| 1 | /* |
| 2 | * Copyright (C) 2003 Jana Saout <jana@saout.de> |
| 3 | * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> |
| 4 | * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. |
| 5 | * Copyright (C) 2013 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/bio.h> |
| 16 | #include <linux/blkdev.h> |
| 17 | #include <linux/mempool.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/crypto.h> |
| 20 | #include <linux/workqueue.h> |
| 21 | #include <linux/kthread.h> |
| 22 | #include <linux/backing-dev.h> |
| 23 | #include <linux/atomic.h> |
| 24 | #include <linux/scatterlist.h> |
| 25 | #include <linux/rbtree.h> |
| 26 | #include <asm/page.h> |
| 27 | #include <asm/unaligned.h> |
| 28 | #include <crypto/hash.h> |
| 29 | #include <crypto/md5.h> |
| 30 | #include <crypto/algapi.h> |
| 31 | |
| 32 | #include <linux/device-mapper.h> |
| 33 | |
| 34 | #define DM_MSG_PREFIX "crypt" |
| 35 | |
| 36 | /* |
| 37 | * context holding the current state of a multi-part conversion |
| 38 | */ |
| 39 | struct convert_context { |
| 40 | struct completion restart; |
| 41 | struct bio *bio_in; |
| 42 | struct bio *bio_out; |
| 43 | struct bvec_iter iter_in; |
| 44 | struct bvec_iter iter_out; |
| 45 | sector_t cc_sector; |
| 46 | atomic_t cc_pending; |
| 47 | struct ablkcipher_request *req; |
| 48 | }; |
| 49 | |
| 50 | /* |
| 51 | * per bio private data |
| 52 | */ |
| 53 | struct dm_crypt_io { |
| 54 | struct crypt_config *cc; |
| 55 | struct bio *base_bio; |
| 56 | struct work_struct work; |
| 57 | |
| 58 | struct convert_context ctx; |
| 59 | |
| 60 | atomic_t io_pending; |
| 61 | int error; |
| 62 | sector_t sector; |
| 63 | |
| 64 | struct rb_node rb_node; |
| 65 | } CRYPTO_MINALIGN_ATTR; |
| 66 | |
| 67 | struct dm_crypt_request { |
| 68 | struct convert_context *ctx; |
| 69 | struct scatterlist sg_in; |
| 70 | struct scatterlist sg_out; |
| 71 | sector_t iv_sector; |
| 72 | }; |
| 73 | |
| 74 | struct crypt_config; |
| 75 | |
| 76 | struct crypt_iv_operations { |
| 77 | int (*ctr)(struct crypt_config *cc, struct dm_target *ti, |
| 78 | const char *opts); |
| 79 | void (*dtr)(struct crypt_config *cc); |
| 80 | int (*init)(struct crypt_config *cc); |
| 81 | int (*wipe)(struct crypt_config *cc); |
| 82 | int (*generator)(struct crypt_config *cc, u8 *iv, |
| 83 | struct dm_crypt_request *dmreq); |
| 84 | int (*post)(struct crypt_config *cc, u8 *iv, |
| 85 | struct dm_crypt_request *dmreq); |
| 86 | }; |
| 87 | |
| 88 | struct iv_essiv_private { |
| 89 | struct crypto_hash *hash_tfm; |
| 90 | u8 *salt; |
| 91 | }; |
| 92 | |
| 93 | struct iv_benbi_private { |
| 94 | int shift; |
| 95 | }; |
| 96 | |
| 97 | #define LMK_SEED_SIZE 64 /* hash + 0 */ |
| 98 | struct iv_lmk_private { |
| 99 | struct crypto_shash *hash_tfm; |
| 100 | u8 *seed; |
| 101 | }; |
| 102 | |
| 103 | #define TCW_WHITENING_SIZE 16 |
| 104 | struct iv_tcw_private { |
| 105 | struct crypto_shash *crc32_tfm; |
| 106 | u8 *iv_seed; |
| 107 | u8 *whitening; |
| 108 | }; |
| 109 | |
| 110 | /* |
| 111 | * Crypt: maps a linear range of a block device |
| 112 | * and encrypts / decrypts at the same time. |
| 113 | */ |
| 114 | enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID, |
| 115 | DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD }; |
| 116 | |
| 117 | /* |
| 118 | * The fields in here must be read only after initialization. |
| 119 | */ |
| 120 | struct crypt_config { |
| 121 | struct dm_dev *dev; |
| 122 | sector_t start; |
| 123 | |
| 124 | /* |
| 125 | * pool for per bio private data, crypto requests and |
| 126 | * encryption requeusts/buffer pages |
| 127 | */ |
| 128 | mempool_t *req_pool; |
| 129 | mempool_t *page_pool; |
| 130 | struct bio_set *bs; |
| 131 | struct mutex bio_alloc_lock; |
| 132 | |
| 133 | struct workqueue_struct *io_queue; |
| 134 | struct workqueue_struct *crypt_queue; |
| 135 | |
| 136 | struct task_struct *write_thread; |
| 137 | wait_queue_head_t write_thread_wait; |
| 138 | struct rb_root write_tree; |
| 139 | |
| 140 | char *cipher; |
| 141 | char *cipher_string; |
| 142 | |
| 143 | struct crypt_iv_operations *iv_gen_ops; |
| 144 | union { |
| 145 | struct iv_essiv_private essiv; |
| 146 | struct iv_benbi_private benbi; |
| 147 | struct iv_lmk_private lmk; |
| 148 | struct iv_tcw_private tcw; |
| 149 | } iv_gen_private; |
| 150 | sector_t iv_offset; |
| 151 | unsigned int iv_size; |
| 152 | |
| 153 | /* ESSIV: struct crypto_cipher *essiv_tfm */ |
| 154 | void *iv_private; |
| 155 | struct crypto_ablkcipher **tfms; |
| 156 | unsigned tfms_count; |
| 157 | |
| 158 | /* |
| 159 | * Layout of each crypto request: |
| 160 | * |
| 161 | * struct ablkcipher_request |
| 162 | * context |
| 163 | * padding |
| 164 | * struct dm_crypt_request |
| 165 | * padding |
| 166 | * IV |
| 167 | * |
| 168 | * The padding is added so that dm_crypt_request and the IV are |
| 169 | * correctly aligned. |
| 170 | */ |
| 171 | unsigned int dmreq_start; |
| 172 | |
| 173 | unsigned int per_bio_data_size; |
| 174 | |
| 175 | unsigned long flags; |
| 176 | unsigned int key_size; |
| 177 | unsigned int key_parts; /* independent parts in key buffer */ |
| 178 | unsigned int key_extra_size; /* additional keys length */ |
| 179 | u8 key[0]; |
| 180 | }; |
| 181 | |
| 182 | #define MIN_IOS 16 |
| 183 | |
| 184 | static void clone_init(struct dm_crypt_io *, struct bio *); |
| 185 | static void kcryptd_queue_crypt(struct dm_crypt_io *io); |
| 186 | static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq); |
| 187 | |
| 188 | /* |
| 189 | * Use this to access cipher attributes that are the same for each CPU. |
| 190 | */ |
| 191 | static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc) |
| 192 | { |
| 193 | return cc->tfms[0]; |
| 194 | } |
| 195 | |
| 196 | /* |
| 197 | * Different IV generation algorithms: |
| 198 | * |
| 199 | * plain: the initial vector is the 32-bit little-endian version of the sector |
| 200 | * number, padded with zeros if necessary. |
| 201 | * |
| 202 | * plain64: the initial vector is the 64-bit little-endian version of the sector |
| 203 | * number, padded with zeros if necessary. |
| 204 | * |
| 205 | * essiv: "encrypted sector|salt initial vector", the sector number is |
| 206 | * encrypted with the bulk cipher using a salt as key. The salt |
| 207 | * should be derived from the bulk cipher's key via hashing. |
| 208 | * |
| 209 | * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 |
| 210 | * (needed for LRW-32-AES and possible other narrow block modes) |
| 211 | * |
| 212 | * null: the initial vector is always zero. Provides compatibility with |
| 213 | * obsolete loop_fish2 devices. Do not use for new devices. |
| 214 | * |
| 215 | * lmk: Compatible implementation of the block chaining mode used |
| 216 | * by the Loop-AES block device encryption system |
| 217 | * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ |
| 218 | * It operates on full 512 byte sectors and uses CBC |
| 219 | * with an IV derived from the sector number, the data and |
| 220 | * optionally extra IV seed. |
| 221 | * This means that after decryption the first block |
| 222 | * of sector must be tweaked according to decrypted data. |
| 223 | * Loop-AES can use three encryption schemes: |
| 224 | * version 1: is plain aes-cbc mode |
| 225 | * version 2: uses 64 multikey scheme with lmk IV generator |
| 226 | * version 3: the same as version 2 with additional IV seed |
| 227 | * (it uses 65 keys, last key is used as IV seed) |
| 228 | * |
| 229 | * tcw: Compatible implementation of the block chaining mode used |
| 230 | * by the TrueCrypt device encryption system (prior to version 4.1). |
| 231 | * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat |
| 232 | * It operates on full 512 byte sectors and uses CBC |
| 233 | * with an IV derived from initial key and the sector number. |
| 234 | * In addition, whitening value is applied on every sector, whitening |
| 235 | * is calculated from initial key, sector number and mixed using CRC32. |
| 236 | * Note that this encryption scheme is vulnerable to watermarking attacks |
| 237 | * and should be used for old compatible containers access only. |
| 238 | * |
| 239 | * plumb: unimplemented, see: |
| 240 | * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 |
| 241 | */ |
| 242 | |
| 243 | static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, |
| 244 | struct dm_crypt_request *dmreq) |
| 245 | { |
| 246 | memset(iv, 0, cc->iv_size); |
| 247 | *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); |
| 248 | |
| 249 | return 0; |
| 250 | } |
| 251 | |
