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.
9 #include <linux/completion.h>
10 #include <linux/err.h>
11 #include <linux/module.h>
12 #include <linux/init.h>
13 #include <linux/kernel.h>
14 #include <linux/bio.h>
15 #include <linux/blkdev.h>
16 #include <linux/mempool.h>
17 #include <linux/slab.h>
18 #include <linux/crypto.h>
19 #include <linux/workqueue.h>
20 #include <linux/backing-dev.h>
21 #include <asm/atomic.h>
22 #include <linux/scatterlist.h>
24 #include <asm/unaligned.h>
28 #define DM_MSG_PREFIX "crypt"
29 #define MESG_STR(x) x, sizeof(x)
32 * context holding the current state of a multi-part conversion
34 struct convert_context {
35 struct completion restart;
38 unsigned int offset_in;
39 unsigned int offset_out;
47 * per bio private data
50 struct dm_target *target;
52 struct work_struct work;
54 struct convert_context ctx;
61 struct dm_crypt_request {
62 struct scatterlist sg_in;
63 struct scatterlist sg_out;
68 struct crypt_iv_operations {
69 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
71 void (*dtr)(struct crypt_config *cc);
72 const char *(*status)(struct crypt_config *cc);
73 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
77 * Crypt: maps a linear range of a block device
78 * and encrypts / decrypts at the same time.
80 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
86 * pool for per bio private data, crypto requests and
87 * encryption requeusts/buffer pages
94 struct workqueue_struct *io_queue;
95 struct workqueue_struct *crypt_queue;
99 struct crypt_iv_operations *iv_gen_ops;
102 struct crypto_cipher *essiv_tfm;
106 unsigned int iv_size;
109 * Layout of each crypto request:
111 * struct ablkcipher_request
114 * struct dm_crypt_request
118 * The padding is added so that dm_crypt_request and the IV are
121 unsigned int dmreq_start;
122 struct ablkcipher_request *req;
124 char cipher[CRYPTO_MAX_ALG_NAME];
125 char chainmode[CRYPTO_MAX_ALG_NAME];
126 struct crypto_blkcipher *tfm;
128 unsigned int key_size;
133 #define MIN_POOL_PAGES 32
134 #define MIN_BIO_PAGES 8
136 static struct kmem_cache *_crypt_io_pool;
138 static void clone_init(struct dm_crypt_io *, struct bio *);
139 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
142 * Different IV generation algorithms:
144 * plain: the initial vector is the 32-bit little-endian version of the sector
145 * number, padded with zeros if necessary.
147 * essiv: "encrypted sector|salt initial vector", the sector number is
148 * encrypted with the bulk cipher using a salt as key. The salt
149 * should be derived from the bulk cipher's key via hashing.
151 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
152 * (needed for LRW-32-AES and possible other narrow block modes)
154 * null: the initial vector is always zero. Provides compatibility with
155 * obsolete loop_fish2 devices. Do not use for new devices.
