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 * per bio private data
34 struct dm_target
*target
;
36 struct work_struct work
;
42 * context holding the current state of a multi-part conversion
44 struct convert_context
{
47 unsigned int offset_in
;
48 unsigned int offset_out
;
57 struct crypt_iv_operations
{
58 int (*ctr
)(struct crypt_config
*cc
, struct dm_target
*ti
,
60 void (*dtr
)(struct crypt_config
*cc
);
61 const char *(*status
)(struct crypt_config
*cc
);
62 int (*generator
)(struct crypt_config
*cc
, u8
*iv
, sector_t sector
);
66 * Crypt: maps a linear range of a block device
67 * and encrypts / decrypts at the same time.
69 enum flags
{ DM_CRYPT_SUSPENDED
, DM_CRYPT_KEY_VALID
};
75 * pool for per bio private data and
76 * for encryption buffer pages
82 struct workqueue_struct
*io_queue
;
83 struct workqueue_struct
*crypt_queue
;
87 struct crypt_iv_operations
*iv_gen_ops
;
90 struct crypto_cipher
*essiv_tfm
;
96 char cipher
[CRYPTO_MAX_ALG_NAME
];
97 char chainmode
[CRYPTO_MAX_ALG_NAME
];
98 struct crypto_blkcipher
*tfm
;
100 unsigned int key_size
;
105 #define MIN_POOL_PAGES 32
106 #define MIN_BIO_PAGES 8
108 static struct kmem_cache
*_crypt_io_pool
;
110 static void clone_init(struct dm_crypt_io
*, struct bio
*);
113 * Different IV generation algorithms:
115 * plain: the initial vector is the 32-bit little-endian version of the sector
116 * number, padded with zeros if necessary.
118 * essiv: "encrypted sector|salt initial vector", the sector number is
119 * encrypted with the bulk cipher using a salt as key. The salt
120 * should be derived from the bulk cipher's key via hashing.
122 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
123 * (needed for LRW-32-AES and possible other narrow block modes)
125 * null: the initial vector is always zero. Provides compatibility with
126 * obsolete loop_fish2 devices. Do not use for new devices.
128 * plumb: unimplemented, see:
129 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
132 static int crypt_iv_plain_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
134 memset(iv
, 0, cc
->iv_size
);
135 *(u32
*)iv
= cpu_to_le32(sector
& 0xffffffff);
140 static int crypt_iv_essiv_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
143 struct crypto_cipher
*essiv_tfm
;
144 struct crypto_hash
*hash_tfm
;
145 struct hash_desc desc
;
146 struct scatterlist sg
;
147 unsigned int saltsize
;
152 ti
->error
= "Digest algorithm missing for ESSIV mode";
156 /* Hash the cipher key with the given hash algorithm */
157 hash_tfm
= crypto_alloc_hash(opts
, 0, CRYPTO_ALG_ASYNC
);
158 if (IS_ERR(hash_tfm
)) {
159 ti
->error
= "Error initializing ESSIV hash";
160 return PTR_ERR(hash_tfm
);
163 saltsize
= crypto_hash_digestsize(hash_tfm
);
164 salt
= kmalloc(saltsize
, GFP_KERNEL
);
166 ti
->error
= "Error kmallocing salt storage in ESSIV";
167 crypto_free_hash(hash_tfm
);
171 sg_set_buf(&sg
, cc
->key
, cc
->key_size
);
173 desc
.flags
= CRYPTO_TFM_REQ_MAY_SLEEP
;
174 err
= crypto_hash_digest(&desc
, &sg
, cc
->key_size
, salt
);
175 crypto_free_hash(hash_tfm
);
178 ti
->error
= "Error calculating hash in ESSIV";
183 /* Setup the essiv_tfm with the given salt */
184 essiv_tfm
= crypto_alloc_cipher(cc
->cipher
, 0, CRYPTO_ALG_ASYNC
);
185 if (IS_ERR(essiv_tfm
)) {
