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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2003 Jana Saout <jana@saout.de>
4 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
5 * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved.
6 * Copyright (C) 2013-2020 Milan Broz <gmazyland@gmail.com>
7 *
8 * This file is released under the GPL.
9 */
10
11#include <linux/completion.h>
12#include <linux/err.h>
13#include <linux/module.h>
14#include <linux/init.h>
15#include <linux/kernel.h>
16#include <linux/key.h>
17#include <linux/bio.h>
18#include <linux/blkdev.h>
19#include <linux/blk-integrity.h>
20#include <linux/mempool.h>
21#include <linux/slab.h>
22#include <linux/crypto.h>
23#include <linux/workqueue.h>
24#include <linux/kthread.h>
25#include <linux/backing-dev.h>
26#include <linux/atomic.h>
27#include <linux/scatterlist.h>
28#include <linux/rbtree.h>
29#include <linux/ctype.h>
30#include <asm/page.h>
31#include <linux/unaligned.h>
32#include <crypto/hash.h>
33#include <crypto/md5.h>
34#include <crypto/skcipher.h>
35#include <crypto/aead.h>
36#include <crypto/authenc.h>
37#include <crypto/utils.h>
38#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
39#include <linux/key-type.h>
40#include <keys/user-type.h>
41#include <keys/encrypted-type.h>
42#include <keys/trusted-type.h>
43
44#include <linux/device-mapper.h>
45
46#include "dm-audit.h"
47
48#define DM_MSG_PREFIX "crypt"
49
50static DEFINE_IDA(workqueue_ida);
51
52/*
53 * context holding the current state of a multi-part conversion
54 */
55struct convert_context {
56 struct completion restart;
57 struct bio *bio_in;
58 struct bvec_iter iter_in;
59 struct bio *bio_out;
60 struct bvec_iter iter_out;
61 atomic_t cc_pending;
62 unsigned int tag_offset;
63 u64 cc_sector;
64 union {
65 struct skcipher_request *req;
66 struct aead_request *req_aead;
67 } r;
68 bool aead_recheck;
69 bool aead_failed;
70
71};
72
73/*
74 * per bio private data
75 */
76struct dm_crypt_io {
77 struct crypt_config *cc;
78 struct bio *base_bio;
79 u8 *integrity_metadata;
80 bool integrity_metadata_from_pool:1;
81
82 struct work_struct work;
83
84 struct convert_context ctx;
85
86 atomic_t io_pending;
87 blk_status_t error;
88 sector_t sector;
89
90 struct bvec_iter saved_bi_iter;
91
92 struct rb_node rb_node;
93} CRYPTO_MINALIGN_ATTR;
94
95struct dm_crypt_request {
96 struct convert_context *ctx;
97 struct scatterlist sg_in[4];
98 struct scatterlist sg_out[4];
99 u64 iv_sector;
100};
101
102struct crypt_config;
103
104struct crypt_iv_operations {
105 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
106 const char *opts);
107 void (*dtr)(struct crypt_config *cc);
108 int (*init)(struct crypt_config *cc);
109 int (*wipe)(struct crypt_config *cc);
110 int (*generator)(struct crypt_config *cc, u8 *iv,
111 struct dm_crypt_request *dmreq);
112 int (*post)(struct crypt_config *cc, u8 *iv,
113 struct dm_crypt_request *dmreq);
114};
115
116struct iv_benbi_private {
117 int shift;
118};
119
120#define LMK_SEED_SIZE 64 /* hash + 0 */
121struct iv_lmk_private {
122 struct crypto_shash *hash_tfm;
123 u8 *seed;
124};
125
126#define TCW_WHITENING_SIZE 16
127struct iv_tcw_private {
128 struct crypto_shash *crc32_tfm;
129 u8 *iv_seed;
130 u8 *whitening;
131};
132
133#define ELEPHANT_MAX_KEY_SIZE 32
134struct iv_elephant_private {
135 struct crypto_skcipher *tfm;
136};
137
138/*
139 * Crypt: maps a linear range of a block device
140 * and encrypts / decrypts at the same time.
141 */
142enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
143 DM_CRYPT_SAME_CPU, DM_CRYPT_HIGH_PRIORITY,
144 DM_CRYPT_NO_OFFLOAD, DM_CRYPT_NO_READ_WORKQUEUE,
145 DM_CRYPT_NO_WRITE_WORKQUEUE, DM_CRYPT_WRITE_INLINE };
146
147enum cipher_flags {
148 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cipher */
149 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */
150 CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */
151 CRYPT_KEY_MAC_SIZE_SET, /* The integrity_key_size option was used */
152};
153
154/*
155 * The fields in here must be read only after initialization.
156 */
157struct crypt_config {
158 struct dm_dev *dev;
159 sector_t start;
160
161 struct percpu_counter n_allocated_pages;
162
163 struct workqueue_struct *io_queue;
164 struct workqueue_struct *crypt_queue;
165
166 spinlock_t write_thread_lock;
167 struct task_struct *write_thread;
168 struct rb_root write_tree;
169
170 char *cipher_string;
171 char *cipher_auth;
172 char *key_string;
173
174 const struct crypt_iv_operations *iv_gen_ops;
175 union {
176 struct iv_benbi_private benbi;
177 struct iv_lmk_private lmk;
178 struct iv_tcw_private tcw;
179 struct iv_elephant_private elephant;
180 } iv_gen_private;
181 u64 iv_offset;
182 unsigned int iv_size;
183 unsigned short sector_size;
184 unsigned char sector_shift;
185
186 union {
187 struct crypto_skcipher **tfms;
188 struct crypto_aead **tfms_aead;
189 } cipher_tfm;
190 unsigned int tfms_count;
191 int workqueue_id;
192 unsigned long cipher_flags;
193
194 /*
195 * Layout of each crypto request:
196 *
197 * struct skcipher_request
198 * context
199 * padding
200 * struct dm_crypt_request
201 * padding
202 * IV
203 *
204 * The padding is added so that dm_crypt_request and the IV are
205 * correctly aligned.
206 */
207 unsigned int dmreq_start;
208
209 unsigned int per_bio_data_size;
210
211 unsigned long flags;
212 unsigned int key_size;
213 unsigned int key_parts; /* independent parts in key buffer */
214 unsigned int key_extra_size; /* additional keys length */
215 unsigned int key_mac_size; /* MAC key size for authenc(...) */
216
217 unsigned int integrity_tag_size;
218 unsigned int integrity_iv_size;
219 unsigned int used_tag_size;
220 unsigned int tuple_size;
221
222 /*
223 * pool for per bio private data, crypto requests,
224 * encryption requeusts/buffer pages and integrity tags
225 */
226 unsigned int tag_pool_max_sectors;
227 mempool_t tag_pool;
228 mempool_t req_pool;
229 mempool_t page_pool;
230
231 struct bio_set bs;
232 struct mutex bio_alloc_lock;
233
234 u8 *authenc_key; /* space for keys in authenc() format (if used) */
235 u8 key[] __counted_by(key_size);
236};
237
238#define MIN_IOS 64
239#define MAX_TAG_SIZE 480
240#define POOL_ENTRY_SIZE 512
241
242static DEFINE_SPINLOCK(dm_crypt_clients_lock);
243static unsigned int dm_crypt_clients_n;
244static volatile unsigned long dm_crypt_pages_per_client;
245#define DM_CRYPT_MEMORY_PERCENT 2
246#define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16)
247#define DM_CRYPT_DEFAULT_MAX_READ_SIZE 131072
248#define DM_CRYPT_DEFAULT_MAX_WRITE_SIZE 131072
249
250static unsigned int max_read_size = 0;
251module_param(max_read_size, uint, 0644);
252MODULE_PARM_DESC(max_read_size, "Maximum size of a read request");
253static unsigned int max_write_size = 0;
254module_param(max_write_size, uint, 0644);
255MODULE_PARM_DESC(max_write_size, "Maximum size of a write request");
256static unsigned get_max_request_size(struct crypt_config *cc, bool wrt)
257{
258 unsigned val, sector_align;
259 val = !wrt ? READ_ONCE(max_read_size) : READ_ONCE(max_write_size);
260 if (likely(!val))
261 val = !wrt ? DM_CRYPT_DEFAULT_MAX_READ_SIZE : DM_CRYPT_DEFAULT_MAX_WRITE_SIZE;
262 if (wrt || cc->used_tag_size) {
263 if (unlikely(val > BIO_MAX_VECS << PAGE_SHIFT))
264 val = BIO_MAX_VECS << PAGE_SHIFT;
265 }
266 sector_align = max(bdev_logical_block_size(cc->dev->bdev), (unsigned)cc->sector_size);
267 val = round_down(val, sector_align);
268 if (unlikely(!val))
269 val = sector_align;
270 return val >> SECTOR_SHIFT;
271}
272
273static void crypt_endio(struct bio *clone);
274static void kcryptd_queue_crypt(struct dm_crypt_io *io);
275static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
276 struct scatterlist *sg);
277
278static bool crypt_integrity_aead(struct crypt_config *cc);
279
280/*
281 * Use this to access cipher attributes that are independent of the key.
282 */
283static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
284{
285 return cc->cipher_tfm.tfms[0];
286}
287
288static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
289{
290 return cc->cipher_tfm.tfms_aead[0];
291}
292
293/*
294 * Different IV generation algorithms:
295 *
296 * plain: the initial vector is the 32-bit little-endian version of the sector
297 * number, padded with zeros if necessary.
298 *
299 * plain64: the initial vector is the 64-bit little-endian version of the sector
300 * number, padded with zeros if necessary.
301 *
302 * plain64be: the initial vector is the 64-bit big-endian version of the sector
303 * number, padded with zeros if necessary.
304 *
305 * essiv: "encrypted sector|salt initial vector", the sector number is
306 * encrypted with the bulk cipher using a salt as key. The salt
307 * should be derived from the bulk cipher's key via hashing.
308 *
309 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
310 * (needed for LRW-32-AES and possible other narrow block modes)
311 *
312 * null: the initial vector is always zero. Provides compatibility with
313 * obsolete loop_fish2 devices. Do not use for new devices.
314 *
315 * lmk: Compatible implementation of the block chaining mode used
316 * by the Loop-AES block device encryption system
317 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
318 * It operates on full 512 byte sectors and uses CBC
319 * with an IV derived from the sector number, the data and
320 * optionally extra IV seed.
321 * This means that after decryption the first block
322 * of sector must be tweaked according to decrypted data.
323 * Loop-AES can use three encryption schemes:
324 * version 1: is plain aes-cbc mode
325 * version 2: uses 64 multikey scheme with lmk IV generator
326 * version 3: the same as version 2 with additional IV seed
327 * (it uses 65 keys, last key is used as IV seed)
328 *
329 * tcw: Compatible implementation of the block chaining mode used
330 * by the TrueCrypt device encryption system (prior to version 4.1).
331 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
332 * It operates on full 512 byte sectors and uses CBC
333 * with an IV derived from initial key and the sector number.
334 * In addition, whitening value is applied on every sector, whitening
335 * is calculated from initial key, sector number and mixed using CRC32.
336 * Note that this encryption scheme is vulnerable to watermarking attacks
337 * and should be used for old compatible containers access only.
338 *
339 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
340 * The IV is encrypted little-endian byte-offset (with the same key
341 * and cipher as the volume).
342 *
343 * elephant: The extended version of eboiv with additional Elephant diffuser
344 * used with Bitlocker CBC mode.
345 * This mode was used in older Windows systems
346 * https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
347 */
348
349static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
350 struct dm_crypt_request *dmreq)
351{
352 memset(iv, 0, cc->iv_size);
353 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
354
355 return 0;
356}
357
358static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
359 struct dm_crypt_request *dmreq)
360{
361 memset(iv, 0, cc->iv_size);
362 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
363
364 return 0;
365}
366
367static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
368 struct dm_crypt_request *dmreq)
369{
370 memset(iv, 0, cc->iv_size);
371 /* iv_size is at least of size u64; usually it is 16 bytes */
372 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
373
374 return 0;
375}
376
377static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
378 struct dm_crypt_request *dmreq)
379{
380 /*
381 * ESSIV encryption of the IV is now handled by the crypto API,
382 * so just pass the plain sector number here.
383 */
384 memset(iv, 0, cc->iv_size);
385 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
386
387 return 0;
388}
389
390static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
391 const char *opts)
392{
393 unsigned int bs;
394 int log;
395
396 if (crypt_integrity_aead(cc))
397 bs = crypto_aead_blocksize(any_tfm_aead(cc));
398 else
399 bs = crypto_skcipher_blocksize(any_tfm(cc));
400 log = ilog2(bs);
401
402 /*
403 * We need to calculate how far we must shift the sector count
404 * to get the cipher block count, we use this shift in _gen.
