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, crypto requests and
84 * encryption requeusts/buffer pages
91 struct workqueue_struct *io_queue;
92 struct workqueue_struct *crypt_queue;
96 struct crypt_iv_operations *iv_gen_ops;
99 struct crypto_cipher *essiv_tfm;
103 unsigned int iv_size;
106 * Layout of each crypto request:
108 * struct ablkcipher_request
111 * struct dm_crypt_request
115 * The padding is added so that dm_crypt_request and the IV are
118 unsigned int dmreq_start;
119 struct ablkcipher_request *req;
121 char cipher[CRYPTO_MAX_ALG_NAME];
122 char chainmode[CRYPTO_MAX_ALG_NAME];
123 struct crypto_blkcipher *tfm;
125 unsigned int key_size;
130 #define MIN_POOL_PAGES 32
131 #define MIN_BIO_PAGES 8
133 static struct kmem_cache *_crypt_io_pool;
135 static void clone_init(struct dm_crypt_io *, struct bio *);
136 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
139 * Different IV generation algorithms:
141 * plain: the initial vector is the 32-bit little-endian version of the sector
142 * number, padded with zeros if necessary.
144 * essiv: "encrypted sector|salt initial vector", the sector number is
145 * encrypted with the bulk cipher using a salt as key. The salt
146 * should be derived from the bulk cipher's key via hashing.
148 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
149 * (needed for LRW-32-AES and possible other narrow block modes)
151 * null: the initial vector is always zero. Provides compatibility with
152 * obsolete loop_fish2 devices. Do not use for new devices.
154 * plumb: unimplemented, see:
155 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
158 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
160 memset(iv, 0, cc->iv_size);
161 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
166 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
169 struct crypto_cipher *essiv_tfm;
170 struct crypto_hash *hash_tfm;
171 struct hash_desc desc;
172 struct scatterlist sg;
173 unsigned int saltsize;
178 ti->error = "Digest algorithm missing for ESSIV mode";
182 /* Hash the cipher key with the given hash algorithm */
183 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
184 if (IS_ERR(hash_tfm)) {
185 ti->error = "Error initializing ESSIV hash";
186 return PTR_ERR(hash_tfm);
189 saltsize = crypto_hash_digestsize(hash_tfm);
190 salt = kmalloc(saltsize, GFP_KERNEL);
192 ti->error = "Error kmallocing salt storage in ESSIV";
193 crypto_free_hash(hash_tfm);
197 sg_init_one(&sg, cc->key, cc->key_size);
199 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
200 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
201 crypto_free_hash(hash_tfm);
204 ti->error = "Error calculating hash in ESSIV";
209 /* Setup the essiv_tfm with the given salt */
210 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
211 if (IS_ERR(essiv_tfm)) {
212 ti->error = "Error allocating crypto tfm for ESSIV";
214 return PTR_ERR(essiv_tfm);
216 if (crypto_cipher_blocksize(essiv_tfm) !=
217 crypto_blkcipher_ivsize(cc->tfm)) {
218 ti->error = "Block size of ESSIV cipher does "
219 "not match IV size of block cipher";
220 crypto_free_cipher(essiv_tfm);
224 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
226 ti->error = "Failed to set key for ESSIV cipher";
227 crypto_free_cipher(essiv_tfm);
233 cc->iv_gen_private.essiv_tfm = essiv_tfm;
237 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
239 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
240 cc->iv_gen_private.essiv_tfm = NULL;
243 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
245 memset(iv, 0, cc->iv_size);
246 *(u64 *)iv = cpu_to_le64(sector);
247 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
251 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
254 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
257 /* we need to calculate how far we must shift the sector count
258 * to get the cipher block count, we use this shift in _gen */
260 if (1 << log != bs) {
261 ti->error = "cypher blocksize is not a power of 2";
266 ti->error = "cypher blocksize is > 512";
270 cc->iv_gen_private.benbi_shift = 9 - log;
275 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
279 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
283 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
285 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
286 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
291 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
293 memset(iv, 0, cc->iv_size);
298 static struct crypt_iv_operations crypt_iv_plain_ops = {
299 .generator = crypt_iv_plain_gen
