blob: 7b0fcfc9eaa5fc0f724d3313360a304b6bbab3a6 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3 * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
Milan Broze48d4bb2006-10-03 01:15:37 -07004 * Copyright (C) 2006 Red Hat, Inc. All rights reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * This file is released under the GPL.
7 */
8
Herbert Xud1806f62006-08-22 20:29:17 +10009#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#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>
Andrew Morton3fcfab12006-10-19 23:28:16 -070019#include <linux/backing-dev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <asm/atomic.h>
David Hardeman378f0582005-09-17 17:55:31 +100021#include <linux/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070022#include <asm/page.h>
Rik Snel48527fa2006-09-03 08:56:39 +100023#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
25#include "dm.h"
26
Alasdair G Kergon72d94862006-06-26 00:27:35 -070027#define DM_MSG_PREFIX "crypt"
Milan Broze48d4bb2006-10-03 01:15:37 -070028#define MESG_STR(x) x, sizeof(x)
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
30/*
31 * per bio private data
32 */
33struct crypt_io {
34 struct dm_target *target;
Milan Broz8b004452006-10-03 01:15:37 -070035 struct bio *base_bio;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 struct work_struct work;
37 atomic_t pending;
38 int error;
Milan Broz23541d22006-10-03 01:15:39 -070039 int post_process;
Linus Torvalds1da177e2005-04-16 15:20:36 -070040};
41
42/*
43 * context holding the current state of a multi-part conversion
44 */
45struct convert_context {
46 struct bio *bio_in;
47 struct bio *bio_out;
48 unsigned int offset_in;
49 unsigned int offset_out;
50 unsigned int idx_in;
51 unsigned int idx_out;
52 sector_t sector;
53 int write;
54};
55
56struct crypt_config;
57
58struct crypt_iv_operations {
59 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
60 const char *opts);
61 void (*dtr)(struct crypt_config *cc);
62 const char *(*status)(struct crypt_config *cc);
63 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
64};
65
66/*
67 * Crypt: maps a linear range of a block device
68 * and encrypts / decrypts at the same time.
69 */
Milan Broze48d4bb2006-10-03 01:15:37 -070070enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
Linus Torvalds1da177e2005-04-16 15:20:36 -070071struct crypt_config {
72 struct dm_dev *dev;
73 sector_t start;
74
75 /*
76 * pool for per bio private data and
77 * for encryption buffer pages
78 */
79 mempool_t *io_pool;
80 mempool_t *page_pool;
Milan Broz6a24c712006-10-03 01:15:40 -070081 struct bio_set *bs;
Linus Torvalds1da177e2005-04-16 15:20:36 -070082
83 /*
84 * crypto related data
85 */
86 struct crypt_iv_operations *iv_gen_ops;
87 char *iv_mode;
Herbert Xu79066ad2006-12-05 13:41:52 -080088 union {
89 struct crypto_cipher *essiv_tfm;
90 int benbi_shift;
91 } iv_gen_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 sector_t iv_offset;
93 unsigned int iv_size;
94
Herbert Xud1806f62006-08-22 20:29:17 +100095 char cipher[CRYPTO_MAX_ALG_NAME];
96 char chainmode[CRYPTO_MAX_ALG_NAME];
97 struct crypto_blkcipher *tfm;
Milan Broze48d4bb2006-10-03 01:15:37 -070098 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -070099 unsigned int key_size;
100 u8 key[0];
101};
102
Milan Broz6a24c712006-10-03 01:15:40 -0700103#define MIN_IOS 16
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104#define MIN_POOL_PAGES 32
105#define MIN_BIO_PAGES 8
106
Christoph Lametere18b8902006-12-06 20:33:20 -0800107static struct kmem_cache *_crypt_io_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700108
Olaf Kirch027581f2007-05-09 02:32:52 -0700109static void clone_init(struct crypt_io *, struct bio *);
110
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 * Different IV generation algorithms:
113 *
Rik Snel3c164bd2006-09-02 18:17:33 +1000114 * plain: the initial vector is the 32-bit little-endian version of the sector
Linus Torvalds1da177e2005-04-16 15:20:36 -0700115 * number, padded with zeros if neccessary.
