11da177e4SLinus Torvalds /* 21da177e4SLinus Torvalds * Copyright (C) 2003 Christophe Saout <christophe@saout.de> 31da177e4SLinus Torvalds * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> 4e48d4bbfSMilan Broz * Copyright (C) 2006 Red Hat, Inc. All rights reserved. 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * This file is released under the GPL. 71da177e4SLinus Torvalds */ 81da177e4SLinus Torvalds 9d1806f6aSHerbert Xu #include <linux/err.h> 101da177e4SLinus Torvalds #include <linux/module.h> 111da177e4SLinus Torvalds #include <linux/init.h> 121da177e4SLinus Torvalds #include <linux/kernel.h> 131da177e4SLinus Torvalds #include <linux/bio.h> 141da177e4SLinus Torvalds #include <linux/blkdev.h> 151da177e4SLinus Torvalds #include <linux/mempool.h> 161da177e4SLinus Torvalds #include <linux/slab.h> 171da177e4SLinus Torvalds #include <linux/crypto.h> 181da177e4SLinus Torvalds #include <linux/workqueue.h> 193fcfab16SAndrew Morton #include <linux/backing-dev.h> 201da177e4SLinus Torvalds #include <asm/atomic.h> 21378f058cSDavid Hardeman #include <linux/scatterlist.h> 221da177e4SLinus Torvalds #include <asm/page.h> 2348527fa7SRik Snel #include <asm/unaligned.h> 241da177e4SLinus Torvalds 251da177e4SLinus Torvalds #include "dm.h" 261da177e4SLinus Torvalds 2772d94861SAlasdair G Kergon #define DM_MSG_PREFIX "crypt" 28e48d4bbfSMilan Broz #define MESG_STR(x) x, sizeof(x) 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds /* 311da177e4SLinus Torvalds * per bio private data 321da177e4SLinus Torvalds */ 33028867acSAlasdair G Kergon struct dm_crypt_io { 341da177e4SLinus Torvalds struct dm_target *target; 358b004457SMilan Broz struct bio *base_bio; 361da177e4SLinus Torvalds struct work_struct work; 371da177e4SLinus Torvalds atomic_t pending; 381da177e4SLinus Torvalds int error; 391da177e4SLinus Torvalds }; 401da177e4SLinus Torvalds 411da177e4SLinus Torvalds /* 421da177e4SLinus Torvalds * context holding the current state of a multi-part conversion 431da177e4SLinus Torvalds */ 441da177e4SLinus Torvalds struct convert_context { 451da177e4SLinus Torvalds struct bio *bio_in; 461da177e4SLinus Torvalds struct bio *bio_out; 471da177e4SLinus Torvalds unsigned int offset_in; 481da177e4SLinus Torvalds unsigned int offset_out; 491da177e4SLinus Torvalds unsigned int idx_in; 501da177e4SLinus Torvalds unsigned int idx_out; 511da177e4SLinus Torvalds sector_t sector; 521da177e4SLinus Torvalds int write; 531da177e4SLinus Torvalds }; 541da177e4SLinus Torvalds 551da177e4SLinus Torvalds struct crypt_config; 561da177e4SLinus Torvalds 571da177e4SLinus Torvalds struct crypt_iv_operations { 581da177e4SLinus Torvalds int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 591da177e4SLinus Torvalds const char *opts); 601da177e4SLinus Torvalds void (*dtr)(struct crypt_config *cc); 611da177e4SLinus Torvalds const char *(*status)(struct crypt_config *cc); 621da177e4SLinus Torvalds int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); 631da177e4SLinus Torvalds }; 641da177e4SLinus Torvalds 651da177e4SLinus Torvalds /* 661da177e4SLinus Torvalds * Crypt: maps a linear range of a block device 671da177e4SLinus Torvalds * and encrypts / decrypts at the same time. 681da177e4SLinus Torvalds */ 69e48d4bbfSMilan Broz enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; 701da177e4SLinus Torvalds struct crypt_config { 711da177e4SLinus Torvalds struct dm_dev *dev; 721da177e4SLinus Torvalds sector_t start; 731da177e4SLinus Torvalds 741da177e4SLinus Torvalds /* 751da177e4SLinus Torvalds * pool for per bio private data and 761da177e4SLinus Torvalds * for encryption buffer pages 771da177e4SLinus Torvalds */ 781da177e4SLinus Torvalds mempool_t *io_pool; 791da177e4SLinus Torvalds mempool_t *page_pool; 806a24c718SMilan Broz struct bio_set *bs; 811da177e4SLinus Torvalds 82cabf08e4SMilan Broz struct workqueue_struct *io_queue; 83cabf08e4SMilan Broz struct workqueue_struct *crypt_queue; 841da177e4SLinus Torvalds /* 851da177e4SLinus Torvalds * crypto related data 861da177e4SLinus Torvalds */ 871da177e4SLinus Torvalds struct crypt_iv_operations *iv_gen_ops; 881da177e4SLinus Torvalds char *iv_mode; 8979066ad3SHerbert Xu union { 9079066ad3SHerbert Xu struct crypto_cipher *essiv_tfm; 9179066ad3SHerbert Xu int benbi_shift; 9279066ad3SHerbert Xu } iv_gen_private; 931da177e4SLinus Torvalds sector_t iv_offset; 941da177e4SLinus Torvalds unsigned int iv_size; 951da177e4SLinus Torvalds 96d1806f6aSHerbert Xu char cipher[CRYPTO_MAX_ALG_NAME]; 97d1806f6aSHerbert Xu char chainmode[CRYPTO_MAX_ALG_NAME]; 98d1806f6aSHerbert Xu struct crypto_blkcipher *tfm; 99e48d4bbfSMilan Broz unsigned long flags; 1001da177e4SLinus Torvalds unsigned int key_size; 1011da177e4SLinus Torvalds u8 key[0]; 1021da177e4SLinus Torvalds }; 1031da177e4SLinus Torvalds 1046a24c718SMilan Broz #define MIN_IOS 16 1051da177e4SLinus Torvalds #define MIN_POOL_PAGES 32 1061da177e4SLinus Torvalds #define MIN_BIO_PAGES 8 1071da177e4SLinus Torvalds 108e18b890bSChristoph Lameter static struct kmem_cache *_crypt_io_pool; 1091da177e4SLinus Torvalds 110028867acSAlasdair G Kergon static void clone_init(struct dm_crypt_io *, struct bio *); 111027581f3SOlaf Kirch 1121da177e4SLinus Torvalds /* 1131da177e4SLinus Torvalds * Different IV generation algorithms: 1141da177e4SLinus Torvalds * 1153c164bd8SRik Snel * plain: the initial vector is the 32-bit little-endian version of the sector 1163a4fa0a2SRobert P. J. Day * number, padded with zeros if necessary. 1171da177e4SLinus Torvalds * 1183c164bd8SRik Snel * essiv: "encrypted sector|salt initial vector", the sector number is 1191da177e4SLinus Torvalds * encrypted with the bulk cipher using a salt as key. The salt 1201da177e4SLinus Torvalds * should be derived from the bulk cipher's key via hashing. 1211da177e4SLinus Torvalds * 12248527fa7SRik Snel * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 12348527fa7SRik Snel * (needed for LRW-32-AES and possible other narrow block modes) 12448527fa7SRik Snel * 12546b47730SLudwig Nussel * null: the initial vector is always zero. Provides compatibility with 12646b47730SLudwig Nussel * obsolete loop_fish2 devices. Do not use for new devices. 