| 1 | /* |
| 2 | * Copyright (C) 2003 Christophe Saout <christophe@saout.de> |
| 3 | * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> |
| 4 | * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved. |
| 5 | * |
| 6 | * This file is released under the GPL. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/completion.h> |
| 10 | #include <linux/err.h> |
| 11 | #include <linux/module.h> |
| 12 | #include <linux/init.h> |
| 13 | #include <linux/kernel.h> |
| 14 | #include <linux/bio.h> |
| 15 | #include <linux/blkdev.h> |
| 16 | #include <linux/mempool.h> |
| 17 | #include <linux/slab.h> |
| 18 | #include <linux/crypto.h> |
| 19 | #include <linux/workqueue.h> |
| 20 | #include <linux/backing-dev.h> |
| 21 | #include <asm/atomic.h> |
| 22 | #include <linux/scatterlist.h> |
| 23 | #include <asm/page.h> |
| 24 | #include <asm/unaligned.h> |
| 25 | |
| 26 | #include "dm.h" |
| 27 | |
| 28 | #define DM_MSG_PREFIX "crypt" |
| 29 | #define MESG_STR(x) x, sizeof(x) |
| 30 | |
| 31 | /* |
| 32 | * context holding the current state of a multi-part conversion |
| 33 | */ |
| 34 | struct convert_context { |
| 35 | struct completion restart; |
| 36 | struct bio *bio_in; |
| 37 | struct bio *bio_out; |
| 38 | unsigned int offset_in; |
| 39 | unsigned int offset_out; |
| 40 | unsigned int idx_in; |
| 41 | unsigned int idx_out; |
| 42 | sector_t sector; |
| 43 | atomic_t pending; |
| 44 | }; |
| 45 | |
| 46 | /* |
| 47 | * per bio private data |
| 48 | */ |
| 49 | struct dm_crypt_io { |
| 50 | struct dm_target *target; |
| 51 | struct bio *base_bio; |
| 52 | struct work_struct work; |
| 53 | |
| 54 | struct convert_context ctx; |
| 55 | |
| 56 | atomic_t pending; |
| 57 | int error; |
| 58 | sector_t sector; |
| 59 | }; |
| 60 | |
| 61 | struct dm_crypt_request { |
| 62 | struct scatterlist sg_in; |
| 63 | struct scatterlist sg_out; |
| 64 | }; |
| 65 | |
| 66 | struct crypt_config; |
| 67 | |
| 68 | struct crypt_iv_operations { |
| 69 | int (*ctr)(struct crypt_config *cc, struct dm_target *ti, |
| 70 | const char *opts); |
| 71 | void (*dtr)(struct crypt_config *cc); |
| 72 | const char *(*status)(struct crypt_config *cc); |
| 73 | int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); |
| 74 | }; |
| 75 | |
| 76 | /* |
| 77 | * Crypt: maps a linear range of a block device |
| 78 | * and encrypts / decrypts at the same time. |
| 79 | */ |
| 80 | enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; |
| 81 | struct crypt_config { |
| 82 | struct dm_dev *dev; |
| 83 | sector_t start; |
| 84 | |
| 85 | /* |
| 86 | * pool for per bio private data, crypto requests and |
| 87 | * encryption requeusts/buffer pages |
| 88 | */ |
| 89 | mempool_t *io_pool; |
| 90 | mempool_t *req_pool; |
| 91 | mempool_t *page_pool; |
| 92 | struct bio_set *bs; |
| 93 | |
| 94 | struct workqueue_struct *io_queue; |
| 95 | struct workqueue_struct *crypt_queue; |
| 96 | wait_queue_head_t writeq; |
| 97 | |
| 98 | /* |
| 99 | * crypto related data |
| 100 | */ |
| 101 | struct crypt_iv_operations *iv_gen_ops; |
| 102 | char *iv_mode; |
| 103 | union { |
| 104 | struct crypto_cipher *essiv_tfm; |
| 105 | int benbi_shift; |
| 106 | } iv_gen_private; |
| 107 | sector_t iv_offset; |
| 108 | unsigned int iv_size; |
| 109 | |
| 110 | /* |
| 111 | * Layout of each crypto request: |
| 112 | * |
| 113 | * struct ablkcipher_request |
| 114 | * context |
| 115 | * padding |
| 116 | * struct dm_crypt_request |
| 117 | * padding |
| 118 | * IV |
| 119 | * |
| 120 | * The padding is added so that dm_crypt_request and the IV are |
| 121 | * correctly aligned. |
| 122 | */ |
| 123 | unsigned int dmreq_start; |
| 124 | struct ablkcipher_request *req; |
| 125 | |
| 126 | char cipher[CRYPTO_MAX_ALG_NAME]; |
| 127 | char chainmode[CRYPTO_MAX_ALG_NAME]; |
| 128 | struct crypto_ablkcipher *tfm; |
| 129 | unsigned long flags; |
| 130 | unsigned int key_size; |
| 131 | u8 key[0]; |
| 132 | }; |
| 133 | |
| 134 | #define MIN_IOS 16 |
| 135 | #define MIN_POOL_PAGES 32 |
| 136 | #define MIN_BIO_PAGES 8 |
| 137 | |
| 138 | static struct kmem_cache *_crypt_io_pool; |
| 139 | |
| 140 | static void clone_init(struct dm_crypt_io *, struct bio *); |
| 141 | static void kcryptd_queue_crypt(struct dm_crypt_io *io); |
| 142 | |
| 143 | /* |
| 144 | * Different IV generation algorithms: |
| 145 | * |
| 146 | * plain: the initial vector is the 32-bit little-endian version of the sector |
| 147 | * number, padded with zeros if necessary. |
| 148 | * |
| 149 | * essiv: "encrypted sector|salt initial vector", the sector number is |
| 150 | * encrypted with the bulk cipher using a salt as key. The salt |
| 151 | * should be derived from the bulk cipher's key via hashing. |
| 152 | * |
| 153 | * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 |
| 154 | * (needed for LRW-32-AES and possible other narrow block modes) |
| 155 | * |
| 156 | * null: the initial vector is always zero. Provides compatibility with |
| 157 | * obsolete loop_fish2 devices. Do not use for new devices. |
| 158 | * |
| 159 | * plumb: unimplemented, see: |
| 160 | * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 |
| 161 | */ |
| 162 | |
