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/key.h>
  16#include <linux/bio.h>
  17#include <linux/blkdev.h>
  18#include <linux/mempool.h>
  19#include <linux/slab.h>
  20#include <linux/crypto.h>
  21#include <linux/workqueue.h>
  22#include <linux/kthread.h>
  23#include <linux/backing-dev.h>
  24#include <linux/atomic.h>
  25#include <linux/scatterlist.h>
  26#include <linux/rbtree.h>
  27#include <linux/ctype.h>
  28#include <asm/page.h>
  29#include <asm/unaligned.h>
  30#include <crypto/hash.h>
  31#include <crypto/md5.h>
  32#include <crypto/algapi.h>
  33#include <crypto/skcipher.h>
 
 
 
  34#include <keys/user-type.h>
  35
  36#include <linux/device-mapper.h>
  37
  38#define DM_MSG_PREFIX "crypt"
  39
  40/*
  41 * context holding the current state of a multi-part conversion
  42 */
  43struct convert_context {
  44	struct completion restart;
  45	struct bio *bio_in;
  46	struct bio *bio_out;
  47	struct bvec_iter iter_in;
  48	struct bvec_iter iter_out;
  49	sector_t cc_sector;
  50	atomic_t cc_pending;
  51	struct skcipher_request *req;
 
 
 
 
  52};
  53
  54/*
  55 * per bio private data
  56 */
  57struct dm_crypt_io {
  58	struct crypt_config *cc;
  59	struct bio *base_bio;
 
 
  60	struct work_struct work;
  61
  62	struct convert_context ctx;
  63
  64	atomic_t io_pending;
  65	int error;
  66	sector_t sector;
  67
  68	struct rb_node rb_node;
  69} CRYPTO_MINALIGN_ATTR;
  70
  71struct dm_crypt_request {
  72	struct convert_context *ctx;
  73	struct scatterlist sg_in;
  74	struct scatterlist sg_out;
  75	sector_t iv_sector;
  76};
  77
  78struct crypt_config;
  79
  80struct crypt_iv_operations {
  81	int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
  82		   const char *opts);
  83	void (*dtr)(struct crypt_config *cc);
  84	int (*init)(struct crypt_config *cc);
  85	int (*wipe)(struct crypt_config *cc);
  86	int (*generator)(struct crypt_config *cc, u8 *iv,
  87			 struct dm_crypt_request *dmreq);
  88	int (*post)(struct crypt_config *cc, u8 *iv,
  89		    struct dm_crypt_request *dmreq);
  90};
  91
  92struct iv_essiv_private {
  93	struct crypto_ahash *hash_tfm;
  94	u8 *salt;
  95};
  96
  97struct iv_benbi_private {
  98	int shift;
  99};
 100
 101#define LMK_SEED_SIZE 64 /* hash + 0 */
 102struct iv_lmk_private {
 103	struct crypto_shash *hash_tfm;
 104	u8 *seed;
 105};
 106
 107#define TCW_WHITENING_SIZE 16
 108struct iv_tcw_private {
 109	struct crypto_shash *crc32_tfm;
 110	u8 *iv_seed;
 111	u8 *whitening;
 112};
 113
 114/*
 115 * Crypt: maps a linear range of a block device
 116 * and encrypts / decrypts at the same time.
 117 */
 118enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
 119	     DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD };
 120
 
 
 
 
 
 121/*
 122 * The fields in here must be read only after initialization.
 123 */
 124struct crypt_config {
 125	struct dm_dev *dev;
 126	sector_t start;
 127
 128	/*
 129	 * pool for per bio private data, crypto requests and
 130	 * encryption requeusts/buffer pages
 131	 */
 132	mempool_t *req_pool;
 133	mempool_t *page_pool;
 134	struct bio_set *bs;
 135	struct mutex bio_alloc_lock;
 136
 137	struct workqueue_struct *io_queue;
 138	struct workqueue_struct *crypt_queue;
 139
 
 140	struct task_struct *write_thread;
 141	wait_queue_head_t write_thread_wait;
 142	struct rb_root write_tree;
 143
 144	char *cipher;
 145	char *cipher_string;
 
 146	char *key_string;
 147
 148	const struct crypt_iv_operations *iv_gen_ops;
 149	union {
 150		struct iv_essiv_private essiv;
 151		struct iv_benbi_private benbi;
 152		struct iv_lmk_private lmk;
 153		struct iv_tcw_private tcw;
 154	} iv_gen_private;
 155	sector_t iv_offset;
 156	unsigned int iv_size;
 
 
 157
 158	/* ESSIV: struct crypto_cipher *essiv_tfm */
 159	void *iv_private;
 160	struct crypto_skcipher **tfms;
 
 161	unsigned tfms_count;
 
 162
 163	/*
 164	 * Layout of each crypto request:
 165	 *
 166	 *   struct skcipher_request
 167	 *      context
 168	 *      padding
 169	 *   struct dm_crypt_request
 170	 *      padding
 171	 *   IV
 172	 *
 173	 * The padding is added so that dm_crypt_request and the IV are
 174	 * correctly aligned.
 175	 */
 176	unsigned int dmreq_start;
 177
 178	unsigned int per_bio_data_size;
 179
 180	unsigned long flags;
 181	unsigned int key_size;
 182	unsigned int key_parts;      /* independent parts in key buffer */
 183	unsigned int key_extra_size; /* additional keys length */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 184	u8 key[0];
 185};
 186
 187#define MIN_IOS        64
 
 
 
 
 
 
 
 
 188
 189static void clone_init(struct dm_crypt_io *, struct bio *);
 190static void kcryptd_queue_crypt(struct dm_crypt_io *io);
 191static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
 
 192
 193/*
 194 * Use this to access cipher attributes that are the same for each CPU.
 195 */
 196static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
 197{
 198	return cc->tfms[0];
 
 
 
 
 
 199}
 200
 201/*
 202 * Different IV generation algorithms:
 203 *
 204 * plain: the initial vector is the 32-bit little-endian version of the sector
 205 *        number, padded with zeros if necessary.
 206 *
 207 * plain64: the initial vector is the 64-bit little-endian version of the sector
 208 *        number, padded with zeros if necessary.
 209 *
 
 
 
 210 * essiv: "encrypted sector|salt initial vector", the sector number is
 211 *        encrypted with the bulk cipher using a salt as key. The salt
 212 *        should be derived from the bulk cipher's key via hashing.
 213 *
 214 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
 215 *        (needed for LRW-32-AES and possible other narrow block modes)
 216 *
 217 * null: the initial vector is always zero.  Provides compatibility with
 218 *       obsolete loop_fish2 devices.  Do not use for new devices.
 219 *
 220 * lmk:  Compatible implementation of the block chaining mode used
 221 *       by the Loop-AES block device encryption system
 222 *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
 223 *       It operates on full 512 byte sectors and uses CBC
 224 *       with an IV derived from the sector number, the data and
 225 *       optionally extra IV seed.
 226 *       This means that after decryption the first block
 227 *       of sector must be tweaked according to decrypted data.
 228 *       Loop-AES can use three encryption schemes:
 229 *         version 1: is plain aes-cbc mode
 230 *         version 2: uses 64 multikey scheme with lmk IV generator
 231 *         version 3: the same as version 2 with additional IV seed
 232 *                   (it uses 65 keys, last key is used as IV seed)
 233 *
 234 * tcw:  Compatible implementation of the block chaining mode used
 235 *       by the TrueCrypt device encryption system (prior to version 4.1).
 236 *       For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
 237 *       It operates on full 512 byte sectors and uses CBC
 238 *       with an IV derived from initial key and the sector number.
 239 *       In addition, whitening value is applied on every sector, whitening
 240 *       is calculated from initial key, sector number and mixed using CRC32.
 241 *       Note that this encryption scheme is vulnerable to watermarking attacks
 242 *       and should be used for old compatible containers access only.
 243 *
 244 * plumb: unimplemented, see:
 245 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
 
