1 /* 2 * Copyright (C) 2003 Jana Saout <jana@saout.de> 3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 4 * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved. 5 * Copyright (C) 2013-2020 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 <linux/key-type.h> 38 #include <keys/user-type.h> 39 #include <keys/encrypted-type.h> 40 41 #include <linux/device-mapper.h> 42 43 #define DM_MSG_PREFIX "crypt" 44 45 /* 46 * context holding the current state of a multi-part conversion 47 */ 48 struct convert_context { 49 struct completion restart; 50 struct bio *bio_in; 51 struct bio *bio_out; 52 struct bvec_iter iter_in; 53 struct bvec_iter iter_out; 54 u64 cc_sector; 55 atomic_t cc_pending; 56 union { 57 struct skcipher_request *req; 58 struct aead_request *req_aead; 59 } r; 60 61 }; 62 63 /* 64 * per bio private data 65 */ 66 struct dm_crypt_io { 67 struct crypt_config *cc; 68 struct bio *base_bio; 69 u8 *integrity_metadata; 70 bool integrity_metadata_from_pool; 71 struct work_struct work; 72 struct tasklet_struct tasklet; 73 74 struct convert_context ctx; 75 76 atomic_t io_pending; 77 blk_status_t error; 78 sector_t sector; 79 80 struct rb_node rb_node; 81 } CRYPTO_MINALIGN_ATTR; 82 83 struct dm_crypt_request { 84 struct convert_context *ctx; 85 struct scatterlist sg_in[4]; 86 struct scatterlist sg_out[4]; 87 u64 iv_sector; 88 }; 89 90 struct crypt_config; 91 92 struct crypt_iv_operations { 93 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 94 const char *opts); 95 void (*dtr)(struct crypt_config *cc); 96 int (*init)(struct crypt_config *cc); 97 int (*wipe)(struct crypt_config *cc); 98 int (*generator)(struct crypt_config *cc, u8 *iv, 99 struct dm_crypt_request *dmreq); 100 int (*post)(struct crypt_config *cc, u8 *iv, 101 struct dm_crypt_request *dmreq); 102 }; 103 104 struct iv_benbi_private { 105 int shift; 106 }; 107 108 #define LMK_SEED_SIZE 64 /* hash + 0 */ 109 struct iv_lmk_private { 110 struct crypto_shash *hash_tfm; 111 u8 *seed; 112 }; 113 114 #define TCW_WHITENING_SIZE 16 115 struct iv_tcw_private { 116 struct crypto_shash *crc32_tfm; 117 u8 *iv_seed; 118 u8 *whitening; 119 }; 120 121 #define ELEPHANT_MAX_KEY_SIZE 32 122 struct iv_elephant_private { 123 struct crypto_skcipher *tfm; 124 }; 125 126 /* 127 * Crypt: maps a linear range of a block device 128 * and encrypts / decrypts at the same time. 129 */ 130 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, 131 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD, 132 DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE, 133 DM_CRYPT_WRITE_INLINE }; 134 135 enum cipher_flags { 136 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */ 137 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ 138 CRYPT_ENCRYPT_PREPROCESS, /* Must preprocess data for encryption (elephant) */ 139 }; 140 141 /* 142 * The fields in here must be read only after initialization. 143 */ 144 struct crypt_config { 145 struct dm_dev *dev; 146 sector_t start; 147 148 struct percpu_counter n_allocated_pages; 149 150 struct workqueue_struct *io_queue; 151 struct workqueue_struct *crypt_queue; 152 153 spinlock_t write_thread_lock; 154 struct task_struct *write_thread; 155 struct rb_root write_tree; 156 157 char *cipher_string; 158 char *cipher_auth; 159 char *key_string; 160 161 const struct crypt_iv_operations *iv_gen_ops; 162 union { 163 struct iv_benbi_private benbi; 164 struct iv_lmk_private lmk; 165 struct iv_tcw_private tcw; 166 struct iv_elephant_private elephant; 167 } iv_gen_private; 168 u64 iv_offset; 169 unsigned int iv_size; 170 unsigned short int sector_size; 171 unsigned char sector_shift; 172 173 union { 174 struct crypto_skcipher **tfms; 175 struct crypto_aead **tfms_aead; 176 } cipher_tfm; 177 unsigned tfms_count; 178 unsigned long cipher_flags; 179 180 /* 181 * Layout of each crypto request: 182 * 183 * struct skcipher_request 184 * context 185 * padding 186 * struct dm_crypt_request 187 * padding 188 * IV 189 * 190 * The padding is added so that dm_crypt_request and the IV are 191 * correctly aligned. 192 */ 193 unsigned int dmreq_start; 194 195 unsigned int per_bio_data_size; 196 197 unsigned long flags; 198 unsigned int key_size; 199 unsigned int key_parts; /* independent parts in key buffer */ 200 unsigned int key_extra_size; /* additional keys length */ 201 unsigned int key_mac_size; /* MAC key size for authenc(...) */ 202 203 unsigned int integrity_tag_size; 204 unsigned int integrity_iv_size; 205 unsigned int on_disk_tag_size; 206 207 /* 208 * pool for per bio private data, crypto requests, 209 * encryption requeusts/buffer pages and integrity tags 210 */ 211 unsigned tag_pool_max_sectors; 212 mempool_t tag_pool; 213 mempool_t req_pool; 214 mempool_t page_pool; 215 216 struct bio_set bs; 217 struct mutex bio_alloc_lock; 218 219 u8 *authenc_key; /* space for keys in authenc() format (if used) */ 220 u8 key[]; 221 }; 222 223 #define MIN_IOS 64 224 #define MAX_TAG_SIZE 480 225 #define POOL_ENTRY_SIZE 512 226 227 static DEFINE_SPINLOCK(dm_crypt_clients_lock); 228 static unsigned dm_crypt_clients_n = 0; 229 static volatile unsigned long dm_crypt_pages_per_client; 230 #define DM_CRYPT_MEMORY_PERCENT 2 231 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_PAGES * 16) 232 233 static void clone_init(struct dm_crypt_io *, struct bio *); 234 static void kcryptd_queue_crypt(struct dm_crypt_io *io); 235 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 236 struct scatterlist *sg); 237 238 static bool crypt_integrity_aead(struct crypt_config *cc); 239 240 /* 241 * Use this to access cipher attributes that are independent of the key. 242 */ 243 static struct crypto_skcipher *any_tfm(struct crypt_config *cc) 244 { 245 return cc->cipher_tfm.tfms[0]; 246 } 247 248 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) 249 { 250 return cc->cipher_tfm.tfms_aead[0]; 251 } 252 253 /* 254 * Different IV generation algorithms: 255 * 256 * plain: the initial vector is the 32-bit little-endian version of the sector 257 * number, padded with zeros if necessary. 258 * 259 * plain64: the initial vector is the 64-bit little-endian version of the sector 260 * number, padded with zeros if necessary. 261 * 262 * plain64be: the initial vector is the 64-bit big-endian version of the sector 263 * number, padded with zeros if necessary. 264 * 265 * essiv: "encrypted sector|salt initial vector", the sector number is 266 * encrypted with the bulk cipher using a salt as key. The salt 267 * should be derived from the bulk cipher's key via hashing. 268 * 269 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 270 * (needed for LRW-32-AES and possible other narrow block modes) 271 * 272 * null: the initial vector is always zero. Provides compatibility with 273 * obsolete loop_fish2 devices. Do not use for new devices. 274 * 275 * lmk: Compatible implementation of the block chaining mode used 276 * by the Loop-AES block device encryption system 277 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ 278 * It operates on full 512 byte sectors and uses CBC 279 * with an IV derived from the sector number, the data and 280 * optionally extra IV seed. 281 * This means that after decryption the first block 282 * of sector must be tweaked according to decrypted data. 283 * Loop-AES can use three encryption schemes: 284 * version 1: is plain aes-cbc mode 285 * version 2: uses 64 multikey scheme with lmk IV generator 286 * version 3: the same as version 2 with additional IV seed 287 * (it uses 65 keys, last key is used as IV seed) 288 * 289 * tcw: Compatible implementation of the block chaining mode used 290 * by the TrueCrypt device encryption system (prior to version 4.1). 291 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat 292 * It operates on full 512 byte sectors and uses CBC 293 * with an IV derived from initial key and the sector number. 294 * In addition, whitening value is applied on every sector, whitening 295 * is calculated from initial key, sector number and mixed using CRC32. 296 * Note that this encryption scheme is vulnerable to watermarking attacks 297 * and should be used for old compatible containers access only. 298 * 299 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode) 300 * The IV is encrypted little-endian byte-offset (with the same key 301 * and cipher as the volume). 302 * 303 * elephant: The extended version of eboiv with additional Elephant diffuser 304 * used with Bitlocker CBC mode. 305 * This mode was used in older Windows systems 306 * https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf 307 */ 308 309 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, 310 struct dm_crypt_request *dmreq) 311 { 312 memset(iv, 0, cc->iv_size); 313 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); 314 315 return 0; 316 } 317 318 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, 319 struct dm_crypt_request *dmreq) 320 { 321 memset(iv, 0, cc->iv_size); 322 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 323 324 return 0; 325 } 326 327 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, 328 struct dm_crypt_request *dmreq) 329 { 330 memset(iv, 0, cc->iv_size); 331 /* iv_size is at least of size u64; usually it is 16 bytes */ 332 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector); 333 334 return 0; 335 } 336 337 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 338 struct dm_crypt_request *dmreq) 339 { 340 /* 341 * ESSIV encryption of the IV is now handled by the crypto API, 342 * so just pass the plain sector number here. 343 */ 344 memset(iv, 0, cc->iv_size); 345 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 346 347 return 0; 348 } 349 350 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 351 const char *opts) 352 { 353 unsigned bs; 354 int log; 355 356 if (crypt_integrity_aead(cc)) 357 bs = crypto_aead_blocksize(any_tfm_aead(cc)); 358 else 359 bs = crypto_skcipher_blocksize(any_tfm(cc)); 360 log = ilog2(bs); 361 362 /* we need to calculate how far we must shift the sector count 363 * to get the cipher block count, we use this shift in _gen */ 364 365 if (1 << log != bs) { 366 ti->error = "cypher blocksize is not a power of 2"; 367 return -EINVAL; 368 } 369 370 if (log > 9) { 371 ti->error = "cypher blocksize is > 512"; 372 return -EINVAL; 373 } 374 375 cc->iv_gen_private.benbi.shift = 9 - log; 376 377 return 0; 378 } 379 380 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 381 { 382 } 383 384 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 385 struct dm_crypt_request *dmreq) 386 { 387 __be64 val; 388 389 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 390 391 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 392 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 393 394 return 0; 395 } 396 397 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 398 struct dm_crypt_request *dmreq) 399 { 400 memset(iv, 0, cc->iv_size); 401 402 return 0; 403 } 404 405 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 406 { 407 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 408 409 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 410 crypto_free_shash(lmk->hash_tfm); 411 lmk->hash_tfm = NULL; 412 413 kfree_sensitive(lmk->seed); 414 lmk->seed = NULL; 415 } 416 417 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 418 const char *opts) 419 { 420 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 421 422 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 423 ti->error = "Unsupported sector size for LMK"; 424 return -EINVAL; 425 } 426 427 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); 428 if (IS_ERR(lmk->hash_tfm)) { 429 ti->error = "Error initializing LMK hash"; 430 return PTR_ERR(lmk->hash_tfm); 431 } 432 433 /* No seed in LMK version 2 */ 434 if (cc->key_parts == cc->tfms_count) { 435 lmk->seed = NULL; 436 return 0; 437 } 438 439 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 440 if (!lmk->seed) { 441 crypt_iv_lmk_dtr(cc); 442 ti->error = "Error kmallocing seed storage in LMK"; 443 return -ENOMEM; 444 } 445 446 return 0; 447 } 448 449 static int crypt_iv_lmk_init(struct crypt_config *cc) 450 { 451 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 452 int subkey_size = cc->key_size / cc->key_parts; 453 454 /* LMK seed is on the position