12746b47730SLudwig Nussel * 1281da177e4SLinus Torvalds * plumb: unimplemented, see: 1291da177e4SLinus Torvalds * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 1301da177e4SLinus Torvalds */ 1311da177e4SLinus Torvalds 1321da177e4SLinus Torvalds static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 1331da177e4SLinus Torvalds { 1341da177e4SLinus Torvalds memset(iv, 0, cc->iv_size); 1351da177e4SLinus Torvalds *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); 1361da177e4SLinus Torvalds 1371da177e4SLinus Torvalds return 0; 1381da177e4SLinus Torvalds } 1391da177e4SLinus Torvalds 1401da177e4SLinus Torvalds static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, 1411da177e4SLinus Torvalds const char *opts) 1421da177e4SLinus Torvalds { 143d1806f6aSHerbert Xu struct crypto_cipher *essiv_tfm; 14435058687SHerbert Xu struct crypto_hash *hash_tfm; 14535058687SHerbert Xu struct hash_desc desc; 1461da177e4SLinus Torvalds struct scatterlist sg; 1471da177e4SLinus Torvalds unsigned int saltsize; 1481da177e4SLinus Torvalds u8 *salt; 149d1806f6aSHerbert Xu int err; 1501da177e4SLinus Torvalds 1511da177e4SLinus Torvalds if (opts == NULL) { 15272d94861SAlasdair G Kergon ti->error = "Digest algorithm missing for ESSIV mode"; 1531da177e4SLinus Torvalds return -EINVAL; 1541da177e4SLinus Torvalds } 1551da177e4SLinus Torvalds 1561da177e4SLinus Torvalds /* Hash the cipher key with the given hash algorithm */ 15735058687SHerbert Xu hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); 15835058687SHerbert Xu if (IS_ERR(hash_tfm)) { 15972d94861SAlasdair G Kergon ti->error = "Error initializing ESSIV hash"; 16035058687SHerbert Xu return PTR_ERR(hash_tfm); 1611da177e4SLinus Torvalds } 1621da177e4SLinus Torvalds 16335058687SHerbert Xu saltsize = crypto_hash_digestsize(hash_tfm); 1641da177e4SLinus Torvalds salt = kmalloc(saltsize, GFP_KERNEL); 1651da177e4SLinus Torvalds if (salt == NULL) { 16672d94861SAlasdair G Kergon ti->error = "Error kmallocing salt storage in ESSIV"; 16735058687SHerbert Xu crypto_free_hash(hash_tfm); 1681da177e4SLinus Torvalds return -ENOMEM; 1691da177e4SLinus Torvalds } 1701da177e4SLinus Torvalds 17168e3f5ddSHerbert Xu sg_init_one(&sg, cc->key, cc->key_size); 17235058687SHerbert Xu desc.tfm = hash_tfm; 17335058687SHerbert Xu desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; 17435058687SHerbert Xu err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); 17535058687SHerbert Xu crypto_free_hash(hash_tfm); 17635058687SHerbert Xu 17735058687SHerbert Xu if (err) { 17835058687SHerbert Xu ti->error = "Error calculating hash in ESSIV"; 179815f9e32SDmitry Monakhov kfree(salt); 18035058687SHerbert Xu return err; 18135058687SHerbert Xu } 1821da177e4SLinus Torvalds 1831da177e4SLinus Torvalds /* Setup the essiv_tfm with the given salt */ 184d1806f6aSHerbert Xu essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 185d1806f6aSHerbert Xu if (IS_ERR(essiv_tfm)) { 18672d94861SAlasdair G Kergon ti->error = "Error allocating crypto tfm for ESSIV"; 1871da177e4SLinus Torvalds kfree(salt); 188d1806f6aSHerbert Xu return PTR_ERR(essiv_tfm); 1891da177e4SLinus Torvalds } 190d1806f6aSHerbert Xu if (crypto_cipher_blocksize(essiv_tfm) != 191d1806f6aSHerbert Xu crypto_blkcipher_ivsize(cc->tfm)) { 19272d94861SAlasdair G Kergon ti->error = "Block size of ESSIV cipher does " 1931da177e4SLinus Torvalds "not match IV size of block cipher"; 194d1806f6aSHerbert Xu crypto_free_cipher(essiv_tfm); 1951da177e4SLinus Torvalds kfree(salt); 1961da177e4SLinus Torvalds return -EINVAL; 1971da177e4SLinus Torvalds } 198d1806f6aSHerbert Xu err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); 199d1806f6aSHerbert Xu if (err) { 20072d94861SAlasdair G Kergon ti->error = "Failed to set key for ESSIV cipher"; 201d1806f6aSHerbert Xu crypto_free_cipher(essiv_tfm); 2021da177e4SLinus Torvalds kfree(salt); 203d1806f6aSHerbert Xu return err; 2041da177e4SLinus Torvalds } 2051da177e4SLinus Torvalds kfree(salt); 2061da177e4SLinus Torvalds 20779066ad3SHerbert Xu cc->iv_gen_private.essiv_tfm = essiv_tfm; 2081da177e4SLinus Torvalds return 0; 2091da177e4SLinus Torvalds } 2101da177e4SLinus Torvalds 2111da177e4SLinus Torvalds static void crypt_iv_essiv_dtr(struct crypt_config *cc) 2121da177e4SLinus Torvalds { 21379066ad3SHerbert Xu crypto_free_cipher(cc->iv_gen_private.essiv_tfm); 21479066ad3SHerbert Xu cc->iv_gen_private.essiv_tfm = NULL; 2151da177e4SLinus Torvalds } 2161da177e4SLinus Torvalds 2171da177e4SLinus Torvalds static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 2181da177e4SLinus Torvalds { 2191da177e4SLinus Torvalds memset(iv, 0, cc->iv_size); 2201da177e4SLinus Torvalds *(u64 *)iv = cpu_to_le64(sector); 22179066ad3SHerbert Xu crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv); 2221da177e4SLinus Torvalds return 0; 2231da177e4SLinus Torvalds } 2241da177e4SLinus Torvalds 22548527fa7SRik Snel static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, 22648527fa7SRik Snel const char *opts) 22748527fa7SRik Snel { 22848527fa7SRik Snel unsigned int bs = crypto_blkcipher_blocksize(cc->tfm); 229f0d1b0b3SDavid Howells int log = ilog2(bs); 23048527fa7SRik Snel 23148527fa7SRik Snel /* we need to calculate how far we must shift the sector count 23248527fa7SRik Snel * to get the cipher block count, we use this shift in _gen */ 23348527fa7SRik Snel 23448527fa7SRik Snel if (1 << log != bs) { 23548527fa7SRik Snel ti->error = "cypher blocksize is not a power of 2"; 23648527fa7SRik Snel return -EINVAL; 23748527fa7SRik Snel } 23848527fa7SRik Snel 23948527fa7SRik Snel if (log > 9) { 24048527fa7SRik Snel ti->error = "cypher blocksize is > 512"; 24148527fa7SRik Snel return -EINVAL; 24248527fa7SRik Snel } 24348527fa7SRik Snel 24479066ad3SHerbert Xu cc->iv_gen_private.benbi_shift = 9 - log; 24548527fa7SRik Snel 24648527fa7SRik Snel return 0; 24748527fa7SRik Snel } 24848527fa7SRik Snel 24948527fa7SRik Snel static void crypt_iv_benbi_dtr(struct crypt_config *cc) 25048527fa7SRik Snel { 25148527fa7SRik Snel } 25248527fa7SRik Snel 25348527fa7SRik Snel static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 25448527fa7SRik Snel { 25579066ad3SHerbert Xu __be64 val; 25679066ad3SHerbert Xu 25748527fa7SRik Snel memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ 25879066ad3SHerbert Xu 25979066ad3SHerbert Xu val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1); 26079066ad3SHerbert Xu put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); 26148527fa7SRik Snel 2621da177e4SLinus Torvalds return 0; 2631da177e4SLinus Torvalds } 2641da177e4SLinus Torvalds 26546b47730SLudwig Nussel static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 26646b47730SLudwig Nussel { 26746b47730SLudwig Nussel memset(iv, 0, cc->iv_size); 26846b47730SLudwig Nussel 26946b47730SLudwig Nussel return 0; 27046b47730SLudwig Nussel } 27146b47730SLudwig Nussel 2721da177e4SLinus Torvalds static struct crypt_iv_operations crypt_iv_plain_ops = { 2731da177e4SLinus Torvalds .generator = crypt_iv_plain_gen 