diff options
Diffstat (limited to 'drivers/md/dm-crypt.c')
| -rw-r--r-- | drivers/md/dm-crypt.c | 3138 |
1 files changed, 3138 insertions, 0 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c new file mode 100644 index 000000000..e38c713e8 --- /dev/null +++ b/drivers/md/dm-crypt.c @@ -0,0 +1,3138 @@ +/* + * Copyright (C) 2003 Jana Saout <jana@saout.de> + * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> + * Copyright (C) 2006-2017 Red Hat, Inc. All rights reserved. + * Copyright (C) 2013-2017 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> +#include <linux/key.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/kthread.h> +#include <linux/backing-dev.h> +#include <linux/atomic.h> +#include <linux/scatterlist.h> +#include <linux/rbtree.h> +#include <linux/ctype.h> +#include <asm/page.h> +#include <asm/unaligned.h> +#include <crypto/hash.h> +#include <crypto/md5.h> +#include <crypto/algapi.h> +#include <crypto/skcipher.h> +#include <crypto/aead.h> +#include <crypto/authenc.h> +#include <linux/rtnetlink.h> /* for struct rtattr and RTA macros only */ +#include <keys/user-type.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; + struct bvec_iter iter_in; + struct bvec_iter iter_out; + u64 cc_sector; + atomic_t cc_pending; + union { + struct skcipher_request *req; + struct aead_request *req_aead; + } r; + +}; + +/* + * per bio private data + */ +struct dm_crypt_io { + struct crypt_config *cc; + struct bio *base_bio; + u8 *integrity_metadata; + bool integrity_metadata_from_pool; + struct work_struct work; + + struct convert_context ctx; + + atomic_t io_pending; + blk_status_t error; + sector_t sector; + + struct rb_node rb_node; +} CRYPTO_MINALIGN_ATTR; + +struct dm_crypt_request { + struct convert_context *ctx; + struct scatterlist sg_in[4]; + struct scatterlist sg_out[4]; + u64 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_shash *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, + DM_CRYPT_SAME_CPU, DM_CRYPT_NO_OFFLOAD }; + +enum cipher_flags { + CRYPT_MODE_INTEGRITY_AEAD, /* Use authenticated mode for cihper */ + CRYPT_IV_LARGE_SECTORS, /* Calculate IV from sector_size, not 512B sectors */ +}; + +/* + * The fields in here must be read only after initialization. + */ +struct crypt_config { + struct dm_dev *dev; + sector_t start; + + struct percpu_counter n_allocated_pages; + + struct workqueue_struct *io_queue; + struct workqueue_struct *crypt_queue; + + spinlock_t write_thread_lock; + struct task_struct *write_thread; + struct rb_root write_tree; + + char *cipher; + char *cipher_string; + char *cipher_auth; + char *key_string; + + const struct crypt_iv_operations *iv_gen_ops; + union { + struct iv_essiv_private essiv; + struct iv_benbi_private benbi; + struct iv_lmk_private lmk; + struct iv_tcw_private tcw; + } iv_gen_private; + u64 iv_offset; + unsigned int iv_size; + unsigned short int sector_size; + unsigned char sector_shift; + + /* ESSIV: struct crypto_cipher *essiv_tfm */ + void *iv_private; + union { + struct crypto_skcipher **tfms; + struct crypto_aead **tfms_aead; + } cipher_tfm; + unsigned tfms_count; + unsigned long cipher_flags; + + /* + * Layout of each crypto request: + * + * struct skcipher_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 int per_bio_data_size; + + unsigned long flags; + unsigned int key_size; + unsigned int key_parts; /* independent parts in key buffer */ + unsigned int key_extra_size; /* additional keys length */ + unsigned int key_mac_size; /* MAC key size for authenc(...) */ + + unsigned int integrity_tag_size; + unsigned int integrity_iv_size; + unsigned int on_disk_tag_size; + + /* + * pool for per bio private data, crypto requests, + * encryption requeusts/buffer pages and integrity tags + */ + unsigned tag_pool_max_sectors; + mempool_t tag_pool; + mempool_t req_pool; + mempool_t page_pool; + + struct bio_set bs; + struct mutex bio_alloc_lock; + + u8 *authenc_key; /* space for keys in authenc() format (if used) */ + u8 key[0]; +}; + +#define MIN_IOS 64 +#define MAX_TAG_SIZE 480 +#define POOL_ENTRY_SIZE 512 + +static DEFINE_SPINLOCK(dm_crypt_clients_lock); +static unsigned dm_crypt_clients_n = 0; +static volatile unsigned long dm_crypt_pages_per_client; +#define DM_CRYPT_MEMORY_PERCENT 2 +#define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_PAGES * 16) + +static void clone_init(struct dm_crypt_io *, struct bio *); +static void kcryptd_queue_crypt(struct dm_crypt_io *io); +static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, + struct scatterlist *sg); + +/* + * Use this to access cipher attributes that are independent of the key. + */ +static struct crypto_skcipher *any_tfm(struct crypt_config *cc) +{ + return cc->cipher_tfm.tfms[0]; +} + +static struct crypto_aead *any_tfm_aead(struct crypt_config *cc) +{ + return cc->cipher_tfm.tfms_aead[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. + * + * plain64be: the initial vector is the 64-bit big-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) + * + * tcw: Compatible implementation of the block chaining mode used + * by the TrueCrypt device encryption system (prior to version 4.1). + * For more info see: https://gitlab.com/cryptsetup/cryptsetup/wikis/TrueCryptOnDiskFormat + * 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, + 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; +} + +static int crypt_iv_plain64be_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + memset(iv, 0, cc->iv_size); + /* iv_size is at least of size u64; usually it is 16 bytes */ + *(__be64 *)&iv[cc->iv_size - sizeof(u64)] = cpu_to_be64(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; + SHASH_DESC_ON_STACK(desc, essiv->hash_tfm); + struct crypto_cipher *essiv_tfm; + int err; + + desc->tfm = essiv->hash_tfm; + desc->flags = 0; + + err = crypto_shash_digest(desc, cc->key, cc->key_size, essiv->salt); + shash_desc_zero(desc); + if (err) + return err; + + essiv_tfm = cc->iv_private; + + err = crypto_cipher_setkey(essiv_tfm, essiv->salt, + crypto_shash_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_shash_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; +} + +/* Allocate the cipher for ESSIV */ +static struct crypto_cipher *alloc_essiv_cipher(struct crypt_config *cc, + struct dm_target *ti, + const u8 *salt, + unsigned int 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) != cc->iv_size) { + 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) +{ + struct crypto_cipher *essiv_tfm; + struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; + + crypto_free_shash(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_shash *hash_tfm = NULL; + u8 *salt = NULL; + int err; + + if (!opts) { + ti->error = "Digest algorithm missing for ESSIV mode"; + return -EINVAL; + } + + /* Allocate hash algorithm */ + hash_tfm = crypto_alloc_shash(opts, 0, 0); + if (IS_ERR(hash_tfm)) { + ti->error = "Error initializing ESSIV hash"; + err = PTR_ERR(hash_tfm); + goto bad; + } + + salt = kzalloc(crypto_shash_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; + + essiv_tfm = alloc_essiv_cipher(cc, ti, salt, + crypto_shash_digestsize(hash_tfm)); + if (IS_ERR(essiv_tfm)) { + crypt_iv_essiv_dtr(cc); + return PTR_ERR(essiv_tfm); + } + cc->iv_private = essiv_tfm; + + return 0; + +bad: + if (hash_tfm && !IS_ERR(hash_tfm)) + crypto_free_shash(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; + int log; + + if (test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags)) + bs = crypto_aead_blocksize(any_tfm_aead(cc)); + else + bs = crypto_skcipher_blocksize(any_tfm(cc)); + 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; + + if (cc->sector_size != (1 << SECTOR_SHIFT)) { + ti->error = "Unsupported sector size for LMK"; + return -EINVAL; + } + + 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; + SHASH_DESC_ON_STACK(desc, lmk->hash_tfm); + struct md5_state md5state; + __le32 buf[4]; + int i, r; + + desc->tfm = lmk->hash_tfm; + desc->flags = 0; + + r = crypto_shash_init(desc); + if (r) + return r; + + if (lmk->seed) { + r = crypto_shash_update(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(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(desc, (u8 *)buf, sizeof(buf)); + if (r) + return r; + + /* No MD5 padding here */ + r = crypto_shash_export(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) +{ + struct scatterlist *sg; + u8 *src; + int r = 0; + + if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) { + sg = crypt_get_sg_data(cc, dmreq->sg_in); + src = kmap_atomic(sg_page(sg)); + r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->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) +{ + struct scatterlist *sg; + u8 *dst; + int r; + + if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) + return 0; + + sg = crypt_get_sg_data(cc, dmreq->sg_out); + dst = kmap_atomic(sg_page(sg)); + r = crypt_iv_lmk_one(cc, iv, dmreq, dst + sg->offset); + + /* Tweak the first block of plaintext sector */ + if (!r) + crypto_xor(dst + sg->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->sector_size != (1 << SECTOR_SHIFT)) { + ti->error = "Unsupported sector size for TCW"; + return -EINVAL; + } + + 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; + __le64 sector = cpu_to_le64(dmreq->iv_sector); + u8 buf[TCW_WHITENING_SIZE]; + SHASH_DESC_ON_STACK(desc, tcw->crc32_tfm); + int i, r; + + /* xor whitening with sector number */ + crypto_xor_cpy(buf, tcw->whitening, (u8 *)§or, 8); + crypto_xor_cpy(&buf[8], tcw->whitening + 8, (u8 *)§or, 8); + + /* calculate crc32 for every 32bit part and xor it */ + desc->tfm = tcw->crc32_tfm; + desc->flags = 0; + for (i = 0; i < 4; i++) { + r = crypto_shash_init(desc); + if (r) + goto out; + r = crypto_shash_update(desc, &buf[i * 4], 4); + if (r) + goto out; + r = crypto_shash_final(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: + memzero_explicit(buf, sizeof(buf)); + return r; +} + +static int crypt_iv_tcw_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + struct scatterlist *sg; + struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw; + __le64 sector = cpu_to_le64(dmreq->iv_sector); + u8 *src; + int r = 0; + + /* Remove whitening from ciphertext */ + if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) { + sg = crypt_get_sg_data(cc, dmreq->sg_in); + src = kmap_atomic(sg_page(sg)); + r = crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset); + kunmap_atomic(src); + } + + /* Calculate IV */ + crypto_xor_cpy(iv, tcw->iv_seed, (u8 *)§or, 8); + if (cc->iv_size > 8) + crypto_xor_cpy(&iv[8], tcw->iv_seed + 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) +{ + struct scatterlist *sg; + u8 *dst; + int r; + + if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) + return 0; + + /* Apply whitening on ciphertext */ + sg = crypt_get_sg_data(cc, dmreq->sg_out); + dst = kmap_atomic(sg_page(sg)); + r = crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset); + kunmap_atomic(dst); + + return r; +} + +static int crypt_iv_random_gen(struct crypt_config *cc, u8 *iv, + struct dm_crypt_request *dmreq) +{ + /* Used only for writes, there must be an additional space to store IV */ + get_random_bytes(iv, cc->iv_size); + return 0; +} + +static const struct crypt_iv_operations crypt_iv_plain_ops = { + .generator = crypt_iv_plain_gen +}; + +static const struct crypt_iv_operations crypt_iv_plain64_ops = { + .generator = crypt_iv_plain64_gen +}; + +static const struct crypt_iv_operations crypt_iv_plain64be_ops = { + .generator = crypt_iv_plain64be_gen +}; + +static const 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 const struct crypt_iv_operations crypt_iv_benbi_ops = { + .ctr = crypt_iv_benbi_ctr, + .dtr = crypt_iv_benbi_dtr, + .generator = crypt_iv_benbi_gen +}; + +static const struct crypt_iv_operations crypt_iv_null_ops = { + .generator = crypt_iv_null_gen +}; + +static const 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 const 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 struct crypt_iv_operations crypt_iv_random_ops = { + .generator = crypt_iv_random_gen +}; + +/* + * Integrity extensions + */ +static bool crypt_integrity_aead(struct crypt_config *cc) +{ + return test_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); +} + +static bool crypt_integrity_hmac(struct crypt_config *cc) +{ + return crypt_integrity_aead(cc) && cc->key_mac_size; +} + +/* Get sg containing data */ +static struct scatterlist *crypt_get_sg_data(struct crypt_config *cc, + struct scatterlist *sg) +{ + if (unlikely(crypt_integrity_aead(cc))) + return &sg[2]; + + return sg; +} + +static int dm_crypt_integrity_io_alloc(struct dm_crypt_io *io, struct bio *bio) +{ + struct bio_integrity_payload *bip; + unsigned int tag_len; + int ret; + + if (!bio_sectors(bio) || !io->cc->on_disk_tag_size) + return 0; + + bip = bio_integrity_alloc(bio, GFP_NOIO, 1); + if (IS_ERR(bip)) + return PTR_ERR(bip); + + tag_len = io->cc->on_disk_tag_size * (bio_sectors(bio) >> io->cc->sector_shift); + + bip->bip_iter.bi_size = tag_len; + bip->bip_iter.bi_sector = io->cc->start + io->sector; + + ret = bio_integrity_add_page(bio, virt_to_page(io->integrity_metadata), + tag_len, offset_in_page(io->integrity_metadata)); + if (unlikely(ret != tag_len)) + return -ENOMEM; + + return 0; +} + +static int crypt_integrity_ctr(struct crypt_config *cc, struct dm_target *ti) +{ +#ifdef CONFIG_BLK_DEV_INTEGRITY + struct blk_integrity *bi = blk_get_integrity(cc->dev->bdev->bd_disk); + struct mapped_device *md = dm_table_get_md(ti->table); + + /* From now we require underlying device with our integrity profile */ + if (!bi || strcasecmp(bi->profile->name, "DM-DIF-EXT-TAG")) { + ti->error = "Integrity profile not supported."; + return -EINVAL; + } + + if (bi->tag_size != cc->on_disk_tag_size || + bi->tuple_size != cc->on_disk_tag_size) { + ti->error = "Integrity profile tag size mismatch."; + return -EINVAL; + } + if (1 << bi->interval_exp != cc->sector_size) { + ti->error = "Integrity profile sector size mismatch."; + return -EINVAL; + } + + if (crypt_integrity_aead(cc)) { + cc->integrity_tag_size = cc->on_disk_tag_size - cc->integrity_iv_size; + DMDEBUG("%s: Integrity AEAD, tag size %u, IV size %u.", dm_device_name(md), + cc->integrity_tag_size, cc->integrity_iv_size); + + if (crypto_aead_setauthsize(any_tfm_aead(cc), cc->integrity_tag_size)) { + ti->error = "Integrity AEAD auth tag size is not supported."; + return -EINVAL; + } + } else if (cc->integrity_iv_size) + DMDEBUG("%s: Additional per-sector space %u bytes for IV.", dm_device_name(md), + cc->integrity_iv_size); + + if ((cc->integrity_tag_size + cc->integrity_iv_size) != bi->tag_size) { + ti->error = "Not enough space for integrity tag in the profile."; + return -EINVAL; + } + + return 0; +#else + ti->error = "Integrity profile not supported."; + return -EINVAL; +#endif +} + +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, + void *req) +{ + return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); +} + +static void *req_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq) +{ + return (void *)((char *)dmreq - cc->dmreq_start); +} + +static u8 *iv_of_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + if (crypt_integrity_aead(cc)) + return (u8 *)ALIGN((unsigned long)(dmreq + 1), + crypto_aead_alignmask(any_tfm_aead(cc)) + 1); + else + return (u8 *)ALIGN((unsigned long)(dmreq + 1), + crypto_skcipher_alignmask(any_tfm(cc)) + 1); +} + +static u8 *org_iv_of_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + return iv_of_dmreq(cc, dmreq) + cc->iv_size; +} + +static uint64_t *org_sector_of_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + cc->iv_size; + return (uint64_t*) ptr; +} + +static unsigned int *org_tag_of_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + u8 *ptr = iv_of_dmreq(cc, dmreq) + cc->iv_size + + cc->iv_size + sizeof(uint64_t); + return (unsigned int*)ptr; +} + +static void *tag_from_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + struct convert_context *ctx = dmreq->ctx; + struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); + + return &io->integrity_metadata[*org_tag_of_dmreq(cc, dmreq) * + cc->on_disk_tag_size]; +} + +static void *iv_tag_from_dmreq(struct crypt_config *cc, + struct dm_crypt_request *dmreq) +{ + return tag_from_dmreq(cc, dmreq) + cc->integrity_tag_size; +} + +static int crypt_convert_block_aead(struct crypt_config *cc, + struct convert_context *ctx, + struct aead_request *req, + unsigned int tag_offset) +{ + 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, *org_iv, *tag_iv, *tag; + uint64_t *sector; + int r = 0; + + BUG_ON(cc->integrity_iv_size && cc->integrity_iv_size != cc->iv_size); + + /* Reject unexpected unaligned bio. */ + if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) + return -EIO; + + dmreq = dmreq_of_req(cc, req); + dmreq->iv_sector = ctx->cc_sector; + if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) + dmreq->iv_sector >>= cc->sector_shift; + dmreq->ctx = ctx; + + *org_tag_of_dmreq(cc, dmreq) = tag_offset; + + sector = org_sector_of_dmreq(cc, dmreq); + *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); + + iv = iv_of_dmreq(cc, dmreq); + org_iv = org_iv_of_dmreq(cc, dmreq); + tag = tag_from_dmreq(cc, dmreq); + tag_iv = iv_tag_from_dmreq(cc, dmreq); + + /* AEAD request: + * |----- AAD -------|------ DATA -------|-- AUTH TAG --| + * | (authenticated) | (auth+encryption) | | + * | sector_LE | IV | sector in/out | tag in/out | + */ + sg_init_table(dmreq->sg_in, 4); + sg_set_buf(&dmreq->sg_in[0], sector, sizeof(uint64_t)); + sg_set_buf(&dmreq->sg_in[1], org_iv, cc->iv_size); + sg_set_page(&dmreq->sg_in[2], bv_in.bv_page, cc->sector_size, bv_in.bv_offset); + sg_set_buf(&dmreq->sg_in[3], tag, cc->integrity_tag_size); + + sg_init_table(dmreq->sg_out, 4); + sg_set_buf(&dmreq->sg_out[0], sector, sizeof(uint64_t)); + sg_set_buf(&dmreq->sg_out[1], org_iv, cc->iv_size); + sg_set_page(&dmreq->sg_out[2], bv_out.bv_page, cc->sector_size, bv_out.bv_offset); + sg_set_buf(&dmreq->sg_out[3], tag, cc->integrity_tag_size); + + if (cc->iv_gen_ops) { + /* For READs use IV stored in integrity metadata */ + if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { + memcpy(org_iv, tag_iv, cc->iv_size); + } else { + r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); + if (r < 0) + return r; + /* Store generated IV in integrity metadata */ + if (cc->integrity_iv_size) + memcpy(tag_iv, org_iv, cc->iv_size); + } + /* Working copy of IV, to be modified in crypto API */ + memcpy(iv, org_iv, cc->iv_size); + } + + aead_request_set_ad(req, sizeof(uint64_t) + cc->iv_size); + if (bio_data_dir(ctx->bio_in) == WRITE) { + aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, + cc->sector_size, iv); + r = crypto_aead_encrypt(req); + if (cc->integrity_tag_size + cc->integrity_iv_size != cc->on_disk_tag_size) + memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0, + cc->on_disk_tag_size - (cc->integrity_tag_size + cc->integrity_iv_size)); + } else { + aead_request_set_crypt(req, dmreq->sg_in, dmreq->sg_out, + cc->sector_size + cc->integrity_tag_size, iv); + r = crypto_aead_decrypt(req); + } + + if (r == -EBADMSG) + DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu", + (unsigned long long)le64_to_cpu(*sector)); + + if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) + r = cc->iv_gen_ops->post(cc, org_iv, dmreq); + + bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); + bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); + + return r; +} + +static int crypt_convert_block_skcipher(struct crypt_config *cc, + struct convert_context *ctx, + struct skcipher_request *req, + unsigned int tag_offset) +{ + 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 scatterlist *sg_in, *sg_out; + struct dm_crypt_request *dmreq; + u8 *iv, *org_iv, *tag_iv; + uint64_t *sector; + int r = 0; + + /* Reject unexpected unaligned bio. */ + if (unlikely(bv_in.bv_len & (cc->sector_size - 1))) + return -EIO; + + dmreq = dmreq_of_req(cc, req); + dmreq->iv_sector = ctx->cc_sector; + if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) + dmreq->iv_sector >>= cc->sector_shift; + dmreq->ctx = ctx; + + *org_tag_of_dmreq(cc, dmreq) = tag_offset; + + iv = iv_of_dmreq(cc, dmreq); + org_iv = org_iv_of_dmreq(cc, dmreq); + tag_iv = iv_tag_from_dmreq(cc, dmreq); + + sector = org_sector_of_dmreq(cc, dmreq); + *sector = cpu_to_le64(ctx->cc_sector - cc->iv_offset); + + /* For skcipher we use only the first sg item */ + sg_in = &dmreq->sg_in[0]; + sg_out = &dmreq->sg_out[0]; + + sg_init_table(sg_in, 1); + sg_set_page(sg_in, bv_in.bv_page, cc->sector_size, bv_in.bv_offset); + + sg_init_table(sg_out, 1); + sg_set_page(sg_out, bv_out.bv_page, cc->sector_size, bv_out.bv_offset); + + if (cc->iv_gen_ops) { + /* For READs use IV stored in integrity metadata */ + if (cc->integrity_iv_size && bio_data_dir(ctx->bio_in) != WRITE) { + memcpy(org_iv, tag_iv, cc->integrity_iv_size); + } else { + r = cc->iv_gen_ops->generator(cc, org_iv, dmreq); + if (r < 0) + return r; + /* Store generated IV in integrity metadata */ + if (cc->integrity_iv_size) + memcpy(tag_iv, org_iv, cc->integrity_iv_size); + } + /* Working copy of IV, to be modified in crypto API */ + memcpy(iv, org_iv, cc->iv_size); + } + + skcipher_request_set_crypt(req, sg_in, sg_out, cc->sector_size, iv); + + if (bio_data_dir(ctx->bio_in) == WRITE) + r = crypto_skcipher_encrypt(req); + else + r = crypto_skcipher_decrypt(req); + + if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post) + r = cc->iv_gen_ops->post(cc, org_iv, dmreq); + + bio_advance_iter(ctx->bio_in, &ctx->iter_in, cc->sector_size); + bio_advance_iter(ctx->bio_out, &ctx->iter_out, cc->sector_size); + + return r; +} + +static void kcryptd_async_done(struct crypto_async_request *async_req, + int error); + +static void crypt_alloc_req_skcipher(struct crypt_config *cc, + struct convert_context *ctx) +{ + unsigned key_index = ctx->cc_sector & (cc->tfms_count - 1); + + if (!ctx->r.req) + ctx->r.req = mempool_alloc(&cc->req_pool, GFP_NOIO); + + skcipher_request_set_tfm(ctx->r.req, cc->cipher_tfm.tfms[key_index]); + + /* + * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs + * requests if driver request queue is full. + */ + skcipher_request_set_callback(ctx->r.req, + CRYPTO_TFM_REQ_MAY_BACKLOG, + kcryptd_async_done, dmreq_of_req(cc, ctx->r.req)); +} + +static void crypt_alloc_req_aead(struct crypt_config *cc, + struct convert_context *ctx) +{ + if (!ctx->r.req_aead) + ctx->r.req_aead = mempool_alloc(&cc->req_pool, GFP_NOIO); + + aead_request_set_tfm(ctx->r.req_aead, cc->cipher_tfm.tfms_aead[0]); + + /* + * Use REQ_MAY_BACKLOG so a cipher driver internally backlogs + * requests if driver request queue is full. + */ + aead_request_set_callback(ctx->r.req_aead, + CRYPTO_TFM_REQ_MAY_BACKLOG, + kcryptd_async_done, dmreq_of_req(cc, ctx->r.req_aead)); +} + +static void crypt_alloc_req(struct crypt_config *cc, + struct convert_context *ctx) +{ + if (crypt_integrity_aead(cc)) + crypt_alloc_req_aead(cc, ctx); + else + crypt_alloc_req_skcipher(cc, ctx); +} + +static void crypt_free_req_skcipher(struct crypt_config *cc, + struct skcipher_request *req, struct bio *base_bio) +{ + struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); + + if ((struct skcipher_request *)(io + 1) != req) + mempool_free(req, &cc->req_pool); +} + +static void crypt_free_req_aead(struct crypt_config *cc, + struct aead_request *req, struct bio *base_bio) +{ + struct dm_crypt_io *io = dm_per_bio_data(base_bio, cc->per_bio_data_size); + + if ((struct aead_request *)(io + 1) != req) + mempool_free(req, &cc->req_pool); +} + +static void crypt_free_req(struct crypt_config *cc, void *req, struct bio *base_bio) +{ + if (crypt_integrity_aead(cc)) + crypt_free_req_aead(cc, req, base_bio); + else + crypt_free_req_skcipher(cc, req, base_bio); +} + +/* + * Encrypt / decrypt data from one bio to another one (can be the same one) + */ +static blk_status_t crypt_convert(struct crypt_config *cc, + struct convert_context *ctx) +{ + unsigned int tag_offset = 0; + unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT; + int r; + + atomic_set(&ctx->cc_pending, 1); + + while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) { + + crypt_alloc_req(cc, ctx); + atomic_inc(&ctx->cc_pending); + + if (crypt_integrity_aead(cc)) + r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, tag_offset); + else + r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, tag_offset); + + switch (r) { + /* + * The request was queued by a crypto driver + * but the driver request queue is full, let's wait. + */ + case -EBUSY: + wait_for_completion(&ctx->restart); + reinit_completion(&ctx->restart); + /* fall through */ + /* + * The request is queued and processed asynchronously, + * completion function kcryptd_async_done() will be called. + */ + case -EINPROGRESS: + ctx->r.req = NULL; + ctx->cc_sector += sector_step; + tag_offset++; + continue; + /* + * The request was already processed (synchronously). + */ + case 0: + atomic_dec(&ctx->cc_pending); + ctx->cc_sector += sector_step; + tag_offset++; + cond_resched(); + continue; + /* + * There was a data integrity error. + */ + case -EBADMSG: + atomic_dec(&ctx->cc_pending); + return BLK_STS_PROTECTION; + /* + * There was an error while processing the request. + */ + default: + atomic_dec(&ctx->cc_pending); + return BLK_STS_IOERR; + } + } + + return 0; +} + +static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone); + +/* + * Generate a new unfragmented bio with the given size + * This should never violate the device limitations (but only because + * max_segment_size is being constrained to PAGE_SIZE). + * + * This function may be called concurrently. If we allocate from the mempool + * concurrently, there is a possibility of deadlock. For example, if we have + * mempool of 256 pages, two processes, each wanting 256, pages allocate from + * the mempool concurrently, it may deadlock in a situation where both processes + * have allocated 128 pages and the mempool is exhausted. + * + * In order to avoid this scenario we allocate the pages under a mutex. + * + * In order to not degrade performance with excessive locking, we try + * non-blocking allocations without a mutex first but on failure we fallback + * to blocking allocations with a mutex. + */ +static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) +{ + struct crypt_config *cc = io->cc; + struct bio *clone; + unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; + gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM; + unsigned i, len, remaining_size; + struct page *page; + +retry: + if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) + mutex_lock(&cc->bio_alloc_lock); + + clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, &cc->bs); + if (!clone) + goto out; + + clone_init(io, clone); + + remaining_size = size; + + for (i = 0; i < nr_iovecs; i++) { + page = mempool_alloc(&cc->page_pool, gfp_mask); + if (!page) { + crypt_free_buffer_pages(cc, clone); + bio_put(clone); + gfp_mask |= __GFP_DIRECT_RECLAIM; + goto retry; + } + + len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size; + + bio_add_page(clone, page, len, 0); + + remaining_size -= len; + } + + /* Allocate space for integrity tags */ + if (dm_crypt_integrity_io_alloc(io, clone)) { + crypt_free_buffer_pages(cc, clone); + bio_put(clone); + clone = NULL; + } +out: + if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM)) + mutex_unlock(&cc->bio_alloc_lock); + + return clone; +} + +static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) +{ + unsigned int i; + struct bio_vec *bv; + + bio_for_each_segment_all(bv, clone, i) { + BUG_ON(!bv->bv_page); + mempool_free(bv->bv_page, &cc->page_pool); + } +} + +static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc, + struct bio *bio, sector_t sector) +{ + io->cc = cc; + io->base_bio = bio; + io->sector = sector; + io->error = 0; + io->ctx.r.req = NULL; + io->integrity_metadata = NULL; + io->integrity_metadata_from_pool = false; + atomic_set(&io->io_pending, 0); +} + +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. + */ +static void crypt_dec_pending(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + struct bio *base_bio = io->base_bio; + blk_status_t error = io->error; + + if (!atomic_dec_and_test(&io->io_pending)) + return; + + if (io->ctx.r.req) + crypt_free_req(cc, io->ctx.r.req, base_bio); + + if (unlikely(io->integrity_metadata_from_pool)) + mempool_free(io->integrity_metadata, &io->cc->tag_pool); + else + kfree(io->integrity_metadata); + + base_bio->bi_status = error; + bio_endio(base_bio); +} + +/* + * 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) +{ + struct dm_crypt_io *io = clone->bi_private; + struct crypt_config *cc = io->cc; + unsigned rw = bio_data_dir(clone); + blk_status_t error; + + /* + * free the processed pages + */ + if (rw == WRITE) + crypt_free_buffer_pages(cc, clone); + + error = clone->bi_status; + 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->cc; + + clone->bi_private = io; + clone->bi_end_io = crypt_endio; + bio_set_dev(clone, cc->dev->bdev); + clone->bi_opf = io->base_bio->bi_opf; +} + +static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp) +{ + struct crypt_config *cc = io->cc; + struct bio *clone; + + /* + * We need the original biovec array in order to decrypt + * the whole bio data *afterwards* -- thanks to immutable + * biovecs we don't need to worry about the block layer + * modifying the biovec array; so leverage bio_clone_fast(). + */ + clone = bio_clone_fast(io->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; + + if (dm_crypt_integrity_io_alloc(io, clone)) { + crypt_dec_pending(io); + bio_put(clone); + return 1; + } + + generic_make_request(clone); + return 0; +} + +static void kcryptd_io_read_work(struct work_struct *work) +{ + struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); + + crypt_inc_pending(io); + if (kcryptd_io_read(io, GFP_NOIO)) + io->error = BLK_STS_RESOURCE; + crypt_dec_pending(io); +} + +static void kcryptd_queue_read(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + + INIT_WORK(&io->work, kcryptd_io_read_work); + queue_work(cc->io_queue, &io->work); +} + +static void kcryptd_io_write(struct dm_crypt_io *io) +{ + struct bio *clone = io->ctx.bio_out; + + generic_make_request(clone); +} + +#define crypt_io_from_node(node) rb_entry((node), struct dm_crypt_io, rb_node) + +static int dmcrypt_write(void *data) +{ + struct crypt_config *cc = data; + struct dm_crypt_io *io; + + while (1) { + struct rb_root write_tree; + struct blk_plug plug; + + spin_lock_irq(&cc->write_thread_lock); +continue_locked: + + if (!RB_EMPTY_ROOT(&cc->write_tree)) + goto pop_from_list; + + set_current_state(TASK_INTERRUPTIBLE); + + spin_unlock_irq(&cc->write_thread_lock); + + if (unlikely(kthread_should_stop())) { + set_current_state(TASK_RUNNING); + break; + } + + schedule(); + + set_current_state(TASK_RUNNING); + spin_lock_irq(&cc->write_thread_lock); + goto continue_locked; + +pop_from_list: + write_tree = cc->write_tree; + cc->write_tree = RB_ROOT; + spin_unlock_irq(&cc->write_thread_lock); + + BUG_ON(rb_parent(write_tree.rb_node)); + + /* + * Note: we cannot walk the tree here with rb_next because + * the structures may be freed when kcryptd_io_write is called. + */ + blk_start_plug(&plug); + do { + io = crypt_io_from_node(rb_first(&write_tree)); + rb_erase(&io->rb_node, &write_tree); + kcryptd_io_write(io); + } while (!RB_EMPTY_ROOT(&write_tree)); + blk_finish_plug(&plug); + } + return 0; +} + +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; + unsigned long flags; + sector_t sector; + struct rb_node **rbp, *parent; + + if (unlikely(io->error)) { + 