186 ti
->error
= "Error allocating crypto tfm for ESSIV";
188 return PTR_ERR(essiv_tfm
);
190 if (crypto_cipher_blocksize(essiv_tfm
) !=
191 crypto_blkcipher_ivsize(cc
->tfm
)) {
192 ti
->error
= "Block size of ESSIV cipher does "
193 "not match IV size of block cipher";
194 crypto_free_cipher(essiv_tfm
);
198 err
= crypto_cipher_setkey(essiv_tfm
, salt
, saltsize
);
200 ti
->error
= "Failed to set key for ESSIV cipher";
201 crypto_free_cipher(essiv_tfm
);
207 cc
->iv_gen_private
.essiv_tfm
= essiv_tfm
;
211 static void crypt_iv_essiv_dtr(struct crypt_config
*cc
)
213 crypto_free_cipher(cc
->iv_gen_private
.essiv_tfm
);
214 cc
->iv_gen_private
.essiv_tfm
= NULL
;
217 static int crypt_iv_essiv_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
219 memset(iv
, 0, cc
->iv_size
);
220 *(u64
*)iv
= cpu_to_le64(sector
);
221 crypto_cipher_encrypt_one(cc
->iv_gen_private
.essiv_tfm
, iv
, iv
);
225 static int crypt_iv_benbi_ctr(struct crypt_config
*cc
, struct dm_target
*ti
,
228 unsigned int bs
= crypto_blkcipher_blocksize(cc
->tfm
);
231 /* we need to calculate how far we must shift the sector count
232 * to get the cipher block count, we use this shift in _gen */
234 if (1 << log
!= bs
) {
235 ti
->error
= "cypher blocksize is not a power of 2";
240 ti
->error
= "cypher blocksize is > 512";
244 cc
->iv_gen_private
.benbi_shift
= 9 - log
;
249 static void crypt_iv_benbi_dtr(struct crypt_config
*cc
)
253 static int crypt_iv_benbi_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
257 memset(iv
, 0, cc
->iv_size
- sizeof(u64
)); /* rest is cleared below */
259 val
= cpu_to_be64(((u64
)sector
<< cc
->iv_gen_private
.benbi_shift
) + 1);
260 put_unaligned(val
, (__be64
*)(iv
+ cc
->iv_size
- sizeof(u64
)));
265 static int crypt_iv_null_gen(struct crypt_config
*cc
, u8
*iv
, sector_t sector
)
267 memset(iv
, 0, cc
->iv_size
);
272 static struct crypt_iv_operations crypt_iv_plain_ops
= {
273 .generator
= crypt_iv_plain_gen
276 static struct crypt_iv_operations crypt_iv_essiv_ops
= {
277 .ctr
= crypt_iv_essiv_ctr
,
278 .dtr
= crypt_iv_essiv_dtr
,
279 .generator
= crypt_iv_essiv_gen
282 static struct crypt_iv_operations crypt_iv_benbi_ops
= {
283 .ctr
= crypt_iv_benbi_ctr
,
284 .dtr
= crypt_iv_benbi_dtr
,
285 .generator
= crypt_iv_benbi_gen
288 static struct crypt_iv_operations crypt_iv_null_ops
= {
289 .generator
= crypt_iv_null_gen
293 crypt_convert_scatterlist(struct crypt_config
*cc
, struct scatterlist
*out
,
294 struct scatterlist
*in
, unsigned int length
,
295 int write
, sector_t sector
)
297 u8 iv
[cc
->iv_size
] __attribute__ ((aligned(__alignof__(u64
))));
298 struct blkcipher_desc desc
= {
301 .flags
= CRYPTO_TFM_REQ_MAY_SLEEP
,
305 if (cc
->iv_gen_ops
) {
306 r
= cc
->iv_gen_ops
->generator(cc
, iv
, sector
);
311 r
= crypto_blkcipher_encrypt_iv(&desc
, out
, in
, length
);
313 r
= crypto_blkcipher_decrypt_iv(&desc
, out
, in
, length
);
316 r
= crypto_blkcipher_encrypt(&desc
, out
, in
, length
);
318 r
= crypto_blkcipher_decrypt(&desc
, out
, in
, length
);
324 static void crypt_convert_init(struct crypt_config
*cc
,
325 struct convert_context
*ctx
,
326 struct bio
*bio_out
, struct bio
*bio_in
,
327 sector_t sector
, int write
)
329 ctx
->bio_in
= bio_in
;
330 ctx
->bio_out
= bio_out
;
333 ctx
->idx_in
= bio_in