of LMK_KEYS + 1 key */ 455 if (lmk->seed) 456 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 457 crypto_shash_digestsize(lmk->hash_tfm)); 458 459 return 0; 460 } 461 462 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 463 { 464 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 465 466 if (lmk->seed) 467 memset(lmk->seed, 0, LMK_SEED_SIZE); 468 469 return 0; 470 } 471 472 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 473 struct dm_crypt_request *dmreq, 474 u8 *data) 475 { 476 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 477 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 478 struct md5_state md5state; 479 __le32 buf[4]; 480 int i, r; 481 482 desc->tfm = lmk->hash_tfm; 483 484 r = crypto_shash_init(desc); 485 if (r) 486 return r; 487 488 if (lmk->seed) { 489 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 490 if (r) 491 return r; 492 } 493 494 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 495 r = crypto_shash_update(desc, data + 16, 16 * 31); 496 if (r) 497 return r; 498 499 /* Sector is cropped to 56 bits here */ 500 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 501 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 502 buf[2] = cpu_to_le32(4024); 503 buf[3] = 0; 504 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 505 if (r) 506 return r; 507 508 /* No MD5 padding here */ 509 r = crypto_shash_export(desc, &md5state); 510 if (r) 511 return r; 512 513 for (i = 0; i < MD5_HASH_WORDS; i++) 514 __cpu_to_le32s(&md5state.hash[i]); 515 memcpy(iv, &md5state.hash, cc->iv_size); 516 517 return 0; 518 } 519 520 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 521 struct dm_crypt_request *dmreq) 522 { 523 struct scatterlist *sg; 524 u8 *src; 525 int r = 0; 526 527 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 528 sg = crypt_get_sg_data(cc, dmreq->sg_in); 529 src = kmap_atomic(sg_page(sg)); 530 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 531 kunmap_atomic(src); 532 } else 533 memset(iv, 0, cc->iv_size); 534 535 return r; 536 } 537 538 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 539 struct dm_crypt_request *dmreq) 540 { 541 struct scatterlist *sg; 542 u8 *dst; 543 int r; 544 545 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 546 return 0; 547 548 sg = crypt_get_sg_data(cc, dmreq->sg_out); 549 dst = kmap_atomic(sg_page(sg)); 550 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 551 552 /* Tweak the first block of plaintext sector */ 553 if (!r) 554 crypto_xor(dst + sg->offset, iv, cc->iv_size); 555 556 kunmap_atomic(dst); 557 return r; 558 } 559 560 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 561 { 562 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 563 564 kfree_sensitive(tcw->iv_seed); 565 tcw->iv_seed = NULL; 566 kfree_sensitive(tcw->whitening); 567 tcw->whitening = NULL; 568 569 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 570 crypto_free_shash(tcw->crc32_tfm); 571 tcw->crc32_tfm = NULL; 572 } 573 574 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 575 const char *opts) 576 { 577 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 578 579 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 580 ti->error = "Unsupported sector size for TCW"; 581 return -EINVAL; 582 } 583 584 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 585 ti->error = "Wrong key size for TCW"; 586 return -EINVAL; 587 } 588 589 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); 590 if (IS_ERR(tcw->crc32_tfm)) { 591 ti->error = "Error initializing CRC32 in TCW"; 592 return PTR_ERR(tcw->crc32_tfm); 593 } 594 595 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 596 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 597 if (!tcw->iv_seed || !tcw->whitening) { 598 crypt_iv_tcw_dtr(cc); 599 ti->error = "Error allocating seed storage in TCW"; 600 return -ENOMEM; 601 } 602 603 return 0; 604 } 605 606 static int crypt_iv_tcw_init(struct crypt_config *cc) 607 { 608 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 609 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 610 611 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 612 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 613 TCW_WHITENING_SIZE); 614 615 return 0; 616 } 617 618 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 619 { 620 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 621 622 memset(tcw->iv_seed, 0, cc->iv_size); 623 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 624 625 return 0; 626 } 627 628 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 629 struct dm_crypt_request *dmreq, 630 u8 *data) 631 { 632 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 633 __le64 sector = cpu_to_le64(dmreq->iv_sector); 634 u8 buf[TCW_WHITENING_SIZE]; 635 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 636 int i, r; 637 638 /* xor whitening with sector number */ 639 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 640 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 641 642 /* calculate crc32 for every 32bit part and xor it */ 643 desc->tfm = tcw->crc32_tfm; 644 for (i = 0; i < 4; i++) { 645 r = crypto_shash_init(desc); 646 if (r) 647 goto out; 648 r = crypto_shash_update(desc, &buf[i * 4], 4); 649 if (r) 650 goto out; 651 r = crypto_shash_final(desc, &buf[i * 4]); 652 if (r) 653 goto out; 654 } 655 crypto_xor(&buf[0], &buf[12], 4); 656 crypto_xor(&buf[4], &buf[8], 4); 657 658 /* apply whitening (8 bytes) to whole sector */ 659 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 660 crypto_xor(data + i * 8, buf, 8); 661 out: 662 memzero_explicit(buf, sizeof(buf)); 663 return r; 664 } 665 666 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 667 struct dm_crypt_request *dmreq) 668 { 669 struct scatterlist *sg; 670 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 671 __le64 sector = cpu_to_le64(dmreq->iv_sector); 672 u8 *src; 673 int r = 0; 674 675 /* Remove whitening from ciphertext */ 676 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 677 sg = crypt_get_sg_data(cc, dmreq->sg_in); 678 src = kmap_atomic(sg_page(sg)); 679 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 680 kunmap_atomic(src); 681 } 682 683 /* Calculate IV */ 684 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 685 if (cc->iv_size > 8) 686 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 687 cc->iv_size - 8); 688 689 return r; 690 } 691 692 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 693 struct dm_crypt_request *dmreq) 694 { 695 struct scatterlist *sg; 696 u8 *dst; 697 int r; 698 699 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 700 return 0; 701 702 /* Apply whitening on ciphertext */ 703 sg = crypt_get_sg_data(cc, dmreq->sg_out); 704 dst = kmap_atomic(sg_page(sg)); 705 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 706 kunmap_atomic(dst); 707 708 return r; 709 } 710 711 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 712 struct dm_crypt_request *dmreq) 713 { 714 /* Used only for writes, there must be an additional space to store IV */ 715 get_random_bytes(iv, cc->iv_size); 716 return 0; 717 } 718 719 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti, 720 const char *opts) 721 { 722 if (crypt_integrity_aead(cc)) { 723 ti->error = "AEAD transforms not supported for EBOIV"; 724 return -EINVAL; 725 } 726 727 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) { 728 ti->error = "Block size of EBOIV cipher does " 729 "not match IV size of block cipher"; 730 return -EINVAL; 731 } 732 733 return 0; 734 } 735 736 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv, 737 struct dm_crypt_request *dmreq) 738 { 739 u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64)); 740 struct skcipher_request *req; 741 struct scatterlist src, dst; 742 struct crypto_wait wait; 743 int err; 744 745 req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO); 746 if (!req) 747 return -ENOMEM; 748 749 memset(buf, 0, cc->iv_size); 750 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 751 752 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size); 753 sg_init_one(&dst, iv, cc->iv_size); 754 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf); 755 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 756 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 757 skcipher_request_free(req); 758 759 return err; 760 } 761 762 static void crypt_iv_elephant_dtr(struct crypt_config *cc) 763 { 764 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 765 766 crypto_free_skcipher(elephant->tfm); 767 elephant->tfm = NULL; 768 } 769 770 static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti, 771 const char *opts) 772 { 773 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 774 int r; 775 776 elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0, 0); 777 if (IS_ERR(elephant->tfm)) { 778 r = PTR_ERR(elephant->tfm); 779 elephant->tfm = NULL; 780 return r; 781 } 782 783 r = crypt_iv_eboiv_ctr(cc, ti, NULL); 784 if (r) 785 crypt_iv_elephant_dtr(cc); 786 return r; 787 } 788 789 static void diffuser_disk_to_cpu(u32 *d, size_t n) 790 { 791 #ifndef __LITTLE_ENDIAN 792 int i; 793 794 for (i = 0; i < n; i++) 795 d[i] = le32_to_cpu((__le32)d[i]); 796 #endif 797 } 798 799 static void diffuser_cpu_to_disk(__le32 *d, size_t n) 800 { 801 #ifndef __LITTLE_ENDIAN 802 int i; 803 804 for (i = 0; i < n; i++) 805 d[i] = cpu_to_le32((u32)d[i]); 806 #endif 807 } 808 809 static void diffuser_a_decrypt(u32 *d, size_t n) 810 { 811 int i, i1, i2, i3; 812 813 for (i = 0; i < 5; i++) { 814 i1 = 0; 815 i2 = n - 2; 816 i3 = n - 5; 817 818 while (i1 < (n - 1)) { 819 d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 820 i1++; i2++; i3++; 821 822 if (i3 >= n) 823 i3 -= n; 824 825 d[i1] += d[i2] ^ d[i3]; 826 i1++; i2++; i3++; 827 828 if (i2 >= n) 829 i2 -= n; 830 831 d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 832 i1++; i2++; i3++; 833 834 d[i1] += d[i2] ^ d[i3]; 835 i1++; i2++; i3++; 836 } 837 } 838 } 839 840 static void diffuser_a_encrypt(u32 *d, size_t n) 841 { 842 int i, i1, i2, i3; 843 844 for (i = 0; i < 5; i++) { 845 i1 = n - 1; 846 i2 = n - 2 - 1; 847 i3 = n - 5 - 1; 848 849 while (i1 > 0) { 850 d[i1] -= d[i2] ^ d[i3]; 851 i1--; i2--; i3--; 852 853 d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19); 854 i1--; i2--; i3--; 855 856 if (i2 < 0) 857 i2 += n; 858 859 d[i1] -= d[i2] ^ d[i3]; 860 i1--; i2--; i3--; 861 862 if (i3 < 0) 863 i3 += n; 864 865 d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23); 866 i1--; i2--; i3--; 867 } 868 } 869 } 870 871 static void diffuser_b_decrypt(u32 *d, size_t n) 872 { 873 int i, i1, i2, i3; 874 875 for (i = 0; i < 3; i++) { 876 i1 = 0; 877 i2 = 2; 878 i3 = 5; 879 880 while (i1 < (n - 1)) { 881 d[i1] += d[i2] ^ d[i3]; 882 i1++; i2++; i3++; 883 884 d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 885 i1++; i2++; i3++; 886 887 if (i2 >= n) 888 i2 -= n; 889 890 d[i1] += d[i2] ^ d[i3]; 891 i1++; i2++; i3++; 892 893 if (i3 >= n) 894 i3 -= n; 895 896 d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 897 i1++; i2++; i3++; 898 } 899 } 900 } 901 902 static void diffuser_b_encrypt(u32 *d, size_t n) 903 { 904 int i, i1, i2, i3; 905 906 for (i = 0; i < 3; i++) { 907 i1 = n - 1; 908 i2 = 2 - 1; 909 i3 = 5 - 1; 910 911 while (i1 > 0) { 912 d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7); 913 i1--; i2--; i3--; 914 915 if (i3 < 0) 916 i3 += n; 917 918 d[i1] -= d[i2] ^ d[i3]; 919 i1--; i2--; i3--; 920 921 if (i2 < 0) 922 i2 += n; 923 924 d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22); 925 i1--; i2--; i3--; 926 927 d[i1] -= d[i2] ^ d[i3]; 928 i1--; i2--; i3--; 929 } 930 } 931 } 932 933 static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq) 934 { 935 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 936 u8 *es, *ks, *data, *data2, *data_offset; 937 struct skcipher_request *req; 938 struct scatterlist *sg, *sg2, src, dst; 939 struct crypto_wait wait; 940 int i, r; 941 942 req = skcipher_request_alloc(elephant->tfm, GFP_NOIO); 943 es = kzalloc(16, GFP_NOIO); /* Key for AES */ 944 ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */ 945 946 if (!req || !es || !ks) { 947 r = -ENOMEM; 948 goto out; 949 } 950 951 *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 952 953 /* E(Ks, e(s)) */ 954 