1/*
   2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
   3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
   4 * Copyright (C) 2006-2015 Red Hat, Inc. All rights reserved.
   5 * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com>
   6 *
   7 * This file is released under the GPL.
   8 */
   9
  10#include <linux/completion.h>
  11#include <linux/err.h>
  12#include <linux/module.h>
  13#include <linux/init.h>
  14#include <linux/kernel.h>
  15#include <linux/bio.h>
  16#include <linux/blkdev.h>
  17#include <linux/mempool.h>
  18#include <linux/slab.h>
  19#include <linux/crypto.h>
  20#include <linux/workqueue.h>
  21#include <linux/kthread.h>
  22#include <linux/backing-dev.h>
  23#include <linux/atomic.h>
  24#include <linux/scatterlist.h>
  25#include <linux/rbtree.h>
  26#include <asm/page.h>
  27#include <asm/unaligned.h>
  28#include <crypto/hash.h>
  29#include <crypto/md5.h>
  30#include <crypto/algapi.h>
  31#include <crypto/skcipher.h>
  32
  33#include <linux/device-mapper.h>
  34
  35#define DM_MSG_PREFIX "crypt"
  36
  37/*
  38 * context holding the current state of a multi-part conversion
  39 */
  40struct convert_context {
  41	struct completion restart;
  42	struct bio *bio_in;
  43	struct bio *bio_out;
  44	struct bvec_iter iter_in;
  45	struct bvec_iter iter_out;
  46	sector_t cc_sector;
  47	atomic_t cc_pending;
  48	struct skcipher_request *req;
  49};
  50
  51/*
  52 * per bio private data
  53 */
  54struct dm_crypt_io {
  55	struct crypt_config *cc;
  56	struct bio *base_bio;
  57	struct work_struct work;
  58
  59	struct convert_context ctx;
  60
  61	atomic_t io_pending;
  62	int error;
  63	sector_t sector;
  64
  65	struct rb_node rb_node;
  66} CRYPTO_MINALIGN_ATTR;
  67
  68struct dm_crypt_request {
  69	struct convert_context *ctx;
  70	struct scatterlist sg_in;
  71	struct scatterlist sg_out;
  72	sector_t iv_sector;
  73};
  74
  75struct crypt_config;
  76
  77struct crypt_iv_operations {
  78	int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
  79		   const char *opts);
  80	void (*dtr)(struct crypt_config *cc);
  81	int (*init)(struct crypt_config *cc);
  82	int (*wipe)(struct crypt_config *cc);
  83	int (*generator)(struct crypt_config *cc, u8 *iv,
  84			 struct dm_crypt_request *dmreq);
  85	int (*post)(struct crypt_config *cc, u8 *iv,
  86		    struct dm_crypt_request *dmreq);
  87};
  88
  89struct iv_essiv_private {
  90	struct crypto_ahash *hash_tfm;
  91	u8 *salt;
  92};
  93
  94struct iv_benbi_private {
  95	int shift;
  96};
  97
  98#define LMK_SEED_SIZE 64 /* hash + 0 */
  99struct iv_lmk_private {
 100	struct crypto_shash *hash_tfm;
 101	u8 *seed;
 102};
 103
 104#define TCW_WHITENING_SIZE 16
 105struct iv_tcw_private {
 106	struct crypto_shash *crc32_tfm;
 107	u8 *iv_seed;
 108	u8 *whitening;
 109};
 110
 111/*
 112 * Crypt: maps a linear range of a block device
 113 * and encrypts / decrypts at the same time.
 114 */
 115enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
 116	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
 117	     DM_CRYPT_EXIT_THREAD};
 118
 119/*
 120 * The fields in here must be read only after initialization.
 121 */
 122struct crypt_config {
 123	struct dm_dev *dev;
 124	sector_t start;
 125
 126	/*
 127	 * pool for per bio private data, crypto requests and
 128	 * encryption requeusts/buffer pages
 129	 */
 
 130	mempool_t *req_pool;
 131	mempool_t *page_pool;
 132	struct bio_set *bs;
 133	struct mutex bio_alloc_lock;
 134
 135	struct workqueue_struct *io_queue;
 136	struct workqueue_struct *crypt_queue;
 137
 138	struct task_struct *write_thread;
 139	wait_queue_head_t write_thread_wait;
 140	struct rb_root write_tree;
 141
 142	char *cipher;
 143	char *cipher_string;
 144
 145	struct crypt_iv_operations *iv_gen_ops;
 146	union {
 147		struct iv_essiv_private essiv;
 148		struct iv_benbi_private benbi;
 149		struct iv_lmk_private lmk;
 150		struct iv_tcw_private tcw;
 151	} iv_gen_private;
 152	sector_t iv_offset;
 153	unsigned int iv_size;
 154
 155	/* ESSIV: struct crypto_cipher *essiv_tfm */
 156	void *iv_private;
 157	struct crypto_skcipher **tfms;
 158	unsigned tfms_count;
 159
 160	/*
 161	 * Layout of each crypto request:
 162	 *
 163	 *   struct skcipher_request
 164	 *      context
 165	 *      padding
 166	 *   struct dm_crypt_request
 167	 *      padding
 168	 *   IV
 169	 *
 170	 * The padding is added so that dm_crypt_request and the IV are
 171	 * correctly aligned.
 172	 */
 173	unsigned int dmreq_start;
 174
 175	unsigned int per_bio_data_size;
 176
 177	unsigned long flags;
 178	unsigned int key_size;
 179	unsigned int key_parts;      /* independent parts in key buffer */
 180	unsigned int key_extra_size; /* additional keys length */
 181	u8 key[0];
 182};
 183
 184#define MIN_IOS        16
 
 
 
