2 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
6 * This file is released under the GPL.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/bio.h>
14 #include <linux/blkdev.h>
15 #include <linux/mempool.h>
16 #include <linux/slab.h>
17 #include <linux/crypto.h>
18 #include <linux/workqueue.h>
19 #include <linux/backing-dev.h>
20 #include <asm/atomic.h>
21 #include <linux/scatterlist.h>
23 #include <asm/unaligned.h>
27 #define DM_MSG_PREFIX "crypt"
28 #define MESG_STR(x) x, sizeof(x)
31 * context holding the current state of a multi-part conversion
33 struct convert_context
{
36 unsigned int offset_in
;
37 unsigned int offset_out
;
44 * per bio private data
47 struct dm_target
*target
;
49 struct work_struct work
;
51 struct convert_context ctx
;
59 struct crypt_iv_operations
{
60 int (*ctr
)(struct crypt_config
*cc
, struct dm_target
*ti
,
62 void (*dtr
)(struct crypt_config
*cc
);
63 const char *(*status
)(struct crypt_config
*cc
);
64 int (*generator
)(struct crypt_config
*cc
, u8
*iv
, sector_t sector
);
68 * Crypt: maps a linear range of a block device
69 * and encrypts / decrypts at the same time.
71 enum flags
{ DM_CRYPT_SUSPENDED
, DM_CRYPT_KEY_VALID
};
77 * pool for per bio private data and
78 * for encryption buffer pages
84 struct workqueue_struct
*io_queue
;
85 struct workqueue_struct
*crypt_queue
;
89 struct crypt_iv_operations
*iv_gen_ops
;
92 struct crypto_cipher
*essiv_tfm
;
98 char cipher
[CRYPTO_MAX_ALG_NAME
];
99 char chainmode
[CRYPTO_MAX_ALG_NAME
];
100 struct crypto_blkcipher
*tfm
;
102 unsigned int key_size
;
107 #define MIN_POOL_PAGES 32
108 #define MIN_BIO_PAGES 8
110 static struct kmem_cache
*_crypt_io_pool
;
112 static void clone_init(struct dm_crypt_io
*, struct bio
*);
115 * Different IV generation algorithms:
117 * plain: the initial vector is the 32-bit little-endian version of the sector
118 * number, padded with zeros if necessary.
120 * essiv: "encrypted sector|salt initial vector", the sector number is
121 * encrypted with the bulk cipher using a salt as key. The salt
122 * should be derived from the bulk cipher's key via hashing.
124 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
125 * (needed for LRW-32-AES and possible other narrow block modes)
127 * null: the initial vector is always zero. Provides compatibility with
128 * obsolete loop_fish2 devices. Do not use for new devices.
130 * plumb: unimplemented, see:
131 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
134 static int crypt_iv_plain_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
136 memset(iv
, 0, cc
->iv_size
);
137 *(u32
*)iv
= cpu_to_le32(sector
& 0xffffffff);
142 static int crypt_iv_essiv_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
145 struct crypto_cipher
*essiv_tfm
;
146 struct crypto_hash
*hash_tfm
;
147 struct hash_desc desc
;
148 struct scatterlist sg
;
149 unsigned int saltsize
;
154 ti
->error
= "Digest algorithm missing for ESSIV mode";
158 /* Hash the cipher key with the given hash algorithm */
159 hash_tfm
= crypto_alloc_hash(opts
, 0, CRYPTO_ALG_ASYNC
);
160 if (IS_ERR(hash_tfm
)) {
161 ti
->error
= "Error initializing ESSIV hash";
162 return PTR_ERR(hash_tfm
);
165 saltsize
= crypto_hash_digestsize(hash_tfm
);
166 salt
= kmalloc(saltsize
, GFP_KERNEL
);
168 ti
->error
= "Error kmallocing salt storage in ESSIV";
169 crypto_free_hash(hash_tfm
);
173 sg_init_one(&sg
, cc
->key
, cc
->key_size