sg_init_one(&src, es, 16); 955 sg_init_one(&dst, ks, 16); 956 skcipher_request_set_crypt(req, &src, &dst, 16, NULL); 957 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 958 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 959 if (r) 960 goto out; 961 962 /* E(Ks, e'(s)) */ 963 es[15] = 0x80; 964 sg_init_one(&dst, &ks[16], 16); 965 r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 966 if (r) 967 goto out; 968 969 sg = crypt_get_sg_data(cc, dmreq->sg_out); 970 data = kmap_atomic(sg_page(sg)); 971 data_offset = data + sg->offset; 972 973 /* Cannot modify original bio, copy to sg_out and apply Elephant to it */ 974 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 975 sg2 = crypt_get_sg_data(cc, dmreq->sg_in); 976 data2 = kmap_atomic(sg_page(sg2)); 977 memcpy(data_offset, data2 + sg2->offset, cc->sector_size); 978 kunmap_atomic(data2); 979 } 980 981 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 982 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32)); 983 diffuser_b_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 984 diffuser_a_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 985 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32)); 986 } 987 988 for (i = 0; i < (cc->sector_size / 32); i++) 989 crypto_xor(data_offset + i * 32, ks, 32); 990 991 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 992 diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32)); 993 diffuser_a_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 994 diffuser_b_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32)); 995 diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32)); 996 } 997 998 kunmap_atomic(data); 999 out: 1000 kfree_sensitive(ks); 1001 kfree_sensitive(es); 1002 skcipher_request_free(req); 1003 return r; 1004 } 1005 1006 static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv, 1007 struct dm_crypt_request *dmreq) 1008 { 1009 int r; 1010 1011 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 1012 r = crypt_iv_elephant(cc, dmreq); 1013 if (r) 1014 return r; 1015 } 1016 1017 return crypt_iv_eboiv_gen(cc, iv, dmreq); 1018 } 1019 1020 static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv, 1021 struct dm_crypt_request *dmreq) 1022 { 1023 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 1024 return crypt_iv_elephant(cc, dmreq); 1025 1026 return 0; 1027 } 1028 1029 static int crypt_iv_elephant_init(struct crypt_config *cc) 1030 { 1031 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1032 int key_offset = cc->key_size - cc->key_extra_size; 1033 1034 return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size); 1035 } 1036 1037 static int crypt_iv_elephant_wipe(struct crypt_config *cc) 1038 { 1039 struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant; 1040 u8 key[ELEPHANT_MAX_KEY_SIZE]; 1041 1042 memset(key, 0, cc->key_extra_size); 1043 return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size); 1044 } 1045 1046 static const struct crypt_iv_operations crypt_iv_plain_ops = { 1047 .generator = crypt_iv_plain_gen 1048 }; 1049 1050 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 1051 .generator = crypt_iv_plain64_gen 1052 }; 1053 1054 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 1055 .generator = crypt_iv_plain64be_gen 1056 }; 1057 1058 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 1059 .generator = crypt_iv_essiv_gen 1060 }; 1061 1062 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 1063 .ctr = crypt_iv_benbi_ctr, 1064 .dtr = crypt_iv_benbi_dtr, 1065 .generator = crypt_iv_benbi_gen 1066 }; 1067 1068 static const struct crypt_iv_operations crypt_iv_null_ops = { 1069 .generator = crypt_iv_null_gen 1070 }; 1071 1072 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 1073 .ctr = crypt_iv_lmk_ctr, 1074 .dtr = crypt_iv_lmk_dtr, 1075 .init = crypt_iv_lmk_init, 1076 .wipe = crypt_iv_lmk_wipe, 1077 .generator = crypt_iv_lmk_gen, 1078 .post = crypt_iv_lmk_post 1079 }; 1080 1081 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 1082 .ctr = crypt_iv_tcw_ctr, 1083 .dtr = crypt_iv_tcw_dtr, 1084 .init = crypt_iv_tcw_init, 1085 .wipe = crypt_iv_tcw_wipe, 1086 .generator = crypt_iv_tcw_gen, 1087 .post = crypt_iv_tcw_post 1088 }; 1089 1090 static struct crypt_iv_operations crypt_iv_random_ops = { 1091 .generator = crypt_iv_random_gen 1092 }; 1093 1094 static struct crypt_iv_operations crypt_iv_eboiv_ops = { 1095 .ctr = crypt_iv_eboiv_ctr, 1096 .generator = crypt_iv_eboiv_gen 1097 }; 1098 1099 static struct crypt_iv_operations crypt_iv_elephant_ops = { 1100 .ctr = crypt_iv_elephant_ctr, 1101 .dtr = crypt_iv_elephant_dtr, 1102 .init = crypt_iv_elephant_init, 1103 .wipe = crypt_iv_elephant_wipe, 1104 .generator = crypt_iv_elephant_gen, 1105 .post = crypt_iv_elephant_post 1106 }; 1107 1108 /* 1109 * Integrity extensions 1110 */ 1111 static bool crypt_integrity_aead(struct crypt_config *cc) 1112 { 1113 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 1114 } 1115 1116 static bool crypt_integrity_hmac(struct crypt_config *cc) 1117 { 1118 return crypt_integrity_aead(cc) && cc->key_mac_size; 1119 } 1120 1121 /* Get sg containing data */ 1122 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 1123 struct scatterlist *sg) 1124 { 1125 if (unlikely(crypt_integrity_aead(cc))) 1126 return &sg[2]; 1127 1128 return sg; 1129 } 1130 1131 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 1132 { 1133 struct bio_integrity_payload *bip; 1134 unsigned int tag_len; 1135 int ret; 1136 1137 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 1138 return 0; 1139 1140 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 1141 if (IS_ERR(bip)) 1142 return PTR_ERR(bip); 1143 1144 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift); 1145 1146 bip->bip_iter.bi_size = tag_len; 1147 bip->bip_iter.bi_sector = io->cc->start + io->sector; 1148 1149 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 1150 tag_len, offset_in_page(io->integrity_metadata)); 1151 if (unlikely(ret != tag_len)) 1152 return -ENOMEM; 1153 1154 return 0; 1155 } 1156 1157 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 1158 { 1159 #ifdef CONFIG_BLK_DEV_INTEGRITY 1160 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 1161 struct mapped_device *md = dm_table_get_md(ti->table); 1162 1163 /* From now we require underlying device with our integrity profile */ 1164 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 1165 ti->error = "Integrity profile not supported."; 1166 return -EINVAL; 1167 } 1168 1169 if (bi->tag_size != cc->on_disk_tag_size || 1170 bi->tuple_size != cc->on_disk_tag_size) { 1171 ti->error = "Integrity profile tag size mismatch."; 1172 return -EINVAL; 1173 } 1174 if (1 << bi->interval_exp != cc->sector_size) { 1175 ti->error = "Integrity profile sector size mismatch."; 1176 return -EINVAL; 1177 } 1178 1179 if (crypt_integrity_aead(cc)) { 1180 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 1181 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), 1182 cc->integrity_tag_size, cc->integrity_iv_size); 1183 1184 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 1185 ti->error = "Integrity AEAD auth tag size is not supported."; 1186 return -EINVAL; 1187 } 1188 } else if (cc->integrity_iv_size) 1189 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), 1190 cc->integrity_iv_size); 1191 1192 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 1193 ti->error = "Not enough space for integrity tag in the profile."; 1194 return -EINVAL; 1195 } 1196 1197 return 0; 1198 #else 1199 ti->error = "Integrity profile not supported."; 1200 return -EINVAL; 1201 #endif 1202 } 1203 1204 static void crypt_convert_init(struct crypt_config *cc, 1205 struct convert_context *ctx, 1206 struct bio *bio_out, struct bio *bio_in, 1207 sector_t sector) 1208 { 1209 ctx->bio_in = bio_in; 1210 ctx->bio_out = bio_out; 1211 if (bio_in) 1212 ctx->iter_in = bio_in->bi_iter; 1213 if (bio_out) 1214 ctx->iter_out = bio_out->bi_iter; 1215 ctx->cc_sector = sector + cc->iv_offset; 1216 init_completion(&ctx->restart); 1217 } 1218 1219 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 1220 void *req) 1221 { 1222 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 1223 } 1224 1225 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 1226 { 1227 return (void *)((char *)dmreq - cc->dmreq_start); 1228 } 1229 1230 static u8 *iv_of_dmreq(struct crypt_config *cc, 1231 struct dm_crypt_request *dmreq) 1232 { 1233 if (crypt_integrity_aead(cc)) 1234 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1235 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 1236 else 1237 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 1238 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 1239 } 1240 1241 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 1242 struct dm_crypt_request *dmreq) 1243 { 1244 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 1245 } 1246 1247 static __le64 *org_sector_of_dmreq(struct crypt_config *cc, 1248 struct dm_crypt_request *dmreq) 1249 { 1250 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 1251 return (__le64 *) ptr; 1252 } 1253 1254 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 1255 struct dm_crypt_request *dmreq) 1256 { 1257 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 1258 cc->iv_size + sizeof(uint64_t); 1259 return (unsigned int*)ptr; 1260 } 1261 1262 static void *tag_from_dmreq(struct crypt_config *cc, 1263 struct dm_crypt_request *dmreq) 1264 { 1265 struct convert_context *ctx = dmreq->ctx; 1266 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1267 1268 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 1269 cc->on_disk_tag_size]; 1270 } 1271 1272 static void *iv_tag_from_dmreq(struct crypt_config *cc, 1273 struct dm_crypt_request *dmreq) 1274 { 1275 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 1276 } 1277 1278 static int crypt_convert_block_aead(struct crypt_config *cc, 1279 struct convert_context *ctx, 1280 struct aead_request *req, 1281 unsigned int tag_offset) 1282 { 1283 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1284 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1285 struct dm_crypt_request *dmreq; 1286 u8 *iv, *org_iv, *tag_iv, *tag; 1287 __le64 *sector; 1288 int r = 0; 1289 1290 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 1291 1292 /* Reject unexpected unaligned bio. */ 1293 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1294 return -EIO; 1295 1296 dmreq = dmreq_of_req(cc, req); 1297 dmreq->iv_sector = ctx->cc_sector; 1298 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1299 dmreq->iv_sector >>= cc->sector_shift; 1300 dmreq->ctx = ctx; 1301 1302 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1303 1304 sector = org_sector_of_dmreq(cc, dmreq); 1305 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1306 1307 iv = iv_of_dmreq(cc, dmreq); 1308 org_iv = org_iv_of_dmreq(cc, dmreq); 1309 tag = tag_from_dmreq(cc, dmreq); 1310 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1311 1312 /* AEAD request: 1313 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 1314 * | (authenticated) | (auth+encryption) | | 1315 * | sector_LE | IV | sector in/out | tag in/out | 1316 */ 1317 sg_init_table(dmreq->sg_in, 4); 1318 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1319 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1320 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1321 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1322 1323 sg_init_table(dmreq->sg_out, 4); 1324 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1325 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1326 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1327 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1328 1329 if (cc->iv_gen_ops) { 1330 /* For READs use IV stored in integrity metadata */ 1331 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1332 memcpy(org_iv, tag_iv, cc->iv_size); 1333 } else { 1334 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1335 if (r < 0) 1336 return r; 1337 /* Store generated IV in integrity metadata */ 1338 if (cc->integrity_iv_size) 1339 memcpy(tag_iv, org_iv, cc->iv_size); 1340 } 1341 /* Working copy of IV, to be modified in crypto API */ 1342 memcpy(iv, org_iv, cc->iv_size); 1343 } 1344 