? bio_in
->bi_idx
: 0;
334 ctx
->idx_out
= bio_out
? bio_out
->bi_idx
: 0;
335 ctx
->sector
= sector
+ cc
->iv_offset
;
340 * Encrypt / decrypt data from one bio to another one (can be the same one)
342 static int crypt_convert(struct crypt_config
*cc
,
343 struct convert_context
*ctx
)
347 while(ctx
->idx_in
< ctx
->bio_in
->bi_vcnt
&&
348 ctx
->idx_out
< ctx
->bio_out
->bi_vcnt
) {
349 struct bio_vec
*bv_in
= bio_iovec_idx(ctx
->bio_in
, ctx
->idx_in
);
350 struct bio_vec
*bv_out
= bio_iovec_idx(ctx
->bio_out
, ctx
->idx_out
);
351 struct scatterlist sg_in
, sg_out
;
353 sg_init_table(&sg_in
, 1);
354 sg_set_page(&sg_in
, bv_in
->bv_page
);
355 sg_in
.offset
= bv_in
->bv_offset
+ ctx
->offset_in
;
356 sg_in
.length
= 1 << SECTOR_SHIFT
;
358 sg_init_table(&sg_out
, 1);
359 sg_set_page(&sg_out
, bv_out
->bv_page
);
360 sg_out
.offset
= bv_out
->bv_offset
+ ctx
->offset_out
;
361 sg_out
.length
= 1 << SECTOR_SHIFT
;
363 ctx
->offset_in
+= sg_in
.length
;
364 if (ctx
->offset_in
>= bv_in
->bv_len
) {
369 ctx
->offset_out
+= sg_out
.length
;
370 if (ctx
->offset_out
>= bv_out
->bv_len
) {
375 r
= crypt_convert_scatterlist(cc
, &sg_out
, &sg_in
, sg_in
.length
,
376 ctx
->write
, ctx
->sector
);
386 static void dm_crypt_bio_destructor(struct bio
*bio
)
388 struct dm_crypt_io
*io
= bio
->bi_private
;
389 struct crypt_config
*cc
= io
->target
->private;
391 bio_free(bio
, cc
->bs
);
395 * Generate a new unfragmented bio with the given size
396 * This should never violate the device limitations
397 * May return a smaller bio when running out of pages
399 static struct bio
*crypt_alloc_buffer(struct dm_crypt_io
*io
, unsigned size
)
401 struct crypt_config
*cc
= io
->target
->private;
403 unsigned int nr_iovecs
= (size
+ PAGE_SIZE
- 1) >> PAGE_SHIFT
;
404 gfp_t gfp_mask
= GFP_NOIO
| __GFP_HIGHMEM
;
407 clone
= bio_alloc_bioset(GFP_NOIO
, nr_iovecs
, cc
->bs
);
411 clone_init(io
, clone
);
413 for (i
= 0; i
< nr_iovecs
; i
++) {
414 struct bio_vec
*bv
= bio_iovec_idx(clone
, i
);
416 bv
->bv_page
= mempool_alloc(cc
->page_pool
, gfp_mask
);
421 * if additional pages cannot be allocated without waiting,
422 * return a partially allocated bio, the caller will then try
423 * to allocate additional bios while submitting this partial bio
425 if (i
== (MIN_BIO_PAGES
- 1))
426 gfp_mask
= (gfp_mask
| __GFP_NOWARN
) & ~__GFP_WAIT
;
429 if (size
> PAGE_SIZE
)
430 bv
->bv_len
= PAGE_SIZE
;
434 clone
->bi_size
+= bv
->bv_len
;
439 if (!clone
->bi_size
) {
447 static void crypt_free_buffer_pages(struct crypt_config
*cc
, struct bio
*clone
)
452 for (i
= 0; i
< clone
->bi_vcnt
; i
++) {
453 bv
= bio_iovec_idx(clone
, i
);
454 BUG_ON(!bv
->bv_page
);
455 mempool_free(bv
->bv_page
, cc
->page_pool
);
461 * One of the bios was finished. Check for completion of
462 * the whole request and correctly clean up the buffer.
464 static void crypt_dec_pending(struct dm_crypt_io
*io
, int error
)
466 struct crypt_config
*cc
= (struct crypt_config
*) io
->target
->private;
471 if (!atomic_dec_and_test(&io
->pending
))
474 bio_endio(io
->base_bio
, io
->error
);
476 mempool_free(io
, cc
->io_pool
);
480 * kcryptd/kcryptd_io:
482 * Needed because it would be very unwise to do decryption in an
485 * kcryptd performs the actual encryption or decryption.