| 252 | static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, |
| 253 | struct dm_crypt_request *dmreq) |
| 254 | { |
| 255 | memset(iv, 0, cc->iv_size); |
| 256 | *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); |
| 257 | |
| 258 | return 0; |
| 259 | } |
| 260 | |
| 261 | /* Initialise ESSIV - compute salt but no local memory allocations */ |
| 262 | static int crypt_iv_essiv_init(struct crypt_config *cc) |
| 263 | { |
| 264 | struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; |
| 265 | struct hash_desc desc; |
| 266 | struct scatterlist sg; |
| 267 | struct crypto_cipher *essiv_tfm; |
| 268 | int err; |
| 269 | |
| 270 | sg_init_one(&sg, cc->key, cc->key_size); |
| 271 | desc.tfm = essiv->hash_tfm; |
| 272 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 273 | |
| 274 | err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt); |
| 275 | if (err) |
| 276 | return err; |
| 277 | |
| 278 | essiv_tfm = cc->iv_private; |
| 279 | |
| 280 | err = crypto_cipher_setkey(essiv_tfm, essiv->salt, |
| 281 | crypto_hash_digestsize(essiv->hash_tfm)); |
| 282 | if (err) |
| 283 | return err; |
| 284 | |
| 285 | return 0; |
| 286 | } |
| 287 | |
| 288 | /* Wipe salt and reset key derived from volume key */ |
| 289 | static int crypt_iv_essiv_wipe(struct crypt_config *cc) |
| 290 | { |
| 291 | struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; |
| 292 | unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm); |
| 293 | struct crypto_cipher *essiv_tfm; |
| 294 | int r, err = 0; |
| 295 | |
| 296 | memset(essiv->salt, 0, salt_size); |
| 297 | |
| 298 | essiv_tfm = cc->iv_private; |
| 299 | r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size); |
| 300 | if (r) |
| 301 | err = r; |
| 302 | |
| 303 | return err; |
| 304 | } |
| 305 | |
| 306 | /* Set up per cpu cipher state */ |
| 307 | static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc, |
| 308 | struct dm_target *ti, |
| 309 | u8 *salt, unsigned saltsize) |
| 310 | { |
| 311 | struct crypto_cipher *essiv_tfm; |
| 312 | int err; |
| 313 | |
| 314 | /* Setup the essiv_tfm with the given salt */ |
| 315 | essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
| 316 | if (IS_ERR(essiv_tfm)) { |
| 317 | ti->error = "Error allocating crypto tfm for ESSIV"; |
| 318 | return essiv_tfm; |
| 319 | } |
| 320 | |
| 321 | if (crypto_cipher_blocksize(essiv_tfm) != |
| 322 | crypto_ablkcipher_ivsize(any_tfm(cc))) { |
| 323 | ti->error = "Block size of ESSIV cipher does " |
| 324 | "not match IV size of block cipher"; |
| 325 | crypto_free_cipher(essiv_tfm); |
| 326 | return ERR_PTR(-EINVAL); |
| 327 | } |
| 328 | |
| 329 | err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); |
| 330 | if (err) { |
| 331 | ti->error = "Failed to set key for ESSIV cipher"; |
| 332 | crypto_free_cipher(essiv_tfm); |
| 333 | return ERR_PTR(err); |
| 334 | } |
| 335 | |
| 336 | return essiv_tfm; |
| 337 | } |
| 338 | |
| 339 | static void crypt_iv_essiv_dtr(struct crypt_config *cc) |
| 340 | { |
| 341 | struct crypto_cipher *essiv_tfm; |
| 342 | struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; |
| 343 | |
| 344 | crypto_free_hash(essiv->hash_tfm); |
| 345 | essiv->hash_tfm = NULL; |
| 346 | |
| 347 | kzfree(essiv->salt); |
| 348 | essiv->salt = NULL; |
| 349 | |
| 350 | essiv_tfm = cc->iv_private; |
| 351 | |
| 352 | if (essiv_tfm) |
| 353 | crypto_free_cipher(essiv_tfm); |
| 354 | |
| 355 | cc->iv_private = NULL; |
| 356 | } |
| 357 | |
| 358 | static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, |
| 359 | const char *opts) |
| 360 | { |
| 361 | struct crypto_cipher *essiv_tfm = NULL; |
| 362 | struct crypto_hash *hash_tfm = NULL; |
| 363 | u8 *salt = NULL; |
| 364 | int err; |
| 365 | |
| 366 | if (!opts) { |
| 367 | ti->error = "Digest algorithm missing for ESSIV mode"; |
| 368 | return -EINVAL; |
| 369 | } |
| 370 | |
| 371 | /* Allocate hash algorithm */ |
| 372 | hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); |
| 373 | if (IS_ERR(hash_tfm)) { |
| 374 | ti->error = "Error initializing ESSIV hash"; |
| 375 | err = PTR_ERR(hash_tfm); |
| 376 | goto bad; |
| 377 | } |
| 378 | |
| 379 | salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL); |
| 380 | if (!salt) { |
| 381 | ti->error = "Error kmallocing salt storage in ESSIV"; |
| 382 | err = -ENOMEM; |
| 383 | goto bad; |
| 384 | } |
| 385 | |
| 386 | cc->iv_gen_private.essiv.salt = salt; |
| 387 | cc->iv_gen_private.essiv.hash_tfm = hash_tfm; |
| 388 | |
| 389 | essiv_tfm = setup_essiv_cpu(cc, ti, salt, |
| 390 | crypto_hash_digestsize(hash_tfm)); |
| 391 | if (IS_ERR(essiv_tfm)) { |
| 392 | crypt_iv_essiv_dtr(cc); |
| 393 | return PTR_ERR(essiv_tfm); |
| 394 | } |
| 395 | cc->iv_private = essiv_tfm; |
| 396 | |
| 397 | return 0; |
| 398 | |
| 399 | bad: |
| 400 | if (hash_tfm && !IS_ERR(hash_tfm)) |
| 401 | crypto_free_hash(hash_tfm); |
| 402 | kfree(salt); |
| 403 | return err; |
| 404 | } |
| 405 | |
| 406 | static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, |
| 407 | struct dm_crypt_request *dmreq) |
| 408 | { |
| 409 | struct crypto_cipher *essiv_tfm = cc->iv_private; |
| 410 | |
| 411 | memset(iv, 0, cc->iv_size); |
| 412 | *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); |
| 413 | crypto_cipher_encrypt_one(essiv_tfm, iv, iv); |
| 414 | |
| 415 | return 0; |
| 416 | } |
| 417 | |
| 418 | static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, |
| 419 | const char *opts) |
| 420 | { |
| 421 | unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc)); |
| 422 | int log = ilog2(bs); |
| 423 | |
| 424 | /* we need to calculate how far we must shift the sector count |
| 425 | * to get the cipher block count, we use this shift in _gen */ |
| 426 | |
| 427 | if (1 << log != bs) { |
| 428 | ti->error = "cypher blocksize is not a power of 2"; |
| 429 | return -EINVAL; |
| 430 | } |
| 431 | |
| 432 | if (log > 9) { |
| 433 | ti->error = "cypher blocksize is > 512"; |
| 434 | return -EINVAL; |
| 435 | } |
| 436 | |
| 437 | cc->iv_gen_private.benbi.shift = 9 - log; |
| 438 | |
| 439 | return 0; |
| 440 | } |
| 441 | |
| 442 | static void crypt_iv_benbi_dtr(struct crypt_config *cc) |
| 443 | { |
| 444 | } |
| 445 | |
| 446 | static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, |
| 447 | struct dm_crypt_request *dmreq) |
| 448 | { |
| 449 | __be64 val; |
| 450 | |
| 451 | memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ |
| 452 | |
| 453 | val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); |
| 454 | put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); |
| 455 | |
| 456 | return 0; |
| 457 | } |
| 458 | |
| 459 | static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, |
| 460 | struct dm_crypt_request *dmreq) |
| 461 | { |
| 462 | memset(iv, 0, cc->iv_size); |
| 463 | |
| 464 | return 0; |
| 465 | } |
| 466 | |
| 467 | static void crypt_iv_lmk_dtr(struct crypt_config *cc) |
| 468 | { |
| 469 | struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| 470 | |
| 471 | if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) |
| 472 | crypto_free_shash(lmk->hash_tfm); |
| 473 | lmk->hash_tfm = NULL; |
| 474 | |
| 475 | kzfree(lmk->seed); |
| 476 | lmk->seed = NULL; |
| 477 | } |
| 478 | |
| 479 | static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, |
| 480 | const char *opts) |
| 481 | { |
| 482 | struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| 483 | |
| 484 | lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); |
| 485 | if (IS_ERR(lmk->hash_tfm)) { |
| 486 | ti->error = "Error initializing LMK hash"; |
| 487 | return PTR_ERR(lmk->hash_tfm); |
| 488 | } |
| 489 | |
| 490 | /* No seed in LMK version 2 */ |
| 491 | if (cc->key_parts == cc->tfms_count) { |
| 492 | lmk->seed = NULL; |
| 493 | return 0; |
| 494 | } |
| 495 | |
| 496 | lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); |
| 497 | if (!lmk->seed) { |
| 498 | crypt_iv_lmk_dtr(cc); |
| 499 | ti->error = "Error kmallocing seed storage in LMK"; |
| 500 | return -ENOMEM; |
| 501 | } |
| 502 | |
| 503 | return 0; |
| 504 | } |
| 505 | |
| 506 | static int crypt_iv_lmk_init(struct crypt_config *cc) |
| 507 | { |
| 508 | struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| 509 | int subkey_size = cc->key_size / cc->key_parts; |
| 510 | |
| 511 | /* LMK seed is on the position of LMK_KEYS + 1 key */ |
| 512 | if (lmk->seed) |
| 513 | memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), |
| 514 | crypto_shash_digestsize(lmk->hash_tfm)); |
| 515 | |
| 516 | return 0; |
| 517 | } |
| 518 | |
| 519 | static int crypt_iv_lmk_wipe(struct crypt_config *cc) |
| 520 | { |
