1/*
   2 * Copyright (C) 2003 Christophe Saout <christophe@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/backing-dev.h>
  22#include <linux/atomic.h>
  23#include <linux/scatterlist.h>
 
 
  24#include <asm/page.h>
  25#include <asm/unaligned.h>
  26#include <crypto/hash.h>
  27#include <crypto/md5.h>
  28#include <crypto/algapi.h>
 
 
 
 
 
  29
  30#include <linux/device-mapper.h>
  31
  32#define DM_MSG_PREFIX "crypt"
  33
  34/*
  35 * context holding the current state of a multi-part conversion
  36 */
  37struct convert_context {
  38	struct completion restart;
  39	struct bio *bio_in;
  40	struct bio *bio_out;
  41	struct bvec_iter iter_in;
  42	struct bvec_iter iter_out;
  43	sector_t cc_sector;
  44	atomic_t cc_pending;
  45	struct ablkcipher_request *req;
 
 
 
 
  46};
  47
  48/*
  49 * per bio private data
  50 */
  51struct dm_crypt_io {
  52	struct crypt_config *cc;
  53	struct bio *base_bio;
 
 
  54	struct work_struct work;
  55
  56	struct convert_context ctx;
  57
  58	atomic_t io_pending;
  59	int error;
  60	sector_t sector;
  61	struct dm_crypt_io *base_io;
  62};
 
  63
  64struct dm_crypt_request {
  65	struct convert_context *ctx;
  66	struct scatterlist sg_in;
  67	struct scatterlist sg_out;
  68	sector_t iv_sector;
  69};
  70
  71struct crypt_config;
  72
  73struct crypt_iv_operations {
  74	int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
  75		   const char *opts);
  76	void (*dtr)(struct crypt_config *cc);
  77	int (*init)(struct crypt_config *cc);
  78	int (*wipe)(struct crypt_config *cc);
  79	int (*generator)(struct crypt_config *cc, u8 *iv,
  80			 struct dm_crypt_request *dmreq);
  81	int (*post)(struct crypt_config *cc, u8 *iv,
  82		    struct dm_crypt_request *dmreq);
  83};
  84
  85struct iv_essiv_private {
  86	struct crypto_hash *hash_tfm;
  87	u8 *salt;
  88};
  89
  90struct iv_benbi_private {
  91	int shift;
  92};
  93
  94#define LMK_SEED_SIZE 64 /* hash + 0 */
  95struct iv_lmk_private {
  96	struct crypto_shash *hash_tfm;
  97	u8 *seed;
  98};
  99
 100#define TCW_WHITENING_SIZE 16
 101struct iv_tcw_private {
 102	struct crypto_shash *crc32_tfm;
 103	u8 *iv_seed;
 104	u8 *whitening;
 105};
 106
 107/*
 108 * Crypt: maps a linear range of a block device
 109 * and encrypts / decrypts at the same time.
 110 */
 111enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
 
 
 
 
 
 
 112
 113/*
 114 * The fields in here must be read only after initialization.
 115 */
 116struct crypt_config {
 117	struct dm_dev *dev;
 118	sector_t start;
 119
 120	/*
 121	 * pool for per bio private data, crypto requests and
 122	 * encryption requeusts/buffer pages
 123	 */
 124	mempool_t *io_pool;
 125	mempool_t *req_pool;
 126	mempool_t *page_pool;
 
 
 
 
 
 127	struct bio_set *bs;
 
 128
 129	struct workqueue_struct *io_queue;
 130	struct workqueue_struct *crypt_queue;
 131
 
 
 
 
 132	char *cipher;
 133	char *cipher_string;
 
 
 134
 135	struct crypt_iv_operations *iv_gen_ops;
 136	union {
 137		struct iv_essiv_private essiv;
 138		struct iv_benbi_private benbi;
 139		struct iv_lmk_private lmk;
 140		struct iv_tcw_private tcw;
 141	} iv_gen_private;
 142	sector_t iv_offset;
 143	unsigned int iv_size;
 
 
 144
 145	/* ESSIV: struct crypto_cipher *essiv_tfm */
 146	void *iv_private;
 147	struct crypto_ablkcipher **tfms;
 
 
 
 148	unsigned tfms_count;
 
 149
 150	/*
 151	 * Layout of each crypto request:
 152	 *
 153	 *   struct ablkcipher_request
 154	 *      context
 155	 *      padding
 156	 *   struct dm_crypt_request
 157	 *      padding
 158	 *   IV
 159	 *
 160	 * The padding is added so that dm_crypt_request and the IV are
 161	 * correctly aligned.
 162	 */
 163	unsigned int dmreq_start;
 164
 
 
 165	unsigned long flags;
 166	unsigned int key_size;
 167	unsigned int key_parts;      /* independent parts in key buffer */
 168	unsigned int key_extra_size; /* additional keys length */
 
 
 
 
 
 
 
 169	u8 key[0];
 170};
 171
 172#define MIN_IOS        16
 173#define MIN_POOL_PAGES 32
 174
 175static struct kmem_cache *_crypt_io_pool;
 
 
 
 
 
 176
 177static void clone_init(struct dm_crypt_io *, struct bio *);
 178static void kcryptd_queue_crypt(struct dm_crypt_io *io);
 179static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
 
 180
 181/*
 182 * Use this to access cipher attributes that are the same for each CPU.
 183 */
 184static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
 
 
 
 
 
 185{
 186	return cc->tfms[0];
 187}
 188
 189/*
 190 * Different IV generation algorithms:
 191 *
 192 * plain: the initial vector is the 32-bit little-endian version of the sector
 193 *        number, padded with zeros if necessary.
 194 *
 195 * plain64: the initial vector is the 64-bit little-endian version of the sector
 196 *        number, padded with zeros if necessary.
 197 *
 
 
 
 198 * essiv: "encrypted sector|salt initial vector", the sector number is
 199 *        encrypted with the bulk cipher using a salt as key. The salt
 200 *        should be derived from the bulk cipher's key via hashing.
 201 *
 202 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
 203 *        (needed for LRW-32-AES and possible other narrow block modes)
 204 *
 205 * null: the initial vector is always zero.  Provides compatibility with
 206 *       obsolete loop_fish2 devices.  Do not use for new devices.
 207 *
 208 * lmk:  Compatible implementation of the block chaining mode used
 209 *       by the Loop-AES block device encryption system
 210 *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
 211 *       It operates on full 512 byte sectors and uses CBC
 212 *       with an IV derived from the sector number, the data and
 213 *       optionally extra IV seed.
 214 *       This means that after decryption the first block
 215 *       of sector must be tweaked according to decrypted data.
 216 *       Loop-AES can use three encryption schemes:
 217 *         version 1: is plain aes-cbc mode
 218 *         version 2: uses 64 multikey scheme with lmk IV generator
 219 *         version 3: the same as version 2 with additional IV seed
 220 *                   (it uses 65 keys, last key is used as IV seed)
 221 *
 222 * tcw:  Compatible implementation of the block chaining mode used
 223 *       by the TrueCrypt device encryption system (prior to version 4.1).
 224 *       For more info see: http://www.truecrypt.org
 225 *       It operates on full 512 byte sectors and uses CBC
 226 *       with an IV derived from initial key and the sector number.
 227 *       In addition, whitening value is applied on every sector, whitening
 228 *       is calculated from initial key, sector number and mixed using CRC32.
 229 *       Note that this encryption scheme is vulnerable to watermarking attacks
 230 *       and should be used for old compatible containers access only.
 231 *
 232 * plumb: unimplemented, see:
 233 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
 234 */
 235
 236static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
 237			      struct dm_crypt_request *dmreq)
 238{
 239	memset(iv, 0, cc->iv_size);
 240	*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
 241
 242	return 0;
 243}
 244
 245static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
 246				struct dm_crypt_request *dmreq)
 247{
 248	memset(iv, 0, cc->iv_size);
 249	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 250
 251	return 0;
 252}
 253
 
