diff options
Diffstat (limited to 'drivers/md/dm-crypt.c')
| -rw-r--r-- | drivers/md/dm-crypt.c | 1914 |
1 files changed, 1914 insertions, 0 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c new file mode 100644 index 00000000..3f06df59 --- /dev/null +++ b/drivers/md/dm-crypt.c @@ -0,0 +1,1914 @@ +/* + * Copyright (C) 2003 Christophe Saout <christophe@saout.de> + * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> + * Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved. + * + * 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> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/mempool.h> +#include <linux/slab.h> +#include <linux/crypto.h> +#include <linux/workqueue.h> +#include <linux/backing-dev.h> +#include <linux/percpu.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 <linux/device-mapper.h> + +#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; + sector_t sector; + atomic_t pending; +}; + +/* + * per bio private data + */ +struct dm_crypt_io { + struct dm_target *target; + struct bio *base_bio; + struct work_struct work; + + struct convert_context ctx; + + atomic_t pending; + int error; + sector_t sector; + 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); + void (*dtr)(struct crypt_config *cc); + 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; +}; + +/* + * 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 }; + +/* + * Duplicated per-CPU state for cipher. + */ +struct crypt_cpu { + struct ablkcipher_request *req; + /* ESSIV: struct crypto_cipher *essiv_tfm */ + void *iv_private; + struct crypto_ablkcipher *tfms[0]; +}; + +/* + * The fields in here must be read only after initialization, + * changing state should be in crypt_cpu. + */ +struct crypt_config { + struct dm_dev *dev; + sector_t start; + + /* + * 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; + + struct crypt_iv_operations *iv_gen_ops; + union { + struct iv_essiv_private essiv; + struct iv_benbi_private benbi; + struct iv_lmk_private lmk; + } iv_gen_private; + sector_t iv_offset; + unsigned int iv_size; + + /* + * Duplicated per cpu state. Access through + * per_cpu_ptr() only. + */ + struct crypt_cpu __percpu *cpu; + 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; + u8 key[0]; +}; + +#define MIN_IOS 16 +#define MIN_POOL_PAGES 32 + +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); + +static struct crypt_cpu *this_crypt_config(struct crypt_config *cc) +{ + return this_cpu_ptr(cc->cpu); +} + +/* + * Use this to access cipher attributes that are the same for each CPU. + */ +static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc) +{ + return __this_cpu_ptr(cc->cpu)->tfms[0]; +} + +/* + * Different IV generation algorithms: + * + * 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. + * + * 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) + * + * 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, + struct dm_crypt_request *dmreq) +{ + memset(iv, 0, cc->iv_size); + *(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff); + + return 0; +} + +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 iv_essiv_private *essiv = &cc->iv_gen_private.essiv; + struct hash_desc desc; + struct scatterlist sg; + struct crypto_cipher *essiv_tfm; + int err, cpu; + + 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; + + for_each_possible_cpu(cpu) { + essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->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 cpu, r, err = 0; + + memset(essiv->salt, 0, salt_size); + + for_each_possible_cpu(cpu) { + essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->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; + } + + 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); + } + + 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) +{ + int cpu; + struct crypt_cpu *cpu_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; + + for_each_possible_cpu(cpu) { + cpu_cc = per_cpu_ptr(cc->cpu, cpu); + essiv_tfm = cpu_cc->iv_private; + + if (essiv_tfm) + crypto_free_cipher(essiv_tfm); + + cpu_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, cpu; + + if (!opts) { + ti->error = "Digest algorithm missing for ESSIV mode"; + return -EINVAL; + } + + /* 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; + } + + salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL); + if (!salt) { + ti->error = "Error kmallocing salt storage in ESSIV"; + err = -ENOMEM; + goto bad; + } + + cc->iv_gen_private.essiv.salt = salt; + cc->iv_gen_private.essiv.hash_tfm = hash_tfm; + + for_each_possible_cpu(cpu) { + 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); + } + per_cpu_ptr(cc->cpu, cpu)->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 = this_crypt_config(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 (log > 9) { + ti->error = "cypher blocksize is > 512"; + return -EINVAL; + } + + cc->iv_gen_private.benbi.shift = 9 - log; + + return 0; +} + +static void crypt_iv_benbi_dtr(struct crypt_config *cc) +{ +} + +static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + __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); + + 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; + u32 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 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 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 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; + 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; + 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) +{ + 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_iovec_idx(ctx->bio_in, ctx->idx_in); + struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); + struct dm_crypt_request *dmreq; + u8 *iv; + int r = 0; + + dmreq = dmreq_of_req(cc, req); + iv = iv_of_dmreq(cc, dmreq); + + dmreq->iv_sector = ctx->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 + ctx->offset_in); + + sg_init_table(&dmreq->sg_out, 1); + sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, + bv_out->bv_offset + ctx->offset_out); + + ctx->offset_in += 1 << SECTOR_SHIFT; + if (ctx->offset_in >= bv_in->bv_len) { + ctx->offset_in = 0; + ctx->idx_in++; + } + + ctx->offset_out += 1 << SECTOR_SHIFT; + if (ctx->offset_out >= bv_out->bv_len) { + ctx->offset_out = 0; + ctx->idx_out++; + } + + if (cc->iv_gen_ops) { + r = cc->iv_gen_ops->generator(cc, iv, dmreq); + if (r < 0) + return r; + } + + 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 kcryptd_async_done(struct crypto_async_request *async_req, + int error); + +static void crypt_alloc_req(struct crypt_config *cc, + struct convert_context *ctx) +{ + struct crypt_cpu *this_cc = this_crypt_config(cc); + unsigned key_index = ctx->sector & (cc->tfms_count - 1); + + if (!this_cc->req) + this_cc->req = mempool_alloc(cc->req_pool, GFP_NOIO); + + ablkcipher_request_set_tfm(this_cc->req, this_cc->tfms[key_index]); + ablkcipher_request_set_callback(this_cc->req, + CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP, + kcryptd_async_done, dmreq_of_req(cc, this_cc->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 crypt_cpu *this_cc = this_crypt_config(cc); + int r; + + atomic_set(&ctx->pending, 1); + + while(ctx->idx_in < ctx->bio_in->bi_vcnt && + ctx->idx_out < ctx->bio_out->bi_vcnt) { + + crypt_alloc_req(cc, ctx); + + atomic_inc(&ctx->pending); + + r = crypt_convert_block(cc, ctx, this_cc->req); + + switch (r) { + /* async */ + case -EBUSY: + wait_for_completion(&ctx->restart); + INIT_COMPLETION(ctx->restart); + /* fall through*/ + case -EINPROGRESS: + this_cc->req = NULL; + ctx->sector++; + continue; + + /* sync */ + case 0: + atomic_dec(&ctx->pending); + ctx->sector++; + cond_resched(); + continue; + + /* error */ + default: + atomic_dec(&ctx->pending); + return r; + } + } + + return 0; +} + +static void dm_crypt_bio_destructor(struct bio *bio) +{ + struct dm_crypt_io *io = bio->bi_private; + struct crypt_config *cc = io->target->private; + + bio_free(bio, cc->bs); +} + +/* + * 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, indicated by + * *out_of_pages set to 1. + */ +static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size, + unsigned *out_of_pages) +{ + struct crypt_config *cc = io->target->private; + struct bio *clone; + unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; + gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; + unsigned i, len; + struct page *page; + + clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); + if (!clone) + return NULL; + + clone_init(io, clone); + *out_of_pages = 0; + + 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 more bios while submitting this partial bio. + */ + gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; + + len = (size > PAGE_SIZE) ? PAGE_SIZE : size; + + if (!bio_add_page(clone, page, len, 0)) { + mempool_free(page, cc->page_pool); + break; + } + + size -= len; + } + + if (!clone->bi_size) { + bio_put(clone); + return NULL; + } + + return clone; +} + +static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) +{ + unsigned int i; + struct bio_vec *bv; + + for (i = 0; i < clone->bi_vcnt; i++) { + bv = bio_iovec_idx(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 dm_target *ti, + struct bio *bio, sector_t sector) +{ + struct crypt_config *cc = ti->private; + struct dm_crypt_io *io; + + io = mempool_alloc(cc->io_pool, GFP_NOIO); + io->target = ti; + io->base_bio = bio; + io->sector = sector; + io->error = 0; + io->base_io = NULL; + atomic_set(&io->pending, 0); + + return io; +} + +static void crypt_inc_pending(struct dm_crypt_io *io) +{ + atomic_inc(&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 crypt_dec_pending(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->target->private; + struct bio *base_bio = io->base_bio; + struct dm_crypt_io *base_io = io->base_io; + int error = io->error; + + if (!atomic_dec_and_test(&io->pending)) + return; + + 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_io: + * + * Needed because it would be very unwise to do decryption in an + * 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 void crypt_endio(struct bio *clone, int error) +{ + struct dm_crypt_io *io = clone->bi_private; + struct crypt_config *cc = io->target->private; + 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); + + 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_config *cc = io->target->private; + + clone->bi_private = io; + clone->bi_end_io = crypt_endio; + clone->bi_bdev = cc->dev->bdev; + clone->bi_rw = io->base_bio->bi_rw; + clone->bi_destructor = dm_crypt_bio_destructor; +} + +static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) +{ + struct crypt_config *cc = io->target->private; + 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_alloc_bioset(gfp, bio_segments(base_bio), cc->bs); + if (!clone) + return 1; + + crypt_inc_pending(io); + + clone_init(io, clone); + clone->bi_idx = 0; + clone->bi_vcnt = bio_segments(base_bio); + clone->bi_size = base_bio->bi_size; + clone->bi_sector = cc->start + io->sector; + memcpy(clone->bi_io_vec, bio_iovec(base_bio), + sizeof(struct bio_vec) * clone->bi_vcnt); + + 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->target->private; + + 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->target->private; + + 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.idx_out < clone->bi_vcnt); + + clone->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->target->private; + struct bio *clone; + struct dm_crypt_io *new_io; + int crypt_finished; + unsigned out_of_pages = 0; + unsigned remaining = io->base_bio->bi_size; + sector_t sector = io->sector; + int r; + + /* + * Prevent io from disappearing until this function completes. + */ + crypt_inc_pending(io); + crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); + + /* + * 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.idx_out = 0; + + remaining -= clone->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.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->target, io->base_bio, + sector); + crypt_inc_pending(new_io); + crypt_convert_init(cc, &new_io->ctx, NULL, + io->base_bio, sector); + new_io->ctx.idx_in = io->ctx.idx_in; + new_io->ctx.offset_in = io->ctx.offset_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_crypt_read_done(struct dm_crypt_io *io) +{ + crypt_dec_pending(io); +} + +static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->target->private; + 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.