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;
43 * context holding the current state of a multi-part conversion
45 struct convert_context {
48 unsigned int offset_in;
49 unsigned int offset_out;
58 struct crypt_iv_operations {
59 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
61 void (*dtr)(struct crypt_config *cc);
62 const char *(*status)(struct crypt_config *cc);
63 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
67 * Crypt: maps a linear range of a block device
68 * and encrypts / decrypts at the same time.
70 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
76 * pool for per bio private data and
77 * for encryption buffer pages
86 struct crypt_iv_operations *iv_gen_ops;
89 struct crypto_cipher *essiv_tfm;
95 char cipher[CRYPTO_MAX_ALG_NAME];
96 char chainmode[CRYPTO_MAX_ALG_NAME];
97 struct crypto_blkcipher *tfm;
99 unsigned int key_size;
104 #define MIN_POOL_PAGES 32
105 #define MIN_BIO_PAGES 8
107 static struct kmem_cache *_crypt_io_pool;
109 static void clone_init(struct dm_crypt_io *, struct bio *);
112 * Different IV generation algorithms:
114 * plain: the initial vector is the 32-bit little-endian version of the sector
115 * number, padded with zeros if neccessary.
117 * essiv: "encrypted sector|salt initial vector", the sector number is
118 * encrypted with the bulk cipher using a salt as key. The salt
119 * should be derived from the bulk cipher's key via hashing.
121 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
122 * (needed for LRW-32-AES and possible other narrow block modes)
124 * null: the initial vector is always zero. Provides compatibility with
125 * obsolete loop_fish2 devices. Do not use for new devices.
127 * plumb: unimplemented, see:
128 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
131 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
133 memset(iv, 0, cc->iv_size);
134 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
139 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
142 struct crypto_cipher *essiv_tfm;
143 struct crypto_hash *hash_tfm;
144 struct hash_desc desc;
145 struct scatterlist sg;
146 unsigned int saltsize;
151 ti->error = "Digest algorithm missing for ESSIV mode";
155 /* Hash the cipher key with the given hash algorithm */
156 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
157 if (IS_ERR(hash_tfm)) {
158 ti->error = "Error initializing ESSIV hash";
159 return PTR_ERR(hash_tfm);
162 saltsize = crypto_hash_digestsize(hash_tfm);
163 salt = kmalloc(saltsize, GFP_KERNEL);
165 ti->error = "Error kmallocing salt storage in ESSIV";
166 crypto_free_hash(hash_tfm);
170 sg_set_buf(&sg, cc->key, cc->key_size);
172 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
173 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
174 crypto_free_hash(hash_tfm);
177 ti->error = "Error calculating hash in ESSIV";
182 /* Setup the essiv_tfm with the given salt */
183 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
184 if (IS_ERR(essiv_tfm)) {
185 ti->error = "Error allocating crypto tfm for ESSIV";
187 return PTR_ERR(essiv_tfm);
189 if (crypto_cipher_blocksize(essiv_tfm) !=
190 crypto_blkcipher_ivsize(cc->tfm)) {
191 ti->error = "Block size of ESSIV cipher does "
192 "not match IV size of block cipher";
193 crypto_free_cipher(essiv_tfm);
197 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
199 ti->error = "Failed to set key for ESSIV cipher";
200 crypto_free_cipher(essiv_tfm);
206 cc->iv_gen_private.essiv_tfm = essiv_tfm;
210 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
212 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
213 cc->iv_gen_private.essiv_tfm = NULL;
216 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
218 memset(iv, 0, cc->iv_size);
219 *(u64 *)iv = cpu_to_le64(sector);
220 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
224 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
227 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
230 /* we need to calculate how far we must shift the sector count
231 * to get the cipher block count, we use this shift in _gen */
233 if (1 << log != bs) {
234 ti->error = "cypher blocksize is not a power of 2";
239 ti->error = "cypher blocksize is > 512";
