linux/drivers/md/dm-crypt.c
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   1/*
   2 * Copyright (C) 2003 Jana Saout <jana@saout.de>
   3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
   4 * Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved.
   5 * Copyright (C) 2013-2020 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 <crypto/aead.h>
  35#include <crypto/authenc.h>
  36#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */
  37#include <linux/key-type.h>
  38#include <keys/user-type.h>
  39#include <keys/encrypted-type.h>
  40#include <keys/trusted-type.h>
  41
  42#include <linux/device-mapper.h>
  43
  44#define DM_MSG_PREFIX "crypt"
  45
  46/*
  47 * context holding the current state of a multi-part conversion
  48 */
  49struct convert_context {
  50        struct completion restart;
  51        struct bio *bio_in;
  52        struct bio *bio_out;
  53        struct bvec_iter iter_in;
  54        struct bvec_iter iter_out;
  55        u64 cc_sector;
  56        atomic_t cc_pending;
  57        union {
  58                struct skcipher_request *req;
  59                struct aead_request *req_aead;
  60        } r;
  61
  62};
  63
  64/*
  65 * per bio private data
  66 */
  67struct dm_crypt_io {
  68        struct crypt_config *cc;
  69        struct bio *base_bio;
  70        u8 *integrity_metadata;
  71        bool integrity_metadata_from_pool;
  72        struct work_struct work;
  73        struct tasklet_struct tasklet;
  74
  75        struct convert_context ctx;
  76
  77        atomic_t io_pending;
  78        blk_status_t error;
  79        sector_t sector;
  80
  81        struct rb_node rb_node;
  82} CRYPTO_MINALIGN_ATTR;
  83
  84struct dm_crypt_request {
  85        struct convert_context *ctx;
  86        struct scatterlist sg_in[4];
  87        struct scatterlist sg_out[4];
  88        u64 iv_sector;
  89};
  90
  91struct crypt_config;
  92
  93struct crypt_iv_operations {
  94        int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
  95                   const char *opts);
  96        void (*dtr)(struct crypt_config *cc);
  97        int (*init)(struct crypt_config *cc);
  98        int (*wipe)(struct crypt_config *cc);
  99        int (*generator)(struct crypt_config *cc, u8 *iv,
 100                         struct dm_crypt_request *dmreq);
 101        int (*post)(struct crypt_config *cc, u8 *iv,
 102                    struct dm_crypt_request *dmreq);
 103};
 104
 105struct iv_benbi_private {
 106        int shift;
 107};
 108
 109#define LMK_SEED_SIZE 64 /* hash + 0 */
 110struct iv_lmk_private {
 111        struct crypto_shash *hash_tfm;
 112        u8 *seed;
 113};
 114
 115#define TCW_WHITENING_SIZE 16
 116struct iv_tcw_private {
 117        struct crypto_shash *crc32_tfm;
 118        u8 *iv_seed;
 119        u8 *whitening;
 120};
 121
 122#define ELEPHANT_MAX_KEY_SIZE 32
 123struct iv_elephant_private {
 124        struct crypto_skcipher *tfm;
 125};
 126
 127/*
 128 * Crypt: maps a linear range of a block device
 129 * and encrypts / decrypts at the same time.
 130 */
 131enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID,
 132             DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD,
 133             DM_CRYPT_NO_READ_WORKQUEUE, DM_CRYPT_NO_WRITE_WORKQUEUE,
 134             DM_CRYPT_WRITE_INLINE };
 135
 136enum cipher_flags {
 137        CRYPT_MODE_INTEGRITY_AEAD,      /* Use authenticated mode for cipher */
 138        CRYPT_IV_LARGE_SECTORS,         /* Calculate IV from sector_size, not 512B sectors */
 139        CRYPT_ENCRYPT_PREPROCESS,       /* Must preprocess data for encryption (elephant) */
 140};
 141
 142/*
 143 * The fields in here must be read only after initialization.
 144 */
 145struct crypt_config {
 146        struct dm_dev *dev;
 147        sector_t start;
 148
 149        struct percpu_counter n_allocated_pages;
 150
 151        struct workqueue_struct *io_queue;
 152        struct workqueue_struct *crypt_queue;
 153
 154        spinlock_t write_thread_lock;
 155        struct task_struct *write_thread;
 156        struct rb_root write_tree;
 157
 158        char *cipher_string;
 159        char *cipher_auth;
 160        char *key_string;
 161
 162        const struct crypt_iv_operations *iv_gen_ops;
 163        union {
 164                struct iv_benbi_private benbi;
 165                struct iv_lmk_private lmk;
 166                struct iv_tcw_private tcw;
 167                struct iv_elephant_private elephant;
 168        } iv_gen_private;
 169        u64 iv_offset;
 170        unsigned int iv_size;
 171        unsigned short int sector_size;
 172        unsigned char sector_shift;
 173
 174        union {
 175                struct crypto_skcipher **tfms;
 176                struct crypto_aead **tfms_aead;
 177        } cipher_tfm;
 178        unsigned tfms_count;
 179        unsigned long cipher_flags;
 180
 181        /*
 182         * Layout of each crypto request:
 183         *
 184         *   struct skcipher_request
 185         *      context
 186         *      padding
 187         *   struct dm_crypt_request
 188         *      padding
 189         *   IV
 190         *
 191         * The padding is added so that dm_crypt_request and the IV are
 192         * correctly aligned.
 193         */
 194        unsigned int dmreq_start;
 195
 196        unsigned int per_bio_data_size;
 197
 198        unsigned long flags;
 199        unsigned int key_size;
 200        unsigned int key_parts;      /* independent parts in key buffer */
 201        unsigned int key_extra_size; /* additional keys length */
 202        unsigned int key_mac_size;   /* MAC key size for authenc(...) */
 203
 204        unsigned int integrity_tag_size;
 205        unsigned int integrity_iv_size;
 206        unsigned int on_disk_tag_size;
 207
 208        /*
 209         * pool for per bio private data, crypto requests,
 210         * encryption requeusts/buffer pages and integrity tags
 211         */
 212        unsigned tag_pool_max_sectors;
 213        mempool_t tag_pool;
 214        mempool_t req_pool;
 215        mempool_t page_pool;
 216
 217        struct bio_set bs;
 218        struct mutex bio_alloc_lock;
 219
 220        u8 *authenc_key; /* space for keys in authenc() format (if used) */
 221        u8 key[];
 222};
 223
 224#define MIN_IOS         64
 225#define MAX_TAG_SIZE    480
 226#define POOL_ENTRY_SIZE 512
 227
 228static DEFINE_SPINLOCK(dm_crypt_clients_lock);
 229static unsigned dm_crypt_clients_n = 0;
 230static volatile unsigned long dm_crypt_pages_per_client;
 231#define DM_CRYPT_MEMORY_PERCENT                 2
 232#define DM_CRYPT_MIN_PAGES_PER_CLIENT           (BIO_MAX_VECS * 16)
 233
 234static void clone_init(struct dm_crypt_io *, struct bio *);
 235static void kcryptd_queue_crypt(struct dm_crypt_io *io);
 236static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
 237                                             struct scatterlist *sg);
 238
 239static bool crypt_integrity_aead(struct crypt_config *cc);
 240
 241/*
 242 * Use this to access cipher attributes that are independent of the key.
 243 */
 244static struct crypto_skcipher *any_tfm(struct crypt_config *cc)
 245{
 246        return cc->cipher_tfm.tfms[0];
 247}
 248
 249static struct crypto_aead *any_tfm_aead(struct crypt_config *cc)
 250{
 251        return cc->cipher_tfm.tfms_aead[0];
 252}
 253
 254/*
 255 * Different IV generation algorithms:
 256 *
 257 * plain: the initial vector is the 32-bit little-endian version of the sector
 258 *        number, padded with zeros if necessary.
 259 *
 260 * plain64: the initial vector is the 64-bit little-endian version of the sector
 261 *        number, padded with zeros if necessary.
 262 *
 263 * plain64be: the initial vector is the 64-bit big-endian version of the sector
 264 *        number, padded with zeros if necessary.
 265 *
 266 * essiv: "encrypted sector|salt initial vector", the sector number is
 267 *        encrypted with the bulk cipher using a salt as key. The salt
 268 *        should be derived from the bulk cipher's key via hashing.
 269 *
 270 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
 271 *        (needed for LRW-32-AES and possible other narrow block modes)
 272 *
 273 * null: the initial vector is always zero.  Provides compatibility with
 274 *       obsolete loop_fish2 devices.  Do not use for new devices.
 275 *
 276 * lmk:  Compatible implementation of the block chaining mode used
 277 *       by the Loop-AES block device encryption system
 278 *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
 279 *       It operates on full 512 byte sectors and uses CBC
 280 *       with an IV derived from the sector number, the data and
 281 *       optionally extra IV seed.
 282 *       This means that after decryption the first block
 283 *       of sector must be tweaked according to decrypted data.
 284 *       Loop-AES can use three encryption schemes:
 285 *         version 1: is plain aes-cbc mode
 286 *         version 2: uses 64 multikey scheme with lmk IV generator
 287 *         version 3: the same as version 2 with additional IV seed
 288 *                   (it uses 65 keys, last key is used as IV seed)
 289 *
 290 * tcw:  Compatible implementation of the block chaining mode used
 291 *       by the TrueCrypt device encryption system (prior to version 4.1).
 292 *       For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat
 293 *       It operates on full 512 byte sectors and uses CBC
 294 *       with an IV derived from initial key and the sector number.
 295 *       In addition, whitening value is applied on every sector, whitening
 296 *       is calculated from initial key, sector number and mixed using CRC32.
 297 *       Note that this encryption scheme is vulnerable to watermarking attacks
 298 *       and should be used for old compatible containers access only.
 299 *
 300 * eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
 301 *        The IV is encrypted little-endian byte-offset (with the same key
 302 *        and cipher as the volume).
 303 *
 304 * elephant: The extended version of eboiv with additional Elephant diffuser
 305 *           used with Bitlocker CBC mode.
 306 *           This mode was used in older Windows systems
 307 *           https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
 308 */
 309
 310static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
 311                              struct dm_crypt_request *dmreq)
 312{
 313        memset(iv, 0, cc->iv_size);
 314        *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
 315
 316        return 0;
 317}
 318
 319static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
 320                                struct dm_crypt_request *dmreq)
 321{
 322        memset(iv, 0, cc->iv_size);
 323        *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 324
 325        return 0;
 326}
 327
 328static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv,
 329                                  struct dm_crypt_request *dmreq)
 330{
 331        memset(iv, 0, cc->iv_size);
 332        /* iv_size is at least of size u64; usually it is 16 bytes */
 333        *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(dmreq->iv_sector);
 334
 335        return 0;
 336}
 337
 338static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
 339                              struct dm_crypt_request *dmreq)
 340{
 341        /*
 342         * ESSIV encryption of the IV is now handled by the crypto API,
 343         * so just pass the plain sector number here.