| 163 | static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
| 164 | { |
| 165 | memset(iv, 0, cc->iv_size); |
| 166 | *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); |
| 167 | |
| 168 | return 0; |
| 169 | } |
| 170 | |
| 171 | static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, |
| 172 | const char *opts) |
| 173 | { |
| 174 | struct crypto_cipher *essiv_tfm; |
| 175 | struct crypto_hash *hash_tfm; |
| 176 | struct hash_desc desc; |
| 177 | struct scatterlist sg; |
| 178 | unsigned int saltsize; |
| 179 | u8 *salt; |
| 180 | int err; |
| 181 | |
| 182 | if (opts == NULL) { |
| 183 | ti->error = "Digest algorithm missing for ESSIV mode"; |
| 184 | return -EINVAL; |
| 185 | } |
| 186 | |
| 187 | /* Hash the cipher key with the given hash algorithm */ |
| 188 | hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); |
| 189 | if (IS_ERR(hash_tfm)) { |
| 190 | ti->error = "Error initializing ESSIV hash"; |
| 191 | return PTR_ERR(hash_tfm); |
| 192 | } |
| 193 | |
| 194 | saltsize = crypto_hash_digestsize(hash_tfm); |
| 195 | salt = kmalloc(saltsize, GFP_KERNEL); |
| 196 | if (salt == NULL) { |
| 197 | ti->error = "Error kmallocing salt storage in ESSIV"; |
| 198 | crypto_free_hash(hash_tfm); |
| 199 | return -ENOMEM; |
| 200 | } |
| 201 | |
| 202 | sg_init_one(&sg, cc->key, cc->key_size); |
| 203 | desc.tfm = hash_tfm; |
| 204 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; |
| 205 | err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); |
| 206 | crypto_free_hash(hash_tfm); |
| 207 | |
| 208 | if (err) { |
| 209 | ti->error = "Error calculating hash in ESSIV"; |
| 210 | kfree(salt); |
| 211 | return err; |
| 212 | } |
| 213 | |
| 214 | /* Setup the essiv_tfm with the given salt */ |
| 215 | essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
| 216 | if (IS_ERR(essiv_tfm)) { |
| 217 | ti->error = "Error allocating crypto tfm for ESSIV"; |
| 218 | kfree(salt); |
| 219 | return PTR_ERR(essiv_tfm); |
| 220 | } |
| 221 | if (crypto_cipher_blocksize(essiv_tfm) != |
| 222 | crypto_ablkcipher_ivsize(cc->tfm)) { |
| 223 | ti->error = "Block size of ESSIV cipher does " |
| 224 | "not match IV size of block cipher"; |
| 225 | crypto_free_cipher(essiv_tfm); |
| 226 | kfree(salt); |
| 227 | return -EINVAL; |
| 228 | } |
| 229 | err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); |
| 230 | if (err) { |
| 231 | ti->error = "Failed to set key for ESSIV cipher"; |
| 232 | crypto_free_cipher(essiv_tfm); |
| 233 | kfree(salt); |
| 234 | return err; |
| 235 | } |
| 236 | kfree(salt); |
| 237 | |
| 238 | cc->iv_gen_private.essiv_tfm = essiv_tfm; |
| 239 | return 0; |
| 240 | } |
| 241 | |
| 242 | static void crypt_iv_essiv_dtr(struct crypt_config *cc) |
| 243 | { |
| 244 | crypto_free_cipher(cc->iv_gen_private.essiv_tfm); |
| 245 | cc->iv_gen_private.essiv_tfm = NULL; |
| 246 | } |
| 247 | |
| 248 | static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
| 249 | { |
| 250 | memset(iv, 0, cc->iv_size); |
| 251 | *(u64 *)iv = cpu_to_le64(sector); |
| 252 | crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv); |
| 253 | return 0; |
| 254 | } |
| 255 | |
| 256 | static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, |
| 257 | const char *opts) |
| 258 | { |
| 259 | unsigned bs = crypto_ablkcipher_blocksize(cc->tfm); |
| 260 | int log = ilog2(bs); |
| 261 | |
| 262 | /* we need to calculate how far we must shift the sector count |
| 263 | * to get the cipher block count, we use this shift in _gen */ |
| 264 | |
| 265 | if (1 << log != bs) { |
| 266 | ti->error = "cypher blocksize is not a power of 2"; |
| 267 | return -EINVAL; |
| 268 | } |
| 269 | |
| 270 | if (log > 9) { |
| 271 | ti->error = "cypher blocksize is > 512"; |
| 272 | return -EINVAL; |
| 273 | } |
| 274 | |
| 275 | cc->iv_gen_private.benbi_shift = 9 - log; |
| 276 | |
| 277 | return 0; |
| 278 | } |
| 279 | |
| 280 | static void crypt_iv_benbi_dtr(struct crypt_config *cc) |
| 281 | { |
| 282 | } |
| 283 | |
| 284 | static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
| 285 | { |
| 286 | __be64 val; |
| 287 | |
| 288 | memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ |
| 289 | |
| 290 | val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1); |
| 291 | put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); |
| 292 | |
| 293 | return 0; |
| 294 | } |
| 295 | |
| 296 | static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
| 297 | { |
| 298 | memset(iv, 0, cc->iv_size); |
| 299 | |
| 300 | return 0; |
| 301 | } |
| 302 | |
| 303 | static struct crypt_iv_operations crypt_iv_plain_ops = { |
| 304 | .generator = crypt_iv_plain_gen |
| 305 | }; |
| 306 | |
| 307 | static struct crypt_iv_operations crypt_iv_essiv_ops = { |
| 308 | .ctr = crypt_iv_essiv_ctr, |
| 309 | .dtr = crypt_iv_essiv_dtr, |
| 310 | .generator = crypt_iv_essiv_gen |
| 311 | }; |
| 312 | |
| 313 | static struct crypt_iv_operations crypt_iv_benbi_ops = { |
| 314 | .ctr = crypt_iv_benbi_ctr, |
| 315 | .dtr = crypt_iv_benbi_dtr, |
| 316 | .generator = crypt_iv_benbi_gen |
| 317 | }; |
| 318 | |
| 319 | static struct crypt_iv_operations crypt_iv_null_ops = { |