 246 */
 247
 248static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
 249			      struct dm_crypt_request *dmreq)
 250{
 251	memset(iv, 0, cc->iv_size);
 252	*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
 253
 254	return 0;
 255}
 256
 257static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
 258				struct dm_crypt_request *dmreq)
 259{
 260	memset(iv, 0, cc->iv_size);
 261	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 262
 263	return 0;
 264}
 265
 266/* Initialise ESSIV - compute salt but no local memory allocations */
 267static int crypt_iv_essiv_init(struct crypt_config *cc)
 268{
 269	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 270	AHASH_REQUEST_ON_STACK(req, essiv->hash_tfm);
 271	struct scatterlist sg;
 272	struct crypto_cipher *essiv_tfm;
 273	int err;
 274
 275	sg_init_one(&sg, cc->key, cc->key_size);
 276	ahash_request_set_tfm(req, essiv->hash_tfm);
 277	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
 278	ahash_request_set_crypt(req, &sg, essiv->salt, cc->key_size);
 279
 280	err = crypto_ahash_digest(req);
 281	ahash_request_zero(req);
 282	if (err)
 283		return err;
 284
 285	essiv_tfm = cc->iv_private;
 286
 287	err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
 288			    crypto_ahash_digestsize(essiv->hash_tfm));
 289	if (err)
 290		return err;
 291
 292	return 0;
 293}
 294
 295/* Wipe salt and reset key derived from volume key */
 296static int crypt_iv_essiv_wipe(struct crypt_config *cc)
 297{
 298	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 299	unsigned salt_size = crypto_ahash_digestsize(essiv->hash_tfm);
 300	struct crypto_cipher *essiv_tfm;
 301	int r, err = 0;
 302
 303	memset(essiv->salt, 0, salt_size);
 304
 305	essiv_tfm = cc->iv_private;
 306	r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
 307	if (r)
 308		err = r;
 309
 310	return err;
 311}
 312
 313/* Set up per cpu cipher state */
 314static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
 315					     struct dm_target *ti,
 316					     u8 *salt, unsigned saltsize)
 317{
 318	struct crypto_cipher *essiv_tfm;
 319	int err;
 320
 321	/* Setup the essiv_tfm with the given salt */
 322	essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
 323	if (IS_ERR(essiv_tfm)) {
 324		ti->error = "Error allocating crypto tfm for ESSIV";
 325		return essiv_tfm;
 326	}
 327
 328	if (crypto_cipher_blocksize(essiv_tfm) !=
 329	    crypto_skcipher_ivsize(any_tfm(cc))) {
 330		ti->error = "Block size of ESSIV cipher does "
 331			    "not match IV size of block cipher";
 332		crypto_free_cipher(essiv_tfm);
 333		return ERR_PTR(-EINVAL);
 334	}
 335
 336	err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
 337	if (err) {
 338		ti->error = "Failed to set key for ESSIV cipher";
 339		crypto_free_cipher(essiv_tfm);
 340		return ERR_PTR(err);
 341	}
 342
 343	return essiv_tfm;
 344}
 345
 346static void crypt_iv_essiv_dtr(struct crypt_config *cc)
 347{
 348	struct crypto_cipher *essiv_tfm;
 349	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 350
 351	crypto_free_ahash(essiv->hash_tfm);
 352	essiv->hash_tfm = NULL;
 353
 354	kzfree(essiv->salt);
 355	essiv->salt = NULL;
 356
 357	essiv_tfm = cc->iv_private;
 358
 359	if (essiv_tfm)
 360		crypto_free_cipher(essiv_tfm);
 361
 362	cc->iv_private = NULL;
 363}
 364
 365static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 366			      const char *opts)
 367{
 368	struct crypto_cipher *essiv_tfm = NULL;
 369	struct crypto_ahash *hash_tfm = NULL;
 370	u8 *salt = NULL;
 371	int err;
 372
 373	if (!opts) {
 374		ti->error = "Digest algorithm missing for ESSIV mode";
 375		return -EINVAL;
 376	}
 377
 378	/* Allocate hash algorithm */
 379	hash_tfm = crypto_alloc_ahash(opts, 0, CRYPTO_ALG_ASYNC);
 380	if (IS_ERR(hash_tfm)) {
 381		ti->error = "Error initializing ESSIV hash";
 382		err = PTR_ERR(hash_tfm);
 383		goto bad;
 384	}
 385
 386	salt = kzalloc(crypto_ahash_digestsize(hash_tfm), GFP_KERNEL);
 387	if (!salt) {
 388		ti->error = "Error kmallocing salt storage in ESSIV";
 389		err = -ENOMEM;
 390		goto bad;
 391	}
 392
 393	cc->iv_gen_private.essiv.salt = salt;
 394	cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
 395
 396	essiv_tfm = setup_essiv_cpu(cc, ti, salt,
 397				crypto_ahash_digestsize(hash_tfm));
 398	if (IS_ERR(essiv_tfm)) {
 399		crypt_iv_essiv_dtr(cc);
 400		return PTR_ERR(essiv_tfm);
 401	}
 402	cc->iv_private = essiv_tfm;
 403
 404	return 0;
 405
 406bad:
 407	if (hash_tfm && !IS_ERR(hash_tfm))
 408		crypto_free_ahash(hash_tfm);
 409	kfree(salt);
 410	return err;
 411}
 412
 413static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
 414			      struct dm_crypt_request *dmreq)
 415{
 416	struct crypto_cipher *essiv_tfm = cc->iv_private;
 417
 
 
 418	memset(iv, 0, cc->iv_size);
 419	*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 420	crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
 421
 422	return 0;
 423}
 424
 425static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
 426			      const char *opts)
 427{
 428	unsigned bs = crypto_skcipher_blocksize(any_tfm(cc));
 429	int log = ilog2(bs);
 430
 431	/* we need to calculate how far we must shift the sector count
 432	 * to get the cipher block count, we use this shift in _gen */
 433
 434	if (1 << log != bs) {
 435		ti->error = "cypher blocksize is not a power of 2";
 436		return -EINVAL;
 437	}
 438
 439	if (log > 9) {
 440		ti->error = "cypher blocksize is > 512";
 441		return -EINVAL;
 442	}
 443
 444	cc->iv_gen_private.benbi.shift = 9 - log;
 445
 446	return 0;
 447}
 448
 449static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 450{
 451}
 452
 453static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
 454			      struct dm_crypt_request *dmreq)
 455{
 456	__be64 val;
 457
 458	memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 459
 460	val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
 461	put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 462
 463	return 0;
 464}
 465
 466static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
 467			     struct dm_crypt_request *dmreq)
 468{
 469	memset(iv, 0, cc->iv_size);
 470
 471	return 0;
 472}
 473
 474static void crypt_iv_lmk_dtr(struct crypt_config *cc)
 475{
 476	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 477
 478	if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
 479		crypto_free_shash(lmk->hash_tfm);
 480	lmk->hash_tfm = NULL;
 481
 482	kzfree(lmk->seed);
 483	lmk->seed = NULL;
 484}
 485
 486static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
 487			    const char *opts)
 488{
 489	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 490
 
 
 
 
 
 491	lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
 492	if (IS_ERR(lmk->hash_tfm)) {
 493		ti->error = "Error initializing LMK hash";
 494		return PTR_ERR(lmk->hash_tfm);
 495	}
 496
 497	/* No seed in LMK version 2 */
 498	if (cc->key_parts == cc->tfms_count) {
 499		lmk->seed = NULL;
 500		return 0;
 501	}
 502
 503	lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
 504	if (!lmk->seed) {
 505		crypt_iv_lmk_dtr(cc);
 506		ti->error = "Error kmallocing seed storage in LMK";
 507		return -ENOMEM;
 508	}
 509
 510	return 0;
 511}
 512
 513static int crypt_iv_lmk_init(struct crypt_config *cc)
 514{
 515	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 516	int subkey_size = cc->key_size / cc->key_parts;
 517
 518	/* LMK seed is on the position of LMK_KEYS + 1 key */
 519	if (lmk->seed)
 520		memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
 521		       crypto_shash_digestsize(lmk->hash_tfm));
 522
 523	return 0;
 524}
 525
 526static int crypt_iv_lmk_wipe(struct crypt_config *cc)
 527{
 528	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 529
 530	if (lmk->seed)
 531		memset(lmk->seed, 0, LMK_SEED_SIZE);
 532
 533	return 0;
 534}
 535
 536static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 537			    struct dm_crypt_request *dmreq,
 538			    u8 *data)
 539{
 540	struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 541	SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
 542	struct md5_state md5state;
 543	__le32 buf[4];
 544	int i, r;
 545
 546	desc->tfm = lmk->hash_tfm;
 547	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 548
 549	r = crypto_shash_init(desc);
 550	if (r)
 551		return r;
 552
 553	if (lmk->seed) {
 554		r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
 555		if (r)
 556			return r;
 557	}
 558
 559	/* Sector is always 512B, block size 16, add data of blocks 1-31 */
 560	r = crypto_shash_update(desc, data + 16, 16 * 31);
 561	if (r)
 562		return r;
 563
 564	/* Sector is cropped to 56 bits here */
 565	buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
 566	buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
 567	buf[2] = cpu_to_le32(4024);
 568	buf[3] = 0;
 569	r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
 570	if (r)
 571		return r;
 572
 573	/* No MD5 padding here */
 574	r = crypto_shash_export(desc, &md5state);
 575	if (r)
 576		return r;
 577
 578	for (i = 0; i < MD5_HASH_WORDS; i++)
 579		__cpu_to_le32s(&md5state.hash[i]);
 580	memcpy(iv, &md5state.hash, cc->iv_size);
 581
 582	return 0;
 583}
 584
 585static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 586			    struct dm_crypt_request *dmreq)
 587{
 
