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 struct mapped_device *md = dm_table_get_md(ti->table); 950 951 /* From now we require underlying device with our integrity profile */ 952 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 953 ti->error = "Integrity profile not supported."; 954 return -EINVAL; 955 } 956 957 if (bi->tag_size != cc->on_disk_tag_size || 958 bi->tuple_size != cc->on_disk_tag_size) { 959 ti->error = "Integrity profile tag size mismatch."; 960 return -EINVAL; 961 } 962 if (1 << bi->interval_exp != cc->sector_size) { 963 ti->error = "Integrity profile sector size mismatch."; 964 return -EINVAL; 965 } 966 967 if (crypt_integrity_aead(cc)) { 968 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 969 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), 970 cc->integrity_tag_size, cc->integrity_iv_size); 971 972 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 973 ti->error = "Integrity AEAD auth tag size is not supported."; 974 return -EINVAL; 975 } 976 } else if (cc->integrity_iv_size) 977 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), 978 cc->integrity_iv_size); 979 980 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 981 ti->error = "Not enough space for integrity tag in the profile."; 982 return -EINVAL; 983 } 984 985 return 0; 986 #else 987 ti->error = "Integrity profile not supported."; 988 return -EINVAL; 989 #endif 990 } 991 992 static void crypt_convert_init(struct crypt_config *cc, 993 struct convert_context *ctx, 994 struct bio *bio_out, struct bio *bio_in, 995 sector_t sector) 996 { 997 ctx->bio_in = bio_in; 998 ctx->bio_out = bio_out; 999 if (bio_in) 1000 ctx->iter_in = bio_in->bi_iter; 1001 if (bio_out) 1002 ctx->iter_out = bio_out->bi_iter; 1003 ctx->cc_sector = sector + cc->iv_offset; 1004 init_completion(&ctx->restart); 1005 } 1006 1007 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1008 void *req) 1009 { 1010 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1011 } 1012 1013 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1014 { 1015 return (void *)((char *)dmreq - cc->dmreq_start); 1016 } 1017 1018 static u8 *iv_of_dmreq(struct crypt_config *cc, 1019 struct dm_crypt_request *dmreq) 1020 { 1021 if (crypt_integrity_aead(cc)) 1022 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1023 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1024 else 1025 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1026 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1027 } 1028 1029 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1030 struct dm_crypt_request *dmreq) 1031 { 1032 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1033 } 1034 1035 static __le64 *org_sector_of_dmreq(struct crypt_config *cc, 1036 struct dm_crypt_request *dmreq) 1037 { 1038 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1039 return (__le64 *) ptr; 1040 } 1041 1042 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1043 struct dm_crypt_request *dmreq) 1044 { 1045 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1046 cc->iv_size + sizeof(uint64_t); 1047 return (unsigned int*)ptr; 1048 } 1049 1050 static void *tag_from_dmreq(struct crypt_config *cc, 1051 struct dm_crypt_request *dmreq) 1052 { 1053 struct convert_context *ctx = dmreq->ctx; 1054 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1055 1056 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1057 cc->on_disk_tag_size]; 1058 } 1059 1060 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1061 struct dm_crypt_request *dmreq) 1062 { 1063 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1064 } 1065 1066 static int crypt_convert_block_aead(struct crypt_config *cc, 1067 struct convert_context *ctx, 1068 struct aead_request *req, 1069 unsigned int tag_offset) 1070 { 1071 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1072 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1073 struct dm_crypt_request *dmreq; 1074 u8 *iv, *org_iv, *tag_iv, *tag; 1075 __le64 *sector; 1076 int r = 0; 1077 1078 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1079 1080 /* Reject unexpected unaligned bio. */ 1081 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1082 return -EIO; 1083 1084 dmreq = dmreq_of_req(cc, req); 1085 dmreq->iv_sector = ctx->cc_sector; 1086 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1087 dmreq->iv_sector >>= cc->sector_shift; 1088 dmreq->ctx = ctx; 1089 1090 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1091 1092 sector = org_sector_of_dmreq(cc, dmreq); 1093 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1094 1095 iv = iv_of_dmreq(cc, dmreq); 1096 org_iv = org_iv_of_dmreq(cc, dmreq); 1097 tag = tag_from_dmreq(cc, dmreq); 1098 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1099 1100 /* AEAD request: 1101 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1102 * | (authenticated) | (auth+encryption) | | 1103 * | sector_LE | IV | sector in/out | tag in/out | 1104 */ 1105 sg_init_table(dmreq->sg_in, 4); 1106 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1107 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1108 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1109 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1110 1111 sg_init_table(dmreq->sg_out, 4); 1112 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1113 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1114 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1115 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1116 1117 if (cc->iv_gen_ops) { 1118 /* For READs use IV stored in integrity metadata */ 1119 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1120 memcpy(org_iv, tag_iv, cc->iv_size); 1121 } else { 1122 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1123 if (r < 0) 1124 return r; 1125 /* Store generated IV in integrity metadata */ 1126 if (cc->integrity_iv_size) 1127 memcpy(tag_iv, org_iv, cc->iv_size); 1128 } 1129 /* Working copy of IV, to be modified in crypto API */ 1130 memcpy(iv, org_iv, cc->iv_size); 1131 } 1132 1133 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1134 if (bio_data_dir(ctx->bio_in) == WRITE) { 1135 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1136 cc->sector_size, iv); 1137 r = crypto_aead_encrypt(req); 1138 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1139 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1140 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1141 } else { 1142 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1143 cc->sector_size + cc->integrity_tag_size, iv); 1144 r = crypto_aead_decrypt(req); 1145 } 1146 1147 if (r == -EBADMSG) { 1148 char b[BDEVNAME_SIZE]; 1149 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 1150 (unsigned long long)le64_to_cpu(*sector)); 1151 } 1152 1153 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1154 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1155 1156 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1157 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1158 1159 return r; 1160 } 1161 1162 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1163 struct convert_context *ctx, 1164 struct skcipher_request *req, 1165 unsigned int tag_offset) 1166 { 1167 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1168 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1169 struct scatterlist *sg_in, *sg_out; 1170 struct dm_crypt_request *dmreq; 1171 u8 *iv, *org_iv, *tag_iv; 1172 __le64 *sector; 1173 int r = 0; 1174 1175 /* Reject unexpected unaligned bio. */ 1176 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1177 return -EIO; 1178 1179 dmreq = dmreq_of_req(cc, req); 1180 dmreq->iv_sector = ctx->cc_sector; 1181 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1182 dmreq->iv_sector >>= cc->sector_shift; 1183 dmreq->ctx = ctx; 1184 1185 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1186 