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->target->private; + + 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->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->target->private; + + INIT_WORK(&io->work, kcryptd_crypt); + queue_work(cc->crypt_queue, &io->work); +} + +/* + * Decode key from its hex representation + */ +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++) { + buffer[0] = *hex++; + buffer[1] = *hex++; + + key[i] = (u8)simple_strtoul(buffer, &endp, 16); + + if (endp != &buffer[2]) + return -EINVAL; + } + + if (*hex != '\0') + return -EINVAL; + + return 0; +} + +/* + * Encode key into its hex representation + */ +static void crypt_encode_key(char *hex, u8 *key, unsigned int size) +{ + unsigned int i; + + for (i = 0; i < size; i++) { + sprintf(hex, "%02x", *key); + hex += 2; + key++; + } +} + +static void crypt_free_tfms(struct crypt_config *cc, int cpu) +{ + struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu); + unsigned i; + + for (i = 0; i < cc->tfms_count; i++) + if (cpu_cc->tfms[i] && !IS_ERR(cpu_cc->tfms[i])) { + crypto_free_ablkcipher(cpu_cc->tfms[i]); + cpu_cc->tfms[i] = NULL; + } +} + +static int crypt_alloc_tfms(struct crypt_config *cc, int cpu, char *ciphermode) +{ + struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu); + unsigned i; + int err; + + for (i = 0; i < cc->tfms_count; i++) { + cpu_cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0); + if (IS_ERR(cpu_cc->tfms[i])) { + err = PTR_ERR(cpu_cc->tfms[i]); + crypt_free_tfms(cc, cpu); + return err; + } + } + + return 0; +} + +static int crypt_setkey_allcpus(struct crypt_config *cc) +{ + unsigned subkey_size = cc->key_size >> ilog2(cc->tfms_count); + int cpu, err = 0, i, r; + + for_each_possible_cpu(cpu) { + for (i = 0; i < cc->tfms_count; i++) { + r = crypto_ablkcipher_setkey(per_cpu_ptr(cc->cpu, cpu)->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)); + + return crypt_setkey_allcpus(cc); +} + +static void crypt_dtr(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; + struct crypt_cpu *cpu_cc; + int cpu; + + ti->private = NULL; + + if (!cc) + return; + + if (cc->io_queue) + destroy_workqueue(cc->io_queue); + if (cc->crypt_queue) + destroy_workqueue(cc->crypt_queue); + + if (cc->cpu) + for_each_possible_cpu(cpu) { + cpu_cc = per_cpu_ptr(cc->cpu, cpu); + if (cpu_cc->req) + mempool_free(cpu_cc->req, cc->req_pool); + crypt_free_tfms(cc, cpu); + } + + 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); + + if (cc->cpu) + free_percpu(cc->cpu); + + 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 cpu, ret = -EINVAL; + char dummy; + + /* Convert to crypto api definition? */ + if (strchr(cipher_in, '(')) { + ti->error = "Bad cipher specification"; + return -EINVAL; + } + + 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->cipher = kstrdup(cipher, GFP_KERNEL); + if (!cc->cipher) + goto bad_mem; + + chainmode = strsep(&tmp, "-"); + ivopts = strsep(&tmp, "-"); + ivmode = strsep(&ivopts, ":"); + + if (tmp) + DMWARN("Ignoring unexpected additional cipher options"); + + cc->cpu = __alloc_percpu(sizeof(*(cc->cpu)) + + cc->tfms_count * sizeof(*(cc->cpu->tfms)), + __alignof__(struct crypt_cpu)); + if (!cc->cpu) { + ti->error = "Cannot allocate per cpu state"; + goto bad_mem; + } + + /* + * 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"; + } + + if (strcmp(chainmode, "ecb") && !ivmode) { + ti->error = "IV mechanism required"; + return -EINVAL; + } + + cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL); + if (!cipher_api) + goto bad_mem; + + ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME, + "%s(%s)", chainmode, cipher); + if (ret < 0) { + kfree(cipher_api); + goto bad_mem; + } + + /* Allocate cipher */ + for_each_possible_cpu(cpu) { + ret = crypt_alloc_tfms(cc, cpu, cipher_api); + if (ret < 0) { + ti->error = "Error allocating crypto tfm"; + goto bad; + } + } + + /* Initialize and set key */ + ret = crypt_set_key(cc, key); + if (ret < 0) { + ti->error = "Error decoding and setting key"; + goto bad; + } + + /* 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 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. + */ + if (cc->key_size % cc->key_parts) + cc->key_parts++; + } else { + ret = -EINVAL; + ti->error = "Invalid IV mode"; + goto bad; + } + + /* 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; + } + } + + /* 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 = "Cannot allocate crypt io mempool"; + goto bad; + } + + 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 = "Cannot allocate page mempool"; + goto bad; + } + + cc->bs = bioset_create(MIN_IOS, 0); + if (!cc->bs) { + ti->error = "Cannot allocate crypt bioset"; + goto bad; + } + + ret = -EINVAL; + if (sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) { + ti->error = "Invalid iv_offset sector"; + goto