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;
58 struct dm_crypt_request {
59 struct scatterlist sg_in;
60 struct scatterlist sg_out;
65 struct crypt_iv_operations {
66 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
68 void (*dtr)(struct crypt_config *cc);
69 const char *(*status)(struct crypt_config *cc);
70 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
74 * Crypt: maps a linear range of a block device
75 * and encrypts / decrypts at the same time.
77 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
83 * pool for per bio private data and
84 * for encryption buffer pages
90 struct workqueue_struct *io_queue;
91 struct workqueue_struct *crypt_queue;
95 struct crypt_iv_operations *iv_gen_ops;
98 struct crypto_cipher *essiv_tfm;
102 unsigned int iv_size;
104 char cipher[CRYPTO_MAX_ALG_NAME];
105 char chainmode[CRYPTO_MAX_ALG_NAME];
106 struct crypto_blkcipher *tfm;
108 unsigned int key_size;
113 #define MIN_POOL_PAGES 32
114 #define MIN_BIO_PAGES 8
116 static struct kmem_cache *_crypt_io_pool;
118 static void clone_init(struct dm_crypt_io *, struct bio *);
119 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
122 * Different IV generation algorithms:
124 * plain: the initial vector is the 32-bit little-endian version of the sector
125 * number, padded with zeros if necessary.
127 * essiv: "encrypted sector|salt initial vector", the sector number is
128 * encrypted with the bulk cipher using a salt as key. The salt
129 * should be derived from the bulk cipher's key via hashing.
131 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
132 * (needed for LRW-32-AES and possible other narrow block modes)
134 * null: the initial vector is always zero. Provides compatibility with
135 * obsolete loop_fish2 devices. Do not use for new devices.
137 * plumb: unimplemented, see:
138 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
141 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
143 memset(iv, 0, cc->iv_size);
144 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
149 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
152 struct crypto_cipher *essiv_tfm;
153 struct crypto_hash *hash_tfm;
154 struct hash_desc desc;
155 struct scatterlist sg;
156 unsigned int saltsize;
161 ti->error = "Digest algorithm missing for ESSIV mode";
165 /* Hash the cipher key with the given hash algorithm */
166 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
167 if (IS_ERR(hash_tfm)) {
168 ti->error = "Error initializing ESSIV hash";
169 return PTR_ERR(hash_tfm);
172 saltsize = crypto_hash_digestsize(hash_tfm);
173 salt = kmalloc(saltsize, GFP_KERNEL);
175 ti->error = "Error kmallocing salt storage in ESSIV";
176 crypto_free_hash(hash_tfm);
180 sg_init_one(&sg, cc->key, cc->key_size);
182 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
183 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
184 crypto_free_hash(hash_tfm);
187 ti->error = "Error calculating hash in ESSIV";
192 /* Setup the essiv_tfm with the given salt */
193 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
194 if (IS_ERR(essiv_tfm)) {
195 ti->error = "Error allocating crypto tfm for ESSIV";
197 return PTR_ERR(essiv_tfm);
199 if (crypto_cipher_blocksize(essiv_tfm) !=
200 crypto_blkcipher_ivsize(cc->tfm)) {
201 ti->error = "Block size of ESSIV cipher does "
202 "not match IV size of block cipher";
203 crypto_free_cipher(essiv_tfm);
207 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
209 ti->error = "Failed to set key for ESSIV cipher";
210 crypto_free_cipher(essiv_tfm);
216 cc->iv_gen_private.essiv_tfm = essiv_tfm;
220 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
222 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
223 cc->iv_gen_private.essiv_tfm = NULL;
226 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
228 memset(iv, 0, cc->iv_size);
229 *(u64 *)iv = cpu_to_le64(sector);
230 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
234 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
237 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
240 /* we need to calculate how far we must shift the sector count
241 * to get the cipher block count, we use this shift in _gen */
243 if (1 << log != bs) {
244 ti->error = "cypher blocksize is not a power of 2";
249 ti->error = "cypher blocksize is > 512";
253 cc->iv_gen_private.benbi_shift = 9 - log;
258 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
