_crypt_request *dmreq,
535 u8 *data)
536{
537 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
538 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
539 struct md5_state md5state;
540 __le32 buf[4];
541 int i, r;
542
543 desc->tfm = lmk->hash_tfm;
544 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
545
546 r = crypto_shash_init(desc);
547 if (r)
548 return r;
549
550 if (lmk->seed) {
551 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
552 if (r)
553 return r;
554 }
555
556 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
557 r = crypto_shash_update(desc, data + 16, 16 * 31);
558 if (r)
559 return r;
560
561 /* Sector is cropped to 56 bits here */
562 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
563 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
564 buf[2] = cpu_to_le32(4024);
565 buf[3] = 0;
566 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
567 if (r)
568 return r;
569
570 /* No MD5 padding here */
571 r = crypto_shash_export(desc, &md5state);
572 if (r)
573 return r;
574
575 for (i = 0; i < MD5_HASH_WORDS; i++)
576 __cpu_to_le32s(&md5state.hash[i]);
577 memcpy(iv, &md5state.hash, cc->iv_size);
578
579 return 0;
580}
581
582static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
583 struct dm_crypt_request *dmreq)
584{
585 u8 *src;
586 int r = 0;
587
588 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
589 src = kmap_atomic(sg_page(&dmreq->sg_in));
590 r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
591 kunmap_atomic(src);
592 } else
593 memset(iv, 0, cc->iv_size);
594
595 return r;
596}
597
598static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
599 struct dm_crypt_request *dmreq)
600{
601 u8 *dst;
602 int r;
603
604 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
605 return 0;
606
607 dst = kmap_atomic(sg_page(&dmreq->sg_out));
608 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
609
610 /* Tweak the first block of plaintext sector */
611 if (!r)
612 crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
613
614 kunmap_atomic(dst);
615 return r;
616}
617
618static void crypt_iv_tcw_dtr(struct crypt_config *cc)
619{
620 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
621
622 kzfree(tcw->iv_seed);
623 tcw->iv_seed = NULL;
624 kzfree(tcw->whitening);
625 tcw->whitening = NULL;
626
627 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
628 crypto_free_shash(tcw->crc32_tfm);
629 tcw->crc32_tfm = NULL;
630}
631
632static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
633 const char *opts)
634{
635 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
636
637 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
638 ti->error = "Wrong key size for TCW";
639 return -EINVAL;
640 }
641
642 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
643 if (IS_ERR(tcw->crc32_tfm)) {
644 ti->error = "Error initializing CRC32 in TCW";
645 return PTR_ERR(tcw->crc32_tfm);
646 }
647
648 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
649 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
650 if (!tcw->iv_seed || !tcw->whitening) {
651 crypt_iv_tcw_dtr(cc);
652 ti->error = "Error allocating seed storage in TCW";
653 return -ENOMEM;
654 }
655
656 return 0;
657}
658
659static int crypt_iv_tcw_init(struct crypt_config *cc)
660{
661 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
662 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
663
664 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
665 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
666 TCW_WHITENING_SIZE);
667
668 return 0;
669}
670
671static int crypt_iv_tcw_wipe(struct crypt_config *cc)
672{
673 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
674
675 memset(tcw->iv_seed, 0, cc->iv_size);
676 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
677
678 return 0;
679}
680
681static int crypt_iv_tcw_whitening(struct crypt_config *cc,
682 struct dm_crypt_request *dmreq,
683 u8 *data)
684{
685 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
686 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
687 u8 buf[TCW_WHITENING_SIZE];
688 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
689 int i, r;
690
691 /* xor whitening with sector number */
692 memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
693 crypto_xor(buf, (u8 *)§or, 8);
694 crypto_xor(&buf[8], (u8 *)§or, 8);
695
696 /* calculate crc32 for every 32bit part and xor it */
697 desc->tfm = tcw->crc32_tfm;
698 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
699 for (i = 0; i < 4; i++) {
700 r = crypto_shash_init(desc);
701 if (r)
702 goto out;
703 r = crypto_shash_update(desc, &buf[i * 4], 4);
704 if (r)
705 goto out;
706 r = crypto_shash_final(desc, &buf[i * 4]);
707 if (r)
708 goto out;
709 }
710 crypto_xor(&buf[0], &buf[12], 4);
711 crypto_xor(&buf[4], &buf[8], 4);
712
713 /* apply whitening (8 bytes) to whole sector */
714 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
715 crypto_xor(data + i * 8, buf, 8);
716out:
717 memzero_explicit(buf, sizeof(buf));
718 return r;
719}
720
721static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
722 struct dm_crypt_request *dmreq)
723{
724 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
725 u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
726 u8 *src;
727 int r = 0;
728
729 /* Remove whitening from ciphertext */
730 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
731 src = kmap_atomic(sg_page(&dmreq->sg_in));
732 r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
733 kunmap_atomic(src);
734 }
735
736 /* Calculate IV */
737 memcpy(iv, tcw->iv_seed, cc->iv_size);
738 crypto_xor(iv, (u8 *)§or, 8);
739 if (cc->iv_size > 8)
740 crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8);
741
742 return r;
743}
744
745static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
