1 /* 2 * Copyright (C) 2003 Jana Saout <jana@saout.de> 3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 4 * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved. 5 * Copyright (C) 2013-2017 Milan Broz <gmazyland@gmail.com> 6 * 7 * This file is released under the GPL. 8 */ 9 10 #include <linux/completion.h> 11 #include <linux/err.h> 12 #include <linux/module.h> 13 #include <linux/init.h> 14 #include <linux/kernel.h> 15 #include <linux/key.h> 16 #include <linux/bio.h> 17 #include <linux/blkdev.h> 18 #include <linux/mempool.h> 19 #include <linux/slab.h> 20 #include <linux/crypto.h> 21 #include <linux/workqueue.h> 22 #include <linux/kthread.h> 23 #include <linux/backing-dev.h> 24 #include <linux/atomic.h> 25 #include <linux/scatterlist.h> 26 #include <linux/rbtree.h> 27 #include <linux/ctype.h> 28 #include <asm/page.h> 29 #include <asm/unaligned.h> 30 #include <crypto/hash.h> 31 #include <crypto/md5.h> 32 #include <crypto/algapi.h> 33 #include <crypto/skcipher.h> 34 #include <crypto/aead.h> 35 #include <crypto/authenc.h> 36 #include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ 37 #include <keys/user-type.h> 38 39 #include <linux/device-mapper.h> 40 41 #define DM_MSG_PREFIX "crypt" 42 43 /* 44 * context holding the current state of a multi-part conversion 45 */ 46 struct convert_context { 47 struct completion restart; 48 struct bio *bio_in; 49 struct bio *bio_out; 50 struct bvec_iter iter_in; 51 struct bvec_iter iter_out; 52 u64 cc_sector; 53 atomic_t cc_pending; 54 union { 55 struct skcipher_request *req; 56 struct aead_request *req_aead; 57 } r; 58 59 }; 60 61 /* 62 * per bio private data 63 */ 64 struct dm_crypt_io { 65 struct crypt_config *cc; 66 struct bio *base_bio; 67 u8 *integrity_metadata; 68 bool integrity_metadata_from_pool; 69 struct work_struct work; 70 71 struct convert_context ctx; 72 73 atomic_t io_pending; 74 blk_status_t error; 75 sector_t sector; 76 77 struct rb_node rb_node; 78 } CRYPTO_MINALIGN_ATTR; 79 80 struct dm_crypt_request { 81 struct convert_context *ctx; 82 struct scatterlist sg_in[4]; 83 struct scatterlist sg_out[4]; 84 u64 iv_sector; 85 }; 86 87 struct crypt_config; 88 89 struct crypt_iv_operations { 90 int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 91 const char *opts); 92 void (*dtr)(struct crypt_config *cc); 93 int (*init)(struct crypt_config *cc); 94 int (*wipe)(struct crypt_config *cc); 95 int (*generator)(struct crypt_config *cc, u8 *iv, 96 struct dm_crypt_request *dmreq); 97 int (*post)(struct crypt_config *cc, u8 *iv, 98 struct dm_crypt_request *dmreq); 99 }; 100 101 struct iv_benbi_private { 102 int shift; 103 }; 104 105 #define LMK_SEED_SIZE 64 /* hash + 0 */ 106 struct iv_lmk_private { 107 struct crypto_shash *hash_tfm; 108 u8 *seed; 109 }; 110 111 #define TCW_WHITENING_SIZE 16 112 struct iv_tcw_private { 113 struct crypto_shash *crc32_tfm; 114 u8 *iv_seed; 115 u8 *whitening; 116 }; 117 118 /* 119 * Crypt: maps a linear range of a block device 120 * and encrypts / decrypts at the same time. 121 */ 122 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, 123 DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD }; 124 125 enum cipher_flags { 126 CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */ 127 CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ 128 }; 129 130 /* 131 * The fields in here must be read only after initialization. 132 */ 133 struct crypt_config { 134 struct dm_dev *dev; 135 sector_t start; 136 137 struct percpu_counter n_allocated_pages; 138 139 struct workqueue_struct *io_queue; 140 struct workqueue_struct *crypt_queue; 141 142 spinlock_t write_thread_lock; 143 struct task_struct *write_thread; 144 struct rb_root write_tree; 145 146 char *cipher_string; 147 char *cipher_auth; 148 char *key_string; 149 150 const struct crypt_iv_operations *iv_gen_ops; 151 union { 152 struct iv_benbi_private benbi; 153 struct iv_lmk_private lmk; 154 struct iv_tcw_private tcw; 155 } iv_gen_private; 156 u64 iv_offset; 157 unsigned int iv_size; 158 unsigned short int sector_size; 159 unsigned char sector_shift; 160 161 union { 162 struct crypto_skcipher **tfms; 163 struct crypto_aead **tfms_aead; 164 } cipher_tfm; 165 unsigned tfms_count; 166 unsigned long cipher_flags; 167 168 /* 169 * Layout of each crypto request: 170 * 171 * struct skcipher_request 172 * context 173 * padding 174 * struct dm_crypt_request 175 * padding 176 * IV 177 * 178 * The padding is added so that dm_crypt_request and the IV are 179 * correctly aligned. 180 */ 181 unsigned int dmreq_start; 182 183 unsigned int per_bio_data_size; 184 185 unsigned long flags; 186 unsigned int key_size; 187 unsigned int key_parts; /* independent parts in key buffer */ 188 unsigned int key_extra_size; /* additional keys length */ 189 unsigned int key_mac_size; /* MAC key size for authenc(...) */ 190 191 unsigned int integrity_tag_size; 192 unsigned int integrity_iv_size; 193 unsigned int on_disk_tag_size; 194 195 /* 196 * pool for per bio private data, crypto requests, 197 * encryption requeusts/buffer pages and integrity tags 198 */ 199 unsigned tag_pool_max_sectors; 200 mempool_t tag_pool; 201 mempool_t req_pool; 202 mempool_t page_pool; 203 204 struct bio_set bs; 205 struct mutex bio_alloc_lock; 206 207 u8 *authenc_key; /* space for keys in authenc() format (if used) */ 208 u8 key[0]; 209 }; 210 211 #define MIN_IOS 64 212 #define MAX_TAG_SIZE 480 213 #define POOL_ENTRY_SIZE 512 214 215 static DEFINE_SPINLOCK(dm_crypt_clients_lock); 216 static unsigned dm_crypt_clients_n = 0; 217 static volatile unsigned long dm_crypt_pages_per_client; 218 #define DM_CRYPT_MEMORY_PERCENT 2 219 #define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_PAGES * 16) 220 221 static void clone_init(struct dm_crypt_io *, struct bio *); 222 static void kcryptd_queue_crypt(struct dm_crypt_io *io); 223 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 224 struct scatterlist *sg); 225 226 /* 227 * Use this to access cipher attributes that are independent of the key. 228 */ 229 static struct crypto_skcipher *any_tfm(struct crypt_config *cc) 230 { 231 return cc->cipher_tfm.tfms[0]; 232 } 233 234 static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) 235 { 236 return cc->cipher_tfm.tfms_aead[0]; 237 } 238 239 /* 240 * Different IV generation algorithms: 241 * 242 * plain: the initial vector is the 32-bit little-endian version of the sector 243 * number, padded with zeros if necessary. 244 * 245 * plain64: the initial vector is the 64-bit little-endian version of the sector 246 * number, padded with zeros if necessary. 247 * 248 * plain64be: the initial vector is the 64-bit big-endian version of the sector 249 * number, padded with zeros if necessary. 250 * 251 * essiv: "encrypted sector|salt initial vector", the sector number is 252 * encrypted with the bulk cipher using a salt as key. The salt 253 * should be derived from the bulk cipher's key via hashing. 254 * 255 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 256 * (needed for LRW-32-AES and possible other narrow block modes) 257 * 258 * null: the initial vector is always zero. Provides compatibility with 259 * obsolete loop_fish2 devices. Do not use for new devices. 260 * 261 * lmk: Compatible implementation of the block chaining mode used 262 * by the Loop-AES block device encryption system 263 * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ 264 * It operates on full 512 byte sectors and uses CBC 265 * with an IV derived from the sector number, the data and 266 * optionally extra IV seed. 267 * This means that after decryption the first block 268 * of sector must be tweaked according to decrypted data. 269 * Loop-AES can use three encryption schemes: 270 * version 1: is plain aes-cbc mode 271 * version 2: uses 64 multikey scheme with lmk IV generator 272 * version 3: the same as version 2 with additional IV seed 273 * (it uses 65 keys, last key is used as IV seed) 274 * 275 * tcw: Compatible implementation of the block chaining mode used 276 * by the TrueCrypt device encryption system (prior to version 4.1). 277 * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat 278 * It operates on full 512 byte sectors and uses CBC 279 * with an IV derived from initial key and the sector number. 280 * In addition, whitening value is applied on every sector, whitening 281 * is calculated from initial key, sector number and mixed using CRC32. 282 * Note that this encryption scheme is vulnerable to watermarking attacks 283 * and should be used for old compatible containers access only. 284 * 285 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode) 286 * The IV is encrypted little-endian byte-offset (with the same key 287 * and cipher as the volume). 288 */ 289 290 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, 291 struct dm_crypt_request *dmreq) 292 { 293 memset(iv, 0, cc->iv_size); 294 *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); 295 296 return 0; 297 } 298 299 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, 300 struct dm_crypt_request *dmreq) 301 { 302 memset(iv, 0, cc->iv_size); 303 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 304 305 return 0; 306 } 307 308 static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, 309 struct dm_crypt_request *dmreq) 310 { 311 memset(iv, 0, cc->iv_size); 312 /* iv_size is at least of size u64; usually it is 16 bytes */ 313 *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector); 314 315 return 0; 316 } 317 318 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, 319 struct dm_crypt_request *dmreq) 320 { 321 /* 322 * ESSIV encryption of the IV is now handled by the crypto API, 323 * so just pass the plain sector number here. 324 */ 325 memset(iv, 0, cc->iv_size); 326 *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); 327 328 return 0; 329 } 330 331 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 332 const char *opts) 333 { 334 unsigned bs = crypto_skcipher_blocksize(any_tfm(cc)); 335 int log = ilog2(bs); 336 337 /* we need to calculate how far we must shift the sector count 338 * to get the cipher block count, we use this shift in _gen */ 339 340 if (1 << log != bs) { 341 ti->error = "cypher blocksize is not a power of 2"; 342 return -EINVAL; 343 } 344 345 if (log > 9) { 346 ti->error = "cypher blocksize is > 512"; 347 return -EINVAL; 348 } 349 350 cc->iv_gen_private.benbi.shift = 9 - log; 351 352 return 0; 353 } 354 355 static void crypt_iv_benbi_dtr(struct crypt_config *cc) 356 { 357 } 358 359 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, 360 struct dm_crypt_request *dmreq) 361 { 362 __be64 val; 363 364 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 365 366 val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); 367 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 368 369 return 0; 370 } 371 372 