 
 
 
 
 
 
 
 
 
 254/* Initialise ESSIV - compute salt but no local memory allocations */
 255static int crypt_iv_essiv_init(struct crypt_config *cc)
 256{
 257	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 258	struct hash_desc desc;
 259	struct scatterlist sg;
 260	struct crypto_cipher *essiv_tfm;
 261	int err;
 262
 263	sg_init_one(&sg, cc->key, cc->key_size);
 264	desc.tfm = essiv->hash_tfm;
 265	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 
 266
 267	err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
 
 268	if (err)
 269		return err;
 270
 271	essiv_tfm = cc->iv_private;
 272
 273	err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
 274			    crypto_hash_digestsize(essiv->hash_tfm));
 275	if (err)
 276		return err;
 277
 278	return 0;
 279}
 280
 281/* Wipe salt and reset key derived from volume key */
 282static int crypt_iv_essiv_wipe(struct crypt_config *cc)
 283{
 284	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 285	unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
 286	struct crypto_cipher *essiv_tfm;
 287	int r, err = 0;
 288
 289	memset(essiv->salt, 0, salt_size);
 290
 291	essiv_tfm = cc->iv_private;
 292	r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
 293	if (r)
 294		err = r;
 295
 296	return err;
 297}
 298
 299/* Set up per cpu cipher state */
 300static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
 301					     struct dm_target *ti,
 302					     u8 *salt, unsigned saltsize)
 
 303{
 304	struct crypto_cipher *essiv_tfm;
 305	int err;
 306
 307	/* Setup the essiv_tfm with the given salt */
 308	essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
 309	if (IS_ERR(essiv_tfm)) {
 310		ti->error = "Error allocating crypto tfm for ESSIV";
 311		return essiv_tfm;
 312	}
 313
 314	if (crypto_cipher_blocksize(essiv_tfm) !=
 315	    crypto_ablkcipher_ivsize(any_tfm(cc))) {
 316		ti->error = "Block size of ESSIV cipher does "
 317			    "not match IV size of block cipher";
 318		crypto_free_cipher(essiv_tfm);
 319		return ERR_PTR(-EINVAL);
 320	}
 321
 322	err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
 323	if (err) {
 324		ti->error = "Failed to set key for ESSIV cipher";
 325		crypto_free_cipher(essiv_tfm);
 326		return ERR_PTR(err);
 327	}
 328
 329	return essiv_tfm;
 330}
 331
 332static void crypt_iv_essiv_dtr(struct crypt_config *cc)
 333{
 334	struct crypto_cipher *essiv_tfm;
 335	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 336
 337	crypto_free_hash(essiv->hash_tfm);
 338	essiv->hash_tfm = NULL;
 339
 340	kzfree(essiv->salt);
 341	essiv->salt = NULL;
 342
 343	essiv_tfm = cc->iv_private;
 344
 345	if (essiv_tfm)
 346		crypto_free_cipher(essiv_tfm);
 347
 348	cc->iv_private = NULL;
 349}
 350
 351static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 352			      const char *opts)
 353{
 354	struct crypto_cipher *essiv_tfm = NULL;
 355	struct crypto_hash *hash_tfm = NULL;
 356	u8 *salt = NULL;
 357	int err;
 358
 359	if (!opts) {
 360		ti->error = "Digest algorithm missing for ESSIV mode";
 361		return -EINVAL;
 362	}
 363
 364	/* Allocate hash algorithm */
 365	hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
 366	if (IS_ERR(hash_tfm)) {
 367		ti->error = "Error initializing ESSIV hash";
 368		err = PTR_ERR(hash_tfm);
 369		goto bad;
 370	}
 371
 372	salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
 373	if (!salt) {
 374		ti->error = "Error kmallocing salt storage in ESSIV";
 375		err = -ENOMEM;
 376		goto bad;
 377	}
 378
 379	cc->iv_gen_private.essiv.salt = salt;
 380	cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
 381
 382	essiv_tfm = setup_essiv_cpu(cc, ti, salt,
 383				crypto_hash_digestsize(hash_tfm));
 384	if (IS_ERR(essiv_tfm)) {
 385		crypt_iv_essiv_dtr(cc);
 386		return PTR_ERR(essiv_tfm);
 387	}
 388	cc->iv_private = essiv_tfm;
 389
 390	return 0;
 391
 392bad:
 393	if (hash_tfm && !IS_ERR(hash_tfm))
 394		crypto_free_hash(hash_tfm);
 395	kfree(salt);
 396	return err;
 397}
 398
 399static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
 400			      struct dm_crypt_request *dmreq)
 401{
 402	struct crypto_cipher *essiv_tfm = cc->iv_private;
 403
 404	memset(iv, 0, cc->iv_size);
 405	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 406	crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
 407
 408	return 0;
 409}
 410
 411static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
 412			      const char *opts)
 413{
 414	unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
 415	int log = ilog2(bs);
 416
 417	/* we need to calculate how far we must shift the sector count
 418	 * to get the cipher block count, we use this shift in _gen */
 419
 420	if (1 << log != bs) {
 421		ti->error = "cypher blocksize is not a power of 2";
 422		return -EINVAL;
 423	}
 424
 425	if (log > 9) {
 426		ti->error = "cypher blocksize is > 512";
 427		return -EINVAL;
 428	}
 429
 430	cc->iv_gen_private.benbi.shift = 9 - log;
 431
 432	return 0;
 433}
 434
 435static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 436{
 437}
 438
 439static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
 440			      struct dm_crypt_request *dmreq)
 441{
 442	__be64 val;
 443
 444	memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 445
 446	val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
 447	put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 448
 449	return 0;
 450}
 451
 452static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
 453			     struct dm_crypt_request *dmreq)
 454{
 455	memset(iv, 0, cc->iv_size);
 456
 457	return 0;
 458}
 459
 460static void crypt_iv_lmk_dtr(struct crypt_config *cc)
 461{
 462	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 463
 464	if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
 465		crypto_free_shash(lmk->hash_tfm);
 466	lmk->hash_tfm = NULL;
 467
 468	kzfree(lmk->seed);
 469	lmk->seed = NULL;
 470}
 471
 472static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
 473			    const char *opts)
 474{
 475	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 476
 
 
 
 
 