243 cc->iv_gen_private.benbi_shift = 9 - log;
248 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
252 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
256 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
258 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
259 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
264 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
266 memset(iv, 0, cc->iv_size);
271 static struct crypt_iv_operations crypt_iv_plain_ops = {
272 .generator = crypt_iv_plain_gen
275 static struct crypt_iv_operations crypt_iv_essiv_ops = {
276 .ctr = crypt_iv_essiv_ctr,
277 .dtr = crypt_iv_essiv_dtr,
278 .generator = crypt_iv_essiv_gen
281 static struct crypt_iv_operations crypt_iv_benbi_ops = {
282 .ctr = crypt_iv_benbi_ctr,
283 .dtr = crypt_iv_benbi_dtr,
284 .generator = crypt_iv_benbi_gen
287 static struct crypt_iv_operations crypt_iv_null_ops = {
288 .generator = crypt_iv_null_gen
292 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
293 struct scatterlist *in, unsigned int length,
294 int write, sector_t sector)
296 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
297 struct blkcipher_desc desc = {
300 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
304 if (cc->iv_gen_ops) {
305 r = cc->iv_gen_ops->generator(cc, iv, sector);
310 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
312 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
315 r = crypto_blkcipher_encrypt(&desc, out, in, length);
317 r = crypto_blkcipher_decrypt(&desc, out, in, length);
324 crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx,
325 struct bio *bio_out, struct bio *bio_in,
326 sector_t sector, int write)
328 ctx->bio_in = bio_in;
329 ctx->bio_out = bio_out;
332 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
333 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
334 ctx->sector = sector + cc->iv_offset;
339 * Encrypt / decrypt data from one bio to another one (can be the same one)
341 static int crypt_convert(struct crypt_config *cc,
342 struct convert_context *ctx)
346 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
347 ctx->idx_out < ctx->bio_out->bi_vcnt) {
348 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
349 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
350 struct scatterlist sg_in = {
351 .page = bv_in->bv_page,
352 .offset = bv_in->bv_offset + ctx->offset_in,
353 .length = 1 << SECTOR_SHIFT
355 struct scatterlist sg_out = {
356 .page = bv_out->bv_page,
357 .offset = bv_out->bv_offset + ctx->offset_out,
358 .length = 1 << SECTOR_SHIFT
361 ctx->offset_in += sg_in.length;
362 if (ctx->offset_in >= bv_in->bv_len) {
367 ctx->offset_out += sg_out.length;
368 if (ctx->offset_out >= bv_out->bv_len) {
373 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
374 ctx->write, ctx->sector);
384 static void dm_crypt_bio_destructor(struct bio *bio)
386 struct dm_crypt_io *io = bio->bi_private;
387 struct crypt_config *cc = io->target->private;
389 bio_free(bio, cc->bs);
393 * Generate a new unfragmented bio with the given size
394 * This should never violate the device limitations
395 * May return a smaller bio when running out of pages
397 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
399 struct crypt_config *cc = io->target->private;
401 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
402 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 struct bio_vec *bv = bio_iovec_idx(clone, i);
414 bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
419 * if additional pages cannot be allocated without waiting,
420 * return a partially allocated bio, the caller will then try
421 * to allocate additional bios while submitting this partial bio
423 if (i == (MIN_BIO_PAGES - 1))
424 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
427 if (size > PAGE_SIZE)
428 bv->bv_len = PAGE_SIZE;
432 clone->bi_size += bv->bv_len;
437 if (!clone->bi_size) {
445 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
450 for (i = 0; i < clone->bi_vcnt; i++) {
451 bv = bio_iovec_idx(clone, i);
452 BUG_ON(!bv->bv_page);
453 mempool_free(bv->bv_page, cc->page_pool);
459 * One of the bios was finished. Check for completion of
460 * the whole request and correctly clean up the buffer.