| 521 | struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| 522 | |
| 523 | if (lmk->seed) |
| 524 | memset(lmk->seed, 0, LMK_SEED_SIZE); |
| 525 | |
| 526 | return 0; |
| 527 | } |
| 528 | |
| 529 | static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, |
| 530 | struct dm_crypt_request *dmreq, |
| 531 | u8 *data) |
| 532 | { |
| 533 | struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; |
| 534 | SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); |
| 535 | struct md5_state md5state; |
| 536 | __le32 buf[4]; |
| 537 | int i, r; |
| 538 | |
| 539 | desc->tfm = lmk->hash_tfm; |
| 540 | desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 541 | |
| 542 | r = crypto_shash_init(desc); |
| 543 | if (r) |
| 544 | return r; |
| 545 | |
| 546 | if (lmk->seed) { |
| 547 | r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE); |
| 548 | if (r) |
| 549 | return r; |
| 550 | } |
| 551 | |
| 552 | /* Sector is always 512B, block size 16, add data of blocks 1-31 */ |
| 553 | r = crypto_shash_update(desc, data + 16, 16 * 31); |
| 554 | if (r) |
| 555 | return r; |
| 556 | |
| 557 | /* Sector is cropped to 56 bits here */ |
| 558 | buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); |
| 559 | buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); |
| 560 | buf[2] = cpu_to_le32(4024); |
| 561 | buf[3] = 0; |
| 562 | r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf)); |
| 563 | if (r) |
| 564 | return r; |
| 565 | |
| 566 | /* No MD5 padding here */ |
| 567 | r = crypto_shash_export(desc, &md5state); |
| 568 | if (r) |
| 569 | return r; |
| 570 | |
| 571 | for (i = 0; i < MD5_HASH_WORDS; i++) |
| 572 | __cpu_to_le32s(&md5state.hash[i]); |
| 573 | memcpy(iv, &md5state.hash, cc->iv_size); |
| 574 | |
| 575 | return 0; |
| 576 | } |
| 577 | |
| 578 | static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, |
| 579 | struct dm_crypt_request *dmreq) |
| 580 | { |
| 581 | u8 *src; |
| 582 | int r = 0; |
| 583 | |
| 584 | if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { |
| 585 | src = kmap_atomic(sg_page(&dmreq->sg_in)); |
| 586 | r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset); |
| 587 | kunmap_atomic(src); |
| 588 | } else |
| 589 | memset(iv, 0, cc->iv_size); |
| 590 | |
| 591 | return r; |
| 592 | } |
| 593 | |
| 594 | static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, |
| 595 | struct dm_crypt_request *dmreq) |
| 596 | { |
| 597 | u8 *dst; |
| 598 | int r; |
| 599 | |
| 600 | if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) |
| 601 | return 0; |
| 602 | |
| 603 | dst = kmap_atomic(sg_page(&dmreq->sg_out)); |
| 604 | r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset); |
| 605 | |
| 606 | /* Tweak the first block of plaintext sector */ |
| 607 | if (!r) |
| 608 | crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size); |
| 609 | |
| 610 | kunmap_atomic(dst); |
| 611 | return r; |
| 612 | } |
| 613 | |
| 614 | static void crypt_iv_tcw_dtr(struct crypt_config *cc) |
| 615 | { |
| 616 | struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; |
| 617 | |
| 618 | kzfree(tcw->iv_seed); |
| 619 | tcw->iv_seed = NULL; |
| 620 | kzfree(tcw->whitening); |
| 621 | tcw->whitening = NULL; |
| 622 | |
| 623 | if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) |
| 624 | crypto_free_shash(tcw->crc32_tfm); |
| 625 | tcw->crc32_tfm = NULL; |
| 626 | } |
| 627 | |
| 628 | static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, |
| 629 | const char *opts) |
| 630 | { |
| 631 | struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; |
| 632 | |
| 633 | if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { |
| 634 | ti->error = "Wrong key size for TCW"; |
| 635 | return -EINVAL; |
| 636 | } |
| 637 | |
| 638 | tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); |
| 639 | if (IS_ERR(tcw->crc32_tfm)) { |
| 640 | ti->error = "Error initializing CRC32 in TCW"; |
| 641 | return PTR_ERR(tcw->crc32_tfm); |
| 642 | } |
| 643 | |
| 644 | tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); |
| 645 | tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); |
| 646 | if (!tcw->iv_seed || !tcw->whitening) { |
| 647 | crypt_iv_tcw_dtr(cc); |
| 648 | ti->error = "Error allocating seed storage in TCW"; |
| 649 | return -ENOMEM; |
| 650 | } |
| 651 | |
| 652 | return 0; |
| 653 | } |
| 654 | |
| 655 | static int crypt_iv_tcw_init(struct crypt_config *cc) |
| 656 | { |
| 657 | struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; |
| 658 | int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; |
| 659 | |
| 660 | memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); |
| 661 | memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], |
| 662 | TCW_WHITENING_SIZE); |
| 663 | |
| 664 | return 0; |
| 665 | } |
| 666 | |
| 667 | static int crypt_iv_tcw_wipe(struct crypt_config *cc) |
| 668 | { |
| 669 | struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; |
| 670 | |
| 671 | memset(tcw->iv_seed, 0, cc->iv_size); |
| 672 | memset(tcw->whitening, 0, TCW_WHITENING_SIZE); |
| 673 | |
| 674 | return 0; |
| 675 | } |
| 676 | |
| 677 | static int crypt_iv_tcw_whitening(struct crypt_config *cc, |
| 678 | struct dm_crypt_request *dmreq, |
| 679 | u8 *data) |
| 680 | { |
| 681 | struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; |
| 682 | u64 sector = cpu_to_le64((u64)dmreq->iv_sector); |
| 683 | u8 buf[TCW_WHITENING_SIZE]; |
| 684 | SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); |
| 685 | int i, r; |
| 686 | |
| 687 | /* xor whitening with sector number */ |
| 688 | memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE); |
| 689 | crypto_xor(buf, (u8 *)§or, 8); |
| 690 | crypto_xor(&buf[8], (u8 *)§or, 8); |
| 691 | |
| 692 | /* calculate crc32 for every 32bit part and xor it */ |
| 693 | desc->tfm = tcw->crc32_tfm; |
| 694 | desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 695 | for (i = 0; i < 4; i++) { |
| 696 | r = crypto_shash_init(desc); |
| 697 | if (r) |
| 698 | goto out; |
| 699 | r = crypto_shash_update(desc, &buf[i * 4], 4); |
| 700 | if (r) |
| 701 | goto out; |
| 702 | r = crypto_shash_final(desc, &buf[i * 4]); |
| 703 | if (r) |
| 704 | goto out; |
| 705 | } |
| 706 | crypto_xor(&buf[0], &buf[12], 4); |
| 707 | crypto_xor(&buf[4], &buf[8], 4); |
| 708 | |
| 709 | /* apply whitening (8 bytes) to whole sector */ |
| 710 | for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) |
| 711 | crypto_xor(data + i * 8, buf, 8); |
| 712 | out: |
| 713 | memzero_explicit(buf, sizeof(buf)); |
| 714 | return r; |
| 715 | } |
| 716 | |
| 717 | static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, |
| 718 | struct dm_crypt_request *dmreq) |
| 719 | { |
| 720 | struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; |
| 721 | u64 sector = cpu_to_le64((u64)dmreq->iv_sector); |
| 722 | u8 *src; |
| 723 | int r = 0; |
| 724 | |
| 725 | /* Remove whitening from ciphertext */ |
| 726 | if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { |
| 727 | src = kmap_atomic(sg_page(&dmreq->sg_in)); |
| 728 | r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset); |
| 729 | kunmap_atomic(src); |
| 730 | } |
| 731 | |
| 732 | /* Calculate IV */ |
| 733 | memcpy(iv, tcw->iv_seed, cc->iv_size); |
| 734 | crypto_xor(iv, (u8 *)§or, 8); |
| 735 | if (cc->iv_size > 8) |
| 736 | crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8); |
| 737 | |
| 738 | return r; |
| 739 | } |
| 740 | |
| 741 | static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, |
| 742 | struct dm_crypt_request *dmreq) |
| 743 | { |
| 744 | u8 *dst; |
| 745 | int r; |
| 746 | |
| 747 | if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) |
| 748 | return 0; |
| 749 | |
| 750 | /* Apply whitening on ciphertext */ |
| 751 | dst = kmap_atomic(sg_page(&dmreq->sg_out)); |
| 752 | r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset); |
| 753 | kunmap_atomic(dst); |
| 754 | |
| 755 | return r; |
| 756 | } |
| 757 | |
| 758 | static struct crypt_iv_operations crypt_iv_plain_ops = { |
| 759 | .generator = crypt_iv_plain_gen |
| 760 | }; |
| 761 | |
| 762 | static struct crypt_iv_operations crypt_iv_plain64_ops = { |
| 763 | .generator = crypt_iv_plain64_gen |
| 764 | }; |
| 765 | |
| 766 | static struct crypt_iv_operations crypt_iv_essiv_ops = { |
| 767 | .ctr = crypt_iv_essiv_ctr, |
| 768 | .dtr = crypt_iv_essiv_dtr, |
| 769 | .init = crypt_iv_essiv_init, |
| 770 | .wipe = crypt_iv_essiv_wipe, |
| 771 | .generator = crypt_iv_essiv_gen |
| 772 | }; |
| 773 | |
| 774 | static struct crypt_iv_operations crypt_iv_benbi_ops = { |
| 775 | .ctr = crypt_iv_benbi_ctr, |
