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;
60 struct crypt_iv_operations {
61 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
63 void (*dtr)(struct crypt_config *cc);
64 const char *(*status)(struct crypt_config *cc);
65 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
69 * Crypt: maps a linear range of a block device
70 * and encrypts / decrypts at the same time.
72 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
78 * pool for per bio private data and
79 * for encryption buffer pages
85 struct workqueue_struct *io_queue;
86 struct workqueue_struct *crypt_queue;
90 struct crypt_iv_operations *iv_gen_ops;
93 struct crypto_cipher *essiv_tfm;
99 char cipher[CRYPTO_MAX_ALG_NAME];
100 char chainmode[CRYPTO_MAX_ALG_NAME];
101 struct crypto_blkcipher *tfm;
103 unsigned int key_size;
108 #define MIN_POOL_PAGES 32
109 #define MIN_BIO_PAGES 8
111 static struct kmem_cache *_crypt_io_pool;
113 static void clone_init(struct dm_crypt_io *, struct bio *);
114 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
117 * Different IV generation algorithms:
119 * plain: the initial vector is the 32-bit little-endian version of the sector
120 * number, padded with zeros if necessary.
122 * essiv: "encrypted sector|salt initial vector", the sector number is
123 * encrypted with the bulk cipher using a salt as key. The salt
124 * should be derived from the bulk cipher's key via hashing.
126 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
127 * (needed for LRW-32-AES and possible other narrow block modes)
129 * null: the initial vector is always zero. Provides compatibility with
130 * obsolete loop_fish2 devices. Do not use for new devices.
132 * plumb: unimplemented, see:
133 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
136 static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
138 memset(iv, 0, cc->iv_size);
139 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
144 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
147 struct crypto_cipher *essiv_tfm;
148 struct crypto_hash *hash_tfm;
149 struct hash_desc desc;
150 struct scatterlist sg;
151 unsigned int saltsize;
156 ti->error = "Digest algorithm missing for ESSIV mode";
160 /* Hash the cipher key with the given hash algorithm */
161 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
162 if (IS_ERR(hash_tfm)) {
163 ti->error = "Error initializing ESSIV hash";
164 return PTR_ERR(hash_tfm);
167 saltsize = crypto_hash_digestsize(hash_tfm);
168 salt = kmalloc(saltsize, GFP_KERNEL);
170 ti->error = "Error kmallocing salt storage in ESSIV";
171 crypto_free_hash(hash_tfm);
175 sg_init_one(&sg, cc->key, cc->key_size);
177 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
178 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
179 crypto_free_hash(hash_tfm);
182 ti->error = "Error calculating hash in ESSIV";
187 /* Setup the essiv_tfm with the given salt */
188 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
189 if (IS_ERR(essiv_tfm)) {
190 ti->error = "Error allocating crypto tfm for ESSIV";
192 return PTR_ERR(essiv_tfm);
194 if (crypto_cipher_blocksize(essiv_tfm) !=
195 crypto_blkcipher_ivsize(cc->tfm)) {
196 ti->error = "Block size of ESSIV cipher does "
197 "not match IV size of block cipher";
198 crypto_free_cipher(essiv_tfm);
202 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
204 ti->error = "Failed to set key for ESSIV cipher";
205 crypto_free_cipher(essiv_tfm);
211 cc->iv_gen_private.essiv_tfm = essiv_tfm;
215 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
217 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
218 cc->iv_gen_private.essiv_tfm = NULL;
221 static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
223 memset(iv, 0, cc->iv_size);
224 *(u64 *)iv = cpu_to_le64(sector);
225 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
229 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
232 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
235 /* we need to calculate how far we must shift the sector count
236 * to get the cipher block count, we use this shift in _gen */
238 if (1 << log != bs) {
239 ti->error = "cypher blocksize is not a power of 2";
244 ti->error = "cypher blocksize is > 512";
248 cc->iv_gen_private.benbi_shift = 9 - log;
253 static void crypt_iv_benbi_dtr(struct crypt_config *cc)
