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 bio *first_clone;
37 struct work_struct work;
44 * context holding the current state of a multi-part conversion
46 struct convert_context {
49 unsigned int offset_in;
50 unsigned int offset_out;
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
87 struct crypt_iv_operations *iv_gen_ops;
89 struct crypto_cipher *iv_gen_private;
93 char cipher[CRYPTO_MAX_ALG_NAME];
94 char chainmode[CRYPTO_MAX_ALG_NAME];
95 struct crypto_blkcipher *tfm;
97 unsigned int key_size;
102 #define MIN_POOL_PAGES 32
103 #define MIN_BIO_PAGES 8
105 static kmem_cache_t *_crypt_io_pool;
108 * Different IV generation algorithms:
110 * plain: the initial vector is the 32-bit little-endian version of the sector
111 * number, padded with zeros if neccessary.
113 * essiv: "encrypted sector|salt initial vector", the sector number is
114 * encrypted with the bulk cipher using a salt as key. The salt
115 * should be derived from the bulk cipher's key via hashing.
117 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
118 * (needed for LRW-32-AES and possible other narrow block modes)
120 * plumb: unimplemented, see:
121 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
124 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
126 memset(iv, 0, cc->iv_size);
127 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
132 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
135 struct crypto_cipher *essiv_tfm;
136 struct crypto_hash *hash_tfm;
137 struct hash_desc desc;
138 struct scatterlist sg;
139 unsigned int saltsize;
144 ti->error = "Digest algorithm missing for ESSIV mode";
148 /* Hash the cipher key with the given hash algorithm */
149 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
150 if (IS_ERR(hash_tfm)) {
151 ti->error = "Error initializing ESSIV hash";
152 return PTR_ERR(hash_tfm);
155 saltsize = crypto_hash_digestsize(hash_tfm);
156 salt = kmalloc(saltsize, GFP_KERNEL);
158 ti->error = "Error kmallocing salt storage in ESSIV";
159 crypto_free_hash(hash_tfm);
163 sg_set_buf(&sg, cc->key, cc->key_size);
165 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
166 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
167 crypto_free_hash(hash_tfm);
170 ti->error = "Error calculating hash in ESSIV";
174 /* Setup the essiv_tfm with the given salt */
175 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
176 if (IS_ERR(essiv_tfm)) {
177 ti->error = "Error allocating crypto tfm for ESSIV";
179 return PTR_ERR(essiv_tfm);
181 if (crypto_cipher_blocksize(essiv_tfm) !=
182 crypto_blkcipher_ivsize(cc->tfm)) {
183 ti->error = "Block size of ESSIV cipher does "
184 "not match IV size of block cipher";
185 crypto_free_cipher(essiv_tfm);
189 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
191 ti->error = "Failed to set key for ESSIV cipher";
192 crypto_free_cipher(essiv_tfm);
198 cc->iv_gen_private = essiv_tfm;
202 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
204 crypto_free_cipher(cc->iv_gen_private);
205 cc->iv_gen_private = NULL;
208 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
210 memset(iv, 0, cc->iv_size);
211 *(u64 *)iv = cpu_to_le64(sector);
212 crypto_cipher_encrypt_one(cc->iv_gen_private, iv, iv);
216 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
219 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
220 int log = long_log2(bs);
222 /* we need to calculate how far we must shift the sector count
223 * to get the cipher block count, we use this shift in _gen */
225 if (1 << log != bs) {
226 ti->error = "cypher blocksize is not a power of 2";
231 ti->error = "cypher blocksize is > 512";
235 cc->iv_gen_private = (void *)(9 - log);
240 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
242 cc->iv_gen_private = NULL;
245 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
247 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
248 put_unaligned(cpu_to_be64(((u64)sector << (u32)cc->iv_gen_private) + 1),
249 (__be64 *)(iv + cc->iv_size - sizeof(u64)));
254 static struct crypt_iv_operations crypt_iv_plain_ops = {
255 .generator = crypt_iv_plain_gen
258 static struct crypt_iv_operations crypt_iv_essiv_ops = {
259 .ctr = crypt_iv_essiv_ctr,
260 .dtr = crypt_iv_essiv_dtr,
261 .generator = crypt_iv_essiv_gen
264 static struct crypt_iv_operations crypt_iv_benbi_ops = {