1345 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1346 if (bio_data_dir(ctx->bio_in) == WRITE) { 1347 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1348 cc->sector_size, iv); 1349 r = crypto_aead_encrypt(req); 1350 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1351 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1352 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1353 } else { 1354 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1355 cc->sector_size + cc->integrity_tag_size, iv); 1356 r = crypto_aead_decrypt(req); 1357 } 1358 1359 if (r == -EBADMSG) { 1360 char b[BDEVNAME_SIZE]; 1361 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 1362 (unsigned long long)le64_to_cpu(*sector)); 1363 } 1364 1365 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1366 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1367 1368 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1369 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1370 1371 return r; 1372 } 1373 1374 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1375 struct convert_context *ctx, 1376 struct skcipher_request *req, 1377 unsigned int tag_offset) 1378 { 1379 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1380 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1381 struct scatterlist *sg_in, *sg_out; 1382 struct dm_crypt_request *dmreq; 1383 u8 *iv, *org_iv, *tag_iv; 1384 __le64 *sector; 1385 int r = 0; 1386 1387 /* Reject unexpected unaligned bio. */ 1388 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1389 return -EIO; 1390 1391 dmreq = dmreq_of_req(cc, req); 1392 dmreq->iv_sector = ctx->cc_sector; 1393 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1394 dmreq->iv_sector >>= cc->sector_shift; 1395 dmreq->ctx = ctx; 1396 1397 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1398 1399 iv = iv_of_dmreq(cc, dmreq); 1400 org_iv = org_iv_of_dmreq(cc, dmreq); 1401 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1402 1403 sector = org_sector_of_dmreq(cc, dmreq); 1404 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1405 1406 /* For skcipher we use only the first sg item */ 1407 sg_in = &dmreq->sg_in[0]; 1408 sg_out = &dmreq->sg_out[0]; 1409 1410 sg_init_table(sg_in, 1); 1411 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1412 1413 sg_init_table(sg_out, 1); 1414 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1415 1416 if (cc->iv_gen_ops) { 1417 /* For READs use IV stored in integrity metadata */ 1418 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1419 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1420 } else { 1421 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1422 if (r < 0) 1423 return r; 1424 /* Data can be already preprocessed in generator */ 1425 if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags)) 1426 sg_in = sg_out; 1427 /* Store generated IV in integrity metadata */ 1428 if (cc->integrity_iv_size) 1429 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1430 } 1431 /* Working copy of IV, to be modified in crypto API */ 1432 memcpy(iv, org_iv, cc->iv_size); 1433 } 1434 1435 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1436 1437 if (bio_data_dir(ctx->bio_in) == WRITE) 1438 r = crypto_skcipher_encrypt(req); 1439 else 1440 r = crypto_skcipher_decrypt(req); 1441 1442 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1443 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1444 1445 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1446 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1447 1448 return r; 1449 } 1450 1451 static void kcryptd_async_done(struct crypto_async_request *async_req, 1452 int error); 1453 1454 static void crypt_alloc_req_skcipher(struct crypt_config *cc, 1455 struct convert_context *ctx) 1456 { 1457 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); 1458 1459 if (!ctx->r.req) 1460 ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO); 1461 1462 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1463 1464 /* 1465 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1466 * requests if driver request queue is full. 1467 */ 1468 skcipher_request_set_callback(ctx->r.req, 1469 CRYPTO_TFM_REQ_MAY_BACKLOG, 1470 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1471 } 1472 1473 static void crypt_alloc_req_aead(struct crypt_config *cc, 1474 struct convert_context *ctx) 1475 { 1476 if (!ctx->r.req_aead) 1477 ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO); 1478 1479 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1480 1481 /* 1482 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1483 * requests if driver request queue is full. 1484 */ 1485 aead_request_set_callback(ctx->r.req_aead, 1486 CRYPTO_TFM_REQ_MAY_BACKLOG, 1487 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1488 } 1489 1490 static void crypt_alloc_req(struct crypt_config *cc, 1491 struct convert_context *ctx) 1492 { 1493 if (crypt_integrity_aead(cc)) 1494 crypt_alloc_req_aead(cc, ctx); 1495 else 1496 crypt_alloc_req_skcipher(cc, ctx); 1497 } 1498 1499 static void crypt_free_req_skcipher(struct crypt_config *cc, 1500 struct skcipher_request *req, struct bio *base_bio) 1501 { 1502 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1503 1504 if ((struct skcipher_request *)(io + 1) != req) 1505 mempool_free(req, &cc->req_pool); 1506 } 1507 1508 static void crypt_free_req_aead(struct crypt_config *cc, 1509 struct aead_request *req, struct bio *base_bio) 1510 { 1511 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1512 1513 if ((struct aead_request *)(io + 1) != req) 1514 mempool_free(req, &cc->req_pool); 1515 } 1516 1517 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1518 { 1519 if (crypt_integrity_aead(cc)) 1520 crypt_free_req_aead(cc, req, base_bio); 1521 else 1522 crypt_free_req_skcipher(cc, req, base_bio); 1523 } 1524 1525 /* 1526 * Encrypt / decrypt data from one bio to another one (can be the same one) 1527 */ 1528 static blk_status_t crypt_convert(struct crypt_config *cc, 1529 struct convert_context *ctx, bool atomic) 1530 { 1531 unsigned int tag_offset = 0; 1532 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1533 int r; 1534 1535 atomic_set(&ctx->cc_pending, 1); 1536 1537 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1538 1539 crypt_alloc_req(cc, ctx); 1540 atomic_inc(&ctx->cc_pending); 1541 1542 if (crypt_integrity_aead(cc)) 1543 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1544 else 1545 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1546 1547 switch (r) { 1548 /* 1549 * The request was queued by a crypto driver 1550 * but the driver request queue is full, let's wait. 1551 */ 1552 case -EBUSY: 1553 wait_for_completion(&ctx->restart); 1554 reinit_completion(&ctx->restart); 1555 /* fall through */ 1556 /* 1557 * The request is queued and processed asynchronously, 1558 * completion function kcryptd_async_done() will be called. 1559 */ 1560 case -EINPROGRESS: 1561 ctx->r.req = NULL; 1562 ctx->cc_sector += sector_step; 1563 tag_offset++; 1564 continue; 1565 /* 1566 * The request was already processed (synchronously). 1567 */ 1568 case 0: 1569 atomic_dec(&ctx->cc_pending); 1570 ctx->cc_sector += sector_step; 1571 tag_offset++; 1572 if (!atomic) 1573 cond_resched(); 1574 continue; 1575 /* 1576 * There was a data integrity error. 1577 */ 1578 case -EBADMSG: 1579 atomic_dec(&ctx->cc_pending); 1580 return BLK_STS_PROTECTION; 1581 /* 1582 * There was an error while processing the request. 1583 */ 1584 default: 1585 atomic_dec(&ctx->cc_pending); 1586 return BLK_STS_IOERR; 1587 } 1588 } 1589 1590 return 0; 1591 } 1592 1593 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1594 1595 /* 1596 * Generate a new unfragmented bio with the given size 1597 * This should never violate the device limitations (but only because 1598 * max_segment_size is being constrained to PAGE_SIZE). 1599 * 1600 * This function may be called concurrently. If we allocate from the mempool 1601 * concurrently, there is a possibility of deadlock. For example, if we have 1602 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1603 * the mempool concurrently, it may deadlock in a situation where both processes 1604 * have allocated 128 pages and the mempool is exhausted. 1605 * 1606 * In order to avoid this scenario we allocate the pages under a mutex. 1607 * 1608 * In order to not degrade performance with excessive locking, we try 1609 * non-blocking allocations without a mutex first but on failure we fallback 1610 * to blocking allocations with a mutex. 1611 */ 1612 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 1613 { 1614 struct crypt_config *cc = io->cc; 1615 struct bio *clone; 1616 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1617 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1618 unsigned i, len, remaining_size; 1619 struct page *page; 1620 1621 retry: 1622 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1623 mutex_lock(&cc->bio_alloc_lock); 1624 1625 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs); 1626 if (!clone) 1627 goto out; 1628 1629 clone_init(io, clone); 1630 1631 remaining_size = size; 1632 1633 for (i = 0; i < nr_iovecs; i++) { 1634 page = mempool_alloc(&cc->page_pool, gfp_mask); 1635 if (!page) { 1636 crypt_free_buffer_pages(cc, clone); 1637 bio_put(clone); 1638 gfp_mask |= __GFP_DIRECT_RECLAIM; 1639 goto retry; 1640 } 1641 1642 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1643 1644 bio_add_page(clone, page, len, 0); 1645 1646 remaining_size -= len; 1647 } 1648 1649 /* Allocate space for integrity tags */ 1650 if (dm_crypt_integrity_io_alloc(io, clone)) { 1651 crypt_free_buffer_pages(cc, clone); 1652 bio_put(clone); 1653 clone = NULL; 1654 } 1655 out: 1656 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1657 mutex_unlock(&cc->bio_alloc_lock); 1658 1659 return clone; 1660 } 1661 1662 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1663 { 1664 struct bio_vec *bv; 1665 struct bvec_iter_all iter_all; 1666 1667 bio_for_each_segment_all(bv, clone, iter_all) { 1668 BUG_ON(!bv->bv_page); 1669 mempool_free(bv->bv_page, &cc->page_pool); 1670 } 1671 } 1672 1673 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1674 struct bio *bio, sector_t sector) 1675 { 1676 io->cc = cc; 1677 io->base_bio = bio; 1678 io->sector = sector; 1679 io->error = 0; 1680 io->ctx.r.req = NULL; 1681 io->integrity_metadata = NULL; 1682 io->integrity_metadata_from_pool = false; 1683 atomic_set(&io->io_pending, 0); 1684 } 1685 1686 static void crypt_inc_pending(struct dm_crypt_io *io) 1687 { 1688 atomic_inc(&io->io_pending); 1689 } 1690 1691 /* 1692 * One of the bios was finished. Check for completion of 1693 * the whole request and correctly clean up the buffer. 1694 */ 1695 static void crypt_dec_pending(struct dm_crypt_io *io) 1696 { 1697 struct crypt_config *cc = io->cc; 1698 struct bio *base_bio = io->base_bio; 1699 blk_status_t error = io->error; 1700 1701 if (!atomic_dec_and_test(&io->io_pending)) 1702 return; 1703 1704 if (io->ctx.r.req) 1705 crypt_free_req(cc, io->ctx.r.req, base_bio); 1706 1707 if (unlikely(io->integrity_metadata_from_pool)) 1708 mempool_free(io->integrity_metadata, &io->cc->tag_pool); 1709 else 1710 kfree(io->integrity_metadata); 1711 1712 base_bio->bi_status = error; 1713 bio_endio(base_bio); 1714 } 1715 1716 /* 1717 * kcryptd/kcryptd_io: 1718 * 1719 * Needed because it would be very unwise to do decryption in an 1720 * interrupt context. 1721 * 1722 * kcryptd performs the actual encryption or decryption. 1723 * 1724 * kcryptd_io performs the IO submission. 1725 * 1726 * They must be separated as otherwise the final stages could be 1727 * starved by new requests which can block in the first stages due 1728 * to memory allocation. 1729 * 1730 * The work is done per CPU global for all dm-crypt instances. 1731 * They should not depend on each other and do not block. 