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;
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 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 neccessary.
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 * plumb: unimplemented, see:
126 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
129 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
131 memset(iv, 0, cc->iv_size);
132 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
137 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
140 struct crypto_cipher *essiv_tfm;
141 struct crypto_hash *hash_tfm;
142 struct hash_desc desc;
143 struct scatterlist sg;
144 unsigned int saltsize;
149 ti->error = "Digest algorithm missing for ESSIV mode";
153 /* Hash the cipher key with the given hash algorithm */
154 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
155 if (IS_ERR(hash_tfm)) {
156 ti->error = "Error initializing ESSIV hash";
157 return PTR_ERR(hash_tfm);
160 saltsize = crypto_hash_digestsize(hash_tfm);
161 salt = kmalloc(saltsize, GFP_KERNEL);
163 ti->error = "Error kmallocing salt storage in ESSIV";
164 crypto_free_hash(hash_tfm);
168 sg_set_buf(&sg, cc->key, cc->key_size);
170 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
171 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
172 crypto_free_hash(hash_tfm);
175 ti->error = "Error calculating hash in ESSIV";
179 /* Setup the essiv_tfm with the given salt */
180 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
181 if (IS_ERR(essiv_tfm)) {
182 ti->error = "Error allocating crypto tfm for ESSIV";
184 return PTR_ERR(essiv_tfm);
186 if (crypto_cipher_blocksize(essiv_tfm) !=
187 crypto_blkcipher_ivsize(cc->tfm)) {
188 ti->error = "Block size of ESSIV cipher does "
189 "not match IV size of block cipher";
190 crypto_free_cipher(essiv_tfm);
194 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
196 ti->error = "Failed to set key for ESSIV cipher";
197 crypto_free_cipher(essiv_tfm);
203 cc->iv_gen_private.essiv_tfm = essiv_tfm;
207 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
209 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
210 cc->iv_gen_private.essiv_tfm = NULL;
213 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
215 memset(iv, 0, cc->iv_size);
216 *(u64 *)iv = cpu_to_le64(sector);
217 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
221 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
224 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
227 /* we need to calculate how far we must shift the sector count
228 * to get the cipher block count, we use this shift in _gen */
230 if (1 << log != bs) {
231 ti->error = "cypher blocksize is not a power of 2";
236 ti->error = "cypher blocksize is > 512";
240 cc->iv_gen_private.benbi_shift = 9 - log;
245 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
249 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
253 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
255 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
256 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
261 static struct crypt_iv_operations crypt_iv_plain_ops = {
262 .generator = crypt_iv_plain_gen
265 static struct crypt_iv_operations crypt_iv_essiv_ops = {
266 .ctr = crypt_iv_essiv_ctr,
267 .dtr = crypt_iv_essiv_dtr,
268 .generator = crypt_iv_essiv_gen
271 static struct crypt_iv_operations crypt_iv_benbi_ops = {
272 .ctr = crypt_iv_benbi_ctr,
273 .dtr = crypt_iv_benbi_dtr,
274 .generator = crypt_iv_benbi_gen
278 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
279 struct scatterlist *in, unsigned int length,
280 int write, sector_t sector)
282 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
283 struct blkcipher_desc desc = {
286 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
290 if (cc->iv_gen_ops) {
291 r = cc->iv_gen_ops->generator(cc, iv, sector);
296 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