 477	lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
 478	if (IS_ERR(lmk->hash_tfm)) {
 479		ti->error = "Error initializing LMK hash";
 480		return PTR_ERR(lmk->hash_tfm);
 481	}
 482
 483	/* No seed in LMK version 2 */
 484	if (cc->key_parts == cc->tfms_count) {
 485		lmk->seed = NULL;
 486		return 0;
 487	}
 488
 489	lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
 490	if (!lmk->seed) {
 491		crypt_iv_lmk_dtr(cc);
 492		ti->error = "Error kmallocing seed storage in LMK";
 493		return -ENOMEM;
 494	}
 495
 496	return 0;
 497}
 498
 499static int crypt_iv_lmk_init(struct crypt_config *cc)
 500{
 501	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 502	int subkey_size = cc->key_size / cc->key_parts;
 503
 504	/* LMK seed is on the position of LMK_KEYS + 1 key */
 505	if (lmk->seed)
 506		memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
 507		       crypto_shash_digestsize(lmk->hash_tfm));
 508
 509	return 0;
 510}
 511
 512static int crypt_iv_lmk_wipe(struct crypt_config *cc)
 513{
 514	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 515
 516	if (lmk->seed)
 517		memset(lmk->seed, 0, LMK_SEED_SIZE);
 518
 519	return 0;
 520}
 521
 522static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 523			    struct dm_crypt_request *dmreq,
 524			    u8 *data)
 525{
 526	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 527	struct {
 528		struct shash_desc desc;
 529		char ctx[crypto_shash_descsize(lmk->hash_tfm)];
 530	} sdesc;
 531	struct md5_state md5state;
 532	__le32 buf[4];
 533	int i, r;
 534
 535	sdesc.desc.tfm = lmk->hash_tfm;
 536	sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 537
 538	r = crypto_shash_init(&sdesc.desc);
 539	if (r)
 540		return r;
 541
 542	if (lmk->seed) {
 543		r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
 544		if (r)
 545			return r;
 546	}
 547
 548	/* Sector is always 512B, block size 16, add data of blocks 1-31 */
 549	r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
 550	if (r)
 551		return r;
 552
 553	/* Sector is cropped to 56 bits here */
 554	buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
 555	buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
 556	buf[2] = cpu_to_le32(4024);
 557	buf[3] = 0;
 558	r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
 559	if (r)
 560		return r;
 561
 562	/* No MD5 padding here */
 563	r = crypto_shash_export(&sdesc.desc, &md5state);
 564	if (r)
 565		return r;
 566
 567	for (i = 0; i < MD5_HASH_WORDS; i++)
 568		__cpu_to_le32s(&md5state.hash[i]);
 569	memcpy(iv, &md5state.hash, cc->iv_size);
 570
 571	return 0;
 572}
 573
 574static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 575			    struct dm_crypt_request *dmreq)
 576{
 
 577	u8 *src;
 578	int r = 0;
 579
 580	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 581		src = kmap_atomic(sg_page(&dmreq->sg_in));
 582		r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
 
 583		kunmap_atomic(src);
 584	} else
 585		memset(iv, 0, cc->iv_size);
 586
 587	return r;
 588}
 589
 590static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
 591			     struct dm_crypt_request *dmreq)
 592{
 
 593	u8 *dst;
 594	int r;
 595
 596	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
 597		return 0;
 598
 599	dst = kmap_atomic(sg_page(&dmreq->sg_out));
 600	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
 
 601
 602	/* Tweak the first block of plaintext sector */
 603	if (!r)
 604		crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
 605
 606	kunmap_atomic(dst);
 607	return r;
 608}
 609
 610static void crypt_iv_tcw_dtr(struct crypt_config *cc)
 611{
 612	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 613
 614	kzfree(tcw->iv_seed);
 615	tcw->iv_seed = NULL;
 616	kzfree(tcw->whitening);
 617	tcw->whitening = NULL;
 618
 619	if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
 620		crypto_free_shash(tcw->crc32_tfm);
 621	tcw->crc32_tfm = NULL;
 622}
 623
 624static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
 625			    const char *opts)
 626{
 627	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 628
 
 
 
 
 
 629	if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
 630		ti->error = "Wrong key size for TCW";
 631		return -EINVAL;
 632	}
 633
 634	tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
 635	if (IS_ERR(tcw->crc32_tfm)) {
 636		ti->error = "Error initializing CRC32 in TCW";
 637		return PTR_ERR(tcw->crc32_tfm);
 638	}
 639
 640	tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
 641	tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
 642	if (!tcw->iv_seed || !tcw->whitening) {
 643		crypt_iv_tcw_dtr(cc);
 644		ti->error = "Error allocating seed storage in TCW";
 645		return -ENOMEM;
 646	}
 647
 648	return 0;
 649}
 650
 651static int crypt_iv_tcw_init(struct crypt_config *cc)
 652{
 653	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 654	int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
 655
 656	memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
 657	memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
 658	       TCW_WHITENING_SIZE);
 659
 660	return 0;
 661}
 662
 663static int crypt_iv_tcw_wipe(struct crypt_config *cc)
 664{
 665	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 666
 667	memset(tcw->iv_seed, 0, cc->iv_size);
 668	memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
 669
 670	return 0;
 671}
 672
 673static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 674				  struct dm_crypt_request *dmreq,
 675				  u8 *data)
 676{
 677	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 678	u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
 679	u8 buf[TCW_WHITENING_SIZE];
 680	struct {
 681		struct shash_desc desc;
 682		char ctx[crypto_shash_descsize(tcw->crc32_tfm)];
 683	} sdesc;
 684	int i, r;
 685
 686	/* xor whitening with sector number */
 687	memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
 688	crypto_xor(buf, (u8 *)&sector, 8);
 689	crypto_xor(&buf[8], (u8 *)&sector, 8);
 690
 691	/* calculate crc32 for every 32bit part and xor it */
 692	sdesc.desc.tfm = tcw->crc32_tfm;
 693	sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 694	for (i = 0; i < 4; i++) {
 695		r = crypto_shash_init(&sdesc.desc);
 696		if (r)
 697			goto out;
 698		r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4);
 699		if (r)
 700			goto out;
 701		r = crypto_shash_final(&sdesc.desc, &buf[i * 4]);
 702		if (r)
 703			goto out;
 704	}
 705	crypto_xor(&buf[0], &buf[12], 4);
 706	crypto_xor(&buf[4], &buf[8], 4);
 707
 708	/* apply whitening (8 bytes) to whole sector */
 709	for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
 710		crypto_xor(data + i * 8, buf, 8);
 711out:
 712	memset(buf, 0, sizeof(buf));
 713	return r;
 714}
 715
 716static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 717			    struct dm_crypt_request *dmreq)
 718{
 
 719	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 720	u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
 721	u8 *src;
 722	int r = 0;
 723
 724	/* Remove whitening from ciphertext */
 725	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
 726		src = kmap_atomic(sg_page(&dmreq->sg_in));
 727		r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
 
 728		kunmap_atomic(src);
 729	}
 730
 731	/* Calculate IV */
 732	memcpy(iv, tcw->iv_seed, cc->iv_size);
 733	crypto_xor(iv, (u8 *)&sector, 8);
 734	if (cc->iv_size > 8)
 735		crypto_xor(&iv[8], (u8 *)&sector, cc->iv_size - 8);
 
 736
 737	return r;
 738}
 739
 740static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 741			     struct dm_crypt_request *dmreq)
 742{
 
 743	u8 *dst;
 744	int r;
 745
 746	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
 747		return 0;
 748
 749	/* Apply whitening on ciphertext */
 750	dst = kmap_atomic(sg_page(&dmreq->sg_out));
 751	r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
 
 752	kunmap_atomic(dst);
 753
 754	return r;
 755}
 756
 757static struct crypt_iv_operations crypt_iv_plain_ops = {
 
 
 
 
 
 
 
 
 758	.generator = crypt_iv_plain_gen
 759};
 760
 761static struct crypt_iv_operations crypt_iv_plain64_ops = {
 762	.generator = crypt_iv_plain64_gen
 763};
 764
 765static struct crypt_iv_operations crypt_iv_essiv_ops = {
 
 
 
