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