2 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2007 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_io(struct work_struct *work);
485 static void kcryptd_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_io);
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_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 kcryptd_io_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 kcryptd_io_write(struct dm_crypt_io *io)
578 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
582 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
584 struct crypt_config *cc = io->target->private;
585 struct bio *base_bio = io->base_bio;
587 unsigned remaining = base_bio->bi_size;
588 sector_t sector = base_bio->bi_sector - io->target->begin;
590 atomic_inc(&io->pending);
592 crypt_convert_init(cc, &io->ctx, NULL, base_bio, sector);
595 * The allocated buffers can be smaller than the whole bio,
596 * so repeat the whole process until all the data can be handled.
599 clone = crypt_alloc_buffer(io, remaining);
600 if (unlikely(!clone)) {
602 crypt_dec_pending(io);
606 io->ctx.bio_out = clone;
609 if (unlikely(crypt_convert(cc, &io->ctx) < 0)) {
610 crypt_free_buffer_pages(cc, clone);
613 crypt_dec_pending(io);
617 /* crypt_convert should have filled the clone bio */
618 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
620 clone->bi_sector = cc->start + sector;
621 remaining -= clone->bi_size;
622 sector += bio_sectors(clone);
624 /* Grab another reference to the io struct
625 * before we kick off the request */
627 atomic_inc(&io->pending);
629 generic_make_request(clone);
631 /* Do not reference clone after this - it
632 * may be gone already. */
634 /* out of memory -> run queues */
636 congestion_wait(WRITE, HZ/100);
640 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
642 if (unlikely(error < 0))
645 crypt_dec_pending(io);
648 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
650 struct crypt_config *cc = io->target->private;
653 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
654 io->base_bio->bi_sector - io->target->begin);
656 r = crypt_convert(cc, &io->ctx);
658 kcryptd_crypt_read_done(io, r);
661 static void kcryptd_io(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)
668 kcryptd_io_write(io);
671 static void kcryptd_crypt(struct work_struct *work)
673 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
675 if (bio_data_dir(io->base_bio) == READ)
676 kcryptd_crypt_read_convert(io);
678 kcryptd_crypt_write_convert(io);
682 * Decode key from its hex representation
684 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
692 for (i = 0; i < size; i++) {
696 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
698 if (endp != &buffer[2])
709 * Encode key into its hex representation
711 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
715 for (i = 0; i < size; i++) {
716 sprintf(hex, "%02x", *key);
722 static int crypt_set_key(struct crypt_config *cc, char *key)
724 unsigned key_size = strlen(key) >> 1;
726 if (cc->key_size && cc->key_size != key_size)
729 cc->key_size = key_size; /* initial settings */
731 if ((!key_size && strcmp(key, "-")) ||
732 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
735 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
740 static int crypt_wipe_key(struct crypt_config *cc)
742 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
743 memset(&cc->key, 0, cc->key_size * sizeof(u8));
748 * Construct an encryption mapping:
749 * <cipher> <key> <iv_offset> <dev_path> <start>
751 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
753 struct crypt_config *cc;
754 struct crypto_blkcipher *tfm;
760 unsigned int key_size;
761 unsigned long long tmpll;
764 ti->error = "Not enough arguments";
769 cipher = strsep(&tmp, "-");
770 chainmode = strsep(&tmp, "-");
771 ivopts = strsep(&tmp, "-");
772 ivmode = strsep(&ivopts, ":");
775 DMWARN("Unexpected additional cipher options");
777 key_size = strlen(argv[1]) >> 1;
779 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
782 "Cannot allocate transparent encryption context";
786 if (crypt_set_key(cc, argv[1])) {
787 ti->error = "Error decoding key";
791 /* Compatiblity mode for old dm-crypt cipher strings */
792 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
797 if (strcmp(chainmode, "ecb") && !ivmode) {
798 ti->error = "This chaining mode requires an IV mechanism";
802 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
803 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
804 ti->error = "Chain mode + cipher name is too long";
808 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
810 ti->error = "Error allocating crypto tfm";
814 strcpy(cc->cipher, cipher);
815 strcpy(cc->chainmode, chainmode);
819 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
820 * See comments at iv code
824 cc->iv_gen_ops = NULL;
825 else if (strcmp(ivmode, "plain") == 0)
826 cc->iv_gen_ops = &crypt_iv_plain_ops;
827 else if (strcmp(ivmode, "essiv") == 0)
828 cc->iv_gen_ops = &crypt_iv_essiv_ops;
829 else if (strcmp(ivmode, "benbi") == 0)
830 cc->iv_gen_ops = &crypt_iv_benbi_ops;
831 else if (strcmp(ivmode, "null") == 0)
832 cc->iv_gen_ops = &crypt_iv_null_ops;
834 ti->error = "Invalid IV mode";
838 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
839 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
842 cc->iv_size = crypto_blkcipher_ivsize(tfm);
844 /* at least a 64 bit sector number should fit in our buffer */