 
 766	.ctr       = crypt_iv_essiv_ctr,
 767	.dtr       = crypt_iv_essiv_dtr,
 768	.init      = crypt_iv_essiv_init,
 769	.wipe      = crypt_iv_essiv_wipe,
 770	.generator = crypt_iv_essiv_gen
 771};
 772
 773static struct crypt_iv_operations crypt_iv_benbi_ops = {
 774	.ctr	   = crypt_iv_benbi_ctr,
 775	.dtr	   = crypt_iv_benbi_dtr,
 776	.generator = crypt_iv_benbi_gen
 777};
 778
 779static struct crypt_iv_operations crypt_iv_null_ops = {
 780	.generator = crypt_iv_null_gen
 781};
 782
 783static struct crypt_iv_operations crypt_iv_lmk_ops = {
 784	.ctr	   = crypt_iv_lmk_ctr,
 785	.dtr	   = crypt_iv_lmk_dtr,
 786	.init	   = crypt_iv_lmk_init,
 787	.wipe	   = crypt_iv_lmk_wipe,
 788	.generator = crypt_iv_lmk_gen,
 789	.post	   = crypt_iv_lmk_post
 790};
 791
 792static struct crypt_iv_operations crypt_iv_tcw_ops = {
 793	.ctr	   = crypt_iv_tcw_ctr,
 794	.dtr	   = crypt_iv_tcw_dtr,
 795	.init	   = crypt_iv_tcw_init,
 796	.wipe	   = crypt_iv_tcw_wipe,
 797	.generator = crypt_iv_tcw_gen,
 798	.post	   = crypt_iv_tcw_post
 799};
 800
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 801static void crypt_convert_init(struct crypt_config *cc,
 802			       struct convert_context *ctx,
 803			       struct bio *bio_out, struct bio *bio_in,
 804			       sector_t sector)
 805{
 806	ctx->bio_in = bio_in;
 807	ctx->bio_out = bio_out;
 808	if (bio_in)
 809		ctx->iter_in = bio_in->bi_iter;
 810	if (bio_out)
 811		ctx->iter_out = bio_out->bi_iter;
 812	ctx->cc_sector = sector + cc->iv_offset;
 813	init_completion(&ctx->restart);
 814}
 815
 816static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
 817					     struct ablkcipher_request *req)
 818{
 819	return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
 820}
 821
 822static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
 823					       struct dm_crypt_request *dmreq)
 824{
 825	return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
 826}
 827
 828static u8 *iv_of_dmreq(struct crypt_config *cc,
 829		       struct dm_crypt_request *dmreq)
 830{
 831	return (u8 *)ALIGN((unsigned long)(dmreq + 1),
 832		crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
 
 
 
 
 833}
 834
 835static int crypt_convert_block(struct crypt_config *cc,
 836			       struct convert_context *ctx,
 837			       struct ablkcipher_request *req)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 838{
 839	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
 840	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
 841	struct dm_crypt_request *dmreq;
 842	u8 *iv;
 843	int r;
 
 
 
 
 
 
 
 844
 845	dmreq = dmreq_of_req(cc, req);
 
 
 
 
 
 
 
 
 
 
 846	iv = iv_of_dmreq(cc, dmreq);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 847
 
 848	dmreq->iv_sector = ctx->cc_sector;
 
 
 849	dmreq->ctx = ctx;
 850	sg_init_table(&dmreq->sg_in, 1);
 851	sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
 852		    bv_in.bv_offset);
 853
 854	sg_init_table(&dmreq->sg_out, 1);
 855	sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
 856		    bv_out.bv_offset);
 857
 858	bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
 859	bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 860
 861	if (cc->iv_gen_ops) {
 862		r = cc->iv_gen_ops->generator(cc, iv, dmreq);
 863		if (r < 0)
 864			return r;
 
 
 
 
 
 
 
 
 
 
 865	}
 866
 867	ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
 868				     1 << SECTOR_SHIFT, iv);
 869
 870	if (bio_data_dir(ctx->bio_in) == WRITE)
 871		r = crypto_ablkcipher_encrypt(req);
 872	else
 873		r = crypto_ablkcipher_decrypt(req);
 874
 875	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
 876		r = cc->iv_gen_ops->post(cc, iv, dmreq);
 
 
 
 877
 878	return r;
 879}
 880
 881static void kcryptd_async_done(struct crypto_async_request *async_req,
 882			       int error);
 883
 884static void crypt_alloc_req(struct crypt_config *cc,
 885			    struct convert_context *ctx)
 886{
 887	unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
 888
 889	if (!ctx->req)
 890		ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
 891
 892	ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
 893	ablkcipher_request_set_callback(ctx->req,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 894	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 895	    kcryptd_async_done, dmreq_of_req(cc, ctx->req));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 896}
 897
 898/*
 899 * Encrypt / decrypt data from one bio to another one (can be the same one)
 900 */
 901static int crypt_convert(struct crypt_config *cc,
 902			 struct convert_context *ctx)
 903{
 
 
 904	int r;
 905
 906	atomic_set(&ctx->cc_pending, 1);
 907
 908	while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
 909
 910		crypt_alloc_req(cc, ctx);
 911
 912		atomic_inc(&ctx->cc_pending);
 913
 914		r = crypt_convert_block(cc, ctx, ctx->req);
 
 
 
 915
 916		switch (r) {
 917		/* async */
 
 
 
 918		case -EBUSY:
 919			wait_for_completion(&ctx->restart);
 920			reinit_completion(&ctx->restart);
 921			/* fall through*/
 
 
 
 
 922		case -EINPROGRESS:
 923			ctx->req = NULL;
 924			ctx->cc_sector++;
 
 925			continue;
 926
 927		/* sync */
 
 928		case 0:
 929			atomic_dec(&ctx->cc_pending);
 930			ctx->cc_sector++;
 
 931			cond_resched();
 932			continue;
 933
 934		/* error */
 
 
 
 
 
 
 
 935		default:
 936			atomic_dec(&ctx->cc_pending);
 937			return r;
 938		}
 939	}
 940
 941	return 0;
 942}
 943
 
 
 944/*
 945 * Generate a new unfragmented bio with the given size
 946 * This should never violate the device limitations
 947 * May return a smaller bio when running out of pages, indicated by
 948 * *out_of_pages set to 1.
 
 
 
 
 
 
 
 
 
 
 
 949 */
 950static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
 951				      unsigned *out_of_pages)
 952{
 953	struct crypt_config *cc = io->cc;
 954	struct bio *clone;
 955	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 956	gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
 957	unsigned i, len;
 958	struct page *page;
 959
 
 
 
 
 960	clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
 961	if (!clone)
 962		return NULL;
 963
 964	clone_init(io, clone);
 965	*out_of_pages = 0;
 
 966
 967	for (i = 0; i < nr_iovecs; i++) {
 968		page = mempool_alloc(cc->page_pool, gfp_mask);
 969		if (!page) {
 970			*out_of_pages = 1;
 971			break;
 
 
 972		}
 973
 974		/*
 975		 * If additional pages cannot be allocated without waiting,
 976		 * return a partially-allocated bio.  The caller will then try
 977		 * to allocate more bios while submitting this partial bio.
 978		 */
 979		gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
 980
 981		len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
 982
 983		if (!bio_add_page(clone, page, len, 0)) {
 984			mempool_free(page, cc->page_pool);
 985			break;
 986		}
 987
 988		size -= len;
 989	}
 990
 991	if (!clone->bi_iter.bi_size) {
 
 
 992		bio_put(clone);
 993		return NULL;
 994	}
 
 
 