 185
 186static void clone_init(struct dm_crypt_io *, struct bio *);
 187static void kcryptd_queue_crypt(struct dm_crypt_io *io);
 188static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
 189
 190/*
 191 * Use this to access cipher attributes that are the same for each CPU.
 192 */
 193static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
 194{
 195	return cc->tfms[0];
 196}
 197
 198/*
 199 * Different IV generation algorithms:
 200 *
 201 * plain: the initial vector is the 32-bit little-endian version of the sector
 202 *        number, padded with zeros if necessary.
 203 *
 204 * plain64: the initial vector is the 64-bit little-endian version of the sector
 205 *        number, padded with zeros if necessary.
 206 *
 207 * essiv: "encrypted sector|salt initial vector", the sector number is
 208 *        encrypted with the bulk cipher using a salt as key. The salt
 209 *        should be derived from the bulk cipher's key via hashing.
 210 *
 211 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
 212 *        (needed for LRW-32-AES and possible other narrow block modes)
 213 *
 214 * null: the initial vector is always zero.  Provides compatibility with
 215 *       obsolete loop_fish2 devices.  Do not use for new devices.
 216 *
 217 * lmk:  Compatible implementation of the block chaining mode used
 218 *       by the Loop-AES block device encryption system
 219 *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
 220 *       It operates on full 512 byte sectors and uses CBC
 221 *       with an IV derived from the sector number, the data and
 222 *       optionally extra IV seed.
 223 *       This means that after decryption the first block
 224 *       of sector must be tweaked according to decrypted data.
 225 *       Loop-AES can use three encryption schemes:
 226 *         version 1: is plain aes-cbc mode
 227 *         version 2: uses 64 multikey scheme with lmk IV generator
 228 *         version 3: the same as version 2 with additional IV seed
 229 *                   (it uses 65 keys, last key is used as IV seed)
 230 *
 231 * tcw:  Compatible implementation of the block chaining mode used
 232 *       by the TrueCrypt device encryption system (prior to version 4.1).
 233 *       For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
 234 *       It operates on full 512 byte sectors and uses CBC
 235 *       with an IV derived from initial key and the sector number.
 236 *       In addition, whitening value is applied on every sector, whitening
 237 *       is calculated from initial key, sector number and mixed using CRC32.
 238 *       Note that this encryption scheme is vulnerable to watermarking attacks
 239 *       and should be used for old compatible containers access only.
 240 *
 241 * plumb: unimplemented, see:
 242 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
 243 */
 244
 245static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
 246			      struct dm_crypt_request *dmreq)
 247{
 248	memset(iv, 0, cc->iv_size);
 249	*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
 250
 251	return 0;
 252}
 253
 254static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
 255				struct dm_crypt_request *dmreq)
 256{
 257	memset(iv, 0, cc->iv_size);
 258	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 259
 260	return 0;
 261}
 262
 263/* Initialise ESSIV - compute salt but no local memory allocations */
 264static int crypt_iv_essiv_init(struct crypt_config *cc)
 265{
 266	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 267	AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
 268	struct scatterlist sg;
 269	struct crypto_cipher *essiv_tfm;
 270	int err;
 271
 272	sg_init_one(&sg, cc->key, cc->key_size);
 273	ahash_request_set_tfm(req, essiv->hash_tfm);
 274	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
 275	ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
 276
 277	err = crypto_ahash_digest(req);
 278	ahash_request_zero(req);
 279	if (err)
 280		return err;
 281
 282	essiv_tfm = cc->iv_private;
 283
 284	err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
 285			    crypto_ahash_digestsize(essiv->hash_tfm));
 286	if (err)
 287		return err;
 288
 289	return 0;
 290}
 291
 292/* Wipe salt and reset key derived from volume key */
 293static int crypt_iv_essiv_wipe(struct crypt_config *cc)
 294{
 295	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 296	unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
 297	struct crypto_cipher *essiv_tfm;
 298	int r, err = 0;
 299
 300	memset(essiv->salt, 0, salt_size);
 301
 302	essiv_tfm = cc->iv_private;
 303	r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
 304	if (r)
 305		err = r;
 306
 307	return err;
 308}
 309
 310/* Set up per cpu cipher state */
 311static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
 312					     struct dm_target *ti,
 313					     u8 *salt, unsigned saltsize)
 314{
 315	struct crypto_cipher *essiv_tfm;
 316	int err;
 317
 318	/* Setup the essiv_tfm with the given salt */
 319	essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
 320	if (IS_ERR(essiv_tfm)) {
 321		ti->error = "Error allocating crypto tfm for ESSIV";
 322		return essiv_tfm;
 323	}
 324
 325	if (crypto_cipher_blocksize(essiv_tfm) !=
 326	    crypto_skcipher_ivsize(any_tfm(cc))) {
 327		ti->error = "Block size of ESSIV cipher does "
 328			    "not match IV size of block cipher";
 329		crypto_free_cipher(essiv_tfm);
 330		return ERR_PTR(-EINVAL);
 331	}
 332
 333	err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
 334	if (err) {
 335		ti->error = "Failed to set key for ESSIV cipher";
 336		crypto_free_cipher(essiv_tfm);
 337		return ERR_PTR(err);
 338	}
 339
 340	return essiv_tfm;
 341}
 342
 343static void crypt_iv_essiv_dtr(struct crypt_config *cc)
 344{
 345	struct crypto_cipher *essiv_tfm;
 346	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 347
 348	crypto_free_ahash(essiv->hash_tfm);
 349	essiv->hash_tfm = NULL;
 350
 351	kzfree(essiv->salt);
 352	essiv->salt = NULL;
 353
 354	essiv_tfm = cc->iv_private;
 355
 356	if (essiv_tfm)
 357		crypto_free_cipher(essiv_tfm);
 358
 359	cc->iv_private = NULL;
 360}
 361
 362static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 363			      const char *opts)
 364{
 365	struct crypto_cipher *essiv_tfm = NULL;
 366	struct crypto_ahash *hash_tfm = NULL;
 367	u8 *salt = NULL;
 368	int err;
 369
 370	if (!opts) {
 371		ti->error = "Digest algorithm missing for ESSIV mode";
 372		return -EINVAL;
 373	}
 374
 375	/* Allocate hash algorithm */
 376	hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
 377	if (IS_ERR(hash_tfm)) {
 378		ti->error = "Error initializing ESSIV hash";
 379		err = PTR_ERR(hash_tfm);
 380		goto bad;
 381	}
 382
 383	salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
 384	if (!salt) {
 385		ti->error = "Error kmallocing salt storage in ESSIV";
 386		err = -ENOMEM;
 387		goto bad;
 388	}
 389
 390	cc->iv_gen_private.essiv.salt = salt;
 391	cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
 392
 393	essiv_tfm = setup_essiv_cpu(cc, ti, salt,
 394				crypto_ahash_digestsize(hash_tfm));
 395	if (IS_ERR(essiv_tfm)) {
 396		crypt_iv_essiv_dtr(cc);
 397		return PTR_ERR(essiv_tfm);
 398	}
 399	cc->iv_private = essiv_tfm;
 400
 401	return 0;
 402
 403bad:
 404	if (hash_tfm && !IS_ERR(hash_tfm))
 405		crypto_free_ahash(hash_tfm);
 406	kfree(salt);
 407	return err;
 408}
 409
 410static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
 411			      struct dm_crypt_request *dmreq)
 412{
 413	struct crypto_cipher *essiv_tfm = cc->iv_private;
 414
 415	memset(iv, 0, cc->iv_size);
 416	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 417	crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
 418
 419	return 0;
 420}
 421
 422static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
 423			      const char *opts)
 424{
 425	unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
 426	int log = ilog2(bs);
 427
 428	/* we need to calculate how far we must shift the sector count
 429	 * to get the cipher block count, we use this shift in _gen */
 430
 431	if (1 << log != bs) {
 432		ti->error = "cypher blocksize is not a power of 2";
 433		return -EINVAL;
 434	}
 435
 436	if (log > 9) {
 437		ti->error = "cypher blocksize is > 512";
 438		return -EINVAL;
 439	}
 440
 441	cc->iv_gen_private.benbi.shift = 9 - log;
 442
 443	return 0;
 444}
 445
 446static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 447{
 448}
 449
 450static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
 451			      struct dm_crypt_request *dmreq)
 452{
 453	__be64 val;
 454
 455	memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 456
 457	val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
 458	put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 459
 460	return 0;
 461}
 462
 463static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
 464			     struct dm_crypt_request *dmreq)
 465{
 466	memset(iv, 0, cc->iv_size);
 467
 468	return 0;
 469}
 470
 471static void crypt_iv_lmk_dtr(struct crypt_config *cc)
 472{
 473	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 474
 475	if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
 476		crypto_free_shash(lmk->hash_tfm);
 477	lmk->hash_tfm = NULL;
 478
 479	kzfree(lmk->seed);
 480	lmk->seed = NULL;
 481}
 482
 483static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
 484			    const char *opts)
 485{
 486	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 487
 488	lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
 489	if (IS_ERR(lmk->hash_tfm)) {
 490		ti->error = "Error initializing LMK hash";
 491		return PTR_ERR(lmk->hash_tfm);
 492	}
 493
 494	/* No seed in LMK version 2 */
 495	if (cc->key_parts == cc->tfms_count) {
 496		lmk->seed = NULL;
 497		return 0;
 498	}
 499
 500	lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
 501	if (!lmk->seed) {
 502		crypt_iv_lmk_dtr(cc);
 503		ti->error = "Error kmallocing seed storage in LMK";
 504		return -ENOMEM;
 505	}
 506
 507	return 0;
 508}
 509
 510static int crypt_iv_lmk_init(struct crypt_config *cc)
 511{
 512	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 513	int subkey_size = cc->key_size / cc->key_parts;
 514
 515	/* LMK seed is on the position of LMK_KEYS + 1 key */
 516	if (lmk->seed)
 517		memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
 518		       crypto_shash_digestsize(lmk->hash_tfm));
 519
 520	return 0;
 521}
 522
 523static int crypt_iv_lmk_wipe(struct crypt_config *cc)
 524{
 525	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 526
 527	if (lmk->seed)
 528		memset(lmk->seed, 0, LMK_SEED_SIZE);
 529
 530	return 0;
 531}
 532
 533static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 534			    struct dm_crypt_request *dmreq,
 535			    u8 *data)
 536{
 537	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 538	SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
 