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, 373 struct dm_crypt_request *dmreq) 374 { 375 memset(iv, 0, cc->iv_size); 376 377 return 0; 378 } 379 380 static void crypt_iv_lmk_dtr(struct crypt_config *cc) 381 { 382 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 383 384 if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) 385 crypto_free_shash(lmk->hash_tfm); 386 lmk->hash_tfm = NULL; 387 388 kzfree(lmk->seed); 389 lmk->seed = NULL; 390 } 391 392 static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, 393 const char *opts) 394 { 395 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 396 397 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 398 ti->error = "Unsupported sector size for LMK"; 399 return -EINVAL; 400 } 401 402 lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); 403 if (IS_ERR(lmk->hash_tfm)) { 404 ti->error = "Error initializing LMK hash"; 405 return PTR_ERR(lmk->hash_tfm); 406 } 407 408 /* No seed in LMK version 2 */ 409 if (cc->key_parts == cc->tfms_count) { 410 lmk->seed = NULL; 411 return 0; 412 } 413 414 lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); 415 if (!lmk->seed) { 416 crypt_iv_lmk_dtr(cc); 417 ti->error = "Error kmallocing seed storage in LMK"; 418 return -ENOMEM; 419 } 420 421 return 0; 422 } 423 424 static int crypt_iv_lmk_init(struct crypt_config *cc) 425 { 426 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 427 int subkey_size = cc->key_size / cc->key_parts; 428 429 /* LMK seed is on the position of LMK_KEYS + 1 key */ 430 if (lmk->seed) 431 memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), 432 crypto_shash_digestsize(lmk->hash_tfm)); 433 434 return 0; 435 } 436 437 static int crypt_iv_lmk_wipe(struct crypt_config *cc) 438 { 439 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 440 441 if (lmk->seed) 442 memset(lmk->seed, 0, LMK_SEED_SIZE); 443 444 return 0; 445 } 446 447 static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, 448 struct dm_crypt_request *dmreq, 449 u8 *data) 450 { 451 struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; 452 SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); 453 struct md5_state md5state; 454 __le32 buf[4]; 455 int i, r; 456 457 desc->tfm = lmk->hash_tfm; 458 459 r = crypto_shash_init(desc); 460 if (r) 461 return r; 462 463 if (lmk->seed) { 464 r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); 465 if (r) 466 return r; 467 } 468 469 /* Sector is always 512B, block size 16, add data of blocks 1-31 */ 470 r = crypto_shash_update(desc, data + 16, 16 * 31); 471 if (r) 472 return r; 473 474 /* Sector is cropped to 56 bits here */ 475 buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); 476 buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); 477 buf[2] = cpu_to_le32(4024); 478 buf[3] = 0; 479 r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); 480 if (r) 481 return r; 482 483 /* No MD5 padding here */ 484 r = crypto_shash_export(desc, &md5state); 485 if (r) 486 return r; 487 488 for (i = 0; i < MD5_HASH_WORDS; i++) 489 __cpu_to_le32s(&md5state.hash[i]); 490 memcpy(iv, &md5state.hash, cc->iv_size); 491 492 return 0; 493 } 494 495 static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, 496 struct dm_crypt_request *dmreq) 497 { 498 struct scatterlist *sg; 499 u8 *src; 500 int r = 0; 501 502 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { 503 sg = crypt_get_sg_data(cc, dmreq->sg_in); 504 src = kmap_atomic(sg_page(sg)); 505 r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset); 506 kunmap_atomic(src); 507 } else 508 memset(iv, 0, cc->iv_size); 509 510 return r; 511 } 512 513 static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, 514 struct dm_crypt_request *dmreq) 515 { 516 struct scatterlist *sg; 517 u8 *dst; 518 int r; 519 520 if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) 521 return 0; 522 523 sg = crypt_get_sg_data(cc, dmreq->sg_out); 524 dst = kmap_atomic(sg_page(sg)); 525 r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); 526 527 /* Tweak the first block of plaintext sector */ 528 if (!r) 529 crypto_xor(dst + sg->offset, iv, cc->iv_size); 530 531 kunmap_atomic(dst); 532 return r; 533 } 534 535 static void crypt_iv_tcw_dtr(struct crypt_config *cc) 536 { 537 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 538 539 kzfree(tcw->iv_seed); 540 tcw->iv_seed = NULL; 541 kzfree(tcw->whitening); 542 tcw->whitening = NULL; 543 544 if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) 545 crypto_free_shash(tcw->crc32_tfm); 546 tcw->crc32_tfm = NULL; 547 } 548 549 static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, 550 const char *opts) 551 { 552 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 553 554 if (cc->sector_size != (1 << SECTOR_SHIFT)) { 555 ti->error = "Unsupported sector size for TCW"; 556 return -EINVAL; 557 } 558 559 if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { 560 ti->error = "Wrong key size for TCW"; 561 return -EINVAL; 562 } 563 564 tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); 565 if (IS_ERR(tcw->crc32_tfm)) { 566 ti->error = "Error initializing CRC32 in TCW"; 567 return PTR_ERR(tcw->crc32_tfm); 568 } 569 570 tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); 571 tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); 572 if (!tcw->iv_seed || !tcw->whitening) { 573 crypt_iv_tcw_dtr(cc); 574 ti->error = "Error allocating seed storage in TCW"; 575 return -ENOMEM; 576 } 577 578 return 0; 579 } 580 581 static int crypt_iv_tcw_init(struct crypt_config *cc) 582 { 583 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 584 int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; 585 586 memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); 587 memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], 588 TCW_WHITENING_SIZE); 589 590 return 0; 591 } 592 593 static int crypt_iv_tcw_wipe(struct crypt_config *cc) 594 { 595 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 596 597 memset(tcw->iv_seed, 0, cc->iv_size); 598 memset(tcw->whitening, 0, TCW_WHITENING_SIZE); 599 600 return 0; 601 } 602 603 static int crypt_iv_tcw_whitening(struct crypt_config *cc, 604 struct dm_crypt_request *dmreq, 605 u8 *data) 606 { 607 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 608 __le64 sector = cpu_to_le64(dmreq->iv_sector); 609 u8 buf[TCW_WHITENING_SIZE]; 610 SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); 611 int i, r; 612 613 /* xor whitening with sector number */ 614 crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); 615 crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); 616 617 /* calculate crc32 for every 32bit part and xor it */ 618 desc->tfm = tcw->crc32_tfm; 619 for (i = 0; i < 4; i++) { 620 r = crypto_shash_init(desc); 621 if (r) 622 goto out; 623 r = crypto_shash_update(desc, &buf[i * 4], 4); 624 if (r) 625 goto out; 626 r = crypto_shash_final(desc, &buf[i * 4]); 627 if (r) 628 goto out; 629 } 630 crypto_xor(&buf[0], &buf[12], 4); 631 crypto_xor(&buf[4], &buf[8], 4); 632 633 /* apply whitening (8 bytes) to whole sector */ 634 for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) 635 crypto_xor(data + i * 8, buf, 8); 636 out: 637 memzero_explicit(buf, sizeof(buf)); 638 return r; 639 } 640 641 static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, 642 struct dm_crypt_request *dmreq) 643 { 644 struct scatterlist *sg; 645 struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; 646 __le64 sector = cpu_to_le64(dmreq->iv_sector); 647 u8 *src; 648 int r = 0; 649 650 /* Remove whitening from ciphertext */ 651 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { 652 sg = crypt_get_sg_data(cc, dmreq->sg_in); 653 src = kmap_atomic(sg_page(sg)); 654 r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); 655 kunmap_atomic(src); 656 } 657 658 /* Calculate IV */ 659 crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); 660 if (cc->iv_size > 8) 661 crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)§or, 662 cc->iv_size - 8); 663 664 return r; 665 } 666 667 static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, 668 struct dm_crypt_request *dmreq) 669 { 670 struct scatterlist *sg; 671 u8 *dst; 672 int r; 673 674 if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) 675 return 0; 676 677 /* Apply whitening on ciphertext */ 678 sg = crypt_get_sg_data(cc, dmreq->sg_out); 679 dst = kmap_atomic(sg_page(sg)); 680 r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); 681 kunmap_atomic(dst); 682 683 return r; 684 } 685 686 static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, 687 struct dm_crypt_request *dmreq) 688 { 689 /* Used only for writes, there must be an additional space to store IV */ 690 get_random_bytes(iv, cc->iv_size); 691 return 0; 692 } 693 694 static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti, 695 const char *opts) 696 { 697 if (test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags)) { 698 ti->error = "AEAD transforms not supported for EBOIV"; 699 return -EINVAL; 700 } 701 702 if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) { 703 ti->error = "Block size of EBOIV cipher does " 704 "not match IV size of block cipher"; 705 return -EINVAL; 706 } 707 708 return 0; 709 } 710 711 static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv, 712 struct dm_crypt_request *dmreq) 713 { 714 u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64)); 715 struct skcipher_request *req; 716 struct scatterlist src, dst; 717 struct crypto_wait wait; 718 int err; 719 720 req = skcipher_request_alloc(any_tfm(cc), GFP_KERNEL | GFP_NOFS); 721 if (!req) 722 return -ENOMEM; 723 724 memset(buf, 0, cc->iv_size); 725 *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size); 726 727 sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size); 728 sg_init_one(&dst, iv, cc->iv_size); 729 skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf); 730 skcipher_request_set_callback(req, 0, crypto_req_done, &wait); 731 err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait); 732 skcipher_request_free(req); 733 734 return err; 735 } 736 737 static const struct crypt_iv_operations crypt_iv_plain_ops = { 738 .generator = crypt_iv_plain_gen 739 }; 740 741 static const struct crypt_iv_operations crypt_iv_plain64_ops = { 742 .generator = crypt_iv_plain64_gen 743 }; 744 745 static const struct crypt_iv_operations crypt_iv_plain64be_ops = { 746 .generator = crypt_iv_plain64be_gen 747 }; 748 749 static const struct crypt_iv_operations crypt_iv_essiv_ops = { 750 .generator = crypt_iv_essiv_gen 751 }; 752 753 static const struct crypt_iv_operations crypt_iv_benbi_ops = { 754 .ctr = crypt_iv_benbi_ctr, 755 .dtr = crypt_iv_benbi_dtr, 756 .generator = crypt_iv_benbi_gen 757 }; 758 759 static const struct crypt_iv_operations crypt_iv_null_ops = { 760 .generator = crypt_iv_null_gen 761 }; 762 763 static const struct