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