2 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4 * Copyright (C) 2006-2007 Red Hat, Inc. All rights reserved.
6 * This file is released under the GPL.
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/bio.h>
14 #include <linux/blkdev.h>
15 #include <linux/mempool.h>
16 #include <linux/slab.h>
17 #include <linux/crypto.h>
18 #include <linux/workqueue.h>
19 #include <linux/backing-dev.h>
20 #include <asm/atomic.h>
21 #include <linux/scatterlist.h>
23 #include <asm/unaligned.h>
27 #define DM_MSG_PREFIX "crypt"
28 #define MESG_STR(x) x, sizeof(x)
31 * context holding the current state of a multi-part conversion
33 struct convert_context {
36 unsigned int offset_in;
37 unsigned int offset_out;
44 * per bio private data
47 struct dm_target *target;
49 struct work_struct work;
51 struct convert_context ctx;
59 struct crypt_iv_operations {
60 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
62 void (*dtr)(struct crypt_config *cc);
63 const char *(*status)(struct crypt_config *cc);
64 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
68 * Crypt: maps a linear range of a block device
69 * and encrypts / decrypts at the same time.
71 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
77 * pool for per bio private data and
78 * for encryption buffer pages
84 struct workqueue_struct *io_queue;
85 struct workqueue_struct *crypt_queue;
89 struct crypt_iv_operations *iv_gen_ops;
92 struct crypto_cipher *essiv_tfm;
98 char cipher[CRYPTO_MAX_ALG_NAME];
99 char chainmode[CRYPTO_MAX_ALG_NAME];
100 struct crypto_blkcipher *tfm;
102 unsigned int key_size;
107 #define MIN_POOL_PAGES 32
108 #define MIN_BIO_PAGES 8
110 static struct kmem_cache *_crypt_io_pool;
112 static void clone_init(struct dm_crypt_io *, struct bio *);
113 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
116 * Different IV generation algorithms:
118 * plain: the initial vector is the 32-bit little-endian version of the sector
119 * number, padded with zeros if necessary.
121 * essiv: "encrypted sector|salt initial vector", the sector number is
122 * encrypted with the bulk cipher using a salt as key. The salt
123 * should be derived from the bulk cipher's key via hashing.
125 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
126 * (needed for LRW-32-AES and possible other narrow block modes)
128 * null: the initial vector is always zero. Provides compatibility with
129 * obsolete loop_fish2 devices. Do not use for new devices.
131 * plumb: unimplemented, see:
132 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
135 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
137 memset(iv, 0, cc->iv_size);
138 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
143 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
146 struct crypto_cipher *essiv_tfm;
147 struct crypto_hash *hash_tfm;
148 struct hash_desc desc;
149 struct scatterlist sg;
150 unsigned int saltsize;
155 ti->error = "Digest algorithm missing for ESSIV mode";
159 /* Hash the cipher key with the given hash algorithm */
160 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
161 if (IS_ERR(hash_tfm)) {
162 ti->error = "Error initializing ESSIV hash";
163 return PTR_ERR(hash_tfm);
166 saltsize = crypto_hash_digestsize(hash_tfm);
167 salt = kmalloc(saltsize, GFP_KERNEL);
169 ti->error = "Error kmallocing salt storage in ESSIV";
170 crypto_free_hash(hash_tfm);
174 sg_init_one(&sg, cc->key, cc->key_size);
176 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
177 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
178 crypto_free_hash(hash_tfm);
181 ti->error = "Error calculating hash in ESSIV";
186 /* Setup the essiv_tfm with the given salt */
187 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
188 if (IS_ERR(essiv_tfm)) {
189 ti->error = "Error allocating crypto tfm for ESSIV";
191 return PTR_ERR(essiv_tfm);
193 if (crypto_cipher_blocksize(essiv_tfm) !=
194 crypto_blkcipher_ivsize(cc->tfm)) {
195 ti->error = "Block size of ESSIV cipher does "
196 "not match IV size of block cipher";
197 crypto_free_cipher(essiv_tfm);
201 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
203 ti->error = "Failed to set key for ESSIV cipher";
204 crypto_free_cipher(essiv_tfm);
210 cc->iv_gen_private.essiv_tfm = essiv_tfm;
214 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
216 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
217 cc->iv_gen_private.essiv_tfm = NULL;
220 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
222 memset(iv, 0, cc->iv_size);
223 *(u64 *)iv = cpu_to_le64(sector);
224 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
228 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