1187 iv = iv_of_dmreq(cc, dmreq); 1188 org_iv = org_iv_of_dmreq(cc, dmreq); 1189 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1190 1191 sector = org_sector_of_dmreq(cc, dmreq); 1192 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1193 1194 /* For skcipher we use only the first sg item */ 1195 sg_in = &dmreq->sg_in[0]; 1196 sg_out = &dmreq->sg_out[0]; 1197 1198 sg_init_table(sg_in, 1); 1199 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1200 1201 sg_init_table(sg_out, 1); 1202 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1203 1204 if (cc->iv_gen_ops) { 1205 /* For READs use IV stored in integrity metadata */ 1206 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1207 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1208 } else { 1209 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1210 if (r < 0) 1211 return r; 1212 /* Store generated IV in integrity metadata */ 1213 if (cc->integrity_iv_size) 1214 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1215 } 1216 /* Working copy of IV, to be modified in crypto API */ 1217 memcpy(iv, org_iv, cc->iv_size); 1218 } 1219 1220 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1221 1222 if (bio_data_dir(ctx->bio_in) == WRITE) 1223 r = crypto_skcipher_encrypt(req); 1224 else 1225 r = crypto_skcipher_decrypt(req); 1226 1227 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1228 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1229 1230 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1231 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1232 1233 return r; 1234 } 1235 1236 static void kcryptd_async_done(struct crypto_async_request *async_req, 1237 int error); 1238 1239 static void crypt_alloc_req_skcipher(struct crypt_config *cc, 1240 struct convert_context *ctx) 1241 { 1242 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); 1243 1244 if (!ctx->r.req) 1245 ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO); 1246 1247 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1248 1249 /* 1250 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1251 * requests if driver request queue is full. 1252 */ 1253 skcipher_request_set_callback(ctx->r.req, 1254 CRYPTO_TFM_REQ_MAY_BACKLOG, 1255 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1256 } 1257 1258 static void crypt_alloc_req_aead(struct crypt_config *cc, 1259 struct convert_context *ctx) 1260 { 1261 if (!ctx->r.req_aead) 1262 ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO); 1263 1264 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1265 1266 /* 1267 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1268 * requests if driver request queue is full. 1269 */ 1270 aead_request_set_callback(ctx->r.req_aead, 1271 CRYPTO_TFM_REQ_MAY_BACKLOG, 1272 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1273 } 1274 1275 static void crypt_alloc_req(struct crypt_config *cc, 1276 struct convert_context *ctx) 1277 { 1278 if (crypt_integrity_aead(cc)) 1279 crypt_alloc_req_aead(cc, ctx); 1280 else 1281 crypt_alloc_req_skcipher(cc, ctx); 1282 } 1283 1284 static void crypt_free_req_skcipher(struct crypt_config *cc, 1285 struct skcipher_request *req, struct bio *base_bio) 1286 { 1287 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1288 1289 if ((struct skcipher_request *)(io + 1) != req) 1290 mempool_free(req, &cc->req_pool); 1291 } 1292 1293 static void crypt_free_req_aead(struct crypt_config *cc, 1294 struct aead_request *req, struct bio *base_bio) 1295 { 1296 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1297 1298 if ((struct aead_request *)(io + 1) != req) 1299 mempool_free(req, &cc->req_pool); 1300 } 1301 1302 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1303 { 1304 if (crypt_integrity_aead(cc)) 1305 crypt_free_req_aead(cc, req, base_bio); 1306 else 1307 crypt_free_req_skcipher(cc, req, base_bio); 1308 } 1309 1310 /* 1311 * Encrypt / decrypt data from one bio to another one (can be the same one) 1312 */ 1313 static blk_status_t crypt_convert(struct crypt_config *cc, 1314 struct convert_context *ctx) 1315 { 1316 unsigned int tag_offset = 0; 1317 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1318 int r; 1319 1320 atomic_set(&ctx->cc_pending, 1); 1321 1322 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1323 1324 crypt_alloc_req(cc, ctx); 1325 atomic_inc(&ctx->cc_pending); 1326 1327 if (crypt_integrity_aead(cc)) 1328 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1329 else 1330 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1331 1332 switch (r) { 1333 /* 1334 * The request was queued by a crypto driver 1335 * but the driver request queue is full, let's wait. 1336 */ 1337 case -EBUSY: 1338 wait_for_completion(&ctx->restart); 1339 reinit_completion(&ctx->restart); 1340 /* fall through */ 1341 /* 1342 * The request is queued and processed asynchronously, 1343 * completion function kcryptd_async_done() will be called. 1344 */ 1345 case -EINPROGRESS: 1346 ctx->r.req = NULL; 1347 ctx->cc_sector += sector_step; 1348 tag_offset++; 1349 continue; 1350 /* 1351 * The request was already processed (synchronously). 1352 */ 1353 case 0: 1354 atomic_dec(&ctx->cc_pending); 1355 ctx->cc_sector += sector_step; 1356 tag_offset++; 1357 cond_resched(); 1358 continue; 1359 /* 1360 * There was a data integrity error. 1361 */ 1362 case -EBADMSG: 1363 atomic_dec(&ctx->cc_pending); 1364 return BLK_STS_PROTECTION; 1365 /* 1366 * There was an error while processing the request. 1367 */ 1368 default: 1369 atomic_dec(&ctx->cc_pending); 1370 return BLK_STS_IOERR; 1371 } 1372 } 1373 1374 return 0; 1375 } 1376 1377 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1378 1379 /* 1380 * Generate a new unfragmented bio with the given size 1381 * This should never violate the device limitations (but only because 1382 * max_segment_size is being constrained to PAGE_SIZE). 1383 * 1384 * This function may be called concurrently. If we allocate from the mempool 1385 * concurrently, there is a possibility of deadlock. For example, if we have 1386 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1387 * the mempool concurrently, it may deadlock in a situation where both processes 1388 * have allocated 128 pages and the mempool is exhausted. 1389 * 1390 * In order to avoid this scenario we allocate the pages under a mutex. 1391 * 1392 * In order to not degrade performance with excessive locking, we try 1393 * non-blocking allocations without a mutex first but on failure we fallback 1394 * to blocking allocations with a mutex. 1395 */ 1396 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 1397 { 1398 struct crypt_config *cc = io->cc; 1399 struct bio *clone; 1400 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1401 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1402 unsigned i, len, remaining_size; 1403 struct page *page; 1404 1405 retry: 1406 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1407 mutex_lock(&cc->bio_alloc_lock); 1408 1409 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs); 1410 if (!clone) 1411 goto out; 1412 1413 clone_init(io, clone); 1414 1415 remaining_size = size; 1416 1417 for (i = 0; i < nr_iovecs; i++) { 1418 page = mempool_alloc(&cc->page_pool, gfp_mask); 1419 if (!page) { 1420 crypt_free_buffer_pages(cc, clone); 1421 bio_put(clone); 1422 gfp_mask |= __GFP_DIRECT_RECLAIM; 1423 goto retry; 1424 } 1425 1426 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1427 1428 bio_add_page(clone, page, len, 0); 1429 1430 remaining_size -= len; 1431 } 1432 1433 /* Allocate space for integrity tags */ 1434 if (dm_crypt_integrity_io_alloc(io, clone)) { 1435 crypt_free_buffer_pages(cc, clone); 1436 bio_put(clone); 1437 clone = NULL; 1438 } 1439 out: 1440 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1441 mutex_unlock(&cc->bio_alloc_lock); 1442 1443 return clone; 1444 } 1445 1446 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1447 { 1448 struct bio_vec *bv; 1449 struct bvec_iter_all iter_all; 1450 1451 bio_for_each_segment_all(bv, clone, iter_all) { 1452 BUG_ON(!bv->bv_page); 1453 mempool_free(bv->bv_page, &cc->page_pool); 1454 } 1455 } 1456 1457 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1458 struct bio *bio, sector_t sector) 1459 { 1460 io->cc = cc; 1461 io->base_bio = bio; 1462 io->sector = sector; 1463 io->error = 0; 1464 io->ctx.r.req = NULL; 1465 io->integrity_metadata = NULL; 1466 io->integrity_metadata_from_pool = false; 1467 atomic_set(&io->io_pending, 0); 1468 } 1469 1470 static void crypt_inc_pending(struct dm_crypt_io *io) 1471 { 1472 atomic_inc(&io->io_pending); 1473 } 1474 1475 /* 1476 * One of the bios was finished. Check for completion of 1477 * the whole request and correctly clean up the buffer. 