116 *
Rik Snel3c164bd2006-09-02 18:17:33 +1000117 * essiv: "encrypted sector|salt initial vector", the sector number is
118 * encrypted with the bulk cipher using a salt as key. The salt
119 * should be derived from the bulk cipher's key via hashing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 *
Rik Snel48527fa2006-09-03 08:56:39 +1000121 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
122 * (needed for LRW-32-AES and possible other narrow block modes)
123 *
Ludwig Nussel46b47732007-05-09 02:32:55 -0700124 * null: the initial vector is always zero. Provides compatibility with
125 * obsolete loop_fish2 devices. Do not use for new devices.
126 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 * plumb: unimplemented, see:
128 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
129 */
130
131static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
132{
133 memset(iv, 0, cc->iv_size);
134 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
135
136 return 0;
137}
138
139static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
140 const char *opts)
141{
Herbert Xud1806f62006-08-22 20:29:17 +1000142 struct crypto_cipher *essiv_tfm;
Herbert Xu35058682006-08-24 19:10:20 +1000143 struct crypto_hash *hash_tfm;
144 struct hash_desc desc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 struct scatterlist sg;
146 unsigned int saltsize;
147 u8 *salt;
Herbert Xud1806f62006-08-22 20:29:17 +1000148 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149
150 if (opts == NULL) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700151 ti->error = "Digest algorithm missing for ESSIV mode";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 return -EINVAL;
153 }
154
155 /* Hash the cipher key with the given hash algorithm */
Herbert Xu35058682006-08-24 19:10:20 +1000156 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
157 if (IS_ERR(hash_tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700158 ti->error = "Error initializing ESSIV hash";
Herbert Xu35058682006-08-24 19:10:20 +1000159 return PTR_ERR(hash_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160 }
161
Herbert Xu35058682006-08-24 19:10:20 +1000162 saltsize = crypto_hash_digestsize(hash_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 salt = kmalloc(saltsize, GFP_KERNEL);
164 if (salt == NULL) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700165 ti->error = "Error kmallocing salt storage in ESSIV";
Herbert Xu35058682006-08-24 19:10:20 +1000166 crypto_free_hash(hash_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 return -ENOMEM;
168 }
169
David Hardeman378f0582005-09-17 17:55:31 +1000170 sg_set_buf(&sg, cc->key, cc->key_size);
Herbert Xu35058682006-08-24 19:10:20 +1000171 desc.tfm = hash_tfm;
172 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
173 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
174 crypto_free_hash(hash_tfm);
175
176 if (err) {
177 ti->error = "Error calculating hash in ESSIV";
178 return err;
179 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
181 /* Setup the essiv_tfm with the given salt */
Herbert Xud1806f62006-08-22 20:29:17 +1000182 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
183 if (IS_ERR(essiv_tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700184 ti->error = "Error allocating crypto tfm for ESSIV";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 kfree(salt);
Herbert Xud1806f62006-08-22 20:29:17 +1000186 return PTR_ERR(essiv_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187 }
Herbert Xud1806f62006-08-22 20:29:17 +1000188 if (crypto_cipher_blocksize(essiv_tfm) !=
189 crypto_blkcipher_ivsize(cc->tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700190 ti->error = "Block size of ESSIV cipher does "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 "not match IV size of block cipher";
Herbert Xud1806f62006-08-22 20:29:17 +1000192 crypto_free_cipher(essiv_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 kfree(salt);
194 return -EINVAL;
195 }
Herbert Xud1806f62006-08-22 20:29:17 +1000196 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
197 if (err) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700198 ti->error = "Failed to set key for ESSIV cipher";