| 320 | .generator = crypt_iv_null_gen |
| 321 | }; |
| 322 | |
| 323 | static void crypt_convert_init(struct crypt_config *cc, |
| 324 | struct convert_context *ctx, |
| 325 | struct bio *bio_out, struct bio *bio_in, |
| 326 | sector_t sector) |
| 327 | { |
| 328 | ctx->bio_in = bio_in; |
| 329 | ctx->bio_out = bio_out; |
| 330 | ctx->offset_in = 0; |
| 331 | ctx->offset_out = 0; |
| 332 | ctx->idx_in = bio_in ? bio_in->bi_idx : 0; |
| 333 | ctx->idx_out = bio_out ? bio_out->bi_idx : 0; |
| 334 | ctx->sector = sector + cc->iv_offset; |
| 335 | init_completion(&ctx->restart); |
| 336 | atomic_set(&ctx->pending, 1); |
| 337 | } |
| 338 | |
| 339 | static int crypt_convert_block(struct crypt_config *cc, |
| 340 | struct convert_context *ctx, |
| 341 | struct ablkcipher_request *req) |
| 342 | { |
| 343 | struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); |
| 344 | struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); |
| 345 | struct dm_crypt_request *dmreq; |
| 346 | u8 *iv; |
| 347 | int r = 0; |
| 348 | |
| 349 | dmreq = (struct dm_crypt_request *)((char *)req + cc->dmreq_start); |
| 350 | iv = (u8 *)ALIGN((unsigned long)(dmreq + 1), |
| 351 | crypto_ablkcipher_alignmask(cc->tfm) + 1); |
| 352 | |
| 353 | sg_init_table(&dmreq->sg_in, 1); |
| 354 | sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, |
| 355 | bv_in->bv_offset + ctx->offset_in); |
| 356 | |
| 357 | sg_init_table(&dmreq->sg_out, 1); |
| 358 | sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, |
| 359 | bv_out->bv_offset + ctx->offset_out); |
| 360 | |
| 361 | ctx->offset_in += 1 << SECTOR_SHIFT; |
| 362 | if (ctx->offset_in >= bv_in->bv_len) { |
| 363 | ctx->offset_in = 0; |
| 364 | ctx->idx_in++; |
| 365 | } |
| 366 | |
| 367 | ctx->offset_out += 1 << SECTOR_SHIFT; |
| 368 | if (ctx->offset_out >= bv_out->bv_len) { |
| 369 | ctx->offset_out = 0; |
| 370 | ctx->idx_out++; |
| 371 | } |
| 372 | |
| 373 | if (cc->iv_gen_ops) { |
| 374 | r = cc->iv_gen_ops->generator(cc, iv, ctx->sector); |
| 375 | if (r < 0) |
| 376 | return r; |
| 377 | } |
| 378 | |
| 379 | ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out, |
| 380 | 1 << SECTOR_SHIFT, iv); |
| 381 | |
| 382 | if (bio_data_dir(ctx->bio_in) == WRITE) |
| 383 | r = crypto_ablkcipher_encrypt(req); |
| 384 | else |
| 385 | r = crypto_ablkcipher_decrypt(req); |
| 386 | |
| 387 | return r; |
| 388 | } |
| 389 | |
| 390 | static void kcryptd_async_done(struct crypto_async_request *async_req, |
| 391 | int error); |
| 392 | static void crypt_alloc_req(struct crypt_config *cc, |
| 393 | struct convert_context *ctx) |
| 394 | { |
| 395 | if (!cc->req) |
| 396 | cc->req = mempool_alloc(cc->req_pool, GFP_NOIO); |
| 397 | ablkcipher_request_set_tfm(cc->req, cc->tfm); |
| 398 | ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG | |
| 399 | CRYPTO_TFM_REQ_MAY_SLEEP, |
| 400 | kcryptd_async_done, ctx); |
| 401 | } |
| 402 | |
| 403 | /* |
| 404 | * Encrypt / decrypt data from one bio to another one (can be the same one) |
| 405 | */ |
| 406 | static int crypt_convert(struct crypt_config *cc, |
| 407 | struct convert_context *ctx) |
| 408 | { |
| 409 | int r; |
| 410 | |
| 411 | while(ctx->idx_in < ctx->bio_in->bi_vcnt && |
| 412 | ctx->idx_out < ctx->bio_out->bi_vcnt) { |
| 413 | |
| 414 | crypt_alloc_req(cc, ctx); |
| 415 | |
| 416 | atomic_inc(&ctx->pending); |
| 417 | |
| 418 | r = crypt_convert_block(cc, ctx, cc->req); |
| 419 | |
| 420 | switch (r) { |
| 421 | /* async */ |
| 422 | case -EBUSY: |
| 423 | wait_for_completion(&ctx->restart); |
| 424 | INIT_COMPLETION(ctx->restart); |
| 425 | /* fall through*/ |
| 426 | case -EINPROGRESS: |
| 427 | cc->req = NULL; |
| 428 | ctx->sector++; |
| 429 | continue; |
| 430 | |
| 431 | /* sync */ |
| 432 | case 0: |
| 433 | atomic_dec(&ctx->pending); |
| 434 | ctx->sector++; |
| 435 | cond_resched(); |
| 436 | continue; |
| 437 | |
| 438 | /* error */ |
| 439 | default: |
| 440 | atomic_dec(&ctx->pending); |
| 441 | return r; |
| 442 | } |
| 443 | } |
| 444 | |
| 445 | return 0; |
| 446 | } |
| 447 | |
| 448 | static void dm_crypt_bio_destructor(struct bio *bio) |
| 449 | { |
| 450 | struct dm_crypt_io *io = bio->bi_private; |
| 451 | struct crypt_config *cc = io->target->private; |
| 452 | |
| 453 | bio_free(bio, cc->bs); |
| 454 | } |
| 455 | |
| 456 | /* |
| 457 | * Generate a new unfragmented bio with the given size |
| 458 | * This should never violate the device limitations |
| 459 | * May return a smaller bio when running out of pages |
| 460 | */ |
| 461 | static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) |
| 462 | { |
| 463 | struct crypt_config *cc = io->target->private; |
| 464 | struct bio *clone; |
| 465 | unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
| 466 | gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; |
| 467 | unsigned i, len; |
| 468 | struct page *page; |
| 469 | |
| 470 | clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); |
| 471 | if (!clone) |
| 472 | return NULL; |
| 473 | |
| 474 | clone_init(io, clone); |
| 475 | |
| 476 | for (i = 0; i < nr_iovecs; i++) { |
| 477 | page = mempool_alloc(cc->page_pool, gfp_mask); |