157 * plumb: unimplemented, see:
158 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
161 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
163 memset(iv, 0, cc->iv_size);
164 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
169 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
172 struct crypto_cipher *essiv_tfm;
173 struct crypto_hash *hash_tfm;
174 struct hash_desc desc;
175 struct scatterlist sg;
176 unsigned int saltsize;
181 ti->error = "Digest algorithm missing for ESSIV mode";
185 /* Hash the cipher key with the given hash algorithm */
186 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
187 if (IS_ERR(hash_tfm)) {
188 ti->error = "Error initializing ESSIV hash";
189 return PTR_ERR(hash_tfm);
192 saltsize = crypto_hash_digestsize(hash_tfm);
193 salt = kmalloc(saltsize, GFP_KERNEL);
195 ti->error = "Error kmallocing salt storage in ESSIV";
196 crypto_free_hash(hash_tfm);
200 sg_init_one(&sg, cc->key, cc->key_size);
202 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
203 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
204 crypto_free_hash(hash_tfm);
207 ti->error = "Error calculating hash in ESSIV";
212 /* Setup the essiv_tfm with the given salt */
213 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
214 if (IS_ERR(essiv_tfm)) {
215 ti->error = "Error allocating crypto tfm for ESSIV";
217 return PTR_ERR(essiv_tfm);
219 if (crypto_cipher_blocksize(essiv_tfm) !=
220 crypto_blkcipher_ivsize(cc->tfm)) {
221 ti->error = "Block size of ESSIV cipher does "
222 "not match IV size of block cipher";
223 crypto_free_cipher(essiv_tfm);
227 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
229 ti->error = "Failed to set key for ESSIV cipher";
230 crypto_free_cipher(essiv_tfm);
236 cc->iv_gen_private.essiv_tfm = essiv_tfm;
240 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
242 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
243 cc->iv_gen_private.essiv_tfm = NULL;
246 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
248 memset(iv, 0, cc->iv_size);
249 *(u64 *)iv = cpu_to_le64(sector);
250 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
254 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
257 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
260 /* we need to calculate how far we must shift the sector count
261 * to get the cipher block count, we use this shift in _gen */
263 if (1 << log != bs) {
264 ti->error = "cypher blocksize is not a power of 2";
269 ti->error = "cypher blocksize is > 512";
273 cc->iv_gen_private.benbi_shift = 9 - log;
278 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
282 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
286 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
288 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
289 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
294 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
296 memset(iv, 0, cc->iv_size);
301 static struct crypt_iv_operations crypt_iv_plain_ops = {
302 .generator = crypt_iv_plain_gen
305 static struct crypt_iv_operations crypt_iv_essiv_ops = {
306 .ctr = crypt_iv_essiv_ctr,
307 .dtr = crypt_iv_essiv_dtr,
308 .generator = crypt_iv_essiv_gen
311 static struct crypt_iv_operations crypt_iv_benbi_ops = {
312 .ctr = crypt_iv_benbi_ctr,
313 .dtr = crypt_iv_benbi_dtr,
314 .generator = crypt_iv_benbi_gen
317 static struct crypt_iv_operations crypt_iv_null_ops = {
318 .generator = crypt_iv_null_gen
322 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
323 struct scatterlist *in, unsigned int length,
324 int write, sector_t sector)
326 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
327 struct blkcipher_desc desc = {
330 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
334 if (cc->iv_gen_ops) {
335 r = cc->iv_gen_ops->generator(cc, iv, sector);
340 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
342 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
345 r = crypto_blkcipher_encrypt(&desc, out, in, length);
347 r = crypto_blkcipher_decrypt(&desc, out, in, length);
353 static void crypt_convert_init(struct crypt_config *cc,
354 struct convert_context *ctx,
355 struct bio *bio_out, struct bio *bio_in,
358 ctx->bio_in = bio_in;
359 ctx->bio_out = bio_out;
362 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
363 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
364 ctx->sector = sector + cc->iv_offset;
365 init_completion(&ctx->restart);
367 * Crypto operation can be asynchronous,
368 * ctx->pending is increased after request submission.
369 * We need to ensure that we don't call the crypt finish
370 * operation before pending got incremented
371 * (dependent on crypt submission return code).
373 atomic_set(&ctx->pending, 2);
376 static int crypt_convert_block(struct crypt_config *cc,
377 struct convert_context *ctx)
379 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
380 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
381 struct dm_crypt_request dmreq;
383 sg_init_table(&dmreq.sg_in, 1);
384 sg_set_page(&dmreq.sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
385 bv_in->bv_offset + ctx->offset_in);
387 sg_init_table(&dmreq.sg_out, 1);
388 sg_set_page(&dmreq.sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
389 bv_out->bv_offset + ctx->offset_out);
391 ctx->offset_in += 1 << SECTOR_SHIFT;
392 if (ctx->offset_in >= bv_in->bv_len) {
397 ctx->offset_out += 1 << SECTOR_SHIFT;
398 if (ctx->offset_out >= bv_out->bv_len) {
403 return crypt_convert_scatterlist(cc, &dmreq.sg_out, &dmreq.sg_in,
405 bio_data_dir(ctx->bio_in) == WRITE,
409 static void kcryptd_async_done(struct crypto_async_request *async_req,
411 static void crypt_alloc_req(struct crypt_config *cc,
412 struct convert_context *ctx)
415 cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
416 ablkcipher_request_set_tfm(cc->req, cc->tfm);
417 ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG |
418 CRYPTO_TFM_REQ_MAY_SLEEP,
419 kcryptd_async_done, ctx);
423 * Encrypt / decrypt data from one bio to another one (can be the same one)
425 static int crypt_convert(struct crypt_config *cc,
426 struct convert_context *ctx)
430 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
431 ctx->idx_out < ctx->bio_out->bi_vcnt) {
432 r = crypt_convert_block(cc, ctx);
440 * If there are pending crypto operation run async
441 * code. Otherwise process return code synchronously.
