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> 231da177e4SLinus Torvalds 241da177e4SLinus Torvalds #include "dm.h" 251da177e4SLinus Torvalds 2672d94861SAlasdair G Kergon #define DM_MSG_PREFIX "crypt" 27e48d4bbfSMilan Broz #define MESG_STR(x) x, sizeof(x) 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds /* 301da177e4SLinus Torvalds * per bio private data 311da177e4SLinus Torvalds */ 321da177e4SLinus Torvalds struct crypt_io { 331da177e4SLinus Torvalds struct dm_target *target; 348b004457SMilan Broz struct bio *base_bio; 351da177e4SLinus Torvalds struct bio *first_clone; 361da177e4SLinus Torvalds struct work_struct work; 371da177e4SLinus Torvalds atomic_t pending; 381da177e4SLinus Torvalds int error; 3923541d2dSMilan Broz int post_process; 401da177e4SLinus Torvalds }; 411da177e4SLinus Torvalds 421da177e4SLinus Torvalds /* 431da177e4SLinus Torvalds * context holding the current state of a multi-part conversion 441da177e4SLinus Torvalds */ 451da177e4SLinus Torvalds struct convert_context { 461da177e4SLinus Torvalds struct bio *bio_in; 471da177e4SLinus Torvalds struct bio *bio_out; 481da177e4SLinus Torvalds unsigned int offset_in; 491da177e4SLinus Torvalds unsigned int offset_out; 501da177e4SLinus Torvalds unsigned int idx_in; 511da177e4SLinus Torvalds unsigned int idx_out; 521da177e4SLinus Torvalds sector_t sector; 531da177e4SLinus Torvalds int write; 541da177e4SLinus Torvalds }; 551da177e4SLinus Torvalds 561da177e4SLinus Torvalds struct crypt_config; 571da177e4SLinus Torvalds 581da177e4SLinus Torvalds struct crypt_iv_operations { 591da177e4SLinus Torvalds int (*ctr)(struct crypt_config *cc, struct dm_target *ti, 601da177e4SLinus Torvalds const char *opts); 611da177e4SLinus Torvalds void (*dtr)(struct crypt_config *cc); 621da177e4SLinus Torvalds const char *(*status)(struct crypt_config *cc); 631da177e4SLinus Torvalds int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); 641da177e4SLinus Torvalds }; 651da177e4SLinus Torvalds 661da177e4SLinus Torvalds /* 671da177e4SLinus Torvalds * Crypt: maps a linear range of a block device 681da177e4SLinus Torvalds * and encrypts / decrypts at the same time. 691da177e4SLinus Torvalds */ 70e48d4bbfSMilan Broz enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; 711da177e4SLinus Torvalds struct crypt_config { 721da177e4SLinus Torvalds struct dm_dev *dev; 731da177e4SLinus Torvalds sector_t start; 741da177e4SLinus Torvalds 751da177e4SLinus Torvalds /* 761da177e4SLinus Torvalds * pool for per bio private data and 771da177e4SLinus Torvalds * for encryption buffer pages 781da177e4SLinus Torvalds */ 791da177e4SLinus Torvalds mempool_t *io_pool; 801da177e4SLinus Torvalds mempool_t *page_pool; 816a24c718SMilan Broz struct bio_set *bs; 821da177e4SLinus Torvalds 831da177e4SLinus Torvalds /* 841da177e4SLinus Torvalds * crypto related data 851da177e4SLinus Torvalds */ 861da177e4SLinus Torvalds struct crypt_iv_operations *iv_gen_ops; 871da177e4SLinus Torvalds char *iv_mode; 88d1806f6aSHerbert Xu struct crypto_cipher *iv_gen_private; 891da177e4SLinus Torvalds sector_t iv_offset; 901da177e4SLinus Torvalds unsigned int iv_size; 911da177e4SLinus Torvalds 92d1806f6aSHerbert Xu char cipher[CRYPTO_MAX_ALG_NAME]; 93d1806f6aSHerbert Xu char chainmode[CRYPTO_MAX_ALG_NAME]; 94d1806f6aSHerbert Xu struct crypto_blkcipher *tfm; 95e48d4bbfSMilan Broz unsigned long flags; 961da177e4SLinus Torvalds unsigned int key_size; 971da177e4SLinus Torvalds u8 key[0]; 981da177e4SLinus Torvalds }; 991da177e4SLinus Torvalds 1006a24c718SMilan Broz #define MIN_IOS 16 1011da177e4SLinus Torvalds #define MIN_POOL_PAGES 32 1021da177e4SLinus Torvalds #define MIN_BIO_PAGES 8 1031da177e4SLinus Torvalds 1041da177e4SLinus Torvalds static kmem_cache_t *_crypt_io_pool; 1051da177e4SLinus Torvalds 1061da177e4SLinus Torvalds /* 1071da177e4SLinus Torvalds * Different IV generation algorithms: 1081da177e4SLinus Torvalds * 1093c164bd8SRik Snel * plain: the initial vector is the 32-bit little-endian version of the sector 1101da177e4SLinus Torvalds * number, padded with zeros if neccessary. 1111da177e4SLinus Torvalds * 1123c164bd8SRik Snel * essiv: "encrypted sector|salt initial vector", the sector number is 1131da177e4SLinus Torvalds * encrypted with the bulk cipher using a salt as key. The salt 1141da177e4SLinus Torvalds * should be derived from the bulk cipher's key via hashing. 1151da177e4SLinus Torvalds * 1161da177e4SLinus Torvalds * plumb: unimplemented, see: 1171da177e4SLinus Torvalds * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 1181da177e4SLinus Torvalds */ 1191da177e4SLinus Torvalds 1201da177e4SLinus Torvalds static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 1211da177e4SLinus Torvalds { 1221da177e4SLinus Torvalds memset(iv, 0, cc->iv_size); 1231da177e4SLinus Torvalds *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); 1241da177e4SLinus Torvalds 1251da177e4SLinus Torvalds return 0; 1261da177e4SLinus Torvalds } 1271da177e4SLinus Torvalds 1281da177e4SLinus Torvalds static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, 1291da177e4SLinus Torvalds const char *opts) 1301da177e4SLinus Torvalds { 131d1806f6aSHerbert Xu struct crypto_cipher *essiv_tfm; 13235058687SHerbert Xu struct crypto_hash *hash_tfm; 13335058687SHerbert Xu struct hash_desc desc; 1341da177e4SLinus Torvalds struct scatterlist sg; 1351da177e4SLinus Torvalds unsigned int saltsize; 1361da177e4SLinus Torvalds u8 *salt; 137d1806f6aSHerbert Xu int err; 1381da177e4SLinus Torvalds 1391da177e4SLinus Torvalds if (opts == NULL) { 14072d94861SAlasdair G Kergon ti->error = "Digest algorithm missing for ESSIV mode"; 1411da177e4SLinus Torvalds return -EINVAL; 1421da177e4SLinus Torvalds } 1431da177e4SLinus Torvalds 1441da177e4SLinus Torvalds /* Hash the cipher key with the given hash algorithm */ 14535058687SHerbert Xu hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); 14635058687SHerbert Xu if (IS_ERR(hash_tfm)) { 14772d94861SAlasdair G Kergon ti->error = "Error initializing ESSIV hash"; 14835058687SHerbert Xu return PTR_ERR(hash_tfm); 1491da177e4SLinus Torvalds } 1501da177e4SLinus Torvalds 15135058687SHerbert Xu saltsize = crypto_hash_digestsize(hash_tfm); 1521da177e4SLinus Torvalds