265 .ctr = crypt_iv_benbi_ctr,
266 .dtr = crypt_iv_benbi_dtr,
267 .generator = crypt_iv_benbi_gen
271 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
272 struct scatterlist *in, unsigned int length,
273 int write, sector_t sector)
276 struct blkcipher_desc desc = {
279 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
283 if (cc->iv_gen_ops) {
284 r = cc->iv_gen_ops->generator(cc, iv, sector);
289 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
291 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
294 r = crypto_blkcipher_encrypt(&desc, out, in, length);
296 r = crypto_blkcipher_decrypt(&desc, out, in, length);
303 crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx,
304 struct bio *bio_out, struct bio *bio_in,
305 sector_t sector, int write)
307 ctx->bio_in = bio_in;
308 ctx->bio_out = bio_out;
311 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
312 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
313 ctx->sector = sector + cc->iv_offset;
318 * Encrypt / decrypt data from one bio to another one (can be the same one)
320 static int crypt_convert(struct crypt_config *cc,
321 struct convert_context *ctx)
325 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
326 ctx->idx_out < ctx->bio_out->bi_vcnt) {
327 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
328 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
329 struct scatterlist sg_in = {
330 .page = bv_in->bv_page,
331 .offset = bv_in->bv_offset + ctx->offset_in,
332 .length = 1 << SECTOR_SHIFT
334 struct scatterlist sg_out = {
335 .page = bv_out->bv_page,
336 .offset = bv_out->bv_offset + ctx->offset_out,
337 .length = 1 << SECTOR_SHIFT
340 ctx->offset_in += sg_in.length;
341 if (ctx->offset_in >= bv_in->bv_len) {
346 ctx->offset_out += sg_out.length;
347 if (ctx->offset_out >= bv_out->bv_len) {
352 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
353 ctx->write, ctx->sector);
363 static void dm_crypt_bio_destructor(struct bio *bio)
365 struct crypt_io *io = bio->bi_private;
366 struct crypt_config *cc = io->target->private;
368 bio_free(bio, cc->bs);
372 * Generate a new unfragmented bio with the given size
373 * This should never violate the device limitations
374 * May return a smaller bio when running out of pages
377 crypt_alloc_buffer(struct crypt_config *cc, unsigned int size,
378 struct bio *base_bio, unsigned int *bio_vec_idx)
381 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
382 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
386 clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);
387 __bio_clone(clone, base_bio);
389 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
394 clone->bi_destructor = dm_crypt_bio_destructor;
396 /* if the last bio was not complete, continue where that one ended */
397 clone->bi_idx = *bio_vec_idx;
398 clone->bi_vcnt = *bio_vec_idx;
400 clone->bi_flags &= ~(1 << BIO_SEG_VALID);
402 /* clone->bi_idx pages have already been allocated */
403 size -= clone->bi_idx * PAGE_SIZE;
405 for (i = clone->bi_idx; i < nr_iovecs; i++) {
406 struct bio_vec *bv = bio_iovec_idx(clone, i);
408 bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
413 * if additional pages cannot be allocated without waiting,
414 * return a partially allocated bio, the caller will then try
415 * to allocate additional bios while submitting this partial bio
417 if ((i - clone->bi_idx) == (MIN_BIO_PAGES - 1))
418 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
421 if (size > PAGE_SIZE)
422 bv->bv_len = PAGE_SIZE;
426 clone->bi_size += bv->bv_len;
431 if (!clone->bi_size) {
437 * Remember the last bio_vec allocated to be able
438 * to correctly continue after the splitting.
440 *bio_vec_idx = clone->bi_vcnt;
445 static void crypt_free_buffer_pages(struct crypt_config *cc,
446 struct bio *clone, unsigned int bytes)
448 unsigned int i, start, end;
452 * This is ugly, but Jens Axboe thinks that using bi_idx in the
453 * endio function is too dangerous at the moment, so I calculate the
454 * correct position using bi_vcnt and bi_size.
455 * The bv_offset and bv_len fields might already be modified but we
456 * know that we always allocated whole pages.
457 * A fix to the bi_idx issue in the kernel is in the works, so
458 * we will hopefully be able to revert to the cleaner solution soon.