 
 
 539	struct md5_state md5state;
 540	__le32 buf[4];
 541	int i, r;
 542
 543	desc->tfm = lmk->hash_tfm;
 544	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 545
 546	r = crypto_shash_init(desc);
 547	if (r)
 548		return r;
 549
 550	if (lmk->seed) {
 551		r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
 552		if (r)
 553			return r;
 554	}
 555
 556	/* Sector is always 512B, block size 16, add data of blocks 1-31 */
 557	r = crypto_shash_update(desc, data + 16, 16 * 31);
 558	if (r)
 559		return r;
 560
 561	/* Sector is cropped to 56 bits here */
 562	buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
 563	buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
 564	buf[2] = cpu_to_le32(4024);
 565	buf[3] = 0;
 566	r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
 567	if (r)
 568		return r;
 569
 570	/* No MD5 padding here */
 571	r = crypto_shash_export(desc, &md5state);
 572	if (r)
 573		return r;
 574
 575	for (i = 0; i < MD5_HASH_WORDS; i++)
 576		__cpu_to_le32s(&md5state.hash[i]);
 577	memcpy(iv, &md5state.hash, cc->iv_size);
 578
 579	return 0;
 580}
 581
 582static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 583			    struct dm_crypt_request *dmreq)
 584{
 585	u8 *src;
 586	int r = 0;
 587
 588	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 589		src = kmap_atomic(sg_page(&dmreq->sg_in));
 590		r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
 591		kunmap_atomic(src);
 592	} else
 593		memset(iv, 0, cc->iv_size);
 594
 595	return r;
 596}
 597
 598static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
 599			     struct dm_crypt_request *dmreq)
 600{
 601	u8 *dst;
 602	int r;
 603
 604	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
 605		return 0;
 606
 607	dst = kmap_atomic(sg_page(&dmreq->sg_out));
 608	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
 609
 610	/* Tweak the first block of plaintext sector */
 611	if (!r)
 612		crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
 613
 614	kunmap_atomic(dst);
 615	return r;
 616}
 617
 618static void crypt_iv_tcw_dtr(struct crypt_config *cc)
 619{
 620	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 621
 622	kzfree(tcw->iv_seed);
 623	tcw->iv_seed = NULL;
 624	kzfree(tcw->whitening);
 625	tcw->whitening = NULL;
 626
 627	if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
 628		crypto_free_shash(tcw->crc32_tfm);
 629	tcw->crc32_tfm = NULL;
 630}
 631
 632static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
 633			    const char *opts)
 634{
 635	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 636
 637	if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
 638		ti->error = "Wrong key size for TCW";
 639		return -EINVAL;
 640	}
 641
 642	tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
 643	if (IS_ERR(tcw->crc32_tfm)) {
 644		ti->error = "Error initializing CRC32 in TCW";
 645		return PTR_ERR(tcw->crc32_tfm);
 646	}
 647
 648	tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
 649	tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
 650	if (!tcw->iv_seed || !tcw->whitening) {
 651		crypt_iv_tcw_dtr(cc);
 652		ti->error = "Error allocating seed storage in TCW";
 653		return -ENOMEM;
 654	}
 655
 656	return 0;
 657}
 658
 659static int crypt_iv_tcw_init(struct crypt_config *cc)
 660{
 661	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 662	int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
 663
 664	memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
 665	memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
 666	       TCW_WHITENING_SIZE);
 667
 668	return 0;
 669}
 670
 671static int crypt_iv_tcw_wipe(struct crypt_config *cc)
 672{
 673	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 674
 675	memset(tcw->iv_seed, 0, cc->iv_size);
 676	memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
 677
 678	return 0;
 679}
 680
 681static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 682				  struct dm_crypt_request *dmreq,
 683				  u8 *data)
 684{
 685	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 686	u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
 687	u8 buf[TCW_WHITENING_SIZE];
 688	SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
 
 
 