 344         */
 345        memset(iv, 0, cc->iv_size);
 346        *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
 347
 348        return 0;
 349}
 350
 351static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
 352                              const char *opts)
 353{
 354        unsigned bs;
 355        int log;
 356
 357        if (crypt_integrity_aead(cc))
 358                bs = crypto_aead_blocksize(any_tfm_aead(cc));
 359        else
 360                bs = crypto_skcipher_blocksize(any_tfm(cc));
 361        log = ilog2(bs);
 362
 363        /* we need to calculate how far we must shift the sector count
 364         * to get the cipher block count, we use this shift in _gen */
 365
 366        if (1 << log != bs) {
 367                ti->error = "cypher blocksize is not a power of 2";
 368                return -EINVAL;
 369        }
 370
 371        if (log > 9) {
 372                ti->error = "cypher blocksize is > 512";
 373                return -EINVAL;
 374        }
 375
 376        cc->iv_gen_private.benbi.shift = 9 - log;
 377
 378        return 0;
 379}
 380
 381static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 382{
 383}
 384
 385static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
 386                              struct dm_crypt_request *dmreq)
 387{
 388        __be64 val;
 389
 390        memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 391
 392        val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
 393        put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 394
 395        return 0;
 396}
 397
 398static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
 399                             struct dm_crypt_request *dmreq)
 400{
 401        memset(iv, 0, cc->iv_size);
 402
 403        return 0;
 404}
 405
 406static void crypt_iv_lmk_dtr(struct crypt_config *cc)
 407{
 408        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 409
 410        if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
 411                crypto_free_shash(lmk->hash_tfm);
 412        lmk->hash_tfm = NULL;
 413
 414        kfree_sensitive(lmk->seed);
 415        lmk->seed = NULL;
 416}
 417
 418static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
 419                            const char *opts)
 420{
 421        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 422
 423        if (cc->sector_size != (1 << SECTOR_SHIFT)) {
 424                ti->error = "Unsupported sector size for LMK";
 425                return -EINVAL;
 426        }
 427
 428        lmk->hash_tfm = crypto_alloc_shash("md5", 0,
 429                                           CRYPTO_ALG_ALLOCATES_MEMORY);
 430        if (IS_ERR(lmk->hash_tfm)) {
 431                ti->error = "Error initializing LMK hash";
 432                return PTR_ERR(lmk->hash_tfm);
 433        }
 434
 435        /* No seed in LMK version 2 */
 436        if (cc->key_parts == cc->tfms_count) {
 437                lmk->seed = NULL;
 438                return 0;
 439        }
 440
 441        lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
 442        if (!lmk->seed) {
 443                crypt_iv_lmk_dtr(cc);
 444                ti->error = "Error kmallocing seed storage in LMK";
 445                return -ENOMEM;
 446        }
 447
 448        return 0;
 449}
 450
 451static int crypt_iv_lmk_init(struct crypt_config *cc)
 452{
 453        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 454        int subkey_size = cc->key_size / cc->key_parts;
 455
 456        /* LMK seed is on the position of LMK_KEYS + 1 key */
 457        if (lmk->seed)
 458                memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
 459                       crypto_shash_digestsize(lmk->hash_tfm));
 460
 461        return 0;
 462}
 463
 464static int crypt_iv_lmk_wipe(struct crypt_config *cc)
 465{
 466        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 467
 468        if (lmk->seed)
 469                memset(lmk->seed, 0, LMK_SEED_SIZE);
 470
 471        return 0;
 472}
 473
 474static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
 475                            struct dm_crypt_request *dmreq,
 476                            u8 *data)
 477{
 478        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
 479        SHASH_DESC_ON_STACK(desc, lmk->hash_tfm);
 480        struct md5_state md5state;
 481        __le32 buf[4];
 482        int i, r;
 483
 484        desc->tfm = lmk->hash_tfm;
 485
 486        r = crypto_shash_init(desc);
 487        if (r)
 488                return r;
 489
 490        if (lmk->seed) {
 491                r = crypto_shash_update(desc, lmk->seed, LMK_SEED_SIZE);
 492                if (r)
 493                        return r;
 494        }
 495
 496        /* Sector is always 512B, block size 16, add data of blocks 1-31 */
 497        r = crypto_shash_update(desc, data + 16, 16 * 31);
 498        if (r)
 499                return r;
 500
 501        /* Sector is cropped to 56 bits here */
 502        buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
 503        buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
 504        buf[2] = cpu_to_le32(4024);
 505        buf[3] = 0;
 506        r = crypto_shash_update(desc, (u8 *)buf, sizeof(buf));
 507        if (r)
 508                return r;
 509
 510        /* No MD5 padding here */
 511        r = crypto_shash_export(desc, &md5state);
 512        if (r)
 513                return r;
 514
 515        for (i = 0; i < MD5_HASH_WORDS; i++)
 516                __cpu_to_le32s(&md5state.hash[i]);
 517        memcpy(iv, &md5state.hash, cc->iv_size);
 518
 519        return 0;
 520}
 521
 522static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
 523                            struct dm_crypt_request *dmreq)
 524{
 525        struct scatterlist *sg;
 526        u8 *src;
 527        int r = 0;
 528
 529        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 530                sg = crypt_get_sg_data(cc, dmreq->sg_in);
 531                src = kmap_atomic(sg_page(sg));
 532                r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
 533                kunmap_atomic(src);
 534        } else
 535                memset(iv, 0, cc->iv_size);
 536
 537        return r;
 538}
 539
 540static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
 541                             struct dm_crypt_request *dmreq)
 542{
 543        struct scatterlist *sg;
 544        u8 *dst;
 545        int r;
 546
 547        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
 548                return 0;
 549
 550        sg = crypt_get_sg_data(cc, dmreq->sg_out);
 551        dst = kmap_atomic(sg_page(sg));
 552        r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset);
 553
 554        /* Tweak the first block of plaintext sector */
 555        if (!r)
 556                crypto_xor(dst + sg->offset, iv, cc->iv_size);
 557
 558        kunmap_atomic(dst);
 559        return r;
 560}
 561
 562static void crypt_iv_tcw_dtr(struct crypt_config *cc)
 563{
 564        struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 565
 566        kfree_sensitive(tcw->iv_seed);
 567        tcw->iv_seed = NULL;
 568        kfree_sensitive(tcw->whitening);
 569        tcw->whitening = NULL;
 570
 571        if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm))
 572                crypto_free_shash(tcw->crc32_tfm);
 573        tcw->crc32_tfm = NULL;
 574}
 575
 576static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti,
 577                            const char *opts)
 578{
 579        struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 580
 581        if (cc->sector_size != (1 << SECTOR_SHIFT)) {
 582                ti->error = "Unsupported sector size for TCW";
 583                return -EINVAL;
 584        }
 585
 586        if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) {
 587                ti->error = "Wrong key size for TCW";
 588                return -EINVAL;
 589        }
 590
 591        tcw->crc32_tfm = crypto_alloc_shash("crc32", 0,
 592                                            CRYPTO_ALG_ALLOCATES_MEMORY);
 593        if (IS_ERR(tcw->crc32_tfm)) {
 594                ti->error = "Error initializing CRC32 in TCW";
 595                return PTR_ERR(tcw->crc32_tfm);
 596        }
 597
 598        tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL);
 599        tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL);
 600        if (!tcw->iv_seed || !tcw->whitening) {
 601                crypt_iv_tcw_dtr(cc);
 602                ti->error = "Error allocating seed storage in TCW";
 603                return -ENOMEM;
 604        }
 605
 606        return 0;
 607}
 608
 609static int crypt_iv_tcw_init(struct crypt_config *cc)
 610{
 611        struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 612        int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE;
 613
 614        memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size);
 615        memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size],
 616               TCW_WHITENING_SIZE);
 617
 618        return 0;
 619}
 620
 621static int crypt_iv_tcw_wipe(struct crypt_config *cc)
 622{
 623        struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 624
 625        memset(tcw->iv_seed, 0, cc->iv_size);
 626        memset(tcw->whitening, 0, TCW_WHITENING_SIZE);
 627
 628        return 0;
 629}
 630
 631static int crypt_iv_tcw_whitening(struct crypt_config *cc,
 632                                  struct dm_crypt_request *dmreq,
 633                                  u8 *data)
 634{
 635        struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 636        __le64 sector = cpu_to_le64(dmreq->iv_sector);
 637        u8 buf[TCW_WHITENING_SIZE];
 638        SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm);
 639        int i, r;
 640
 641        /* xor whitening with sector number */
 642        crypto_xor_cpy(buf, tcw->whitening, (u8 *)&sector, 8);
 643        crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)&sector, 8);
 644
 645        /* calculate crc32 for every 32bit part and xor it */
 646        desc->tfm = tcw->crc32_tfm;
 647        for (i = 0; i < 4; i++) {
 648                r = crypto_shash_init(desc);
 649                if (r)
 650                        goto out;
 651                r = crypto_shash_update(desc, &buf[i * 4], 4);
 652                if (r)
 653                        goto out;
 654                r = crypto_shash_final(desc, &buf[i * 4]);
 655                if (r)
 656                        goto out;
 657        }
 658        crypto_xor(&buf[0], &buf[12], 4);
 659        crypto_xor(&buf[4], &buf[8], 4);
 660
 661        /* apply whitening (8 bytes) to whole sector */
 662        for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++)
 663                crypto_xor(data + i * 8, buf, 8);
 664out:
 665        memzero_explicit(buf, sizeof(buf));
 666        return r;
 667}
 668
 669static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv,
 670                            struct dm_crypt_request *dmreq)
 671{
 672        struct scatterlist *sg;
 673        struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
 674        __le64 sector = cpu_to_le64(dmreq->iv_sector);
 675        u8 *src;
 676        int r = 0;
 677
 678        /* Remove whitening from ciphertext */
 679        if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
 680                sg = crypt_get_sg_data(cc, dmreq->sg_in);
 681                src = kmap_atomic(sg_page(sg));
 682                r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
 683                kunmap_atomic(src);
 684        }
 685
 686        /* Calculate IV */
 687        crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)&sector, 8);
 688        if (cc->iv_size > 8)
 689                crypto_xor_cpy(&iv[8], tcw->iv_seed + 8, (u8 *)&sector,
 690                               cc->iv_size - 8);
 691
 692        return r;
 693}
 694
 695static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 696                             struct dm_crypt_request *dmreq)
 697{
 698        struct scatterlist *sg;
 699        u8 *dst;
 700        int r;
 701
 702        if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
 703                return 0;
 704
 705        /* Apply whitening on ciphertext */
 706        sg = crypt_get_sg_data(cc, dmreq->sg_out);
 707        dst = kmap_atomic(sg_page(sg));
 708        r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
 709        kunmap_atomic(dst);
 710
 711        return r;
 712}
 713
 714static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv,
 715                                struct dm_crypt_request *dmreq)
 716{
 717        /* Used only for writes, there must be an additional space to store IV */
 718        get_random_bytes(iv, cc->iv_size);
 719        return 0;
 720}
 721
 722static int crypt_iv_eboiv_ctr(struct crypt_config *cc, struct dm_target *ti,
 723                            const char *opts)
 724{
 725        if (crypt_integrity_aead(cc)) {
 726                ti->error = "AEAD transforms not supported for EBOIV";
 727                return -EINVAL;
 728        }
 729
 730        if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
 731                ti->error = "Block size of EBOIV cipher does "
 732                            "not match IV size of block cipher";
 733                return -EINVAL;
 734        }
 735
 736        return 0;
 737}
 738
 739static int crypt_iv_eboiv_gen(struct crypt_config *cc, u8 *iv,
 740                            struct dm_crypt_request *dmreq)
 741{
 742        u8 buf[MAX_CIPHER_BLOCKSIZE] __aligned(__alignof__(__le64));
 743        struct skcipher_request *req;
 744        struct scatterlist src, dst;
 745        DECLARE_CRYPTO_WAIT(wait);
 746        int err;
 747
 748        req = skcipher_request_alloc(any_tfm(cc), GFP_NOIO);
 749        if (!req)
 750                return -ENOMEM;
 751
 752        memset(buf, 0, cc->iv_size);
 753        *(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
 754
 755        sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
 756        sg_init_one(&dst, iv, cc->iv_size);
 757        skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
 758        skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
 759        err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
 760        skcipher_request_free(req);
 761
 762        return err;
 763}
 764
 765static void crypt_iv_elephant_dtr(struct crypt_config *cc)
 766{
 767        struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
 768
 769        crypto_free_skcipher(elephant->tfm);
 770        elephant->tfm = NULL;
 771}
 772
 773static int crypt_iv_elephant_ctr(struct crypt_config *cc, struct dm_target *ti,
 774                            const char *opts)
 775{
 776        struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
 777        int r;
 778
 779        elephant->tfm = crypto_alloc_skcipher("ecb(aes)", 0,
 780                                              CRYPTO_ALG_ALLOCATES_MEMORY);
 781        if (IS_ERR(elephant->tfm)) {
 782                r = PTR_ERR(elephant->tfm);
 783                elephant->tfm = NULL;
 784                return r;
 785        }
 786
 787        r = crypt_iv_eboiv_ctr(cc, ti, NULL);
 788        if (r)
 789                crypt_iv_elephant_dtr(cc);
 790        return r;
 791}
 792
 793static void diffuser_disk_to_cpu(u32 *d, size_t n)
 794{
 795#ifndef __LITTLE_ENDIAN
 796        int i;
 797
 798        for (i = 0; i < n; i++)
 799                d[i] = le32_to_cpu((__le32)d[i]);
 800#endif
 801}
 802
 803static void diffuser_cpu_to_disk(__le32 *d, size_t n)
 804{
 805#ifndef __LITTLE_ENDIAN
 806        int i;
 807
 808        for (i = 0; i < n; i++)
 809                d[i] = cpu_to_le32((u32)d[i]);
 810#endif
 811}
 812
 813static void diffuser_a_decrypt(u32 *d, size_t n)
 814{
 815        int i, i1, i2, i3;
 816
 817        for (i = 0; i < 5; i++) {
 818                i1 = 0;
 819                i2 = n - 2;
 820                i3 = n - 5;
 821
 822                while (i1 < (n - 1)) {
 823                        d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
 824                        i1++; i2++; i3++;
 825
 826                        if (i3 >= n)
 827                                i3 -= n;
 828
 829                        d[i1] += d[i2] ^ d[i3];
 830                        i1++; i2++; i3++;
 831
 832                        if (i2 >= n)
 833                                i2 -= n;
 834
 835                        d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
 836                        i1++; i2++; i3++;
 837
 838                        d[i1] += d[i2] ^ d[i3];
 839                        i1++; i2++; i3++;
 840                }
 841        }
 842}
 843
 844static void diffuser_a_encrypt(u32 *d, size_t n)
 845{
 846        int i, i1, i2, i3;
 847
 848        for (i = 0; i < 5; i++) {
 849                i1 = n - 1;
 850                i2 = n - 2 - 1;
 851                i3 = n - 5 - 1;
 852
 853                while (i1 > 0) {
 854                        d[i1] -= d[i2] ^ d[i3];
 855                        i1--; i2--; i3--;
 856
 857                        d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
 858                        i1--; i2--; i3--;
 859
 860                        if (i2 < 0)
 861                                i2 += n;
 862
 863                        d[i1] -= d[i2] ^ d[i3];
 864                        i1--; i2--; i3--;
 865
 866                        if (i3 < 0)
 867                                i3 += n;
 868
 869                        d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
 870                        i1--; i2--; i3--;
 871                }
 872        }
 873}
 874
 875static void diffuser_b_decrypt(u32 *d, size_t n)
 876{
 877        int i, i1, i2, i3;
 878
 879        for (i = 0; i < 3; i++) {
 880                i1 = 0;
 881                i2 = 2;
 882                i3 = 5;
 883
 884                while (i1 < (n - 1)) {
 885                        d[i1] += d[i2] ^ d[i3];
 886                        i1++; i2++; i3++;
 887
 888                        d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
 889                        i1++; i2++; i3++;
 890
 891                        if (i2 >= n)
 892                                i2 -= n;
 893
 894                        d[i1] += d[i2] ^ d[i3];
 895                        i1++; i2++; i3++;
 896
 897                        if (i3 >= n)
 898                                i3 -= n;
 899
 900                        d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
 901                        i1++; i2++; i3++;
 902                }
 903        }
 904}
 905
 906static void diffuser_b_encrypt(u32 *d, size_t n)
 907{
 908        int i, i1, i2, i3;
 909
 910        for (i = 0; i < 3; i++) {
 911                i1 = n - 1;
 912                i2 = 2 - 1;
 913                i3 = 5 - 1;
 914
 915                while (i1 > 0) {
 916                        d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
 917                        i1--; i2--; i3--;
 918
 919                        if (i3 < 0)
 920                                i3 += n;
 921
 922                        d[i1] -= d[i2] ^ d[i3];
 923                        i1--; i2--; i3--;
 924
 925                        if (i2 < 0)
 926                                i2 += n;
 927
 928                        d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
 929                        i1--; i2--; i3--;
 930
 931                        d[i1] -= d[i2] ^ d[i3];
 932                        i1--; i2--; i3--;
 933                }
 934        }
 935}
 936
 937static int crypt_iv_elephant(struct crypt_config *cc, struct dm_crypt_request *dmreq)
 938{
 939        struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
 940        u8 *es, *ks, *data, *data2, *data_offset;
 941        struct skcipher_request *req;
 942        struct scatterlist *sg, *sg2, src, dst;
 943        DECLARE_CRYPTO_WAIT(wait);
 944        int i, r;
 945
 946        req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
 947        es = kzalloc(16, GFP_NOIO); /* Key for AES */
 948        ks = kzalloc(32, GFP_NOIO); /* Elephant sector key */
 949
 950        if (!req || !es || !ks) {
 951                r = -ENOMEM;
 952                goto out;
 953        }
 954
 955        *(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
 956
 957        /* E(Ks, e(s)) */
 958        sg_init_one(&src, es, 16);
 959        sg_init_one(&dst, ks, 16);