salt = kmalloc(saltsize, GFP_KERNEL); 1531da177e4SLinus Torvalds if (salt == NULL) { 15472d94861SAlasdair G Kergon ti->error = "Error kmallocing salt storage in ESSIV"; 15535058687SHerbert Xu crypto_free_hash(hash_tfm); 1561da177e4SLinus Torvalds return -ENOMEM; 1571da177e4SLinus Torvalds } 1581da177e4SLinus Torvalds 159378f058cSDavid Hardeman sg_set_buf(&sg, cc->key, cc->key_size); 16035058687SHerbert Xu desc.tfm = hash_tfm; 16135058687SHerbert Xu desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; 16235058687SHerbert Xu err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); 16335058687SHerbert Xu crypto_free_hash(hash_tfm); 16435058687SHerbert Xu 16535058687SHerbert Xu if (err) { 16635058687SHerbert Xu ti->error = "Error calculating hash in ESSIV"; 16735058687SHerbert Xu return err; 16835058687SHerbert Xu } 1691da177e4SLinus Torvalds 1701da177e4SLinus Torvalds /* Setup the essiv_tfm with the given salt */ 171d1806f6aSHerbert Xu essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 172d1806f6aSHerbert Xu if (IS_ERR(essiv_tfm)) { 17372d94861SAlasdair G Kergon ti->error = "Error allocating crypto tfm for ESSIV"; 1741da177e4SLinus Torvalds kfree(salt); 175d1806f6aSHerbert Xu return PTR_ERR(essiv_tfm); 1761da177e4SLinus Torvalds } 177d1806f6aSHerbert Xu if (crypto_cipher_blocksize(essiv_tfm) != 178d1806f6aSHerbert Xu crypto_blkcipher_ivsize(cc->tfm)) { 17972d94861SAlasdair G Kergon ti->error = "Block size of ESSIV cipher does " 1801da177e4SLinus Torvalds "not match IV size of block cipher"; 181d1806f6aSHerbert Xu crypto_free_cipher(essiv_tfm); 1821da177e4SLinus Torvalds kfree(salt); 1831da177e4SLinus Torvalds return -EINVAL; 1841da177e4SLinus Torvalds } 185d1806f6aSHerbert Xu err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); 186d1806f6aSHerbert Xu if (err) { 18772d94861SAlasdair G Kergon ti->error = "Failed to set key for ESSIV cipher"; 188d1806f6aSHerbert Xu crypto_free_cipher(essiv_tfm); 1891da177e4SLinus Torvalds kfree(salt); 190d1806f6aSHerbert Xu return err; 1911da177e4SLinus Torvalds } 1921da177e4SLinus Torvalds kfree(salt); 1931da177e4SLinus Torvalds 194d1806f6aSHerbert Xu cc->iv_gen_private = essiv_tfm; 1951da177e4SLinus Torvalds return 0; 1961da177e4SLinus Torvalds } 1971da177e4SLinus Torvalds 1981da177e4SLinus Torvalds static void crypt_iv_essiv_dtr(struct crypt_config *cc) 1991da177e4SLinus Torvalds { 200d1806f6aSHerbert Xu crypto_free_cipher(cc->iv_gen_private); 2011da177e4SLinus Torvalds cc->iv_gen_private = NULL; 2021da177e4SLinus Torvalds } 2031da177e4SLinus Torvalds 2041da177e4SLinus Torvalds static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) 2051da177e4SLinus Torvalds { 2061da177e4SLinus Torvalds memset(iv, 0, cc->iv_size); 2071da177e4SLinus Torvalds *(u64 *)iv = cpu_to_le64(sector); 208d1806f6aSHerbert Xu crypto_cipher_encrypt_one(cc->iv_gen_private, iv, iv); 2091da177e4SLinus Torvalds return 0; 2101da177e4SLinus Torvalds } 2111da177e4SLinus Torvalds 2121da177e4SLinus Torvalds static struct crypt_iv_operations crypt_iv_plain_ops = { 2131da177e4SLinus Torvalds .generator = crypt_iv_plain_gen 2141da177e4SLinus Torvalds }; 2151da177e4SLinus Torvalds 2161da177e4SLinus Torvalds static struct crypt_iv_operations crypt_iv_essiv_ops = { 2171da177e4SLinus Torvalds .ctr = crypt_iv_essiv_ctr, 2181da177e4SLinus Torvalds .dtr = crypt_iv_essiv_dtr, 2191da177e4SLinus Torvalds .generator = crypt_iv_essiv_gen 2201da177e4SLinus Torvalds }; 2211da177e4SLinus Torvalds 2221da177e4SLinus Torvalds 223858119e1SArjan van de Ven static int 2241da177e4SLinus Torvalds crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out, 2251da177e4SLinus Torvalds struct scatterlist *in, unsigned int length, 2261da177e4SLinus Torvalds int write, sector_t sector) 2271da177e4SLinus Torvalds { 2281da177e4SLinus Torvalds u8 iv[cc->iv_size]; 229d1806f6aSHerbert Xu struct blkcipher_desc desc = { 230d1806f6aSHerbert Xu .tfm = cc->tfm, 231d1806f6aSHerbert Xu .info = iv, 232d1806f6aSHerbert Xu .flags = CRYPTO_TFM_REQ_MAY_SLEEP, 233d1806f6aSHerbert Xu }; 2341da177e4SLinus Torvalds int r; 2351da177e4SLinus Torvalds 2361da177e4SLinus Torvalds if (cc->iv_gen_ops) { 2371da177e4SLinus Torvalds r = cc->iv_gen_ops->generator(cc, iv, sector); 2381da177e4SLinus Torvalds if (r < 0) 2391da177e4SLinus Torvalds return r; 2401da177e4SLinus Torvalds 2411da177e4SLinus Torvalds if (write) 242d1806f6aSHerbert Xu r = crypto_blkcipher_encrypt_iv(&desc, out, in, length); 2431da177e4SLinus Torvalds else 244d1806f6aSHerbert Xu r = crypto_blkcipher_decrypt_iv(&desc, out, in, length); 2451da177e4SLinus Torvalds } else { 2461da177e4SLinus Torvalds if (write) 247d1806f6aSHerbert Xu r = crypto_blkcipher_encrypt(&desc, out, in, length); 2481da177e4SLinus Torvalds else 249d1806f6aSHerbert Xu r = crypto_blkcipher_decrypt(&desc, out, in, length); 2501da177e4SLinus Torvalds } 2511da177e4SLinus Torvalds 2521da177e4SLinus Torvalds return r; 2531da177e4SLinus Torvalds } 2541da177e4SLinus Torvalds 2551da177e4SLinus Torvalds static void 2561da177e4SLinus Torvalds crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx, 2571da177e4SLinus Torvalds struct bio *bio_out, struct bio *bio_in, 2581da177e4SLinus Torvalds sector_t sector, int write) 2591da177e4SLinus Torvalds { 2601da177e4SLinus Torvalds ctx->bio_in = bio_in; 2611da177e4SLinus Torvalds ctx->bio_out = bio_out; 2621da177e4SLinus Torvalds ctx->offset_in = 0; 2631da177e4SLinus Torvalds ctx->offset_out = 0; 2641da177e4SLinus Torvalds ctx->idx_in = bio_in ? bio_in->bi_idx : 0; 2651da177e4SLinus Torvalds ctx->idx_out = bio_out ? bio_out->bi_idx : 0; 2661da177e4SLinus Torvalds ctx->sector = sector + cc->iv_offset; 2671da177e4SLinus Torvalds ctx->write = write; 2681da177e4SLinus Torvalds } 2691da177e4SLinus Torvalds 2701da177e4SLinus Torvalds /* 2711da177e4SLinus Torvalds * Encrypt / decrypt data from one bio to another one (can be the same one) 2721da177e4SLinus Torvalds */ 2731da177e4SLinus Torvalds static int crypt_convert(struct crypt_config *cc, 2741da177e4SLinus Torvalds struct convert_context *ctx) 2751da177e4SLinus Torvalds { 2761da177e4SLinus Torvalds int r = 0; 2771da177e4SLinus Torvalds 2781da177e4SLinus Torvalds while(ctx->idx_in < ctx->bio_in->bi_vcnt && 2791da177e4SLinus Torvalds ctx->idx_out < ctx->bio_out->bi_vcnt) { 2801da177e4SLinus Torvalds struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); 2811da177e4SLinus Torvalds struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); 2821da177e4SLinus Torvalds struct scatterlist sg_in = { 2831da177e4SLinus Torvalds .page = bv_in->bv_page, 2841da177e4SLinus Torvalds .offset = bv_in->bv_offset + ctx->offset_in, 2851da177e4SLinus Torvalds .length = 1 << SECTOR_SHIFT 2861da177e4SLinus Torvalds }; 2871da177e4SLinus Torvalds struct scatterlist sg_out = { 2881da177e4SLinus Torvalds .page = bv_out->bv_page, 2891da177e4SLinus Torvalds .offset = bv_out->bv_offset + ctx->offset_out, 2901da177e4SLinus Torvalds .length = 1 << SECTOR_SHIFT 2911da177e4SLinus Torvalds }; 2921da177e4SLinus Torvalds 2931da177e4SLinus Torvalds ctx->offset_in += sg_in.length; 2941da177e4SLinus Torvalds if (ctx->offset_in >= bv_in->bv_len) { 2951da177e4SLinus Torvalds ctx->offset_in = 0; 2961da177e4SLinus Torvalds ctx->idx_in++; 2971da177e4SLinus Torvalds } 2981da177e4SLinus Torvalds 2991da177e4SLinus Torvalds ctx->offset_out += sg_out.length; 3001da177e4SLinus Torvalds if (ctx->offset_out >= bv_out->bv_len) { 3011da177e4SLinus Torvalds ctx->offset_out = 0; 3021da177e4SLinus Torvalds ctx->idx_out++; 3031da177e4SLinus Torvalds } 3041da177e4SLinus Torvalds 3051da177e4SLinus Torvalds r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, 3061da177e4SLinus Torvalds ctx->write, ctx->sector); 3071da177e4SLinus Torvalds if (r < 0) 3081da177e4SLinus Torvalds break; 3091da177e4SLinus Torvalds 3101da177e4SLinus Torvalds ctx->sector++; 3111da177e4SLinus Torvalds } 3121da177e4SLinus Torvalds 3131da177e4SLinus Torvalds return r; 3141da177e4SLinus Torvalds } 3151da177e4SLinus Torvalds 3166a24c718SMilan Broz static void dm_crypt_bio_destructor(struct bio *bio) 3176a24c718SMilan Broz { 3186a24c718SMilan Broz struct crypt_io *io = bio->bi_private; 3196a24c718SMilan Broz struct crypt_config *cc = io->target->private; 3206a24c718SMilan Broz 3216a24c718SMilan Broz bio_free(bio, cc->bs); 3226a24c718SMilan Broz } 3236a24c718SMilan Broz 3241da177e4SLinus Torvalds /* 3251da177e4SLinus Torvalds * Generate a new unfragmented bio with the given size 3261da177e4SLinus Torvalds * This should never violate the device limitations 3271da177e4SLinus Torvalds * May return a smaller bio when running out of pages 3281da177e4SLinus Torvalds */ 3291da177e4SLinus Torvalds static struct bio * 3301da177e4SLinus Torvalds crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, 3311da177e4SLinus Torvalds struct bio *base_bio, unsigned int *bio_vec_idx) 3321da177e4SLinus Torvalds { 3338b004457SMilan Broz struct bio *clone; 3341da177e4SLinus Torvalds unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; 335b4e3ca1aSAl Viro gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; 3361da177e4SLinus Torvalds unsigned int i; 3371da177e4SLinus Torvalds 3386a24c718SMilan Broz if (base_bio) { 3396a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs); 3406a24c718SMilan Broz __bio_clone(clone, base_bio); 3416a24c718SMilan Broz } else 3426a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); 3436a24c718SMilan Broz 3448b004457SMilan Broz if (!clone) 3451da177e4SLinus Torvalds return NULL; 3461da177e4SLinus Torvalds 3476a24c718SMilan Broz clone->bi_destructor = dm_crypt_bio_destructor; 3486a24c718SMilan Broz 3491da177e4SLinus Torvalds /* if the last bio was not complete, continue where that one ended */ 3508b004457SMilan Broz clone->bi_idx = *bio_vec_idx; 3518b004457SMilan Broz clone->bi_vcnt = *bio_vec_idx; 3528b004457SMilan Broz clone->bi_size = 0; 3538b004457SMilan Broz clone->bi_flags &= ~(1 << BIO_SEG_VALID); 3541da177e4SLinus Torvalds 3558b004457SMilan Broz /* clone->bi_idx pages have already been allocated */ 3568b004457SMilan Broz size -= clone->bi_idx * PAGE_SIZE; 3571da177e4SLinus Torvalds 3588b004457SMilan Broz for (i = clone->bi_idx; i < nr_iovecs; i++) { 3598b004457SMilan Broz struct bio_vec *bv = bio_iovec_idx(clone, i); 3601da177e4SLinus Torvalds 3611da177e4SLinus Torvalds bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask); 3621da177e4SLinus Torvalds if (!bv->bv_page) 3631da177e4SLinus Torvalds break; 3641da177e4SLinus Torvalds 3651da177e4SLinus Torvalds /* 3661da177e4SLinus Torvalds * if additional pages cannot be allocated without waiting, 3671da177e4SLinus Torvalds * return a partially allocated bio, the caller will then try 3681da177e4SLinus Torvalds * to allocate additional bios while submitting this partial bio 3691da177e4SLinus Torvalds */ 3708b004457SMilan Broz if ((i - clone->bi_idx) == (MIN_BIO_PAGES - 1)) 3711da177e4SLinus Torvalds gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; 3721da177e4SLinus Torvalds 3731da177e4SLinus Torvalds bv->bv_offset = 0; 3741da177e4SLinus Torvalds if (size > PAGE_SIZE) 3751da177e4SLinus Torvalds bv->bv_len = PAGE_SIZE; 3761da177e4SLinus Torvalds else 3771da177e4SLinus Torvalds bv->bv_len = size; 3781da177e4SLinus Torvalds 3798b004457SMilan Broz clone->bi_size += bv->bv_len; 3808b004457SMilan Broz clone->bi_vcnt++; 3811da177e4SLinus Torvalds size -= bv->bv_len; 3821da177e4SLinus Torvalds } 3831da177e4SLinus Torvalds 3848b004457SMilan Broz if (!clone->bi_size) { 3858b004457SMilan Broz bio_put(clone); 3861da177e4SLinus Torvalds return NULL; 3871da177e4SLinus Torvalds } 3881da177e4SLinus Torvalds 3891da177e4SLinus Torvalds /* 3901da177e4SLinus Torvalds * Remember the last bio_vec allocated to be able 3911da177e4SLinus Torvalds * to correctly continue after the splitting. 3921da177e4SLinus Torvalds */ 3938b004457SMilan Broz *bio_vec_idx = clone->bi_vcnt; 3941da177e4SLinus Torvalds 3958b004457SMilan Broz return clone; 3961da177e4SLinus Torvalds } 3971da177e4SLinus Torvalds 3981da177e4SLinus Torvalds static void crypt_free_buffer_pages(struct crypt_config *cc, 3998b004457SMilan Broz struct bio *clone, unsigned int bytes) 4001da177e4SLinus Torvalds { 4011da177e4SLinus Torvalds unsigned int i, start, end; 4021da177e4SLinus Torvalds struct bio_vec *bv; 4031da177e4SLinus Torvalds 4041da177e4SLinus Torvalds /* 4051da177e4SLinus Torvalds * This is ugly, but Jens Axboe thinks that using bi_idx in the 4061da177e4SLinus Torvalds * endio function is too dangerous at the moment, so I calculate the 4071da177e4SLinus Torvalds * correct position using bi_vcnt and bi_size. 4081da177e4SLinus Torvalds * The bv_offset and bv_len fields might already be modified but we 4091da177e4SLinus Torvalds * know that we always allocated whole pages. 