231 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
234 /* we need to calculate how far we must shift the sector count
235 * to get the cipher block count, we use this shift in _gen */
237 if (1 << log != bs) {
238 ti->error = "cypher blocksize is not a power of 2";
243 ti->error = "cypher blocksize is > 512";
247 cc->iv_gen_private.benbi_shift = 9 - log;
252 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
256 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
260 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
262 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
263 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
268 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
270 memset(iv, 0, cc->iv_size);
275 static struct crypt_iv_operations crypt_iv_plain_ops = {
276 .generator = crypt_iv_plain_gen
279 static struct crypt_iv_operations crypt_iv_essiv_ops = {
280 .ctr = crypt_iv_essiv_ctr,
281 .dtr = crypt_iv_essiv_dtr,
282 .generator = crypt_iv_essiv_gen
285 static struct crypt_iv_operations crypt_iv_benbi_ops = {
286 .ctr = crypt_iv_benbi_ctr,
287 .dtr = crypt_iv_benbi_dtr,
288 .generator = crypt_iv_benbi_gen
291 static struct crypt_iv_operations crypt_iv_null_ops = {
292 .generator = crypt_iv_null_gen
296 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
297 struct scatterlist *in, unsigned int length,
298 int write, sector_t sector)
300 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
301 struct blkcipher_desc desc = {
304 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
308 if (cc->iv_gen_ops) {
309 r = cc->iv_gen_ops->generator(cc, iv, sector);
314 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
316 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
319 r = crypto_blkcipher_encrypt(&desc, out, in, length);
321 r = crypto_blkcipher_decrypt(&desc, out, in, length);
327 static void crypt_convert_init(struct crypt_config *cc,
328 struct convert_context *ctx,
329 struct bio *bio_out, struct bio *bio_in,
332 ctx->bio_in = bio_in;
333 ctx->bio_out = bio_out;
336 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
337 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
338 ctx->sector = sector + cc->iv_offset;
342 * Encrypt / decrypt data from one bio to another one (can be the same one)
344 static int crypt_convert(struct crypt_config *cc,
345 struct convert_context *ctx)
349 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
350 ctx->idx_out < ctx->bio_out->bi_vcnt) {
351 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
352 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
353 struct scatterlist sg_in, sg_out;
355 sg_init_table(&sg_in, 1);
356 sg_set_page(&sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, bv_in->bv_offset + ctx->offset_in);
358 sg_init_table(&sg_out, 1);
359 sg_set_page(&sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, bv_out->bv_offset + ctx->offset_out);
361 ctx->offset_in += sg_in.length;
362 if (ctx->offset_in >= bv_in->bv_len) {
367 ctx->offset_out += sg_out.length;
368 if (ctx->offset_out >= bv_out->bv_len) {
373 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
374 bio_data_dir(ctx->bio_in) == WRITE, ctx->sector);
384 static void dm_crypt_bio_destructor(struct bio *bio)
386 struct dm_crypt_io *io = bio->bi_private;
387 struct crypt_config *cc = io->target->private;
389 bio_free(bio, cc->bs);
393 * Generate a new unfragmented bio with the given size
394 * This should never violate the device limitations
395 * May return a smaller bio when running out of pages
397 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
399 struct crypt_config *cc = io->target->private;
401 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
402 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 page = mempool_alloc(cc->page_pool, gfp_mask);
418 * if additional pages cannot be allocated without waiting,
419 * return a partially allocated bio, the caller will then try
420 * to allocate additional bios while submitting this partial bio
422 if (i == (MIN_BIO_PAGES - 1))
423 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
425 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
427 if (!bio_add_page(clone, page, len, 0)) {
428 mempool_free(page, cc->page_pool);
435 if (!clone->bi_size) {
443 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
448 for (i = 0; i < clone->bi_vcnt; i++) {
449 bv = bio_iovec_idx(clone, i);
450 BUG_ON(!bv->bv_page);
451 mempool_free(bv->bv_page, cc->page_pool);
457 * One of the bios was finished. Check for completion of
458 * the whole request and correctly clean up the buffer.