462 static void dec_pending(struct dm_crypt_io *io, int error)
464 struct crypt_config *cc = (struct crypt_config *) io->target->private;
469 if (!atomic_dec_and_test(&io->pending))
472 bio_endio(io->base_bio, io->error);
474 mempool_free(io, cc->io_pool);
480 * Needed because it would be very unwise to do decryption in an
483 static struct workqueue_struct *_kcryptd_workqueue;
484 static void kcryptd_do_work(struct work_struct *work);
486 static void kcryptd_queue_io(struct dm_crypt_io *io)
488 INIT_WORK(&io->work, kcryptd_do_work);
489 queue_work(_kcryptd_workqueue, &io->work);
492 static void crypt_endio(struct bio *clone, int error)
494 struct dm_crypt_io *io = clone->bi_private;
495 struct crypt_config *cc = io->target->private;
496 unsigned read_io = bio_data_dir(clone) == READ;
499 * free the processed pages
502 crypt_free_buffer_pages(cc, clone);
506 if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
512 io->post_process = 1;
513 kcryptd_queue_io(io);
518 dec_pending(io, error);
521 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
523 struct crypt_config *cc = io->target->private;
525 clone->bi_private = io;
526 clone->bi_end_io = crypt_endio;
527 clone->bi_bdev = cc->dev->bdev;
528 clone->bi_rw = io->base_bio->bi_rw;
529 clone->bi_destructor = dm_crypt_bio_destructor;
532 static void process_read(struct dm_crypt_io *io)
534 struct crypt_config *cc = io->target->private;
535 struct bio *base_bio = io->base_bio;
537 sector_t sector = base_bio->bi_sector - io->target->begin;
539 atomic_inc(&io->pending);
542 * The block layer might modify the bvec array, so always
543 * copy the required bvecs because we need the original
544 * one in order to decrypt the whole bio data *afterwards*.
546 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
547 if (unlikely(!clone)) {
548 dec_pending(io, -ENOMEM);
552 clone_init(io, clone);
554 clone->bi_vcnt = bio_segments(base_bio);
555 clone->bi_size = base_bio->bi_size;
556 clone->bi_sector = cc->start + sector;
557 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
558 sizeof(struct bio_vec) * clone->bi_vcnt);
560 generic_make_request(clone);
563 static void process_write(struct dm_crypt_io *io)
565 struct crypt_config *cc = io->target->private;
566 struct bio *base_bio = io->base_bio;
568 struct convert_context ctx;
569 unsigned remaining = base_bio->bi_size;
570 sector_t sector = base_bio->bi_sector - io->target->begin;
572 atomic_inc(&io->pending);
574 crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
577 * The allocated buffers can be smaller than the whole bio,
578 * so repeat the whole process until all the data can be handled.
581 clone = crypt_alloc_buffer(io, remaining);
582 if (unlikely(!clone)) {
583 dec_pending(io, -ENOMEM);
590 if (unlikely(crypt_convert(cc, &ctx) < 0)) {
591 crypt_free_buffer_pages(cc, clone);
593 dec_pending(io, -EIO);
597 /* crypt_convert should have filled the clone bio */
598 BUG_ON(ctx.idx_out < clone->bi_vcnt);
600 clone->bi_sector = cc->start + sector;
601 remaining -= clone->bi_size;
602 sector += bio_sectors(clone);
604 /* Grab another reference to the io struct
605 * before we kick off the request */
607 atomic_inc(&io->pending);
609 generic_make_request(clone);
611 /* Do not reference clone after this - it
612 * may be gone already. */
614 /* out of memory -> run queues */
616 congestion_wait(WRITE, HZ/100);
620 static void process_read_endio(struct dm_crypt_io *io)
622 struct crypt_config *cc = io->target->private;
623 struct convert_context ctx;
625 crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,
626 io->base_bio->bi_sector - io->target->begin, 0);
628 dec_pending(io, crypt_convert(cc, &ctx));
631 static void kcryptd_do_work(struct work_struct *work)
633 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
635 if (io->post_process)
636 process_read_endio(io);
637 else if (bio_data_dir(io->base_bio) == READ)
644 * Decode key from its hex representation
646 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