crypt_iv_operations crypt_iv_lmk_ops = { 764 .ctr = crypt_iv_lmk_ctr, 765 .dtr = crypt_iv_lmk_dtr, 766 .init = crypt_iv_lmk_init, 767 .wipe = crypt_iv_lmk_wipe, 768 .generator = crypt_iv_lmk_gen, 769 .post = crypt_iv_lmk_post 770 }; 771 772 static const struct crypt_iv_operations crypt_iv_tcw_ops = { 773 .ctr = crypt_iv_tcw_ctr, 774 .dtr = crypt_iv_tcw_dtr, 775 .init = crypt_iv_tcw_init, 776 .wipe = crypt_iv_tcw_wipe, 777 .generator = crypt_iv_tcw_gen, 778 .post = crypt_iv_tcw_post 779 }; 780 781 static struct crypt_iv_operations crypt_iv_random_ops = { 782 .generator = crypt_iv_random_gen 783 }; 784 785 static struct crypt_iv_operations crypt_iv_eboiv_ops = { 786 .ctr = crypt_iv_eboiv_ctr, 787 .generator = crypt_iv_eboiv_gen 788 }; 789 790 /* 791 * Integrity extensions 792 */ 793 static bool crypt_integrity_aead(struct crypt_config *cc) 794 { 795 return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 796 } 797 798 static bool crypt_integrity_hmac(struct crypt_config *cc) 799 { 800 return crypt_integrity_aead(cc) && cc->key_mac_size; 801 } 802 803 /* Get sg containing data */ 804 static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, 805 struct scatterlist *sg) 806 { 807 if (unlikely(crypt_integrity_aead(cc))) 808 return &sg[2]; 809 810 return sg; 811 } 812 813 static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) 814 { 815 struct bio_integrity_payload *bip; 816 unsigned int tag_len; 817 int ret; 818 819 if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) 820 return 0; 821 822 bip = bio_integrity_alloc(bio, GFP_NOIO, 1); 823 if (IS_ERR(bip)) 824 return PTR_ERR(bip); 825 826 tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift); 827 828 bip->bip_iter.bi_size = tag_len; 829 bip->bip_iter.bi_sector = io->cc->start + io->sector; 830 831 ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), 832 tag_len, offset_in_page(io->integrity_metadata)); 833 if (unlikely(ret != tag_len)) 834 return -ENOMEM; 835 836 return 0; 837 } 838 839 static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) 840 { 841 #ifdef CONFIG_BLK_DEV_INTEGRITY 842 struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); 843 struct mapped_device *md = dm_table_get_md(ti->table); 844 845 /* From now we require underlying device with our integrity profile */ 846 if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { 847 ti->error = "Integrity profile not supported."; 848 return -EINVAL; 849 } 850 851 if (bi->tag_size != cc->on_disk_tag_size || 852 bi->tuple_size != cc->on_disk_tag_size) { 853 ti->error = "Integrity profile tag size mismatch."; 854 return -EINVAL; 855 } 856 if (1 << bi->interval_exp != cc->sector_size) { 857 ti->error = "Integrity profile sector size mismatch."; 858 return -EINVAL; 859 } 860 861 if (crypt_integrity_aead(cc)) { 862 cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; 863 DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), 864 cc->integrity_tag_size, cc->integrity_iv_size); 865 866 if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { 867 ti->error = "Integrity AEAD auth tag size is not supported."; 868 return -EINVAL; 869 } 870 } else if (cc->integrity_iv_size) 871 DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), 872 cc->integrity_iv_size); 873 874 if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { 875 ti->error = "Not enough space for integrity tag in the profile."; 876 return -EINVAL; 877 } 878 879 return 0; 880 #else 881 ti->error = "Integrity profile not supported."; 882 return -EINVAL; 883 #endif 884 } 885 886 static void crypt_convert_init(struct crypt_config *cc, 887 struct convert_context *ctx, 888 struct bio *bio_out, struct bio *bio_in, 889 sector_t sector) 890 { 891 ctx->bio_in = bio_in; 892 ctx->bio_out = bio_out; 893 if (bio_in) 894 ctx->iter_in = bio_in->bi_iter; 895 if (bio_out) 896 ctx->iter_out = bio_out->bi_iter; 897 ctx->cc_sector = sector + cc->iv_offset; 898 init_completion(&ctx->restart); 899 } 900 901 static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, 902 void *req) 903 { 904 return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); 905 } 906 907 static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) 908 { 909 return (void *)((char *)dmreq - cc->dmreq_start); 910 } 911 912 static u8 *iv_of_dmreq(struct crypt_config *cc, 913 struct dm_crypt_request *dmreq) 914 { 915 if (crypt_integrity_aead(cc)) 916 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 917 crypto_aead_alignmask(any_tfm_aead(cc)) + 1); 918 else 919 return (u8 *)ALIGN((unsigned long)(dmreq + 1), 920 crypto_skcipher_alignmask(any_tfm(cc)) + 1); 921 } 922 923 static u8 *org_iv_of_dmreq(struct crypt_config *cc, 924 struct dm_crypt_request *dmreq) 925 { 926 return iv_of_dmreq(cc, dmreq) + cc->iv_size; 927 } 928 929 static __le64 *org_sector_of_dmreq(struct crypt_config *cc, 930 struct dm_crypt_request *dmreq) 931 { 932 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; 933 return (__le64 *) ptr; 934 } 935 936 static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, 937 struct dm_crypt_request *dmreq) 938 { 939 u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + 940 cc->iv_size + sizeof(uint64_t); 941 return (unsigned int*)ptr; 942 } 943 944 static void *tag_from_dmreq(struct crypt_config *cc, 945 struct dm_crypt_request *dmreq) 946 { 947 struct convert_context *ctx = dmreq->ctx; 948 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 949 950 return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * 951 cc->on_disk_tag_size]; 952 } 953 954 static void *iv_tag_from_dmreq(struct crypt_config *cc, 955 struct dm_crypt_request *dmreq) 956 { 957 return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; 958 } 959 960 static int crypt_convert_block_aead(struct crypt_config *cc, 961 struct convert_context *ctx, 962 struct aead_request *req, 963 unsigned int tag_offset) 964 { 965 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 966 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 967 struct dm_crypt_request *dmreq; 968 u8 *iv, *org_iv, *tag_iv, *tag; 969 __le64 *sector; 970 int r = 0; 971 972 BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); 973 974 /* Reject unexpected unaligned bio. */ 975 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 976 return -EIO; 977 978 dmreq = dmreq_of_req(cc, req); 979 dmreq->iv_sector = ctx->cc_sector; 980 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 981 dmreq->iv_sector >>= cc->sector_shift; 982 dmreq->ctx = ctx; 983 984 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 985 986 sector = org_sector_of_dmreq(cc, dmreq); 987 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 988 989 iv = iv_of_dmreq(cc, dmreq); 990 org_iv = org_iv_of_dmreq(cc, dmreq); 991 tag = tag_from_dmreq(cc, dmreq); 992 tag_iv = iv_tag_from_dmreq(cc, dmreq); 993 994 /* AEAD request: 995 * |----- AAD -------|------ DATA -------|-- AUTH TAG --| 996 * | (authenticated) | (auth+encryption) | | 997 * | sector_LE | IV | sector in/out | tag in/out | 998 */ 999 sg_init_table(dmreq->sg_in, 4); 1000 sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); 1001 sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); 1002 sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1003 sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); 1004 1005 sg_init_table(dmreq->sg_out, 4); 1006 sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); 1007 sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); 1008 sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1009 sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); 1010 1011 if (cc->iv_gen_ops) { 1012 /* For READs use IV stored in integrity metadata */ 1013 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1014 memcpy(org_iv, tag_iv, cc->iv_size); 1015 } else { 1016 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1017 if (r < 0) 1018 return r; 1019 /* Store generated IV in integrity metadata */ 1020 if (cc->integrity_iv_size) 1021 memcpy(tag_iv, org_iv, cc->iv_size); 1022 } 1023 /* Working copy of IV, to be modified in crypto API */ 1024 memcpy(iv, org_iv, cc->iv_size); 1025 } 1026 1027 aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); 1028 if (bio_data_dir(ctx->bio_in) == WRITE) { 1029 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1030 cc->sector_size, iv); 1031 r = crypto_aead_encrypt(req); 1032 if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) 1033 memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, 1034 cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); 1035 } else { 1036 aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, 1037 cc->sector_size + cc->integrity_tag_size, iv); 1038 r = crypto_aead_decrypt(req); 1039 } 1040 1041 if (r == -EBADMSG) { 1042 char b[BDEVNAME_SIZE]; 1043 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 1044 (unsigned long long)le64_to_cpu(*sector)); 1045 } 1046 1047 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1048 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1049 1050 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1051 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1052 1053 return r; 1054 } 1055 1056 static int crypt_convert_block_skcipher(struct crypt_config *cc, 1057 struct convert_context *ctx, 1058 struct skcipher_request *req, 1059 unsigned int tag_offset) 1060 { 1061 struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); 1062 struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); 1063 struct scatterlist *sg_in, *sg_out; 1064 struct dm_crypt_request *dmreq; 1065 u8 *iv, *org_iv, *tag_iv; 1066 __le64 *sector; 1067 int r = 0; 1068 1069 /* Reject unexpected unaligned bio. */ 1070 if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) 1071 return -EIO; 1072 1073 dmreq = dmreq_of_req(cc, req); 1074 dmreq->iv_sector = ctx->cc_sector; 1075 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 1076 dmreq->iv_sector >>= cc->sector_shift; 1077 dmreq->ctx = ctx; 1078 1079 *org_tag_of_dmreq(cc, dmreq) = tag_offset; 1080 1081 iv = iv_of_dmreq(cc, dmreq); 1082 org_iv = org_iv_of_dmreq(cc, dmreq); 1083 tag_iv = iv_tag_from_dmreq(cc, dmreq); 1084 1085 sector = org_sector_of_dmreq(cc, dmreq); 1086 *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); 1087 1088 /* For skcipher we use only the first sg item */ 1089 sg_in = &dmreq->sg_in[0]; 1090 sg_out = &dmreq->sg_out[0]; 1091 1092 sg_init_table(sg_in, 1); 1093 sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); 1094 1095 sg_init_table(sg_out, 1); 1096 sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); 1097 1098 if (cc->iv_gen_ops) { 1099 /* For READs use IV stored in integrity metadata */ 1100 if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { 1101 memcpy(org_iv, tag_iv, cc->integrity_iv_size); 1102 } else { 1103 r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); 1104 if (r < 0) 1105 return