460 static void crypt_dec_pending(struct dm_crypt_io *io)
462 struct crypt_config *cc = io->target->private;
464 if (!atomic_dec_and_test(&io->pending))
467 bio_endio(io->base_bio, io->error);
468 mempool_free(io, cc->io_pool);
472 * kcryptd/kcryptd_io:
474 * Needed because it would be very unwise to do decryption in an
477 * kcryptd performs the actual encryption or decryption.
479 * kcryptd_io performs the IO submission.
481 * They must be separated as otherwise the final stages could be
482 * starved by new requests which can block in the first stages due
483 * to memory allocation.
485 static void crypt_endio(struct bio *clone, int error)
487 struct dm_crypt_io *io = clone->bi_private;
488 struct crypt_config *cc = io->target->private;
489 unsigned rw = bio_data_dir(clone);
491 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
495 * free the processed pages
498 crypt_free_buffer_pages(cc, clone);
502 if (rw == READ && !error) {
503 kcryptd_queue_crypt(io);
510 crypt_dec_pending(io);
513 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
515 struct crypt_config *cc = io->target->private;
517 clone->bi_private = io;
518 clone->bi_end_io = crypt_endio;
519 clone->bi_bdev = cc->dev->bdev;
520 clone->bi_rw = io->base_bio->bi_rw;
521 clone->bi_destructor = dm_crypt_bio_destructor;
524 static void kcryptd_io_read(struct dm_crypt_io *io)
526 struct crypt_config *cc = io->target->private;
527 struct bio *base_bio = io->base_bio;
529 sector_t sector = base_bio->bi_sector - io->target->begin;
531 atomic_inc(&io->pending);
534 * The block layer might modify the bvec array, so always
535 * copy the required bvecs because we need the original
536 * one in order to decrypt the whole bio data *afterwards*.
538 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
539 if (unlikely(!clone)) {
541 crypt_dec_pending(io);
545 clone_init(io, clone);
547 clone->bi_vcnt = bio_segments(base_bio);
548 clone->bi_size = base_bio->bi_size;
549 clone->bi_sector = cc->start + sector;
550 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
551 sizeof(struct bio_vec) * clone->bi_vcnt);
553 generic_make_request(clone);
556 static void kcryptd_io_write(struct dm_crypt_io *io)
560 static void kcryptd_io(struct work_struct *work)
562 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
564 if (bio_data_dir(io->base_bio) == READ)
567 kcryptd_io_write(io);
570 static void kcryptd_queue_io(struct dm_crypt_io *io)
572 struct crypt_config *cc = io->target->private;
574 INIT_WORK(&io->work, kcryptd_io);
575 queue_work(cc->io_queue, &io->work);
578 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int error)
582 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
584 struct crypt_config *cc = io->target->private;
585 struct bio *base_bio = io->base_bio;
587 unsigned remaining = base_bio->bi_size;
588 sector_t sector = base_bio->bi_sector - io->target->begin;
590 atomic_inc(&io->pending);
592 crypt_convert_init(cc, &io->ctx, NULL, base_bio, sector);
595 * The allocated buffers can be smaller than the whole bio,
596 * so repeat the whole process until all the data can be handled.