 995
 996	return clone;
 997}
 998
 999static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1000{
1001	unsigned int i;
1002	struct bio_vec *bv;
1003
1004	bio_for_each_segment_all(bv, clone, i) {
1005		BUG_ON(!bv->bv_page);
1006		mempool_free(bv->bv_page, cc->page_pool);
1007		bv->bv_page = NULL;
1008	}
1009}
1010
1011static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc,
1012					  struct bio *bio, sector_t sector)
1013{
1014	struct dm_crypt_io *io;
1015
1016	io = mempool_alloc(cc->io_pool, GFP_NOIO);
1017	io->cc = cc;
1018	io->base_bio = bio;
1019	io->sector = sector;
1020	io->error = 0;
1021	io->base_io = NULL;
1022	io->ctx.req = NULL;
 
1023	atomic_set(&io->io_pending, 0);
1024
1025	return io;
1026}
1027
1028static void crypt_inc_pending(struct dm_crypt_io *io)
1029{
1030	atomic_inc(&io->io_pending);
1031}
1032
1033/*
1034 * One of the bios was finished. Check for completion of
1035 * the whole request and correctly clean up the buffer.
1036 * If base_io is set, wait for the last fragment to complete.
1037 */
1038static void crypt_dec_pending(struct dm_crypt_io *io)
1039{
1040	struct crypt_config *cc = io->cc;
1041	struct bio *base_bio = io->base_bio;
1042	struct dm_crypt_io *base_io = io->base_io;
1043	int error = io->error;
1044
1045	if (!atomic_dec_and_test(&io->io_pending))
1046		return;
1047
1048	if (io->ctx.req)
1049		mempool_free(io->ctx.req, cc->req_pool);
1050	mempool_free(io, cc->io_pool);
1051
1052	if (likely(!base_io))
1053		bio_endio(base_bio, error);
1054	else {
1055		if (error && !base_io->error)
1056			base_io->error = error;
1057		crypt_dec_pending(base_io);
1058	}
1059}
1060
1061/*
1062 * kcryptd/kcryptd_io:
1063 *
1064 * Needed because it would be very unwise to do decryption in an
1065 * interrupt context.
1066 *
1067 * kcryptd performs the actual encryption or decryption.
1068 *
1069 * kcryptd_io performs the IO submission.
1070 *
1071 * They must be separated as otherwise the final stages could be
1072 * starved by new requests which can block in the first stages due
1073 * to memory allocation.
1074 *
1075 * The work is done per CPU global for all dm-crypt instances.
1076 * They should not depend on each other and do not block.
1077 */
1078static void crypt_endio(struct bio *clone, int error)
1079{
1080	struct dm_crypt_io *io = clone->bi_private;
1081	struct crypt_config *cc = io->cc;
1082	unsigned rw = bio_data_dir(clone);
1083
1084	if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
1085		error = -EIO;
1086
1087	/*
1088	 * free the processed pages
1089	 */
1090	if (rw == WRITE)
1091		crypt_free_buffer_pages(cc, clone);
1092
 
1093	bio_put(clone);
1094
1095	if (rw == READ && !error) {
1096		kcryptd_queue_crypt(io);
1097		return;
1098	}
1099
1100	if (unlikely(error))
1101		io->error = error;
1102
1103	crypt_dec_pending(io);
1104}
1105
1106static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1107{
1108	struct crypt_config *cc = io->cc;
1109
1110	clone->bi_private = io;
1111	clone->bi_end_io  = crypt_endio;
1112	clone->bi_bdev    = cc->dev->bdev;
1113	clone->bi_rw      = io->base_bio->bi_rw;
1114}
1115
1116static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1117{
1118	struct crypt_config *cc = io->cc;
1119	struct bio *base_bio = io->base_bio;
1120	struct bio *clone;
1121
1122	/*
1123	 * The block layer might modify the bvec array, so always
1124	 * copy the required bvecs because we need the original
1125	 * one in order to decrypt the whole bio data *afterwards*.
 
1126	 */
1127	clone = bio_clone_bioset(base_bio, gfp, cc->bs);
1128	if (!clone)
1129		return 1;
1130
1131	crypt_inc_pending(io);
1132
1133	clone_init(io, clone);
1134	clone->bi_iter.bi_sector = cc->start + io->sector;
1135
 
 
 
 
 
 
1136	generic_make_request(clone);
1137	return 0;
1138}
1139
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1140static void kcryptd_io_write(struct dm_crypt_io *io)
1141{
1142	struct bio *clone = io->ctx.bio_out;
 
1143	generic_make_request(clone);
1144}
1145
1146static void kcryptd_io(struct work_struct *work)
 
 
1147{
1148	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
1149
1150	if (bio_data_dir(io->base_bio) == READ) {
1151		crypt_inc_pending(io);
1152		if (kcryptd_io_read(io, GFP_NOIO))
1153			io->error = -ENOMEM;
1154		crypt_dec_pending(io);
1155	} else
1156		kcryptd_io_write(io);
1157}
1158
1159static void kcryptd_queue_io(struct dm_crypt_io *io)
1160{
1161	struct crypt_config *cc = io->cc;
1162
1163	INIT_WORK(&io->work, kcryptd_io);
1164	queue_work(cc->io_queue, &io->work);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1165}
1166
1167static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1168{
1169	struct bio *clone = io->ctx.bio_out;
1170	struct crypt_config *cc = io->cc;
 
 
 
1171
1172	if (unlikely(io->error < 0)) {
1173		crypt_free_buffer_pages(cc, clone);
1174		bio_put(clone);
1175		crypt_dec_pending(io);
1176		return;
1177	}
1178
1179	/* crypt_convert should have filled the clone bio */
1180	BUG_ON(io->ctx.iter_out.bi_size);
1181
1182	clone->bi_iter.bi_sector = cc->start + io->sector;
1183
1184	if (async)
1185		kcryptd_queue_io(io);
1186	else
1187		generic_make_request(clone);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1188}
1189
1190static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1191{
1192	struct crypt_config *cc = io->cc;
1193	struct bio *clone;
1194	struct dm_crypt_io *new_io;
1195	int crypt_finished;
1196	unsigned out_of_pages = 0;
1197	unsigned remaining = io->base_bio->bi_iter.bi_size;
1198	sector_t sector = io->sector;
1199	int r;
1200
1201	/*
1202	 * Prevent io from disappearing until this function completes.
1203	 */
1204	crypt_inc_pending(io);
1205	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1206
1207	/*
1208	 * The allocated buffers can be smaller than the whole bio,
1209	 * so repeat the whole process until all the data can be handled.
1210	 */
1211	while (remaining) {
1212		clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
1213		if (unlikely(!clone)) {
1214			io->error = -ENOMEM;
1215			break;
1216		}
1217
1218		io->ctx.bio_out = clone;
1219		io->ctx.iter_out = clone->bi_iter;
1220
1221		remaining -= clone->bi_iter.bi_size;
1222		sector += bio_sectors(clone);
1223
1224		crypt_inc_pending(io);
1225
1226		r = crypt_convert(cc, &io->ctx);
1227		if (r < 0)
1228			io->error = -EIO;
1229
1230		crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1231
1232		/* Encryption was already finished, submit io now */
1233		if (crypt_finished) {
1234			kcryptd_crypt_write_io_submit(io, 0);
1235
1236			/*
1237			 * If there was an error, do not try next fragments.
1238			 * For async, error is processed in async handler.
1239			 */
1240			if (unlikely(r < 0))
1241				break;
1242
1243			io->sector = sector;
1244		}
1245
1246		/*
1247		 * Out of memory -> run queues
1248		 * But don't wait if split was due to the io size restriction
1249		 */
1250		if (unlikely(out_of_pages))
1251			congestion_wait(BLK_RW_ASYNC, HZ/100);
1252
1253		/*
1254		 * With async crypto it is unsafe to share the crypto context
1255		 * between fragments, so switch to a new dm_crypt_io structure.
1256		 */
1257		if (unlikely(!crypt_finished && remaining)) {
1258			new_io = crypt_io_alloc(io->cc, io->base_bio,
1259						sector);
1260			crypt_inc_pending(new_io);
1261			crypt_convert_init(cc, &new_io->ctx, NULL,
1262					   io->base_bio, sector);
1263			new_io->ctx.iter_in = io->ctx.iter_in;
1264
1265			/*
1266			 * Fragments after the first use the base_io
1267			 * pending count.
1268			 */
1269			if (!io->base_io)
1270				new_io->base_io = io;
1271			else {
1272				new_io->base_io = io->base_io;
1273				crypt_inc_pending(io->base_io);
1274				crypt_dec_pending(io);
1275			}
1276
1277			io = new_io;
1278		}
 
