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 1161da177e4SLinus Torvalds * number, padded with zeros if neccessary. 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 171378f058cSDavid Hardeman sg_set_buf(&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); 3511da177e4SLinus Torvalds struct scatterlist sg_in = { 3521da177e4SLinus Torvalds .page = bv_in->bv_page, 3531da177e4SLinus Torvalds .offset = bv_in->bv_offset + ctx->offset_in, 3541da177e4SLinus Torvalds .length = 1 << SECTOR_SHIFT 3551da177e4SLinus Torvalds }; 3561da177e4SLinus Torvalds struct scatterlist sg_out = { 3571da177e4SLinus Torvalds .page = bv_out->bv_page, 3581da177e4SLinus Torvalds .offset = bv_out->bv_offset + ctx->offset_out, 3591da177e4SLinus Torvalds .length = 1 << SECTOR_SHIFT 3601da177e4SLinus Torvalds }; 3611da177e4SLinus Torvalds 3621da177e4SLinus Torvalds ctx->offset_in += sg_in.length; 3631da177e4SLinus Torvalds if (ctx->offset_in >= bv_in->bv_len) { 3641da177e4SLinus Torvalds ctx->offset_in = 0; 3651da177e4SLinus Torvalds ctx->idx_in++; 3661da177e4SLinus Torvalds } 3671da177e4SLinus Torvalds 3681da177e4SLinus Torvalds ctx->offset_out += sg_out.length; 3691da177e4SLinus Torvalds if (ctx->offset_out >= bv_out->bv_len) { 3701da177e4SLinus Torvalds ctx->offset_out = 0; 3711da177e4SLinus Torvalds ctx->idx_out++; 3721da177e4SLinus Torvalds } 3731da177e4SLinus Torvalds 3741da177e4SLinus Torvalds r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, 3751da177e4SLinus Torvalds ctx->write, ctx->sector); 3761da177e4SLinus Torvalds if (r < 0) 3771da177e4SLinus Torvalds break; 3781da177e4SLinus Torvalds 3791da177e4SLinus Torvalds ctx->sector++; 3801da177e4SLinus Torvalds } 3811da177e4SLinus Torvalds 3821da177e4SLinus Torvalds return r; 3831da177e4SLinus Torvalds } 3841da177e4SLinus Torvalds 3856a24c718SMilan Broz static void dm_crypt_bio_destructor(struct bio *bio) 3866a24c718SMilan Broz { 387028867acSAlasdair G Kergon struct dm_crypt_io *io = bio->bi_private; 3886a24c718SMilan Broz struct crypt_config *cc = io->target->private; 3896a24c718SMilan Broz 3906a24c718SMilan Broz bio_free(bio, cc->bs); 3916a24c718SMilan Broz } 3926a24c718SMilan Broz 3931da177e4SLinus Torvalds /* 3941da177e4SLinus Torvalds * Generate a new unfragmented bio with the given size 3951da177e4SLinus Torvalds * This should never violate the device limitations 3961da177e4SLinus Torvalds * May return a smaller bio when running out of pages 3971da177e4SLinus Torvalds */ 398028867acSAlasdair G Kergon static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) 3991da177e4SLinus Torvalds { 400027581f3SOlaf Kirch struct crypt_config *cc = io->target->private; 4018b004457SMilan Broz struct bio *clone; 4021da177e4SLinus Torvalds unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 403b4e3ca1aSAl Viro gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; 4041da177e4SLinus Torvalds unsigned int i; 4051da177e4SLinus Torvalds 4066a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); 4078b004457SMilan Broz if (!clone) 4081da177e4SLinus Torvalds return NULL; 4091da177e4SLinus Torvalds 410027581f3SOlaf Kirch clone_init(io, clone); 4116a24c718SMilan Broz 412f97380bcSOlaf Kirch for (i = 0; i < nr_iovecs; i++) { 4138b004457SMilan Broz struct bio_vec *bv = bio_iovec_idx(clone, i); 4141da177e4SLinus Torvalds 4151da177e4SLinus Torvalds bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask); 4161da177e4SLinus Torvalds if (!bv->bv_page) 4171da177e4SLinus Torvalds break; 4181da177e4SLinus Torvalds 4191da177e4SLinus Torvalds /* 4201da177e4SLinus Torvalds * if additional pages cannot be allocated without waiting, 4211da177e4SLinus Torvalds * return a partially allocated bio, the caller will then try 4221da177e4SLinus Torvalds * to allocate additional bios while submitting this partial bio 4231da177e4SLinus Torvalds */ 424f97380bcSOlaf Kirch if (i == (MIN_BIO_PAGES - 1)) 4251da177e4SLinus Torvalds gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; 4261da177e4SLinus Torvalds 4271da177e4SLinus Torvalds bv->bv_offset = 0; 4281da177e4SLinus Torvalds if (size > PAGE_SIZE) 4291da177e4SLinus Torvalds bv->bv_len = PAGE_SIZE; 4301da177e4SLinus Torvalds else 4311da177e4SLinus Torvalds bv->bv_len = size; 4321da177e4SLinus Torvalds 4338b004457SMilan Broz clone->bi_size += bv->bv_len; 4348b004457SMilan Broz clone->bi_vcnt++; 4351da177e4SLinus Torvalds size -= bv->bv_len; 4361da177e4SLinus Torvalds } 4371da177e4SLinus Torvalds 4388b004457SMilan Broz if (!clone->bi_size) { 