| 776 | .dtr = crypt_iv_benbi_dtr, |
| 777 | .generator = crypt_iv_benbi_gen |
| 778 | }; |
| 779 | |
| 780 | static struct crypt_iv_operations crypt_iv_null_ops = { |
| 781 | .generator = crypt_iv_null_gen |
| 782 | }; |
| 783 | |
| 784 | static struct crypt_iv_operations crypt_iv_lmk_ops = { |
| 785 | .ctr = crypt_iv_lmk_ctr, |
| 786 | .dtr = crypt_iv_lmk_dtr, |
| 787 | .init = crypt_iv_lmk_init, |
| 788 | .wipe = crypt_iv_lmk_wipe, |
| 789 | .generator = crypt_iv_lmk_gen, |
| 790 | .post = crypt_iv_lmk_post |
| 791 | }; |
| 792 | |
| 793 | static struct crypt_iv_operations crypt_iv_tcw_ops = { |
| 794 | .ctr = crypt_iv_tcw_ctr, |
| 795 | .dtr = crypt_iv_tcw_dtr, |
| 796 | .init = crypt_iv_tcw_init, |
| 797 | .wipe = crypt_iv_tcw_wipe, |
| 798 | .generator = crypt_iv_tcw_gen, |
| 799 | .post = crypt_iv_tcw_post |
| 800 | }; |
| 801 | |
| 802 | static void crypt_convert_init(struct crypt_config *cc, |
| 803 | struct convert_context *ctx, |
| 804 | struct bio *bio_out, struct bio *bio_in, |
| 805 | sector_t sector) |
| 806 | { |
| 807 | ctx->bio_in = bio_in; |
| 808 | ctx->bio_out = bio_out; |
| 809 | if (bio_in) |
| 810 | ctx->iter_in = bio_in->bi_iter; |
| 811 | if (bio_out) |
| 812 | ctx->iter_out = bio_out->bi_iter; |
| 813 | ctx->cc_sector = sector + cc->iv_offset; |
| 814 | init_completion(&ctx->restart); |
| 815 | } |
| 816 | |
| 817 | static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, |
| 818 | struct ablkcipher_request *req) |
| 819 | { |
| 820 | return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); |
| 821 | } |
| 822 | |
| 823 | static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc, |
| 824 | struct dm_crypt_request *dmreq) |
| 825 | { |
| 826 | return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start); |
| 827 | } |
| 828 | |
| 829 | static u8 *iv_of_dmreq(struct crypt_config *cc, |
| 830 | struct dm_crypt_request *dmreq) |
| 831 | { |
| 832 | return (u8 *)ALIGN((unsigned long)(dmreq + 1), |
| 833 | crypto_ablkcipher_alignmask(any_tfm(cc)) + 1); |
| 834 | } |
| 835 | |
| 836 | static int crypt_convert_block(struct crypt_config *cc, |
| 837 | struct convert_context *ctx, |
| 838 | struct ablkcipher_request *req) |
| 839 | { |
| 840 | struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); |
| 841 | struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); |
| 842 | struct dm_crypt_request *dmreq; |
| 843 | u8 *iv; |
| 844 | int r; |
| 845 | |
| 846 | dmreq = dmreq_of_req(cc, req); |
| 847 | iv = iv_of_dmreq(cc, dmreq); |
| 848 | |
| 849 | dmreq->iv_sector = ctx->cc_sector; |
| 850 | dmreq->ctx = ctx; |
| 851 | sg_init_table(&dmreq->sg_in, 1); |
| 852 | sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT, |
| 853 | bv_in.bv_offset); |
| 854 | |
| 855 | sg_init_table(&dmreq->sg_out, 1); |
| 856 | sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT, |
| 857 | bv_out.bv_offset); |
| 858 | |
| 859 | bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT); |
| 860 | bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT); |
| 861 | |
| 862 | if (cc->iv_gen_ops) { |
| 863 | r = cc->iv_gen_ops->generator(cc, iv, dmreq); |
| 864 | if (r < 0) |
| 865 | return r; |
| 866 | } |
| 867 | |
| 868 | ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out, |
| 869 | 1 << SECTOR_SHIFT, iv); |
| 870 | |
| 871 | if (bio_data_dir(ctx->bio_in) == WRITE) |
| 872 | r = crypto_ablkcipher_encrypt(req); |
| 873 | else |
| 874 | r = crypto_ablkcipher_decrypt(req); |
| 875 | |
| 876 | if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) |
| 877 | r = cc->iv_gen_ops->post(cc, iv, dmreq); |
| 878 | |
| 879 | return r; |
| 880 | } |
| 881 | |
| 882 | static void kcryptd_async_done(struct crypto_async_request *async_req, |
| 883 | int error); |
| 884 | |
| 885 | static void crypt_alloc_req(struct crypt_config *cc, |
| 886 | struct convert_context *ctx) |
| 887 | { |
| 888 | unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); |
| 889 | |
| 890 | if (!ctx->req) |
| 891 | ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO); |
| 892 | |
| 893 | ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]); |
| 894 | ablkcipher_request_set_callback(ctx->req, |
| 895 | CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, |
| 896 | kcryptd_async_done, dmreq_of_req(cc, ctx->req)); |
| 897 | } |
| 898 | |
| 899 | static void crypt_free_req(struct crypt_config *cc, |
| 900 | struct ablkcipher_request *req, struct bio *base_bio) |
| 901 | { |
| 902 | struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); |
| 903 | |
| 904 | if ((struct ablkcipher_request *)(io + 1) != req) |
| 905 | mempool_free(req, cc->req_pool); |
| 906 | } |
| 907 | |
| 908 | /* |
| 909 | * Encrypt / decrypt data from one bio to another one (can be the same one) |
| 910 | */ |
| 911 | static int crypt_convert(struct crypt_config *cc, |
| 912 | struct convert_context *ctx) |
| 913 | { |
| 914 | int r; |
| 915 | |
| 916 | atomic_set(&ctx->cc_pending, 1); |
| 917 | |
| 918 | while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { |
| 919 | |
| 920 | crypt_alloc_req(cc, ctx); |
| 921 | |
| 922 | atomic_inc(&ctx->cc_pending); |
| 923 | |
| 924 | r = crypt_convert_block(cc, ctx, ctx->req); |
| 925 | |
| 926 | switch (r) { |
| 927 | /* async */ |
| 928 | case -EINPROGRESS: |
| 929 | case -EBUSY: |
| 930 | wait_for_completion(&ctx->restart); |
| 931 | reinit_completion(&ctx->restart); |
| 932 | ctx->req = NULL; |
| 933 | ctx->cc_sector++; |
| 934 | continue; |
| 935 | |
| 936 | /* sync */ |
| 937 | case 0: |
| 938 | atomic_dec(&ctx->cc_pending); |
| 939 | ctx->cc_sector++; |
| 940 | cond_resched(); |
| 941 | continue; |
| 942 | |
| 943 | /* error */ |
| 944 | default: |
| 945 | atomic_dec(&ctx->cc_pending); |
| 946 | return r; |
| 947 | } |
| 948 | } |
| 949 | |
| 950 | return 0; |
| 951 | } |
| 952 | |
| 953 | static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); |
| 954 | |
| 955 | /* |
| 956 | * Generate a new unfragmented bio with the given size |
| 957 | * This should never violate the device limitations |
| 958 | * |
| 959 | * This function may be called concurrently. If we allocate from the mempool |
| 960 | * concurrently, there is a possibility of deadlock. For example, if we have |
| 961 | * mempool of 256 pages, two processes, each wanting 256, pages allocate from |
| 962 | * the mempool concurrently, it may deadlock in a situation where both processes |
| 963 | * have allocated 128 pages and the mempool is exhausted. |
| 964 | * |
| 965 | * In order to avoid this scenario we allocate the pages under a mutex. |
| 966 | * |
| 967 | * In order to not degrade performance with excessive locking, we try |
| 968 | * non-blocking allocations without a mutex first but on failure we fallback |
| 969 | * to blocking allocations with a mutex. |
| 970 | */ |
| 971 | static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) |
| 972 | { |
| 973 | struct crypt_config *cc = io->cc; |
| 974 | struct bio *clone; |
| 975 | unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 976 | gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; |
| 977 | unsigned i, len, remaining_size; |
| 978 | struct page *page; |
| 979 | struct bio_vec *bvec; |
| 980 | |
| 981 | retry: |
| 982 | if (unlikely(gfp_mask & __GFP_WAIT)) |
| 983 | mutex_lock(&cc->bio_alloc_lock); |
| 984 | |
| 985 | clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); |
| 986 | if (!clone) |
| 987 | goto return_clone; |
| 988 | |
| 989 | clone_init(io, clone); |
| 990 | |
| 991 | remaining_size = size; |
| 992 | |
| 993 | for (i = 0; i < nr_iovecs; i++) { |
| 994 | page = mempool_alloc(cc->page_pool, gfp_mask); |
| 995 | if (!page) { |
| 996 | crypt_free_buffer_pages(cc, clone); |
| 997 | bio_put(clone); |
| 998 | gfp_mask |= __GFP_WAIT; |
| 999 | goto retry; |
| 1000 | } |
| 1001 | |
| 1002 | len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; |
| 1003 | |
| 1004 | bvec = &clone->bi_io_vec[clone->bi_vcnt++]; |
| 1005 | bvec->bv_page = page; |
| 1006 | bvec->bv_len = len; |
| 1007 | bvec->bv_offset = 0; |
| 1008 | |
| 1009 | clone->bi_iter.bi_size += len; |
| 1010 | |
| 1011 | remaining_size -= len; |
| 1012 | } |
| 1013 | |
| 1014 | return_clone: |
| 1015 | if (unlikely(gfp_mask & __GFP_WAIT)) |
| 1016 | mutex_unlock(&cc->bio_alloc_lock); |
| 1017 | |
| 1018 | return clone; |
| 1019 | } |
| 1020 | |
| 1021 | static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) |
| 1022 | { |
| 1023 | unsigned int i; |
| 1024 | struct bio_vec *bv; |
| 1025 | |
| 1026 | bio_for_each_segment_all(bv, clone, i) { |
| 1027 | BUG_ON(!bv->bv_page); |
| 1028 | mempool_free(bv->bv_page, cc->page_pool); |