 588	u8 *src;
 589	int r = 0;
 590
 591	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 592		src = kmap_atomic(sg_page(&dmreq->sg_in));
 593		r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
 
 594		kunmap_atomic(src);
 595	} else
 596		memset(iv, 0, cc->iv_size);
 597
 598	return r;
 599}
 600
 601static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
 602			     struct dm_crypt_request *dmreq)
 603{
 
 604	u8 *dst;
 605	int r;
 606
 607	if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
 608		return 0;
 609
 610	dst = kmap_atomic(sg_page(&dmreq->sg_out));
 611	r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
 
 612
 613	/* Tweak the first block of plaintext sector */
 614	if (!r)
 615		crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
 616
 617	kunmap_atomic(dst);
 618	return r;
 619}
 620
 621static void crypt_iv_tcw_dtr(struct crypt_config *cc)
 622{
 623	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 624
 625	kzfree(tcw->iv_seed);
 626	tcw->iv_seed = NULL;
 627	kzfree(tcw->whitening);
 628	tcw->whitening = NULL;
 629
 630	if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
 631		crypto_free_shash(tcw->crc32_tfm);
 632	tcw->crc32_tfm = NULL;
 633}
 634
 635static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
 636			    const char *opts)
 637{
 638	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 639
 
 
 
 
 
 640	if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
 641		ti->error = "Wrong key size for TCW";
 642		return -EINVAL;
 643	}
 644
 645	tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0);
 646	if (IS_ERR(tcw->crc32_tfm)) {
 647		ti->error = "Error initializing CRC32 in TCW";
 648		return PTR_ERR(tcw->crc32_tfm);
 649	}
 650
 651	tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
 652	tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
 653	if (!tcw->iv_seed || !tcw->whitening) {
 654		crypt_iv_tcw_dtr(cc);
 655		ti->error = "Error allocating seed storage in TCW";
 656		return -ENOMEM;
 657	}
 658
 659	return 0;
 660}
 661
 662static int crypt_iv_tcw_init(struct crypt_config *cc)
 663{
 664	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 665	int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
 666
 667	memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
 668	memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
 669	       TCW_WHITENING_SIZE);
 670
 671	return 0;
 672}
 673
 674static int crypt_iv_tcw_wipe(struct crypt_config *cc)
 675{
 676	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 677
 678	memset(tcw->iv_seed, 0, cc->iv_size);
 679	memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
 680
 681	return 0;
 682}
 683
 684static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 685				  struct dm_crypt_request *dmreq,
 686				  u8 *data)
 687{
 688	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 689	__le64 sector = cpu_to_le64(dmreq->iv_sector);
 690	u8 buf[TCW_WHITENING_SIZE];
 691	SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
 692	int i, r;
 693
 694	/* xor whitening with sector number */
 695	memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE);
 696	crypto_xor(buf, (u8 *)&sector, 8);
 697	crypto_xor(&buf[8], (u8 *)&sector, 8);
 698
 699	/* calculate crc32 for every 32bit part and xor it */
 700	desc->tfm = tcw->crc32_tfm;
 701	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
 702	for (i = 0; i < 4; i++) {
 703		r = crypto_shash_init(desc);
 704		if (r)
 705			goto out;
 706		r = crypto_shash_update(desc, &buf[i * 4], 4);
 707		if (r)
 708			goto out;
 709		r = crypto_shash_final(desc, &buf[i * 4]);
 710		if (r)
 711			goto out;
 712	}
 713	crypto_xor(&buf[0], &buf[12], 4);
 714	crypto_xor(&buf[4], &buf[8], 4);
 715
 716	/* apply whitening (8 bytes) to whole sector */
 717	for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
 718		crypto_xor(data + i * 8, buf, 8);
 719out:
 720	memzero_explicit(buf, sizeof(buf));
 721	return r;
 722}
 723
 724static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 725			    struct dm_crypt_request *dmreq)
 726{
 
 727	struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 728	__le64 sector = cpu_to_le64(dmreq->iv_sector);
 729	u8 *src;
 730	int r = 0;
 731
 732	/* Remove whitening from ciphertext */
 733	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
 734		src = kmap_atomic(sg_page(&dmreq->sg_in));
 735		r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset);
 
 736		kunmap_atomic(src);
 737	}
 738
 739	/* Calculate IV */
 740	memcpy(iv, tcw->iv_seed, cc->iv_size);
 741	crypto_xor(iv, (u8 *)&sector, 8);
 742	if (cc->iv_size > 8)
 743		crypto_xor(&iv[8], (u8 *)&sector, cc->iv_size - 8);
 
 744
 745	return r;
 746}
 747
 748static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 749			     struct dm_crypt_request *dmreq)
 750{
 
 751	u8 *dst;
 752	int r;
 753
 754	if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
 755		return 0;
 756
 757	/* Apply whitening on ciphertext */
 758	dst = kmap_atomic(sg_page(&dmreq->sg_out));
 759	r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset);
 
 760	kunmap_atomic(dst);
 761
 762	return r;
 763}
 764
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 765static const struct crypt_iv_operations crypt_iv_plain_ops = {
 766	.generator = crypt_iv_plain_gen
 767};
 768
 769static const struct crypt_iv_operations crypt_iv_plain64_ops = {
 770	.generator = crypt_iv_plain64_gen
 771};
 772
 
 
 
 
 773static const struct crypt_iv_operations crypt_iv_essiv_ops = {
 774	.ctr       = crypt_iv_essiv_ctr,
 775	.dtr       = crypt_iv_essiv_dtr,
 776	.init      = crypt_iv_essiv_init,
 777	.wipe      = crypt_iv_essiv_wipe,
 778	.generator = crypt_iv_essiv_gen
 779};
 780
 781static const struct crypt_iv_operations crypt_iv_benbi_ops = {
 782	.ctr	   = crypt_iv_benbi_ctr,
 783	.dtr	   = crypt_iv_benbi_dtr,
 784	.generator = crypt_iv_benbi_gen
 785};
 786
 787static const struct crypt_iv_operations crypt_iv_null_ops = {
 788	.generator = crypt_iv_null_gen
 789};
 790
 791static const struct crypt_iv_operations crypt_iv_lmk_ops = {
 792	.ctr	   = crypt_iv_lmk_ctr,
 793	.dtr	   = crypt_iv_lmk_dtr,
 794	.init	   = crypt_iv_lmk_init,
 795	.wipe	   = crypt_iv_lmk_wipe,
 796	.generator = crypt_iv_lmk_gen,
 797	.post	   = crypt_iv_lmk_post
 798};
 799
 800static const struct crypt_iv_operations crypt_iv_tcw_ops = {
 801	.ctr	   = crypt_iv_tcw_ctr,
 802	.dtr	   = crypt_iv_tcw_dtr,
 803	.init	   = crypt_iv_tcw_init,
 804	.wipe	   = crypt_iv_tcw_wipe,
 805	.generator = crypt_iv_tcw_gen,
 806	.post	   = crypt_iv_tcw_post
 807};
 808
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 809static void crypt_convert_init(struct crypt_config *cc,
 810			       struct convert_context *ctx,
 811			       struct bio *bio_out, struct bio *bio_in,
 812			       sector_t sector)
 813{
 814	ctx->bio_in = bio_in;
 815	ctx->bio_out = bio_out;
 816	if (bio_in)
 817		ctx->iter_in = bio_in->bi_iter;
 818	if (bio_out)
 819		ctx->iter_out = bio_out->bi_iter;
 820	ctx->cc_sector = sector + cc->iv_offset;
 821	init_completion(&ctx->restart);
 822}
 823
 824static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
 825					     struct skcipher_request *req)
 826{
 827	return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
 828}
 829
 830static struct skcipher_request *req_of_dmreq(struct crypt_config *cc,
 831					       struct dm_crypt_request *dmreq)
 832{
 833	return (struct skcipher_request *)((char *)dmreq - cc->dmreq_start);
 834}
 835
 836static u8 *iv_of_dmreq(struct crypt_config *cc,
 837		       struct dm_crypt_request *dmreq)
 838{
 839	return (u8 *)ALIGN((unsigned long)(dmreq + 1),
 840		crypto_skcipher_alignmask(any_tfm(cc)) + 1);
 
 
 