405 */
406 if (1 << log != bs) {
407 ti->error = "cypher blocksize is not a power of 2";
408 return -EINVAL;
409 }
410
411 if (log > 9) {
412 ti->error = "cypher blocksize is > 512";
413 return -EINVAL;
414 }
415
416 cc->iv_gen_private.benbi.shift = 9 - log;
417
418 return 0;
419}
420
421static void crypt_iv_benbi_dtr(struct crypt_config *cc)
422{
423}
424
425static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
426 struct dm_crypt_request *dmreq)
427{
428 __be64 val;
429
430 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
431
432 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
433 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
434
435 return 0;
436}
437
438static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
439 struct dm_crypt_request *dmreq)
440{
441 memset(iv, 0, cc->iv_size);
442
443 return 0;
444}
445
446static void crypt_iv_lmk_dtr(struct crypt_config *cc)
447{
448 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
449
450 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
451 crypto_free_shash(lmk->hash_tfm);
452 lmk->hash_tfm = NULL;
453
454 kfree_sensitive(lmk->seed);
455 lmk->seed = NULL;
456}
457
458static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
459 const char *opts)
460{
461 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
462
463 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
464 ti->error = "Unsupported sector size for LMK";
465 return -EINVAL;
466 }
467
468 lmk->hash_tfm = crypto_alloc_shash("md5", 0,
469 CRYPTO_ALG_ALLOCATES_MEMORY);
470 if (IS_ERR(lmk->hash_tfm)) {
471 ti->error = "Error initializing LMK hash";
472 return PTR_ERR(lmk->hash_tfm);
473 }
474
475 /* No seed in LMK version 2 */
476 if (cc->key_parts == cc->tfms_count) {
477 lmk->seed = NULL;
478 return 0;
479 }
480
481 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
482 if (!lmk->seed) {
483 crypt_iv_lmk_dtr(cc);
484 ti->error = "Error kmallocing seed storage in LMK";
485 return -ENOMEM;
486 }
487
488 return 0;
489}
490
491static int crypt_iv_lmk_init(struct crypt_config *cc)
492{
493 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
494 int subkey_size = cc->key_size / cc->key_parts;
495
496 /* LMK seed is on the position of LMK_KEYS + 1 key */
497 if (lmk->seed)
498 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
499 crypto_shash_digestsize(lmk->hash_tfm));
500
501 return 0;
502}
503
504static int crypt_iv_lmk_wipe(struct crypt_config *cc)
505{
506 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
507
508 if (lmk->seed)
509 memset(lmk->seed, 0, LMK_SEED_SIZE);
510
511 return 0;
512}
513
514static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
515 struct dm_crypt_request *dmreq,
516 u8 *data)
517{
518 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
519 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
520 struct md5_state md5state;
521 __le32 buf[4];
522 int i, r;
523
524 desc->tfm = lmk->hash_tfm;
525
526 r = crypto_shash_init(desc);
527 if (r)
528 return r;
529
530 if (lmk->seed) {
531 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
532 if (r)
533 return r;
534 }
535
536 /* Sector is always 512B, block size 16, add data of blocks 1-31 */
537 r = crypto_shash_update(desc, data + 16, 16 * 31);
538 if (r)
539 return r;
540
541 /* Sector is cropped to 56 bits here */
542 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
543 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
544 buf[2] = cpu_to_le32(4024);
545 buf[3] = 0;
546 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
547 if (r)
548 return r;
549
550 /* No MD5 padding here */
551 r = crypto_shash_export(desc, &md5state);
552 if (r)
553 return r;
554
555 for (i = 0; i < MD5_HASH_WORDS; i++)
556 __cpu_to_le32s(&md5state.hash[i]);
557 memcpy(iv, &md5state.hash, cc->iv_size);
558
559 return 0;
560}
561
562static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
563 struct dm_crypt_request *dmreq)
564{
565 struct scatterlist *sg;
566 u8 *src;
567 int r = 0;
568
569 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
570 sg = crypt_get_sg_data(cc, dmreq->sg_in);
571 src = kmap_local_page(sg_page(sg));
572 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
573 kunmap_local(src);
574 } else
575 memset(iv, 0, cc->iv_size);
576
577 return r;
578}
579
580static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
581 struct dm_crypt_request *dmreq)
582{
583 struct scatterlist *sg;
584 u8 *dst;
585 int r;
586
587 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
588 return 0;
589
590 sg = crypt_get_sg_data(cc, dmreq->sg_out);
591 dst = kmap_local_page(sg_page(sg));
592 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
593
594 /* Tweak the first block of plaintext sector */
595 if (!r)
596 crypto_xor(dst + sg->offset, iv, cc->iv_size);
597
598 kunmap_local(dst);
599 return r;
600}
601
602static void crypt_iv_tcw_dtr(struct crypt_config *cc)
603{
604 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
605
606 kfree_sensitive(tcw->iv_seed);
607 tcw->iv_seed = NULL;
608 kfree_sensitive(tcw->whitening);
609 tcw->whitening = NULL;
610
611 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
612 crypto_free_shash(tcw->crc32_tfm);
613 tcw->crc32_tfm = NULL;
614}
615
616static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
617 const char *opts)
618{
619 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
620
621 if (cc->sector_size != (1 << SECTOR_SHIFT)) {
622 ti->error = "Unsupported sector size for TCW";
623 return -EINVAL;
624 }
625
626 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
627 ti->error = "Wrong key size for TCW";
628 return -EINVAL;
629 }
630
631 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0,
632 CRYPTO_ALG_ALLOCATES_MEMORY);
633 if (IS_ERR(tcw->crc32_tfm)) {
634 ti->error = "Error initializing CRC32 in TCW";
635 return PTR_ERR(tcw->crc32_tfm);
636 }
637
638 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
639 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
640 if (!tcw->iv_seed || !tcw->whitening) {
641 crypt_iv_tcw_dtr(cc);
642 ti->error = "Error allocating seed storage in TCW";
643 return -ENOMEM;
644 }
645
646 return 0;
647}
648
649static int crypt_iv_tcw_init(struct crypt_config *cc)
650{
651 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
652 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
653
654 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
655 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
656 TCW_WHITENING_SIZE);
657
658 return 0;
659}
660
661static int crypt_iv_tcw_wipe(struct crypt_config *cc)
662{
663 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
664
665 memset(tcw->iv_seed, 0, cc->iv_size);
666 memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
667
668 return 0;
669}
670
671static int crypt_iv_tcw_whitening(struct crypt_config *cc,
672 struct dm_crypt_request *dmreq,
673 u8 *data)
674{
675 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
676 __le64 sector = cpu_to_le64(dmreq->iv_sector);
677 u8 buf[TCW_WHITENING_SIZE];
678 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
679 int i, r;
680
681 /* xor whitening with sector number */
682 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8);
683 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8);
684
685 /* calculate crc32 for every 32bit part and xor it */
686 desc->tfm = tcw->crc32_tfm;
687 for (i = 0; i < 4; i++) {
688 r = crypto_shash_digest(desc, &buf[i * 4], 4, &buf[i * 4]);
689 if (r)
690 goto out;
691 }
692 crypto_xor(&buf[0], &buf[12], 4);
693 crypto_xor(&buf[4], &buf[8], 4);
694
695 /* apply whitening (8 bytes) to whole sector */
696 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
697 crypto_xor(data + i * 8, buf, 8);
698out:
699 memzero_explicit(buf, sizeof(buf));
700 return r;
701}
702
703static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
704 struct dm_crypt_request *dmreq)
705{
706 struct scatterlist *sg;
707 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
708 __le64 sector = cpu_to_le64(dmreq->iv_sector);
709 u8 *src;
710 int r = 0;
711
712 /* Remove whitening from ciphertext */
713 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
714 sg = crypt_get_sg_data(cc, dmreq->sg_in);
715 src = kmap_local_page(sg_page(sg));
716 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
717 kunmap_local(src);
718 }
719
720 /* Calculate IV */
721 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8);
722 if (cc->iv_size > 8)
723 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or,
724 cc->iv_size - 8);
725
726 return r;
727}
728
729static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
730 struct dm_crypt_request *dmreq)
731{
732 struct scatterlist *sg;
733 u8 *dst;
734 int r;
735
736 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
737 return 0;
738
739 /* Apply whitening on ciphertext */
740 sg = crypt_get_sg_data(cc, dmreq->sg_out);
741 dst = kmap_local_page(sg_page(sg));
742 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
743 kunmap_local(dst);
744
745 return r;
746}
747
748static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
749 struct dm_crypt_request *dmreq)
750{
751 /* Used only for writes, there must be an additional space to store IV */
752 get_random_bytes(iv, cc->iv_size);
753 return 0;
754}
755
756static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti,
757 const char *opts)
758{
759 if (crypt_integrity_aead(cc)) {
760 ti->error = "AEAD transforms not supported for EBOIV";
761 return -EINVAL;
762 }
763
764 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
765 ti->error = "Block size of EBOIV cipher does not match IV size of block cipher";
766 return -EINVAL;
767 }
768
769 return 0;
770}
771
772static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
773 struct dm_crypt_request *dmreq)
774{
775 struct crypto_skcipher *tfm = any_tfm(cc);
776 struct skcipher_request *req;
777 struct scatterlist src, dst;
778 DECLARE_CRYPTO_WAIT(wait);
779 unsigned int reqsize;
780 int err;
781 u8 *buf;
782
783 reqsize = sizeof(*req) + crypto_skcipher_reqsize(tfm);
784 reqsize = ALIGN(reqsize, __alignof__(__le64));
785
786 req = kmalloc(reqsize + cc->iv_size, GFP_NOIO);
787 if (!req)
788 return -ENOMEM;
789
790 skcipher_request_set_tfm(req, tfm);
791
792 buf = (u8 *)req + reqsize;
793 memset(buf, 0, cc->iv_size);
794 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
795
796 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
797 sg_init_one(&dst, iv, cc->iv_size);
798 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
799 skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
800 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
801 kfree_sensitive(req);
802
803 return err;
804}
805
806static void crypt_iv_elephant_dtr(struct crypt_config *cc)
807{
808 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
809
810 crypto_free_skcipher(elephant->tfm);
811 elephant->tfm = NULL;
812}
813
814static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti,
815 const char *opts)
816{
817 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
818 int r;
819
820 elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0,
821 CRYPTO_ALG_ALLOCATES_MEMORY);
822 if (IS_ERR(elephant->tfm)) {
823 r = PTR_ERR(elephant->tfm);
824 elephant->tfm = NULL;
825 return r;
826 }
827
828 r = crypt_iv_eboiv_ctr(cc, ti, NULL);
829 if (r)
830 crypt_iv_elephant_dtr(cc);
831 return r;
832}
833
834static void diffuser_disk_to_cpu(u32 *d, size_t n)
835{
836#ifndef __LITTLE_ENDIAN
837 int i;
838
839 for (i = 0; i < n; i++)
840 d[i] = le32_to_cpu((__le32)d[i]);
841#endif
842}
843
844static void diffuser_cpu_to_disk(__le32 *d, size_t n)
845{
846#ifndef __LITTLE_ENDIAN
847 int i;
848
849 for (i = 0; i < n; i++)
850 d[i] = cpu_to_le32((u32)d[i]);
851#endif
852}
853
854static void diffuser_a_decrypt(u32 *d, size_t n)
855{
856 int i, i1, i2, i3;
857
858 for (i = 0; i < 5; i++) {
859 i1 = 0;
860 i2 = n - 2;
861 i3 = n - 5;
862
863 while (i1 < (n - 1)) {
864 d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
865 i1++; i2++; i3++;
866
867 if (i3 >= n)
868 i3 -= n;
869
870 d[i1] += d[i2] ^ d[i3];
871 i1++; i2++; i3++;
872
873 if (i2 >= n)
874 i2 -= n;
875
876 d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
877 i1++; i2++; i3++;
878
879 d[i1] += d[i2] ^ d[i3];
880 i1++; i2++; i3++;
881 }
882 }
883}
884
885static void diffuser_a_encrypt(u32 *d, size_t n)
886{
887 int i, i1, i2, i3;
888
889 for (i = 0; i < 5; i++) {
890 i1 = n - 1;
891 i2 = n - 2 - 1;
892 i3 = n - 5 - 1;
893
894 while (i1 > 0) {
895 d[i1] -= d[i2] ^ d[i3];
896 i1--; i2--; i3--;
897
898 d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
899 i1--; i2--; i3--;
900
901 if (i2 < 0)
902 i2 += n;
903
904 d[i1] -= d[i2] ^ d[i3];
905 i1--; i2--; i3--;
906
907 if (i3 < 0)
908 i3 += n;
909
910 d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
911 i1--; i2--; i3--;
912 }
913 }
914}
915
916static void diffuser_b_decrypt(u32 *d, size_t n)
917{
918 int i, i1, i2, i3;
919
920 for (i = 0; i < 3; i++) {
921 i1 = 0;
922 i2 = 2;
923 i3 = 5;
924
925 while (i1 < (n - 1)) {
926 d[i1] += d[i2] ^ d[i3];
927 i1++; i2++; i3++;
928
929 d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
930 i1++; i2++; i3++;
931
932 if (i2 >= n)
933 i2 -= n;
934
935 d[i1] += d[i2] ^ d[i3];
936 i1++; i2++; i3++;
937
938 if (i3 >= n)
939 i3 -= n;
940
941 d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
942 i1++; i2++; i3++;
943 }
944 }
945}
946
947static void diffuser_b_encrypt(u32 *d, size_t n)
948{
949 int i, i1, i2, i3;
950
951 for (i = 0; i < 3; i++) {
952 i1 = n - 1;
953 i2 = 2 - 1;
954 i3 = 5 - 1;
955
956 while (i1 > 0) {
957 d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
958 i1--; i2--; i3--;
959
960 if (i3 < 0)
961 i3 += n;
962
963 d[i1] -= d[i2] ^ d[i3];
964 i1--; i2--; i3--;
965
966 if (i2 < 0)
967 i2 += n;
968
969 d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
970 i1--; i2--; i3--;
971
972 d[i1] -= d[i2] ^ d[i3];
973 i1--; i2--; i3--;
974 }
975 }
976}
977
978static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq)
979{
980 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
981 u8 *es, *ks, *data, *data2, *data_offset;
982 struct skcipher_request *req;
983 struct scatterlist *sg, *sg2, src, dst;
984 DECLARE_CRYPTO_WAIT(wait);
985 int i, r;
986
987 req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
988 es = kzalloc(16, GFP_NOIO); /* Key for AES */
989 ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */
990
991 if (!req || !es || !ks) {
992 r = -ENOMEM;
993 goto out;
994 }
995
996 *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
997
998 /* E(Ks, e(s)) */
999 sg_init_one(&src, es, 16);
1000 sg_init_one(&dst, ks, 16);
1001 skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
1002 skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
1003 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
1004 if (r)
1005 goto out;
1006
1007 /* E(Ks, e'(s)) */
1008 es[15] = 0x80;
1009 sg_init_one(&dst, &ks[16], 16);
1010 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
1011 if (r)
1012 goto out;
1013
1014 sg = crypt_get_sg_data(cc, dmreq->sg_out);
1015 data = kmap_local_page(sg_page(sg));
1016 data_offset = data + sg->offset;
1017
1018 /* Cannot modify original bio, copy to sg_out and apply Elephant to it */
1019 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1020 sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
1021 data2 = kmap_local_page(sg_page(sg2));
1022 memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
1023 kunmap_local(data2);
1024 }
1025
1026 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
1027 diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32));
