// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2003 Jana Saout <jana@saout.de>
* Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
* Copyright (C) 2006-2020 Red Hat, Inc. All rights reserved.
* Copyright (C) 2013-2020 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/blk-integrity.h>
#include <linux/crc32.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 <linux/unaligned.h>
#include <crypto/hash.h>
#include <crypto/md5.h>
#include <crypto/skcipher.h>
#include <crypto/aead.h>
#include <crypto/authenc.h>
#include <crypto/utils.h>
#include <linux/rtnetlink.h>
/* for struct rtattr and RTA macros only */
#include <linux/key-type.h>
#include <keys/user-type.h>
#include <keys/encrypted-type.h>
#include <keys/trusted-type.h>
#include <linux/device-mapper.h>
#include "dm-audit.h"
#define DM_MSG_PREFIX
"crypt"
static DEFINE_IDA(workqueue_ida);
/*
* context holding the current state of a multi-part conversion
*/
struct convert_context {
struct completion restart;
struct bio *bio_in;
struct bvec_iter iter_in;
struct bio *bio_out;
struct bvec_iter iter_out;
atomic_t cc_pending;
unsigned int tag_offset;
u64 cc_sector;
union {
struct skcipher_request *req;
struct aead_request *req_aead;
} r;
bool aead_recheck;
bool aead_failed;
};
/*
* per bio private data
*/
struct dm_crypt_io {
struct crypt_config *cc;
struct bio *base_bio;
u8 *integrity_metadata;
bool integrity_metadata_from_pool:1;
struct work_struct work;
struct convert_context ctx;
atomic_t io_pending;
blk_status_t error;
sector_t sector;
struct bvec_iter saved_bi_iter;
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_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 {
u8 *iv_seed;
u8 *whitening;
};
#define ELEPHANT_MAX_KEY_SIZE 32
struct iv_elephant_private {
struct crypto_skcipher *tfm;
};
/*
* 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_HIGH_PRIORITY,
DM_CRYPT_NO_OFFLOAD, DM_CRYPT_NO_READ_WORKQUEUE,
DM_CRYPT_NO_WRITE_WORKQUEUE, DM_CRYPT_WRITE_INLINE };
enum cipher_flags {
CRYPT_MODE_INTEGRITY_AEAD,
/* Use authenticated mode for cipher */
CRYPT_IV_LARGE_SECTORS,
/* Calculate IV from sector_size, not 512B sectors */
CRYPT_ENCRYPT_PREPROCESS,
/* Must preprocess data for encryption (elephant) */
CRYPT_KEY_MAC_SIZE_SET,
/* The integrity_key_size option was used */
};
/*
* 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_string;
char *cipher_auth;
char *key_string;
const struct crypt_iv_operations *iv_gen_ops;
union {
struct iv_benbi_private benbi;
struct iv_lmk_private lmk;
struct iv_tcw_private tcw;
struct iv_elephant_private elephant;
} iv_gen_private;
u64 iv_offset;
unsigned int iv_size;
unsigned short sector_size;
unsigned char sector_shift;
union {
struct crypto_skcipher **tfms;
struct crypto_aead **tfms_aead;
} cipher_tfm;
unsigned int tfms_count;
int workqueue_id;
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 used_tag_size;
unsigned int tuple_size;
/*
* pool for per bio private data, crypto requests,
* encryption requeusts/buffer pages and integrity tags
*/
unsigned int 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[] __counted_by(key_size);
};
#define MIN_IOS 64
#define MAX_TAG_SIZE 480
#define POOL_ENTRY_SIZE 512
static DEFINE_SPINLOCK(dm_crypt_clients_lock);
static unsigned int dm_crypt_clients_n;
static volatile unsigned long dm_crypt_pages_per_client;
#define DM_CRYPT_MEMORY_PERCENT 2
#define DM_CRYPT_MIN_PAGES_PER_CLIENT (BIO_MAX_VECS * 16)
#define DM_CRYPT_DEFAULT_MAX_READ_SIZE 131072
#define DM_CRYPT_DEFAULT_MAX_WRITE_SIZE 131072
static unsigned int max_read_size = 0;
module_param(max_read_size, uint, 0644);
MODULE_PARM_DESC(max_read_size,
"Maximum size of a read request");
static unsigned int max_write_size = 0;
module_param(max_write_size, uint, 0644);
MODULE_PARM_DESC(max_write_size,
"Maximum size of a write request");
static unsigned get_max_request_sectors(
struct dm_target *ti,
struct bio *bio)
{
struct crypt_config *cc = ti->
private;
unsigned val, sector_align;
bool wrt = op_is_write(bio_op(bio));
if (wrt) {
/*
* For zoned devices, splitting write operations creates the
* risk of deadlocking queue freeze operations with zone write
* plugging BIO work when the reminder of a split BIO is
* issued. So always allow the entire BIO to proceed.