 
 841}
 842
 843static int crypt_convert_block(struct crypt_config *cc,
 844			       struct convert_context *ctx,
 845			       struct skcipher_request *req)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 846{
 847	struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
 848	struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
 849	struct dm_crypt_request *dmreq;
 850	u8 *iv;
 851	int r;
 
 
 
 
 
 
 
 852
 853	dmreq = dmreq_of_req(cc, req);
 
 
 
 
 
 
 
 
 
 
 854	iv = iv_of_dmreq(cc, dmreq);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 855
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 856	dmreq->iv_sector = ctx->cc_sector;
 
 
 857	dmreq->ctx = ctx;
 858	sg_init_table(&dmreq->sg_in, 1);
 859	sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT,
 860		    bv_in.bv_offset);
 861
 862	sg_init_table(&dmreq->sg_out, 1);
 863	sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT,
 864		    bv_out.bv_offset);
 865
 866	bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT);
 867	bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 868
 869	if (cc->iv_gen_ops) {
 870		r = cc->iv_gen_ops->generator(cc, iv, dmreq);
 871		if (r < 0)
 872			return r;
 
 
 
 
 
 
 
 
 
 
 873	}
 874
 875	skcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
 876				   1 << SECTOR_SHIFT, iv);
 877
 878	if (bio_data_dir(ctx->bio_in) == WRITE)
 879		r = crypto_skcipher_encrypt(req);
 880	else
 881		r = crypto_skcipher_decrypt(req);
 882
 883	if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
 884		r = cc->iv_gen_ops->post(cc, iv, dmreq);
 
 
 
 885
 886	return r;
 887}
 888
 889static void kcryptd_async_done(struct crypto_async_request *async_req,
 890			       int error);
 891
 892static void crypt_alloc_req(struct crypt_config *cc,
 893			    struct convert_context *ctx)
 894{
 895	unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
 896
 897	if (!ctx->req)
 898		ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO);
 899
 900	skcipher_request_set_tfm(ctx->req, cc->tfms[key_index]);
 901
 902	/*
 903	 * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
 904	 * requests if driver request queue is full.
 905	 */
 906	skcipher_request_set_callback(ctx->req,
 907	    CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
 908	    kcryptd_async_done, dmreq_of_req(cc, ctx->req));
 909}
 910
 911static void crypt_free_req(struct crypt_config *cc,
 912			   struct skcipher_request *req, struct bio *base_bio)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 913{
 914	struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
 915
 916	if ((struct skcipher_request *)(io + 1) != req)
 917		mempool_free(req, cc->req_pool);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 918}
 919
 920/*
 921 * Encrypt / decrypt data from one bio to another one (can be the same one)
 922 */
 923static int crypt_convert(struct crypt_config *cc,
 924			 struct convert_context *ctx)
 925{
 
 
 926	int r;
 927
 928	atomic_set(&ctx->cc_pending, 1);
 929
 930	while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
 931
 932		crypt_alloc_req(cc, ctx);
 933
 934		atomic_inc(&ctx->cc_pending);
 935
 936		r = crypt_convert_block(cc, ctx, ctx->req);
 
 
 
 937
 938		switch (r) {
 939		/*
 940		 * The request was queued by a crypto driver
 941		 * but the driver request queue is full, let's wait.
 942		 */
 943		case -EBUSY:
 944			wait_for_completion(&ctx->restart);
 945			reinit_completion(&ctx->restart);
 946			/* fall through */
 947		/*
 948		 * The request is queued and processed asynchronously,
 949		 * completion function kcryptd_async_done() will be called.
 950		 */
 951		case -EINPROGRESS:
 952			ctx->req = NULL;
 953			ctx->cc_sector++;
 
 954			continue;
 955		/*
 956		 * The request was already processed (synchronously).
 957		 */
 958		case 0:
 959			atomic_dec(&ctx->cc_pending);
 960			ctx->cc_sector++;
 
 961			cond_resched();
 962			continue;
 963
 964		/* There was an error while processing the request. */
 
 
 
 
 
 
 
 965		default:
 966			atomic_dec(&ctx->cc_pending);
 967			return r;
 968		}
 969	}
 970
 971	return 0;
 972}
 973
 974static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
 975
 976/*
 977 * Generate a new unfragmented bio with the given size
 978 * This should never violate the device limitations (but only because
 979 * max_segment_size is being constrained to PAGE_SIZE).
 980 *
 981 * This function may be called concurrently. If we allocate from the mempool
 982 * concurrently, there is a possibility of deadlock. For example, if we have
 983 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
 984 * the mempool concurrently, it may deadlock in a situation where both processes
 985 * have allocated 128 pages and the mempool is exhausted.
 986 *
 987 * In order to avoid this scenario we allocate the pages under a mutex.
 988 *
 989 * In order to not degrade performance with excessive locking, we try
 990 * non-blocking allocations without a mutex first but on failure we fallback
 991 * to blocking allocations with a mutex.
 992 */
 993static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
 994{
 995	struct crypt_config *cc = io->cc;
 996	struct bio *clone;
 997	unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 998	gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
 999	unsigned i, len, remaining_size;
1000	struct page *page;
1001
1002retry:
1003	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1004		mutex_lock(&cc->bio_alloc_lock);
1005
1006	clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
1007	if (!clone)
1008		goto return_clone;
1009
1010	clone_init(io, clone);
1011
1012	remaining_size = size;
1013
1014	for (i = 0; i < nr_iovecs; i++) {
1015		page = mempool_alloc(cc->page_pool, gfp_mask);
1016		if (!page) {
1017			crypt_free_buffer_pages(cc, clone);
1018			bio_put(clone);
1019			gfp_mask |= __GFP_DIRECT_RECLAIM;
1020			goto retry;
1021		}
1022
1023		len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1024
1025		bio_add_page(clone, page, len, 0);
1026
1027		remaining_size -= len;
1028	}
1029
1030return_clone:
 
 
 
 
 
 
1031	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1032		mutex_unlock(&cc->bio_alloc_lock);
1033
1034	return clone;
1035}
1036
1037static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1038{
1039	unsigned int i;
1040	struct bio_vec *bv;
 
1041
1042	bio_for_each_segment_all(bv, clone, i) {
1043		BUG_ON(!bv->bv_page);
1044		mempool_free(bv->bv_page, cc->page_pool);
1045		bv->bv_page = NULL;
1046	}
1047}
1048
1049static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1050			  struct bio *bio, sector_t sector)
1051{
1052	io->cc = cc;
1053	io->base_bio = bio;
1054	io->sector = sector;
1055	io->error = 0;
1056	io->ctx.req = NULL;
 
 
1057	atomic_set(&io->io_pending, 0);
1058}
1059
1060static void crypt_inc_pending(struct dm_crypt_io *io)
1061{
1062	atomic_inc(&io->io_pending);
1063}
1064
1065/*
1066 * One of the bios was finished. Check for completion of
1067 * the whole request and correctly clean up the buffer.
1068 */
1069static void crypt_dec_pending(struct dm_crypt_io *io)
1070{
1071	struct crypt_config *cc = io->cc;
1072	struct bio *base_bio = io->base_bio;
1073	int error = io->error;
1074
1075	if (!atomic_dec_and_test(&io->io_pending))
1076		return;
1077
1078	if (io->ctx.req)
1079		crypt_free_req(cc, io->ctx.req, base_bio);
 
 
 
 
 
1080
1081	base_bio->bi_error = error;
1082	bio_endio(base_bio);
1083}
1084
1085/*
1086 * kcryptd/kcryptd_io:
1087 *
1088 * Needed because it would be very unwise to do decryption in an
1089 * interrupt context.
1090 *
1091 * kcryptd performs the actual encryption or decryption.
1092 *
1093 * kcryptd_io performs the IO submission.
1094 *
1095 * They must be separated as otherwise the final stages could be
1096 * starved by new requests which can block in the first stages due
1097 * to memory allocation.
1098 *
1099 * The work is done per CPU global for all dm-crypt instances.
1100 * They should not depend on each other and do not block.
1101 */
1102static void crypt_endio(struct bio *clone)
1103{
1104	struct dm_crypt_io *io = clone->bi_private;
1105	struct crypt_config *cc = io->cc;
1106	unsigned rw = bio_data_dir(clone);
1107	int error;
1108
1109	/*
1110	 * free the processed pages
1111	 */
1112	if (rw == WRITE)
1113		crypt_free_buffer_pages(cc, clone);
1114
1115	error = clone->bi_error;
1116	bio_put(clone);
1117
1118	if (rw == READ && !error) {
1119		kcryptd_queue_crypt(io);
1120		return;
1121	}
1122
1123	if (unlikely(error))
1124		io->error = error;
1125
1126	crypt_dec_pending(io);
1127}
1128
1129static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1130{
1131	struct crypt_config *cc = io->cc;
1132
1133	clone->bi_private = io;
1134	clone->bi_end_io  = crypt_endio;
1135	clone->bi_bdev    = cc->dev->bdev;
1136	clone->bi_opf	  = io->base_bio->bi_opf;
1137}
1138
1139static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1140{
1141	struct crypt_config *cc = io->cc;
1142	struct bio *clone;
1143
1144	/*
1145	 * We need the original biovec array in order to decrypt
1146	 * the whole bio data *afterwards* -- thanks to immutable
1147	 * biovecs we don't need to worry about the block layer
1148	 * modifying the biovec array; so leverage bio_clone_fast().
1149	 */
1150	clone = bio_clone_fast(io->base_bio, gfp, cc->bs);
1151	if (!clone)
1152		return 1;
1153
1154	crypt_inc_pending(io);
1155
1156	clone_init(io, clone);
1157	clone->bi_iter.bi_sector = cc->start + io->sector;
1158
 