| 478 | if (!page) |
| 479 | break; |
| 480 | |
| 481 | /* |
| 482 | * if additional pages cannot be allocated without waiting, |
| 483 | * return a partially allocated bio, the caller will then try |
| 484 | * to allocate additional bios while submitting this partial bio |
| 485 | */ |
| 486 | if (i == (MIN_BIO_PAGES - 1)) |
| 487 | gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; |
| 488 | |
| 489 | len = (size > PAGE_SIZE) ? PAGE_SIZE : size; |
| 490 | |
| 491 | if (!bio_add_page(clone, page, len, 0)) { |
| 492 | mempool_free(page, cc->page_pool); |
| 493 | break; |
| 494 | } |
| 495 | |
| 496 | size -= len; |
| 497 | } |
| 498 | |
| 499 | if (!clone->bi_size) { |
| 500 | bio_put(clone); |
| 501 | return NULL; |
| 502 | } |
| 503 | |
| 504 | return clone; |
| 505 | } |
| 506 | |
| 507 | static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) |
| 508 | { |
| 509 | unsigned int i; |
| 510 | struct bio_vec *bv; |
| 511 | |
| 512 | for (i = 0; i < clone->bi_vcnt; i++) { |
| 513 | bv = bio_iovec_idx(clone, i); |
| 514 | BUG_ON(!bv->bv_page); |
| 515 | mempool_free(bv->bv_page, cc->page_pool); |
| 516 | bv->bv_page = NULL; |
| 517 | } |
| 518 | } |
| 519 | |
| 520 | /* |
| 521 | * One of the bios was finished. Check for completion of |
| 522 | * the whole request and correctly clean up the buffer. |
| 523 | */ |
| 524 | static void crypt_dec_pending(struct dm_crypt_io *io) |
| 525 | { |
| 526 | struct crypt_config *cc = io->target->private; |
| 527 | |
| 528 | if (!atomic_dec_and_test(&io->pending)) |
| 529 | return; |
| 530 | |
| 531 | bio_endio(io->base_bio, io->error); |
| 532 | mempool_free(io, cc->io_pool); |
| 533 | } |
| 534 | |
| 535 | /* |
| 536 | * kcryptd/kcryptd_io: |
| 537 | * |
| 538 | * Needed because it would be very unwise to do decryption in an |
| 539 | * interrupt context. |
| 540 | * |
| 541 | * kcryptd performs the actual encryption or decryption. |
| 542 | * |
| 543 | * kcryptd_io performs the IO submission. |
| 544 | * |
| 545 | * They must be separated as otherwise the final stages could be |
| 546 | * starved by new requests which can block in the first stages due |
| 547 | * to memory allocation. |
| 548 | */ |
| 549 | static void crypt_endio(struct bio *clone, int error) |
| 550 | { |
| 551 | struct dm_crypt_io *io = clone->bi_private; |
| 552 | struct crypt_config *cc = io->target->private; |
| 553 | unsigned rw = bio_data_dir(clone); |
| 554 | |
| 555 | if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) |
| 556 | error = -EIO; |
| 557 | |
| 558 | /* |
| 559 | * free the processed pages |
| 560 | */ |
| 561 | if (rw == WRITE) |
| 562 | crypt_free_buffer_pages(cc, clone); |
| 563 | |
| 564 | bio_put(clone); |
| 565 | |
| 566 | if (rw == READ && !error) { |
| 567 | kcryptd_queue_crypt(io); |
| 568 | return; |
| 569 | } |
| 570 | |
| 571 | if (unlikely(error)) |
| 572 | io->error = error; |
| 573 | |
| 574 | crypt_dec_pending(io); |
| 575 | } |
| 576 | |
| 577 | static void clone_init(struct dm_crypt_io *io, struct bio *clone) |
| 578 | { |
| 579 | struct crypt_config *cc = io->target->private; |
| 580 | |
| 581 | clone->bi_private = io; |
| 582 | clone->bi_end_io = crypt_endio; |
| 583 | clone->bi_bdev = cc->dev->bdev; |
| 584 | clone->bi_rw = io->base_bio->bi_rw; |
| 585 | clone->bi_destructor = dm_crypt_bio_destructor; |
| 586 | } |
| 587 | |
| 588 | static void kcryptd_io_read(struct dm_crypt_io *io) |
| 589 | { |
| 590 | struct crypt_config *cc = io->target->private; |
| 591 | struct bio *base_bio = io->base_bio; |
| 592 | struct bio *clone; |
| 593 | |
| 594 | atomic_inc(&io->pending); |
| 595 | |
| 596 | /* |
| 597 | * The block layer might modify the bvec array, so always |
| 598 | * copy the required bvecs because we need the original |
| 599 | * one in order to decrypt the whole bio data *afterwards*. |
| 600 | */ |
| 601 | clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); |
| 602 | if (unlikely(!clone)) { |
| 603 | io->error = -ENOMEM; |
| 604 | crypt_dec_pending(io); |
| 605 | return; |
| 606 | } |
| 607 | |
| 608 | clone_init(io, clone); |
| 609 | clone->bi_idx = 0; |
| 610 | clone->bi_vcnt = bio_segments(base_bio); |
| 611 | clone->bi_size = base_bio->bi_size; |
| 612 | clone->bi_sector = cc->start + io->sector; |
| 613 | memcpy(clone->bi_io_vec, bio_iovec(base_bio), |
| 614 | sizeof(struct bio_vec) * clone->bi_vcnt); |
| 615 | |
| 616 | generic_make_request(clone); |
| 617 | } |
| 618 | |
| 619 | static void kcryptd_io_write(struct dm_crypt_io *io) |
| 620 | { |
| 621 | struct bio *clone = io->ctx.bio_out; |
| 622 | struct crypt_config *cc = io->target->private; |
| 623 | |
| 624 | generic_make_request(clone); |
| 625 | wake_up(&cc->writeq); |
| 626 | } |
| 627 | |
| 628 | static void kcryptd_io(struct work_struct *work) |
| 629 | { |
| 630 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
| 631 | |
| 632 | if (bio_data_dir(io->base_bio) == READ) |
| 633 | kcryptd_io_read(io); |
| 634 | else |
| 635 | kcryptd_io_write(io); |
| 636 | } |
| 637 | |
| 638 | static void kcryptd_queue_io(struct dm_crypt_io *io) |
| 639 | { |
| 640 | struct crypt_config *cc = io->target->private; |