746 struct dm_crypt_request *dmreq)
747{
748 u8 *dst;
749 int r;
750
751 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
752 return 0;
753
754 /* Apply whitening on ciphertext */
755 dst = kmap_atomic(sg_page(&dmreq->sg_out));
756 r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
757 kunmap_atomic(dst);
758
759 return r;
760}
761
762static struct crypt_iv_operations crypt_iv_plain_ops = {
763 .generator = crypt_iv_plain_gen
764};
765
766static struct crypt_iv_operations crypt_iv_plain64_ops = {
767 .generator = crypt_iv_plain64_gen
768};
769
770static struct crypt_iv_operations crypt_iv_essiv_ops = {
771 .ctr = crypt_iv_essiv_ctr,
772 .dtr = crypt_iv_essiv_dtr,
773 .init = crypt_iv_essiv_init,
774 .wipe = crypt_iv_essiv_wipe,
775 .generator = crypt_iv_essiv_gen
776};
777
778static struct crypt_iv_operations crypt_iv_benbi_ops = {
779 .ctr = crypt_iv_benbi_ctr,
780 .dtr = crypt_iv_benbi_dtr,
781 .generator = crypt_iv_benbi_gen
782};
783
784static struct crypt_iv_operations crypt_iv_null_ops = {
785 .generator = crypt_iv_null_gen
786};
787
788static struct crypt_iv_operations crypt_iv_lmk_ops = {
789 .ctr = crypt_iv_lmk_ctr,
790 .dtr = crypt_iv_lmk_dtr,
791 .init = crypt_iv_lmk_init,
792 .wipe = crypt_iv_lmk_wipe,
793 .generator = crypt_iv_lmk_gen,
794 .post = crypt_iv_lmk_post
795};
796
797static struct crypt_iv_operations crypt_iv_tcw_ops = {
798 .ctr = crypt_iv_tcw_ctr,
799 .dtr = crypt_iv_tcw_dtr,
800 .init = crypt_iv_tcw_init,
801 .wipe = crypt_iv_tcw_wipe,
802 .generator = crypt_iv_tcw_gen,
803 .post = crypt_iv_tcw_post
804};
805
806static void crypt_convert_init(struct crypt_config *cc,
807 struct convert_context *ctx,
808 struct bio *bio_out, struct bio *bio_in,
809 sector_t sector)
810{
811 ctx->bio_in = bio_in;
812 ctx->bio_out = bio_out;
813 if (bio_in)
814 ctx->iter_in = bio_in->bi_iter;
815 if (bio_out)
816 ctx->iter_out = bio_out->bi_iter;
817 ctx->cc_sector = sector + cc->iv_offset;
818 init_completion(&ctx->restart);
819}
820
821static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
822 struct skcipher_request *req)
823{
824 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
825}
826
827static struct skcipher_request *req_of_dmreq(struct crypt_config *cc,
828 struct dm_crypt_request *dmreq)
829{
830 return (struct skcipher_request *)((char *)dmreq - cc->dmreq_start);
831}
832
833static u8 *iv_of_dmreq(struct crypt_config *cc,
834 struct dm_crypt_request *dmreq)
835{
836 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
837 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
838}
839
840static int crypt_convert_block(struct crypt_config *cc,
841 struct convert_context *ctx,
842 struct skcipher_request *req)
843{
844 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
845 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
846 struct dm_crypt_request *dmreq;
847 u8 *iv;
848 int r;
849
850 dmreq = dmreq_of_req(cc, req);
851 iv = iv_of_dmreq(cc, dmreq);
852
853 dmreq->iv_sector = ctx->cc_sector;
854 dmreq->ctx = ctx;
855 sg_init_table(&dmreq->sg_in, 1);
856 sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
857 bv_in.bv_offset);
858
859 sg_init_table(&dmreq->sg_out, 1);
860 sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
861 bv_out.bv_offset);
862
863 bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
864 bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
865
866 if (cc->iv_gen_ops) {
867 r = cc->iv_gen_ops->generator(cc, iv, dmreq);
868 if (r < 0)
869 return r;
870 }
871
872 skcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
873 1 << SECTOR_SHIFT, iv);
874
875 if (bio_data_dir(ctx->bio_in) == WRITE)
876 r = crypto_skcipher_encrypt(req);
877 else
878 r = crypto_skcipher_decrypt(req);
879
880 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
881 r = cc->iv_gen_ops->post(cc, iv, dmreq);
882
883 return r;
884}
885
886static void kcryptd_async_done(struct crypto_async_request *async_req,
887 int error);
888
889static void crypt_alloc_req(struct crypt_config *cc,
890 struct convert_context *ctx)
891{
892 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
893
894 if (!ctx->req)
895 ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
896
897 skcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
898
899 /*
900 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
901 * requests if driver request queue is full.
902 */
903 skcipher_request_set_callback(ctx->req,
904 CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
905 kcryptd_async_done, dmreq_of_req(cc, ctx->req));
906}
907
908static void crypt_free_req(struct crypt_config *cc,
909 struct skcipher_request *req, struct bio *base_bio)
910{
911 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
912
913 if ((struct skcipher_request *)(io + 1) != req)
914 mempool_free(req, cc->req_pool);
915}
916
917/*
918 * Encrypt / decrypt data from one bio to another one (can be the same one)
919 */
920static int crypt_convert(struct crypt_config *cc,
921 struct convert_context *ctx)
922{
923 int r;
924
925 atomic_set(&ctx->cc_pending, 1);
926
927 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
928
929 crypt_alloc_req(cc, ctx);
930
931 atomic_inc(&ctx->cc_pending);
932
933 r = crypt_convert_block(cc, ctx, ctx->req);
934
935 switch (r) {
936 /*
937 * The request was queued by a crypto driver
938 * but the driver request queue is full, let's wait.
939 */
940 case -EBUSY:
941 wait_for_completion(&ctx->restart);
942 reinit_completion(&ctx->restart);
943 /* fall through */
944 /*
945 * The request is queued and processed asynchronously,
946 * completion function kcryptd_async_done() will be called.
947 */
948 case -EINPROGRESS:
949 ctx->req = NULL;
950 ctx->cc_sector++;
951 continue;
952 /*
953 * The request was already processed (synchronously).
