1 /* 2 * Copyright (C) 2003 Jana Saout <jana@saout.de> 3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 4 * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved. 5 * Copyright (C) 2013-2017 Milan Broz <gmazyland@gmail.com> 6 * 7 * This file is released under the GPL. 8 */ 9 10 #include <linux/completion.h> 11 #include <linux/err.h> 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/key.h> 16 #include <linux/bio.h> 17 #include <linux/blkdev.h> 18 #include <linux/mempool.h> 19 #include <linux/slab.h> 20 #include <linux/crypto.h> 21 #include <linux/workqueue.h> 22 #include <linux/kthread.h> 23 #include <linux/backing-dev.h> 24 #include <linux/atomic.h> 25 #include <linux/scatterlist.h> 26 #include <linux/rbtree.h> 27 #include <linux/ctype.h> 28 #include <asm/page.h> 29 #include <asm/unaligned.h> 30 #include <crypto/hash.h> 31 #include <crypto/md5.h> 32 #include <crypto/algapi.h> 33 #include <crypto/skcipher.h> 34 #include <crypto/aead.h> 35 #include <crypto/authenc.h> 36 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ 37 #include <keys/user-type.h> 38 39 #include <linux/device-mapper.h> 40 41 #define DM_MSG_PREFIX "crypt" 42 43 /* 44 * context holding the current state of a multi-part conversion 45 */ 46 struct convert_context { 47 struct completion restart; 48 struct bio *bio_in; 49 struct bio *bio_out; 50 struct bvec_iter iter_in; 51 struct bvec_iter iter_out; 52 sector_t cc_sector; 53 atomic_t cc_pending; 54 union { 55 struct skcipher_request *req; 56 struct aead_request *req_aead; 57 } r; 58 59 }; 60 61 /* 62 * per bio private data 63 */ 64 struct dm_crypt_io { 65 struct crypt_config *cc; 66 struct bio *base_bio; 67 u8 *integrity_metadata; 68 bool integrity_metadata_from_pool; 69 struct work_struct work; 70 71 struct convert_context ctx; 72 73 atomic_t io_pending; 74 blk_status_t error; 75 sector_t sector; 76 77 struct rb_node rb_node; 78 } CRYPTO_MINALIGN_ATTR; 79 80 struct dm_crypt_request { 81 struct convert_context *ctx; 82 struct scatterlist sg_in[4]; 83 struct scatterlist sg_out[4]; 84 sector_t iv_sector; 85 }; 86 87 struct crypt_config; 88 89 struct crypt_iv_operations { 90 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 91 const char *opts); 92 void (*dtr)(struct crypt_config *cc); 93 int (*init)(struct crypt_config *cc); 94 int (*wipe)(struct crypt_config *cc); 95 int (*generator)(struct crypt_config *cc, u8 *iv, 96 struct dm_crypt_request *dmreq); 97 int (*post)(struct crypt_config *cc, u8 *iv, 98 struct dm_crypt_request *dmreq); 99 }; 100 101 struct iv_essiv_private { 102 struct crypto_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 sector_t 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 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; 336 337 err = crypto_shash_digest(desc, cc->key, cc->key_size, essiv->salt); 338 shash_desc_zero(desc); 339 if (err) 340 return err; 341 342 essiv_tfm = cc->iv_private; 343 344 err = crypto_cipher_setkey(essiv_tfm, essiv->salt, 345 crypto_shash_digestsize(essiv->hash_tfm)); 346 if (err) 347 return err; 348 349 return 0; 350 } 351 352 /* Wipe salt and reset key derived from volume key */ 353 static int crypt_iv_essiv_wipe(struct crypt_config *cc) 354 { 355 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; 356 unsigned salt_size = crypto_shash_digestsize(essiv->hash_tfm); 357 struct crypto_cipher *essiv_tfm; 358 int r, err = 0; 359 360 memset(essiv->salt, 0, salt_size); 361 362 essiv_tfm = cc->iv_private; 363 r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size); 364 if (r) 365 err = r; 366 367 return err; 368 } 369 370 /* Allocate the cipher for ESSIV */ 371 static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc, 372 struct dm_target *ti, 373 const u8 *salt, 374 unsigned int saltsize) 375 { 376 struct crypto_cipher *essiv_tfm; 377 int err; 378 379 /* Setup the essiv_tfm with the given salt */ 380 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 381 if (IS_ERR(essiv_tfm)) { 382 ti->error = "Error allocating crypto tfm for ESSIV"; 383 return essiv_tfm; 384 } 385 386 if (crypto_cipher_blocksize(essiv_tfm) != cc->iv_size) { 387 ti->error = "Block size of ESSIV cipher does " 388 "not match IV size of block cipher"; 389 crypto_free_cipher(essiv_tfm); 390 return ERR_PTR(-EINVAL); 391 } 392 393 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); 394 if (err) { 395 ti->error = "Failed to set key for ESSIV cipher"; 396 crypto_free_cipher(essiv_tfm); 397 return ERR_PTR(err); 398 } 399 400 return essiv_tfm; 401 } 402 403 static void crypt_iv_essiv_dtr(struct crypt_config *cc) 404 { 405 struct crypto_cipher *essiv_tfm; 406 struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; 407 408 crypto_free_shash(essiv->hash_tfm); 409 essiv->hash_tfm = NULL; 410 411 kzfree(essiv->salt); 412 essiv->salt = NULL; 413 414 essiv_tfm = cc->iv_private; 415 416 if (essiv_tfm) 417 crypto_free_cipher(essiv_tfm); 418 419 cc->iv_private = NULL; 420 } 421 422 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, 423 const char *opts) 424 { 425 struct crypto_cipher *essiv_tfm = NULL; 426 struct crypto_shash *hash_tfm = NULL; 427 u8 *salt = NULL; 428 int err; 429 430 if (!opts) { 431 ti->error = "Digest algorithm missing for ESSIV mode"; 432 return -EINVAL; 433 } 434 435 /* Allocate hash algorithm */ 436 hash_tfm = crypto_alloc_shash(opts, 0, 0); 437 if (IS_ERR(hash_tfm)) { 438 ti->error = "Error initializing ESSIV hash"; 439 err = PTR_ERR(hash_tfm); 440 goto bad; 441 } 442 443 salt = kzalloc(crypto_shash_digestsize(hash_tfm), GFP_KERNEL); 444 if (!salt) { 445 ti->error = "Error kmallocing salt storage in ESSIV"; 446 err = -ENOMEM; 447 goto bad; 448 } 449 450 cc->iv_gen_private.essiv.salt = salt; 451 cc->iv_gen_private.essiv.hash_tfm = hash_tfm; 452 453 essiv_tfm = alloc_essiv_cipher(cc, ti, salt, 454 crypto_shash_digestsize(hash_tfm)); 455 if (IS_ERR(essiv_tfm)) { 456 crypt_iv_essiv_dtr(cc); 457 return PTR_ERR(essiv_tfm); 458 } 459 cc->iv_private = essiv_tfm; 460 461 return 0; 462 463 bad: 464 if (hash_tfm && !IS_ERR(hash_tfm)) 465 crypto_free_shash(hash_tfm); 466 kfree(salt); 467 return err; 468 } 469 470 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 471 struct dm_crypt_request *dmreq) 472 { 473 struct crypto_cipher *essiv_tfm = cc->iv_private; 474 475 memset(iv, 0, cc->iv_size); 476 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 477 crypto_cipher_encrypt_one(essiv_tfm, iv, iv); 478 479 return 0; 480 } 481 482 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 483 const char *opts) 484 { 485 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc)); 486 int log = ilog2(bs); 487 488 /* we need to calculate how far we must shift the sector count 489 * to get the cipher block count, we use this shift in _gen */ 490 491 if (1 << log != bs) { 492 ti->error = "cypher blocksize is not a power of 2"; 493 return -EINVAL; 494 } 495 496 if (log > 9) { 497 ti->error = "cypher blocksize is > 512"; 498 return -EINVAL; 499 } 500 501 cc->iv_gen_private.benbi.shift = 9 - log; 502 503 return 0; 504 } 505 506 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 507 { 508 } 509 510 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 511 struct dm_crypt_request *dmreq) 512 { 513 __be64 val; 514 515 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 516 517 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 518 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 519 520 return 0; 521 } 522 523 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 524 struct dm_crypt_request *dmreq) 525 { 526 memset(iv, 0, cc->iv_size); 527 528 return 0; 529 } 530 531 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 532 { 533 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 534 535 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 536 crypto_free_shash(lmk->hash_tfm); 537 lmk->hash_tfm = NULL; 538 539 kzfree(lmk->seed); 540 lmk->seed = NULL; 541 } 542 543 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 544 const char *opts) 545 { 546 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 547 548 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 549 ti->error = "Unsupported sector size for LMK"; 550 return -EINVAL; 551 } 552 553 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); 554 if (IS_ERR(lmk->hash_tfm)) { 555 ti->error = "Error initializing LMK hash"; 556 return PTR_ERR(lmk->hash_tfm); 557 } 558 559 /* No seed in LMK version 2 */ 560 if (cc->key_parts == cc->tfms_count) { 561 lmk->seed = NULL; 562 return 0; 563 } 564 565 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 566 if (!lmk->seed) { 567 crypt_iv_lmk_dtr(cc); 568 ti->error = "Error kmallocing seed storage in LMK"; 569 return -ENOMEM; 570 } 571 572 return 0; 573 } 574 575 static int crypt_iv_lmk_init(struct crypt_config *cc) 576 { 577 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 578 int subkey_size = cc->key_size / cc->key_parts; 579 580 /* LMK seed is on the position of LMK_KEYS + 1 key */ 581 if (lmk->seed) 582 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 583 crypto_shash_digestsize(lmk->hash_tfm)); 584 585 return 0; 586 } 587 588 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 589 { 590 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 591 592 if (lmk->seed) 593 memset(lmk->seed, 0, LMK_SEED_SIZE); 594 595 return 0; 596 } 597 598 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 599 struct dm_crypt_request *dmreq, 600 u8 *data) 601 { 602 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 603 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 604 struct md5_state md5state; 605 __le32 buf[4]; 606 int i, r; 607 608 desc->tfm = lmk->hash_tfm; 609 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; 610 611 r = crypto_shash_init(desc); 612 if (r) 613 return r; 614 615 if (lmk->seed) { 616 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 617 if (r) 618 return r; 619 } 620 621 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 622 r = crypto_shash_update(desc, data + 16, 16 * 31); 623 if (r) 624 return r; 625 626 /* Sector is cropped to 56 bits here */ 627 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 628 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 629 buf[2] = cpu_to_le32(4024); 630 buf[3] = 0; 631 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 632 if (r) 633 return r; 634 635 /* No MD5 padding here */ 636 r = crypto_shash_export(desc, &md5state); 637 if (r) 638 return r; 639 640 for (i = 0; i < MD5_HASH_WORDS; i++) 641 __cpu_to_le32s(&md5state.hash[i]); 642 memcpy(iv, &md5state.hash, cc->iv_size); 643 644 return 0; 645 } 646 647 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 648 struct dm_crypt_request *dmreq) 649 { 650 struct scatterlist *sg; 651 u8 *src; 652 int r = 0; 653 654 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 655 sg = crypt_get_sg_data(cc, dmreq->sg_in); 656 src = kmap_atomic(sg_page(sg)); 657 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 658 kunmap_atomic(src); 659 } else 660 memset(iv, 0, cc->iv_size); 661 662 return r; 663 } 664 665 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 666 struct dm_crypt_request *dmreq) 667 { 668 struct scatterlist *sg; 669 u8 *dst; 670 int r; 671 672 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 673 return 0; 674 675 sg = crypt_get_sg_data(cc, dmreq->sg_out); 676 dst = kmap_atomic(sg_page(sg)); 677 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 678 679 /* Tweak the first block of plaintext sector */ 680 if (!r) 681 crypto_xor(dst + sg->offset, iv, cc->iv_size); 682 683 kunmap_atomic(dst); 684 return r; 685 } 686 687 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 688 { 689 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 690 691 kzfree(tcw->iv_seed); 692 tcw->iv_seed = NULL; 693 kzfree(tcw->whitening); 694 tcw->whitening = NULL; 695 696 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 697 crypto_free_shash(tcw->crc32_tfm); 698 tcw->crc32_tfm = NULL; 699 } 700 701 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 702 const char *opts) 703 { 704 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 705 706 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 707 ti->error = "Unsupported sector size for TCW"; 708 return -EINVAL; 709 } 710 711 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 712 ti->error = "Wrong key size for TCW"; 713 return -EINVAL; 714 } 715 716 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); 717 if (IS_ERR(tcw->crc32_tfm)) { 718 ti->error = "Error initializing CRC32 in TCW"; 719 return PTR_ERR(tcw->crc32_tfm); 720 } 721 722 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 723 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 724 if (!tcw->iv_seed || !tcw->whitening) { 725 crypt_iv_tcw_dtr(cc); 726 ti->error = "Error allocating seed storage in TCW"; 727 return -ENOMEM; 728 } 729 730 return 0; 731 } 732 733 static int crypt_iv_tcw_init(struct crypt_config *cc) 734 { 735 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 736 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 737 738 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 739 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 740 TCW_WHITENING_SIZE); 741 742 return 0; 743 } 744 745 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 746 { 747 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 748 749 memset(tcw->iv_seed, 0, cc->iv_size); 750 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 751 752 return 0; 753 } 754 755 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 756 struct dm_crypt_request *dmreq, 757 u8 *data) 758 { 759 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 760 __le64 sector = cpu_to_le64(dmreq->iv_sector); 761 u8 buf[TCW_WHITENING_SIZE]; 762 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 763 int i, r; 764 765 /* xor whitening with sector number */ 766 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 767 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 768 769 /* calculate crc32 for every 32bit part and xor it */ 770 desc->tfm = tcw->crc32_tfm; 771 desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; 772 for (i = 0; i < 4; i++) { 773 r = crypto_shash_init(desc); 774 if (r) 775 goto out; 776 r = crypto_shash_update(desc, &buf[i * 4], 4); 777 if (r) 778 goto out; 779 r = crypto_shash_final(desc, &buf[i * 4]); 780 if (r) 781 goto out; 782 } 783 crypto_xor(&buf[0], &buf[12], 4); 784 crypto_xor(&buf[4], &buf[8], 4); 785 786 /* apply whitening (8 bytes) to whole sector */ 787 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 788 crypto_xor(data + i * 8, buf, 8); 789 out: 790 memzero_explicit(buf, sizeof(buf)); 791 return r; 792 } 793 794 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 795 struct dm_crypt_request *dmreq) 796 { 797 struct scatterlist *sg; 798 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 799 __le64 sector = cpu_to_le64(dmreq->iv_sector); 800 u8 *src; 801 int r = 0; 802 803 /* Remove whitening from ciphertext */ 804 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 805 sg = crypt_get_sg_data(cc, dmreq->sg_in); 806 src = kmap_atomic(sg_page(sg)); 807 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 808 kunmap_atomic(src); 809 } 810 811 /* Calculate IV */ 812 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 813 if (cc->iv_size > 8) 814 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 815 cc->iv_size - 8); 816 817 return r; 818 } 819 820 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 821 struct dm_crypt_request *dmreq) 822 { 823 struct scatterlist *sg; 824 u8 *dst; 825 int r; 826 827 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 828 return 0; 829 830 /* Apply whitening on ciphertext */ 831 sg = crypt_get_sg_data(cc, dmreq->sg_out); 832 dst = kmap_atomic(sg_page(sg)); 833 