r; 1106 /* Store generated IV in integrity metadata */ 1107 if (cc->integrity_iv_size) 1108 memcpy(tag_iv, org_iv, cc->integrity_iv_size); 1109 } 1110 /* Working copy of IV, to be modified in crypto API */ 1111 memcpy(iv, org_iv, cc->iv_size); 1112 } 1113 1114 skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); 1115 1116 if (bio_data_dir(ctx->bio_in) == WRITE) 1117 r = crypto_skcipher_encrypt(req); 1118 else 1119 r = crypto_skcipher_decrypt(req); 1120 1121 if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) 1122 r = cc->iv_gen_ops->post(cc, org_iv, dmreq); 1123 1124 bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); 1125 bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); 1126 1127 return r; 1128 } 1129 1130 static void kcryptd_async_done(struct crypto_async_request *async_req, 1131 int error); 1132 1133 static void crypt_alloc_req_skcipher(struct crypt_config *cc, 1134 struct convert_context *ctx) 1135 { 1136 unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); 1137 1138 if (!ctx->r.req) 1139 ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO); 1140 1141 skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); 1142 1143 /* 1144 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1145 * requests if driver request queue is full. 1146 */ 1147 skcipher_request_set_callback(ctx->r.req, 1148 CRYPTO_TFM_REQ_MAY_BACKLOG, 1149 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); 1150 } 1151 1152 static void crypt_alloc_req_aead(struct crypt_config *cc, 1153 struct convert_context *ctx) 1154 { 1155 if (!ctx->r.req_aead) 1156 ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO); 1157 1158 aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); 1159 1160 /* 1161 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs 1162 * requests if driver request queue is full. 1163 */ 1164 aead_request_set_callback(ctx->r.req_aead, 1165 CRYPTO_TFM_REQ_MAY_BACKLOG, 1166 kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); 1167 } 1168 1169 static void crypt_alloc_req(struct crypt_config *cc, 1170 struct convert_context *ctx) 1171 { 1172 if (crypt_integrity_aead(cc)) 1173 crypt_alloc_req_aead(cc, ctx); 1174 else 1175 crypt_alloc_req_skcipher(cc, ctx); 1176 } 1177 1178 static void crypt_free_req_skcipher(struct crypt_config *cc, 1179 struct skcipher_request *req, struct bio *base_bio) 1180 { 1181 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1182 1183 if ((struct skcipher_request *)(io + 1) != req) 1184 mempool_free(req, &cc->req_pool); 1185 } 1186 1187 static void crypt_free_req_aead(struct crypt_config *cc, 1188 struct aead_request *req, struct bio *base_bio) 1189 { 1190 struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); 1191 1192 if ((struct aead_request *)(io + 1) != req) 1193 mempool_free(req, &cc->req_pool); 1194 } 1195 1196 static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) 1197 { 1198 if (crypt_integrity_aead(cc)) 1199 crypt_free_req_aead(cc, req, base_bio); 1200 else 1201 crypt_free_req_skcipher(cc, req, base_bio); 1202 } 1203 1204 /* 1205 * Encrypt / decrypt data from one bio to another one (can be the same one) 1206 */ 1207 static blk_status_t crypt_convert(struct crypt_config *cc, 1208 struct convert_context *ctx) 1209 { 1210 unsigned int tag_offset = 0; 1211 unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; 1212 int r; 1213 1214 atomic_set(&ctx->cc_pending, 1); 1215 1216 while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { 1217 1218 crypt_alloc_req(cc, ctx); 1219 atomic_inc(&ctx->cc_pending); 1220 1221 if (crypt_integrity_aead(cc)) 1222 r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); 1223 else 1224 r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); 1225 1226 switch (r) { 1227 /* 1228 * The request was queued by a crypto driver 1229 * but the driver request queue is full, let's wait. 1230 */ 1231 case -EBUSY: 1232 wait_for_completion(&ctx->restart); 1233 reinit_completion(&ctx->restart); 1234 /* fall through */ 1235 /* 1236 * The request is queued and processed asynchronously, 1237 * completion function kcryptd_async_done() will be called. 1238 */ 1239 case -EINPROGRESS: 1240 ctx->r.req = NULL; 1241 ctx->cc_sector += sector_step; 1242 tag_offset++; 1243 continue; 1244 /* 1245 * The request was already processed (synchronously). 1246 */ 1247 case 0: 1248 atomic_dec(&ctx->cc_pending); 1249 ctx->cc_sector += sector_step; 1250 tag_offset++; 1251 cond_resched(); 1252 continue; 1253 /* 1254 * There was a data integrity error. 1255 */ 1256 case -EBADMSG: 1257 atomic_dec(&ctx->cc_pending); 1258 return BLK_STS_PROTECTION; 1259 /* 1260 * There was an error while processing the request. 1261 */ 1262 default: 1263 atomic_dec(&ctx->cc_pending); 1264 return BLK_STS_IOERR; 1265 } 1266 } 1267 1268 return 0; 1269 } 1270 1271 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); 1272 1273 /* 1274 * Generate a new unfragmented bio with the given size 1275 * This should never violate the device limitations (but only because 1276 * max_segment_size is being constrained to PAGE_SIZE). 1277 * 1278 * This function may be called concurrently. If we allocate from the mempool 1279 * concurrently, there is a possibility of deadlock. For example, if we have 1280 * mempool of 256 pages, two processes, each wanting 256, pages allocate from 1281 * the mempool concurrently, it may deadlock in a situation where both processes 1282 * have allocated 128 pages and the mempool is exhausted. 1283 * 1284 * In order to avoid this scenario we allocate the pages under a mutex. 1285 * 1286 * In order to not degrade performance with excessive locking, we try 1287 * non-blocking allocations without a mutex first but on failure we fallback 1288 * to blocking allocations with a mutex. 1289 */ 1290 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 1291 { 1292 struct crypt_config *cc = io->cc; 1293 struct bio *clone; 1294 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 1295 gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; 1296 unsigned i, len, remaining_size; 1297 struct page *page; 1298 1299 retry: 1300 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1301 mutex_lock(&cc->bio_alloc_lock); 1302 1303 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs); 1304 if (!clone) 1305 goto out; 1306 1307 clone_init(io, clone); 1308 1309 remaining_size = size; 1310 1311 for (i = 0; i < nr_iovecs; i++) { 1312 page = mempool_alloc(&cc->page_pool, gfp_mask); 1313 if (!page) { 1314 crypt_free_buffer_pages(cc, clone); 1315 bio_put(clone); 1316 gfp_mask |= __GFP_DIRECT_RECLAIM; 1317 goto retry; 1318 } 1319 1320 len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; 1321 1322 bio_add_page(clone, page, len, 0); 1323 1324 remaining_size -= len; 1325 } 1326 1327 /* Allocate space for integrity tags */ 1328 if (dm_crypt_integrity_io_alloc(io, clone)) { 1329 crypt_free_buffer_pages(cc, clone); 1330 bio_put(clone); 1331 clone = NULL; 1332 } 1333 out: 1334 if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) 1335 mutex_unlock(&cc->bio_alloc_lock); 1336 1337 return clone; 1338 } 1339 1340 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 1341 { 1342 struct bio_vec *bv; 1343 struct bvec_iter_all iter_all; 1344 1345 bio_for_each_segment_all(bv, clone, iter_all) { 1346 BUG_ON(!bv->bv_page); 1347 mempool_free(bv->bv_page, &cc->page_pool); 1348 } 1349 } 1350 1351 static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, 1352 struct bio *bio, sector_t sector) 1353 { 1354 io->cc = cc; 1355 io->base_bio = bio; 1356 io->sector = sector; 1357 io->error = 0; 1358 io->ctx.r.req = NULL; 1359 io->integrity_metadata = NULL; 1360 io->integrity_metadata_from_pool = false; 1361 atomic_set(&io->io_pending, 0); 1362 } 1363 1364 static void crypt_inc_pending(struct dm_crypt_io *io) 1365 { 1366 atomic_inc(&io->io_pending); 1367 } 1368 1369 /* 1370 * One of the bios was finished. Check for completion of 1371 * the whole request and correctly clean up the buffer. 1372 */ 1373 static void crypt_dec_pending(struct dm_crypt_io *io) 1374 { 1375 struct crypt_config *cc = io->cc; 1376 struct bio *base_bio = io->base_bio; 1377 blk_status_t error = io->error; 1378 1379 if (!atomic_dec_and_test(&io->io_pending)) 1380 return; 1381 1382 if (io->ctx.r.req) 1383 crypt_free_req(cc, io->ctx.r.req, base_bio); 1384 1385 if (unlikely(io->integrity_metadata_from_pool)) 1386 mempool_free(io->integrity_metadata, &io->cc->tag_pool); 1387 else 1388 kfree(io->integrity_metadata); 1389 1390 base_bio->bi_status = error; 1391 bio_endio(base_bio); 1392 } 1393 1394 /* 1395 * kcryptd/kcryptd_io: 1396 * 1397 * Needed because it would be very unwise to do decryption in an 1398 * interrupt context. 1399 * 1400 * kcryptd performs the actual encryption or decryption. 1401 * 1402 * kcryptd_io performs the IO submission. 1403 * 1404 * They must be separated as otherwise the final stages could be 1405 * starved by new requests which can block in the first stages due 1406 * to memory allocation. 1407 * 1408 * The work is done per CPU global for all dm-crypt instances. 1409 * They should not depend on each other and do not block. 1410 */ 1411 static void crypt_endio(struct bio *clone) 1412 { 1413 struct dm_crypt_io *io = clone->bi_private; 1414 struct crypt_config *cc = io->cc; 1415 unsigned rw = bio_data_dir(clone); 1416 blk_status_t error; 1417 1418 /* 1419 * free the processed pages 1420 */ 1421 if (rw == WRITE) 1422 crypt_free_buffer_pages(cc, clone); 1423 1424 error = clone->bi_status; 1425 bio_put(clone); 1426 1427 if (rw == READ && !error) { 1428 kcryptd_queue_crypt(io); 1429 return; 1430 } 1431 1432 if (unlikely(error)) 1433 io->error = error; 1434 1435 crypt_dec_pending(io); 1436 } 1437 1438 static void clone_init(struct dm_crypt_io *io, struct bio *clone) 1439 { 1440 struct crypt_config *cc = io->cc; 1441 1442 clone->bi_private = io; 1443 clone->bi_end_io = crypt_endio; 1444 bio_set_dev(clone, cc->dev->bdev); 1445 clone->bi_opf = io->base_bio->bi_opf; 1446 } 1447 1448 static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) 1449 { 1450 struct crypt_config *cc = io->cc; 1451 struct bio *clone; 1452 1453 /* 1454 * We need the original biovec array in order to decrypt 1455 * the whole bio data *afterwards* -- thanks to immutable 1456 * biovecs we don't need to worry about the block layer 1457 * modifying the biovec array; so leverage bio_clone_fast(). 