| 1029 | bv->bv_page = NULL; |
| 1030 | } |
| 1031 | } |
| 1032 | |
| 1033 | static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, |
| 1034 | struct bio *bio, sector_t sector) |
| 1035 | { |
| 1036 | io->cc = cc; |
| 1037 | io->base_bio = bio; |
| 1038 | io->sector = sector; |
| 1039 | io->error = 0; |
| 1040 | io->ctx.req = NULL; |
| 1041 | atomic_set(&io->io_pending, 0); |
| 1042 | } |
| 1043 | |
| 1044 | static void crypt_inc_pending(struct dm_crypt_io *io) |
| 1045 | { |
| 1046 | atomic_inc(&io->io_pending); |
| 1047 | } |
| 1048 | |
| 1049 | /* |
| 1050 | * One of the bios was finished. Check for completion of |
| 1051 | * the whole request and correctly clean up the buffer. |
| 1052 | */ |
| 1053 | static void crypt_dec_pending(struct dm_crypt_io *io) |
| 1054 | { |
| 1055 | struct crypt_config *cc = io->cc; |
| 1056 | struct bio *base_bio = io->base_bio; |
| 1057 | int error = io->error; |
| 1058 | |
| 1059 | if (!atomic_dec_and_test(&io->io_pending)) |
| 1060 | return; |
| 1061 | |
| 1062 | if (io->ctx.req) |
| 1063 | crypt_free_req(cc, io->ctx.req, base_bio); |
| 1064 | |
| 1065 | bio_endio(base_bio, error); |
| 1066 | } |
| 1067 | |
| 1068 | /* |
| 1069 | * kcryptd/kcryptd_io: |
| 1070 | * |
| 1071 | * Needed because it would be very unwise to do decryption in an |
| 1072 | * interrupt context. |
| 1073 | * |
| 1074 | * kcryptd performs the actual encryption or decryption. |
| 1075 | * |
| 1076 | * kcryptd_io performs the IO submission. |
| 1077 | * |
| 1078 | * They must be separated as otherwise the final stages could be |
| 1079 | * starved by new requests which can block in the first stages due |
| 1080 | * to memory allocation. |
| 1081 | * |
| 1082 | * The work is done per CPU global for all dm-crypt instances. |
| 1083 | * They should not depend on each other and do not block. |
| 1084 | */ |
| 1085 | static void crypt_endio(struct bio *clone, int error) |
| 1086 | { |
| 1087 | struct dm_crypt_io *io = clone->bi_private; |
| 1088 | struct crypt_config *cc = io->cc; |
| 1089 | unsigned rw = bio_data_dir(clone); |
| 1090 | |
| 1091 | if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) |
| 1092 | error = -EIO; |
| 1093 | |
| 1094 | /* |
| 1095 | * free the processed pages |
| 1096 | */ |
| 1097 | if (rw == WRITE) |
| 1098 | crypt_free_buffer_pages(cc, clone); |
| 1099 | |
| 1100 | bio_put(clone); |
| 1101 | |
| 1102 | if (rw == READ && !error) { |
| 1103 | kcryptd_queue_crypt(io); |
| 1104 | return; |
| 1105 | } |
| 1106 | |
| 1107 | if (unlikely(error)) |
| 1108 | io->error = error; |
| 1109 | |
| 1110 | crypt_dec_pending(io); |
| 1111 | } |
| 1112 | |
| 1113 | static void clone_init(struct dm_crypt_io *io, struct bio *clone) |
| 1114 | { |
| 1115 | struct crypt_config *cc = io->cc; |
| 1116 | |
| 1117 | clone->bi_private = io; |
| 1118 | clone->bi_end_io = crypt_endio; |
| 1119 | clone->bi_bdev = cc->dev->bdev; |
| 1120 | clone->bi_rw = io->base_bio->bi_rw; |
| 1121 | } |
| 1122 | |
| 1123 | static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) |
| 1124 | { |
| 1125 | struct crypt_config *cc = io->cc; |
| 1126 | struct bio *clone; |
| 1127 | |
| 1128 | /* |
| 1129 | * We need the original biovec array in order to decrypt |
| 1130 | * the whole bio data *afterwards* -- thanks to immutable |
| 1131 | * biovecs we don't need to worry about the block layer |
| 1132 | * modifying the biovec array; so leverage bio_clone_fast(). |
| 1133 | */ |
| 1134 | clone = bio_clone_fast(io->base_bio, gfp, cc->bs); |
| 1135 | if (!clone) |
| 1136 | return 1; |
| 1137 | |
| 1138 | crypt_inc_pending(io); |
| 1139 | |
| 1140 | clone_init(io, clone); |
| 1141 | clone->bi_iter.bi_sector = cc->start + io->sector; |
| 1142 | |
| 1143 | generic_make_request(clone); |
| 1144 | return 0; |
| 1145 | } |
| 1146 | |
| 1147 | static void kcryptd_io_read_work(struct work_struct *work) |
| 1148 | { |
| 1149 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
| 1150 | |
| 1151 | crypt_inc_pending(io); |
| 1152 | if (kcryptd_io_read(io, GFP_NOIO)) |
| 1153 | io->error = -ENOMEM; |
| 1154 | crypt_dec_pending(io); |
| 1155 | } |
| 1156 | |
| 1157 | static void kcryptd_queue_read(struct dm_crypt_io *io) |
| 1158 | { |
| 1159 | struct crypt_config *cc = io->cc; |
| 1160 | |
| 1161 | INIT_WORK(&io->work, kcryptd_io_read_work); |
| 1162 | queue_work(cc->io_queue, &io->work); |
| 1163 | } |
| 1164 | |
| 1165 | static void kcryptd_io_write(struct dm_crypt_io *io) |
| 1166 | { |
| 1167 | struct bio *clone = io->ctx.bio_out; |
| 1168 | |
| 1169 | generic_make_request(clone); |
| 1170 | } |
| 1171 | |
| 1172 | #define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) |
| 1173 | |
| 1174 | static int dmcrypt_write(void *data) |
| 1175 | { |
| 1176 | struct crypt_config *cc = data; |
| 1177 | struct dm_crypt_io *io; |
| 1178 | |
| 1179 | while (1) { |
| 1180 | struct rb_root write_tree; |
| 1181 | struct blk_plug plug; |
| 1182 | |
| 1183 | DECLARE_WAITQUEUE(wait, current); |
| 1184 | |
| 1185 | spin_lock_irq(&cc->write_thread_wait.lock); |
| 1186 | continue_locked: |
| 1187 | |
| 1188 | if (!RB_EMPTY_ROOT(&cc->write_tree)) |
| 1189 | goto pop_from_list; |
| 1190 | |
| 1191 | __set_current_state(TASK_INTERRUPTIBLE); |
| 1192 | __add_wait_queue(&cc->write_thread_wait, &wait); |
| 1193 | |
| 1194 | spin_unlock_irq(&cc->write_thread_wait.lock); |
| 1195 | |
| 1196 | if (unlikely(kthread_should_stop())) { |
| 1197 | set_task_state(current, TASK_RUNNING); |
| 1198 | remove_wait_queue(&cc->write_thread_wait, &wait); |
| 1199 | break; |
| 1200 | } |
| 1201 | |
| 1202 | schedule(); |
| 1203 | |
| 1204 | set_task_state(current, TASK_RUNNING); |
| 1205 | spin_lock_irq(&cc->write_thread_wait.lock); |
| 1206 | __remove_wait_queue(&cc->write_thread_wait, &wait); |
| 1207 | goto continue_locked; |
| 1208 | |
| 1209 | pop_from_list: |
| 1210 | write_tree = cc->write_tree; |
| 1211 | cc->write_tree = RB_ROOT; |
| 1212 | spin_unlock_irq(&cc->write_thread_wait.lock); |
| 1213 | |
| 1214 | BUG_ON(rb_parent(write_tree.rb_node)); |
| 1215 | |
| 1216 | /* |
| 1217 | * Note: we cannot walk the tree here with rb_next because |
| 1218 | * the structures may be freed when kcryptd_io_write is called. |
| 1219 | */ |
| 1220 | blk_start_plug(&plug); |
| 1221 | do { |
| 1222 | io = crypt_io_from_node(rb_first(&write_tree)); |
| 1223 | rb_erase(&io->rb_node, &write_tree); |
| 1224 | kcryptd_io_write(io); |
| 1225 | } while (!RB_EMPTY_ROOT(&write_tree)); |
| 1226 | blk_finish_plug(&plug); |
| 1227 | } |
| 1228 | return 0; |
| 1229 | } |
| 1230 | |
| 1231 | static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) |
| 1232 | { |
| 1233 | struct bio *clone = io->ctx.bio_out; |
| 1234 | struct crypt_config *cc = io->cc; |
| 1235 | unsigned long flags; |
| 1236 | sector_t sector; |
| 1237 | struct rb_node **rbp, *parent; |
| 1238 | |
| 1239 | if (unlikely(io->error < 0)) { |
| 1240 | crypt_free_buffer_pages(cc, clone); |
| 1241 | bio_put(clone); |
| 1242 | crypt_dec_pending(io); |
| 1243 | return; |
| 1244 | } |
| 1245 | |
| 1246 | /* crypt_convert should have filled the clone bio */ |
| 1247 | BUG_ON(io->ctx.iter_out.bi_size); |
| 1248 | |
| 1249 | clone->bi_iter.bi_sector = cc->start + io->sector; |
| 1250 | |
| 1251 | if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) { |
| 1252 | generic_make_request(clone); |
| 1253 | return; |
| 1254 | } |
| 1255 | |
| 1256 | spin_lock_irqsave(&cc->write_thread_wait.lock, flags); |
| 1257 | rbp = &cc->write_tree.rb_node; |
| 1258 | parent = NULL; |
| 1259 | sector = io->sector; |
| 1260 | while (*rbp) { |
| 1261 | parent = *rbp; |
| 1262 | if (sector < crypt_io_from_node(parent)->sector) |
| 1263 | rbp = &(*rbp)->rb_left; |
| 1264 | else |
| 1265 | rbp = &(*rbp)->rb_right; |
| 1266 | } |
| 1267 | rb_link_node(&io->rb_node, parent, rbp); |
| 1268 | rb_insert_color(&io->rb_node, &cc->write_tree); |
| 1269 | |
| 1270 | wake_up_locked(&cc->write_thread_wait); |
| 1271 | spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags); |
| 1272 | } |
| 1273 | |
| 1274 | static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) |
| 1275 | { |
| 1276 | struct crypt_config *cc = io->cc; |
| 1277 | struct bio *clone; |
| 1278 | int crypt_finished; |
| 1279 | sector_t sector = io->sector; |
| 1280 | int r; |
| 1281 | |
| 1282 | /* |
| 1283 | * Prevent io from disappearing until this function completes. |
| 1284 | */ |
| 1285 | crypt_inc_pending(io); |
| 1286 | crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); |
| 1287 | |
| 1288 | clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); |
| 1289 | if (unlikely(!clone)) { |