1028 diffuser_b_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1029 diffuser_a_decrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1030 diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32));
1031 }
1032
1033 for (i = 0; i < (cc->sector_size / 32); i++)
1034 crypto_xor(data_offset + i * 32, ks, 32);
1035
1036 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1037 diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size / sizeof(u32));
1038 diffuser_a_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1039 diffuser_b_encrypt((u32 *)data_offset, cc->sector_size / sizeof(u32));
1040 diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size / sizeof(u32));
1041 }
1042
1043 kunmap_local(data);
1044out:
1045 kfree_sensitive(ks);
1046 kfree_sensitive(es);
1047 skcipher_request_free(req);
1048 return r;
1049}
1050
1051static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv,
1052 struct dm_crypt_request *dmreq)
1053{
1054 int r;
1055
1056 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1057 r = crypt_iv_elephant(cc, dmreq);
1058 if (r)
1059 return r;
1060 }
1061
1062 return crypt_iv_eboiv_gen(cc, iv, dmreq);
1063}
1064
1065static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv,
1066 struct dm_crypt_request *dmreq)
1067{
1068 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
1069 return crypt_iv_elephant(cc, dmreq);
1070
1071 return 0;
1072}
1073
1074static int crypt_iv_elephant_init(struct crypt_config *cc)
1075{
1076 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1077 int key_offset = cc->key_size - cc->key_extra_size;
1078
1079 return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
1080}
1081
1082static int crypt_iv_elephant_wipe(struct crypt_config *cc)
1083{
1084 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1085 u8 key[ELEPHANT_MAX_KEY_SIZE];
1086
1087 memset(key, 0, cc->key_extra_size);
1088 return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
1089}
1090
1091static const struct crypt_iv_operations crypt_iv_plain_ops = {
1092 .generator = crypt_iv_plain_gen
1093};
1094
1095static const struct crypt_iv_operations crypt_iv_plain64_ops = {
1096 .generator = crypt_iv_plain64_gen
1097};
1098
1099static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
1100 .generator = crypt_iv_plain64be_gen
1101};
1102
1103static const struct crypt_iv_operations crypt_iv_essiv_ops = {
1104 .generator = crypt_iv_essiv_gen
1105};
1106
1107static const struct crypt_iv_operations crypt_iv_benbi_ops = {
1108 .ctr = crypt_iv_benbi_ctr,
1109 .dtr = crypt_iv_benbi_dtr,
1110 .generator = crypt_iv_benbi_gen
1111};
1112
1113static const struct crypt_iv_operations crypt_iv_null_ops = {
1114 .generator = crypt_iv_null_gen
1115};
1116
1117static const struct crypt_iv_operations crypt_iv_lmk_ops = {
1118 .ctr = crypt_iv_lmk_ctr,
1119 .dtr = crypt_iv_lmk_dtr,
1120 .init = crypt_iv_lmk_init,
1121 .wipe = crypt_iv_lmk_wipe,
1122 .generator = crypt_iv_lmk_gen,
1123 .post = crypt_iv_lmk_post
1124};
1125
1126static const struct crypt_iv_operations crypt_iv_tcw_ops = {
1127 .ctr = crypt_iv_tcw_ctr,
1128 .dtr = crypt_iv_tcw_dtr,
1129 .init = crypt_iv_tcw_init,
1130 .wipe = crypt_iv_tcw_wipe,
1131 .generator = crypt_iv_tcw_gen,
1132 .post = crypt_iv_tcw_post
1133};
1134
1135static const struct crypt_iv_operations crypt_iv_random_ops = {
1136 .generator = crypt_iv_random_gen
1137};
1138
1139static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
1140 .ctr = crypt_iv_eboiv_ctr,
1141 .generator = crypt_iv_eboiv_gen
1142};
1143
1144static const struct crypt_iv_operations crypt_iv_elephant_ops = {
1145 .ctr = crypt_iv_elephant_ctr,
1146 .dtr = crypt_iv_elephant_dtr,
1147 .init = crypt_iv_elephant_init,
1148 .wipe = crypt_iv_elephant_wipe,
1149 .generator = crypt_iv_elephant_gen,
1150 .post = crypt_iv_elephant_post
1151};
1152
1153/*
1154 * Integrity extensions
1155 */
1156static bool crypt_integrity_aead(struct crypt_config *cc)
1157{
1158 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
1159}
1160
1161static bool crypt_integrity_hmac(struct crypt_config *cc)
1162{
1163 return crypt_integrity_aead(cc) && cc->key_mac_size;
1164}
1165
1166/* Get sg containing data */
1167static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
1168 struct scatterlist *sg)
1169{
1170 if (unlikely(crypt_integrity_aead(cc)))
1171 return &sg[2];
1172
1173 return sg;
1174}
1175
1176static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
1177{
1178 struct bio_integrity_payload *bip;
1179 unsigned int tag_len;
1180 int ret;
1181
1182 if (!bio_sectors(bio) || !io->cc->tuple_size)
1183 return 0;
1184
1185 bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
1186 if (IS_ERR(bip))
1187 return PTR_ERR(bip);
1188
1189 tag_len = io->cc->tuple_size * (bio_sectors(bio) >> io->cc->sector_shift);
1190
1191 bip->bip_iter.bi_sector = io->cc->start + io->sector;
1192
1193 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
1194 tag_len, offset_in_page(io->integrity_metadata));
1195 if (unlikely(ret != tag_len))
1196 return -ENOMEM;
1197
1198 return 0;
1199}
1200
1201static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
1202{
1203#ifdef CONFIG_BLK_DEV_INTEGRITY
1204 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
1205 struct mapped_device *md = dm_table_get_md(ti->table);
1206
1207 /* We require an underlying device with non-PI metadata */
1208 if (!bi || bi->csum_type != BLK_INTEGRITY_CSUM_NONE) {
1209 ti->error = "Integrity profile not supported.";
1210 return -EINVAL;
1211 }
1212
1213 if (bi->tuple_size < cc->used_tag_size) {
1214 ti->error = "Integrity profile tag size mismatch.";
1215 return -EINVAL;
1216 }
1217 cc->tuple_size = bi->tuple_size;
1218 if (1 << bi->interval_exp != cc->sector_size) {
1219 ti->error = "Integrity profile sector size mismatch.";
1220 return -EINVAL;
1221 }
1222
1223 if (crypt_integrity_aead(cc)) {
1224 cc->integrity_tag_size = cc->used_tag_size - cc->integrity_iv_size;
1225 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
1226 cc->integrity_tag_size, cc->integrity_iv_size);
1227
1228 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
1229 ti->error = "Integrity AEAD auth tag size is not supported.";
1230 return -EINVAL;
1231 }
1232 } else if (cc->integrity_iv_size)
1233 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
1234 cc->integrity_iv_size);
1235
1236 if ((cc->integrity_tag_size + cc->integrity_iv_size) > cc->tuple_size) {
1237 ti->error = "Not enough space for integrity tag in the profile.";
1238 return -EINVAL;
1239 }
1240
1241 return 0;
1242#else
1243 ti->error = "Integrity profile not supported.";
1244 return -EINVAL;
1245#endif
1246}
1247
1248static void crypt_convert_init(struct crypt_config *cc,
1249 struct convert_context *ctx,
1250 struct bio *bio_out, struct bio *bio_in,
1251 sector_t sector)
1252{
1253 ctx->bio_in = bio_in;
1254 ctx->bio_out = bio_out;
1255 if (bio_in)
1256 ctx->iter_in = bio_in->bi_iter;
1257 if (bio_out)
1258 ctx->iter_out = bio_out->bi_iter;
1259 ctx->cc_sector = sector + cc->iv_offset;
1260 ctx->tag_offset = 0;
1261 init_completion(&ctx->restart);
1262}
1263
1264static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1265 void *req)
1266{
1267 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1268}
1269
1270static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1271{
1272 return (void *)((char *)dmreq - cc->dmreq_start);
1273}
1274
1275static u8 *iv_of_dmreq(struct crypt_config *cc,
1276 struct dm_crypt_request *dmreq)
1277{
1278 if (crypt_integrity_aead(cc))
1279 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1280 crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1281 else
1282 return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1283 crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1284}
1285
1286static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1287 struct dm_crypt_request *dmreq)
1288{
1289 return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1290}
1291
1292static __le64 *org_sector_of_dmreq(struct crypt_config *cc,
1293 struct dm_crypt_request *dmreq)
1294{
1295 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1296
1297 return (__le64 *) ptr;
1298}
1299
1300static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1301 struct dm_crypt_request *dmreq)
1302{
1303 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1304 cc->iv_size + sizeof(uint64_t);
1305
1306 return (unsigned int *)ptr;
1307}
1308
1309static void *tag_from_dmreq(struct crypt_config *cc,
1310 struct dm_crypt_request *dmreq)
1311{
1312 struct convert_context *ctx = dmreq->ctx;
1313 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1314
1315 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1316 cc->tuple_size];
1317}
1318
1319static void *iv_tag_from_dmreq(struct crypt_config *cc,
1320 struct dm_crypt_request *dmreq)
1321{
1322 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1323}
1324
1325static int crypt_convert_block_aead(struct crypt_config *cc,
1326 struct convert_context *ctx,
1327 struct aead_request *req,
1328 unsigned int tag_offset)
1329{
1330 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1331 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1332 struct dm_crypt_request *dmreq;
1333 u8 *iv, *org_iv, *tag_iv, *tag;
1334 __le64 *sector;
1335 int r = 0;
1336
1337 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1338
1339 /* Reject unexpected unaligned bio. */
1340 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1341 return -EIO;
1342
1343 dmreq = dmreq_of_req(cc, req);
1344 dmreq->iv_sector = ctx->cc_sector;
1345 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1346 dmreq->iv_sector >>= cc->sector_shift;
1347 dmreq->ctx = ctx;
1348
1349 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1350
1351 sector = org_sector_of_dmreq(cc, dmreq);
1352 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1353
1354 iv = iv_of_dmreq(cc, dmreq);
1355 org_iv = org_iv_of_dmreq(cc, dmreq);
1356 tag = tag_from_dmreq(cc, dmreq);
1357 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1358
1359 /* AEAD request:
1360 * |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1361 * | (authenticated) | (auth+encryption) | |
1362 * | sector_LE | IV | sector in/out | tag in/out |
1363 */
1364 sg_init_table(dmreq->sg_in, 4);
1365 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1366 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1367 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1368 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1369
1370 sg_init_table(dmreq->sg_out, 4);
1371 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1372 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1373 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1374 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1375
1376 if (cc->iv_gen_ops) {
1377 /* For READs use IV stored in integrity metadata */
1378 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1379 memcpy(org_iv, tag_iv, cc->iv_size);
1380 } else {
1381 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1382 if (r < 0)
1383 return r;
1384 /* Store generated IV in integrity metadata */
1385 if (cc->integrity_iv_size)
1386 memcpy(tag_iv, org_iv, cc->iv_size);
1387 }
1388 /* Working copy of IV, to be modified in crypto API */
1389 memcpy(iv, org_iv, cc->iv_size);
1390 }
1391
1392 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1393 if (bio_data_dir(ctx->bio_in) == WRITE) {
1394 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1395 cc->sector_size, iv);
1396 r = crypto_aead_encrypt(req);
1397 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->tuple_size)
1398 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1399 cc->tuple_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1400 } else {
1401 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1402 cc->sector_size + cc->integrity_tag_size, iv);
1403 r = crypto_aead_decrypt(req);
1404 }
1405
1406 if (r == -EBADMSG) {
1407 sector_t s = le64_to_cpu(*sector);
1408
1409 ctx->aead_failed = true;
1410 if (ctx->aead_recheck) {
1411 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
1412 ctx->bio_in->bi_bdev, s);
1413 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
1414 ctx->bio_in, s, 0);
1415 }
1416 }
1417
1418 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1419 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1420
1421 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1422 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1423
1424 return r;
1425}
1426
1427static int crypt_convert_block_skcipher(struct crypt_config *cc,
1428 struct convert_context *ctx,
1429 struct skcipher_request *req,
1430 unsigned int tag_offset)
1431{
1432 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1433 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1434 struct scatterlist *sg_in, *sg_out;
1435 struct dm_crypt_request *dmreq;
1436 u8 *iv, *org_iv, *tag_iv;
1437 __le64 *sector;
1438 int r = 0;
1439
1440 /* Reject unexpected unaligned bio. */
1441 if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1442 return -EIO;
1443
1444 dmreq = dmreq_of_req(cc, req);
1445 dmreq->iv_sector = ctx->cc_sector;
1446 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1447 dmreq->iv_sector >>= cc->sector_shift;
1448 dmreq->ctx = ctx;
1449
1450 *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1451
1452 iv = iv_of_dmreq(cc, dmreq);
1453 org_iv = org_iv_of_dmreq(cc, dmreq);
1454 tag_iv = iv_tag_from_dmreq(cc, dmreq);
1455
1456 sector = org_sector_of_dmreq(cc, dmreq);
1457 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1458
1459 /* For skcipher we use only the first sg item */
1460 sg_in = &dmreq->sg_in[0];
1461 sg_out = &dmreq->sg_out[0];
1462
1463 sg_init_table(sg_in, 1);
1464 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1465
1466 sg_init_table(sg_out, 1);
1467 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1468
1469 if (cc->iv_gen_ops) {
1470 /* For READs use IV stored in integrity metadata */
1471 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1472 memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1473 } else {
1474 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1475 if (r < 0)
1476 return r;
1477 /* Data can be already preprocessed in generator */
1478 if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
1479 sg_in = sg_out;
1480 /* Store generated IV in integrity metadata */
1481 if (cc->integrity_iv_size)
1482 memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1483 }
1484 /* Working copy of IV, to be modified in crypto API */
1485 memcpy(iv, org_iv, cc->iv_size);
1486 }
1487
1488 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1489
1490 if (bio_data_dir(ctx->bio_in) == WRITE)
1491 r = crypto_skcipher_encrypt(req);
1492 else
1493 r = crypto_skcipher_decrypt(req);
1494
1495 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1496 r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1497
1498 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1499 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1500
1501 return r;
1502}
1503
1504static void kcryptd_async_done(void *async_req, int error);
1505
1506static int crypt_alloc_req_skcipher(struct crypt_config *cc,
1507 struct convert_context *ctx)
1508{
1509 unsigned int key_index = ctx->cc_sector & (cc->tfms_count - 1);
1510
1511 if (!ctx->r.req) {
1512 ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1513 if (!ctx->r.req)
1514 return -ENOMEM;
1515 }
1516
1517 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1518
1519 /*
1520 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1521 * requests if driver request queue is full.