460 i = clone->bi_vcnt - 1;
461 bv = bio_iovec_idx(clone, i);
462 end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - clone->bi_size;
465 start >>= PAGE_SHIFT;
467 end = clone->bi_vcnt;
471 for (i = start; i < end; i++) {
472 bv = bio_iovec_idx(clone, i);
473 BUG_ON(!bv->bv_page);
474 mempool_free(bv->bv_page, cc->page_pool);
480 * One of the bios was finished. Check for completion of
481 * the whole request and correctly clean up the buffer.
483 static void dec_pending(struct crypt_io *io, int error)
485 struct crypt_config *cc = (struct crypt_config *) io->target->private;
490 if (!atomic_dec_and_test(&io->pending))
494 bio_put(io->first_clone);
496 bio_endio(io->base_bio, io->base_bio->bi_size, io->error);
498 mempool_free(io, cc->io_pool);
504 * Needed because it would be very unwise to do decryption in an
507 static struct workqueue_struct *_kcryptd_workqueue;
508 static void kcryptd_do_work(struct work_struct *work);
510 static void kcryptd_queue_io(struct crypt_io *io)
512 INIT_WORK(&io->work, kcryptd_do_work);
513 queue_work(_kcryptd_workqueue, &io->work);
516 static int crypt_endio(struct bio *clone, unsigned int done, int error)
518 struct crypt_io *io = clone->bi_private;
519 struct crypt_config *cc = io->target->private;
520 unsigned read_io = bio_data_dir(clone) == READ;
523 * free the processed pages, even if
524 * it's only a partially completed write
527 crypt_free_buffer_pages(cc, clone, done);
529 /* keep going - not finished yet */
530 if (unlikely(clone->bi_size))
536 if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
542 io->post_process = 1;
543 kcryptd_queue_io(io);
548 dec_pending(io, error);
552 static void clone_init(struct crypt_io *io, struct bio *clone)
554 struct crypt_config *cc = io->target->private;
556 clone->bi_private = io;
557 clone->bi_end_io = crypt_endio;
558 clone->bi_bdev = cc->dev->bdev;
559 clone->bi_rw = io->base_bio->bi_rw;
562 static void process_read(struct crypt_io *io)
564 struct crypt_config *cc = io->target->private;
565 struct bio *base_bio = io->base_bio;
567 sector_t sector = base_bio->bi_sector - io->target->begin;
569 atomic_inc(&io->pending);
572 * The block layer might modify the bvec array, so always
573 * copy the required bvecs because we need the original
574 * one in order to decrypt the whole bio data *afterwards*.
576 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
577 if (unlikely(!clone)) {
578 dec_pending(io, -ENOMEM);
582 clone_init(io, clone);
583 clone->bi_destructor = dm_crypt_bio_destructor;
585 clone->bi_vcnt = bio_segments(base_bio);
586 clone->bi_size = base_bio->bi_size;
587 clone->bi_sector = cc->start + sector;
588 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
589 sizeof(struct bio_vec) * clone->bi_vcnt);
591 generic_make_request(clone);
594 static void process_write(struct crypt_io *io)
596 struct crypt_config *cc = io->target->private;
597 struct bio *base_bio = io->base_bio;
599 struct convert_context ctx;
600 unsigned remaining = base_bio->bi_size;
601 sector_t sector = base_bio->bi_sector - io->target->begin;
602 unsigned bvec_idx = 0;
604 atomic_inc(&io->pending);
606 crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
609 * The allocated buffers can be smaller than the whole bio,
610 * so repeat the whole process until all the data can be handled.