302 static struct crypt_iv_operations crypt_iv_essiv_ops = {
303 .ctr = crypt_iv_essiv_ctr,
304 .dtr = crypt_iv_essiv_dtr,
305 .generator = crypt_iv_essiv_gen
308 static struct crypt_iv_operations crypt_iv_benbi_ops = {
309 .ctr = crypt_iv_benbi_ctr,
310 .dtr = crypt_iv_benbi_dtr,
311 .generator = crypt_iv_benbi_gen
314 static struct crypt_iv_operations crypt_iv_null_ops = {
315 .generator = crypt_iv_null_gen
319 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
320 struct scatterlist *in, unsigned int length,
321 int write, sector_t sector)
323 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
324 struct blkcipher_desc desc = {
327 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
331 if (cc->iv_gen_ops) {
332 r = cc->iv_gen_ops->generator(cc, iv, sector);
337 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
339 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
342 r = crypto_blkcipher_encrypt(&desc, out, in, length);
344 r = crypto_blkcipher_decrypt(&desc, out, in, length);
350 static void crypt_convert_init(struct crypt_config *cc,
351 struct convert_context *ctx,
352 struct bio *bio_out, struct bio *bio_in,
355 ctx->bio_in = bio_in;
356 ctx->bio_out = bio_out;
359 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
360 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
361 ctx->sector = sector + cc->iv_offset;
364 static int crypt_convert_block(struct crypt_config *cc,
365 struct convert_context *ctx)
367 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
368 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
369 struct dm_crypt_request dmreq;
371 sg_init_table(&dmreq.sg_in, 1);
372 sg_set_page(&dmreq.sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
373 bv_in->bv_offset + ctx->offset_in);
375 sg_init_table(&dmreq.sg_out, 1);
376 sg_set_page(&dmreq.sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
377 bv_out->bv_offset + ctx->offset_out);
379 ctx->offset_in += 1 << SECTOR_SHIFT;
380 if (ctx->offset_in >= bv_in->bv_len) {
385 ctx->offset_out += 1 << SECTOR_SHIFT;
386 if (ctx->offset_out >= bv_out->bv_len) {
391 return crypt_convert_scatterlist(cc, &dmreq.sg_out, &dmreq.sg_in,
393 bio_data_dir(ctx->bio_in) == WRITE,
397 static void crypt_alloc_req(struct crypt_config *cc,
398 struct convert_context *ctx)
401 cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
405 * Encrypt / decrypt data from one bio to another one (can be the same one)
407 static int crypt_convert(struct crypt_config *cc,
408 struct convert_context *ctx)
412 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
413 ctx->idx_out < ctx->bio_out->bi_vcnt) {
414 r = crypt_convert_block(cc, ctx);
424 static void dm_crypt_bio_destructor(struct bio *bio)
426 struct dm_crypt_io *io = bio->bi_private;
427 struct crypt_config *cc = io->target->private;
429 bio_free(bio, cc->bs);
433 * Generate a new unfragmented bio with the given size
434 * This should never violate the device limitations
435 * May return a smaller bio when running out of pages
437 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
439 struct crypt_config *cc = io->target->private;
441 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
442 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
446 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
450 clone_init(io, clone);
452 for (i = 0; i < nr_iovecs; i++) {
453 page = mempool_alloc(cc->page_pool, gfp_mask);
458 * if additional pages cannot be allocated without waiting,
459 * return a partially allocated bio, the caller will then try
460 * to allocate additional bios while submitting this partial bio
462 if (i == (MIN_BIO_PAGES - 1))
463 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
465 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
467 if (!bio_add_page(clone, page, len, 0)) {
468 mempool_free(page, cc->page_pool);
475 if (!clone->bi_size) {
483 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
488 for (i = 0; i < clone->bi_vcnt; i++) {
489 bv = bio_iovec_idx(clone, i);
490 BUG_ON(!bv->bv_page);
491 mempool_free(bv->bv_page, cc->page_pool);
497 * One of the bios was finished. Check for completion of
498 * the whole request and correctly clean up the buffer.
500 static void crypt_dec_pending(struct dm_crypt_io *io)
502 struct crypt_config *cc = io->target->private;
504 if (!atomic_dec_and_test(&io->pending))
507 bio_endio(io->base_bio, io->error);
508 mempool_free(io, cc->io_pool);
512 * kcryptd/kcryptd_io:
514 * Needed because it would be very unwise to do decryption in an
517 * kcryptd performs the actual encryption or decryption.