| 1290 | io->error = -EIO; |
| 1291 | goto dec; |
| 1292 | } |
| 1293 | |
| 1294 | io->ctx.bio_out = clone; |
| 1295 | io->ctx.iter_out = clone->bi_iter; |
| 1296 | |
| 1297 | sector += bio_sectors(clone); |
| 1298 | |
| 1299 | crypt_inc_pending(io); |
| 1300 | r = crypt_convert(cc, &io->ctx); |
| 1301 | if (r) |
| 1302 | io->error = -EIO; |
| 1303 | crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending); |
| 1304 | |
| 1305 | /* Encryption was already finished, submit io now */ |
| 1306 | if (crypt_finished) { |
| 1307 | kcryptd_crypt_write_io_submit(io, 0); |
| 1308 | io->sector = sector; |
| 1309 | } |
| 1310 | |
| 1311 | dec: |
| 1312 | crypt_dec_pending(io); |
| 1313 | } |
| 1314 | |
| 1315 | static void kcryptd_crypt_read_done(struct dm_crypt_io *io) |
| 1316 | { |
| 1317 | crypt_dec_pending(io); |
| 1318 | } |
| 1319 | |
| 1320 | static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) |
| 1321 | { |
| 1322 | struct crypt_config *cc = io->cc; |
| 1323 | int r = 0; |
| 1324 | |
| 1325 | crypt_inc_pending(io); |
| 1326 | |
| 1327 | crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, |
| 1328 | io->sector); |
| 1329 | |
| 1330 | r = crypt_convert(cc, &io->ctx); |
| 1331 | if (r < 0) |
| 1332 | io->error = -EIO; |
| 1333 | |
| 1334 | if (atomic_dec_and_test(&io->ctx.cc_pending)) |
| 1335 | kcryptd_crypt_read_done(io); |
| 1336 | |
| 1337 | crypt_dec_pending(io); |
| 1338 | } |
| 1339 | |
| 1340 | static void kcryptd_async_done(struct crypto_async_request *async_req, |
| 1341 | int error) |
| 1342 | { |
| 1343 | struct dm_crypt_request *dmreq = async_req->data; |
| 1344 | struct convert_context *ctx = dmreq->ctx; |
| 1345 | struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); |
| 1346 | struct crypt_config *cc = io->cc; |
| 1347 | |
| 1348 | if (error == -EINPROGRESS) |
| 1349 | return; |
| 1350 | |
| 1351 | if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) |
| 1352 | error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq); |
| 1353 | |
| 1354 | if (error < 0) |
| 1355 | io->error = -EIO; |
| 1356 | |
| 1357 | crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); |
| 1358 | |
| 1359 | if (!atomic_dec_and_test(&ctx->cc_pending)) |
| 1360 | goto done; |
| 1361 | |
| 1362 | if (bio_data_dir(io->base_bio) == READ) |
| 1363 | kcryptd_crypt_read_done(io); |
| 1364 | else |
| 1365 | kcryptd_crypt_write_io_submit(io, 1); |
| 1366 | done: |
| 1367 | if (!completion_done(&ctx->restart)) |
| 1368 | complete(&ctx->restart); |
| 1369 | } |
| 1370 | |
| 1371 | static void kcryptd_crypt(struct work_struct *work) |
| 1372 | { |
| 1373 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
| 1374 | |
| 1375 | if (bio_data_dir(io->base_bio) == READ) |
| 1376 | kcryptd_crypt_read_convert(io); |
| 1377 | else |
| 1378 | kcryptd_crypt_write_convert(io); |
| 1379 | } |
| 1380 | |
| 1381 | static void kcryptd_queue_crypt(struct dm_crypt_io *io) |
| 1382 | { |
| 1383 | struct crypt_config *cc = io->cc; |
| 1384 | |
| 1385 | INIT_WORK(&io->work, kcryptd_crypt); |
| 1386 | queue_work(cc->crypt_queue, &io->work); |
| 1387 | } |
| 1388 | |
| 1389 | /* |
| 1390 | * Decode key from its hex representation |
| 1391 | */ |
| 1392 | static int crypt_decode_key(u8 *key, char *hex, unsigned int size) |
| 1393 | { |
| 1394 | char buffer[3]; |
| 1395 | unsigned int i; |
| 1396 | |
| 1397 | buffer[2] = '\0'; |
| 1398 | |
| 1399 | for (i = 0; i < size; i++) { |
| 1400 | buffer[0] = *hex++; |
| 1401 | buffer[1] = *hex++; |
| 1402 | |
| 1403 | if (kstrtou8(buffer, 16, &key[i])) |
| 1404 | return -EINVAL; |
| 1405 | } |
| 1406 | |
| 1407 | if (*hex != '\0') |
| 1408 | return -EINVAL; |
| 1409 | |
| 1410 | return 0; |
| 1411 | } |
| 1412 | |
| 1413 | static void crypt_free_tfms(struct crypt_config *cc) |
| 1414 | { |
| 1415 | unsigned i; |
| 1416 | |
| 1417 | if (!cc->tfms) |
| 1418 | return; |
| 1419 | |
| 1420 | for (i = 0; i < cc->tfms_count; i++) |
| 1421 | if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) { |
| 1422 | crypto_free_ablkcipher(cc->tfms[i]); |
| 1423 | cc->tfms[i] = NULL; |
| 1424 | } |
| 1425 | |
| 1426 | kfree(cc->tfms); |
| 1427 | cc->tfms = NULL; |
| 1428 | } |
| 1429 | |
| 1430 | static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) |
| 1431 | { |
| 1432 | unsigned i; |
| 1433 | int err; |
| 1434 | |
| 1435 | cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *), |
| 1436 | GFP_KERNEL); |
| 1437 | if (!cc->tfms) |
| 1438 | return -ENOMEM; |
| 1439 | |
| 1440 | for (i = 0; i < cc->tfms_count; i++) { |
| 1441 | cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0); |
| 1442 | if (IS_ERR(cc->tfms[i])) { |
| 1443 | err = PTR_ERR(cc->tfms[i]); |
| 1444 | crypt_free_tfms(cc); |
| 1445 | return err; |
| 1446 | } |
| 1447 | } |
| 1448 | |
| 1449 | return 0; |
| 1450 | } |
| 1451 | |
| 1452 | static int crypt_setkey_allcpus(struct crypt_config *cc) |
| 1453 | { |
| 1454 | unsigned subkey_size; |
| 1455 | int err = 0, i, r; |
| 1456 | |
| 1457 | /* Ignore extra keys (which are used for IV etc) */ |
| 1458 | subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); |
| 1459 | |
| 1460 | for (i = 0; i < cc->tfms_count; i++) { |
| 1461 | r = crypto_ablkcipher_setkey(cc->tfms[i], |
| 1462 | cc->key + (i * subkey_size), |
| 1463 | subkey_size); |
| 1464 | if (r) |
| 1465 | err = r; |
| 1466 | } |
| 1467 | |
| 1468 | return err; |
| 1469 | } |
| 1470 | |
| 1471 | static int crypt_set_key(struct crypt_config *cc, char *key) |
| 1472 | { |
| 1473 | int r = -EINVAL; |
| 1474 | int key_string_len = strlen(key); |
| 1475 | |
| 1476 | /* The key size may not be changed. */ |
| 1477 | if (cc->key_size != (key_string_len >> 1)) |
| 1478 | goto out; |
| 1479 | |
| 1480 | /* Hyphen (which gives a key_size of zero) means there is no key. */ |
| 1481 | if (!cc->key_size && strcmp(key, "-")) |
| 1482 | goto out; |
| 1483 | |
| 1484 | if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0) |
| 1485 | goto out; |
| 1486 | |
| 1487 | set_bit(DM_CRYPT_KEY_VALID, &cc->flags); |
| 1488 | |
| 1489 | r = crypt_setkey_allcpus(cc); |
| 1490 | |
| 1491 | out: |
| 1492 | /* Hex key string not needed after here, so wipe it. */ |
| 1493 | memset(key, '0', key_string_len); |
| 1494 | |
| 1495 | return r; |
| 1496 | } |
| 1497 | |
| 1498 | static int crypt_wipe_key(struct crypt_config *cc) |
| 1499 | { |
| 1500 | clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); |
| 1501 | memset(&cc->key, 0, cc->key_size * sizeof(u8)); |
| 1502 | |
| 1503 | return crypt_setkey_allcpus(cc); |
| 1504 | } |
| 1505 | |
| 1506 | static void crypt_dtr(struct dm_target *ti) |
| 1507 | { |
| 1508 | struct crypt_config *cc = ti->private; |
| 1509 | |
| 1510 | ti->private = NULL; |
| 1511 | |
| 1512 | if (!cc) |
| 1513 | return; |
| 1514 | |
| 1515 | if (cc->write_thread) |
| 1516 | kthread_stop(cc->write_thread); |
| 1517 | |
| 1518 | if (cc->io_queue) |
| 1519 | destroy_workqueue(cc->io_queue); |
| 1520 | if (cc->crypt_queue) |
| 1521 | destroy_workqueue(cc->crypt_queue); |
| 1522 | |
| 1523 | crypt_free_tfms(cc); |
| 1524 | |
| 1525 | if (cc->bs) |
| 1526 | bioset_free(cc->bs); |
| 1527 | |
| 1528 | if (cc->page_pool) |
| 1529 | mempool_destroy(cc->page_pool); |
| 1530 | if (cc->req_pool) |
| 1531 | mempool_destroy(cc->req_pool); |
| 1532 | |
| 1533 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
| 1534 | cc->iv_gen_ops->dtr(cc); |
| 1535 | |
| 1536 | if (cc->dev) |
| 1537 | dm_put_device(ti, cc->dev); |
| 1538 | |
| 1539 | kzfree(cc->cipher); |
| 1540 | kzfree(cc->cipher_string); |
| 1541 | |
| 1542 | /* Must zero key material before freeing */ |
| 1543 | kzfree(cc); |
| 1544 | } |
| 1545 | |
| 1546 | static int crypt_ctr_cipher(struct dm_target *ti, |
| 1547 | char *cipher_in, char *key) |
| 1548 | { |
| 1549 | struct crypt_config *cc = ti->private; |
| 1550 | char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount; |
| 1551 | char *cipher_api = NULL; |
| 1552 | int ret = -EINVAL; |
| 1553 | char dummy; |
| 1554 | |
| 1555 | /* Convert to crypto api definition? */ |
| 1556 | if (strchr(cipher_in, '(')) { |
| 1557 | ti->error = "Bad cipher specification"; |
| 1558 | return -EINVAL; |
| 1559 | } |
| 1560 | |
| 1561 | cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); |
| 1562 | if (!cc->cipher_string) |
| 1563 | goto bad_mem; |
| 1564 | |
| 1565 | /* |
| 1566 | * Legacy dm-crypt cipher specification |
| 1567 | * cipher[:keycount]-mode-iv:ivopts |
| 1568 | */ |
| 1569 | tmp = cipher_in; |
| 1570 | keycount = strsep(&tmp, "-"); |
| 1571 | cipher = strsep(&keycount, ":"); |
| 1572 | |
| 1573 | if (!keycount) |
| 1574 | cc->tfms_count = 1; |