1522 */
1523 skcipher_request_set_callback(ctx->r.req,
1524 CRYPTO_TFM_REQ_MAY_BACKLOG,
1525 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1526
1527 return 0;
1528}
1529
1530static int crypt_alloc_req_aead(struct crypt_config *cc,
1531 struct convert_context *ctx)
1532{
1533 if (!ctx->r.req_aead) {
1534 ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1535 if (!ctx->r.req_aead)
1536 return -ENOMEM;
1537 }
1538
1539 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1540
1541 /*
1542 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1543 * requests if driver request queue is full.
1544 */
1545 aead_request_set_callback(ctx->r.req_aead,
1546 CRYPTO_TFM_REQ_MAY_BACKLOG,
1547 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1548
1549 return 0;
1550}
1551
1552static int crypt_alloc_req(struct crypt_config *cc,
1553 struct convert_context *ctx)
1554{
1555 if (crypt_integrity_aead(cc))
1556 return crypt_alloc_req_aead(cc, ctx);
1557 else
1558 return crypt_alloc_req_skcipher(cc, ctx);
1559}
1560
1561static void crypt_free_req_skcipher(struct crypt_config *cc,
1562 struct skcipher_request *req, struct bio *base_bio)
1563{
1564 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1565
1566 if ((struct skcipher_request *)(io + 1) != req)
1567 mempool_free(req, &cc->req_pool);
1568}
1569
1570static void crypt_free_req_aead(struct crypt_config *cc,
1571 struct aead_request *req, struct bio *base_bio)
1572{
1573 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1574
1575 if ((struct aead_request *)(io + 1) != req)
1576 mempool_free(req, &cc->req_pool);
1577}
1578
1579static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1580{
1581 if (crypt_integrity_aead(cc))
1582 crypt_free_req_aead(cc, req, base_bio);
1583 else
1584 crypt_free_req_skcipher(cc, req, base_bio);
1585}
1586
1587/*
1588 * Encrypt / decrypt data from one bio to another one (can be the same one)
1589 */
1590static blk_status_t crypt_convert(struct crypt_config *cc,
1591 struct convert_context *ctx, bool atomic, bool reset_pending)
1592{
1593 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1594 int r;
1595
1596 /*
1597 * if reset_pending is set we are dealing with the bio for the first time,
1598 * else we're continuing to work on the previous bio, so don't mess with
1599 * the cc_pending counter
1600 */
1601 if (reset_pending)
1602 atomic_set(&ctx->cc_pending, 1);
1603
1604 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1605
1606 r = crypt_alloc_req(cc, ctx);
1607 if (r) {
1608 complete(&ctx->restart);
1609 return BLK_STS_DEV_RESOURCE;
1610 }
1611
1612 atomic_inc(&ctx->cc_pending);
1613
1614 if (crypt_integrity_aead(cc))
1615 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, ctx->tag_offset);
1616 else
1617 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, ctx->tag_offset);
1618
1619 switch (r) {
1620 /*
1621 * The request was queued by a crypto driver
1622 * but the driver request queue is full, let's wait.
1623 */
1624 case -EBUSY:
1625 if (in_interrupt()) {
1626 if (try_wait_for_completion(&ctx->restart)) {
1627 /*
1628 * we don't have to block to wait for completion,
1629 * so proceed
1630 */
1631 } else {
1632 /*
1633 * we can't wait for completion without blocking
1634 * exit and continue processing in a workqueue
1635 */
1636 ctx->r.req = NULL;
1637 ctx->tag_offset++;
1638 ctx->cc_sector += sector_step;
1639 return BLK_STS_DEV_RESOURCE;
1640 }
1641 } else {
1642 wait_for_completion(&ctx->restart);
1643 }
1644 reinit_completion(&ctx->restart);
1645 fallthrough;
1646 /*
1647 * The request is queued and processed asynchronously,
1648 * completion function kcryptd_async_done() will be called.
1649 */
1650 case -EINPROGRESS:
1651 ctx->r.req = NULL;
1652 ctx->tag_offset++;
1653 ctx->cc_sector += sector_step;
1654 continue;
1655 /*
1656 * The request was already processed (synchronously).
1657 */
1658 case 0:
1659 atomic_dec(&ctx->cc_pending);
1660 ctx->cc_sector += sector_step;
1661 ctx->tag_offset++;
1662 if (!atomic)
1663 cond_resched();
1664 continue;
1665 /*
1666 * There was a data integrity error.
1667 */
1668 case -EBADMSG:
1669 atomic_dec(&ctx->cc_pending);
1670 return BLK_STS_PROTECTION;
1671 /*
1672 * There was an error while processing the request.
1673 */
1674 default:
1675 atomic_dec(&ctx->cc_pending);
1676 return BLK_STS_IOERR;
1677 }
1678 }
1679
1680 return 0;
1681}
1682
1683static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1684
1685/*
1686 * Generate a new unfragmented bio with the given size
1687 * This should never violate the device limitations (but if it did then block
1688 * core should split the bio as needed).
1689 *
1690 * This function may be called concurrently. If we allocate from the mempool
1691 * concurrently, there is a possibility of deadlock. For example, if we have
1692 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1693 * the mempool concurrently, it may deadlock in a situation where both processes
1694 * have allocated 128 pages and the mempool is exhausted.
1695 *
1696 * In order to avoid this scenario we allocate the pages under a mutex.
1697 *
1698 * In order to not degrade performance with excessive locking, we try
1699 * non-blocking allocations without a mutex first but on failure we fallback
1700 * to blocking allocations with a mutex.
1701 *
1702 * In order to reduce allocation overhead, we try to allocate compound pages in
1703 * the first pass. If they are not available, we fall back to the mempool.
1704 */
1705static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned int size)
1706{
1707 struct crypt_config *cc = io->cc;
1708 struct bio *clone;
1709 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1710 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1711 unsigned int remaining_size;
1712 unsigned int order = MAX_PAGE_ORDER;
1713
1714retry:
1715 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1716 mutex_lock(&cc->bio_alloc_lock);
1717
1718 clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf,
1719 GFP_NOIO, &cc->bs);
1720 clone->bi_private = io;
1721 clone->bi_end_io = crypt_endio;
1722 clone->bi_ioprio = io->base_bio->bi_ioprio;
1723
1724 remaining_size = size;
1725
1726 while (remaining_size) {
1727 struct page *pages;
1728 unsigned size_to_add;
1729 unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
1730 order = min(order, remaining_order);
1731
1732 while (order > 0) {
1733 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) +
1734 (1 << order) > dm_crypt_pages_per_client))
1735 goto decrease_order;
1736 pages = alloc_pages(gfp_mask
1737 | __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP,
1738 order);
1739 if (likely(pages != NULL)) {
1740 percpu_counter_add(&cc->n_allocated_pages, 1 << order);
1741 goto have_pages;
1742 }
1743decrease_order:
1744 order--;
1745 }
1746
1747 pages = mempool_alloc(&cc->page_pool, gfp_mask);
1748 if (!pages) {
1749 crypt_free_buffer_pages(cc, clone);
1750 bio_put(clone);
1751 gfp_mask |= __GFP_DIRECT_RECLAIM;
1752 order = 0;
1753 goto retry;
1754 }
1755
1756have_pages:
1757 size_to_add = min((unsigned)PAGE_SIZE << order, remaining_size);
1758 __bio_add_page(clone, pages, size_to_add, 0);
1759 remaining_size -= size_to_add;
1760 }
1761
1762 /* Allocate space for integrity tags */
1763 if (dm_crypt_integrity_io_alloc(io, clone)) {
1764 crypt_free_buffer_pages(cc, clone);
1765 bio_put(clone);
1766 clone = NULL;
1767 }
1768
1769 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1770 mutex_unlock(&cc->bio_alloc_lock);
1771
1772 return clone;
1773}
1774
1775static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1776{
1777 struct folio_iter fi;
1778
1779 if (clone->bi_vcnt > 0) { /* bio_for_each_folio_all crashes with an empty bio */
1780 bio_for_each_folio_all(fi, clone) {
1781 if (folio_test_large(fi.folio)) {
1782 percpu_counter_sub(&cc->n_allocated_pages,
1783 1 << folio_order(fi.folio));
1784 folio_put(fi.folio);
1785 } else {
1786 mempool_free(&fi.folio->page, &cc->page_pool);
1787 }
1788 }
1789 }
1790}
1791
1792static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1793 struct bio *bio, sector_t sector)
1794{
1795 io->cc = cc;
1796 io->base_bio = bio;
1797 io->sector = sector;
1798 io->error = 0;
1799 io->ctx.aead_recheck = false;
1800 io->ctx.aead_failed = false;
1801 io->ctx.r.req = NULL;
1802 io->integrity_metadata = NULL;
1803 io->integrity_metadata_from_pool = false;
1804 atomic_set(&io->io_pending, 0);
1805}
1806
1807static void crypt_inc_pending(struct dm_crypt_io *io)
1808{
1809 atomic_inc(&io->io_pending);
1810}
1811
1812static void kcryptd_queue_read(struct dm_crypt_io *io);
1813
1814/*
1815 * One of the bios was finished. Check for completion of
1816 * the whole request and correctly clean up the buffer.
1817 */
1818static void crypt_dec_pending(struct dm_crypt_io *io)
1819{
1820 struct crypt_config *cc = io->cc;
1821 struct bio *base_bio = io->base_bio;
1822 blk_status_t error = io->error;
1823
1824 if (!atomic_dec_and_test(&io->io_pending))
1825 return;
1826
1827 if (likely(!io->ctx.aead_recheck) && unlikely(io->ctx.aead_failed) &&
1828 cc->used_tag_size && bio_data_dir(base_bio) == READ) {
1829 io->ctx.aead_recheck = true;
1830 io->ctx.aead_failed = false;
1831 io->error = 0;
1832 kcryptd_queue_read(io);
1833 return;
1834 }
1835
1836 if (io->ctx.r.req)
1837 crypt_free_req(cc, io->ctx.r.req, base_bio);
1838
1839 if (unlikely(io->integrity_metadata_from_pool))
1840 mempool_free(io->integrity_metadata, &io->cc->tag_pool);
1841 else
1842 kfree(io->integrity_metadata);
1843
1844 base_bio->bi_status = error;
1845
1846 bio_endio(base_bio);
1847}
1848
1849/*
1850 * kcryptd/kcryptd_io:
1851 *
1852 * Needed because it would be very unwise to do decryption in an
1853 * interrupt context.
1854 *
1855 * kcryptd performs the actual encryption or decryption.
1856 *
1857 * kcryptd_io performs the IO submission.
1858 *
1859 * They must be separated as otherwise the final stages could be
1860 * starved by new requests which can block in the first stages due
1861 * to memory allocation.
1862 *
1863 * The work is done per CPU global for all dm-crypt instances.
1864 * They should not depend on each other and do not block.
1865 */
1866static void crypt_endio(struct bio *clone)
1867{
1868 struct dm_crypt_io *io = clone->bi_private;
1869 struct crypt_config *cc = io->cc;
1870 unsigned int rw = bio_data_dir(clone);
1871 blk_status_t error = clone->bi_status;
1872
1873 if (io->ctx.aead_recheck && !error) {
1874 kcryptd_queue_crypt(io);
1875 return;
1876 }
1877
1878 /*
1879 * free the processed pages
1880 */
1881 if (rw == WRITE || io->ctx.aead_recheck)
1882 crypt_free_buffer_pages(cc, clone);
1883
1884 bio_put(clone);
1885
1886 if (rw == READ && !error) {
1887 kcryptd_queue_crypt(io);
1888 return;
1889 }
1890
1891 if (unlikely(error))
1892 io->error = error;
1893
1894 crypt_dec_pending(io);
1895}
1896
1897#define CRYPT_MAP_READ_GFP GFP_NOWAIT
1898
1899static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1900{
1901 struct crypt_config *cc = io->cc;
1902 struct bio *clone;
1903
1904 if (io->ctx.aead_recheck) {
1905 if (!(gfp & __GFP_DIRECT_RECLAIM))
1906 return 1;
1907 crypt_inc_pending(io);
1908 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1909 if (unlikely(!clone)) {
1910 crypt_dec_pending(io);
1911 return 1;
1912 }
1913 clone->bi_iter.bi_sector = cc->start + io->sector;
1914 crypt_convert_init(cc, &io->ctx, clone, clone, io->sector);
1915 io->saved_bi_iter = clone->bi_iter;
1916 dm_submit_bio_remap(io->base_bio, clone);
1917 return 0;
1918 }
1919
1920 /*
1921 * We need the original biovec array in order to decrypt the whole bio
1922 * data *afterwards* -- thanks to immutable biovecs we don't need to
1923 * worry about the block layer modifying the biovec array; so leverage
1924 * bio_alloc_clone().
1925 */
1926 clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs);
1927 if (!clone)
1928 return 1;
1929 clone->bi_private = io;
1930 clone->bi_end_io = crypt_endio;
1931
1932 crypt_inc_pending(io);
1933
1934 clone->bi_iter.bi_sector = cc->start + io->sector;
1935
1936 if (dm_crypt_integrity_io_alloc(io, clone)) {
1937 crypt_dec_pending(io);
1938 bio_put(clone);
1939 return 1;
1940 }
1941
1942 dm_submit_bio_remap(io->base_bio, clone);
1943 return 0;
1944}
1945
1946static void kcryptd_io_read_work(struct work_struct *work)
1947{
1948 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1949
1950 crypt_inc_pending(io);
1951 if (kcryptd_io_read(io, GFP_NOIO))
1952 io->error = BLK_STS_RESOURCE;
1953 crypt_dec_pending(io);
1954}
1955
1956static void kcryptd_queue_read(struct dm_crypt_io *io)
1957{
1958 struct crypt_config *cc = io->cc;
1959
1960 INIT_WORK(&io->work, kcryptd_io_read_work);
1961 queue_work(cc->io_queue, &io->work);
1962}
1963
1964static void kcryptd_io_write(struct dm_crypt_io *io)
1965{
1966 struct bio *clone = io->ctx.bio_out;
1967
1968 dm_submit_bio_remap(io->base_bio, clone);
1969}
1970
1971#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1972
1973static int dmcrypt_write(void *data)
1974{
1975 struct crypt_config *cc = data;
1976 struct dm_crypt_io *io;
1977
1978 while (1) {
1979 struct rb_root write_tree;
1980 struct blk_plug plug;
1981
1982 spin_lock_irq(&cc->write_thread_lock);
1983continue_locked:
1984
1985 if (!RB_EMPTY_ROOT(&cc->write_tree))
1986 goto pop_from_list;
1987
1988 set_current_state(TASK_INTERRUPTIBLE);
1989
1990 spin_unlock_irq(&cc->write_thread_lock);
1991
1992 if (unlikely(kthread_should_stop())) {
1993 set_current_state(TASK_RUNNING);
1994 break;
1995 }
1996
1997 schedule();
1998
1999 spin_lock_irq(&cc->write_thread_lock);
2000 goto continue_locked;
2001
2002pop_from_list:
2003 write_tree = cc->write_tree;
2004 cc->write_tree = RB_ROOT;
2005 spin_unlock_irq(&cc->write_thread_lock);
2006
2007 BUG_ON(rb_parent(write_tree.rb_node));
2008
2009 /*
2010 * Note: we cannot walk the tree here with rb_next because
2011 * the structures may be freed when kcryptd_io_write is called.