519 * kcryptd_io performs the IO submission.
521 * They must be separated as otherwise the final stages could be
522 * starved by new requests which can block in the first stages due
523 * to memory allocation.
525 static void crypt_endio(struct bio *clone, int error)
527 struct dm_crypt_io *io = clone->bi_private;
528 struct crypt_config *cc = io->target->private;
529 unsigned rw = bio_data_dir(clone);
531 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
535 * free the processed pages
538 crypt_free_buffer_pages(cc, clone);
542 if (rw == READ && !error) {
543 kcryptd_queue_crypt(io);
550 crypt_dec_pending(io);
553 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
555 struct crypt_config *cc = io->target->private;
557 clone->bi_private = io;
558 clone->bi_end_io = crypt_endio;
559 clone->bi_bdev = cc->dev->bdev;
560 clone->bi_rw = io->base_bio->bi_rw;
561 clone->bi_destructor = dm_crypt_bio_destructor;
564 static void kcryptd_io_read(struct dm_crypt_io *io)
566 struct crypt_config *cc = io->target->private;
567 struct bio *base_bio = io->base_bio;
570 atomic_inc(&io->pending);
573 * The block layer might modify the bvec array, so always
574 * copy the required bvecs because we need the original
575 * one in order to decrypt the whole bio data *afterwards*.
577 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
578 if (unlikely(!clone)) {
580 crypt_dec_pending(io);
584 clone_init(io, clone);
586 clone->bi_vcnt = bio_segments(base_bio);
587 clone->bi_size = base_bio->bi_size;
588 clone->bi_sector = cc->start + io->sector;
589 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
590 sizeof(struct bio_vec) * clone->bi_vcnt);
592 generic_make_request(clone);
595 static void kcryptd_io_write(struct dm_crypt_io *io)
599 static void kcryptd_io(struct work_struct *work)
601 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
603 if (bio_data_dir(io->base_bio) == READ)
606 kcryptd_io_write(io);
609 static void kcryptd_queue_io(struct dm_crypt_io *io)
611 struct crypt_config *cc = io->target->private;
613 INIT_WORK(&io->work, kcryptd_io);
614 queue_work(cc->io_queue, &io->work);
617 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
619 struct bio *clone = io->ctx.bio_out;
620 struct crypt_config *cc = io->target->private;
622 if (unlikely(error < 0)) {
623 crypt_free_buffer_pages(cc, clone);
629 /* crypt_convert should have filled the clone bio */
630 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
632 clone->bi_sector = cc->start + io->sector;
633 io->sector += bio_sectors(clone);
635 atomic_inc(&io->pending);
636 generic_make_request(clone);
639 static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)
641 struct crypt_config *cc = io->target->private;
643 unsigned remaining = io->base_bio->bi_size;
647 * The allocated buffers can be smaller than the whole bio,
648 * so repeat the whole process until all the data can be handled.
651 clone = crypt_alloc_buffer(io, remaining);
652 if (unlikely(!clone)) {
657 io->ctx.bio_out = clone;
660 remaining -= clone->bi_size;
662 r = crypt_convert(cc, &io->ctx);
664 kcryptd_crypt_write_io_submit(io, r);
668 /* out of memory -> run queues */
669 if (unlikely(remaining))
670 congestion_wait(WRITE, HZ/100);
674 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
676 struct crypt_config *cc = io->target->private;
679 * Prevent io from disappearing until this function completes.