 960        skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
 961        skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
 962        r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
 963        if (r)
 964                goto out;
 965
 966        /* E(Ks, e'(s)) */
 967        es[15] = 0x80;
 968        sg_init_one(&dst, &ks[16], 16);
 969        r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
 970        if (r)
 971                goto out;
 972
 973        sg = crypt_get_sg_data(cc, dmreq->sg_out);
 974        data = kmap_atomic(sg_page(sg));
 975        data_offset = data + sg->offset;
 976
 977        /* Cannot modify original bio, copy to sg_out and apply Elephant to it */
 978        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 979                sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
 980                data2 = kmap_atomic(sg_page(sg2));
 981                memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
 982                kunmap_atomic(data2);
 983        }
 984
 985        if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
 986                diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32));
 987                diffuser_b_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
 988                diffuser_a_decrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
 989                diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32));
 990        }
 991
 992        for (i = 0; i < (cc->sector_size / 32); i++)
 993                crypto_xor(data_offset + i * 32, ks, 32);
 994
 995        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
 996                diffuser_disk_to_cpu((u32*)data_offset, cc->sector_size / sizeof(u32));
 997                diffuser_a_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
 998                diffuser_b_encrypt((u32*)data_offset, cc->sector_size / sizeof(u32));
 999                diffuser_cpu_to_disk((__le32*)data_offset, cc->sector_size / sizeof(u32));
1000        }
1001
1002        kunmap_atomic(data);
1003out:
1004        kfree_sensitive(ks);
1005        kfree_sensitive(es);
1006        skcipher_request_free(req);
1007        return r;
1008}
1009
1010static int crypt_iv_elephant_gen(struct crypt_config *cc, u8 *iv,
1011                            struct dm_crypt_request *dmreq)
1012{
1013        int r;
1014
1015        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
1016                r = crypt_iv_elephant(cc, dmreq);
1017                if (r)
1018                        return r;
1019        }
1020
1021        return crypt_iv_eboiv_gen(cc, iv, dmreq);
1022}
1023
1024static int crypt_iv_elephant_post(struct crypt_config *cc, u8 *iv,
1025                                  struct dm_crypt_request *dmreq)
1026{
1027        if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
1028                return crypt_iv_elephant(cc, dmreq);
1029
1030        return 0;
1031}
1032
1033static int crypt_iv_elephant_init(struct crypt_config *cc)
1034{
1035        struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1036        int key_offset = cc->key_size - cc->key_extra_size;
1037
1038        return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
1039}
1040
1041static int crypt_iv_elephant_wipe(struct crypt_config *cc)
1042{
1043        struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
1044        u8 key[ELEPHANT_MAX_KEY_SIZE];
1045
1046        memset(key, 0, cc->key_extra_size);
1047        return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
1048}
1049
1050static const struct crypt_iv_operations crypt_iv_plain_ops = {
1051        .generator = crypt_iv_plain_gen
1052};
1053
1054static const struct crypt_iv_operations crypt_iv_plain64_ops = {
1055        .generator = crypt_iv_plain64_gen
1056};
1057
1058static const struct crypt_iv_operations crypt_iv_plain64be_ops = {
1059        .generator = crypt_iv_plain64be_gen
1060};
1061
1062static const struct crypt_iv_operations crypt_iv_essiv_ops = {
1063        .generator = crypt_iv_essiv_gen
1064};
1065
1066static const struct crypt_iv_operations crypt_iv_benbi_ops = {
1067        .ctr       = crypt_iv_benbi_ctr,
1068        .dtr       = crypt_iv_benbi_dtr,
1069        .generator = crypt_iv_benbi_gen
1070};
1071
1072static const struct crypt_iv_operations crypt_iv_null_ops = {
1073        .generator = crypt_iv_null_gen
1074};
1075
1076static const struct crypt_iv_operations crypt_iv_lmk_ops = {
1077        .ctr       = crypt_iv_lmk_ctr,
1078        .dtr       = crypt_iv_lmk_dtr,
1079        .init      = crypt_iv_lmk_init,
1080        .wipe      = crypt_iv_lmk_wipe,
1081        .generator = crypt_iv_lmk_gen,
1082        .post      = crypt_iv_lmk_post
1083};
1084
1085static const struct crypt_iv_operations crypt_iv_tcw_ops = {
1086        .ctr       = crypt_iv_tcw_ctr,
1087        .dtr       = crypt_iv_tcw_dtr,
1088        .init      = crypt_iv_tcw_init,
1089        .wipe      = crypt_iv_tcw_wipe,
1090        .generator = crypt_iv_tcw_gen,
1091        .post      = crypt_iv_tcw_post
1092};
1093
1094static const struct crypt_iv_operations crypt_iv_random_ops = {
1095        .generator = crypt_iv_random_gen
1096};
1097
1098static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
1099        .ctr       = crypt_iv_eboiv_ctr,
1100        .generator = crypt_iv_eboiv_gen
1101};
1102
1103static const struct crypt_iv_operations crypt_iv_elephant_ops = {
1104        .ctr       = crypt_iv_elephant_ctr,
1105        .dtr       = crypt_iv_elephant_dtr,
1106        .init      = crypt_iv_elephant_init,
1107        .wipe      = crypt_iv_elephant_wipe,
1108        .generator = crypt_iv_elephant_gen,
1109        .post      = crypt_iv_elephant_post
1110};
1111
1112/*
1113 * Integrity extensions
1114 */
1115static bool crypt_integrity_aead(struct crypt_config *cc)
1116{
1117        return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
1118}
1119
1120static bool crypt_integrity_hmac(struct crypt_config *cc)
1121{
1122        return crypt_integrity_aead(cc) && cc->key_mac_size;
1123}
1124
1125/* Get sg containing data */
1126static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc,
1127                                             struct scatterlist *sg)
1128{
1129        if (unlikely(crypt_integrity_aead(cc)))
1130                return &sg[2];
1131
1132        return sg;
1133}
1134
1135static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio)
1136{
1137        struct bio_integrity_payload *bip;
1138        unsigned int tag_len;
1139        int ret;
1140
1141        if (!bio_sectors(bio) || !io->cc->on_disk_tag_size)
1142                return 0;
1143
1144        bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
1145        if (IS_ERR(bip))
1146                return PTR_ERR(bip);
1147
1148        tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift);
1149
1150        bip->bip_iter.bi_size = tag_len;
1151        bip->bip_iter.bi_sector = io->cc->start + io->sector;
1152
1153        ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata),
1154                                     tag_len, offset_in_page(io->integrity_metadata));
1155        if (unlikely(ret != tag_len))
1156                return -ENOMEM;
1157
1158        return 0;
1159}
1160
1161static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti)
1162{
1163#ifdef CONFIG_BLK_DEV_INTEGRITY
1164        struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk);
1165        struct mapped_device *md = dm_table_get_md(ti->table);
1166
1167        /* From now we require underlying device with our integrity profile */
1168        if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) {
1169                ti->error = "Integrity profile not supported.";
1170                return -EINVAL;
1171        }
1172
1173        if (bi->tag_size != cc->on_disk_tag_size ||
1174            bi->tuple_size != cc->on_disk_tag_size) {
1175                ti->error = "Integrity profile tag size mismatch.";
1176                return -EINVAL;
1177        }
1178        if (1 << bi->interval_exp != cc->sector_size) {
1179                ti->error = "Integrity profile sector size mismatch.";
1180                return -EINVAL;
1181        }
1182
1183        if (crypt_integrity_aead(cc)) {
1184                cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size;
1185                DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md),
1186                       cc->integrity_tag_size, cc->integrity_iv_size);
1187
1188                if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) {
1189                        ti->error = "Integrity AEAD auth tag size is not supported.";
1190                        return -EINVAL;
1191                }
1192        } else if (cc->integrity_iv_size)
1193                DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md),
1194                       cc->integrity_iv_size);
1195
1196        if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) {
1197                ti->error = "Not enough space for integrity tag in the profile.";
1198                return -EINVAL;
1199        }
1200
1201        return 0;
1202#else
1203        ti->error = "Integrity profile not supported.";
1204        return -EINVAL;
1205#endif
1206}
1207
1208static void crypt_convert_init(struct crypt_config *cc,
1209                               struct convert_context *ctx,
1210                               struct bio *bio_out, struct bio *bio_in,
1211                               sector_t sector)
1212{
1213        ctx->bio_in = bio_in;
1214        ctx->bio_out = bio_out;
1215        if (bio_in)
1216                ctx->iter_in = bio_in->bi_iter;
1217        if (bio_out)
1218                ctx->iter_out = bio_out->bi_iter;
1219        ctx->cc_sector = sector + cc->iv_offset;
1220        init_completion(&ctx->restart);
1221}
1222
1223static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
1224                                             void *req)
1225{
1226        return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
1227}
1228
1229static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq)
1230{
1231        return (void *)((char *)dmreq - cc->dmreq_start);
1232}
1233
1234static u8 *iv_of_dmreq(struct crypt_config *cc,
1235                       struct dm_crypt_request *dmreq)
1236{
1237        if (crypt_integrity_aead(cc))
1238                return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1239                        crypto_aead_alignmask(any_tfm_aead(cc)) + 1);
1240        else
1241                return (u8 *)ALIGN((unsigned long)(dmreq + 1),
1242                        crypto_skcipher_alignmask(any_tfm(cc)) + 1);
1243}
1244
1245static u8 *org_iv_of_dmreq(struct crypt_config *cc,
1246                       struct dm_crypt_request *dmreq)
1247{
1248        return iv_of_dmreq(cc, dmreq) + cc->iv_size;
1249}
1250
1251static __le64 *org_sector_of_dmreq(struct crypt_config *cc,
1252                       struct dm_crypt_request *dmreq)
1253{
1254        u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size;
1255        return (__le64 *) ptr;
1256}
1257
1258static unsigned int *org_tag_of_dmreq(struct crypt_config *cc,
1259                       struct dm_crypt_request *dmreq)
1260{
1261        u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size +
1262                  cc->iv_size + sizeof(uint64_t);
1263        return (unsigned int*)ptr;
1264}
1265
1266static void *tag_from_dmreq(struct crypt_config *cc,
1267                                struct dm_crypt_request *dmreq)
1268{
1269        struct convert_context *ctx = dmreq->ctx;
1270        struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1271
1272        return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) *
1273                cc->on_disk_tag_size];
1274}
1275
1276static void *iv_tag_from_dmreq(struct crypt_config *cc,
1277                               struct dm_crypt_request *dmreq)
1278{
1279        return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size;
1280}
1281
1282static int crypt_convert_block_aead(struct crypt_config *cc,
1283                                     struct convert_context *ctx,
1284                                     struct aead_request *req,
1285                                     unsigned int tag_offset)
1286{
1287        struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1288        struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1289        struct dm_crypt_request *dmreq;
1290        u8 *iv, *org_iv, *tag_iv, *tag;
1291        __le64 *sector;
1292        int r = 0;
1293
1294        BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size);
1295
1296        /* Reject unexpected unaligned bio. */
1297        if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1298                return -EIO;
1299
1300        dmreq = dmreq_of_req(cc, req);
1301        dmreq->iv_sector = ctx->cc_sector;
1302        if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1303                dmreq->iv_sector >>= cc->sector_shift;
1304        dmreq->ctx = ctx;
1305
1306        *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1307
1308        sector = org_sector_of_dmreq(cc, dmreq);
1309        *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1310
1311        iv = iv_of_dmreq(cc, dmreq);
1312        org_iv = org_iv_of_dmreq(cc, dmreq);
1313        tag = tag_from_dmreq(cc, dmreq);
1314        tag_iv = iv_tag_from_dmreq(cc, dmreq);
1315
1316        /* AEAD request:
1317         *  |----- AAD -------|------ DATA -------|-- AUTH TAG --|
1318         *  | (authenticated) | (auth+encryption) |              |
1319         *  | sector_LE |  IV |  sector in/out    |  tag in/out  |
1320         */
1321        sg_init_table(dmreq->sg_in, 4);
1322        sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t));
1323        sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size);
1324        sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1325        sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size);
1326
1327        sg_init_table(dmreq->sg_out, 4);
1328        sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t));
1329        sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size);
1330        sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1331        sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size);
1332
1333        if (cc->iv_gen_ops) {
1334                /* For READs use IV stored in integrity metadata */
1335                if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1336                        memcpy(org_iv, tag_iv, cc->iv_size);
1337                } else {
1338                        r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1339                        if (r < 0)
1340                                return r;
1341                        /* Store generated IV in integrity metadata */
1342                        if (cc->integrity_iv_size)
1343                                memcpy(tag_iv, org_iv, cc->iv_size);
1344                }
1345                /* Working copy of IV, to be modified in crypto API */
1346                memcpy(iv, org_iv, cc->iv_size);
1347        }
1348
1349        aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size);
1350        if (bio_data_dir(ctx->bio_in) == WRITE) {
1351                aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1352                                       cc->sector_size, iv);
1353                r = crypto_aead_encrypt(req);
1354                if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size)
1355                        memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
1356                               cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size));
1357        } else {
1358                aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out,
1359                                       cc->sector_size + cc->integrity_tag_size, iv);
1360                r = crypto_aead_decrypt(req);
1361        }
1362
1363        if (r == -EBADMSG) {
1364                char b[BDEVNAME_SIZE];
1365                DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b),
1366                            (unsigned long long)le64_to_cpu(*sector));
1367        }
1368
1369        if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1370                r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1371
1372        bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1373        bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1374
1375        return r;
1376}
1377
1378static int crypt_convert_block_skcipher(struct crypt_config *cc,
1379                                        struct convert_context *ctx,
1380                                        struct skcipher_request *req,
1381                                        unsigned int tag_offset)
1382{
1383        struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in);
1384        struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out);
1385        struct scatterlist *sg_in, *sg_out;
1386        struct dm_crypt_request *dmreq;
1387        u8 *iv, *org_iv, *tag_iv;
1388        __le64 *sector;
1389        int r = 0;
1390
1391        /* Reject unexpected unaligned bio. */
1392        if (unlikely(bv_in.bv_len & (cc->sector_size - 1)))
1393                return -EIO;
1394
1395        dmreq = dmreq_of_req(cc, req);
1396        dmreq->iv_sector = ctx->cc_sector;
1397        if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
1398                dmreq->iv_sector >>= cc->sector_shift;
1399        dmreq->ctx = ctx;
1400
1401        *org_tag_of_dmreq(cc, dmreq) = tag_offset;
1402
1403        iv = iv_of_dmreq(cc, dmreq);
1404        org_iv = org_iv_of_dmreq(cc, dmreq);
1405        tag_iv = iv_tag_from_dmreq(cc, dmreq);
1406
1407        sector = org_sector_of_dmreq(cc, dmreq);
1408        *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset);
1409
1410        /* For skcipher we use only the first sg item */
1411        sg_in  = &dmreq->sg_in[0];
1412        sg_out = &dmreq->sg_out[0];
1413
1414        sg_init_table(sg_in, 1);
1415        sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset);
1416
1417        sg_init_table(sg_out, 1);
1418        sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset);
1419
1420        if (cc->iv_gen_ops) {
1421                /* For READs use IV stored in integrity metadata */
1422                if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) {
1423                        memcpy(org_iv, tag_iv, cc->integrity_iv_size);
1424                } else {
1425                        r = cc->iv_gen_ops->generator(cc, org_iv, dmreq);
1426                        if (r < 0)
1427                                return r;
1428                        /* Data can be already preprocessed in generator */
1429                        if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
1430                                sg_in = sg_out;
1431                        /* Store generated IV in integrity metadata */
1432                        if (cc->integrity_iv_size)
1433                                memcpy(tag_iv, org_iv, cc->integrity_iv_size);
1434                }
1435                /* Working copy of IV, to be modified in crypto API */
1436                memcpy(iv, org_iv, cc->iv_size);
1437        }
1438
1439        skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv);
1440
1441        if (bio_data_dir(ctx->bio_in) == WRITE)
1442                r = crypto_skcipher_encrypt(req);
1443        else
1444                r = crypto_skcipher_decrypt(req);
1445
1446        if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
1447                r = cc->iv_gen_ops->post(cc, org_iv, dmreq);
1448
1449        bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size);
1450        bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size);
1451
1452        return r;
1453}
1454
1455static void kcryptd_async_done(struct crypto_async_request *async_req,
1456                               int error);
1457
1458static int crypt_alloc_req_skcipher(struct crypt_config *cc,
1459                                     struct convert_context *ctx)
1460{
1461        unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1);
1462
1463        if (!ctx->r.req) {
1464                ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1465                if (!ctx->r.req)
1466                        return -ENOMEM;
1467        }
1468
1469        skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]);
1470
1471        /*
1472         * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1473         * requests if driver request queue is full.
