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