diff options
Diffstat (limited to 'drivers/md/dm-crypt.c')
| -rw-r--r-- | drivers/md/dm-crypt.c | 2244 |
1 files changed, 1638 insertions, 606 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c index e7a650f9ca0..4cba2d808af 100644 --- a/drivers/md/dm-crypt.c +++ b/drivers/md/dm-crypt.c @@ -1,10 +1,14 @@ /* - * Copyright (C) 2003 Christophe Saout <christophe@saout.de> + * Copyright (C) 2003 Jana Saout <jana@saout.de> * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> + * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. + * Copyright (C) 2013 Milan Broz <gmazyland@gmail.com> * * This file is released under the GPL. */ +#include <linux/completion.h> +#include <linux/err.h> #include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> @@ -14,466 +18,1340 @@ #include <linux/slab.h> #include <linux/crypto.h> #include <linux/workqueue.h> -#include <asm/atomic.h> +#include <linux/backing-dev.h> +#include <linux/atomic.h> #include <linux/scatterlist.h> #include <asm/page.h> +#include <asm/unaligned.h> +#include <crypto/hash.h> +#include <crypto/md5.h> +#include <crypto/algapi.h> -#include "dm.h" +#include <linux/device-mapper.h> -#define PFX "crypt: " - -/* - * per bio private data - */ -struct crypt_io { - struct dm_target *target; - struct bio *bio; - struct bio *first_clone; - struct work_struct work; - atomic_t pending; - int error; -}; +#define DM_MSG_PREFIX "crypt" /* * context holding the current state of a multi-part conversion */ struct convert_context { + struct completion restart; struct bio *bio_in; struct bio *bio_out; - unsigned int offset_in; - unsigned int offset_out; - unsigned int idx_in; - unsigned int idx_out; + struct bvec_iter iter_in; + struct bvec_iter iter_out; + sector_t cc_sector; + atomic_t cc_pending; + struct ablkcipher_request *req; +}; + +/* + * per bio private data + */ +struct dm_crypt_io { + struct crypt_config *cc; + struct bio *base_bio; + struct work_struct work; + + struct convert_context ctx; + + atomic_t io_pending; + int error; sector_t sector; - int write; + struct dm_crypt_io *base_io; +}; + +struct dm_crypt_request { + struct convert_context *ctx; + struct scatterlist sg_in; + struct scatterlist sg_out; + sector_t iv_sector; }; struct crypt_config; struct crypt_iv_operations { int (*ctr)(struct crypt_config *cc, struct dm_target *ti, - const char *opts); + const char *opts); void (*dtr)(struct crypt_config *cc); - const char *(*status)(struct crypt_config *cc); - int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); + int (*init)(struct crypt_config *cc); + int (*wipe)(struct crypt_config *cc); + int (*generator)(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq); + int (*post)(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq); +}; + +struct iv_essiv_private { + struct crypto_hash *hash_tfm; + u8 *salt; +}; + +struct iv_benbi_private { + int shift; +}; + +#define LMK_SEED_SIZE 64 /* hash + 0 */ +struct iv_lmk_private { + struct crypto_shash *hash_tfm; + u8 *seed; +}; + +#define TCW_WHITENING_SIZE 16 +struct iv_tcw_private { + struct crypto_shash *crc32_tfm; + u8 *iv_seed; + u8 *whitening; }; /* * Crypt: maps a linear range of a block device * and encrypts / decrypts at the same time. */ +enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; + +/* + * The fields in here must be read only after initialization. + */ struct crypt_config { struct dm_dev *dev; sector_t start; /* - * pool for per bio private data and - * for encryption buffer pages + * pool for per bio private data, crypto requests and + * encryption requeusts/buffer pages */ mempool_t *io_pool; + mempool_t *req_pool; mempool_t *page_pool; + struct bio_set *bs; + + struct workqueue_struct *io_queue; + struct workqueue_struct *crypt_queue; + + char *cipher; + char *cipher_string; - /* - * crypto related data - */ struct crypt_iv_operations *iv_gen_ops; - char *iv_mode; - void *iv_gen_private; + union { + struct iv_essiv_private essiv; + struct iv_benbi_private benbi; + struct iv_lmk_private lmk; + struct iv_tcw_private tcw; + } iv_gen_private; sector_t iv_offset; unsigned int iv_size; - struct crypto_tfm *tfm; + /* ESSIV: struct crypto_cipher *essiv_tfm */ + void *iv_private; + struct crypto_ablkcipher **tfms; + unsigned tfms_count; + + /* + * Layout of each crypto request: + * + * struct ablkcipher_request + * context + * padding + * struct dm_crypt_request + * padding + * IV + * + * The padding is added so that dm_crypt_request and the IV are + * correctly aligned. + */ + unsigned int dmreq_start; + + unsigned long flags; unsigned int key_size; + unsigned int key_parts; /* independent parts in key buffer */ + unsigned int key_extra_size; /* additional keys length */ u8 key[0]; }; -#define MIN_IOS 256 +#define MIN_IOS 16 #define MIN_POOL_PAGES 32 -#define MIN_BIO_PAGES 8 -static kmem_cache_t *_crypt_io_pool; +static struct kmem_cache *_crypt_io_pool; + +static void clone_init(struct dm_crypt_io *, struct bio *); +static void kcryptd_queue_crypt(struct dm_crypt_io *io); +static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq); /* - * Mempool alloc and free functions for the page + * Use this to access cipher attributes that are the same for each CPU. */ -static void *mempool_alloc_page(gfp_t gfp_mask, void *data) +static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc) { - return alloc_page(gfp_mask); + return cc->tfms[0]; } -static void mempool_free_page(void *page, void *data) -{ - __free_page(page); -} - - /* * Different IV generation algorithms: * - * plain: the initial vector is the 32-bit low-endian version of the sector - * number, padded with zeros if neccessary. + * plain: the initial vector is the 32-bit little-endian version of the sector + * number, padded with zeros if necessary. + * + * plain64: the initial vector is the 64-bit little-endian version of the sector + * number, padded with zeros if necessary. + * + * essiv: "encrypted sector|salt initial vector", the sector number is + * encrypted with the bulk cipher using a salt as key. The salt + * should be derived from the bulk cipher's key via hashing. + * + * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 + * (needed for LRW-32-AES and possible other narrow block modes) + * + * null: the initial vector is always zero. Provides compatibility with + * obsolete loop_fish2 devices. Do not use for new devices. * - * ess_iv: "encrypted sector|salt initial vector", the sector number is - * encrypted with the bulk cipher using a salt as key. The salt - * should be derived from the bulk cipher's key via hashing. + * lmk: Compatible implementation of the block chaining mode used + * by the Loop-AES block device encryption system + * designed by Jari Ruusu. See http://loop-aes.sourceforge.net/ + * It operates on full 512 byte sectors and uses CBC + * with an IV derived from the sector number, the data and + * optionally extra IV seed. + * This means that after decryption the first block + * of sector must be tweaked according to decrypted data. + * Loop-AES can use three encryption schemes: + * version 1: is plain aes-cbc mode + * version 2: uses 64 multikey scheme with lmk IV generator + * version 3: the same as version 2 with additional IV seed + * (it uses 65 keys, last key is used as IV seed) + * + * tcw: Compatible implementation of the block chaining mode used + * by the TrueCrypt device encryption system (prior to version 4.1). + * For more info see: http://www.truecrypt.org + * It operates on full 512 byte sectors and uses CBC + * with an IV derived from initial key and the sector number. + * In addition, whitening value is applied on every sector, whitening + * is calculated from initial key, sector number and mixed using CRC32. + * Note that this encryption scheme is vulnerable to watermarking attacks + * and should be used for old compatible containers access only. * * plumb: unimplemented, see: * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 */ -static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) +static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) { memset(iv, 0, cc->iv_size); - *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); + *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); return 0; } -static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, - const