4398b004457SMilan Broz bio_put(clone); 4401da177e4SLinus Torvalds return NULL; 4411da177e4SLinus Torvalds } 4421da177e4SLinus Torvalds 4438b004457SMilan Broz return clone; 4441da177e4SLinus Torvalds } 4451da177e4SLinus Torvalds 446644bd2f0SNeil Brown static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) 4471da177e4SLinus Torvalds { 448644bd2f0SNeil Brown unsigned int i; 4491da177e4SLinus Torvalds struct bio_vec *bv; 4501da177e4SLinus Torvalds 451644bd2f0SNeil Brown for (i = 0; i < clone->bi_vcnt; i++) { 4528b004457SMilan Broz bv = bio_iovec_idx(clone, i); 4531da177e4SLinus Torvalds BUG_ON(!bv->bv_page); 4541da177e4SLinus Torvalds mempool_free(bv->bv_page, cc->page_pool); 4551da177e4SLinus Torvalds bv->bv_page = NULL; 4561da177e4SLinus Torvalds } 4571da177e4SLinus Torvalds } 4581da177e4SLinus Torvalds 4591da177e4SLinus Torvalds /* 4601da177e4SLinus Torvalds * One of the bios was finished. Check for completion of 4611da177e4SLinus Torvalds * the whole request and correctly clean up the buffer. 4621da177e4SLinus Torvalds */ 46380fd6626SMilan Broz static void crypt_dec_pending(struct dm_crypt_io *io, int error) 4641da177e4SLinus Torvalds { 4651da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) io->target->private; 4661da177e4SLinus Torvalds 4671da177e4SLinus Torvalds if (error < 0) 4681da177e4SLinus Torvalds io->error = error; 4691da177e4SLinus Torvalds 4701da177e4SLinus Torvalds if (!atomic_dec_and_test(&io->pending)) 4711da177e4SLinus Torvalds return; 4721da177e4SLinus Torvalds 4736712ecf8SNeilBrown bio_endio(io->base_bio, io->error); 4741da177e4SLinus Torvalds 4751da177e4SLinus Torvalds mempool_free(io, cc->io_pool); 4761da177e4SLinus Torvalds } 4771da177e4SLinus Torvalds 4781da177e4SLinus Torvalds /* 479cabf08e4SMilan Broz * kcryptd/kcryptd_io: 4801da177e4SLinus Torvalds * 4811da177e4SLinus Torvalds * Needed because it would be very unwise to do decryption in an 48223541d2dSMilan Broz * interrupt context. 483cabf08e4SMilan Broz * 484cabf08e4SMilan Broz * kcryptd performs the actual encryption or decryption. 485cabf08e4SMilan Broz * 486cabf08e4SMilan Broz * kcryptd_io performs the IO submission. 487cabf08e4SMilan Broz * 488cabf08e4SMilan Broz * They must be separated as otherwise the final stages could be 489cabf08e4SMilan Broz * starved by new requests which can block in the first stages due 490cabf08e4SMilan Broz * to memory allocation. 4911da177e4SLinus Torvalds */ 492c4028958SDavid Howells static void kcryptd_do_work(struct work_struct *work); 493cabf08e4SMilan Broz static void kcryptd_do_crypt(struct work_struct *work); 4941da177e4SLinus Torvalds 495028867acSAlasdair G Kergon static void kcryptd_queue_io(struct dm_crypt_io *io) 4961da177e4SLinus Torvalds { 4979934a8beSMilan Broz struct crypt_config *cc = io->target->private; 4989934a8beSMilan Broz 499c4028958SDavid Howells INIT_WORK(&io->work, kcryptd_do_work); 500cabf08e4SMilan Broz queue_work(cc->io_queue, &io->work); 501cabf08e4SMilan Broz } 502cabf08e4SMilan Broz 503cabf08e4SMilan Broz static void kcryptd_queue_crypt(struct dm_crypt_io *io) 504cabf08e4SMilan Broz { 505cabf08e4SMilan Broz struct crypt_config *cc = io->target->private; 506cabf08e4SMilan Broz 507cabf08e4SMilan Broz INIT_WORK(&io->work, kcryptd_do_crypt); 508cabf08e4SMilan Broz queue_work(cc->crypt_queue, &io->work); 5091da177e4SLinus Torvalds } 5101da177e4SLinus Torvalds 5116712ecf8SNeilBrown static void crypt_endio(struct bio *clone, int error) 5128b004457SMilan Broz { 513028867acSAlasdair G Kergon struct dm_crypt_io *io = clone->bi_private; 5148b004457SMilan Broz struct crypt_config *cc = io->target->private; 5158b004457SMilan Broz unsigned read_io = bio_data_dir(clone) == READ; 5168b004457SMilan Broz 5178b004457SMilan Broz /* 5186712ecf8SNeilBrown * free the processed pages 5198b004457SMilan Broz */ 5206712ecf8SNeilBrown if (!read_io) { 521644bd2f0SNeil Brown crypt_free_buffer_pages(cc, clone); 5228b004457SMilan Broz goto out; 5236712ecf8SNeilBrown } 5248b004457SMilan Broz 5258b004457SMilan Broz if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) { 5268b004457SMilan Broz error = -EIO; 5278b004457SMilan Broz goto out; 5288b004457SMilan Broz } 5298b004457SMilan Broz 5308b004457SMilan Broz bio_put(clone); 531cabf08e4SMilan Broz kcryptd_queue_crypt(io); 5326712ecf8SNeilBrown return; 5338b004457SMilan Broz 5348b004457SMilan Broz out: 5358b004457SMilan Broz bio_put(clone); 53680fd6626SMilan Broz crypt_dec_pending(io, error); 5378b004457SMilan Broz } 5388b004457SMilan Broz 