 689	int i, r;
 690
 691	/* xor whitening with sector number */
 692	memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
 693	crypto_xor(buf, (u8 *)&sector, 8);
 694	crypto_xor(&buf[8], (u8 *)&sector, 8);
 695
 696	/* calculate crc32 for every 32bit part and xor it */
 697	desc->tfm = tcw->crc32_tfm;
 698	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 699	for (i = 0; i < 4; i++) {
 700		r = crypto_shash_init(desc);
 701		if (r)
 702			goto out;
 703		r = crypto_shash_update(desc, &buf[i * 4], 4);
 704		if (r)
 705			goto out;
 706		r = crypto_shash_final(desc, &buf[i * 4]);
 707		if (r)
 708			goto out;
 709	}
 710	crypto_xor(&buf[0], &buf[12], 4);
 711	crypto_xor(&buf[4], &buf[8], 4);
 712
 713	/* apply whitening (8 bytes) to whole sector */
 714	for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
 715		crypto_xor(data + i * 8, buf, 8);
 716out:
 717	memzero_explicit(buf, sizeof(buf));
 718	return r;
 719}
 720
 721static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 722			    struct dm_crypt_request *dmreq)
 723{
 724	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 725	u64 sector = cpu_to_le64((u64)dmreq->iv_sector);
 726	u8 *src;
 727	int r = 0;
 728
 729	/* Remove whitening from ciphertext */
 730	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
 731		src = kmap_atomic(sg_page(&dmreq->sg_in));
 732		r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
 733		kunmap_atomic(src);
 734	}
 735
 736	/* Calculate IV */
 737	memcpy(iv, tcw->iv_seed, cc->iv_size);
 738	crypto_xor(iv, (u8 *)&sector, 8);
 739	if (cc->iv_size > 8)
 740		crypto_xor(&iv[8], (u8 *)&sector, cc->iv_size - 8);
 741
 742	return r;
 743}
 744
 745static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 746			     struct dm_crypt_request *dmreq)
 747{
 748	u8 *dst;
 749	int r;
 750
 751	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
 752		return 0;
 753
 754	/* Apply whitening on ciphertext */
 755	dst = kmap_atomic(sg_page(&dmreq->sg_out));
 756	r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
 757	kunmap_atomic(dst);
 758
 759	return r;
 760}
 761
 762static struct crypt_iv_operations crypt_iv_plain_ops = {
 763	.generator = crypt_iv_plain_gen
 764};
 765
 766static struct crypt_iv_operations crypt_iv_plain64_ops = {
 767	.generator = crypt_iv_plain64_gen
 768};
 769
 770static struct crypt_iv_operations crypt_iv_essiv_ops = {
 771	.ctr       = crypt_iv_essiv_ctr,
 772	.dtr       = crypt_iv_essiv_dtr,
 773	.init      = crypt_iv_essiv_init,
 774	.wipe      = crypt_iv_essiv_wipe,
 775	.generator = crypt_iv_essiv_gen
 776};
 777
 778static struct crypt_iv_operations crypt_iv_benbi_ops = {
 779	.ctr	   = crypt_iv_benbi_ctr,
 780	.dtr	   = crypt_iv_benbi_dtr,
 781	.generator = crypt_iv_benbi_gen
 782};
 783
 784static struct crypt_iv_operations crypt_iv_null_ops = {
 785	.generator = crypt_iv_null_gen
 786};
 787
 788static struct crypt_iv_operations crypt_iv_lmk_ops = {
 789	.ctr	   = crypt_iv_lmk_ctr,
 790	.dtr	   = crypt_iv_lmk_dtr,
 791	.init	   = crypt_iv_lmk_init,
 792	.wipe	   = crypt_iv_lmk_wipe,
 793	.generator = crypt_iv_lmk_gen,
 794	.post	   = crypt_iv_lmk_post
 795};
 796
 797static struct crypt_iv_operations crypt_iv_tcw_ops = {
 798	.ctr	   = crypt_iv_tcw_ctr,
 799	.dtr	   = crypt_iv_tcw_dtr,
 800	.init	   = crypt_iv_tcw_init,
 801	.wipe	   = crypt_iv_tcw_wipe,
 802	.generator = crypt_iv_tcw_gen,
 803	.post	   = crypt_iv_tcw_post
 804};
 805
 806static void crypt_convert_init(struct crypt_config *cc,
 807			       struct convert_context *ctx,
 808			       struct bio *bio_out, struct bio *bio_in,
 809			       sector_t sector)
 810{
 811	ctx->bio_in = bio_in;
 812	ctx->bio_out = bio_out;
 813	if (bio_in)
 814		ctx->iter_in = bio_in->bi_iter;
 815	if (bio_out)
 816		ctx->iter_out = bio_out->bi_iter;
 817	ctx->cc_sector = sector + cc->iv_offset;
 818	init_completion(&ctx->restart);
 819}
 820
 821static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
 822					     struct skcipher_request *req)
 823{
 824	return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
 825}
 826
 827static struct skcipher_request *req_of_dmreq(struct crypt_config *cc,
 828					       struct dm_crypt_request *dmreq)
 829{
 830	return (struct skcipher_request *)((char *)dmreq - cc->dmreq_start);
 831}
 832
 833static u8 *iv_of_dmreq(struct crypt_config *cc,
 834		       struct dm_crypt_request *dmreq)
 835{
 836	return (u8 *)ALIGN((unsigned long)(dmreq + 1),
 837		crypto_skcipher_alignmask(any_tfm(cc)) + 1);
 838}
 839
 840static int crypt_convert_block(struct crypt_config *cc,
 841			       struct convert_context *ctx,
 842			       struct skcipher_request *req)
 843{
 844	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
 845	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
 846	struct dm_crypt_request *dmreq;
 847	u8 *iv;
 848	int r;
 849
 850	dmreq = dmreq_of_req(cc, req);
 851	iv = iv_of_dmreq(cc, dmreq);
 852
 853	dmreq->iv_sector = ctx->cc_sector;
 854	dmreq->ctx = ctx;
 855	sg_init_table(&dmreq->sg_in, 1);
 856	sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
 857		    bv_in.bv_offset);
 858
 859	sg_init_table(&dmreq->sg_out, 1);
 860	sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
 861		    bv_out.bv_offset);
 862
 863	bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
 864	bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
 865
 866	if (cc->iv_gen_ops) {
 867		r = cc->iv_gen_ops->generator(cc, iv, dmreq);
 868		if (r < 0)
 869			return r;
 870	}
 871
 872	skcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
 873				   1 << SECTOR_SHIFT, iv);
 874
 875	if (bio_data_dir(ctx->bio_in) == WRITE)
 876		r = crypto_skcipher_encrypt(req);
 877	else
 878		r = crypto_skcipher_decrypt(req);
 879
 880	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
 881		r = cc->iv_gen_ops->post(cc, iv, dmreq);
 882
 883	return r;
 884}
 885
 886static void kcryptd_async_done(struct crypto_async_request *async_req,
 887			       int error);
 888
 889static void crypt_alloc_req(struct crypt_config *cc,
 890			    struct convert_context *ctx)
 891{
 892	unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
 893
 894	if (!ctx->req)
 895		ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
 896
 897	skcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
 898
 899	/*
 900	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
 901	 * requests if driver request queue is full.
 902	 */
 903	skcipher_request_set_callback(ctx->req,
 904	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 905	    kcryptd_async_done, dmreq_of_req(cc, ctx->req));
 906}
 907
 908static void crypt_free_req(struct crypt_config *cc,
 909			   struct skcipher_request *req, struct bio *base_bio)
 910{
 911	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
 912
 913	if ((struct skcipher_request *)(io + 1) != req)
 914		mempool_free(req, cc->req_pool);
 915}
 916
 917/*
 918 * Encrypt / decrypt data from one bio to another one (can be the same one)
 919 */
 920static int crypt_convert(struct crypt_config *cc,
 921			 struct convert_context *ctx)
 922{
 923	int r;
 924
 925	atomic_set(&ctx->cc_pending, 1);
 926
 927	while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
 928
 929		crypt_alloc_req(cc, ctx);
 930
 931		atomic_inc(&ctx->cc_pending);
 932
 933		r = crypt_convert_block(cc, ctx, ctx->req);
 934
 935		switch (r) {
 936		/*
 937		 * The request was queued by a crypto driver
 938		 * but the driver request queue is full, let's wait.
 939		 */
 940		case -EBUSY:
 941			wait_for_completion(&ctx->restart);
 942			reinit_completion(&ctx->restart);
 943			/* fall through */
 944		/*
 945		 * The request is queued and processed asynchronously,
 946		 * completion function kcryptd_async_done() will be called.
 947		 */
 948		case -EINPROGRESS:
 949			ctx->req = NULL;
 950			ctx->cc_sector++;
 951			continue;
 952		/*
 953		 * The request was already processed (synchronously).
 954		 */
 955		case 0:
 956			atomic_dec(&ctx->cc_pending);
 957			ctx->cc_sector++;
 958			cond_resched();
 959			continue;
 960
 961		/* There was an error while processing the request. */
 962		default:
 963			atomic_dec(&ctx->cc_pending);
 964			return r;
 965		}
 966	}
 967
 968	return 0;
 969}
 970
 971static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
 972
 973/*
 974 * Generate a new unfragmented bio with the given size
 975 * This should never violate the device limitations (but only because
 976 * max_segment_size is being constrained to PAGE_SIZE).
 977 *
 978 * This function may be called concurrently. If we allocate from the mempool
 979 * concurrently, there is a possibility of deadlock. For example, if we have
 980 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
 981 * the mempool concurrently, it may deadlock in a situation where both processes
 982 * have allocated 128 pages and the mempool is exhausted.
 983 *
 984 * In order to avoid this scenario we allocate the pages under a mutex.
 985 *
 986 * In order to not degrade performance with excessive locking, we try
 987 * non-blocking allocations without a mutex first but on failure we fallback
 988 * to blocking allocations with a mutex.
 989 */
 990static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
 
 991{
 992	struct crypt_config *cc = io->cc;
 993	struct bio *clone;
 994	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 995	gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
 996	unsigned i, len, remaining_size;
 997	struct page *page;
 998	struct bio_vec *bvec;
 999
1000retry:
1001	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1002		mutex_lock(&cc->bio_alloc_lock);
1003
1004	clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1005	if (!clone)
1006		goto return_clone;
1007
1008	clone_init(io, clone);
1009
1010	remaining_size = size;
1011
1012	for (i = 0; i < nr_iovecs; i++) {
1013		page = mempool_alloc(cc->page_pool, gfp_mask);
1014		if (!page) {
1015			crypt_free_buffer_pages(cc, clone);
1016			bio_put(clone);
1017			gfp_mask |= __GFP_DIRECT_RECLAIM;
1018			goto retry;
1019		}
1020
1021		len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
 
 
 
 
 
1022
1023		bvec = &clone->bi_io_vec[clone->bi_vcnt++];
1024		bvec->bv_page = page;
1025		bvec->bv_len = len;
1026		bvec->bv_offset = 0;
1027
1028		clone->bi_iter.bi_size += len;
 
 
 
1029
1030		remaining_size -= len;
1031	}
1032
1033return_clone:
1034	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1035		mutex_unlock(&cc->bio_alloc_lock);
 
1036
1037	return clone;
1038}
1039
1040static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1041{
1042	unsigned int i;
1043	struct bio_vec *bv;
1044
1045	bio_for_each_segment_all(bv, clone, i) {
1046		BUG_ON(!bv->bv_page);
1047		mempool_free(bv->bv_page, cc->page_pool);
1048		bv->bv_page = NULL;
1049	}
1050}
1051
1052static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1053			  struct bio *bio, sector_t sector)
1054{
 
 
 
1055	io->cc = cc;
1056	io->base_bio = bio;
1057	io->sector = sector;
1058	io->error = 0;
 
1059	io->ctx.req = NULL;
1060	atomic_set(&io->io_pending, 0);
 
 
1061}
1062
1063static void crypt_inc_pending(struct dm_crypt_io *io)
1064{
1065	atomic_inc(&io->io_pending);
1066}
1067
1068/*
1069 * One of the bios was finished. Check for completion of
1070 * the whole request and correctly clean up the buffer.
 