);
175 desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
176 err
= crypto_hash_digest(&desc
, &sg
, cc
->key_size
, salt
);
177 crypto_free_hash(hash_tfm
);
180 ti
->error
= "Error calculating hash in ESSIV";
185 /* Setup the essiv_tfm with the given salt */
186 essiv_tfm
= crypto_alloc_cipher(cc
->cipher
, 0, CRYPTO_ALG_ASYNC
);
187 if (IS_ERR(essiv_tfm
)) {
188 ti
->error
= "Error allocating crypto tfm for ESSIV";
190 return PTR_ERR(essiv_tfm
);
192 if (crypto_cipher_blocksize(essiv_tfm
) !=
193 crypto_blkcipher_ivsize(cc
->tfm
)) {
194 ti
->error
= "Block size of ESSIV cipher does "
195 "not match IV size of block cipher";
196 crypto_free_cipher(essiv_tfm
);
200 err
= crypto_cipher_setkey(essiv_tfm
, salt
, saltsize
);
202 ti
->error
= "Failed to set key for ESSIV cipher";
203 crypto_free_cipher(essiv_tfm
);
209 cc
->iv_gen_private
.essiv_tfm
= essiv_tfm
;
213 static void crypt_iv_essiv_dtr(struct crypt_config
*cc
)
215 crypto_free_cipher(cc
->iv_gen_private
.essiv_tfm
);
216 cc
->iv_gen_private
.essiv_tfm
= NULL
;
219 static int crypt_iv_essiv_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
221 memset(iv
, 0, cc
->iv_size
);
222 *(u64
*)iv
= cpu_to_le64(sector
);
223 crypto_cipher_encrypt_one(cc
->iv_gen_private
.essiv_tfm
, iv
, iv
);
227 static int crypt_iv_benbi_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
230 unsigned int bs
= crypto_blkcipher_blocksize(cc
->tfm
);
233 /* we need to calculate how far we must shift the sector count
234 * to get the cipher block count, we use this shift in _gen */
236 if (1 << log
!= bs
) {
237 ti
->error
= "cypher blocksize is not a power of 2";
242 ti
->error
= "cypher blocksize is > 512";
246 cc
->iv_gen_private
.benbi_shift
= 9 - log
;
251 static void crypt_iv_benbi_dtr(struct crypt_config
*cc
)
255 static int crypt_iv_benbi_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
259 memset(iv
, 0, cc
->iv_size
- sizeof(u64
)); /* rest is cleared below */
261 val
= cpu_to_be64(((u64
)sector
<< cc
->iv_gen_private
.benbi_shift
) + 1);
262 put_unaligned(val
, (__be64
*)(iv
+ cc
->iv_size
- sizeof(u64
)));
267 static int crypt_iv_null_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
269 memset(iv
, 0, cc
->iv_size
);
274 static struct crypt_iv_operations crypt_iv_plain_ops
= {
275 .generator
= crypt_iv_plain_gen
278 static struct crypt_iv_operations crypt_iv_essiv_ops
= {
279 .ctr
= crypt_iv_essiv_ctr
,
280 .dtr
= crypt_iv_essiv_dtr
,
281 .generator
= crypt_iv_essiv_gen
284 static struct crypt_iv_operations crypt_iv_benbi_ops
= {
285 .ctr
= crypt_iv_benbi_ctr
,
286 .dtr
= crypt_iv_benbi_dtr
,
287 .generator
= crypt_iv_benbi_gen
290 static struct crypt_iv_operations crypt_iv_null_ops
= {
291 .generator
= crypt_iv_null_gen
295 crypt_convert_scatterlist(struct crypt_config
*cc
, struct scatterlist
*out
,
296 struct scatterlist
*in
, unsigned int length
,
297 int write
, sector_t sector
)
299 u8 iv
[cc
->iv_size
] __attribute__ ((aligned(__alignof__(u64
))));
300 struct blkcipher_desc desc
= {
303 .flags
= CRYPTO_TFM_REQ_MAY_SLEEP
,
307 if (cc
->iv_gen_ops
) {
308 r
= cc
->iv_gen_ops
->generator(cc
, iv
, sector
);
313 r
= crypto_blkcipher_encrypt_iv(&desc
, out
, in
, length
);
315 r
= crypto_blkcipher_decrypt_iv(&desc
, out
, in
, length
);
318 r
= crypto_blkcipher_encrypt(&desc
, out
, in
, length
);
320 r
= crypto_blkcipher_decrypt(&desc
, out
, in
, length
);