2012 */
2013 blk_start_plug(&plug);
2014 do {
2015 io = crypt_io_from_node(rb_first(&write_tree));
2016 rb_erase(&io->rb_node, &write_tree);
2017 kcryptd_io_write(io);
2018 cond_resched();
2019 } while (!RB_EMPTY_ROOT(&write_tree));
2020 blk_finish_plug(&plug);
2021 }
2022 return 0;
2023}
2024
2025static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
2026{
2027 struct bio *clone = io->ctx.bio_out;
2028 struct crypt_config *cc = io->cc;
2029 unsigned long flags;
2030 sector_t sector;
2031 struct rb_node **rbp, *parent;
2032
2033 if (unlikely(io->error)) {
2034 crypt_free_buffer_pages(cc, clone);
2035 bio_put(clone);
2036 crypt_dec_pending(io);
2037 return;
2038 }
2039
2040 /* crypt_convert should have filled the clone bio */
2041 BUG_ON(io->ctx.iter_out.bi_size);
2042
2043 clone->bi_iter.bi_sector = cc->start + io->sector;
2044
2045 if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
2046 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
2047 dm_submit_bio_remap(io->base_bio, clone);
2048 return;
2049 }
2050
2051 spin_lock_irqsave(&cc->write_thread_lock, flags);
2052 if (RB_EMPTY_ROOT(&cc->write_tree))
2053 wake_up_process(cc->write_thread);
2054 rbp = &cc->write_tree.rb_node;
2055 parent = NULL;
2056 sector = io->sector;
2057 while (*rbp) {
2058 parent = *rbp;
2059 if (sector < crypt_io_from_node(parent)->sector)
2060 rbp = &(*rbp)->rb_left;
2061 else
2062 rbp = &(*rbp)->rb_right;
2063 }
2064 rb_link_node(&io->rb_node, parent, rbp);
2065 rb_insert_color(&io->rb_node, &cc->write_tree);
2066 spin_unlock_irqrestore(&cc->write_thread_lock, flags);
2067}
2068
2069static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
2070 struct convert_context *ctx)
2071
2072{
2073 if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
2074 return false;
2075
2076 /*
2077 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
2078 * constraints so they do not need to be issued inline by
2079 * kcryptd_crypt_write_convert().
2080 */
2081 switch (bio_op(ctx->bio_in)) {
2082 case REQ_OP_WRITE:
2083 case REQ_OP_WRITE_ZEROES:
2084 return true;
2085 default:
2086 return false;
2087 }
2088}
2089
2090static void kcryptd_crypt_write_continue(struct work_struct *work)
2091{
2092 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2093 struct crypt_config *cc = io->cc;
2094 struct convert_context *ctx = &io->ctx;
2095 int crypt_finished;
2096 blk_status_t r;
2097
2098 wait_for_completion(&ctx->restart);
2099 reinit_completion(&ctx->restart);
2100
2101 r = crypt_convert(cc, &io->ctx, true, false);
2102 if (r)
2103 io->error = r;
2104 crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2105 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2106 /* Wait for completion signaled by kcryptd_async_done() */
2107 wait_for_completion(&ctx->restart);
2108 crypt_finished = 1;
2109 }
2110
2111 /* Encryption was already finished, submit io now */
2112 if (crypt_finished)
2113 kcryptd_crypt_write_io_submit(io, 0);
2114
2115 crypt_dec_pending(io);
2116}
2117
2118static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
2119{
2120 struct crypt_config *cc = io->cc;
2121 struct convert_context *ctx = &io->ctx;
2122 struct bio *clone;
2123 int crypt_finished;
2124 blk_status_t r;
2125
2126 /*
2127 * Prevent io from disappearing until this function completes.
2128 */
2129 crypt_inc_pending(io);
2130 crypt_convert_init(cc, ctx, NULL, io->base_bio, io->sector);
2131
2132 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
2133 if (unlikely(!clone)) {
2134 io->error = BLK_STS_IOERR;
2135 goto dec;
2136 }
2137
2138 io->ctx.bio_out = clone;
2139 io->ctx.iter_out = clone->bi_iter;
2140
2141 if (crypt_integrity_aead(cc)) {
2142 bio_copy_data(clone, io->base_bio);
2143 io->ctx.bio_in = clone;
2144 io->ctx.iter_in = clone->bi_iter;
2145 }
2146
2147 crypt_inc_pending(io);
2148 r = crypt_convert(cc, ctx,
2149 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
2150 /*
2151 * Crypto API backlogged the request, because its queue was full
2152 * and we're in softirq context, so continue from a workqueue
2153 * (TODO: is it actually possible to be in softirq in the write path?)
2154 */
2155 if (r == BLK_STS_DEV_RESOURCE) {
2156 INIT_WORK(&io->work, kcryptd_crypt_write_continue);
2157 queue_work(cc->crypt_queue, &io->work);
2158 return;
2159 }
2160 if (r)
2161 io->error = r;
2162 crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2163 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2164 /* Wait for completion signaled by kcryptd_async_done() */
2165 wait_for_completion(&ctx->restart);
2166 crypt_finished = 1;
2167 }
2168
2169 /* Encryption was already finished, submit io now */
2170 if (crypt_finished)
2171 kcryptd_crypt_write_io_submit(io, 0);
2172
2173dec:
2174 crypt_dec_pending(io);
2175}
2176
2177static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
2178{
2179 if (io->ctx.aead_recheck) {
2180 if (!io->error) {
2181 io->ctx.bio_in->bi_iter = io->saved_bi_iter;
2182 bio_copy_data(io->base_bio, io->ctx.bio_in);
2183 }
2184 crypt_free_buffer_pages(io->cc, io->ctx.bio_in);
2185 bio_put(io->ctx.bio_in);
2186 }
2187 crypt_dec_pending(io);
2188}
2189
2190static void kcryptd_crypt_read_continue(struct work_struct *work)
2191{
2192 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2193 struct crypt_config *cc = io->cc;
2194 blk_status_t r;
2195
2196 wait_for_completion(&io->ctx.restart);
2197 reinit_completion(&io->ctx.restart);
2198
2199 r = crypt_convert(cc, &io->ctx, true, false);
2200 if (r)
2201 io->error = r;
2202
2203 if (atomic_dec_and_test(&io->ctx.cc_pending))
2204 kcryptd_crypt_read_done(io);
2205
2206 crypt_dec_pending(io);
2207}
2208
2209static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
2210{
2211 struct crypt_config *cc = io->cc;
2212 blk_status_t r;
2213
2214 crypt_inc_pending(io);
2215
2216 if (io->ctx.aead_recheck) {
2217 io->ctx.cc_sector = io->sector + cc->iv_offset;
2218 r = crypt_convert(cc, &io->ctx,
2219 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
2220 } else {
2221 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
2222 io->sector);
2223
2224 r = crypt_convert(cc, &io->ctx,
2225 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
2226 }
2227 /*
2228 * Crypto API backlogged the request, because its queue was full
2229 * and we're in softirq context, so continue from a workqueue
2230 */
2231 if (r == BLK_STS_DEV_RESOURCE) {
2232 INIT_WORK(&io->work, kcryptd_crypt_read_continue);
2233 queue_work(cc->crypt_queue, &io->work);
2234 return;
2235 }
2236 if (r)
2237 io->error = r;
2238
2239 if (atomic_dec_and_test(&io->ctx.cc_pending))
2240 kcryptd_crypt_read_done(io);
2241
2242 crypt_dec_pending(io);
2243}
2244
2245static void kcryptd_async_done(void *data, int error)
2246{
2247 struct dm_crypt_request *dmreq = data;
2248 struct convert_context *ctx = dmreq->ctx;
2249 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
2250 struct crypt_config *cc = io->cc;
2251
2252 /*
2253 * A request from crypto driver backlog is going to be processed now,
2254 * finish the completion and continue in crypt_convert().
2255 * (Callback will be called for the second time for this request.)
2256 */
2257 if (error == -EINPROGRESS) {
2258 complete(&ctx->restart);
2259 return;
2260 }
2261
2262 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
2263 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
2264
2265 if (error == -EBADMSG) {
2266 sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
2267
2268 ctx->aead_failed = true;
2269 if (ctx->aead_recheck) {
2270 DMERR_LIMIT("%pg: INTEGRITY AEAD ERROR, sector %llu",
2271 ctx->bio_in->bi_bdev, s);
2272 dm_audit_log_bio(DM_MSG_PREFIX, "integrity-aead",
2273 ctx->bio_in, s, 0);
2274 }
2275 io->error = BLK_STS_PROTECTION;
2276 } else if (error < 0)
2277 io->error = BLK_STS_IOERR;
2278
2279 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
2280
2281 if (!atomic_dec_and_test(&ctx->cc_pending))
2282 return;
2283
2284 /*
2285 * The request is fully completed: for inline writes, let
2286 * kcryptd_crypt_write_convert() do the IO submission.
2287 */
2288 if (bio_data_dir(io->base_bio) == READ) {
2289 kcryptd_crypt_read_done(io);
2290 return;
2291 }
2292
2293 if (kcryptd_crypt_write_inline(cc, ctx)) {
2294 complete(&ctx->restart);
2295 return;
2296 }
2297
2298 kcryptd_crypt_write_io_submit(io, 1);
2299}
2300
2301static void kcryptd_crypt(struct work_struct *work)
2302{
2303 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2304
2305 if (bio_data_dir(io->base_bio) == READ)
2306 kcryptd_crypt_read_convert(io);
2307 else
2308 kcryptd_crypt_write_convert(io);
2309}
2310
2311static void kcryptd_queue_crypt(struct dm_crypt_io *io)
2312{
2313 struct crypt_config *cc = io->cc;
2314
2315 if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
2316 (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
2317 /*
2318 * in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
2319 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but
2320 * it is being executed with irqs disabled.
2321 */
2322 if (in_hardirq() || irqs_disabled()) {
2323 INIT_WORK(&io->work, kcryptd_crypt);
2324 queue_work(system_bh_wq, &io->work);
2325 return;
2326 } else {
2327 kcryptd_crypt(&io->work);
2328 return;
2329 }
2330 }
2331
2332 INIT_WORK(&io->work, kcryptd_crypt);
2333 queue_work(cc->crypt_queue, &io->work);
2334}
2335
2336static void crypt_free_tfms_aead(struct crypt_config *cc)
2337{
2338 if (!cc->cipher_tfm.tfms_aead)
2339 return;
2340
2341 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2342 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
2343 cc->cipher_tfm.tfms_aead[0] = NULL;
2344 }
2345
2346 kfree(cc->cipher_tfm.tfms_aead);
2347 cc->cipher_tfm.tfms_aead = NULL;
2348}
2349
2350static void crypt_free_tfms_skcipher(struct crypt_config *cc)
2351{
2352 unsigned int i;
2353
2354 if (!cc->cipher_tfm.tfms)
2355 return;
2356
2357 for (i = 0; i < cc->tfms_count; i++)
2358 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
2359 crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
2360 cc->cipher_tfm.tfms[i] = NULL;
2361 }
2362
2363 kfree(cc->cipher_tfm.tfms);
2364 cc->cipher_tfm.tfms = NULL;
2365}
2366
2367static void crypt_free_tfms(struct crypt_config *cc)
2368{
2369 if (crypt_integrity_aead(cc))
2370 crypt_free_tfms_aead(cc);
2371 else
2372 crypt_free_tfms_skcipher(cc);
2373}
2374
2375static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
2376{
2377 unsigned int i;
2378 int err;
2379
2380 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
2381 sizeof(struct crypto_skcipher *),
2382 GFP_KERNEL);
2383 if (!cc->cipher_tfm.tfms)
2384 return -ENOMEM;
2385
2386 for (i = 0; i < cc->tfms_count; i++) {
2387 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0,
2388 CRYPTO_ALG_ALLOCATES_MEMORY);
2389 if (IS_ERR(cc->cipher_tfm.tfms[i])) {
2390 err = PTR_ERR(cc->cipher_tfm.tfms[i]);
2391 crypt_free_tfms(cc);
2392 return err;
2393 }
2394 }
2395
2396 /*
2397 * dm-crypt performance can vary greatly depending on which crypto
2398 * algorithm implementation is used. Help people debug performance
2399 * problems by logging the ->cra_driver_name.
2400 */
2401 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2402 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
2403 return 0;
2404}
2405
2406static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
2407{
2408 int err;
2409
2410 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
2411 if (!cc->cipher_tfm.tfms)
2412 return -ENOMEM;
2413
2414 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0,
2415 CRYPTO_ALG_ALLOCATES_MEMORY);
2416 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2417 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
2418 crypt_free_tfms(cc);
2419 return err;
2420 }
2421
2422 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2423 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
2424 return 0;
2425}
2426
2427static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
2428{
2429 if (crypt_integrity_aead(cc))
2430 return crypt_alloc_tfms_aead(cc, ciphermode);
2431 else
2432 return crypt_alloc_tfms_skcipher(cc, ciphermode);
2433}
2434
2435static unsigned int crypt_subkey_size(struct crypt_config *cc)
2436{
2437 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
2438}
2439
2440static unsigned int crypt_authenckey_size(struct crypt_config *cc)
2441{
2442 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
2443}
2444
2445/*
2446 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
2447 * the key must be for some reason in special format.