539028867acSAlasdair G Kergon static void clone_init(struct dm_crypt_io *io, struct bio *clone) 5408b004457SMilan Broz { 5418b004457SMilan Broz struct crypt_config *cc = io->target->private; 5428b004457SMilan Broz 5438b004457SMilan Broz clone->bi_private = io; 5448b004457SMilan Broz clone->bi_end_io = crypt_endio; 5458b004457SMilan Broz clone->bi_bdev = cc->dev->bdev; 5468b004457SMilan Broz clone->bi_rw = io->base_bio->bi_rw; 547027581f3SOlaf Kirch clone->bi_destructor = dm_crypt_bio_destructor; 5488b004457SMilan Broz } 5498b004457SMilan Broz 550028867acSAlasdair G Kergon static void process_read(struct dm_crypt_io *io) 5518b004457SMilan Broz { 5528b004457SMilan Broz struct crypt_config *cc = io->target->private; 5538b004457SMilan Broz struct bio *base_bio = io->base_bio; 5548b004457SMilan Broz struct bio *clone; 55593e605c2SMilan Broz sector_t sector = base_bio->bi_sector - io->target->begin; 55693e605c2SMilan Broz 55793e605c2SMilan Broz atomic_inc(&io->pending); 5588b004457SMilan Broz 5598b004457SMilan Broz /* 5608b004457SMilan Broz * The block layer might modify the bvec array, so always 5618b004457SMilan Broz * copy the required bvecs because we need the original 5628b004457SMilan Broz * one in order to decrypt the whole bio data *afterwards*. 5638b004457SMilan Broz */ 5646a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); 56593e605c2SMilan Broz if (unlikely(!clone)) { 56680fd6626SMilan Broz crypt_dec_pending(io, -ENOMEM); 56723541d2dSMilan Broz return; 56893e605c2SMilan Broz } 5698b004457SMilan Broz 5708b004457SMilan Broz clone_init(io, clone); 5718b004457SMilan Broz clone->bi_idx = 0; 5728b004457SMilan Broz clone->bi_vcnt = bio_segments(base_bio); 5738b004457SMilan Broz clone->bi_size = base_bio->bi_size; 57493e605c2SMilan Broz clone->bi_sector = cc->start + sector; 5758b004457SMilan Broz memcpy(clone->bi_io_vec, bio_iovec(base_bio), 5768b004457SMilan Broz sizeof(struct bio_vec) * clone->bi_vcnt); 5778b004457SMilan Broz 57893e605c2SMilan Broz generic_make_request(clone); 5798b004457SMilan Broz } 5808b004457SMilan Broz 581028867acSAlasdair G Kergon static void process_write(struct dm_crypt_io *io) 5828b004457SMilan Broz { 5838b004457SMilan Broz struct crypt_config *cc = io->target->private; 5848b004457SMilan Broz struct bio *base_bio = io->base_bio; 5858b004457SMilan Broz struct bio *clone; 58693e605c2SMilan Broz struct convert_context ctx; 58793e605c2SMilan Broz unsigned remaining = base_bio->bi_size; 58893e605c2SMilan Broz sector_t sector = base_bio->bi_sector - io->target->begin; 5898b004457SMilan Broz 59093e605c2SMilan Broz atomic_inc(&io->pending); 59193e605c2SMilan Broz 59293e605c2SMilan Broz crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1); 59393e605c2SMilan Broz 59493e605c2SMilan Broz /* 59593e605c2SMilan Broz * The allocated buffers can be smaller than the whole bio, 59693e605c2SMilan Broz * so repeat the whole process until all the data can be handled. 59793e605c2SMilan Broz */ 59893e605c2SMilan Broz while (remaining) { 599f97380bcSOlaf Kirch clone = crypt_alloc_buffer(io, remaining); 60023541d2dSMilan Broz if (unlikely(!clone)) { 60180fd6626SMilan Broz crypt_dec_pending(io, -ENOMEM); 60223541d2dSMilan Broz return; 60323541d2dSMilan Broz } 6048b004457SMilan Broz 60593e605c2SMilan Broz ctx.bio_out = clone; 606f97380bcSOlaf Kirch ctx.idx_out = 0; 6078b004457SMilan Broz 60893e605c2SMilan Broz if (unlikely(crypt_convert(cc, &ctx) < 0)) { 609644bd2f0SNeil Brown crypt_free_buffer_pages(cc, clone); 6108b004457SMilan Broz bio_put(clone); 61180fd6626SMilan Broz crypt_dec_pending(io, -EIO); 61223541d2dSMilan Broz return; 6138b004457SMilan Broz } 6148b004457SMilan Broz 615f97380bcSOlaf Kirch /* crypt_convert should have filled the clone bio */ 616f97380bcSOlaf Kirch BUG_ON(ctx.idx_out < clone->bi_vcnt); 617f97380bcSOlaf Kirch 6188b004457SMilan Broz clone->bi_sector = cc->start + sector; 61993e605c2SMilan Broz remaining -= clone->bi_size; 62093e605c2SMilan Broz sector += bio_sectors(clone); 62193e605c2SMilan Broz 6222f9941b6SOlaf Kirch /* Grab another reference to the io struct 6232f9941b6SOlaf Kirch * before we kick off the request */ 62423541d2dSMilan Broz if (remaining) 62523541d2dSMilan Broz atomic_inc(&io->pending); 62623541d2dSMilan Broz 62793e605c2SMilan Broz generic_make_request(clone); 62893e605c2SMilan Broz 62998221eb7SOlaf Kirch /* Do not reference clone after this - it 63098221eb7SOlaf Kirch * may be gone already. */ 63198221eb7SOlaf Kirch 63293e605c2SMilan Broz /* out of memory -> run