257 static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
261 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
263 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
264 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
269 static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
271 memset(iv, 0, cc->iv_size);
276 static struct crypt_iv_operations crypt_iv_plain_ops = {
277 .generator = crypt_iv_plain_gen
280 static struct crypt_iv_operations crypt_iv_essiv_ops = {
281 .ctr = crypt_iv_essiv_ctr,
282 .dtr = crypt_iv_essiv_dtr,
283 .generator = crypt_iv_essiv_gen
286 static struct crypt_iv_operations crypt_iv_benbi_ops = {
287 .ctr = crypt_iv_benbi_ctr,
288 .dtr = crypt_iv_benbi_dtr,
289 .generator = crypt_iv_benbi_gen
292 static struct crypt_iv_operations crypt_iv_null_ops = {
293 .generator = crypt_iv_null_gen
297 crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
298 struct scatterlist *in, unsigned int length,
299 int write, sector_t sector)
301 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
302 struct blkcipher_desc desc = {
305 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
309 if (cc->iv_gen_ops) {
310 r = cc->iv_gen_ops->generator(cc, iv, sector);
315 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
317 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
320 r = crypto_blkcipher_encrypt(&desc, out, in, length);
322 r = crypto_blkcipher_decrypt(&desc, out, in, length);
328 static void crypt_convert_init(struct crypt_config *cc,
329 struct convert_context *ctx,
330 struct bio *bio_out, struct bio *bio_in,
333 ctx->bio_in = bio_in;
334 ctx->bio_out = bio_out;
337 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
338 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
339 ctx->sector = sector + cc->iv_offset;
343 * Encrypt / decrypt data from one bio to another one (can be the same one)
345 static int crypt_convert(struct crypt_config *cc,
346 struct convert_context *ctx)
350 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
351 ctx->idx_out < ctx->bio_out->bi_vcnt) {
352 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
353 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
354 struct scatterlist sg_in, sg_out;
356 sg_init_table(&sg_in, 1);
357 sg_set_page(&sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, bv_in->bv_offset + ctx->offset_in);
359 sg_init_table(&sg_out, 1);
360 sg_set_page(&sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, bv_out->bv_offset + ctx->offset_out);
362 ctx->offset_in += sg_in.length;
363 if (ctx->offset_in >= bv_in->bv_len) {
368 ctx->offset_out += sg_out.length;
369 if (ctx->offset_out >= bv_out->bv_len) {
374 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
375 bio_data_dir(ctx->bio_in) == WRITE, ctx->sector);
385 static void dm_crypt_bio_destructor(struct bio *bio)
387 struct dm_crypt_io *io = bio->bi_private;
388 struct crypt_config *cc = io->target->private;
390 bio_free(bio, cc->bs);
394 * Generate a new unfragmented bio with the given size
395 * This should never violate the device limitations
396 * May return a smaller bio when running out of pages
398 static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
400 struct crypt_config *cc = io->target->private;
402 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
403 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
407 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
411 clone_init(io, clone);
413 for (i = 0; i < nr_iovecs; i++) {
414 page = mempool_alloc(cc->page_pool, gfp_mask);
419 * if additional pages cannot be allocated without waiting,
420 * return a partially allocated bio, the caller will then try
421 * to allocate additional bios while submitting this partial bio
423 if (i == (MIN_BIO_PAGES - 1))
424 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
426 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
428 if (!bio_add_page(clone, page, len, 0)) {
429 mempool_free(page, cc->page_pool);
436 if (!clone->bi_size) {
444 static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
449 for (i = 0; i < clone->bi_vcnt; i++) {
450 bv = bio_iovec_idx(clone, i);
451 BUG_ON(!bv->bv_page);
452 mempool_free(bv->bv_page, cc->page_pool);
458 * One of the bios was finished. Check for completion of
459 * the whole request and correctly clean up the buffer.