1474         */
1475        skcipher_request_set_callback(ctx->r.req,
1476            CRYPTO_TFM_REQ_MAY_BACKLOG,
1477            kcryptd_async_done, dmreq_of_req(cc, ctx->r.req));
1478
1479        return 0;
1480}
1481
1482static int crypt_alloc_req_aead(struct crypt_config *cc,
1483                                 struct convert_context *ctx)
1484{
1485        if (!ctx->r.req_aead) {
1486                ctx->r.req_aead = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
1487                if (!ctx->r.req_aead)
1488                        return -ENOMEM;
1489        }
1490
1491        aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]);
1492
1493        /*
1494         * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs
1495         * requests if driver request queue is full.
1496         */
1497        aead_request_set_callback(ctx->r.req_aead,
1498            CRYPTO_TFM_REQ_MAY_BACKLOG,
1499            kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead));
1500
1501        return 0;
1502}
1503
1504static int crypt_alloc_req(struct crypt_config *cc,
1505                            struct convert_context *ctx)
1506{
1507        if (crypt_integrity_aead(cc))
1508                return crypt_alloc_req_aead(cc, ctx);
1509        else
1510                return crypt_alloc_req_skcipher(cc, ctx);
1511}
1512
1513static void crypt_free_req_skcipher(struct crypt_config *cc,
1514                                    struct skcipher_request *req, struct bio *base_bio)
1515{
1516        struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1517
1518        if ((struct skcipher_request *)(io + 1) != req)
1519                mempool_free(req, &cc->req_pool);
1520}
1521
1522static void crypt_free_req_aead(struct crypt_config *cc,
1523                                struct aead_request *req, struct bio *base_bio)
1524{
1525        struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size);
1526
1527        if ((struct aead_request *)(io + 1) != req)
1528                mempool_free(req, &cc->req_pool);
1529}
1530
1531static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio)
1532{
1533        if (crypt_integrity_aead(cc))
1534                crypt_free_req_aead(cc, req, base_bio);
1535        else
1536                crypt_free_req_skcipher(cc, req, base_bio);
1537}
1538
1539/*
1540 * Encrypt / decrypt data from one bio to another one (can be the same one)
1541 */
1542static blk_status_t crypt_convert(struct crypt_config *cc,
1543                         struct convert_context *ctx, bool atomic, bool reset_pending)
1544{
1545        unsigned int tag_offset = 0;
1546        unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
1547        int r;
1548
1549        /*
1550         * if reset_pending is set we are dealing with the bio for the first time,
1551         * else we're continuing to work on the previous bio, so don't mess with
1552         * the cc_pending counter
1553         */
1554        if (reset_pending)
1555                atomic_set(&ctx->cc_pending, 1);
1556
1557        while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
1558
1559                r = crypt_alloc_req(cc, ctx);
1560                if (r) {
1561                        complete(&ctx->restart);
1562                        return BLK_STS_DEV_RESOURCE;
1563                }
1564
1565                atomic_inc(&ctx->cc_pending);
1566
1567                if (crypt_integrity_aead(cc))
1568                        r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset);
1569                else
1570                        r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset);
1571
1572                switch (r) {
1573                /*
1574                 * The request was queued by a crypto driver
1575                 * but the driver request queue is full, let's wait.
1576                 */
1577                case -EBUSY:
1578                        if (in_interrupt()) {
1579                                if (try_wait_for_completion(&ctx->restart)) {
1580                                        /*
1581                                         * we don't have to block to wait for completion,
1582                                         * so proceed
1583                                         */
1584                                } else {
1585                                        /*
1586                                         * we can't wait for completion without blocking
1587                                         * exit and continue processing in a workqueue
1588                                         */
1589                                        ctx->r.req = NULL;
1590                                        ctx->cc_sector += sector_step;
1591                                        tag_offset++;
1592                                        return BLK_STS_DEV_RESOURCE;
1593                                }
1594                        } else {
1595                                wait_for_completion(&ctx->restart);
1596                        }
1597                        reinit_completion(&ctx->restart);
1598                        fallthrough;
1599                /*
1600                 * The request is queued and processed asynchronously,
1601                 * completion function kcryptd_async_done() will be called.
1602                 */
1603                case -EINPROGRESS:
1604                        ctx->r.req = NULL;
1605                        ctx->cc_sector += sector_step;
1606                        tag_offset++;
1607                        continue;
1608                /*
1609                 * The request was already processed (synchronously).
1610                 */
1611                case 0:
1612                        atomic_dec(&ctx->cc_pending);
1613                        ctx->cc_sector += sector_step;
1614                        tag_offset++;
1615                        if (!atomic)
1616                                cond_resched();
1617                        continue;
1618                /*
1619                 * There was a data integrity error.
1620                 */
1621                case -EBADMSG:
1622                        atomic_dec(&ctx->cc_pending);
1623                        return BLK_STS_PROTECTION;
1624                /*
1625                 * There was an error while processing the request.
1626                 */
1627                default:
1628                        atomic_dec(&ctx->cc_pending);
1629                        return BLK_STS_IOERR;
1630                }
1631        }
1632
1633        return 0;
1634}
1635
1636static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone);
1637
1638/*
1639 * Generate a new unfragmented bio with the given size
1640 * This should never violate the device limitations (but only because
1641 * max_segment_size is being constrained to PAGE_SIZE).
1642 *
1643 * This function may be called concurrently. If we allocate from the mempool
1644 * concurrently, there is a possibility of deadlock. For example, if we have
1645 * mempool of 256 pages, two processes, each wanting 256, pages allocate from
1646 * the mempool concurrently, it may deadlock in a situation where both processes
1647 * have allocated 128 pages and the mempool is exhausted.
1648 *
1649 * In order to avoid this scenario we allocate the pages under a mutex.
1650 *
1651 * In order to not degrade performance with excessive locking, we try
1652 * non-blocking allocations without a mutex first but on failure we fallback
1653 * to blocking allocations with a mutex.
1654 */
1655static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
1656{
1657        struct crypt_config *cc = io->cc;
1658        struct bio *clone;
1659        unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
1660        gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
1661        unsigned i, len, remaining_size;
1662        struct page *page;
1663
1664retry:
1665        if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1666                mutex_lock(&cc->bio_alloc_lock);
1667
1668        clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs);
1669        if (!clone)
1670                goto out;
1671
1672        clone_init(io, clone);
1673
1674        remaining_size = size;
1675
1676        for (i = 0; i < nr_iovecs; i++) {
1677                page = mempool_alloc(&cc->page_pool, gfp_mask);
1678                if (!page) {
1679                        crypt_free_buffer_pages(cc, clone);
1680                        bio_put(clone);
1681                        gfp_mask |= __GFP_DIRECT_RECLAIM;
1682                        goto retry;
1683                }
1684
1685                len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
1686
1687                bio_add_page(clone, page, len, 0);
1688
1689                remaining_size -= len;
1690        }
1691
1692        /* Allocate space for integrity tags */
1693        if (dm_crypt_integrity_io_alloc(io, clone)) {
1694                crypt_free_buffer_pages(cc, clone);
1695                bio_put(clone);
1696                clone = NULL;
1697        }
1698out:
1699        if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
1700                mutex_unlock(&cc->bio_alloc_lock);
1701
1702        return clone;
1703}
1704
1705static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
1706{
1707        struct bio_vec *bv;
1708        struct bvec_iter_all iter_all;
1709
1710        bio_for_each_segment_all(bv, clone, iter_all) {
1711                BUG_ON(!bv->bv_page);
1712                mempool_free(bv->bv_page, &cc->page_pool);
1713        }
1714}
1715
1716static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
1717                          struct bio *bio, sector_t sector)
1718{
1719        io->cc = cc;
1720        io->base_bio = bio;
1721        io->sector = sector;
1722        io->error = 0;
1723        io->ctx.r.req = NULL;
1724        io->integrity_metadata = NULL;
1725        io->integrity_metadata_from_pool = false;
1726        atomic_set(&io->io_pending, 0);
1727}
1728
1729static void crypt_inc_pending(struct dm_crypt_io *io)
1730{
1731        atomic_inc(&io->io_pending);
1732}
1733
1734static void kcryptd_io_bio_endio(struct work_struct *work)
1735{
1736        struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1737        bio_endio(io->base_bio);
1738}
1739
1740/*
1741 * One of the bios was finished. Check for completion of
1742 * the whole request and correctly clean up the buffer.
1743 */
1744static void crypt_dec_pending(struct dm_crypt_io *io)
1745{
1746        struct crypt_config *cc = io->cc;
1747        struct bio *base_bio = io->base_bio;
1748        blk_status_t error = io->error;
1749
1750        if (!atomic_dec_and_test(&io->io_pending))
1751                return;
1752
1753        if (io->ctx.r.req)
1754                crypt_free_req(cc, io->ctx.r.req, base_bio);
1755
1756        if (unlikely(io->integrity_metadata_from_pool))
1757                mempool_free(io->integrity_metadata, &io->cc->tag_pool);
1758        else
1759                kfree(io->integrity_metadata);
1760
1761        base_bio->bi_status = error;
1762
1763        /*
1764         * If we are running this function from our tasklet,
1765         * we can't call bio_endio() here, because it will call
1766         * clone_endio() from dm.c, which in turn will
1767         * free the current struct dm_crypt_io structure with
1768         * our tasklet. In this case we need to delay bio_endio()
1769         * execution to after the tasklet is done and dequeued.
1770         */
1771        if (tasklet_trylock(&io->tasklet)) {
1772                tasklet_unlock(&io->tasklet);
1773                bio_endio(base_bio);
1774                return;
1775        }
1776
1777        INIT_WORK(&io->work, kcryptd_io_bio_endio);
1778        queue_work(cc->io_queue, &io->work);
1779}
1780
1781/*
1782 * kcryptd/kcryptd_io:
1783 *
1784 * Needed because it would be very unwise to do decryption in an
1785 * interrupt context.
1786 *
1787 * kcryptd performs the actual encryption or decryption.
1788 *
1789 * kcryptd_io performs the IO submission.
1790 *
1791 * They must be separated as otherwise the final stages could be
1792 * starved by new requests which can block in the first stages due
1793 * to memory allocation.
1794 *
1795 * The work is done per CPU global for all dm-crypt instances.
1796 * They should not depend on each other and do not block.
1797 */
1798static void crypt_endio(struct bio *clone)
1799{
1800        struct dm_crypt_io *io = clone->bi_private;
1801        struct crypt_config *cc = io->cc;
1802        unsigned rw = bio_data_dir(clone);
1803        blk_status_t error;
1804
1805        /*
1806         * free the processed pages
1807         */
1808        if (rw == WRITE)
1809                crypt_free_buffer_pages(cc, clone);
1810
1811        error = clone->bi_status;
1812        bio_put(clone);
1813
1814        if (rw == READ && !error) {
1815                kcryptd_queue_crypt(io);
1816                return;
1817        }
1818
1819        if (unlikely(error))
1820                io->error = error;
1821
1822        crypt_dec_pending(io);
1823}
1824
1825static void clone_init(struct dm_crypt_io *io, struct bio *clone)
1826{
1827        struct crypt_config *cc = io->cc;
1828
1829        clone->bi_private = io;
1830        clone->bi_end_io  = crypt_endio;
1831        bio_set_dev(clone, cc->dev->bdev);
1832        clone->bi_opf     = io->base_bio->bi_opf;
1833}
1834
1835static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
1836{
1837        struct crypt_config *cc = io->cc;
1838        struct bio *clone;
1839
1840        /*
1841         * We need the original biovec array in order to decrypt
1842         * the whole bio data *afterwards* -- thanks to immutable
1843         * biovecs we don't need to worry about the block layer
1844         * modifying the biovec array; so leverage bio_clone_fast().