| 1575 | else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || |
| 1576 | !is_power_of_2(cc->tfms_count)) { |
| 1577 | ti->error = "Bad cipher key count specification"; |
| 1578 | return -EINVAL; |
| 1579 | } |
| 1580 | cc->key_parts = cc->tfms_count; |
| 1581 | cc->key_extra_size = 0; |
| 1582 | |
| 1583 | cc->cipher = kstrdup(cipher, GFP_KERNEL); |
| 1584 | if (!cc->cipher) |
| 1585 | goto bad_mem; |
| 1586 | |
| 1587 | chainmode = strsep(&tmp, "-"); |
| 1588 | ivopts = strsep(&tmp, "-"); |
| 1589 | ivmode = strsep(&ivopts, ":"); |
| 1590 | |
| 1591 | if (tmp) |
| 1592 | DMWARN("Ignoring unexpected additional cipher options"); |
| 1593 | |
| 1594 | /* |
| 1595 | * For compatibility with the original dm-crypt mapping format, if |
| 1596 | * only the cipher name is supplied, use cbc-plain. |
| 1597 | */ |
| 1598 | if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) { |
| 1599 | chainmode = "cbc"; |
| 1600 | ivmode = "plain"; |
| 1601 | } |
| 1602 | |
| 1603 | if (strcmp(chainmode, "ecb") && !ivmode) { |
| 1604 | ti->error = "IV mechanism required"; |
| 1605 | return -EINVAL; |
| 1606 | } |
| 1607 | |
| 1608 | cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); |
| 1609 | if (!cipher_api) |
| 1610 | goto bad_mem; |
| 1611 | |
| 1612 | ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, |
| 1613 | "%s(%s)", chainmode, cipher); |
| 1614 | if (ret < 0) { |
| 1615 | kfree(cipher_api); |
| 1616 | goto bad_mem; |
| 1617 | } |
| 1618 | |
| 1619 | /* Allocate cipher */ |
| 1620 | ret = crypt_alloc_tfms(cc, cipher_api); |
| 1621 | if (ret < 0) { |
| 1622 | ti->error = "Error allocating crypto tfm"; |
| 1623 | goto bad; |
| 1624 | } |
| 1625 | |
| 1626 | /* Initialize IV */ |
| 1627 | cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc)); |
| 1628 | if (cc->iv_size) |
| 1629 | /* at least a 64 bit sector number should fit in our buffer */ |
| 1630 | cc->iv_size = max(cc->iv_size, |
| 1631 | (unsigned int)(sizeof(u64) / sizeof(u8))); |
| 1632 | else if (ivmode) { |
| 1633 | DMWARN("Selected cipher does not support IVs"); |
| 1634 | ivmode = NULL; |
| 1635 | } |
| 1636 | |
| 1637 | /* Choose ivmode, see comments at iv code. */ |
| 1638 | if (ivmode == NULL) |
| 1639 | cc->iv_gen_ops = NULL; |
| 1640 | else if (strcmp(ivmode, "plain") == 0) |
| 1641 | cc->iv_gen_ops = &crypt_iv_plain_ops; |
| 1642 | else if (strcmp(ivmode, "plain64") == 0) |
| 1643 | cc->iv_gen_ops = &crypt_iv_plain64_ops; |
| 1644 | else if (strcmp(ivmode, "essiv") == 0) |
| 1645 | cc->iv_gen_ops = &crypt_iv_essiv_ops; |
| 1646 | else if (strcmp(ivmode, "benbi") == 0) |
| 1647 | cc->iv_gen_ops = &crypt_iv_benbi_ops; |
| 1648 | else if (strcmp(ivmode, "null") == 0) |
| 1649 | cc->iv_gen_ops = &crypt_iv_null_ops; |
| 1650 | else if (strcmp(ivmode, "lmk") == 0) { |
| 1651 | cc->iv_gen_ops = &crypt_iv_lmk_ops; |
| 1652 | /* |
| 1653 | * Version 2 and 3 is recognised according |
| 1654 | * to length of provided multi-key string. |
| 1655 | * If present (version 3), last key is used as IV seed. |
| 1656 | * All keys (including IV seed) are always the same size. |
| 1657 | */ |
| 1658 | if (cc->key_size % cc->key_parts) { |
| 1659 | cc->key_parts++; |
| 1660 | cc->key_extra_size = cc->key_size / cc->key_parts; |
| 1661 | } |
| 1662 | } else if (strcmp(ivmode, "tcw") == 0) { |
| 1663 | cc->iv_gen_ops = &crypt_iv_tcw_ops; |
| 1664 | cc->key_parts += 2; /* IV + whitening */ |
| 1665 | cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; |
| 1666 | } else { |
| 1667 | ret = -EINVAL; |
| 1668 | ti->error = "Invalid IV mode"; |
| 1669 | goto bad; |
| 1670 | } |
| 1671 | |
| 1672 | /* Initialize and set key */ |
| 1673 | ret = crypt_set_key(cc, key); |
| 1674 | if (ret < 0) { |
| 1675 | ti->error = "Error decoding and setting key"; |
| 1676 | goto bad; |
| 1677 | } |
| 1678 | |
| 1679 | /* Allocate IV */ |
| 1680 | if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { |
| 1681 | ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); |
| 1682 | if (ret < 0) { |
| 1683 | ti->error = "Error creating IV"; |
| 1684 | goto bad; |
| 1685 | } |
| 1686 | } |
| 1687 | |
| 1688 | /* Initialize IV (set keys for ESSIV etc) */ |
| 1689 | if (cc->iv_gen_ops && cc->iv_gen_ops->init) { |
| 1690 | ret = cc->iv_gen_ops->init(cc); |
| 1691 | if (ret < 0) { |
| 1692 | ti->error = "Error initialising IV"; |
| 1693 | goto bad; |
| 1694 | } |
| 1695 | } |
| 1696 | |
| 1697 | ret = 0; |
| 1698 | bad: |
| 1699 | kfree(cipher_api); |
| 1700 | return ret; |
| 1701 | |
| 1702 | bad_mem: |
| 1703 | ti->error = "Cannot allocate cipher strings"; |
| 1704 | return -ENOMEM; |
| 1705 | } |
| 1706 | |
| 1707 | /* |
| 1708 | * Construct an encryption mapping: |
| 1709 | * <cipher> <key> <iv_offset> <dev_path> <start> |
| 1710 | */ |
| 1711 | static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
| 1712 | { |
| 1713 | struct crypt_config *cc; |
| 1714 | unsigned int key_size, opt_params; |
| 1715 | unsigned long long tmpll; |
| 1716 | int ret; |
| 1717 | size_t iv_size_padding; |
| 1718 | struct dm_arg_set as; |
| 1719 | const char *opt_string; |
| 1720 | char dummy; |
| 1721 | |
| 1722 | static struct dm_arg _args[] = { |
| 1723 | {0, 3, "Invalid number of feature args"}, |
| 1724 | }; |
| 1725 | |
| 1726 | if (argc < 5) { |
| 1727 | ti->error = "Not enough arguments"; |
| 1728 | return -EINVAL; |
| 1729 | } |
| 1730 | |
| 1731 | key_size = strlen(argv[1]) >> 1; |
| 1732 | |
| 1733 | cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); |
| 1734 | if (!cc) { |
| 1735 | ti->error = "Cannot allocate encryption context"; |
| 1736 | return -ENOMEM; |
| 1737 | } |
| 1738 | cc->key_size = key_size; |
| 1739 | |
| 1740 | ti->private = cc; |
| 1741 | ret = crypt_ctr_cipher(ti, argv[0], argv[1]); |
| 1742 | if (ret < 0) |
| 1743 | goto bad; |
| 1744 | |
| 1745 | cc->dmreq_start = sizeof(struct ablkcipher_request); |
| 1746 | cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc)); |
| 1747 | cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); |
| 1748 | |
| 1749 | if (crypto_ablkcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) { |
| 1750 | /* Allocate the padding exactly */ |
| 1751 | iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) |
| 1752 | & crypto_ablkcipher_alignmask(any_tfm(cc)); |
| 1753 | } else { |
| 1754 | /* |
| 1755 | * If the cipher requires greater alignment than kmalloc |
| 1756 | * alignment, we don't know the exact position of the |
| 1757 | * initialization vector. We must assume worst case. |
| 1758 | */ |
| 1759 | iv_size_padding = crypto_ablkcipher_alignmask(any_tfm(cc)); |
| 1760 | } |
| 1761 | |
| 1762 | ret = -ENOMEM; |
| 1763 | cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + |
| 1764 | sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size); |
| 1765 | if (!cc->req_pool) { |
| 1766 | ti->error = "Cannot allocate crypt request mempool"; |
| 1767 | goto bad; |
| 1768 | } |
| 1769 | |
| 1770 | cc->per_bio_data_size = ti->per_bio_data_size = |
| 1771 | ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + |
| 1772 | sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size, |
| 1773 | ARCH_KMALLOC_MINALIGN); |
| 1774 | |
| 1775 | cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0); |
| 1776 | if (!cc->page_pool) { |
| 1777 | ti->error = "Cannot allocate page mempool"; |
| 1778 | goto bad; |
| 1779 | } |
| 1780 | |
| 1781 | cc->bs = bioset_create(MIN_IOS, 0); |
| 1782 | if (!cc->bs) { |
| 1783 | ti->error = "Cannot allocate crypt bioset"; |
| 1784 | goto bad; |
| 1785 | } |
| 1786 | |
| 1787 | mutex_init(&cc->bio_alloc_lock); |
| 1788 | |
| 1789 | ret = -EINVAL; |
| 1790 | if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) { |
| 1791 | ti->error = "Invalid iv_offset sector"; |
| 1792 | goto bad; |
| 1793 | } |
| 1794 | cc->iv_offset = tmpll; |
| 1795 | |
| 1796 | if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) { |
| 1797 | ti->error = "Device lookup failed"; |
| 1798 | goto bad; |
| 1799 | } |
| 1800 | |
| 1801 | if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { |
| 1802 | ti->error = "Invalid device sector"; |
| 1803 | goto bad; |
| 1804 | } |
| 1805 | cc->start = tmpll; |
| 1806 | |
| 1807 | argv += 5; |
| 1808 | argc -= 5; |
| 1809 | |
| 1810 | /* Optional parameters */ |
| 1811 | if (argc) { |
| 1812 | as.argc = argc; |
| 1813 | as.argv = argv; |
| 1814 | |
| 1815 | ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); |
| 1816 | if (ret) |
| 1817 | goto bad; |
| 1818 | |
| 1819 | ret = -EINVAL; |
| 1820 | while (opt_params--) { |
| 1821 | opt_string = dm_shift_arg(&as); |
| 1822 | if (!opt_string) { |