1071 */
1072static void crypt_dec_pending(struct dm_crypt_io *io)
1073{
1074	struct crypt_config *cc = io->cc;
1075	struct bio *base_bio = io->base_bio;
 
1076	int error = io->error;
1077
1078	if (!atomic_dec_and_test(&io->io_pending))
1079		return;
1080
1081	if (io->ctx.req)
1082		crypt_free_req(cc, io->ctx.req, base_bio);
 
1083
1084	base_bio->bi_error = error;
1085	bio_endio(base_bio);
 
 
 
 
 
1086}
1087
1088/*
1089 * kcryptd/kcryptd_io:
1090 *
1091 * Needed because it would be very unwise to do decryption in an
1092 * interrupt context.
1093 *
1094 * kcryptd performs the actual encryption or decryption.
1095 *
1096 * kcryptd_io performs the IO submission.
1097 *
1098 * They must be separated as otherwise the final stages could be
1099 * starved by new requests which can block in the first stages due
1100 * to memory allocation.
1101 *
1102 * The work is done per CPU global for all dm-crypt instances.
1103 * They should not depend on each other and do not block.
1104 */
1105static void crypt_endio(struct bio *clone)
1106{
1107	struct dm_crypt_io *io = clone->bi_private;
1108	struct crypt_config *cc = io->cc;
1109	unsigned rw = bio_data_dir(clone);
1110	int error;
 
 
1111
1112	/*
1113	 * free the processed pages
1114	 */
1115	if (rw == WRITE)
1116		crypt_free_buffer_pages(cc, clone);
1117
1118	error = clone->bi_error;
1119	bio_put(clone);
1120
1121	if (rw == READ && !error) {
1122		kcryptd_queue_crypt(io);
1123		return;
1124	}
1125
1126	if (unlikely(error))
1127		io->error = error;
1128
1129	crypt_dec_pending(io);
1130}
1131
1132static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1133{
1134	struct crypt_config *cc = io->cc;
1135
1136	clone->bi_private = io;
1137	clone->bi_end_io  = crypt_endio;
1138	clone->bi_bdev    = cc->dev->bdev;
1139	clone->bi_rw      = io->base_bio->bi_rw;
1140}
1141
1142static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1143{
1144	struct crypt_config *cc = io->cc;
 
1145	struct bio *clone;
1146
1147	/*
1148	 * We need the original biovec array in order to decrypt
1149	 * the whole bio data *afterwards* -- thanks to immutable
1150	 * biovecs we don't need to worry about the block layer
1151	 * modifying the biovec array; so leverage bio_clone_fast().
1152	 */
1153	clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1154	if (!clone)
1155		return 1;
1156
1157	crypt_inc_pending(io);
1158
1159	clone_init(io, clone);
1160	clone->bi_iter.bi_sector = cc->start + io->sector;
1161
1162	generic_make_request(clone);
1163	return 0;
1164}
1165
1166static void kcryptd_io_read_work(struct work_struct *work)
1167{
1168	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1169
1170	crypt_inc_pending(io);
1171	if (kcryptd_io_read(io, GFP_NOIO))
1172		io->error = -ENOMEM;
1173	crypt_dec_pending(io);
1174}
1175
1176static void kcryptd_queue_read(struct dm_crypt_io *io)
1177{
1178	struct crypt_config *cc = io->cc;
1179
1180	INIT_WORK(&io->work, kcryptd_io_read_work);
1181	queue_work(cc->io_queue, &io->work);
1182}
1183
1184static void kcryptd_io_write(struct dm_crypt_io *io)
1185{
1186	struct bio *clone = io->ctx.bio_out;
1187
1188	generic_make_request(clone);
1189}
1190
1191#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1192
1193static int dmcrypt_write(void *data)
1194{
1195	struct crypt_config *cc = data;
1196	struct dm_crypt_io *io;
1197
1198	while (1) {
1199		struct rb_root write_tree;
1200		struct blk_plug plug;
1201
1202		DECLARE_WAITQUEUE(wait, current);
1203
1204		spin_lock_irq(&cc->write_thread_wait.lock);
1205continue_locked:
1206
1207		if (!RB_EMPTY_ROOT(&cc->write_tree))
1208			goto pop_from_list;
1209
1210		if (unlikely(test_bit(DM_CRYPT_EXIT_THREAD, &cc->flags))) {
1211			spin_unlock_irq(&cc->write_thread_wait.lock);
1212			break;
1213		}
1214
1215		__set_current_state(TASK_INTERRUPTIBLE);
1216		__add_wait_queue(&cc->write_thread_wait, &wait);
1217
1218		spin_unlock_irq(&cc->write_thread_wait.lock);
1219
1220		schedule();
1221
1222		spin_lock_irq(&cc->write_thread_wait.lock);
1223		__remove_wait_queue(&cc->write_thread_wait, &wait);
1224		goto continue_locked;
1225
1226pop_from_list:
1227		write_tree = cc->write_tree;
1228		cc->write_tree = RB_ROOT;
1229		spin_unlock_irq(&cc->write_thread_wait.lock);
 
 
 
 
1230
1231		BUG_ON(rb_parent(write_tree.rb_node));
 
 
1232
1233		/*
1234		 * Note: we cannot walk the tree here with rb_next because
1235		 * the structures may be freed when kcryptd_io_write is called.
1236		 */
1237		blk_start_plug(&plug);
1238		do {
1239			io = crypt_io_from_node(rb_first(&write_tree));
1240			rb_erase(&io->rb_node, &write_tree);
1241			kcryptd_io_write(io);
1242		} while (!RB_EMPTY_ROOT(&write_tree));
1243		blk_finish_plug(&plug);
1244	}
1245	return 0;
1246}
1247
1248static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1249{
1250	struct bio *clone = io->ctx.bio_out;
1251	struct crypt_config *cc = io->cc;
1252	unsigned long flags;
1253	sector_t sector;
1254	struct rb_node **rbp, *parent;
1255
1256	if (unlikely(io->error < 0)) {
1257		crypt_free_buffer_pages(cc, clone);
1258		bio_put(clone);
1259		crypt_dec_pending(io);
1260		return;
1261	}
1262
1263	/* crypt_convert should have filled the clone bio */
1264	BUG_ON(io->ctx.iter_out.bi_size);
1265
1266	clone->bi_iter.bi_sector = cc->start + io->sector;
1267
1268	if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
 
 
1269		generic_make_request(clone);
1270		return;
1271	}
1272
1273	spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
1274	rbp = &cc->write_tree.rb_node;
1275	parent = NULL;
1276	sector = io->sector;
1277	while (*rbp) {
1278		parent = *rbp;
1279		if (sector < crypt_io_from_node(parent)->sector)
1280			rbp = &(*rbp)->rb_left;
1281		else
1282			rbp = &(*rbp)->rb_right;
1283	}
1284	rb_link_node(&io->rb_node, parent, rbp);
1285	rb_insert_color(&io->rb_node, &cc->write_tree);
1286
1287	wake_up_locked(&cc->write_thread_wait);
1288	spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1289}
1290
1291static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1292{
1293	struct crypt_config *cc = io->cc;
1294	struct bio *clone;
 
1295	int crypt_finished;
 