 
 
 
 
 
1159	generic_make_request(clone);
1160	return 0;
1161}
1162
1163static void kcryptd_io_read_work(struct work_struct *work)
1164{
1165	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1166
1167	crypt_inc_pending(io);
1168	if (kcryptd_io_read(io, GFP_NOIO))
1169		io->error = -ENOMEM;
1170	crypt_dec_pending(io);
1171}
1172
1173static void kcryptd_queue_read(struct dm_crypt_io *io)
1174{
1175	struct crypt_config *cc = io->cc;
1176
1177	INIT_WORK(&io->work, kcryptd_io_read_work);
1178	queue_work(cc->io_queue, &io->work);
1179}
1180
1181static void kcryptd_io_write(struct dm_crypt_io *io)
1182{
1183	struct bio *clone = io->ctx.bio_out;
1184
1185	generic_make_request(clone);
1186}
1187
1188#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1189
1190static int dmcrypt_write(void *data)
1191{
1192	struct crypt_config *cc = data;
1193	struct dm_crypt_io *io;
1194
1195	while (1) {
1196		struct rb_root write_tree;
1197		struct blk_plug plug;
1198
1199		DECLARE_WAITQUEUE(wait, current);
1200
1201		spin_lock_irq(&cc->write_thread_wait.lock);
1202continue_locked:
1203
1204		if (!RB_EMPTY_ROOT(&cc->write_tree))
1205			goto pop_from_list;
1206
1207		set_current_state(TASK_INTERRUPTIBLE);
1208		__add_wait_queue(&cc->write_thread_wait, &wait);
1209
1210		spin_unlock_irq(&cc->write_thread_wait.lock);
1211
1212		if (unlikely(kthread_should_stop())) {
1213			set_task_state(current, TASK_RUNNING);
1214			remove_wait_queue(&cc->write_thread_wait, &wait);
1215			break;
1216		}
1217
1218		schedule();
1219
1220		set_task_state(current, TASK_RUNNING);
1221		spin_lock_irq(&cc->write_thread_wait.lock);
1222		__remove_wait_queue(&cc->write_thread_wait, &wait);
1223		goto continue_locked;
1224
1225pop_from_list:
1226		write_tree = cc->write_tree;
1227		cc->write_tree = RB_ROOT;
1228		spin_unlock_irq(&cc->write_thread_wait.lock);
1229
1230		BUG_ON(rb_parent(write_tree.rb_node));
1231
1232		/*
1233		 * Note: we cannot walk the tree here with rb_next because
1234		 * the structures may be freed when kcryptd_io_write is called.
1235		 */
1236		blk_start_plug(&plug);
1237		do {
1238			io = crypt_io_from_node(rb_first(&write_tree));
1239			rb_erase(&io->rb_node, &write_tree);
1240			kcryptd_io_write(io);
1241		} while (!RB_EMPTY_ROOT(&write_tree));
1242		blk_finish_plug(&plug);
1243	}
1244	return 0;
1245}
1246
1247static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1248{
1249	struct bio *clone = io->ctx.bio_out;
1250	struct crypt_config *cc = io->cc;
1251	unsigned long flags;
1252	sector_t sector;
1253	struct rb_node **rbp, *parent;
1254
1255	if (unlikely(io->error < 0)) {
1256		crypt_free_buffer_pages(cc, clone);
1257		bio_put(clone);
1258		crypt_dec_pending(io);
1259		return;
1260	}
1261
1262	/* crypt_convert should have filled the clone bio */
1263	BUG_ON(io->ctx.iter_out.bi_size);
1264
1265	clone->bi_iter.bi_sector = cc->start + io->sector;
1266
1267	if (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) {
1268		generic_make_request(clone);
1269		return;
1270	}
1271
1272	spin_lock_irqsave(&cc->write_thread_wait.lock, flags);
 
 
1273	rbp = &cc->write_tree.rb_node;
1274	parent = NULL;
1275	sector = io->sector;
1276	while (*rbp) {
1277		parent = *rbp;
1278		if (sector < crypt_io_from_node(parent)->sector)
1279			rbp = &(*rbp)->rb_left;
1280		else
1281			rbp = &(*rbp)->rb_right;
1282	}
1283	rb_link_node(&io->rb_node, parent, rbp);
1284	rb_insert_color(&io->rb_node, &cc->write_tree);
1285
1286	wake_up_locked(&cc->write_thread_wait);
1287	spin_unlock_irqrestore(&cc->write_thread_wait.lock, flags);
1288}
1289
1290static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1291{
1292	struct crypt_config *cc = io->cc;
1293	struct bio *clone;
1294	int crypt_finished;
1295	sector_t sector = io->sector;
1296	int r;
1297
1298	/*
1299	 * Prevent io from disappearing until this function completes.
1300	 */
1301	crypt_inc_pending(io);
1302	crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1303
1304	clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
1305	if (unlikely(!clone)) {
1306		io->error = -EIO;
1307		goto dec;
1308	}
1309
1310	io->ctx.bio_out = clone;
1311	io->ctx.iter_out = clone->bi_iter;
1312
1313	sector += bio_sectors(clone);
1314
1315	crypt_inc_pending(io);
1316	r = crypt_convert(cc, &io->ctx);
1317	if (r)
1318		io->error = -EIO;
1319	crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending);
1320
1321	/* Encryption was already finished, submit io now */
1322	if (crypt_finished) {
1323		kcryptd_crypt_write_io_submit(io, 0);
1324		io->sector = sector;
1325	}
1326
1327dec:
1328	crypt_dec_pending(io);
1329}
1330
1331static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
1332{
1333	crypt_dec_pending(io);
1334}
1335
1336static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1337{
1338	struct crypt_config *cc = io->cc;
1339	int r = 0;
1340
1341	crypt_inc_pending(io);
1342
1343	crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1344			   io->sector);
1345
1346	r = crypt_convert(cc, &io->ctx);
1347	if (r < 0)
1348		io->error = -EIO;
1349
1350	if (atomic_dec_and_test(&io->ctx.cc_pending))
1351		kcryptd_crypt_read_done(io);
1352
1353	crypt_dec_pending(io);
1354}
1355
1356static void kcryptd_async_done(struct crypto_async_request *async_req,
1357			       int error)
1358{
1359	struct dm_crypt_request *dmreq = async_req->data;
1360	struct convert_context *ctx = dmreq->ctx;
1361	struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1362	struct crypt_config *cc = io->cc;
1363
1364	/*
1365	 * A request from crypto driver backlog is going to be processed now,
1366	 * finish the completion and continue in crypt_convert().
1367	 * (Callback will be called for the second time for this request.)
1368	 */
1369	if (error == -EINPROGRESS) {
1370		complete(&ctx->restart);
1371		return;
1372	}
1373
1374	if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1375		error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1376
1377	if (error < 0)
1378		io->error = -EIO;
 
 
 
 
 
1379
1380	crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
1381
1382	if (!atomic_dec_and_test(&ctx->cc_pending))
1383		return;
1384
1385	if (bio_data_dir(io->base_bio) == READ)
1386		kcryptd_crypt_read_done(io);
1387	else
1388		kcryptd_crypt_write_io_submit(io, 1);
1389}
1390
1391static void kcryptd_crypt(struct work_struct *work)
1392{
1393	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1394
1395	if (bio_data_dir(io->base_bio) == READ)
1396		kcryptd_crypt_read_convert(io);
1397	else
1398		kcryptd_crypt_write_convert(io);
1399}
1400
1401static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1402{
1403	struct crypt_config *cc = io->cc;
1404
1405	INIT_WORK(&io->work, kcryptd_crypt);
1406	queue_work(cc->crypt_queue, &io->work);
1407}
1408
1409/*
1410 * Decode key from its hex representation
1411 */
1412static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1413{
1414	char buffer[3];
1415	unsigned int i;
1416
1417	buffer[2] = '\0';
1418
1419	for (i = 0; i < size; i++) {
1420		buffer[0] = *hex++;
1421		buffer[1] = *hex++;
1422
1423		if (kstrtou8(buffer, 16, &key[i]))
1424			return -EINVAL;
 