487 * kcryptd_io performs the IO submission.
489 * They must be separated as otherwise the final stages could be
490 * starved by new requests which can block in the first stages due
491 * to memory allocation.
493 static void kcryptd_do_work(struct work_struct
*work
);
494 static void kcryptd_do_crypt(struct work_struct
*work
);
496 static void kcryptd_queue_io(struct dm_crypt_io
*io
)
498 struct crypt_config
*cc
= io
->target
->private;
500 INIT_WORK(&io
->work
, kcryptd_do_work
);
501 queue_work(cc
->io_queue
, &io
->work
);
504 static void kcryptd_queue_crypt(struct dm_crypt_io
*io
)
506 struct crypt_config
*cc
= io
->target
->private;
508 INIT_WORK(&io
->work
, kcryptd_do_crypt
);
509 queue_work(cc
->crypt_queue
, &io
->work
);
512 static void crypt_endio(struct bio
*clone
, int error
)
514 struct dm_crypt_io
*io
= clone
->bi_private
;
515 struct crypt_config
*cc
= io
->target
->private;
516 unsigned read_io
= bio_data_dir(clone
) == READ
;
519 * free the processed pages
522 crypt_free_buffer_pages(cc
, clone
);
526 if (unlikely(!bio_flagged(clone
, BIO_UPTODATE
))) {
532 kcryptd_queue_crypt(io
);
537 crypt_dec_pending(io
, error
);
540 static void clone_init(struct dm_crypt_io
*io
, struct bio
*clone
)
542 struct crypt_config
*cc
= io
->target
->private;
544 clone
->bi_private
= io
;
545 clone
->bi_end_io
= crypt_endio
;
546 clone
->bi_bdev
= cc
->dev
->bdev
;
547 clone
->bi_rw
= io
->base_bio
->bi_rw
;
548 clone
->bi_destructor
= dm_crypt_bio_destructor
;
551 static void process_read(struct dm_crypt_io
*io
)
553 struct crypt_config
*cc
= io
->target
->private;
554 struct bio
*base_bio
= io
->base_bio
;
556 sector_t sector
= base_bio
->bi_sector
- io
->target
->begin
;
558 atomic_inc(&io
->pending
);
561 * The block layer might modify the bvec array, so always
562 * copy the required bvecs because we need the original
563 * one in order to decrypt the whole bio data *afterwards*.
565 clone
= bio_alloc_bioset(GFP_NOIO
, bio_segments(base_bio
), cc
->bs
);
566 if (unlikely(!clone
)) {
567 crypt_dec_pending(io
, -ENOMEM
);
571 clone_init(io
, clone
);
573 clone
->bi_vcnt
= bio_segments(base_bio
);
574 clone
->bi_size
= base_bio
->bi_size
;
575 clone
->bi_sector
= cc
->start
+ sector
;
576 memcpy(clone
->bi_io_vec
, bio_iovec(base_bio
),
577 sizeof(struct bio_vec
) * clone
->bi_vcnt
);
579 generic_make_request(clone
);
582 static void process_write(struct dm_crypt_io
*io
)
584 struct crypt_config
*cc
= io
->target
->private;
585 struct bio
*base_bio
= io
->base_bio
;
587 struct convert_context ctx
;
588 unsigned remaining
= base_bio
->bi_size
;
589 sector_t sector
= base_bio
->bi_sector
- io
->target
->begin
;
591 atomic_inc(&io
->pending
);
593 crypt_convert_init(cc
, &ctx
, NULL
, base_bio
, sector
, 1);
596 * The allocated buffers can be smaller than the whole bio,
597 * so repeat the whole process until all the data can be handled.