 
1279	}
1280
 
1281	crypt_dec_pending(io);
1282}
1283
1284static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1285{
1286	crypt_dec_pending(io);
1287}
1288
1289static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1290{
1291	struct crypt_config *cc = io->cc;
1292	int r = 0;
1293
1294	crypt_inc_pending(io);
1295
1296	crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1297			   io->sector);
1298
1299	r = crypt_convert(cc, &io->ctx);
1300	if (r < 0)
1301		io->error = -EIO;
1302
1303	if (atomic_dec_and_test(&io->ctx.cc_pending))
1304		kcryptd_crypt_read_done(io);
1305
1306	crypt_dec_pending(io);
1307}
1308
1309static void kcryptd_async_done(struct crypto_async_request *async_req,
1310			       int error)
1311{
1312	struct dm_crypt_request *dmreq = async_req->data;
1313	struct convert_context *ctx = dmreq->ctx;
1314	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1315	struct crypt_config *cc = io->cc;
1316
 
 
 
 
 
1317	if (error == -EINPROGRESS) {
1318		complete(&ctx->restart);
1319		return;
1320	}
1321
1322	if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1323		error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1324
1325	if (error < 0)
1326		io->error = -EIO;
 
 
 
 
1327
1328	mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
1329
1330	if (!atomic_dec_and_test(&ctx->cc_pending))
1331		return;
1332
1333	if (bio_data_dir(io->base_bio) == READ)
1334		kcryptd_crypt_read_done(io);
1335	else
1336		kcryptd_crypt_write_io_submit(io, 1);
1337}
1338
1339static void kcryptd_crypt(struct work_struct *work)
1340{
1341	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1342
1343	if (bio_data_dir(io->base_bio) == READ)
1344		kcryptd_crypt_read_convert(io);
1345	else
1346		kcryptd_crypt_write_convert(io);
1347}
1348
1349static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1350{
1351	struct crypt_config *cc = io->cc;
1352
1353	INIT_WORK(&io->work, kcryptd_crypt);
1354	queue_work(cc->crypt_queue, &io->work);
1355}
1356
1357/*
1358 * Decode key from its hex representation
1359 */
1360static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1361{
1362	char buffer[3];
1363	unsigned int i;
1364
1365	buffer[2] = '\0';
1366
1367	for (i = 0; i < size; i++) {
1368		buffer[0] = *hex++;
1369		buffer[1] = *hex++;
1370
1371		if (kstrtou8(buffer, 16, &key[i]))
1372			return -EINVAL;
 
1373	}
1374
1375	if (*hex != '\0')
1376		return -EINVAL;
1377
1378	return 0;
1379}
1380
1381static void crypt_free_tfms(struct crypt_config *cc)
1382{
1383	unsigned i;
1384
1385	if (!cc->tfms)
1386		return;
1387
1388	for (i = 0; i < cc->tfms_count; i++)
1389		if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1390			crypto_free_ablkcipher(cc->tfms[i]);
1391			cc->tfms[i] = NULL;
1392		}
1393
1394	kfree(cc->tfms);
1395	cc->tfms = NULL;
1396}
1397
1398static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
 
 
 
 
 
 
 
 
1399{
1400	unsigned i;
1401	int err;
1402
1403	cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *),
1404			   GFP_KERNEL);
1405	if (!cc->tfms)
1406		return -ENOMEM;
1407
1408	for (i = 0; i < cc->tfms_count; i++) {
1409		cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1410		if (IS_ERR(cc->tfms[i])) {
1411			err = PTR_ERR(cc->tfms[i]);
1412			crypt_free_tfms(cc);
1413			return err;
1414		}
1415	}
1416
1417	return 0;
1418}
1419
1420static int crypt_setkey_allcpus(struct crypt_config *cc)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1421{
1422	unsigned subkey_size;
1423	int err = 0, i, r;
1424
1425	/* Ignore extra keys (which are used for IV etc) */
1426	subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
 
 
 
 
 
 
 
 
 
1427
1428	for (i = 0; i < cc->tfms_count; i++) {
1429		r = crypto_ablkcipher_setkey(cc->tfms[i],
1430					     cc->key + (i * subkey_size),
1431					     subkey_size);
 
 
 
 
 
 
 
 
1432		if (r)
1433			err = r;
1434	}
1435
 
 
 
1436	return err;
1437}
1438
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1439static int crypt_set_key(struct crypt_config *cc, char *key)
1440{
1441	int r = -EINVAL;
1442	int key_string_len = strlen(key);
1443
1444	/* The key size may not be changed. */
1445	if (cc->key_size != (key_string_len >> 1))
1446		goto out;
1447
1448	/* Hyphen (which gives a key_size of zero) means there is no key. */
1449	if (!cc->key_size && strcmp(key, "-"))
1450		goto out;
1451
1452	if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
 
 
1453		goto out;
 
 
 
 
1454
1455	set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
 
 
 
 
 
1456
1457	r = crypt_setkey_allcpus(cc);
 
 
1458
1459out:
1460	/* Hex key string not needed after here, so wipe it. */
1461	memset(key, '0', key_string_len);
1462
1463	return r;
1464}
1465
1466static int crypt_wipe_key(struct crypt_config *cc)
1467{
 
 
1468	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
 
 
 
1469	memset(&cc->key, 0, cc->key_size * sizeof(u8));
1470
1471	return crypt_setkey_allcpus(cc);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1472}
1473
1474static void crypt_dtr(struct dm_target *ti)
1475{
1476	struct crypt_config *cc = ti->private;
1477
1478	ti->private = NULL;
1479
1480	if (!cc)
1481		return;
1482
 
 
 
1483	if (cc->io_queue)
1484		destroy_workqueue(cc->io_queue);
1485	if (cc->crypt_queue)
1486		destroy_workqueue(cc->crypt_queue);
1487
1488	crypt_free_tfms(cc);
1489
1490	if (cc->bs)
1491		bioset_free(cc->bs);
1492
 
 
 
 
1493	if (cc->page_pool)
1494		mempool_destroy(cc->page_pool);
1495	if (cc->req_pool)
1496		mempool_destroy(cc->req_pool);
1497	if (cc->io_pool)
1498		mempool_destroy(cc->io_pool);
1499
1500	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1501		cc->iv_gen_ops->dtr(cc);
1502
1503	if (cc->dev)
1504		dm_put_device(ti, cc->dev);
1505
1506	kzfree(cc->cipher);
1507	kzfree(cc->cipher_string);
 
 
 
 
 
1508
1509	/* Must zero key material before freeing */
1510	kzfree(cc);
 
 
 
 
 