298 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
301 r = crypto_blkcipher_encrypt(&desc, out, in, length);
303 r = crypto_blkcipher_decrypt(&desc, out, in, length);
310 crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx,
311 struct bio *bio_out, struct bio *bio_in,
312 sector_t sector, int write)
314 ctx->bio_in = bio_in;
315 ctx->bio_out = bio_out;
318 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
319 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
320 ctx->sector = sector + cc->iv_offset;
325 * Encrypt / decrypt data from one bio to another one (can be the same one)
327 static int crypt_convert(struct crypt_config *cc,
328 struct convert_context *ctx)
332 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
333 ctx->idx_out < ctx->bio_out->bi_vcnt) {
334 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
335 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
336 struct scatterlist sg_in = {
337 .page = bv_in->bv_page,
338 .offset = bv_in->bv_offset + ctx->offset_in,
339 .length = 1 << SECTOR_SHIFT
341 struct scatterlist sg_out = {
342 .page = bv_out->bv_page,
343 .offset = bv_out->bv_offset + ctx->offset_out,
344 .length = 1 << SECTOR_SHIFT
347 ctx->offset_in += sg_in.length;
348 if (ctx->offset_in >= bv_in->bv_len) {
353 ctx->offset_out += sg_out.length;
354 if (ctx->offset_out >= bv_out->bv_len) {
359 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
360 ctx->write, ctx->sector);
370 static void dm_crypt_bio_destructor(struct bio *bio)
372 struct crypt_io *io = bio->bi_private;
373 struct crypt_config *cc = io->target->private;
375 bio_free(bio, cc->bs);
379 * Generate a new unfragmented bio with the given size
380 * This should never violate the device limitations
381 * May return a smaller bio when running out of pages
384 crypt_alloc_buffer(struct crypt_io *io, unsigned int size,
385 struct bio *base_bio, unsigned int *bio_vec_idx)
387 struct crypt_config *cc = io->target->private;
389 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
390 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
394 clone = bio_alloc_bioset(GFP_NOIO, base_bio->bi_max_vecs, cc->bs);
395 __bio_clone(clone, base_bio);
397 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
402 clone_init(io, clone);
404 /* if the last bio was not complete, continue where that one ended */
405 clone->bi_idx = *bio_vec_idx;
406 clone->bi_vcnt = *bio_vec_idx;
408 clone->bi_flags &= ~(1 << BIO_SEG_VALID);
410 /* clone->bi_idx pages have already been allocated */
411 size -= clone->bi_idx * PAGE_SIZE;
413 for (i = clone->bi_idx; 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 - clone->bi_idx) == (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) {
445 * Remember the last bio_vec allocated to be able
446 * to correctly continue after the splitting.
448 *bio_vec_idx = clone->bi_vcnt;
453 static void crypt_free_buffer_pages(struct crypt_config *cc,
454 struct bio *clone, unsigned int bytes)
456 unsigned int i, start, end;
460 * This is ugly, but Jens Axboe thinks that using bi_idx in the
461 * endio function is too dangerous at the moment, so I calculate the
462 * correct position using bi_vcnt and bi_size.
463 * The bv_offset and bv_len fields might already be modified but we
464 * know that we always allocated whole pages.
465 * A fix to the bi_idx issue in the kernel is in the works, so
466 * we will hopefully be able to revert to the cleaner solution soon.
468 i = clone->bi_vcnt - 1;
469 bv = bio_iovec_idx(clone, i);
470 end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - clone->bi_size;
473 start >>= PAGE_SHIFT;
475 end = clone->bi_vcnt;
479 for (i = start; i < end; i++) {
480 bv = bio_iovec_idx(clone, i);
481 BUG_ON(!bv->bv_page);
482 mempool_free(bv->bv_page, cc->page_pool);
488 * One of the bios was finished. Check for completion of
489 * the whole request and correctly clean up the buffer.