954 */
955 case 0:
956 atomic_dec(&ctx->cc_pending);
957 ctx->cc_sector++;
958 cond_resched();
959 continue;
960
961 /* There was an error while processing the request. */
962 default:
963 atomic_dec(&ctx->cc_pending);
964 return r;
965 }
966 }
967
968 return 0;
969}
970
971static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
972
973/*
974 * Generate a new unfragmented bio with the given size
975 * This should never violate the device limitations (but only because
976 * max_segment_size is being constrained to PAGE_SIZE).
977 *
978 * This function may be called concurrently. If we allocate from the mempool
979 * concurrently, there is a possibility of deadlock. For example, if we have
980 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
981 * the mempool concurrently, it may deadlock in a situation where both processes
982 * have allocated 128 pages and the mempool is exhausted.
983 *
984 * In order to avoid this scenario we allocate the pages under a mutex.
985 *
986 * In order to not degrade performance with excessive locking, we try
987 * non-blocking allocations without a mutex first but on failure we fallback
988 * to blocking allocations with a mutex.
989 */
990static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
991{
992 struct crypt_config *cc = io->cc;
993 struct bio *clone;
994 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
995 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
996 unsigned i, len, remaining_size;
997 struct page *page;
998 struct bio_vec *bvec;
999
1000retry:
1001 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1002 mutex_lock(&cc->bio_alloc_lock);
1003
1004 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1005 if (!clone)
1006 goto return_clone;
1007
1008 clone_init(io, clone);
1009
1010 remaining_size = size;
1011
1012 for (i = 0; i < nr_iovecs; i++) {
1013 page = mempool_alloc(cc->page_pool, gfp_mask);
1014 if (!page) {
1015 crypt_free_buffer_pages(cc, clone);
1016 bio_put(clone);
1017 gfp_mask |= __GFP_DIRECT_RECLAIM;
1018 goto retry;
1019 }
1020
1021 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1022
1023 bvec = &clone->bi_io_vec[clone->bi_vcnt++];
1024 bvec->bv_page = page;
1025 bvec->bv_len = len;
1026 bvec->bv_offset = 0;
1027
1028 clone->bi_iter.bi_size += len;
1029
1030 remaining_size -= len;
1031 }
1032
1033return_clone:
1034 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1035 mutex_unlock(&cc->bio_alloc_lock);
1036
1037 return clone;
1038}
1039
1040static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1041{
1042 unsigned int i;
1043 struct bio_vec *bv;
1044
1045 bio_for_each_segment_all(bv, clone, i) {
1046 BUG_ON(!bv->bv_page);
1047 mempool_free(bv->bv_page, cc->page_pool);
1048 bv->bv_page = NULL;
1049 }
1050}
1051
1052static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1053 struct bio *bio, sector_t sector)
1054{
1055 io->cc = cc;
1056 io->base_bio = bio;
1057 io->sector = sector;
1058 io->error = 0;
1059 io->ctx.req = NULL;
1060 atomic_set(&io->io_pending, 0);
1061}
1062
1063static void crypt_inc_pending(struct dm_crypt_io *io)
1064{
1065 atomic_inc(&io->io_pending);
1066}
1067
1068/*
1069 * One of the bios was finished. Check for completion of
1070 * the whole request and correctly clean up the buffer.
1071 */
1072static void crypt_dec_pending(struct dm_crypt_io *io)
1073{
1074 struct crypt_config *cc = io->cc;
1075 struct bio *base_bio = io->base_bio;
1076 int error = io->error;
1077
1078 if (!atomic_dec_and_test(&io->io_pending))
1079 return;
1080
1081 if (io->ctx.req)
1082 crypt_free_req(cc, io->ctx.req, base_bio);
1083
1084 base_bio->bi_error = error;
1085 bio_endio(base_bio);
1086}
1087
1088/*
1089 * kcryptd/kcryptd_io:
1090 *
1091 * Needed because it would be very unwise to do decryption in an
1092 * interrupt context.
1093 *
1094 * kcryptd performs the actual encryption or decryption.
1095 *
1096 * kcryptd_io performs the IO submission.
1097 *
1098 * They must be separated as otherwise the final stages could be
1099 * starved by new requests which can block in the first stages due
1100 * to memory allocation.
1101 *
1102 * The work is done per CPU global for all dm-crypt instances.
1103 * They should not depend on each other and do not block.
1104 */
1105static void crypt_endio(struct bio *clone)
1106{
1107 struct dm_crypt_io *io = clone->bi_private;
1108 struct crypt_config *cc = io->cc;
1109 unsigned rw = bio_data_dir(clone);
1110 int error;
1111
1112 /*
1113 * free the processed pages
1114 */
1115 if (rw == WRITE)
1116 crypt_free_buffer_pages(cc, clone);
1117
1118 error = clone->bi_error;
1119 bio_put(clone);
1120
1121 if (rw == READ && !error) {
1122 kcryptd_queue_crypt(io);
1123 return;
1124 }
1125
1126 if (unlikely(error))
1127 io->error = error;
1128
1129 crypt_dec_pending(io);
1130}
1131
1132static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1133{
1134 struct crypt_config *cc = io->cc;
1135
1136 clone->bi_private = io;
1137 clone->bi_end_io = crypt_endio;
1138 clone->bi_bdev = cc->dev->bdev;
1139 clone->bi_rw = io->base_bio->bi_rw;
1140}
1141
1142static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1143{
1144 struct crypt_config *cc = io->cc;
1145 struct bio *clone;
1146
1147 /*
1148 * We need the original biovec array in order to decrypt
1149 * the whole bio data *afterwards* -- thanks to immutable
1150 * biovecs we don't need to worry about the block layer
1151 * modifying the biovec array; so leverage bio_clone_fast().