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 (likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) { + generic_make_request(clone); + return; + } + + spin_lock_irqsave(&cc->write_thread_lock, flags); + if (RB_EMPTY_ROOT(&cc->write_tree)) + wake_up_process(cc->write_thread); + rbp = &cc->write_tree.rb_node; + parent = NULL; + sector = io->sector; + while (*rbp) { + parent = *rbp; + if (sector < crypt_io_from_node(parent)->sector) + rbp = &(*rbp)->rb_left; + else + rbp = &(*rbp)->rb_right; + } + rb_link_node(&io->rb_node, parent, rbp); + rb_insert_color(&io->rb_node, &cc->write_tree); + spin_unlock_irqrestore(&cc->write_thread_lock, flags); +} + +static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) +{ + struct crypt_config *cc = io->cc; + struct bio *clone; + int crypt_finished; + sector_t sector = io->sector; + blk_status_t r; + + /* + * Prevent io from disappearing until this function completes. + */ + crypt_inc_pending(io); + crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); + + clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size); + if (unlikely(!clone)) { + io->error = BLK_STS_IOERR; + goto dec; + } + + io->ctx.bio_out = clone; + io->ctx.iter_out = clone->bi_iter; + + sector += bio_sectors(clone); + + crypt_inc_pending(io); + r = crypt_convert(cc, &io->ctx); + if (r) + io->error = r; + 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); + io->sector = sector; + } + +dec: + 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->cc; + blk_status_t r; + + 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) + io->error = r; + + 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; + + /* + * A request from crypto driver backlog is going to be processed now, + * finish the completion and continue in crypt_convert(). + * (Callback will be called for the second time for this request.) + */ + 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, org_iv_of_dmreq(cc, dmreq), dmreq); + + if (error == -EBADMSG) { + DMERR_LIMIT("INTEGRITY AEAD ERROR, sector %llu", + (unsigned long long)le64_to_cpu(*org_sector_of_dmreq(cc, dmreq))); + io->error = BLK_STS_PROTECTION; + } else if (error < 0) + io->error = BLK_STS_IOERR; + + crypt_free_req(cc, req_of_dmreq(cc, dmreq), io->base_bio); + + 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); +} + +static void crypt_free_tfms_aead(struct crypt_config *cc) +{ + if (!cc->cipher_tfm.tfms_aead) + return; + + if (cc->cipher_tfm.tfms_aead[0] && !IS_ERR(cc->cipher_tfm.tfms_aead[0])) { + crypto_free_aead(cc->cipher_tfm.tfms_aead[0]); + cc->cipher_tfm.tfms_aead[0] = NULL; + } + + kfree(cc->cipher_tfm.tfms_aead); + cc->cipher_tfm.tfms_aead = NULL; +} + +static void crypt_free_tfms_skcipher(struct crypt_config *cc) +{ + unsigned i; + + if (!cc->cipher_tfm.tfms) + return; + + for (i = 0; i < cc->tfms_count; i++) + if (cc->cipher_tfm.tfms[i] && !IS_ERR(cc->cipher_tfm.tfms[i])) { + crypto_free_skcipher(cc->cipher_tfm.tfms[i]); + cc->cipher_tfm.tfms[i] = NULL; + } + + kfree(cc->cipher_tfm.tfms); + cc->cipher_tfm.tfms = NULL; +} + +static void crypt_free_tfms(struct crypt_config *cc) +{ + if (crypt_integrity_aead(cc)) + crypt_free_tfms_aead(cc); + else + crypt_free_tfms_skcipher(cc); +} + +static int crypt_alloc_tfms_skcipher(struct crypt_config *cc, char *ciphermode) +{ + unsigned i; + int err; + + cc->cipher_tfm.tfms = kcalloc(cc->tfms_count, + sizeof(struct crypto_skcipher *), + GFP_KERNEL); + if (!cc->cipher_tfm.tfms) + return -ENOMEM; + + for (i = 0; i < cc->tfms_count; i++) { + cc->cipher_tfm.tfms[i] = crypto_alloc_skcipher(ciphermode, 0, 0); + if (IS_ERR(cc->cipher_tfm.tfms[i])) { + err = PTR_ERR(cc->cipher_tfm.tfms[i]); + crypt_free_tfms(cc); + return err; + } + } + + return 0; +} + +static int crypt_alloc_tfms_aead(struct crypt_config *cc, char *ciphermode) +{ + int err; + + cc->cipher_tfm.tfms = kmalloc(sizeof(struct crypto_aead *), GFP_KERNEL); + if (!cc->cipher_tfm.tfms) + return -ENOMEM; + + cc->cipher_tfm.tfms_aead[0] = crypto_alloc_aead(ciphermode, 0, 0); + if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) { + err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]); + crypt_free_tfms(cc); + return err; + } + + return 0; +} + +static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode) +{ + if (crypt_integrity_aead(cc)) + return crypt_alloc_tfms_aead(cc, ciphermode); + else + return crypt_alloc_tfms_skcipher(cc, ciphermode); +} + +static unsigned crypt_subkey_size(struct crypt_config *cc) +{ + return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count); +} + +static unsigned crypt_authenckey_size(struct crypt_config *cc) +{ + return crypt_subkey_size(cc) + RTA_SPACE(sizeof(struct crypto_authenc_key_param)); +} + +/* + * If AEAD is composed like authenc(hmac(sha256),xts(aes)), + * the key must be for some reason in special format. + * This funcion converts cc->key to this special format. + */ +static void crypt_copy_authenckey(char *p, const void *key, + unsigned enckeylen, unsigned authkeylen) +{ + struct crypto_authenc_key_param *param; + struct rtattr *rta; + + rta = (struct rtattr *)p; + param = RTA_DATA(rta); + param->enckeylen = cpu_to_be32(enckeylen); + rta->rta_len = RTA_LENGTH(sizeof(*param)); + rta->rta_type = CRYPTO_AUTHENC_KEYA_PARAM; + p += RTA_SPACE(sizeof(*param)); + memcpy(p, key + enckeylen, authkeylen); + p += authkeylen; + memcpy(p, key, enckeylen); +} + +static int crypt_setkey(struct crypt_config *cc) +{ + unsigned subkey_size; + int err = 0, i, r; + + /* Ignore extra keys (which are used for IV etc) */ + subkey_size = crypt_subkey_size(cc); + + if (crypt_integrity_hmac(cc)) { + if (subkey_size < cc->key_mac_size) + return -EINVAL; + + crypt_copy_authenckey(cc->authenc_key, cc->key, + subkey_size - cc->key_mac_size, + cc->key_mac_size); + } + + for (i = 0; i < cc->tfms_count; i++) { + if (crypt_integrity_hmac(cc)) + r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], + cc->authenc_key, crypt_authenckey_size(cc)); + else if (crypt_integrity_aead(cc)) + r = crypto_aead_setkey(cc->cipher_tfm.tfms_aead[i], + cc->key + (i * subkey_size), + subkey_size); + else + r = crypto_skcipher_setkey(cc->cipher_tfm.tfms[i], + cc->key + (i * subkey_size), + subkey_size); + if (r) + err = r; + } + + if (crypt_integrity_hmac(cc)) + memzero_explicit(cc->authenc_key, crypt_authenckey_size(cc)); + + return err; +} + +#ifdef CONFIG_KEYS + +static bool contains_whitespace(const char *str) +{ + while (*str) + if (isspace(*str++)) + return true; + return false; +} + +static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) +{ + char *new_key_string, *key_desc; + int ret; + struct key *key; + const struct user_key_payload *ukp; + + /* + * Reject key_string with whitespace. dm core currently lacks code for + * proper whitespace escaping in arguments on DM_TABLE_STATUS path. + */ + if (contains_whitespace(key_string)) { + DMERR("whitespace chars not allowed in key string"); + return -EINVAL; + } + + /* look for next ':' separating key_type from key_description */ + key_desc = strpbrk(key_string, ":"); + if (!key_desc || key_desc == key_string || !strlen(key_desc + 1)) + return -EINVAL; + + if (strncmp(key_string, "logon:", key_desc - key_string + 1) && + strncmp(key_string, "user:", key_desc - key_string + 1)) + return -EINVAL; + + new_key_string = kstrdup(key_string, GFP_KERNEL); + if (!new_key_string) + return -ENOMEM; + + key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user, + key_desc + 1, NULL); + if (IS_ERR(key)) { + kzfree(new_key_string); + return PTR_ERR(key); + } + + down_read(&key->sem); + + ukp = user_key_payload_locked(key); + if (!ukp) { + up_read(&key->sem); + key_put(key); + kzfree(new_key_string); + return -EKEYREVOKED; + } + + if (cc->key_size != ukp->datalen) { + up_read(&key->sem); + key_put(key); + kzfree(new_key_string); + return -EINVAL; + } + + memcpy(cc->key, ukp->data, cc->key_size); + + up_read(&key->sem); + key_put(key); + + /* clear