1458 */ 1459 clone = bio_clone_fast(io->base_bio, gfp, &cc->bs); 1460 if (!clone) 1461 return 1; 1462 1463 crypt_inc_pending(io); 1464 1465 clone_init(io, clone); 1466 clone->bi_iter.bi_sector = cc->start + io->sector; 1467 1468 if (dm_crypt_integrity_io_alloc(io, clone)) { 1469 crypt_dec_pending(io); 1470 bio_put(clone); 1471 return 1; 1472 } 1473 1474 generic_make_request(clone); 1475 return 0; 1476 } 1477 1478 static void kcryptd_io_read_work(struct work_struct *work) 1479 { 1480 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1481 1482 crypt_inc_pending(io); 1483 if (kcryptd_io_read(io, GFP_NOIO)) 1484 io->error = BLK_STS_RESOURCE; 1485 crypt_dec_pending(io); 1486 } 1487 1488 static void kcryptd_queue_read(struct dm_crypt_io *io) 1489 { 1490 struct crypt_config *cc = io->cc; 1491 1492 INIT_WORK(&io->work, kcryptd_io_read_work); 1493 queue_work(cc->io_queue, &io->work); 1494 } 1495 1496 static void kcryptd_io_write(struct dm_crypt_io *io) 1497 { 1498 struct bio *clone = io->ctx.bio_out; 1499 1500 generic_make_request(clone); 1501 } 1502 1503 #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) 1504 1505 static int dmcrypt_write(void *data) 1506 { 1507 struct crypt_config *cc = data; 1508 struct dm_crypt_io *io; 1509 1510 while (1) { 1511 struct rb_root write_tree; 1512 struct blk_plug plug; 1513 1514 spin_lock_irq(&cc->write_thread_lock); 1515 continue_locked: 1516 1517 if (!RB_EMPTY_ROOT(&cc->write_tree)) 1518 goto pop_from_list; 1519 1520 set_current_state(TASK_INTERRUPTIBLE); 1521 1522 spin_unlock_irq(&cc->write_thread_lock); 1523 1524 if (unlikely(kthread_should_stop())) { 1525 set_current_state(TASK_RUNNING); 1526 break; 1527 } 1528 1529 schedule(); 1530 1531 set_current_state(TASK_RUNNING); 1532 spin_lock_irq(&cc->write_thread_lock); 1533 goto continue_locked; 1534 1535 pop_from_list: 1536 write_tree = cc->write_tree; 1537 cc->write_tree = RB_ROOT; 1538 spin_unlock_irq(&cc->write_thread_lock); 1539 1540 BUG_ON(rb_parent(write_tree.rb_node)); 1541 1542 /* 1543 * Note: we cannot walk the tree here with rb_next because 1544 * the structures may be freed when kcryptd_io_write is called. 1545 */ 1546 blk_start_plug(&plug); 1547 do { 1548 io = crypt_io_from_node(rb_first(&write_tree)); 1549 rb_erase(&io->rb_node, &write_tree); 1550 kcryptd_io_write(io); 1551 } while (!RB_EMPTY_ROOT(&write_tree)); 1552 blk_finish_plug(&plug); 1553 } 1554 return 0; 1555 } 1556 1557 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) 1558 { 1559 struct bio *clone = io->ctx.bio_out; 1560 struct crypt_config *cc = io->cc; 1561 unsigned long flags; 1562 sector_t sector; 1563 struct rb_node **rbp, *parent; 1564 1565 if (unlikely(io->error)) { 1566 crypt_free_buffer_pages(cc, clone); 1567 bio_put(clone); 1568 crypt_dec_pending(io); 1569 return; 1570 } 1571 1572 /* crypt_convert should have filled the clone bio */ 1573 BUG_ON(io->ctx.iter_out.bi_size); 1574 1575 clone->bi_iter.bi_sector = cc->start + io->sector; 1576 1577 if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) { 1578 generic_make_request(clone); 1579 return; 1580 } 1581 1582 spin_lock_irqsave(&cc->write_thread_lock, flags); 1583 if (RB_EMPTY_ROOT(&cc->write_tree)) 1584 wake_up_process(cc->write_thread); 1585 rbp = &cc->write_tree.rb_node; 1586 parent = NULL; 1587 sector = io->sector; 1588 while (*rbp) { 1589 parent = *rbp; 1590 if (sector < crypt_io_from_node(parent)->sector) 1591 rbp = &(*rbp)->rb_left; 1592 else 1593 rbp = &(*rbp)->rb_right; 1594 } 1595 rb_link_node(&io->rb_node, parent, rbp); 1596 rb_insert_color(&io->rb_node, &cc->write_tree); 1597 spin_unlock_irqrestore(&cc->write_thread_lock, flags); 1598 } 1599 1600 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) 1601 { 1602 struct crypt_config *cc = io->cc; 1603 struct bio *clone; 1604 int crypt_finished; 1605 sector_t sector = io->sector; 1606 blk_status_t r; 1607 1608 /* 1609 * Prevent io from disappearing until this function completes. 1610 */ 1611 crypt_inc_pending(io); 1612 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); 1613 1614 clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); 1615 if (unlikely(!clone)) { 1616 io->error = BLK_STS_IOERR; 1617 goto dec; 1618 } 1619 1620 io->ctx.bio_out = clone; 1621 io->ctx.iter_out = clone->bi_iter; 1622 1623 sector += bio_sectors(clone); 1624 1625 crypt_inc_pending(io); 1626 r = crypt_convert(cc, &io->ctx); 1627 if (r) 1628 io->error = r; 1629 crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending); 1630 1631 /* Encryption was already finished, submit io now */ 1632 if (crypt_finished) { 1633 kcryptd_crypt_write_io_submit(io, 0); 1634 io->sector = sector; 1635 } 1636 1637 dec: 1638 crypt_dec_pending(io); 1639 } 1640 1641 static void kcryptd_crypt_read_done(struct dm_crypt_io *io) 1642 { 1643 crypt_dec_pending(io); 1644 } 1645 1646 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) 1647 { 1648 struct crypt_config *cc = io->cc; 1649 blk_status_t r; 1650 1651 crypt_inc_pending(io); 1652 1653 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, 1654 io->sector); 1655 1656 r = crypt_convert(cc, &io->ctx); 1657 if (r) 1658 io->error = r; 1659 1660 if (atomic_dec_and_test(&io->ctx.cc_pending)) 1661 kcryptd_crypt_read_done(io); 1662 1663 crypt_dec_pending(io); 1664 } 1665 1666 static void kcryptd_async_done(struct crypto_async_request *async_req, 1667 int error) 1668 { 1669 struct dm_crypt_request *dmreq = async_req->data; 1670 struct convert_context *ctx = dmreq->ctx; 1671 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); 1672 struct crypt_config *cc = io->cc; 1673 1674 /* 1675 * A request from crypto driver backlog is going to be processed now, 1676 * finish the completion and continue in crypt_convert(). 1677 * (Callback will be called for the second time for this request.) 1678 */ 1679 if (error == -EINPROGRESS) { 1680 complete(&ctx->restart); 1681 return; 1682 } 1683 1684 if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) 1685 error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq); 1686 1687 if (error == -EBADMSG) { 1688 char b[BDEVNAME_SIZE]; 1689 DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b), 1690 (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); 1691 io->error = BLK_STS_PROTECTION; 1692 } else if (error < 0) 1693 io->error = BLK_STS_IOERR; 1694 1695 crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); 1696 1697 if (!atomic_dec_and_test(&ctx->cc_pending)) 1698 return; 1699 1700 if (bio_data_dir(io->base_bio) == READ) 1701 kcryptd_crypt_read_done(io); 1702 else 1703 kcryptd_crypt_write_io_submit(io, 1); 1704 } 1705 1706 static void kcryptd_crypt(struct work_struct *work) 1707 { 1708 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 1709 1710 if (bio_data_dir(io->base_bio) == READ) 1711 kcryptd_crypt_read_convert(io); 1712 else 1713 kcryptd_crypt_write_convert(io); 1714 } 1715 1716 static void kcryptd_queue_crypt(struct dm_crypt_io *io) 1717 { 1718 struct crypt_config *cc = io->cc; 1719 1720 INIT_WORK(&io->work, kcryptd_crypt); 1721 queue_work(cc->crypt_queue, &io->work); 1722 } 1723 1724 static void crypt_free_tfms_aead(struct crypt_config *cc) 1725 { 1726 if (!cc->cipher_tfm.tfms_aead) 1727 return; 1728 1729 if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1730 crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); 1731 cc->cipher_tfm.tfms_aead[0] = NULL; 1732 } 1733 1734 kfree(cc->cipher_tfm.tfms_aead); 1735 cc->cipher_tfm.tfms_aead = NULL; 1736 } 1737 1738 static void crypt_free_tfms_skcipher(struct crypt_config *cc) 1739 { 1740 unsigned i; 1741 1742 if (!cc->cipher_tfm.tfms) 1743 return; 1744 1745 for (i = 0; i < cc->tfms_count; i++) 1746 if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { 1747 crypto_free_skcipher(cc->cipher_tfm.tfms[i]); 1748 cc->cipher_tfm.tfms[i] = NULL; 1749 } 1750 1751 kfree(cc->cipher_tfm.tfms); 1752 cc->cipher_tfm.tfms = NULL; 1753 } 1754 1755 static void crypt_free_tfms(struct crypt_config *cc) 1756 { 1757 if (crypt_integrity_aead(cc)) 1758 crypt_free_tfms_aead(cc); 1759 else 1760 crypt_free_tfms_skcipher(cc); 1761 } 1762 1763 static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) 1764 { 1765 unsigned i; 1766 int err; 1767 1768 cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, 1769 sizeof(struct crypto_skcipher *), 1770 GFP_KERNEL); 1771 if (!cc->cipher_tfm.tfms) 1772 return -ENOMEM; 1773 1774 for (i = 0; i < cc->tfms_count; i++) { 1775 cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0); 1776 if (IS_ERR(cc->cipher_tfm.tfms[i])) { 1777 err = PTR_ERR(cc->cipher_tfm.tfms[i]); 1778 crypt_free_tfms(cc); 1779 return err; 1780 } 1781 } 1782 1783 /* 1784 * dm-crypt performance can vary greatly depending on which crypto 1785 * algorithm implementation is used. Help people debug performance 1786 * problems by logging the ->cra_driver_name. 1787 */ 1788 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 1789 crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name); 1790 return 0; 1791 } 1792 1793 static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) 1794 { 1795 int err; 1796 1797 cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); 1798 if (!cc->cipher_tfm.tfms) 1799 return -ENOMEM; 1800 1801 cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0); 1802 if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { 1803 err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); 1804 crypt_free_tfms(cc); 1805 return err; 1806 } 1807 1808 DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode, 1809 crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name); 1810 return 0; 1811 } 1812 1813 static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) 1814 { 1815 if (crypt_integrity_aead(cc)) 1816 return crypt_alloc_tfms_aead(cc, ciphermode); 1817 else 1818 return crypt_alloc_tfms_skcipher(cc, ciphermode); 1819 } 1820 1821 static unsigned crypt_subkey_size(struct crypt_config *cc) 1822 { 1823 return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); 1824 } 1825 1826 static unsigned crypt_authenckey_size(struct crypt_config *cc) 1827 { 1828 return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); 1829 } 1830 1831 /* 1832 * If AEAD is composed like authenc(hmac(sha256),xts(aes)), 1833 * the key must be for some reason in special format. 1834 * This funcion converts cc->key to this special format. 