 
1511}
1512
1513static int crypt_ctr_cipher(struct dm_target *ti,
1514			    char *cipher_in, char *key)
1515{
1516	struct crypt_config *cc = ti->private;
1517	char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1518	char *cipher_api = NULL;
1519	int ret = -EINVAL;
1520	char dummy;
1521
1522	/* Convert to crypto api definition? */
1523	if (strchr(cipher_in, '(')) {
1524		ti->error = "Bad cipher specification";
1525		return -EINVAL;
1526	}
1527
1528	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1529	if (!cc->cipher_string)
1530		goto bad_mem;
1531
1532	/*
1533	 * Legacy dm-crypt cipher specification
1534	 * cipher[:keycount]-mode-iv:ivopts
1535	 */
1536	tmp = cipher_in;
1537	keycount = strsep(&tmp, "-");
1538	cipher = strsep(&keycount, ":");
1539
1540	if (!keycount)
1541		cc->tfms_count = 1;
1542	else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1543		 !is_power_of_2(cc->tfms_count)) {
1544		ti->error = "Bad cipher key count specification";
1545		return -EINVAL;
1546	}
1547	cc->key_parts = cc->tfms_count;
1548	cc->key_extra_size = 0;
1549
1550	cc->cipher = kstrdup(cipher, GFP_KERNEL);
1551	if (!cc->cipher)
1552		goto bad_mem;
1553
1554	chainmode = strsep(&tmp, "-");
1555	ivopts = strsep(&tmp, "-");
1556	ivmode = strsep(&ivopts, ":");
1557
1558	if (tmp)
1559		DMWARN("Ignoring unexpected additional cipher options");
1560
1561	/*
1562	 * For compatibility with the original dm-crypt mapping format, if
1563	 * only the cipher name is supplied, use cbc-plain.
1564	 */
1565	if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1566		chainmode = "cbc";
1567		ivmode = "plain";
1568	}
1569
1570	if (strcmp(chainmode, "ecb") && !ivmode) {
1571		ti->error = "IV mechanism required";
1572		return -EINVAL;
1573	}
1574
1575	cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1576	if (!cipher_api)
1577		goto bad_mem;
1578
1579	ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1580		       "%s(%s)", chainmode, cipher);
1581	if (ret < 0) {
1582		kfree(cipher_api);
1583		goto bad_mem;
1584	}
1585
1586	/* Allocate cipher */
1587	ret = crypt_alloc_tfms(cc, cipher_api);
1588	if (ret < 0) {
1589		ti->error = "Error allocating crypto tfm";
1590		goto bad;
 
1591	}
 
1592
1593	/* Initialize IV */
1594	cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1595	if (cc->iv_size)
1596		/* at least a 64 bit sector number should fit in our buffer */
1597		cc->iv_size = max(cc->iv_size,
1598				  (unsigned int)(sizeof(u64) / sizeof(u8)));
1599	else if (ivmode) {
1600		DMWARN("Selected cipher does not support IVs");
1601		ivmode = NULL;
1602	}
1603
1604	/* Choose ivmode, see comments at iv code. */
1605	if (ivmode == NULL)
1606		cc->iv_gen_ops = NULL;
1607	else if (strcmp(ivmode, "plain") == 0)
1608		cc->iv_gen_ops = &crypt_iv_plain_ops;
1609	else if (strcmp(ivmode, "plain64") == 0)
1610		cc->iv_gen_ops = &crypt_iv_plain64_ops;
1611	else if (strcmp(ivmode, "essiv") == 0)
1612		cc->iv_gen_ops = &crypt_iv_essiv_ops;
1613	else if (strcmp(ivmode, "benbi") == 0)
1614		cc->iv_gen_ops = &crypt_iv_benbi_ops;
1615	else if (strcmp(ivmode, "null") == 0)
1616		cc->iv_gen_ops = &crypt_iv_null_ops;
1617	else if (strcmp(ivmode, "lmk") == 0) {
1618		cc->iv_gen_ops = &crypt_iv_lmk_ops;
1619		/*
1620		 * Version 2 and 3 is recognised according
1621		 * to length of provided multi-key string.
1622		 * If present (version 3), last key is used as IV seed.
1623		 * All keys (including IV seed) are always the same size.
1624		 */
1625		if (cc->key_size % cc->key_parts) {
1626			cc->key_parts++;
1627			cc->key_extra_size = cc->key_size / cc->key_parts;
1628		}
1629	} else if (strcmp(ivmode, "tcw") == 0) {
1630		cc->iv_gen_ops = &crypt_iv_tcw_ops;
1631		cc->key_parts += 2; /* IV + whitening */
1632		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1633	} else {
1634		ret = -EINVAL;
1635		ti->error = "Invalid IV mode";
1636		goto bad;
1637	}
1638
 
 
 
 
 
 
 
 
 
 
 
 
1639	/* Initialize and set key */
1640	ret = crypt_set_key(cc, key);
1641	if (ret < 0) {
1642		ti->error = "Error decoding and setting key";
1643		goto bad;
1644	}
1645
1646	/* Allocate IV */
1647	if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1648		ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1649		if (ret < 0) {
1650			ti->error = "Error creating IV";
1651			goto bad;
1652		}
1653	}
1654
1655	/* Initialize IV (set keys for ESSIV etc) */
1656	if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1657		ret = cc->iv_gen_ops->init(cc);
1658		if (ret < 0) {
1659			ti->error = "Error initialising IV";
1660			goto bad;
1661		}
1662	}
1663
1664	ret = 0;
1665bad:
1666	kfree(cipher_api);
 
1667	return ret;
 
1668
1669bad_mem:
1670	ti->error = "Cannot allocate cipher strings";
1671	return -ENOMEM;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1672}
1673
1674/*
1675 * Construct an encryption mapping:
1676 * <cipher> <key> <iv_offset> <dev_path> <start>
1677 */
1678static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1679{
1680	struct crypt_config *cc;
1681	unsigned int key_size, opt_params;
 
1682	unsigned long long tmpll;
1683	int ret;
1684	struct dm_arg_set as;
1685	const char *opt_string;
1686	char dummy;
1687
1688	static struct dm_arg _args[] = {
1689		{0, 1, "Invalid number of feature args"},
1690	};
1691
1692	if (argc < 5) {
1693		ti->error = "Not enough arguments";
1694		return -EINVAL;
1695	}
1696
1697	key_size = strlen(argv[1]) >> 1;
 
 
 
 
1698
1699	cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1700	if (!cc) {
1701		ti->error = "Cannot allocate encryption context";
1702		return -ENOMEM;
1703	}
1704	cc->key_size = key_size;
 
 
1705
1706	ti->private = cc;
1707	ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
 
 
 
 
 
 
1708	if (ret < 0)
1709		goto bad;
1710
1711	ret = -ENOMEM;
1712	cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
1713	if (!cc->io_pool) {
1714		ti->error = "Cannot allocate crypt io mempool";
 
 
 
 
 
1715		goto bad;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1716	}
1717
1718	cc->dmreq_start = sizeof(struct ablkcipher_request);
1719	cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1720	cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
1721	cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) &
1722			   ~(crypto_tfm_ctx_alignment() - 1);
1723
1724	cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1725			sizeof(struct dm_crypt_request) + cc->iv_size);
 
 
 
 
 
 
1726	if (!cc->req_pool) {
1727		ti->error = "Cannot allocate crypt request mempool";
1728		goto bad;
1729	}
1730
1731	cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
 
 
 
 
1732	if (!cc->page_pool) {
1733		ti->error = "Cannot allocate page mempool";
1734		goto bad;
1735	}
1736
1737	cc->bs = bioset_create(MIN_IOS, 0);
1738	if (!cc->bs) {
1739		ti->error = "Cannot allocate crypt bioset";
1740		goto bad;
1741	}
1742
 