262 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
266 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
268 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
269 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
274 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
276 memset(iv, 0, cc->iv_size);
281 static struct crypt_iv_operations crypt_iv_plain_ops = {
282 .generator = crypt_iv_plain_gen
285 static struct crypt_iv_operations crypt_iv_essiv_ops = {
286 .ctr = crypt_iv_essiv_ctr,
287 .dtr = crypt_iv_essiv_dtr,
288 .generator = crypt_iv_essiv_gen
291 static struct crypt_iv_operations crypt_iv_benbi_ops = {
292 .ctr = crypt_iv_benbi_ctr,
293 .dtr = crypt_iv_benbi_dtr,
294 .generator = crypt_iv_benbi_gen
297 static struct crypt_iv_operations crypt_iv_null_ops = {
298 .generator = crypt_iv_null_gen
302 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
303 struct scatterlist *in, unsigned int length,
304 int write, sector_t sector)
306 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
307 struct blkcipher_desc desc = {
310 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
314 if (cc->iv_gen_ops) {
315 r = cc->iv_gen_ops->generator(cc, iv, sector);
320 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
322 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
325 r = crypto_blkcipher_encrypt(&desc, out, in, length);
327 r = crypto_blkcipher_decrypt(&desc, out, in, length);
333 static void crypt_convert_init(struct crypt_config *cc,
334 struct convert_context *ctx,
335 struct bio *bio_out, struct bio *bio_in,
338 ctx->bio_in = bio_in;
339 ctx->bio_out = bio_out;
342 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
343 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
344 ctx->sector = sector + cc->iv_offset;
347 static int crypt_convert_block(struct crypt_config *cc,
348 struct convert_context *ctx)
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 dm_crypt_request dmreq;
354 sg_init_table(&dmreq.sg_in, 1);
355 sg_set_page(&dmreq.sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
356 bv_in->bv_offset + ctx->offset_in);
358 sg_init_table(&dmreq.sg_out, 1);
359 sg_set_page(&dmreq.sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
360 bv_out->bv_offset + ctx->offset_out);
362 ctx->offset_in += 1 << SECTOR_SHIFT;
363 if (ctx->offset_in >= bv_in->bv_len) {
368 ctx->offset_out += 1 << SECTOR_SHIFT;
369 if (ctx->offset_out >= bv_out->bv_len) {
374 return crypt_convert_scatterlist(cc, &dmreq.sg_out, &dmreq.sg_in,
376 bio_data_dir(ctx->bio_in) == WRITE,
381 * Encrypt / decrypt data from one bio to another one (can be the same one)
383 static int crypt_convert(struct crypt_config *cc,
384 struct convert_context *ctx)
388 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
389 ctx->idx_out < ctx->bio_out->bi_vcnt) {
390 r = crypt_convert_block(cc, ctx);
400 static void dm_crypt_bio_destructor(struct bio *bio)
402 struct dm_crypt_io *io = bio->bi_private;
403 struct crypt_config *cc = io->target->private;
405 bio_free(bio, cc->bs);
409 * Generate a new unfragmented bio with the given size
410 * This should never violate the device limitations
411 * May return a smaller bio when running out of pages
413 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
415 struct crypt_config *cc = io->target->private;
417 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
418 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
422 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
426 clone_init(io, clone);
428 for (i = 0; i < nr_iovecs; i++) {
429 page = mempool_alloc(cc->page_pool, gfp_mask);
434 * if additional pages cannot be allocated without waiting,
435 * return a partially allocated bio, the caller will then try
436 * to allocate additional bios while submitting this partial bio
438 if (i == (MIN_BIO_PAGES - 1))
439 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
441 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
443 if (!bio_add_page(clone, page, len, 0)) {
444 mempool_free(page, cc->page_pool);
451 if (!clone->bi_size) {
459 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
464 for (i = 0; i < clone->bi_vcnt; i++) {
465 bv = bio_iovec_idx(clone, i);
466 BUG_ON(!bv->bv_page);
467 mempool_free(bv->bv_page, cc->page_pool);
473 * One of the bios was finished. Check for completion of
474 * the whole request and correctly clean up the buffer.