 
1296	sector_t sector = io->sector;
1297	int r;
1298
1299	/*
1300	 * Prevent io from disappearing until this function completes.
1301	 */
1302	crypt_inc_pending(io);
1303	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1304
1305	clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1306	if (unlikely(!clone)) {
1307		io->error = -EIO;
1308		goto dec;
1309	}
 
 
 
 
 
1310
1311	io->ctx.bio_out = clone;
1312	io->ctx.iter_out = clone->bi_iter;
1313
1314	sector += bio_sectors(clone);
 
1315
1316	crypt_inc_pending(io);
1317	r = crypt_convert(cc, &io->ctx);
1318	if (r)
1319		io->error = -EIO;
1320	crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1321
1322	/* Encryption was already finished, submit io now */
1323	if (crypt_finished) {
1324		kcryptd_crypt_write_io_submit(io, 0);
1325		io->sector = sector;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1326	}
1327
1328dec:
1329	crypt_dec_pending(io);
1330}
1331
1332static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1333{
1334	crypt_dec_pending(io);
1335}
1336
1337static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1338{
1339	struct crypt_config *cc = io->cc;
1340	int r = 0;
1341
1342	crypt_inc_pending(io);
1343
1344	crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1345			   io->sector);
1346
1347	r = crypt_convert(cc, &io->ctx);
1348	if (r < 0)
1349		io->error = -EIO;
1350
1351	if (atomic_dec_and_test(&io->ctx.cc_pending))
1352		kcryptd_crypt_read_done(io);
1353
1354	crypt_dec_pending(io);
1355}
1356
1357static void kcryptd_async_done(struct crypto_async_request *async_req,
1358			       int error)
1359{
1360	struct dm_crypt_request *dmreq = async_req->data;
1361	struct convert_context *ctx = dmreq->ctx;
1362	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1363	struct crypt_config *cc = io->cc;
1364
1365	/*
1366	 * A request from crypto driver backlog is going to be processed now,
1367	 * finish the completion and continue in crypt_convert().
1368	 * (Callback will be called for the second time for this request.)
1369	 */
1370	if (error == -EINPROGRESS) {
1371		complete(&ctx->restart);
1372		return;
1373	}
1374
1375	if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1376		error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1377
1378	if (error < 0)
1379		io->error = -EIO;
1380
1381	crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1382
1383	if (!atomic_dec_and_test(&ctx->cc_pending))
1384		return;
1385
1386	if (bio_data_dir(io->base_bio) == READ)
1387		kcryptd_crypt_read_done(io);
1388	else
1389		kcryptd_crypt_write_io_submit(io, 1);
1390}
1391
1392static void kcryptd_crypt(struct work_struct *work)
1393{
1394	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1395
1396	if (bio_data_dir(io->base_bio) == READ)
1397		kcryptd_crypt_read_convert(io);
1398	else
1399		kcryptd_crypt_write_convert(io);
1400}
1401
1402static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1403{
1404	struct crypt_config *cc = io->cc;
1405
1406	INIT_WORK(&io->work, kcryptd_crypt);
1407	queue_work(cc->crypt_queue, &io->work);
1408}
1409
1410/*
1411 * Decode key from its hex representation
1412 */
1413static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1414{
1415	char buffer[3];
1416	unsigned int i;
1417
1418	buffer[2] = '\0';
1419
1420	for (i = 0; i < size; i++) {
1421		buffer[0] = *hex++;
1422		buffer[1] = *hex++;
1423
1424		if (kstrtou8(buffer, 16, &key[i]))
1425			return -EINVAL;
1426	}
1427
1428	if (*hex != '\0')
1429		return -EINVAL;
1430
1431	return 0;
1432}
1433
1434static void crypt_free_tfms(struct crypt_config *cc)
1435{
1436	unsigned i;
1437
1438	if (!cc->tfms)
1439		return;
1440
1441	for (i = 0; i < cc->tfms_count; i++)
1442		if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1443			crypto_free_skcipher(cc->tfms[i]);
1444			cc->tfms[i] = NULL;
1445		}
1446
1447	kfree(cc->tfms);
1448	cc->tfms = NULL;
1449}
1450
1451static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
1452{
1453	unsigned i;
1454	int err;
1455
1456	cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
1457			   GFP_KERNEL);
1458	if (!cc->tfms)
1459		return -ENOMEM;
1460
1461	for (i = 0; i < cc->tfms_count; i++) {
1462		cc->tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1463		if (IS_ERR(cc->tfms[i])) {
1464			err = PTR_ERR(cc->tfms[i]);
1465			crypt_free_tfms(cc);
1466			return err;
1467		}
1468	}
1469
1470	return 0;
1471}
1472
1473static int crypt_setkey_allcpus(struct crypt_config *cc)
1474{
1475	unsigned subkey_size;
1476	int err = 0, i, r;
1477
1478	/* Ignore extra keys (which are used for IV etc) */
1479	subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
1480
1481	for (i = 0; i < cc->tfms_count; i++) {
1482		r = crypto_skcipher_setkey(cc->tfms[i],
1483					   cc->key + (i * subkey_size),
1484					   subkey_size);
1485		if (r)
1486			err = r;
1487	}
1488
1489	return err;
1490}
1491
1492static int crypt_set_key(struct crypt_config *cc, char *key)
1493{
1494	int r = -EINVAL;
1495	int key_string_len = strlen(key);
1496
1497	/* The key size may not be changed. */
1498	if (cc->key_size != (key_string_len >> 1))
1499		goto out;
1500
1501	/* Hyphen (which gives a key_size of zero) means there is no key. */
1502	if (!cc->key_size && strcmp(key, "-"))
1503		goto out;
1504
1505	if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1506		goto out;
1507
1508	set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1509
1510	r = crypt_setkey_allcpus(cc);
1511
1512out:
1513	/* Hex key string not needed after here, so wipe it. */
1514	memset(key, '0', key_string_len);
1515
1516	return r;
1517}
1518
1519static int crypt_wipe_key(struct crypt_config *cc)
1520{
1521	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1522	memset(&cc->key, 0, cc->key_size * sizeof(u8));
1523
1524	return crypt_setkey_allcpus(cc);
1525}
1526
1527static void crypt_dtr(struct dm_target *ti)
1528{
1529	struct crypt_config *cc = ti->private;
1530
1531	ti->private = NULL;
1532
1533	if (!cc)
1534		return;
1535
1536	if (cc->write_thread) {
1537		spin_lock_irq(&cc->write_thread_wait.lock);
1538		set_bit(DM_CRYPT_EXIT_THREAD, &cc->flags);
1539		wake_up_locked(&cc->write_thread_wait);
1540		spin_unlock_irq(&cc->write_thread_wait.lock);
1541		kthread_stop(cc->write_thread);
1542	}
1543
1544	if (cc->io_queue)
1545		destroy_workqueue(cc->io_queue);
1546	if (cc->crypt_queue)
1547		destroy_workqueue(cc->crypt_queue);
1548
1549	crypt_free_tfms(cc);
1550
1551	if (cc->bs)
1552		bioset_free(cc->bs);
1553
1554	mempool_destroy(cc->page_pool);
1555	mempool_destroy(cc->req_pool);
 
 
 