461 static void crypt_dec_pending(struct dm_crypt_io *io)
463 struct crypt_config *cc = io->target->private;
465 if (!atomic_dec_and_test(&io->pending))
468 bio_endio(io->base_bio, io->error);
469 mempool_free(io, cc->io_pool);
473 * kcryptd/kcryptd_io:
475 * Needed because it would be very unwise to do decryption in an
478 * kcryptd performs the actual encryption or decryption.
480 * kcryptd_io performs the IO submission.
482 * They must be separated as otherwise the final stages could be
483 * starved by new requests which can block in the first stages due
484 * to memory allocation.
486 static void crypt_endio(struct bio *clone, int error)
488 struct dm_crypt_io *io = clone->bi_private;
489 struct crypt_config *cc = io->target->private;
490 unsigned rw = bio_data_dir(clone);
492 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
496 * free the processed pages
499 crypt_free_buffer_pages(cc, clone);
503 if (rw == READ && !error) {
504 kcryptd_queue_crypt(io);
511 crypt_dec_pending(io);
514 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
516 struct crypt_config *cc = io->target->private;
518 clone->bi_private = io;
519 clone->bi_end_io = crypt_endio;
520 clone->bi_bdev = cc->dev->bdev;
521 clone->bi_rw = io->base_bio->bi_rw;
522 clone->bi_destructor = dm_crypt_bio_destructor;
525 static void kcryptd_io_read(struct dm_crypt_io *io)
527 struct crypt_config *cc = io->target->private;
528 struct bio *base_bio = io->base_bio;
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 + io->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)
580 struct bio *clone = io->ctx.bio_out;
581 struct crypt_config *cc = io->target->private;
583 if (unlikely(error < 0)) {
584 crypt_free_buffer_pages(cc, clone);
587 crypt_dec_pending(io);
591 /* crypt_convert should have filled the clone bio */
592 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
594 clone->bi_sector = cc->start + io->sector;
595 io->sector += bio_sectors(clone);
598 static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
600 struct crypt_config *cc = io->target->private;
602 unsigned remaining = io->base_bio->bi_size;
605 atomic_inc(&io->pending);
607 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
610 * The allocated buffers can be smaller than the whole bio,
611 * so repeat the whole process until all the data can be handled.
614 clone = crypt_alloc_buffer(io, remaining);
615 if (unlikely(!clone)) {
617 crypt_dec_pending(io);
621 io->ctx.bio_out = clone;
624 remaining -= clone->bi_size;
626 r = crypt_convert(cc, &io->ctx);
628 kcryptd_crypt_write_io_submit(io, r);
632 /* Grab another reference to the io struct
633 * before we kick off the request */
635 atomic_inc(&io->pending);
637 generic_make_request(clone);
639 /* Do not reference clone after this - it
640 * may be gone already. */
642 /* out of memory -> run queues */
643 if (unlikely(remaining))
644 congestion_wait(WRITE, HZ/100);
648 static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
650 if (unlikely(error < 0))
653 crypt_dec_pending(io);
656 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
658 struct crypt_config *cc = io->target->private;
661 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
664 r = crypt_convert(cc, &io->ctx);
666 kcryptd_crypt_read_done(io, r);
669 static void kcryptd_crypt(struct work_struct *work)
671 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
673 if (bio_data_dir(io->base_bio) == READ)
674 kcryptd_crypt_read_convert(io);
676 kcryptd_crypt_write_convert(io);
679 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
681 struct crypt_config *cc = io->target->private;
683 INIT_WORK(&io->work, kcryptd_crypt);
684 queue_work(cc->crypt_queue, &io->work);
688 * Decode key from its hex representation
690 static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
698 for (i = 0; i < size; i++) {
702 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
704 if (endp != &buffer[2])
715 * Encode key into its hex representation
717 static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