2741da177e4SLinus Torvalds }; 2751da177e4SLinus Torvalds 2761da177e4SLinus Torvalds static struct crypt_iv_operations crypt_iv_essiv_ops = { 2771da177e4SLinus Torvalds .ctr = crypt_iv_essiv_ctr, 2781da177e4SLinus Torvalds .dtr = crypt_iv_essiv_dtr, 2791da177e4SLinus Torvalds .generator = crypt_iv_essiv_gen 2801da177e4SLinus Torvalds }; 2811da177e4SLinus Torvalds 28248527fa7SRik Snel static struct crypt_iv_operations crypt_iv_benbi_ops = { 28348527fa7SRik Snel .ctr = crypt_iv_benbi_ctr, 28448527fa7SRik Snel .dtr = crypt_iv_benbi_dtr, 28548527fa7SRik Snel .generator = crypt_iv_benbi_gen 28648527fa7SRik Snel }; 2871da177e4SLinus Torvalds 28846b47730SLudwig Nussel static struct crypt_iv_operations crypt_iv_null_ops = { 28946b47730SLudwig Nussel .generator = crypt_iv_null_gen 29046b47730SLudwig Nussel }; 29146b47730SLudwig Nussel 292858119e1SArjan van de Ven static int 2931da177e4SLinus Torvalds crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out, 2941da177e4SLinus Torvalds struct scatterlist *in, unsigned int length, 2951da177e4SLinus Torvalds int write, sector_t sector) 2961da177e4SLinus Torvalds { 29745789328SHerbert Xu u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64)))); 298d1806f6aSHerbert Xu struct blkcipher_desc desc = { 299d1806f6aSHerbert Xu .tfm = cc->tfm, 300d1806f6aSHerbert Xu .info = iv, 301d1806f6aSHerbert Xu .flags = CRYPTO_TFM_REQ_MAY_SLEEP, 302d1806f6aSHerbert Xu }; 3031da177e4SLinus Torvalds int r; 3041da177e4SLinus Torvalds 3051da177e4SLinus Torvalds if (cc->iv_gen_ops) { 3061da177e4SLinus Torvalds r = cc->iv_gen_ops->generator(cc, iv, sector); 3071da177e4SLinus Torvalds if (r < 0) 3081da177e4SLinus Torvalds return r; 3091da177e4SLinus Torvalds 3101da177e4SLinus Torvalds if (write) 311d1806f6aSHerbert Xu r = crypto_blkcipher_encrypt_iv(&desc, out, in, length); 3121da177e4SLinus Torvalds else 313d1806f6aSHerbert Xu r = crypto_blkcipher_decrypt_iv(&desc, out, in, length); 3141da177e4SLinus Torvalds } else { 3151da177e4SLinus Torvalds if (write) 316d1806f6aSHerbert Xu r = crypto_blkcipher_encrypt(&desc, out, in, length); 3171da177e4SLinus Torvalds else 318d1806f6aSHerbert Xu r = crypto_blkcipher_decrypt(&desc, out, in, length); 3191da177e4SLinus Torvalds } 3201da177e4SLinus Torvalds 3211da177e4SLinus Torvalds return r; 3221da177e4SLinus Torvalds } 3231da177e4SLinus Torvalds 324d469f841SMilan Broz static void crypt_convert_init(struct crypt_config *cc, 325d469f841SMilan Broz struct convert_context *ctx, 3261da177e4SLinus Torvalds struct bio *bio_out, struct bio *bio_in, 3271da177e4SLinus Torvalds sector_t sector, int write) 3281da177e4SLinus Torvalds { 3291da177e4SLinus Torvalds ctx->bio_in = bio_in; 3301da177e4SLinus Torvalds ctx->bio_out = bio_out; 3311da177e4SLinus Torvalds ctx->offset_in = 0; 3321da177e4SLinus Torvalds ctx->offset_out = 0; 3331da177e4SLinus Torvalds ctx->idx_in = bio_in ? bio_in->bi_idx : 0; 3341da177e4SLinus Torvalds ctx->idx_out = bio_out ? bio_out->bi_idx : 0; 3351da177e4SLinus Torvalds ctx->sector = sector + cc->iv_offset; 3361da177e4SLinus Torvalds ctx->write = write; 3371da177e4SLinus Torvalds } 3381da177e4SLinus Torvalds 3391da177e4SLinus Torvalds /* 3401da177e4SLinus Torvalds * Encrypt / decrypt data from one bio to another one (can be the same one) 3411da177e4SLinus Torvalds */ 3421da177e4SLinus Torvalds static int crypt_convert(struct crypt_config *cc, 3431da177e4SLinus Torvalds struct convert_context *ctx) 3441da177e4SLinus Torvalds { 3451da177e4SLinus Torvalds int r = 0; 3461da177e4SLinus Torvalds 3471da177e4SLinus Torvalds while(ctx->idx_in < ctx->bio_in->bi_vcnt && 3481da177e4SLinus Torvalds ctx->idx_out < ctx->bio_out->bi_vcnt) { 3491da177e4SLinus Torvalds struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); 3501da177e4SLinus Torvalds struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); 35145711f1aSJens Axboe struct scatterlist sg_in, sg_out; 35245711f1aSJens Axboe 35345711f1aSJens Axboe sg_init_table(&sg_in, 1); 354642f1490SJens Axboe sg_set_page(&sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, bv_in->bv_offset + ctx->offset_in); 35545711f1aSJens Axboe 35645711f1aSJens Axboe sg_init_table(&sg_out, 1); 357642f1490SJens Axboe sg_set_page(&sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, bv_out->bv_offset + ctx->offset_out); 3581da177e4SLinus Torvalds 3591da177e4SLinus Torvalds ctx->offset_in += sg_in.length; 3601da177e4SLinus Torvalds if (ctx->offset_in >= bv_in->bv_len) { 3611da177e4SLinus Torvalds ctx->offset_in = 0; 3621da177e4SLinus Torvalds ctx->idx_in++; 3631da177e4SLinus Torvalds } 3641da177e4SLinus Torvalds 3651da177e4SLinus Torvalds ctx->offset_out += sg_out.length; 3661da177e4SLinus Torvalds if (ctx->offset_out >= bv_out->bv_len) { 3671da177e4SLinus Torvalds ctx->offset_out = 0; 3681da177e4SLinus Torvalds ctx->idx_out++; 3691da177e4SLinus Torvalds } 3701da177e4SLinus Torvalds 3711da177e4SLinus Torvalds r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, 3721da177e4SLinus Torvalds ctx->write, ctx->sector); 3731da177e4SLinus Torvalds if (r < 0) 3741da177e4SLinus Torvalds break; 3751da177e4SLinus Torvalds 3761da177e4SLinus Torvalds ctx->sector++; 3771da177e4SLinus Torvalds } 3781da177e4SLinus Torvalds 3791da177e4SLinus Torvalds return r; 3801da177e4SLinus Torvalds } 3811da177e4SLinus Torvalds 3826a24c718SMilan Broz static void dm_crypt_bio_destructor(struct bio *bio) 3836a24c718SMilan Broz { 384028867acSAlasdair G Kergon struct dm_crypt_io *io = bio->bi_private; 3856a24c718SMilan Broz struct crypt_config *cc = io->target->private; 3866a24c718SMilan Broz 3876a24c718SMilan Broz bio_free(bio, cc->bs); 3886a24c718SMilan Broz } 3896a24c718SMilan Broz 3901da177e4SLinus Torvalds /* 3911da177e4SLinus Torvalds * Generate a new unfragmented bio with the given size 3921da177e4SLinus Torvalds * This should never violate the device limitations 3931da177e4SLinus Torvalds * May return a smaller bio when running out of pages 3941da177e4SLinus Torvalds */ 395028867acSAlasdair G Kergon static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 3961da177e4SLinus Torvalds { 397027581f3SOlaf Kirch struct crypt_config *cc = io->target->private; 3988b004457SMilan Broz struct bio *clone; 3991da177e4SLinus Torvalds unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 400b4e3ca1aSAl Viro gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; 40191e10625SMilan Broz unsigned i, len; 40291e10625SMilan Broz struct page *page; 4031da177e4SLinus Torvalds 4046a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); 4058b004457SMilan Broz if (!clone) 