1845         */
1846        clone = bio_clone_fast(io->base_bio, gfp, &cc->bs);
1847        if (!clone)
1848                return 1;
1849
1850        crypt_inc_pending(io);
1851
1852        clone_init(io, clone);
1853        clone->bi_iter.bi_sector = cc->start + io->sector;
1854
1855        if (dm_crypt_integrity_io_alloc(io, clone)) {
1856                crypt_dec_pending(io);
1857                bio_put(clone);
1858                return 1;
1859        }
1860
1861        submit_bio_noacct(clone);
1862        return 0;
1863}
1864
1865static void kcryptd_io_read_work(struct work_struct *work)
1866{
1867        struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1868
1869        crypt_inc_pending(io);
1870        if (kcryptd_io_read(io, GFP_NOIO))
1871                io->error = BLK_STS_RESOURCE;
1872        crypt_dec_pending(io);
1873}
1874
1875static void kcryptd_queue_read(struct dm_crypt_io *io)
1876{
1877        struct crypt_config *cc = io->cc;
1878
1879        INIT_WORK(&io->work, kcryptd_io_read_work);
1880        queue_work(cc->io_queue, &io->work);
1881}
1882
1883static void kcryptd_io_write(struct dm_crypt_io *io)
1884{
1885        struct bio *clone = io->ctx.bio_out;
1886
1887        submit_bio_noacct(clone);
1888}
1889
1890#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node)
1891
1892static int dmcrypt_write(void *data)
1893{
1894        struct crypt_config *cc = data;
1895        struct dm_crypt_io *io;
1896
1897        while (1) {
1898                struct rb_root write_tree;
1899                struct blk_plug plug;
1900
1901                spin_lock_irq(&cc->write_thread_lock);
1902continue_locked:
1903
1904                if (!RB_EMPTY_ROOT(&cc->write_tree))
1905                        goto pop_from_list;
1906
1907                set_current_state(TASK_INTERRUPTIBLE);
1908
1909                spin_unlock_irq(&cc->write_thread_lock);
1910
1911                if (unlikely(kthread_should_stop())) {
1912                        set_current_state(TASK_RUNNING);
1913                        break;
1914                }
1915
1916                schedule();
1917
1918                set_current_state(TASK_RUNNING);
1919                spin_lock_irq(&cc->write_thread_lock);
1920                goto continue_locked;
1921
1922pop_from_list:
1923                write_tree = cc->write_tree;
1924                cc->write_tree = RB_ROOT;
1925                spin_unlock_irq(&cc->write_thread_lock);
1926
1927                BUG_ON(rb_parent(write_tree.rb_node));
1928
1929                /*
1930                 * Note: we cannot walk the tree here with rb_next because
1931                 * the structures may be freed when kcryptd_io_write is called.
1932                 */
1933                blk_start_plug(&plug);
1934                do {
1935                        io = crypt_io_from_node(rb_first(&write_tree));
1936                        rb_erase(&io->rb_node, &write_tree);
1937                        kcryptd_io_write(io);
1938                } while (!RB_EMPTY_ROOT(&write_tree));
1939                blk_finish_plug(&plug);
1940        }
1941        return 0;
1942}
1943
1944static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
1945{
1946        struct bio *clone = io->ctx.bio_out;
1947        struct crypt_config *cc = io->cc;
1948        unsigned long flags;
1949        sector_t sector;
1950        struct rb_node **rbp, *parent;
1951
1952        if (unlikely(io->error)) {
1953                crypt_free_buffer_pages(cc, clone);
1954                bio_put(clone);
1955                crypt_dec_pending(io);
1956                return;
1957        }
1958
1959        /* crypt_convert should have filled the clone bio */
1960        BUG_ON(io->ctx.iter_out.bi_size);
1961
1962        clone->bi_iter.bi_sector = cc->start + io->sector;
1963
1964        if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
1965            test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
1966                submit_bio_noacct(clone);
1967                return;
1968        }
1969
1970        spin_lock_irqsave(&cc->write_thread_lock, flags);
1971        if (RB_EMPTY_ROOT(&cc->write_tree))
1972                wake_up_process(cc->write_thread);
1973        rbp = &cc->write_tree.rb_node;
1974        parent = NULL;
1975        sector = io->sector;
1976        while (*rbp) {
1977                parent = *rbp;
1978                if (sector < crypt_io_from_node(parent)->sector)
1979                        rbp = &(*rbp)->rb_left;
1980                else
1981                        rbp = &(*rbp)->rb_right;
1982        }
1983        rb_link_node(&io->rb_node, parent, rbp);
1984        rb_insert_color(&io->rb_node, &cc->write_tree);
1985        spin_unlock_irqrestore(&cc->write_thread_lock, flags);
1986}
1987
1988static bool kcryptd_crypt_write_inline(struct crypt_config *cc,
1989                                       struct convert_context *ctx)
1990
1991{
1992        if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
1993                return false;
1994
1995        /*
1996         * Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
1997         * constraints so they do not need to be issued inline by
1998         * kcryptd_crypt_write_convert().
1999         */
2000        switch (bio_op(ctx->bio_in)) {
2001        case REQ_OP_WRITE:
2002        case REQ_OP_WRITE_SAME:
2003        case REQ_OP_WRITE_ZEROES:
2004                return true;
2005        default:
2006                return false;
2007        }
2008}
2009
2010static void kcryptd_crypt_write_continue(struct work_struct *work)
2011{
2012        struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2013        struct crypt_config *cc = io->cc;
2014        struct convert_context *ctx = &io->ctx;
2015        int crypt_finished;
2016        sector_t sector = io->sector;
2017        blk_status_t r;
2018
2019        wait_for_completion(&ctx->restart);
2020        reinit_completion(&ctx->restart);
2021
2022        r = crypt_convert(cc, &io->ctx, true, false);
2023        if (r)
2024                io->error = r;
2025        crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2026        if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2027                /* Wait for completion signaled by kcryptd_async_done() */
2028                wait_for_completion(&ctx->restart);
2029                crypt_finished = 1;
2030        }
2031
2032        /* Encryption was already finished, submit io now */
2033        if (crypt_finished) {
2034                kcryptd_crypt_write_io_submit(io, 0);
2035                io->sector = sector;
2036        }
2037
2038        crypt_dec_pending(io);
2039}
2040
2041static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
2042{
2043        struct crypt_config *cc = io->cc;
2044        struct convert_context *ctx = &io->ctx;
2045        struct bio *clone;
2046        int crypt_finished;
2047        sector_t sector = io->sector;
2048        blk_status_t r;
2049
2050        /*
2051         * Prevent io from disappearing until this function completes.
2052         */
2053        crypt_inc_pending(io);
2054        crypt_convert_init(cc, ctx, NULL, io->base_bio, sector);
2055
2056        clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
2057        if (unlikely(!clone)) {
2058                io->error = BLK_STS_IOERR;
2059                goto dec;
2060        }
2061
2062        io->ctx.bio_out = clone;
2063        io->ctx.iter_out = clone->bi_iter;
2064
2065        sector += bio_sectors(clone);
2066
2067        crypt_inc_pending(io);
2068        r = crypt_convert(cc, ctx,
2069                          test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags), true);
2070        /*
2071         * Crypto API backlogged the request, because its queue was full
2072         * and we're in softirq context, so continue from a workqueue
2073         * (TODO: is it actually possible to be in softirq in the write path?)
2074         */
2075        if (r == BLK_STS_DEV_RESOURCE) {
2076                INIT_WORK(&io->work, kcryptd_crypt_write_continue);
2077                queue_work(cc->crypt_queue, &io->work);
2078                return;
2079        }
2080        if (r)
2081                io->error = r;
2082        crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
2083        if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
2084                /* Wait for completion signaled by kcryptd_async_done() */
2085                wait_for_completion(&ctx->restart);
2086                crypt_finished = 1;
2087        }
2088
2089        /* Encryption was already finished, submit io now */
2090        if (crypt_finished) {
2091                kcryptd_crypt_write_io_submit(io, 0);
2092                io->sector = sector;
2093        }
2094
2095dec:
2096        crypt_dec_pending(io);
2097}
2098
2099static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
2100{
2101        crypt_dec_pending(io);
2102}
2103
2104static void kcryptd_crypt_read_continue(struct work_struct *work)
2105{
2106        struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2107        struct crypt_config *cc = io->cc;
2108        blk_status_t r;
2109
2110        wait_for_completion(&io->ctx.restart);
2111        reinit_completion(&io->ctx.restart);
2112
2113        r = crypt_convert(cc, &io->ctx, true, false);
2114        if (r)
2115                io->error = r;
2116
2117        if (atomic_dec_and_test(&io->ctx.cc_pending))
2118                kcryptd_crypt_read_done(io);
2119
2120        crypt_dec_pending(io);
2121}
2122
2123static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
2124{
2125        struct crypt_config *cc = io->cc;
2126        blk_status_t r;
2127
2128        crypt_inc_pending(io);
2129
2130        crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
2131                           io->sector);
2132
2133        r = crypt_convert(cc, &io->ctx,
2134                          test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags), true);
2135        /*
2136         * Crypto API backlogged the request, because its queue was full
2137         * and we're in softirq context, so continue from a workqueue
2138         */
2139        if (r == BLK_STS_DEV_RESOURCE) {
2140                INIT_WORK(&io->work, kcryptd_crypt_read_continue);
2141                queue_work(cc->crypt_queue, &io->work);
2142                return;
2143        }
2144        if (r)
2145                io->error = r;
2146
2147        if (atomic_dec_and_test(&io->ctx.cc_pending))
2148                kcryptd_crypt_read_done(io);
2149
2150        crypt_dec_pending(io);
2151}
2152
2153static void kcryptd_async_done(struct crypto_async_request *async_req,
2154                               int error)
2155{
2156        struct dm_crypt_request *dmreq = async_req->data;
2157        struct convert_context *ctx = dmreq->ctx;
2158        struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
2159        struct crypt_config *cc = io->cc;
2160
2161        /*
2162         * A request from crypto driver backlog is going to be processed now,
2163         * finish the completion and continue in crypt_convert().
2164         * (Callback will be called for the second time for this request.)
2165         */
2166        if (error == -EINPROGRESS) {
2167                complete(&ctx->restart);
2168                return;
2169        }
2170
2171        if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
2172                error = cc->iv_gen_ops->post(cc, org_iv_of_dmreq(cc, dmreq), dmreq);
2173
2174        if (error == -EBADMSG) {
2175                char b[BDEVNAME_SIZE];
2176                DMERR_LIMIT("%s: INTEGRITY AEAD ERROR, sector %llu", bio_devname(ctx->bio_in, b),
2177                            (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq)));
2178                io->error = BLK_STS_PROTECTION;
2179        } else if (error < 0)
2180                io->error = BLK_STS_IOERR;
2181
2182        crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio);
2183
2184        if (!atomic_dec_and_test(&ctx->cc_pending))
2185                return;
2186
2187        /*
2188         * The request is fully completed: for inline writes, let
2189         * kcryptd_crypt_write_convert() do the IO submission.
2190         */
2191        if (bio_data_dir(io->base_bio) == READ) {
2192                kcryptd_crypt_read_done(io);
2193                return;
2194        }
2195
2196        if (kcryptd_crypt_write_inline(cc, ctx)) {
2197                complete(&ctx->restart);
2198                return;
2199        }
2200
2201        kcryptd_crypt_write_io_submit(io, 1);
2202}
2203
2204static void kcryptd_crypt(struct work_struct *work)
2205{
2206        struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
2207
2208        if (bio_data_dir(io->base_bio) == READ)
2209                kcryptd_crypt_read_convert(io);
2210        else
2211                kcryptd_crypt_write_convert(io);
2212}
2213
2214static void kcryptd_crypt_tasklet(unsigned long work)
2215{
2216        kcryptd_crypt((struct work_struct *)work);
2217}
2218
2219static void kcryptd_queue_crypt(struct dm_crypt_io *io)
2220{
2221        struct crypt_config *cc = io->cc;
2222
2223        if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)) ||
2224            (bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
2225                /*
2226                 * in_irq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
2227                 * irqs_disabled(): the kernel may run some IO completion from the idle thread, but
2228                 * it is being executed with irqs disabled.
2229                 */
2230                if (in_irq() || irqs_disabled()) {
2231                        tasklet_init(&io->tasklet, kcryptd_crypt_tasklet, (unsigned long)&io->work);
2232                        tasklet_schedule(&io->tasklet);
2233                        return;
2234                }
2235
2236                kcryptd_crypt(&io->work);
2237                return;
2238        }
2239
2240        INIT_WORK(&io->work, kcryptd_crypt);
2241        queue_work(cc->crypt_queue, &io->work);
2242}
2243
2244static void crypt_free_tfms_aead(struct crypt_config *cc)
2245{
2246        if (!cc->cipher_tfm.tfms_aead)
2247                return;
2248
2249        if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2250                crypto_free_aead(cc->cipher_tfm.tfms_aead[0]);
2251                cc->cipher_tfm.tfms_aead[0] = NULL;
2252        }
2253
2254        kfree(cc->cipher_tfm.tfms_aead);
2255        cc->cipher_tfm.tfms_aead = NULL;
2256}
2257
2258static void crypt_free_tfms_skcipher(struct crypt_config *cc)
2259{
2260        unsigned i;
2261
2262        if (!cc->cipher_tfm.tfms)
2263                return;
2264
2265        for (i = 0; i < cc->tfms_count; i++)
2266                if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) {
2267                        crypto_free_skcipher(cc->cipher_tfm.tfms[i]);
2268                        cc->cipher_tfm.tfms[i] = NULL;
2269                }
2270
2271        kfree(cc->cipher_tfm.tfms);
2272        cc->cipher_tfm.tfms = NULL;
2273}
2274
2275static void crypt_free_tfms(struct crypt_config *cc)
2276{
2277        if (crypt_integrity_aead(cc))
2278                crypt_free_tfms_aead(cc);
2279        else
2280                crypt_free_tfms_skcipher(cc);
2281}
2282
2283static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode)
2284{
2285        unsigned i;
2286        int err;
2287
2288        cc->cipher_tfm.tfms = kcalloc(cc->tfms_count,
2289                                      sizeof(struct crypto_skcipher *),
2290                                      GFP_KERNEL);
2291        if (!cc->cipher_tfm.tfms)
2292                return -ENOMEM;
2293
2294        for (i = 0; i < cc->tfms_count; i++) {
2295                cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0,
2296                                                CRYPTO_ALG_ALLOCATES_MEMORY);
2297                if (IS_ERR(cc->cipher_tfm.tfms[i])) {
2298                        err = PTR_ERR(cc->cipher_tfm.tfms[i]);
2299                        crypt_free_tfms(cc);
2300                        return err;
2301                }
2302        }
2303
2304        /*
2305         * dm-crypt performance can vary greatly depending on which crypto
2306         * algorithm implementation is used.  Help people debug performance
2307         * problems by logging the ->cra_driver_name.