*/
if (ti->emulate_zone_append)
return bio_sectors(bio);
val = min_not_zero(READ_ONCE(max_write_size),
DM_CRYPT_DEFAULT_MAX_WRITE_SIZE);
}
else {
val = min_not_zero(READ_ONCE(max_read_size),
DM_CRYPT_DEFAULT_MAX_READ_SIZE);
}
if (wrt || cc->used_tag_size)
val = min(val, BIO_MAX_VECS << PAGE_SHIFT);
sector_align = max(bdev_logical_block_size(cc->dev->bdev),
(
unsigned)cc->sector_size);
val = round_down(val, sector_align);
if (unlikely(!val))
val = sector_align;
return val >> SECTOR_SHIFT;
}
static void crypt_endio(
struct bio *clone);
static void kcryptd_queue_crypt(
struct dm_crypt_io *io);
static struct scatterlist *crypt_get_sg_data(
struct crypt_config *cc,
struct scatterlist *sg);
static bool crypt_integrity_aead(
struct crypt_config *cc);
/*
* 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.
*
* eboiv: Encrypted byte-offset IV (used in Bitlocker in CBC mode)
* The IV is encrypted little-endian byte-offset (with the same key
* and cipher as the volume).
*
* elephant: The extended version of eboiv with additional Elephant diffuser
* used with Bitlocker CBC mode.
* This mode was used in older Windows systems
* https://download.microsoft.com/download/0/2/3/0238acaf-d3bf-4a6d-b3d6-0a0be4bbb36e/bitlockercipher200608.pdf
*/
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;
}
static int crypt_iv_essiv_gen(
struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
/*
* ESSIV encryption of the IV is now handled by the crypto API,
* so just pass the plain sector number here.
*/
memset(iv, 0, cc->iv_size);
*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
return 0;
}
static int crypt_iv_benbi_ctr(
struct crypt_config *cc,
struct dm_target *ti,
const char *opts)
{
unsigned int bs;
int log;
if (crypt_integrity_aead(cc))
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;
kfree_sensitive(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,
CRYPTO_ALG_ALLOCATES_MEMORY);
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);
union {
struct md5_state md5state;
u8 state[CRYPTO_MD5_STATESIZE];
} u;
__le32 buf[4];
int i, r;
desc->tfm = lmk->hash_tfm;
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, &u.md5state);
if (r)
return r;
for (i = 0; i < MD5_HASH_WORDS; i++)
__cpu_to_le32s(&u.md5state.hash[i]);
memcpy(iv, &u.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_local_page(sg_page(sg));
r = crypt_iv_lmk_one(cc, iv, dmreq, src + sg->offset);
kunmap_local(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_local_page(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_local(dst);
return r;
}
static void crypt_iv_tcw_dtr(
struct crypt_config *cc)
{
struct iv_tcw_private *tcw = &cc->iv_gen_private.tcw;
kfree_sensitive(tcw->iv_seed);
tcw->iv_seed = NULL;
kfree_sensitive(tcw->whitening);
tcw->whitening = 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->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 void 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];
int i;
/* 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 */
for (i = 0; i < 4; i++)
put_unaligned_le32(crc32(0, &buf[i * 4], 4), &buf[i * 4]);
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);
memzero_explicit(buf,
sizeof(buf));
}
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;
/* Remove whitening from ciphertext */
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
sg = crypt_get_sg_data(cc, dmreq->sg_in);
src = kmap_local_page(sg_page(sg));
crypt_iv_tcw_whitening(cc, dmreq, src + sg->offset);
kunmap_local(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 0;
}
static int crypt_iv_tcw_post(
struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct scatterlist *sg;
u8 *dst;
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_local_page(sg_page(sg));
crypt_iv_tcw_whitening(cc, dmreq, dst + sg->offset);