326 static void crypt_convert_init(struct crypt_config
*cc
,
327 struct convert_context
*ctx
,
328 struct bio
*bio_out
, struct bio
*bio_in
,
331 ctx
->bio_in
= bio_in
;
332 ctx
->bio_out
= bio_out
;
335 ctx
->idx_in
= bio_in
? bio_in
->bi_idx
: 0;
336 ctx
->idx_out
= bio_out
? bio_out
->bi_idx
: 0;
337 ctx
->sector
= sector
+ cc
->iv_offset
;
341 * Encrypt / decrypt data from one bio to another one (can be the same one)
343 static int crypt_convert(struct crypt_config
*cc
,
344 struct convert_context
*ctx
)
348 while(ctx
->idx_in
< ctx
->bio_in
->bi_vcnt
&&
349 ctx
->idx_out
< ctx
->bio_out
->bi_vcnt
) {
350 struct bio_vec
*bv_in
= bio_iovec_idx(ctx
->bio_in
, ctx
->idx_in
);
351 struct bio_vec
*bv_out
= bio_iovec_idx(ctx
->bio_out
, ctx
->idx_out
);
352 struct scatterlist sg_in
, sg_out
;
354 sg_init_table(&sg_in
, 1);
355 sg_set_page(&sg_in
, bv_in
->bv_page
, 1 << SECTOR_SHIFT
, bv_in
->bv_offset
+ ctx
->offset_in
);
357 sg_init_table(&sg_out
, 1);
358 sg_set_page(&sg_out
, bv_out
->bv_page
, 1 << SECTOR_SHIFT
, bv_out
->bv_offset
+ ctx
->offset_out
);
360 ctx
->offset_in
+= sg_in
.length
;
361 if (ctx
->offset_in
>= bv_in
->bv_len
) {
366 ctx
->offset_out
+= sg_out
.length
;
367 if (ctx
->offset_out
>= bv_out
->bv_len
) {
372 r
= crypt_convert_scatterlist(cc
, &sg_out
, &sg_in
, sg_in
.length
,
373 bio_data_dir(ctx
->bio_in
) == WRITE
, ctx
->sector
);
383 static void dm_crypt_bio_destructor(struct bio
*bio
)
385 struct dm_crypt_io
*io
= bio
->bi_private
;
386 struct crypt_config
*cc
= io
->target
->private;
388 bio_free(bio
, cc
->bs
);
392 * Generate a new unfragmented bio with the given size
393 * This should never violate the device limitations
394 * May return a smaller bio when running out of pages
396 static struct bio
*crypt_alloc_buffer(struct dm_crypt_io
*io
, unsigned size
)
398 struct crypt_config
*cc
= io
->target
->private;
400 unsigned int nr_iovecs
= (size
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
401 gfp_t gfp_mask
= GFP_NOIO
| __GFP_HIGHMEM
;
405 clone
= bio_alloc_bioset(GFP_NOIO
, nr_iovecs
, cc
->bs
);
409 clone_init(io
, clone
);
411 for (i
= 0; i
< nr_iovecs
; i
++) {
412 page
= mempool_alloc(cc
->page_pool
, gfp_mask
);
417 * if additional pages cannot be allocated without waiting,
418 * return a partially allocated bio, the caller will then try
419 * to allocate additional bios while submitting this partial bio
421 if (i
== (MIN_BIO_PAGES
- 1))
422 gfp_mask
= (gfp_mask
| __GFP_NOWARN
) & ~__GFP_WAIT
;
424 len
= (size
> PAGE_SIZE
) ? PAGE_SIZE
: size
;
426 if (!bio_add_page(clone
, page
, len
, 0)) {
427 mempool_free(page
, cc
->page_pool
);
434 if (!clone
->bi_size
) {
442 static void crypt_free_buffer_pages(struct crypt_config
*cc
, struct bio
*clone
)
447 for (i
= 0; i
< clone
->bi_vcnt
; i
++) {
448 bv
= bio_iovec_idx(clone
, i
);
449 BUG_ON(!bv
->bv_page
);
450 mempool_free(bv
->bv_page
, cc
->page_pool
);
456 * One of the bios was finished. Check for completion of
457 * the whole request and correctly clean up the buffer.
459 static void crypt_dec_pending(struct dm_crypt_io
*io
)
461 struct crypt_config
*cc
= io
->target
->private;
463 if (!atomic_dec_and_test(&io
->pending
))
466 bio_endio(io
->base_bio
, io
->error
);
467 mempool_free(io
, cc
->io_pool
);
471 * kcryptd/kcryptd_io:
473 * Needed because it would be very unwise to do decryption in an
476 * kcryptd performs the actual encryption or decryption.