1152 */
1153 clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1154 if (!clone)
1155 return 1;
1156
1157 crypt_inc_pending(io);
1158
1159 clone_init(io, clone);
1160 clone->bi_iter.bi_sector = cc->start + io->sector;
1161
1162 generic_make_request(clone);
1163 return 0;
1164}
1165
1166static void kcryptd_io_read_work(struct work_struct *work)
1167{
1168 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1169
1170 crypt_inc_pending(io);
1171 if (kcryptd_io_read(io, GFP_NOIO))
1172 io->error = -ENOMEM;
1173 crypt_dec_pending(io);
1174}
1175
1176static void kcryptd_queue_read(struct dm_crypt_io *io)
1177{
1178 struct crypt_config *cc = io->cc;
1179
1180 INIT_WORK(&io->work, kcryptd_io_read_work);
1181 queue_work(cc->io_queue, &io->work);
1182}
1183
1184static void kcryptd_io_write(struct dm_crypt_io *io)
1185{
1186 struct bio *clone = io->ctx.bio_out;
1187
1188 generic_make_request(clone);
1189}
1190
1191#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1192
1193static int dmcrypt_write(void *data)
1194{
1195 struct crypt_config *cc = data;
1196 struct dm_crypt_io *io;
1197
1198 while (1) {
1199 struct rb_root write_tree;
1200 struct blk_plug plug;
1201
1202 DECLARE_WAITQUEUE(wait, current);
1203
1204 spin_lock_irq(&cc->write_thread_wait.lock);
1205continue_locked:
1206
1207 if (!RB_EMPTY_ROOT(&cc->write_tree))
1208 goto pop_from_list;
1209
1210 if (unlikely(test_bit(DM_CRYPT_EXIT_THREAD, &cc->flags))) {
1211 spin_unlock_irq(&cc->write_thread_wait.lock);
1212 break;
1213 }
1214
1215 __set_current_state(TASK_INTERRUPTIBLE);
1216 __add_wait_queue(&cc->write_thread_wait, &wait);
1217
1218 spin_unlock_irq(&cc->write_thread_wait.lock);
1219
1220 schedule();
1221
1222 spin_lock_irq(&cc->write_thread_wait.lock);
1223 __remove_wait_queue(&cc->write_thread_wait, &wait);
1224 goto continue_locked;
1225
1226pop_from_list:
1227 write_tree = cc->write_tree;
1228 cc->write_tree = RB_ROOT;
1229 spin_unlock_irq(&cc->write_thread_wait.lock);
1230
1231 BUG_ON(rb_parent(write_tree.rb_node));
1232
1233 /*
1234 * Note: we cannot walk the tree here with rb_next because
1235 * the structures may be freed when kcryptd_io_write is called.
1236 */
1237 blk_start_plug(&plug);
1238 do {
1239 io = crypt_io_from_node(rb_first(&write_tree));
1240 rb_erase(&io->rb_node, &write_tree);
1241 kcryptd_io_write(io);
1242 } while (!RB_EMPTY_ROOT(&write_tree));
1243 blk_finish_plug(&plug);
1244 }
1245 return 0;
1246}
1247
1248static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1249{
1250 struct bio *clone = io->ctx.bio_out;
1251 struct crypt_config *cc = io->cc;
1252 unsigned long flags;
1253 sector_t sector;
1254 struct rb_node **rbp, *parent;
1255
1256 if (unlikely(io->error < 0)) {
1257 crypt_free_buffer_pages(cc, clone);
1258 bio_put(clone);
1259 crypt_dec_pending(io);
1260 return;
1261 }
1262
1263 /* crypt_convert should have filled the clone bio */
1264 BUG_ON(io->ctx.iter_out.bi_size);
1265
1266 clone->bi_iter.bi_sector = cc->start + io->sector;
1267
1268 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1269 generic_make_request(clone);
1270 return;
1271 }
1272
1273 spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1274 rbp = &cc->write_tree.rb_node;
1275 parent = NULL;
1276 sector = io->sector;
1277 while (*rbp) {
1278 parent = *rbp;
1279 if (sector < crypt_io_from_node(parent)->sector)
1280 rbp = &(*rbp)->rb_left;
1281 else
1282 rbp = &(*rbp)->rb_right;
1283 }
1284 rb_link_node(&io->rb_node, parent, rbp);
1285 rb_insert_color(&io->rb_node, &cc->write_tree);
1286
1287 wake_up_locked(&cc->write_thread_wait);
1288 spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1289}
1290
1291static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1292{
1293 struct crypt_config *cc = io->cc;
1294 struct bio *clone;
1295 int crypt_finished;
1296 sector_t sector = io->sector;
1297 int r;
1298
1299 /*
1300 * Prevent io from disappearing until this function completes.