654 for (i = 0; i < size; i++) {
658 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
660 if (endp != &buffer[2])
671 * Encode key into its hex representation
673 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
677 for (i = 0; i < size; i++) {
678 sprintf(hex, "%02x", *key);
684 static int crypt_set_key(struct crypt_config *cc, char *key)
686 unsigned key_size = strlen(key) >> 1;
688 if (cc->key_size && cc->key_size != key_size)
691 cc->key_size = key_size; /* initial settings */
693 if ((!key_size && strcmp(key, "-")) ||
694 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
697 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
702 static int crypt_wipe_key(struct crypt_config *cc)
704 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
705 memset(&cc->key, 0, cc->key_size * sizeof(u8));
710 * Construct an encryption mapping:
711 * <cipher> <key> <iv_offset> <dev_path> <start>
713 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
715 struct crypt_config *cc;
716 struct crypto_blkcipher *tfm;
722 unsigned int key_size;
723 unsigned long long tmpll;
726 ti->error = "Not enough arguments";
731 cipher = strsep(&tmp, "-");
732 chainmode = strsep(&tmp, "-");
733 ivopts = strsep(&tmp, "-");
734 ivmode = strsep(&ivopts, ":");
737 DMWARN("Unexpected additional cipher options");
739 key_size = strlen(argv[1]) >> 1;
741 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
744 "Cannot allocate transparent encryption context";
748 if (crypt_set_key(cc, argv[1])) {
749 ti->error = "Error decoding key";
753 /* Compatiblity mode for old dm-crypt cipher strings */
754 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
759 if (strcmp(chainmode, "ecb") && !ivmode) {
760 ti->error = "This chaining mode requires an IV mechanism";
764 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", chainmode,
765 cipher) >= CRYPTO_MAX_ALG_NAME) {
766 ti->error = "Chain mode + cipher name is too long";
770 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
772 ti->error = "Error allocating crypto tfm";
776 strcpy(cc->cipher, cipher);
777 strcpy(cc->chainmode, chainmode);
781 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
782 * See comments at iv code
786 cc->iv_gen_ops = NULL;
787 else if (strcmp(ivmode, "plain") == 0)
788 cc->iv_gen_ops = &crypt_iv_plain_ops;
789 else if (strcmp(ivmode, "essiv") == 0)
790 cc->iv_gen_ops = &crypt_iv_essiv_ops;
791 else if (strcmp(ivmode, "benbi") == 0)
792 cc->iv_gen_ops = &crypt_iv_benbi_ops;
793 else if (strcmp(ivmode, "null") == 0)
794 cc->iv_gen_ops = &crypt_iv_null_ops;
796 ti->error = "Invalid IV mode";
800 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
801 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
804 cc->iv_size = crypto_blkcipher_ivsize(tfm);
806 /* at least a 64 bit sector number should fit in our buffer */
807 cc->iv_size = max(cc->iv_size,
808 (unsigned int)(sizeof(u64) / sizeof(u8)));
810 if (cc->iv_gen_ops) {
811 DMWARN("Selected cipher does not support IVs");
812 if (cc->iv_gen_ops->dtr)
813 cc->iv_gen_ops->dtr(cc);
814 cc->iv_gen_ops = NULL;
818 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
820 ti->error = "Cannot allocate crypt io mempool";
824 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
825 if (!cc->page_pool) {
826 ti->error = "Cannot allocate page mempool";
830 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
832 ti->error = "Cannot allocate crypt bioset";
836 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
837 ti->error = "Error setting key";
841 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
842 ti->error = "Invalid iv_offset sector";
845 cc->iv_offset = tmpll;
847 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
848 ti->error = "Invalid device sector";
853 if (dm_get_device(ti, argv[3], cc->start, ti->len,
854 dm_table_get_mode(ti->table), &cc->dev)) {
855 ti->error = "Device lookup failed";
859 if (ivmode && cc->iv_gen_ops) {
862 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