721 for (i = 0; i < size; i++) {
722 sprintf(hex, "%02x", *key);
728 static int crypt_set_key(struct crypt_config *cc, char *key)
730 unsigned key_size = strlen(key) >> 1;
732 if (cc->key_size && cc->key_size != key_size)
735 cc->key_size = key_size; /* initial settings */
737 if ((!key_size && strcmp(key, "-")) ||
738 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
741 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
746 static int crypt_wipe_key(struct crypt_config *cc)
748 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
749 memset(&cc->key, 0, cc->key_size * sizeof(u8));
754 * Construct an encryption mapping:
755 * <cipher> <key> <iv_offset> <dev_path> <start>
757 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
759 struct crypt_config *cc;
760 struct crypto_blkcipher *tfm;
766 unsigned int key_size;
767 unsigned long long tmpll;
770 ti->error = "Not enough arguments";
775 cipher = strsep(&tmp, "-");
776 chainmode = strsep(&tmp, "-");
777 ivopts = strsep(&tmp, "-");
778 ivmode = strsep(&ivopts, ":");
781 DMWARN("Unexpected additional cipher options");
783 key_size = strlen(argv[1]) >> 1;
785 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
788 "Cannot allocate transparent encryption context";
792 if (crypt_set_key(cc, argv[1])) {
793 ti->error = "Error decoding key";
797 /* Compatiblity mode for old dm-crypt cipher strings */
798 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
803 if (strcmp(chainmode, "ecb") && !ivmode) {
804 ti->error = "This chaining mode requires an IV mechanism";
808 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
809 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
810 ti->error = "Chain mode + cipher name is too long";
814 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
816 ti->error = "Error allocating crypto tfm";
820 strcpy(cc->cipher, cipher);
821 strcpy(cc->chainmode, chainmode);
825 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
826 * See comments at iv code
830 cc->iv_gen_ops = NULL;
831 else if (strcmp(ivmode, "plain") == 0)
832 cc->iv_gen_ops = &crypt_iv_plain_ops;
833 else if (strcmp(ivmode, "essiv") == 0)
834 cc->iv_gen_ops = &crypt_iv_essiv_ops;
835 else if (strcmp(ivmode, "benbi") == 0)
836 cc->iv_gen_ops = &crypt_iv_benbi_ops;
837 else if (strcmp(ivmode, "null") == 0)
838 cc->iv_gen_ops = &crypt_iv_null_ops;
840 ti->error = "Invalid IV mode";
844 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
845 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
848 cc->iv_size = crypto_blkcipher_ivsize(tfm);
850 /* at least a 64 bit sector number should fit in our buffer */
851 cc->iv_size = max(cc->iv_size,
852 (unsigned int)(sizeof(u64) / sizeof(u8)));
854 if (cc->iv_gen_ops) {
855 DMWARN("Selected cipher does not support IVs");
856 if (cc->iv_gen_ops->dtr)
857 cc->iv_gen_ops->dtr(cc);
858 cc->iv_gen_ops = NULL;
862 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
864 ti->error = "Cannot allocate crypt io mempool";
868 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
869 if (!cc->page_pool) {
870 ti->error = "Cannot allocate page mempool";
874 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
876 ti->error = "Cannot allocate crypt bioset";
880 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
881 ti->error = "Error setting key";
885 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
886 ti->error = "Invalid iv_offset sector";
889 cc->iv_offset = tmpll;
891 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
892 ti->error = "Invalid device sector";
897 if (dm_get_device(ti, argv[3], cc->start, ti->len,
898 dm_table_get_mode(ti->table), &cc->dev)) {
899 ti->error = "Device lookup failed";
903 if (ivmode && cc->iv_gen_ops) {
906 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
908 ti->error = "Error kmallocing iv_mode string";
909 goto bad_ivmode_string;
911 strcpy(cc->iv_mode, ivmode);
915 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
917 ti->error = "Couldn't create kcryptd io queue";
921 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