478 * kcryptd_io performs the IO submission.
480 * They must be separated as otherwise the final stages could be
481 * starved by new requests which can block in the first stages due
482 * to memory allocation.
484 static void kcryptd_do_work(struct work_struct
*work
);
485 static void kcryptd_do_crypt(struct work_struct
*work
);
487 static void kcryptd_queue_io(struct dm_crypt_io
*io
)
489 struct crypt_config
*cc
= io
->target
->private;
491 INIT_WORK(&io
->work
, kcryptd_do_work
);
492 queue_work(cc
->io_queue
, &io
->work
);
495 static void kcryptd_queue_crypt(struct dm_crypt_io
*io
)
497 struct crypt_config
*cc
= io
->target
->private;
499 INIT_WORK(&io
->work
, kcryptd_do_crypt
);
500 queue_work(cc
->crypt_queue
, &io
->work
);
503 static void crypt_endio(struct bio
*clone
, int error
)
505 struct dm_crypt_io
*io
= clone
->bi_private
;
506 struct crypt_config
*cc
= io
->target
->private;
507 unsigned rw
= bio_data_dir(clone
);
509 if (unlikely(!bio_flagged(clone
, BIO_UPTODATE
) && !error
))
513 * free the processed pages
516 crypt_free_buffer_pages(cc
, clone
);
520 if (rw
== READ
&& !error
) {
521 kcryptd_queue_crypt(io
);
528 crypt_dec_pending(io
);
531 static void clone_init(struct dm_crypt_io
*io
, struct bio
*clone
)
533 struct crypt_config
*cc
= io
->target
->private;
535 clone
->bi_private
= io
;
536 clone
->bi_end_io
= crypt_endio
;
537 clone
->bi_bdev
= cc
->dev
->bdev
;
538 clone
->bi_rw
= io
->base_bio
->bi_rw
;
539 clone
->bi_destructor
= dm_crypt_bio_destructor
;
542 static void process_read(struct dm_crypt_io
*io
)
544 struct crypt_config
*cc
= io
->target
->private;
545 struct bio
*base_bio
= io
->base_bio
;
547 sector_t sector
= base_bio
->bi_sector
- io
->target
->begin
;
549 atomic_inc(&io
->pending
);
552 * The block layer might modify the bvec array, so always
553 * copy the required bvecs because we need the original
554 * one in order to decrypt the whole bio data *afterwards*.
556 clone
= bio_alloc_bioset(GFP_NOIO
, bio_segments(base_bio
), cc
->bs
);
557 if (unlikely(!clone
)) {
559 crypt_dec_pending(io
);
563 clone_init(io
, clone
);
565 clone
->bi_vcnt
= bio_segments(base_bio
);
566 clone
->bi_size
= base_bio
->bi_size
;
567 clone
->bi_sector
= cc
->start
+ sector
;
568 memcpy(clone
->bi_io_vec
, bio_iovec(base_bio
),
569 sizeof(struct bio_vec
) * clone
->bi_vcnt
);
571 generic_make_request(clone
);
574 static void process_write(struct dm_crypt_io
*io
)
576 struct crypt_config
*cc
= io
->target
->private;
577 struct bio
*base_bio
= io
->base_bio
;
579 unsigned remaining
= base_bio
->bi_size
;
580 sector_t sector
= base_bio
->bi_sector
- io
->target
->begin
;
582 atomic_inc(&io
->pending
);
584 crypt_convert_init(cc
, &io
->ctx
, NULL
, base_bio
, sector
);
587 * The allocated buffers can be smaller than the whole bio,
588 * so repeat the whole process until all the data can be handled.