613 clone = crypt_alloc_buffer(cc, base_bio->bi_size,
614 io->first_clone, &bvec_idx);
615 if (unlikely(!clone)) {
616 dec_pending(io, -ENOMEM);
622 if (unlikely(crypt_convert(cc, &ctx) < 0)) {
623 crypt_free_buffer_pages(cc, clone, clone->bi_size);
625 dec_pending(io, -EIO);
629 clone_init(io, clone);
630 clone->bi_sector = cc->start + sector;
632 if (!io->first_clone) {
634 * hold a reference to the first clone, because it
635 * holds the bio_vec array and that can't be freed
636 * before all other clones are released
639 io->first_clone = clone;
642 remaining -= clone->bi_size;
643 sector += bio_sectors(clone);
645 /* prevent bio_put of first_clone */
647 atomic_inc(&io->pending);
649 generic_make_request(clone);
651 /* out of memory -> run queues */
653 congestion_wait(bio_data_dir(clone), HZ/100);
657 static void process_read_endio(struct crypt_io *io)
659 struct crypt_config *cc = io->target->private;
660 struct convert_context ctx;
662 crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,
663 io->base_bio->bi_sector - io->target->begin, 0);
665 dec_pending(io, crypt_convert(cc, &ctx));
668 static void kcryptd_do_work(struct work_struct *work)
670 struct crypt_io *io = container_of(work, struct crypt_io, work);
672 if (io->post_process)
673 process_read_endio(io);
674 else if (bio_data_dir(io->base_bio) == READ)
681 * Decode key from its hex representation
683 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
691 for (i = 0; i < size; i++) {
695 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
697 if (endp != &buffer[2])
708 * Encode key into its hex representation
710 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
714 for (i = 0; i < size; i++) {
715 sprintf(hex, "%02x", *key);
721 static int crypt_set_key(struct crypt_config *cc, char *key)
723 unsigned key_size = strlen(key) >> 1;
725 if (cc->key_size && cc->key_size != key_size)
728 cc->key_size = key_size; /* initial settings */
730 if ((!key_size && strcmp(key, "-")) ||
731 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
734 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
739 static int crypt_wipe_key(struct crypt_config *cc)
741 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
742 memset(&cc->key, 0, cc->key_size * sizeof(u8));
747 * Construct an encryption mapping:
748 * <cipher> <key> <iv_offset> <dev_path> <start>
750 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
752 struct crypt_config *cc;
753 struct crypto_blkcipher *tfm;
759 unsigned int key_size;
760 unsigned long long tmpll;
763 ti->error = "Not enough arguments";
768 cipher = strsep(&tmp, "-");
769 chainmode = strsep(&tmp, "-");
770 ivopts = strsep(&tmp, "-");
771 ivmode = strsep(&ivopts, ":");
774 DMWARN("Unexpected additional cipher options");
776 key_size = strlen(argv[1]) >> 1;
778 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
781 "Cannot allocate transparent encryption context";
785 if (crypt_set_key(cc, argv[1])) {
786 ti->error = "Error decoding key";
790 /* Compatiblity mode for old dm-crypt cipher strings */
791 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
796 if (strcmp(chainmode, "ecb") && !ivmode) {
797 ti->error = "This chaining mode requires an IV mechanism";
801 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", chainmode,
802 cipher) >= CRYPTO_MAX_ALG_NAME) {
803 ti->error = "Chain mode + cipher name is too long";
807 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
809 ti->error = "Error allocating crypto tfm";
813 strcpy(cc->cipher, cipher);
814 strcpy(cc->chainmode, chainmode);
818 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
819 * See comments at iv code
823 cc->iv_gen_ops = NULL;
824 else if (strcmp(ivmode, "plain") == 0)
825 cc->iv_gen_ops = &crypt_iv_plain_ops;
826 else if (strcmp(ivmode, "essiv") == 0)
827 cc->iv_gen_ops = &crypt_iv_essiv_ops;
828 else if (strcmp(ivmode, "benbi") == 0)
829 cc->iv_gen_ops = &crypt_iv_benbi_ops;
831 ti->error = "Invalid IV mode";
835 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
836 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
839 cc->iv_size = crypto_blkcipher_ivsize(tfm);
841 /* at least a 64 bit sector number should fit in our buffer */
842 cc->iv_size = max(cc->iv_size,
843 (unsigned int)(sizeof(u64) / sizeof(u8)));
845 if (cc->iv_gen_ops) {
846 DMWARN("Selected cipher does not support IVs");
847 if (cc->iv_gen_ops->dtr)
848 cc->iv_gen_ops->dtr(cc);
849 cc->iv_gen_ops = NULL;
853 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
855 ti->error = "Cannot allocate crypt io mempool";
859 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
860 if (!cc->page_pool) {