600 clone
= crypt_alloc_buffer(io
, remaining
);
601 if (unlikely(!clone
)) {
602 crypt_dec_pending(io
, -ENOMEM
);
609 if (unlikely(crypt_convert(cc
, &ctx
) < 0)) {
610 crypt_free_buffer_pages(cc
, clone
);
612 crypt_dec_pending(io
, -EIO
);
616 /* crypt_convert should have filled the clone bio */
617 BUG_ON(ctx
.idx_out
< clone
->bi_vcnt
);
619 clone
->bi_sector
= cc
->start
+ sector
;
620 remaining
-= clone
->bi_size
;
621 sector
+= bio_sectors(clone
);
623 /* Grab another reference to the io struct
624 * before we kick off the request */
626 atomic_inc(&io
->pending
);
628 generic_make_request(clone
);
630 /* Do not reference clone after this - it
631 * may be gone already. */
633 /* out of memory -> run queues */
635 congestion_wait(WRITE
, HZ
/100);
639 static void process_read_endio(struct dm_crypt_io
*io
)
641 struct crypt_config
*cc
= io
->target
->private;
642 struct convert_context ctx
;
644 crypt_convert_init(cc
, &ctx
, io
->base_bio
, io
->base_bio
,
645 io
->base_bio
->bi_sector
- io
->target
->begin
, 0);
647 crypt_dec_pending(io
, crypt_convert(cc
, &ctx
));
650 static void kcryptd_do_work(struct work_struct
*work
)
652 struct dm_crypt_io
*io
= container_of(work
, struct dm_crypt_io
, work
);
654 if (bio_data_dir(io
->base_bio
) == READ
)
658 static void kcryptd_do_crypt(struct work_struct
*work
)
660 struct dm_crypt_io
*io
= container_of(work
, struct dm_crypt_io
, work
);
662 if (bio_data_dir(io
->base_bio
) == READ
)
663 process_read_endio(io
);
669 * Decode key from its hex representation
671 static int crypt_decode_key(u8
*key
, char *hex
, unsigned int size
)
679 for (i
= 0; i
< size
; i
++) {
683 key
[i
] = (u8
)simple_strtoul(buffer
, &endp
, 16);
685 if (endp
!= &buffer
[2])
696 * Encode key into its hex representation
698 static void crypt_encode_key(char *hex
, u8
*key
, unsigned int size
)
702 for (i
= 0; i
< size
; i
++) {
703 sprintf(hex
, "%02x", *key
);
709 static int crypt_set_key(struct crypt_config
*cc
, char *key
)
711 unsigned key_size
= strlen(key
) >> 1;
713 if (cc
->key_size
&& cc
->key_size
!= key_size
)
716 cc
->key_size
= key_size
; /* initial settings */
718 if ((!key_size
&& strcmp(key
, "-")) ||
719 (key_size
&& crypt_decode_key(cc
->key
, key
, key_size
) < 0))
722 set_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
);
727 static int crypt_wipe_key(struct crypt_config
*cc
)
729 clear_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
);
730 memset(&cc
->key
, 0, cc
->key_size
* sizeof(u8
));
735 * Construct an encryption mapping:
736 * <cipher> <key> <iv_offset> <dev_path> <start>
738 static int crypt_ctr(struct dm_target
*ti
, unsigned int argc
, char **argv
)
740 struct crypt_config
*cc
;
741 struct crypto_blkcipher
*tfm
;
747 unsigned int key_size
;
748 unsigned long long tmpll
;
751 ti
->error
= "Not enough arguments";
756 cipher
= strsep(&tmp
, "-");
757 chainmode
= strsep(&tmp
, "-");
758 ivopts
= strsep(&tmp
, "-");
759 ivmode
= strsep(&ivopts
, ":");
762 DMWARN("Unexpected additional cipher options");
764 key_size
= strlen(argv
[1]) >> 1;
766 cc
= kzalloc(sizeof(*cc
) + key_size
* sizeof(u8
), GFP_KERNEL
);
769 "Cannot allocate transparent encryption context";
773 if (crypt_set_key(cc
, argv
[1])) {
774 ti
->error
= "Error decoding key";
778 /* Compatiblity mode for old dm-crypt cipher strings */
779 if (!chainmode
|| (strcmp(chainmode
, "plain") == 0 && !ivmode
)) {
784 if (strcmp(chainmode