1301 */
1302 crypt_inc_pending(io);
1303 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1304
1305 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1306 if (unlikely(!clone)) {
1307 io->error = -EIO;
1308 goto dec;
1309 }
1310
1311 io->ctx.bio_out = clone;
1312 io->ctx.iter_out = clone->bi_iter;
1313
1314 sector += bio_sectors(clone);
1315
1316 crypt_inc_pending(io);
1317 r = crypt_convert(cc, &io->ctx);
1318 if (r)
1319 io->error = -EIO;
1320 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1321
1322 /* Encryption was already finished, submit io now */
1323 if (crypt_finished) {
1324 kcryptd_crypt_write_io_submit(io, 0);
1325 io->sector = sector;
1326 }
1327
1328dec:
1329 crypt_dec_pending(io);
1330}
1331
1332static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1333{
1334 crypt_dec_pending(io);
1335}
1336
1337static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1338{
1339 struct crypt_config *cc = io->cc;
1340 int r = 0;
1341
1342 crypt_inc_pending(io);
1343
1344 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1345 io->sector);
1346
1347 r = crypt_convert(cc, &io->ctx);
1348 if (r < 0)
1349 io->error = -EIO;
1350
1351 if (atomic_dec_and_test(&io->ctx.cc_pending))
1352 kcryptd_crypt_read_done(io);
1353
1354 crypt_dec_pending(io);
1355}
1356
1357static void kcryptd_async_done(struct crypto_async_request *async_req,
1358 int error)
1359{
1360 struct dm_crypt_request *dmreq = async_req->data;
1361 struct convert_context *ctx = dmreq->ctx;
1362 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1363 struct crypt_config *cc = io->cc;
1364
1365 /*
1366 * A request from crypto driver backlog is going to be processed now,
1367 * finish the completion and continue in crypt_convert().
1368 * (Callback will be called for the second time for this request.)
1369 */
1370 if (error == -EINPROGRESS) {
1371 complete(&ctx->restart);
1372 return;
1373 }
1374
1375 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1376 error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1377
1378 if (error < 0)
1379 io->error = -EIO;
1380
1381 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1382
1383 if (!atomic_dec_and_test(&ctx->cc_pending))
1384 return;
1385
1386 if (bio_data_dir(io->base_bio) == READ)
1387 kcryptd_crypt_read_done(io);
1388 else
1389 kcryptd_crypt_write_io_submit(io, 1);
1390}
1391
1392static void kcryptd_crypt(struct work_struct *work)
1393{
1394 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1395
1396 if (bio_data_dir(io->base_bio) == READ)
1397 kcryptd_crypt_read_convert(io);
1398 else
1399 kcryptd_crypt_write_convert(io);
1400}
1401
1402static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1403{
1404 struct crypt_config *cc = io->cc;
1405
1406 INIT_WORK(&io->work, kcryptd_crypt);
1407 queue_work(cc->crypt_queue, &io->work);
1408}
1409
1410/*
1411 * Decode key from its hex representation
1412 */
1413static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1414{
1415 char buffer[3];
1416 unsigned int i;
1417
1418 buffer[2] = '\0';
1419
1420 for (i = 0; i < size; i++) {
1421 buffer[0] = *hex++;
1422 buffer[1] = *hex++;
1423
1424 if (kstrtou8(buffer, 16, &key[i]))
1425 return -EINVAL;
1426 }
1427
1428 if (*hex != '\0')
1429 return -EINVAL;
1430
1431 return 0;
1432}
1433
1434static void crypt_free_tfms(struct crypt_config *cc)
1435{
1436 unsigned i;
1437
1438 if (!cc->tfms)
1439 return;
1440
1441 for (i = 0; i < cc->tfms_count; i++)
1442 if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1443 crypto_free_skcipher(cc->tfms[i]);
1444 cc->tfms[i] = NULL;
1445 }
1446
1447 kfree(cc->tfms);
1448 cc->tfms = NULL;
1449}
1450
1451static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1452{
1453 unsigned i;
1454 int err;
1455
1456 cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
1457 GFP_KERNEL);
1458 if (!cc->tfms)
1459 return -ENOMEM;
1460
1461 for (i = 0; i < cc->tfms_count; i++) {
1462 cc->tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1463 if (IS_ERR(cc->tfms[i])) {
1464 err = PTR_ERR(cc->tfms[i]);
1465 crypt_free_tfms(cc);
1466 return err;
1467 }
1468 }
1469
1470 return 0;
1471}
1472
1473static int crypt_setkey_allcpus(struct crypt_config *cc)
1474{
1475 unsigned subkey_size;
1476 int err = 0, i, r;
1477
1478 /* Ignore extra keys (which are used for IV etc) */
1479 subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1480
1481 for (i = 0; i < cc->tfms_count; i++) {
1482 r = crypto_skcipher_setkey(cc->tfms[i],
1483 cc->key + (i * subkey_size),
1484 subkey_size);
1485 if (r)
1486 err = r;
1487 }
1488
1489 return err;
1490}
1491
1492static int crypt_set_key(struct crypt_config *cc, char *key)
1493{
1494 int r = -EINVAL;
1495 int key_string_len = strlen(key);
1496
1497 /* The key size may not be changed. */
1498 if (cc->key_size != (key_string_len >> 1))
1499 goto out;
1500
1501 /* Hyphen (which gives a key_size of zero) means there is no key. */
1502 if (!cc->key_size && strcmp(key, "-"))