kunmap_local(dst);
return 0;
}
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 int crypt_iv_eboiv_ctr(
struct crypt_config *cc,
struct dm_target *ti,
const char *opts)
{
if (crypt_integrity_aead(cc)) {
ti->error =
"AEAD transforms not supported for EBOIV";
return -EINVAL;
}
if (crypto_skcipher_blocksize(any_tfm(cc)) != cc->iv_size) {
ti->error =
"Block size of EBOIV cipher does not match IV size of block cipher";
return -EINVAL;
}
return 0;
}
static int crypt_iv_eboiv_gen(
struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
struct crypto_skcipher *tfm = any_tfm(cc);
struct skcipher_request *req;
struct scatterlist src, dst;
DECLARE_CRYPTO_WAIT(wait);
unsigned int reqsize;
int err;
u8 *buf;
reqsize =
sizeof(*req) + crypto_skcipher_reqsize(tfm);
reqsize = ALIGN(reqsize, __alignof__(__le64));
req = kmalloc(reqsize + cc->iv_size, GFP_NOIO);
if (!req)
return -ENOMEM;
skcipher_request_set_tfm(req, tfm);
buf = (u8 *)req + reqsize;
memset(buf, 0, cc->iv_size);
*(__le64 *)buf = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
sg_init_one(&src, page_address(ZERO_PAGE(0)), cc->iv_size);
sg_init_one(&dst, iv, cc->iv_size);
skcipher_request_set_crypt(req, &src, &dst, cc->iv_size, buf);
skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
err = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
kfree_sensitive(req);
return err;
}
static void crypt_iv_elephant_dtr(
struct crypt_config *cc)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
crypto_free_skcipher(elephant->tfm);
elephant->tfm = NULL;
}
static int crypt_iv_elephant_ctr(
struct crypt_config *cc,
struct dm_target *ti,
const char *opts)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
int r;
elephant->tfm = crypto_alloc_skcipher(
"ecb(aes)", 0,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(elephant->tfm)) {
r = PTR_ERR(elephant->tfm);
elephant->tfm = NULL;
return r;
}
r = crypt_iv_eboiv_ctr(cc, ti, NULL);
if (r)
crypt_iv_elephant_dtr(cc);
return r;
}
static void diffuser_disk_to_cpu(u32 *d, size_t n)
{
#ifndef __LITTLE_ENDIAN
int i;
for (i = 0; i < n; i++)
d[i] = le32_to_cpu((__le32)d[i]);
#endif
}
static void diffuser_cpu_to_disk(__le32 *d, size_t n)
{
#ifndef __LITTLE_ENDIAN
int i;
for (i = 0; i < n; i++)
d[i] = cpu_to_le32((u32)d[i]);
#endif
}
static void diffuser_a_decrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 5; i++) {
i1 = 0;
i2 = n - 2;
i3 = n - 5;
while (i1 < (n - 1)) {
d[i1] += d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
i1++; i2++; i3++;
if (i3 >= n)
i3 -= n;
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
if (i2 >= n)
i2 -= n;
d[i1] += d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
i1++; i2++; i3++;
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
}
}
}
static void diffuser_a_encrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 5; i++) {
i1 = n - 1;
i2 = n - 2 - 1;
i3 = n - 5 - 1;
while (i1 > 0) {
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
d[i1] -= d[i2] ^ (d[i3] << 13 | d[i3] >> 19);
i1--; i2--; i3--;
if (i2 < 0)
i2 += n;
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
if (i3 < 0)
i3 += n;
d[i1] -= d[i2] ^ (d[i3] << 9 | d[i3] >> 23);
i1--; i2--; i3--;
}
}
}
static void diffuser_b_decrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 3; i++) {
i1 = 0;
i2 = 2;
i3 = 5;
while (i1 < (n - 1)) {
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
d[i1] += d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
i1++; i2++; i3++;
if (i2 >= n)
i2 -= n;
d[i1] += d[i2] ^ d[i3];
i1++; i2++; i3++;
if (i3 >= n)
i3 -= n;
d[i1] += d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
i1++; i2++; i3++;
}
}
}
static void diffuser_b_encrypt(u32 *d, size_t n)
{
int i, i1, i2, i3;
for (i = 0; i < 3; i++) {
i1 = n - 1;
i2 = 2 - 1;
i3 = 5 - 1;
while (i1 > 0) {
d[i1] -= d[i2] ^ (d[i3] << 25 | d[i3] >> 7);