442 * The step of 2 ensures that async finish doesn't
443 * call crypto finish too early.
445 if (atomic_sub_return(2, &ctx->pending))
451 static void dm_crypt_bio_destructor(struct bio *bio)
453 struct dm_crypt_io *io = bio->bi_private;
454 struct crypt_config *cc = io->target->private;
456 bio_free(bio, cc->bs);
460 * Generate a new unfragmented bio with the given size
461 * This should never violate the device limitations
462 * May return a smaller bio when running out of pages
464 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
466 struct crypt_config *cc = io->target->private;
468 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
469 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
473 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
477 clone_init(io, clone);
479 for (i = 0; i < nr_iovecs; i++) {
480 page = mempool_alloc(cc->page_pool, gfp_mask);
485 * if additional pages cannot be allocated without waiting,
486 * return a partially allocated bio, the caller will then try
487 * to allocate additional bios while submitting this partial bio
489 if (i == (MIN_BIO_PAGES - 1))
490 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
492 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
494 if (!bio_add_page(clone, page, len, 0)) {
495 mempool_free(page, cc->page_pool);
502 if (!clone->bi_size) {
510 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
515 for (i = 0; i < clone->bi_vcnt; i++) {
516 bv = bio_iovec_idx(clone, i);
517 BUG_ON(!bv->bv_page);
518 mempool_free(bv->bv_page, cc->page_pool);
524 * One of the bios was finished. Check for completion of
525 * the whole request and correctly clean up the buffer.
527 static void crypt_dec_pending(struct dm_crypt_io *io)
529 struct crypt_config *cc = io->target->private;
531 if (!atomic_dec_and_test(&io->pending))
534 bio_endio(io->base_bio, io->error);
535 mempool_free(io, cc->io_pool);
539 * kcryptd/kcryptd_io:
541 * Needed because it would be very unwise to do decryption in an
544 * kcryptd performs the actual encryption or decryption.
546 * kcryptd_io performs the IO submission.
548 * They must be separated as otherwise the final stages could be
549 * starved by new requests which can block in the first stages due
550 * to memory allocation.
552 static void crypt_endio(struct bio *clone, int error)
554 struct dm_crypt_io *io = clone->bi_private;
555 struct crypt_config *cc = io->target->private;
556 unsigned rw = bio_data_dir(clone);
558 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
562 * free the processed pages
565 crypt_free_buffer_pages(cc, clone);
569 if (rw == READ && !error) {
570 kcryptd_queue_crypt(io);
577 crypt_dec_pending(io);
580 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
582 struct crypt_config *cc = io->target->private;
584 clone->bi_private = io;
585 clone->bi_end_io = crypt_endio;
586 clone->bi_bdev = cc->dev->bdev;
587 clone->bi_rw = io->base_bio->bi_rw;
588 clone->bi_destructor = dm_crypt_bio_destructor;
591 static void kcryptd_io_read(struct dm_crypt_io *io)
593 struct crypt_config *cc = io->target->private;
594 struct bio *base_bio = io->base_bio;
597 atomic_inc(&io->pending);
600 * The block layer might modify the bvec array, so always
601 * copy the required bvecs because we need the original
602 * one in order to decrypt the whole bio data *afterwards*.