4101da177e4SLinus Torvalds * A fix to the bi_idx issue in the kernel is in the works, so 4111da177e4SLinus Torvalds * we will hopefully be able to revert to the cleaner solution soon. 4121da177e4SLinus Torvalds */ 4138b004457SMilan Broz i = clone->bi_vcnt - 1; 4148b004457SMilan Broz bv = bio_iovec_idx(clone, i); 4158b004457SMilan Broz end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - clone->bi_size; 4161da177e4SLinus Torvalds start = end - bytes; 4171da177e4SLinus Torvalds 4181da177e4SLinus Torvalds start >>= PAGE_SHIFT; 4198b004457SMilan Broz if (!clone->bi_size) 4208b004457SMilan Broz end = clone->bi_vcnt; 4211da177e4SLinus Torvalds else 4221da177e4SLinus Torvalds end >>= PAGE_SHIFT; 4231da177e4SLinus Torvalds 4241da177e4SLinus Torvalds for (i = start; i < end; i++) { 4258b004457SMilan Broz bv = bio_iovec_idx(clone, i); 4261da177e4SLinus Torvalds BUG_ON(!bv->bv_page); 4271da177e4SLinus Torvalds mempool_free(bv->bv_page, cc->page_pool); 4281da177e4SLinus Torvalds bv->bv_page = NULL; 4291da177e4SLinus Torvalds } 4301da177e4SLinus Torvalds } 4311da177e4SLinus Torvalds 4321da177e4SLinus Torvalds /* 4331da177e4SLinus Torvalds * One of the bios was finished. Check for completion of 4341da177e4SLinus Torvalds * the whole request and correctly clean up the buffer. 4351da177e4SLinus Torvalds */ 4361da177e4SLinus Torvalds static void dec_pending(struct crypt_io *io, int error) 4371da177e4SLinus Torvalds { 4381da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) io->target->private; 4391da177e4SLinus Torvalds 4401da177e4SLinus Torvalds if (error < 0) 4411da177e4SLinus Torvalds io->error = error; 4421da177e4SLinus Torvalds 4431da177e4SLinus Torvalds if (!atomic_dec_and_test(&io->pending)) 4441da177e4SLinus Torvalds return; 4451da177e4SLinus Torvalds 4461da177e4SLinus Torvalds if (io->first_clone) 4471da177e4SLinus Torvalds bio_put(io->first_clone); 4481da177e4SLinus Torvalds 4498b004457SMilan Broz bio_endio(io->base_bio, io->base_bio->bi_size, io->error); 4501da177e4SLinus Torvalds 4511da177e4SLinus Torvalds mempool_free(io, cc->io_pool); 4521da177e4SLinus Torvalds } 4531da177e4SLinus Torvalds 4541da177e4SLinus Torvalds /* 4551da177e4SLinus Torvalds * kcryptd: 4561da177e4SLinus Torvalds * 4571da177e4SLinus Torvalds * Needed because it would be very unwise to do decryption in an 45823541d2dSMilan Broz * interrupt context. 4591da177e4SLinus Torvalds */ 4601da177e4SLinus Torvalds static struct workqueue_struct *_kcryptd_workqueue; 461c4028958SDavid Howells static void kcryptd_do_work(struct work_struct *work); 4621da177e4SLinus Torvalds 4631da177e4SLinus Torvalds static void kcryptd_queue_io(struct crypt_io *io) 4641da177e4SLinus Torvalds { 465c4028958SDavid Howells INIT_WORK(&io->work, kcryptd_do_work); 4661da177e4SLinus Torvalds queue_work(_kcryptd_workqueue, &io->work); 4671da177e4SLinus Torvalds } 4681da177e4SLinus Torvalds 4698b004457SMilan Broz static int crypt_endio(struct bio *clone, unsigned int done, int error) 4708b004457SMilan Broz { 4718b004457SMilan Broz struct crypt_io *io = clone->bi_private; 4728b004457SMilan Broz struct crypt_config *cc = io->target->private; 4738b004457SMilan Broz unsigned read_io = bio_data_dir(clone) == READ; 4748b004457SMilan Broz 4758b004457SMilan Broz /* 4768b004457SMilan Broz * free the processed pages, even if 4778b004457SMilan Broz * it's only a partially completed write 4788b004457SMilan Broz */ 4798b004457SMilan Broz if (!read_io) 4808b004457SMilan Broz crypt_free_buffer_pages(cc, clone, done); 4818b004457SMilan Broz 48223541d2dSMilan Broz /* keep going - not finished yet */ 4838b004457SMilan Broz if (unlikely(clone->bi_size)) 4848b004457SMilan Broz return 1; 4858b004457SMilan Broz 4868b004457SMilan Broz if (!read_io) 4878b004457SMilan Broz goto out; 4888b004457SMilan Broz 4898b004457SMilan Broz if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) { 4908b004457SMilan Broz error = -EIO; 4918b004457SMilan Broz goto out; 4928b004457SMilan Broz } 4938b004457SMilan Broz 4948b004457SMilan Broz bio_put(clone); 49523541d2dSMilan Broz io->post_process = 1; 4968b004457SMilan Broz kcryptd_queue_io(io); 4978b004457SMilan Broz return 0; 4988b004457SMilan Broz 4998b004457SMilan Broz out: 5008b004457SMilan Broz bio_put(clone); 5018b004457SMilan Broz dec_pending(io, error); 5028b004457SMilan Broz return error; 5038b004457SMilan Broz } 5048b004457SMilan Broz 5058b004457SMilan Broz static void clone_init(struct crypt_io *io, struct bio *clone) 5068b004457SMilan Broz { 5078b004457SMilan Broz struct crypt_config *cc = io->target->private; 5088b004457SMilan Broz 5098b004457SMilan Broz clone->bi_private = io; 5108b004457SMilan Broz clone->bi_end_io = crypt_endio; 5118b004457SMilan Broz clone->bi_bdev = cc->dev->bdev; 5128b004457SMilan Broz clone->bi_rw = io->base_bio->bi_rw; 5138b004457SMilan Broz } 5148b004457SMilan Broz 51523541d2dSMilan Broz static void process_read(struct crypt_io *io) 5168b004457SMilan Broz { 5178b004457SMilan Broz struct crypt_config *cc = io->target->private; 5188b004457SMilan Broz struct bio *base_bio = io->base_bio; 5198b004457SMilan Broz struct bio *clone; 52093e605c2SMilan Broz sector_t sector = base_bio->bi_sector - io->target->begin; 52193e605c2SMilan Broz 52293e605c2SMilan Broz atomic_inc(&io->pending); 5238b004457SMilan Broz 5248b004457SMilan Broz /* 5258b004457SMilan Broz * The block layer might modify the bvec array, so always 5268b004457SMilan Broz * copy the required bvecs because we need the original 5278b004457SMilan Broz * one in order to decrypt the whole bio data *afterwards*. 