2308         */
2309        DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2310               crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
2311        return 0;
2312}
2313
2314static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode)
2315{
2316        int err;
2317
2318        cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL);
2319        if (!cc->cipher_tfm.tfms)
2320                return -ENOMEM;
2321
2322        cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0,
2323                                                CRYPTO_ALG_ALLOCATES_MEMORY);
2324        if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
2325                err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
2326                crypt_free_tfms(cc);
2327                return err;
2328        }
2329
2330        DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
2331               crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
2332        return 0;
2333}
2334
2335static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
2336{
2337        if (crypt_integrity_aead(cc))
2338                return crypt_alloc_tfms_aead(cc, ciphermode);
2339        else
2340                return crypt_alloc_tfms_skcipher(cc, ciphermode);
2341}
2342
2343static unsigned crypt_subkey_size(struct crypt_config *cc)
2344{
2345        return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
2346}
2347
2348static unsigned crypt_authenckey_size(struct crypt_config *cc)
2349{
2350        return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param));
2351}
2352
2353/*
2354 * If AEAD is composed like authenc(hmac(sha256),xts(aes)),
2355 * the key must be for some reason in special format.
2356 * This funcion converts cc->key to this special format.
2357 */
2358static void crypt_copy_authenckey(char *p, const void *key,
2359                                  unsigned enckeylen, unsigned authkeylen)
2360{
2361        struct crypto_authenc_key_param *param;
2362        struct rtattr *rta;
2363
2364        rta = (struct rtattr *)p;
2365        param = RTA_DATA(rta);
2366        param->enckeylen = cpu_to_be32(enckeylen);
2367        rta->rta_len = RTA_LENGTH(sizeof(*param));
2368        rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM;
2369        p += RTA_SPACE(sizeof(*param));
2370        memcpy(p, key + enckeylen, authkeylen);
2371        p += authkeylen;
2372        memcpy(p, key, enckeylen);
2373}
2374
2375static int crypt_setkey(struct crypt_config *cc)
2376{
2377        unsigned subkey_size;
2378        int err = 0, i, r;
2379
2380        /* Ignore extra keys (which are used for IV etc) */
2381        subkey_size = crypt_subkey_size(cc);
2382
2383        if (crypt_integrity_hmac(cc)) {
2384                if (subkey_size < cc->key_mac_size)
2385                        return -EINVAL;
2386
2387                crypt_copy_authenckey(cc->authenc_key, cc->key,
2388                                      subkey_size - cc->key_mac_size,
2389                                      cc->key_mac_size);
2390        }
2391
2392        for (i = 0; i < cc->tfms_count; i++) {
2393                if (crypt_integrity_hmac(cc))
2394                        r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2395                                cc->authenc_key, crypt_authenckey_size(cc));
2396                else if (crypt_integrity_aead(cc))
2397                        r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i],
2398                                               cc->key + (i * subkey_size),
2399                                               subkey_size);
2400                else
2401                        r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i],
2402                                                   cc->key + (i * subkey_size),
2403                                                   subkey_size);
2404                if (r)
2405                        err = r;
2406        }
2407
2408        if (crypt_integrity_hmac(cc))
2409                memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc));
2410
2411        return err;
2412}
2413
2414#ifdef CONFIG_KEYS
2415
2416static bool contains_whitespace(const char *str)
2417{
2418        while (*str)
2419                if (isspace(*str++))
2420                        return true;
2421        return false;
2422}
2423
2424static int set_key_user(struct crypt_config *cc, struct key *key)
2425{
2426        const struct user_key_payload *ukp;
2427
2428        ukp = user_key_payload_locked(key);
2429        if (!ukp)
2430                return -EKEYREVOKED;
2431
2432        if (cc->key_size != ukp->datalen)
2433                return -EINVAL;
2434
2435        memcpy(cc->key, ukp->data, cc->key_size);
2436
2437        return 0;
2438}
2439
2440static int set_key_encrypted(struct crypt_config *cc, struct key *key)
2441{
2442        const struct encrypted_key_payload *ekp;
2443
2444        ekp = key->payload.data[0];
2445        if (!ekp)
2446                return -EKEYREVOKED;
2447
2448        if (cc->key_size != ekp->decrypted_datalen)
2449                return -EINVAL;
2450
2451        memcpy(cc->key, ekp->decrypted_data, cc->key_size);
2452
2453        return 0;
2454}
2455
2456static int set_key_trusted(struct crypt_config *cc, struct key *key)
2457{
2458        const struct trusted_key_payload *tkp;
2459
2460        tkp = key->payload.data[0];
2461        if (!tkp)
2462                return -EKEYREVOKED;
2463
2464        if (cc->key_size != tkp->key_len)
2465                return -EINVAL;
2466
2467        memcpy(cc->key, tkp->key, cc->key_size);
2468
2469        return 0;
2470}
2471
2472static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2473{
2474        char *new_key_string, *key_desc;
2475        int ret;
2476        struct key_type *type;
2477        struct key *key;
2478        int (*set_key)(struct crypt_config *cc, struct key *key);
2479
2480        /*
2481         * Reject key_string with whitespace. dm core currently lacks code for
2482         * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
2483         */
2484        if (contains_whitespace(key_string)) {
2485                DMERR("whitespace chars not allowed in key string");
2486                return -EINVAL;
2487        }
2488
2489        /* look for next ':' separating key_type from key_description */
2490        key_desc = strpbrk(key_string, ":");
2491        if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
2492                return -EINVAL;
2493
2494        if (!strncmp(key_string, "logon:", key_desc - key_string + 1)) {
2495                type = &key_type_logon;
2496                set_key = set_key_user;
2497        } else if (!strncmp(key_string, "user:", key_desc - key_string + 1)) {
2498                type = &key_type_user;
2499                set_key = set_key_user;
2500        } else if (IS_ENABLED(CONFIG_ENCRYPTED_KEYS) &&
2501                   !strncmp(key_string, "encrypted:", key_desc - key_string + 1)) {
2502                type = &key_type_encrypted;
2503                set_key = set_key_encrypted;
2504        } else if (IS_ENABLED(CONFIG_TRUSTED_KEYS) &&
2505                   !strncmp(key_string, "trusted:", key_desc - key_string + 1)) {
2506                type = &key_type_trusted;
2507                set_key = set_key_trusted;
2508        } else {
2509                return -EINVAL;
2510        }
2511
2512        new_key_string = kstrdup(key_string, GFP_KERNEL);
2513        if (!new_key_string)
2514                return -ENOMEM;
2515
2516        key = request_key(type, key_desc + 1, NULL);
2517        if (IS_ERR(key)) {
2518                kfree_sensitive(new_key_string);
2519                return PTR_ERR(key);
2520        }
2521
2522        down_read(&key->sem);
2523
2524        ret = set_key(cc, key);
2525        if (ret < 0) {
2526                up_read(&key->sem);
2527                key_put(key);
2528                kfree_sensitive(new_key_string);
2529                return ret;
2530        }
2531
2532        up_read(&key->sem);
2533        key_put(key);
2534
2535        /* clear the flag since following operations may invalidate previously valid key */
2536        clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2537
2538        ret = crypt_setkey(cc);
2539
2540        if (!ret) {
2541                set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2542                kfree_sensitive(cc->key_string);
2543                cc->key_string = new_key_string;
2544        } else
2545                kfree_sensitive(new_key_string);
2546
2547        return ret;
2548}
2549
2550static int get_key_size(char **key_string)
2551{
2552        char *colon, dummy;
2553        int ret;
2554
2555        if (*key_string[0] != ':')
2556                return strlen(*key_string) >> 1;
2557
2558        /* look for next ':' in key string */
2559        colon = strpbrk(*key_string + 1, ":");
2560        if (!colon)
2561                return -EINVAL;
2562
2563        if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
2564                return -EINVAL;
2565
2566        *key_string = colon;
2567
2568        /* remaining key string should be :<logon|user>:<key_desc> */
2569
2570        return ret;
2571}
2572
2573#else
2574
2575static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
2576{
2577        return -EINVAL;
2578}
2579
2580static int get_key_size(char **key_string)
2581{
2582        return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
2583}
2584
2585#endif /* CONFIG_KEYS */
2586
2587static int crypt_set_key(struct crypt_config *cc, char *key)
2588{
2589        int r = -EINVAL;
2590        int key_string_len = strlen(key);
2591
2592        /* Hyphen (which gives a key_size of zero) means there is no key. */
2593        if (!cc->key_size && strcmp(key, "-"))
2594                goto out;
2595
2596        /* ':' means the key is in kernel keyring, short-circuit normal key processing */
2597        if (key[0] == ':') {
2598                r = crypt_set_keyring_key(cc, key + 1);
2599                goto out;
2600        }
2601
2602        /* clear the flag since following operations may invalidate previously valid key */
2603        clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2604
2605        /* wipe references to any kernel keyring key */
2606        kfree_sensitive(cc->key_string);
2607        cc->key_string = NULL;
2608
2609        /* Decode key from its hex representation. */
2610        if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0)
2611                goto out;
2612
2613        r = crypt_setkey(cc);
2614        if (!r)
2615                set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2616
2617out:
2618        /* Hex key string not needed after here, so wipe it. */
2619        memset(key, '0', key_string_len);
2620
2621        return r;
2622}
2623
2624static int crypt_wipe_key(struct crypt_config *cc)
2625{
2626        int r;
2627
2628        clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
2629        get_random_bytes(&cc->key, cc->key_size);
2630
2631        /* Wipe IV private keys */
2632        if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
2633                r = cc->iv_gen_ops->wipe(cc);
2634                if (r)
2635                        return r;
2636        }
2637
2638        kfree_sensitive(cc->key_string);
2639        cc->key_string = NULL;
2640        r = crypt_setkey(cc);
2641        memset(&cc->key, 0, cc->key_size * sizeof(u8));
2642
2643        return r;
2644}
2645
2646static void crypt_calculate_pages_per_client(void)
2647{
2648        unsigned long pages = (totalram_pages() - totalhigh_pages()) * DM_CRYPT_MEMORY_PERCENT / 100;
2649
2650        if (!dm_crypt_clients_n)
2651                return;
2652
2653        pages /= dm_crypt_clients_n;
2654        if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT)
2655                pages = DM_CRYPT_MIN_PAGES_PER_CLIENT;
2656        dm_crypt_pages_per_client = pages;
2657}
2658
2659static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data)
2660{
2661        struct crypt_config *cc = pool_data;
2662        struct page *page;
2663
2664        if (unlikely(percpu_counter_compare(&cc->n_allocated_pages, dm_crypt_pages_per_client) >= 0) &&
2665            likely(gfp_mask & __GFP_NORETRY))
2666                return NULL;
2667
2668        page = alloc_page(gfp_mask);
2669        if (likely(page != NULL))
2670                percpu_counter_add(&cc->n_allocated_pages, 1);
2671
2672        return page;
2673}
2674
2675static void crypt_page_free(void *page, void *pool_data)
2676{
2677        struct crypt_config *cc = pool_data;
2678
2679        __free_page(page);
2680        percpu_counter_sub(&cc->n_allocated_pages, 1);
2681}
2682
2683static void crypt_dtr(struct dm_target *ti)
2684{
2685        struct crypt_config *cc = ti->private;
2686
2687        ti->private = NULL;
2688
2689        if (!cc)
2690                return;
2691
2692        if (cc->write_thread)
2693                kthread_stop(cc->write_thread);
2694
2695        if (cc->io_queue)
2696                destroy_workqueue(cc->io_queue);
2697        if (cc->crypt_queue)
2698                destroy_workqueue(cc->crypt_queue);
2699
2700        crypt_free_tfms(cc);
2701
2702        bioset_exit(&cc->bs);
2703
2704        mempool_exit(&cc->page_pool);
2705        mempool_exit(&cc->req_pool);
2706        mempool_exit(&cc->tag_pool);
2707
2708        WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0);
2709        percpu_counter_destroy(&cc->n_allocated_pages);
2710
2711        if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
2712                cc->iv_gen_ops->dtr(cc);
2713
2714        if (cc->dev)
2715                dm_put_device(ti, cc->dev);
2716
2717        kfree_sensitive(cc->cipher_string);
2718        kfree_sensitive(cc->key_string);
2719        kfree_sensitive(cc->cipher_auth);
2720        kfree_sensitive(cc->authenc_key);
2721
2722        mutex_destroy(&cc->bio_alloc_lock);
2723
2724        /* Must zero key material before freeing */
2725        kfree_sensitive(cc);
2726
2727        spin_lock(&dm_crypt_clients_lock);
2728        WARN_ON(!dm_crypt_clients_n);
2729        dm_crypt_clients_n--;
2730        crypt_calculate_pages_per_client();
2731        spin_unlock(&dm_crypt_clients_lock);
2732}
2733
2734static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode)
2735{
2736        struct crypt_config *cc = ti->private;
2737
2738        if (crypt_integrity_aead(cc))
2739                cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2740        else
2741                cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2742
2743        if (cc->iv_size)
2744                /* at least a 64 bit sector number should fit in our buffer */
2745                cc->iv_size = max(cc->iv_size,
2746                                  (unsigned int)(sizeof(u64) / sizeof(u8)));
2747        else if (ivmode) {
2748                DMWARN("Selected cipher does not support IVs");
2749                ivmode = NULL;
2750        }
2751
2752        /* Choose ivmode, see comments at iv code. */
2753        if (ivmode == NULL)
2754                cc->iv_gen_ops = NULL;
2755        else if (strcmp(ivmode, "plain") == 0)
2756                cc->iv_gen_ops = &crypt_iv_plain_ops;
2757        else if (strcmp(ivmode, "plain64") == 0)
2758                cc->iv_gen_ops = &crypt_iv_plain64_ops;
2759        else if (strcmp(ivmode, "plain64be") == 0)
2760                cc->iv_gen_ops = &crypt_iv_plain64be_ops;
2761        else if (strcmp(ivmode, "essiv") == 0)
2762                cc->iv_gen_ops = &crypt_iv_essiv_ops;
2763        else if (strcmp(ivmode, "benbi") == 0)
2764                cc->iv_gen_ops = &crypt_iv_benbi_ops;
2765        else if (strcmp(ivmode, "null") == 0)
2766                cc->iv_gen_ops = &crypt_iv_null_ops;
2767        else if (strcmp(ivmode, "eboiv") == 0)
2768                cc->iv_gen_ops = &crypt_iv_eboiv_ops;
2769        else if (strcmp(ivmode, "elephant") == 0) {
2770                cc->iv_gen_ops = &crypt_iv_elephant_ops;
2771                cc->key_parts = 2;
2772                cc->key_extra_size = cc->key_size / 2;
2773                if (cc->key_extra_size > ELEPHANT_MAX_KEY_SIZE)
2774                        return -EINVAL;
2775                set_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags);
2776        } else if (strcmp(ivmode, "lmk") == 0) {
2777                cc->iv_gen_ops = &crypt_iv_lmk_ops;
2778                /*
2779                 * Version 2 and 3 is recognised according
2780                 * to length of provided multi-key string.