| 641 | |
| 642 | INIT_WORK(&io->work, kcryptd_io); |
| 643 | queue_work(cc->io_queue, &io->work); |
| 644 | } |
| 645 | |
| 646 | static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, |
| 647 | int error, int async) |
| 648 | { |
| 649 | struct bio *clone = io->ctx.bio_out; |
| 650 | struct crypt_config *cc = io->target->private; |
| 651 | |
| 652 | if (unlikely(error < 0)) { |
| 653 | crypt_free_buffer_pages(cc, clone); |
| 654 | bio_put(clone); |
| 655 | io->error = -EIO; |
| 656 | return; |
| 657 | } |
| 658 | |
| 659 | /* crypt_convert should have filled the clone bio */ |
| 660 | BUG_ON(io->ctx.idx_out < clone->bi_vcnt); |
| 661 | |
| 662 | clone->bi_sector = cc->start + io->sector; |
| 663 | io->sector += bio_sectors(clone); |
| 664 | |
| 665 | if (async) |
| 666 | kcryptd_queue_io(io); |
| 667 | else { |
| 668 | atomic_inc(&io->pending); |
| 669 | generic_make_request(clone); |
| 670 | } |
| 671 | } |
| 672 | |
| 673 | static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io) |
| 674 | { |
| 675 | struct crypt_config *cc = io->target->private; |
| 676 | struct bio *clone; |
| 677 | unsigned remaining = io->base_bio->bi_size; |
| 678 | int r; |
| 679 | |
| 680 | /* |
| 681 | * The allocated buffers can be smaller than the whole bio, |
| 682 | * so repeat the whole process until all the data can be handled. |
| 683 | */ |
| 684 | while (remaining) { |
| 685 | clone = crypt_alloc_buffer(io, remaining); |
| 686 | if (unlikely(!clone)) { |
| 687 | io->error = -ENOMEM; |
| 688 | return; |
| 689 | } |
| 690 | |
| 691 | io->ctx.bio_out = clone; |
| 692 | io->ctx.idx_out = 0; |
| 693 | |
| 694 | remaining -= clone->bi_size; |
| 695 | |
| 696 | r = crypt_convert(cc, &io->ctx); |
| 697 | |
| 698 | if (atomic_dec_and_test(&io->ctx.pending)) { |
| 699 | /* processed, no running async crypto */ |
| 700 | kcryptd_crypt_write_io_submit(io, r, 0); |
| 701 | if (unlikely(r < 0)) |
| 702 | return; |
| 703 | } else |
| 704 | atomic_inc(&io->pending); |
| 705 | |
| 706 | /* out of memory -> run queues */ |
| 707 | if (unlikely(remaining)) { |
| 708 | /* wait for async crypto then reinitialize pending */ |
| 709 | wait_event(cc->writeq, !atomic_read(&io->ctx.pending)); |
| 710 | atomic_set(&io->ctx.pending, 1); |
| 711 | congestion_wait(WRITE, HZ/100); |
| 712 | } |
| 713 | } |
| 714 | } |
| 715 | |
| 716 | static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) |
| 717 | { |
| 718 | struct crypt_config *cc = io->target->private; |
| 719 | |
| 720 | /* |
| 721 | * Prevent io from disappearing until this function completes. |
| 722 | */ |
| 723 | atomic_inc(&io->pending); |
| 724 | |
| 725 | crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector); |
| 726 | kcryptd_crypt_write_convert_loop(io); |
| 727 | |
| 728 | crypt_dec_pending(io); |
| 729 | } |
| 730 | |
| 731 | static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error) |
| 732 | { |
| 733 | if (unlikely(error < 0)) |
| 734 | io->error = -EIO; |
| 735 | |
| 736 | crypt_dec_pending(io); |
| 737 | } |
| 738 | |
| 739 | static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) |
| 740 | { |
| 741 | struct crypt_config *cc = io->target->private; |
| 742 | int r = 0; |
| 743 | |
| 744 | atomic_inc(&io->pending); |
| 745 | |
| 746 | crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, |
| 747 | io->sector); |
| 748 | |
| 749 | r = crypt_convert(cc, &io->ctx); |
| 750 | |
| 751 | if (atomic_dec_and_test(&io->ctx.pending)) |
| 752 | kcryptd_crypt_read_done(io, r); |
| 753 | |
| 754 | crypt_dec_pending(io); |
| 755 | } |
| 756 | |
| 757 | static void kcryptd_async_done(struct crypto_async_request *async_req, |
| 758 | int error) |
| 759 | { |
| 760 | struct convert_context *ctx = async_req->data; |
| 761 | struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); |
| 762 | struct crypt_config *cc = io->target->private; |
| 763 | |
| 764 | if (error == -EINPROGRESS) { |
| 765 | complete(&ctx->restart); |
| 766 | return; |
| 767 | } |
| 768 | |
| 769 | mempool_free(ablkcipher_request_cast(async_req), cc->req_pool); |
| 770 | |
| 771 | if (!atomic_dec_and_test(&ctx->pending)) |
| 772 | return; |
| 773 | |
| 774 | if (bio_data_dir(io->base_bio) == READ) |
| 775 | kcryptd_crypt_read_done(io, error); |
| 776 | else |
| 777 | kcryptd_crypt_write_io_submit(io, error, 1); |
| 778 | } |
| 779 | |
| 780 | static void kcryptd_crypt(struct work_struct *work) |
| 781 | { |
| 782 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
| 783 | |
| 784 | if (bio_data_dir(io->base_bio) == READ) |
| 785 | kcryptd_crypt_read_convert(io); |
| 786 | else |
| 787 | kcryptd_crypt_write_convert(io); |
| 788 | } |
| 789 | |
| 790 | static void kcryptd_queue_crypt(struct dm_crypt_io *io) |
| 791 | { |
| 792 | struct crypt_config *cc = io->target->private; |
| 793 | |
| 794 | INIT_WORK(&io->work, kcryptd_crypt); |
| 795 | queue_work(cc->crypt_queue, &io->work); |
| 796 | } |
| 797 | |
| 798 | /* |
| 799 | * Decode key from its hex representation |
| 800 | */ |
| 801 | static int crypt_decode_key(u8 *key, char *hex, unsigned int size) |
| 802 | { |
| 803 | char buffer[3]; |
| 804 | char *endp; |