char *opts) +static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + memset(iv, 0, cc->iv_size); + *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); + + return 0; +} + +/* Initialise ESSIV - compute salt but no local memory allocations */ +static int crypt_iv_essiv_init(struct crypt_config *cc) { - struct crypto_tfm *essiv_tfm; - struct crypto_tfm *hash_tfm; + struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; + struct hash_desc desc; struct scatterlist sg; - unsigned int saltsize; - u8 *salt; + struct crypto_cipher *essiv_tfm; + int err; - if (opts == NULL) { - ti->error = PFX "Digest algorithm missing for ESSIV mode"; - return -EINVAL; + sg_init_one(&sg, cc->key, cc->key_size); + desc.tfm = essiv->hash_tfm; + desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt); + if (err) + return err; + + essiv_tfm = cc->iv_private; + + err = crypto_cipher_setkey(essiv_tfm, essiv->salt, + crypto_hash_digestsize(essiv->hash_tfm)); + if (err) + return err; + + return 0; +} + +/* Wipe salt and reset key derived from volume key */ +static int crypt_iv_essiv_wipe(struct crypt_config *cc) +{ + struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; + unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm); + struct crypto_cipher *essiv_tfm; + int r, err = 0; + + memset(essiv->salt, 0, salt_size); + + essiv_tfm = cc->iv_private; + r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size); + if (r) + err = r; + + return err; +} + +/* Set up per cpu cipher state */ +static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc, + struct dm_target *ti, + u8 *salt, unsigned saltsize) +{ + struct crypto_cipher *essiv_tfm; + int err; + + /* Setup the essiv_tfm with the given salt */ + essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(essiv_tfm)) { + ti->error = "Error allocating crypto tfm for ESSIV"; + return essiv_tfm; } - /* Hash the cipher key with the given hash algorithm */ - hash_tfm = crypto_alloc_tfm(opts, CRYPTO_TFM_REQ_MAY_SLEEP); - if (hash_tfm == NULL) { - ti->error = PFX "Error initializing ESSIV hash"; - return -EINVAL; + if (crypto_cipher_blocksize(essiv_tfm) != + crypto_ablkcipher_ivsize(any_tfm(cc))) { + ti->error = "Block size of ESSIV cipher does " + "not match IV size of block cipher"; + crypto_free_cipher(essiv_tfm); + return ERR_PTR(-EINVAL); } - if (crypto_tfm_alg_type(hash_tfm) != CRYPTO_ALG_TYPE_DIGEST) { - ti->error = PFX "Expected digest algorithm for ESSIV hash"; - crypto_free_tfm(hash_tfm); + err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); + if (err) { + ti->error = "Failed to set key for ESSIV cipher"; + crypto_free_cipher(essiv_tfm); + return ERR_PTR(err); + } + + return essiv_tfm; +} + +static void crypt_iv_essiv_dtr(struct crypt_config *cc) +{ + struct crypto_cipher *essiv_tfm; + struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; + + crypto_free_hash(essiv->hash_tfm); + essiv->hash_tfm = NULL; + + kzfree(essiv->salt); + essiv->salt = NULL; + + essiv_tfm = cc->iv_private; + + if (essiv_tfm) + crypto_free_cipher(essiv_tfm); + + cc->iv_private = NULL; +} + +static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, + const char *opts) +{ + struct crypto_cipher *essiv_tfm = NULL; + struct crypto_hash *hash_tfm = NULL; + u8 *salt = NULL; + int err; + + if (!opts) { + ti->error = "Digest algorithm missing for ESSIV mode"; return -EINVAL; } - saltsize = crypto_tfm_alg_digestsize(hash_tfm); - salt = kmalloc(saltsize, GFP_KERNEL); - if (salt == NULL) { - ti->error = PFX "Error kmallocing salt storage in ESSIV"; - crypto_free_tfm(hash_tfm); - return -ENOMEM; + /* Allocate hash algorithm */ + hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); + if (IS_ERR(hash_tfm)) { + ti->error = "Error initializing ESSIV hash"; + err = PTR_ERR(hash_tfm); + goto bad; } - sg_set_buf(&sg, cc->key, cc->key_size); - crypto_digest_digest(hash_tfm, &sg, 1, salt); - crypto_free_tfm(hash_tfm); + salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL); + if (!salt) { + ti->error = "Error kmallocing salt storage in ESSIV"; + err = -ENOMEM; + goto bad; + } - /* Setup the essiv_tfm with the given salt */ - essiv_tfm = crypto_alloc_tfm(crypto_tfm_alg_name(cc->tfm), - CRYPTO_TFM_MODE_ECB | - CRYPTO_TFM_REQ_MAY_SLEEP); - if (essiv_tfm == NULL) { - ti->error = PFX "Error allocating crypto tfm for ESSIV"; - kfree(salt); - return -EINVAL; + cc->iv_gen_private.essiv.salt = salt; + cc->iv_gen_private.essiv.hash_tfm = hash_tfm; + + essiv_tfm = setup_essiv_cpu(cc, ti, salt, + crypto_hash_digestsize(hash_tfm)); + if (IS_ERR(essiv_tfm)) { + crypt_iv_essiv_dtr(cc); + return PTR_ERR(essiv_tfm); } - if (crypto_tfm_alg_blocksize(essiv_tfm) - != crypto_tfm_alg_ivsize(cc->tfm)) { - ti->error = PFX "Block size of ESSIV cipher does " - "not match IV size of block cipher"; - crypto_free_tfm(essiv_tfm); - kfree(salt); + cc->iv_private = essiv_tfm; + + return 0; + +bad: + if (hash_tfm && !IS_ERR(hash_tfm)) + crypto_free_hash(hash_tfm); + kfree(salt); + return err; +} + +static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + struct crypto_cipher *essiv_tfm = cc->iv_private; + + memset(iv, 0, cc->iv_size); + *(__le64 *)iv = cpu_to_le64(dmreq->iv_sector); + crypto_cipher_encrypt_one(essiv_tfm, iv, iv); + + return 0; +} + +static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, + const char *opts) +{ + unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc)); + int log = ilog2(bs); + + /* we need to calculate how far we must shift the sector count + * to get the cipher block count, we use this shift in _gen */ + + if (1 << log != bs) { + ti->error = "cypher blocksize is not a power of 2"; return -EINVAL; } - if (crypto_cipher_setkey(essiv_tfm, salt, saltsize) < 0) { - ti->error = PFX "Failed to set key for ESSIV cipher"; - crypto_free_tfm(essiv_tfm); - kfree(salt); + + if (log > 9) { + ti->error = "cypher blocksize is > 512"; return -EINVAL; } - kfree(salt); - cc->iv_gen_private = (void *)essiv_tfm; + cc->iv_gen_private.benbi.shift = 9 - log; + return 0; } -static void crypt_iv_essiv_dtr(struct crypt_config *cc) +static void crypt_iv_benbi_dtr(struct crypt_config *cc) { - crypto_free_tfm((struct crypto_tfm *)cc->iv_gen_private); - cc->iv_gen_private = NULL; } -static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) +static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) { - struct scatterlist sg; + __be64 val; + + memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ + val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1); + put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); + + return 0; +} + +static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ memset(iv, 0, cc->iv_size); - *(u64 *)iv = cpu_to_le64(sector); - sg_set_buf(&sg, iv, cc->iv_size); - crypto_cipher_encrypt((struct crypto_tfm *)cc->iv_gen_private, - &sg, &sg, cc->iv_size); + return 0; +} + +static void crypt_iv_lmk_dtr(struct crypt_config *cc) +{ + struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; + + if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm)) + crypto_free_shash(lmk->hash_tfm); + lmk->hash_tfm = NULL; + + kzfree(lmk->seed); + lmk->seed = NULL; +} + +static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti, + const char *opts) +{ + struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; + + lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0); + if (IS_ERR(lmk->hash_tfm)) { + ti->error = "Error initializing LMK hash"; + return PTR_ERR(lmk->hash_tfm); + } + + /* No seed in LMK version 2 */ + if (cc->key_parts == cc->tfms_count) { + lmk->seed = NULL; + return 0; + } + + lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL); + if (!lmk->seed) { + crypt_iv_lmk_dtr(cc); + ti->error = "Error kmallocing seed storage in LMK"; + return -ENOMEM; + } + + return 0; +} + +static int crypt_iv_lmk_init(struct crypt_config *cc) +{ + struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; + int subkey_size = cc->key_size / cc->key_parts; + + /* LMK seed is on the position of LMK_KEYS + 1 key */ + if (lmk->seed) + memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size), + crypto_shash_digestsize(lmk->hash_tfm)); + + return 0; +} + +static int crypt_iv_lmk_wipe(struct crypt_config *cc) +{ + struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; + + if (lmk->seed) + memset(lmk->seed, 0, LMK_SEED_SIZE); + + return 0; +} + +static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq, + u8 *data) +{ + struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk; + struct { + struct shash_desc desc; + char ctx[crypto_shash_descsize(lmk->hash_tfm)]; + } sdesc; + struct md5_state md5state; + __le32 buf[4]; + int i, r; + + sdesc.desc.tfm = lmk->hash_tfm; + sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + + r = crypto_shash_init(&sdesc.desc); + if (r) + return r; + + if (lmk->seed) { + r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE); + if (r) + return r; + } + + /* Sector is always 512B, block size 16, add data of blocks 1-31 */ + r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31); + if (r) + return r; + + /* Sector is cropped to 56 bits here */ + buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF); + buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000); + buf[2] = cpu_to_le32(4024); + buf[3] = 0; + r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf)); + if (r) + return r; + + /* No MD5 padding here */ + r = crypto_shash_export(&sdesc.desc, &md5state); + if (r) + return r; + + for (i = 0; i < MD5_HASH_WORDS; i++) + __cpu_to_le32s(&md5state.hash[i]); + memcpy(iv, &md5state.hash, cc->iv_size); + + return 0; +} + +static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + u8 *src; + int r = 0; + + if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { + src = kmap_atomic(sg_page(&dmreq->sg_in)); + r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset); + kunmap_atomic(src); + } else + memset(iv, 0, cc->iv_size); + + return r; +} + +static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + u8 *dst; + int r; + + if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) + return 0; + + dst = kmap_atomic(sg_page(&dmreq->sg_out)); + r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset); + + /* Tweak the first block of plaintext sector */ + if (!r) + crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size); + + kunmap_atomic(dst); + return r; +} + +static void crypt_iv_tcw_dtr(struct crypt_config *cc) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + + kzfree(tcw->iv_seed); + tcw->iv_seed = NULL; + kzfree(tcw->whitening); + tcw->whitening = NULL; + + if (tcw->crc32_tfm && !IS_ERR(tcw->crc32_tfm)) + crypto_free_shash(tcw->crc32_tfm); + tcw->crc32_tfm = NULL; +} + +static int crypt_iv_tcw_ctr(struct crypt_config *cc, struct dm_target *ti, + const char *opts) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + + if (cc->key_size <= (cc->iv_size + TCW_WHITENING_SIZE)) { + ti->error = "Wrong key size for TCW"; + return -EINVAL; + } + + tcw->crc32_tfm = crypto_alloc_shash("crc32", 0, 0); + if (IS_ERR(tcw->crc32_tfm)) { + ti->error = "Error initializing CRC32 in TCW"; + return PTR_ERR(tcw->crc32_tfm); + } + + tcw->iv_seed = kzalloc(cc->iv_size, GFP_KERNEL); + tcw->whitening = kzalloc(TCW_WHITENING_SIZE, GFP_KERNEL); + if (!tcw->iv_seed || !tcw->whitening) { + crypt_iv_tcw_dtr(cc); + ti->error = "Error allocating seed storage in TCW"; + return -ENOMEM; + } + + return 0; +} + +static int crypt_iv_tcw_init(struct crypt_config *cc) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + int key_offset = cc->key_size - cc->iv_size - TCW_WHITENING_SIZE; + + memcpy(tcw->iv_seed, &cc->key[key_offset], cc->iv_size); + memcpy(tcw->whitening, &cc->key[key_offset + cc->iv_size], + TCW_WHITENING_SIZE); + + return 0; +} + +static int crypt_iv_tcw_wipe(struct crypt_config *cc) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + + memset(tcw->iv_seed, 0, cc->iv_size); + memset(tcw->whitening, 0, TCW_WHITENING_SIZE); return 0; } +static int crypt_iv_tcw_whitening(struct crypt_config *cc, + struct dm_crypt_request *dmreq, + u8 *data) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + u64 sector = cpu_to_le64((u64)dmreq->iv_sector); + u8 buf[TCW_WHITENING_SIZE]; + struct { + struct shash_desc desc; + char ctx[crypto_shash_descsize(tcw->crc32_tfm)]; + } sdesc; + int i, r; + + /* xor whitening with sector number */ + memcpy(buf, tcw->whitening, TCW_WHITENING_SIZE); + crypto_xor(buf, (u8 *)§or, 8); + crypto_xor(&buf[8], (u8 *)§or, 8); + + /* calculate crc32 for every 32bit part and xor it */ + sdesc.desc.tfm = tcw->crc32_tfm; + sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; + for (i = 0; i < 4; i++) { + r = crypto_shash_init(&sdesc.desc); + if (r) + goto out; + r = crypto_shash_update(&sdesc.desc, &buf[i * 4], 4); + if (r) + goto out; + r = crypto_shash_final(&sdesc.desc, &buf[i * 4]); + if (r) + goto out; + } + crypto_xor(&buf[0], &buf[12], 4); + crypto_xor(&buf[4], &buf[8], 4); + + /* apply whitening (8 bytes) to whole sector */ + for (i = 0; i < ((1 << SECTOR_SHIFT) / 8); i++) + crypto_xor(data + i * 8, buf, 8); +out: + memset(buf, 0, sizeof(buf)); + return r; +} + +static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + u64 sector = cpu_to_le64((u64)dmreq->iv_sector); + u8 *src; + int r = 0; + + /* Remove whitening from ciphertext */ + if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { + src = kmap_atomic(sg_page(&dmreq->sg_in)); + r = crypt_iv_tcw_whitening(cc, dmreq, src + dmreq->sg_in.offset); + kunmap_atomic(src); + } + + /* Calculate IV */ + memcpy(iv, tcw->iv_seed, cc->iv_size); + crypto_xor(iv, (u8 *)§or, 8); + if (cc->iv_size > 8) + crypto_xor(&iv[8], (u8 *)§or, cc->iv_size - 8); + + return r; +} + +static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + u8 *dst; + int r; + + if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) + return 0; + + /* Apply whitening on ciphertext */ + dst = kmap_atomic(sg_page(&dmreq->sg_out)); + r = crypt_iv_tcw_whitening(cc, dmreq, dst + dmreq->sg_out.offset); + kunmap_atomic(dst); + + return r; +} + static struct crypt_iv_operations crypt_iv_plain_ops = { .generator = crypt_iv_plain_gen }; +static struct crypt_iv_operations crypt_iv_plain64_ops = { + .generator = crypt_iv_plain64_gen +}; + static struct crypt_iv_operations crypt_iv_essiv_ops = { .ctr = crypt_iv_essiv_ctr, .dtr = crypt_iv_essiv_dtr, + .init = crypt_iv_essiv_init, + .wipe = crypt_iv_essiv_wipe, .generator = crypt_iv_essiv_gen }; +static struct crypt_iv_operations crypt_iv_benbi_ops = { + .ctr = crypt_iv_benbi_ctr, + .dtr = crypt_iv_benbi_dtr, + .generator = crypt_iv_benbi_gen +}; -static int -crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out, - struct scatterlist *in, unsigned int length, - int write, sector_t sector) +static struct crypt_iv_operations crypt_iv_null_ops = { + .generator = crypt_iv_null_gen +}; + +static struct crypt_iv_operations crypt_iv_lmk_ops = { + .ctr = crypt_iv_lmk_ctr, + .dtr = crypt_iv_lmk_dtr, + .init = crypt_iv_lmk_init, + .wipe = crypt_iv_lmk_wipe, + .generator = crypt_iv_lmk_gen, + .post = crypt_iv_lmk_post +}; + +static struct crypt_iv_operations crypt_iv_tcw_ops = { + .ctr = crypt_iv_tcw_ctr, + .dtr = crypt_iv_tcw_dtr, + .init = crypt_iv_tcw_init, + .wipe = crypt_iv_tcw_wipe, + .generator = crypt_iv_tcw_gen, + .post = crypt_iv_tcw_post +}; + +static void crypt_convert_init(struct crypt_config *cc, + struct convert_context *ctx, + struct bio *bio_out, struct bio *bio_in, + sector_t sector) +{ + ctx->bio_in = bio_in; + ctx->bio_out = bio_out; + if (bio_in) + ctx->iter_in = bio_in->bi_iter; + if (bio_out) + ctx->iter_out = bio_out->bi_iter; + ctx->cc_sector = sector + cc->iv_offset; + init_completion(&ctx->restart); +} + +static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, + struct ablkcipher_request *req) +{ + return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); +} + +static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) { - u8 iv[cc->iv_size]; + return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start); +} + +static u8 *iv_of_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + return (u8 *)ALIGN((unsigned long)(dmreq + 1), + crypto_ablkcipher_alignmask(any_tfm(cc)) + 1); +} + +static int crypt_convert_block(struct crypt_config *cc, + struct convert_context *ctx, + struct ablkcipher_request *req) +{ + struct bio_vec bv_in = bio_iter_iovec(ctx->bio_in, ctx->iter_in); + struct bio_vec bv_out = bio_iter_iovec(ctx->bio_out, ctx->iter_out); + struct dm_crypt_request *dmreq; + u8 *iv; int r; + dmreq = dmreq_of_req(cc, req); + iv = iv_of_dmreq(cc, dmreq); + + dmreq->iv_sector = ctx->cc_sector; + dmreq->ctx = ctx; + sg_init_table(&dmreq->sg_in, 1); + sg_set_page(&dmreq->sg_in, bv_in.bv_page, 1 << SECTOR_SHIFT, + bv_in.bv_offset); + + sg_init_table(&dmreq->sg_out, 1); + sg_set_page(&dmreq->sg_out, bv_out.bv_page, 1 << SECTOR_SHIFT, + bv_out.bv_offset); + + bio_advance_iter(ctx->bio_in, &ctx->iter_in, 1 << SECTOR_SHIFT); + bio_advance_iter(ctx->bio_out, &ctx->iter_out, 1 << SECTOR_SHIFT); + if (cc->iv_gen_ops) { - r = cc->iv_gen_ops->generator(cc, iv, sector); + r = cc->iv_gen_ops->generator(cc, iv, dmreq); if (r < 0) return r; - - if (write) - r = crypto_cipher_encrypt_iv(cc->tfm, out, in, length, iv); - else - r = crypto_cipher_decrypt_iv(cc->tfm, out, in, length, iv); - } else { - if (write) - r = crypto_cipher_encrypt(cc->tfm, out, in, length); - else - r = crypto_cipher_decrypt(cc->tfm, out, in, length); } + ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out, + 1 << SECTOR_SHIFT, iv); + + if (bio_data_dir(ctx->bio_in) == WRITE) + r = crypto_ablkcipher_encrypt(req); + else + r = crypto_ablkcipher_decrypt(req); + + if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) + r = cc->iv_gen_ops->post(cc, iv, dmreq); + return r; } -static void -crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx, - struct bio *bio_out, struct bio *bio_in, - sector_t sector, int write) +static void kcryptd_async_done(struct crypto_async_request *async_req, + int error); + +static void crypt_alloc_req(struct crypt_config *cc, + struct convert_context *ctx) { - ctx->bio_in = bio_in; - ctx->bio_out = bio_out; - ctx->offset_in = 0; - ctx->offset_out = 0; - ctx->idx_in = bio_in ? bio_in->bi_idx : 0; - ctx->idx_out = bio_out ? bio_out->bi_idx : 0; - ctx->sector = sector + cc->iv_offset; - ctx->write = write; + unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); + + if (!ctx->req) + ctx->req = mempool_alloc(cc->req_pool, GFP_NOIO); + + ablkcipher_request_set_tfm(ctx->req, cc->tfms[key_index]); + ablkcipher_request_set_callback(ctx->req, + CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + kcryptd_async_done, dmreq_of_req(cc, ctx->req)); } /* * Encrypt / decrypt data from one bio to another one (can be the same one) */ static int crypt_convert(struct crypt_config *cc, - struct convert_context *ctx) + struct convert_context *ctx) { - int r = 0; + int r; - while(ctx->idx_in < ctx->bio_in->bi_vcnt && - ctx->idx_out < ctx->bio_out->bi_vcnt) { - struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); - struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); - struct scatterlist sg_in = { - .page = bv_in->bv_page, - .offset = bv_in->bv_offset + ctx->offset_in, - .length = 1 << SECTOR_SHIFT - }; - struct scatterlist sg_out = { - .page = bv_out->bv_page, - .offset = bv_out->bv_offset + ctx->offset_out, - .length = 1 << SECTOR_SHIFT - }; - - ctx->offset_in += sg_in.length; - if (ctx->offset_in >= bv_in->bv_len) { - ctx->offset_in = 0; - ctx->idx_in++; - } + atomic_set(&ctx->cc_pending, 1); - ctx->offset_out += sg_out.length; - if (ctx->offset_out >= bv_out->bv_len) { - ctx->offset_out = 0; - ctx->idx_out++; - } + while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { - r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, - ctx->write, ctx->sector); - if (r < 0) - break; + crypt_alloc_req(cc, ctx); + + atomic_inc(&ctx->cc_pending); + + r = crypt_convert_block(cc, ctx, ctx->req); + + switch (r) { + /* async */ + case -EBUSY: + wait_for_completion(&ctx->restart); + reinit_completion(&ctx->restart); + /* fall through*/ + case -EINPROGRESS: + ctx->req = NULL; + ctx->cc_sector++; + continue; - ctx->sector++; + /* sync */ + case 0: + atomic_dec(&ctx->cc_pending); + ctx->cc_sector++; + cond_resched(); + continue; + + /* error */ + default: + atomic_dec(&ctx->cc_pending); + return r; + } } - return r; + return 0; } /* * Generate a new unfragmented bio with the given size * This should never violate the device limitations - * May return a smaller bio when running out of pages + * May return a smaller bio when running out of pages, indicated by + * *out_of_pages set to 1. */ -static struct bio * -crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, - struct bio *base_bio, unsigned int *bio_vec_idx) +static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size, + unsigned *out_of_pages) { - struct bio *bio; + struct crypt_config *cc = io->cc; + struct bio *clone; unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; - unsigned int i; + unsigned i, len; + struct page *page; - /* - * Use __GFP_NOMEMALLOC to tell the VM to act less aggressively and - * to fail earlier. This is not necessary but increases throughput. - * FIXME: Is this really intelligent? - */ - if (base_bio) - bio = bio_clone(base_bio, GFP_NOIO|__GFP_NOMEMALLOC); - else - bio = bio_alloc(GFP_NOIO|__GFP_NOMEMALLOC, nr_iovecs); - if (!bio) + clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); + if (!clone) return NULL; - /* if the last bio was not complete, continue where that one ended */ - bio->bi_idx = *bio_vec_idx; - bio->bi_vcnt = *bio_vec_idx; - bio->bi_size = 0; - bio->bi_flags &= ~(1 << BIO_SEG_VALID); - - /* bio->bi_idx pages have already been allocated */ - size -= bio->bi_idx * PAGE_SIZE; - - for(i = bio->bi_idx; i < nr_iovecs; i++) { - struct bio_vec *bv = bio_iovec_idx(bio, i); + clone_init(io, clone); + *out_of_pages = 0; - bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask); - if (!bv->bv_page) + for (i = 0; i < nr_iovecs; i++) { + page = mempool_alloc(cc->page_pool, gfp_mask); + if (!page) { + *out_of_pages = 1; break; + } /* - * if additional pages cannot be allocated without waiting, - * return a partially allocated bio, the caller will then try - * to allocate additional bios while submitting this partial bio + * If additional pages cannot be allocated without waiting, + * return a partially-allocated bio. The caller will then try + * to allocate more bios while submitting this partial bio. */ - if ((i - bio->bi_idx) == (MIN_BIO_PAGES - 1)) - gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; + gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; - bv->bv_offset = 0; - if (size > PAGE_SIZE) - bv->bv_len = PAGE_SIZE; - else - bv->bv_len = size; + len = (size > PAGE_SIZE) ? PAGE_SIZE : size; - bio->bi_size += bv->bv_len; - bio->bi_vcnt++; - size -= bv->bv_len; + if (!bio_add_page(clone, page, len, 0)) { + mempool_free(page, cc->page_pool); + break; + } + + size -= len; } - if (!bio->bi_size) { - bio_put(bio); + if (!clone->bi_iter.bi_size) { + bio_put(clone); return NULL; } - /* - * Remember the last bio_vec allocated to be able - * to correctly continue after the splitting. - */ - *bio_vec_idx = bio->bi_vcnt; - - return bio; + return clone; } -static void crypt_free_buffer_pages(struct crypt_config *cc, - struct bio *bio, unsigned int bytes) +static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) { - unsigned int i, start, end; + unsigned int i; struct bio_vec *bv; - /* - * This is ugly, but Jens Axboe thinks that using bi_idx in the - * endio function is too dangerous at the moment, so I calculate the - * correct position using bi_vcnt and bi_size. - * The bv_offset and bv_len fields might already be modified but we - * know that we always allocated whole pages. - * A fix to the bi_idx issue in the kernel is in the works, so - * we will hopefully be able to revert to the cleaner solution soon. - */ - i = bio->bi_vcnt - 1; - bv = bio_iovec_idx(bio, i); - end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - bio->bi_size; - start = end - bytes; - - start >>= PAGE_SHIFT; - if (!bio->bi_size) - end = bio->bi_vcnt; - else - end >>= PAGE_SHIFT; - - for(i = start; i < end; i++) { - bv = bio_iovec_idx(bio, i); + bio_for_each_segment_all(bv, clone, i) { BUG_ON(!bv->bv_page); mempool_free(bv->bv_page, cc->page_pool); bv->bv_page = NULL; } } +static struct dm_crypt_io *crypt_io_alloc(struct crypt_config *cc, + struct bio *bio, sector_t sector) +{ + struct dm_crypt_io *io; + + io = mempool_alloc(cc->io_pool, GFP_NOIO); + io->cc = cc; + io->base_bio = bio; + io->sector = sector; + io->error = 0; + io->base_io = NULL; + io->ctx.req = NULL; + atomic_set(&io->io_pending, 