476 static void crypt_dec_pending(struct dm_crypt_io *io)
478 struct crypt_config *cc = io->target->private;
480 if (!atomic_dec_and_test(&io->pending))
483 bio_endio(io->base_bio, io->error);
484 mempool_free(io, cc->io_pool);
488 * kcryptd/kcryptd_io:
490 * Needed because it would be very unwise to do decryption in an
493 * kcryptd performs the actual encryption or decryption.
495 * kcryptd_io performs the IO submission.
497 * They must be separated as otherwise the final stages could be
498 * starved by new requests which can block in the first stages due
499 * to memory allocation.
501 static void crypt_endio(struct bio *clone, int error)
503 struct dm_crypt_io *io = clone->bi_private;
504 struct crypt_config *cc = io->target->private;
505 unsigned rw = bio_data_dir(clone);
507 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
511 * free the processed pages
514 crypt_free_buffer_pages(cc, clone);
518 if (rw == READ && !error) {
519 kcryptd_queue_crypt(io);
526 crypt_dec_pending(io);
529 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
531 struct crypt_config *cc = io->target->private;
533 clone->bi_private = io;
534 clone->bi_end_io = crypt_endio;
535 clone->bi_bdev = cc->dev->bdev;
536 clone->bi_rw = io->base_bio->bi_rw;
537 clone->bi_destructor = dm_crypt_bio_destructor;
540 static void kcryptd_io_read(struct dm_crypt_io *io)
542 struct crypt_config *cc = io->target->private;
543 struct bio *base_bio = io->base_bio;
546 atomic_inc(&io->pending);
549 * The block layer might modify the bvec array, so always
550 * copy the required bvecs because we need the original
551 * one in order to decrypt the whole bio data *afterwards*.
553 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
554 if (unlikely(!clone)) {
556 crypt_dec_pending(io);
560 clone_init(io, clone);
562 clone->bi_vcnt = bio_segments(base_bio);
563 clone->bi_size = base_bio->bi_size;
564 clone->bi_sector = cc->start + io->sector;
565 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
566 sizeof(struct bio_vec) * clone->bi_vcnt);
568 generic_make_request(clone);
571 static void kcryptd_io_write(struct dm_crypt_io *io)
575 static void kcryptd_io(struct work_struct *work)
577 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
579 if (bio_data_dir(io->base_bio) == READ)
582 kcryptd_io_write(io);
585 static void kcryptd_queue_io(struct dm_crypt_io *io)
587 struct crypt_config *cc = io->target->private;
589 INIT_WORK(&io->work, kcryptd_io);
590 queue_work(cc->io_queue, &io->work);
593 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
595 struct bio *clone = io->ctx.bio_out;
596 struct crypt_config *cc = io->target->private;
598 if (unlikely(error < 0)) {
599 crypt_free_buffer_pages(cc, clone);
605 /* crypt_convert should have filled the clone bio */
606 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
608 clone->bi_sector = cc->start + io->sector;
609 io->sector += bio_sectors(clone);
611 atomic_inc(&io->pending);
612 generic_make_request(clone);
615 static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)
617 struct crypt_config *cc = io->target->private;
619 unsigned remaining = io->base_bio->bi_size;
623 * The allocated buffers can be smaller than the whole bio,
624 * so repeat the whole process until all the data can be handled.
627 clone = crypt_alloc_buffer(io, remaining);
628 if (unlikely(!clone)) {
633 io->ctx.bio_out = clone;
636 remaining -= clone->bi_size;
638 r = crypt_convert(cc, &io->ctx);
640 kcryptd_crypt_write_io_submit(io, r);
644 /* out of memory -> run queues */
645 if (unlikely(remaining))
646 congestion_wait(WRITE, HZ/100);
650 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
652 struct crypt_config *cc = io->target->private;
655 * Prevent io from disappearing until this function completes.