1478 */ 1479 static void crypt_dec_pending(struct dm_crypt_io *io) 1480 { 1481 struct crypt_config *cc = io->cc; 1482 struct bio *base_bio = io->base_bio; 1483 blk_status_t error = io->error; 1484 1485 if (!atomic_dec_and_test(&io->io_pending)) 1486 return; 1487 1488 if (io->ctx.r.req) 1489 crypt_free_req(cc, io->ctx.r.req, base_bio); 1490 1491 if (unlikely(io->integrity_metadata_from_pool)) 1492 mempool_free(io->integrity_metadata, &io->cc->tag_pool); 1493 else 1494 kfree(io->integrity_metadata); 1495 1496 base_bio->bi_status = error; 1497 bio_endio(base_bio); 1498 } 1499 1500 /* 1501 * kcryptd/kcryptd_io: 1502 * 1503 * Needed because it would be very unwise to do decryption in an 1504 * interrupt context. 1505 * 1506 * kcryptd performs the actual encryption or decryption. 1507 * 1508 * kcryptd_io performs the IO submission. 1509 * 1510 * They must be separated as otherwise the final stages could be 1511 * starved by new requests which can block in the first stages due 1512 * to memory allocation. 1513 * 1514 * The work is done per CPU global for all dm-crypt instances. 1515 * They should not depend on each other and do not block. 1516 */ 1517 static void crypt_endio(struct bio *clone) 1518 { 1519 struct dm_crypt_io *io = clone->bi_private; 1520 struct crypt_config *cc = io->cc; 1521 unsigned rw = bio_data_dir(clone); 1522 blk_status_t error; 1523 1524 /* 1525 * free the processed pages 1526 */ 1527 if (rw == WRITE) 1528 crypt_free_buffer_pages(cc, clone); 1529 1530 error = clone->bi_status; 1531 bio_put(clone); 1532 1533 if (rw == READ && !error) { 1534 kcryptd_queue_crypt(io); 1535 return; 1536 } 1537 1538 if (unlikely(error)) 1539 io->error = error; 1540 1541 crypt_dec_pending(io); 1542 } 1543 1544 static void clone_init(struct dm_crypt_io *io, struct bio *clone) 1545 { 1546 struct crypt_config *cc = io->cc; 1547 1548 clone->bi_private = io; 1549 clone->bi_end_io = crypt_endio; 1550 bio_set_dev(clone, cc->dev->bdev); 1551 clone->bi_opf = io->base_bio->bi_opf; 1552 } 1553 1554 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1555 { 1556 struct crypt_config *cc = io->cc; 1557 struct bio *clone; 1558 1559 /* 1560 * We need the original biovec array in order to decrypt 1561 * the whole bio data *afterwards* -- thanks to immutable 1562 * biovecs we don't need to worry about the block layer 1563 * modifying the biovec array; so leverage bio_clone_fast(). 1564 */ 1565 clone = bio_clone_fast(io->base_bio, gfp, &cc->bs); 1566 if (!clone) 1567 return 1; 1568 1569 crypt_inc_pending(io); 1570 1571 clone_init(io, clone); 1572 clone->bi_iter.bi_sector = cc->start + io->sector; 1573 1574 if (dm_crypt_integrity_io_alloc(io, clone)) { 1575 crypt_dec_pending(io); 1576 bio_put(clone); 1577 return 1; 1578 } 1579 1580 generic_make_request(clone); 1581 return 0; 1582 } 1583 1584 static void kcryptd_io_read_work(struct work_struct *work) 1585 { 1586 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1587 1588 crypt_inc_pending(io); 1589 if (kcryptd_io_read(io, GFP_NOIO)) 1590 io->error = BLK_STS_RESOURCE; 1591 crypt_dec_pending(io); 1592 } 1593 1594 static void kcryptd_queue_read(struct dm_crypt_io *io) 1595 { 1596 struct crypt_config *cc = io->cc; 1597 1598 INIT_WORK(&io->work, kcryptd_io_read_work); 1599 queue_work(cc->io_queue, &io->work); 1600 } 1601 1602 static void kcryptd_io_write(struct dm_crypt_io *io) 1603 { 1604 struct bio *clone = io->ctx.bio_out; 1605 1606 generic_make_request(clone); 1607 } 1608 1609 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1610 1611 static int dmcrypt_write(void *data) 1612 { 1613 struct crypt_config *cc = data; 1614 struct dm_crypt_io *io; 1615 1616 while (1) { 1617 struct rb_root write_tree; 1618 struct blk_plug plug; 1619 1620 spin_lock_irq(&cc->write_thread_lock); 1621 continue_locked: 1622 1623 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1624 goto pop_from_list; 1625 1626 set_current_state(TASK_INTERRUPTIBLE); 1627 1628 spin_unlock_irq(&cc->write_thread_lock); 1629 1630 if (unlikely(kthread_should_stop())) { 1631 set_current_state(TASK_RUNNING); 1632 break; 1633 } 1634 1635 schedule(); 1636 1637 set_current_state(TASK_RUNNING); 1638 spin_lock_irq(&cc->write_thread_lock); 1639 goto continue_locked; 1640 1641 pop_from_list: 1642 write_tree = cc->write_tree; 1643 cc->write_tree = RB_ROOT; 1644 spin_unlock_irq(&cc->write_thread_lock); 1645 1646 BUG_ON(rb_parent(write_tree.rb_node)); 1647 1648 /* 1649 * Note: we cannot walk the tree here with rb_next because 1650 * the structures may be freed when kcryptd_io_write is called. 1651 */ 1652 blk_start_plug(&plug); 1653 do { 1654 io = crypt_io_from_node(rb_first(&write_tree)); 1655 rb_erase(&io->rb_node, &write_tree); 1656 kcryptd_io_write(io); 1657 } while (!RB_EMPTY_ROOT(&write_tree)); 1658 blk_finish_plug(&plug); 1659 } 1660 return 0; 1661 } 1662 1663 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1664 { 1665 struct bio *clone = io->ctx.bio_out; 1666 struct crypt_config *cc = io->cc; 1667 unsigned long flags; 1668 sector_t sector; 1669 struct rb_node **rbp, *parent; 1670 1671 if (unlikely(io->error)) { 1672 crypt_free_buffer_pages(cc, clone); 1673 bio_put(clone); 1674 crypt_dec_pending(io); 1675 return; 1676 } 1677 1678 /* crypt_convert should have filled the clone bio */ 1679 BUG_ON(io->ctx.iter_out.bi_size); 1680 1681 clone->bi_iter.bi_sector = cc->start + io->sector; 1682 1683 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) { 1684 generic_make_request(clone); 1685 return; 1686 } 1687 1688 spin_lock_irqsave(&cc->write_thread_lock, flags); 1689 if (RB_EMPTY_ROOT(&cc->write_tree)) 1690 wake_up_process(cc->write_thread); 1691 rbp = &cc->write_tree.rb_node; 1692 parent = NULL; 1693 sector = io->sector; 1694 while (*rbp) { 1695 parent = *rbp; 1696 if (sector < crypt_io_from_node(parent)->sector) 1697 rbp = &(*rbp)->rb_left; 1698 else 1699 rbp = &(*rbp)->rb_right; 1700 } 1701 rb_link_node(&io->rb_node, parent, rbp); 1702 rb_insert_color(&io->rb_node, &cc->write_tree); 1703 spin_unlock_irqrestore(&cc->write_thread_lock, flags); 1704 } 1705 1706 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 1707 { 1708 struct crypt_config *cc = io->cc; 1709 struct bio *clone; 1710 int crypt_finished; 1711 sector_t sector = io->sector; 1712 blk_status_t r; 1713 1714 /* 1715 * Prevent io from disappearing until this function completes. 