604 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
605 if (unlikely(!clone)) {
607 crypt_dec_pending(io);
611 clone_init(io, clone);
613 clone->bi_vcnt = bio_segments(base_bio);
614 clone->bi_size = base_bio->bi_size;
615 clone->bi_sector = cc->start + io->sector;
616 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
617 sizeof(struct bio_vec) * clone->bi_vcnt);
619 generic_make_request(clone);
622 static void kcryptd_io_write(struct dm_crypt_io *io)
624 struct bio *clone = io->ctx.bio_out;
626 generic_make_request(clone);
629 static void kcryptd_io(struct work_struct *work)
631 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
633 if (bio_data_dir(io->base_bio) == READ)
636 kcryptd_io_write(io);
639 static void kcryptd_queue_io(struct dm_crypt_io *io)
641 struct crypt_config *cc = io->target->private;
643 INIT_WORK(&io->work, kcryptd_io);
644 queue_work(cc->io_queue, &io->work);
647 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
648 int error, int async)
650 struct bio *clone = io->ctx.bio_out;
651 struct crypt_config *cc = io->target->private;
653 if (unlikely(error < 0)) {
654 crypt_free_buffer_pages(cc, clone);
660 /* crypt_convert should have filled the clone bio */
661 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
663 clone->bi_sector = cc->start + io->sector;
664 io->sector += bio_sectors(clone);
667 kcryptd_queue_io(io);
669 atomic_inc(&io->pending);
670 generic_make_request(clone);
674 static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)
676 struct crypt_config *cc = io->target->private;
678 unsigned remaining = io->base_bio->bi_size;
682 * The allocated buffers can be smaller than the whole bio,
683 * so repeat the whole process until all the data can be handled.
686 clone = crypt_alloc_buffer(io, remaining);
687 if (unlikely(!clone)) {
692 io->ctx.bio_out = clone;
695 remaining -= clone->bi_size;
697 r = crypt_convert(cc, &io->ctx);
699 kcryptd_crypt_write_io_submit(io, r, 0);
703 /* out of memory -> run queues */
704 if (unlikely(remaining))
705 congestion_wait(WRITE, HZ/100);
709 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
711 struct crypt_config *cc = io->target->private;
714 * Prevent io from disappearing until this function completes.
716 atomic_inc(&io->pending);
718 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
719 kcryptd_crypt_write_convert_loop(io);
721 crypt_dec_pending(io);
724 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
726 if (unlikely(error < 0))
729 crypt_dec_pending(io);
732 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
734 struct crypt_config *cc = io->target->private;
737 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
740 r = crypt_convert(cc, &io->ctx);
742 kcryptd_crypt_read_done(io, r);
745 static void kcryptd_async_done(struct crypto_async_request *async_req,
748 struct convert_context *ctx = async_req->data;
749 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
750 struct crypt_config *cc = io->target->private;
752 if (error == -EINPROGRESS) {
753 complete(&ctx->restart);
757 mempool_free(ablkcipher_request_cast(async_req), cc->req_pool);
759 if (!atomic_dec_and_test(&ctx->pending))
762 if (bio_data_dir(io->base_bio) == READ)
763 kcryptd_crypt_read_done(io, error);
765 kcryptd_crypt_write_io_submit(io, error, 1);
768 static void kcryptd_crypt(struct work_struct *work)
770 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
772 if (bio_data_dir(io->base_bio) == READ)
773 kcryptd_crypt_read_convert(io);
775 kcryptd_crypt_write_convert(io);
778 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
780 struct crypt_config *cc = io->target->private;
782 INIT_WORK(&io->work, kcryptd_crypt);
783 queue_work(cc->crypt_queue, &io->work);
787 * Decode key from its hex representation
789 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
797 for (i = 0; i < size; i++) {
801 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
803 if (endp != &buffer[2])
814 * Encode key into its hex representation
816 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
820 for (i = 0; i < size; i++) {
821 sprintf(hex, "%02x", *key);
827 static int crypt_set_key(struct crypt_config *cc, char *key)
829 unsigned key_size = strlen(key) >> 1;