591 clone
= crypt_alloc_buffer(io
, remaining
);
592 if (unlikely(!clone
)) {
594 crypt_dec_pending(io
);
598 io
->ctx
.bio_out
= clone
;
601 if (unlikely(crypt_convert(cc
, &io
->ctx
) < 0)) {
602 crypt_free_buffer_pages(cc
, clone
);
605 crypt_dec_pending(io
);
609 /* crypt_convert should have filled the clone bio */
610 BUG_ON(io
->ctx
.idx_out
< clone
->bi_vcnt
);
612 clone
->bi_sector
= cc
->start
+ sector
;
613 remaining
-= clone
->bi_size
;
614 sector
+= bio_sectors(clone
);
616 /* Grab another reference to the io struct
617 * before we kick off the request */
619 atomic_inc(&io
->pending
);
621 generic_make_request(clone
);
623 /* Do not reference clone after this - it
624 * may be gone already. */
626 /* out of memory -> run queues */
628 congestion_wait(WRITE
, HZ
/100);
632 static void crypt_read_done(struct dm_crypt_io
*io
, int error
)
634 if (unlikely(error
< 0))
637 crypt_dec_pending(io
);
640 static void process_read_endio(struct dm_crypt_io
*io
)
642 struct crypt_config
*cc
= io
->target
->private;
645 crypt_convert_init(cc
, &io
->ctx
, io
->base_bio
, io
->base_bio
,
646 io
->base_bio
->bi_sector
- io
->target
->begin
);
648 r
= crypt_convert(cc
, &io
->ctx
);
650 crypt_read_done(io
, r
);
653 static void kcryptd_do_work(struct work_struct
*work
)
655 struct dm_crypt_io
*io
= container_of(work
, struct dm_crypt_io
, work
);
657 if (bio_data_dir(io
->base_bio
) == READ
)
661 static void kcryptd_do_crypt(struct work_struct
*work
)
663 struct dm_crypt_io
*io
= container_of(work
, struct dm_crypt_io
, work
);
665 if (bio_data_dir(io
->base_bio
) == READ
)
666 process_read_endio(io
);
672 * Decode key from its hex representation
674 static int crypt_decode_key(u8
*key
, char *hex
, unsigned int size
)
682 for (i
= 0; i
< size
; i
++) {
686 key
[i
] = (u8
)simple_strtoul(buffer
, &endp
, 16);
688 if (endp
!= &buffer
[2])
699 * Encode key into its hex representation
701 static void crypt_encode_key(char *hex
, u8
*key
, unsigned int size
)
705 for (i
= 0; i
< size
; i
++) {
706 sprintf(hex
, "%02x", *key
);
712 static int crypt_set_key(struct crypt_config
*cc
, char *key
)
714 unsigned key_size
= strlen(key
) >> 1;
716 if (cc
->key_size
&& cc
->key_size
!= key_size
)
719 cc
->key_size
= key_size
; /* initial settings */
721 if ((!key_size
&& strcmp(key
, "-")) ||
722 (key_size
&& crypt_decode_key(cc
->key
, key
, key_size
) < 0))
725 set_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
);
730 static int crypt_wipe_key(struct crypt_config
*cc
)
732 clear_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
);
733 memset(&cc
->key
, 0, cc
->key_size
* sizeof(u8
));
738 * Construct an encryption mapping:
739 * <cipher> <key> <iv_offset> <dev_path> <start>
741 static int crypt_ctr(struct dm_target
*ti
, unsigned int argc
, char **argv
)
743 struct crypt_config
*cc
;
744 struct crypto_blkcipher
*tfm
;
750 unsigned int key_size
;
751 unsigned long long tmpll
;
754 ti
->error
= "Not enough arguments";
759 cipher
= strsep(&tmp
, "-");
760 chainmode
= strsep(&tmp
, "-");
761 ivopts
= strsep(&tmp
, "-");
762 ivmode
= strsep(&ivopts
, ":");
765 DMWARN("Unexpected additional cipher options");
767 key_size
= strlen(argv
[1]) >> 1;
769 cc
= kzalloc(sizeof(*cc
) + key_size
* sizeof(u8
), GFP_KERNEL
);
772 "Cannot allocate transparent encryption context";
776 if (crypt_set_key(cc
, argv
[1])) {
777 ti
->error
= "Error decoding key";
781 /* Compatiblity mode for old dm-crypt cipher strings */