2448 * This funcion converts cc->key to this special format.
2449 */
2450static void crypt_copy_authenckey(char *p, const void *key,
2451 unsigned int enckeylen, unsigned int authkeylen)
2452{
2453 struct crypto_authenc_key_param *param;
2454 struct rtattr *rta;
2455
2456 rta = (struct rtattr *)p;
2457 param = RTA_DATA(rta);
2458 param->enckeylen = cpu_to_be32(enckeylen);
2459 rta->rta_len = RTA_LENGTH(sizeof(*param));
2460 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
2461 p += RTA_SPACE(sizeof(*param));
2462 memcpy(p, key + enckeylen, authkeylen);
2463 p += authkeylen;
2464 memcpy(p, key, enckeylen);
2465}
2466
2467static int crypt_setkey(struct crypt_config *cc)
2468{
2469 unsigned int subkey_size;
2470 int err = 0, i, r;
2471
2472 /* Ignore extra keys (which are used for IV etc) */
2473 subkey_size = crypt_subkey_size(cc);
2474
2475 if (crypt_integrity_hmac(cc)) {
2476 if (subkey_size < cc->key_mac_size)
2477 return -EINVAL;
2478
2479 crypt_copy_authenckey(cc->authenc_key, cc->key,
2480 subkey_size - cc->key_mac_size,
2481 cc->key_mac_size);
2482 }
2483
2484 for (i = 0; i < cc->tfms_count; i++) {
2485 if (crypt_integrity_hmac(cc))
2486 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2487 cc->authenc_key, crypt_authenckey_size(cc));
2488 else if (crypt_integrity_aead(cc))
2489 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2490 cc->key + (i * subkey_size),
2491 subkey_size);
2492 else
2493 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
2494 cc->key + (i * subkey_size),
2495 subkey_size);
2496 if (r)
2497 err = r;
2498 }
2499
2500 if (crypt_integrity_hmac(cc))
2501 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
2502
2503 return err;
2504}
2505
2506#ifdef CONFIG_KEYS
2507
2508static bool contains_whitespace(const char *str)
2509{
2510 while (*str)
2511 if (isspace(*str++))
2512 return true;
2513 return false;
2514}
2515
2516static int set_key_user(struct crypt_config *cc, struct key *key)
2517{
2518 const struct user_key_payload *ukp;
2519
2520 ukp = user_key_payload_locked(key);
2521 if (!ukp)
2522 return -EKEYREVOKED;
2523
2524 if (cc->key_size != ukp->datalen)
2525 return -EINVAL;
2526
2527 memcpy(cc->key, ukp->data, cc->key_size);
2528
2529 return 0;
2530}
2531
2532static int set_key_encrypted(struct crypt_config *cc, struct key *key)
2533{
2534 const struct encrypted_key_payload *ekp;
2535
2536 ekp = key->payload.data[0];
2537 if (!ekp)
2538 return -EKEYREVOKED;
2539
2540 if (cc->key_size != ekp->decrypted_datalen)
2541 return -EINVAL;
2542
2543 memcpy(cc->key, ekp->decrypted_data, cc->key_size);
2544
2545 return 0;
2546}
2547
2548static int set_key_trusted(struct crypt_config *cc, struct key *key)
2549{
2550 const struct trusted_key_payload *tkp;
2551
2552 tkp = key->payload.data[0];
2553 if (!tkp)
2554 return -EKEYREVOKED;
2555
2556 if (cc->key_size != tkp->key_len)
2557 return -EINVAL;
2558
2559 memcpy(cc->key, tkp->key, cc->key_size);
2560
2561 return 0;
2562}
2563
2564static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2565{
2566 char *new_key_string, *key_desc;
2567 int ret;
2568 struct key_type *type;
2569 struct key *key;
2570 int (*set_key)(struct crypt_config *cc, struct key *key);
2571
2572 /*
2573 * Reject key_string with whitespace. dm core currently lacks code for
2574 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2575 */
2576 if (contains_whitespace(key_string)) {
2577 DMERR("whitespace chars not allowed in key string");
2578 return -EINVAL;
2579 }
2580
2581 /* look for next ':' separating key_type from key_description */
2582 key_desc = strchr(key_string, ':');
2583 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2584 return -EINVAL;
2585
2586 if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
2587 type = &key_type_logon;
2588 set_key = set_key_user;
2589 } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
2590 type = &key_type_user;
2591 set_key = set_key_user;
2592 } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
2593 !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
2594 type = &key_type_encrypted;
2595 set_key = set_key_encrypted;
2596 } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
2597 !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
2598 type = &key_type_trusted;
2599 set_key = set_key_trusted;
2600 } else {
2601 return -EINVAL;
2602 }
2603
2604 new_key_string = kstrdup(key_string, GFP_KERNEL);
2605 if (!new_key_string)
2606 return -ENOMEM;
2607
2608 key = request_key(type, key_desc + 1, NULL);
2609 if (IS_ERR(key)) {
2610 ret = PTR_ERR(key);
2611 goto free_new_key_string;
2612 }
2613
2614 down_read(&key->sem);
2615 ret = set_key(cc, key);
2616 up_read(&key->sem);
2617 key_put(key);
2618 if (ret < 0)
2619 goto free_new_key_string;
2620
2621 /* clear the flag since following operations may invalidate previously valid key */
2622 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2623
2624 ret = crypt_setkey(cc);
2625 if (ret)
2626 goto free_new_key_string;
2627
2628 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2629 kfree_sensitive(cc->key_string);
2630 cc->key_string = new_key_string;
2631 return 0;
2632
2633free_new_key_string:
2634 kfree_sensitive(new_key_string);
2635 return ret;
2636}
2637
2638static int get_key_size(char **key_string)
2639{
2640 char *colon, dummy;
2641 int ret;
2642
2643 if (*key_string[0] != ':')
2644 return strlen(*key_string) >> 1;
2645
2646 /* look for next ':' in key string */
2647 colon = strpbrk(*key_string + 1, ":");
2648 if (!colon)
2649 return -EINVAL;
2650
2651 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2652 return -EINVAL;
2653
2654 *key_string = colon;
2655
2656 /* remaining key string should be :<logon|user>:<key_desc> */
2657
2658 return ret;
2659}
2660
2661#else
2662
2663static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2664{
2665 return -EINVAL;
2666}
2667
2668static int get_key_size(char **key_string)
2669{
2670 return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1);
2671}
2672
2673#endif /* CONFIG_KEYS */
2674
2675static int crypt_set_key(struct crypt_config *cc, char *key)
2676{
2677 int r = -EINVAL;
2678 int key_string_len = strlen(key);
2679
2680 /* Hyphen (which gives a key_size of zero) means there is no key. */
2681 if (!cc->key_size && strcmp(key, "-"))
2682 goto out;
2683
2684 /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2685 if (key[0] == ':') {
2686 r = crypt_set_keyring_key(cc, key + 1);
2687 goto out;
2688 }
2689
2690 /* clear the flag since following operations may invalidate previously valid key */
2691 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2692
2693 /* wipe references to any kernel keyring key */
2694 kfree_sensitive(cc->key_string);
2695 cc->key_string = NULL;
2696
2697 /* Decode key from its hex representation. */
2698 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2699 goto out;
2700
2701 r = crypt_setkey(cc);
2702 if (!r)
2703 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2704
2705out:
2706 /* Hex key string not needed after here, so wipe it. */
2707 memset(key, '0', key_string_len);
2708
2709 return r;
2710}
2711
2712static int crypt_wipe_key(struct crypt_config *cc)
2713{
2714 int r;
2715
2716 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2717 get_random_bytes(&cc->key, cc->key_size);
2718
2719 /* Wipe IV private keys */
2720 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2721 r = cc->iv_gen_ops->wipe(cc);
2722 if (r)
2723 return r;
2724 }
2725
2726 kfree_sensitive(cc->key_string);
2727 cc->key_string = NULL;
2728 r = crypt_setkey(cc);
2729 memset(&cc->key, 0, cc->key_size * sizeof(u8));
2730
2731 return r;
2732}
2733
2734static void crypt_calculate_pages_per_client(void)
2735{
2736 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
2737
2738 if (!dm_crypt_clients_n)
2739 return;
2740
2741 pages /= dm_crypt_clients_n;
2742 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2743 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2744 dm_crypt_pages_per_client = pages;
2745}
2746
2747static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2748{
2749 struct crypt_config *cc = pool_data;
2750 struct page *page;
2751
2752 /*
2753 * Note, percpu_counter_read_positive() may over (and under) estimate
2754 * the current usage by at most (batch - 1) * num_online_cpus() pages,
2755 * but avoids potential spinlock contention of an exact result.
2756 */
2757 if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) &&
2758 likely(gfp_mask & __GFP_NORETRY))
2759 return NULL;
2760
2761 page = alloc_page(gfp_mask);
2762 if (likely(page != NULL))
2763 percpu_counter_add(&cc->n_allocated_pages, 1);
2764
2765 return page;
2766}
2767
2768static void crypt_page_free(void *page, void *pool_data)
2769{
2770 struct crypt_config *cc = pool_data;
2771
2772 __free_page(page);
2773 percpu_counter_sub(&cc->n_allocated_pages, 1);
2774}
2775
2776static void crypt_dtr(struct dm_target *ti)
2777{
2778 struct crypt_config *cc = ti->private;
2779
2780 ti->private = NULL;
2781
2782 if (!cc)
2783 return;
2784
2785 if (cc->write_thread)
2786 kthread_stop(cc->write_thread);
2787
2788 if (cc->io_queue)
2789 destroy_workqueue(cc->io_queue);
2790 if (cc->crypt_queue)
2791 destroy_workqueue(cc->crypt_queue);
2792
2793 if (cc->workqueue_id)
2794 ida_free(&workqueue_ida, cc->workqueue_id);
2795
2796 crypt_free_tfms(cc);
2797
2798 bioset_exit(&cc->bs);
2799
2800 mempool_exit(&cc->page_pool);
2801 mempool_exit(&cc->req_pool);
2802 mempool_exit(&cc->tag_pool);
2803
2804 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2805 percpu_counter_destroy(&cc->n_allocated_pages);
2806
2807 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2808 cc->iv_gen_ops->dtr(cc);
2809
2810 if (cc->dev)
2811 dm_put_device(ti, cc->dev);
2812
2813 kfree_sensitive(cc->cipher_string);
2814 kfree_sensitive(cc->key_string);
2815 kfree_sensitive(cc->cipher_auth);
2816 kfree_sensitive(cc->authenc_key);
2817
2818 mutex_destroy(&cc->bio_alloc_lock);
2819
2820 /* Must zero key material before freeing */
2821 kfree_sensitive(cc);
2822
2823 spin_lock(&dm_crypt_clients_lock);
2824 WARN_ON(!dm_crypt_clients_n);
2825 dm_crypt_clients_n--;
2826 crypt_calculate_pages_per_client();
2827 spin_unlock(&dm_crypt_clients_lock);
2828
2829 dm_audit_log_dtr(DM_MSG_PREFIX, ti, 1);
2830}
2831
2832static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2833{
2834 struct crypt_config *cc = ti->private;
2835
2836 if (crypt_integrity_aead(cc))
2837 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2838 else
2839 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2840
2841 if (cc->iv_size)
2842 /* at least a 64 bit sector number should fit in our buffer */
2843 cc->iv_size = max(cc->iv_size,
2844 (unsigned int)(sizeof(u64) / sizeof(u8)));
2845 else if (ivmode) {
2846 DMWARN("Selected cipher does not support IVs");
2847 ivmode = NULL;
2848 }
2849
2850 /* Choose ivmode, see comments at iv code. */
2851 if (ivmode == NULL)
2852 cc->iv_gen_ops = NULL;
2853 else if (strcmp(ivmode, "plain") == 0)
2854 cc->iv_gen_ops = &crypt_iv_plain_ops;
2855 else if (strcmp(ivmode, "plain64") == 0)
2856 cc->iv_gen_ops = &crypt_iv_plain64_ops;
2857 else if (strcmp(ivmode, "plain64be") == 0)
2858 cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2859 else if (strcmp(ivmode, "essiv") == 0)
2860 cc->iv_gen_ops = &crypt_iv_essiv_ops;
2861 else if (strcmp(ivmode, "benbi") == 0)
2862 cc->iv_gen_ops = &crypt_iv_benbi_ops;
2863 else if (strcmp(ivmode, "null") == 0)
2864 cc->iv_gen_ops = &crypt_iv_null_ops;
2865 else if (strcmp(ivmode, "eboiv") == 0)
2866 cc->iv_gen_ops = &crypt_iv_eboiv_ops;
2867 else if (strcmp(ivmode, "elephant") == 0) {
2868 cc->iv_gen_ops = &crypt_iv_elephant_ops;
2869 cc->key_parts = 2;
2870 cc->key_extra_size = cc->key_size / 2;
2871 if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE)
2872 return -EINVAL;
2873 set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags);
2874 } else if (strcmp(ivmode, "lmk") == 0) {
2875 cc->iv_gen_ops = &crypt_iv_lmk_ops;
2876 /*
2877 * Version 2 and 3 is recognised according
2878 * to length of provided multi-key string.
2879 * If present (version 3), last key is used as IV seed.
2880 * All keys (including IV seed) are always the same size.
2881 */
2882 if (cc->key_size % cc->key_parts) {
2883 cc->key_parts++;
2884 cc->key_extra_size = cc->key_size / cc->key_parts;
2885 }
2886 } else if (strcmp(ivmode, "tcw") == 0) {
2887 cc->iv_gen_ops = &crypt_iv_tcw_ops;
2888 cc->key_parts += 2; /* IV + whitening */
2889 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2890 } else if (strcmp(ivmode, "random") == 0) {
2891 cc->iv_gen_ops = &crypt_iv_random_ops;
2892 /* Need storage space in integrity fields. */
2893 cc->integrity_iv_size = cc->iv_size;
2894 } else {
2895 ti->error = "Invalid IV mode";
2896 return -EINVAL;
2897 }
2898
2899 return 0;
2900}
2901
2902/*
2903 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2904 * The HMAC is needed to calculate tag size (HMAC digest size).
2905 * This should be probably done by crypto-api calls (once available...)