599 clone = crypt_alloc_buffer(io, remaining);
600 if (unlikely(!clone)) {
602 crypt_dec_pending(io);
606 io->ctx.bio_out = clone;
609 if (unlikely(crypt_convert(cc, &io->ctx) < 0)) {
610 crypt_free_buffer_pages(cc, clone);
613 crypt_dec_pending(io);
617 /* crypt_convert should have filled the clone bio */
618 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
620 clone->bi_sector = cc->start + sector;
621 remaining -= clone->bi_size;
622 sector += bio_sectors(clone);
624 /* Grab another reference to the io struct
625 * before we kick off the request */
627 atomic_inc(&io->pending);
629 generic_make_request(clone);
631 /* Do not reference clone after this - it
632 * may be gone already. */
634 /* out of memory -> run queues */
636 congestion_wait(WRITE, HZ/100);
640 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
642 if (unlikely(error < 0))
645 crypt_dec_pending(io);
648 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
650 struct crypt_config *cc = io->target->private;
653 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
654 io->base_bio->bi_sector - io->target->begin);
656 r = crypt_convert(cc, &io->ctx);
658 kcryptd_crypt_read_done(io, r);
661 static void kcryptd_crypt(struct work_struct *work)
663 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
665 if (bio_data_dir(io->base_bio) == READ)
666 kcryptd_crypt_read_convert(io);
668 kcryptd_crypt_write_convert(io);
671 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
673 struct crypt_config *cc = io->target->private;
675 INIT_WORK(&io->work, kcryptd_crypt);
676 queue_work(cc->crypt_queue, &io->work);
680 * Decode key from its hex representation
682 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
690 for (i = 0; i < size; i++) {
694 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
696 if (endp != &buffer[2])
707 * Encode key into its hex representation
709 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
713 for (i = 0; i < size; i++) {
714 sprintf(hex, "%02x", *key);
720 static int crypt_set_key(struct crypt_config *cc, char *key)
722 unsigned key_size = strlen(key) >> 1;
724 if (cc->key_size && cc->key_size != key_size)
727 cc->key_size = key_size; /* initial settings */
729 if ((!key_size && strcmp(key, "-")) ||
730 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
733 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
738 static int crypt_wipe_key(struct crypt_config *cc)
740 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
741 memset(&cc->key, 0, cc->key_size * sizeof(u8));
746 * Construct an encryption mapping:
747 * <cipher> <key> <iv_offset> <dev_path> <start>
749 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
751 struct crypt_config *cc;
752 struct crypto_blkcipher *tfm;
758 unsigned int key_size;
759 unsigned long long tmpll;
762 ti->error = "Not enough arguments";
767 cipher = strsep(&tmp, "-");
768 chainmode = strsep(&tmp, "-");
769 ivopts = strsep(&tmp, "-");
770 ivmode = strsep(&ivopts, ":");
773 DMWARN("Unexpected additional cipher options");
775 key_size = strlen(argv[1]) >> 1;
777 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
780 "Cannot allocate transparent encryption context";
784 if (crypt_set_key(cc, argv[1])) {
785 ti->error = "Error decoding key";
789 /* Compatiblity mode for old dm-crypt cipher strings */
790 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
795 if (strcmp(chainmode, "ecb") && !ivmode) {
796 ti->error = "This chaining mode requires an IV mechanism";
800 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
801 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
802 ti->error = "Chain mode + cipher name is too long";
806 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
808 ti->error = "Error allocating crypto tfm";
812 strcpy(cc->cipher, cipher);
813 strcpy(cc->chainmode, chainmode);
817 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
818 * See comments at iv code
822 cc->iv_gen_ops = NULL;
823 else if (strcmp(ivmode, "plain") == 0)
824 cc->iv_gen_ops = &crypt_iv_plain_ops;
825 else if (strcmp(ivmode, "essiv") == 0)
826 cc->iv_gen_ops = &crypt_iv_essiv_ops;
827 else if (strcmp(ivmode, "benbi") == 0)
828 cc->iv_gen_ops = &crypt_iv_benbi_ops;
829 else if (strcmp(ivmode, "null") == 0)
830 cc->iv_gen_ops = &crypt_iv_null_ops;
832 ti->error = "Invalid IV mode";
836 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
837 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
840 cc->iv_size = crypto_blkcipher_ivsize(tfm);
842 /* at least a 64 bit sector number should fit in our buffer */
843 cc->iv_size = max(cc->iv_size,
844 (unsigned int)(sizeof(u64) / sizeof(u8)));
846 if (cc->iv_gen_ops) {
847 DMWARN("Selected cipher does not support IVs");
848 if (cc->iv_gen_ops->dtr)
849 cc->iv_gen_ops->dtr(cc);
850 cc->iv_gen_ops = NULL;
854 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
856 ti->error = "Cannot allocate crypt io mempool";
860 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
