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