0); + + return io; +} + +static void crypt_inc_pending(struct dm_crypt_io *io) +{ + atomic_inc(&io->io_pending); +} + /* * One of the bios was finished. Check for completion of * the whole request and correctly clean up the buffer. + * If base_io is set, wait for the last fragment to complete. */ -static void dec_pending(struct crypt_io *io, int error) +static void crypt_dec_pending(struct dm_crypt_io *io) { - struct crypt_config *cc = (struct crypt_config *) io->target->private; + struct crypt_config *cc = io->cc; + struct bio *base_bio = io->base_bio; + struct dm_crypt_io *base_io = io->base_io; + int error = io->error; - if (error < 0) - io->error = error; - - if (!atomic_dec_and_test(&io->pending)) + if (!atomic_dec_and_test(&io->io_pending)) return; - if (io->first_clone) - bio_put(io->first_clone); - - bio_endio(io->bio, io->bio->bi_size, io->error); - + if (io->ctx.req) + mempool_free(io->ctx.req, cc->req_pool); mempool_free(io, cc->io_pool); + + if (likely(!base_io)) + bio_endio(base_bio, error); + else { + if (error && !base_io->error) + base_io->error = error; + crypt_dec_pending(base_io); + } } /* - * kcryptd: + * kcryptd/kcryptd_io: * * Needed because it would be very unwise to do decryption in an - * interrupt context, so bios returning from read requests get - * queued here. + * interrupt context. + * + * kcryptd performs the actual encryption or decryption. + * + * kcryptd_io performs the IO submission. + * + * They must be separated as otherwise the final stages could be + * starved by new requests which can block in the first stages due + * to memory allocation. + * + * The work is done per CPU global for all dm-crypt instances. + * They should not depend on each other and do not block. */ -static struct workqueue_struct *_kcryptd_workqueue; +static void crypt_endio(struct bio *clone, int error) +{ + struct dm_crypt_io *io = clone->bi_private; + struct crypt_config *cc = io->cc; + unsigned rw = bio_data_dir(clone); + + if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) + error = -EIO; + + /* + * free the processed pages + */ + if (rw == WRITE) + crypt_free_buffer_pages(cc, clone); -static void kcryptd_do_work(void *data) + bio_put(clone); + + if (rw == READ && !error) { + kcryptd_queue_crypt(io); + return; + } + + if (unlikely(error)) + io->error = error; + + crypt_dec_pending(io); +} + +static void clone_init(struct dm_crypt_io *io, struct bio *clone) { - struct crypt_io *io = (struct crypt_io *) data; - struct crypt_config *cc = (struct crypt_config *) io->target->private; - struct convert_context ctx; + struct crypt_config *cc = io->cc; + + clone->bi_private = io; + clone->bi_end_io = crypt_endio; + clone->bi_bdev = cc->dev->bdev; + clone->bi_rw = io->base_bio->bi_rw; +} + +static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) +{ + struct crypt_config *cc = io->cc; + struct bio *base_bio = io->base_bio; + struct bio *clone; + + /* + * The block layer might modify the bvec array, so always + * copy the required bvecs because we need the original + * one in order to decrypt the whole bio data *afterwards*. + */ + clone = bio_clone_bioset(base_bio, gfp, cc->bs); + if (!clone) + return 1; + + crypt_inc_pending(io); + + clone_init(io, clone); + clone->bi_iter.bi_sector = cc->start + io->sector; + + generic_make_request(clone); + return 0; +} + +static void kcryptd_io_write(struct dm_crypt_io *io) +{ + struct bio *clone = io->ctx.bio_out; + generic_make_request(clone); +} + +static void kcryptd_io(struct work_struct *work) +{ + struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); + + if (bio_data_dir(io->base_bio) == READ) { + crypt_inc_pending(io); + if (kcryptd_io_read(io, GFP_NOIO)) + io->error = -ENOMEM; + crypt_dec_pending(io); + } else + kcryptd_io_write(io); +} + +static void kcryptd_queue_io(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + + INIT_WORK(&io->work, kcryptd_io); + queue_work(cc->io_queue, &io->work); +} + +static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async) +{ + struct bio *clone = io->ctx.bio_out; + struct crypt_config *cc = io->cc; + + if (unlikely(io->error < 0)) { + crypt_free_buffer_pages(cc, clone); + bio_put(clone); + crypt_dec_pending(io); + return; + } + + /* crypt_convert should have filled the clone bio */ + BUG_ON(io->ctx.iter_out.bi_size); + + clone->bi_iter.bi_sector = cc->start + io->sector; + + if (async) + kcryptd_queue_io(io); + else + generic_make_request(clone); +} + +static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + struct bio *clone; + struct dm_crypt_io *new_io; + int crypt_finished; + unsigned out_of_pages = 0; + unsigned remaining = io->base_bio->bi_iter.bi_size; + sector_t sector = io->sector; int r; - crypt_convert_init(cc, &ctx, io->bio, io->bio, - io->bio->bi_sector - io->target->begin, 0); - r = crypt_convert(cc, &ctx); + /* + * Prevent io from disappearing until this function completes. + */ + crypt_inc_pending(io); + crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); - dec_pending(io, r); + /* + * The allocated buffers can be smaller than the whole bio, + * so repeat the whole process until all the data can be handled. + */ + while (remaining) { + clone = crypt_alloc_buffer(io, remaining, &out_of_pages); + if (unlikely(!clone)) { + io->error = -ENOMEM; + break; + } + + io->ctx.bio_out = clone; + io->ctx.iter_out = clone->bi_iter; + + remaining -= clone->bi_iter.bi_size; + sector += bio_sectors(clone); + + crypt_inc_pending(io); + + r = crypt_convert(cc, &io->ctx); + if (r < 0) + io->error = -EIO; + + crypt_finished = atomic_dec_and_test(&io->ctx.cc_pending); + + /* Encryption was already finished, submit io now */ + if (crypt_finished) { + kcryptd_crypt_write_io_submit(io, 0); + + /* + * If there was an error, do not try next fragments. + * For async, error is processed in async handler. + */ + if (unlikely(r < 0)) + break; + + io->sector = sector; + } + + /* + * Out of memory -> run queues + * But don't wait if split was due to the io size restriction + */ + if (unlikely(out_of_pages)) + congestion_wait(BLK_RW_ASYNC, HZ/100); + + /* + * With async crypto it is unsafe to share the crypto context + * between fragments, so switch to a new dm_crypt_io structure. + */ + if (unlikely(!crypt_finished && remaining)) { + new_io = crypt_io_alloc(io->cc, io->base_bio, + sector); + crypt_inc_pending(new_io); + crypt_convert_init(cc, &new_io->ctx, NULL, + io->base_bio, sector); + new_io->ctx.iter_in = io->ctx.iter_in; + + /* + * Fragments after the first use the base_io + * pending count. + */ + if (!io->base_io) + new_io->base_io = io; + else { + new_io->base_io = io->base_io; + crypt_inc_pending(io->base_io); + crypt_dec_pending(io); + } + + io = new_io; + } + } + + crypt_dec_pending(io); } -static void kcryptd_queue_io(struct crypt_io *io) +static void kcryptd_crypt_read_done(struct dm_crypt_io *io) { - INIT_WORK(&io->work, kcryptd_do_work, io); - queue_work(_kcryptd_workqueue, &io->work); + crypt_dec_pending(io); +} + +static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + int r = 0; + + crypt_inc_pending(io); + + crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, + io->sector); + + r = crypt_convert(cc, &io->ctx); + if (r < 0) + io->error = -EIO; + + if (atomic_dec_and_test(&io->ctx.cc_pending)) + kcryptd_crypt_read_done(io); + + crypt_dec_pending(io); +} + +static void kcryptd_async_done(struct crypto_async_request *async_req, + int error) +{ + struct dm_crypt_request *dmreq = async_req->data; + struct convert_context *ctx = dmreq->ctx; + struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); + struct crypt_config *cc = io->cc; + + if (error == -EINPROGRESS) { + complete(&ctx->restart); + return; + } + + if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post) + error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq); + + if (error < 0) + io->error = -EIO; + + mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool); + + if (!atomic_dec_and_test(&ctx->cc_pending)) + return; + + if (bio_data_dir(io->base_bio) == READ) + kcryptd_crypt_read_done(io); + else + kcryptd_crypt_write_io_submit(io, 1); +} + +static void kcryptd_crypt(struct work_struct *work) +{ + struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); + + if (bio_data_dir(io->base_bio) == READ) + kcryptd_crypt_read_convert(io); + else + kcryptd_crypt_write_convert(io); +} + +static void kcryptd_queue_crypt(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + + INIT_WORK(&io->work, kcryptd_crypt); + queue_work(cc->crypt_queue, &io->work); } /* @@ -482,18 +1360,15 @@ static void kcryptd_queue_io(struct crypt_io *io) static int crypt_decode_key(u8 *key, char *hex, unsigned int size) { char buffer[3]; - char *endp; unsigned int i; buffer[2] = '\0'; - for(i = 0; i < size; i++) { + for (i = 0; i < size; i++) { buffer[0] = *hex++; buffer[1] = *hex++; - key[i] = (u8)simple_strtoul(buffer, &endp, 16); - - if (endp != &buffer[2]) + if (kstrtou8(buffer, 16, &key[i])) return -EINVAL; } @@ -503,467 +1378,624 @@ static int crypt_decode_key(u8 *key, char *hex, unsigned int size) return 0; } -/* - * Encode key into its hex representation - */ -static void crypt_encode_key(char *hex, u8 *key, unsigned int size) +static void crypt_free_tfms(struct crypt_config *cc) { - unsigned int i; + unsigned i; - for(i = 0; i < size; i++) { - sprintf(hex, "%02x", *key); - hex += 2; - key++; + if (!cc->tfms) + return; + + for (i = 0; i < cc->tfms_count; i++) + if (cc->tfms[i] && !IS_ERR(cc->tfms[i])) { + crypto_free_ablkcipher(cc->tfms[i]); + cc->tfms[i] = NULL; + } + + kfree(cc->tfms); + cc->tfms = NULL; +} + +static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) +{ + unsigned i; + int err; + + cc->tfms = kmalloc(cc->tfms_count * sizeof(struct crypto_ablkcipher *), + GFP_KERNEL); + if (!cc->tfms) + return -ENOMEM; + + for (i = 0; i < cc->tfms_count; i++) { + cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0); + if (IS_ERR(cc->tfms[i])) { + err = PTR_ERR(cc->tfms[i]); + crypt_free_tfms(cc); + return err; + } } + + return 0; } -/* - * Construct an encryption mapping: - * <cipher> <key> <iv_offset> <dev_path> <start> - */ -static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) +static int crypt_setkey_allcpus(struct crypt_config *cc) { - struct crypt_config *cc; - struct crypto_tfm *tfm; - char *tmp; - char *cipher; - char *chainmode; - char *ivmode; - char *ivopts; - unsigned int crypto_flags; - unsigned int key_size; + unsigned subkey_size; + int err = 0, i, r; + + /* Ignore extra keys (which are used for IV etc) */ + subkey_size = (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); + + for (i = 0; i < cc->tfms_count; i++) { + r = crypto_ablkcipher_setkey(cc->tfms[i], + cc->key + (i * subkey_size), + subkey_size); + if (r) + err = r; + } + + return err; +} + +static int crypt_set_key(struct crypt_config *cc, char *key) +{ + int r = -EINVAL; + int key_string_len = strlen(key); + + /* The key size may not be changed. */ + if (cc->key_size != (key_string_len >> 1)) + goto out; + + /* Hyphen (which gives a key_size of zero) means there is no key. */ + if (!cc->key_size && strcmp(key, "-")) + goto out; + + if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0) + goto out; + + set_bit(DM_CRYPT_KEY_VALID, &cc->flags); + + r = crypt_setkey_allcpus(cc); + +out: + /* Hex key string not needed after here, so wipe it. */ + memset(key, '0', key_string_len); + + return r; +} + +static int crypt_wipe_key(struct crypt_config *cc) +{ + clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); + memset(&cc->key, 0, cc->key_size * sizeof(u8)); - if (argc != 5) { - ti->error = PFX "Not enough arguments"; + return crypt_setkey_allcpus(cc); +} + +static void crypt_dtr(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; + + ti->private = NULL; + + if (!cc) + return; + + if (cc->io_queue) + destroy_workqueue(cc->io_queue); + if (cc->crypt_queue) + destroy_workqueue(cc->crypt_queue); + + crypt_free_tfms(cc); + + if (cc->bs) + bioset_free(cc->bs); + + if (cc->page_pool) + mempool_destroy(cc->page_pool); + if (cc->req_pool) + mempool_destroy(cc->req_pool); + if (cc->io_pool) + mempool_destroy(cc->io_pool); + + if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) + cc->iv_gen_ops->dtr(cc); + + if (cc->dev) + dm_put_device(ti, cc->dev); + + kzfree(cc->cipher); + kzfree(cc->cipher_string); + + /* Must zero key material before freeing */ + kzfree(cc); +} + +static int crypt_ctr_cipher(struct dm_target *ti, + char *cipher_in, char *key) +{ + struct crypt_config *cc = ti->private; + char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount; + char *cipher_api = NULL; + int ret = -EINVAL; + char dummy; + + /* Convert to crypto api definition? */ + if (strchr(cipher_in, '(')) { + ti->error = "Bad cipher specification"; return -EINVAL; } - tmp = argv[0]; - cipher = strsep(&tmp, "-"); + cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); + if (!cc->cipher_string) + goto bad_mem; + + /* + * Legacy dm-crypt cipher specification + * cipher[:keycount]-mode-iv:ivopts + */ + tmp = cipher_in; + keycount = strsep(&tmp, "-"); + cipher = strsep(&keycount, ":"); + + if (!keycount) + cc->tfms_count = 1; + else if (sscanf(keycount, "%u%c", &cc->tfms_count, &dummy) != 1 || + !is_power_of_2(cc->tfms_count)) { + ti->error = "Bad cipher key count specification"; + return -EINVAL; + } + cc->key_parts = cc->tfms_count; + cc->key_extra_size = 0; + + cc->cipher = kstrdup(cipher, GFP_KERNEL); + if (!cc->cipher) + goto bad_mem; + chainmode = strsep(&tmp, "-"); ivopts = strsep(&tmp, "-"); ivmode = strsep(&ivopts, ":"); if (tmp) - DMWARN(PFX "Unexpected additional cipher options"); - - key_size = strlen(argv[1]) >> 1; - - cc = kmalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); - if (cc == NULL) { - ti->error = - PFX "Cannot allocate transparent encryption context"; - return -ENOMEM; - } - - cc->key_size = key_size; - if ((!key_size && strcmp(argv[1], "-") != 0) || - (key_size && crypt_decode_key(cc->key, argv[1], key_size) < 0)) { - ti->error = PFX "Error decoding key"; - goto bad1; - } + DMWARN("Ignoring unexpected additional cipher options"); - /* Compatiblity mode for old dm-crypt cipher strings */ - if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { + /* + * For compatibility with the original dm-crypt mapping format, if + * only the cipher name is supplied, use cbc-plain. + */ + if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) { chainmode = "cbc"; ivmode = "plain"; } - /* Choose crypto_flags according to chainmode */ - if (strcmp(chainmode, "cbc") == 0) - crypto_flags = CRYPTO_TFM_MODE_CBC; - else if (strcmp(chainmode, "ecb") == 0) - crypto_flags = CRYPTO_TFM_MODE_ECB; - else { - ti->error = PFX "Unknown chaining mode"; - goto bad1; + if (strcmp(chainmode, "ecb") && !ivmode) { + ti->error = "IV mechanism required"; + return -EINVAL; } - if (crypto_flags != CRYPTO_TFM_MODE_ECB && !ivmode) { - ti->error = PFX "This chaining mode requires an IV mechanism"; - goto bad1; - } + cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); + if (!cipher_api) + goto bad_mem; - tfm = crypto_alloc_tfm(cipher, crypto_flags | CRYPTO_TFM_REQ_MAY_SLEEP); - if (!tfm) { - ti->error = PFX "Error allocating crypto tfm"; - goto bad1; - } - if (crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER) { - ti->error = PFX "Expected cipher algorithm"; - goto bad2; + ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, + "%s(%s)", chainmode, cipher); + if (ret < 0) { + kfree(cipher_api); + goto bad_mem; } - cc->tfm = tfm; + /* Allocate cipher */ + ret = crypt_alloc_tfms(cc, cipher_api); + if (ret < 0) { + ti->error = "Error allocating crypto tfm"; + goto bad; + } - /* - * Choose ivmode. Valid modes: "plain", "essiv:<esshash>". - * See comments at iv code - */ + /* Initialize IV */ + cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc)); + if (cc->iv_size) + /* at least a 64 bit sector number should fit in our buffer */ + cc->iv_size = max(cc->iv_size, + (unsigned int)(sizeof(u64) / sizeof(u8))); + else if (ivmode) { + DMWARN("Selected cipher does not support IVs"); + ivmode = NULL; + } + /* Choose ivmode, see comments at iv code. */ if (ivmode == NULL) cc->iv_gen_ops = NULL; else if (strcmp(ivmode, "plain") == 0) cc->iv_gen_ops = &crypt_iv_plain_ops; + else if (strcmp(ivmode, "plain64") == 0) + cc->iv_gen_ops = &crypt_iv_plain64_ops; else if (strcmp(ivmode, "essiv") == 0) cc->iv_gen_ops = &crypt_iv_essiv_ops; - else { - ti->error = PFX "Invalid IV mode"; - goto bad2; + else if (strcmp(ivmode, "benbi") == 