 
1743	ret = -EINVAL;
1744	if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
 
1745		ti->error = "Invalid iv_offset sector";
1746		goto bad;
1747	}
1748	cc->iv_offset = tmpll;
1749
1750	if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
 
1751		ti->error = "Device lookup failed";
1752		goto bad;
1753	}
1754
 
1755	if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1756		ti->error = "Invalid device sector";
1757		goto bad;
1758	}
1759	cc->start = tmpll;
1760
1761	argv += 5;
1762	argc -= 5;
1763
1764	/* Optional parameters */
1765	if (argc) {
1766		as.argc = argc;
1767		as.argv = argv;
1768
1769		ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1770		if (ret)
1771			goto bad;
1772
1773		opt_string = dm_shift_arg(&as);
1774
1775		if (opt_params == 1 && opt_string &&
1776		    !strcasecmp(opt_string, "allow_discards"))
1777			ti->num_discard_bios = 1;
1778		else if (opt_params) {
1779			ret = -EINVAL;
1780			ti->error = "Invalid feature arguments";
 
1781			goto bad;
1782		}
 
 
1783	}
1784
1785	ret = -ENOMEM;
1786	cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1787	if (!cc->io_queue) {
1788		ti->error = "Couldn't create kcryptd io queue";
1789		goto bad;
1790	}
1791
1792	cc->crypt_queue = alloc_workqueue("kcryptd",
1793					  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
 
 
 
 
1794	if (!cc->crypt_queue) {
1795		ti->error = "Couldn't create kcryptd queue";
1796		goto bad;
1797	}
1798
 
 
 
 
 
 
 
 
 
 
 
 
1799	ti->num_flush_bios = 1;
1800	ti->discard_zeroes_data_unsupported = true;
1801
1802	return 0;
1803
1804bad:
1805	crypt_dtr(ti);
1806	return ret;
1807}
1808
1809static int crypt_map(struct dm_target *ti, struct bio *bio)
1810{
1811	struct dm_crypt_io *io;
1812	struct crypt_config *cc = ti->private;
1813
1814	/*
1815	 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1816	 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1817	 * - for REQ_DISCARD caller must use flush if IO ordering matters
1818	 */
1819	if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1820		bio->bi_bdev = cc->dev->bdev;
 
1821		if (bio_sectors(bio))
1822			bio->bi_iter.bi_sector = cc->start +
1823				dm_target_offset(ti, bio->bi_iter.bi_sector);
1824		return DM_MAPIO_REMAPPED;
1825	}
1826
1827	io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1828
1829	if (bio_data_dir(io->base_bio) == READ) {
1830		if (kcryptd_io_read(io, GFP_NOWAIT))
1831			kcryptd_queue_io(io);
1832	} else
1833		kcryptd_queue_crypt(io);
1834
1835	return DM_MAPIO_SUBMITTED;
1836}
1837
1838static void crypt_status(struct dm_target *ti, status_type_t type,
1839			 unsigned status_flags, char *result, unsigned maxlen)
1840{
1841	struct crypt_config *cc = ti->private;
1842	unsigned i, sz = 0;
 
1843
1844	switch (type) {
1845	case STATUSTYPE_INFO:
1846		result[0] = '\0';
1847		break;
1848
1849	case STATUSTYPE_TABLE:
1850		DMEMIT("%s ", cc->cipher_string);
1851
1852		if (cc->key_size > 0)
1853			for (i = 0; i < cc->key_size; i++)
1854				DMEMIT("%02x", cc->key[i]);
1855		else
 
 
 
1856			DMEMIT("-");
1857
1858		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1859				cc->dev->name, (unsigned long long)cc->start);
1860
1861		if (ti->num_discard_bios)
1862			DMEMIT(" 1 allow_discards");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1863
1864		break;
1865	}
1866}
1867
1868static void crypt_postsuspend(struct dm_target *ti)
1869{
1870	struct crypt_config *cc = ti->private;
1871
1872	set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1873}
1874
1875static int crypt_preresume(struct dm_target *ti)
1876{
1877	struct crypt_config *cc = ti->private;
1878
1879	if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1880		DMERR("aborting resume - crypt key is not set.");
1881		return -EAGAIN;
1882	}
1883
1884	return 0;
1885}
1886
1887static void crypt_resume(struct dm_target *ti)
1888{
1889	struct crypt_config *cc = ti->private;
1890
1891	clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1892}
1893
1894/* Message interface
1895 *	key set <key>
1896 *	key wipe
1897 */
1898static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
 
1899{
1900	struct crypt_config *cc = ti->private;
1901	int ret = -EINVAL;
1902
1903	if (argc < 2)
1904		goto error;
1905
1906	if (!strcasecmp(argv[0], "key")) {
1907		if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1908			DMWARN("not suspended during key manipulation.");
1909			return -EINVAL;
1910		}
1911		if (argc == 3 && !strcasecmp(argv[1], "set")) {
 
 
 
 
 
 
 
1912			ret = crypt_set_key(cc, argv[2]);
1913			if (ret)
1914				return ret;
1915			if (cc->iv_gen_ops && cc->iv_gen_ops->init)
1916				ret = cc->iv_gen_ops->init(cc);
 
 
 
1917			return ret;
1918		}
1919		if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
1920			if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
1921				ret = cc->iv_gen_ops->wipe(cc);
1922				if (ret)
1923					return ret;
1924			}
1925			return crypt_wipe_key(cc);
1926		}
1927	}
1928
1929error:
1930	DMWARN("unrecognised message received.");
1931	return -EINVAL;
1932}
1933
1934static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1935		       struct bio_vec *biovec, int max_size)
1936{
1937	struct crypt_config *cc = ti->private;
1938	struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1939
1940	if (!q->merge_bvec_fn)
1941		return max_size;
1942
1943	bvm->bi_bdev = cc->dev->bdev;
1944	bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
1945
1946	return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
1947}
1948
1949static int crypt_iterate_devices(struct dm_target *ti,
1950				 iterate_devices_callout_fn fn, void *data)
1951{
1952	struct crypt_config *cc = ti->private;
1953
1954	return fn(ti, cc->dev, cc->start, ti->len, data);
 
 
 
 
 
 
 
 
 
 
 
 
1955}
1956
1957static struct target_type crypt_target = {
1958	.name   = "crypt",
1959	.version = {1, 13, 0},
1960	.module = THIS_MODULE,
1961	.ctr    = crypt_ctr,
1962	.dtr    = crypt_dtr,
1963	.map    = crypt_map,
1964	.status = crypt_status,
1965	.postsuspend = crypt_postsuspend,
1966	.preresume = crypt_preresume,
1967	.resume = crypt_resume,
1968	.message = crypt_message,
1969	.merge  = crypt_merge,
1970	.iterate_devices = crypt_iterate_devices,
 
1971};
1972
1973static int __init dm_crypt_init(void)
1974{
1975	int r;
1976
1977	_crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1978	if (!_crypt_io_pool)
1979		return -ENOMEM;
1980
1981	r = dm_register_target(&crypt_target);
1982	if (r < 0) {
1983		DMERR("register failed %d", r);
1984		kmem_cache_destroy(_crypt_io_pool);
1985	}
1986
1987	return r;
1988}
1989
1990static void __exit dm_crypt_exit(void)
1991{
1992	dm_unregister_target(&crypt_target);
1993	kmem_cache_destroy(_crypt_io_pool);
1994}
1995
1996module_init(dm_crypt_init);
1997module_exit(dm_crypt_exit);
1998
1999MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
2000MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2001MODULE_LICENSE("GPL");