1503 goto out;
1504
1505 if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1506 goto out;
1507
1508 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1509
1510 r = crypt_setkey_allcpus(cc);
1511
1512out:
1513 /* Hex key string not needed after here, so wipe it. */
1514 memset(key, '0', key_string_len);
1515
1516 return r;
1517}
1518
1519static int crypt_wipe_key(struct crypt_config *cc)
1520{
1521 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1522 memset(&cc->key, 0, cc->key_size * sizeof(u8));
1523
1524 return crypt_setkey_allcpus(cc);
1525}
1526
1527static void crypt_dtr(struct dm_target *ti)
1528{
1529 struct crypt_config *cc = ti->private;
1530
1531 ti->private = NULL;
1532
1533 if (!cc)
1534 return;
1535
1536 if (cc->write_thread) {
1537 spin_lock_irq(&cc->write_thread_wait.lock);
1538 set_bit(DM_CRYPT_EXIT_THREAD, &cc->flags);
1539 wake_up_locked(&cc->write_thread_wait);
1540 spin_unlock_irq(&cc->write_thread_wait.lock);
1541 kthread_stop(cc->write_thread);
1542 }
1543
1544 if (cc->io_queue)
1545 destroy_workqueue(cc->io_queue);
1546 if (cc->crypt_queue)
1547 destroy_workqueue(cc->crypt_queue);
1548
1549 crypt_free_tfms(cc);
1550
1551 if (cc->bs)
1552 bioset_free(cc->bs);
1553
1554 mempool_destroy(cc->page_pool);
1555 mempool_destroy(cc->req_pool);
1556
1557 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1558 cc->iv_gen_ops->dtr(cc);
1559
1560 if (cc->dev)
1561 dm_put_device(ti, cc->dev);
1562
1563 kzfree(cc->cipher);
1564 kzfree(cc->cipher_string);
1565
1566 /* Must zero key material before freeing */
1567 kzfree(cc);
1568}
1569
1570static int crypt_ctr_cipher(struct dm_target *ti,
1571 char *cipher_in, char *key)
1572{
1573 struct crypt_config *cc = ti->private;
1574 char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1575 char *cipher_api = NULL;
1576 int ret = -EINVAL;
1577 char dummy;
1578
1579 /* Convert to crypto api definition? */
1580 if (strchr(cipher_in, '(')) {
1581 ti->error = "Bad cipher specification";
1582 return -EINVAL;
1583 }
1584
1585 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1586 if (!cc->cipher_string)
1587 goto bad_mem;
1588
1589 /*
1590 * Legacy dm-crypt cipher specification
1591 * cipher[:keycount]-mode-iv:ivopts
1592 */
1593 tmp = cipher_in;
1594 keycount = strsep(&tmp, "-");
1595 cipher = strsep(&keycount, ":");
1596
1597 if (!keycount)
1598 cc->tfms_count = 1;
1599 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1600 !is_power_of_2(cc->tfms_count)) {
1601 ti->error = "Bad cipher key count specification";
1602 return -EINVAL;
1603 }
1604 cc->key_parts = cc->tfms_count;
1605 cc->key_extra_size = 0;
1606
1607 cc->cipher = kstrdup(cipher, GFP_KERNEL);
1608 if (!cc->cipher)
1609 goto bad_mem;
1610
1611 chainmode = strsep(&tmp, "-");
1612 ivopts = strsep(&tmp, "-");
1613 ivmode = strsep(&ivopts, ":");
1614
1615 if (tmp)
1616 DMWARN("Ignoring unexpected additional cipher options");
1617
1618 /*
1619 * For compatibility with the original dm-crypt mapping format, if
1620 * only the cipher name is supplied, use cbc-plain.
1621 */
1622 if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1623 chainmode = "cbc";
1624 ivmode = "plain";
1625 }
1626
1627 if (strcmp(chainmode, "ecb") && !ivmode) {
1628 ti->error = "IV mechanism required";
1629 return -EINVAL;
1630 }
1631
1632 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1633 if (!cipher_api)
1634 goto bad_mem;
1635
1636 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1637 "%s(%s)", chainmode, cipher);
1638 if (ret < 0) {
1639 kfree(cipher_api);
1640 goto bad_mem;
1641 }
1642
1643 /* Allocate cipher */
1644 ret = crypt_alloc_tfms(cc, cipher_api);
1645 if (ret < 0) {
1646 ti->error = "Error allocating crypto tfm";
1647 goto bad;
1648 }
1649
1650 /* Initialize IV */
1651 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
1652 if (cc->iv_size)
1653 /* at least a 64 bit sector number should fit in our buffer */
1654 cc->iv_size = max(cc->iv_size,
1655 (unsigned int)(sizeof(u64) / sizeof(u8)));
1656 else if (ivmode) {
1657 DMWARN("Selected cipher does not support IVs");
1658 ivmode = NULL;
1659 }
1660
1661 /* Choose ivmode, see comments at iv code. */
1662 if (ivmode == NULL)
1663 cc->iv_gen_ops = NULL;
1664 else if (strcmp(ivmode, "plain") == 0)
1665 cc->iv_gen_ops = &crypt_iv_plain_ops;
1666 else if (strcmp(ivmode, "plain64") == 0)
1667 cc->iv_gen_ops = &crypt_iv_plain64_ops;
1668 else if (strcmp(ivmode, "essiv") == 0)
1669 cc->iv_gen_ops = &crypt_iv_essiv_ops;
1670 else if (strcmp(ivmode, "benbi") == 0)
1671 cc->iv_gen_ops = &crypt_iv_benbi_ops;
1672 else if (strcmp(ivmode, "null") == 0)
1673 cc->iv_gen_ops = &crypt_iv_null_ops;
1674 else if (strcmp(ivmode, "lmk") == 0) {
1675 cc->iv_gen_ops = &crypt_iv_lmk_ops;
1676 /*
1677 * Version 2 and 3 is recognised according
1678 * to length of provided multi-key string.
1679 * If present (version 3), last key is used as IV seed.
1680 * All keys (including IV seed) are always the same size.