2906 */
2907static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2908{
2909 char *start, *end, *mac_alg = NULL;
2910 struct crypto_ahash *mac;
2911
2912 if (!strstarts(cipher_api, "authenc("))
2913 return 0;
2914
2915 start = strchr(cipher_api, '(');
2916 end = strchr(cipher_api, ',');
2917 if (!start || !end || ++start > end)
2918 return -EINVAL;
2919
2920 mac_alg = kmemdup_nul(start, end - start, GFP_KERNEL);
2921 if (!mac_alg)
2922 return -ENOMEM;
2923
2924 mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
2925 kfree(mac_alg);
2926
2927 if (IS_ERR(mac))
2928 return PTR_ERR(mac);
2929
2930 if (!test_bit(CRYPT_KEY_MAC_SIZE_SET, &cc->cipher_flags))
2931 cc->key_mac_size = crypto_ahash_digestsize(mac);
2932 crypto_free_ahash(mac);
2933
2934 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2935 if (!cc->authenc_key)
2936 return -ENOMEM;
2937
2938 return 0;
2939}
2940
2941static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2942 char **ivmode, char **ivopts)
2943{
2944 struct crypt_config *cc = ti->private;
2945 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME];
2946 int ret = -EINVAL;
2947
2948 cc->tfms_count = 1;
2949
2950 /*
2951 * New format (capi: prefix)
2952 * capi:cipher_api_spec-iv:ivopts
2953 */
2954 tmp = &cipher_in[strlen("capi:")];
2955
2956 /* Separate IV options if present, it can contain another '-' in hash name */
2957 *ivopts = strrchr(tmp, ':');
2958 if (*ivopts) {
2959 **ivopts = '\0';
2960 (*ivopts)++;
2961 }
2962 /* Parse IV mode */
2963 *ivmode = strrchr(tmp, '-');
2964 if (*ivmode) {
2965 **ivmode = '\0';
2966 (*ivmode)++;
2967 }
2968 /* The rest is crypto API spec */
2969 cipher_api = tmp;
2970
2971 /* Alloc AEAD, can be used only in new format. */
2972 if (crypt_integrity_aead(cc)) {
2973 ret = crypt_ctr_auth_cipher(cc, cipher_api);
2974 if (ret < 0) {
2975 ti->error = "Invalid AEAD cipher spec";
2976 return ret;
2977 }
2978 }
2979
2980 if (*ivmode && !strcmp(*ivmode, "lmk"))
2981 cc->tfms_count = 64;
2982
2983 if (*ivmode && !strcmp(*ivmode, "essiv")) {
2984 if (!*ivopts) {
2985 ti->error = "Digest algorithm missing for ESSIV mode";
2986 return -EINVAL;
2987 }
2988 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)",
2989 cipher_api, *ivopts);
2990 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
2991 ti->error = "Cannot allocate cipher string";
2992 return -ENOMEM;
2993 }
2994 cipher_api = buf;
2995 }
2996
2997 cc->key_parts = cc->tfms_count;
2998
2999 /* Allocate cipher */
3000 ret = crypt_alloc_tfms(cc, cipher_api);
3001 if (ret < 0) {
3002 ti->error = "Error allocating crypto tfm";
3003 return ret;
3004 }
3005
3006 if (crypt_integrity_aead(cc))
3007 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
3008 else
3009 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
3010
3011 return 0;
3012}
3013
3014static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
3015 char **ivmode, char **ivopts)
3016{
3017 struct crypt_config *cc = ti->private;
3018 char *tmp, *cipher, *chainmode, *keycount;
3019 char *cipher_api = NULL;
3020 int ret = -EINVAL;
3021 char dummy;
3022
3023 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
3024 ti->error = "Bad cipher specification";
3025 return -EINVAL;
3026 }
3027
3028 /*
3029 * Legacy dm-crypt cipher specification
3030 * cipher[:keycount]-mode-iv:ivopts
3031 */
3032 tmp = cipher_in;
3033 keycount = strsep(&tmp, "-");
3034 cipher = strsep(&keycount, ":");
3035
3036 if (!keycount)
3037 cc->tfms_count = 1;
3038 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
3039 !is_power_of_2(cc->tfms_count)) {
3040 ti->error = "Bad cipher key count specification";
3041 return -EINVAL;
3042 }
3043 cc->key_parts = cc->tfms_count;
3044
3045 chainmode = strsep(&tmp, "-");
3046 *ivmode = strsep(&tmp, ":");
3047 *ivopts = tmp;
3048
3049 /*
3050 * For compatibility with the original dm-crypt mapping format, if
3051 * only the cipher name is supplied, use cbc-plain.
3052 */
3053 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
3054 chainmode = "cbc";
3055 *ivmode = "plain";
3056 }
3057
3058 if (strcmp(chainmode, "ecb") && !*ivmode) {
3059 ti->error = "IV mechanism required";
3060 return -EINVAL;
3061 }
3062
3063 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
3064 if (!cipher_api)
3065 goto bad_mem;
3066
3067 if (*ivmode && !strcmp(*ivmode, "essiv")) {
3068 if (!*ivopts) {
3069 ti->error = "Digest algorithm missing for ESSIV mode";
3070 kfree(cipher_api);
3071 return -EINVAL;
3072 }
3073 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
3074 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts);
3075 } else {
3076 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
3077 "%s(%s)", chainmode, cipher);
3078 }
3079 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
3080 kfree(cipher_api);
3081 goto bad_mem;
3082 }
3083
3084 /* Allocate cipher */
3085 ret = crypt_alloc_tfms(cc, cipher_api);
3086 if (ret < 0) {
3087 ti->error = "Error allocating crypto tfm";
3088 kfree(cipher_api);
3089 return ret;
3090 }
3091 kfree(cipher_api);
3092
3093 return 0;
3094bad_mem:
3095 ti->error = "Cannot allocate cipher strings";
3096 return -ENOMEM;
3097}
3098
3099static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
3100{
3101 struct crypt_config *cc = ti->private;
3102 char *ivmode = NULL, *ivopts = NULL;
3103 int ret;
3104
3105 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
3106 if (!cc->cipher_string) {
3107 ti->error = "Cannot allocate cipher strings";
3108 return -ENOMEM;
3109 }
3110
3111 if (strstarts(cipher_in, "capi:"))
3112 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
3113 else
3114 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
3115 if (ret)
3116 return ret;
3117
3118 /* Initialize IV */
3119 ret = crypt_ctr_ivmode(ti, ivmode);
3120 if (ret < 0)
3121 return ret;
3122
3123 /* Initialize and set key */
3124 ret = crypt_set_key(cc, key);
3125 if (ret < 0) {
3126 ti->error = "Error decoding and setting key";
3127 return ret;
3128 }
3129
3130 /* Allocate IV */
3131 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
3132 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
3133 if (ret < 0) {
3134 ti->error = "Error creating IV";
3135 return ret;
3136 }
3137 }
3138
3139 /* Initialize IV (set keys for ESSIV etc) */
3140 if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
3141 ret = cc->iv_gen_ops->init(cc);
3142 if (ret < 0) {
3143 ti->error = "Error initialising IV";
3144 return ret;
3145 }
3146 }
3147
3148 /* wipe the kernel key payload copy */
3149 if (cc->key_string)
3150 memset(cc->key, 0, cc->key_size * sizeof(u8));
3151
3152 return ret;
3153}
3154
3155static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
3156{
3157 struct crypt_config *cc = ti->private;
3158 struct dm_arg_set as;
3159 static const struct dm_arg _args[] = {
3160 {0, 9, "Invalid number of feature args"},
3161 };
3162 unsigned int opt_params, val;
3163 const char *opt_string, *sval;
3164 char dummy;
3165 int ret;
3166
3167 /* Optional parameters */
3168 as.argc = argc;
3169 as.argv = argv;
3170
3171 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
3172 if (ret)
3173 return ret;
3174
3175 while (opt_params--) {
3176 opt_string = dm_shift_arg(&as);
3177 if (!opt_string) {
3178 ti->error = "Not enough feature arguments";
3179 return -EINVAL;
3180 }
3181
3182 if (!strcasecmp(opt_string, "allow_discards"))
3183 ti->num_discard_bios = 1;
3184
3185 else if (!strcasecmp(opt_string, "same_cpu_crypt"))
3186 set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3187 else if (!strcasecmp(opt_string, "high_priority"))
3188 set_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags);
3189
3190 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
3191 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3192 else if (!strcasecmp(opt_string, "no_read_workqueue"))
3193 set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3194 else if (!strcasecmp(opt_string, "no_write_workqueue"))
3195 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3196 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
3197 if (val == 0 || val > MAX_TAG_SIZE) {
3198 ti->error = "Invalid integrity arguments";
3199 return -EINVAL;
3200 }
3201 cc->used_tag_size = val;
3202 sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
3203 if (!strcasecmp(sval, "aead")) {
3204 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
3205 } else if (strcasecmp(sval, "none")) {
3206 ti->error = "Unknown integrity profile";
3207 return -EINVAL;
3208 }
3209
3210 cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
3211 if (!cc->cipher_auth)
3212 return -ENOMEM;
3213 } else if (sscanf(opt_string, "integrity_key_size:%u%c", &val, &dummy) == 1) {
3214 if (!val) {
3215 ti->error = "Invalid integrity_key_size argument";
3216 return -EINVAL;
3217 }
3218 cc->key_mac_size = val;
3219 set_bit(CRYPT_KEY_MAC_SIZE_SET, &cc->cipher_flags);
3220 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
3221 if (cc->sector_size < (1 << SECTOR_SHIFT) ||
3222 cc->sector_size > 4096 ||
3223 (cc->sector_size & (cc->sector_size - 1))) {
3224 ti->error = "Invalid feature value for sector_size";
3225 return -EINVAL;
3226 }
3227 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
3228 ti->error = "Device size is not multiple of sector_size feature";
3229 return -EINVAL;
3230 }
3231 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
3232 } else if (!strcasecmp(opt_string, "iv_large_sectors"))
3233 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3234 else {
3235 ti->error = "Invalid feature arguments";
3236 return -EINVAL;
3237 }
3238 }
3239
3240 return 0;
3241}
3242
3243#ifdef CONFIG_BLK_DEV_ZONED
3244static int crypt_report_zones(struct dm_target *ti,
3245 struct dm_report_zones_args *args, unsigned int nr_zones)
3246{
3247 struct crypt_config *cc = ti->private;
3248
3249 return dm_report_zones(cc->dev->bdev, cc->start,
3250 cc->start + dm_target_offset(ti, args->next_sector),
3251 args, nr_zones);
3252}
3253#else
3254#define crypt_report_zones NULL
3255#endif
3256
3257/*
3258 * Construct an encryption mapping:
3259 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
3260 */
3261static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3262{
3263 struct crypt_config *cc;
3264 const char *devname = dm_table_device_name(ti->table);
3265 int key_size, wq_id;
3266 unsigned int align_mask;
3267 unsigned int common_wq_flags;
3268 unsigned long long tmpll;
3269 int ret;
3270 size_t iv_size_padding, additional_req_size;
3271 char dummy;
3272
3273 if (argc < 5) {
3274 ti->error = "Not enough arguments";
3275 return -EINVAL;
3276 }
3277
3278 key_size = get_key_size(&argv[1]);
3279 if (key_size < 0) {
3280 ti->error = "Cannot parse key size";
3281 return -EINVAL;
3282 }
3283
3284 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
3285 if (!cc) {
3286 ti->error = "Cannot allocate encryption context";
3287 return -ENOMEM;
3288 }
3289 cc->key_size = key_size;
3290 cc->sector_size = (1 << SECTOR_SHIFT);
3291 cc->sector_shift = 0;
3292
3293 ti->private = cc;
3294
3295 spin_lock(&dm_crypt_clients_lock);
3296 dm_crypt_clients_n++;
3297 crypt_calculate_pages_per_client();
3298 spin_unlock(&dm_crypt_clients_lock);
3299
3300 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
3301 if (ret < 0)
3302 goto bad;
3303
3304 /* Optional parameters need to be read before cipher constructor */
3305 if (argc > 5) {
3306 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
3307 if (ret)
3308 goto bad;
3309 }
3310
3311 ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
3312 if (ret < 0)
3313 goto bad;
3314
3315 if (crypt_integrity_aead(cc)) {
3316 cc->dmreq_start = sizeof(struct aead_request);
3317 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
3318 align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
3319 } else {
3320 cc->dmreq_start = sizeof(struct skcipher_request);
3321 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
3322 align_mask = crypto_skcipher_alignmask(any_tfm(cc));
3323 }
3324 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
3325
3326 if (align_mask < CRYPTO_MINALIGN) {
3327 /* Allocate the padding exactly */
3328 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
3329 & align_mask;
3330 } else {
3331 /*
3332 * If the cipher requires greater alignment than kmalloc
3333 * alignment, we don't know the exact position of the
3334 * initialization vector. We must assume worst case.
3335 */
3336 iv_size_padding = align_mask;
3337 }
3338
3339 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */
3340 additional_req_size = sizeof(struct dm_crypt_request) +
3341 iv_size_padding + cc->iv_size +
3342 cc->iv_size +
3343 sizeof(uint64_t) +
3344 sizeof(unsigned int);
3345
3346 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
3347 if (ret) {
3348 ti->error = "Cannot allocate crypt request mempool";
3349 goto bad;
3350 }
3351
3352 cc->per_bio_data_size = ti->per_io_data_size =
3353 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
3354 ARCH_DMA_MINALIGN);
3355
3356 ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc);
3357 if (ret) {
3358 ti->error = "Cannot allocate page mempool";
3359 goto bad;
3360 }
3361
3362 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
3363 if (ret) {
3364 ti->error = "Cannot allocate crypt bioset";
3365 goto bad;
3366 }
3367
3368 mutex_init(&cc->bio_alloc_lock);
3369
3370 ret = -EINVAL;
3371 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
3372 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
3373 ti->error = "Invalid iv_offset sector";
3374 goto bad;
3375 }
3376 cc->iv_offset = tmpll;
3377
3378 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
3379 if (ret) {
3380 ti->error = "Device lookup failed";
3381 goto bad;
3382 }
3383
3384 ret = -EINVAL;
3385 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
3386 ti->error = "Invalid device sector";
3387 goto bad;
3388 }
3389 cc->start = tmpll;
3390
3391 if (bdev_is_zoned(cc->dev->bdev)) {
3392 /*
3393 * For zoned block devices, we need to preserve the issuer write
3394 * ordering. To do so, disable write workqueues and force inline
3395 * encryption completion.