681 atomic_inc(&io->pending);
683 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
684 kcryptd_crypt_write_convert_loop(io);
686 crypt_dec_pending(io);
689 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
691 if (unlikely(error < 0))
694 crypt_dec_pending(io);
697 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
699 struct crypt_config *cc = io->target->private;
702 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
705 r = crypt_convert(cc, &io->ctx);
707 kcryptd_crypt_read_done(io, r);
710 static void kcryptd_crypt(struct work_struct *work)
712 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
714 if (bio_data_dir(io->base_bio) == READ)
715 kcryptd_crypt_read_convert(io);
717 kcryptd_crypt_write_convert(io);
720 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
722 struct crypt_config *cc = io->target->private;
724 INIT_WORK(&io->work, kcryptd_crypt);
725 queue_work(cc->crypt_queue, &io->work);
729 * Decode key from its hex representation
731 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
739 for (i = 0; i < size; i++) {
743 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
745 if (endp != &buffer[2])
756 * Encode key into its hex representation
758 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
762 for (i = 0; i < size; i++) {
763 sprintf(hex, "%02x", *key);
769 static int crypt_set_key(struct crypt_config *cc, char *key)
771 unsigned key_size = strlen(key) >> 1;
773 if (cc->key_size && cc->key_size != key_size)
776 cc->key_size = key_size; /* initial settings */
778 if ((!key_size && strcmp(key, "-")) ||
779 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
782 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
787 static int crypt_wipe_key(struct crypt_config *cc)
789 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
790 memset(&cc->key, 0, cc->key_size * sizeof(u8));
795 * Construct an encryption mapping:
796 * <cipher> <key> <iv_offset> <dev_path> <start>
798 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
800 struct crypt_config *cc;
801 struct crypto_blkcipher *tfm;
807 unsigned int key_size;
808 unsigned long long tmpll;
811 ti->error = "Not enough arguments";
816 cipher = strsep(&tmp, "-");
817 chainmode = strsep(&tmp, "-");
818 ivopts = strsep(&tmp, "-");
819 ivmode = strsep(&ivopts, ":");
822 DMWARN("Unexpected additional cipher options");
824 key_size = strlen(argv[1]) >> 1;
826 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
829 "Cannot allocate transparent encryption context";
833 if (crypt_set_key(cc, argv[1])) {
834 ti->error = "Error decoding key";
838 /* Compatiblity mode for old dm-crypt cipher strings */
839 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
844 if (strcmp(chainmode, "ecb") && !ivmode) {
845 ti->error = "This chaining mode requires an IV mechanism";
849 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
850 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
851 ti->error = "Chain mode + cipher name is too long";
855 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
857 ti->error = "Error allocating crypto tfm";
861 strcpy(cc->cipher, cipher);
862 strcpy(cc->chainmode, chainmode);
866 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
867 * See comments at iv code
871 cc->iv_gen_ops = NULL;
872 else if (strcmp(ivmode, "plain") == 0)
873 cc->iv_gen_ops = &crypt_iv_plain_ops;
874 else if (strcmp(ivmode, "essiv") == 0)
875 cc->iv_gen_ops = &crypt_iv_essiv_ops;
876 else if (strcmp(ivmode, "benbi") == 0)
877 cc->iv_gen_ops = &crypt_iv_benbi_ops;
878 else if (strcmp(ivmode, "null") == 0)
879 cc->iv_gen_ops = &crypt_iv_null_ops;
881 ti->error = "Invalid IV mode";
885 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
886 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
889 cc->iv_size = crypto_blkcipher_ivsize(tfm);
891 /* at least a 64 bit sector number should fit in our buffer */
892 cc->iv_size = max(cc->iv_size,
893 (unsigned int)(sizeof(u64) / sizeof(u8)));
895 if (cc->iv_gen_ops) {
896 DMWARN("Selected cipher does not support IVs");
897 if (cc->iv_gen_ops->dtr)
898 cc->iv_gen_ops->dtr(cc);
899 cc->iv_gen_ops = NULL;
903 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
905 ti->error = "Cannot allocate crypt io mempool";
909 cc->dmreq_start = sizeof(struct ablkcipher_request);
910 cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
912 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
913 sizeof(struct dm_crypt_request) + cc->iv_size);
915 ti->error = "Cannot allocate crypt request mempool";
920 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
921 if (!cc->page_pool) {
922 ti->error = "Cannot allocate page mempool";
926 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
928 ti->error = "Cannot allocate crypt bioset";
932 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
933 ti->error = "Error setting key";
937 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