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 834 kunmap_atomic(dst); 835 836 return r; 837 } 838 839 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 840 struct dm_crypt_request *dmreq) 841 { 842 /* Used only for writes, there must be an additional space to store IV */ 843 get_random_bytes(iv, cc->iv_size); 844 return 0; 845 } 846 847 static const struct crypt_iv_operations crypt_iv_plain_ops = { 848 .generator = crypt_iv_plain_gen 849 }; 850 851 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 852 .generator = crypt_iv_plain64_gen 853 }; 854 855 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 856 .generator = crypt_iv_plain64be_gen 857 }; 858 859 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 860 .ctr = crypt_iv_essiv_ctr, 861 .dtr = crypt_iv_essiv_dtr, 862 .init = crypt_iv_essiv_init, 863 .wipe = crypt_iv_essiv_wipe, 864 .generator = crypt_iv_essiv_gen 865 }; 866 867 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 868 .ctr = crypt_iv_benbi_ctr, 869 .dtr = crypt_iv_benbi_dtr, 870 .generator = crypt_iv_benbi_gen 871 }; 872 873 static const struct crypt_iv_operations crypt_iv_null_ops = { 874 .generator = crypt_iv_null_gen 875 }; 876 877 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 878 .ctr = crypt_iv_lmk_ctr, 879 .dtr = crypt_iv_lmk_dtr, 880 .init = crypt_iv_lmk_init, 881 .wipe = crypt_iv_lmk_wipe, 882 .generator = crypt_iv_lmk_gen, 883 .post = crypt_iv_lmk_post 884 }; 885 886 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 887 .ctr = crypt_iv_tcw_ctr, 888 .dtr = crypt_iv_tcw_dtr, 889 .init = crypt_iv_tcw_init, 890 .wipe = crypt_iv_tcw_wipe, 891 .generator = crypt_iv_tcw_gen, 892 .post = crypt_iv_tcw_post 893 }; 894 895 static struct crypt_iv_operations crypt_iv_random_ops = { 896 .generator = crypt_iv_random_gen 897 }; 898 899 /* 900 * Integrity extensions 901 */ 902 static bool crypt_integrity_aead(struct crypt_config *cc) 903 { 904 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 905 } 906 907 static bool crypt_integrity_hmac(struct crypt_config *cc) 908 { 909 return crypt_integrity_aead(cc) && cc->key_mac_size; 910 } 911 912 /* Get sg containing data */ 913 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 914 struct scatterlist *sg) 915 { 916 if (unlikely(crypt_integrity_aead(cc))) 917 return &sg[2]; 918 919 return sg; 920 } 921 922 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 923 { 924 struct bio_integrity_payload *bip; 925 unsigned int tag_len; 926 int ret; 927 928 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 929 return 0; 930 931 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 932 if (IS_ERR(bip)) 933 return PTR_ERR(bip); 934 935 tag_len = io->cc->on_disk_tag_size * bio_sectors(bio); 936 937 bip->bip_iter.bi_size = tag_len; 938 bip->bip_iter.bi_sector = io->cc->start + io->sector; 939 940 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 941 tag_len, offset_in_page(io->integrity_metadata)); 942 if (unlikely(ret != tag_len)) 943 return -ENOMEM; 944 945 return 0; 946 } 947 948 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 949 { 950 #ifdef CONFIG_BLK_DEV_INTEGRITY 951 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 952 953 /* From now we require underlying device with our integrity profile */ 954 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 955 ti->error = "Integrity profile not supported."; 956 return -EINVAL; 957 } 958 959 if (bi->tag_size != cc->on_disk_tag_size || 960 bi->tuple_size != cc->on_disk_tag_size) { 961 ti->error = "Integrity profile tag size mismatch."; 962 return -EINVAL; 963 } 964 if (1 << bi->interval_exp != cc->sector_size) { 965 ti->error = "Integrity profile sector size mismatch."; 966 return -EINVAL; 967 } 968 969 if (crypt_integrity_aead(cc)) { 970 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 971 DMINFO("Integrity AEAD, tag size %u, IV size %u.", 972 cc->integrity_tag_size, cc->integrity_iv_size); 973 974 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 975 ti->error = "Integrity AEAD auth tag size is not supported."; 976 return -EINVAL; 977 } 978 } else if (cc->integrity_iv_size) 979 DMINFO("Additional per-sector space %u bytes for IV.", 980 cc->integrity_iv_size); 981 982 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 983 ti->error = "Not enough space for integrity tag in the profile."; 984 return -EINVAL; 985 } 986 987 return 0; 988 #else 989 ti->error = "Integrity profile not supported."; 990 return -EINVAL; 991 #endif 992 } 993 994 static void crypt_convert_init(struct crypt_config *cc, 995 struct convert_context *ctx, 996 struct bio *bio_out, struct bio *bio_in, 997 sector_t sector) 998 { 999 ctx->bio_in = bio_in; 1000 ctx->bio_out = bio_out; 1001 if (bio_in) 1002 ctx->iter_in = bio_in->bi_iter; 1003 if (bio_out) 1004 ctx->iter_out = bio_out->bi_iter; 1005 ctx->cc_sector = sector + cc->iv_offset; 1006 init_completion(&ctx->restart); 1007 } 1008 1009 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1010 void *req) 1011 { 1012 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1013 } 1014 1015 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1016 { 1017 return (void *)((char *)dmreq - cc->dmreq_start); 1018 } 1019 1020 static u8 *iv_of_dmreq(struct crypt_config *cc, 1021 struct dm_crypt_request *dmreq) 1022 { 1023 if (crypt_integrity_aead(cc)) 1024 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1025 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1026 else 1027 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1028 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1029 } 1030 1031 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1032 struct dm_crypt_request *dmreq) 1033 { 1034 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1035 } 1036 1037 static uint64_t *org_sector_of_dmreq(struct crypt_config *cc, 1038 struct dm_crypt_request *dmreq) 1039 { 1040 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1041 return (uint64_t*) ptr; 1042 } 1043 1044 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1045 struct dm_crypt_request *dmreq) 1046 { 1047 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1048 cc->iv_size + sizeof(uint64_t); 1049 return (unsigned int*)ptr; 1050 } 1051 1052 static void *tag_from_dmreq(struct crypt_config *cc, 1053 struct dm_crypt_request *dmreq) 1054 { 1055 struct convert_context *ctx = dmreq->ctx; 1056 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1057 1058 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1059 cc->on_disk_tag_size]; 1060 } 1061 1062 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1063 struct dm_crypt_request *dmreq) 1064 { 1065 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1066 } 1067 1068 static int crypt_convert_block_aead(struct crypt_config *cc, 1069 struct convert_context *ctx, 1070 struct aead_request *req, 1071 unsigned int tag_offset) 1072 { 1073 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1074 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1075 struct dm_crypt_request *dmreq; 1076 u8 *iv, *org_iv, *tag_iv, *tag; 1077 uint64_t *sector; 1078 int r = 0; 1079 1080 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1081 1082 /* Reject unexpected unaligned bio. */ 1083 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1084 return -EIO; 1085 1086 dmreq = dmreq_of_req(cc, req); 1087 dmreq->iv_sector = ctx->cc_sector; 1088 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1089 dmreq->iv_sector >>= cc->sector_shift; 1090 dmreq->ctx = ctx; 1091 1092 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1093 1094 sector = org_sector_of_dmreq(cc, dmreq); 1095 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1096 1097 iv = iv_of_dmreq(cc, dmreq); 1098 org_iv = org_iv_of_dmreq(cc, dmreq); 1099 tag = tag_from_dmreq(cc, dmreq); 1100 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1101 1102 /* AEAD request: 1103 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1104 * | (authenticated) | (auth+encryption) | | 1105 * | sector_LE | IV | sector in/out | tag in/out | 1106 */ 1107 sg_init_table(dmreq->sg_in, 4); 1108 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1109 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1110 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1111 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1112 1113 sg_init_table(dmreq->sg_out, 4); 1114 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1115 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1116 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1117 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1118 1119 if (cc->iv_gen_ops) { 1120 /* For READs use IV stored in integrity metadata */ 1121 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1122 memcpy(org_iv, tag_iv, cc->iv_size); 1123 } else { 1124 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1125 if (r < 0) 1126 return r; 1127 /* Store generated IV in integrity metadata */ 1128 if (cc->integrity_iv_size) 1129 memcpy(tag_iv, org_iv, cc->iv_size); 1130 } 1131 /* Working copy of IV, to be modified in crypto API */ 1132 memcpy(iv, org_iv, cc->iv_size); 1133 } 1134 1135 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1136 if (bio_data_dir(ctx->bio_in) == WRITE) { 1137 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1138 cc->sector_size, iv); 1139 r = crypto_aead_encrypt(req); 1140 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1141 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1142 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1143 } else { 1144 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1145 cc->sector_size + cc->integrity_tag_size, iv); 1146 r = crypto_aead_decrypt(req); 1147 } 1148 1149 if (r == -EBADMSG) 1150 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu", 1151 (unsigned long long)le64_to_cpu(*sector)); 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 uint64_t *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 | CRYPTO_TFM_REQ_MAY_SLEEP, 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 | CRYPTO_TFM_REQ_MAY_SLEEP, 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 unsigned int i; 1449 struct bio_vec *bv; 1450 1451 bio_for_each_segment_all(bv, clone, i) { 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 DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu", 1795 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); 1796 io->error = BLK_STS_PROTECTION; 1797 } else if (error < 0) 1798 io->error = BLK_STS_IOERR; 1799 1800 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 1801 1802 if (!atomic_dec_and_test(&ctx->cc_pending)) 1803 return; 1804 1805 if (bio_data_dir(io->base_bio) == READ) 1806 kcryptd_crypt_read_done(io); 1807 else 1808 kcryptd_crypt_write_io_submit(io, 1); 1809 } 1810 1811 static void kcryptd_crypt(struct work_struct *work) 1812 { 1813 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1814 1815 if (bio_data_dir(io->base_bio) == READ) 1816 kcryptd_crypt_read_convert(io); 1817 else 1818 kcryptd_crypt_write_convert(io); 1819 } 1820 1821 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 1822 { 1823 struct crypt_config *cc = io->cc; 1824 1825 INIT_WORK(&io->work, kcryptd_crypt); 1826 queue_work(cc->crypt_queue, &io->work); 1827 } 1828 1829 static void crypt_free_tfms_aead(struct crypt_config *cc) 1830 { 1831 if (!cc->cipher_tfm.tfms_aead) 1832 return; 1833 1834 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1835 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 1836 cc->cipher_tfm.tfms_aead[0] = NULL; 1837 } 1838 1839 kfree(cc->cipher_tfm.tfms_aead); 1840 cc->cipher_tfm.tfms_aead = NULL; 1841 } 1842 1843 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 1844 { 1845 unsigned i; 1846 1847 if (!cc->cipher_tfm.tfms) 1848 return; 1849 1850 for (i = 0; i < cc->tfms_count; i++) 1851 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 1852 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 1853 cc->cipher_tfm.tfms[i] = NULL; 1854 } 1855 1856 kfree(cc->cipher_tfm.tfms); 1857 cc->cipher_tfm.tfms = NULL; 1858 } 1859 1860 static void crypt_free_tfms(struct crypt_config *cc) 1861 { 1862 if (crypt_integrity_aead(cc)) 1863 crypt_free_tfms_aead(cc); 1864 else 1865 crypt_free_tfms_skcipher(cc); 1866 } 1867 1868 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 1869 { 1870 unsigned i; 1871 int err; 1872 1873 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 1874 sizeof(struct crypto_skcipher *), 1875 GFP_KERNEL); 1876 if (!cc->cipher_tfm.tfms) 1877 return -ENOMEM; 1878 1879 for (i = 0; i < cc->tfms_count; i++) { 1880 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0); 1881 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 1882 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 1883 crypt_free_tfms(cc); 1884 return err; 1885 } 1886 } 1887 1888 return 0; 1889 } 1890 1891 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 1892 { 1893 int err; 1894 1895 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 1896 if (!cc->cipher_tfm.tfms) 1897 return -ENOMEM; 1898 1899 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0); 1900 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1901 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 1902 crypt_free_tfms(cc); 1903 return err; 1904 } 1905 1906 return 0; 1907 } 1908 1909 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 1910 { 1911 if (crypt_integrity_aead(cc)) 1912 return crypt_alloc_tfms_aead(cc, ciphermode); 1913 else 1914 return crypt_alloc_tfms_skcipher(cc, ciphermode); 1915 } 1916 1917 static unsigned crypt_subkey_size(struct crypt_config *cc) 1918 { 1919 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 1920 } 1921 1922 static unsigned crypt_authenckey_size(struct crypt_config *cc) 1923 { 1924 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 1925 } 1926 1927 /* 1928 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 1929 * the key must be for some reason in special format. 1930 * This funcion converts cc->key to this special format. 1931 */ 1932 static void crypt_copy_authenckey(char *p, const void *key, 1933 unsigned enckeylen, unsigned authkeylen) 1934 { 1935 struct crypto_authenc_key_param *param; 1936 struct rtattr *rta; 1937 1938 rta = (struct rtattr *)p; 1939 param = RTA_DATA(rta); 1940 param->enckeylen = cpu_to_be32(enckeylen); 1941 rta->rta_len = RTA_LENGTH(sizeof(*param)); 1942 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 1943 p += RTA_SPACE(sizeof(*param)); 1944 memcpy(p, key + enckeylen, authkeylen); 1945 p += authkeylen; 1946 memcpy(p, key, enckeylen); 1947 } 1948 1949 static int crypt_setkey(struct crypt_config *cc) 1950 { 1951 unsigned subkey_size; 1952 int err = 0, i, r; 1953 1954 /* Ignore extra keys (which are used for IV etc) */ 1955 subkey_size = crypt_subkey_size(cc); 1956 1957 if (crypt_integrity_hmac(cc)) { 1958 if (subkey_size < cc->key_mac_size) 1959 return -EINVAL; 1960 1961 crypt_copy_authenckey(cc->authenc_key, cc->key, 1962 subkey_size - cc->key_mac_size, 1963 cc->key_mac_size); 1964 } 1965 1966 for (i = 0; i < cc->tfms_count; i++) { 1967 if (crypt_integrity_hmac(cc)) 1968 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1969 cc->authenc_key, crypt_authenckey_size(cc)); 1970 else if (crypt_integrity_aead(cc)) 1971 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1972 cc->key + (i * subkey_size), 1973 subkey_size); 1974 else 1975 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 1976 cc->key + (i * subkey_size), 1977 subkey_size); 1978 if (r) 1979 err = r; 1980 } 1981 1982 if (crypt_integrity_hmac(cc)) 1983 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 1984 1985 return err; 1986 } 1987 1988 #ifdef CONFIG_KEYS 1989 1990 static bool contains_whitespace(const char *str) 1991 { 1992 while (*str) 1993 if (isspace(*str++)) 1994 return true; 1995 return false; 1996 } 1997 