| 805 | unsigned int i; |
| 806 | |
| 807 | buffer[2] = '\0'; |
| 808 | |
| 809 | for (i = 0; i < size; i++) { |
| 810 | buffer[0] = *hex++; |
| 811 | buffer[1] = *hex++; |
| 812 | |
| 813 | key[i] = (u8)simple_strtoul(buffer, &endp, 16); |
| 814 | |
| 815 | if (endp != &buffer[2]) |
| 816 | return -EINVAL; |
| 817 | } |
| 818 | |
| 819 | if (*hex != '\0') |
| 820 | return -EINVAL; |
| 821 | |
| 822 | return 0; |
| 823 | } |
| 824 | |
| 825 | /* |
| 826 | * Encode key into its hex representation |
| 827 | */ |
| 828 | static void crypt_encode_key(char *hex, u8 *key, unsigned int size) |
| 829 | { |
| 830 | unsigned int i; |
| 831 | |
| 832 | for (i = 0; i < size; i++) { |
| 833 | sprintf(hex, "%02x", *key); |
| 834 | hex += 2; |
| 835 | key++; |
| 836 | } |
| 837 | } |
| 838 | |
| 839 | static int crypt_set_key(struct crypt_config *cc, char *key) |
| 840 | { |
| 841 | unsigned key_size = strlen(key) >> 1; |
| 842 | |
| 843 | if (cc->key_size && cc->key_size != key_size) |
| 844 | return -EINVAL; |
| 845 | |
| 846 | cc->key_size = key_size; /* initial settings */ |
| 847 | |
| 848 | if ((!key_size && strcmp(key, "-")) || |
| 849 | (key_size && crypt_decode_key(cc->key, key, key_size) < 0)) |
| 850 | return -EINVAL; |
| 851 | |
| 852 | set_bit(DM_CRYPT_KEY_VALID, &cc->flags); |
| 853 | |
| 854 | return 0; |
| 855 | } |
| 856 | |
| 857 | static int crypt_wipe_key(struct crypt_config *cc) |
| 858 | { |
| 859 | clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); |
| 860 | memset(&cc->key, 0, cc->key_size * sizeof(u8)); |
| 861 | return 0; |
| 862 | } |
| 863 | |
| 864 | /* |
| 865 | * Construct an encryption mapping: |
| 866 | * <cipher> <key> <iv_offset> <dev_path> <start> |
| 867 | */ |
| 868 | static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) |
| 869 | { |
| 870 | struct crypt_config *cc; |
| 871 | struct crypto_ablkcipher *tfm; |
| 872 | char *tmp; |
| 873 | char *cipher; |
| 874 | char *chainmode; |
| 875 | char *ivmode; |
| 876 | char *ivopts; |
| 877 | unsigned int key_size; |
| 878 | unsigned long long tmpll; |
| 879 | |
| 880 | if (argc != 5) { |
| 881 | ti->error = "Not enough arguments"; |
| 882 | return -EINVAL; |
| 883 | } |
| 884 | |
| 885 | tmp = argv[0]; |
| 886 | cipher = strsep(&tmp, "-"); |
| 887 | chainmode = strsep(&tmp, "-"); |
| 888 | ivopts = strsep(&tmp, "-"); |
| 889 | ivmode = strsep(&ivopts, ":"); |
| 890 | |
| 891 | if (tmp) |
| 892 | DMWARN("Unexpected additional cipher options"); |
| 893 | |
| 894 | key_size = strlen(argv[1]) >> 1; |
| 895 | |
| 896 | cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); |
| 897 | if (cc == NULL) { |
| 898 | ti->error = |
| 899 | "Cannot allocate transparent encryption context"; |
| 900 | return -ENOMEM; |
| 901 | } |
| 902 | |
| 903 | if (crypt_set_key(cc, argv[1])) { |
| 904 | ti->error = "Error decoding key"; |
| 905 | goto bad_cipher; |
| 906 | } |
| 907 | |
| 908 | /* Compatiblity mode for old dm-crypt cipher strings */ |
| 909 | if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { |
| 910 | chainmode = "cbc"; |
| 911 | ivmode = "plain"; |
| 912 | } |
| 913 | |
| 914 | if (strcmp(chainmode, "ecb") && !ivmode) { |
| 915 | ti->error = "This chaining mode requires an IV mechanism"; |
| 916 | goto bad_cipher; |
| 917 | } |
| 918 | |
| 919 | if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", |
| 920 | chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) { |
| 921 | ti->error = "Chain mode + cipher name is too long"; |
| 922 | goto bad_cipher; |
| 923 | } |
| 924 | |
| 925 | tfm = crypto_alloc_ablkcipher(cc->cipher, 0, 0); |
| 926 | if (IS_ERR(tfm)) { |
| 927 | ti->error = "Error allocating crypto tfm"; |
| 928 | goto bad_cipher; |
| 929 | } |
| 930 | |
| 931 | strcpy(cc->cipher, cipher); |
| 932 | strcpy(cc->chainmode, chainmode); |
| 933 | cc->tfm = tfm; |
| 934 | |
| 935 | /* |
| 936 | * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi". |
| 937 | * See comments at iv code |
| 938 | */ |
| 939 | |
| 940 | if (ivmode == NULL) |
| 941 | cc->iv_gen_ops = NULL; |
| 942 | else if (strcmp(ivmode, "plain") == 0) |
| 943 | cc->iv_gen_ops = &crypt_iv_plain_ops; |
| 944 | else if (strcmp(ivmode, "essiv") == 0) |
| 945 | cc->iv_gen_ops = &crypt_iv_essiv_ops; |
| 946 | else if (strcmp(ivmode, "benbi") == 0) |
| 947 | cc->iv_gen_ops = &crypt_iv_benbi_ops; |
| 948 | else if (strcmp(ivmode, "null") == 0) |
| 949 | cc->iv_gen_ops = &crypt_iv_null_ops; |
| 950 | else { |
| 951 | ti->error = "Invalid IV mode"; |
| 952 | goto bad_ivmode; |
| 953 | } |
| 954 | |
| 955 | if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && |
| 956 | cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) |
| 957 | goto bad_ivmode; |
| 958 | |
| 959 | cc->iv_size = crypto_ablkcipher_ivsize(tfm); |
| 960 | if (cc->iv_size) |
| 961 | /* at least a 64 bit sector number should fit in our buffer */ |
| 962 | cc->iv_size = max(cc->iv_size, |
| 963 | (unsigned int)(sizeof(u64) / sizeof(u8))); |
| 964 | else { |
| 965 | if (cc->iv_gen_ops) { |
| 966 | DMWARN("Selected cipher does not support IVs"); |
| 967 | if (cc->iv_gen_ops->dtr) |
| 968 | cc->iv_gen_ops->dtr(cc); |