the flag since following operations may invalidate previously valid key */ + clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); + + ret = crypt_setkey(cc); + + if (!ret) { + set_bit(DM_CRYPT_KEY_VALID, &cc->flags); + kzfree(cc->key_string); + cc->key_string = new_key_string; + } else + kzfree(new_key_string); + + return ret; +} + +static int get_key_size(char **key_string) +{ + char *colon, dummy; + int ret; + + if (*key_string[0] != ':') + return strlen(*key_string) >> 1; + + /* look for next ':' in key string */ + colon = strpbrk(*key_string + 1, ":"); + if (!colon) + return -EINVAL; + + if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':') + return -EINVAL; + + *key_string = colon; + + /* remaining key string should be :<logon|user>:<key_desc> */ + + return ret; +} + +#else + +static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string) +{ + return -EINVAL; +} + +static int get_key_size(char **key_string) +{ + return (*key_string[0] == ':') ? -EINVAL : (int)(strlen(*key_string) >> 1); +} + +#endif + +static int crypt_set_key(struct crypt_config *cc, char *key) +{ + int r = -EINVAL; + int key_string_len = strlen(key); + + /* Hyphen (which gives a key_size of zero) means there is no key. */ + if (!cc->key_size && strcmp(key, "-")) + goto out; + + /* ':' means the key is in kernel keyring, short-circuit normal key processing */ + if (key[0] == ':') { + r = crypt_set_keyring_key(cc, key + 1); + goto out; + } + + /* clear the flag since following operations may invalidate previously valid key */ + clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); + + /* wipe references to any kernel keyring key */ + kzfree(cc->key_string); + cc->key_string = NULL; + + /* Decode key from its hex representation. */ + if (cc->key_size && hex2bin(cc->key, key, cc->key_size) < 0) + goto out; + + r = crypt_setkey(cc); + if (!r) + set_bit(DM_CRYPT_KEY_VALID, &cc->flags); + +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) +{ + int r; + + clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); + get_random_bytes(&cc->key, cc->key_size); + kzfree(cc->key_string); + cc->key_string = NULL; + r = crypt_setkey(cc); + memset(&cc->key, 0, cc->key_size * sizeof(u8)); + + return r; +} + +static void crypt_calculate_pages_per_client(void) +{ + unsigned long pages = (totalram_pages - totalhigh_pages) * DM_CRYPT_MEMORY_PERCENT / 100; + + if (!dm_crypt_clients_n) + return; + + pages /= dm_crypt_clients_n; + if (pages < DM_CRYPT_MIN_PAGES_PER_CLIENT) + pages = DM_CRYPT_MIN_PAGES_PER_CLIENT; + dm_crypt_pages_per_client = pages; +} + +static void *crypt_page_alloc(gfp_t gfp_mask, void *pool_data) +{ + struct crypt_config *cc = pool_data; + struct page *page; + + /* + * Note, percpu_counter_read_positive() may over (and under) estimate + * the current usage by at most (batch - 1) * num_online_cpus() pages, + * but avoids potential spinlock contention of an exact result. + */ + if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) >= dm_crypt_pages_per_client) && + likely(gfp_mask & __GFP_NORETRY)) + return NULL; + + page = alloc_page(gfp_mask); + if (likely(page != NULL)) + percpu_counter_add(&cc->n_allocated_pages, 1); + + return page; +} + +static void crypt_page_free(void *page, void *pool_data) +{ + struct crypt_config *cc = pool_data; + + __free_page(page); + percpu_counter_sub(&cc->n_allocated_pages, 1); +} + +static void crypt_dtr(struct dm_target *ti) +{ + struct crypt_config *cc = ti->private; + + ti->private = NULL; + + if (!cc) + return; + + if (cc->write_thread) + kthread_stop(cc->write_thread); + + if (cc->io_queue) + destroy_workqueue(cc->io_queue); + if (cc->crypt_queue) + destroy_workqueue(cc->crypt_queue); + + crypt_free_tfms(cc); + + bioset_exit(&cc->bs); + + mempool_exit(&cc->page_pool); + mempool_exit(&cc->req_pool); + mempool_exit(&cc->tag_pool); + + WARN_ON(percpu_counter_sum(&cc->n_allocated_pages) != 0); + percpu_counter_destroy(&cc->n_allocated_pages); + + 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); + kzfree(cc->key_string); + kzfree(cc->cipher_auth); + kzfree(cc->authenc_key); + + mutex_destroy(&cc->bio_alloc_lock); + + /* Must zero key material before freeing */ + kzfree(cc); + + spin_lock(&dm_crypt_clients_lock); + WARN_ON(!dm_crypt_clients_n); + dm_crypt_clients_n--; + crypt_calculate_pages_per_client(); + spin_unlock(&dm_crypt_clients_lock); +} + +static int crypt_ctr_ivmode(struct dm_target *ti, const char *ivmode) +{ + struct crypt_config *cc = ti->private; + + if (crypt_integrity_aead(cc)) + cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); + else + cc->iv_size = crypto_skcipher_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, "plain64be") == 0) + cc->iv_gen_ops = &crypt_iv_plain64be_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. + * 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 if (strcmp(ivmode, "random") == 0) { + cc->iv_gen_ops = &crypt_iv_random_ops; + /* Need storage space in integrity fields. */ + cc->integrity_iv_size = cc->iv_size; + } else { + ti->error = "Invalid IV mode"; + return -EINVAL; + } + + return 0; +} + +/* + * Workaround to parse cipher algorithm from crypto API spec. + * The cc->cipher is currently used only in ESSIV. + * This should be probably done by crypto-api calls (once available...) + */ +static int crypt_ctr_blkdev_cipher(struct crypt_config *cc) +{ + const char *alg_name = NULL; + char *start, *end; + + if (crypt_integrity_aead(cc)) { + alg_name = crypto_tfm_alg_name(crypto_aead_tfm(any_tfm_aead(cc))); + if (!alg_name) + return -EINVAL; + if (crypt_integrity_hmac(cc)) { + alg_name = strchr(alg_name, ','); + if (!alg_name) + return -EINVAL; + } + alg_name++; + } else { + alg_name = crypto_tfm_alg_name(crypto_skcipher_tfm(any_tfm(cc))); + if (!alg_name) + return -EINVAL; + } + + start = strchr(alg_name, '('); + end = strchr(alg_name, ')'); + + if (!start && !end) { + cc->cipher = kstrdup(alg_name, GFP_KERNEL); + return cc->cipher ? 0 : -ENOMEM; + } + + if (!start || !end || ++start >= end) + return -EINVAL; + + cc->cipher = kzalloc(end - start + 1, GFP_KERNEL); + if (!cc->cipher) + return -ENOMEM; + + strncpy(cc->cipher, start, end - start); + + return 0; +} + +/* + * Workaround to parse HMAC algorithm from AEAD crypto API spec. + * The HMAC is needed to calculate tag size (HMAC digest size). + * This should be probably done by crypto-api calls (once available...) + */ +static int crypt_ctr_auth_cipher(struct crypt_config *cc, char *cipher_api) +{ + char *start, *end, *mac_alg = NULL; + struct crypto_ahash *mac; + + if (!strstarts(cipher_api, "authenc(")) + return 0; + + start = strchr(cipher_api, '('); + end = strchr(cipher_api, ','); + if (!start || !end || ++start > end) + return -EINVAL; + + mac_alg = kzalloc(end - start + 1, GFP_KERNEL); + if (!mac_alg) + return -ENOMEM; + strncpy(mac_alg, start, end - start); + + mac = crypto_alloc_ahash(mac_alg, 0, 0); + kfree(mac_alg); + + if (IS_ERR(mac)) + return PTR_ERR(mac); + + cc->key_mac_size = crypto_ahash_digestsize(mac); + crypto_free_ahash(mac); + + cc->authenc_key = kmalloc(crypt_authenckey_size(cc), GFP_KERNEL); + if (!cc->authenc_key) + return -ENOMEM; + + return 0; +} + +static int crypt_ctr_cipher_new(struct dm_target *ti, char *cipher_in, char *key, + char **ivmode, char **ivopts) +{ + struct crypt_config *cc = ti->private; + char *tmp, *cipher_api; + int ret = -EINVAL; + + cc->tfms_count = 1; + + /* + * New format (capi: prefix) + * capi:cipher_api_spec-iv:ivopts + */ + tmp = &cipher_in[strlen("capi:")]; + + /* Separate IV options if present, it can contain another '-' in hash name */ + *ivopts = strrchr(tmp, ':'); + if (*ivopts) { + **ivopts = '\0'; + (*ivopts)++; + } + /* Parse IV mode */ + *ivmode = strrchr(tmp, '-'); + if (*ivmode) { + **ivmode = '\0'; + (*ivmode)++; + } + /* The rest is crypto API spec */ + cipher_api = tmp; + + if (*ivmode && !strcmp(*ivmode, "lmk")) + cc->tfms_count = 64; + + cc->key_parts = cc->tfms_count; + + /* Allocate cipher */ + ret = crypt_alloc_tfms(cc, cipher_api); + if (ret < 0) { + ti->error = "Error allocating crypto tfm"; + return ret; + } + + /* Alloc AEAD, can be used only in new format. */ + if (crypt_integrity_aead(cc)) { + ret = crypt_ctr_auth_cipher(cc, cipher_api); + if (ret < 0) { + ti->error = "Invalid AEAD cipher spec"; + return -ENOMEM; + } + cc->iv_size = crypto_aead_ivsize(any_tfm_aead(cc)); + } else + cc->iv_size = crypto_skcipher_ivsize(any_tfm(cc)); + + ret = crypt_ctr_blkdev_cipher(cc); + if (ret < 0) { + ti->error = "Cannot allocate cipher string"; + return -ENOMEM; + } + + return 0; +} + +static int crypt_ctr_cipher_old(struct dm_target *ti, char *cipher_in, char *key, + char **ivmode, char **ivopts) +{ + struct crypt_config *cc = ti->private; + char *tmp, *cipher, *chainmode, *keycount; + char *cipher_api = NULL; + int ret = -EINVAL; + char dummy; + + if (strchr(cipher_in, '(') || crypt_integrity_aead(cc)) { + ti->error = "Bad cipher specification"; + return -EINVAL; + } + + /* + * 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, "-"); + *ivmode = strsep(&tmp, ":"); + *ivopts = tmp; + + /* + * 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 */ + ret = crypt_alloc_tfms(cc, cipher_api); + if (ret < 0) { + ti->error = "Error allocating crypto tfm"; + kfree(cipher_api); + return ret; + } + kfree(cipher_api); + + return 0; +bad_mem: + ti->error = "Cannot allocate cipher strings"; + return -ENOMEM; +} + +static int crypt_ctr_cipher(struct dm_target *ti, char *cipher_in, char *key) +{ + struct crypt_config *cc = ti->private; + char *ivmode = NULL, *ivopts = NULL; + int ret; + + cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL); + if (!cc->cipher_string) { + ti->error = "Cannot allocate cipher strings"; + return -ENOMEM; + } + + if (strstarts(cipher_in, "capi:")) + ret = crypt_ctr_cipher_new(ti, cipher_in, key, &ivmode, &ivopts); + else + ret = crypt_ctr_cipher_old(ti, cipher_in, key, &ivmode, &ivopts); + if (ret) + return ret; + + /* Initialize IV */ + ret = crypt_ctr_ivmode(ti, ivmode); + if (ret < 0) + return ret; + + /* Initialize and set key */ + ret = crypt_set_key(cc, key); + if (ret < 0) { + ti->error = "Error decoding and setting key"; + return ret; + } + + /* 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"; + return ret; + } + } + + /* 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"; + return ret; + } + } + + /* wipe the kernel key payload copy */ + if (cc->key_string) + memset(cc->key, 0, cc->key_size * sizeof(u8)); + + return ret; +} + +static int crypt_ctr_optional(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct crypt_config *cc = ti->private; + struct dm_arg_set as; + static const struct dm_arg _args[] = { + {0, 6, "Invalid number of feature args"}, + }; + unsigned int opt_params, val; + const char *opt_string, *sval; + char dummy; + int ret; + + /* Optional parameters */ + as.argc = argc; + as.argv = argv; + + ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error); + if (ret) + return ret; + + while (opt_params--) { + opt_string = dm_shift_arg(&as); + if (!opt_string) { + ti->error = "Not enough feature arguments"; + return -EINVAL; + } + + if (!strcasecmp(opt_string, "allow_discards")) + ti->num_discard_bios = 1; + + else if (!strcasecmp(opt_string, "same_cpu_crypt")) + set_bit(DM_CRYPT_SAME_CPU, &cc->flags); + + else if (!strcasecmp(opt_string, "submit_from_crypt_cpus")) + set_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); + else if (sscanf(opt_string, "integrity:%u:", &val) == 1) { + if (val == 0 || val > MAX_TAG_SIZE) { + ti->error = "Invalid integrity arguments"; + return -EINVAL; + } + cc->on_disk_tag_size = val; + sval = strchr(opt_string + strlen("integrity:"), ':') + 1; + if (!strcasecmp(sval, "aead")) { + set_bit(CRYPT_MODE_INTEGRITY_AEAD, &cc->cipher_flags); + } else if (strcasecmp(sval, "none")) { + ti->error = "Unknown integrity profile"; + return -EINVAL; + } + + cc->cipher_auth = kstrdup(sval, GFP_KERNEL); + if (!cc->cipher_auth) + return -ENOMEM; + } else if (sscanf(opt_string, "sector_size:%hu%c", &cc->sector_size, &dummy) == 1) { + if (cc->sector_size < (1 << SECTOR_SHIFT) || + cc->sector_size > 4096 || + (cc->sector_size & (cc->sector_size - 1))) { + ti->error = "Invalid feature value for sector_size"; + return -EINVAL; + } + if (ti->len & ((cc->sector_size >> SECTOR_SHIFT) - 1)) { + ti->error = "Device size is not multiple of sector_size feature"; + return -EINVAL; + } + cc->sector_shift = __ffs(cc->sector_size) - SECTOR_SHIFT; + } else if (!strcasecmp(opt_string, "iv_large_sectors")) + set_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); + else { + ti->error = "Invalid feature arguments"; + return -EINVAL; + } + } + + return 0; +} + +/* + * Construct an encryption mapping: + * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start> + */ +static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) +{ + struct crypt_config *cc; + int key_size; + unsigned int align_mask; + unsigned long long tmpll; + int ret; + size_t iv_size_padding, additional_req_size; + char dummy; + + if (argc < 5) { + ti->error = "Not enough arguments"; + return -EINVAL; + } + + key_size = get_key_size(&argv[1]); + if (key_size < 0) { + ti->error = "Cannot parse key size"; + return -EINVAL; + } + + 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; + cc->sector_size = (1 << SECTOR_SHIFT); + cc->sector_shift = 0; + + ti->private = cc; + + spin_lock(&dm_crypt_clients_lock); + dm_crypt_clients_n++; + crypt_calculate_pages_per_client(); + spin_unlock(&dm_crypt_clients_lock); + + ret = percpu_counter_init(&cc->n_allocated_pages, 0, GFP_KERNEL); + if (ret < 0) + goto bad; + + /* Optional parameters need to be read before cipher constructor */ + if (argc > 5) { + ret = crypt_ctr_optional(ti, argc - 5, &argv[5]); + if (ret) + goto bad; + } + + ret = crypt_ctr_cipher(ti, argv[0], argv[1]); + if (ret < 0) + goto bad; + + if (crypt_integrity_aead(cc)) { + cc->dmreq_start = sizeof(struct aead_request); + cc->dmreq_start += crypto_aead_reqsize(any_tfm_aead(cc)); + align_mask = crypto_aead_alignmask(any_tfm_aead(cc)); + } else { + cc->dmreq_start = sizeof(struct skcipher_request); + cc->dmreq_start += crypto_skcipher_reqsize(any_tfm(cc)); + align_mask = crypto_skcipher_alignmask(any_tfm(cc)); + } + cc->dmreq_start = ALIGN(cc->dmreq_start, __alignof__(struct dm_crypt_request)); + + if (align_mask < CRYPTO_MINALIGN) { + /* Allocate the padding exactly */ + iv_size_padding = -(cc->dmreq_start + sizeof(struct dm_crypt_request)) + & align_mask; + } else { + /* + * If the cipher requires greater alignment than kmalloc + * alignment, we don't know the exact position of the + * initialization vector. We must assume worst case. + */ + iv_size_padding = align_mask; + } + + /* ...