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 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 * 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 = {
352 .page = bv_in->bv_page,
353 .offset = bv_in->bv_offset + ctx->offset_in,
354 .length = 1 << SECTOR_SHIFT
356 struct scatterlist sg_out = {
357 .page = bv_out->bv_page,
358 .offset = bv_out->bv_offset + ctx->offset_out,
359 .length = 1 << SECTOR_SHIFT
362 ctx->offset_in += sg_in.length;
363 if (ctx->offset_in >= bv_in->bv_len) {
368 ctx->offset_out += sg_out.length;
369 if (ctx->offset_out >= bv_out->bv_len) {
374 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
375 ctx->write, ctx->sector);
385 static void dm_crypt_bio_destructor(struct bio *bio)
387 struct dm_crypt_io *io = bio->bi_private;
388 struct crypt_config *cc = io->target->private;
390 bio_free(bio, cc->bs);
394 * Generate a new unfragmented bio with the given size
395 * This should never violate the device limitations
396 * May return a smaller bio when running out of pages
398 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
400 struct crypt_config *cc = io->target->private;
402 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
403 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
406 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
410 clone_init(io, clone);
412 for (i = 0; i < nr_iovecs; i++) {
413 struct bio_vec *bv = bio_iovec_idx(clone, i);
415 bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
420 * if additional pages cannot be allocated without waiting,
421 * return a partially allocated bio, the caller will then try
422 * to allocate additional bios while submitting this partial bio
424 if (i == (MIN_BIO_PAGES - 1))
425 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
428 if (size > PAGE_SIZE)
429 bv->bv_len = PAGE_SIZE;
433 clone->bi_size += bv->bv_len;
438 if (!clone->bi_size) {
446 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
451 for (i = 0; i < clone->bi_vcnt; i++) {
452 bv = bio_iovec_idx(clone, i);
453 BUG_ON(!bv->bv_page);
454 mempool_free(bv->bv_page, cc->page_pool);
460 * One of the bios was finished. Check for completion of
461 * the whole request and correctly clean up the buffer.
463 static void crypt_dec_pending(struct dm_crypt_io *io, int error)
465 struct crypt_config *cc = (struct crypt_config *) io->target->private;
470 if (!atomic_dec_and_test(&io->pending))
473 bio_endio(io->base_bio, io->error);
475 mempool_free(io, cc->io_pool);
479 * kcryptd/kcryptd_io:
481 * Needed because it would be very unwise to do decryption in an
484 * kcryptd performs the actual encryption or decryption.
486 * kcryptd_io performs the IO submission.
488 * They must be separated as otherwise the final stages could be
489 * starved by new requests which can block in the first stages due
490 * to memory allocation.
492 static void kcryptd_do_work(struct work_struct *work);
493 static void kcryptd_do_crypt(struct work_struct *work);
495 static void kcryptd_queue_io(struct dm_crypt_io *io)
497 struct crypt_config *cc = io->target->private;
499 INIT_WORK(&io->work, kcryptd_do_work);
500 queue_work(cc->io_queue, &io->work);
503 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
505 struct crypt_config *cc = io->target->private;
507 INIT_WORK(&io->work, kcryptd_do_crypt);
508 queue_work(cc->crypt_queue, &io->work);
511 static void crypt_endio(struct bio *clone, int error)
513 struct dm_crypt_io *io = clone->bi_private;
514 struct crypt_config *cc = io->target->private;
515 unsigned read_io = bio_data_dir(clone) == READ;
518 * free the processed pages
521 crypt_free_buffer_pages(cc, clone);
525 if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
531 kcryptd_queue_crypt(io);
536 crypt_dec_pending(io, error);
539 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
541 struct crypt_config *cc = io->target->private;
543 clone->bi_private = io;
544 clone->bi_end_io = crypt_endio;
545 clone->bi_bdev = cc->dev->bdev;
546 clone->bi_rw = io->base_bio->bi_rw;
547 clone->bi_destructor = dm_crypt_bio_destructor;
550 static void process_read(struct dm_crypt_io *io)
552 struct crypt_config *cc = io->target->private;
553 struct bio *base_bio = io->base_bio;
555 sector_t sector = base_bio->bi_sector - io->target->begin;
557 atomic_inc(&io->pending);
560 * The block layer might modify the bvec array, so always
561 * copy the required bvecs because we need the original
562 * one in order to decrypt the whole bio data *afterwards*.