1998 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 1999 { 2000 char *new_key_string, *key_desc; 2001 int ret; 2002 struct key *key; 2003 const struct user_key_payload *ukp; 2004 2005 /* 2006 * Reject key_string with whitespace. dm core currently lacks code for 2007 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2008 */ 2009 if (contains_whitespace(key_string)) { 2010 DMERR("whitespace chars not allowed in key string"); 2011 return -EINVAL; 2012 } 2013 2014 /* look for next ':' separating key_type from key_description */ 2015 key_desc = strpbrk(key_string, ":"); 2016 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2017 return -EINVAL; 2018 2019 if (strncmp(key_string, "logon:", key_desc - key_string + 1) && 2020 strncmp(key_string, "user:", key_desc - key_string + 1)) 2021 return -EINVAL; 2022 2023 new_key_string = kstrdup(key_string, GFP_KERNEL); 2024 if (!new_key_string) 2025 return -ENOMEM; 2026 2027 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user, 2028 key_desc + 1, NULL); 2029 if (IS_ERR(key)) { 2030 kzfree(new_key_string); 2031 return PTR_ERR(key); 2032 } 2033 2034 down_read(&key->sem); 2035 2036 ukp = user_key_payload_locked(key); 2037 if (!ukp) { 2038 up_read(&key->sem); 2039 key_put(key); 2040 kzfree(new_key_string); 2041 return -EKEYREVOKED; 2042 } 2043 2044 if (cc->key_size != ukp->datalen) { 2045 up_read(&key->sem); 2046 key_put(key); 2047 kzfree(new_key_string); 2048 return -EINVAL; 2049 } 2050 2051 memcpy(cc->key, ukp->data, cc->key_size); 2052 2053 up_read(&key->sem); 2054 key_put(key); 2055 2056 /* clear the flag since following operations may invalidate previously valid key */ 2057 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2058 2059 ret = crypt_setkey(cc); 2060 2061 if (!ret) { 2062 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2063 kzfree(cc->key_string); 2064 cc->key_string = new_key_string; 2065 } else 2066 kzfree(new_key_string); 2067 2068 return ret; 2069 } 2070 2071 static int get_key_size(char **key_string) 2072 { 2073 char *colon, dummy; 2074 int ret; 2075 2076 if (*key_string[0] != ':') 2077 return strlen(*key_string) >> 1; 2078 2079 /* look for next ':' in key string */ 2080 colon = strpbrk(*key_string + 1, ":"); 2081 if (!colon) 2082 return -EINVAL; 2083 2084 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2085 return -EINVAL; 2086 2087 *key_string = colon; 2088 2089 /* remaining key string should be :<logon|user>:<key_desc> */ 2090 2091 return ret; 2092 } 2093 2094 #else 2095 2096 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2097 { 2098 return -EINVAL; 2099 } 2100 2101 static int get_key_size(char **key_string) 2102 { 2103 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2104 } 2105 2106 #endif 2107 2108 static int crypt_set_key(struct crypt_config *cc, char *key) 2109 { 2110 int r = -EINVAL; 2111 int key_string_len = strlen(key); 2112 2113 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2114 if (!cc->key_size && strcmp(key, "-")) 2115 goto out; 2116 2117 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2118 if (key[0] == ':') { 2119 r = crypt_set_keyring_key(cc, key + 1); 2120 goto out; 2121 } 2122 2123 /* clear the flag since following operations may invalidate previously valid key */ 2124 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2125 2126 /* wipe references to any kernel keyring key */ 2127 kzfree(cc->key_string); 2128 cc->key_string = NULL; 2129 2130 /* Decode key from its hex representation. */ 2131 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2132 goto out; 2133 2134 r = crypt_setkey(cc); 2135 if (!r) 2136 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2137 2138 out: 2139 /* Hex key string not needed after here, so wipe it. */ 2140 memset(key, '0', key_string_len); 2141 2142 return r; 2143 } 2144 2145 static int crypt_wipe_key(struct crypt_config *cc) 2146 { 2147 int r; 2148 2149 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2150 get_random_bytes(&cc->key, cc->key_size); 2151 kzfree(cc->key_string); 2152 cc->key_string = NULL; 2153 r = crypt_setkey(cc); 2154 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2155 2156 return r; 2157 } 2158 2159 static void crypt_calculate_pages_per_client(void) 2160 { 2161 unsigned long pages = (totalram_pages - totalhigh_pages) * DM_CRYPT_MEMORY_PERCENT / 100; 2162 2163 if (!dm_crypt_clients_n) 2164 return; 2165 2166 pages /= dm_crypt_clients_n; 2167 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2168 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2169 dm_crypt_pages_per_client = pages; 2170 } 2171 2172 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2173 { 2174 struct crypt_config *cc = pool_data; 2175 struct page *page; 2176 2177 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) && 2178 likely(gfp_mask & __GFP_NORETRY)) 2179 return NULL; 2180 2181 page = alloc_page(gfp_mask); 2182 if (likely(page != NULL)) 2183 percpu_counter_add(&cc->n_allocated_pages, 1); 2184 2185 return page; 2186 } 2187 2188 static void crypt_page_free(void *page, void *pool_data) 2189 { 2190 struct crypt_config *cc = pool_data; 2191 2192 __free_page(page); 2193 percpu_counter_sub(&cc->n_allocated_pages, 1); 2194 } 2195 2196 static void crypt_dtr(struct dm_target *ti) 2197 { 2198 struct crypt_config *cc = ti->private; 2199 2200 ti->private = NULL; 2201 2202 if (!cc) 2203 return; 2204 2205 if (cc->write_thread) 2206 kthread_stop(cc->write_thread); 2207 2208 if (cc->io_queue) 2209 destroy_workqueue(cc->io_queue); 2210 if (cc->crypt_queue) 2211 destroy_workqueue(cc->crypt_queue); 2212 2213 crypt_free_tfms(cc); 2214 2215 bioset_exit(&cc->bs); 2216 2217 mempool_exit(&cc->page_pool); 2218 mempool_exit(&cc->req_pool); 2219 mempool_exit(&cc->tag_pool); 2220 2221 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2222 percpu_counter_destroy(&cc->n_allocated_pages); 2223 2224 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2225 cc->iv_gen_ops->dtr(cc); 2226 2227 if (cc->dev) 2228 dm_put_device(ti, cc->dev); 2229 2230 kzfree(cc->cipher); 2231 kzfree(cc->cipher_string); 2232 kzfree(cc->key_string); 2233 kzfree(cc->cipher_auth); 2234 kzfree(cc->authenc_key); 2235 2236 mutex_destroy(&cc->bio_alloc_lock); 2237 2238 /* Must zero key material before freeing */ 2239 kzfree(cc); 2240 2241 spin_lock(&dm_crypt_clients_lock); 2242 WARN_ON(!dm_crypt_clients_n); 2243 dm_crypt_clients_n--; 2244 crypt_calculate_pages_per_client(); 2245 spin_unlock(&dm_crypt_clients_lock); 2246 } 2247 2248 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2249 { 2250 struct crypt_config *cc = ti->private; 2251 2252 if (crypt_integrity_aead(cc)) 2253 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2254 else 2255 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2256 2257 if (cc->iv_size) 2258 /* at least a 64 bit sector number should fit in our buffer */ 2259 cc->iv_size = max(cc->iv_size, 2260 (unsigned int)(sizeof(u64) / sizeof(u8))); 2261 else if (ivmode) { 2262 DMWARN("Selected cipher does not support IVs"); 2263 ivmode = NULL; 2264 } 2265 2266 /* Choose ivmode, see comments at iv code. */ 2267 if (ivmode == NULL) 2268 cc->iv_gen_ops = NULL; 2269 else if (strcmp(ivmode, "plain") == 0) 2270 cc->iv_gen_ops = &crypt_iv_plain_ops; 2271 else if (strcmp(ivmode, "plain64") == 0) 2272 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2273 else if (strcmp(ivmode, "plain64be") == 0) 2274 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2275 else if (strcmp(ivmode, "essiv") == 0) 2276 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2277 else if (strcmp(ivmode, "benbi") == 0) 2278 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2279 else if (strcmp(ivmode, "null") == 0) 2280 cc->iv_gen_ops = &crypt_iv_null_ops; 2281 else if (strcmp(ivmode, "lmk") == 0) { 2282 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2283 /* 2284 * Version 2 and 3 is recognised according 2285 * to length of provided multi-key string. 