782 if (!chainmode
|| (strcmp(chainmode
, "plain") == 0 && !ivmode
)) {
787 if (strcmp(chainmode
, "ecb") && !ivmode
) {
788 ti
->error
= "This chaining mode requires an IV mechanism";
792 if (snprintf(cc
->cipher
, CRYPTO_MAX_ALG_NAME
, "%s(%s)",
793 chainmode
, cipher
) >= CRYPTO_MAX_ALG_NAME
) {
794 ti
->error
= "Chain mode + cipher name is too long";
798 tfm
= crypto_alloc_blkcipher(cc
->cipher
, 0, CRYPTO_ALG_ASYNC
);
800 ti
->error
= "Error allocating crypto tfm";
804 strcpy(cc
->cipher
, cipher
);
805 strcpy(cc
->chainmode
, chainmode
);
809 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
810 * See comments at iv code
814 cc
->iv_gen_ops
= NULL
;
815 else if (strcmp(ivmode
, "plain") == 0)
816 cc
->iv_gen_ops
= &crypt_iv_plain_ops
;
817 else if (strcmp(ivmode
, "essiv") == 0)
818 cc
->iv_gen_ops
= &crypt_iv_essiv_ops
;
819 else if (strcmp(ivmode
, "benbi") == 0)
820 cc
->iv_gen_ops
= &crypt_iv_benbi_ops
;
821 else if (strcmp(ivmode
, "null") == 0)
822 cc
->iv_gen_ops
= &crypt_iv_null_ops
;
824 ti
->error
= "Invalid IV mode";
828 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->ctr
&&
829 cc
->iv_gen_ops
->ctr(cc
, ti
, ivopts
) < 0)
832 cc
->iv_size
= crypto_blkcipher_ivsize(tfm
);
834 /* at least a 64 bit sector number should fit in our buffer */
835 cc
->iv_size
= max(cc
->iv_size
,
836 (unsigned int)(sizeof(u64
) / sizeof(u8
)));
838 if (cc
->iv_gen_ops
) {
839 DMWARN("Selected cipher does not support IVs");
840 if (cc
->iv_gen_ops
->dtr
)
841 cc
->iv_gen_ops
->dtr(cc
);
842 cc
->iv_gen_ops
= NULL
;
846 cc
->io_pool
= mempool_create_slab_pool(MIN_IOS
, _crypt_io_pool
);
848 ti
->error
= "Cannot allocate crypt io mempool";
852 cc
->page_pool
= mempool_create_page_pool(MIN_POOL_PAGES
, 0);
853 if (!cc
->page_pool
) {
854 ti
->error
= "Cannot allocate page mempool";
858 cc
->bs
= bioset_create(MIN_IOS
, MIN_IOS
);
860 ti
->error
= "Cannot allocate crypt bioset";
864 if (crypto_blkcipher_setkey(tfm
, cc
->key
, key_size
) < 0) {
865 ti
->error
= "Error setting key";
869 if (sscanf(argv
[2], "%llu", &tmpll
) != 1) {
870 ti
->error
= "Invalid iv_offset sector";
873 cc
->iv_offset
= tmpll
;
875 if (sscanf(argv
[4], "%llu", &tmpll
) != 1) {
876 ti
->error
= "Invalid device sector";
881 if (dm_get_device(ti
, argv
[3], cc
->start
, ti
->len
,
882 dm_table_get_mode(ti
->table
), &cc
->dev
)) {
883 ti
->error
= "Device lookup failed";
887 if (ivmode
&& cc
->iv_gen_ops
) {
890 cc
->iv_mode
= kmalloc(strlen(ivmode
) + 1, GFP_KERNEL
);
892 ti
->error
= "Error kmallocing iv_mode string";
893 goto bad_ivmode_string
;
895 strcpy(cc
->iv_mode
, ivmode
);
899 cc
->io_queue
= create_singlethread_workqueue("kcryptd_io");
901 ti
->error
= "Couldn't create kcryptd io queue";
905 cc
->crypt_queue
= create_singlethread_workqueue("kcryptd");
906 if (!cc
->crypt_queue
) {
907 ti
->error
= "Couldn't create kcryptd queue";
908 goto bad_crypt_queue
;
915 destroy_workqueue(cc
->io_queue
);
919 dm_put_device(ti
, cc
->dev
);
923 mempool_destroy(cc
->page_pool
);
925 mempool_destroy(cc
->io_pool
);
927 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->dtr
)
928 cc
->iv_gen_ops
->dtr(cc
);
930 crypto_free_blkcipher(tfm
);
932 /* Must zero key material before freeing */
933 memset(cc
, 0, sizeof(*cc
) + cc
->key_size
* sizeof(u8
));
938 static void crypt_dtr(struct dm_target
*ti
)
940 struct crypt_config
*cc
= (struct crypt_config
*) ti
->private;
942 destroy_workqueue(cc
->io_queue
);
943 destroy_workqueue(cc
->crypt_queue