1716 */ 1717 crypt_inc_pending(io); 1718 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); 1719 1720 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 1721 if (unlikely(!clone)) { 1722 io->error = BLK_STS_IOERR; 1723 goto dec; 1724 } 1725 1726 io->ctx.bio_out = clone; 1727 io->ctx.iter_out = clone->bi_iter; 1728 1729 sector += bio_sectors(clone); 1730 1731 crypt_inc_pending(io); 1732 r = crypt_convert(cc, &io->ctx); 1733 if (r) 1734 io->error = r; 1735 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending); 1736 1737 /* Encryption was already finished, submit io now */ 1738 if (crypt_finished) { 1739 kcryptd_crypt_write_io_submit(io, 0); 1740 io->sector = sector; 1741 } 1742 1743 dec: 1744 crypt_dec_pending(io); 1745 } 1746 1747 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 1748 { 1749 crypt_dec_pending(io); 1750 } 1751 1752 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 1753 { 1754 struct crypt_config *cc = io->cc; 1755 blk_status_t r; 1756 1757 crypt_inc_pending(io); 1758 1759 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 1760 io->sector); 1761 1762 r = crypt_convert(cc, &io->ctx); 1763 if (r) 1764 io->error = r; 1765 1766 if (atomic_dec_and_test(&io->ctx.cc_pending)) 1767 kcryptd_crypt_read_done(io); 1768 1769 crypt_dec_pending(io); 1770 } 1771 1772 static void kcryptd_async_done(struct crypto_async_request *async_req, 1773 int error) 1774 { 1775 struct dm_crypt_request *dmreq = async_req->data; 1776 struct convert_context *ctx = dmreq->ctx; 1777 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1778 struct crypt_config *cc = io->cc; 1779 1780 /* 1781 * A request from crypto driver backlog is going to be processed now, 1782 * finish the completion and continue in crypt_convert(). 1783 * (Callback will be called for the second time for this request.) 1784 */ 1785 if (error == -EINPROGRESS) { 1786 complete(&ctx->restart); 1787 return; 1788 } 1789 1790 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 1791 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 1792 1793 if (error == -EBADMSG) { 1794 char b[BDEVNAME_SIZE]; 1795 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 1796 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); 1797 io->error = BLK_STS_PROTECTION; 1798 } else if (error < 0) 1799 io->error = BLK_STS_IOERR; 1800 1801 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 1802 1803 if (!atomic_dec_and_test(&ctx->cc_pending)) 1804 return; 1805 1806 if (bio_data_dir(io->base_bio) == READ) 1807 kcryptd_crypt_read_done(io); 1808 else 1809 kcryptd_crypt_write_io_submit(io, 1); 1810 } 1811 1812 static void kcryptd_crypt(struct work_struct *work) 1813 { 1814 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1815 1816 if (bio_data_dir(io->base_bio) == READ) 1817 kcryptd_crypt_read_convert(io); 1818 else 1819 kcryptd_crypt_write_convert(io); 1820 } 1821 1822 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 1823 { 1824 struct crypt_config *cc = io->cc; 1825 1826 INIT_WORK(&io->work, kcryptd_crypt); 1827 queue_work(cc->crypt_queue, &io->work); 1828 } 1829 1830 static void crypt_free_tfms_aead(struct crypt_config *cc) 1831 { 1832 if (!cc->cipher_tfm.tfms_aead) 1833 return; 1834 1835 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1836 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 1837 cc->cipher_tfm.tfms_aead[0] = NULL; 1838 } 1839 1840 kfree(cc->cipher_tfm.tfms_aead); 1841 cc->cipher_tfm.tfms_aead = NULL; 1842 } 1843 1844 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 1845 { 1846 unsigned i; 1847 1848 if (!cc->cipher_tfm.tfms) 1849 return; 1850 1851 for (i = 0; i < cc->tfms_count; i++) 1852 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 1853 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 1854 cc->cipher_tfm.tfms[i] = NULL; 1855 } 1856 1857 kfree(cc->cipher_tfm.tfms); 1858 cc->cipher_tfm.tfms = NULL; 1859 } 1860 1861 static void crypt_free_tfms(struct crypt_config *cc) 1862 { 1863 if (crypt_integrity_aead(cc)) 1864 crypt_free_tfms_aead(cc); 1865 else 1866 crypt_free_tfms_skcipher(cc); 1867 } 1868 1869 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 1870 { 1871 unsigned i; 1872 int err; 1873 1874 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 1875 sizeof(struct crypto_skcipher *), 1876 GFP_KERNEL); 1877 if (!cc->cipher_tfm.tfms) 1878 return -ENOMEM; 1879 1880 for (i = 0; i < cc->tfms_count; i++) { 1881 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0); 1882 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 1883 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 1884 crypt_free_tfms(cc); 1885 return err; 1886 } 1887 } 1888 1889 /* 1890 * dm-crypt performance can vary greatly depending on which crypto 1891 * algorithm implementation is used. Help people debug performance 1892 * problems by logging the ->cra_driver_name. 1893 */ 1894 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 1895 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); 1896 return 0; 1897 } 1898 1899 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 1900 { 1901 int err; 1902 1903 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 1904 if (!cc->cipher_tfm.tfms) 1905 return -ENOMEM; 1906 1907 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0); 1908 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1909 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 1910 crypt_free_tfms(cc); 1911 return err; 1912 } 1913 1914 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 1915 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); 1916 return 0; 1917 } 1918 1919 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 1920 { 1921 if (crypt_integrity_aead(cc)) 1922 return crypt_alloc_tfms_aead(cc, ciphermode); 1923 else 1924 return crypt_alloc_tfms_skcipher(cc, ciphermode); 1925 } 1926 1927 static unsigned crypt_subkey_size(struct crypt_config *cc) 1928 { 1929 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 1930 } 1931 1932 static unsigned crypt_authenckey_size(struct crypt_config *cc) 1933 { 1934 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 1935 } 1936 1937 /* 1938 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 1939 * the key must be for some reason in special format. 1940 * This funcion converts cc->key to this special format. 1941 */ 1942 static void crypt_copy_authenckey(char *p, const void *key, 1943 unsigned enckeylen, unsigned authkeylen) 1944 { 1945 struct crypto_authenc_key_param *param; 1946 struct rtattr *rta; 1947 1948 rta = (struct rtattr *)p; 1949 param = RTA_DATA(rta); 1950 param->enckeylen = cpu_to_be32(enckeylen); 1951 rta->rta_len = RTA_LENGTH(sizeof(*param)); 1952 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 1953 p += RTA_SPACE(sizeof(*param)); 1954 memcpy(p, key + enckeylen, authkeylen); 1955 p += authkeylen; 1956 memcpy(p, key, enckeylen); 1957 } 1958 1959 static int crypt_setkey(struct crypt_config *cc) 1960 { 1961 unsigned subkey_size; 1962 int err = 0, i, r; 1963 1964 /* Ignore extra keys (which are used for IV etc) */ 1965 subkey_size = crypt_subkey_size(cc); 1966 1967 if (crypt_integrity_hmac(cc)) { 1968 if (subkey_size < cc->key_mac_size) 1969 return -EINVAL; 1970 1971 crypt_copy_authenckey(cc->authenc_key, cc->key, 1972 subkey_size - cc->key_mac_size, 1973 cc->key_mac_size); 1974 } 1975 1976 for (i = 0; i < cc->tfms_count; i++) { 1977 if (crypt_integrity_hmac(cc)) 1978 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1979 cc->authenc_key, crypt_authenckey_size(cc)); 1980 else if (crypt_integrity_aead(cc)) 1981 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1982 cc->key + (i * subkey_size), 1983 subkey_size); 1984 else 1985 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 1986 cc->key + (i * subkey_size), 1987 subkey_size); 1988 if (r) 1989 err = r; 1990 } 1991 1992 if (crypt_integrity_hmac(cc)) 1993 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 1994 1995 return err; 1996 } 1997 1998 #ifdef CONFIG_KEYS 1999 2000 static bool contains_whitespace(const char *str) 2001 { 2002 while (*str) 2003 if (isspace(*str++)) 2004 return true; 2005 return false; 2006 } 2007 2008 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2009 { 2010 char *new_key_string, *key_desc; 2011 int ret; 2012 struct key *key; 2013 const struct user_key_payload *ukp; 2014 2015 /* 2016 * Reject key_string with whitespace. dm core currently lacks code for 2017 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2018 */ 2019 if (contains_whitespace(key_string)) { 2020 DMERR("whitespace chars not allowed in key string"); 2021 return -EINVAL; 