2286 * If present (version 3), last key is used as IV seed. 2287 * All keys (including IV seed) are always the same size. 2288 */ 2289 if (cc->key_size % cc->key_parts) { 2290 cc->key_parts++; 2291 cc->key_extra_size = cc->key_size / cc->key_parts; 2292 } 2293 } else if (strcmp(ivmode, "tcw") == 0) { 2294 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2295 cc->key_parts += 2; /* IV + whitening */ 2296 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2297 } else if (strcmp(ivmode, "random") == 0) { 2298 cc->iv_gen_ops = &crypt_iv_random_ops; 2299 /* Need storage space in integrity fields. */ 2300 cc->integrity_iv_size = cc->iv_size; 2301 } else { 2302 ti->error = "Invalid IV mode"; 2303 return -EINVAL; 2304 } 2305 2306 return 0; 2307 } 2308 2309 /* 2310 * Workaround to parse cipher algorithm from crypto API spec. 2311 * The cc->cipher is currently used only in ESSIV. 2312 * This should be probably done by crypto-api calls (once available...) 2313 */ 2314 static int crypt_ctr_blkdev_cipher(struct crypt_config *cc) 2315 { 2316 const char *alg_name = NULL; 2317 char *start, *end; 2318 2319 if (crypt_integrity_aead(cc)) { 2320 alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc))); 2321 if (!alg_name) 2322 return -EINVAL; 2323 if (crypt_integrity_hmac(cc)) { 2324 alg_name = strchr(alg_name, ','); 2325 if (!alg_name) 2326 return -EINVAL; 2327 } 2328 alg_name++; 2329 } else { 2330 alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc))); 2331 if (!alg_name) 2332 return -EINVAL; 2333 } 2334 2335 start = strchr(alg_name, '('); 2336 end = strchr(alg_name, ')'); 2337 2338 if (!start && !end) { 2339 cc->cipher = kstrdup(alg_name, GFP_KERNEL); 2340 return cc->cipher ? 0 : -ENOMEM; 2341 } 2342 2343 if (!start || !end || ++start >= end) 2344 return -EINVAL; 2345 2346 cc->cipher = kzalloc(end - start + 1, GFP_KERNEL); 2347 if (!cc->cipher) 2348 return -ENOMEM; 2349 2350 strncpy(cc->cipher, start, end - start); 2351 2352 return 0; 2353 } 2354 2355 /* 2356 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2357 * The HMAC is needed to calculate tag size (HMAC digest size). 2358 * This should be probably done by crypto-api calls (once available...) 2359 */ 2360 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2361 { 2362 char *start, *end, *mac_alg = NULL; 2363 struct crypto_ahash *mac; 2364 2365 if (!strstarts(cipher_api, "authenc(")) 2366 return 0; 2367 2368 start = strchr(cipher_api, '('); 2369 end = strchr(cipher_api, ','); 2370 if (!start || !end || ++start > end) 2371 return -EINVAL; 2372 2373 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2374 if (!mac_alg) 2375 return -ENOMEM; 2376 strncpy(mac_alg, start, end - start); 2377 2378 mac = crypto_alloc_ahash(mac_alg, 0, 0); 2379 kfree(mac_alg); 2380 2381 if (IS_ERR(mac)) 2382 return PTR_ERR(mac); 2383 2384 cc->key_mac_size = crypto_ahash_digestsize(mac); 2385 crypto_free_ahash(mac); 2386 2387 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2388 if (!cc->authenc_key) 2389 return -ENOMEM; 2390 2391 return 0; 2392 } 2393 2394 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2395 char **ivmode, char **ivopts) 2396 { 2397 struct crypt_config *cc = ti->private; 2398 char *tmp, *cipher_api; 2399 int ret = -EINVAL; 2400 2401 cc->tfms_count = 1; 2402 2403 /* 2404 * New format (capi: prefix) 2405 * capi:cipher_api_spec-iv:ivopts 2406 */ 2407 tmp = &cipher_in[strlen("capi:")]; 2408 cipher_api = strsep(&tmp, "-"); 2409 *ivmode = strsep(&tmp, ":"); 2410 *ivopts = tmp; 2411 2412 if (*ivmode && !strcmp(*ivmode, "lmk")) 2413 cc->tfms_count = 64; 2414 2415 cc->key_parts = cc->tfms_count; 2416 2417 /* Allocate cipher */ 2418 ret = crypt_alloc_tfms(cc, cipher_api); 2419 if (ret < 0) { 2420 ti->error = "Error allocating crypto tfm"; 2421 return ret; 2422 } 2423 2424 /* Alloc AEAD, can be used only in new format. */ 2425 if (crypt_integrity_aead(cc)) { 2426 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2427 if (ret < 0) { 2428 ti->error = "Invalid AEAD cipher spec"; 2429 return -ENOMEM; 2430 } 2431 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2432 } else 2433 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2434 2435 ret = crypt_ctr_blkdev_cipher(cc); 2436 if (ret < 0) { 2437 ti->error = "Cannot allocate cipher string"; 2438 return -ENOMEM; 2439 } 2440 2441 return 0; 2442 } 2443 2444 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2445 char **ivmode, char **ivopts) 2446 { 2447 struct crypt_config *cc = ti->private; 2448 char *tmp, *cipher, *chainmode, *keycount; 2449 char *cipher_api = NULL; 2450 int ret = -EINVAL; 2451 char dummy; 2452 2453 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2454 ti->error = "Bad cipher specification"; 2455 return -EINVAL; 2456 } 2457 2458 /* 2459 * Legacy dm-crypt cipher specification 2460 * cipher[:keycount]-mode-iv:ivopts 2461 */ 2462 tmp = cipher_in; 2463 keycount = strsep(&tmp, "-"); 2464 cipher = strsep(&keycount, ":"); 2465 2466 if (!keycount) 2467 cc->tfms_count = 1; 2468 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2469 !is_power_of_2(cc->tfms_count)) { 2470 ti->error = "Bad cipher key count specification"; 2471 return -EINVAL; 2472 } 2473 cc->key_parts = cc->tfms_count; 2474 2475 cc->cipher = kstrdup(cipher, GFP_KERNEL); 2476 if (!cc->cipher) 2477 goto bad_mem; 2478 2479 chainmode = strsep(&tmp, "-"); 2480 *ivopts = strsep(&tmp, "-"); 2481 *ivmode = strsep(&*ivopts, ":"); 2482 2483 if (tmp) 2484 DMWARN("Ignoring unexpected additional cipher options"); 2485 2486 /* 2487 * For compatibility with the original dm-crypt mapping format, if 2488 * only the cipher name is supplied, use cbc-plain. 2489 */ 2490 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2491 chainmode = "cbc"; 2492 *ivmode = "plain"; 2493 } 2494 2495 if (strcmp(chainmode, "ecb") && !*ivmode) { 2496 ti->error = "IV mechanism required"; 2497 return -EINVAL; 2498 } 2499 2500 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2501 if (!cipher_api) 2502 goto bad_mem; 2503 2504 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2505 "%s(%s)", chainmode, cipher); 2506 if (ret < 0) { 2507 kfree(cipher_api); 2508 goto bad_mem; 2509 } 2510 2511 /* Allocate cipher */ 2512 ret = crypt_alloc_tfms(cc, cipher_api); 2513 if (ret < 0) { 2514 ti->error = "Error allocating crypto tfm"; 2515 kfree(cipher_api); 2516 return ret; 2517 } 2518 kfree(cipher_api); 2519 2520 return 0; 2521 bad_mem: 2522 ti->error = "Cannot allocate cipher strings"; 2523 return -ENOMEM; 2524 } 2525 2526 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 2527 { 2528 struct crypt_config *cc = ti->private; 2529 char *ivmode = NULL, *ivopts = NULL; 2530 int ret; 2531 2532 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 2533 if (!cc->cipher_string) { 2534 ti->error = "Cannot allocate cipher strings"; 2535 return -ENOMEM; 2536 } 2537 2538 if (strstarts(cipher_in, "capi:")) 2539 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 2540 else 2541 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 2542 if (ret) 2543 return ret; 2544 2545 /* Initialize IV */ 2546 ret = crypt_ctr_ivmode(ti, ivmode); 2547 if (ret < 0) 2548 return ret; 2549 2550 /* Initialize and set key */ 2551 ret = crypt_set_key(cc, key); 2552 if (ret < 0) { 2553 ti->error = "Error decoding and setting key"; 2554 return ret; 2555 } 2556 2557 /* Allocate IV */ 2558 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 2559 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 2560 if (ret < 0) { 2561 ti->error = "Error creating IV"; 2562 return ret; 2563 } 2564 } 2565 2566 /* Initialize IV (set keys for ESSIV etc) */ 2567 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 2568 ret = cc->iv_gen_ops->init(cc); 2569 if (ret < 0) { 2570 ti->error = "Error initialising IV"; 2571 return ret; 2572 } 2573 } 2574 2575 /* wipe the kernel key payload copy */ 2576 if (cc->key_string) 2577 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2578 2579 return ret; 2580 } 2581 2582 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 2583 { 2584 struct crypt_config *cc = ti->private; 2585 struct dm_arg_set as; 2586 static const struct dm_arg _args[] = { 2587 {0, 6, "Invalid number of feature args"}, 2588 }; 2589 unsigned int opt_params, val; 2590 const char *opt_string, *sval; 2591 char dummy; 2592 int ret; 2593 2594 /* Optional parameters */ 2595 as.argc = argc; 2596 as.argv = argv; 2597 2598 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 2599 if (ret) 2600 return ret; 2601 2602 while (opt_params--) { 2603 opt_string = dm_shift_arg(&as); 2604 if (!opt_string) { 2605 ti->error = "Not enough feature arguments"; 2606 return -EINVAL; 2607 } 2608 2609 if (!strcasecmp(opt_string, "allow_discards")) 2610 ti->num_discard_bios = 1; 2611 2612 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 2613 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2614 2615 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 2616 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2617 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 2618 if (val == 0 || val > MAX_TAG_SIZE) { 2619 ti->error = "Invalid integrity arguments"; 2620 return -EINVAL; 2621 } 2622 cc->on_disk_tag_size = val; 2623 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 2624 if (!strcasecmp(sval, "aead")) { 2625 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 2626 } else if (strcasecmp(sval, "none")) { 2627 ti->error = "Unknown integrity profile"; 2628 return -EINVAL; 2629 } 2630 2631 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 2632 if (!cc->cipher_auth) 2633 return -ENOMEM; 2634 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 2635 if (cc->sector_size < (1 << SECTOR_SHIFT) || 2636 cc->sector_size > 4096 || 2637 (cc->sector_size & (cc->sector_size - 1))) { 2638 ti->error = "Invalid feature value for sector_size"; 2639 return -EINVAL; 2640 } 2641 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 2642 ti->error = "Device size is not multiple of sector_size feature"; 2643 return -EINVAL; 2644 } 2645 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 2646 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 2647 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2648 else { 2649 ti->error = "Invalid feature arguments"; 2650 return -EINVAL; 2651 } 2652 } 2653 2654 return 0; 2655 } 2656 2657 /* 2658 * Construct an encryption mapping: 2659 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 2660 */ 2661 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 2662 { 2663 struct crypt_config *cc; 2664 int key_size; 2665 unsigned int align_mask; 2666 unsigned long long tmpll; 2667 int ret; 2668 size_t iv_size_padding, additional_req_size; 2669 char dummy; 2670 2671 if (argc < 5) { 2672 ti->error = "Not enough arguments"; 2673 return -EINVAL; 2674 } 2675 2676 key_size = get_key_size(&argv[1]); 2677 if (key_size < 0) { 2678 ti->error = "Cannot parse key size"; 2679 return -EINVAL; 2680 } 2681 2682 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); 2683 if (!cc) { 2684 ti->error = "Cannot allocate encryption context"; 2685 return -ENOMEM; 2686 } 2687 cc->key_size = key_size; 2688 cc->sector_size = (1 << SECTOR_SHIFT); 2689 cc->sector_shift = 0; 2690 2691 ti->private = cc; 2692 2693 spin_lock(&dm_crypt_clients_lock); 2694 dm_crypt_clients_n++; 2695 crypt_calculate_pages_per_client(); 2696 spin_unlock(&dm_crypt_clients_lock); 2697 2698 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 2699 if (ret < 0) 2700 goto bad; 2701 2702 /* Optional parameters need to be read before cipher constructor */ 2703 if (argc > 5) { 2704 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 2705 if (ret) 2706 goto bad; 2707 } 2708 2709 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 2710 if (ret < 0) 2711 goto bad; 2712 2713 if (crypt_integrity_aead(cc)) { 2714 cc->dmreq_start = sizeof(struct aead_request); 2715 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 2716 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 2717 } else { 2718 cc->dmreq_start = sizeof(struct skcipher_request); 2719 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 2720 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 2721 } 2722 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 2723 2724 if (align_mask < CRYPTO_MINALIGN) { 2725 /* Allocate the padding exactly */ 2726 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 2727 & align_mask; 2728 } else { 2729 /* 2730 * If the cipher requires greater alignment than kmalloc 2731 * alignment, we don't know the exact position of the 2732 * initialization vector. We must assume worst case. 2733 */ 2734 iv_size_padding = align_mask; 2735 } 2736 2737 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 2738 additional_req_size = sizeof(struct dm_crypt_request) + 2739 iv_size_padding + cc->iv_size + 2740 cc->iv_size + 2741 sizeof(uint64_t) + 2742 sizeof(unsigned int); 2743 2744 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 2745 if (ret) { 2746 ti->error = "Cannot allocate crypt request mempool"; 2747 goto bad; 2748 } 2749 2750 cc->per_bio_data_size = ti->per_io_data_size = 2751 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 2752 ARCH_KMALLOC_MINALIGN); 2753 2754 ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc); 2755 if (ret) { 2756 ti->error = "Cannot allocate page mempool"; 2757 goto bad; 2758 } 2759 2760 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 2761 if (ret) { 2762 ti->error = "Cannot allocate crypt bioset"; 2763 goto bad; 2764 } 2765 2766 mutex_init(&cc->bio_alloc_lock); 2767 2768 ret = -EINVAL; 2769 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 2770 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 2771 ti->error = "Invalid iv_offset sector"; 2772 goto bad; 2773 } 2774 cc->iv_offset = tmpll; 2775 2776 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 2777 if (ret) { 2778 ti->error = "Device lookup failed"; 2779 goto bad; 2780 } 2781 2782 ret = -EINVAL; 2783 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { 2784 ti->error = "Invalid device sector"; 2785 goto bad; 2786 } 2787 cc->start = tmpll; 2788 2789 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 2790 ret = crypt_integrity_ctr(cc, ti); 2791 if (ret) 2792 goto bad; 2793 2794 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 2795 if (!cc->tag_pool_max_sectors) 2796 cc->tag_pool_max_sectors = 1; 2797 2798 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 2799 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 2800 if (ret) { 2801 ti->error = "Cannot allocate integrity tags mempool"; 2802 goto bad; 2803 } 2804 2805 cc->tag_pool_max_sectors <<= cc->sector_shift; 2806 } 2807 2808 ret = -ENOMEM; 2809 cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); 2810 if (!cc->io_queue) { 2811 ti->error = "Couldn't create kcryptd io queue"; 2812 goto bad; 2813 } 2814 2815 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2816 cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); 2817 else 2818 cc->crypt_queue = alloc_workqueue("kcryptd", 2819 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 2820 num_online_cpus()); 2821 if (!cc->crypt_queue) { 2822 ti->error = "Couldn't create kcryptd queue"; 2823 goto bad; 2824 } 2825 2826 spin_lock_init(&cc->write_thread_lock); 2827 cc->write_tree = RB_ROOT; 2828 2829 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); 2830 if (IS_ERR(cc->write_thread)) { 2831 ret = PTR_ERR(cc->write_thread); 2832 cc->write_thread = NULL; 2833 ti->error = "Couldn't spawn write thread"; 2834 goto bad; 2835 } 2836 wake_up_process(cc->write_thread); 2837 2838 ti->num_flush_bios = 1; 2839 2840 return 0; 2841 2842 bad: 2843 crypt_dtr(ti); 2844 return ret; 2845 } 2846 2847 static int crypt_map(struct dm_target *ti, struct bio *bio) 2848 { 2849 struct dm_crypt_io *io; 2850 struct crypt_config *cc = ti->private; 2851 2852 /* 2853 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 2854 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 2855 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 2856 */ 2857 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 2858 bio_op(bio) == REQ_OP_DISCARD)) { 2859 bio_set_dev(bio, cc->dev->bdev); 2860 if (bio_sectors(bio)) 2861 bio->bi_iter.bi_sector = cc->start + 2862 dm_target_offset(ti, bio->bi_iter.bi_sector); 2863 return DM_MAPIO_REMAPPED; 2864 } 2865 2866 /* 2867 * Check if bio is too large, split as needed. 