1835 */ 1836 static void crypt_copy_authenckey(char *p, const void *key, 1837 unsigned enckeylen, unsigned authkeylen) 1838 { 1839 struct crypto_authenc_key_param *param; 1840 struct rtattr *rta; 1841 1842 rta = (struct rtattr *)p; 1843 param = RTA_DATA(rta); 1844 param->enckeylen = cpu_to_be32(enckeylen); 1845 rta->rta_len = RTA_LENGTH(sizeof(*param)); 1846 rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; 1847 p += RTA_SPACE(sizeof(*param)); 1848 memcpy(p, key + enckeylen, authkeylen); 1849 p += authkeylen; 1850 memcpy(p, key, enckeylen); 1851 } 1852 1853 static int crypt_setkey(struct crypt_config *cc) 1854 { 1855 unsigned subkey_size; 1856 int err = 0, i, r; 1857 1858 /* Ignore extra keys (which are used for IV etc) */ 1859 subkey_size = crypt_subkey_size(cc); 1860 1861 if (crypt_integrity_hmac(cc)) { 1862 if (subkey_size < cc->key_mac_size) 1863 return -EINVAL; 1864 1865 crypt_copy_authenckey(cc->authenc_key, cc->key, 1866 subkey_size - cc->key_mac_size, 1867 cc->key_mac_size); 1868 } 1869 1870 for (i = 0; i < cc->tfms_count; i++) { 1871 if (crypt_integrity_hmac(cc)) 1872 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1873 cc->authenc_key, crypt_authenckey_size(cc)); 1874 else if (crypt_integrity_aead(cc)) 1875 r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], 1876 cc->key + (i * subkey_size), 1877 subkey_size); 1878 else 1879 r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], 1880 cc->key + (i * subkey_size), 1881 subkey_size); 1882 if (r) 1883 err = r; 1884 } 1885 1886 if (crypt_integrity_hmac(cc)) 1887 memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); 1888 1889 return err; 1890 } 1891 1892 #ifdef CONFIG_KEYS 1893 1894 static bool contains_whitespace(const char *str) 1895 { 1896 while (*str) 1897 if (isspace(*str++)) 1898 return true; 1899 return false; 1900 } 1901 1902 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 1903 { 1904 char *new_key_string, *key_desc; 1905 int ret; 1906 struct key *key; 1907 const struct user_key_payload *ukp; 1908 1909 /* 1910 * Reject key_string with whitespace. dm core currently lacks code for 1911 * proper whitespace escaping in arguments on DM_TABLE_STATUS path. 1912 */ 1913 if (contains_whitespace(key_string)) { 1914 DMERR("whitespace chars not allowed in key string"); 1915 return -EINVAL; 1916 } 1917 1918 /* look for next ':' separating key_type from key_description */ 1919 key_desc = strpbrk(key_string, ":"); 1920 if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) 1921 return -EINVAL; 1922 1923 if (strncmp(key_string, "logon:", key_desc - key_string + 1) && 1924 strncmp(key_string, "user:", key_desc - key_string + 1)) 1925 return -EINVAL; 1926 1927 new_key_string = kstrdup(key_string, GFP_KERNEL); 1928 if (!new_key_string) 1929 return -ENOMEM; 1930 1931 key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user, 1932 key_desc + 1, NULL); 1933 if (IS_ERR(key)) { 1934 kzfree(new_key_string); 1935 return PTR_ERR(key); 1936 } 1937 1938 down_read(&key->sem); 1939 1940 ukp = user_key_payload_locked(key); 1941 if (!ukp) { 1942 up_read(&key->sem); 1943 key_put(key); 1944 kzfree(new_key_string); 1945 return -EKEYREVOKED; 1946 } 1947 1948 if (cc->key_size != ukp->datalen) { 1949 up_read(&key->sem); 1950 key_put(key); 1951 kzfree(new_key_string); 1952 return -EINVAL; 1953 } 1954 1955 memcpy(cc->key, ukp->data, cc->key_size); 1956 1957 up_read(&key->sem); 1958 key_put(key); 1959 1960 /* clear the flag since following operations may invalidate previously valid key */ 1961 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 1962 1963 ret = crypt_setkey(cc); 1964 1965 if (!ret) { 1966 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 1967 kzfree(cc->key_string); 1968 cc->key_string = new_key_string; 1969 } else 1970 kzfree(new_key_string); 1971 1972 return ret; 1973 } 1974 1975 static int get_key_size(char **key_string) 1976 { 1977 char *colon, dummy; 1978 int ret; 1979 1980 if (*key_string[0] != ':') 1981 return strlen(*key_string) >> 1; 1982 1983 /* look for next ':' in key string */ 1984 colon = strpbrk(*key_string + 1, ":"); 1985 if (!colon) 1986 return -EINVAL; 1987 1988 if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') 1989 return -EINVAL; 1990 1991 *key_string = colon; 1992 1993 /* remaining key string should be :<logon|user>:<key_desc> */ 1994 1995 return ret; 1996 } 1997 1998 #else 1999 2000 static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) 2001 { 2002 return -EINVAL; 2003 } 2004 2005 static int get_key_size(char **key_string) 2006 { 2007 return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1; 2008 } 2009 2010 #endif 2011 2012 static int crypt_set_key(struct crypt_config *cc, char *key) 2013 { 2014 int r = -EINVAL; 2015 int key_string_len = strlen(key); 2016 2017 /* Hyphen (which gives a key_size of zero) means there is no key. */ 2018 if (!cc->key_size && strcmp(key, "-")) 2019 goto out; 2020 2021 /* ':' means the key is in kernel keyring, short-circuit normal key processing */ 2022 if (key[0] == ':') { 2023 r = crypt_set_keyring_key(cc, key + 1); 2024 goto out; 2025 } 2026 2027 /* clear the flag since following operations may invalidate previously valid key */ 2028 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2029 2030 /* wipe references to any kernel keyring key */ 2031 kzfree(cc->key_string); 2032 cc->key_string = NULL; 2033 2034 /* Decode key from its hex representation. */ 2035 if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) 2036 goto out; 2037 2038 r = crypt_setkey(cc); 2039 if (!r) 2040 set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2041 2042 out: 2043 /* Hex key string not needed after here, so wipe it. */ 2044 memset(key, '0', key_string_len); 2045 2046 return r; 2047 } 2048 2049 static int crypt_wipe_key(struct crypt_config *cc) 2050 { 2051 int r; 2052 2053 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 2054 get_random_bytes(&cc->key, cc->key_size); 2055 2056 /* Wipe IV private keys */ 2057 if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { 2058 r = cc->iv_gen_ops->wipe(cc); 2059 if (r) 2060 return r; 2061 } 2062 2063 kzfree(cc->key_string); 2064 cc->key_string = NULL; 2065 r = crypt_setkey(cc); 2066 memset(&cc->key, 0, cc->key_size * sizeof(u8)); 2067 2068 return r; 2069 } 2070 2071 static void crypt_calculate_pages_per_client(void) 2072 { 2073 unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100; 2074 2075 if (!dm_crypt_clients_n) 2076 return; 2077 2078 pages /= dm_crypt_clients_n; 2079 if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) 2080 pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; 2081 dm_crypt_pages_per_client = pages; 2082 } 2083 2084 static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) 2085 { 2086 struct crypt_config *cc = pool_data; 2087 struct page *page; 2088 2089 if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) && 2090 likely(gfp_mask & __GFP_NORETRY)) 2091 return NULL; 2092 2093 page = alloc_page(gfp_mask); 2094 if (likely(page != NULL)) 2095 percpu_counter_add(&cc->n_allocated_pages, 1); 2096 2097 return page; 2098 } 2099 2100 static void crypt_page_free(void *page, void *pool_data) 2101 { 2102 struct crypt_config *cc = pool_data; 2103 2104 __free_page(page); 2105 percpu_counter_sub(&cc->n_allocated_pages, 1); 2106 } 2107 2108 static void crypt_dtr(struct dm_target *ti) 2109 { 2110 struct crypt_config *cc = ti->private; 2111 2112 ti->private = NULL; 2113 2114 if (!cc) 2115 return; 2116 2117 if (cc->write_thread) 2118 kthread_stop(cc->write_thread); 2119 2120 if (cc->io_queue) 2121 destroy_workqueue(cc->io_queue); 2122 if (cc->crypt_queue) 2123 destroy_workqueue(cc->crypt_queue); 2124 2125 crypt_free_tfms(cc); 2126 2127 bioset_exit(&cc->bs); 2128 2129 mempool_exit(&cc->page_pool); 2130 mempool_exit(&cc->req_pool); 2131 mempool_exit(&cc->tag_pool); 2132 2133 WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); 2134 percpu_counter_destroy(&cc->n_allocated_pages); 2135 2136 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 2137 cc->iv_gen_ops->dtr(cc); 2138 2139 if (cc->dev) 2140 dm_put_device(ti, cc->dev); 2141 2142 kzfree(cc->cipher_string); 2143 kzfree(cc->key_string); 2144 kzfree(cc->cipher_auth); 2145 kzfree(cc->authenc_key); 2146 2147 mutex_destroy(&cc->bio_alloc_lock); 2148 2149 /* Must zero key material before freeing */ 2150 kzfree(cc); 2151 2152 spin_lock(&dm_crypt_clients_lock); 2153 WARN_ON(!dm_crypt_clients_n); 2154 dm_crypt_clients_n--; 2155 crypt_calculate_pages_per_client(); 2156 spin_unlock(&dm_crypt_clients_lock); 2157 } 2158 2159 static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) 2160 { 2161 struct crypt_config *cc = ti->private; 2162 2163 if (crypt_integrity_aead(cc)) 2164 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2165 else 2166 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2167 2168 if (cc->iv_size) 2169 /* at least a 64 bit sector number should fit in our buffer */ 2170 cc->iv_size = max(cc->iv_size, 2171 (unsigned int)(sizeof(u64) / sizeof(u8))); 2172 else if (ivmode) { 2173 DMWARN("Selected cipher does not support IVs"); 2174 ivmode = NULL; 2175 } 2176 2177 /* Choose ivmode, see comments at iv code. */ 2178 if (ivmode == NULL) 2179 cc->iv_gen_ops = NULL; 2180 else if (strcmp(ivmode, "plain") == 0) 2181 cc->iv_gen_ops = &crypt_iv_plain_ops; 2182 else if (strcmp(ivmode, "plain64") == 0) 2183 cc->iv_gen_ops = &crypt_iv_plain64_ops; 2184 else if (strcmp(ivmode, "plain64be") == 0) 2185 cc->iv_gen_ops = &crypt_iv_plain64be_ops; 2186 else if (strcmp(ivmode, "essiv") == 0) 2187 cc->iv_gen_ops = &crypt_iv_essiv_ops; 2188 else if (strcmp(ivmode, "benbi") == 0) 2189 cc->iv_gen_ops = &crypt_iv_benbi_ops; 2190 else if (strcmp(ivmode, "null") == 0) 2191 cc->iv_gen_ops = &crypt_iv_null_ops; 2192 else if (strcmp(ivmode, "eboiv") == 0) 2193 cc->iv_gen_ops = &crypt_iv_eboiv_ops; 2194 else if (strcmp(ivmode, "lmk") == 0) { 2195 cc->iv_gen_ops = &crypt_iv_lmk_ops; 2196 /* 2197 * Version 2 and 3 is recognised according 2198 * to length of provided multi-key string. 2199 * If present (version 3), last key is used as IV seed. 2200 * All keys (including IV seed) are always the same size. 2201 */ 2202 if (cc->key_size % cc->key_parts) { 2203 cc->key_parts++; 2204 cc->key_extra_size = cc->key_size / cc->key_parts; 2205 } 2206 } else if (strcmp(ivmode, "tcw") == 0) { 2207 cc->iv_gen_ops = &crypt_iv_tcw_ops; 2208 cc->key_parts += 2; /* IV + whitening */ 2209 cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; 2210 } else if (strcmp(ivmode, "random") == 0) { 2211 cc->iv_gen_ops = &crypt_iv_random_ops; 2212 /* Need storage space in integrity fields. */ 2213 cc->integrity_iv_size = cc->iv_size; 2214 } else { 2215 ti->error = "Invalid IV mode"; 2216 return -EINVAL; 2217 } 2218 2219 return 0; 2220 } 2221 2222 /* 2223 * Workaround to parse HMAC algorithm from AEAD crypto API spec. 2224 * The HMAC is needed to calculate tag size (HMAC digest size). 2225 * This should be probably done by crypto-api calls (once available...) 