2022 } 2023 2024 /* look for next ':' separating key_type from key_description */ 2025 key_desc = strpbrk(key_string, ":"); 2026 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2027 return -EINVAL; 2028 2029 if (strncmp(key_string, "logon:", key_desc - key_string + 1) && 2030 strncmp(key_string, "user:", key_desc - key_string + 1)) 2031 return -EINVAL; 2032 2033 new_key_string = kstrdup(key_string, GFP_KERNEL); 2034 if (!new_key_string) 2035 return -ENOMEM; 2036 2037 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user, 2038 key_desc + 1, NULL); 2039 if (IS_ERR(key)) { 2040 kzfree(new_key_string); 2041 return PTR_ERR(key); 2042 } 2043 2044 down_read(&key->sem); 2045 2046 ukp = user_key_payload_locked(key); 2047 if (!ukp) { 2048 up_read(&key->sem); 2049 key_put(key); 2050 kzfree(new_key_string); 2051 return -EKEYREVOKED; 2052 } 2053 2054 if (cc->key_size != ukp->datalen) { 2055 up_read(&key->sem); 2056 key_put(key); 2057 kzfree(new_key_string); 2058 return -EINVAL; 2059 } 2060 2061 memcpy(cc->key, ukp->data, cc->key_size); 2062 2063 up_read(&key->sem); 2064 key_put(key); 2065 2066 /* clear the flag since following operations may invalidate previously valid key */ 2067 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2068 2069 ret = crypt_setkey(cc); 2070 2071 if (!ret) { 2072 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2073 kzfree(cc->key_string); 2074 cc->key_string = new_key_string; 2075 } else 2076 kzfree(new_key_string); 2077 2078 return ret; 2079 } 2080 2081 static int get_key_size(char **key_string) 2082 { 2083 char *colon, dummy; 2084 int ret; 2085 2086 if (*key_string[0] != ':') 2087 return strlen(*key_string) >> 1; 2088 2089 /* look for next ':' in key string */ 2090 colon = strpbrk(*key_string + 1, ":"); 2091 if (!colon) 2092 return -EINVAL; 2093 2094 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2095 return -EINVAL; 2096 2097 *key_string = colon; 2098 2099 /* remaining key string should be :<logon|user>:<key_desc> */ 2100 2101 return ret; 2102 } 2103 2104 #else 2105 2106 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2107 { 2108 return -EINVAL; 2109 } 2110 2111 static int get_key_size(char **key_string) 2112 { 2113 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2114 } 2115 2116 #endif 2117 2118 static int crypt_set_key(struct crypt_config *cc, char *key) 2119 { 2120 int r = -EINVAL; 2121 int key_string_len = strlen(key); 2122 2123 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2124 if (!cc->key_size && strcmp(key, "-")) 2125 goto out; 2126 2127 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2128 if (key[0] == ':') { 2129 r = crypt_set_keyring_key(cc, key + 1); 2130 goto out; 2131 } 2132 2133 /* clear the flag since following operations may invalidate previously valid key */ 2134 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2135 2136 /* wipe references to any kernel keyring key */ 2137 kzfree(cc->key_string); 2138 cc->key_string = NULL; 2139 2140 /* Decode key from its hex representation. */ 2141 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2142 goto out; 2143 2144 r = crypt_setkey(cc); 2145 if (!r) 2146 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2147 2148 out: 2149 /* Hex key string not needed after here, so wipe it. */ 2150 memset(key, '0', key_string_len); 2151 2152 return r; 2153 } 2154 2155 static int crypt_wipe_key(struct crypt_config *cc) 2156 { 2157 int r; 2158 2159 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2160 get_random_bytes(&cc->key, cc->key_size); 2161 kzfree(cc->key_string); 2162 cc->key_string = NULL; 2163 r = crypt_setkey(cc); 2164 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2165 2166 return r; 2167 } 2168 2169 static void crypt_calculate_pages_per_client(void) 2170 { 2171 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100; 2172 2173 if (!dm_crypt_clients_n) 2174 return; 2175 2176 pages /= dm_crypt_clients_n; 2177 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2178 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2179 dm_crypt_pages_per_client = pages; 2180 } 2181 2182 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2183 { 2184 struct crypt_config *cc = pool_data; 2185 struct page *page; 2186 2187 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) && 2188 likely(gfp_mask & __GFP_NORETRY)) 2189 return NULL; 2190 2191 page = alloc_page(gfp_mask); 2192 if (likely(page != NULL)) 2193 percpu_counter_add(&cc->n_allocated_pages, 1); 2194 2195 return page; 2196 } 2197 2198 static void crypt_page_free(void *page, void *pool_data) 2199 { 2200 struct crypt_config *cc = pool_data; 2201 2202 __free_page(page); 2203 percpu_counter_sub(&cc->n_allocated_pages, 1); 2204 } 2205 2206 static void crypt_dtr(struct dm_target *ti) 2207 { 2208 struct crypt_config *cc = ti->private; 2209 2210 ti->private = NULL; 2211 2212 if (!cc) 2213 return; 2214 2215 if (cc->write_thread) 2216 kthread_stop(cc->write_thread); 2217 2218 if (cc->io_queue) 2219 destroy_workqueue(cc->io_queue); 2220 if (cc->crypt_queue) 2221 destroy_workqueue(cc->crypt_queue); 2222 2223 crypt_free_tfms(cc); 2224 2225 bioset_exit(&cc->bs); 2226 2227 mempool_exit(&cc->page_pool); 2228 mempool_exit(&cc->req_pool); 2229 mempool_exit(&cc->tag_pool); 2230 2231 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2232 percpu_counter_destroy(&cc->n_allocated_pages); 2233 2234 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2235 cc->iv_gen_ops->dtr(cc); 2236 2237 if (cc->dev) 2238 dm_put_device(ti, cc->dev); 2239 2240 kzfree(cc->cipher); 2241 kzfree(cc->cipher_string); 2242 kzfree(cc->key_string); 2243 kzfree(cc->cipher_auth); 2244 kzfree(cc->authenc_key); 2245 2246 mutex_destroy(&cc->bio_alloc_lock); 2247 2248 /* Must zero key material before freeing */ 2249 kzfree(cc); 2250 2251 spin_lock(&dm_crypt_clients_lock); 2252 WARN_ON(!dm_crypt_clients_n); 2253 dm_crypt_clients_n--; 2254 crypt_calculate_pages_per_client(); 2255 spin_unlock(&dm_crypt_clients_lock); 2256 } 2257 2258 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2259 { 2260 struct crypt_config *cc = ti->private; 2261 2262 if (crypt_integrity_aead(cc)) 2263 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2264 else 2265 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2266 2267 if (cc->iv_size) 2268 /* at least a 64 bit sector number should fit in our buffer */ 2269 cc->iv_size = max(cc->iv_size, 2270 (unsigned int)(sizeof(u64) / sizeof(u8))); 2271 else if (ivmode) { 2272 DMWARN("Selected cipher does not support IVs"); 2273 ivmode = NULL; 2274 } 2275 2276 /* Choose ivmode, see comments at iv code. */ 2277 if (ivmode == NULL) 2278 cc->iv_gen_ops = NULL; 2279 else if (strcmp(ivmode, "plain") == 0) 2280 cc->iv_gen_ops = &crypt_iv_plain_ops; 2281 else if (strcmp(ivmode, "plain64") == 0) 2282 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2283 else if (strcmp(ivmode, "plain64be") == 0) 2284 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2285 else if (strcmp(ivmode, "essiv") == 0) 2286 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2287 else if (strcmp(ivmode, "benbi") == 0) 2288 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2289 else if (strcmp(ivmode, "null") == 0) 2290 cc->iv_gen_ops = &crypt_iv_null_ops; 2291 else if (strcmp(ivmode, "lmk") == 0) { 2292 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2293 /* 2294 * Version 2 and 3 is recognised according 2295 * to length of provided multi-key string. 