1681 */
1682 if (cc->key_size % cc->key_parts) {
1683 cc->key_parts++;
1684 cc->key_extra_size = cc->key_size / cc->key_parts;
1685 }
1686 } else if (strcmp(ivmode, "tcw") == 0) {
1687 cc->iv_gen_ops = &crypt_iv_tcw_ops;
1688 cc->key_parts += 2; /* IV + whitening */
1689 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1690 } else {
1691 ret = -EINVAL;
1692 ti->error = "Invalid IV mode";
1693 goto bad;
1694 }
1695
1696 /* Initialize and set key */
1697 ret = crypt_set_key(cc, key);
1698 if (ret < 0) {
1699 ti->error = "Error decoding and setting key";
1700 goto bad;
1701 }
1702
1703 /* Allocate IV */
1704 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1705 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1706 if (ret < 0) {
1707 ti->error = "Error creating IV";
1708 goto bad;
1709 }
1710 }
1711
1712 /* Initialize IV (set keys for ESSIV etc) */
1713 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1714 ret = cc->iv_gen_ops->init(cc);
1715 if (ret < 0) {
1716 ti->error = "Error initialising IV";
1717 goto bad;
1718 }
1719 }
1720
1721 ret = 0;
1722bad:
1723 kfree(cipher_api);
1724 return ret;
1725
1726bad_mem:
1727 ti->error = "Cannot allocate cipher strings";
1728 return -ENOMEM;
1729}
1730
1731/*
1732 * Construct an encryption mapping:
1733 * <cipher> <key> <iv_offset> <dev_path> <start>
1734 */
1735static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1736{
1737 struct crypt_config *cc;
1738 unsigned int key_size, opt_params;
1739 unsigned long long tmpll;
1740 int ret;
1741 size_t iv_size_padding;
1742 struct dm_arg_set as;
1743 const char *opt_string;
1744 char dummy;
1745
1746 static struct dm_arg _args[] = {
1747 {0, 3, "Invalid number of feature args"},
1748 };
1749
1750 if (argc < 5) {
1751 ti->error = "Not enough arguments";
1752 return -EINVAL;
1753 }
1754
1755 key_size = strlen(argv[1]) >> 1;
1756
1757 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1758 if (!cc) {
1759 ti->error = "Cannot allocate encryption context";
1760 return -ENOMEM;
1761 }
1762 cc->key_size = key_size;
1763
1764 ti->private = cc;
1765 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1766 if (ret < 0)
1767 goto bad;
1768
1769 cc->dmreq_start = sizeof(struct skcipher_request);
1770 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
1771 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1772
1773 if (crypto_skcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1774 /* Allocate the padding exactly */
1775 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1776 & crypto_skcipher_alignmask(any_tfm(cc));
1777 } else {
1778 /*
1779 * If the cipher requires greater alignment than kmalloc
1780 * alignment, we don't know the exact position of the
1781 * initialization vector. We must assume worst case.
1782 */
1783 iv_size_padding = crypto_skcipher_alignmask(any_tfm(cc));
1784 }
1785
1786 ret = -ENOMEM;
1787 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1788 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1789 if (!cc->req_pool) {
1790 ti->error = "Cannot allocate crypt request mempool";
1791 goto bad;
1792 }
1793
1794 cc->per_bio_data_size = ti->per_io_data_size =
1795 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1796 sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1797 ARCH_KMALLOC_MINALIGN);
1798
1799 cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1800 if (!cc->page_pool) {
1801 ti->error = "Cannot allocate page mempool";
1802 goto bad;
1803 }
1804
1805 cc->bs = bioset_create(MIN_IOS, 0);
1806 if (!cc->bs) {
1807 ti->error = "Cannot allocate crypt bioset";
1808 goto bad;
1809 }
1810
1811 mutex_init(&cc->bio_alloc_lock);
1812
1813 ret = -EINVAL;
1814 if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1815 ti->error = "Invalid iv_offset sector";
1816 goto bad;
1817 }
1818 cc->iv_offset = tmpll;
1819
1820 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
1821 if (ret) {
1822 ti->error = "Device lookup failed";
1823 goto bad;
1824 }
1825
1826 ret = -EINVAL;
1827 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1828 ti->error = "Invalid device sector";
1829 goto bad;
1830 }
1831 cc->start = tmpll;
1832
1833 argv += 5;
1834 argc -= 5;
1835
1836 /* Optional parameters */
1837 if (argc) {
1838 as.argc = argc;
1839 as.argv = argv;
1840
1841 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1842 if (ret)
1843 goto bad;
1844
1845 ret = -EINVAL;
1846 while (opt_params--) {
1847 opt_string = dm_shift_arg(&as);
1848 if (!opt_string) {
1849 ti->error = "Not enough feature arguments";
1850 goto bad;
1851 }
1852
1853 if (!strcasecmp(opt_string, "allow_discards"))
1854 ti->num_discard_bios = 1;
1855
1856 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1857 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1858
1859 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
1860 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1861
1862 else {
1863 ti->error = "Invalid feature arguments";
1864 goto bad;
1865 }
1866 }
1867 }
1868
1869 ret = -ENOMEM;
1870 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1871 if (!cc->io_queue) {
1872 ti->error = "Couldn't create kcryptd io queue";
1873 goto bad;
1874 }
1875
1876 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1877 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1878 else
1879 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
1880 num_online_cpus());
1881 if (!cc->crypt_queue) {
1882 ti->error = "Couldn't create kcryptd queue";
1883 goto bad;
1884 }
1885
1886 init_waitqueue_head(&cc->write_thread_wait);
1887 cc->write_tree = RB_ROOT;
1888
1889 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
1890 if (IS_ERR(cc->write_thread)) {
1891 ret = PTR_ERR(cc->write_thread);