922 if (!cc->crypt_queue) {
923 ti->error = "Couldn't create kcryptd queue";
924 goto bad_crypt_queue;
931 destroy_workqueue(cc->io_queue);
935 dm_put_device(ti, cc->dev);
939 mempool_destroy(cc->page_pool);
941 mempool_destroy(cc->io_pool);
943 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
944 cc->iv_gen_ops->dtr(cc);
946 crypto_free_blkcipher(tfm);
948 /* Must zero key material before freeing */
949 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
954 static void crypt_dtr(struct dm_target *ti)
956 struct crypt_config *cc = (struct crypt_config *) ti->private;
958 destroy_workqueue(cc->io_queue);
959 destroy_workqueue(cc->crypt_queue);
962 mempool_destroy(cc->page_pool);
963 mempool_destroy(cc->io_pool);
966 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
967 cc->iv_gen_ops->dtr(cc);
968 crypto_free_blkcipher(cc->tfm);
969 dm_put_device(ti, cc->dev);
971 /* Must zero key material before freeing */
972 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
976 static int crypt_map(struct dm_target *ti, struct bio *bio,
977 union map_info *map_context)
979 struct crypt_config *cc = ti->private;
980 struct dm_crypt_io *io;
982 io = mempool_alloc(cc->io_pool, GFP_NOIO);
985 io->sector = bio->bi_sector - ti->begin;
987 atomic_set(&io->pending, 0);
989 if (bio_data_dir(io->base_bio) == READ)
990 kcryptd_queue_io(io);
992 kcryptd_queue_crypt(io);
994 return DM_MAPIO_SUBMITTED;
997 static int crypt_status(struct dm_target *ti, status_type_t type,
998 char *result, unsigned int maxlen)
1000 struct crypt_config *cc = (struct crypt_config *) ti->private;
1001 unsigned int sz = 0;
1004 case STATUSTYPE_INFO:
1008 case STATUSTYPE_TABLE:
1010 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1013 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
1015 if (cc->key_size > 0) {
1016 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1019 crypt_encode_key(result + sz, cc->key, cc->key_size);
1020 sz += cc->key_size << 1;
1027 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1028 cc->dev->name, (unsigned long long)cc->start);
1034 static void crypt_postsuspend(struct dm_target *ti)
1036 struct crypt_config *cc = ti->private;
1038 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1041 static int crypt_preresume(struct dm_target *ti)
1043 struct crypt_config *cc = ti->private;
1045 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1046 DMERR("aborting resume - crypt key is not set.");
1053 static void crypt_resume(struct dm_target *ti)
1055 struct crypt_config *cc = ti->private;
1057 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1060 /* Message interface
1064 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1066 struct crypt_config *cc = ti->private;
1071 if (!strnicmp(argv[0], MESG_STR("key"))) {
1072 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1073 DMWARN("not suspended during key manipulation.");
1076 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1077 return crypt_set_key(cc, argv[2]);
1078 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1079 return crypt_wipe_key(cc);
1083 DMWARN("unrecognised message received.");
1087 static struct target_type crypt_target = {
1089 .version= {1, 5, 0},
1090 .module = THIS_MODULE,
1094 .status = crypt_status,
1095 .postsuspend = crypt_postsuspend,
1096 .preresume = crypt_preresume,
1097 .resume = crypt_resume,
1098 .message = crypt_message,
1101 static int __init dm_crypt_init(void)
1105 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1106 if (!_crypt_io_pool)
1109 r = dm_register_target(&crypt_target);
1111 DMERR("register failed %d", r);
1112 kmem_cache_destroy(_crypt_io_pool);
1118 static void __exit dm_crypt_exit(void)
1120 int r = dm_unregister_target(&crypt_target);
1123 DMERR("unregister failed %d", r);
1125 kmem_cache_destroy(_crypt_io_pool);
1128 module_init(dm_crypt_init);
1129 module_exit(dm_crypt_exit);
1131 MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1132 MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1133 MODULE_LICENSE("GPL");