2296 * If present (version 3), last key is used as IV seed. 2297 * All keys (including IV seed) are always the same size. 2298 */ 2299 if (cc->key_size % cc->key_parts) { 2300 cc->key_parts++; 2301 cc->key_extra_size = cc->key_size / cc->key_parts; 2302 } 2303 } else if (strcmp(ivmode, "tcw") == 0) { 2304 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2305 cc->key_parts += 2; /* IV + whitening */ 2306 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2307 } else if (strcmp(ivmode, "random") == 0) { 2308 cc->iv_gen_ops = &crypt_iv_random_ops; 2309 /* Need storage space in integrity fields. */ 2310 cc->integrity_iv_size = cc->iv_size; 2311 } else { 2312 ti->error = "Invalid IV mode"; 2313 return -EINVAL; 2314 } 2315 2316 return 0; 2317 } 2318 2319 /* 2320 * Workaround to parse cipher algorithm from crypto API spec. 2321 * The cc->cipher is currently used only in ESSIV. 2322 * This should be probably done by crypto-api calls (once available...) 2323 */ 2324 static int crypt_ctr_blkdev_cipher(struct crypt_config *cc) 2325 { 2326 const char *alg_name = NULL; 2327 char *start, *end; 2328 2329 if (crypt_integrity_aead(cc)) { 2330 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc))); 2331 if (!alg_name) 2332 return -EINVAL; 2333 if (crypt_integrity_hmac(cc)) { 2334 alg_name = strchr(alg_name, ','); 2335 if (!alg_name) 2336 return -EINVAL; 2337 } 2338 alg_name++; 2339 } else { 2340 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc))); 2341 if (!alg_name) 2342 return -EINVAL; 2343 } 2344 2345 start = strchr(alg_name, '('); 2346 end = strchr(alg_name, ')'); 2347 2348 if (!start && !end) { 2349 cc->cipher = kstrdup(alg_name, GFP_KERNEL); 2350 return cc->cipher ? 0 : -ENOMEM; 2351 } 2352 2353 if (!start || !end || ++start >= end) 2354 return -EINVAL; 2355 2356 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL); 2357 if (!cc->cipher) 2358 return -ENOMEM; 2359 2360 strncpy(cc->cipher, start, end - start); 2361 2362 return 0; 2363 } 2364 2365 /* 2366 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2367 * The HMAC is needed to calculate tag size (HMAC digest size). 2368 * This should be probably done by crypto-api calls (once available...) 2369 */ 2370 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2371 { 2372 char *start, *end, *mac_alg = NULL; 2373 struct crypto_ahash *mac; 2374 2375 if (!strstarts(cipher_api, "authenc(")) 2376 return 0; 2377 2378 start = strchr(cipher_api, '('); 2379 end = strchr(cipher_api, ','); 2380 if (!start || !end || ++start > end) 2381 return -EINVAL; 2382 2383 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2384 if (!mac_alg) 2385 return -ENOMEM; 2386 strncpy(mac_alg, start, end - start); 2387 2388 mac = crypto_alloc_ahash(mac_alg, 0, 0); 2389 kfree(mac_alg); 2390 2391 if (IS_ERR(mac)) 2392 return PTR_ERR(mac); 2393 2394 cc->key_mac_size = crypto_ahash_digestsize(mac); 2395 crypto_free_ahash(mac); 2396 2397 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2398 if (!cc->authenc_key) 2399 return -ENOMEM; 2400 2401 return 0; 2402 } 2403 2404 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2405 char **ivmode, char **ivopts) 2406 { 2407 struct crypt_config *cc = ti->private; 2408 char *tmp, *cipher_api; 2409 int ret = -EINVAL; 2410 2411 cc->tfms_count = 1; 2412 2413 /* 2414 * New format (capi: prefix) 2415 * capi:cipher_api_spec-iv:ivopts 2416 */ 2417 tmp = &cipher_in[strlen("capi:")]; 2418 2419 /* Separate IV options if present, it can contain another '-' in hash name */ 2420 *ivopts = strrchr(tmp, ':'); 2421 if (*ivopts) { 2422 **ivopts = '\0'; 2423 (*ivopts)++; 2424 } 2425 /* Parse IV mode */ 2426 *ivmode = strrchr(tmp, '-'); 2427 if (*ivmode) { 2428 **ivmode = '\0'; 2429 (*ivmode)++; 2430 } 2431 /* The rest is crypto API spec */ 2432 cipher_api = tmp; 2433 2434 if (*ivmode && !strcmp(*ivmode, "lmk")) 2435 cc->tfms_count = 64; 2436 2437 cc->key_parts = cc->tfms_count; 2438 2439 /* Allocate cipher */ 2440 ret = crypt_alloc_tfms(cc, cipher_api); 2441 if (ret < 0) { 2442 ti->error = "Error allocating crypto tfm"; 2443 return ret; 2444 } 2445 2446 /* Alloc AEAD, can be used only in new format. */ 2447 if (crypt_integrity_aead(cc)) { 2448 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2449 if (ret < 0) { 2450 ti->error = "Invalid AEAD cipher spec"; 2451 return -ENOMEM; 2452 } 2453 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2454 } else 2455 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2456 2457 ret = crypt_ctr_blkdev_cipher(cc); 2458 if (ret < 0) { 2459 ti->error = "Cannot allocate cipher string"; 2460 return -ENOMEM; 2461 } 2462 2463 return 0; 2464 } 2465 2466 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2467 char **ivmode, char **ivopts) 2468 { 2469 struct crypt_config *cc = ti->private; 2470 char *tmp, *cipher, *chainmode, *keycount; 2471 char *cipher_api = NULL; 2472 int ret = -EINVAL; 2473 char dummy; 2474 2475 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2476 ti->error = "Bad cipher specification"; 2477 return -EINVAL; 2478 } 2479 2480 /* 2481 * Legacy dm-crypt cipher specification 2482 * cipher[:keycount]-mode-iv:ivopts 2483 */ 2484 tmp = cipher_in; 2485 keycount = strsep(&tmp, "-"); 2486 cipher = strsep(&keycount, ":"); 2487 2488 if (!keycount) 2489 cc->tfms_count = 1; 2490 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2491 !is_power_of_2(cc->tfms_count)) { 2492 ti->error = "Bad cipher key count specification"; 2493 return -EINVAL; 2494 } 2495 cc->key_parts = cc->tfms_count; 2496 2497 cc->cipher = kstrdup(cipher, GFP_KERNEL); 2498 if (!cc->cipher) 2499 goto bad_mem; 2500 2501 chainmode = strsep(&tmp, "-"); 2502 *ivmode = strsep(&tmp, ":"); 2503 *ivopts = tmp; 2504 2505 /* 2506 * For compatibility with the original dm-crypt mapping format, if 2507 * only the cipher name is supplied, use cbc-plain. 2508 */ 2509 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2510 chainmode = "cbc"; 2511 *ivmode = "plain"; 2512 } 2513 2514 if (strcmp(chainmode, "ecb") && !*ivmode) { 2515 ti->error = "IV mechanism required"; 2516 return -EINVAL; 2517 } 2518 2519 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2520 if (!cipher_api) 2521 goto bad_mem; 2522 2523 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2524 "%s(%s)", chainmode, cipher); 2525 if (ret < 0) { 2526 kfree(cipher_api); 2527 goto bad_mem; 2528 } 2529 2530 /* Allocate cipher */ 2531 ret = crypt_alloc_tfms(cc, cipher_api); 2532 if (ret < 0) { 2533 ti->error = "Error allocating crypto tfm"; 2534 kfree(cipher_api); 2535 return ret; 2536 } 2537 kfree(cipher_api); 2538 2539 return 0; 2540 bad_mem: 2541 ti->error = "Cannot allocate cipher strings"; 2542 return -ENOMEM; 2543 } 2544 2545 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 2546 { 2547 struct crypt_config *cc = ti->private; 2548 char *ivmode = NULL, *ivopts = NULL; 2549 int ret; 2550 2551 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 2552 if (!cc->cipher_string) { 2553 ti->error = "Cannot allocate cipher strings"; 2554 return -ENOMEM; 2555 } 2556 2557 if (strstarts(cipher_in, "capi:")) 2558 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 2559 else 2560 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 2561 if (ret) 2562 return ret; 2563 2564 /* Initialize IV */ 2565 ret = crypt_ctr_ivmode(ti, ivmode); 2566 if (ret < 0) 2567 return ret; 2568 2569 /* Initialize and set key */ 2570 ret = crypt_set_key(cc, key); 2571 if (ret < 0) { 2572 ti->error = "Error decoding and setting key"; 2573 return ret; 2574 } 2575 2576 /* Allocate IV */ 2577 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 2578 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 2579 if (ret < 0) { 2580 ti->error = "Error creating IV"; 2581 return ret; 2582 } 2583 } 2584 2585 /* Initialize IV (set keys for ESSIV etc) */ 2586 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 2587 ret = cc->iv_gen_ops->init(cc); 2588 if (ret < 0) { 2589 ti->error = "Error initialising IV"; 2590 return ret; 2591 } 2592 } 2593 2594 /* wipe the kernel key payload copy */ 2595 if (cc->key_string) 2596 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2597 2598 return ret; 2599 } 2600 2601 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 2602 { 2603 struct crypt_config *cc = ti->private; 2604 struct dm_arg_set as; 2605 static const struct