1732 */ 1733 static void crypt_endio(struct bio *clone) 1734 { 1735 struct dm_crypt_io *io = clone->bi_private; 1736 struct crypt_config *cc = io->cc; 1737 unsigned rw = bio_data_dir(clone); 1738 blk_status_t error; 1739 1740 /* 1741 * free the processed pages 1742 */ 1743 if (rw == WRITE) 1744 crypt_free_buffer_pages(cc, clone); 1745 1746 error = clone->bi_status; 1747 bio_put(clone); 1748 1749 if (rw == READ && !error) { 1750 kcryptd_queue_crypt(io); 1751 return; 1752 } 1753 1754 if (unlikely(error)) 1755 io->error = error; 1756 1757 crypt_dec_pending(io); 1758 } 1759 1760 static void clone_init(struct dm_crypt_io *io, struct bio *clone) 1761 { 1762 struct crypt_config *cc = io->cc; 1763 1764 clone->bi_private = io; 1765 clone->bi_end_io = crypt_endio; 1766 bio_set_dev(clone, cc->dev->bdev); 1767 clone->bi_opf = io->base_bio->bi_opf; 1768 } 1769 1770 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1771 { 1772 struct crypt_config *cc = io->cc; 1773 struct bio *clone; 1774 1775 /* 1776 * We need the original biovec array in order to decrypt 1777 * the whole bio data *afterwards* -- thanks to immutable 1778 * biovecs we don't need to worry about the block layer 1779 * modifying the biovec array; so leverage bio_clone_fast(). 1780 */ 1781 clone = bio_clone_fast(io->base_bio, gfp, &cc->bs); 1782 if (!clone) 1783 return 1; 1784 1785 crypt_inc_pending(io); 1786 1787 clone_init(io, clone); 1788 clone->bi_iter.bi_sector = cc->start + io->sector; 1789 1790 if (dm_crypt_integrity_io_alloc(io, clone)) { 1791 crypt_dec_pending(io); 1792 bio_put(clone); 1793 return 1; 1794 } 1795 1796 submit_bio_noacct(clone); 1797 return 0; 1798 } 1799 1800 static void kcryptd_io_read_work(struct work_struct *work) 1801 { 1802 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1803 1804 crypt_inc_pending(io); 1805 if (kcryptd_io_read(io, GFP_NOIO)) 1806 io->error = BLK_STS_RESOURCE; 1807 crypt_dec_pending(io); 1808 } 1809 1810 static void kcryptd_queue_read(struct dm_crypt_io *io) 1811 { 1812 struct crypt_config *cc = io->cc; 1813 1814 INIT_WORK(&io->work, kcryptd_io_read_work); 1815 queue_work(cc->io_queue, &io->work); 1816 } 1817 1818 static void kcryptd_io_write(struct dm_crypt_io *io) 1819 { 1820 struct bio *clone = io->ctx.bio_out; 1821 1822 submit_bio_noacct(clone); 1823 } 1824 1825 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1826 1827 static int dmcrypt_write(void *data) 1828 { 1829 struct crypt_config *cc = data; 1830 struct dm_crypt_io *io; 1831 1832 while (1) { 1833 struct rb_root write_tree; 1834 struct blk_plug plug; 1835 1836 spin_lock_irq(&cc->write_thread_lock); 1837 continue_locked: 1838 1839 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1840 goto pop_from_list; 1841 1842 set_current_state(TASK_INTERRUPTIBLE); 1843 1844 spin_unlock_irq(&cc->write_thread_lock); 1845 1846 if (unlikely(kthread_should_stop())) { 1847 set_current_state(TASK_RUNNING); 1848 break; 1849 } 1850 1851 schedule(); 1852 1853 set_current_state(TASK_RUNNING); 1854 spin_lock_irq(&cc->write_thread_lock); 1855 goto continue_locked; 1856 1857 pop_from_list: 1858 write_tree = cc->write_tree; 1859 cc->write_tree = RB_ROOT; 1860 spin_unlock_irq(&cc->write_thread_lock); 1861 1862 BUG_ON(rb_parent(write_tree.rb_node)); 1863 1864 /* 1865 * Note: we cannot walk the tree here with rb_next because 1866 * the structures may be freed when kcryptd_io_write is called. 1867 */ 1868 blk_start_plug(&plug); 1869 do { 1870 io = crypt_io_from_node(rb_first(&write_tree)); 1871 rb_erase(&io->rb_node, &write_tree); 1872 kcryptd_io_write(io); 1873 } while (!RB_EMPTY_ROOT(&write_tree)); 1874 blk_finish_plug(&plug); 1875 } 1876 return 0; 1877 } 1878 1879 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1880 { 1881 struct bio *clone = io->ctx.bio_out; 1882 struct crypt_config *cc = io->cc; 1883 unsigned long flags; 1884 sector_t sector; 1885 struct rb_node **rbp, *parent; 1886 1887 if (unlikely(io->error)) { 1888 crypt_free_buffer_pages(cc, clone); 1889 bio_put(clone); 1890 crypt_dec_pending(io); 1891 return; 1892 } 1893 1894 /* crypt_convert should have filled the clone bio */ 1895 BUG_ON(io->ctx.iter_out.bi_size); 1896 1897 clone->bi_iter.bi_sector = cc->start + io->sector; 1898 1899 if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) || 1900 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) { 1901 submit_bio_noacct(clone); 1902 return; 1903 } 1904 1905 spin_lock_irqsave(&cc->write_thread_lock, flags); 1906 if (RB_EMPTY_ROOT(&cc->write_tree)) 1907 wake_up_process(cc->write_thread); 1908 rbp = &cc->write_tree.rb_node; 1909 parent = NULL; 1910 sector = io->sector; 1911 while (*rbp) { 1912 parent = *rbp; 1913 if (sector < crypt_io_from_node(parent)->sector) 1914 rbp = &(*rbp)->rb_left; 1915 else 1916 rbp = &(*rbp)->rb_right; 1917 } 1918 rb_link_node(&io->rb_node, parent, rbp); 1919 rb_insert_color(&io->rb_node, &cc->write_tree); 1920 spin_unlock_irqrestore(&cc->write_thread_lock, flags); 1921 } 1922 1923 static bool kcryptd_crypt_write_inline(struct crypt_config *cc, 1924 struct convert_context *ctx) 1925 1926 { 1927 if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags)) 1928 return false; 1929 1930 /* 1931 * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering 1932 * constraints so they do not need to be issued inline by 1933 * kcryptd_crypt_write_convert(). 1934 */ 1935 switch (bio_op(ctx->bio_in)) { 1936 case REQ_OP_WRITE: 1937 case REQ_OP_WRITE_SAME: 1938 case REQ_OP_WRITE_ZEROES: 1939 return true; 1940 default: 1941 return false; 1942 } 1943 } 1944 1945 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 1946 { 1947 struct crypt_config *cc = io->cc; 1948 struct convert_context *ctx = &io->ctx; 1949 struct bio *clone; 1950 int crypt_finished; 1951 sector_t sector = io->sector; 1952 blk_status_t r; 1953 1954 /* 1955 * Prevent io from disappearing until this function completes. 1956 */ 1957 crypt_inc_pending(io); 1958 crypt_convert_init(cc, ctx, NULL, io->base_bio, sector); 1959 1960 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 1961 if (unlikely(!clone)) { 1962 io->error = BLK_STS_IOERR; 1963 goto dec; 1964 } 1965 1966 io->ctx.bio_out = clone; 1967 io->ctx.iter_out = clone->bi_iter; 1968 1969 sector += bio_sectors(clone); 1970 1971 crypt_inc_pending(io); 1972 r = crypt_convert(cc, ctx, 1973 test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)); 1974 if (r) 1975 io->error = r; 1976 crypt_finished = atomic_dec_and_test(&ctx->cc_pending); 1977 if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) { 1978 /* Wait for completion signaled by kcryptd_async_done() */ 1979 wait_for_completion(&ctx->restart); 1980 crypt_finished = 1; 1981 } 1982 1983 /* Encryption was already finished, submit io now */ 1984 if (crypt_finished) { 1985 kcryptd_crypt_write_io_submit(io, 0); 1986 io->sector = sector; 1987 } 1988 1989 dec: 1990 crypt_dec_pending(io); 1991 } 1992 1993 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 1994 { 1995 crypt_dec_pending(io); 1996 } 1997 1998 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 1999 { 2000 struct crypt_config *cc = io->cc; 2001 blk_status_t r; 2002 2003 crypt_inc_pending(io); 2004 2005 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 2006 io->sector); 2007 2008 r = crypt_convert(cc, &io->ctx, 2009 test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)); 2010 if (r) 2011 io->error = r; 2012 2013 if (atomic_dec_and_test(&io->ctx.cc_pending)) 2014 kcryptd_crypt_read_done(io); 2015 2016 crypt_dec_pending(io); 2017 } 2018 2019 static void kcryptd_async_done(struct crypto_async_request *async_req, 2020 int error) 2021 { 2022 struct dm_crypt_request *dmreq = async_req->data; 2023 struct convert_context *ctx = dmreq->ctx; 2024 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 2025 struct crypt_config *cc = io->cc; 2026 2027 /* 2028 * A request from crypto driver backlog is going to be processed now, 2029 * finish the completion and continue in crypt_convert(). 2030 * (Callback will be called for the second time for this request.) 2031 */ 2032 if (error == -EINPROGRESS) { 2033 complete(&ctx->restart); 2034 return; 2035 } 2036 2037 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 2038 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 2039 2040 if (error == -EBADMSG) { 2041 char b[BDEVNAME_SIZE]; 2042 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 2043 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); 2044 io->error = BLK_STS_PROTECTION; 2045 } else if (error < 0) 2046 io->error = BLK_STS_IOERR; 2047 2048 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 2049 2050 if (!atomic_dec_and_test(&ctx->cc_pending)) 2051 return; 2052 2053 /* 2054 * The request is fully completed: for inline writes, let 2055 * kcryptd_crypt_write_convert() do the IO submission. 2056 */ 2057 if (bio_data_dir(io->base_bio) == READ) { 2058 kcryptd_crypt_read_done(io); 2059 return; 2060 } 2061 2062 if (kcryptd_crypt_write_inline(cc, ctx)) { 2063 complete(&ctx->restart); 2064 return; 2065 } 2066 2067 kcryptd_crypt_write_io_submit(io, 1); 2068 } 2069 2070 static void kcryptd_crypt(struct work_struct *work) 2071 { 2072 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 2073 2074 if (bio_data_dir(io->base_bio) == READ) 2075 kcryptd_crypt_read_convert(io); 2076 else 2077 kcryptd_crypt_write_convert(io); 2078 } 2079 2080 static void kcryptd_crypt_tasklet(unsigned long work) 2081 { 2082 kcryptd_crypt((struct work_struct *)work); 2083 } 2084 2085 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 2086 { 2087 struct crypt_config *cc = io->cc; 2088 2089 if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) || 2090 (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) { 2091 if (in_irq()) { 2092 /* Crypto API's "skcipher_walk_first() refuses to work in hard IRQ context */ 2093 tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work); 2094 tasklet_schedule(&io->tasklet); 2095 return; 2096 } 2097 2098 kcryptd_crypt(&io->work); 2099 return; 2100 } 2101 2102 INIT_WORK(&io->work, kcryptd_crypt); 2103 queue_work(cc->crypt_queue, &io->work); 2104 } 2105 2106 static void crypt_free_tfms_aead(struct crypt_config *cc) 2107 { 2108 if (!cc->cipher_tfm.tfms_aead) 2109 return; 2110 2111 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2112 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 2113 cc->cipher_tfm.tfms_aead[0] = NULL; 2114 } 2115 2116 kfree(cc->cipher_tfm.tfms_aead); 2117 cc->cipher_tfm.tfms_aead = NULL; 2118 } 2119 2120 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 2121 { 2122 unsigned i; 2123 2124 if (!cc->cipher_tfm.tfms) 2125 return; 2126 2127 for (i = 0; i < cc->tfms_count; i++) 2128 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 2129 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 2130 cc->cipher_tfm.tfms[i] = NULL; 2131 } 2132 2133 kfree(cc->cipher_tfm.tfms); 2134 cc->cipher_tfm.tfms = NULL; 2135 } 2136 2137 static void crypt_free_tfms(struct crypt_config *cc) 2138 { 2139 if (crypt_integrity_aead(cc)) 2140 crypt_free_tfms_aead(cc); 2141 else 2142 crypt_free_tfms_skcipher(cc); 2143 } 2144 2145 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 2146 { 2147 unsigned i; 2148 int err; 2149 2150 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 2151 sizeof(struct crypto_skcipher *), 2152 GFP_KERNEL); 2153 if (!cc->cipher_tfm.tfms) 2154 return -ENOMEM; 2155 2156 for (i = 0; i < cc->tfms_count; i++) { 2157 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0); 2158 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 2159 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 2160 crypt_free_tfms(cc); 2161 return err; 2162 } 2163 } 2164 2165 /* 2166 * dm-crypt performance can vary greatly depending on which crypto 2167 * algorithm implementation is used. Help people debug performance 2168 * problems by logging the ->cra_driver_name. 2169 */ 2170 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2171 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); 2172 return 0; 2173 } 2174 2175 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 2176 { 2177 int err; 2178 2179 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 2180 if (!cc->cipher_tfm.tfms) 2181 return -ENOMEM; 2182 2183 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0); 2184 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 2185 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 2186 crypt_free_tfms(cc); 2187 return err; 2188 } 2189 2190 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 2191 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); 2192 return 0; 2193 } 2194 2195 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 2196 { 2197 if (crypt_integrity_aead(cc)) 2198 return crypt_alloc_tfms_aead(cc, ciphermode); 2199 else 2200 return crypt_alloc_tfms_skcipher(cc, ciphermode); 2201 } 2202 2203 static unsigned crypt_subkey_size(struct crypt_config *cc) 2204 { 2205 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 2206 } 2207 2208 static unsigned crypt_authenckey_size(struct crypt_config *cc) 2209 { 2210 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 2211 } 2212 2213 /* 2214 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 2215 * the key must be for some reason in special format. 