2781                 * If present (version 3), last key is used as IV seed.
2782                 * All keys (including IV seed) are always the same size.
2783                 */
2784                if (cc->key_size % cc->key_parts) {
2785                        cc->key_parts++;
2786                        cc->key_extra_size = cc->key_size / cc->key_parts;
2787                }
2788        } else if (strcmp(ivmode, "tcw") == 0) {
2789                cc->iv_gen_ops = &crypt_iv_tcw_ops;
2790                cc->key_parts += 2; /* IV + whitening */
2791                cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE;
2792        } else if (strcmp(ivmode, "random") == 0) {
2793                cc->iv_gen_ops = &crypt_iv_random_ops;
2794                /* Need storage space in integrity fields. */
2795                cc->integrity_iv_size = cc->iv_size;
2796        } else {
2797                ti->error = "Invalid IV mode";
2798                return -EINVAL;
2799        }
2800
2801        return 0;
2802}
2803
2804/*
2805 * Workaround to parse HMAC algorithm from AEAD crypto API spec.
2806 * The HMAC is needed to calculate tag size (HMAC digest size).
2807 * This should be probably done by crypto-api calls (once available...)
2808 */
2809static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api)
2810{
2811        char *start, *end, *mac_alg = NULL;
2812        struct crypto_ahash *mac;
2813
2814        if (!strstarts(cipher_api, "authenc("))
2815                return 0;
2816
2817        start = strchr(cipher_api, '(');
2818        end = strchr(cipher_api, ',');
2819        if (!start || !end || ++start > end)
2820                return -EINVAL;
2821
2822        mac_alg = kzalloc(end - start + 1, GFP_KERNEL);
2823        if (!mac_alg)
2824                return -ENOMEM;
2825        strncpy(mac_alg, start, end - start);
2826
2827        mac = crypto_alloc_ahash(mac_alg, 0, CRYPTO_ALG_ALLOCATES_MEMORY);
2828        kfree(mac_alg);
2829
2830        if (IS_ERR(mac))
2831                return PTR_ERR(mac);
2832
2833        cc->key_mac_size = crypto_ahash_digestsize(mac);
2834        crypto_free_ahash(mac);
2835
2836        cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL);
2837        if (!cc->authenc_key)
2838                return -ENOMEM;
2839
2840        return 0;
2841}
2842
2843static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key,
2844                                char **ivmode, char **ivopts)
2845{
2846        struct crypt_config *cc = ti->private;
2847        char *tmp, *cipher_api, buf[CRYPTO_MAX_ALG_NAME];
2848        int ret = -EINVAL;
2849
2850        cc->tfms_count = 1;
2851
2852        /*
2853         * New format (capi: prefix)
2854         * capi:cipher_api_spec-iv:ivopts
2855         */
2856        tmp = &cipher_in[strlen("capi:")];
2857
2858        /* Separate IV options if present, it can contain another '-' in hash name */
2859        *ivopts = strrchr(tmp, ':');
2860        if (*ivopts) {
2861                **ivopts = '\0';
2862                (*ivopts)++;
2863        }
2864        /* Parse IV mode */
2865        *ivmode = strrchr(tmp, '-');
2866        if (*ivmode) {
2867                **ivmode = '\0';
2868                (*ivmode)++;
2869        }
2870        /* The rest is crypto API spec */
2871        cipher_api = tmp;
2872
2873        /* Alloc AEAD, can be used only in new format. */
2874        if (crypt_integrity_aead(cc)) {
2875                ret = crypt_ctr_auth_cipher(cc, cipher_api);
2876                if (ret < 0) {
2877                        ti->error = "Invalid AEAD cipher spec";
2878                        return -ENOMEM;
2879                }
2880        }
2881
2882        if (*ivmode && !strcmp(*ivmode, "lmk"))
2883                cc->tfms_count = 64;
2884
2885        if (*ivmode && !strcmp(*ivmode, "essiv")) {
2886                if (!*ivopts) {
2887                        ti->error = "Digest algorithm missing for ESSIV mode";
2888                        return -EINVAL;
2889                }
2890                ret = snprintf(buf, CRYPTO_MAX_ALG_NAME, "essiv(%s,%s)",
2891                               cipher_api, *ivopts);
2892                if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
2893                        ti->error = "Cannot allocate cipher string";
2894                        return -ENOMEM;
2895                }
2896                cipher_api = buf;
2897        }
2898
2899        cc->key_parts = cc->tfms_count;
2900
2901        /* Allocate cipher */
2902        ret = crypt_alloc_tfms(cc, cipher_api);
2903        if (ret < 0) {
2904                ti->error = "Error allocating crypto tfm";
2905                return ret;
2906        }
2907
2908        if (crypt_integrity_aead(cc))
2909                cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc));
2910        else
2911                cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc));
2912
2913        return 0;
2914}
2915
2916static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key,
2917                                char **ivmode, char **ivopts)
2918{
2919        struct crypt_config *cc = ti->private;
2920        char *tmp, *cipher, *chainmode, *keycount;
2921        char *cipher_api = NULL;
2922        int ret = -EINVAL;
2923        char dummy;
2924
2925        if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) {
2926                ti->error = "Bad cipher specification";
2927                return -EINVAL;
2928        }
2929
2930        /*
2931         * Legacy dm-crypt cipher specification
2932         * cipher[:keycount]-mode-iv:ivopts
2933         */
2934        tmp = cipher_in;
2935        keycount = strsep(&tmp, "-");
2936        cipher = strsep(&keycount, ":");
2937
2938        if (!keycount)
2939                cc->tfms_count = 1;
2940        else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 ||
2941                 !is_power_of_2(cc->tfms_count)) {
2942                ti->error = "Bad cipher key count specification";
2943                return -EINVAL;
2944        }
2945        cc->key_parts = cc->tfms_count;
2946
2947        chainmode = strsep(&tmp, "-");
2948        *ivmode = strsep(&tmp, ":");
2949        *ivopts = tmp;
2950
2951        /*
2952         * For compatibility with the original dm-crypt mapping format, if
2953         * only the cipher name is supplied, use cbc-plain.
2954         */
2955        if (!chainmode || (!strcmp(chainmode, "plain") && !*ivmode)) {
2956                chainmode = "cbc";
2957                *ivmode = "plain";
2958        }
2959
2960        if (strcmp(chainmode, "ecb") && !*ivmode) {
2961                ti->error = "IV mechanism required";
2962                return -EINVAL;
2963        }
2964
2965        cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
2966        if (!cipher_api)
2967                goto bad_mem;
2968
2969        if (*ivmode && !strcmp(*ivmode, "essiv")) {
2970                if (!*ivopts) {
2971                        ti->error = "Digest algorithm missing for ESSIV mode";
2972                        kfree(cipher_api);
2973                        return -EINVAL;
2974                }
2975                ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2976                               "essiv(%s(%s),%s)", chainmode, cipher, *ivopts);
2977        } else {
2978                ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
2979                               "%s(%s)", chainmode, cipher);
2980        }
2981        if (ret < 0 || ret >= CRYPTO_MAX_ALG_NAME) {
2982                kfree(cipher_api);
2983                goto bad_mem;
2984        }
2985
2986        /* Allocate cipher */
2987        ret = crypt_alloc_tfms(cc, cipher_api);
2988        if (ret < 0) {
2989                ti->error = "Error allocating crypto tfm";
2990                kfree(cipher_api);
2991                return ret;
2992        }
2993        kfree(cipher_api);
2994
2995        return 0;
2996bad_mem:
2997        ti->error = "Cannot allocate cipher strings";
2998        return -ENOMEM;
2999}
3000
3001static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key)
3002{
3003        struct crypt_config *cc = ti->private;
3004        char *ivmode = NULL, *ivopts = NULL;
3005        int ret;
3006
3007        cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
3008        if (!cc->cipher_string) {
3009                ti->error = "Cannot allocate cipher strings";
3010                return -ENOMEM;
3011        }
3012
3013        if (strstarts(cipher_in, "capi:"))
3014                ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts);
3015        else
3016                ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts);
3017        if (ret)
3018                return ret;
3019
3020        /* Initialize IV */
3021        ret = crypt_ctr_ivmode(ti, ivmode);
3022        if (ret < 0)
3023                return ret;
3024
3025        /* Initialize and set key */
3026        ret = crypt_set_key(cc, key);
3027        if (ret < 0) {
3028                ti->error = "Error decoding and setting key";
3029                return ret;
3030        }
3031
3032        /* Allocate IV */
3033        if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
3034                ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
3035                if (ret < 0) {
3036                        ti->error = "Error creating IV";
3037                        return ret;
3038                }
3039        }
3040
3041        /* Initialize IV (set keys for ESSIV etc) */
3042        if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
3043                ret = cc->iv_gen_ops->init(cc);
3044                if (ret < 0) {
3045                        ti->error = "Error initialising IV";
3046                        return ret;
3047                }
3048        }
3049
3050        /* wipe the kernel key payload copy */
3051        if (cc->key_string)
3052                memset(cc->key, 0, cc->key_size * sizeof(u8));
3053
3054        return ret;
3055}
3056
3057static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv)
3058{
3059        struct crypt_config *cc = ti->private;
3060        struct dm_arg_set as;
3061        static const struct dm_arg _args[] = {
3062                {0, 8, "Invalid number of feature args"},
3063        };
3064        unsigned int opt_params, val;
3065        const char *opt_string, *sval;
3066        char dummy;
3067        int ret;
3068
3069        /* Optional parameters */
3070        as.argc = argc;
3071        as.argv = argv;
3072
3073        ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
3074        if (ret)
3075                return ret;
3076
3077        while (opt_params--) {
3078                opt_string = dm_shift_arg(&as);
3079                if (!opt_string) {
3080                        ti->error = "Not enough feature arguments";
3081                        return -EINVAL;
3082                }
3083
3084                if (!strcasecmp(opt_string, "allow_discards"))
3085                        ti->num_discard_bios = 1;
3086
3087                else if (!strcasecmp(opt_string, "same_cpu_crypt"))
3088                        set_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3089
3090                else if (!strcasecmp(opt_string, "submit_from_crypt_cpus"))
3091                        set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3092                else if (!strcasecmp(opt_string, "no_read_workqueue"))
3093                        set_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3094                else if (!strcasecmp(opt_string, "no_write_workqueue"))
3095                        set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3096                else if (sscanf(opt_string, "integrity:%u:", &val) == 1) {
3097                        if (val == 0 || val > MAX_TAG_SIZE) {
3098                                ti->error = "Invalid integrity arguments";
3099                                return -EINVAL;
3100                        }
3101                        cc->on_disk_tag_size = val;
3102                        sval = strchr(opt_string + strlen("integrity:"), ':') + 1;
3103                        if (!strcasecmp(sval, "aead")) {
3104                                set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags);
3105                        } else  if (strcasecmp(sval, "none")) {
3106                                ti->error = "Unknown integrity profile";
3107                                return -EINVAL;
3108                        }
3109
3110                        cc->cipher_auth = kstrdup(sval, GFP_KERNEL);
3111                        if (!cc->cipher_auth)
3112                                return -ENOMEM;
3113                } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) {
3114                        if (cc->sector_size < (1 << SECTOR_SHIFT) ||
3115                            cc->sector_size > 4096 ||
3116                            (cc->sector_size & (cc->sector_size - 1))) {
3117                                ti->error = "Invalid feature value for sector_size";
3118                                return -EINVAL;
3119                        }
3120                        if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) {
3121                                ti->error = "Device size is not multiple of sector_size feature";
3122                                return -EINVAL;
3123                        }
3124                        cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT;
3125                } else if (!strcasecmp(opt_string, "iv_large_sectors"))
3126                        set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3127                else {
3128                        ti->error = "Invalid feature arguments";
3129                        return -EINVAL;
3130                }
3131        }
3132
3133        return 0;
3134}
3135
3136#ifdef CONFIG_BLK_DEV_ZONED
3137static int crypt_report_zones(struct dm_target *ti,
3138                struct dm_report_zones_args *args, unsigned int nr_zones)
3139{
3140        struct crypt_config *cc = ti->private;
3141        sector_t sector = cc->start + dm_target_offset(ti, args->next_sector);
3142
3143        args->start = cc->start;
3144        return blkdev_report_zones(cc->dev->bdev, sector, nr_zones,
3145                                   dm_report_zones_cb, args);
3146}
3147#else
3148#define crypt_report_zones NULL
3149#endif
3150
3151/*
3152 * Construct an encryption mapping:
3153 * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
3154 */
3155static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3156{
3157        struct crypt_config *cc;
3158        const char *devname = dm_table_device_name(ti->table);
3159        int key_size;
3160        unsigned int align_mask;
3161        unsigned long long tmpll;
3162        int ret;
3163        size_t iv_size_padding, additional_req_size;
3164        char dummy;
3165
3166        if (argc < 5) {
3167                ti->error = "Not enough arguments";
3168                return -EINVAL;
3169        }
3170
3171        key_size = get_key_size(&argv[1]);
3172        if (key_size < 0) {
3173                ti->error = "Cannot parse key size";
3174                return -EINVAL;
3175        }
3176
3177        cc = kzalloc(struct_size(cc, key, key_size), GFP_KERNEL);
3178        if (!cc) {
3179                ti->error = "Cannot allocate encryption context";
3180                return -ENOMEM;
3181        }
3182        cc->key_size = key_size;
3183        cc->sector_size = (1 << SECTOR_SHIFT);
3184        cc->sector_shift = 0;
3185
3186        ti->private = cc;
3187
3188        spin_lock(&dm_crypt_clients_lock);
3189        dm_crypt_clients_n++;
3190        crypt_calculate_pages_per_client();
3191        spin_unlock(&dm_crypt_clients_lock);
3192
3193        ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL);
3194        if (ret < 0)
3195                goto bad;
3196
3197        /* Optional parameters need to be read before cipher constructor */
3198        if (argc > 5) {
3199                ret = crypt_ctr_optional(ti, argc - 5, &argv[5]);
3200                if (ret)
3201                        goto bad;
3202        }
3203
3204        ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
3205        if (ret < 0)
3206                goto bad;
3207
3208        if (crypt_integrity_aead(cc)) {
3209                cc->dmreq_start = sizeof(struct aead_request);
3210                cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc));
3211                align_mask = crypto_aead_alignmask(any_tfm_aead(cc));
3212        } else {
3213                cc->dmreq_start = sizeof(struct skcipher_request);
3214                cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc));
3215                align_mask = crypto_skcipher_alignmask(any_tfm(cc));
3216        }
3217        cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request));
3218
3219        if (align_mask < CRYPTO_MINALIGN) {
3220                /* Allocate the padding exactly */
3221                iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request))
3222                                & align_mask;
3223        } else {
3224                /*
3225                 * If the cipher requires greater alignment than kmalloc
3226                 * alignment, we don't know the exact position of the
3227                 * initialization vector. We must assume worst case.