Herbert Xud1806f62006-08-22 20:29:17 +1000199 crypto_free_cipher(essiv_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 kfree(salt);
Herbert Xud1806f62006-08-22 20:29:17 +1000201 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 }
203 kfree(salt);
204
Herbert Xu79066ad2006-12-05 13:41:52 -0800205 cc->iv_gen_private.essiv_tfm = essiv_tfm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 return 0;
207}
208
209static void crypt_iv_essiv_dtr(struct crypt_config *cc)
210{
Herbert Xu79066ad2006-12-05 13:41:52 -0800211 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
212 cc->iv_gen_private.essiv_tfm = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213}
214
215static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
216{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 memset(iv, 0, cc->iv_size);
218 *(u64 *)iv = cpu_to_le64(sector);
Herbert Xu79066ad2006-12-05 13:41:52 -0800219 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 return 0;
221}
222
Rik Snel48527fa2006-09-03 08:56:39 +1000223static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
224 const char *opts)
225{
226 unsigned int bs = crypto_blkcipher_blocksize(cc->tfm);
David Howellsf0d1b0b2006-12-08 02:37:49 -0800227 int log = ilog2(bs);
Rik Snel48527fa2006-09-03 08:56:39 +1000228
229 /* we need to calculate how far we must shift the sector count
230 * to get the cipher block count, we use this shift in _gen */
231
232 if (1 << log != bs) {
233 ti->error = "cypher blocksize is not a power of 2";
234 return -EINVAL;
235 }
236
237 if (log > 9) {
238 ti->error = "cypher blocksize is > 512";
239 return -EINVAL;
240 }
241
Herbert Xu79066ad2006-12-05 13:41:52 -0800242 cc->iv_gen_private.benbi_shift = 9 - log;
Rik Snel48527fa2006-09-03 08:56:39 +1000243
244 return 0;
245}
246
247static void crypt_iv_benbi_dtr(struct crypt_config *cc)
248{
Rik Snel48527fa2006-09-03 08:56:39 +1000249}
250
251static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
252{
Herbert Xu79066ad2006-12-05 13:41:52 -0800253 __be64 val;
254
Rik Snel48527fa2006-09-03 08:56:39 +1000255 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
Herbert Xu79066ad2006-12-05 13:41:52 -0800256
257 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
258 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
Rik Snel48527fa2006-09-03 08:56:39 +1000259
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260 return 0;
261}
262
Ludwig Nussel46b47732007-05-09 02:32:55 -0700263static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
264{
265 memset(iv, 0, cc->iv_size);
266
267 return 0;
268}
269
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270static struct crypt_iv_operations crypt_iv_plain_ops = {
271 .generator = crypt_iv_plain_gen
272};
273
274static struct crypt_iv_operations crypt_iv_essiv_ops = {
275 .ctr = crypt_iv_essiv_ctr,
276 .dtr = crypt_iv_essiv_dtr,
277 .generator = crypt_iv_essiv_gen
278};
279
Rik Snel48527fa2006-09-03 08:56:39 +1000280static struct crypt_iv_operations crypt_iv_benbi_ops = {
281 .ctr = crypt_iv_benbi_ctr,
282 .dtr = crypt_iv_benbi_dtr,
283 .generator = crypt_iv_benbi_gen
284};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285
Ludwig Nussel46b47732007-05-09 02:32:55 -0700286static struct crypt_iv_operations crypt_iv_null_ops = {
287 .generator = crypt_iv_null_gen
288};
289
Arjan van de Ven858119e2006-01-14 13:20:43 -0800290static int
Linus Torvalds1da177e2005-04-16 15:20:36 -0700291crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out,
292 struct scatterlist *in, unsigned int length,
293 int write, sector_t sector)
294{
Herbert Xu45789322006-09-03 08:58:41 +1000295 u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64))));
Herbert Xud1806f62006-08-22 20:29:17 +1000296 struct blkcipher_desc desc = {
297 .tfm = cc->tfm,
298 .info = iv,
299 .flags = CRYPTO_TFM_REQ_MAY_SLEEP,
300 };
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 int r;
302
303 if (cc->iv_gen_ops) {
304 r = cc->iv_gen_ops->generator(cc, iv, sector);
305 if (r < 0)
306 return r;
307
308 if (write)
Herbert Xud1806f62006-08-22 20:29:17 +1000309 r = crypto_blkcipher_encrypt_iv(&desc, out, in, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310 else
Herbert Xud1806f62006-08-22 20:29:17 +1000311 r = crypto_blkcipher_decrypt_iv(&desc, out, in, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 } else {