| IV + padding | original IV | original sec. number | bio tag offset | */ + additional_req_size = sizeof(struct dm_crypt_request) + + iv_size_padding + cc->iv_size + + cc->iv_size + + sizeof(uint64_t) + + sizeof(unsigned int); + + ret = mempool_init_kmalloc_pool(&cc->req_pool, MIN_IOS, cc->dmreq_start + additional_req_size); + if (ret) { + ti->error = "Cannot allocate crypt request mempool"; + goto bad; + } + + cc->per_bio_data_size = ti->per_io_data_size = + ALIGN(sizeof(struct dm_crypt_io) + cc->dmreq_start + additional_req_size, + ARCH_KMALLOC_MINALIGN); + + ret = mempool_init(&cc->page_pool, BIO_MAX_PAGES, crypt_page_alloc, crypt_page_free, cc); + if (ret) { + ti->error = "Cannot allocate page mempool"; + goto bad; + } + + ret = bioset_init(&cc->bs, MIN_IOS, 0, BIOSET_NEED_BVECS); + if (ret) { + ti->error = "Cannot allocate crypt bioset"; + goto bad; + } + + mutex_init(&cc->bio_alloc_lock); + + ret = -EINVAL; + if ((sscanf(argv[2], "%llu%c", &tmpll, &dummy) != 1) || + (tmpll & ((cc->sector_size >> SECTOR_SHIFT) - 1))) { + ti->error = "Invalid iv_offset sector"; + goto bad; + } + cc->iv_offset = tmpll; + + ret = dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev); + if (ret) { + ti->error = "Device lookup failed"; + goto bad; + } + + ret = -EINVAL; + if (sscanf(argv[4], "%llu%c", &tmpll, &dummy) != 1 || tmpll != (sector_t)tmpll) { + ti->error = "Invalid device sector"; + goto bad; + } + cc->start = tmpll; + + if (crypt_integrity_aead(cc) || cc->integrity_iv_size) { + ret = crypt_integrity_ctr(cc, ti); + if (ret) + goto bad; + + cc->tag_pool_max_sectors = POOL_ENTRY_SIZE / cc->on_disk_tag_size; + if (!cc->tag_pool_max_sectors) + cc->tag_pool_max_sectors = 1; + + ret = mempool_init_kmalloc_pool(&cc->tag_pool, MIN_IOS, + cc->tag_pool_max_sectors * cc->on_disk_tag_size); + if (ret) { + ti->error = "Cannot allocate integrity tags mempool"; + goto bad; + } + + cc->tag_pool_max_sectors <<= cc->sector_shift; + } + + ret = -ENOMEM; + cc->io_queue = alloc_workqueue("kcryptd_io", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); + if (!cc->io_queue) { + ti->error = "Couldn't create kcryptd io queue"; + goto bad; + } + + if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) + cc->crypt_queue = alloc_workqueue("kcryptd", WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM, 1); + else + cc->crypt_queue = alloc_workqueue("kcryptd", + WQ_HIGHPRI | WQ_CPU_INTENSIVE | WQ_MEM_RECLAIM | WQ_UNBOUND, + num_online_cpus()); + if (!cc->crypt_queue) { + ti->error = "Couldn't create kcryptd queue"; + goto bad; + } + + spin_lock_init(&cc->write_thread_lock); + cc->write_tree = RB_ROOT; + + cc->write_thread = kthread_create(dmcrypt_write, cc, "dmcrypt_write"); + if (IS_ERR(cc->write_thread)) { + ret = PTR_ERR(cc->write_thread); + cc->write_thread = NULL; + ti->error = "Couldn't spawn write thread"; + goto bad; + } + wake_up_process(cc->write_thread); + + ti->num_flush_bios = 1; + ti->limit_swap_bios = true; + + return 0; + +bad: + crypt_dtr(ti); + return ret; +} + +static int crypt_map(struct dm_target *ti, struct bio *bio) +{ + struct dm_crypt_io *io; + struct crypt_config *cc = ti->private; + + /* + * If bio is REQ_PREFLUSH or REQ_OP_DISCARD, just bypass crypt queues. + * - for REQ_PREFLUSH device-mapper core ensures that no IO is in-flight + * - for REQ_OP_DISCARD caller must use flush if IO ordering matters + */ + if (unlikely(bio->bi_opf & REQ_PREFLUSH || + bio_op(bio) == REQ_OP_DISCARD)) { + bio_set_dev(bio, 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; + } + + /* + * Check if bio is too large, split as needed. + */ + if (unlikely(bio->bi_iter.bi_size > (BIO_MAX_PAGES << PAGE_SHIFT)) && + (bio_data_dir(bio) == WRITE || cc->on_disk_tag_size)) + dm_accept_partial_bio(bio, ((BIO_MAX_PAGES << PAGE_SHIFT) >> SECTOR_SHIFT)); + + /* + * Ensure that bio is a multiple of internal sector encryption size + * and is aligned to this size as defined in IO hints. + */ + if (unlikely((bio->bi_iter.bi_sector & ((cc->sector_size >> SECTOR_SHIFT) - 1)) != 0)) + return DM_MAPIO_KILL; + + if (unlikely(bio->bi_iter.bi_size & (cc->sector_size - 1))) + return DM_MAPIO_KILL; + + io = dm_per_bio_data(bio, cc->per_bio_data_size); + crypt_io_init(io, cc, bio, dm_target_offset(ti, bio->bi_iter.bi_sector)); + + if (cc->on_disk_tag_size) { + unsigned tag_len = cc->on_disk_tag_size * (bio_sectors(bio) >> cc->sector_shift); + + if (unlikely(tag_len > KMALLOC_MAX_SIZE) || + unlikely(!(io->integrity_metadata = kmalloc(tag_len, + GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN)))) { + if (bio_sectors(bio) > cc->tag_pool_max_sectors) + dm_accept_partial_bio(bio, cc->tag_pool_max_sectors); + io->integrity_metadata = mempool_alloc(&cc->tag_pool, GFP_NOIO); + io->integrity_metadata_from_pool = true; + } + } + + if (crypt_integrity_aead(cc)) + io->ctx.r.req_aead = (struct aead_request *)(io + 1); + else + io->ctx.r.req = (struct skcipher_request *)(io + 1); + + if (bio_data_dir(io->base_bio) == READ) { + if (kcryptd_io_read(io, GFP_NOWAIT)) + kcryptd_queue_read(io); + } else + kcryptd_queue_crypt(io); + + return DM_MAPIO_SUBMITTED; +} + +static char hex2asc(unsigned char c) +{ + return c + '0' + ((unsigned)(9 - c) >> 4 & 0x27); +} + +static void crypt_status(struct dm_target *ti, status_type_t type, + unsigned status_flags, char *result, unsigned maxlen) +{ + struct crypt_config *cc = ti->private; + unsigned i, sz = 0; + int num_feature_args = 0; + + switch (type) { + case STATUSTYPE_INFO: + result[0] = '\0'; + break; + + case STATUSTYPE_TABLE: + DMEMIT("%s ", cc->cipher_string); + + if (cc->key_size > 0) { + if (cc->key_string) + DMEMIT(":%u:%s", cc->key_size, cc->key_string); + else { + for (i = 0; i < cc->key_size; i++) { + DMEMIT("%c%c", hex2asc(cc->key[i] >> 4), + hex2asc(cc->key[i] & 0xf)); + } + } + } else + DMEMIT("-"); + + DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, + cc->dev->name, (unsigned long long)cc->start); + + num_feature_args += !!ti->num_discard_bios; + num_feature_args += test_bit(DM_CRYPT_SAME_CPU, &cc->flags); + num_feature_args += test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags); + num_feature_args += cc->sector_size != (1 << SECTOR_SHIFT); + num_feature_args += test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags); + if (cc->on_disk_tag_size) + num_feature_args++; + if (num_feature_args) { + DMEMIT(" %d", num_feature_args); + if (ti->num_discard_bios) + DMEMIT(" allow_discards"); + if (test_bit(DM_CRYPT_SAME_CPU, &cc->flags)) + DMEMIT(" same_cpu_crypt"); + if (test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) + DMEMIT(" submit_from_crypt_cpus"); + if (cc->on_disk_tag_size) + DMEMIT(" integrity:%u:%s", cc->on_disk_tag_size, cc->cipher_auth); + if (cc->sector_size != (1 << SECTOR_SHIFT)) + DMEMIT(" sector_size:%d", cc->sector_size); + if (test_bit(CRYPT_IV_LARGE_SECTORS, &cc->cipher_flags)) + DMEMIT(" iv_large_sectors"); + } + + break; + } +} + +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, + char *result, unsigned maxlen) +{ + struct crypt_config *cc = ti->private; + int key_size, 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")) { + /* The key size may not be changed. */ + key_size = get_key_size(&argv[2]); + if (key_size < 0 || cc->key_size != key_size) { + memset(argv[2], '0', strlen(argv[2])); + return -EINVAL; + } + + 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); + /* wipe the kernel key payload copy */ + if (cc->key_string) + memset(cc->key, 0, cc->key_size * sizeof(u8)); + 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_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 void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits) +{ + struct crypt_config *cc = ti->private; + + /* + * Unfortunate constraint that is required to avoid the potential + * for exceeding underlying device's max_segments limits -- due to + * crypt_alloc_buffer() possibly allocating pages for the encryption + * bio that are not as physically contiguous as the original bio. + */ + limits->max_segment_size = PAGE_SIZE; + + limits->logical_block_size = + max_t(unsigned, limits->logical_block_size, cc->sector_size); + limits->physical_block_size = + max_t(unsigned, limits->physical_block_size, cc->sector_size); + limits->io_min = max_t(unsigned, limits->io_min, cc->sector_size); +} + +static struct target_type crypt_target = { + .name = "crypt", + .version = {1, 18, 1}, + .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, + .iterate_devices = crypt_iterate_devices, + .io_hints = crypt_io_hints, +}; + +static int __init dm_crypt_init(void) +{ + int r; + + r = dm_register_target(&crypt_target); + if (r < 0) + DMERR("register failed %d", r); + + return r; +} + +static void __exit dm_crypt_exit(void) +{ + dm_unregister_target(&crypt_target); +} + +module_init(dm_crypt_init); +module_exit(dm_crypt_exit); + +MODULE_AUTHOR("Jana Saout <jana@saout.de>"); +MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); +MODULE_LICENSE("GPL"); |