1425	}
1426
1427	if (*hex != '\0')
1428		return -EINVAL;
1429
1430	return 0;
1431}
1432
1433static void crypt_free_tfms(struct crypt_config *cc)
1434{
1435	unsigned i;
1436
1437	if (!cc->tfms)
1438		return;
1439
1440	for (i = 0; i < cc->tfms_count; i++)
1441		if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) {
1442			crypto_free_skcipher(cc->tfms[i]);
1443			cc->tfms[i] = NULL;
1444		}
1445
1446	kfree(cc->tfms);
1447	cc->tfms = NULL;
1448}
1449
1450static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
 
 
 
 
 
 
 
 
1451{
1452	unsigned i;
1453	int err;
1454
1455	cc->tfms = kzalloc(cc->tfms_count * sizeof(struct crypto_skcipher *),
1456			   GFP_KERNEL);
1457	if (!cc->tfms)
 
1458		return -ENOMEM;
1459
1460	for (i = 0; i < cc->tfms_count; i++) {
1461		cc->tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0);
1462		if (IS_ERR(cc->tfms[i])) {
1463			err = PTR_ERR(cc->tfms[i]);
1464			crypt_free_tfms(cc);
1465			return err;
1466		}
1467	}
1468
 
 
 
 
 
 
 
1469	return 0;
1470}
1471
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1472static int crypt_setkey(struct crypt_config *cc)
1473{
1474	unsigned subkey_size;
1475	int err = 0, i, r;
1476
1477	/* Ignore extra keys (which are used for IV etc) */
1478	subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
 
 
 
 
 
 
 
 
 
1479
1480	for (i = 0; i < cc->tfms_count; i++) {
1481		r = crypto_skcipher_setkey(cc->tfms[i],
1482					   cc->key + (i * subkey_size),
1483					   subkey_size);
 
 
 
 
 
 
 
 
1484		if (r)
1485			err = r;
1486	}
1487
 
 
 
1488	return err;
1489}
1490
1491#ifdef CONFIG_KEYS
1492
1493static bool contains_whitespace(const char *str)
1494{
1495	while (*str)
1496		if (isspace(*str++))
1497			return true;
1498	return false;
1499}
1500
1501static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
1502{
1503	char *new_key_string, *key_desc;
1504	int ret;
1505	struct key *key;
1506	const struct user_key_payload *ukp;
1507
1508	/*
1509	 * Reject key_string with whitespace. dm core currently lacks code for
1510	 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
1511	 */
1512	if (contains_whitespace(key_string)) {
1513		DMERR("whitespace chars not allowed in key string");
1514		return -EINVAL;
1515	}
1516
1517	/* look for next ':' separating key_type from key_description */
1518	key_desc = strpbrk(key_string, ":");
1519	if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
1520		return -EINVAL;
1521
1522	if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
1523	    strncmp(key_string, "user:", key_desc - key_string + 1))
1524		return -EINVAL;
1525
1526	new_key_string = kstrdup(key_string, GFP_KERNEL);
1527	if (!new_key_string)
1528		return -ENOMEM;
1529
1530	key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
1531			  key_desc + 1, NULL);
1532	if (IS_ERR(key)) {
1533		kzfree(new_key_string);
1534		return PTR_ERR(key);
1535	}
1536
1537	down_read(&key->sem);
1538
1539	ukp = user_key_payload(key);
1540	if (!ukp) {
1541		up_read(&key->sem);
1542		key_put(key);
1543		kzfree(new_key_string);
1544		return -EKEYREVOKED;
1545	}
1546
1547	if (cc->key_size != ukp->datalen) {
1548		up_read(&key->sem);
1549		key_put(key);
1550		kzfree(new_key_string);
1551		return -EINVAL;
1552	}
1553
1554	memcpy(cc->key, ukp->data, cc->key_size);
1555
1556	up_read(&key->sem);
1557	key_put(key);
1558
1559	/* clear the flag since following operations may invalidate previously valid key */
1560	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1561
1562	ret = crypt_setkey(cc);
1563
1564	/* wipe the kernel key payload copy in each case */
1565	memset(cc->key, 0, cc->key_size * sizeof(u8));
1566
1567	if (!ret) {
1568		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1569		kzfree(cc->key_string);
1570		cc->key_string = new_key_string;
1571	} else
1572		kzfree(new_key_string);
1573
1574	return ret;
1575}
1576
1577static int get_key_size(char **key_string)
1578{
1579	char *colon, dummy;
1580	int ret;
1581
1582	if (*key_string[0] != ':')
1583		return strlen(*key_string) >> 1;
1584
1585	/* look for next ':' in key string */
1586	colon = strpbrk(*key_string + 1, ":");
1587	if (!colon)
1588		return -EINVAL;
1589
1590	if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
1591		return -EINVAL;
1592
1593	*key_string = colon;
1594
1595	/* remaining key string should be :<logon|user>:<key_desc> */
1596
1597	return ret;
1598}
1599
1600#else
1601
1602static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
1603{
1604	return -EINVAL;
1605}
1606
1607static int get_key_size(char **key_string)
1608{
1609	return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
1610}
1611
1612#endif
1613
1614static int crypt_set_key(struct crypt_config *cc, char *key)
1615{
1616	int r = -EINVAL;
1617	int key_string_len = strlen(key);
1618
1619	/* Hyphen (which gives a key_size of zero) means there is no key. */
1620	if (!cc->key_size && strcmp(key, "-"))
1621		goto out;
1622
1623	/* ':' means the key is in kernel keyring, short-circuit normal key processing */
1624	if (key[0] == ':') {
1625		r = crypt_set_keyring_key(cc, key + 1);
1626		goto out;
1627	}
1628
1629	/* clear the flag since following operations may invalidate previously valid key */
1630	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1631
1632	/* wipe references to any kernel keyring key */
1633	kzfree(cc->key_string);
1634	cc->key_string = NULL;
1635
1636	if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
 
1637		goto out;
1638
1639	r = crypt_setkey(cc);
1640	if (!r)
1641		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1642
1643out:
1644	/* Hex key string not needed after here, so wipe it. */
1645	memset(key, '0', key_string_len);
1646
1647	return r;
1648}
1649
1650static int crypt_wipe_key(struct crypt_config *cc)
1651{
 
 
1652	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1653	memset(&cc->key, 0, cc->key_size * sizeof(u8));
 
 
 
 
 
 
 
 
1654	kzfree(cc->key_string);
1655	cc->key_string = NULL;
 
 
1656
1657	return crypt_setkey(cc);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1658}
1659
1660static void crypt_dtr(struct dm_target *ti)
1661{
1662	struct crypt_config *cc = ti->private;
1663
1664	ti->private = NULL;
1665
1666	if (!cc)
1667		return;
1668
1669	if (cc->write_thread)
1670		kthread_stop(cc->write_thread);
1671
1672	if (cc->io_queue)
1673		destroy_workqueue(cc->io_queue);
1674	if (cc->crypt_queue)
1675		destroy_workqueue(cc->crypt_queue);
1676
1677	crypt_free_tfms(cc);
1678
1679	if (cc->bs)
1680		bioset_free(cc->bs);
1681
1682	mempool_destroy(cc->page_pool);
1683	mempool_destroy(cc->req_pool);
 
 
 
 
1684
1685	if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1686		cc->iv_gen_ops->dtr(cc);
1687
1688	if (cc->dev)
1689		dm_put_device(ti, cc->dev);
1690
1691	kzfree(cc->cipher);
1692	kzfree(cc->cipher_string);
1693	kzfree(cc->key_string);
 
 
 
 
1694
1695	/* Must zero key material before freeing */
1696	kzfree(cc);
 
 
 
 
 