| 969 | cc->iv_gen_ops = NULL; |
| 970 | } |
| 971 | } |
| 972 | |
| 973 | cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); |
| 974 | if (!cc->io_pool) { |
| 975 | ti->error = "Cannot allocate crypt io mempool"; |
| 976 | goto bad_slab_pool; |
| 977 | } |
| 978 | |
| 979 | cc->dmreq_start = sizeof(struct ablkcipher_request); |
| 980 | cc->dmreq_start += crypto_ablkcipher_reqsize(tfm); |
| 981 | cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment()); |
| 982 | cc->dmreq_start += crypto_ablkcipher_alignmask(tfm) & |
| 983 | ~(crypto_tfm_ctx_alignment() - 1); |
| 984 | |
| 985 | cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + |
| 986 | sizeof(struct dm_crypt_request) + cc->iv_size); |
| 987 | if (!cc->req_pool) { |
| 988 | ti->error = "Cannot allocate crypt request mempool"; |
| 989 | goto bad_req_pool; |
| 990 | } |
| 991 | cc->req = NULL; |
| 992 | |
| 993 | cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); |
| 994 | if (!cc->page_pool) { |
| 995 | ti->error = "Cannot allocate page mempool"; |
| 996 | goto bad_page_pool; |
| 997 | } |
| 998 | |
| 999 | cc->bs = bioset_create(MIN_IOS, MIN_IOS); |
| 1000 | if (!cc->bs) { |
| 1001 | ti->error = "Cannot allocate crypt bioset"; |
| 1002 | goto bad_bs; |
| 1003 | } |
| 1004 | |
| 1005 | if (crypto_ablkcipher_setkey(tfm, cc->key, key_size) < 0) { |
| 1006 | ti->error = "Error setting key"; |
| 1007 | goto bad_device; |
| 1008 | } |
| 1009 | |
| 1010 | if (sscanf(argv[2], "%llu", &tmpll) != 1) { |
| 1011 | ti->error = "Invalid iv_offset sector"; |
| 1012 | goto bad_device; |
| 1013 | } |
| 1014 | cc->iv_offset = tmpll; |
| 1015 | |
| 1016 | if (sscanf(argv[4], "%llu", &tmpll) != 1) { |
| 1017 | ti->error = "Invalid device sector"; |
| 1018 | goto bad_device; |
| 1019 | } |
| 1020 | cc->start = tmpll; |
| 1021 | |
| 1022 | if (dm_get_device(ti, argv[3], cc->start, ti->len, |
| 1023 | dm_table_get_mode(ti->table), &cc->dev)) { |
| 1024 | ti->error = "Device lookup failed"; |
| 1025 | goto bad_device; |
| 1026 | } |
| 1027 | |
| 1028 | if (ivmode && cc->iv_gen_ops) { |
| 1029 | if (ivopts) |
| 1030 | *(ivopts - 1) = ':'; |
| 1031 | cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); |
| 1032 | if (!cc->iv_mode) { |
| 1033 | ti->error = "Error kmallocing iv_mode string"; |
| 1034 | goto bad_ivmode_string; |
| 1035 | } |
| 1036 | strcpy(cc->iv_mode, ivmode); |
| 1037 | } else |
| 1038 | cc->iv_mode = NULL; |
| 1039 | |
| 1040 | cc->io_queue = create_singlethread_workqueue("kcryptd_io"); |
| 1041 | if (!cc->io_queue) { |
| 1042 | ti->error = "Couldn't create kcryptd io queue"; |
| 1043 | goto bad_io_queue; |
| 1044 | } |
| 1045 | |
| 1046 | cc->crypt_queue = create_singlethread_workqueue("kcryptd"); |
| 1047 | if (!cc->crypt_queue) { |
| 1048 | ti->error = "Couldn't create kcryptd queue"; |
| 1049 | goto bad_crypt_queue; |
| 1050 | } |
| 1051 | |
| 1052 | init_waitqueue_head(&cc->writeq); |
| 1053 | ti->private = cc; |
| 1054 | return 0; |
| 1055 | |
| 1056 | bad_crypt_queue: |
| 1057 | destroy_workqueue(cc->io_queue); |
| 1058 | bad_io_queue: |
| 1059 | kfree(cc->iv_mode); |
| 1060 | bad_ivmode_string: |
| 1061 | dm_put_device(ti, cc->dev); |
| 1062 | bad_device: |
| 1063 | bioset_free(cc->bs); |
| 1064 | bad_bs: |
| 1065 | mempool_destroy(cc->page_pool); |
| 1066 | bad_page_pool: |
| 1067 | mempool_destroy(cc->req_pool); |
| 1068 | bad_req_pool: |
| 1069 | mempool_destroy(cc->io_pool); |
| 1070 | bad_slab_pool: |
| 1071 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
| 1072 | cc->iv_gen_ops->dtr(cc); |
| 1073 | bad_ivmode: |
| 1074 | crypto_free_ablkcipher(tfm); |
| 1075 | bad_cipher: |
| 1076 | /* Must zero key material before freeing */ |
| 1077 | memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); |
| 1078 | kfree(cc); |
| 1079 | return -EINVAL; |
| 1080 | } |
| 1081 | |
| 1082 | static void crypt_dtr(struct dm_target *ti) |
| 1083 | { |
| 1084 | struct crypt_config *cc = (struct crypt_config *) ti->private; |
| 1085 | |
| 1086 | destroy_workqueue(cc->io_queue); |
| 1087 | destroy_workqueue(cc->crypt_queue); |
| 1088 | |
| 1089 | if (cc->req) |
| 1090 | mempool_free(cc->req, cc->req_pool); |
| 1091 | |
| 1092 | bioset_free(cc->bs); |
| 1093 | mempool_destroy(cc->page_pool); |
| 1094 | mempool_destroy(cc->req_pool); |
| 1095 | mempool_destroy(cc->io_pool); |
| 1096 | |
| 1097 | kfree(cc->iv_mode); |
| 1098 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
| 1099 | cc->iv_gen_ops->dtr(cc); |
| 1100 | crypto_free_ablkcipher(cc->tfm); |
| 1101 | dm_put_device(ti, cc->dev); |
| 1102 | |
| 1103 | /* Must zero key material before freeing */ |
| 1104 | memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); |
| 1105 | kfree(cc); |
| 1106 | } |
| 1107 | |
| 1108 | static int crypt_map(struct dm_target *ti, struct bio *bio, |
| 1109 | union map_info *map_context) |
| 1110 | { |
| 1111 | struct crypt_config *cc = ti->private; |
| 1112 | struct dm_crypt_io *io; |
| 1113 | |
| 1114 | io = mempool_alloc(cc->io_pool, GFP_NOIO); |
| 1115 | io->target = ti; |
| 1116 | io->base_bio = bio; |
| 1117 | io->sector = bio->bi_sector - ti->begin; |
| 1118 | io->error = 0; |