queues */ 63393e605c2SMilan Broz if (remaining) 63498221eb7SOlaf Kirch congestion_wait(WRITE, HZ/100); 63593e605c2SMilan Broz } 6368b004457SMilan Broz } 6378b004457SMilan Broz 638028867acSAlasdair G Kergon static void process_read_endio(struct dm_crypt_io *io) 6398b004457SMilan Broz { 6408b004457SMilan Broz struct crypt_config *cc = io->target->private; 6418b004457SMilan Broz struct convert_context ctx; 6428b004457SMilan Broz 6438b004457SMilan Broz crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio, 6448b004457SMilan Broz io->base_bio->bi_sector - io->target->begin, 0); 6458b004457SMilan Broz 64680fd6626SMilan Broz crypt_dec_pending(io, crypt_convert(cc, &ctx)); 6478b004457SMilan Broz } 6488b004457SMilan Broz 649c4028958SDavid Howells static void kcryptd_do_work(struct work_struct *work) 6508b004457SMilan Broz { 651028867acSAlasdair G Kergon struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 6528b004457SMilan Broz 653cabf08e4SMilan Broz if (bio_data_dir(io->base_bio) == READ) 65423541d2dSMilan Broz process_read(io); 655cabf08e4SMilan Broz } 656cabf08e4SMilan Broz 657cabf08e4SMilan Broz static void kcryptd_do_crypt(struct work_struct *work) 658cabf08e4SMilan Broz { 659cabf08e4SMilan Broz struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); 660cabf08e4SMilan Broz 661cabf08e4SMilan Broz if (bio_data_dir(io->base_bio) == READ) 662cabf08e4SMilan Broz process_read_endio(io); 66323541d2dSMilan Broz else 66423541d2dSMilan Broz process_write(io); 6658b004457SMilan Broz } 6668b004457SMilan Broz 6671da177e4SLinus Torvalds /* 6681da177e4SLinus Torvalds * Decode key from its hex representation 6691da177e4SLinus Torvalds */ 6701da177e4SLinus Torvalds static int crypt_decode_key(u8 *key, char *hex, unsigned int size) 6711da177e4SLinus Torvalds { 6721da177e4SLinus Torvalds char buffer[3]; 6731da177e4SLinus Torvalds char *endp; 6741da177e4SLinus Torvalds unsigned int i; 6751da177e4SLinus Torvalds 6761da177e4SLinus Torvalds buffer[2] = '\0'; 6771da177e4SLinus Torvalds 6781da177e4SLinus Torvalds for (i = 0; i < size; i++) { 6791da177e4SLinus Torvalds buffer[0] = *hex++; 6801da177e4SLinus Torvalds buffer[1] = *hex++; 6811da177e4SLinus Torvalds 6821da177e4SLinus Torvalds key[i] = (u8)simple_strtoul(buffer, &endp, 16); 6831da177e4SLinus Torvalds 6841da177e4SLinus Torvalds if (endp != &buffer[2]) 6851da177e4SLinus Torvalds return -EINVAL; 6861da177e4SLinus Torvalds } 6871da177e4SLinus Torvalds 6881da177e4SLinus Torvalds if (*hex != '\0') 6891da177e4SLinus Torvalds return -EINVAL; 6901da177e4SLinus Torvalds 6911da177e4SLinus Torvalds return 0; 6921da177e4SLinus Torvalds } 6931da177e4SLinus Torvalds 6941da177e4SLinus Torvalds /* 6951da177e4SLinus Torvalds * Encode key into its hex representation 6961da177e4SLinus Torvalds */ 6971da177e4SLinus Torvalds static void crypt_encode_key(char *hex, u8 *key, unsigned int size) 6981da177e4SLinus Torvalds { 6991da177e4SLinus Torvalds unsigned int i; 7001da177e4SLinus Torvalds 7011da177e4SLinus Torvalds for (i = 0; i < size; i++) { 7021da177e4SLinus Torvalds sprintf(hex, "%02x", *key); 7031da177e4SLinus Torvalds hex += 2; 7041da177e4SLinus Torvalds key++; 7051da177e4SLinus Torvalds } 7061da177e4SLinus Torvalds } 7071da177e4SLinus Torvalds 708e48d4bbfSMilan Broz static int crypt_set_key(struct crypt_config *cc, char *key) 709e48d4bbfSMilan Broz { 710e48d4bbfSMilan Broz unsigned key_size = strlen(key) >> 1; 711e48d4bbfSMilan Broz 712e48d4bbfSMilan Broz if (cc->key_size && cc->key_size != key_size) 713e48d4bbfSMilan Broz return -EINVAL; 714e48d4bbfSMilan Broz 715e48d4bbfSMilan Broz cc->key_size = key_size; /* initial settings */ 716e48d4bbfSMilan Broz 717e48d4bbfSMilan Broz if ((!key_size && strcmp(key, "-")) || 718e48d4bbfSMilan Broz (key_size && crypt_decode_key(cc->key, key, key_size) < 0)) 719e48d4bbfSMilan Broz return -EINVAL; 720e48d4bbfSMilan Broz 721e48d4bbfSMilan Broz set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 722e48d4bbfSMilan Broz 723e48d4bbfSMilan Broz return 0; 724e48d4bbfSMilan Broz } 725e48d4bbfSMilan Broz 726e48d4bbfSMilan Broz static int crypt_wipe_key(struct crypt_config *cc) 727e48d4bbfSMilan Broz { 728e48d4bbfSMilan Broz clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 729e48d4bbfSMilan Broz memset(&cc->key, 0, cc->key_size * sizeof(u8)); 730e48d4bbfSMilan Broz return 0; 731e48d4bbfSMilan Broz } 732e48d4bbfSMilan Broz 7331da177e4SLinus Torvalds /* 7341da177e4SLinus Torvalds * Construct an encryption mapping: 7351da177e4SLinus Torvalds * <cipher> <key> <iv_offset> <dev_path> <start> 7361da177e4SLinus Torvalds */ 7371da177e4SLinus Torvalds static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 7381da177e4SLinus Torvalds { 7391da177e4SLinus Torvalds struct crypt_config *cc; 740d1806f6aSHerbert Xu struct crypto_blkcipher *tfm; 7411da177e4SLinus Torvalds char *tmp; 7421da177e4SLinus Torvalds char *cipher; 7431da177e4SLinus Torvalds char *chainmode; 7441da177e4SLinus Torvalds char *ivmode; 7451da177e4SLinus Torvalds char *ivopts; 7461da177e4SLinus Torvalds unsigned int key_size; 7474ee218cdSAndrew Morton unsigned long long tmpll; 7481da177e4SLinus Torvalds 7491da177e4SLinus Torvalds if (argc != 5) { 75072d94861SAlasdair G Kergon ti->error = "Not enough arguments"; 7511da177e4SLinus Torvalds return -EINVAL; 7521da177e4SLinus Torvalds } 7531da177e4SLinus Torvalds 7541da177e4SLinus Torvalds tmp = argv[0]; 7551da177e4SLinus Torvalds cipher = strsep(&tmp, "-"); 7561da177e4SLinus Torvalds chainmode = strsep(&tmp, "-"); 7571da177e4SLinus Torvalds ivopts = strsep(&tmp, "-"); 7581da177e4SLinus Torvalds ivmode = strsep(&ivopts, ":"); 7591da177e4SLinus Torvalds 7601da177e4SLinus Torvalds if (tmp) 76172d94861SAlasdair G Kergon DMWARN("Unexpected additional cipher options"); 7621da177e4SLinus Torvalds 7631da177e4SLinus Torvalds key_size = strlen(argv[1]) >> 1; 7641da177e4SLinus Torvalds 765e48d4bbfSMilan Broz cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); 7661da177e4SLinus Torvalds if (cc == NULL) { 7671da177e4SLinus Torvalds ti->error = 76872d94861SAlasdair G Kergon "Cannot allocate transparent encryption context"; 7691da177e4SLinus Torvalds return -ENOMEM; 7701da177e4SLinus Torvalds } 7711da177e4SLinus Torvalds 772e48d4bbfSMilan Broz if (crypt_set_key(cc, argv[1])) { 77372d94861SAlasdair G Kergon ti->error = "Error decoding key"; 774636d5786SMilan Broz goto bad_cipher; 7751da177e4SLinus Torvalds } 7761da177e4SLinus Torvalds 7771da177e4SLinus Torvalds /* Compatiblity mode for old dm-crypt cipher strings */ 7781da177e4SLinus Torvalds if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { 7791da177e4SLinus Torvalds chainmode = "cbc"; 7801da177e4SLinus Torvalds ivmode = "plain"; 7811da177e4SLinus Torvalds } 7821da177e4SLinus Torvalds 783d1806f6aSHerbert Xu if (strcmp(chainmode, "ecb") && !ivmode) { 78472d94861SAlasdair G Kergon ti->error = "This chaining mode requires an IV mechanism"; 785636d5786SMilan Broz goto bad_cipher; 7861da177e4SLinus Torvalds } 7871da177e4SLinus Torvalds 788d469f841SMilan Broz if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", 789d469f841SMilan Broz chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) { 790d1806f6aSHerbert Xu ti->error = "Chain mode + cipher name is too long"; 791636d5786SMilan Broz goto bad_cipher; 792d1806f6aSHerbert Xu } 793d1806f6aSHerbert Xu 794d1806f6aSHerbert Xu tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 795d1806f6aSHerbert Xu if (IS_ERR(tfm)) { 79672d94861SAlasdair G Kergon ti->error = "Error allocating crypto tfm"; 797636d5786SMilan Broz goto bad_cipher; 7981da177e4SLinus Torvalds } 7991da177e4SLinus Torvalds 800d1806f6aSHerbert Xu strcpy(cc->cipher, cipher); 801d1806f6aSHerbert Xu strcpy(cc->chainmode, chainmode); 8021da177e4SLinus Torvalds cc->tfm = tfm; 8031da177e4SLinus Torvalds 8041da177e4SLinus Torvalds /* 80548527fa7SRik Snel * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi". 8061da177e4SLinus Torvalds * See comments at iv code 8071da177e4SLinus Torvalds */ 8081da177e4SLinus Torvalds 8091da177e4SLinus Torvalds if (ivmode == NULL) 8101da177e4SLinus Torvalds cc->iv_gen_ops = NULL; 8111da177e4SLinus Torvalds else if (strcmp(ivmode, "plain") == 0) 8121da177e4SLinus Torvalds cc->iv_gen_ops = &crypt_iv_plain_ops; 8131da177e4SLinus Torvalds else if (strcmp(ivmode, "essiv") == 0) 8141da177e4SLinus Torvalds cc->iv_gen_ops = &crypt_iv_essiv_ops; 81548527fa7SRik Snel else if (strcmp(ivmode, "benbi") == 0) 81648527fa7SRik Snel cc->iv_gen_ops = &crypt_iv_benbi_ops; 81746b47730SLudwig Nussel else if (strcmp(ivmode, "null") == 0) 81846b47730SLudwig Nussel cc->iv_gen_ops = &crypt_iv_null_ops; 8191da177e4SLinus Torvalds else { 82072d94861SAlasdair G Kergon ti->error = "Invalid IV mode"; 821636d5786SMilan Broz goto bad_ivmode; 8221da177e4SLinus Torvalds } 8231da177e4SLinus Torvalds 8241da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && 8251da177e4SLinus Torvalds cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) 826636d5786SMilan Broz goto bad_ivmode; 8271da177e4SLinus