491 static void dec_pending(struct crypt_io *io, int error)
493 struct crypt_config *cc = (struct crypt_config *) io->target->private;
498 if (!atomic_dec_and_test(&io->pending))
502 bio_put(io->first_clone);
504 bio_endio(io->base_bio, io->base_bio->bi_size, io->error);
506 mempool_free(io, cc->io_pool);
512 * Needed because it would be very unwise to do decryption in an
515 static struct workqueue_struct *_kcryptd_workqueue;
516 static void kcryptd_do_work(struct work_struct *work);
518 static void kcryptd_queue_io(struct crypt_io *io)
520 INIT_WORK(&io->work, kcryptd_do_work);
521 queue_work(_kcryptd_workqueue, &io->work);
524 static int crypt_endio(struct bio *clone, unsigned int done, int error)
526 struct crypt_io *io = clone->bi_private;
527 struct crypt_config *cc = io->target->private;
528 unsigned read_io = bio_data_dir(clone) == READ;
531 * free the processed pages, even if
532 * it's only a partially completed write
535 crypt_free_buffer_pages(cc, clone, done);
537 /* keep going - not finished yet */
538 if (unlikely(clone->bi_size))
544 if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
550 io->post_process = 1;
551 kcryptd_queue_io(io);
556 dec_pending(io, error);
560 static void clone_init(struct crypt_io *io, struct bio *clone)
562 struct crypt_config *cc = io->target->private;
564 clone->bi_private = io;
565 clone->bi_end_io = crypt_endio;
566 clone->bi_bdev = cc->dev->bdev;
567 clone->bi_rw = io->base_bio->bi_rw;
568 clone->bi_destructor = dm_crypt_bio_destructor;
571 static void process_read(struct crypt_io *io)
573 struct crypt_config *cc = io->target->private;
574 struct bio *base_bio = io->base_bio;
576 sector_t sector = base_bio->bi_sector - io->target->begin;
578 atomic_inc(&io->pending);
581 * The block layer might modify the bvec array, so always
582 * copy the required bvecs because we need the original
583 * one in order to decrypt the whole bio data *afterwards*.
585 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
586 if (unlikely(!clone)) {
587 dec_pending(io, -ENOMEM);
591 clone_init(io, clone);
593 clone->bi_vcnt = bio_segments(base_bio);
594 clone->bi_size = base_bio->bi_size;
595 clone->bi_sector = cc->start + sector;
596 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
597 sizeof(struct bio_vec) * clone->bi_vcnt);
599 generic_make_request(clone);
602 static void process_write(struct crypt_io *io)
604 struct crypt_config *cc = io->target->private;
605 struct bio *base_bio = io->base_bio;
607 struct convert_context ctx;
608 unsigned remaining = base_bio->bi_size;
609 sector_t sector = base_bio->bi_sector - io->target->begin;
610 unsigned bvec_idx = 0;
612 atomic_inc(&io->pending);
614 crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
617 * The allocated buffers can be smaller than the whole bio,
618 * so repeat the whole process until all the data can be handled.
621 clone = crypt_alloc_buffer(io, base_bio->bi_size,
622 io->first_clone, &bvec_idx);
623 if (unlikely(!clone)) {
624 dec_pending(io, -ENOMEM);
630 if (unlikely(crypt_convert(cc, &ctx) < 0)) {
631 crypt_free_buffer_pages(cc, clone, clone->bi_size);
633 dec_pending(io, -EIO);
637 clone->bi_sector = cc->start + sector;
639 if (!io->first_clone) {
641 * hold a reference to the first clone, because it
642 * holds the bio_vec array and that can't be freed
643 * before all other clones are released
646 io->first_clone = clone;
649 remaining -= clone->bi_size;
650 sector += bio_sectors(clone);
652 /* prevent bio_put of first_clone */
654 atomic_inc(&io->pending);
656 generic_make_request(clone);
658 /* out of memory -> run queues */
660 congestion_wait(bio_data_dir(clone), HZ/100);
664 static void process_read_endio(struct crypt_io *io)
666 struct crypt_config *cc = io->target->private;
667 struct convert_context ctx;
669 crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,
670 io->base_bio->bi_sector - io->target->begin, 0);
672 dec_pending(io, crypt_convert(cc, &ctx));
675 static void kcryptd_do_work(struct work_struct *work)
677 struct crypt_io *io = container_of(work, struct crypt_io, work);