);
946 mempool_destroy(cc
->page_pool
);
947 mempool_destroy(cc
->io_pool
);
950 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->dtr
)
951 cc
->iv_gen_ops
->dtr(cc
);
952 crypto_free_blkcipher(cc
->tfm
);
953 dm_put_device(ti
, cc
->dev
);
955 /* Must zero key material before freeing */
956 memset(cc
, 0, sizeof(*cc
) + cc
->key_size
* sizeof(u8
));
960 static int crypt_map(struct dm_target
*ti
, struct bio
*bio
,
961 union map_info
*map_context
)
963 struct crypt_config
*cc
= ti
->private;
964 struct dm_crypt_io
*io
;
966 io
= mempool_alloc(cc
->io_pool
, GFP_NOIO
);
970 atomic_set(&io
->pending
, 0);
972 if (bio_data_dir(io
->base_bio
) == READ
)
973 kcryptd_queue_io(io
);
975 kcryptd_queue_crypt(io
);
977 return DM_MAPIO_SUBMITTED
;
980 static int crypt_status(struct dm_target
*ti
, status_type_t type
,
981 char *result
, unsigned int maxlen
)
983 struct crypt_config
*cc
= (struct crypt_config
*) ti
->private;
987 case STATUSTYPE_INFO
:
991 case STATUSTYPE_TABLE
:
993 DMEMIT("%s-%s-%s ", cc
->cipher
, cc
->chainmode
,
996 DMEMIT("%s-%s ", cc
->cipher
, cc
->chainmode
);
998 if (cc
->key_size
> 0) {
999 if ((maxlen
- sz
) < ((cc
->key_size
<< 1) + 1))
1002 crypt_encode_key(result
+ sz
, cc
->key
, cc
->key_size
);
1003 sz
+= cc
->key_size
<< 1;
1010 DMEMIT(" %llu %s %llu", (unsigned long long)cc
->iv_offset
,
1011 cc
->dev
->name
, (unsigned long long)cc
->start
);
1017 static void crypt_postsuspend(struct dm_target
*ti
)
1019 struct crypt_config
*cc
= ti
->private;
1021 set_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
);
1024 static int crypt_preresume(struct dm_target
*ti
)
1026 struct crypt_config
*cc
= ti
->private;
1028 if (!test_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
)) {
1029 DMERR("aborting resume - crypt key is not set.");
1036 static void crypt_resume(struct dm_target
*ti
)
1038 struct crypt_config
*cc
= ti
->private;
1040 clear_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
);
1043 /* Message interface
1047 static int crypt_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
1049 struct crypt_config
*cc
= ti
->private;
1054 if (!strnicmp(argv
[0], MESG_STR("key"))) {
1055 if (!test_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
)) {
1056 DMWARN("not suspended during key manipulation.");
1059 if (argc
== 3 && !strnicmp(argv
[1], MESG_STR("set")))
1060 return crypt_set_key(cc
, argv
[2]);
1061 if (argc
== 2 && !strnicmp(argv
[1], MESG_STR("wipe")))
1062 return crypt_wipe_key(cc
);
1066 DMWARN("unrecognised message received.");
1070 static struct target_type crypt_target
= {
1072 .version
= {1, 5, 0},
1073 .module
= THIS_MODULE
,
1077 .status
= crypt_status
,
1078 .postsuspend
= crypt_postsuspend
,
1079 .preresume
= crypt_preresume
,
1080 .resume
= crypt_resume
,
1081 .message
= crypt_message
,
1084 static int __init
dm_crypt_init(void)
1088 _crypt_io_pool
= KMEM_CACHE(dm_crypt_io
, 0);
1089 if (!_crypt_io_pool
)
1092 r
= dm_register_target(&crypt_target
);
1094 DMERR("register failed %d", r
);
1095 kmem_cache_destroy(_crypt_io_pool
);
1101 static void __exit
dm_crypt_exit(void)
1103 int r
= dm_unregister_target(&crypt_target
);
1106 DMERR("unregister failed %d", r
);
1108 kmem_cache_destroy(_crypt_io_pool
);
1111 module_init(dm_crypt_init
);
1112 module_exit(dm_crypt_exit
);
1114 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1115 MODULE_DESCRIPTION(DM_NAME
" target for transparent encryption / decryption");
1116 MODULE_LICENSE("GPL");