Torvalds 828d1806f6aSHerbert Xu cc->iv_size = crypto_blkcipher_ivsize(tfm); 829d1806f6aSHerbert Xu if (cc->iv_size) 8301da177e4SLinus Torvalds /* at least a 64 bit sector number should fit in our buffer */ 831d1806f6aSHerbert Xu cc->iv_size = max(cc->iv_size, 8321da177e4SLinus Torvalds (unsigned int)(sizeof(u64) / sizeof(u8))); 8331da177e4SLinus Torvalds else { 8341da177e4SLinus Torvalds if (cc->iv_gen_ops) { 83572d94861SAlasdair G Kergon DMWARN("Selected cipher does not support IVs"); 8361da177e4SLinus Torvalds if (cc->iv_gen_ops->dtr) 8371da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 8381da177e4SLinus Torvalds cc->iv_gen_ops = NULL; 8391da177e4SLinus Torvalds } 8401da177e4SLinus Torvalds } 8411da177e4SLinus Torvalds 84293d2341cSMatthew Dobson cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); 8431da177e4SLinus Torvalds if (!cc->io_pool) { 84472d94861SAlasdair G Kergon ti->error = "Cannot allocate crypt io mempool"; 845636d5786SMilan Broz goto bad_slab_pool; 8461da177e4SLinus Torvalds } 8471da177e4SLinus Torvalds 848a19b27ceSMatthew Dobson cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); 8491da177e4SLinus Torvalds if (!cc->page_pool) { 85072d94861SAlasdair G Kergon ti->error = "Cannot allocate page mempool"; 851636d5786SMilan Broz goto bad_page_pool; 8521da177e4SLinus Torvalds } 8531da177e4SLinus Torvalds 8545972511bSJens Axboe cc->bs = bioset_create(MIN_IOS, MIN_IOS); 8556a24c718SMilan Broz if (!cc->bs) { 8566a24c718SMilan Broz ti->error = "Cannot allocate crypt bioset"; 8576a24c718SMilan Broz goto bad_bs; 8586a24c718SMilan Broz } 8596a24c718SMilan Broz 860d1806f6aSHerbert Xu if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) { 86172d94861SAlasdair G Kergon ti->error = "Error setting key"; 862636d5786SMilan Broz goto bad_device; 8631da177e4SLinus Torvalds } 8641da177e4SLinus Torvalds 8654ee218cdSAndrew Morton if (sscanf(argv[2], "%llu", &tmpll) != 1) { 86672d94861SAlasdair G Kergon ti->error = "Invalid iv_offset sector"; 867636d5786SMilan Broz goto bad_device; 8681da177e4SLinus Torvalds } 8694ee218cdSAndrew Morton cc->iv_offset = tmpll; 8701da177e4SLinus Torvalds 8714ee218cdSAndrew Morton if (sscanf(argv[4], "%llu", &tmpll) != 1) { 87272d94861SAlasdair G Kergon ti->error = "Invalid device sector"; 873636d5786SMilan Broz goto bad_device; 8741da177e4SLinus Torvalds } 8754ee218cdSAndrew Morton cc->start = tmpll; 8761da177e4SLinus Torvalds 8771da177e4SLinus Torvalds if (dm_get_device(ti, argv[3], cc->start, ti->len, 8781da177e4SLinus Torvalds dm_table_get_mode(ti->table), &cc->dev)) { 87972d94861SAlasdair G Kergon ti->error = "Device lookup failed"; 880636d5786SMilan Broz goto bad_device; 8811da177e4SLinus Torvalds } 8821da177e4SLinus Torvalds 8831da177e4SLinus Torvalds if (ivmode && cc->iv_gen_ops) { 8841da177e4SLinus Torvalds if (ivopts) 8851da177e4SLinus Torvalds *(ivopts - 1) = ':'; 8861da177e4SLinus Torvalds cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); 8871da177e4SLinus Torvalds if (!cc->iv_mode) { 88872d94861SAlasdair G Kergon ti->error = "Error kmallocing iv_mode string"; 889636d5786SMilan Broz goto bad_ivmode_string; 8901da177e4SLinus Torvalds } 8911da177e4SLinus Torvalds strcpy(cc->iv_mode, ivmode); 8921da177e4SLinus Torvalds } else 8931da177e4SLinus Torvalds cc->iv_mode = NULL; 8941da177e4SLinus Torvalds 895cabf08e4SMilan Broz cc->io_queue = create_singlethread_workqueue("kcryptd_io"); 896cabf08e4SMilan Broz if (!cc->io_queue) { 897cabf08e4SMilan Broz ti->error = "Couldn't create kcryptd io queue"; 898cabf08e4SMilan Broz goto bad_io_queue; 899cabf08e4SMilan Broz } 900cabf08e4SMilan Broz 901cabf08e4SMilan Broz cc->crypt_queue = create_singlethread_workqueue("kcryptd"); 902cabf08e4SMilan Broz if (!cc->crypt_queue) { 9039934a8beSMilan Broz ti->error = "Couldn't create kcryptd queue"; 904cabf08e4SMilan Broz goto bad_crypt_queue; 9059934a8beSMilan Broz } 9069934a8beSMilan Broz 9071da177e4SLinus Torvalds ti->private = cc; 9081da177e4SLinus Torvalds return 0; 9091da177e4SLinus Torvalds 910cabf08e4SMilan Broz bad_crypt_queue: 911cabf08e4SMilan Broz destroy_workqueue(cc->io_queue); 912cabf08e4SMilan Broz bad_io_queue: 9139934a8beSMilan Broz kfree(cc->iv_mode); 914636d5786SMilan Broz bad_ivmode_string: 91555b42c5aSDmitry Monakhov dm_put_device(ti, cc->dev); 916636d5786SMilan Broz bad_device: 9176a24c718SMilan Broz bioset_free(cc->bs); 9186a24c718SMilan Broz bad_bs: 9191da177e4SLinus Torvalds mempool_destroy(cc->page_pool); 920636d5786SMilan Broz bad_page_pool: 