679 if (io->post_process)
680 process_read_endio(io);
681 else if (bio_data_dir(io->base_bio) == READ)
688 * Decode key from its hex representation
690 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
698 for (i = 0; i < size; i++) {
702 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
704 if (endp != &buffer[2])
715 * Encode key into its hex representation
717 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
721 for (i = 0; i < size; i++) {
722 sprintf(hex, "%02x", *key);
728 static int crypt_set_key(struct crypt_config *cc, char *key)
730 unsigned key_size = strlen(key) >> 1;
732 if (cc->key_size && cc->key_size != key_size)
735 cc->key_size = key_size; /* initial settings */
737 if ((!key_size && strcmp(key, "-")) ||
738 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
741 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
746 static int crypt_wipe_key(struct crypt_config *cc)
748 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
749 memset(&cc->key, 0, cc->key_size * sizeof(u8));
754 * Construct an encryption mapping:
755 * <cipher> <key> <iv_offset> <dev_path> <start>
757 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
759 struct crypt_config *cc;
760 struct crypto_blkcipher *tfm;
766 unsigned int key_size;
767 unsigned long long tmpll;
770 ti->error = "Not enough arguments";
775 cipher = strsep(&tmp, "-");
776 chainmode = strsep(&tmp, "-");
777 ivopts = strsep(&tmp, "-");
778 ivmode = strsep(&ivopts, ":");
781 DMWARN("Unexpected additional cipher options");
783 key_size = strlen(argv[1]) >> 1;
785 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
788 "Cannot allocate transparent encryption context";
792 if (crypt_set_key(cc, argv[1])) {
793 ti->error = "Error decoding key";
797 /* Compatiblity mode for old dm-crypt cipher strings */
798 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
803 if (strcmp(chainmode, "ecb") && !ivmode) {
804 ti->error = "This chaining mode requires an IV mechanism";
808 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", chainmode,
809 cipher) >= CRYPTO_MAX_ALG_NAME) {
810 ti->error = "Chain mode + cipher name is too long";
814 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
816 ti->error = "Error allocating crypto tfm";
820 strcpy(cc->cipher, cipher);
821 strcpy(cc->chainmode, chainmode);
825 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
826 * See comments at iv code
830 cc->iv_gen_ops = NULL;
831 else if (strcmp(ivmode, "plain") == 0)
832 cc->iv_gen_ops = &crypt_iv_plain_ops;
833 else if (strcmp(ivmode, "essiv") == 0)
834 cc->iv_gen_ops = &crypt_iv_essiv_ops;
835 else if (strcmp(ivmode, "benbi") == 0)
836 cc->iv_gen_ops = &crypt_iv_benbi_ops;
838 ti->error = "Invalid IV mode";
842 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
843 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
846 cc->iv_size = crypto_blkcipher_ivsize(tfm);
848 /* at least a 64 bit sector number should fit in our buffer */
849 cc->iv_size = max(cc->iv_size,
850 (unsigned int)(sizeof(u64) / sizeof(u8)));
852 if (cc->iv_gen_ops) {
853 DMWARN("Selected cipher does not support IVs");
854 if (cc->iv_gen_ops->dtr)
855 cc->iv_gen_ops->dtr(cc);
856 cc->iv_gen_ops = NULL;
860 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
862 ti->error = "Cannot allocate crypt io mempool";
866 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
867 if (!cc->page_pool) {
868 ti->error = "Cannot allocate page mempool";
872 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
874 ti->error = "Cannot allocate crypt bioset";
878 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
879 ti->error = "Error setting key";
883 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
884 ti->error = "Invalid iv_offset sector";
887 cc->iv_offset = tmpll;
889 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
890 ti->error = "Invalid device sector";
895 if (dm_get_device(ti, argv[3], cc->start, ti->len,
896 dm_table_get_mode(ti->table), &cc->dev)) {
897 ti->error = "Device lookup failed";
901 if (ivmode && cc->iv_gen_ops) {