i1--; i2--; i3--;
if (i3 < 0)
i3 += n;
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
if (i2 < 0)
i2 += n;
d[i1] -= d[i2] ^ (d[i3] << 10 | d[i3] >> 22);
i1--; i2--; i3--;
d[i1] -= d[i2] ^ d[i3];
i1--; i2--; i3--;
}
}
}
static int crypt_iv_elephant(
struct crypt_config *cc,
struct dm_crypt_request *dmreq)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
u8 *es, *ks, *data, *data2, *data_offset;
struct skcipher_request *req;
struct scatterlist *sg, *sg2, src, dst;
DECLARE_CRYPTO_WAIT(wait);
int i, r;
req = skcipher_request_alloc(elephant->tfm, GFP_NOIO);
es = kzalloc(16, GFP_NOIO);
/* Key for AES */
ks = kzalloc(32, GFP_NOIO);
/* Elephant sector key */
if (!req || !es || !ks) {
r = -ENOMEM;
goto out;
}
*(__le64 *)es = cpu_to_le64(dmreq->iv_sector * cc->sector_size);
/* E(Ks, e(s)) */
sg_init_one(&src, es, 16);
sg_init_one(&dst, ks, 16);
skcipher_request_set_crypt(req, &src, &dst, 16, NULL);
skcipher_request_set_callback(req, 0, crypto_req_done, &wait);
r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
if (r)
goto out;
/* E(Ks, e'(s)) */
es[15] = 0x80;
sg_init_one(&dst, &ks[16], 16);
r = crypto_wait_req(crypto_skcipher_encrypt(req), &wait);
if (r)
goto out;
sg = crypt_get_sg_data(cc, dmreq->sg_out);
data = kmap_local_page(sg_page(sg));
data_offset = data + sg->offset;
/* Cannot modify original bio, copy to sg_out and apply Elephant to it */
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
sg2 = crypt_get_sg_data(cc, dmreq->sg_in);
data2 = kmap_local_page(sg_page(sg2));
memcpy(data_offset, data2 + sg2->offset, cc->sector_size);
kunmap_local(data2);
}
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE) {
diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size /
sizeof(u32));
diffuser_b_decrypt((u32 *)data_offset, cc->sector_size /
sizeof(u32));
diffuser_a_decrypt((u32 *)data_offset, cc->sector_size /
sizeof(u32));
diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size /
sizeof(u32));
}
for (i = 0; i < (cc->sector_size / 32); i++)
crypto_xor(data_offset + i * 32, ks, 32);
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
diffuser_disk_to_cpu((u32 *)data_offset, cc->sector_size /
sizeof(u32));
diffuser_a_encrypt((u32 *)data_offset, cc->sector_size /
sizeof(u32));
diffuser_b_encrypt((u32 *)data_offset, cc->sector_size /
sizeof(u32));
diffuser_cpu_to_disk((__le32 *)data_offset, cc->sector_size /
sizeof(u32));
}
kunmap_local(data);
out:
kfree_sensitive(ks);
kfree_sensitive(es);
skcipher_request_free(req);
return r;
}
static int crypt_iv_elephant_gen(
struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
int r;
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
r = crypt_iv_elephant(cc, dmreq);
if (r)
return r;
}
return crypt_iv_eboiv_gen(cc, iv, dmreq);
}
static int crypt_iv_elephant_post(
struct crypt_config *cc, u8 *iv,
struct dm_crypt_request *dmreq)
{
if (bio_data_dir(dmreq->ctx->bio_in) != WRITE)
return crypt_iv_elephant(cc, dmreq);
return 0;
}
static int crypt_iv_elephant_init(
struct crypt_config *cc)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
int key_offset = cc->key_size - cc->key_extra_size;
return crypto_skcipher_setkey(elephant->tfm, &cc->key[key_offset], cc->key_extra_size);
}
static int crypt_iv_elephant_wipe(
struct crypt_config *cc)
{
struct iv_elephant_private *elephant = &cc->iv_gen_private.elephant;
u8 key[ELEPHANT_MAX_KEY_SIZE];
memset(key, 0, cc->key_extra_size);
return crypto_skcipher_setkey(elephant->tfm, key, cc->key_extra_size);
}
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 = {
.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 const struct crypt_iv_operations crypt_iv_random_ops = {
.generator = crypt_iv_random_gen
};
static const struct crypt_iv_operations crypt_iv_eboiv_ops = {
.ctr = crypt_iv_eboiv_ctr,
.generator = crypt_iv_eboiv_gen
