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