bad; + } + cc->iv_offset = tmpll; + + if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) { + ti->error = "Device lookup failed"; + goto bad; + } + + if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1) { + ti->error = "Invalid device sector"; + goto bad; + } + cc->start = tmpll; + + argv += 5; + argc -= 5; + + /* Optional parameters */ + if (argc) { + as.argc = argc; + as.argv = argv; + + ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); + if (ret) + goto bad; + + opt_string = dm_shift_arg(&as); + + if (opt_params == 1 && opt_string && + !strcasecmp(opt_string, "allow_discards")) + ti->num_discard_requests = 1; + else if (opt_params) { + ret = -EINVAL; + ti->error = "Invalid feature arguments"; + goto bad; + } + } + + ret = -ENOMEM; + cc->io_queue = alloc_workqueue("kcryptd_io", + WQ_NON_REENTRANT| + WQ_MEM_RECLAIM, + 1); + if (!cc->io_queue) { + ti->error = "Couldn't create kcryptd io queue"; + goto bad; + } + + cc->crypt_queue = alloc_workqueue("kcryptd", + WQ_NON_REENTRANT| + WQ_CPU_INTENSIVE| + WQ_MEM_RECLAIM, + 1); + if (!cc->crypt_queue) { + ti->error = "Couldn't create kcryptd queue"; + goto bad; + } + + ti->num_flush_requests = 1; + ti->discard_zeroes_data_unsupported = 1; + + return 0; + +bad: + crypt_dtr(ti); + return ret; +} + +static int crypt_map(struct dm_target *ti, struct bio *bio, + union map_info *map_context) +{ + struct dm_crypt_io *io; + struct crypt_config *cc; + + /* + * 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 (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) { + cc = ti->private; + bio->bi_bdev = cc->dev->bdev; + if (bio_sectors(bio)) + bio->bi_sector = cc->start + dm_target_offset(ti, bio->bi_sector); + return DM_MAPIO_REMAPPED; + } + + io = crypt_io_alloc(ti, bio, dm_target_offset(ti, bio->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 int crypt_status(struct dm_target *ti, status_type_t type, + char *result, unsigned int maxlen) +{ + struct crypt_config *cc = ti->private; + unsigned int sz = 0; + + switch (type) { + case STATUSTYPE_INFO: + result[0] = '\0'; + break; + + case STATUSTYPE_TABLE: + DMEMIT("%s ", cc->cipher_string); + + 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++] = '-'; + } + + DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, + cc->dev->name, (unsigned long long)cc->start); + + if (ti->num_discard_requests) + DMEMIT(" 1 allow_discards"); + + break; + } + return 0; +} + +static void crypt_postsuspend(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; + + set_bit(DM_CRYPT_SUSPENDED, &cc->flags); +} + +static int crypt_preresume(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; + + if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { + DMERR("aborting resume - crypt key is not set."); + return -EAGAIN; + } + + return 0; +} + +static void crypt_resume(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; + + clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); +} + +/* 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; + + if (argc < 2) + goto error; + + 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); + } + } + +error: + DMWARN("unrecognised message received."); + return -EINVAL; +} + +static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm, + struct bio_vec *biovec, int max_size) +{ + struct crypt_config *cc = ti->private; + struct request_queue *q = bdev_get_queue(cc->dev->bdev); + + if (!q->merge_bvec_fn) + return max_size; + + bvm->bi_bdev = cc->dev->bdev; + bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector); + + return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); +} + +static int crypt_iterate_devices(struct dm_target *ti, + iterate_devices_callout_fn fn, void *data) +{ + struct crypt_config *cc = ti->private; + + return fn(ti, cc->dev, cc->start, ti->len, data); +} + +static struct target_type crypt_target = { + .name = "crypt", + .version = {1, 11, 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(dm_crypt_io, 0); + if (!_crypt_io_pool) + return -ENOMEM; + + r = dm_register_target(&crypt_target); + if (r < 0) { + DMERR("register failed %d", r); + kmem_cache_destroy(_crypt_io_pool); + } + + return r; +} + +static void __exit dm_crypt_exit(void) +{ + 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_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); +MODULE_LICENSE("GPL"); |