938 ti->error = "Invalid iv_offset sector";
941 cc->iv_offset = tmpll;
943 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
944 ti->error = "Invalid device sector";
949 if (dm_get_device(ti, argv[3], cc->start, ti->len,
950 dm_table_get_mode(ti->table), &cc->dev)) {
951 ti->error = "Device lookup failed";
955 if (ivmode && cc->iv_gen_ops) {
958 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
960 ti->error = "Error kmallocing iv_mode string";
961 goto bad_ivmode_string;
963 strcpy(cc->iv_mode, ivmode);
967 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
969 ti->error = "Couldn't create kcryptd io queue";
973 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
974 if (!cc->crypt_queue) {
975 ti->error = "Couldn't create kcryptd queue";
976 goto bad_crypt_queue;
983 destroy_workqueue(cc->io_queue);
987 dm_put_device(ti, cc->dev);
991 mempool_destroy(cc->page_pool);
993 mempool_destroy(cc->req_pool);
995 mempool_destroy(cc->io_pool);
997 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
998 cc->iv_gen_ops->dtr(cc);
1000 crypto_free_blkcipher(tfm);
1002 /* Must zero key material before freeing */
1003 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
1008 static void crypt_dtr(struct dm_target *ti)
1010 struct crypt_config *cc = (struct crypt_config *) ti->private;
1012 destroy_workqueue(cc->io_queue);
1013 destroy_workqueue(cc->crypt_queue);
1016 mempool_free(cc->req, cc->req_pool);
1018 bioset_free(cc->bs);
1019 mempool_destroy(cc->page_pool);
1020 mempool_destroy(cc->req_pool);
1021 mempool_destroy(cc->io_pool);
1024 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1025 cc->iv_gen_ops->dtr(cc);
1026 crypto_free_blkcipher(cc->tfm);
1027 dm_put_device(ti, cc->dev);
1029 /* Must zero key material before freeing */
1030 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
1034 static int crypt_map(struct dm_target *ti, struct bio *bio,
1035 union map_info *map_context)
1037 struct crypt_config *cc = ti->private;
1038 struct dm_crypt_io *io;
1040 io = mempool_alloc(cc->io_pool, GFP_NOIO);
1043 io->sector = bio->bi_sector - ti->begin;
1045 atomic_set(&io->pending, 0);
1047 if (bio_data_dir(io->base_bio) == READ)
1048 kcryptd_queue_io(io);
1050 kcryptd_queue_crypt(io);
1052 return DM_MAPIO_SUBMITTED;
1055 static int crypt_status(struct dm_target *ti, status_type_t type,
1056 char *result, unsigned int maxlen)
1058 struct crypt_config *cc = (struct crypt_config *) ti->private;
1059 unsigned int sz = 0;
1062 case STATUSTYPE_INFO:
1066 case STATUSTYPE_TABLE:
1068 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1071 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
1073 if (cc->key_size > 0) {
1074 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1077 crypt_encode_key(result + sz, cc->key, cc->key_size);
1078 sz += cc->key_size << 1;
1085 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1086 cc->dev->name, (unsigned long long)cc->start);
1092 static void crypt_postsuspend(struct dm_target *ti)
1094 struct crypt_config *cc = ti->private;
1096 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1099 static int crypt_preresume(struct dm_target *ti)
1101 struct crypt_config *cc = ti->private;
1103 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1104 DMERR("aborting resume - crypt key is not set.");
1111 static void crypt_resume(struct dm_target *ti)
1113 struct crypt_config *cc = ti->private;
1115 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1118 /* Message interface
1122 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1124 struct crypt_config *cc = ti->private;
1129 if (!strnicmp(argv[0], MESG_STR("key"))) {
1130 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1131 DMWARN("not suspended during key manipulation.");
1134 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1135 return crypt_set_key(cc, argv[2]);
1136 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1137 return crypt_wipe_key(cc);
1141 DMWARN("unrecognised message received.");
1145 static struct target_type crypt_target = {
1147 .version= {1, 5, 0},
1148 .module = THIS_MODULE,
1152 .status = crypt_status,
1153 .postsuspend = crypt_postsuspend,
1154 .preresume = crypt_preresume,
1155 .resume = crypt_resume,
1156 .message = crypt_message,
1159 static int __init dm_crypt_init(void)
1163 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1164 if (!_crypt_io_pool)
1167 r = dm_register_target(&crypt_target);
1169 DMERR("register failed %d", r);
1170 kmem_cache_destroy(_crypt_io_pool);
1176 static void __exit dm_crypt_exit(void)
1178 int r = dm_unregister_target(&crypt_target);
1181 DMERR("unregister failed %d", r);
1183 kmem_cache_destroy(_crypt_io_pool);
1186 module_init(dm_crypt_init);
1187 module_exit(dm_crypt_exit);
1189 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1190 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1191 MODULE_LICENSE("GPL");