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