 
1556
1557	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1558		cc->iv_gen_ops->dtr(cc);
1559
1560	if (cc->dev)
1561		dm_put_device(ti, cc->dev);
1562
1563	kzfree(cc->cipher);
1564	kzfree(cc->cipher_string);
1565
1566	/* Must zero key material before freeing */
1567	kzfree(cc);
1568}
1569
1570static int crypt_ctr_cipher(struct dm_target *ti,
1571			    char *cipher_in, char *key)
1572{
1573	struct crypt_config *cc = ti->private;
1574	char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1575	char *cipher_api = NULL;
1576	int ret = -EINVAL;
1577	char dummy;
1578
1579	/* Convert to crypto api definition? */
1580	if (strchr(cipher_in, '(')) {
1581		ti->error = "Bad cipher specification";
1582		return -EINVAL;
1583	}
1584
1585	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1586	if (!cc->cipher_string)
1587		goto bad_mem;
1588
1589	/*
1590	 * Legacy dm-crypt cipher specification
1591	 * cipher[:keycount]-mode-iv:ivopts
1592	 */
1593	tmp = cipher_in;
1594	keycount = strsep(&tmp, "-");
1595	cipher = strsep(&keycount, ":");
1596
1597	if (!keycount)
1598		cc->tfms_count = 1;
1599	else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1600		 !is_power_of_2(cc->tfms_count)) {
1601		ti->error = "Bad cipher key count specification";
1602		return -EINVAL;
1603	}
1604	cc->key_parts = cc->tfms_count;
1605	cc->key_extra_size = 0;
1606
1607	cc->cipher = kstrdup(cipher, GFP_KERNEL);
1608	if (!cc->cipher)
1609		goto bad_mem;
1610
1611	chainmode = strsep(&tmp, "-");
1612	ivopts = strsep(&tmp, "-");
1613	ivmode = strsep(&ivopts, ":");
1614
1615	if (tmp)
1616		DMWARN("Ignoring unexpected additional cipher options");
1617
1618	/*
1619	 * For compatibility with the original dm-crypt mapping format, if
1620	 * only the cipher name is supplied, use cbc-plain.
1621	 */
1622	if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1623		chainmode = "cbc";
1624		ivmode = "plain";
1625	}
1626
1627	if (strcmp(chainmode, "ecb") && !ivmode) {
1628		ti->error = "IV mechanism required";
1629		return -EINVAL;
1630	}
1631
1632	cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1633	if (!cipher_api)
1634		goto bad_mem;
1635
1636	ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1637		       "%s(%s)", chainmode, cipher);
1638	if (ret < 0) {
1639		kfree(cipher_api);
1640		goto bad_mem;
1641	}
1642
1643	/* Allocate cipher */
1644	ret = crypt_alloc_tfms(cc, cipher_api);
1645	if (ret < 0) {
1646		ti->error = "Error allocating crypto tfm";
1647		goto bad;
1648	}
1649
1650	/* Initialize IV */
1651	cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
1652	if (cc->iv_size)
1653		/* at least a 64 bit sector number should fit in our buffer */
1654		cc->iv_size = max(cc->iv_size,
1655				  (unsigned int)(sizeof(u64) / sizeof(u8)));
1656	else if (ivmode) {
1657		DMWARN("Selected cipher does not support IVs");
1658		ivmode = NULL;
1659	}
1660
1661	/* Choose ivmode, see comments at iv code. */
1662	if (ivmode == NULL)
1663		cc->iv_gen_ops = NULL;
1664	else if (strcmp(ivmode, "plain") == 0)
1665		cc->iv_gen_ops = &crypt_iv_plain_ops;
1666	else if (strcmp(ivmode, "plain64") == 0)
1667		cc->iv_gen_ops = &crypt_iv_plain64_ops;
1668	else if (strcmp(ivmode, "essiv") == 0)
1669		cc->iv_gen_ops = &crypt_iv_essiv_ops;
1670	else if (strcmp(ivmode, "benbi") == 0)
1671		cc->iv_gen_ops = &crypt_iv_benbi_ops;
1672	else if (strcmp(ivmode, "null") == 0)
1673		cc->iv_gen_ops = &crypt_iv_null_ops;
1674	else if (strcmp(ivmode, "lmk") == 0) {
1675		cc->iv_gen_ops = &crypt_iv_lmk_ops;
1676		/*
1677		 * Version 2 and 3 is recognised according
1678		 * to length of provided multi-key string.
1679		 * If present (version 3), last key is used as IV seed.
1680		 * All keys (including IV seed) are always the same size.
1681		 */
1682		if (cc->key_size % cc->key_parts) {
1683			cc->key_parts++;
1684			cc->key_extra_size = cc->key_size / cc->key_parts;
1685		}
1686	} else if (strcmp(ivmode, "tcw") == 0) {
1687		cc->iv_gen_ops = &crypt_iv_tcw_ops;
1688		cc->key_parts += 2; /* IV + whitening */
1689		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1690	} else {
1691		ret = -EINVAL;
1692		ti->error = "Invalid IV mode";
1693		goto bad;
1694	}
1695
1696	/* Initialize and set key */
1697	ret = crypt_set_key(cc, key);
1698	if (ret < 0) {
1699		ti->error = "Error decoding and setting key";
1700		goto bad;
1701	}
1702
1703	/* Allocate IV */
1704	if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1705		ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1706		if (ret < 0) {
1707			ti->error = "Error creating IV";
1708			goto bad;
1709		}
1710	}
1711
1712	/* Initialize IV (set keys for ESSIV etc) */
1713	if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1714		ret = cc->iv_gen_ops->init(cc);
1715		if (ret < 0) {
1716			ti->error = "Error initialising IV";
1717			goto bad;
1718		}
1719	}
1720
1721	ret = 0;
1722bad:
1723	kfree(cipher_api);
1724	return ret;
1725
1726bad_mem:
1727	ti->error = "Cannot allocate cipher strings";
1728	return -ENOMEM;
1729}
1730
1731/*
1732 * Construct an encryption mapping:
1733 * <cipher> <key> <iv_offset> <dev_path> <start>
1734 */
1735static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1736{
1737	struct crypt_config *cc;
1738	unsigned int key_size, opt_params;
1739	unsigned long long tmpll;
1740	int ret;
1741	size_t iv_size_padding;
1742	struct dm_arg_set as;
1743	const char *opt_string;
1744	char dummy;
1745
1746	static struct dm_arg _args[] = {
1747		{0, 3, "Invalid number of feature args"},
1748	};
1749
1750	if (argc < 5) {
1751		ti->error = "Not enough arguments";
1752		return -EINVAL;
1753	}
1754
1755	key_size = strlen(argv[1]) >> 1;
1756
1757	cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1758	if (!cc) {
1759		ti->error = "Cannot allocate encryption context";
1760		return -ENOMEM;
1761	}
1762	cc->key_size = key_size;
1763
1764	ti->private = cc;
1765	ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1766	if (ret < 0)
1767		goto bad;
1768
1769	cc->dmreq_start = sizeof(struct skcipher_request);
1770	cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
1771	cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1772
1773	if (crypto_skcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1774		/* Allocate the padding exactly */
1775		iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1776				& crypto_skcipher_alignmask(any_tfm(cc));
1777	} else {
1778		/*
1779		 * If the cipher requires greater alignment than kmalloc
1780		 * alignment, we don't know the exact position of the
1781		 * initialization vector. We must assume worst case.
1782		 */
1783		iv_size_padding = crypto_skcipher_alignmask(any_tfm(cc));
1784	}
1785
1786	ret = -ENOMEM;
 
 
 
 
 