0) + cc->iv_gen_ops = &crypt_iv_benbi_ops; + else if (strcmp(ivmode, "null") == 0) + cc->iv_gen_ops = &crypt_iv_null_ops; + else if (strcmp(ivmode, "lmk") == 0) { + cc->iv_gen_ops = &crypt_iv_lmk_ops; + /* + * Version 2 and 3 is recognised according + * to length of provided multi-key string. + * If present (version 3), last key is used as IV seed. + * All keys (including IV seed) are always the same size. + */ + if (cc->key_size % cc->key_parts) { + cc->key_parts++; + cc->key_extra_size = cc->key_size / cc->key_parts; + } + } else if (strcmp(ivmode, "tcw") == 0) { + cc->iv_gen_ops = &crypt_iv_tcw_ops; + cc->key_parts += 2; /* IV + whitening */ + cc->key_extra_size = cc->iv_size + TCW_WHITENING_SIZE; + } else { + ret = -EINVAL; + ti->error = "Invalid IV mode"; + goto bad; } - if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && - cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) - goto bad2; + /* Initialize and set key */ + ret = crypt_set_key(cc, key); + if (ret < 0) { + ti->error = "Error decoding and setting key"; + goto bad; + } - if (tfm->crt_cipher.cit_decrypt_iv && tfm->crt_cipher.cit_encrypt_iv) - /* at least a 64 bit sector number should fit in our buffer */ - cc->iv_size = max(crypto_tfm_alg_ivsize(tfm), - (unsigned int)(sizeof(u64) / sizeof(u8))); - else { - cc->iv_size = 0; - if (cc->iv_gen_ops) { - DMWARN(PFX "Selected cipher does not support IVs"); - if (cc->iv_gen_ops->dtr) - cc->iv_gen_ops->dtr(cc); - cc->iv_gen_ops = NULL; + /* Allocate IV */ + if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) { + ret = cc->iv_gen_ops->ctr(cc, ti, ivopts); + if (ret < 0) { + ti->error = "Error creating IV"; + goto bad; } } - cc->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab, - mempool_free_slab, _crypt_io_pool); + /* Initialize IV (set keys for ESSIV etc) */ + if (cc->iv_gen_ops && cc->iv_gen_ops->init) { + ret = cc->iv_gen_ops->init(cc); + if (ret < 0) { + ti->error = "Error initialising IV"; + goto bad; + } + } + + ret = 0; +bad: + kfree(cipher_api); + return ret; + +bad_mem: + ti->error = "Cannot allocate cipher strings"; + return -ENOMEM; +} + +/* + * Construct an encryption mapping: + * <cipher> <key> <iv_offset> <dev_path> <start> + */ +static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct crypt_config *cc; + unsigned int key_size, opt_params; + unsigned long long tmpll; + int ret; + struct dm_arg_set as; + const char *opt_string; + char dummy; + + static struct dm_arg _args[] = { + {0, 1, "Invalid number of feature args"}, + }; + + if (argc < 5) { + ti->error = "Not enough arguments"; + return -EINVAL; + } + + key_size = strlen(argv[1]) >> 1; + + cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); + if (!cc) { + ti->error = "Cannot allocate encryption context"; + return -ENOMEM; + } + cc->key_size = key_size; + + ti->private = cc; + ret = crypt_ctr_cipher(ti, argv[0], argv[1]); + if (ret < 0) + goto bad; + + ret = -ENOMEM; + cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); if (!cc->io_pool) { - ti->error = PFX "Cannot allocate crypt io mempool"; - goto bad3; + ti->error = "Cannot allocate crypt io mempool"; + goto bad; } - cc->page_pool = mempool_create(MIN_POOL_PAGES, mempool_alloc_page, - mempool_free_page, NULL); + cc->dmreq_start = sizeof(struct ablkcipher_request); + cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc)); + cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment()); + cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) & + ~(crypto_tfm_ctx_alignment() - 1); + + cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + + sizeof(struct dm_crypt_request) + cc->iv_size); + if (!cc->req_pool) { + ti->error = "Cannot allocate crypt request mempool"; + goto bad; + } + + cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); if (!cc->page_pool) { - ti->error = PFX "Cannot allocate page mempool"; - goto bad4; + ti->error = "Cannot allocate page mempool"; + goto bad; } - if (tfm->crt_cipher.cit_setkey(tfm, cc->key, key_size) < 0) { - ti->error = PFX "Error setting key"; - goto bad5; + cc->bs = bioset_create(MIN_IOS, 0); + if (!cc->bs) { + ti->error = "Cannot allocate crypt bioset"; + goto bad; } - if (sscanf(argv[2], SECTOR_FORMAT, &cc->iv_offset) != 1) { - ti->error = PFX "Invalid iv_offset sector"; - goto bad5; + ret = -EINVAL; + if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) { + ti->error = "Invalid iv_offset sector"; + goto bad; } + cc->iv_offset = tmpll; - if (sscanf(argv[4], SECTOR_FORMAT, &cc->start) != 1) { - ti->error = PFX "Invalid device sector"; - goto bad5; + if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) { + ti->error = "Device lookup failed"; + goto bad; } - if (dm_get_device(ti, argv[3], cc->start, ti->len, - dm_table_get_mode(ti->table), &cc->dev)) { - ti->error = PFX "Device lookup failed"; - goto bad5; + if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { + ti->error = "Invalid device sector"; + goto bad; } + cc->start = tmpll; - if (ivmode && cc->iv_gen_ops) { - if (ivopts) - *(ivopts - 1) = ':'; - cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); - if (!cc->iv_mode) { - ti->error = PFX "Error kmallocing iv_mode string"; - goto bad5; - } - strcpy(cc->iv_mode, ivmode); - } else - cc->iv_mode = NULL; + argv += 5; + argc -= 5; - ti->private = cc; - return 0; + /* Optional parameters */ + if (argc) { + as.argc = argc; + as.argv = argv; -bad5: - mempool_destroy(cc->page_pool); -bad4: - mempool_destroy(cc->io_pool); -bad3: - if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) - cc->iv_gen_ops->dtr(cc); -bad2: - crypto_free_tfm(tfm); -bad1: - /* Must zero key material before freeing */ - memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); - kfree(cc); - return -EINVAL; -} + ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); + if (ret) + goto bad; -static void crypt_dtr(struct dm_target *ti) -{ - struct crypt_config *cc = (struct crypt_config *) ti->private; + opt_string = dm_shift_arg(&as); - mempool_destroy(cc->page_pool); - mempool_destroy(cc->io_pool); + if (opt_params == 1 && opt_string && + !strcasecmp(opt_string, "allow_discards")) + ti->num_discard_bios = 1; + else if (opt_params) { + ret = -EINVAL; + ti->error = "Invalid feature arguments"; + goto bad; + } + } - kfree(cc->iv_mode); - if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) - cc->iv_gen_ops->dtr(cc); - crypto_free_tfm(cc->tfm); - dm_put_device(ti, cc->dev); + ret = -ENOMEM; + cc->io_queue = alloc_workqueue("kcryptd_io", WQ_MEM_RECLAIM, 1); + if (!cc->io_queue) { + ti->error = "Couldn't create kcryptd io queue"; + goto bad; + } - /* Must zero key material before freeing */ - memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); - kfree(cc); -} + cc->crypt_queue = alloc_workqueue("kcryptd", + WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); + if (!cc->crypt_queue) { + ti->error = "Couldn't create kcryptd queue"; + goto bad; + } -static int crypt_endio(struct bio *bio, unsigned int done, int error) -{ - struct crypt_io *io = (struct crypt_io *) bio->bi_private; - struct crypt_config *cc = (struct crypt_config *) io->target->private; + ti->num_flush_bios = 1; + ti->discard_zeroes_data_unsupported = true; - if (bio_data_dir(bio) == WRITE) { - /* - * free the processed pages, even if - * it's only a partially completed write - */ - crypt_free_buffer_pages(cc, bio, done); - } + return 0; - if (bio->bi_size) - return 1; +bad: + crypt_dtr(ti); + return ret; +} - bio_put(bio); +static int crypt_map(struct dm_target *ti, struct bio *bio) +{ + struct dm_crypt_io *io; + struct crypt_config *cc = ti->private; /* - * successful reads are decrypted by the worker thread + * If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues. + * - for REQ_FLUSH device-mapper core ensures that no IO is in-flight + * - for REQ_DISCARD caller must use flush if IO ordering matters */ - if ((bio_data_dir(bio) == READ) - && bio_flagged(bio, BIO_UPTODATE)) { - kcryptd_queue_io(io); - return 0; + if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) { + bio->bi_bdev = cc->dev->bdev; + if (bio_sectors(bio)) + bio->bi_iter.bi_sector = cc->start + + dm_target_offset(ti, bio->bi_iter.bi_sector); + return DM_MAPIO_REMAPPED; } - dec_pending(io, error); - return error; + io = crypt_io_alloc(cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); + + if (bio_data_dir(io->base_bio) == READ) { + if (kcryptd_io_read(io, GFP_NOWAIT)) + kcryptd_queue_io(io); + } else + kcryptd_queue_crypt(io); + + return DM_MAPIO_SUBMITTED; } -static inline struct bio * -crypt_clone(struct crypt_config *cc, struct crypt_io *io, struct bio *bio, - sector_t sector, unsigned int *bvec_idx, - struct convert_context *ctx) +static void crypt_status(struct dm_target *ti, status_type_t type, + unsigned status_flags, char *result, unsigned maxlen) { - struct bio *clone; + struct crypt_config *cc = ti->private; + unsigned i, sz = 0; - if (bio_data_dir(bio) == WRITE) { - clone = crypt_alloc_buffer(cc, bio->bi_size, - io->first_clone, bvec_idx); - if (clone) { - ctx->bio_out = clone; - if (crypt_convert(cc, ctx) < 0) { - crypt_free_buffer_pages(cc, clone, - clone->bi_size); - bio_put(clone); - return NULL; - } - } - } else { - /* - * The block layer might modify the bvec array, so always - * copy the required bvecs because we need the original - * one in order to decrypt the whole bio data *afterwards*. - */ - clone = bio_alloc(GFP_NOIO, bio_segments(bio)); - if (clone) { - clone->bi_idx = 0; - clone->bi_vcnt = bio_segments(bio); - clone->bi_size = bio->bi_size; - memcpy(clone->bi_io_vec, bio_iovec(bio), - sizeof(struct bio_vec) * clone->bi_vcnt); - } - } + switch (type) { + case STATUSTYPE_INFO: + result[0] = '\0'; + break; - if (!clone) - return NULL; + case STATUSTYPE_TABLE: + DMEMIT("%s ", cc->cipher_string); - clone->bi_private = io; - clone->bi_end_io = crypt_endio; - clone->bi_bdev = cc->dev->bdev; - clone->bi_sector = cc->start + sector; - clone->bi_rw = bio->bi_rw; + if (cc->key_size > 0) + for (i = 0; i < cc->key_size; i++) + DMEMIT("%02x", cc->key[i]); + else + DMEMIT("-"); - return clone; + DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, + cc->dev->name, (unsigned long long)cc->start); + + if (ti->num_discard_bios) + DMEMIT(" 1 allow_discards"); + + break; + } } -static int crypt_map(struct dm_target *ti, struct bio *bio, - union map_info *map_context) +static void crypt_postsuspend(struct dm_target *ti) { - struct crypt_config *cc = (struct crypt_config *) ti->private; - struct crypt_io *io = mempool_alloc(cc->io_pool, GFP_NOIO); - struct convert_context ctx; - struct bio *clone; - unsigned int remaining = bio->bi_size; - sector_t sector = bio->bi_sector - ti->begin; - unsigned int bvec_idx = 0; + struct crypt_config *cc = ti->private; - io->target = ti; - io->bio = bio; - io->first_clone = NULL; - io->error = 0; - atomic_set(&io->pending, 1); /* hold a reference */ + set_bit(DM_CRYPT_SUSPENDED, &cc->flags); +} - if (bio_data_dir(bio) == WRITE) - crypt_convert_init(cc, &ctx, NULL, bio, sector, 1); +static int crypt_preresume(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; - /* - * The allocated buffers can be smaller than the whole bio, - * so repeat the whole process until all the data can be handled. - */ - while (remaining) { - clone = crypt_clone(cc, io, bio, sector, &bvec_idx, &ctx); - if (!clone) - goto cleanup; + if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { + DMERR("aborting resume - crypt key is not set."); + return -EAGAIN; + } - if (!io->first_clone) { - /* - * hold a reference to the first clone, because it - * holds the bio_vec array and that can't be freed - * before all other clones are released - */ - bio_get(clone); - io->first_clone = clone; - } - atomic_inc(&io->pending); + return 0; +} - remaining -= clone->bi_size; - sector += bio_sectors(clone); +static void crypt_resume(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; - generic_make_request(clone); + clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); +} - /* out of memory -> run queues */ - if (remaining) - blk_congestion_wait(bio_data_dir(clone), HZ/100); - } +/* Message interface + * key set <key> + * key wipe + */ +static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) +{ + struct crypt_config *cc = ti->private; + int ret = -EINVAL; - /* drop reference, clones could have returned before we reach this */ - dec_pending(io, 0); - return 0; + if (argc < 2) + goto error; -cleanup: - if (io->first_clone) { - dec_pending(io, -ENOMEM); - return 0; + if (!strcasecmp(argv[0], "key")) { + if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { + DMWARN("not suspended during key manipulation."); + return -EINVAL; + } + if (argc == 3 && !strcasecmp(argv[1], "set")) { + ret = crypt_set_key(cc, argv[2]); + if (ret) + return ret; + if (cc->iv_gen_ops && cc->iv_gen_ops->init) + ret = cc->iv_gen_ops->init(cc); + return ret; + } + if (argc == 2 && !strcasecmp(argv[1], "wipe")) { + if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) { + ret = cc->iv_gen_ops->wipe(cc); + if (ret) + return ret; + } + return crypt_wipe_key(cc); + } } - /* if no bio has been dispatched yet, we can directly return the error */ - mempool_free(io, cc->io_pool); - return -ENOMEM; +error: + DMWARN("unrecognised message received."); + return -EINVAL; } -static int crypt_status(struct dm_target *ti, status_type_t type, - char *result, unsigned int maxlen) +static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm, + struct bio_vec *biovec, int max_size) { - struct crypt_config *cc = (struct crypt_config *) ti->private; - const char *cipher; - const char *chainmode = NULL; - unsigned int sz = 0; + struct crypt_config *cc = ti->private; + struct request_queue *q = bdev_get_queue(cc->dev->bdev); - switch (type) { - case STATUSTYPE_INFO: - result[0] = '\0'; - break; + if (!q->merge_bvec_fn) + return max_size; - case STATUSTYPE_TABLE: - cipher = crypto_tfm_alg_name(cc->tfm); + bvm->bi_bdev = cc->dev->bdev; + bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector); - switch(cc->tfm->crt_cipher.cit_mode) { - case CRYPTO_TFM_MODE_CBC: - chainmode = "cbc"; - break; - case CRYPTO_TFM_MODE_ECB: - chainmode = "ecb"; - break; - default: - BUG(); - } + return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); +} - if (cc->iv_mode) - DMEMIT("%s-%s-%s ", cipher, chainmode, cc->iv_mode); - else - DMEMIT("%s-%s ", cipher, chainmode); - - if (cc->key_size > 0) { - if ((maxlen - sz) < ((cc->key_size << 1) + 1)) - return -ENOMEM; - - crypt_encode_key(result + sz, cc->key, cc->key_size); - sz += cc->key_size << 1; - } else { - if (sz >= maxlen) - return -ENOMEM; - result[sz++] = '-'; - } +static int crypt_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct crypt_config *cc = ti->private; - DMEMIT(" " SECTOR_FORMAT " %s " SECTOR_FORMAT, - cc->iv_offset, cc->dev->name, cc->start); - break; - } - return 0; + return fn(ti, cc->dev, cc->start, ti->len, data); } static struct target_type crypt_target = { .name = "crypt", - .version= {1, 1, 0}, + .version = {1, 13, 0}, .module = THIS_MODULE, .ctr = crypt_ctr, .dtr = crypt_dtr, .map = crypt_map, .status = crypt_status, + .postsuspend = crypt_postsuspend, + .preresume = crypt_preresume, + .resume = crypt_resume, + .message = crypt_message, + .merge = crypt_merge, + .iterate_devices = crypt_iterate_devices, }; static int __init dm_crypt_init(void) { int r; - _crypt_io_pool = kmem_cache_create("dm-crypt_io", - sizeof(struct crypt_io), - 0, 0, NULL, NULL); + _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0); if (!_crypt_io_pool) return -ENOMEM; - _kcryptd_workqueue = create_workqueue("kcryptd"); - if (!_kcryptd_workqueue) { - r = -ENOMEM; - DMERR(PFX "couldn't create kcryptd"); - goto bad1; - } - r = dm_register_target(&crypt_target); if (r < 0) { - DMERR(PFX "register failed %d", r); - goto bad2; + DMERR("register failed %d", r); + kmem_cache_destroy(_crypt_io_pool); } - return 0; - -bad2: - destroy_workqueue(_kcryptd_workqueue); -bad1: - kmem_cache_destroy(_crypt_io_pool); return r; } static void __exit dm_crypt_exit(void) { - int r = dm_unregister_target(&crypt_target); - - if (r < 0) - DMERR(PFX "unregister failed %d", r); - - destroy_workqueue(_kcryptd_workqueue); + dm_unregister_target(&crypt_target); kmem_cache_destroy(_crypt_io_pool); } module_init(dm_crypt_init); module_exit(dm_crypt_exit); -MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); +MODULE_AUTHOR("Jana Saout <jana@saout.de>"); MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); MODULE_LICENSE("GPL"); |