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