4061da177e4SLinus Torvalds return NULL; 4071da177e4SLinus Torvalds 408027581f3SOlaf Kirch clone_init(io, clone); 4096a24c718SMilan Broz 410f97380bcSOlaf Kirch for (i = 0; i < nr_iovecs; i++) { 41191e10625SMilan Broz page = mempool_alloc(cc->page_pool, gfp_mask); 41291e10625SMilan Broz if (!page) 4131da177e4SLinus Torvalds break; 4141da177e4SLinus Torvalds 4151da177e4SLinus Torvalds /* 4161da177e4SLinus Torvalds * if additional pages cannot be allocated without waiting, 4171da177e4SLinus Torvalds * return a partially allocated bio, the caller will then try 4181da177e4SLinus Torvalds * to allocate additional bios while submitting this partial bio 4191da177e4SLinus Torvalds */ 420f97380bcSOlaf Kirch if (i == (MIN_BIO_PAGES - 1)) 4211da177e4SLinus Torvalds gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; 4221da177e4SLinus Torvalds 42391e10625SMilan Broz len = (size > PAGE_SIZE) ? PAGE_SIZE : size; 4241da177e4SLinus Torvalds 42591e10625SMilan Broz if (!bio_add_page(clone, page, len, 0)) { 42691e10625SMilan Broz mempool_free(page, cc->page_pool); 42791e10625SMilan Broz break; 42891e10625SMilan Broz } 42991e10625SMilan Broz 43091e10625SMilan Broz size -= len; 4311da177e4SLinus Torvalds } 4321da177e4SLinus Torvalds 4338b004457SMilan Broz if (!clone->bi_size) { 4348b004457SMilan Broz bio_put(clone); 4351da177e4SLinus Torvalds return NULL; 4361da177e4SLinus Torvalds } 4371da177e4SLinus Torvalds 4388b004457SMilan Broz return clone; 4391da177e4SLinus Torvalds } 4401da177e4SLinus Torvalds 441644bd2f0SNeil Brown static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 4421da177e4SLinus Torvalds { 443644bd2f0SNeil Brown unsigned int i; 4441da177e4SLinus Torvalds struct bio_vec *bv; 4451da177e4SLinus Torvalds 446644bd2f0SNeil Brown for (i = 0; i < clone->bi_vcnt; i++) { 4478b004457SMilan Broz bv = bio_iovec_idx(clone, i); 4481da177e4SLinus Torvalds BUG_ON(!bv->bv_page); 4491da177e4SLinus Torvalds mempool_free(bv->bv_page, cc->page_pool); 4501da177e4SLinus Torvalds bv->bv_page = NULL; 4511da177e4SLinus Torvalds } 4521da177e4SLinus Torvalds } 4531da177e4SLinus Torvalds 4541da177e4SLinus Torvalds /* 4551da177e4SLinus Torvalds * One of the bios was finished. Check for completion of 4561da177e4SLinus Torvalds * the whole request and correctly clean up the buffer. 4571da177e4SLinus Torvalds */ 45880fd6626SMilan Broz static void crypt_dec_pending(struct dm_crypt_io *io, int error) 4591da177e4SLinus Torvalds { 4601da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) io->target->private; 4611da177e4SLinus Torvalds 4621da177e4SLinus Torvalds if (error < 0) 4631da177e4SLinus Torvalds io->error = error; 4641da177e4SLinus Torvalds 4651da177e4SLinus Torvalds if (!atomic_dec_and_test(&io->pending)) 4661da177e4SLinus Torvalds return; 4671da177e4SLinus Torvalds 4686712ecf8SNeilBrown bio_endio(io->base_bio, io->error); 4691da177e4SLinus Torvalds 4701da177e4SLinus Torvalds mempool_free(io, cc->io_pool); 4711da177e4SLinus Torvalds } 4721da177e4SLinus Torvalds 4731da177e4SLinus Torvalds /* 474cabf08e4SMilan Broz * kcryptd/kcryptd_io: 4751da177e4SLinus Torvalds * 4761da177e4SLinus Torvalds * Needed because it would be very unwise to do decryption in an 47723541d2dSMilan Broz * interrupt context. 478cabf08e4SMilan Broz * 479cabf08e4SMilan Broz * kcryptd performs the actual encryption or decryption. 480cabf08e4SMilan Broz * 481cabf08e4SMilan Broz * kcryptd_io performs the IO submission. 482cabf08e4SMilan Broz * 483cabf08e4SMilan Broz * They must be separated as otherwise the final stages could be 484cabf08e4SMilan Broz * starved by new requests which can block in the first stages due 485cabf08e4SMilan Broz * to memory allocation. 4861da177e4SLinus Torvalds */ 487c4028958SDavid Howells static void kcryptd_do_work(struct work_struct *work); 488cabf08e4SMilan Broz static void kcryptd_do_crypt(struct work_struct *work); 4891da177e4SLinus Torvalds 490028867acSAlasdair G Kergon static void kcryptd_queue_io(struct dm_crypt_io *io) 4911da177e4SLinus Torvalds { 4929934a8beSMilan Broz struct crypt_config *cc = io->target->private; 4939934a8beSMilan Broz 494c4028958SDavid Howells INIT_WORK(&io->work, kcryptd_do_work); 495cabf08e4SMilan Broz queue_work(cc->io_queue, &io->work); 496cabf08e4SMilan Broz } 497cabf08e4SMilan Broz 498cabf08e4SMilan Broz static void kcryptd_queue_crypt(struct dm_crypt_io *io) 499cabf08e4SMilan Broz { 500cabf08e4SMilan Broz struct crypt_config *cc = io->target->private; 501cabf08e4SMilan Broz 502cabf08e4SMilan Broz INIT_WORK(&io->work, kcryptd_do_crypt); 503cabf08e4SMilan Broz queue_work(cc->crypt_queue, &io->work); 5041da177e4SLinus Torvalds } 5051da177e4SLinus Torvalds 5066712ecf8SNeilBrown static void crypt_endio(struct bio *clone, int error) 5078b004457SMilan Broz { 508028867acSAlasdair G Kergon struct dm_crypt_io *io = clone->bi_private; 5098b004457SMilan Broz struct crypt_config *cc = io->target->private; 5108b004457SMilan Broz unsigned read_io = bio_data_dir(clone) == READ; 5118b004457SMilan Broz 512adfe4770SMilan Broz if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) 513adfe4770SMilan Broz error = -EIO; 514adfe4770SMilan Broz 5158b004457SMilan Broz /* 5166712ecf8SNeilBrown * free the processed pages 5178b004457SMilan Broz */ 5186712ecf8SNeilBrown if (!read_io) { 519644bd2f0SNeil Brown crypt_free_buffer_pages(cc, clone); 5208b004457SMilan Broz goto out; 5216712ecf8SNeilBrown } 5228b004457SMilan Broz 523adfe4770SMilan Broz if (unlikely(error)) 5248b004457SMilan Broz goto out; 5258b004457SMilan Broz 5268b004457SMilan Broz bio_put(clone); 527cabf08e4SMilan Broz kcryptd_queue_crypt(io); 5286712ecf8SNeilBrown return; 5298b004457SMilan Broz 5308b004457SMilan Broz out: 5318b004457SMilan Broz bio_put(clone); 53280fd6626SMilan Broz crypt_dec_pending(io, error); 5338b004457SMilan Broz } 5348b004457SMilan Broz 535028867acSAlasdair G Kergon static void clone_init(struct dm_crypt_io *io, struct bio *clone) 5368b004457SMilan Broz { 5378b004457SMilan Broz struct crypt_config *cc = io->target->private; 5388b004457SMilan Broz 5398b004457SMilan Broz clone->bi_private = io; 5408b004457SMilan Broz clone->bi_end_io = crypt_endio; 5418b004457SMilan Broz clone->bi_bdev = cc->dev->bdev; 5428b004457SMilan Broz clone->bi_rw = io->base_bio->bi_rw; 543027581f3SOlaf Kirch clone->bi_destructor = dm_crypt_bio_destructor; 5448b004457SMilan Broz } 5458b004457SMilan Broz 546028867acSAlasdair G Kergon static void process_read(struct dm_crypt_io *io) 5478b004457SMilan Broz { 5488b004457SMilan Broz struct crypt_config *cc = io->target->private; 5498b004457SMilan Broz struct bio *base_bio = io->base_bio; 5508b004457SMilan Broz struct bio *clone; 55193e605c2SMilan Broz sector_t sector = base_bio->bi_sector - io->target->begin; 55293e605c2SMilan Broz 55393e605c2SMilan Broz atomic_inc(&io->pending); 5548b004457SMilan Broz 5558b004457SMilan Broz /* 5568b004457SMilan Broz * The block layer might modify the bvec array, so always 5578b004457SMilan Broz * copy the required bvecs because we need the original 5588b004457SMilan Broz * one in order to decrypt the whole bio data *afterwards*. 