861 if (!cc->page_pool) {
862 ti->error = "Cannot allocate page mempool";
866 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
868 ti->error = "Cannot allocate crypt bioset";
872 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
873 ti->error = "Error setting key";
877 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
878 ti->error = "Invalid iv_offset sector";
881 cc->iv_offset = tmpll;
883 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
884 ti->error = "Invalid device sector";
889 if (dm_get_device(ti, argv[3], cc->start, ti->len,
890 dm_table_get_mode(ti->table), &cc->dev)) {
891 ti->error = "Device lookup failed";
895 if (ivmode && cc->iv_gen_ops) {
898 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
900 ti->error = "Error kmallocing iv_mode string";
901 goto bad_ivmode_string;
903 strcpy(cc->iv_mode, ivmode);
907 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
909 ti->error = "Couldn't create kcryptd io queue";
913 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
914 if (!cc->crypt_queue) {
915 ti->error = "Couldn't create kcryptd queue";
916 goto bad_crypt_queue;
923 destroy_workqueue(cc->io_queue);
927 dm_put_device(ti, cc->dev);
931 mempool_destroy(cc->page_pool);
933 mempool_destroy(cc->io_pool);
935 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
936 cc->iv_gen_ops->dtr(cc);
938 crypto_free_blkcipher(tfm);
940 /* Must zero key material before freeing */
941 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
946 static void crypt_dtr(struct dm_target *ti)
948 struct crypt_config *cc = (struct crypt_config *) ti->private;
950 destroy_workqueue(cc->io_queue);
951 destroy_workqueue(cc->crypt_queue);
954 mempool_destroy(cc->page_pool);
955 mempool_destroy(cc->io_pool);
958 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
959 cc->iv_gen_ops->dtr(cc);
960 crypto_free_blkcipher(cc->tfm);
961 dm_put_device(ti, cc->dev);
963 /* Must zero key material before freeing */
964 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
968 static int crypt_map(struct dm_target *ti, struct bio *bio,
969 union map_info *map_context)
971 struct crypt_config *cc = ti->private;
972 struct dm_crypt_io *io;
974 io = mempool_alloc(cc->io_pool, GFP_NOIO);
978 atomic_set(&io->pending, 0);
980 if (bio_data_dir(io->base_bio) == READ)
981 kcryptd_queue_io(io);
983 kcryptd_queue_crypt(io);
985 return DM_MAPIO_SUBMITTED;
988 static int crypt_status(struct dm_target *ti, status_type_t type,
989 char *result, unsigned int maxlen)
991 struct crypt_config *cc = (struct crypt_config *) ti->private;
995 case STATUSTYPE_INFO:
999 case STATUSTYPE_TABLE:
1001 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1004 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
1006 if (cc->key_size > 0) {
1007 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1010 crypt_encode_key(result + sz, cc->key, cc->key_size);
1011 sz += cc->key_size << 1;
1018 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1019 cc->dev->name, (unsigned long long)cc->start);
1025 static void crypt_postsuspend(struct dm_target *ti)
1027 struct crypt_config *cc = ti->private;
1029 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1032 static int crypt_preresume(struct dm_target *ti)
1034 struct crypt_config *cc = ti->private;
1036 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1037 DMERR("aborting resume - crypt key is not set.");
1044 static void crypt_resume(struct dm_target *ti)
1046 struct crypt_config *cc = ti->private;
1048 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1051 /* Message interface
1055 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1057 struct crypt_config *cc = ti->private;
1062 if (!strnicmp(argv[0], MESG_STR("key"))) {
1063 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1064 DMWARN("not suspended during key manipulation.");
1067 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1068 return crypt_set_key(cc, argv[2]);
1069 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1070 return crypt_wipe_key(cc);
1074 DMWARN("unrecognised message received.");
1078 static struct target_type crypt_target = {
1080 .version= {1, 5, 0},
1081 .module = THIS_MODULE,
1085 .status = crypt_status,
1086 .postsuspend = crypt_postsuspend,
1087 .preresume = crypt_preresume,
1088 .resume = crypt_resume,
1089 .message = crypt_message,
1092 static int __init dm_crypt_init(void)
1096 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1097 if (!_crypt_io_pool)
1100 r = dm_register_target(&crypt_target);
1102 DMERR("register failed %d", r);
1103 kmem_cache_destroy(_crypt_io_pool);
1109 static void __exit dm_crypt_exit(void)
1111 int r = dm_unregister_target(&crypt_target);
1114 DMERR("unregister failed %d", r);
1116 kmem_cache_destroy(_crypt_io_pool);
1119 module_init(dm_crypt_init);
1120 module_exit(dm_crypt_exit);
1122 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1123 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1124 MODULE_LICENSE("GPL");