9211da177e4SLinus Torvalds mempool_destroy(cc->io_pool); 922636d5786SMilan Broz bad_slab_pool: 9231da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 9241da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 925636d5786SMilan Broz bad_ivmode: 926d1806f6aSHerbert Xu crypto_free_blkcipher(tfm); 927636d5786SMilan Broz bad_cipher: 9289d3520a3SStefan Rompf /* Must zero key material before freeing */ 9299d3520a3SStefan Rompf memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); 9301da177e4SLinus Torvalds kfree(cc); 9311da177e4SLinus Torvalds return -EINVAL; 9321da177e4SLinus Torvalds } 9331da177e4SLinus Torvalds 9341da177e4SLinus Torvalds static void crypt_dtr(struct dm_target *ti) 9351da177e4SLinus Torvalds { 9361da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) ti->private; 9371da177e4SLinus Torvalds 938cabf08e4SMilan Broz destroy_workqueue(cc->io_queue); 939cabf08e4SMilan Broz destroy_workqueue(cc->crypt_queue); 94080b16c19SMilan Broz 9416a24c718SMilan Broz bioset_free(cc->bs); 9421da177e4SLinus Torvalds mempool_destroy(cc->page_pool); 9431da177e4SLinus Torvalds mempool_destroy(cc->io_pool); 9441da177e4SLinus Torvalds 9451da177e4SLinus Torvalds kfree(cc->iv_mode); 9461da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 9471da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 948d1806f6aSHerbert Xu crypto_free_blkcipher(cc->tfm); 9491da177e4SLinus Torvalds dm_put_device(ti, cc->dev); 9509d3520a3SStefan Rompf 9519d3520a3SStefan Rompf /* Must zero key material before freeing */ 9529d3520a3SStefan Rompf memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); 9531da177e4SLinus Torvalds kfree(cc); 9541da177e4SLinus Torvalds } 9551da177e4SLinus Torvalds 9561da177e4SLinus Torvalds static int crypt_map(struct dm_target *ti, struct bio *bio, 9571da177e4SLinus Torvalds union map_info *map_context) 9581da177e4SLinus Torvalds { 9598b004457SMilan Broz struct crypt_config *cc = ti->private; 960028867acSAlasdair G Kergon struct dm_crypt_io *io; 9611da177e4SLinus Torvalds 962e48d4bbfSMilan Broz io = mempool_alloc(cc->io_pool, GFP_NOIO); 9631da177e4SLinus Torvalds io->target = ti; 9648b004457SMilan Broz io->base_bio = bio; 965cabf08e4SMilan Broz io->error = 0; 96693e605c2SMilan Broz atomic_set(&io->pending, 0); 967cabf08e4SMilan Broz 968cabf08e4SMilan Broz if (bio_data_dir(io->base_bio) == READ) 96923541d2dSMilan Broz kcryptd_queue_io(io); 970cabf08e4SMilan Broz else 971cabf08e4SMilan Broz kcryptd_queue_crypt(io); 9721da177e4SLinus Torvalds 973d2a7ad29SKiyoshi Ueda return DM_MAPIO_SUBMITTED; 9741da177e4SLinus Torvalds } 9751da177e4SLinus Torvalds 9761da177e4SLinus Torvalds static int crypt_status(struct dm_target *ti, status_type_t type, 9771da177e4SLinus Torvalds char *result, unsigned int maxlen) 9781da177e4SLinus Torvalds { 9791da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) ti->private; 9801da177e4SLinus Torvalds unsigned int sz = 0; 9811da177e4SLinus Torvalds 9821da177e4SLinus Torvalds switch (type) { 9831da177e4SLinus Torvalds case STATUSTYPE_INFO: 9841da177e4SLinus Torvalds result[0] = '\0'; 9851da177e4SLinus Torvalds break; 9861da177e4SLinus Torvalds 9871da177e4SLinus Torvalds case STATUSTYPE_TABLE: 9881da177e4SLinus Torvalds if (cc->iv_mode) 98937af6560SChristophe Saout DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode, 99037af6560SChristophe Saout cc->iv_mode); 9911da177e4SLinus Torvalds else 99237af6560SChristophe Saout DMEMIT("%s-%s ", cc->cipher, cc->chainmode); 9931da177e4SLinus Torvalds 9941da177e4SLinus Torvalds if (cc->key_size > 0) { 9951da177e4SLinus Torvalds if ((maxlen - sz) < ((cc->key_size << 1) + 1)) 9961da177e4SLinus Torvalds return -ENOMEM; 9971da177e4SLinus Torvalds 9981da177e4SLinus Torvalds crypt_encode_key(result + sz, cc->key, cc->key_size); 9991da177e4SLinus Torvalds sz += cc->key_size << 1; 10001da177e4SLinus Torvalds } else { 10011da177e4SLinus Torvalds if (sz >= maxlen) 10021da177e4SLinus Torvalds return -ENOMEM; 10031da177e4SLinus Torvalds result[sz++] = '-'; 10041da177e4SLinus Torvalds } 10051da177e4SLinus Torvalds 10064ee218cdSAndrew Morton DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 10074ee218cdSAndrew Morton cc->dev->name, (unsigned long long)cc->start); 10081da177e4SLinus Torvalds break; 10091da177e4SLinus Torvalds } 10101da177e4SLinus Torvalds return 0; 10111da177e4SLinus Torvalds } 10121da177e4SLinus Torvalds 1013e48d4bbfSMilan Broz static void crypt_postsuspend(struct dm_target *ti) 1014e48d4bbfSMilan Broz { 