1892 cc->write_thread = NULL;
1893 ti->error = "Couldn't spawn write thread";
1894 goto bad;
1895 }
1896 wake_up_process(cc->write_thread);
1897
1898 ti->num_flush_bios = 1;
1899 ti->discard_zeroes_data_unsupported = true;
1900
1901 return 0;
1902
1903bad:
1904 crypt_dtr(ti);
1905 return ret;
1906}
1907
1908static int crypt_map(struct dm_target *ti, struct bio *bio)
1909{
1910 struct dm_crypt_io *io;
1911 struct crypt_config *cc = ti->private;
1912
1913 /*
1914 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1915 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1916 * - for REQ_DISCARD caller must use flush if IO ordering matters
1917 */
1918 if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1919 bio->bi_bdev = cc->dev->bdev;
1920 if (bio_sectors(bio))
1921 bio->bi_iter.bi_sector = cc->start +
1922 dm_target_offset(ti, bio->bi_iter.bi_sector);
1923 return DM_MAPIO_REMAPPED;
1924 }
1925
1926 io = dm_per_bio_data(bio, cc->per_bio_data_size);
1927 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
1928 io->ctx.req = (struct skcipher_request *)(io + 1);
1929
1930 if (bio_data_dir(io->base_bio) == READ) {
1931 if (kcryptd_io_read(io, GFP_NOWAIT))
1932 kcryptd_queue_read(io);
1933 } else
1934 kcryptd_queue_crypt(io);
1935
1936 return DM_MAPIO_SUBMITTED;
1937}
1938
1939static void crypt_status(struct dm_target *ti, status_type_t type,
1940 unsigned status_flags, char *result, unsigned maxlen)
1941{
1942 struct crypt_config *cc = ti->private;
1943 unsigned i, sz = 0;
1944 int num_feature_args = 0;
1945
1946 switch (type) {
1947 case STATUSTYPE_INFO:
1948 result[0] = '\0';
1949 break;
1950
1951 case STATUSTYPE_TABLE:
1952 DMEMIT("%s ", cc->cipher_string);
1953
1954 if (cc->key_size > 0)
1955 for (i = 0; i < cc->key_size; i++)
1956 DMEMIT("%02x", cc->key[i]);
1957 else
1958 DMEMIT("-");
1959
1960 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1961 cc->dev->name, (unsigned long long)cc->start);
1962
1963 num_feature_args += !!ti->num_discard_bios;
1964 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1965 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1966 if (num_feature_args) {
1967 DMEMIT(" %d", num_feature_args);
1968 if (ti->num_discard_bios)
1969 DMEMIT(" allow_discards");
1970 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1971 DMEMIT(" same_cpu_crypt");
1972 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
1973 DMEMIT(" submit_from_crypt_cpus");
1974 }
1975
1976 break;
1977 }
1978}
1979
1980static void crypt_postsuspend(struct dm_target *ti)
1981{
1982 struct crypt_config *cc = ti->private;
1983
1984 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1985}
1986
1987static int crypt_preresume(struct dm_target *ti)
1988{
1989 struct crypt_config *cc = ti->private;
1990
1991 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1992 DMERR("aborting resume - crypt key is not set.");
1993 return -EAGAIN;
1994 }
1995
1996 return 0;
1997}
1998
1999static void crypt_resume(struct dm_target *ti)
2000{
2001 struct crypt_config *cc = ti->private;
2002
2003 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2004}
2005
2006/* Message interface
2007 * key set <key>
2008 * key wipe
2009 */
2010static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
2011{
2012 struct crypt_config *cc = ti->private;
2013 int ret = -EINVAL;
2014
2015 if (argc < 2)
2016 goto error;
2017
2018 if (!strcasecmp(argv[0], "key")) {
2019 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2020 DMWARN("not suspended during key manipulation.");
2021 return -EINVAL;
2022 }
2023 if (argc == 3 && !strcasecmp(argv[1], "set")) {
2024 ret = crypt_set_key(cc, argv[2]);
2025 if (ret)
2026 return ret;
2027 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2028 ret = cc->iv_gen_ops->init(cc);
2029 return ret;
2030 }
2031 if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
2032 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2033 ret = cc->iv_gen_ops->wipe(cc);
2034 if (ret)
2035 return ret;
2036 }
2037 return crypt_wipe_key(cc);
2038 }
2039 }
2040
2041error:
2042 DMWARN("unrecognised message received.");
2043 return -EINVAL;
2044}
2045
2046static int crypt_iterate_devices(struct dm_target *ti,
2047 iterate_devices_callout_fn fn, void *data)
2048{
2049 struct crypt_config *cc = ti->private;
2050
2051 return fn(ti, cc->dev, cc->start, ti->len, data);
2052}
2053
2054static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
2055{
2056 /*
2057 * Unfortunate constraint that is required to avoid the potential
2058 * for exceeding underlying device's max_segments limits -- due to
2059 * crypt_alloc_buffer() possibly allocating pages for the encryption
2060 * bio that are not as physically contiguous as the original bio.
2061 */
2062 limits->max_segment_size = PAGE_SIZE;
2063}
2064
2065static struct target_type crypt_target = {
2066 .name = "crypt",
2067 .version = {1, 14, 1},
2068 .module = THIS_MODULE,
2069 .ctr = crypt_ctr,
2070 .dtr = crypt_dtr,
2071 .map = crypt_map,
2072 .status = crypt_status,
2073 .postsuspend = crypt_postsuspend,
2074 .preresume = crypt_preresume,
2075 .resume = crypt_resume,
2076 .message = crypt_message,
2077 .iterate_devices = crypt_iterate_devices,
2078 .io_hints = crypt_io_hints,
2079};
2080
2081static int __init dm_crypt_init(void)
2082{
2083 int r;
2084
2085 r = dm_register_target(&crypt_target);
2086 if (r < 0)
2087 DMERR("register failed %d", r);
2088
2089 return r;
2090}
2091
2092static void __exit dm_crypt_exit(void)
2093{
2094 dm_unregister_target(&crypt_target);
2095}
2096
2097module_init(dm_crypt_init);
2098module_exit(dm_crypt_exit);
2099
2100MODULE_AUTHOR("Jana Saout <jana@saout.de>");
2101MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2102MODULE_LICENSE("GPL");