, "ecb") && !ivmode
) {
785 ti
->error
= "This chaining mode requires an IV mechanism";
789 if (snprintf(cc
->cipher
, CRYPTO_MAX_ALG_NAME
, "%s(%s)",
790 chainmode
, cipher
) >= CRYPTO_MAX_ALG_NAME
) {
791 ti
->error
= "Chain mode + cipher name is too long";
795 tfm
= crypto_alloc_blkcipher(cc
->cipher
, 0, CRYPTO_ALG_ASYNC
);
797 ti
->error
= "Error allocating crypto tfm";
801 strcpy(cc
->cipher
, cipher
);
802 strcpy(cc
->chainmode
, chainmode
);
806 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
807 * See comments at iv code
811 cc
->iv_gen_ops
= NULL
;
812 else if (strcmp(ivmode
, "plain") == 0)
813 cc
->iv_gen_ops
= &crypt_iv_plain_ops
;
814 else if (strcmp(ivmode
, "essiv") == 0)
815 cc
->iv_gen_ops
= &crypt_iv_essiv_ops
;
816 else if (strcmp(ivmode
, "benbi") == 0)
817 cc
->iv_gen_ops
= &crypt_iv_benbi_ops
;
818 else if (strcmp(ivmode
, "null") == 0)
819 cc
->iv_gen_ops
= &crypt_iv_null_ops
;
821 ti
->error
= "Invalid IV mode";
825 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->ctr
&&
826 cc
->iv_gen_ops
->ctr(cc
, ti
, ivopts
) < 0)
829 cc
->iv_size
= crypto_blkcipher_ivsize(tfm
);
831 /* at least a 64 bit sector number should fit in our buffer */
832 cc
->iv_size
= max(cc
->iv_size
,
833 (unsigned int)(sizeof(u64
) / sizeof(u8
)));
835 if (cc
->iv_gen_ops
) {
836 DMWARN("Selected cipher does not support IVs");
837 if (cc
->iv_gen_ops
->dtr
)
838 cc
->iv_gen_ops
->dtr(cc
);
839 cc
->iv_gen_ops
= NULL
;
843 cc
->io_pool
= mempool_create_slab_pool(MIN_IOS
, _crypt_io_pool
);
845 ti
->error
= "Cannot allocate crypt io mempool";
849 cc
->page_pool
= mempool_create_page_pool(MIN_POOL_PAGES
, 0);
850 if (!cc
->page_pool
) {
851 ti
->error
= "Cannot allocate page mempool";
855 cc
->bs
= bioset_create(MIN_IOS
, MIN_IOS
);
857 ti
->error
= "Cannot allocate crypt bioset";
861 if (crypto_blkcipher_setkey(tfm
, cc
->key
, key_size
) < 0) {
862 ti
->error
= "Error setting key";
866 if (sscanf(argv
[2], "%llu", &tmpll
) != 1) {
867 ti
->error
= "Invalid iv_offset sector";
870 cc
->iv_offset
= tmpll
;
872 if (sscanf(argv
[4], "%llu", &tmpll
) != 1) {
873 ti
->error
= "Invalid device sector";
878 if (dm_get_device(ti
, argv
[3], cc
->start
, ti
->len
,
879 dm_table_get_mode(ti
->table
), &cc
->dev
)) {
880 ti
->error
= "Device lookup failed";
884 if (ivmode
&& cc
->iv_gen_ops
) {
887 cc
->iv_mode
= kmalloc(strlen(ivmode
) + 1, GFP_KERNEL
);
889 ti
->error
= "Error kmallocing iv_mode string";
890 goto bad_ivmode_string
;
892 strcpy(cc
->iv_mode
, ivmode
);
896 cc
->io_queue
= create_singlethread_workqueue("kcryptd_io");
898 ti
->error
= "Couldn't create kcryptd io queue";
902 cc
->crypt_queue
= create_singlethread_workqueue("kcryptd");
903 if (!cc
->crypt_queue
) {
904 ti
->error
= "Couldn't create kcryptd queue";
905 goto bad_crypt_queue
;
912 destroy_workqueue(cc
->io_queue
);
916 dm_put_device(ti
, cc
->dev
);
920 mempool_destroy(cc
->page_pool
);
922 mempool_destroy(cc
->io_pool
);
924 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->dtr
)
925 cc
->iv_gen_ops
->dtr(cc
);
927 crypto_free_blkcipher(tfm
);
929 /* Must zero key material before freeing */
930 memset(cc
, 0, sizeof(*cc
) + cc
->key_size
* sizeof(u8
));
935 static void crypt_dtr(struct dm_target
*ti
)
937 struct crypt_config
*cc
= (struct crypt_config
*) ti
->private;
939 destroy_workqueue(cc
->io_queue
);
940 destroy_workqueue(cc
->crypt_queue
);