};
static const struct crypt_iv_operations crypt_iv_elephant_ops = {
.ctr = crypt_iv_elephant_ctr,
.dtr = crypt_iv_elephant_dtr,
.init = crypt_iv_elephant_init,
.wipe = crypt_iv_elephant_wipe,
.generator = crypt_iv_elephant_gen,
.post = crypt_iv_elephant_post
};
/*
* 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->tuple_size)
return 0;
bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
if (IS_ERR(bip))
return PTR_ERR(bip);
tag_len = io->cc->tuple_size * (bio_sectors(bio) >> io->cc->sector_shift);
bip->bip_iter.bi_sector = bio->bi_iter.bi_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);
/* We require an underlying device with non-PI metadata */
if (!bi || bi->csum_type != BLK_INTEGRITY_CSUM_NONE) {
ti->error =
"Integrity profile not supported.";
return -EINVAL;
}
if (bi->metadata_size < cc->used_tag_size) {
ti->error =
"Integrity profile tag size mismatch.";
return -EINVAL;
}
cc->tuple_size = bi->metadata_size;
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->used_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) > cc->tuple_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;
ctx->tag_offset = 0;
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 __le64 *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 (__le64 *) 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->tuple_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;
__le64 *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->tuple_size)
memset(tag + cc->integrity_tag_size + cc->integrity_iv_size, 0,
cc->tuple_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) {
sector_t s = le64_to_cpu(*sector);
ctx->aead_failed =
true;
if (ctx->aead_recheck) {
DMERR_LIMIT(
"%pg: INTEGRITY AEAD ERROR, sector %llu",
ctx->bio_in->bi_bdev, s);
dm_audit_log_bio(DM_MSG_PREFIX,
"integrity-aead",
ctx->bio_in, s, 0);
}
}
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;
__le64 *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;
/* Data can be already preprocessed in generator */
if (test_bit(CRYPT_ENCRYPT_PREPROCESS, &cc->cipher_flags))
sg_in = sg_out;
/* 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(
void *async_req,
int error);
static int crypt_alloc_req_skcipher(
struct crypt_config *cc,
struct convert_context *ctx)
{
unsigned int key_index = ctx->cc_sector & (cc->tfms_count - 1);
if (!ctx->r.req) {
ctx->r.req = mempool_alloc(&cc->req_pool, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
if (!ctx->r.req)
return -ENOMEM;
}
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));
return 0;
}
static int 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, in_interrupt() ? GFP_ATOMIC : GFP_NOIO);
if (!ctx->r.req_aead)
return -ENOMEM;
}
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));
return 0;
}
static int crypt_alloc_req(
struct crypt_config *cc,
struct convert_context *ctx)
{
if (crypt_integrity_aead(cc))
return crypt_alloc_req_aead(cc, ctx);
else
return 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,
bool atomic,
bool reset_pending)
{
unsigned int sector_step = cc->sector_size >> SECTOR_SHIFT;
int r;
/*
* if reset_pending is set we are dealing with the bio for the first time,
* else we're continuing to work on the previous bio, so don't mess with
* the cc_pending counter
*/
if (reset_pending)
atomic_set(&ctx->cc_pending, 1);
while (ctx->iter_in.bi_size && ctx->iter_out.bi_size) {
r = crypt_alloc_req(cc, ctx);
if (r) {
complete(&ctx->restart);
return BLK_STS_DEV_RESOURCE;
}
atomic_inc(&ctx->cc_pending);
if (crypt_integrity_aead(cc))
r = crypt_convert_block_aead(cc, ctx, ctx->r.req_aead, ctx->tag_offset);
else
r = crypt_convert_block_skcipher(cc, ctx, ctx->r.req, ctx->tag_offset);
switch (r) {
/*
* The request was queued by a crypto driver
* but the driver request queue is full, let's wait.