 
1697}
1698
1699static int crypt_ctr_cipher(struct dm_target *ti,
1700			    char *cipher_in, char *key)
1701{
1702	struct crypt_config *cc = ti->private;
1703	char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1704	char *cipher_api = NULL;
1705	int ret = -EINVAL;
1706	char dummy;
1707
1708	/* Convert to crypto api definition? */
1709	if (strchr(cipher_in, '(')) {
1710		ti->error = "Bad cipher specification";
1711		return -EINVAL;
1712	}
1713
1714	cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1715	if (!cc->cipher_string)
1716		goto bad_mem;
1717
1718	/*
1719	 * Legacy dm-crypt cipher specification
1720	 * cipher[:keycount]-mode-iv:ivopts
1721	 */
1722	tmp = cipher_in;
1723	keycount = strsep(&tmp, "-");
1724	cipher = strsep(&keycount, ":");
1725
1726	if (!keycount)
1727		cc->tfms_count = 1;
1728	else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
1729		 !is_power_of_2(cc->tfms_count)) {
1730		ti->error = "Bad cipher key count specification";
1731		return -EINVAL;
1732	}
1733	cc->key_parts = cc->tfms_count;
1734	cc->key_extra_size = 0;
1735
1736	cc->cipher = kstrdup(cipher, GFP_KERNEL);
1737	if (!cc->cipher)
1738		goto bad_mem;
1739
1740	chainmode = strsep(&tmp, "-");
1741	ivopts = strsep(&tmp, "-");
1742	ivmode = strsep(&ivopts, ":");
1743
1744	if (tmp)
1745		DMWARN("Ignoring unexpected additional cipher options");
1746
1747	/*
1748	 * For compatibility with the original dm-crypt mapping format, if
1749	 * only the cipher name is supplied, use cbc-plain.
1750	 */
1751	if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1752		chainmode = "cbc";
1753		ivmode = "plain";
1754	}
1755
1756	if (strcmp(chainmode, "ecb") && !ivmode) {
1757		ti->error = "IV mechanism required";
1758		return -EINVAL;
1759	}
1760
1761	cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1762	if (!cipher_api)
1763		goto bad_mem;
1764
1765	ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1766		       "%s(%s)", chainmode, cipher);
1767	if (ret < 0) {
 
 
 
 
 
 
 
 
 
 
1768		kfree(cipher_api);
1769		goto bad_mem;
1770	}
1771
1772	/* Allocate cipher */
1773	ret = crypt_alloc_tfms(cc, cipher_api);
1774	if (ret < 0) {
1775		ti->error = "Error allocating crypto tfm";
1776		goto bad;
 
1777	}
 
1778
1779	/* Initialize IV */
1780	cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
1781	if (cc->iv_size)
1782		/* at least a 64 bit sector number should fit in our buffer */
1783		cc->iv_size = max(cc->iv_size,
1784				  (unsigned int)(sizeof(u64) / sizeof(u8)));
1785	else if (ivmode) {
1786		DMWARN("Selected cipher does not support IVs");
1787		ivmode = NULL;
1788	}
1789
1790	/* Choose ivmode, see comments at iv code. */
1791	if (ivmode == NULL)
1792		cc->iv_gen_ops = NULL;
1793	else if (strcmp(ivmode, "plain") == 0)
1794		cc->iv_gen_ops = &crypt_iv_plain_ops;
1795	else if (strcmp(ivmode, "plain64") == 0)
1796		cc->iv_gen_ops = &crypt_iv_plain64_ops;
1797	else if (strcmp(ivmode, "essiv") == 0)
1798		cc->iv_gen_ops = &crypt_iv_essiv_ops;
1799	else if (strcmp(ivmode, "benbi") == 0)
1800		cc->iv_gen_ops = &crypt_iv_benbi_ops;
1801	else if (strcmp(ivmode, "null") == 0)
1802		cc->iv_gen_ops = &crypt_iv_null_ops;
1803	else if (strcmp(ivmode, "lmk") == 0) {
1804		cc->iv_gen_ops = &crypt_iv_lmk_ops;
1805		/*
1806		 * Version 2 and 3 is recognised according
1807		 * to length of provided multi-key string.
1808		 * If present (version 3), last key is used as IV seed.
1809		 * All keys (including IV seed) are always the same size.
1810		 */
1811		if (cc->key_size % cc->key_parts) {
1812			cc->key_parts++;
1813			cc->key_extra_size = cc->key_size / cc->key_parts;
1814		}
1815	} else if (strcmp(ivmode, "tcw") == 0) {
1816		cc->iv_gen_ops = &crypt_iv_tcw_ops;
1817		cc->key_parts += 2; /* IV + whitening */
1818		cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
1819	} else {
1820		ret = -EINVAL;
1821		ti->error = "Invalid IV mode";
1822		goto bad;
1823	}
1824
 
 
 
 
 
 
 
 
 
 
 
 
1825	/* Initialize and set key */
1826	ret = crypt_set_key(cc, key);
1827	if (ret < 0) {
1828		ti->error = "Error decoding and setting key";
1829		goto bad;
1830	}
1831
1832	/* Allocate IV */
1833	if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1834		ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1835		if (ret < 0) {
1836			ti->error = "Error creating IV";
1837			goto bad;
1838		}
1839	}
1840
1841	/* Initialize IV (set keys for ESSIV etc) */
1842	if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1843		ret = cc->iv_gen_ops->init(cc);
1844		if (ret < 0) {
1845			ti->error = "Error initialising IV";
1846			goto bad;
1847		}
1848	}
1849
1850	ret = 0;
1851bad:
1852	kfree(cipher_api);
 
1853	return ret;
 
1854
1855bad_mem:
1856	ti->error = "Cannot allocate cipher strings";
1857	return -ENOMEM;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1858}
1859
1860/*
1861 * Construct an encryption mapping:
1862 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
1863 */
1864static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1865{
1866	struct crypt_config *cc;
 
1867	int key_size;
1868	unsigned int opt_params;
1869	unsigned long long tmpll;
1870	int ret;
1871	size_t iv_size_padding;
1872	struct dm_arg_set as;
1873	const char *opt_string;
1874	char dummy;
1875
1876	static struct dm_arg _args[] = {
1877		{0, 3, "Invalid number of feature args"},
1878	};
1879
1880	if (argc < 5) {
1881		ti->error = "Not enough arguments";
1882		return -EINVAL;
1883	}
1884
1885	key_size = get_key_size(&argv[1]);
1886	if (key_size < 0) {
1887		ti->error = "Cannot parse key size";
1888		return -EINVAL;
1889	}
1890
1891	cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1892	if (!cc) {
1893		ti->error = "Cannot allocate encryption context";
1894		return -ENOMEM;
1895	}
1896	cc->key_size = key_size;
 
 
1897
1898	ti->private = cc;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1899	ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1900	if (ret < 0)
1901		goto bad;
1902
1903	cc->dmreq_start = sizeof(struct skcipher_request);
1904	cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
 
 
 
 
 
 
 
1905	cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
1906
1907	if (crypto_skcipher_alignmask(any_tfm(cc)) < CRYPTO_MINALIGN) {
1908		/* Allocate the padding exactly */
1909		iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
1910				& crypto_skcipher_alignmask(any_tfm(cc));
1911	} else {
1912		/*
1913		 * If the cipher requires greater alignment than kmalloc
1914		 * alignment, we don't know the exact position of the
1915		 * initialization vector. We must assume worst case.
1916		 */
1917		iv_size_padding = crypto_skcipher_alignmask(any_tfm(cc));
1918	}
1919
1920	ret = -ENOMEM;
1921	cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1922			sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size);
1923	if (!cc->req_pool) {
 
 
 
 
 
1924		ti->error = "Cannot allocate crypt request mempool";
1925		goto bad;
1926	}
1927
1928	cc->per_bio_data_size = ti->per_io_data_size =
1929		ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start +
1930		      sizeof(struct dm_crypt_request) + iv_size_padding + cc->iv_size,
1931		      ARCH_KMALLOC_MINALIGN);
1932
1933	cc->page_pool = mempool_create_page_pool(BIO_MAX_PAGES, 0);
1934	if (!cc->page_pool) {
1935		ti->error = "Cannot allocate page mempool";
1936		goto bad;
1937	}
1938
1939	cc->bs = bioset_create(MIN_IOS, 0);
1940	if (!cc->bs) {
1941		ti->error = "Cannot allocate crypt bioset";
1942		goto bad;
1943	}
1944
1945	mutex_init(&cc->bio_alloc_lock);
1946
1947	ret = -EINVAL;
1948	if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) {
 