3396 */
3397 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3398 set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
3399
3400 /*
3401 * All zone append writes to a zone of a zoned block device will
3402 * have the same BIO sector, the start of the zone. When the
3403 * cypher IV mode uses sector values, all data targeting a
3404 * zone will be encrypted using the first sector numbers of the
3405 * zone. This will not result in write errors but will
3406 * cause most reads to fail as reads will use the sector values
3407 * for the actual data locations, resulting in IV mismatch.
3408 * To avoid this problem, ask DM core to emulate zone append
3409 * operations with regular writes.
3410 */
3411 DMDEBUG("Zone append operations will be emulated");
3412 ti->emulate_zone_append = true;
3413 }
3414
3415 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
3416 ret = crypt_integrity_ctr(cc, ti);
3417 if (ret)
3418 goto bad;
3419
3420 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->tuple_size;
3421 if (!cc->tag_pool_max_sectors)
3422 cc->tag_pool_max_sectors = 1;
3423
3424 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
3425 cc->tag_pool_max_sectors * cc->tuple_size);
3426 if (ret) {
3427 ti->error = "Cannot allocate integrity tags mempool";
3428 goto bad;
3429 }
3430
3431 cc->tag_pool_max_sectors <<= cc->sector_shift;
3432 }
3433
3434 wq_id = ida_alloc_min(&workqueue_ida, 1, GFP_KERNEL);
3435 if (wq_id < 0) {
3436 ti->error = "Couldn't get workqueue id";
3437 ret = wq_id;
3438 goto bad;
3439 }
3440 cc->workqueue_id = wq_id;
3441
3442 ret = -ENOMEM;
3443 common_wq_flags = WQ_MEM_RECLAIM | WQ_SYSFS;
3444 if (test_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags))
3445 common_wq_flags |= WQ_HIGHPRI;
3446
3447 cc->io_queue = alloc_workqueue("kcryptd_io-%s-%d", common_wq_flags, 1, devname, wq_id);
3448 if (!cc->io_queue) {
3449 ti->error = "Couldn't create kcryptd io queue";
3450 goto bad;
3451 }
3452
3453 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) {
3454 cc->crypt_queue = alloc_workqueue("kcryptd-%s-%d",
3455 common_wq_flags | WQ_CPU_INTENSIVE,
3456 1, devname, wq_id);
3457 } else {
3458 /*
3459 * While crypt_queue is certainly CPU intensive, the use of
3460 * WQ_CPU_INTENSIVE is meaningless with WQ_UNBOUND.
3461 */
3462 cc->crypt_queue = alloc_workqueue("kcryptd-%s-%d",
3463 common_wq_flags | WQ_UNBOUND,
3464 num_online_cpus(), devname, wq_id);
3465 }
3466 if (!cc->crypt_queue) {
3467 ti->error = "Couldn't create kcryptd queue";
3468 goto bad;
3469 }
3470
3471 spin_lock_init(&cc->write_thread_lock);
3472 cc->write_tree = RB_ROOT;
3473
3474 cc->write_thread = kthread_run(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
3475 if (IS_ERR(cc->write_thread)) {
3476 ret = PTR_ERR(cc->write_thread);
3477 cc->write_thread = NULL;
3478 ti->error = "Couldn't spawn write thread";
3479 goto bad;
3480 }
3481 if (test_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags))
3482 set_user_nice(cc->write_thread, MIN_NICE);
3483
3484 ti->num_flush_bios = 1;
3485 ti->limit_swap_bios = true;
3486 ti->accounts_remapped_io = true;
3487
3488 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 1);
3489 return 0;
3490
3491bad:
3492 dm_audit_log_ctr(DM_MSG_PREFIX, ti, 0);
3493 crypt_dtr(ti);
3494 return ret;
3495}
3496
3497static int crypt_map(struct dm_target *ti, struct bio *bio)
3498{
3499 struct dm_crypt_io *io;
3500 struct crypt_config *cc = ti->private;
3501 unsigned max_sectors;
3502
3503 /*
3504 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
3505 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
3506 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
3507 */
3508 if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
3509 bio_op(bio) == REQ_OP_DISCARD)) {
3510 bio_set_dev(bio, cc->dev->bdev);
3511 if (bio_sectors(bio))
3512 bio->bi_iter.bi_sector = cc->start +
3513 dm_target_offset(ti, bio->bi_iter.bi_sector);
3514 return DM_MAPIO_REMAPPED;
3515 }
3516
3517 /*
3518 * Check if bio is too large, split as needed.
3519 */
3520 max_sectors = get_max_request_size(cc, bio_data_dir(bio) == WRITE);
3521 if (unlikely(bio_sectors(bio) > max_sectors))
3522 dm_accept_partial_bio(bio, max_sectors);
3523
3524 /*
3525 * Ensure that bio is a multiple of internal sector encryption size
3526 * and is aligned to this size as defined in IO hints.
3527 */
3528 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
3529 return DM_MAPIO_KILL;
3530
3531 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
3532 return DM_MAPIO_KILL;
3533
3534 io = dm_per_bio_data(bio, cc->per_bio_data_size);
3535 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
3536
3537 if (cc->tuple_size) {
3538 unsigned int tag_len = cc->tuple_size * (bio_sectors(bio) >> cc->sector_shift);
3539
3540 if (unlikely(tag_len > KMALLOC_MAX_SIZE))
3541 io->integrity_metadata = NULL;
3542 else
3543 io->integrity_metadata = kmalloc(tag_len, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
3544
3545 if (unlikely(!io->integrity_metadata)) {
3546 if (bio_sectors(bio) > cc->tag_pool_max_sectors)
3547 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
3548 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
3549 io->integrity_metadata_from_pool = true;
3550 }
3551 }
3552
3553 if (crypt_integrity_aead(cc))
3554 io->ctx.r.req_aead = (struct aead_request *)(io + 1);
3555 else
3556 io->ctx.r.req = (struct skcipher_request *)(io + 1);
3557
3558 if (bio_data_dir(io->base_bio) == READ) {
3559 if (kcryptd_io_read(io, CRYPT_MAP_READ_GFP))
3560 kcryptd_queue_read(io);
3561 } else
3562 kcryptd_queue_crypt(io);
3563
3564 return DM_MAPIO_SUBMITTED;
3565}
3566
3567static char hex2asc(unsigned char c)
3568{
3569 return c + '0' + ((unsigned int)(9 - c) >> 4 & 0x27);
3570}
3571
3572static void crypt_status(struct dm_target *ti, status_type_t type,
3573 unsigned int status_flags, char *result, unsigned int maxlen)
3574{
3575 struct crypt_config *cc = ti->private;
3576 unsigned int i, sz = 0;
3577 int num_feature_args = 0;
3578
3579 switch (type) {
3580 case STATUSTYPE_INFO:
3581 result[0] = '\0';
3582 break;
3583
3584 case STATUSTYPE_TABLE:
3585 DMEMIT("%s ", cc->cipher_string);
3586
3587 if (cc->key_size > 0) {
3588 if (cc->key_string)
3589 DMEMIT(":%u:%s", cc->key_size, cc->key_string);
3590 else {
3591 for (i = 0; i < cc->key_size; i++) {
3592 DMEMIT("%c%c", hex2asc(cc->key[i] >> 4),
3593 hex2asc(cc->key[i] & 0xf));
3594 }
3595 }
3596 } else
3597 DMEMIT("-");
3598
3599 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
3600 cc->dev->name, (unsigned long long)cc->start);
3601
3602 num_feature_args += !!ti->num_discard_bios;
3603 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3604 num_feature_args += test_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags);
3605 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3606 num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3607 num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3608 num_feature_args += !!cc->used_tag_size;
3609 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
3610 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3611 num_feature_args += test_bit(CRYPT_KEY_MAC_SIZE_SET, &cc->cipher_flags);
3612 if (num_feature_args) {
3613 DMEMIT(" %d", num_feature_args);
3614 if (ti->num_discard_bios)
3615 DMEMIT(" allow_discards");
3616 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3617 DMEMIT(" same_cpu_crypt");
3618 if (test_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags))
3619 DMEMIT(" high_priority");
3620 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
3621 DMEMIT(" submit_from_crypt_cpus");
3622 if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags))
3623 DMEMIT(" no_read_workqueue");
3624 if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
3625 DMEMIT(" no_write_workqueue");
3626 if (cc->used_tag_size)
3627 DMEMIT(" integrity:%u:%s", cc->used_tag_size, cc->cipher_auth);
3628 if (cc->sector_size != (1 << SECTOR_SHIFT))
3629 DMEMIT(" sector_size:%d", cc->sector_size);
3630 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
3631 DMEMIT(" iv_large_sectors");
3632 if (test_bit(CRYPT_KEY_MAC_SIZE_SET, &cc->cipher_flags))
3633 DMEMIT(" integrity_key_size:%u", cc->key_mac_size);
3634 }
3635 break;
3636
3637 case STATUSTYPE_IMA:
3638 DMEMIT_TARGET_NAME_VERSION(ti->type);
3639 DMEMIT(",allow_discards=%c", ti->num_discard_bios ? 'y' : 'n');
3640 DMEMIT(",same_cpu_crypt=%c", test_bit(DM_CRYPT_SAME_CPU, &cc->flags) ? 'y' : 'n');
3641 DMEMIT(",high_priority=%c", test_bit(DM_CRYPT_HIGH_PRIORITY, &cc->flags) ? 'y' : 'n');
3642 DMEMIT(",submit_from_crypt_cpus=%c", test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags) ?
3643 'y' : 'n');
3644 DMEMIT(",no_read_workqueue=%c", test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags) ?
3645 'y' : 'n');
3646 DMEMIT(",no_write_workqueue=%c", test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags) ?
3647 'y' : 'n');
3648 DMEMIT(",iv_large_sectors=%c", test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags) ?
3649 'y' : 'n');
3650
3651 if (cc->used_tag_size)
3652 DMEMIT(",integrity_tag_size=%u,cipher_auth=%s",
3653 cc->used_tag_size, cc->cipher_auth);
3654 if (cc->sector_size != (1 << SECTOR_SHIFT))
3655 DMEMIT(",sector_size=%d", cc->sector_size);
3656 if (cc->cipher_string)
3657 DMEMIT(",cipher_string=%s", cc->cipher_string);
3658
3659 DMEMIT(",key_size=%u", cc->key_size);
3660 DMEMIT(",key_parts=%u", cc->key_parts);
3661 DMEMIT(",key_extra_size=%u", cc->key_extra_size);
3662 DMEMIT(",key_mac_size=%u", cc->key_mac_size);
3663 DMEMIT(";");
3664 break;
3665 }
3666}
3667
3668static void crypt_postsuspend(struct dm_target *ti)
3669{
3670 struct crypt_config *cc = ti->private;
3671
3672 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3673}
3674
3675static int crypt_preresume(struct dm_target *ti)
3676{
3677 struct crypt_config *cc = ti->private;
3678
3679 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3680 DMERR("aborting resume - crypt key is not set.");
3681 return -EAGAIN;
3682 }
3683
3684 return 0;
3685}
3686
3687static void crypt_resume(struct dm_target *ti)
3688{
3689 struct crypt_config *cc = ti->private;
3690
3691 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3692}
3693
3694/* Message interface
3695 * key set <key>
3696 * key wipe
3697 */
3698static int crypt_message(struct dm_target *ti, unsigned int argc, char **argv,
3699 char *result, unsigned int maxlen)
3700{
3701 struct crypt_config *cc = ti->private;
3702 int key_size, ret = -EINVAL;
3703
3704 if (argc < 2)
3705 goto error;
3706
3707 if (!strcasecmp(argv[0], "key")) {
3708 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3709 DMWARN("not suspended during key manipulation.");
3710 return -EINVAL;
3711 }
3712 if (argc == 3 && !strcasecmp(argv[1], "set")) {
3713 /* The key size may not be changed. */
3714 key_size = get_key_size(&argv[2]);
3715 if (key_size < 0 || cc->key_size != key_size) {
3716 memset(argv[2], '0', strlen(argv[2]));
3717 return -EINVAL;
3718 }
3719
3720 ret = crypt_set_key(cc, argv[2]);
3721 if (ret)
3722 return ret;
3723 if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3724 ret = cc->iv_gen_ops->init(cc);
3725 /* wipe the kernel key payload copy */
3726 if (cc->key_string)
3727 memset(cc->key, 0, cc->key_size * sizeof(u8));
3728 return ret;
3729 }
3730 if (argc == 2 && !strcasecmp(argv[1], "wipe"))
3731 return crypt_wipe_key(cc);
3732 }
3733
3734error:
3735 DMWARN("unrecognised message received.");
3736 return -EINVAL;
3737}
3738
3739static int crypt_iterate_devices(struct dm_target *ti,
3740 iterate_devices_callout_fn fn, void *data)
3741{
3742 struct crypt_config *cc = ti->private;
3743
3744 return fn(ti, cc->dev, cc->start, ti->len, data);
3745}
3746
3747static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3748{
3749 struct crypt_config *cc = ti->private;
3750
3751 limits->logical_block_size =
3752 max_t(unsigned int, limits->logical_block_size, cc->sector_size);
3753 limits->physical_block_size =
3754 max_t(unsigned int, limits->physical_block_size, cc->sector_size);
3755 limits->io_min = max_t(unsigned int, limits->io_min, cc->sector_size);
3756 limits->dma_alignment = limits->logical_block_size - 1;
3757}
3758
3759static struct target_type crypt_target = {
3760 .name = "crypt",
3761 .version = {1, 28, 0},
3762 .module = THIS_MODULE,
3763 .ctr = crypt_ctr,
3764 .dtr = crypt_dtr,
3765 .features = DM_TARGET_ZONED_HM,
3766 .report_zones = crypt_report_zones,
3767 .map = crypt_map,
3768 .status = crypt_status,
3769 .postsuspend = crypt_postsuspend,
3770 .preresume = crypt_preresume,
3771 .resume = crypt_resume,
3772 .message = crypt_message,
3773 .iterate_devices = crypt_iterate_devices,
3774 .io_hints = crypt_io_hints,
3775};
3776module_dm(crypt);
3777
3778MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3779MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3780MODULE_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");