dm_arg _args[] = { 2606 {0, 6, "Invalid number of feature args"}, 2607 }; 2608 unsigned int opt_params, val; 2609 const char *opt_string, *sval; 2610 char dummy; 2611 int ret; 2612 2613 /* Optional parameters */ 2614 as.argc = argc; 2615 as.argv = argv; 2616 2617 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 2618 if (ret) 2619 return ret; 2620 2621 while (opt_params--) { 2622 opt_string = dm_shift_arg(&as); 2623 if (!opt_string) { 2624 ti->error = "Not enough feature arguments"; 2625 return -EINVAL; 2626 } 2627 2628 if (!strcasecmp(opt_string, "allow_discards")) 2629 ti->num_discard_bios = 1; 2630 2631 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 2632 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2633 2634 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 2635 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2636 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 2637 if (val == 0 || val > MAX_TAG_SIZE) { 2638 ti->error = "Invalid integrity arguments"; 2639 return -EINVAL; 2640 } 2641 cc->on_disk_tag_size = val; 2642 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 2643 if (!strcasecmp(sval, "aead")) { 2644 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 2645 } else if (strcasecmp(sval, "none")) { 2646 ti->error = "Unknown integrity profile"; 2647 return -EINVAL; 2648 } 2649 2650 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 2651 if (!cc->cipher_auth) 2652 return -ENOMEM; 2653 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 2654 if (cc->sector_size < (1 << SECTOR_SHIFT) || 2655 cc->sector_size > 4096 || 2656 (cc->sector_size & (cc->sector_size - 1))) { 2657 ti->error = "Invalid feature value for sector_size"; 2658 return -EINVAL; 2659 } 2660 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 2661 ti->error = "Device size is not multiple of sector_size feature"; 2662 return -EINVAL; 2663 } 2664 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 2665 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 2666 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2667 else { 2668 ti->error = "Invalid feature arguments"; 2669 return -EINVAL; 2670 } 2671 } 2672 2673 return 0; 2674 } 2675 2676 /* 2677 * Construct an encryption mapping: 2678 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 2679 */ 2680 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 2681 { 2682 struct crypt_config *cc; 2683 const char *devname = dm_table_device_name(ti->table); 2684 int key_size; 2685 unsigned int align_mask; 2686 unsigned long long tmpll; 2687 int ret; 2688 size_t iv_size_padding, additional_req_size; 2689 char dummy; 2690 2691 if (argc < 5) { 2692 ti->error = "Not enough arguments"; 2693 return -EINVAL; 2694 } 2695 2696 key_size = get_key_size(&argv[1]); 2697 if (key_size < 0) { 2698 ti->error = "Cannot parse key size"; 2699 return -EINVAL; 2700 } 2701 2702 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); 2703 if (!cc) { 2704 ti->error = "Cannot allocate encryption context"; 2705 return -ENOMEM; 2706 } 2707 cc->key_size = key_size; 2708 cc->sector_size = (1 << SECTOR_SHIFT); 2709 cc->sector_shift = 0; 2710 2711 ti->private = cc; 2712 2713 spin_lock(&dm_crypt_clients_lock); 2714 dm_crypt_clients_n++; 2715 crypt_calculate_pages_per_client(); 2716 spin_unlock(&dm_crypt_clients_lock); 2717 2718 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 2719 if (ret < 0) 2720 goto bad; 2721 2722 /* Optional parameters need to be read before cipher constructor */ 2723 if (argc > 5) { 2724 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 2725 if (ret) 2726 goto bad; 2727 } 2728 2729 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 2730 if (ret < 0) 2731 goto bad; 2732 2733 if (crypt_integrity_aead(cc)) { 2734 cc->dmreq_start = sizeof(struct aead_request); 2735 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 2736 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 2737 } else { 2738 cc->dmreq_start = sizeof(struct skcipher_request); 2739 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 2740 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 2741 } 2742 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 2743 2744 if (align_mask < CRYPTO_MINALIGN) { 2745 /* Allocate the padding exactly */ 2746 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 2747 & align_mask; 2748 } else { 2749 /* 2750 * If the cipher requires greater alignment than kmalloc 2751 * alignment, we don't know the exact position of the 2752 * initialization vector. We must assume worst case. 2753 */ 2754 iv_size_padding = align_mask; 2755 } 2756 2757 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 2758 additional_req_size = sizeof(struct dm_crypt_request) + 2759 iv_size_padding + cc->iv_size + 2760 cc->iv_size + 2761 sizeof(uint64_t) + 2762 sizeof(unsigned int); 2763 2764 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 2765 if (ret) { 2766 ti->error = "Cannot allocate crypt request mempool"; 2767 goto bad; 2768 } 2769 2770 cc->per_bio_data_size = ti->per_io_data_size = 2771 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 2772 ARCH_KMALLOC_MINALIGN); 2773 2774 ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc); 2775 if (ret) { 2776 ti->error = "Cannot allocate page mempool"; 2777 goto bad; 2778 } 2779 2780 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 2781 if (ret) { 2782 ti->error = "Cannot allocate crypt bioset"; 2783 goto bad; 2784 } 2785 2786 mutex_init(&cc->bio_alloc_lock); 2787 2788 ret = -EINVAL; 2789 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 2790 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 2791 ti->error = "Invalid iv_offset sector"; 2792 goto bad; 2793 } 2794 cc->iv_offset = tmpll; 2795 2796 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 2797 if (ret) { 2798 ti->error = "Device lookup failed"; 2799 goto bad; 2800 } 2801 2802 ret = -EINVAL; 2803 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { 2804 ti->error = "Invalid device sector"; 2805 goto bad; 2806 } 2807 cc->start = tmpll; 2808 2809 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 2810 ret = crypt_integrity_ctr(cc, ti); 2811 if (ret) 2812 goto bad; 2813 2814 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 2815 if (!cc->tag_pool_max_sectors) 2816 cc->tag_pool_max_sectors = 1; 2817 2818 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 2819 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 2820 if (ret) { 2821 ti->error = "Cannot allocate integrity tags mempool"; 2822 goto bad; 2823 } 2824 2825 cc->tag_pool_max_sectors <<= cc->sector_shift; 2826 } 2827 2828 ret = -ENOMEM; 2829 cc->io_queue = alloc_workqueue("kcryptd_io/%s", 2830 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 2831 1, devname); 2832 if (!cc->io_queue) { 2833 ti->error = "Couldn't create kcryptd io queue"; 2834 goto bad; 2835 } 2836 2837 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2838 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 2839 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 2840 1, devname); 2841 else 2842 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 2843 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 2844 num_online_cpus(), devname); 2845 if (!cc->crypt_queue) { 2846 ti->error = "Couldn't create kcryptd queue"; 2847 goto bad; 2848 } 2849 2850 spin_lock_init(&cc->write_thread_lock); 2851 cc->write_tree = RB_ROOT; 2852 2853 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname); 2854 if (IS_ERR(cc->write_thread)) { 2855 ret = PTR_ERR(cc->write_thread); 2856 cc->write_thread = NULL; 2857 ti->error = "Couldn't spawn write thread"; 2858 goto bad; 2859 } 2860 wake_up_process(cc->write_thread); 2861 2862 ti->num_flush_bios = 1; 2863 2864 return 0; 2865 2866 bad: 2867 crypt_dtr(ti); 2868 return ret; 2869 } 2870 2871 static int crypt_map(struct dm_target *ti, struct bio *bio) 2872 { 2873 struct dm_crypt_io *io; 2874 struct crypt_config *cc = ti->private; 2875 2876 /* 2877 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 2878 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 2879 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 2880 */ 2881 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 2882 bio_op(bio) == REQ_OP_DISCARD)) { 2883 bio_set_dev(bio, cc->dev->bdev); 2884 if (bio_sectors(bio)) 2885 bio->bi_iter.bi_sector = cc->start + 2886 dm_target_offset(ti, bio->bi_iter.bi_sector); 2887 return DM_MAPIO_REMAPPED; 2888 } 2889 2890 /* 2891 * Check if bio is too large, split as needed. 