564 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
565 if (unlikely(!clone)) {
566 crypt_dec_pending(io, -ENOMEM);
570 clone_init(io, clone);
572 clone->bi_vcnt = bio_segments(base_bio);
573 clone->bi_size = base_bio->bi_size;
574 clone->bi_sector = cc->start + sector;
575 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
576 sizeof(struct bio_vec) * clone->bi_vcnt);
578 generic_make_request(clone);
581 static void process_write(struct dm_crypt_io *io)
583 struct crypt_config *cc = io->target->private;
584 struct bio *base_bio = io->base_bio;
586 struct convert_context ctx;
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, &ctx, NULL, base_bio, sector, 1);
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)) {
601 crypt_dec_pending(io, -ENOMEM);
608 if (unlikely(crypt_convert(cc, &ctx) < 0)) {
609 crypt_free_buffer_pages(cc, clone);
611 crypt_dec_pending(io, -EIO);
615 /* crypt_convert should have filled the clone bio */
616 BUG_ON(ctx.idx_out < clone->bi_vcnt);
618 clone->bi_sector = cc->start + sector;
619 remaining -= clone->bi_size;
620 sector += bio_sectors(clone);
622 /* Grab another reference to the io struct
623 * before we kick off the request */
625 atomic_inc(&io->pending);
627 generic_make_request(clone);
629 /* Do not reference clone after this - it
630 * may be gone already. */
632 /* out of memory -> run queues */
634 congestion_wait(WRITE, HZ/100);
638 static void process_read_endio(struct dm_crypt_io *io)
640 struct crypt_config *cc = io->target->private;
641 struct convert_context ctx;
643 crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,
644 io->base_bio->bi_sector - io->target->begin, 0);
646 crypt_dec_pending(io, crypt_convert(cc, &ctx));
649 static void kcryptd_do_work(struct work_struct *work)
651 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
653 if (bio_data_dir(io->base_bio) == READ)
657 static void kcryptd_do_crypt(struct work_struct *work)
659 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
661 if (bio_data_dir(io->base_bio) == READ)
662 process_read_endio(io);
668 * Decode key from its hex representation
670 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
678 for (i = 0; i < size; i++) {
682 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
684 if (endp != &buffer[2])
695 * Encode key into its hex representation
697 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
701 for (i = 0; i < size; i++) {
702 sprintf(hex, "%02x", *key);
708 static int crypt_set_key(struct crypt_config *cc, char *key)
710 unsigned key_size = strlen(key) >> 1;
712 if (cc->key_size && cc->key_size != key_size)
715 cc->key_size = key_size; /* initial settings */
717 if ((!key_size && strcmp(key, "-")) ||
718 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
721 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
726 static int crypt_wipe_key(struct crypt_config *cc)
728 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
729 memset(&cc->key, 0, cc->key_size * sizeof(u8));
734 * Construct an encryption mapping:
735 * <cipher> <key> <iv_offset> <dev_path> <start>
737 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
739 struct crypt_config *cc;
740 struct crypto_blkcipher *tfm;
746 unsigned int key_size;
747 unsigned long long tmpll;
750 ti->error = "Not enough arguments";
755 cipher = strsep(&tmp, "-");
756 chainmode = strsep(&tmp, "-");
757 ivopts = strsep(&tmp, "-");
758 ivmode = strsep(&ivopts, ":");
761 DMWARN("Unexpected additional cipher options");
763 key_size = strlen(argv[1]) >> 1;
765 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
768 "Cannot allocate transparent encryption context";
772 if (crypt_set_key(cc, argv[1])) {
773 ti->error = "Error decoding key";
777 /* Compatiblity mode for old dm-crypt cipher strings */
778 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
783 if (strcmp(chainmode, "ecb") && !ivmode) {
784 ti->error = "This chaining mode requires an IV mechanism";
788 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
789 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
790 ti->error = "Chain mode + cipher name is too long";
794 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
796 ti->error = "Error allocating crypto tfm";
800 strcpy(cc->cipher, cipher);
801 strcpy(cc->chainmode, chainmode);
805 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
806 * See comments at iv code
810 cc->iv_gen_ops = NULL;
811 else if (strcmp(ivmode, "plain") == 0)
812 cc->iv_gen_ops = &crypt_iv_plain_ops;
813 else if (strcmp(ivmode, "essiv") == 0)
814 cc->iv_gen_ops = &crypt_iv_essiv_ops;
815 else if (strcmp(ivmode, "benbi") == 0)
816 cc->iv_gen_ops = &crypt_iv_benbi_ops;
817 else if (strcmp(ivmode, "null") == 0)
818 cc->iv_gen_ops = &crypt_iv_null_ops;
820 ti->error = "Invalid IV mode";
824 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
825 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
828 cc->iv_size = crypto_blkcipher_ivsize(tfm);
830 /* at least a 64 bit sector number should fit in our buffer */