861 ti->error = "Cannot allocate page mempool";
865 cc->bs = bioset_create(MIN_IOS, MIN_IOS, 4);
867 ti->error = "Cannot allocate crypt bioset";
871 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
872 ti->error = "Error setting key";
876 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
877 ti->error = "Invalid iv_offset sector";
880 cc->iv_offset = tmpll;
882 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
883 ti->error = "Invalid device sector";
888 if (dm_get_device(ti, argv[3], cc->start, ti->len,
889 dm_table_get_mode(ti->table), &cc->dev)) {
890 ti->error = "Device lookup failed";
894 if (ivmode && cc->iv_gen_ops) {
897 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
899 ti->error = "Error kmallocing iv_mode string";
902 strcpy(cc->iv_mode, ivmode);
912 mempool_destroy(cc->page_pool);
914 mempool_destroy(cc->io_pool);
916 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
917 cc->iv_gen_ops->dtr(cc);
919 crypto_free_blkcipher(tfm);
921 /* Must zero key material before freeing */
922 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
927 static void crypt_dtr(struct dm_target *ti)
929 struct crypt_config *cc = (struct crypt_config *) ti->private;
932 mempool_destroy(cc->page_pool);
933 mempool_destroy(cc->io_pool);
936 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
937 cc->iv_gen_ops->dtr(cc);
938 crypto_free_blkcipher(cc->tfm);
939 dm_put_device(ti, cc->dev);
941 /* Must zero key material before freeing */
942 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
946 static int crypt_map(struct dm_target *ti, struct bio *bio,
947 union map_info *map_context)
949 struct crypt_config *cc = ti->private;
952 io = mempool_alloc(cc->io_pool, GFP_NOIO);
955 io->first_clone = NULL;
956 io->error = io->post_process = 0;
957 atomic_set(&io->pending, 0);
958 kcryptd_queue_io(io);
963 static int crypt_status(struct dm_target *ti, status_type_t type,
964 char *result, unsigned int maxlen)
966 struct crypt_config *cc = (struct crypt_config *) ti->private;
970 case STATUSTYPE_INFO:
974 case STATUSTYPE_TABLE:
976 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
979 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
981 if (cc->key_size > 0) {
982 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
985 crypt_encode_key(result + sz, cc->key, cc->key_size);
986 sz += cc->key_size << 1;
993 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
994 cc->dev->name, (unsigned long long)cc->start);
1000 static void crypt_postsuspend(struct dm_target *ti)
1002 struct crypt_config *cc = ti->private;
1004 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1007 static int crypt_preresume(struct dm_target *ti)
1009 struct crypt_config *cc = ti->private;
1011 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1012 DMERR("aborting resume - crypt key is not set.");
1019 static void crypt_resume(struct dm_target *ti)
1021 struct crypt_config *cc = ti->private;
1023 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1026 /* Message interface
1030 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1032 struct crypt_config *cc = ti->private;
1037 if (!strnicmp(argv[0], MESG_STR("key"))) {
1038 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1039 DMWARN("not suspended during key manipulation.");
1042 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1043 return crypt_set_key(cc, argv[2]);
1044 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1045 return crypt_wipe_key(cc);
1049 DMWARN("unrecognised message received.");
1053 static struct target_type crypt_target = {
1055 .version= {1, 3, 0},
1056 .module = THIS_MODULE,
1060 .status = crypt_status,
1061 .postsuspend = crypt_postsuspend,
1062 .preresume = crypt_preresume,
1063 .resume = crypt_resume,
1064 .message = crypt_message,
1067 static int __init dm_crypt_init(void)
1071 _crypt_io_pool = kmem_cache_create("dm-crypt_io",
1072 sizeof(struct crypt_io),
1074 if (!_crypt_io_pool)
1077 _kcryptd_workqueue = create_workqueue("kcryptd");
1078 if (!_kcryptd_workqueue) {
1080 DMERR("couldn't create kcryptd");
1084 r = dm_register_target(&crypt_target);
1086 DMERR("register failed %d", r);
1093 destroy_workqueue(_kcryptd_workqueue);
1095 kmem_cache_destroy(_crypt_io_pool);
1099 static void __exit dm_crypt_exit(void)
1101 int r = dm_unregister_target(&crypt_target);
1104 DMERR("unregister failed %d", r);
1106 destroy_workqueue(_kcryptd_workqueue);
1107 kmem_cache_destroy(_crypt_io_pool);
1110 module_init(dm_crypt_init);
1111 module_exit(dm_crypt_exit);
1113 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1114 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1115 MODULE_LICENSE("GPL");