943 mempool_destroy(cc
->page_pool
);
944 mempool_destroy(cc
->io_pool
);
947 if (cc
->iv_gen_ops
&& cc
->iv_gen_ops
->dtr
)
948 cc
->iv_gen_ops
->dtr(cc
);
949 crypto_free_blkcipher(cc
->tfm
);
950 dm_put_device(ti
, cc
->dev
);
952 /* Must zero key material before freeing */
953 memset(cc
, 0, sizeof(*cc
) + cc
->key_size
* sizeof(u8
));
957 static int crypt_map(struct dm_target
*ti
, struct bio
*bio
,
958 union map_info
*map_context
)
960 struct crypt_config
*cc
= ti
->private;
961 struct dm_crypt_io
*io
;
963 io
= mempool_alloc(cc
->io_pool
, GFP_NOIO
);
967 atomic_set(&io
->pending
, 0);
969 if (bio_data_dir(io
->base_bio
) == READ
)
970 kcryptd_queue_io(io
);
972 kcryptd_queue_crypt(io
);
974 return DM_MAPIO_SUBMITTED
;
977 static int crypt_status(struct dm_target
*ti
, status_type_t type
,
978 char *result
, unsigned int maxlen
)
980 struct crypt_config
*cc
= (struct crypt_config
*) ti
->private;
984 case STATUSTYPE_INFO
:
988 case STATUSTYPE_TABLE
:
990 DMEMIT("%s-%s-%s ", cc
->cipher
, cc
->chainmode
,
993 DMEMIT("%s-%s ", cc
->cipher
, cc
->chainmode
);
995 if (cc
->key_size
> 0) {
996 if ((maxlen
- sz
) < ((cc
->key_size
<< 1) + 1))
999 crypt_encode_key(result
+ sz
, cc
->key
, cc
->key_size
);
1000 sz
+= cc
->key_size
<< 1;
1007 DMEMIT(" %llu %s %llu", (unsigned long long)cc
->iv_offset
,
1008 cc
->dev
->name
, (unsigned long long)cc
->start
);
1014 static void crypt_postsuspend(struct dm_target
*ti
)
1016 struct crypt_config
*cc
= ti
->private;
1018 set_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
);
1021 static int crypt_preresume(struct dm_target
*ti
)
1023 struct crypt_config
*cc
= ti
->private;
1025 if (!test_bit(DM_CRYPT_KEY_VALID
, &cc
->flags
)) {
1026 DMERR("aborting resume - crypt key is not set.");
1033 static void crypt_resume(struct dm_target
*ti
)
1035 struct crypt_config
*cc
= ti
->private;
1037 clear_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
);
1040 /* Message interface
1044 static int crypt_message(struct dm_target
*ti
, unsigned argc
, char **argv
)
1046 struct crypt_config
*cc
= ti
->private;
1051 if (!strnicmp(argv
[0], MESG_STR("key"))) {
1052 if (!test_bit(DM_CRYPT_SUSPENDED
, &cc
->flags
)) {
1053 DMWARN("not suspended during key manipulation.");
1056 if (argc
== 3 && !strnicmp(argv
[1], MESG_STR("set")))
1057 return crypt_set_key(cc
, argv
[2]);
1058 if (argc
== 2 && !strnicmp(argv
[1], MESG_STR("wipe")))
1059 return crypt_wipe_key(cc
);
1063 DMWARN("unrecognised message received.");
1067 static struct target_type crypt_target
= {
1069 .version
= {1, 5, 0},
1070 .module
= THIS_MODULE
,
1074 .status
= crypt_status
,
1075 .postsuspend
= crypt_postsuspend
,
1076 .preresume
= crypt_preresume
,
1077 .resume
= crypt_resume
,
1078 .message
= crypt_message
,
1081 static int __init
dm_crypt_init(void)
1085 _crypt_io_pool
= KMEM_CACHE(dm_crypt_io
, 0);
1086 if (!_crypt_io_pool
)
1089 r
= dm_register_target(&crypt_target
);
1091 DMERR("register failed %d", r
);
1092 kmem_cache_destroy(_crypt_io_pool
);
1098 static void __exit
dm_crypt_exit(void)
1100 int r
= dm_unregister_target(&crypt_target
);
1103 DMERR("unregister failed %d", r
);
1105 kmem_cache_destroy(_crypt_io_pool
);
1108 module_init(dm_crypt_init
);
1109 module_exit(dm_crypt_exit
);
1111 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1112 MODULE_DESCRIPTION(DM_NAME
" target for transparent encryption / decryption");
1113 MODULE_LICENSE("GPL");