5288b004457SMilan Broz */ 5296a24c718SMilan Broz clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); 53093e605c2SMilan Broz if (unlikely(!clone)) { 53193e605c2SMilan Broz dec_pending(io, -ENOMEM); 53223541d2dSMilan Broz return; 53393e605c2SMilan Broz } 5348b004457SMilan Broz 5358b004457SMilan Broz clone_init(io, clone); 5366a24c718SMilan Broz clone->bi_destructor = dm_crypt_bio_destructor; 5378b004457SMilan Broz clone->bi_idx = 0; 5388b004457SMilan Broz clone->bi_vcnt = bio_segments(base_bio); 5398b004457SMilan Broz clone->bi_size = base_bio->bi_size; 54093e605c2SMilan Broz clone->bi_sector = cc->start + sector; 5418b004457SMilan Broz memcpy(clone->bi_io_vec, bio_iovec(base_bio), 5428b004457SMilan Broz sizeof(struct bio_vec) * clone->bi_vcnt); 5438b004457SMilan Broz 54493e605c2SMilan Broz generic_make_request(clone); 5458b004457SMilan Broz } 5468b004457SMilan Broz 54723541d2dSMilan Broz static void process_write(struct crypt_io *io) 5488b004457SMilan Broz { 5498b004457SMilan Broz struct crypt_config *cc = io->target->private; 5508b004457SMilan Broz struct bio *base_bio = io->base_bio; 5518b004457SMilan Broz struct bio *clone; 55293e605c2SMilan Broz struct convert_context ctx; 55393e605c2SMilan Broz unsigned remaining = base_bio->bi_size; 55493e605c2SMilan Broz sector_t sector = base_bio->bi_sector - io->target->begin; 55593e605c2SMilan Broz unsigned bvec_idx = 0; 5568b004457SMilan Broz 55793e605c2SMilan Broz atomic_inc(&io->pending); 55893e605c2SMilan Broz 55993e605c2SMilan Broz crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1); 56093e605c2SMilan Broz 56193e605c2SMilan Broz /* 56293e605c2SMilan Broz * The allocated buffers can be smaller than the whole bio, 56393e605c2SMilan Broz * so repeat the whole process until all the data can be handled. 56493e605c2SMilan Broz */ 56593e605c2SMilan Broz while (remaining) { 5668b004457SMilan Broz clone = crypt_alloc_buffer(cc, base_bio->bi_size, 56793e605c2SMilan Broz io->first_clone, &bvec_idx); 56823541d2dSMilan Broz if (unlikely(!clone)) { 56923541d2dSMilan Broz dec_pending(io, -ENOMEM); 57023541d2dSMilan Broz return; 57123541d2dSMilan Broz } 5728b004457SMilan Broz 57393e605c2SMilan Broz ctx.bio_out = clone; 5748b004457SMilan Broz 57593e605c2SMilan Broz if (unlikely(crypt_convert(cc, &ctx) < 0)) { 57693e605c2SMilan Broz crypt_free_buffer_pages(cc, clone, clone->bi_size); 5778b004457SMilan Broz bio_put(clone); 57823541d2dSMilan Broz dec_pending(io, -EIO); 57923541d2dSMilan Broz return; 5808b004457SMilan Broz } 5818b004457SMilan Broz 5828b004457SMilan Broz clone_init(io, clone); 5838b004457SMilan Broz clone->bi_sector = cc->start + sector; 5848b004457SMilan Broz 58593e605c2SMilan Broz if (!io->first_clone) { 58693e605c2SMilan Broz /* 58793e605c2SMilan Broz * hold a reference to the first clone, because it 58893e605c2SMilan Broz * holds the bio_vec array and that can't be freed 58993e605c2SMilan Broz * before all other clones are released 59093e605c2SMilan Broz */ 59193e605c2SMilan Broz bio_get(clone); 59293e605c2SMilan Broz io->first_clone = clone; 59393e605c2SMilan Broz } 59493e605c2SMilan Broz 59593e605c2SMilan Broz remaining -= clone->bi_size; 59693e605c2SMilan Broz sector += bio_sectors(clone); 59793e605c2SMilan Broz 59823541d2dSMilan Broz /* prevent bio_put of first_clone */ 59923541d2dSMilan Broz if (remaining) 60023541d2dSMilan Broz atomic_inc(&io->pending); 60123541d2dSMilan Broz 60293e605c2SMilan Broz generic_make_request(clone); 60393e605c2SMilan Broz 60493e605c2SMilan Broz /* out of memory -> run queues */ 60593e605c2SMilan Broz if (remaining) 6063fcfab16SAndrew Morton congestion_wait(bio_data_dir(clone), HZ/100); 60793e605c2SMilan Broz } 6088b004457SMilan Broz } 6098b004457SMilan Broz 6108b004457SMilan Broz static void process_read_endio(struct crypt_io *io) 6118b004457SMilan Broz { 6128b004457SMilan Broz struct crypt_config *cc = io->target->private; 6138b004457SMilan Broz struct convert_context ctx; 6148b004457SMilan Broz 6158b004457SMilan Broz crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio, 6168b004457SMilan Broz io->base_bio->bi_sector - io->target->begin, 0); 6178b004457SMilan Broz 6188b004457SMilan Broz dec_pending(io, crypt_convert(cc, &ctx)); 6198b004457SMilan Broz } 6208b004457SMilan Broz 621c4028958SDavid Howells static void kcryptd_do_work(struct work_struct *work) 6228b004457SMilan Broz { 623c4028958SDavid Howells struct crypt_io *io = container_of(work, struct crypt_io, work); 6248b004457SMilan Broz 62523541d2dSMilan Broz if (io->post_process) 6268b004457SMilan Broz process_read_endio(io); 62723541d2dSMilan Broz else if (bio_data_dir(io->base_bio) == READ) 62823541d2dSMilan Broz process_read(io); 62923541d2dSMilan Broz else 63023541d2dSMilan Broz process_write(io); 6318b004457SMilan Broz } 6328b004457SMilan Broz 6331da177e4SLinus Torvalds /* 6341da177e4SLinus Torvalds * Decode key from its hex representation 6351da177e4SLinus Torvalds */ 6361da177e4SLinus Torvalds static int crypt_decode_key(u8 *key, char *hex, unsigned int size) 6371da177e4SLinus Torvalds { 6381da177e4SLinus Torvalds char buffer[3]; 6391da177e4SLinus Torvalds char *endp; 6401da177e4SLinus Torvalds unsigned int i; 6411da177e4SLinus Torvalds 6421da177e4SLinus Torvalds buffer[2] = '\0'; 6431da177e4SLinus Torvalds 6441da177e4SLinus Torvalds for (i = 0; i < size; i++) { 6451da177e4SLinus Torvalds buffer[0] = *hex++; 6461da177e4SLinus Torvalds buffer[1] = *hex++; 6471da177e4SLinus Torvalds 6481da177e4SLinus Torvalds key[i] = (u8)simple_strtoul(buffer, &endp, 16); 6491da177e4SLinus Torvalds 6501da177e4SLinus Torvalds if (endp != &buffer[2]) 6511da177e4SLinus Torvalds return -EINVAL; 6521da177e4SLinus Torvalds } 6531da177e4SLinus Torvalds 6541da177e4SLinus Torvalds if (*hex != '\0') 6551da177e4SLinus Torvalds return -EINVAL; 6561da177e4SLinus Torvalds 6571da177e4SLinus Torvalds return 0; 6581da177e4SLinus Torvalds } 6591da177e4SLinus Torvalds 6601da177e4SLinus Torvalds /* 6611da177e4SLinus Torvalds * Encode key into its hex representation 6621da177e4SLinus Torvalds */ 6631da177e4SLinus Torvalds static void crypt_encode_key(char *hex, u8 *key, unsigned int size) 6641da177e4SLinus Torvalds { 6651da177e4SLinus Torvalds unsigned int i; 6661da177e4SLinus Torvalds 6671da177e4SLinus Torvalds for (i = 0; i < size; i++) { 6681da177e4SLinus Torvalds sprintf(hex, "%02x", *key); 6691da177e4SLinus Torvalds hex += 2; 6701da177e4SLinus Torvalds key++; 6711da177e4SLinus Torvalds } 