5598b004457SMilan Broz */ 5606a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); 56193e605c2SMilan Broz if (unlikely(!clone)) { 56280fd6626SMilan Broz crypt_dec_pending(io, -ENOMEM); 56323541d2dSMilan Broz return; 56493e605c2SMilan Broz } 5658b004457SMilan Broz 5668b004457SMilan Broz clone_init(io, clone); 5678b004457SMilan Broz clone->bi_idx = 0; 5688b004457SMilan Broz clone->bi_vcnt = bio_segments(base_bio); 5698b004457SMilan Broz clone->bi_size = base_bio->bi_size; 57093e605c2SMilan Broz clone->bi_sector = cc->start + sector; 5718b004457SMilan Broz memcpy(clone->bi_io_vec, bio_iovec(base_bio), 5728b004457SMilan Broz sizeof(struct bio_vec) * clone->bi_vcnt); 5738b004457SMilan Broz 57493e605c2SMilan Broz generic_make_request(clone); 5758b004457SMilan Broz } 5768b004457SMilan Broz 577028867acSAlasdair G Kergon static void process_write(struct dm_crypt_io *io) 5788b004457SMilan Broz { 5798b004457SMilan Broz struct crypt_config *cc = io->target->private; 5808b004457SMilan Broz struct bio *base_bio = io->base_bio; 5818b004457SMilan Broz struct bio *clone; 58293e605c2SMilan Broz struct convert_context ctx; 58393e605c2SMilan Broz unsigned remaining = base_bio->bi_size; 58493e605c2SMilan Broz sector_t sector = base_bio->bi_sector - io->target->begin; 5858b004457SMilan Broz 58693e605c2SMilan Broz atomic_inc(&io->pending); 58793e605c2SMilan Broz 58893e605c2SMilan Broz crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1); 58993e605c2SMilan Broz 59093e605c2SMilan Broz /* 59193e605c2SMilan Broz * The allocated buffers can be smaller than the whole bio, 59293e605c2SMilan Broz * so repeat the whole process until all the data can be handled. 59393e605c2SMilan Broz */ 59493e605c2SMilan Broz while (remaining) { 595f97380bcSOlaf Kirch clone = crypt_alloc_buffer(io, remaining); 59623541d2dSMilan Broz if (unlikely(!clone)) { 59780fd6626SMilan Broz crypt_dec_pending(io, -ENOMEM); 59823541d2dSMilan Broz return; 59923541d2dSMilan Broz } 6008b004457SMilan Broz 60193e605c2SMilan Broz ctx.bio_out = clone; 602f97380bcSOlaf Kirch ctx.idx_out = 0; 6038b004457SMilan Broz 60493e605c2SMilan Broz if (unlikely(crypt_convert(cc, &ctx) < 0)) { 605644bd2f0SNeil Brown crypt_free_buffer_pages(cc, clone); 6068b004457SMilan Broz bio_put(clone); 60780fd6626SMilan Broz crypt_dec_pending(io, -EIO); 60823541d2dSMilan Broz return; 6098b004457SMilan Broz } 6108b004457SMilan Broz 611f97380bcSOlaf Kirch /* crypt_convert should have filled the clone bio */ 612f97380bcSOlaf Kirch BUG_ON(ctx.idx_out < clone->bi_vcnt); 613f97380bcSOlaf Kirch 6148b004457SMilan Broz clone->bi_sector = cc->start + sector; 61593e605c2SMilan Broz remaining -= clone->bi_size; 61693e605c2SMilan Broz sector += bio_sectors(clone); 61793e605c2SMilan Broz 6182f9941b6SOlaf Kirch /* Grab another reference to the io struct 6192f9941b6SOlaf Kirch * before we kick off the request */ 62023541d2dSMilan Broz if (remaining) 62123541d2dSMilan Broz atomic_inc(&io->pending); 62223541d2dSMilan Broz 62393e605c2SMilan Broz generic_make_request(clone); 62493e605c2SMilan Broz 62598221eb7SOlaf Kirch /* Do not reference clone after this - it 62698221eb7SOlaf Kirch * may be gone already. */ 62798221eb7SOlaf Kirch 62893e605c2SMilan Broz /* out of memory -> run queues */ 62993e605c2SMilan Broz if (remaining) 63098221eb7SOlaf Kirch congestion_wait(WRITE, HZ/100); 63193e605c2SMilan Broz } 6328b004457SMilan Broz } 6338b004457SMilan Broz 634028867acSAlasdair G Kergon static void process_read_endio(struct dm_crypt_io *io) 6358b004457SMilan Broz { 6368b004457SMilan Broz struct crypt_config *cc = io->target->private; 6378b004457SMilan Broz struct convert_context ctx; 6388b004457SMilan Broz 6398b004457SMilan Broz crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio, 6408b004457SMilan Broz io->base_bio->bi_sector - io->target->begin, 0); 6418b004457SMilan Broz 64280fd6626SMilan Broz crypt_dec_pending(io, crypt_convert(cc, &ctx)); 6438b004457SMilan Broz } 6448b004457SMilan Broz 645c4028958SDavid Howells static void kcryptd_do_work(struct work_struct *work) 6468b004457SMilan Broz { 647028867acSAlasdair G Kergon struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 6488b004457SMilan Broz 649cabf08e4SMilan Broz if (bio_data_dir(io->base_bio) == READ) 65023541d2dSMilan Broz process_read(io); 651cabf08e4SMilan Broz } 652cabf08e4SMilan Broz 653cabf08e4SMilan Broz static void kcryptd_do_crypt(struct work_struct *work) 654cabf08e4SMilan Broz { 655cabf08e4SMilan Broz struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 656cabf08e4SMilan Broz 657cabf08e4SMilan Broz if (bio_data_dir(io->base_bio) == READ) 658cabf08e4SMilan Broz process_read_endio(io); 65923541d2dSMilan Broz else 66023541d2dSMilan Broz process_write(io); 6618b004457SMilan Broz } 6628b004457SMilan Broz 6631da177e4SLinus Torvalds /* 6641da177e4SLinus Torvalds * Decode key from its hex representation 6651da177e4SLinus Torvalds */ 6661da177e4SLinus Torvalds static int crypt_decode_key(u8 *key, char *hex, unsigned int size) 6671da177e4SLinus Torvalds { 6681da177e4SLinus Torvalds char buffer[3]; 6691da177e4SLinus Torvalds char *endp; 6701da177e4SLinus Torvalds unsigned int i; 6711da177e4SLinus Torvalds 6721da177e4SLinus Torvalds buffer[2] = '\0'; 6731da177e4SLinus Torvalds 6741da177e4SLinus Torvalds for (i = 0; i < size; i++) { 6751da177e4SLinus Torvalds buffer[0] = *hex++; 6761da177e4SLinus Torvalds buffer[1] = *hex++; 6771da177e4SLinus Torvalds 6781da177e4SLinus Torvalds key[i] = (u8)simple_strtoul(buffer, &endp, 16); 6791da177e4SLinus Torvalds 6801da177e4SLinus Torvalds if (endp != &buffer[2]) 6811da177e4SLinus Torvalds return -EINVAL; 6821da177e4SLinus Torvalds } 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds if (*hex != '\0') 6851da177e4SLinus Torvalds return -EINVAL; 6861da177e4SLinus Torvalds 6871da177e4SLinus Torvalds return 0; 6881da177e4SLinus Torvalds } 6891da177e4SLinus Torvalds 6901da177e4SLinus Torvalds /* 6911da177e4SLinus Torvalds * Encode key into its hex representation 6921da177e4SLinus Torvalds */ 6931da177e4SLinus Torvalds