845 cc->iv_size = max(cc->iv_size,
846 (unsigned int)(sizeof(u64) / sizeof(u8)));
848 if (cc->iv_gen_ops) {
849 DMWARN("Selected cipher does not support IVs");
850 if (cc->iv_gen_ops->dtr)
851 cc->iv_gen_ops->dtr(cc);
852 cc->iv_gen_ops = NULL;
856 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
858 ti->error = "Cannot allocate crypt io mempool";
862 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
863 if (!cc->page_pool) {
864 ti->error = "Cannot allocate page mempool";
868 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
870 ti->error = "Cannot allocate crypt bioset";
874 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
875 ti->error = "Error setting key";
879 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
880 ti->error = "Invalid iv_offset sector";
883 cc->iv_offset = tmpll;
885 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
886 ti->error = "Invalid device sector";
891 if (dm_get_device(ti, argv[3], cc->start, ti->len,
892 dm_table_get_mode(ti->table), &cc->dev)) {
893 ti->error = "Device lookup failed";
897 if (ivmode && cc->iv_gen_ops) {
900 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
902 ti->error = "Error kmallocing iv_mode string";
903 goto bad_ivmode_string;
905 strcpy(cc->iv_mode, ivmode);
909 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
911 ti->error = "Couldn't create kcryptd io queue";
915 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
916 if (!cc->crypt_queue) {
917 ti->error = "Couldn't create kcryptd queue";
918 goto bad_crypt_queue;
925 destroy_workqueue(cc->io_queue);
929 dm_put_device(ti, cc->dev);
933 mempool_destroy(cc->page_pool);
935 mempool_destroy(cc->io_pool);
937 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
938 cc->iv_gen_ops->dtr(cc);
940 crypto_free_blkcipher(tfm);
942 /* Must zero key material before freeing */
943 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
948 static void crypt_dtr(struct dm_target *ti)
950 struct crypt_config *cc = (struct crypt_config *) ti->private;
952 destroy_workqueue(cc->io_queue);
953 destroy_workqueue(cc->crypt_queue);
956 mempool_destroy(cc->page_pool);
957 mempool_destroy(cc->io_pool);
960 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
961 cc->iv_gen_ops->dtr(cc);
962 crypto_free_blkcipher(cc->tfm);
963 dm_put_device(ti, cc->dev);
965 /* Must zero key material before freeing */
966 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
970 static int crypt_map(struct dm_target *ti, struct bio *bio,
971 union map_info *map_context)
973 struct crypt_config *cc = ti->private;
974 struct dm_crypt_io *io;
976 io = mempool_alloc(cc->io_pool, GFP_NOIO);
980 atomic_set(&io->pending, 0);
982 if (bio_data_dir(io->base_bio) == READ)
983 kcryptd_queue_io(io);
985 kcryptd_queue_crypt(io);
987 return DM_MAPIO_SUBMITTED;
990 static int crypt_status(struct dm_target *ti, status_type_t type,
991 char *result, unsigned int maxlen)
993 struct crypt_config *cc = (struct crypt_config *) ti->private;
997 case STATUSTYPE_INFO:
1001 case STATUSTYPE_TABLE:
1003 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1006 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
1008 if (cc->key_size > 0) {
1009 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1012 crypt_encode_key(result + sz, cc->key, cc->key_size);
1013 sz += cc->key_size << 1;
1020 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1021 cc->dev->name, (unsigned long long)cc->start);
1027 static void crypt_postsuspend(struct dm_target *ti)
1029 struct crypt_config *cc = ti->private;
1031 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1034 static int crypt_preresume(struct dm_target *ti)
1036 struct crypt_config *cc = ti->private;
1038 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1039 DMERR("aborting resume - crypt key is not set.");
1046 static void crypt_resume(struct dm_target *ti)
1048 struct crypt_config *cc = ti->private;
1050 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1053 /* Message interface
1057 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1059 struct crypt_config *cc = ti->private;
1064 if (!strnicmp(argv[0], MESG_STR("key"))) {
1065 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1066 DMWARN("not suspended during key manipulation.");
1069 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1070 return crypt_set_key(cc, argv[2]);
1071 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1072 return crypt_wipe_key(cc);
1076 DMWARN("unrecognised message received.");
1080 static struct target_type crypt_target = {
1082 .version= {1, 5, 0},
1083 .module = THIS_MODULE,
1087 .status = crypt_status,
1088 .postsuspend = crypt_postsuspend,
1089 .preresume = crypt_preresume,
1090 .resume = crypt_resume,
1091 .message = crypt_message,
1094 static int __init dm_crypt_init(void)
1098 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1099 if (!_crypt_io_pool)
1102 r = dm_register_target(&crypt_target);
1104 DMERR("register failed %d", r);
1105 kmem_cache_destroy(_crypt_io_pool);
1111 static void __exit dm_crypt_exit(void)
1113 int r = dm_unregister_target(&crypt_target);
1116 DMERR("unregister failed %d", r);
1118 kmem_cache_destroy(_crypt_io_pool);
1121 module_init(dm_crypt_init);
1122 module_exit(dm_crypt_exit);
1124 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1125 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1126 MODULE_LICENSE("GPL");