657 atomic_inc(&io->pending);
659 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
660 kcryptd_crypt_write_convert_loop(io);
662 crypt_dec_pending(io);
665 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
667 if (unlikely(error < 0))
670 crypt_dec_pending(io);
673 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
675 struct crypt_config *cc = io->target->private;
678 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
681 r = crypt_convert(cc, &io->ctx);
683 kcryptd_crypt_read_done(io, r);
686 static void kcryptd_crypt(struct work_struct *work)
688 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
690 if (bio_data_dir(io->base_bio) == READ)
691 kcryptd_crypt_read_convert(io);
693 kcryptd_crypt_write_convert(io);
696 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
698 struct crypt_config *cc = io->target->private;
700 INIT_WORK(&io->work, kcryptd_crypt);
701 queue_work(cc->crypt_queue, &io->work);
705 * Decode key from its hex representation
707 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
715 for (i = 0; i < size; i++) {
719 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
721 if (endp != &buffer[2])
732 * Encode key into its hex representation
734 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
738 for (i = 0; i < size; i++) {
739 sprintf(hex, "%02x", *key);
745 static int crypt_set_key(struct crypt_config *cc, char *key)
747 unsigned key_size = strlen(key) >> 1;
749 if (cc->key_size && cc->key_size != key_size)
752 cc->key_size = key_size; /* initial settings */
754 if ((!key_size && strcmp(key, "-")) ||
755 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
758 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
763 static int crypt_wipe_key(struct crypt_config *cc)
765 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
766 memset(&cc->key, 0, cc->key_size * sizeof(u8));
771 * Construct an encryption mapping:
772 * <cipher> <key> <iv_offset> <dev_path> <start>
774 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
776 struct crypt_config *cc;
777 struct crypto_blkcipher *tfm;
783 unsigned int key_size;
784 unsigned long long tmpll;
787 ti->error = "Not enough arguments";
792 cipher = strsep(&tmp, "-");
793 chainmode = strsep(&tmp, "-");
794 ivopts = strsep(&tmp, "-");
795 ivmode = strsep(&ivopts, ":");
798 DMWARN("Unexpected additional cipher options");
800 key_size = strlen(argv[1]) >> 1;
802 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
805 "Cannot allocate transparent encryption context";
809 if (crypt_set_key(cc, argv[1])) {
810 ti->error = "Error decoding key";
814 /* Compatiblity mode for old dm-crypt cipher strings */
815 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
820 if (strcmp(chainmode, "ecb") && !ivmode) {
821 ti->error = "This chaining mode requires an IV mechanism";
825 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
826 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
827 ti->error = "Chain mode + cipher name is too long";
831 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
833 ti->error = "Error allocating crypto tfm";
837 strcpy(cc->cipher, cipher);
838 strcpy(cc->chainmode, chainmode);
842 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
843 * See comments at iv code
847 cc->iv_gen_ops = NULL;
848 else if (strcmp(ivmode, "plain") == 0)
849 cc->iv_gen_ops = &crypt_iv_plain_ops;
850 else if (strcmp(ivmode, "essiv") == 0)
851 cc->iv_gen_ops = &crypt_iv_essiv_ops;
852 else if (strcmp(ivmode, "benbi") == 0)
853 cc->iv_gen_ops = &crypt_iv_benbi_ops;
854 else if (strcmp(ivmode, "null") == 0)
855 cc->iv_gen_ops = &crypt_iv_null_ops;
857 ti->error = "Invalid IV mode";
861 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
862 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
865 cc->iv_size = crypto_blkcipher_ivsize(tfm);
867 /* at least a 64 bit sector number should fit in our buffer */
868 cc->iv_size = max(cc->iv_size,
869 (unsigned int)(sizeof(u64) / sizeof(u8)));
871 if (cc->iv_gen_ops) {
872 DMWARN("Selected cipher does not support IVs");
873 if (cc->iv_gen_ops->dtr)
874 cc->iv_gen_ops->dtr(cc);
875 cc->iv_gen_ops = NULL;
879 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
881 ti->error = "Cannot allocate crypt io mempool";
885 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
886 if (!cc->page_pool) {
887 ti->error = "Cannot allocate page mempool";
891 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
893 ti->error = "Cannot allocate crypt bioset";
897 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
898 ti->error = "Error setting key";
902 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
903 ti->error = "Invalid iv_offset sector";