6721da177e4SLinus Torvalds } 6731da177e4SLinus Torvalds 674e48d4bbfSMilan Broz static int crypt_set_key(struct crypt_config *cc, char *key) 675e48d4bbfSMilan Broz { 676e48d4bbfSMilan Broz unsigned key_size = strlen(key) >> 1; 677e48d4bbfSMilan Broz 678e48d4bbfSMilan Broz if (cc->key_size && cc->key_size != key_size) 679e48d4bbfSMilan Broz return -EINVAL; 680e48d4bbfSMilan Broz 681e48d4bbfSMilan Broz cc->key_size = key_size; /* initial settings */ 682e48d4bbfSMilan Broz 683e48d4bbfSMilan Broz if ((!key_size && strcmp(key, "-")) || 684e48d4bbfSMilan Broz (key_size && crypt_decode_key(cc->key, key, key_size) < 0)) 685e48d4bbfSMilan Broz return -EINVAL; 686e48d4bbfSMilan Broz 687e48d4bbfSMilan Broz set_bit(DM_CRYPT_KEY_VALID, &cc->flags); 688e48d4bbfSMilan Broz 689e48d4bbfSMilan Broz return 0; 690e48d4bbfSMilan Broz } 691e48d4bbfSMilan Broz 692e48d4bbfSMilan Broz static int crypt_wipe_key(struct crypt_config *cc) 693e48d4bbfSMilan Broz { 694e48d4bbfSMilan Broz clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); 695e48d4bbfSMilan Broz memset(&cc->key, 0, cc->key_size * sizeof(u8)); 696e48d4bbfSMilan Broz return 0; 697e48d4bbfSMilan Broz } 698e48d4bbfSMilan Broz 6991da177e4SLinus Torvalds /* 7001da177e4SLinus Torvalds * Construct an encryption mapping: 7011da177e4SLinus Torvalds * <cipher> <key> <iv_offset> <dev_path> <start> 7021da177e4SLinus Torvalds */ 7031da177e4SLinus Torvalds static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) 7041da177e4SLinus Torvalds { 7051da177e4SLinus Torvalds struct crypt_config *cc; 706d1806f6aSHerbert Xu struct crypto_blkcipher *tfm; 7071da177e4SLinus Torvalds char *tmp; 7081da177e4SLinus Torvalds char *cipher; 7091da177e4SLinus Torvalds char *chainmode; 7101da177e4SLinus Torvalds char *ivmode; 7111da177e4SLinus Torvalds char *ivopts; 7121da177e4SLinus Torvalds unsigned int key_size; 7134ee218cdSAndrew Morton unsigned long long tmpll; 7141da177e4SLinus Torvalds 7151da177e4SLinus Torvalds if (argc != 5) { 71672d94861SAlasdair G Kergon ti->error = "Not enough arguments"; 7171da177e4SLinus Torvalds return -EINVAL; 7181da177e4SLinus Torvalds } 7191da177e4SLinus Torvalds 7201da177e4SLinus Torvalds tmp = argv[0]; 7211da177e4SLinus Torvalds cipher = strsep(&tmp, "-"); 7221da177e4SLinus Torvalds chainmode = strsep(&tmp, "-"); 7231da177e4SLinus Torvalds ivopts = strsep(&tmp, "-"); 7241da177e4SLinus Torvalds ivmode = strsep(&ivopts, ":"); 7251da177e4SLinus Torvalds 7261da177e4SLinus Torvalds if (tmp) 72772d94861SAlasdair G Kergon DMWARN("Unexpected additional cipher options"); 7281da177e4SLinus Torvalds 7291da177e4SLinus Torvalds key_size = strlen(argv[1]) >> 1; 7301da177e4SLinus Torvalds 731e48d4bbfSMilan Broz cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); 7321da177e4SLinus Torvalds if (cc == NULL) { 7331da177e4SLinus Torvalds ti->error = 73472d94861SAlasdair G Kergon "Cannot allocate transparent encryption context"; 7351da177e4SLinus Torvalds return -ENOMEM; 7361da177e4SLinus Torvalds } 7371da177e4SLinus Torvalds 738e48d4bbfSMilan Broz if (crypt_set_key(cc, argv[1])) { 73972d94861SAlasdair G Kergon ti->error = "Error decoding key"; 7401da177e4SLinus Torvalds goto bad1; 7411da177e4SLinus Torvalds } 7421da177e4SLinus Torvalds 7431da177e4SLinus Torvalds /* Compatiblity mode for old dm-crypt cipher strings */ 7441da177e4SLinus Torvalds if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { 7451da177e4SLinus Torvalds chainmode = "cbc"; 7461da177e4SLinus Torvalds ivmode = "plain"; 7471da177e4SLinus Torvalds } 7481da177e4SLinus Torvalds 749d1806f6aSHerbert Xu if (strcmp(chainmode, "ecb") && !ivmode) { 75072d94861SAlasdair G Kergon ti->error = "This chaining mode requires an IV mechanism"; 7511da177e4SLinus Torvalds goto bad1; 7521da177e4SLinus Torvalds } 7531da177e4SLinus Torvalds 754d1806f6aSHerbert Xu if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", chainmode, 755d1806f6aSHerbert Xu cipher) >= CRYPTO_MAX_ALG_NAME) { 756d1806f6aSHerbert Xu ti->error = "Chain mode + cipher name is too long"; 757d1806f6aSHerbert Xu goto bad1; 758d1806f6aSHerbert Xu } 759d1806f6aSHerbert Xu 760d1806f6aSHerbert Xu tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); 761d1806f6aSHerbert Xu if (IS_ERR(tfm)) { 76272d94861SAlasdair G Kergon ti->error = "Error allocating crypto tfm"; 7631da177e4SLinus Torvalds goto bad1; 7641da177e4SLinus Torvalds } 7651da177e4SLinus Torvalds 766d1806f6aSHerbert Xu strcpy(cc->cipher, cipher); 767d1806f6aSHerbert Xu strcpy(cc->chainmode, chainmode); 7681da177e4SLinus Torvalds cc->tfm = tfm; 7691da177e4SLinus Torvalds 7701da177e4SLinus Torvalds /* 7711da177e4SLinus Torvalds * Choose ivmode. Valid modes: "plain", "essiv:<esshash>". 7721da177e4SLinus Torvalds * See comments at iv code 7731da177e4SLinus Torvalds */ 7741da177e4SLinus Torvalds 7751da177e4SLinus Torvalds if (ivmode == NULL) 7761da177e4SLinus Torvalds cc->iv_gen_ops = NULL; 7771da177e4SLinus Torvalds else if (strcmp(ivmode, "plain") == 0) 7781da177e4SLinus Torvalds cc->iv_gen_ops = &crypt_iv_plain_ops; 7791da177e4SLinus Torvalds else if (strcmp(ivmode, "essiv") == 0) 7801da177e4SLinus Torvalds cc->iv_gen_ops = &crypt_iv_essiv_ops; 7811da177e4SLinus Torvalds else { 78272d94861SAlasdair G Kergon ti->error = "Invalid IV mode"; 7831da177e4SLinus Torvalds goto bad2; 7841da177e4SLinus Torvalds } 7851da177e4SLinus Torvalds 7861da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && 7871da177e4SLinus Torvalds cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) 7881da177e4SLinus Torvalds goto bad2; 7891da177e4SLinus Torvalds 790d1806f6aSHerbert Xu cc->iv_size = crypto_blkcipher_ivsize(tfm); 791d1806f6aSHerbert Xu if (cc->iv_size) 7921da177e4SLinus Torvalds /* at least a 64 bit sector number should fit in our buffer */ 793d1806f6aSHerbert Xu cc->iv_size = max(cc->iv_size, 7941da177e4SLinus Torvalds (unsigned int)(sizeof(u64) / sizeof(u8))); 7951da177e4SLinus Torvalds else { 7961da177e4SLinus Torvalds if (cc->iv_gen_ops) { 79772d94861SAlasdair G Kergon DMWARN("Selected cipher does not support IVs"); 7981da177e4SLinus Torvalds if (cc->iv_gen_ops->dtr) 7991da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 8001da177e4SLinus Torvalds cc->iv_gen_ops = NULL; 