2226 */ 2227 static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) 2228 { 2229 char *start, *end, *mac_alg = NULL; 2230 struct crypto_ahash *mac; 2231 2232 if (!strstarts(cipher_api, "authenc(")) 2233 return 0; 2234 2235 start = strchr(cipher_api, '('); 2236 end = strchr(cipher_api, ','); 2237 if (!start || !end || ++start > end) 2238 return -EINVAL; 2239 2240 mac_alg = kzalloc(end - start + 1, GFP_KERNEL); 2241 if (!mac_alg) 2242 return -ENOMEM; 2243 strncpy(mac_alg, start, end - start); 2244 2245 mac = crypto_alloc_ahash(mac_alg, 0, 0); 2246 kfree(mac_alg); 2247 2248 if (IS_ERR(mac)) 2249 return PTR_ERR(mac); 2250 2251 cc->key_mac_size = crypto_ahash_digestsize(mac); 2252 crypto_free_ahash(mac); 2253 2254 cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); 2255 if (!cc->authenc_key) 2256 return -ENOMEM; 2257 2258 return 0; 2259 } 2260 2261 static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, 2262 char **ivmode, char **ivopts) 2263 { 2264 struct crypt_config *cc = ti->private; 2265 char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME]; 2266 int ret = -EINVAL; 2267 2268 cc->tfms_count = 1; 2269 2270 /* 2271 * New format (capi: prefix) 2272 * capi:cipher_api_spec-iv:ivopts 2273 */ 2274 tmp = &cipher_in[strlen("capi:")]; 2275 2276 /* Separate IV options if present, it can contain another '-' in hash name */ 2277 *ivopts = strrchr(tmp, ':'); 2278 if (*ivopts) { 2279 **ivopts = '\0'; 2280 (*ivopts)++; 2281 } 2282 /* Parse IV mode */ 2283 *ivmode = strrchr(tmp, '-'); 2284 if (*ivmode) { 2285 **ivmode = '\0'; 2286 (*ivmode)++; 2287 } 2288 /* The rest is crypto API spec */ 2289 cipher_api = tmp; 2290 2291 /* Alloc AEAD, can be used only in new format. */ 2292 if (crypt_integrity_aead(cc)) { 2293 ret = crypt_ctr_auth_cipher(cc, cipher_api); 2294 if (ret < 0) { 2295 ti->error = "Invalid AEAD cipher spec"; 2296 return -ENOMEM; 2297 } 2298 } 2299 2300 if (*ivmode && !strcmp(*ivmode, "lmk")) 2301 cc->tfms_count = 64; 2302 2303 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2304 if (!*ivopts) { 2305 ti->error = "Digest algorithm missing for ESSIV mode"; 2306 return -EINVAL; 2307 } 2308 ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)", 2309 cipher_api, *ivopts); 2310 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2311 ti->error = "Cannot allocate cipher string"; 2312 return -ENOMEM; 2313 } 2314 cipher_api = buf; 2315 } 2316 2317 cc->key_parts = cc->tfms_count; 2318 2319 /* Allocate cipher */ 2320 ret = crypt_alloc_tfms(cc, cipher_api); 2321 if (ret < 0) { 2322 ti->error = "Error allocating crypto tfm"; 2323 return ret; 2324 } 2325 2326 if (crypt_integrity_aead(cc)) 2327 cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); 2328 else 2329 cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); 2330 2331 return 0; 2332 } 2333 2334 static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, 2335 char **ivmode, char **ivopts) 2336 { 2337 struct crypt_config *cc = ti->private; 2338 char *tmp, *cipher, *chainmode, *keycount; 2339 char *cipher_api = NULL; 2340 int ret = -EINVAL; 2341 char dummy; 2342 2343 if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { 2344 ti->error = "Bad cipher specification"; 2345 return -EINVAL; 2346 } 2347 2348 /* 2349 * Legacy dm-crypt cipher specification 2350 * cipher[:keycount]-mode-iv:ivopts 2351 */ 2352 tmp = cipher_in; 2353 keycount = strsep(&tmp, "-"); 2354 cipher = strsep(&keycount, ":"); 2355 2356 if (!keycount) 2357 cc->tfms_count = 1; 2358 else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || 2359 !is_power_of_2(cc->tfms_count)) { 2360 ti->error = "Bad cipher key count specification"; 2361 return -EINVAL; 2362 } 2363 cc->key_parts = cc->tfms_count; 2364 2365 chainmode = strsep(&tmp, "-"); 2366 *ivmode = strsep(&tmp, ":"); 2367 *ivopts = tmp; 2368 2369 /* 2370 * For compatibility with the original dm-crypt mapping format, if 2371 * only the cipher name is supplied, use cbc-plain. 2372 */ 2373 if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) { 2374 chainmode = "cbc"; 2375 *ivmode = "plain"; 2376 } 2377 2378 if (strcmp(chainmode, "ecb") && !*ivmode) { 2379 ti->error = "IV mechanism required"; 2380 return -EINVAL; 2381 } 2382 2383 cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); 2384 if (!cipher_api) 2385 goto bad_mem; 2386 2387 if (*ivmode && !strcmp(*ivmode, "essiv")) { 2388 if (!*ivopts) { 2389 ti->error = "Digest algorithm missing for ESSIV mode"; 2390 kfree(cipher_api); 2391 return -EINVAL; 2392 } 2393 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2394 "essiv(%s(%s),%s)", chainmode, cipher, *ivopts); 2395 } else { 2396 ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, 2397 "%s(%s)", chainmode, cipher); 2398 } 2399 if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) { 2400 kfree(cipher_api); 2401 goto bad_mem; 2402 } 2403 2404 /* Allocate cipher */ 2405 ret = crypt_alloc_tfms(cc, cipher_api); 2406 if (ret < 0) { 2407 ti->error = "Error allocating crypto tfm"; 2408 kfree(cipher_api); 2409 return ret; 2410 } 2411 kfree(cipher_api); 2412 2413 return 0; 2414 bad_mem: 2415 ti->error = "Cannot allocate cipher strings"; 2416 return -ENOMEM; 2417 } 2418 2419 static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) 2420 { 2421 struct crypt_config *cc = ti->private; 2422 char *ivmode = NULL, *ivopts = NULL; 2423 int ret; 2424 2425 cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); 2426 if (!cc->cipher_string) { 2427 ti->error = "Cannot allocate cipher strings"; 2428 return -ENOMEM; 2429 } 2430 2431 if (strstarts(cipher_in, "capi:")) 2432 ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); 2433 else 2434 ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); 2435 if (ret) 2436 return ret; 2437 2438 /* Initialize IV */ 2439 ret = crypt_ctr_ivmode(ti, ivmode); 2440 if (ret < 0) 2441 return ret; 2442 2443 /* Initialize and set key */ 2444 ret = crypt_set_key(cc, key); 2445 if (ret < 0) { 2446 ti->error = "Error decoding and setting key"; 2447 return ret; 2448 } 2449 2450 /* Allocate IV */ 2451 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { 2452 ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); 2453 if (ret < 0) { 2454 ti->error = "Error creating IV"; 2455 return ret; 2456 } 2457 } 2458 2459 /* Initialize IV (set keys for ESSIV etc) */ 2460 if (cc->iv_gen_ops && cc->iv_gen_ops->init) { 2461 ret = cc->iv_gen_ops->init(cc); 2462 if (ret < 0) { 2463 ti->error = "Error initialising IV"; 2464 return ret; 2465 } 2466 } 2467 2468 /* wipe the kernel key payload copy */ 2469 if (cc->key_string) 2470 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2471 2472 return ret; 2473 } 2474 2475 static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) 2476 { 2477 struct crypt_config *cc = ti->private; 2478 struct dm_arg_set as; 2479 static const struct dm_arg _args[] = { 2480 {0, 6, "Invalid number of feature args"}, 2481 }; 2482 unsigned int opt_params, val; 2483 const char *opt_string, *sval; 2484 char dummy; 2485 int ret; 2486 2487 /* Optional parameters */ 2488 as.argc = argc; 2489 as.argv = argv; 2490 2491 ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); 2492 if (ret) 2493 return ret; 2494 2495 while (opt_params--) { 2496 opt_string = dm_shift_arg(&as); 2497 if (!opt_string) { 2498 ti->error = "Not enough feature arguments"; 2499 return -EINVAL; 2500 } 2501 2502 if (!strcasecmp(opt_string, "allow_discards")) 2503 ti->num_discard_bios = 1; 2504 2505 else if (!strcasecmp(opt_string, "same_cpu_crypt")) 2506 set_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2507 2508 else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) 2509 set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2510 else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { 2511 if (val == 0 || val > MAX_TAG_SIZE) { 2512 ti->error = "Invalid integrity arguments"; 2513 return -EINVAL; 2514 } 2515 cc->on_disk_tag_size = val; 2516 sval = strchr(opt_string + strlen("integrity:"), ':') + 1; 2517 if (!strcasecmp(sval, "aead")) { 2518 set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); 2519 } else if (strcasecmp(sval, "none")) { 2520 ti->error = "Unknown integrity profile"; 2521 return -EINVAL; 2522 } 2523 2524 cc->cipher_auth = kstrdup(sval, GFP_KERNEL); 2525 if (!cc->cipher_auth) 2526 return -ENOMEM; 2527 } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { 2528 if (cc->sector_size < (1 << SECTOR_SHIFT) || 2529 cc->sector_size > 4096 || 2530 (cc->sector_size & (cc->sector_size - 1))) { 2531 ti->error = "Invalid feature value for sector_size"; 2532 return -EINVAL; 2533 } 2534 if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { 2535 ti->error = "Device size is not multiple of sector_size feature"; 2536 return -EINVAL; 2537 } 2538 cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; 2539 } else if (!strcasecmp(opt_string, "iv_large_sectors")) 2540 set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2541 else { 2542 ti->error = "Invalid feature arguments"; 2543 return -EINVAL; 2544 } 2545 } 2546 2547 return 0; 2548 } 2549 2550 /* 2551 * Construct an encryption mapping: 2552 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> 2553 */ 2554 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 2555 { 2556 struct crypt_config *cc; 2557 const char *devname = dm_table_device_name(ti->table); 2558 int key_size; 2559 unsigned int align_mask; 2560 unsigned long long tmpll; 2561 int ret; 2562 size_t iv_size_padding, additional_req_size; 2563 char dummy; 2564 2565 if (argc < 5) { 2566 ti->error = "Not enough arguments"; 2567 return -EINVAL; 2568 } 2569 2570 key_size = get_key_size(&argv[1]); 2571 if (key_size < 0) { 2572 ti->error = "Cannot parse key size"; 2573 return -EINVAL; 2574 } 2575 2576 cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL); 2577 if (!cc) { 2578 ti->error = "Cannot allocate encryption context"; 2579 return -ENOMEM; 2580 } 2581 cc->key_size = key_size; 2582 cc->sector_size = (1 << SECTOR_SHIFT); 2583 cc->sector_shift = 0; 2584 2585 ti->private = cc; 2586 2587 spin_lock(&dm_crypt_clients_lock); 2588 dm_crypt_clients_n++; 2589 crypt_calculate_pages_per_client(); 2590 spin_unlock(&dm_crypt_clients_lock); 2591 2592 ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); 2593 if (ret < 0) 2594 goto bad; 2595 2596 /* Optional parameters need to be read before cipher constructor */ 2597 if (argc > 5) { 2598 ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); 2599 if (ret) 2600 goto bad; 2601 } 2602 2603 ret = crypt_ctr_cipher(ti, argv[0], argv[1]); 2604 if (ret < 0) 2605 goto bad; 2606 2607 if (crypt_integrity_aead(cc)) { 2608 cc->dmreq_start = sizeof(struct aead_request); 2609 cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); 2610 align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); 2611 } else { 2612 cc->dmreq_start = sizeof(struct skcipher_request); 2613 cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); 2614 align_mask = crypto_skcipher_alignmask(any_tfm(cc)); 2615 } 2616 cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); 2617 2618 if (align_mask < CRYPTO_MINALIGN) { 2619 /* Allocate the padding exactly */ 2620 iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) 2621 & align_mask; 2622 } else { 2623 /* 2624 * If the cipher requires greater alignment than kmalloc 2625 * alignment, we don't know the exact position of the 2626 * initialization vector. We must assume worst case. 2627 */ 2628 iv_size_padding = align_mask; 2629 } 2630 2631 /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ 2632 additional_req_size = sizeof(struct dm_crypt_request) + 2633 iv_size_padding + cc->iv_size + 2634 cc->iv_size + 2635 sizeof(uint64_t) + 2636 sizeof(unsigned int); 2637 