*/
case -EBUSY:
if (in_interrupt()) {
if (try_wait_for_completion(&ctx->restart)) {
/*
* we don't have to block to wait for completion,
* so proceed
*/
}
else {
/*
* we can't wait for completion without blocking
* exit and continue processing in a workqueue
*/
ctx->r.req = NULL;
ctx->tag_offset++;
ctx->cc_sector += sector_step;
return BLK_STS_DEV_RESOURCE;
}
}
else {
wait_for_completion(&ctx->restart);
}
reinit_completion(&ctx->restart);
fallthrough;
/*
* The request is queued and processed asynchronously,
* completion function kcryptd_async_done() will be called.
*/
case -EINPROGRESS:
ctx->r.req = NULL;
ctx->tag_offset++;
ctx->cc_sector += sector_step;
continue;
/*
* The request was already processed (synchronously).
*/
case 0:
atomic_dec(&ctx->cc_pending);
ctx->cc_sector += sector_step;
ctx->tag_offset++;
if (!atomic)
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 if it did then block
* core should split the bio as needed).
*
* 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.
*
* In order to reduce allocation overhead, we try to allocate compound pages in
* the first pass. If they are not available, we fall back to the mempool.
*/
static struct bio *crypt_alloc_buffer(
struct dm_crypt_io *io,
unsigned int 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 int remaining_size;
unsigned int order = MAX_PAGE_ORDER;
retry:
if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
mutex_lock(&cc->bio_alloc_lock);
clone = bio_alloc_bioset(cc->dev->bdev, nr_iovecs, io->base_bio->bi_opf,
GFP_NOIO, &cc->bs);
clone->bi_private = io;
clone->bi_end_io = crypt_endio;
clone->bi_ioprio = io->base_bio->bi_ioprio;
clone->bi_iter.bi_sector = cc->start + io->sector;
remaining_size = size;
while (remaining_size) {
struct page *pages;
unsigned size_to_add;
unsigned remaining_order = __fls((remaining_size + PAGE_SIZE - 1) >> PAGE_SHIFT);
order = min(order, remaining_order);
while (order > 0) {
if (unlikely(percpu_counter_read_positive(&cc->n_allocated_pages) +
(1 << order) > dm_crypt_pages_per_client))
goto decrease_order;
pages = alloc_pages(gfp_mask
| __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN | __GFP_COMP,
order);
if (likely(pages != NULL)) {
percpu_counter_add(&cc->n_allocated_pages, 1 << order);
goto have_pages;
}
decrease_order:
order--;
}
pages = mempool_alloc(&cc->page_pool, gfp_mask);
if (!pages) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
gfp_mask |= __GFP_DIRECT_RECLAIM;
order = 0;
goto retry;
}
have_pages:
size_to_add = min((
unsigned)PAGE_SIZE << order, remaining_size);
__bio_add_page(clone, pages, size_to_add, 0);
remaining_size -= size_to_add;
}
/* Allocate space for integrity tags */
if (dm_crypt_integrity_io_alloc(io, clone)) {
crypt_free_buffer_pages(cc, clone);
bio_put(clone);
clone = NULL;
}
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)
{
struct folio_iter fi;
if (clone->bi_vcnt > 0) {
/* bio_for_each_folio_all crashes with an empty bio */
bio_for_each_folio_all(fi, clone) {
if (folio_test_large(fi.folio)) {
percpu_counter_sub(&cc->n_allocated_pages,
1 << folio_order(fi.folio));
folio_put(fi.folio);
}
else {
mempool_free(&fi.folio->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.aead_recheck =
false;
io->ctx.aead_failed =
false;
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);
}
static void kcryptd_queue_read(
struct dm_crypt_io *io);
/*
* 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 (likely(!io->ctx.aead_recheck) && unlikely(io->ctx.aead_failed) &&
cc->used_tag_size && bio_data_dir(base_bio) == READ) {
io->ctx.aead_recheck =
true;
io->ctx.aead_failed =
false;
io->error = 0;
kcryptd_queue_read(io);
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 int rw = bio_data_dir(clone);
blk_status_t error = clone->bi_status;
if (io->ctx.aead_recheck && !error) {
kcryptd_queue_crypt(io);
return;
}
/*
* free the processed pages
*/
if (rw == WRITE || io->ctx.aead_recheck)
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);
}
#define CRYPT_MAP_READ_GFP GFP_NOWAIT
static int kcryptd_io_read(
struct dm_crypt_io *io, gfp_t gfp)
{
struct crypt_config *cc = io->cc;
struct bio *clone;
if (io->ctx.aead_recheck) {
if (!(gfp & __GFP_DIRECT_RECLAIM))
return 1;
crypt_inc_pending(io);
clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
if (unlikely(!clone)) {
crypt_dec_pending(io);
return 1;
}
crypt_convert_init(cc, &io->ctx, clone, clone, io->sector);
io->saved_bi_iter = clone->bi_iter;
dm_submit_bio_remap(io->base_bio, clone);
return 0;
}
/*
* 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_alloc_clone().