3228                 */
3229                iv_size_padding = align_mask;
3230        }
3231
3232        /*  ...| IV + padding | original IV | original sec. number | bio tag offset | */
3233        additional_req_size = sizeof(struct dm_crypt_request) +
3234                iv_size_padding + cc->iv_size +
3235                cc->iv_size +
3236                sizeof(uint64_t) +
3237                sizeof(unsigned int);
3238
3239        ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size);
3240        if (ret) {
3241                ti->error = "Cannot allocate crypt request mempool";
3242                goto bad;
3243        }
3244
3245        cc->per_bio_data_size = ti->per_io_data_size =
3246                ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size,
3247                      ARCH_KMALLOC_MINALIGN);
3248
3249        ret = mempool_init(&cc->page_pool, BIO_MAX_VECS, crypt_page_alloc, crypt_page_free, cc);
3250        if (ret) {
3251                ti->error = "Cannot allocate page mempool";
3252                goto bad;
3253        }
3254
3255        ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS);
3256        if (ret) {
3257                ti->error = "Cannot allocate crypt bioset";
3258                goto bad;
3259        }
3260
3261        mutex_init(&cc->bio_alloc_lock);
3262
3263        ret = -EINVAL;
3264        if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) ||
3265            (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) {
3266                ti->error = "Invalid iv_offset sector";
3267                goto bad;
3268        }
3269        cc->iv_offset = tmpll;
3270
3271        ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev);
3272        if (ret) {
3273                ti->error = "Device lookup failed";
3274                goto bad;
3275        }
3276
3277        ret = -EINVAL;
3278        if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) {
3279                ti->error = "Invalid device sector";
3280                goto bad;
3281        }
3282        cc->start = tmpll;
3283
3284        /*
3285         * For zoned block devices, we need to preserve the issuer write
3286         * ordering. To do so, disable write workqueues and force inline
3287         * encryption completion.
3288         */
3289        if (bdev_is_zoned(cc->dev->bdev)) {
3290                set_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3291                set_bit(DM_CRYPT_WRITE_INLINE, &cc->flags);
3292        }
3293
3294        if (crypt_integrity_aead(cc) || cc->integrity_iv_size) {
3295                ret = crypt_integrity_ctr(cc, ti);
3296                if (ret)
3297                        goto bad;
3298
3299                cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size;
3300                if (!cc->tag_pool_max_sectors)
3301                        cc->tag_pool_max_sectors = 1;
3302
3303                ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS,
3304                        cc->tag_pool_max_sectors * cc->on_disk_tag_size);
3305                if (ret) {
3306                        ti->error = "Cannot allocate integrity tags mempool";
3307                        goto bad;
3308                }
3309
3310                cc->tag_pool_max_sectors <<= cc->sector_shift;
3311        }
3312
3313        ret = -ENOMEM;
3314        cc->io_queue = alloc_workqueue("kcryptd_io/%s", WQ_MEM_RECLAIM, 1, devname);
3315        if (!cc->io_queue) {
3316                ti->error = "Couldn't create kcryptd io queue";
3317                goto bad;
3318        }
3319
3320        if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3321                cc->crypt_queue = alloc_workqueue("kcryptd/%s", WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM,
3322                                                  1, devname);
3323        else
3324                cc->crypt_queue = alloc_workqueue("kcryptd/%s",
3325                                                  WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND,
3326                                                  num_online_cpus(), devname);
3327        if (!cc->crypt_queue) {
3328                ti->error = "Couldn't create kcryptd queue";
3329                goto bad;
3330        }
3331
3332        spin_lock_init(&cc->write_thread_lock);
3333        cc->write_tree = RB_ROOT;
3334
3335        cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write/%s", devname);
3336        if (IS_ERR(cc->write_thread)) {
3337                ret = PTR_ERR(cc->write_thread);
3338                cc->write_thread = NULL;
3339                ti->error = "Couldn't spawn write thread";
3340                goto bad;
3341        }
3342        wake_up_process(cc->write_thread);
3343
3344        ti->num_flush_bios = 1;
3345        ti->limit_swap_bios = true;
3346
3347        return 0;
3348
3349bad:
3350        crypt_dtr(ti);
3351        return ret;
3352}
3353
3354static int crypt_map(struct dm_target *ti, struct bio *bio)
3355{
3356        struct dm_crypt_io *io;
3357        struct crypt_config *cc = ti->private;
3358
3359        /*
3360         * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues.
3361         * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight
3362         * - for REQ_OP_DISCARD caller must use flush if IO ordering matters
3363         */
3364        if (unlikely(bio->bi_opf & REQ_PREFLUSH ||
3365            bio_op(bio) == REQ_OP_DISCARD)) {
3366                bio_set_dev(bio, cc->dev->bdev);
3367                if (bio_sectors(bio))
3368                        bio->bi_iter.bi_sector = cc->start +
3369                                dm_target_offset(ti, bio->bi_iter.bi_sector);
3370                return DM_MAPIO_REMAPPED;
3371        }
3372
3373        /*
3374         * Check if bio is too large, split as needed.
3375         */
3376        if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_VECS << PAGE_SHIFT)) &&
3377            (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size))
3378                dm_accept_partial_bio(bio, ((BIO_MAX_VECS << PAGE_SHIFT) >> SECTOR_SHIFT));
3379
3380        /*
3381         * Ensure that bio is a multiple of internal sector encryption size
3382         * and is aligned to this size as defined in IO hints.
3383         */
3384        if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0))
3385                return DM_MAPIO_KILL;
3386
3387        if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1)))
3388                return DM_MAPIO_KILL;
3389
3390        io = dm_per_bio_data(bio, cc->per_bio_data_size);
3391        crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector));
3392
3393        if (cc->on_disk_tag_size) {
3394                unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift);
3395
3396                if (unlikely(tag_len > KMALLOC_MAX_SIZE) ||
3397                    unlikely(!(io->integrity_metadata = kmalloc(tag_len,
3398                                GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) {
3399                        if (bio_sectors(bio) > cc->tag_pool_max_sectors)
3400                                dm_accept_partial_bio(bio, cc->tag_pool_max_sectors);
3401                        io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO);
3402                        io->integrity_metadata_from_pool = true;
3403                }
3404        }
3405
3406        if (crypt_integrity_aead(cc))
3407                io->ctx.r.req_aead = (struct aead_request *)(io + 1);
3408        else
3409                io->ctx.r.req = (struct skcipher_request *)(io + 1);
3410
3411        if (bio_data_dir(io->base_bio) == READ) {
3412                if (kcryptd_io_read(io, GFP_NOWAIT))
3413                        kcryptd_queue_read(io);
3414        } else
3415                kcryptd_queue_crypt(io);
3416
3417        return DM_MAPIO_SUBMITTED;
3418}
3419
3420static void crypt_status(struct dm_target *ti, status_type_t type,
3421                         unsigned status_flags, char *result, unsigned maxlen)
3422{
3423        struct crypt_config *cc = ti->private;
3424        unsigned i, sz = 0;
3425        int num_feature_args = 0;
3426
3427        switch (type) {
3428        case STATUSTYPE_INFO:
3429                result[0] = '\0';
3430                break;
3431
3432        case STATUSTYPE_TABLE:
3433                DMEMIT("%s ", cc->cipher_string);
3434
3435                if (cc->key_size > 0) {
3436                        if (cc->key_string)
3437                                DMEMIT(":%u:%s", cc->key_size, cc->key_string);
3438                        else
3439                                for (i = 0; i < cc->key_size; i++)
3440                                        DMEMIT("%02x", cc->key[i]);
3441                } else
3442                        DMEMIT("-");
3443
3444                DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
3445                                cc->dev->name, (unsigned long long)cc->start);
3446
3447                num_feature_args += !!ti->num_discard_bios;
3448                num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags);
3449                num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags);
3450                num_feature_args += test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags);
3451                num_feature_args += test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags);
3452                num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT);
3453                num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags);
3454                if (cc->on_disk_tag_size)
3455                        num_feature_args++;
3456                if (num_feature_args) {
3457                        DMEMIT(" %d", num_feature_args);
3458                        if (ti->num_discard_bios)
3459                                DMEMIT(" allow_discards");
3460                        if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags))
3461                                DMEMIT(" same_cpu_crypt");
3462                        if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags))
3463                                DMEMIT(" submit_from_crypt_cpus");
3464                        if (test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags))
3465                                DMEMIT(" no_read_workqueue");
3466                        if (test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))
3467                                DMEMIT(" no_write_workqueue");
3468                        if (cc->on_disk_tag_size)
3469                                DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth);
3470                        if (cc->sector_size != (1 << SECTOR_SHIFT))
3471                                DMEMIT(" sector_size:%d", cc->sector_size);
3472                        if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags))
3473                                DMEMIT(" iv_large_sectors");
3474                }
3475
3476                break;
3477        }
3478}
3479
3480static void crypt_postsuspend(struct dm_target *ti)
3481{
3482        struct crypt_config *cc = ti->private;
3483
3484        set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3485}
3486
3487static int crypt_preresume(struct dm_target *ti)
3488{
3489        struct crypt_config *cc = ti->private;
3490
3491        if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
3492                DMERR("aborting resume - crypt key is not set.");
3493                return -EAGAIN;
3494        }
3495
3496        return 0;
3497}
3498
3499static void crypt_resume(struct dm_target *ti)
3500{
3501        struct crypt_config *cc = ti->private;
3502
3503        clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
3504}
3505
3506/* Message interface
3507 *      key set <key>
3508 *      key wipe
3509 */
3510static int crypt_message(struct dm_target *ti, unsigned argc, char **argv,
3511                         char *result, unsigned maxlen)
3512{
3513        struct crypt_config *cc = ti->private;
3514        int key_size, ret = -EINVAL;
3515
3516        if (argc < 2)
3517                goto error;
3518
3519        if (!strcasecmp(argv[0], "key")) {
3520                if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
3521                        DMWARN("not suspended during key manipulation.");
3522                        return -EINVAL;
3523                }
3524                if (argc == 3 && !strcasecmp(argv[1], "set")) {
3525                        /* The key size may not be changed. */
3526                        key_size = get_key_size(&argv[2]);
3527                        if (key_size < 0 || cc->key_size != key_size) {
3528                                memset(argv[2], '0', strlen(argv[2]));
3529                                return -EINVAL;
3530                        }
3531
3532                        ret = crypt_set_key(cc, argv[2]);
3533                        if (ret)
3534                                return ret;
3535                        if (cc->iv_gen_ops && cc->iv_gen_ops->init)
3536                                ret = cc->iv_gen_ops->init(cc);
3537                        /* wipe the kernel key payload copy */
3538                        if (cc->key_string)
3539                                memset(cc->key, 0, cc->key_size * sizeof(u8));
3540                        return ret;
3541                }
3542                if (argc == 2 && !strcasecmp(argv[1], "wipe"))
3543                        return crypt_wipe_key(cc);
3544        }
3545
3546error:
3547        DMWARN("unrecognised message received.");
3548        return -EINVAL;
3549}
3550
3551static int crypt_iterate_devices(struct dm_target *ti,
3552                                 iterate_devices_callout_fn fn, void *data)
3553{
3554        struct crypt_config *cc = ti->private;
3555
3556        return fn(ti, cc->dev, cc->start, ti->len, data);
3557}
3558
3559static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
3560{
3561        struct crypt_config *cc = ti->private;
3562
3563        /*
3564         * Unfortunate constraint that is required to avoid the potential
3565         * for exceeding underlying device's max_segments limits -- due to
3566         * crypt_alloc_buffer() possibly allocating pages for the encryption
3567         * bio that are not as physically contiguous as the original bio.
3568         */
3569        limits->max_segment_size = PAGE_SIZE;
3570
3571        limits->logical_block_size =
3572                max_t(unsigned, limits->logical_block_size, cc->sector_size);
3573        limits->physical_block_size =
3574                max_t(unsigned, limits->physical_block_size, cc->sector_size);
3575        limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size);
3576}
3577
3578static struct target_type crypt_target = {
3579        .name   = "crypt",
3580        .version = {1, 23, 0},
3581        .module = THIS_MODULE,
3582        .ctr    = crypt_ctr,
3583        .dtr    = crypt_dtr,
3584        .features = DM_TARGET_ZONED_HM,
3585        .report_zones = crypt_report_zones,
3586        .map    = crypt_map,
3587        .status = crypt_status,
3588        .postsuspend = crypt_postsuspend,
3589        .preresume = crypt_preresume,
3590        .resume = crypt_resume,
3591        .message = crypt_message,
3592        .iterate_devices = crypt_iterate_devices,
3593        .io_hints = crypt_io_hints,
3594};
3595
3596static int __init dm_crypt_init(void)
3597{
3598        int r;
3599
3600        r = dm_register_target(&crypt_target);
3601        if (r < 0)
3602                DMERR("register failed %d", r);
3603
3604        return r;
3605}
3606
3607static void __exit dm_crypt_exit(void)
3608{
3609        dm_unregister_target(&crypt_target);
3610}
3611
3612module_init(dm_crypt_init);
3613module_exit(dm_crypt_exit);
3614
3615MODULE_AUTHOR("Jana Saout <jana@saout.de>");
3616MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
3617MODULE_LICENSE("GPL");
3618