2638 ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); 2639 if (ret) { 2640 ti->error = "Cannot allocate crypt request mempool"; 2641 goto bad; 2642 } 2643 2644 cc->per_bio_data_size = ti->per_io_data_size = 2645 ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, 2646 ARCH_KMALLOC_MINALIGN); 2647 2648 ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc); 2649 if (ret) { 2650 ti->error = "Cannot allocate page mempool"; 2651 goto bad; 2652 } 2653 2654 ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); 2655 if (ret) { 2656 ti->error = "Cannot allocate crypt bioset"; 2657 goto bad; 2658 } 2659 2660 mutex_init(&cc->bio_alloc_lock); 2661 2662 ret = -EINVAL; 2663 if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || 2664 (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { 2665 ti->error = "Invalid iv_offset sector"; 2666 goto bad; 2667 } 2668 cc->iv_offset = tmpll; 2669 2670 ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); 2671 if (ret) { 2672 ti->error = "Device lookup failed"; 2673 goto bad; 2674 } 2675 2676 ret = -EINVAL; 2677 if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { 2678 ti->error = "Invalid device sector"; 2679 goto bad; 2680 } 2681 cc->start = tmpll; 2682 2683 if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { 2684 ret = crypt_integrity_ctr(cc, ti); 2685 if (ret) 2686 goto bad; 2687 2688 cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; 2689 if (!cc->tag_pool_max_sectors) 2690 cc->tag_pool_max_sectors = 1; 2691 2692 ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, 2693 cc->tag_pool_max_sectors * cc->on_disk_tag_size); 2694 if (ret) { 2695 ti->error = "Cannot allocate integrity tags mempool"; 2696 goto bad; 2697 } 2698 2699 cc->tag_pool_max_sectors <<= cc->sector_shift; 2700 } 2701 2702 ret = -ENOMEM; 2703 cc->io_queue = alloc_workqueue("kcryptd_io/%s", 2704 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 2705 1, devname); 2706 if (!cc->io_queue) { 2707 ti->error = "Couldn't create kcryptd io queue"; 2708 goto bad; 2709 } 2710 2711 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2712 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 2713 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 2714 1, devname); 2715 else 2716 cc->crypt_queue = alloc_workqueue("kcryptd/%s", 2717 WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, 2718 num_online_cpus(), devname); 2719 if (!cc->crypt_queue) { 2720 ti->error = "Couldn't create kcryptd queue"; 2721 goto bad; 2722 } 2723 2724 spin_lock_init(&cc->write_thread_lock); 2725 cc->write_tree = RB_ROOT; 2726 2727 cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname); 2728 if (IS_ERR(cc->write_thread)) { 2729 ret = PTR_ERR(cc->write_thread); 2730 cc->write_thread = NULL; 2731 ti->error = "Couldn't spawn write thread"; 2732 goto bad; 2733 } 2734 wake_up_process(cc->write_thread); 2735 2736 ti->num_flush_bios = 1; 2737 2738 return 0; 2739 2740 bad: 2741 crypt_dtr(ti); 2742 return ret; 2743 } 2744 2745 static int crypt_map(struct dm_target *ti, struct bio *bio) 2746 { 2747 struct dm_crypt_io *io; 2748 struct crypt_config *cc = ti->private; 2749 2750 /* 2751 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. 2752 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight 2753 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters 2754 */ 2755 if (unlikely(bio->bi_opf & REQ_PREFLUSH || 2756 bio_op(bio) == REQ_OP_DISCARD)) { 2757 bio_set_dev(bio, cc->dev->bdev); 2758 if (bio_sectors(bio)) 2759 bio->bi_iter.bi_sector = cc->start + 2760 dm_target_offset(ti, bio->bi_iter.bi_sector); 2761 return DM_MAPIO_REMAPPED; 2762 } 2763 2764 /* 2765 * Check if bio is too large, split as needed. 2766 */ 2767 if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && 2768 (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) 2769 dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); 2770 2771 /* 2772 * Ensure that bio is a multiple of internal sector encryption size 2773 * and is aligned to this size as defined in IO hints. 2774 */ 2775 if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) 2776 return DM_MAPIO_KILL; 2777 2778 if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) 2779 return DM_MAPIO_KILL; 2780 2781 io = dm_per_bio_data(bio, cc->per_bio_data_size); 2782 crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); 2783 2784 if (cc->on_disk_tag_size) { 2785 unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); 2786 2787 if (unlikely(tag_len > KMALLOC_MAX_SIZE) || 2788 unlikely(!(io->integrity_metadata = kmalloc(tag_len, 2789 GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { 2790 if (bio_sectors(bio) > cc->tag_pool_max_sectors) 2791 dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); 2792 io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); 2793 io->integrity_metadata_from_pool = true; 2794 } 2795 } 2796 2797 if (crypt_integrity_aead(cc)) 2798 io->ctx.r.req_aead = (struct aead_request *)(io + 1); 2799 else 2800 io->ctx.r.req = (struct skcipher_request *)(io + 1); 2801 2802 if (bio_data_dir(io->base_bio) == READ) { 2803 if (kcryptd_io_read(io, GFP_NOWAIT)) 2804 kcryptd_queue_read(io); 2805 } else 2806 kcryptd_queue_crypt(io); 2807 2808 return DM_MAPIO_SUBMITTED; 2809 } 2810 2811 static void crypt_status(struct dm_target *ti, status_type_t type, 2812 unsigned status_flags, char *result, unsigned maxlen) 2813 { 2814 struct crypt_config *cc = ti->private; 2815 unsigned i, sz = 0; 2816 int num_feature_args = 0; 2817 2818 switch (type) { 2819 case STATUSTYPE_INFO: 2820 result[0] = '\0'; 2821 break; 2822 2823 case STATUSTYPE_TABLE: 2824 DMEMIT("%s ", cc->cipher_string); 2825 2826 if (cc->key_size > 0) { 2827 if (cc->key_string) 2828 DMEMIT(":%u:%s", cc->key_size, cc->key_string); 2829 else 2830 for (i = 0; i < cc->key_size; i++) 2831 DMEMIT("%02x", cc->key[i]); 2832 } else 2833 DMEMIT("-"); 2834 2835 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 2836 cc->dev->name, (unsigned long long)cc->start); 2837 2838 num_feature_args += !!ti->num_discard_bios; 2839 num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); 2840 num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); 2841 num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); 2842 num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); 2843 if (cc->on_disk_tag_size) 2844 num_feature_args++; 2845 if (num_feature_args) { 2846 DMEMIT(" %d", num_feature_args); 2847 if (ti->num_discard_bios) 2848 DMEMIT(" allow_discards"); 2849 if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) 2850 DMEMIT(" same_cpu_crypt"); 2851 if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) 2852 DMEMIT(" submit_from_crypt_cpus"); 2853 if (cc->on_disk_tag_size) 2854 DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); 2855 if (cc->sector_size != (1 << SECTOR_SHIFT)) 2856 DMEMIT(" sector_size:%d", cc->sector_size); 2857 if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) 2858 DMEMIT(" iv_large_sectors"); 2859 } 2860 2861 break; 2862 } 2863 } 2864 2865 static void crypt_postsuspend(struct dm_target *ti) 2866 { 2867 struct crypt_config *cc = ti->private; 2868 2869 set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2870 } 2871 2872 static int crypt_preresume(struct dm_target *ti) 2873 { 2874 struct crypt_config *cc = ti->private; 2875 2876 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 2877 DMERR("aborting resume - crypt key is not set."); 2878 return -EAGAIN; 2879 } 2880 2881 return 0; 2882 } 2883 2884 static void crypt_resume(struct dm_target *ti) 2885 { 2886 struct crypt_config *cc = ti->private; 2887 2888 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 2889 } 2890 2891 /* Message interface 2892 * key set <key> 2893 * key wipe 2894 */ 2895 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv, 2896 char *result, unsigned maxlen) 2897 { 2898 struct crypt_config *cc = ti->private; 2899 int key_size, ret = -EINVAL; 2900 2901 if (argc < 2) 2902 goto error; 2903 2904 if (!strcasecmp(argv[0], "key")) { 2905 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 2906 DMWARN("not suspended during key manipulation."); 2907 return -EINVAL; 2908 } 2909 if (argc == 3 && !strcasecmp(argv[1], "set")) { 2910 /* The key size may not be changed. */ 2911 key_size = get_key_size(&argv[2]); 2912 if (key_size < 0 || cc->key_size != key_size) { 2913 memset(argv[2], '0', strlen(argv[2])); 2914 return -EINVAL; 2915 } 2916 2917 ret = crypt_set_key(cc, argv[2]); 2918 if (ret) 2919 return ret; 2920 if (cc->iv_gen_ops && cc->iv_gen_ops->init) 2921 ret = cc->iv_gen_ops->init(cc); 2922 /* wipe the kernel key payload copy */ 2923 if (cc->key_string) 2924 memset(cc->key, 0, cc->key_size * sizeof(u8)); 2925 return ret; 2926 } 2927 if (argc == 2 && !strcasecmp(argv[1], "wipe")) 2928 return crypt_wipe_key(cc); 2929 } 2930 2931 error: 2932 DMWARN("unrecognised message received."); 2933 return -EINVAL; 2934 } 2935 2936 static int crypt_iterate_devices(struct dm_target *ti, 2937 iterate_devices_callout_fn fn, void *data) 2938 { 2939 struct crypt_config *cc = ti->private; 2940 2941 return fn(ti, cc->dev, cc->start, ti->len, data); 2942 } 2943 2944 static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) 2945 { 2946 struct crypt_config *cc = ti->private; 2947 2948 /* 2949 * Unfortunate constraint that is required to avoid the potential 2950 * for exceeding underlying device's max_segments limits -- due to 2951 * crypt_alloc_buffer() possibly allocating pages for the encryption 2952 * bio that are not as physically contiguous as the original bio. 2953 */ 2954 limits->max_segment_size = PAGE_SIZE; 2955 2956 limits->logical_block_size = 2957 max_t(unsigned short, limits->logical_block_size, cc->sector_size); 2958 limits->physical_block_size = 2959 max_t(unsigned, limits->physical_block_size, cc->sector_size); 2960 limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); 2961 } 2962 2963 static struct target_type crypt_target = { 2964 .name = "crypt", 2965 .version = {1, 19, 0}, 2966 .module = THIS_MODULE, 2967 .ctr = crypt_ctr, 2968 .dtr = crypt_dtr, 2969 .map = crypt_map, 2970 .status = crypt_status, 2971 .postsuspend = crypt_postsuspend, 2972 .preresume = crypt_preresume, 2973 .resume = crypt_resume, 2974 .message = crypt_message, 2975 .iterate_devices = crypt_iterate_devices, 2976 .io_hints = crypt_io_hints, 2977 }; 2978 2979 static int __init dm_crypt_init(void) 2980 { 2981 int r; 2982 2983 r = dm_register_target(&crypt_target); 2984 if (r < 0) 2985 DMERR("register failed %d", r); 2986 2987 return r; 2988 } 2989 2990 static void __exit dm_crypt_exit(void) 2991 { 2992 dm_unregister_target(&crypt_target); 2993 } 2994 2995 module_init(dm_crypt_init); 2996 module_exit(dm_crypt_exit); 2997 2998 MODULE_AUTHOR("Jana Saout <jana@saout.de>"); 2999 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 3000 MODULE_LICENSE("GPL"); 3001