*/
clone = bio_alloc_clone(cc->dev->bdev, io->base_bio, gfp, &cc->bs);
if (!clone)
return 1;
clone->bi_iter.bi_sector = cc->start + io->sector;
clone->bi_private = io;
clone->bi_end_io = crypt_endio;
crypt_inc_pending(io);
if (dm_crypt_integrity_io_alloc(io, clone)) {
crypt_dec_pending(io);
bio_put(clone);
return 1;
}
dm_submit_bio_remap(io->base_bio, 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;
dm_submit_bio_remap(io->base_bio, 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();
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);
cond_resched();
}
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);
if ((likely(!async) && test_bit(DM_CRYPT_NO_OFFLOAD, &cc->flags)) ||
test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags)) {
dm_submit_bio_remap(io->base_bio, 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 bool kcryptd_crypt_write_inline(
struct crypt_config *cc,
struct convert_context *ctx)
{
if (!test_bit(DM_CRYPT_WRITE_INLINE, &cc->flags))
return false;
/*
* Note: zone append writes (REQ_OP_ZONE_APPEND) do not have ordering
* constraints so they do not need to be issued inline by
* kcryptd_crypt_write_convert().
*/
switch (bio_op(ctx->bio_in)) {
case REQ_OP_WRITE:
case REQ_OP_WRITE_ZEROES:
return true;
default:
return false;
}
}
static void kcryptd_crypt_write_continue(
struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work,
struct dm_crypt_io, work);
struct crypt_config *cc = io->cc;
struct convert_context *ctx = &io->ctx;
int crypt_finished;
blk_status_t r;
wait_for_completion(&ctx->restart);
reinit_completion(&ctx->restart);
r = crypt_convert(cc, &io->ctx,
false,
false);
if (r)
io->error = r;
crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
/* Wait for completion signaled by kcryptd_async_done() */
wait_for_completion(&ctx->restart);
crypt_finished = 1;
}
/* Encryption was already finished, submit io now */
if (crypt_finished)
kcryptd_crypt_write_io_submit(io, 0);
crypt_dec_pending(io);
}
static void kcryptd_crypt_write_convert(
struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
struct convert_context *ctx = &io->ctx;
struct bio *clone;
int crypt_finished;
blk_status_t r;
/*
* Prevent io from disappearing until this function completes.
*/
crypt_inc_pending(io);
crypt_convert_init(cc, ctx, NULL, io->base_bio, io->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;
if (crypt_integrity_aead(cc)) {
bio_copy_data(clone, io->base_bio);
io->ctx.bio_in = clone;
io->ctx.iter_in = clone->bi_iter;
}
crypt_inc_pending(io);
r = crypt_convert(cc, ctx,
test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags),
true);
/*
* Crypto API backlogged the request, because its queue was full
* and we're in softirq context, so continue from a workqueue
* (TODO: is it actually possible to be in softirq in the write path?)