904 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
906 ti->error = "Error kmallocing iv_mode string";
909 strcpy(cc->iv_mode, ivmode);
919 mempool_destroy(cc->page_pool);
921 mempool_destroy(cc->io_pool);
923 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
924 cc->iv_gen_ops->dtr(cc);
926 crypto_free_blkcipher(tfm);
928 /* Must zero key material before freeing */
929 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
934 static void crypt_dtr(struct dm_target *ti)
936 struct crypt_config *cc = (struct crypt_config *) ti->private;
939 mempool_destroy(cc->page_pool);
940 mempool_destroy(cc->io_pool);
943 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
944 cc->iv_gen_ops->dtr(cc);
945 crypto_free_blkcipher(cc->tfm);
946 dm_put_device(ti, cc->dev);
948 /* Must zero key material before freeing */
949 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
953 static int crypt_map(struct dm_target *ti, struct bio *bio,
954 union map_info *map_context)
956 struct crypt_config *cc = ti->private;
959 if (bio_barrier(bio))
962 io = mempool_alloc(cc->io_pool, GFP_NOIO);
965 io->first_clone = NULL;
966 io->error = io->post_process = 0;
967 atomic_set(&io->pending, 0);
968 kcryptd_queue_io(io);
970 return DM_MAPIO_SUBMITTED;
973 static int crypt_status(struct dm_target *ti, status_type_t type,
974 char *result, unsigned int maxlen)
976 struct crypt_config *cc = (struct crypt_config *) ti->private;
980 case STATUSTYPE_INFO:
984 case STATUSTYPE_TABLE:
986 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
989 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
991 if (cc->key_size > 0) {
992 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
995 crypt_encode_key(result + sz, cc->key, cc->key_size);
996 sz += cc->key_size << 1;
1003 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1004 cc->dev->name, (unsigned long long)cc->start);
1010 static void crypt_postsuspend(struct dm_target *ti)
1012 struct crypt_config *cc = ti->private;
1014 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1017 static int crypt_preresume(struct dm_target *ti)
1019 struct crypt_config *cc = ti->private;
1021 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1022 DMERR("aborting resume - crypt key is not set.");
1029 static void crypt_resume(struct dm_target *ti)
1031 struct crypt_config *cc = ti->private;
1033 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1036 /* Message interface
1040 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1042 struct crypt_config *cc = ti->private;
1047 if (!strnicmp(argv[0], MESG_STR("key"))) {
1048 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1049 DMWARN("not suspended during key manipulation.");
1052 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1053 return crypt_set_key(cc, argv[2]);
1054 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1055 return crypt_wipe_key(cc);
1059 DMWARN("unrecognised message received.");
1063 static struct target_type crypt_target = {
1065 .version= {1, 3, 0},
1066 .module = THIS_MODULE,
1070 .status = crypt_status,
1071 .postsuspend = crypt_postsuspend,
1072 .preresume = crypt_preresume,
1073 .resume = crypt_resume,
1074 .message = crypt_message,
1077 static int __init dm_crypt_init(void)
1081 _crypt_io_pool = kmem_cache_create("dm-crypt_io",
1082 sizeof(struct crypt_io),
1084 if (!_crypt_io_pool)
1087 _kcryptd_workqueue = create_workqueue("kcryptd");
1088 if (!_kcryptd_workqueue) {
1090 DMERR("couldn't create kcryptd");
1094 r = dm_register_target(&crypt_target);
1096 DMERR("register failed %d", r);
1103 destroy_workqueue(_kcryptd_workqueue);
1105 kmem_cache_destroy(_crypt_io_pool);
1109 static void __exit dm_crypt_exit(void)
1111 int r = dm_unregister_target(&crypt_target);
1114 DMERR("unregister failed %d", r);
1116 destroy_workqueue(_kcryptd_workqueue);
1117 kmem_cache_destroy(_crypt_io_pool);
1120 module_init(dm_crypt_init);
1121 module_exit(dm_crypt_exit);
1123 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1124 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1125 MODULE_LICENSE("GPL");