1787	cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1788			sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1789	if (!cc->req_pool) {
1790		ti->error = "Cannot allocate crypt request mempool";
1791		goto bad;
1792	}
1793
1794	cc->per_bio_data_size = ti->per_io_data_size =
1795		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1796		      sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1797		      ARCH_KMALLOC_MINALIGN);
1798
1799	cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1800	if (!cc->page_pool) {
1801		ti->error = "Cannot allocate page mempool";
1802		goto bad;
1803	}
1804
1805	cc->bs = bioset_create(MIN_IOS, 0);
1806	if (!cc->bs) {
1807		ti->error = "Cannot allocate crypt bioset";
1808		goto bad;
1809	}
1810
1811	mutex_init(&cc->bio_alloc_lock);
1812
1813	ret = -EINVAL;
1814	if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
1815		ti->error = "Invalid iv_offset sector";
1816		goto bad;
1817	}
1818	cc->iv_offset = tmpll;
1819
1820	ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
1821	if (ret) {
1822		ti->error = "Device lookup failed";
1823		goto bad;
1824	}
1825
1826	ret = -EINVAL;
1827	if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1828		ti->error = "Invalid device sector";
1829		goto bad;
1830	}
1831	cc->start = tmpll;
1832
1833	argv += 5;
1834	argc -= 5;
1835
1836	/* Optional parameters */
1837	if (argc) {
1838		as.argc = argc;
1839		as.argv = argv;
1840
1841		ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1842		if (ret)
1843			goto bad;
1844
1845		ret = -EINVAL;
1846		while (opt_params--) {
1847			opt_string = dm_shift_arg(&as);
1848			if (!opt_string) {
1849				ti->error = "Not enough feature arguments";
1850				goto bad;
1851			}
1852
1853			if (!strcasecmp(opt_string, "allow_discards"))
1854				ti->num_discard_bios = 1;
1855
1856			else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1857				set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1858
1859			else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
1860				set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1861
1862			else {
1863				ti->error = "Invalid feature arguments";
1864				goto bad;
1865			}
1866		}
1867	}
1868
1869	ret = -ENOMEM;
1870	cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
1871	if (!cc->io_queue) {
1872		ti->error = "Couldn't create kcryptd io queue";
1873		goto bad;
1874	}
1875
1876	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1877		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
1878	else
1879		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
1880						  num_online_cpus());
1881	if (!cc->crypt_queue) {
1882		ti->error = "Couldn't create kcryptd queue";
1883		goto bad;
1884	}
1885
1886	init_waitqueue_head(&cc->write_thread_wait);
1887	cc->write_tree = RB_ROOT;
1888
1889	cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
1890	if (IS_ERR(cc->write_thread)) {
1891		ret = PTR_ERR(cc->write_thread);
1892		cc->write_thread = NULL;
1893		ti->error = "Couldn't spawn write thread";
1894		goto bad;
1895	}
1896	wake_up_process(cc->write_thread);
1897
1898	ti->num_flush_bios = 1;
1899	ti->discard_zeroes_data_unsupported = true;
1900
1901	return 0;
1902
1903bad:
1904	crypt_dtr(ti);
1905	return ret;
1906}
1907
1908static int crypt_map(struct dm_target *ti, struct bio *bio)
1909{
1910	struct dm_crypt_io *io;
1911	struct crypt_config *cc = ti->private;
1912
1913	/*
1914	 * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1915	 * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1916	 * - for REQ_DISCARD caller must use flush if IO ordering matters
1917	 */
1918	if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1919		bio->bi_bdev = cc->dev->bdev;
1920		if (bio_sectors(bio))
1921			bio->bi_iter.bi_sector = cc->start +
1922				dm_target_offset(ti, bio->bi_iter.bi_sector);
1923		return DM_MAPIO_REMAPPED;
1924	}
1925
1926	io = dm_per_bio_data(bio, cc->per_bio_data_size);
1927	crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
1928	io->ctx.req = (struct skcipher_request *)(io + 1);
1929
1930	if (bio_data_dir(io->base_bio) == READ) {
1931		if (kcryptd_io_read(io, GFP_NOWAIT))
1932			kcryptd_queue_read(io);
1933	} else
1934		kcryptd_queue_crypt(io);
1935
1936	return DM_MAPIO_SUBMITTED;
1937}
1938
1939static void crypt_status(struct dm_target *ti, status_type_t type,
1940			 unsigned status_flags, char *result, unsigned maxlen)
1941{
1942	struct crypt_config *cc = ti->private;
1943	unsigned i, sz = 0;
1944	int num_feature_args = 0;
1945
1946	switch (type) {
1947	case STATUSTYPE_INFO:
1948		result[0] = '\0';
1949		break;
1950
1951	case STATUSTYPE_TABLE:
1952		DMEMIT("%s ", cc->cipher_string);
1953
1954		if (cc->key_size > 0)
1955			for (i = 0; i < cc->key_size; i++)
1956				DMEMIT("%02x", cc->key[i]);
1957		else
1958			DMEMIT("-");
1959
1960		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1961				cc->dev->name, (unsigned long long)cc->start);
1962
1963		num_feature_args += !!ti->num_discard_bios;
1964		num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1965		num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1966		if (num_feature_args) {
1967			DMEMIT(" %d", num_feature_args);
1968			if (ti->num_discard_bios)
1969				DMEMIT(" allow_discards");
1970			if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
1971				DMEMIT(" same_cpu_crypt");
1972			if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
1973				DMEMIT(" submit_from_crypt_cpus");
1974		}
1975
1976		break;
1977	}
1978}
1979
1980static void crypt_postsuspend(struct dm_target *ti)
1981{
1982	struct crypt_config *cc = ti->private;
1983
1984	set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1985}
1986
1987static int crypt_preresume(struct dm_target *ti)
1988{
1989	struct crypt_config *cc = ti->private;
1990
1991	if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1992		DMERR("aborting resume - crypt key is not set.");
1993		return -EAGAIN;
1994	}
1995
1996	return 0;
1997}
1998
1999static void crypt_resume(struct dm_target *ti)
2000{
2001	struct crypt_config *cc = ti->private;
2002
2003	clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2004}
2005
2006/* Message interface
2007 *	key set <key>
2008 *	key wipe
2009 */
2010static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
2011{
2012	struct crypt_config *cc = ti->private;
2013	int ret = -EINVAL;
2014
2015	if (argc < 2)
2016		goto error;
2017
2018	if (!strcasecmp(argv[0], "key")) {
2019		if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2020			DMWARN("not suspended during key manipulation.");
2021			return -EINVAL;
2022		}
2023		if (argc == 3 && !strcasecmp(argv[1], "set")) {
2024			ret = crypt_set_key(cc, argv[2]);
2025			if (ret)
2026				return ret;
2027			if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2028				ret = cc->iv_gen_ops->init(cc);
2029			return ret;
2030		}
2031		if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
2032			if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2033				ret = cc->iv_gen_ops->wipe(cc);
2034				if (ret)
2035					return ret;
2036			}
2037			return crypt_wipe_key(cc);
2038		}
2039	}
2040
2041error:
2042	DMWARN("unrecognised message received.");
2043	return -EINVAL;
2044}
2045
2046static int crypt_iterate_devices(struct dm_target *ti,
2047				 iterate_devices_callout_fn fn, void *data)
2048{
2049	struct crypt_config *cc = ti->private;
 
2050
2051	return fn(ti, cc->dev, cc->start, ti->len, data);
 
 
 
 
 
 
2052}
2053
2054static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
2055{
2056	/*
2057	 * Unfortunate constraint that is required to avoid the potential
2058	 * for exceeding underlying device's max_segments limits -- due to
2059	 * crypt_alloc_buffer() possibly allocating pages for the encryption
2060	 * bio that are not as physically contiguous as the original bio.
2061	 */
2062	limits->max_segment_size = PAGE_SIZE;
2063}
2064
2065static struct target_type crypt_target = {
2066	.name   = "crypt",
2067	.version = {1, 14, 1},
2068	.module = THIS_MODULE,
2069	.ctr    = crypt_ctr,
2070	.dtr    = crypt_dtr,
2071	.map    = crypt_map,
2072	.status = crypt_status,
2073	.postsuspend = crypt_postsuspend,
2074	.preresume = crypt_preresume,
2075	.resume = crypt_resume,
2076	.message = crypt_message,
 
2077	.iterate_devices = crypt_iterate_devices,
2078	.io_hints = crypt_io_hints,
2079};
2080
2081static int __init dm_crypt_init(void)
2082{
2083	int r;
2084
 
 
 
 
2085	r = dm_register_target(&crypt_target);
2086	if (r < 0)
2087		DMERR("register failed %d", r);
 
 
2088
2089	return r;
2090}
2091
2092static void __exit dm_crypt_exit(void)
2093{
2094	dm_unregister_target(&crypt_target);
 
2095}
2096
2097module_init(dm_crypt_init);
2098module_exit(dm_crypt_exit);
2099
2100MODULE_AUTHOR("Jana Saout <jana@saout.de>");
2101MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2102MODULE_LICENSE("GPL");