*/
if (r == BLK_STS_DEV_RESOURCE) {
INIT_WORK(&io->work, kcryptd_crypt_write_continue);
queue_work(cc->crypt_queue, &io->work);
return;
}
if (r)
io->error = r;
crypt_finished = atomic_dec_and_test(&ctx->cc_pending);
if (!crypt_finished && kcryptd_crypt_write_inline(cc, ctx)) {
/* Wait for completion signaled by kcryptd_async_done() */
wait_for_completion(&ctx->restart);
crypt_finished = 1;
}
/* Encryption was already finished, submit io now */
if (crypt_finished)
kcryptd_crypt_write_io_submit(io, 0);
dec:
crypt_dec_pending(io);
}
static void kcryptd_crypt_read_done(
struct dm_crypt_io *io)
{
if (io->ctx.aead_recheck) {
if (!io->error) {
io->ctx.bio_in->bi_iter = io->saved_bi_iter;
bio_copy_data(io->base_bio, io->ctx.bio_in);
}
crypt_free_buffer_pages(io->cc, io->ctx.bio_in);
bio_put(io->ctx.bio_in);
}
crypt_dec_pending(io);
}
static void kcryptd_crypt_read_continue(
struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work,
struct dm_crypt_io, work);
struct crypt_config *cc = io->cc;
blk_status_t r;
wait_for_completion(&io->ctx.restart);
reinit_completion(&io->ctx.restart);
r = crypt_convert(cc, &io->ctx,
false,
false);
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_crypt_read_convert(
struct dm_crypt_io *io)
{
struct crypt_config *cc = io->cc;
blk_status_t r;
crypt_inc_pending(io);
if (io->ctx.aead_recheck) {
r = crypt_convert(cc, &io->ctx,
test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags),
true);
}
else {
crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
io->sector);
r = crypt_convert(cc, &io->ctx,
test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags),
true);
}
/*
* Crypto API backlogged the request, because its queue was full
* and we're in softirq context, so continue from a workqueue
*/
if (r == BLK_STS_DEV_RESOURCE) {
INIT_WORK(&io->work, kcryptd_crypt_read_continue);
queue_work(cc->crypt_queue, &io->work);
return;
}
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(
void *data,
int error)
{
struct dm_crypt_request *dmreq = 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) {
sector_t s = le64_to_cpu(*org_sector_of_dmreq(cc, dmreq));
ctx->aead_failed =
true;
if (ctx->aead_recheck) {
DMERR_LIMIT(
"%pg: INTEGRITY AEAD ERROR, sector %llu",
ctx->bio_in->bi_bdev, s);
dm_audit_log_bio(DM_MSG_PREFIX,
"integrity-aead",
ctx->bio_in, s, 0);
}
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;
/*
* The request is fully completed: for inline writes, let
* kcryptd_crypt_write_convert() do the IO submission.
*/
if (bio_data_dir(io->base_bio) == READ) {
kcryptd_crypt_read_done(io);
return;
}
if (kcryptd_crypt_write_inline(cc, ctx)) {
complete(&ctx->restart);
return;
}
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;
if ((bio_data_dir(io->base_bio) == READ && test_bit(DM_CRYPT_NO_READ_WORKQUEUE, &cc->flags)
) ||
(bio_data_dir(io->base_bio) == WRITE && test_bit(DM_CRYPT_NO_WRITE_WORKQUEUE, &cc->flags))) {
/*
* in_hardirq(): Crypto API's skcipher_walk_first() refuses to work in hard IRQ context.
* irqs_disabled(): the kernel may run some IO completion from the idle thread, but
* it is being executed with irqs disabled.
*/
if (in_hardirq() || irqs_disabled()) {
INIT_WORK(&io->work, kcryptd_crypt);
queue_work(system_bh_wq, &io->work);
return;
} else {
kcryptd_crypt(&io->work);
return;
}
}
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 int 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 int 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,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(cc->cipher_tfm.tfms[i])) {
err = PTR_ERR(cc->cipher_tfm.tfms[i]);
crypt_free_tfms(cc);
return err;
}
}
/*
* dm-crypt performance can vary greatly depending on which crypto
* algorithm implementation is used. Help people debug performance
* problems by logging the ->cra_driver_name.
*/
DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
crypto_skcipher_alg(any_tfm(cc))->base.cra_driver_name);
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,
CRYPTO_ALG_ALLOCATES_MEMORY);
if (IS_ERR(cc->cipher_tfm.tfms_aead[0])) {
err = PTR_ERR(cc->cipher_tfm.tfms_aead[0]);
crypt_free_tfms(cc);
return err;
}
DMDEBUG_LIMIT("%s using implementation \"%s\"", ciphermode,
crypto_aead_alg(any_tfm_aead(cc))->base.cra_driver_name);
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 int crypt_subkey_size(struct crypt_config *cc)
{
return (cc->key_size - cc->key_extra_size) >> ilog2(cc->tfms_count);
}
static unsigned int 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 int enckeylen, unsigned int 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 int 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,
--> --------------------
--> maximum size reached
--> --------------------