1015e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1016e48d4bbfSMilan Broz 1017e48d4bbfSMilan Broz set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 1018e48d4bbfSMilan Broz } 1019e48d4bbfSMilan Broz 1020e48d4bbfSMilan Broz static int crypt_preresume(struct dm_target *ti) 1021e48d4bbfSMilan Broz { 1022e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1023e48d4bbfSMilan Broz 1024e48d4bbfSMilan Broz if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 1025e48d4bbfSMilan Broz DMERR("aborting resume - crypt key is not set."); 1026e48d4bbfSMilan Broz return -EAGAIN; 1027e48d4bbfSMilan Broz } 1028e48d4bbfSMilan Broz 1029e48d4bbfSMilan Broz return 0; 1030e48d4bbfSMilan Broz } 1031e48d4bbfSMilan Broz 1032e48d4bbfSMilan Broz static void crypt_resume(struct dm_target *ti) 1033e48d4bbfSMilan Broz { 1034e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1035e48d4bbfSMilan Broz 1036e48d4bbfSMilan Broz clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 1037e48d4bbfSMilan Broz } 1038e48d4bbfSMilan Broz 1039e48d4bbfSMilan Broz /* Message interface 1040e48d4bbfSMilan Broz * key set <key> 1041e48d4bbfSMilan Broz * key wipe 1042e48d4bbfSMilan Broz */ 1043e48d4bbfSMilan Broz static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) 1044e48d4bbfSMilan Broz { 1045e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 1046e48d4bbfSMilan Broz 1047e48d4bbfSMilan Broz if (argc < 2) 1048e48d4bbfSMilan Broz goto error; 1049e48d4bbfSMilan Broz 1050e48d4bbfSMilan Broz if (!strnicmp(argv[0], MESG_STR("key"))) { 1051e48d4bbfSMilan Broz if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 1052e48d4bbfSMilan Broz DMWARN("not suspended during key manipulation."); 1053e48d4bbfSMilan Broz return -EINVAL; 1054e48d4bbfSMilan Broz } 1055e48d4bbfSMilan Broz if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) 1056e48d4bbfSMilan Broz return crypt_set_key(cc, argv[2]); 1057e48d4bbfSMilan Broz if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) 1058e48d4bbfSMilan Broz return crypt_wipe_key(cc); 1059e48d4bbfSMilan Broz } 1060e48d4bbfSMilan Broz 1061e48d4bbfSMilan Broz error: 1062e48d4bbfSMilan Broz DMWARN("unrecognised message received."); 1063e48d4bbfSMilan Broz return -EINVAL; 1064e48d4bbfSMilan Broz } 1065e48d4bbfSMilan Broz 10661da177e4SLinus Torvalds static struct target_type crypt_target = { 10671da177e4SLinus Torvalds .name = "crypt", 106846b47730SLudwig Nussel .version= {1, 5, 0}, 10691da177e4SLinus Torvalds .module = THIS_MODULE, 10701da177e4SLinus Torvalds .ctr = crypt_ctr, 10711da177e4SLinus Torvalds .dtr = crypt_dtr, 10721da177e4SLinus Torvalds .map = crypt_map, 10731da177e4SLinus Torvalds .status = crypt_status, 1074e48d4bbfSMilan Broz .postsuspend = crypt_postsuspend, 1075e48d4bbfSMilan Broz .preresume = crypt_preresume, 1076e48d4bbfSMilan Broz .resume = crypt_resume, 1077e48d4bbfSMilan Broz .message = crypt_message, 10781da177e4SLinus Torvalds }; 10791da177e4SLinus Torvalds 10801da177e4SLinus Torvalds static int __init dm_crypt_init(void) 10811da177e4SLinus Torvalds { 10821da177e4SLinus Torvalds int r; 10831da177e4SLinus Torvalds 1084028867acSAlasdair G Kergon _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0); 10851da177e4SLinus Torvalds if (!_crypt_io_pool) 10861da177e4SLinus Torvalds return -ENOMEM; 10871da177e4SLinus Torvalds 10881da177e4SLinus Torvalds r = dm_register_target(&crypt_target); 10891da177e4SLinus Torvalds if (r < 0) { 109072d94861SAlasdair G Kergon DMERR("register failed %d", r); 10919934a8beSMilan Broz kmem_cache_destroy(_crypt_io_pool); 10921da177e4SLinus Torvalds } 10931da177e4SLinus Torvalds 10941da177e4SLinus Torvalds return r; 10951da177e4SLinus Torvalds } 10961da177e4SLinus Torvalds 10971da177e4SLinus Torvalds static void __exit dm_crypt_exit(void) 10981da177e4SLinus Torvalds { 10991da177e4SLinus Torvalds int r = dm_unregister_target(&crypt_target); 11001da177e4SLinus Torvalds 11011da177e4SLinus Torvalds if (r < 0) 110272d94861SAlasdair G Kergon DMERR("unregister failed %d", r); 11031da177e4SLinus Torvalds 11041da177e4SLinus Torvalds kmem_cache_destroy(_crypt_io_pool); 11051da177e4SLinus Torvalds } 11061da177e4SLinus Torvalds 11071da177e4SLinus Torvalds module_init(dm_crypt_init); 11081da177e4SLinus Torvalds module_exit(dm_crypt_exit); 11091da177e4SLinus Torvalds 11101da177e4SLinus Torvalds MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); 11111da177e4SLinus Torvalds MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 11121da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1113