2892 */ 2893 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && 2894 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 2895 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); 2896 2897 /* 2898 * Ensure that bio is a multiple of internal sector encryption size 2899 * and is aligned to this size as defined in IO hints. 2900 */ 2901 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 2902 return DM_MAPIO_KILL; 2903 2904 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 2905 return DM_MAPIO_KILL; 2906 2907 io = dm_per_bio_data(bio, cc->per_bio_data_size); 2908 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 2909 2910 if (cc->on_disk_tag_size) { 2911 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 2912 2913 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 2914 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 2915 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 2916 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 2917 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 2918 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 2919 io->integrity_metadata_from_pool = true; 2920 } 2921 } 2922 2923 if (crypt_integrity_aead(cc)) 2924 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 2925 else 2926 io->ctx.r.req = (struct skcipher_request *)(io + 1); 2927 2928 if (bio_data_dir(io->base_bio) == READ) { 2929 if (kcryptd_io_read(io, GFP_NOWAIT)) 2930 kcryptd_queue_read(io); 2931 } else 2932 kcryptd_queue_crypt(io); 2933 2934 return DM_MAPIO_SUBMITTED; 2935 } 2936 2937 static void crypt_status(struct dm_target *ti, status_type_t type, 2938 unsigned status_flags, char *result, unsigned maxlen) 2939 { 2940 struct crypt_config *cc = ti->private; 2941 unsigned i, sz = 0; 2942 int num_feature_args = 0; 2943 2944 switch (type) { 2945 case STATUSTYPE_INFO: 2946 result[0] = '\0'; 2947 break; 2948 2949 case STATUSTYPE_TABLE: 2950 DMEMIT("%s ", cc->cipher_string); 2951 2952 if (cc->key_size > 0) { 2953 if (cc->key_string) 2954 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 2955 else 2956 for (i = 0; i < cc->key_size; i++) 2957 DMEMIT("%02x", cc->key[i]); 2958 } else 2959 DMEMIT("-"); 2960 2961 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 2962 cc->dev->name, (unsigned long long)cc->start); 2963 2964 num_feature_args += !!ti->num_discard_bios; 2965 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2966 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2967 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 2968 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2969 if (cc->on_disk_tag_size) 2970 num_feature_args++; 2971 if (num_feature_args) { 2972 DMEMIT(" %d", num_feature_args); 2973 if (ti->num_discard_bios) 2974 DMEMIT(" allow_discards"); 2975 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2976 DMEMIT(" same_cpu_crypt"); 2977 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 2978 DMEMIT(" submit_from_crypt_cpus"); 2979 if (cc->on_disk_tag_size) 2980 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 2981 if (cc->sector_size != (1 << SECTOR_SHIFT)) 2982 DMEMIT(" sector_size:%d", cc->sector_size); 2983 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 2984 DMEMIT(" iv_large_sectors"); 2985 } 2986 2987 break; 2988 } 2989 } 2990 2991 static void crypt_postsuspend(struct dm_target *ti) 2992 { 2993 struct crypt_config *cc = ti->private; 2994 2995 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2996 } 2997 2998 static int crypt_preresume(struct dm_target *ti) 2999 { 3000 struct crypt_config *cc = ti->private; 3001 3002 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 3003 DMERR("aborting resume - crypt key is not set."); 3004 return -EAGAIN; 3005 } 3006 3007 return 0; 3008 } 3009 3010 static void crypt_resume(struct dm_target *ti) 3011 { 3012 struct crypt_config *cc = ti->private; 3013 3014 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3015 } 3016 3017 /* Message interface 3018 * key set <key> 3019 * key wipe 3020 */ 3021 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv, 3022 char *result, unsigned maxlen) 3023 { 3024 struct crypt_config *cc = ti->private; 3025 int key_size, ret = -EINVAL; 3026 3027 if (argc < 2) 3028 goto error; 3029 3030 if (!strcasecmp(argv[0], "key")) { 3031 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 3032 DMWARN("not suspended during key manipulation."); 3033 return -EINVAL; 3034 } 3035 if (argc == 3 && !strcasecmp(argv[1], "set")) { 3036 /* The key size may not be changed. */ 3037 key_size = get_key_size(&argv[2]); 3038 if (key_size < 0 || cc->key_size != key_size) { 3039 memset(argv[2], '0', strlen(argv[2])); 3040 return -EINVAL; 3041 } 3042 3043 ret = crypt_set_key(cc, argv[2]); 3044 if (ret) 3045 return ret; 3046 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 3047 ret = cc->iv_gen_ops->init(cc); 3048 /* wipe the kernel key payload copy */ 3049 if (cc->key_string) 3050 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3051 return ret; 3052 } 3053 if (argc == 2 && !strcasecmp(argv[1], "wipe")) { 3054 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 3055 ret = cc->iv_gen_ops->wipe(cc); 3056 if (ret) 3057 return ret; 3058 } 3059 return crypt_wipe_key(cc); 3060 } 3061 } 3062 3063 error: 3064 DMWARN("unrecognised message received."); 3065 return -EINVAL; 3066 } 3067 3068 static int crypt_iterate_devices(struct dm_target *ti, 3069 iterate_devices_callout_fn fn, void *data) 3070 { 3071 struct crypt_config *cc = ti->private; 3072 3073 return fn(ti, cc->dev, cc->start, ti->len, data); 3074 } 3075 3076 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3077 { 3078 struct crypt_config *cc = ti->private; 3079 3080 /* 3081 * Unfortunate constraint that is required to avoid the potential 3082 * for exceeding underlying device's max_segments limits -- due to 3083 * crypt_alloc_buffer() possibly allocating pages for the encryption 3084 * bio that are not as physically contiguous as the original bio. 3085 */ 3086 limits->max_segment_size = PAGE_SIZE; 3087 3088 limits->logical_block_size = 3089 max_t(unsigned short, limits->logical_block_size, cc->sector_size); 3090 limits->physical_block_size = 3091 max_t(unsigned, limits->physical_block_size, cc->sector_size); 3092 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); 3093 } 3094 3095 static struct target_type crypt_target = { 3096 .name = "crypt", 3097 .version = {1, 18, 1}, 3098 .module = THIS_MODULE, 3099 .ctr = crypt_ctr, 3100 .dtr = crypt_dtr, 3101 .map = crypt_map, 3102 .status = crypt_status, 3103 .postsuspend = crypt_postsuspend, 3104 .preresume = crypt_preresume, 3105 .resume = crypt_resume, 3106 .message = crypt_message, 3107 .iterate_devices = crypt_iterate_devices, 3108 .io_hints = crypt_io_hints, 3109 }; 3110 3111 static int __init dm_crypt_init(void) 3112 { 3113 int r; 3114 3115 r = dm_register_target(&crypt_target); 3116 if (r < 0) 3117 DMERR("register failed %d", r); 3118 3119 return r; 3120 } 3121 3122 static void __exit dm_crypt_exit(void) 3123 { 3124 dm_unregister_target(&crypt_target); 3125 } 3126 3127 module_init(dm_crypt_init); 3128 module_exit(dm_crypt_exit); 3129 3130 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3131 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3132 MODULE_LICENSE("GPL"); 3133