906 cc->iv_offset = tmpll;
908 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
909 ti->error = "Invalid device sector";
914 if (dm_get_device(ti, argv[3], cc->start, ti->len,
915 dm_table_get_mode(ti->table), &cc->dev)) {
916 ti->error = "Device lookup failed";
920 if (ivmode && cc->iv_gen_ops) {
923 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
925 ti->error = "Error kmallocing iv_mode string";
926 goto bad_ivmode_string;
928 strcpy(cc->iv_mode, ivmode);
932 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
934 ti->error = "Couldn't create kcryptd io queue";
938 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
939 if (!cc->crypt_queue) {
940 ti->error = "Couldn't create kcryptd queue";
941 goto bad_crypt_queue;
948 destroy_workqueue(cc->io_queue);
952 dm_put_device(ti, cc->dev);
956 mempool_destroy(cc->page_pool);
958 mempool_destroy(cc->io_pool);
960 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
961 cc->iv_gen_ops->dtr(cc);
963 crypto_free_blkcipher(tfm);
965 /* Must zero key material before freeing */
966 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
971 static void crypt_dtr(struct dm_target *ti)
973 struct crypt_config *cc = (struct crypt_config *) ti->private;
975 destroy_workqueue(cc->io_queue);
976 destroy_workqueue(cc->crypt_queue);
979 mempool_destroy(cc->page_pool);
980 mempool_destroy(cc->io_pool);
983 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
984 cc->iv_gen_ops->dtr(cc);
985 crypto_free_blkcipher(cc->tfm);
986 dm_put_device(ti, cc->dev);
988 /* Must zero key material before freeing */
989 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
993 static int crypt_map(struct dm_target *ti, struct bio *bio,
994 union map_info *map_context)
996 struct crypt_config *cc = ti->private;
997 struct dm_crypt_io *io;
999 io = mempool_alloc(cc->io_pool, GFP_NOIO);
1002 io->sector = bio->bi_sector - ti->begin;
1004 atomic_set(&io->pending, 0);
1006 if (bio_data_dir(io->base_bio) == READ)
1007 kcryptd_queue_io(io);
1009 kcryptd_queue_crypt(io);
1011 return DM_MAPIO_SUBMITTED;
1014 static int crypt_status(struct dm_target *ti, status_type_t type,
1015 char *result, unsigned int maxlen)
1017 struct crypt_config *cc = (struct crypt_config *) ti->private;
1018 unsigned int sz = 0;
1021 case STATUSTYPE_INFO:
1025 case STATUSTYPE_TABLE:
1027 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1030 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
1032 if (cc->key_size > 0) {
1033 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1036 crypt_encode_key(result + sz, cc->key, cc->key_size);
1037 sz += cc->key_size << 1;
1044 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1045 cc->dev->name, (unsigned long long)cc->start);
1051 static void crypt_postsuspend(struct dm_target *ti)
1053 struct crypt_config *cc = ti->private;
1055 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1058 static int crypt_preresume(struct dm_target *ti)
1060 struct crypt_config *cc = ti->private;
1062 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1063 DMERR("aborting resume - crypt key is not set.");
1070 static void crypt_resume(struct dm_target *ti)
1072 struct crypt_config *cc = ti->private;
1074 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1077 /* Message interface
1081 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1083 struct crypt_config *cc = ti->private;
1088 if (!strnicmp(argv[0], MESG_STR("key"))) {
1089 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1090 DMWARN("not suspended during key manipulation.");
1093 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1094 return crypt_set_key(cc, argv[2]);
1095 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1096 return crypt_wipe_key(cc);
1100 DMWARN("unrecognised message received.");
1104 static struct target_type crypt_target = {
1106 .version= {1, 5, 0},
1107 .module = THIS_MODULE,
1111 .status = crypt_status,
1112 .postsuspend = crypt_postsuspend,
1113 .preresume = crypt_preresume,
1114 .resume = crypt_resume,
1115 .message = crypt_message,
1118 static int __init dm_crypt_init(void)
1122 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1123 if (!_crypt_io_pool)
1126 r = dm_register_target(&crypt_target);
1128 DMERR("register failed %d", r);
1129 kmem_cache_destroy(_crypt_io_pool);
1135 static void __exit dm_crypt_exit(void)
1137 int r = dm_unregister_target(&crypt_target);
1140 DMERR("unregister failed %d", r);
1142 kmem_cache_destroy(_crypt_io_pool);
1145 module_init(dm_crypt_init);
1146 module_exit(dm_crypt_exit);
1148 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1149 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1150 MODULE_LICENSE("GPL");