| 1119 | atomic_set(&io->pending, 0); |
| 1120 | |
| 1121 | if (bio_data_dir(io->base_bio) == READ) |
| 1122 | kcryptd_queue_io(io); |
| 1123 | else |
| 1124 | kcryptd_queue_crypt(io); |
| 1125 | |
| 1126 | return DM_MAPIO_SUBMITTED; |
| 1127 | } |
| 1128 | |
| 1129 | static int crypt_status(struct dm_target *ti, status_type_t type, |
| 1130 | char *result, unsigned int maxlen) |
| 1131 | { |
| 1132 | struct crypt_config *cc = (struct crypt_config *) ti->private; |
| 1133 | unsigned int sz = 0; |
| 1134 | |
| 1135 | switch (type) { |
| 1136 | case STATUSTYPE_INFO: |
| 1137 | result[0] = '\0'; |
| 1138 | break; |
| 1139 | |
| 1140 | case STATUSTYPE_TABLE: |
| 1141 | if (cc->iv_mode) |
| 1142 | DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode, |
| 1143 | cc->iv_mode); |
| 1144 | else |
| 1145 | DMEMIT("%s-%s ", cc->cipher, cc->chainmode); |
| 1146 | |
| 1147 | if (cc->key_size > 0) { |
| 1148 | if ((maxlen - sz) < ((cc->key_size << 1) + 1)) |
| 1149 | return -ENOMEM; |
| 1150 | |
| 1151 | crypt_encode_key(result + sz, cc->key, cc->key_size); |
| 1152 | sz += cc->key_size << 1; |
| 1153 | } else { |
| 1154 | if (sz >= maxlen) |
| 1155 | return -ENOMEM; |
| 1156 | result[sz++] = '-'; |
| 1157 | } |
| 1158 | |
| 1159 | DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, |
| 1160 | cc->dev->name, (unsigned long long)cc->start); |
| 1161 | break; |
| 1162 | } |
| 1163 | return 0; |
| 1164 | } |
| 1165 | |
| 1166 | static void crypt_postsuspend(struct dm_target *ti) |
| 1167 | { |
| 1168 | struct crypt_config *cc = ti->private; |
| 1169 | |
| 1170 | set_bit(DM_CRYPT_SUSPENDED, &cc->flags); |
| 1171 | } |
| 1172 | |
| 1173 | static int crypt_preresume(struct dm_target *ti) |
| 1174 | { |
| 1175 | struct crypt_config *cc = ti->private; |
| 1176 | |
| 1177 | if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { |
| 1178 | DMERR("aborting resume - crypt key is not set."); |
| 1179 | return -EAGAIN; |
| 1180 | } |
| 1181 | |
| 1182 | return 0; |
| 1183 | } |
| 1184 | |
| 1185 | static void crypt_resume(struct dm_target *ti) |
| 1186 | { |
| 1187 | struct crypt_config *cc = ti->private; |
| 1188 | |
| 1189 | clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); |
| 1190 | } |
| 1191 | |
| 1192 | /* Message interface |
| 1193 | * key set <key> |
| 1194 | * key wipe |
| 1195 | */ |
| 1196 | static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) |
| 1197 | { |
| 1198 | struct crypt_config *cc = ti->private; |
| 1199 | |
| 1200 | if (argc < 2) |
| 1201 | goto error; |
| 1202 | |
| 1203 | if (!strnicmp(argv[0], MESG_STR("key"))) { |
| 1204 | if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { |
| 1205 | DMWARN("not suspended during key manipulation."); |
| 1206 | return -EINVAL; |
| 1207 | } |
| 1208 | if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) |
| 1209 | return crypt_set_key(cc, argv[2]); |
| 1210 | if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) |
| 1211 | return crypt_wipe_key(cc); |
| 1212 | } |
| 1213 | |
| 1214 | error: |
| 1215 | DMWARN("unrecognised message received."); |
| 1216 | return -EINVAL; |
| 1217 | } |
| 1218 | |
| 1219 | static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm, |
| 1220 | struct bio_vec *biovec, int max_size) |
| 1221 | { |
| 1222 | struct crypt_config *cc = ti->private; |
| 1223 | struct request_queue *q = bdev_get_queue(cc->dev->bdev); |
| 1224 | |
| 1225 | if (!q->merge_bvec_fn) |
| 1226 | return max_size; |
| 1227 | |
| 1228 | bvm->bi_bdev = cc->dev->bdev; |
| 1229 | bvm->bi_sector = cc->start + bvm->bi_sector - ti->begin; |
| 1230 | |
| 1231 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); |
| 1232 | } |
| 1233 | |
| 1234 | static struct target_type crypt_target = { |
| 1235 | .name = "crypt", |
| 1236 | .version= {1, 6, 0}, |
| 1237 | .module = THIS_MODULE, |
| 1238 | .ctr = crypt_ctr, |
| 1239 | .dtr = crypt_dtr, |
| 1240 | .map = crypt_map, |
| 1241 | .status = crypt_status, |
| 1242 | .postsuspend = crypt_postsuspend, |
| 1243 | .preresume = crypt_preresume, |
| 1244 | .resume = crypt_resume, |
| 1245 | .message = crypt_message, |
| 1246 | .merge = crypt_merge, |
| 1247 | }; |
| 1248 | |
| 1249 | static int __init dm_crypt_init(void) |
| 1250 | { |
| 1251 | int r; |
| 1252 | |
| 1253 | _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0); |
| 1254 | if (!_crypt_io_pool) |
| 1255 | return -ENOMEM; |
| 1256 | |
| 1257 | r = dm_register_target(&crypt_target); |
| 1258 | if (r < 0) { |
| 1259 | DMERR("register failed %d", r); |
| 1260 | kmem_cache_destroy(_crypt_io_pool); |
| 1261 | } |
| 1262 | |
| 1263 | return r; |
| 1264 | } |
| 1265 | |
| 1266 | static void __exit dm_crypt_exit(void) |
| 1267 | { |
| 1268 | int r = dm_unregister_target(&crypt_target); |
| 1269 | |
| 1270 | if (r < 0) |
| 1271 | DMERR("unregister failed %d", r); |
| 1272 | |
| 1273 | kmem_cache_destroy(_crypt_io_pool); |
| 1274 | } |
| 1275 | |
| 1276 | module_init(dm_crypt_init); |
| 1277 | module_exit(dm_crypt_exit); |
| 1278 | |
| 1279 | MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); |
| 1280 | MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); |
| 1281 | MODULE_LICENSE("GPL"); |