831 cc->iv_size = max(cc->iv_size,
832 (unsigned int)(sizeof(u64) / sizeof(u8)));
834 if (cc->iv_gen_ops) {
835 DMWARN("Selected cipher does not support IVs");
836 if (cc->iv_gen_ops->dtr)
837 cc->iv_gen_ops->dtr(cc);
838 cc->iv_gen_ops = NULL;
842 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
844 ti->error = "Cannot allocate crypt io mempool";
848 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
849 if (!cc->page_pool) {
850 ti->error = "Cannot allocate page mempool";
854 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
856 ti->error = "Cannot allocate crypt bioset";
860 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
861 ti->error = "Error setting key";
865 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
866 ti->error = "Invalid iv_offset sector";
869 cc->iv_offset = tmpll;
871 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
872 ti->error = "Invalid device sector";
877 if (dm_get_device(ti, argv[3], cc->start, ti->len,
878 dm_table_get_mode(ti->table), &cc->dev)) {
879 ti->error = "Device lookup failed";
883 if (ivmode && cc->iv_gen_ops) {
886 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
888 ti->error = "Error kmallocing iv_mode string";
889 goto bad_ivmode_string;
891 strcpy(cc->iv_mode, ivmode);
895 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
897 ti->error = "Couldn't create kcryptd io queue";
901 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
902 if (!cc->crypt_queue) {
903 ti->error = "Couldn't create kcryptd queue";
904 goto bad_crypt_queue;
911 destroy_workqueue(cc->io_queue);
915 dm_put_device(ti, cc->dev);
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;
938 destroy_workqueue(cc->io_queue);
939 destroy_workqueue(cc->crypt_queue);
942 mempool_destroy(cc->page_pool);
943 mempool_destroy(cc->io_pool);
946 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
947 cc->iv_gen_ops->dtr(cc);
948 crypto_free_blkcipher(cc->tfm);
949 dm_put_device(ti, cc->dev);
951 /* Must zero key material before freeing */
952 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
956 static int crypt_map(struct dm_target *ti, struct bio *bio,
957 union map_info *map_context)
959 struct crypt_config *cc = ti->private;
960 struct dm_crypt_io *io;
962 io = mempool_alloc(cc->io_pool, GFP_NOIO);
966 atomic_set(&io->pending, 0);
968 if (bio_data_dir(io->base_bio) == READ)
969 kcryptd_queue_io(io);
971 kcryptd_queue_crypt(io);
973 return DM_MAPIO_SUBMITTED;
976 static int crypt_status(struct dm_target *ti, status_type_t type,
977 char *result, unsigned int maxlen)
979 struct crypt_config *cc = (struct crypt_config *) ti->private;
983 case STATUSTYPE_INFO:
987 case STATUSTYPE_TABLE:
989 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
992 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
994 if (cc->key_size > 0) {
995 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
998 crypt_encode_key(result + sz, cc->key, cc->key_size);
999 sz += cc->key_size << 1;
1006 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1007 cc->dev->name, (unsigned long long)cc->start);
1013 static void crypt_postsuspend(struct dm_target *ti)
1015 struct crypt_config *cc = ti->private;
1017 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1020 static int crypt_preresume(struct dm_target *ti)
1022 struct crypt_config *cc = ti->private;
1024 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1025 DMERR("aborting resume - crypt key is not set.");
1032 static void crypt_resume(struct dm_target *ti)
1034 struct crypt_config *cc = ti->private;
1036 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1039 /* Message interface
1043 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1045 struct crypt_config *cc = ti->private;
1050 if (!strnicmp(argv[0], MESG_STR("key"))) {
1051 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1052 DMWARN("not suspended during key manipulation.");
1055 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1056 return crypt_set_key(cc, argv[2]);
1057 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1058 return crypt_wipe_key(cc);
1062 DMWARN("unrecognised message received.");
1066 static struct target_type crypt_target = {
1068 .version= {1, 5, 0},
1069 .module = THIS_MODULE,
1073 .status = crypt_status,
1074 .postsuspend = crypt_postsuspend,
1075 .preresume = crypt_preresume,
1076 .resume = crypt_resume,
1077 .message = crypt_message,
1080 static int __init dm_crypt_init(void)
1084 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1085 if (!_crypt_io_pool)
1088 r = dm_register_target(&crypt_target);
1090 DMERR("register failed %d", r);
1091 kmem_cache_destroy(_crypt_io_pool);
1097 static void __exit dm_crypt_exit(void)
1099 int r = dm_unregister_target(&crypt_target);
1102 DMERR("unregister failed %d", r);
1104 kmem_cache_destroy(_crypt_io_pool);
1107 module_init(dm_crypt_init);
1108 module_exit(dm_crypt_exit);
1110 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1111 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1112 MODULE_LICENSE("GPL");