2868 */ 2869 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && 2870 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 2871 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); 2872 2873 /* 2874 * Ensure that bio is a multiple of internal sector encryption size 2875 * and is aligned to this size as defined in IO hints. 2876 */ 2877 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 2878 return DM_MAPIO_KILL; 2879 2880 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 2881 return DM_MAPIO_KILL; 2882 2883 io = dm_per_bio_data(bio, cc->per_bio_data_size); 2884 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 2885 2886 if (cc->on_disk_tag_size) { 2887 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 2888 2889 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 2890 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 2891 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 2892 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 2893 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 2894 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 2895 io->integrity_metadata_from_pool = true; 2896 } 2897 } 2898 2899 if (crypt_integrity_aead(cc)) 2900 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 2901 else 2902 io->ctx.r.req = (struct skcipher_request *)(io + 1); 2903 2904 if (bio_data_dir(io->base_bio) == READ) { 2905 if (kcryptd_io_read(io, GFP_NOWAIT)) 2906 kcryptd_queue_read(io); 2907 } else 2908 kcryptd_queue_crypt(io); 2909 2910 return DM_MAPIO_SUBMITTED; 2911 } 2912 2913 static void crypt_status(struct dm_target *ti, status_type_t type, 2914 unsigned status_flags, char *result, unsigned maxlen) 2915 { 2916 struct crypt_config *cc = ti->private; 2917 unsigned i, sz = 0; 2918 int num_feature_args = 0; 2919 2920 switch (type) { 2921 case STATUSTYPE_INFO: 2922 result[0] = '\0'; 2923 break; 2924 2925 case STATUSTYPE_TABLE: 2926 DMEMIT("%s ", cc->cipher_string); 2927 2928 if (cc->key_size > 0) { 2929 if (cc->key_string) 2930 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 2931 else 2932 for (i = 0; i < cc->key_size; i++) 2933 DMEMIT("%02x", cc->key[i]); 2934 } else 2935 DMEMIT("-"); 2936 2937 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 2938 cc->dev->name, (unsigned long long)cc->start); 2939 2940 num_feature_args += !!ti->num_discard_bios; 2941 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2942 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2943 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 2944 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2945 if (cc->on_disk_tag_size) 2946 num_feature_args++; 2947 if (num_feature_args) { 2948 DMEMIT(" %d", num_feature_args); 2949 if (ti->num_discard_bios) 2950 DMEMIT(" allow_discards"); 2951 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2952 DMEMIT(" same_cpu_crypt"); 2953 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 2954 DMEMIT(" submit_from_crypt_cpus"); 2955 if (cc->on_disk_tag_size) 2956 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 2957 if (cc->sector_size != (1 << SECTOR_SHIFT)) 2958 DMEMIT(" sector_size:%d", cc->sector_size); 2959 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 2960 DMEMIT(" iv_large_sectors"); 2961 } 2962 2963 break; 2964 } 2965 } 2966 2967 static void crypt_postsuspend(struct dm_target *ti) 2968 { 2969 struct crypt_config *cc = ti->private; 2970 2971 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2972 } 2973 2974 static int crypt_preresume(struct dm_target *ti) 2975 { 2976 struct crypt_config *cc = ti->private; 2977 2978 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 2979 DMERR("aborting resume - crypt key is not set."); 2980 return -EAGAIN; 2981 } 2982 2983 return 0; 2984 } 2985 2986 static void crypt_resume(struct dm_target *ti) 2987 { 2988 struct crypt_config *cc = ti->private; 2989 2990 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2991 } 2992 2993 /* Message interface 2994 * key set <key> 2995 * key wipe 2996 */ 2997 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv, 2998 char *result, unsigned maxlen) 2999 { 3000 struct crypt_config *cc = ti->private; 3001 int key_size, ret = -EINVAL; 3002 3003 if (argc < 2) 3004 goto error; 3005 3006 if (!strcasecmp(argv[0], "key")) { 3007 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 3008 DMWARN("not suspended during key manipulation."); 3009 return -EINVAL; 3010 } 3011 if (argc == 3 && !strcasecmp(argv[1], "set")) { 3012 /* The key size may not be changed. */ 3013 key_size = get_key_size(&argv[2]); 3014 if (key_size < 0 || cc->key_size != key_size) { 3015 memset(argv[2], '0', strlen(argv[2])); 3016 return -EINVAL; 3017 } 3018 3019 ret = crypt_set_key(cc, argv[2]); 3020 if (ret) 3021 return ret; 3022 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 3023 ret = cc->iv_gen_ops->init(cc); 3024 /* wipe the kernel key payload copy */ 3025 if (cc->key_string) 3026 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3027 return ret; 3028 } 3029 if (argc == 2 && !strcasecmp(argv[1], "wipe")) { 3030 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 3031 ret = cc->iv_gen_ops->wipe(cc); 3032 if (ret) 3033 return ret; 3034 } 3035 return crypt_wipe_key(cc); 3036 } 3037 } 3038 3039 error: 3040 DMWARN("unrecognised message received."); 3041 return -EINVAL; 3042 } 3043 3044 static int crypt_iterate_devices(struct dm_target *ti, 3045 iterate_devices_callout_fn fn, void *data) 3046 { 3047 struct crypt_config *cc = ti->private; 3048 3049 return fn(ti, cc->dev, cc->start, ti->len, data); 3050 } 3051 3052 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3053 { 3054 struct crypt_config *cc = ti->private; 3055 3056 /* 3057 * Unfortunate constraint that is required to avoid the potential 3058 * for exceeding underlying device's max_segments limits -- due to 3059 * crypt_alloc_buffer() possibly allocating pages for the encryption 3060 * bio that are not as physically contiguous as the original bio. 3061 */ 3062 limits->max_segment_size = PAGE_SIZE; 3063 3064 limits->logical_block_size = 3065 max_t(unsigned short, limits->logical_block_size, cc->sector_size); 3066 limits->physical_block_size = 3067 max_t(unsigned, limits->physical_block_size, cc->sector_size); 3068 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); 3069 } 3070 3071 static struct target_type crypt_target = { 3072 .name = "crypt", 3073 .version = {1, 18, 1}, 3074 .module = THIS_MODULE, 3075 .ctr = crypt_ctr, 3076 .dtr = crypt_dtr, 3077 .map = crypt_map, 3078 .status = crypt_status, 3079 .postsuspend = crypt_postsuspend, 3080 .preresume = crypt_preresume, 3081 .resume = crypt_resume, 3082 .message = crypt_message, 3083 .iterate_devices = crypt_iterate_devices, 3084 .io_hints = crypt_io_hints, 3085 }; 3086 3087 static int __init dm_crypt_init(void) 3088 { 3089 int r; 3090 3091 r = dm_register_target(&crypt_target); 3092 if (r < 0) 3093 DMERR("register failed %d", r); 3094 3095 return r; 3096 } 3097 3098 static void __exit dm_crypt_exit(void) 3099 { 3100 dm_unregister_target(&crypt_target); 3101 } 3102 3103 module_init(dm_crypt_init); 3104 module_exit(dm_crypt_exit); 3105 3106 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3107 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3108 MODULE_LICENSE("GPL"); 3109