| 1823 | ti->error = "Not enough feature arguments"; |
| 1824 | goto bad; |
| 1825 | } |
| 1826 | |
| 1827 | if (!strcasecmp(opt_string, "allow_discards")) |
| 1828 | ti->num_discard_bios = 1; |
| 1829 | |
| 1830 | else if (!strcasecmp(opt_string, "same_cpu_crypt")) |
| 1831 | set_bit(DM_CRYPT_SAME_CPU, &cc->flags); |
| 1832 | |
| 1833 | else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) |
| 1834 | set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); |
| 1835 | |
| 1836 | else { |
| 1837 | ti->error = "Invalid feature arguments"; |
| 1838 | goto bad; |
| 1839 | } |
| 1840 | } |
| 1841 | } |
| 1842 | |
| 1843 | ret = -ENOMEM; |
| 1844 | cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1); |
| 1845 | if (!cc->io_queue) { |
| 1846 | ti->error = "Couldn't create kcryptd io queue"; |
| 1847 | goto bad; |
| 1848 | } |
| 1849 | |
| 1850 | if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) |
| 1851 | cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); |
| 1852 | else |
| 1853 | cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, |
| 1854 | num_online_cpus()); |
| 1855 | if (!cc->crypt_queue) { |
| 1856 | ti->error = "Couldn't create kcryptd queue"; |
| 1857 | goto bad; |
| 1858 | } |
| 1859 | |
| 1860 | init_waitqueue_head(&cc->write_thread_wait); |
| 1861 | cc->write_tree = RB_ROOT; |
| 1862 | |
| 1863 | cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); |
| 1864 | if (IS_ERR(cc->write_thread)) { |
| 1865 | ret = PTR_ERR(cc->write_thread); |
| 1866 | cc->write_thread = NULL; |
| 1867 | ti->error = "Couldn't spawn write thread"; |
| 1868 | goto bad; |
| 1869 | } |
| 1870 | wake_up_process(cc->write_thread); |
| 1871 | |
| 1872 | ti->num_flush_bios = 1; |
| 1873 | ti->discard_zeroes_data_unsupported = true; |
| 1874 | |
| 1875 | return 0; |
| 1876 | |
| 1877 | bad: |
| 1878 | crypt_dtr(ti); |
| 1879 | return ret; |
| 1880 | } |
| 1881 | |
| 1882 | static int crypt_map(struct dm_target *ti, struct bio *bio) |
| 1883 | { |
| 1884 | struct dm_crypt_io *io; |
| 1885 | struct crypt_config *cc = ti->private; |
| 1886 | |
| 1887 | /* |
| 1888 | * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues. |
| 1889 | * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight |
| 1890 | * - for REQ_DISCARD caller must use flush if IO ordering matters |
| 1891 | */ |
| 1892 | if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) { |
| 1893 | bio->bi_bdev = cc->dev->bdev; |
| 1894 | if (bio_sectors(bio)) |
| 1895 | bio->bi_iter.bi_sector = cc->start + |
| 1896 | dm_target_offset(ti, bio->bi_iter.bi_sector); |
| 1897 | return DM_MAPIO_REMAPPED; |
| 1898 | } |
| 1899 | |
| 1900 | io = dm_per_bio_data(bio, cc->per_bio_data_size); |
| 1901 | crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); |
| 1902 | io->ctx.req = (struct ablkcipher_request *)(io + 1); |
| 1903 | |
| 1904 | if (bio_data_dir(io->base_bio) == READ) { |
| 1905 | if (kcryptd_io_read(io, GFP_NOWAIT)) |
| 1906 | kcryptd_queue_read(io); |
| 1907 | } else |
| 1908 | kcryptd_queue_crypt(io); |
| 1909 | |
| 1910 | return DM_MAPIO_SUBMITTED; |
| 1911 | } |
| 1912 | |
| 1913 | static void crypt_status(struct dm_target *ti, status_type_t type, |
| 1914 | unsigned status_flags, char *result, unsigned maxlen) |
| 1915 | { |
| 1916 | struct crypt_config *cc = ti->private; |
| 1917 | unsigned i, sz = 0; |
| 1918 | int num_feature_args = 0; |
| 1919 | |
| 1920 | switch (type) { |
| 1921 | case STATUSTYPE_INFO: |
| 1922 | result[0] = '\0'; |
| 1923 | break; |
| 1924 | |
| 1925 | case STATUSTYPE_TABLE: |
| 1926 | DMEMIT("%s ", cc->cipher_string); |
| 1927 | |
| 1928 | if (cc->key_size > 0) |
| 1929 | for (i = 0; i < cc->key_size; i++) |
| 1930 | DMEMIT("%02x", cc->key[i]); |
| 1931 | else |
| 1932 | DMEMIT("-"); |
| 1933 | |
| 1934 | DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, |
| 1935 | cc->dev->name, (unsigned long long)cc->start); |
| 1936 | |
| 1937 | num_feature_args += !!ti->num_discard_bios; |
| 1938 | num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); |
| 1939 | num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); |
| 1940 | if (num_feature_args) { |
| 1941 | DMEMIT(" %d", num_feature_args); |
| 1942 | if (ti->num_discard_bios) |
| 1943 | DMEMIT(" allow_discards"); |
| 1944 | if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) |
| 1945 | DMEMIT(" same_cpu_crypt"); |
| 1946 | if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) |
| 1947 | DMEMIT(" submit_from_crypt_cpus"); |
| 1948 | } |
| 1949 | |
| 1950 | break; |
| 1951 | } |
| 1952 | } |
| 1953 | |
| 1954 | static void crypt_postsuspend(struct dm_target *ti) |
| 1955 | { |
| 1956 | struct crypt_config *cc = ti->private; |
| 1957 | |
| 1958 | set_bit(DM_CRYPT_SUSPENDED, &cc->flags); |
| 1959 | } |
| 1960 | |
| 1961 | static int crypt_preresume(struct dm_target *ti) |
| 1962 | { |
| 1963 | struct crypt_config *cc = ti->private; |
| 1964 | |
| 1965 | if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { |
| 1966 | DMERR("aborting resume - crypt key is not set."); |
| 1967 | return -EAGAIN; |
| 1968 | } |
| 1969 | |
| 1970 | return 0; |
| 1971 | } |
| 1972 | |
| 1973 | static void crypt_resume(struct dm_target *ti) |
| 1974 | { |
| 1975 | struct crypt_config *cc = ti->private; |
| 1976 | |
| 1977 | clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); |
| 1978 | } |
| 1979 | |
| 1980 | /* Message interface |
| 1981 | * key set <key> |
| 1982 | * key wipe |
| 1983 | */ |
| 1984 | static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) |
| 1985 | { |
| 1986 | struct crypt_config *cc = ti->private; |
| 1987 | int ret = -EINVAL; |
| 1988 | |
| 1989 | if (argc < 2) |
| 1990 | goto error; |
| 1991 | |
| 1992 | if (!strcasecmp(argv[0], "key")) { |
| 1993 | if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { |
| 1994 | DMWARN("not suspended during key manipulation."); |
| 1995 | return -EINVAL; |
| 1996 | } |
| 1997 | if (argc == 3 && !strcasecmp(argv[1], "set")) { |
| 1998 | ret = crypt_set_key(cc, argv[2]); |
| 1999 | if (ret) |
| 2000 | return ret; |
| 2001 | if (cc->iv_gen_ops && cc->iv_gen_ops->init) |
| 2002 | ret = cc->iv_gen_ops->init(cc); |
| 2003 | return ret; |
| 2004 | } |
| 2005 | if (argc == 2 && !strcasecmp(argv[1], "wipe")) { |
| 2006 | if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { |
| 2007 | ret = cc->iv_gen_ops->wipe(cc); |
| 2008 | if (ret) |
| 2009 | return ret; |
| 2010 | } |
| 2011 | return crypt_wipe_key(cc); |
| 2012 | } |
| 2013 | } |
| 2014 | |
| 2015 | error: |
| 2016 | DMWARN("unrecognised message received."); |
| 2017 | return -EINVAL; |
| 2018 | } |
| 2019 | |
| 2020 | static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm, |
| 2021 | struct bio_vec *biovec, int max_size) |
| 2022 | { |
| 2023 | struct crypt_config *cc = ti->private; |
| 2024 | struct request_queue *q = bdev_get_queue(cc->dev->bdev); |
| 2025 | |
| 2026 | if (!q->merge_bvec_fn) |
| 2027 | return max_size; |
| 2028 | |
| 2029 | bvm->bi_bdev = cc->dev->bdev; |
| 2030 | bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector); |
| 2031 | |
| 2032 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); |
| 2033 | } |
| 2034 | |
| 2035 | static int crypt_iterate_devices(struct dm_target *ti, |
| 2036 | iterate_devices_callout_fn fn, void *data) |
| 2037 | { |
| 2038 | struct crypt_config *cc = ti->private; |
| 2039 | |
| 2040 | return fn(ti, cc->dev, cc->start, ti->len, data); |
| 2041 | } |
| 2042 | |
| 2043 | static struct target_type crypt_target = { |
| 2044 | .name = "crypt", |
| 2045 | .version = {1, 14, 0}, |
| 2046 | .module = THIS_MODULE, |
| 2047 | .ctr = crypt_ctr, |
| 2048 | .dtr = crypt_dtr, |
| 2049 | .map = crypt_map, |
| 2050 | .status = crypt_status, |
| 2051 | .postsuspend = crypt_postsuspend, |
| 2052 | .preresume = crypt_preresume, |
| 2053 | .resume = crypt_resume, |
| 2054 | .message = crypt_message, |
| 2055 | .merge = crypt_merge, |
| 2056 | .iterate_devices = crypt_iterate_devices, |
| 2057 | }; |
| 2058 | |
| 2059 | static int __init dm_crypt_init(void) |
| 2060 | { |
| 2061 | int r; |
| 2062 | |
| 2063 | r = dm_register_target(&crypt_target); |
| 2064 | if (r < 0) |
| 2065 | DMERR("register failed %d", r); |
| 2066 | |
| 2067 | return r; |
| 2068 | } |
| 2069 | |
| 2070 | static void __exit dm_crypt_exit(void) |
| 2071 | { |
| 2072 | dm_unregister_target(&crypt_target); |
| 2073 | } |
| 2074 | |
| 2075 | module_init(dm_crypt_init); |
| 2076 | module_exit(dm_crypt_exit); |
| 2077 | |
| 2078 | MODULE_AUTHOR("Jana Saout <jana@saout.de>"); |
| 2079 | MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); |
| 2080 | MODULE_LICENSE("GPL"); |