8011da177e4SLinus Torvalds } 8021da177e4SLinus Torvalds } 8031da177e4SLinus Torvalds 80493d2341cSMatthew Dobson cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); 8051da177e4SLinus Torvalds if (!cc->io_pool) { 80672d94861SAlasdair G Kergon ti->error = "Cannot allocate crypt io mempool"; 8071da177e4SLinus Torvalds goto bad3; 8081da177e4SLinus Torvalds } 8091da177e4SLinus Torvalds 810a19b27ceSMatthew Dobson cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); 8111da177e4SLinus Torvalds if (!cc->page_pool) { 81272d94861SAlasdair G Kergon ti->error = "Cannot allocate page mempool"; 8131da177e4SLinus Torvalds goto bad4; 8141da177e4SLinus Torvalds } 8151da177e4SLinus Torvalds 8166a24c718SMilan Broz cc->bs = bioset_create(MIN_IOS, MIN_IOS, 4); 8176a24c718SMilan Broz if (!cc->bs) { 8186a24c718SMilan Broz ti->error = "Cannot allocate crypt bioset"; 8196a24c718SMilan Broz goto bad_bs; 8206a24c718SMilan Broz } 8216a24c718SMilan Broz 822d1806f6aSHerbert Xu if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) { 82372d94861SAlasdair G Kergon ti->error = "Error setting key"; 8241da177e4SLinus Torvalds goto bad5; 8251da177e4SLinus Torvalds } 8261da177e4SLinus Torvalds 8274ee218cdSAndrew Morton if (sscanf(argv[2], "%llu", &tmpll) != 1) { 82872d94861SAlasdair G Kergon ti->error = "Invalid iv_offset sector"; 8291da177e4SLinus Torvalds goto bad5; 8301da177e4SLinus Torvalds } 8314ee218cdSAndrew Morton cc->iv_offset = tmpll; 8321da177e4SLinus Torvalds 8334ee218cdSAndrew Morton if (sscanf(argv[4], "%llu", &tmpll) != 1) { 83472d94861SAlasdair G Kergon ti->error = "Invalid device sector"; 8351da177e4SLinus Torvalds goto bad5; 8361da177e4SLinus Torvalds } 8374ee218cdSAndrew Morton cc->start = tmpll; 8381da177e4SLinus Torvalds 8391da177e4SLinus Torvalds if (dm_get_device(ti, argv[3], cc->start, ti->len, 8401da177e4SLinus Torvalds dm_table_get_mode(ti->table), &cc->dev)) { 84172d94861SAlasdair G Kergon ti->error = "Device lookup failed"; 8421da177e4SLinus Torvalds goto bad5; 8431da177e4SLinus Torvalds } 8441da177e4SLinus Torvalds 8451da177e4SLinus Torvalds if (ivmode && cc->iv_gen_ops) { 8461da177e4SLinus Torvalds if (ivopts) 8471da177e4SLinus Torvalds *(ivopts - 1) = ':'; 8481da177e4SLinus Torvalds cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); 8491da177e4SLinus Torvalds if (!cc->iv_mode) { 85072d94861SAlasdair G Kergon ti->error = "Error kmallocing iv_mode string"; 8511da177e4SLinus Torvalds goto bad5; 8521da177e4SLinus Torvalds } 8531da177e4SLinus Torvalds strcpy(cc->iv_mode, ivmode); 8541da177e4SLinus Torvalds } else 8551da177e4SLinus Torvalds cc->iv_mode = NULL; 8561da177e4SLinus Torvalds 8571da177e4SLinus Torvalds ti->private = cc; 8581da177e4SLinus Torvalds return 0; 8591da177e4SLinus Torvalds 8601da177e4SLinus Torvalds bad5: 8616a24c718SMilan Broz bioset_free(cc->bs); 8626a24c718SMilan Broz bad_bs: 8631da177e4SLinus Torvalds mempool_destroy(cc->page_pool); 8641da177e4SLinus Torvalds bad4: 8651da177e4SLinus Torvalds mempool_destroy(cc->io_pool); 8661da177e4SLinus Torvalds bad3: 8671da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 8681da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 8691da177e4SLinus Torvalds bad2: 870d1806f6aSHerbert Xu crypto_free_blkcipher(tfm); 8711da177e4SLinus Torvalds bad1: 8729d3520a3SStefan Rompf /* Must zero key material before freeing */ 8739d3520a3SStefan Rompf memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); 8741da177e4SLinus Torvalds kfree(cc); 8751da177e4SLinus Torvalds return -EINVAL; 8761da177e4SLinus Torvalds } 8771da177e4SLinus Torvalds 8781da177e4SLinus Torvalds static void crypt_dtr(struct dm_target *ti) 8791da177e4SLinus Torvalds { 8801da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) ti->private; 8811da177e4SLinus Torvalds 8826a24c718SMilan Broz bioset_free(cc->bs); 8831da177e4SLinus Torvalds mempool_destroy(cc->page_pool); 8841da177e4SLinus Torvalds mempool_destroy(cc->io_pool); 8851da177e4SLinus Torvalds 8861da177e4SLinus Torvalds kfree(cc->iv_mode); 8871da177e4SLinus Torvalds if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) 8881da177e4SLinus Torvalds cc->iv_gen_ops->dtr(cc); 889d1806f6aSHerbert Xu crypto_free_blkcipher(cc->tfm); 8901da177e4SLinus Torvalds dm_put_device(ti, cc->dev); 8919d3520a3SStefan Rompf 8929d3520a3SStefan Rompf /* Must zero key material before freeing */ 8939d3520a3SStefan Rompf memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); 8941da177e4SLinus Torvalds kfree(cc); 8951da177e4SLinus Torvalds } 8961da177e4SLinus Torvalds 8971da177e4SLinus Torvalds static int crypt_map(struct dm_target *ti, struct bio *bio, 8981da177e4SLinus Torvalds union map_info *map_context) 8991da177e4SLinus Torvalds { 9008b004457SMilan Broz struct crypt_config *cc = ti->private; 901e48d4bbfSMilan Broz struct crypt_io *io; 9021da177e4SLinus Torvalds 903e48d4bbfSMilan Broz io = mempool_alloc(cc->io_pool, GFP_NOIO); 9041da177e4SLinus Torvalds io->target = ti; 9058b004457SMilan Broz io->base_bio = bio; 9061da177e4SLinus Torvalds io->first_clone = NULL; 90723541d2dSMilan Broz io->error = io->post_process = 0; 90893e605c2SMilan Broz atomic_set(&io->pending, 0); 90923541d2dSMilan Broz kcryptd_queue_io(io); 9101da177e4SLinus Torvalds 91123541d2dSMilan Broz return 0; 9121da177e4SLinus Torvalds } 9131da177e4SLinus Torvalds 9141da177e4SLinus Torvalds static int crypt_status(struct dm_target *ti, status_type_t type, 9151da177e4SLinus Torvalds char *result, unsigned int maxlen) 9161da177e4SLinus Torvalds { 9171da177e4SLinus Torvalds struct crypt_config *cc = (struct crypt_config *) ti->private; 9181da177e4SLinus Torvalds unsigned int sz = 0; 9191da177e4SLinus Torvalds 9201da177e4SLinus Torvalds switch (type) { 9211da177e4SLinus Torvalds case STATUSTYPE_INFO: 9221da177e4SLinus Torvalds result[0] = '\0'; 9231da177e4SLinus Torvalds break; 9241da177e4SLinus Torvalds 9251da177e4SLinus Torvalds case STATUSTYPE_TABLE: 9261da177e4SLinus Torvalds if (cc->iv_mode) 92737af6560SChristophe Saout DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode, 92837af6560SChristophe Saout cc->iv_mode); 9291da177e4SLinus Torvalds else 93037af6560SChristophe Saout DMEMIT("%s-%s ", cc->cipher, cc->chainmode); 