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