2216 * This funcion converts cc->key to this special format. 2217 */ 2218 static void crypt_copy_authenckey(char *p, const void *key, 2219 unsigned enckeylen, unsigned authkeylen) 2220 { 2221 struct crypto_authenc_key_param *param; 2222 struct rtattr *rta; 2223 2224 rta = (struct rtattr *)p; 2225 param = RTA_DATA(rta); 2226 param->enckeylen = cpu_to_be32(enckeylen); 2227 rta->rta_len = RTA_LENGTH(sizeof(*param)); 2228 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 2229 p += RTA_SPACE(sizeof(*param)); 2230 memcpy(p, key + enckeylen, authkeylen); 2231 p += authkeylen; 2232 memcpy(p, key, enckeylen); 2233 } 2234 2235 static int crypt_setkey(struct crypt_config *cc) 2236 { 2237 unsigned subkey_size; 2238 int err = 0, i, r; 2239 2240 /* Ignore extra keys (which are used for IV etc) */ 2241 subkey_size = crypt_subkey_size(cc); 2242 2243 if (crypt_integrity_hmac(cc)) { 2244 if (subkey_size < cc->key_mac_size) 2245 return -EINVAL; 2246 2247 crypt_copy_authenckey(cc->authenc_key, cc->key, 2248 subkey_size - cc->key_mac_size, 2249 cc->key_mac_size); 2250 } 2251 2252 for (i = 0; i < cc->tfms_count; i++) { 2253 if (crypt_integrity_hmac(cc)) 2254 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2255 cc->authenc_key, crypt_authenckey_size(cc)); 2256 else if (crypt_integrity_aead(cc)) 2257 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 2258 cc->key + (i * subkey_size), 2259 subkey_size); 2260 else 2261 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 2262 cc->key + (i * subkey_size), 2263 subkey_size); 2264 if (r) 2265 err = r; 2266 } 2267 2268 if (crypt_integrity_hmac(cc)) 2269 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 2270 2271 return err; 2272 } 2273 2274 #ifdef CONFIG_KEYS 2275 2276 static bool contains_whitespace(const char *str) 2277 { 2278 while (*str) 2279 if (isspace(*str++)) 2280 return true; 2281 return false; 2282 } 2283 2284 static int set_key_user(struct crypt_config *cc, struct key *key) 2285 { 2286 const struct user_key_payload *ukp; 2287 2288 ukp = user_key_payload_locked(key); 2289 if (!ukp) 2290 return -EKEYREVOKED; 2291 2292 if (cc->key_size != ukp->datalen) 2293 return -EINVAL; 2294 2295 memcpy(cc->key, ukp->data, cc->key_size); 2296 2297 return 0; 2298 } 2299 2300 #if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE) 2301 static int set_key_encrypted(struct crypt_config *cc, struct key *key) 2302 { 2303 const struct encrypted_key_payload *ekp; 2304 2305 ekp = key->payload.data[0]; 2306 if (!ekp) 2307 return -EKEYREVOKED; 2308 2309 if (cc->key_size != ekp->decrypted_datalen) 2310 return -EINVAL; 2311 2312 memcpy(cc->key, ekp->decrypted_data, cc->key_size); 2313 2314 return 0; 2315 } 2316 #endif /* CONFIG_ENCRYPTED_KEYS */ 2317 2318 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2319 { 2320 char *new_key_string, *key_desc; 2321 int ret; 2322 struct key_type *type; 2323 struct key *key; 2324 int (*set_key)(struct crypt_config *cc, struct key *key); 2325 2326 /* 2327 * Reject key_string with whitespace. dm core currently lacks code for 2328 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 2329 */ 2330 if (contains_whitespace(key_string)) { 2331 DMERR("whitespace chars not allowed in key string"); 2332 return -EINVAL; 2333 } 2334 2335 /* look for next ':' separating key_type from key_description */ 2336 key_desc = strpbrk(key_string, ":"); 2337 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 2338 return -EINVAL; 2339 2340 if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) { 2341 type = &key_type_logon; 2342 set_key = set_key_user; 2343 } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) { 2344 type = &key_type_user; 2345 set_key = set_key_user; 2346 #if defined(CONFIG_ENCRYPTED_KEYS) || defined(CONFIG_ENCRYPTED_KEYS_MODULE) 2347 } else if (!strncmp(key_string, "encrypted:", key_desc - key_string + 1)) { 2348 type = &key_type_encrypted; 2349 set_key = set_key_encrypted; 2350 #endif 2351 } else { 2352 return -EINVAL; 2353 } 2354 2355 new_key_string = kstrdup(key_string, GFP_KERNEL); 2356 if (!new_key_string) 2357 return -ENOMEM; 2358 2359 key = request_key(type, key_desc + 1, NULL); 2360 if (IS_ERR(key)) { 2361 kfree_sensitive(new_key_string); 2362 return PTR_ERR(key); 2363 } 2364 2365 down_read(&key->sem); 2366 2367 ret = set_key(cc, key); 2368 if (ret < 0) { 2369 up_read(&key->sem); 2370 key_put(key); 2371 kfree_sensitive(new_key_string); 2372 return ret; 2373 } 2374 2375 up_read(&key->sem); 2376 key_put(key); 2377 2378 /* clear the flag since following operations may invalidate previously valid key */ 2379 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2380 2381 ret = crypt_setkey(cc); 2382 2383 if (!ret) { 2384 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2385 kfree_sensitive(cc->key_string); 2386 cc->key_string = new_key_string; 2387 } else 2388 kfree_sensitive(new_key_string); 2389 2390 return ret; 2391 } 2392 2393 static int get_key_size(char **key_string) 2394 { 2395 char *colon, dummy; 2396 int ret; 2397 2398 if (*key_string[0] != ':') 2399 return strlen(*key_string) >> 1; 2400 2401 /* look for next ':' in key string */ 2402 colon = strpbrk(*key_string + 1, ":"); 2403 if (!colon) 2404 return -EINVAL; 2405 2406 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 2407 return -EINVAL; 2408 2409 *key_string = colon; 2410 2411 /* remaining key string should be :<logon|user>:<key_desc> */ 2412 2413 return ret; 2414 } 2415 2416 #else 2417 2418 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2419 { 2420 return -EINVAL; 2421 } 2422 2423 static int get_key_size(char **key_string) 2424 { 2425 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2426 } 2427 2428 #endif /* CONFIG_KEYS */ 2429 2430 static int crypt_set_key(struct crypt_config *cc, char *key) 2431 { 2432 int r = -EINVAL; 2433 int key_string_len = strlen(key); 2434 2435 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2436 if (!cc->key_size && strcmp(key, "-")) 2437 goto out; 2438 2439 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2440 if (key[0] == ':') { 2441 r = crypt_set_keyring_key(cc, key + 1); 2442 goto out; 2443 } 2444 2445 /* clear the flag since following operations may invalidate previously valid key */ 2446 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2447 2448 /* wipe references to any kernel keyring key */ 2449 kfree_sensitive(cc->key_string); 2450 cc->key_string = NULL; 2451 2452 /* Decode key from its hex representation. */ 2453 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2454 goto out; 2455 2456 r = crypt_setkey(cc); 2457 if (!r) 2458 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2459 2460 out: 2461 /* Hex key string not needed after here, so wipe it. */ 2462 memset(key, '0', key_string_len); 2463 2464 return r; 2465 } 2466 2467 static int crypt_wipe_key(struct crypt_config *cc) 2468 { 2469 int r; 2470 2471 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2472 get_random_bytes(&cc->key, cc->key_size); 2473 2474 /* Wipe IV private keys */ 2475 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 2476 r = cc->iv_gen_ops->wipe(cc); 2477 if (r) 2478 return r; 2479 } 2480 2481 kfree_sensitive(cc->key_string); 2482 cc->key_string = NULL; 2483 r = crypt_setkey(cc); 2484 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2485 2486 return r; 2487 } 2488 2489 static void crypt_calculate_pages_per_client(void) 2490 { 2491 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100; 2492 2493 if (!dm_crypt_clients_n) 2494 return; 2495 2496 pages /= dm_crypt_clients_n; 2497 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2498 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2499 dm_crypt_pages_per_client = pages; 2500 } 2501 2502 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2503 { 2504 struct crypt_config *cc = pool_data; 2505 struct page *page; 2506 2507 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) && 2508 likely(gfp_mask & __GFP_NORETRY)) 2509 return NULL; 2510 2511 page = alloc_page(gfp_mask); 2512 if (likely(page != NULL)) 2513 percpu_counter_add(&cc->n_allocated_pages, 1); 2514 2515 return page; 2516 } 2517 2518 static void crypt_page_free(void *page, void *pool_data) 2519 { 2520 struct crypt_config *cc = pool_data; 2521 2522 __free_page(page); 2523 percpu_counter_sub(&cc->n_allocated_pages, 1); 2524 } 2525 2526 static void crypt_dtr(struct dm_target *ti) 2527 { 2528 struct crypt_config *cc = ti->private; 2529 2530 ti->private = NULL; 2531 2532 if (!cc) 2533 return; 2534 2535 if (cc->write_thread) 2536 kthread_stop(cc->write_thread); 2537 2538 if (cc->io_queue) 2539 destroy_workqueue(cc->io_queue); 2540 if (cc->crypt_queue) 2541 destroy_workqueue(cc->crypt_queue); 2542 2543 crypt_free_tfms(cc); 2544 2545 bioset_exit(&cc->bs); 2546 2547 mempool_exit(&cc->page_pool); 2548 mempool_exit(&cc->req_pool); 2549 mempool_exit(&cc->tag_pool); 2550 2551 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2552 percpu_counter_destroy(&cc->n_allocated_pages); 2553 2554 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2555 cc->iv_gen_ops->dtr(cc); 2556 2557 if (cc->dev) 2558 dm_put_device(ti, cc->dev); 2559 2560 kfree_sensitive(cc->cipher_string); 2561 kfree_sensitive(cc->key_string); 2562 kfree_sensitive(cc->cipher_auth); 2563 kfree_sensitive(cc->authenc_key); 2564 2565 mutex_destroy(&cc->bio_alloc_lock); 2566 2567 /* Must zero key material before freeing */ 2568 kfree_sensitive(cc); 2569 2570 spin_lock(&dm_crypt_clients_lock); 2571 WARN_ON(!dm_crypt_clients_n); 2572 dm_crypt_clients_n--; 2573 crypt_calculate_pages_per_client(); 2574 spin_unlock(&dm_crypt_clients_lock); 2575 } 2576 2577 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2578 { 2579 struct crypt_config *cc = ti->private; 2580 2581 if (crypt_integrity_aead(cc)) 2582 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2583 else 2584 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2585 2586 if (cc->iv_size) 2587 /* at least a 64 bit sector number should fit in our buffer */ 2588 cc->iv_size = max(cc->iv_size, 2589 (unsigned int)(sizeof(u64) / sizeof(u8))); 2590 else if (ivmode) { 2591 DMWARN("Selected cipher does not support IVs"); 2592 ivmode = NULL; 2593 } 2594 2595 /* Choose ivmode, see comments at iv code. */ 2596 if (ivmode == NULL) 2597 cc->iv_gen_ops = NULL; 2598 else if (strcmp(ivmode, "plain") == 0) 2599 cc->iv_gen_ops = &crypt_iv_plain_ops; 2600 else if (strcmp(ivmode, "plain64") == 0) 2601 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2602 else if (strcmp(ivmode, "plain64be") == 0) 2603 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2604 else if (strcmp(ivmode, "essiv") == 0) 2605 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2606 else if (strcmp(ivmode, "benbi") == 0) 2607 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2608 else if (strcmp(ivmode, "null") == 0) 2609 cc->iv_gen_ops = &crypt_iv_null_ops; 2610 else if (strcmp(ivmode, "eboiv") == 0) 2611 cc->iv_gen_ops = &crypt_iv_eboiv_ops; 2612 else if (strcmp(ivmode, "elephant") == 0) { 2613 cc->iv_gen_ops = &crypt_iv_elephant_ops; 2614 cc->key_parts = 2; 2615 cc->key_extra_size = cc->key_size / 2; 2616 if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE) 2617 return -EINVAL; 2618 set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags); 2619 } else if (strcmp(ivmode, "lmk") == 0) { 2620 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2621 /* 2622 * Version 2 and 3 is recognised according 2623 * to length of provided multi-key string. 