static void crypt_encode_key(char *hex, u8 *key, unsigned int size) 6941da177e4SLinus Torvalds { 6951da177e4SLinus Torvalds unsigned int i; 6961da177e4SLinus Torvalds 6971da177e4SLinus Torvalds for (i = 0; i < size; i++) { 6981da177e4SLinus Torvalds sprintf(hex, "%02x", *key); 6991da177e4SLinus Torvalds hex += 2; 7001da177e4SLinus Torvalds key++; 7011da177e4SLinus Torvalds } 7021da177e4SLinus Torvalds } 7031da177e4SLinus Torvalds 704e48d4bbfSMilan Broz static int crypt_set_key(struct crypt_config *cc, char *key) 705e48d4bbfSMilan Broz { 706e48d4bbfSMilan Broz unsigned key_size = strlen(key) >> 1; 707e48d4bbfSMilan Broz 708e48d4bbfSMilan Broz if (cc->key_size && cc->key_size != key_size) 709e48d4bbfSMilan Broz return -EINVAL; 710e48d4bbfSMilan Broz 711e48d4bbfSMilan Broz cc->key_size = key_size; /* initial settings */ 712e48d4bbfSMilan Broz 713e48d4bbfSMilan Broz if ((!key_size && strcmp(key, "-")) || 714e48d4bbfSMilan Broz (key_size && crypt_decode_key(cc->key, key, key_size) < 0)) 715e48d4bbfSMilan Broz return -EINVAL; 716e48d4bbfSMilan Broz 717e48d4bbfSMilan Broz set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 718e48d4bbfSMilan Broz 719e48d4bbfSMilan Broz return 0; 720e48d4bbfSMilan Broz } 721e48d4bbfSMilan Broz 722e48d4bbfSMilan Broz static int crypt_wipe_key(struct crypt_config *cc) 723e48d4bbfSMilan Broz { 724e48d4bbfSMilan Broz clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 725e48d4bbfSMilan Broz memset(&cc->key, 0, cc->key_size * sizeof(u8)); 726e48d4bbfSMilan Broz return 0; 727e48d4bbfSMilan Broz } 728e48d4bbfSMilan Broz 7291da177e4SLinus Torvalds /* 7301da177e4SLinus Torvalds * Construct an encryption mapping: 7311da177e4SLinus Torvalds * <cipher> <key> <iv_offset> <dev_path> <start> 7321da177e4SLinus Torvalds */ 7331da177e4SLinus Torvalds static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 7341da177e4SLinus Torvalds { 7351da177e4SLinus Torvalds struct crypt_config *cc; 736d1806f6aSHerbert Xu struct crypto_blkcipher *tfm; 7371da177e4SLinus Torvalds char *tmp; 7381da177e4SLinus Torvalds char *cipher; 7391da177e4SLinus Torvalds char *chainmode; 7401da177e4SLinus Torvalds char *ivmode; 7411da177e4SLinus Torvalds char *ivopts; 7421da177e4SLinus Torvalds unsigned int key_size; 7434ee218cdSAndrew Morton unsigned long long tmpll; 7441da177e4SLinus Torvalds 7451da177e4SLinus Torvalds if (argc != 5) { 74672d94861SAlasdair G Kergon ti->error = "Not enough arguments"; 7471da177e4SLinus Torvalds return -EINVAL; 7481da177e4SLinus Torvalds } 7491da177e4SLinus Torvalds 7501da177e4SLinus Torvalds tmp = argv[0]; 7511da177e4SLinus Torvalds cipher = strsep(&tmp, "-"); 7521da177e4SLinus Torvalds chainmode = strsep(&tmp, "-"); 7531da177e4SLinus Torvalds ivopts = strsep(&tmp, "-"); 7541da177e4SLinus Torvalds ivmode = strsep(&ivopts, ":"); 7551da177e4SLinus Torvalds 7561da177e4SLinus Torvalds if (tmp) 75772d94861SAlasdair G Kergon DMWARN("Unexpected additional cipher options"); 7581da177e4SLinus Torvalds 7591da177e4SLinus Torvalds key_size = strlen(argv[1]) >> 1; 7601da177e4SLinus Torvalds 761e48d4bbfSMilan Broz cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); 7621da177e4SLinus Torvalds if (cc == NULL) { 7631da177e4SLinus Torvalds ti->error = 76472d94861SAlasdair G Kergon "Cannot allocate transparent encryption context"; 7651da177e4SLinus Torvalds return -ENOMEM; 7661da177e4SLinus Torvalds } 7671da177e4SLinus Torvalds 768e48d4bbfSMilan Broz if (crypt_set_key(cc, argv[1])) { 76972d94861SAlasdair G Kergon ti->error = "Error decoding key"; 770636d5786SMilan Broz goto bad_cipher; 7711da177e4SLinus Torvalds } 7721da177e4SLinus Torvalds 7731da177e4SLinus Torvalds /* Compatiblity mode for old dm-crypt cipher strings */ 7741da177e4SLinus Torvalds if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { 7751da177e4SLinus Torvalds chainmode = "cbc"; 7761da177e4SLinus Torvalds ivmode = "plain"; 7771da177e4SLinus Torvalds } 7781da177e4SLinus Torvalds 779d1806f6aSHerbert Xu if (strcmp(chainmode, "ecb") && !ivmode) { 78072d94861SAlasdair G Kergon ti->error = "This chaining mode requires an IV mechanism"; 781636d5786SMilan Broz goto bad_cipher; 7821da177e4SLinus Torvalds } 7831da177e4SLinus Torvalds 784d469f841SMilan Broz if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", 785d469f841SMilan Broz chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) { 786d1806f6aSHerbert Xu ti->error = "Chain mode + cipher name is too long"; 787636d5786SMilan Broz goto bad_cipher; 788d1806f6aSHerbert Xu } 789d1806f6aSHerbert Xu 790d1806f6aSHerbert Xu tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 791d1806f6aSHerbert Xu if (IS_ERR(tfm)) { 79272d94861SAlasdair G Kergon ti->error = "Error allocating crypto tfm"; 793636d5786SMilan Broz goto bad_cipher; 7941da177e4SLinus Torvalds } 7951da177e4SLinus Torvalds 796d1806f6aSHerbert Xu strcpy(cc->cipher, cipher); 797d1806f6aSHerbert Xu strcpy(cc->chainmode, chainmode); 7981da177e4SLinus Torvalds cc->tfm = tfm; 7991da177e4SLinus Torvalds 8001da177e4SLinus Torvalds /* 80148527fa7SRik Snel * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi". 8021da177e4SLinus Torvalds * See comments at iv code 8031da177e4SLinus Torvalds */ 8041da177e4SLinus Torvalds 8051da177e4SLinus Torvalds if (ivmode == NULL) 8061da177e4SLinus Torvalds cc->iv_gen_ops = NULL; 8071da177e4SLinus Torvalds else if (strcmp(ivmode, "plain") == 0) 8081da177e4SLinus Torvalds cc->iv_gen_ops = &crypt_iv_plain_ops; 8091da177e4SLinus Torvalds else if (strcmp(ivmode, "essiv") == 0) 8101da177e4SLinus Torvalds cc->iv_gen_ops = &crypt_iv_essiv_ops; 81148527fa7SRik Snel else if (strcmp(ivmode, "benbi") == 0) 81248527fa7SRik Snel cc->iv_gen_ops = &crypt_iv_benbi_ops; 81346b47730SLudwig Nussel else if (strcmp(ivmode, "null") == 0) 81446b47730SLudwig Nussel cc->iv_gen_ops = &crypt_iv_null_ops; 8151da177e4SLinus Torvalds else { 81672d94861SAlasdair G Kergon ti->error = "Invalid IV mode"; 817636d5786SMilan Broz goto bad_ivmode; 8181da177e4SLinus Torvalds } 8191da177e4SLinus Torvalds 8201da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && 8211da177e4SLinus Torvalds cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) 822636d5786SMilan Broz goto bad_ivmode; 8231da177e4SLinus Torvalds 824d1806f6aSHerbert Xu cc->iv_size = crypto_blkcipher_ivsize(tfm); 825d1806f6aSHerbert Xu if (cc->iv_size) 8261da177e4SLinus Torvalds /* at least a 64 bit sector number should fit in our buffer */ 827d1806f6aSHerbert Xu cc->iv_size = max(cc->iv_size, 8281da177e4SLinus Torvalds (unsigned int)(sizeof(u64) / sizeof(u8))); 8291da177e4SLinus Torvalds else { 8301da177e4SLinus Torvalds if (cc->iv_gen_ops) { 83172d94861SAlasdair G Kergon DMWARN("Selected cipher does not support IVs"); 8321da177e4SLinus Torvalds if (cc->iv_gen_ops->dtr) 8331da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 8341da177e4SLinus Torvalds cc->iv_gen_ops = NULL; 8351da177e4SLinus Torvalds } 8361da177e4SLinus Torvalds } 8371da177e4SLinus Torvalds 83893d2341cSMatthew Dobson cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); 8391da177e4SLinus Torvalds if (!cc->io_pool) { 84072d94861SAlasdair G Kergon ti->error = "Cannot allocate crypt io mempool"; 841636d5786SMilan Broz goto bad_slab_pool; 8421da177e4SLinus Torvalds } 8431da177e4SLinus Torvalds 844a19b27ceSMatthew Dobson cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); 8451da177e4SLinus Torvalds if (!cc->page_pool) { 84672d94861SAlasdair G Kergon ti->error = "Cannot allocate page mempool"; 847636d5786SMilan Broz goto bad_page_pool; 8481da177e4SLinus Torvalds } 8491da177e4SLinus Torvalds 8505972511bSJens Axboe cc->bs = bioset_create(MIN_IOS, MIN_IOS); 8516a24c718SMilan Broz if (!cc->bs) { 8526a24c718SMilan Broz ti->error = "Cannot allocate crypt bioset"; 8536a24c718SMilan Broz goto bad_bs; 8546a24c718SMilan Broz } 8556a24c718SMilan Broz 856d1806f6aSHerbert Xu if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) { 85772d94861SAlasdair G Kergon ti->error = "Error setting key"; 858636d5786SMilan Broz goto bad_device; 8591da177e4SLinus Torvalds } 8601da177e4SLinus Torvalds 8614ee218cdSAndrew Morton if (sscanf(argv[2], "%llu", &tmpll) != 1) { 86272d94861SAlasdair G Kergon ti->error = "Invalid iv_offset sector"; 863636d5786SMilan Broz goto bad_device; 8641da177e4SLinus Torvalds } 8654ee218cdSAndrew Morton cc->iv_offset = tmpll; 8661da177e4SLinus Torvalds 8674ee218cdSAndrew Morton if (sscanf(argv[4], "%llu", &tmpll) != 1) { 86872d94861SAlasdair G Kergon ti->error = "Invalid device sector"; 869636d5786SMilan Broz goto bad_device; 8701da177e4SLinus Torvalds } 8714ee218cdSAndrew Morton cc->start = tmpll; 8721da177e4SLinus Torvalds 8731da177e4SLinus Torvalds if (dm_get_device(ti, argv[3], cc->start, ti->len, 8741da177e4SLinus Torvalds dm_table_get_mode(ti->table), &cc->dev)) { 87572d94861SAlasdair G Kergon ti->error = "Device lookup failed"; 876636d5786SMilan Broz goto bad_device; 8771da177e4SLinus Torvalds } 8781da177e4SLinus Torvalds 8791da177e4SLinus Torvalds if (ivmode && cc->iv_gen_ops) { 8801da177e4SLinus Torvalds if (ivopts) 8811da177e4SLinus Torvalds *(ivopts - 1) = ':'; 8821da177e4SLinus Torvalds cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); 8831da177e4SLinus Torvalds if (!cc->iv_mode) { 88472d94861SAlasdair G Kergon ti->error = "Error kmallocing iv_mode string"; 885636d5786SMilan Broz goto bad_ivmode_string; 8861da177e4SLinus Torvalds } 8871da177e4SLinus Torvalds strcpy(cc->iv_mode, ivmode); 8881da177e4SLinus Torvalds } else 8891da177e4SLinus Torvalds cc->iv_mode = NULL; 8901da177e4SLinus Torvalds 891cabf08e4SMilan Broz cc->io_queue = create_singlethread_workqueue("kcryptd_io"); 892cabf08e4SMilan Broz if (!cc->io_queue) { 893cabf08e4SMilan Broz ti->error = "Couldn't create kcryptd io queue"; 894cabf08e4SMilan Broz goto bad_io_queue; 895cabf08e4SMilan Broz } 896cabf08e4SMilan Broz 897cabf08e4SMilan Broz cc->crypt_queue = create_singlethread_workqueue("kcryptd"); 898cabf08e4SMilan Broz if (!cc->crypt_queue) { 8999934a8beSMilan Broz ti->error = "Couldn't create kcryptd queue"; 900cabf08e4SMilan Broz goto bad_crypt_queue; 9019934a8beSMilan Broz } 9029934a8beSMilan Broz 9031da177e4SLinus Torvalds ti->private = cc; 9041da177e4SLinus Torvalds return 0; 9051da177e4SLinus Torvalds 906cabf08e4SMilan Broz bad_crypt_queue: 907cabf08e4SMilan Broz destroy_workqueue(cc->io_queue); 908cabf08e4SMilan Broz bad_io_queue: 9099934a8beSMilan Broz kfree(cc->iv_mode); 910636d5786SMilan Broz bad_ivmode_string: 91155b42c5aSDmitry Monakhov dm_put_device(ti, cc->dev); 912636d5786SMilan Broz bad_device: 9136a24c718SMilan Broz bioset_free(cc->bs); 9146a24c718SMilan Broz bad_bs: 9151da177e4SLinus Torvalds mempool_destroy(cc->page_pool); 916636d5786SMilan Broz bad_page_pool: 9171da177e4SLinus Torvalds mempool_destroy(cc->io_pool); 918636d5786SMilan Broz bad_slab_pool: 9191da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 9201da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 921636d5786SMilan Broz bad_ivmode: 922d1806f6aSHerbert Xu crypto_free_blkcipher(tfm); 923636d5786SMilan Broz bad_cipher: 9249d3520a3SStefan Rompf /* Must zero key material before freeing */ 9259d3520a3SStefan Rompf memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); 9261da177e4SLinus Torvalds kfree(cc); 9271da177e4SLinus Torvalds return -EINVAL; 9281da177e4SLinus Torvalds } 9291da177e4SLinus Torvalds 9301da177e4SLinus Torvalds static void crypt_dtr(struct dm_target *ti) 9311da177e4SLinus Torvalds { 9321da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) ti->private; 9331da177e4SLinus Torvalds 934cabf08e4SMilan Broz destroy_workqueue(cc->io_queue); 935cabf08e4SMilan Broz destroy_workqueue(cc->crypt_queue); 93680b16c19SMilan Broz 9376a24c718SMilan Broz bioset_free(cc->bs); 9381da177e4SLinus Torvalds mempool_destroy(cc->page_pool); 9391da177e4SLinus Torvalds mempool_destroy(cc->io_pool); 9401da177e4SLinus Torvalds 9411da177e4SLinus Torvalds kfree(cc->iv_mode); 9421da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 9431da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 944d1806f6aSHerbert Xu crypto_free_blkcipher(cc->tfm); 9451da177e4SLinus Torvalds dm_put_device(ti, cc->dev); 9469d3520a3SStefan Rompf 9479d3520a3SStefan Rompf /* Must zero key material before freeing */ 9489d3520a3SStefan Rompf memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); 9491da177e4SLinus Torvalds kfree(cc); 9501da177e4SLinus Torvalds } 9511da177e4SLinus Torvalds 9521da177e4SLinus Torvalds static int crypt_map(struct dm_target *ti, struct bio *bio, 9531da177e4SLinus Torvalds union map_info *map_context) 9541da177e4SLinus Torvalds { 9558b004457SMilan Broz struct crypt_config *cc = ti->private; 956028867acSAlasdair G Kergon struct dm_crypt_io *io; 9571da177e4SLinus Torvalds 958e48d4bbfSMilan Broz io = mempool_alloc(cc->io_pool, GFP_NOIO); 9591da177e4SLinus Torvalds io->target = ti; 9608b004457SMilan Broz io->base_bio = bio; 961cabf08e4SMilan Broz io->error = 0; 96293e605c2SMilan Broz atomic_set(&io->pending, 0); 963cabf08e4SMilan Broz 964cabf08e4SMilan Broz if (bio_data_dir(io->base_bio) == READ) 96523541d2dSMilan Broz kcryptd_queue_io(io); 966cabf08e4SMilan Broz else 967cabf08e4SMilan