864 ti->error = "Error kmallocing iv_mode string";
867 strcpy(cc->iv_mode, ivmode);
875 dm_put_device(ti, cc->dev);
879 mempool_destroy(cc->page_pool);
881 mempool_destroy(cc->io_pool);
883 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
884 cc->iv_gen_ops->dtr(cc);
886 crypto_free_blkcipher(tfm);
888 /* Must zero key material before freeing */
889 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
894 static void crypt_dtr(struct dm_target *ti)
896 struct crypt_config *cc = (struct crypt_config *) ti->private;
898 flush_workqueue(_kcryptd_workqueue);
901 mempool_destroy(cc->page_pool);
902 mempool_destroy(cc->io_pool);
905 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
906 cc->iv_gen_ops->dtr(cc);
907 crypto_free_blkcipher(cc->tfm);
908 dm_put_device(ti, cc->dev);
910 /* Must zero key material before freeing */
911 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
915 static int crypt_map(struct dm_target *ti, struct bio *bio,
916 union map_info *map_context)
918 struct crypt_config *cc = ti->private;
919 struct dm_crypt_io *io;
921 io = mempool_alloc(cc->io_pool, GFP_NOIO);
924 io->error = io->post_process = 0;
925 atomic_set(&io->pending, 0);
926 kcryptd_queue_io(io);
928 return DM_MAPIO_SUBMITTED;
931 static int crypt_status(struct dm_target *ti, status_type_t type,
932 char *result, unsigned int maxlen)
934 struct crypt_config *cc = (struct crypt_config *) ti->private;
938 case STATUSTYPE_INFO:
942 case STATUSTYPE_TABLE:
944 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
947 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
949 if (cc->key_size > 0) {
950 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
953 crypt_encode_key(result + sz, cc->key, cc->key_size);
954 sz += cc->key_size << 1;
961 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
962 cc->dev->name, (unsigned long long)cc->start);
968 static void crypt_postsuspend(struct dm_target *ti)
970 struct crypt_config *cc = ti->private;
972 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
975 static int crypt_preresume(struct dm_target *ti)
977 struct crypt_config *cc = ti->private;
979 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
980 DMERR("aborting resume - crypt key is not set.");
987 static void crypt_resume(struct dm_target *ti)
989 struct crypt_config *cc = ti->private;
991 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
998 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1000 struct crypt_config *cc = ti->private;
1005 if (!strnicmp(argv[0], MESG_STR("key"))) {
1006 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1007 DMWARN("not suspended during key manipulation.");
1010 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1011 return crypt_set_key(cc, argv[2]);
1012 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1013 return crypt_wipe_key(cc);
1017 DMWARN("unrecognised message received.");
1021 static struct target_type crypt_target = {
1023 .version= {1, 5, 0},
1024 .module = THIS_MODULE,
1028 .status = crypt_status,
1029 .postsuspend = crypt_postsuspend,
1030 .preresume = crypt_preresume,
1031 .resume = crypt_resume,
1032 .message = crypt_message,
1035 static int __init dm_crypt_init(void)
1039 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1040 if (!_crypt_io_pool)
1043 _kcryptd_workqueue = create_workqueue("kcryptd");
1044 if (!_kcryptd_workqueue) {
1046 DMERR("couldn't create kcryptd");
1050 r = dm_register_target(&crypt_target);
1052 DMERR("register failed %d", r);
1059 destroy_workqueue(_kcryptd_workqueue);
1061 kmem_cache_destroy(_crypt_io_pool);
1065 static void __exit dm_crypt_exit(void)
1067 int r = dm_unregister_target(&crypt_target);
1070 DMERR("unregister failed %d", r);
1072 destroy_workqueue(_kcryptd_workqueue);
1073 kmem_cache_destroy(_crypt_io_pool);
1076 module_init(dm_crypt_init);
1077 module_exit(dm_crypt_exit);
1079 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1080 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1081 MODULE_LICENSE("GPL");