2624 * If present (version 3), last key is used as IV seed. 2625 * All keys (including IV seed) are always the same size. 2626 */ 2627 if (cc->key_size % cc->key_parts) { 2628 cc->key_parts++; 2629 cc->key_extra_size = cc->key_size / cc->key_parts; 2630 } 2631 } else if (strcmp(ivmode, "tcw") == 0) { 2632 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2633 cc->key_parts += 2; /* IV + whitening */ 2634 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2635 } else if (strcmp(ivmode, "random") == 0) { 2636 cc->iv_gen_ops = &crypt_iv_random_ops; 2637 /* Need storage space in integrity fields. */ 2638 cc->integrity_iv_size = cc->iv_size; 2639 } else { 2640 ti->error = "Invalid IV mode"; 2641 return -EINVAL; 2642 } 2643 2644 return 0; 2645 } 2646 2647 /* 2648 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2649 * The HMAC is needed to calculate tag size (HMAC digest size). 2650 * This should be probably done by crypto-api calls (once available...) 2651 */ 2652 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2653 { 2654 char *start, *end, *mac_alg = NULL; 2655 struct crypto_ahash *mac; 2656 2657 if (!strstarts(cipher_api, "authenc(")) 2658 return 0; 2659 2660 start = strchr(cipher_api, '('); 2661 end = strchr(cipher_api, ','); 2662 if (!start || !end || ++start > end) 2663 return -EINVAL; 2664 2665 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2666 if (!mac_alg) 2667 return -ENOMEM; 2668 strncpy(mac_alg, start, end - start); 2669 2670 mac = crypto_alloc_ahash(mac_alg, 0, 0); 2671 kfree(mac_alg); 2672 2673 if (IS_ERR(mac)) 2674 return PTR_ERR(mac); 2675 2676 cc->key_mac_size = crypto_ahash_digestsize(mac); 2677 crypto_free_ahash(mac); 2678 2679 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2680 if (!cc->authenc_key) 2681 return -ENOMEM; 2682 2683 return 0; 2684 } 2685 2686 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2687 char **ivmode, char **ivopts) 2688 { 2689 struct crypt_config *cc = ti->private; 2690 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME]; 2691 int ret = -EINVAL; 2692 2693 cc->tfms_count = 1; 2694 2695 /* 2696 * New format (capi: prefix) 2697 * capi:cipher_api_spec-iv:ivopts 2698 */ 2699 tmp = &cipher_in[strlen("capi:")]; 2700 2701 /* Separate IV options if present, it can contain another '-' in hash name */ 2702 *ivopts = strrchr(tmp, ':'); 2703 if (*ivopts) { 2704 **ivopts = '\0'; 2705 (*ivopts)++; 2706 } 2707 /* Parse IV mode */ 2708 *ivmode = strrchr(tmp, '-'); 2709 if (*ivmode) { 2710 **ivmode = '\0'; 2711 (*ivmode)++; 2712 } 2713 /* The rest is crypto API spec */ 2714 cipher_api = tmp; 2715 2716 /* Alloc AEAD, can be used only in new format. */ 2717 if (crypt_integrity_aead(cc)) { 2718 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2719 if (ret < 0) { 2720 ti->error = "Invalid AEAD cipher spec"; 2721 return -ENOMEM; 2722 } 2723 } 2724 2725 if (*ivmode && !strcmp(*ivmode, "lmk")) 2726 cc->tfms_count = 64; 2727 2728 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2729 if (!*ivopts) { 2730 ti->error = "Digest algorithm missing for ESSIV mode"; 2731 return -EINVAL; 2732 } 2733 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)", 2734 cipher_api, *ivopts); 2735 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2736 ti->error = "Cannot allocate cipher string"; 2737 return -ENOMEM; 2738 } 2739 cipher_api = buf; 2740 } 2741 2742 cc->key_parts = cc->tfms_count; 2743 2744 /* Allocate cipher */ 2745 ret = crypt_alloc_tfms(cc, cipher_api); 2746 if (ret < 0) { 2747 ti->error = "Error allocating crypto tfm"; 2748 return ret; 2749 } 2750 2751 if (crypt_integrity_aead(cc)) 2752 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2753 else 2754 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2755 2756 return 0; 2757 } 2758 2759 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2760 char **ivmode, char **ivopts) 2761 { 2762 struct crypt_config *cc = ti->private; 2763 char *tmp, *cipher, *chainmode, *keycount; 2764 char *cipher_api = NULL; 2765 int ret = -EINVAL; 2766 char dummy; 2767 2768 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2769 ti->error = "Bad cipher specification"; 2770 return -EINVAL; 2771 } 2772 2773 /* 2774 * Legacy dm-crypt cipher specification 2775 * cipher[:keycount]-mode-iv:ivopts 2776 */ 2777 tmp = cipher_in; 2778 keycount = strsep(&tmp, "-"); 2779 cipher = strsep(&keycount, ":"); 2780 2781 if (!keycount) 2782 cc->tfms_count = 1; 2783 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2784 !is_power_of_2(cc->tfms_count)) { 2785 ti->error = "Bad cipher key count specification"; 2786 return -EINVAL; 2787 } 2788 cc->key_parts = cc->tfms_count; 2789 2790 chainmode = strsep(&tmp, "-"); 2791 *ivmode = strsep(&tmp, ":"); 2792 *ivopts = tmp; 2793 2794 /* 2795 * For compatibility with the original dm-crypt mapping format, if 2796 * only the cipher name is supplied, use cbc-plain. 2797 */ 2798 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2799 chainmode = "cbc"; 2800 *ivmode = "plain"; 2801 } 2802 2803 if (strcmp(chainmode, "ecb") && !*ivmode) { 2804 ti->error = "IV mechanism required"; 2805 return -EINVAL; 2806 } 2807 2808 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2809 if (!cipher_api) 2810 goto bad_mem; 2811 2812 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2813 if (!*ivopts) { 2814 ti->error = "Digest algorithm missing for ESSIV mode"; 2815 kfree(cipher_api); 2816 return -EINVAL; 2817 } 2818 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2819 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts); 2820 } else { 2821 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2822 "%s(%s)", chainmode, cipher); 2823 } 2824 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2825 kfree(cipher_api); 2826 goto bad_mem; 2827 } 2828 2829 /* Allocate cipher */ 2830 ret = crypt_alloc_tfms(cc, cipher_api); 2831 if (ret < 0) { 2832 ti->error = "Error allocating crypto tfm"; 2833 kfree(cipher_api); 2834 return ret; 2835 } 2836 kfree(cipher_api); 2837 2838 return 0; 2839 bad_mem: 2840 ti->error = "Cannot allocate cipher strings"; 2841 return -ENOMEM; 2842 } 2843 2844 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 2845 { 2846 struct crypt_config *cc = ti->private; 2847 char *ivmode = NULL, *ivopts = NULL; 2848 int ret; 2849 2850 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 2851 if (!cc->cipher_string) { 2852 ti->error = "Cannot allocate cipher strings"; 2853 return -ENOMEM; 2854 } 2855 2856 if (strstarts(cipher_in, "capi:")) 2857 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 2858 else 2859 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 2860 if (ret) 2861 return ret; 2862 2863 /* Initialize IV */ 2864 ret = crypt_ctr_ivmode(ti, ivmode); 2865 if (ret < 0) 2866 return ret; 2867 2868 /* Initialize and set key */ 2869 ret = crypt_set_key(cc, key); 2870 if (ret < 0) { 2871 ti->error = "Error decoding and setting key"; 2872 return ret; 2873 } 2874 2875 /* Allocate IV */ 2876 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 2877 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 2878 if (ret < 0) { 2879 ti->error = "Error creating IV"; 2880 return ret; 2881 } 2882 } 2883 2884 /* Initialize IV (set keys for ESSIV etc) */ 2885 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 2886 ret = cc->iv_gen_ops->init(cc); 2887 if (ret < 0) { 2888 ti->error = "Error initialising IV"; 2889 return ret; 2890 } 2891 } 2892 2893 /* wipe the kernel key payload copy */ 2894 if (cc->key_string) 2895 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2896 2897 return ret; 2898 } 2899 2900 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 2901 { 2902 struct crypt_config *cc = ti->private; 2903 struct dm_arg_set as; 2904 static const struct dm_arg _args[] = { 2905 {0, 8, "Invalid number of feature args"}, 2906 }; 2907 unsigned int opt_params, val; 2908 const char *opt_string, *sval; 2909 char dummy; 2910 int ret; 2911 2912 /* Optional parameters */ 2913 as.argc = argc; 2914 as.argv = argv; 2915 2916 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 2917 if (ret) 2918 return ret; 2919 2920 while (opt_params--) { 2921 opt_string = dm_shift_arg(&as); 2922 if (!opt_string) { 2923 ti->error = "Not enough feature arguments"; 2924 return -EINVAL; 2925 } 2926 2927 if (!strcasecmp(opt_string, "allow_discards")) 2928 ti->num_discard_bios = 1; 2929 2930 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 2931 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2932 2933 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 2934 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2935 else if (!strcasecmp(opt_string, "no_read_workqueue")) 2936 set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 2937 else if (!strcasecmp(opt_string, "no_write_workqueue")) 2938 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 2939 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 2940 if (val == 0 || val > MAX_TAG_SIZE) { 2941 ti->error = "Invalid integrity arguments"; 2942 return -EINVAL; 2943 } 2944 cc->on_disk_tag_size = val; 2945 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 2946 if (!strcasecmp(sval, "aead")) { 2947 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 2948 } else if (strcasecmp(sval, "none")) { 2949 ti->error = "Unknown integrity profile"; 2950 return -EINVAL; 2951 } 2952 2953 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 2954 if (!cc->cipher_auth) 2955 return -ENOMEM; 2956 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 2957 if (cc->sector_size < (1 << SECTOR_SHIFT) || 2958 cc->sector_size > 4096 || 2959 (cc->sector_size & (cc->sector_size - 1))) { 2960 ti->error = "Invalid feature value for sector_size"; 2961 return -EINVAL; 2962 } 2963 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 2964 ti->error = "Device size is not multiple of sector_size feature"; 2965 return -EINVAL; 2966 } 2967 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 2968 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 2969 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2970 else { 2971 ti->error = "Invalid feature arguments"; 2972 return -EINVAL; 2973 } 2974 } 2975 2976 return 0; 2977 } 2978 2979 #ifdef CONFIG_BLK_DEV_ZONED 2980 2981 static int crypt_report_zones(struct dm_target *ti, 2982 struct dm_report_zones_args *args, unsigned int nr_zones) 2983 { 2984 struct crypt_config *cc = ti->private; 2985 sector_t sector = cc->start + dm_target_offset(ti, args->next_sector); 2986 2987 args->start = cc->start; 2988 return blkdev_report_zones(cc->dev->bdev, sector, nr_zones, 2989 dm_report_zones_cb, args); 2990 } 2991 2992 #endif 2993 2994 /* 2995 * Construct an encryption mapping: 2996 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 2997 */ 2998 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 2999 { 3000 struct crypt_config *cc; 3001 const char *devname = dm_table_device_name(ti->table); 3002 int key_size; 3003 unsigned int align_mask; 3004 unsigned long long tmpll; 3005 int ret; 3006 size_t iv_size_padding, additional_req_size; 3007 char dummy; 3008 3009 if (argc < 5) { 3010 ti->error = "Not enough arguments"; 3011 return -EINVAL; 3012 } 3013 3014 key_size = get_key_size(&argv[1]); 3015 if (key_size < 0) { 3016 ti->error = "Cannot parse key size"; 3017 return -EINVAL; 3018 } 3019 3020 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL); 3021 if (!cc) { 3022 ti->error = "Cannot allocate encryption context"; 3023 return -ENOMEM; 3024 } 3025 cc->key_size = key_size; 3026 cc->sector_size = (1 << SECTOR_SHIFT); 3027 cc->sector_shift = 0; 3028 3029 ti->private = cc; 3030 3031 spin_lock(&dm_crypt_clients_lock); 3032 dm_crypt_clients_n++; 3033 crypt_calculate_pages_per_client(); 3034 spin_unlock(&dm_crypt_clients_lock); 3035 3036 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 3037 if (ret < 0) 3038 goto bad; 3039 3040 /* Optional parameters need to be read before cipher constructor */ 3041 if (argc > 5) { 3042 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 3043 if (ret) 3044 goto bad; 3045 } 3046 3047 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 3048 if (ret < 0) 3049 goto bad; 3050 3051 if (crypt_integrity_aead(cc)) { 3052 cc->dmreq_start = sizeof(struct aead_request); 3053 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 3054 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 3055 } else { 3056 cc->dmreq_start = sizeof(struct skcipher_request); 3057 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 3058 