Broz kcryptd_queue_crypt(io); 9681da177e4SLinus Torvalds 969d2a7ad29SKiyoshi Ueda return DM_MAPIO_SUBMITTED; 9701da177e4SLinus Torvalds } 9711da177e4SLinus Torvalds 9721da177e4SLinus Torvalds static int crypt_status(struct dm_target *ti, status_type_t type, 9731da177e4SLinus Torvalds char *result, unsigned int maxlen) 9741da177e4SLinus Torvalds { 9751da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) ti->private; 9761da177e4SLinus Torvalds unsigned int sz = 0; 9771da177e4SLinus Torvalds 9781da177e4SLinus Torvalds switch (type) { 9791da177e4SLinus Torvalds case STATUSTYPE_INFO: 9801da177e4SLinus Torvalds result[0] = '\0'; 9811da177e4SLinus Torvalds break; 9821da177e4SLinus Torvalds 9831da177e4SLinus Torvalds case STATUSTYPE_TABLE: 9841da177e4SLinus Torvalds if (cc->iv_mode) 98537af6560SChristophe Saout DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode, 98637af6560SChristophe Saout cc->iv_mode); 9871da177e4SLinus Torvalds else 98837af6560SChristophe Saout DMEMIT("%s-%s ", cc->cipher, cc->chainmode); 9891da177e4SLinus Torvalds 9901da177e4SLinus Torvalds if (cc->key_size > 0) { 9911da177e4SLinus Torvalds if ((maxlen - sz) < ((cc->key_size << 1) + 1)) 9921da177e4SLinus Torvalds return -ENOMEM; 9931da177e4SLinus Torvalds 9941da177e4SLinus Torvalds crypt_encode_key(result + sz, cc->key, cc->key_size); 9951da177e4SLinus Torvalds sz += cc->key_size << 1; 9961da177e4SLinus Torvalds } else { 9971da177e4SLinus Torvalds if (sz >= maxlen) 9981da177e4SLinus Torvalds return -ENOMEM; 9991da177e4SLinus Torvalds result[sz++] = '-'; 10001da177e4SLinus Torvalds } 10011da177e4SLinus Torvalds 10024ee218cdSAndrew Morton DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 10034ee218cdSAndrew Morton cc->dev->name, (unsigned long long)cc->start); 10041da177e4SLinus Torvalds break; 10051da177e4SLinus Torvalds } 10061da177e4SLinus Torvalds return 0; 10071da177e4SLinus Torvalds } 10081da177e4SLinus Torvalds 1009e48d4bbfSMilan Broz static void crypt_postsuspend(struct dm_target *ti) 1010e48d4bbfSMilan Broz { 1011e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1012e48d4bbfSMilan Broz 1013e48d4bbfSMilan Broz set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 1014e48d4bbfSMilan Broz } 1015e48d4bbfSMilan Broz 1016e48d4bbfSMilan Broz static int crypt_preresume(struct dm_target *ti) 1017e48d4bbfSMilan Broz { 1018e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1019e48d4bbfSMilan Broz 1020e48d4bbfSMilan Broz if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 1021e48d4bbfSMilan Broz DMERR("aborting resume - crypt key is not set."); 1022e48d4bbfSMilan Broz return -EAGAIN; 1023e48d4bbfSMilan Broz } 1024e48d4bbfSMilan Broz 1025e48d4bbfSMilan Broz return 0; 1026e48d4bbfSMilan Broz } 1027e48d4bbfSMilan Broz 1028e48d4bbfSMilan Broz static void crypt_resume(struct dm_target *ti) 1029e48d4bbfSMilan Broz { 1030e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1031e48d4bbfSMilan Broz 1032e48d4bbfSMilan Broz clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 1033e48d4bbfSMilan Broz } 1034e48d4bbfSMilan Broz 1035e48d4bbfSMilan Broz /* Message interface 1036e48d4bbfSMilan Broz * key set <key> 1037e48d4bbfSMilan Broz * key wipe 1038e48d4bbfSMilan Broz */ 1039e48d4bbfSMilan Broz static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) 1040e48d4bbfSMilan Broz { 1041e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1042e48d4bbfSMilan Broz 1043e48d4bbfSMilan Broz if (argc < 2) 1044e48d4bbfSMilan Broz goto error; 1045e48d4bbfSMilan Broz 1046e48d4bbfSMilan Broz if (!strnicmp(argv[0], MESG_STR("key"))) { 1047e48d4bbfSMilan Broz if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 1048e48d4bbfSMilan Broz DMWARN("not suspended during key manipulation."); 1049e48d4bbfSMilan Broz return -EINVAL; 1050e48d4bbfSMilan Broz } 1051e48d4bbfSMilan Broz if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) 1052e48d4bbfSMilan Broz return crypt_set_key(cc, argv[2]); 1053e48d4bbfSMilan Broz if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) 1054e48d4bbfSMilan Broz return crypt_wipe_key(cc); 1055e48d4bbfSMilan Broz } 1056e48d4bbfSMilan Broz 1057e48d4bbfSMilan Broz error: 1058e48d4bbfSMilan Broz DMWARN("unrecognised message received."); 1059e48d4bbfSMilan Broz return -EINVAL; 1060e48d4bbfSMilan Broz } 1061e48d4bbfSMilan Broz 10621da177e4SLinus Torvalds static struct target_type crypt_target = { 10631da177e4SLinus Torvalds .name = "crypt", 106446b47730SLudwig Nussel .version= {1, 5, 0}, 10651da177e4SLinus Torvalds .module = THIS_MODULE, 10661da177e4SLinus Torvalds .ctr = crypt_ctr, 10671da177e4SLinus Torvalds .dtr = crypt_dtr, 10681da177e4SLinus Torvalds .map = crypt_map, 10691da177e4SLinus Torvalds .status = crypt_status, 1070e48d4bbfSMilan Broz .postsuspend = crypt_postsuspend, 1071e48d4bbfSMilan Broz .preresume = crypt_preresume, 1072e48d4bbfSMilan Broz .resume = crypt_resume, 1073e48d4bbfSMilan Broz .message = crypt_message, 10741da177e4SLinus Torvalds }; 10751da177e4SLinus Torvalds 10761da177e4SLinus Torvalds static int __init dm_crypt_init(void) 10771da177e4SLinus Torvalds { 10781da177e4SLinus Torvalds int r; 10791da177e4SLinus Torvalds 1080028867acSAlasdair G Kergon _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0); 10811da177e4SLinus Torvalds if (!_crypt_io_pool) 10821da177e4SLinus Torvalds return -ENOMEM; 10831da177e4SLinus Torvalds 10841da177e4SLinus Torvalds r = dm_register_target(&crypt_target); 10851da177e4SLinus Torvalds if (r < 0) { 108672d94861SAlasdair G Kergon DMERR("register failed %d", r); 10879934a8beSMilan Broz kmem_cache_destroy(_crypt_io_pool); 10881da177e4SLinus Torvalds } 10891da177e4SLinus Torvalds 10901da177e4SLinus Torvalds return r; 10911da177e4SLinus Torvalds } 10921da177e4SLinus Torvalds 10931da177e4SLinus Torvalds static void __exit dm_crypt_exit(void) 10941da177e4SLinus Torvalds { 10951da177e4SLinus Torvalds int r = dm_unregister_target(&crypt_target); 10961da177e4SLinus Torvalds 10971da177e4SLinus Torvalds if (r < 0) 109872d94861SAlasdair G Kergon DMERR("unregister failed %d", r); 10991da177e4SLinus Torvalds 11001da177e4SLinus Torvalds kmem_cache_destroy(_crypt_io_pool); 11011da177e4SLinus Torvalds } 11021da177e4SLinus Torvalds 11031da177e4SLinus Torvalds module_init(dm_crypt_init); 11041da177e4SLinus Torvalds module_exit(dm_crypt_exit); 11051da177e4SLinus Torvalds 11061da177e4SLinus Torvalds MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); 11071da177e4SLinus Torvalds MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 11081da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1109