831 if (cc->key_size && cc->key_size != key_size)
834 cc->key_size = key_size; /* initial settings */
836 if ((!key_size && strcmp(key, "-")) ||
837 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
840 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
845 static int crypt_wipe_key(struct crypt_config *cc)
847 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
848 memset(&cc->key, 0, cc->key_size * sizeof(u8));
853 * Construct an encryption mapping:
854 * <cipher> <key> <iv_offset> <dev_path> <start>
856 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
858 struct crypt_config *cc;
859 struct crypto_blkcipher *tfm;
865 unsigned int key_size;
866 unsigned long long tmpll;
869 ti->error = "Not enough arguments";
874 cipher = strsep(&tmp, "-");
875 chainmode = strsep(&tmp, "-");
876 ivopts = strsep(&tmp, "-");
877 ivmode = strsep(&ivopts, ":");
880 DMWARN("Unexpected additional cipher options");
882 key_size = strlen(argv[1]) >> 1;
884 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
887 "Cannot allocate transparent encryption context";
891 if (crypt_set_key(cc, argv[1])) {
892 ti->error = "Error decoding key";
896 /* Compatiblity mode for old dm-crypt cipher strings */
897 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
902 if (strcmp(chainmode, "ecb") && !ivmode) {
903 ti->error = "This chaining mode requires an IV mechanism";
907 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
908 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
909 ti->error = "Chain mode + cipher name is too long";
913 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
915 ti->error = "Error allocating crypto tfm";
919 strcpy(cc->cipher, cipher);
920 strcpy(cc->chainmode, chainmode);
924 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
925 * See comments at iv code
929 cc->iv_gen_ops = NULL;
930 else if (strcmp(ivmode, "plain") == 0)
931 cc->iv_gen_ops = &crypt_iv_plain_ops;
932 else if (strcmp(ivmode, "essiv") == 0)
933 cc->iv_gen_ops = &crypt_iv_essiv_ops;
934 else if (strcmp(ivmode, "benbi") == 0)
935 cc->iv_gen_ops = &crypt_iv_benbi_ops;
936 else if (strcmp(ivmode, "null") == 0)
937 cc->iv_gen_ops = &crypt_iv_null_ops;
939 ti->error = "Invalid IV mode";
943 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
944 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
947 cc->iv_size = crypto_blkcipher_ivsize(tfm);
949 /* at least a 64 bit sector number should fit in our buffer */
950 cc->iv_size = max(cc->iv_size,
951 (unsigned int)(sizeof(u64) / sizeof(u8)));
953 if (cc->iv_gen_ops) {
954 DMWARN("Selected cipher does not support IVs");
955 if (cc->iv_gen_ops->dtr)
956 cc->iv_gen_ops->dtr(cc);
957 cc->iv_gen_ops = NULL;
961 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
963 ti->error = "Cannot allocate crypt io mempool";
967 cc->dmreq_start = sizeof(struct ablkcipher_request);
968 cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
970 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
971 sizeof(struct dm_crypt_request) + cc->iv_size);
973 ti->error = "Cannot allocate crypt request mempool";
978 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
979 if (!cc->page_pool) {
980 ti->error = "Cannot allocate page mempool";
984 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
986 ti->error = "Cannot allocate crypt bioset";
990 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
991 ti->error = "Error setting key";
995 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
996 ti->error = "Invalid iv_offset sector";
999 cc->iv_offset = tmpll;
1001 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
1002 ti->error = "Invalid device sector";
1007 if (dm_get_device(ti, argv[3], cc->start, ti->len,
1008 dm_table_get_mode(ti->table), &cc->dev)) {
1009 ti->error = "Device lookup failed";
1013 if (ivmode && cc->iv_gen_ops) {
1015 *(ivopts - 1) = ':';
1016 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
1018 ti->error = "Error kmallocing iv_mode string";
1019 goto bad_ivmode_string;
1021 strcpy(cc->iv_mode, ivmode);
1025 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
1026 if (!cc->io_queue) {
1027 ti->error = "Couldn't create kcryptd io queue";
1031 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