9311da177e4SLinus Torvalds 9321da177e4SLinus Torvalds if (cc->key_size > 0) { 9331da177e4SLinus Torvalds if ((maxlen - sz) < ((cc->key_size << 1) + 1)) 9341da177e4SLinus Torvalds return -ENOMEM; 9351da177e4SLinus Torvalds 9361da177e4SLinus Torvalds crypt_encode_key(result + sz, cc->key, cc->key_size); 9371da177e4SLinus Torvalds sz += cc->key_size << 1; 9381da177e4SLinus Torvalds } else { 9391da177e4SLinus Torvalds if (sz >= maxlen) 9401da177e4SLinus Torvalds return -ENOMEM; 9411da177e4SLinus Torvalds result[sz++] = '-'; 9421da177e4SLinus Torvalds } 9431da177e4SLinus Torvalds 9444ee218cdSAndrew Morton DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, 9454ee218cdSAndrew Morton cc->dev->name, (unsigned long long)cc->start); 9461da177e4SLinus Torvalds break; 9471da177e4SLinus Torvalds } 9481da177e4SLinus Torvalds return 0; 9491da177e4SLinus Torvalds } 9501da177e4SLinus Torvalds 951e48d4bbfSMilan Broz static void crypt_postsuspend(struct dm_target *ti) 952e48d4bbfSMilan Broz { 953e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 954e48d4bbfSMilan Broz 955e48d4bbfSMilan Broz set_bit(DM_CRYPT_SUSPENDED, &cc->flags); 956e48d4bbfSMilan Broz } 957e48d4bbfSMilan Broz 958e48d4bbfSMilan Broz static int crypt_preresume(struct dm_target *ti) 959e48d4bbfSMilan Broz { 960e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 961e48d4bbfSMilan Broz 962e48d4bbfSMilan Broz if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { 963e48d4bbfSMilan Broz DMERR("aborting resume - crypt key is not set."); 964e48d4bbfSMilan Broz return -EAGAIN; 965e48d4bbfSMilan Broz } 966e48d4bbfSMilan Broz 967e48d4bbfSMilan Broz return 0; 968e48d4bbfSMilan Broz } 969e48d4bbfSMilan Broz 970e48d4bbfSMilan Broz static void crypt_resume(struct dm_target *ti) 971e48d4bbfSMilan Broz { 972e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 973e48d4bbfSMilan Broz 974e48d4bbfSMilan Broz clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); 975e48d4bbfSMilan Broz } 976e48d4bbfSMilan Broz 977e48d4bbfSMilan Broz /* Message interface 978e48d4bbfSMilan Broz * key set <key> 979e48d4bbfSMilan Broz * key wipe 980e48d4bbfSMilan Broz */ 981e48d4bbfSMilan Broz static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) 982e48d4bbfSMilan Broz { 983e48d4bbfSMilan Broz struct crypt_config *cc = ti->private; 984e48d4bbfSMilan Broz 985e48d4bbfSMilan Broz if (argc < 2) 986e48d4bbfSMilan Broz goto error; 987e48d4bbfSMilan Broz 988e48d4bbfSMilan Broz if (!strnicmp(argv[0], MESG_STR("key"))) { 989e48d4bbfSMilan Broz if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { 990e48d4bbfSMilan Broz DMWARN("not suspended during key manipulation."); 991e48d4bbfSMilan Broz return -EINVAL; 992e48d4bbfSMilan Broz } 993e48d4bbfSMilan Broz if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) 994e48d4bbfSMilan Broz return crypt_set_key(cc, argv[2]); 995e48d4bbfSMilan Broz if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) 996e48d4bbfSMilan Broz return crypt_wipe_key(cc); 997e48d4bbfSMilan Broz } 998e48d4bbfSMilan Broz 999e48d4bbfSMilan Broz error: 1000e48d4bbfSMilan Broz DMWARN("unrecognised message received."); 1001e48d4bbfSMilan Broz return -EINVAL; 1002e48d4bbfSMilan Broz } 1003e48d4bbfSMilan Broz 10041da177e4SLinus Torvalds static struct target_type crypt_target = { 10051da177e4SLinus Torvalds .name = "crypt", 100623541d2dSMilan Broz .version= {1, 3, 0}, 10071da177e4SLinus Torvalds .module = THIS_MODULE, 10081da177e4SLinus Torvalds .ctr = crypt_ctr, 10091da177e4SLinus Torvalds .dtr = crypt_dtr, 10101da177e4SLinus Torvalds .map = crypt_map, 10111da177e4SLinus Torvalds .status = crypt_status, 1012e48d4bbfSMilan Broz .postsuspend = crypt_postsuspend, 1013e48d4bbfSMilan Broz .preresume = crypt_preresume, 1014e48d4bbfSMilan Broz .resume = crypt_resume, 1015e48d4bbfSMilan Broz .message = crypt_message, 10161da177e4SLinus Torvalds }; 10171da177e4SLinus Torvalds 10181da177e4SLinus Torvalds static int __init dm_crypt_init(void) 10191da177e4SLinus Torvalds { 10201da177e4SLinus Torvalds int r; 10211da177e4SLinus Torvalds 10221da177e4SLinus Torvalds _crypt_io_pool = kmem_cache_create("dm-crypt_io", 10231da177e4SLinus Torvalds sizeof(struct crypt_io), 10241da177e4SLinus Torvalds 0, 0, NULL, NULL); 10251da177e4SLinus Torvalds if (!_crypt_io_pool) 10261da177e4SLinus Torvalds return -ENOMEM; 10271da177e4SLinus Torvalds 10281da177e4SLinus Torvalds _kcryptd_workqueue = create_workqueue("kcryptd"); 10291da177e4SLinus Torvalds if (!_kcryptd_workqueue) { 10301da177e4SLinus Torvalds r = -ENOMEM; 103172d94861SAlasdair G Kergon DMERR("couldn't create kcryptd"); 10321da177e4SLinus Torvalds goto bad1; 10331da177e4SLinus Torvalds } 10341da177e4SLinus Torvalds 10351da177e4SLinus Torvalds r = dm_register_target(&crypt_target); 10361da177e4SLinus Torvalds if (r < 0) { 103772d94861SAlasdair G Kergon DMERR("register failed %d", r); 10381da177e4SLinus Torvalds goto bad2; 10391da177e4SLinus Torvalds } 10401da177e4SLinus Torvalds 10411da177e4SLinus Torvalds return 0; 10421da177e4SLinus Torvalds 10431da177e4SLinus Torvalds bad2: 10441da177e4SLinus Torvalds destroy_workqueue(_kcryptd_workqueue); 10451da177e4SLinus Torvalds bad1: 10461da177e4SLinus Torvalds kmem_cache_destroy(_crypt_io_pool); 10471da177e4SLinus Torvalds return r; 10481da177e4SLinus Torvalds } 10491da177e4SLinus Torvalds 10501da177e4SLinus Torvalds static void __exit dm_crypt_exit(void) 10511da177e4SLinus Torvalds { 10521da177e4SLinus Torvalds int r = dm_unregister_target(&crypt_target); 10531da177e4SLinus Torvalds 10541da177e4SLinus Torvalds if (r < 0) 105572d94861SAlasdair G Kergon DMERR("unregister failed %d", r); 10561da177e4SLinus Torvalds 10571da177e4SLinus Torvalds destroy_workqueue(_kcryptd_workqueue); 10581da177e4SLinus Torvalds kmem_cache_destroy(_crypt_io_pool); 10591da177e4SLinus Torvalds } 10601da177e4SLinus Torvalds 10611da177e4SLinus Torvalds module_init(dm_crypt_init); 10621da177e4SLinus Torvalds module_exit(dm_crypt_exit); 10631da177e4SLinus Torvalds 10641da177e4SLinus Torvalds MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); 10651da177e4SLinus Torvalds MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); 10661da177e4SLinus Torvalds MODULE_LICENSE("GPL"); 1067