1949		ti->error = "Invalid iv_offset sector";
1950		goto bad;
1951	}
1952	cc->iv_offset = tmpll;
1953
1954	ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
1955	if (ret) {
1956		ti->error = "Device lookup failed";
1957		goto bad;
1958	}
1959
1960	ret = -EINVAL;
1961	if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) {
1962		ti->error = "Invalid device sector";
1963		goto bad;
1964	}
1965	cc->start = tmpll;
1966
1967	argv += 5;
1968	argc -= 5;
1969
1970	/* Optional parameters */
1971	if (argc) {
1972		as.argc = argc;
1973		as.argv = argv;
1974
1975		ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1976		if (ret)
1977			goto bad;
1978
1979		ret = -EINVAL;
1980		while (opt_params--) {
1981			opt_string = dm_shift_arg(&as);
1982			if (!opt_string) {
1983				ti->error = "Not enough feature arguments";
1984				goto bad;
1985			}
1986
1987			if (!strcasecmp(opt_string, "allow_discards"))
1988				ti->num_discard_bios = 1;
1989
1990			else if (!strcasecmp(opt_string, "same_cpu_crypt"))
1991				set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
1992
1993			else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
1994				set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
1995
1996			else {
1997				ti->error = "Invalid feature arguments";
1998				goto bad;
1999			}
2000		}
 
 
2001	}
2002
2003	ret = -ENOMEM;
2004	cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1);
 
 
2005	if (!cc->io_queue) {
2006		ti->error = "Couldn't create kcryptd io queue";
2007		goto bad;
2008	}
2009
2010	if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2011		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1);
 
 
2012	else
2013		cc->crypt_queue = alloc_workqueue("kcryptd", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
2014						  num_online_cpus());
 
2015	if (!cc->crypt_queue) {
2016		ti->error = "Couldn't create kcryptd queue";
2017		goto bad;
2018	}
2019
2020	init_waitqueue_head(&cc->write_thread_wait);
2021	cc->write_tree = RB_ROOT;
2022
2023	cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write");
2024	if (IS_ERR(cc->write_thread)) {
2025		ret = PTR_ERR(cc->write_thread);
2026		cc->write_thread = NULL;
2027		ti->error = "Couldn't spawn write thread";
2028		goto bad;
2029	}
2030	wake_up_process(cc->write_thread);
2031
2032	ti->num_flush_bios = 1;
2033	ti->discard_zeroes_data_unsupported = true;
2034
2035	return 0;
2036
2037bad:
2038	crypt_dtr(ti);
2039	return ret;
2040}
2041
2042static int crypt_map(struct dm_target *ti, struct bio *bio)
2043{
2044	struct dm_crypt_io *io;
2045	struct crypt_config *cc = ti->private;
2046
2047	/*
2048	 * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
2049	 * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
2050	 * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
2051	 */
2052	if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
2053	    bio_op(bio) == REQ_OP_DISCARD)) {
2054		bio->bi_bdev = cc->dev->bdev;
2055		if (bio_sectors(bio))
2056			bio->bi_iter.bi_sector = cc->start +
2057				dm_target_offset(ti, bio->bi_iter.bi_sector);
2058		return DM_MAPIO_REMAPPED;
2059	}
2060
2061	/*
2062	 * Check if bio is too large, split as needed.
2063	 */
2064	if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) &&
2065	    bio_data_dir(bio) == WRITE)
2066		dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT));
2067
 
 
 
 
 
 
 
 
 
 
2068	io = dm_per_bio_data(bio, cc->per_bio_data_size);
2069	crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
2070	io->ctx.req = (struct skcipher_request *)(io + 1);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2071
2072	if (bio_data_dir(io->base_bio) == READ) {
2073		if (kcryptd_io_read(io, GFP_NOWAIT))
2074			kcryptd_queue_read(io);
2075	} else
2076		kcryptd_queue_crypt(io);
2077
2078	return DM_MAPIO_SUBMITTED;
2079}
2080
2081static void crypt_status(struct dm_target *ti, status_type_t type,
2082			 unsigned status_flags, char *result, unsigned maxlen)
2083{
2084	struct crypt_config *cc = ti->private;
2085	unsigned i, sz = 0;
2086	int num_feature_args = 0;
2087
2088	switch (type) {
2089	case STATUSTYPE_INFO:
2090		result[0] = '\0';
2091		break;
2092
2093	case STATUSTYPE_TABLE:
2094		DMEMIT("%s ", cc->cipher_string);
2095
2096		if (cc->key_size > 0) {
2097			if (cc->key_string)
2098				DMEMIT(":%u:%s", cc->key_size, cc->key_string);
2099			else
2100				for (i = 0; i < cc->key_size; i++)
2101					DMEMIT("%02x", cc->key[i]);
2102		} else
2103			DMEMIT("-");
2104
2105		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
2106				cc->dev->name, (unsigned long long)cc->start);
2107
2108		num_feature_args += !!ti->num_discard_bios;
2109		num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
2110		num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
 
 
 
 
2111		if (num_feature_args) {
2112			DMEMIT(" %d", num_feature_args);
2113			if (ti->num_discard_bios)
2114				DMEMIT(" allow_discards");
2115			if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
2116				DMEMIT(" same_cpu_crypt");
2117			if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
2118				DMEMIT(" submit_from_crypt_cpus");
 
 
 
 
 
 
2119		}
2120
2121		break;
2122	}
2123}
2124
2125static void crypt_postsuspend(struct dm_target *ti)
2126{
2127	struct crypt_config *cc = ti->private;
2128
2129	set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2130}
2131
2132static int crypt_preresume(struct dm_target *ti)
2133{
2134	struct crypt_config *cc = ti->private;
2135
2136	if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
2137		DMERR("aborting resume - crypt key is not set.");
2138		return -EAGAIN;
2139	}
2140
2141	return 0;
2142}
2143
2144static void crypt_resume(struct dm_target *ti)
2145{
2146	struct crypt_config *cc = ti->private;
2147
2148	clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
2149}
2150
2151/* Message interface
2152 *	key set <key>
2153 *	key wipe
2154 */
2155static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
 
2156{
2157	struct crypt_config *cc = ti->private;
2158	int key_size, ret = -EINVAL;
2159
2160	if (argc < 2)
2161		goto error;
2162
2163	if (!strcasecmp(argv[0], "key")) {
2164		if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
2165			DMWARN("not suspended during key manipulation.");
2166			return -EINVAL;
2167		}
2168		if (argc == 3 && !strcasecmp(argv[1], "set")) {
2169			/* The key size may not be changed. */
2170			key_size = get_key_size(&argv[2]);
2171			if (key_size < 0 || cc->key_size != key_size) {
2172				memset(argv[2], '0', strlen(argv[2]));
2173				return -EINVAL;
2174			}
2175
2176			ret = crypt_set_key(cc, argv[2]);
2177			if (ret)
2178				return ret;
2179			if (cc->iv_gen_ops && cc->iv_gen_ops->init)
2180				ret = cc->iv_gen_ops->init(cc);
 
 
 
2181			return ret;
2182		}
2183		if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
2184			if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2185				ret = cc->iv_gen_ops->wipe(cc);
2186				if (ret)
2187					return ret;
2188			}
2189			return crypt_wipe_key(cc);
2190		}
2191	}
2192
2193error:
2194	DMWARN("unrecognised message received.");
2195	return -EINVAL;
2196}
2197
2198static int crypt_iterate_devices(struct dm_target *ti,
2199				 iterate_devices_callout_fn fn, void *data)
2200{
2201	struct crypt_config *cc = ti->private;
2202
2203	return fn(ti, cc->dev, cc->start, ti->len, data);
2204}
2205
2206static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
2207{
 
 
2208	/*
2209	 * Unfortunate constraint that is required to avoid the potential
2210	 * for exceeding underlying device's max_segments limits -- due to
2211	 * crypt_alloc_buffer() possibly allocating pages for the encryption
2212	 * bio that are not as physically contiguous as the original bio.
2213	 */
2214	limits->max_segment_size = PAGE_SIZE;
 
 
 
 
 
 
2215}
2216
2217static struct target_type crypt_target = {
2218	.name   = "crypt",
2219	.version = {1, 15, 0},
2220	.module = THIS_MODULE,
2221	.ctr    = crypt_ctr,
2222	.dtr    = crypt_dtr,
2223	.map    = crypt_map,
2224	.status = crypt_status,
2225	.postsuspend = crypt_postsuspend,
2226	.preresume = crypt_preresume,
2227	.resume = crypt_resume,
2228	.message = crypt_message,
2229	.iterate_devices = crypt_iterate_devices,
2230	.io_hints = crypt_io_hints,
2231};
2232
2233static int __init dm_crypt_init(void)
2234{
2235	int r;
2236
2237	r = dm_register_target(&crypt_target);
2238	if (r < 0)
2239		DMERR("register failed %d", r);
2240
2241	return r;
2242}
2243
2244static void __exit dm_crypt_exit(void)
2245{
2246	dm_unregister_target(&crypt_target);
2247}
2248
2249module_init(dm_crypt_init);
2250module_exit(dm_crypt_exit);
2251
2252MODULE_AUTHOR("Jana Saout <jana@saout.de>");
2253MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
2254MODULE_LICENSE("GPL");