1032 if (!cc->crypt_queue) {
1033 ti->error = "Couldn't create kcryptd queue";
1034 goto bad_crypt_queue;
1041 destroy_workqueue(cc->io_queue);
1045 dm_put_device(ti, cc->dev);
1047 bioset_free(cc->bs);
1049 mempool_destroy(cc->page_pool);
1051 mempool_destroy(cc->req_pool);
1053 mempool_destroy(cc->io_pool);
1055 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1056 cc->iv_gen_ops->dtr(cc);
1058 crypto_free_blkcipher(tfm);
1060 /* Must zero key material before freeing */
1061 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
1066 static void crypt_dtr(struct dm_target *ti)
1068 struct crypt_config *cc = (struct crypt_config *) ti->private;
1070 destroy_workqueue(cc->io_queue);
1071 destroy_workqueue(cc->crypt_queue);
1074 mempool_free(cc->req, cc->req_pool);
1076 bioset_free(cc->bs);
1077 mempool_destroy(cc->page_pool);
1078 mempool_destroy(cc->req_pool);
1079 mempool_destroy(cc->io_pool);
1082 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1083 cc->iv_gen_ops->dtr(cc);
1084 crypto_free_blkcipher(cc->tfm);
1085 dm_put_device(ti, cc->dev);
1087 /* Must zero key material before freeing */
1088 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
1092 static int crypt_map(struct dm_target *ti, struct bio *bio,
1093 union map_info *map_context)
1095 struct crypt_config *cc = ti->private;
1096 struct dm_crypt_io *io;
1098 io = mempool_alloc(cc->io_pool, GFP_NOIO);
1101 io->sector = bio->bi_sector - ti->begin;
1103 atomic_set(&io->pending, 0);
1105 if (bio_data_dir(io->base_bio) == READ)
1106 kcryptd_queue_io(io);
1108 kcryptd_queue_crypt(io);
1110 return DM_MAPIO_SUBMITTED;
1113 static int crypt_status(struct dm_target *ti, status_type_t type,
1114 char *result, unsigned int maxlen)
1116 struct crypt_config *cc = (struct crypt_config *) ti->private;
1117 unsigned int sz = 0;
1120 case STATUSTYPE_INFO:
1124 case STATUSTYPE_TABLE:
1126 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1129 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
1131 if (cc->key_size > 0) {
1132 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1135 crypt_encode_key(result + sz, cc->key, cc->key_size);
1136 sz += cc->key_size << 1;
1143 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1144 cc->dev->name, (unsigned long long)cc->start);
1150 static void crypt_postsuspend(struct dm_target *ti)
1152 struct crypt_config *cc = ti->private;
1154 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1157 static int crypt_preresume(struct dm_target *ti)
1159 struct crypt_config *cc = ti->private;
1161 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1162 DMERR("aborting resume - crypt key is not set.");
1169 static void crypt_resume(struct dm_target *ti)
1171 struct crypt_config *cc = ti->private;
1173 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1176 /* Message interface
1180 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1182 struct crypt_config *cc = ti->private;
1187 if (!strnicmp(argv[0], MESG_STR("key"))) {
1188 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1189 DMWARN("not suspended during key manipulation.");
1192 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1193 return crypt_set_key(cc, argv[2]);
1194 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1195 return crypt_wipe_key(cc);
1199 DMWARN("unrecognised message received.");
1203 static struct target_type crypt_target = {
1205 .version= {1, 5, 0},
1206 .module = THIS_MODULE,
1210 .status = crypt_status,
1211 .postsuspend = crypt_postsuspend,
1212 .preresume = crypt_preresume,
1213 .resume = crypt_resume,
1214 .message = crypt_message,
1217 static int __init dm_crypt_init(void)
1221 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1222 if (!_crypt_io_pool)
1225 r = dm_register_target(&crypt_target);
1227 DMERR("register failed %d", r);
1228 kmem_cache_destroy(_crypt_io_pool);
1234 static void __exit dm_crypt_exit(void)
1236 int r = dm_unregister_target(&crypt_target);
1239 DMERR("unregister failed %d", r);
1241 kmem_cache_destroy(_crypt_io_pool);
1244 module_init(dm_crypt_init);
1245 module_exit(dm_crypt_exit);
1247 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1248 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1249 MODULE_LICENSE("GPL");