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 3059 } 3060 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 3061 3062 if (align_mask < CRYPTO_MINALIGN) { 3063 /* Allocate the padding exactly */ 3064 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 3065 & align_mask; 3066 } else { 3067 /* 3068 * If the cipher requires greater alignment than kmalloc 3069 * alignment, we don't know the exact position of the 3070 * initialization vector. We must assume worst case. 3071 */ 3072 iv_size_padding = align_mask; 3073 } 3074 3075 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 3076 additional_req_size = sizeof(struct dm_crypt_request) + 3077 iv_size_padding + cc->iv_size + 3078 cc->iv_size + 3079 sizeof(uint64_t) + 3080 sizeof(unsigned int); 3081 3082 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 3083 if (ret) { 3084 ti->error = "Cannot allocate crypt request mempool"; 3085 goto bad; 3086 } 3087 3088 cc->per_bio_data_size = ti->per_io_data_size = 3089 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 3090 ARCH_KMALLOC_MINALIGN); 3091 3092 ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc); 3093 if (ret) { 3094 ti->error = "Cannot allocate page mempool"; 3095 goto bad; 3096 } 3097 3098 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 3099 if (ret) { 3100 ti->error = "Cannot allocate crypt bioset"; 3101 goto bad; 3102 } 3103 3104 mutex_init(&cc->bio_alloc_lock); 3105 3106 ret = -EINVAL; 3107 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 3108 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 3109 ti->error = "Invalid iv_offset sector"; 3110 goto bad; 3111 } 3112 cc->iv_offset = tmpll; 3113 3114 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 3115 if (ret) { 3116 ti->error = "Device lookup failed"; 3117 goto bad; 3118 } 3119 3120 ret = -EINVAL; 3121 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { 3122 ti->error = "Invalid device sector"; 3123 goto bad; 3124 } 3125 cc->start = tmpll; 3126 3127 /* 3128 * For zoned block devices, we need to preserve the issuer write 3129 * ordering. To do so, disable write workqueues and force inline 3130 * encryption completion. 3131 */ 3132 if (bdev_is_zoned(cc->dev->bdev)) { 3133 set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3134 set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags); 3135 } 3136 3137 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 3138 ret = crypt_integrity_ctr(cc, ti); 3139 if (ret) 3140 goto bad; 3141 3142 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 3143 if (!cc->tag_pool_max_sectors) 3144 cc->tag_pool_max_sectors = 1; 3145 3146 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 3147 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 3148 if (ret) { 3149 ti->error = "Cannot allocate integrity tags mempool"; 3150 goto bad; 3151 } 3152 3153 cc->tag_pool_max_sectors <<= cc->sector_shift; 3154 } 3155 3156 ret = -ENOMEM; 3157 cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname); 3158 if (!cc->io_queue) { 3159 ti->error = "Couldn't create kcryptd io queue"; 3160 goto bad; 3161 } 3162 3163 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3164 cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 3165 1, devname); 3166 else 3167 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 3168 WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 3169 num_online_cpus(), devname); 3170 if (!cc->crypt_queue) { 3171 ti->error = "Couldn't create kcryptd queue"; 3172 goto bad; 3173 } 3174 3175 spin_lock_init(&cc->write_thread_lock); 3176 cc->write_tree = RB_ROOT; 3177 3178 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname); 3179 if (IS_ERR(cc->write_thread)) { 3180 ret = PTR_ERR(cc->write_thread); 3181 cc->write_thread = NULL; 3182 ti->error = "Couldn't spawn write thread"; 3183 goto bad; 3184 } 3185 wake_up_process(cc->write_thread); 3186 3187 ti->num_flush_bios = 1; 3188 3189 return 0; 3190 3191 bad: 3192 crypt_dtr(ti); 3193 return ret; 3194 } 3195 3196 static int crypt_map(struct dm_target *ti, struct bio *bio) 3197 { 3198 struct dm_crypt_io *io; 3199 struct crypt_config *cc = ti->private; 3200 3201 /* 3202 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 3203 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 3204 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 3205 */ 3206 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 3207 bio_op(bio) == REQ_OP_DISCARD)) { 3208 bio_set_dev(bio, cc->dev->bdev); 3209 if (bio_sectors(bio)) 3210 bio->bi_iter.bi_sector = cc->start + 3211 dm_target_offset(ti, bio->bi_iter.bi_sector); 3212 return DM_MAPIO_REMAPPED; 3213 } 3214 3215 /* 3216 * Check if bio is too large, split as needed. 3217 */ 3218 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && 3219 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 3220 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); 3221 3222 /* 3223 * Ensure that bio is a multiple of internal sector encryption size 3224 * and is aligned to this size as defined in IO hints. 3225 */ 3226 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 3227 return DM_MAPIO_KILL; 3228 3229 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 3230 return DM_MAPIO_KILL; 3231 3232 io = dm_per_bio_data(bio, cc->per_bio_data_size); 3233 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 3234 3235 if (cc->on_disk_tag_size) { 3236 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 3237 3238 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 3239 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 3240 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 3241 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 3242 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 3243 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 3244 io->integrity_metadata_from_pool = true; 3245 } 3246 } 3247 3248 if (crypt_integrity_aead(cc)) 3249 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 3250 else 3251 io->ctx.r.req = (struct skcipher_request *)(io + 1); 3252 3253 if (bio_data_dir(io->base_bio) == READ) { 3254 if (kcryptd_io_read(io, GFP_NOWAIT)) 3255 kcryptd_queue_read(io); 3256 } else 3257 kcryptd_queue_crypt(io); 3258 3259 return DM_MAPIO_SUBMITTED; 3260 } 3261 3262 static void crypt_status(struct dm_target *ti, status_type_t type, 3263 unsigned status_flags, char *result, unsigned maxlen) 3264 { 3265 struct crypt_config *cc = ti->private; 3266 unsigned i, sz = 0; 3267 int num_feature_args = 0; 3268 3269 switch (type) { 3270 case STATUSTYPE_INFO: 3271 result[0] = '\0'; 3272 break; 3273 3274 case STATUSTYPE_TABLE: 3275 DMEMIT("%s ", cc->cipher_string); 3276 3277 if (cc->key_size > 0) { 3278 if (cc->key_string) 3279 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 3280 else 3281 for (i = 0; i < cc->key_size; i++) 3282 DMEMIT("%02x", cc->key[i]); 3283 } else 3284 DMEMIT("-"); 3285 3286 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 3287 cc->dev->name, (unsigned long long)cc->start); 3288 3289 num_feature_args += !!ti->num_discard_bios; 3290 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 3291 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 3292 num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags); 3293 num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags); 3294 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 3295 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 3296 if (cc->on_disk_tag_size) 3297 num_feature_args++; 3298 if (num_feature_args) { 3299 DMEMIT(" %d", num_feature_args); 3300 if (ti->num_discard_bios) 3301 DMEMIT(" allow_discards"); 3302 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 3303 DMEMIT(" same_cpu_crypt"); 3304 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 3305 DMEMIT(" submit_from_crypt_cpus"); 3306 if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) 3307 DMEMIT(" no_read_workqueue"); 3308 if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) 3309 DMEMIT(" no_write_workqueue"); 3310 if (cc->on_disk_tag_size) 3311 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 3312 if (cc->sector_size != (1 << SECTOR_SHIFT)) 3313 DMEMIT(" sector_size:%d", cc->sector_size); 3314 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 3315 DMEMIT(" iv_large_sectors"); 3316 } 3317 3318 break; 3319 } 3320 } 3321 3322 static void crypt_postsuspend(struct dm_target *ti) 3323 { 3324 struct crypt_config *cc = ti->private; 3325 3326 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3327 } 3328 3329 static int crypt_preresume(struct dm_target *ti) 3330 { 3331 struct crypt_config *cc = ti->private; 3332 3333 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 3334 DMERR("aborting resume - crypt key is not set."); 3335 return -EAGAIN; 3336 } 3337 3338 return 0; 3339 } 3340 3341 static void crypt_resume(struct dm_target *ti) 3342 { 3343 struct crypt_config *cc = ti->private; 3344 3345 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 3346 } 3347 3348 /* Message interface 3349 * key set <key> 3350 * key wipe 3351 */ 3352 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv, 3353 char *result, unsigned maxlen) 3354 { 3355 struct crypt_config *cc = ti->private; 3356 int key_size, ret = -EINVAL; 3357 3358 if (argc < 2) 3359 goto error; 3360 3361 if (!strcasecmp(argv[0], "key")) { 3362 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 3363 DMWARN("not suspended during key manipulation."); 3364 return -EINVAL; 3365 } 3366 if (argc == 3 && !strcasecmp(argv[1], "set")) { 3367 /* The key size may not be changed. */ 3368 key_size = get_key_size(&argv[2]); 3369 if (key_size < 0 || cc->key_size != key_size) { 3370 memset(argv[2], '0', strlen(argv[2])); 3371 return -EINVAL; 3372 } 3373 3374 ret = crypt_set_key(cc, argv[2]); 3375 if (ret) 3376 return ret; 3377 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 3378 ret = cc->iv_gen_ops->init(cc); 3379 /* wipe the kernel key payload copy */ 3380 if (cc->key_string) 3381 memset(cc->key, 0, cc->key_size * sizeof(u8)); 3382 return ret; 3383 } 3384 if (argc == 2 && !strcasecmp(argv[1], "wipe")) 3385 return crypt_wipe_key(cc); 3386 } 3387 3388 error: 3389 DMWARN("unrecognised message received."); 3390 return -EINVAL; 3391 } 3392 3393 static int crypt_iterate_devices(struct dm_target *ti, 3394 iterate_devices_callout_fn fn, void *data) 3395 { 3396 struct crypt_config *cc = ti->private; 3397 3398 return fn(ti, cc->dev, cc->start, ti->len, data); 3399 } 3400 3401 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 3402 { 3403 struct crypt_config *cc = ti->private; 3404 3405 /* 3406 * Unfortunate constraint that is required to avoid the potential 3407 * for exceeding underlying device's max_segments limits -- due to 3408 * crypt_alloc_buffer() possibly allocating pages for the encryption 3409 * bio that are not as physically contiguous as the original bio. 3410 */ 3411 limits->max_segment_size = PAGE_SIZE; 3412 3413 limits->logical_block_size = 3414 max_t(unsigned, limits->logical_block_size, cc->sector_size); 3415 limits->physical_block_size = 3416 max_t(unsigned, limits->physical_block_size, cc->sector_size); 3417 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); 3418 } 3419 3420 static struct target_type crypt_target = { 3421 .name = "crypt", 3422 .version = {1, 22, 0}, 3423 .module = THIS_MODULE, 3424 .ctr = crypt_ctr, 3425 .dtr = crypt_dtr, 3426 #ifdef CONFIG_BLK_DEV_ZONED 3427 .features = DM_TARGET_ZONED_HM, 3428 .report_zones = crypt_report_zones, 3429 #endif 3430 .map = crypt_map, 3431 .status = crypt_status, 3432 .postsuspend = crypt_postsuspend, 3433 .preresume = crypt_preresume, 3434 .resume = crypt_resume, 3435 .message = crypt_message, 3436 .iterate_devices = crypt_iterate_devices, 3437 .io_hints = crypt_io_hints, 3438 }; 3439 3440 static int __init dm_crypt_init(void) 3441 { 3442 int r; 3443 3444 r = dm_register_target(&crypt_target); 3445 if (r < 0) 3446 DMERR("register failed %d", r); 3447 3448 return r; 3449 } 3450 3451 static void __exit dm_crypt_exit(void) 3452 { 3453 dm_unregister_target(&crypt_target); 3454 } 3455 3456 module_init(dm_crypt_init); 3457 module_exit(dm_crypt_exit); 3458 3459 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 3460 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3461 MODULE_LICENSE("GPL"); 3462