313 if (write)
Herbert Xud1806f62006-08-22 20:29:17 +1000314 r = crypto_blkcipher_encrypt(&desc, out, in, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 else
Herbert Xud1806f62006-08-22 20:29:17 +1000316 r = crypto_blkcipher_decrypt(&desc, out, in, length);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 }
318
319 return r;
320}
321
322static void
323crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx,
324 struct bio *bio_out, struct bio *bio_in,
325 sector_t sector, int write)
326{
327 ctx->bio_in = bio_in;
328 ctx->bio_out = bio_out;
329 ctx->offset_in = 0;
330 ctx->offset_out = 0;
331 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
332 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
333 ctx->sector = sector + cc->iv_offset;
334 ctx->write = write;
335}
336
337/*
338 * Encrypt / decrypt data from one bio to another one (can be the same one)
339 */
340static int crypt_convert(struct crypt_config *cc,
341 struct convert_context *ctx)
342{
343 int r = 0;
344
345 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
346 ctx->idx_out < ctx->bio_out->bi_vcnt) {
347 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
348 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
349 struct scatterlist sg_in = {
350 .page = bv_in->bv_page,
351 .offset = bv_in->bv_offset + ctx->offset_in,
352 .length = 1 << SECTOR_SHIFT
353 };
354 struct scatterlist sg_out = {
355 .page = bv_out->bv_page,
356 .offset = bv_out->bv_offset + ctx->offset_out,
357 .length = 1 << SECTOR_SHIFT
358 };
359
360 ctx->offset_in += sg_in.length;
361 if (ctx->offset_in >= bv_in->bv_len) {
362 ctx->offset_in = 0;
363 ctx->idx_in++;
364 }
365
366 ctx->offset_out += sg_out.length;
367 if (ctx->offset_out >= bv_out->bv_len) {
368 ctx->offset_out = 0;
369 ctx->idx_out++;
370 }
371
372 r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length,
373 ctx->write, ctx->sector);
374 if (r < 0)
375 break;
376
377 ctx->sector++;
378 }
379
380 return r;
381}
382
Milan Broz6a24c712006-10-03 01:15:40 -0700383 static void dm_crypt_bio_destructor(struct bio *bio)
384 {
385 struct crypt_io *io = bio->bi_private;
386 struct crypt_config *cc = io->target->private;
387
388 bio_free(bio, cc->bs);
389 }
390
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391/*
392 * Generate a new unfragmented bio with the given size
393 * This should never violate the device limitations
394 * May return a smaller bio when running out of pages
395 */
Olaf Kirchf97380b2007-05-09 02:32:54 -0700396static struct bio *crypt_alloc_buffer(struct crypt_io *io, unsigned int size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397{
Olaf Kirch027581f2007-05-09 02:32:52 -0700398 struct crypt_config *cc = io->target->private;
Milan Broz8b004452006-10-03 01:15:37 -0700399 struct bio *clone;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
Al Virob4e3ca12005-10-21 03:22:34 -0400401 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402 unsigned int i;
403
Olaf Kirch2f9941b2007-05-09 02:32:53 -0700404 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
Milan Broz8b004452006-10-03 01:15:37 -0700405 if (!clone)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407
Olaf Kirch027581f2007-05-09 02:32:52 -0700408 clone_init(io, clone);
Milan Broz6a24c712006-10-03 01:15:40 -0700409
Olaf Kirchf97380b2007-05-09 02:32:54 -0700410 for (i = 0; i < nr_iovecs; i++) {
Milan Broz8b004452006-10-03 01:15:37 -0700411 struct bio_vec *bv = bio_iovec_idx(clone, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
413 bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask);
414 if (!bv->bv_page)
415 break;
416
417 /*
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
421 */
Olaf Kirchf97380b2007-05-09 02:32:54 -0700422 if (i == (MIN_BIO_PAGES - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
424
425 bv->bv_offset = 0;
426 if (size > PAGE_SIZE)
427 bv->bv_len = PAGE_SIZE;
428 else
429 bv->bv_len = size;
430
Milan Broz8b004452006-10-03 01:15:37 -0700431 clone->bi_size += bv->bv_len;
432 clone->bi_vcnt++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 size -= bv->bv_len;
434 }
435
Milan Broz8b004452006-10-03 01:15:37 -0700436 if (!clone->bi_size) {
437 bio_put(clone);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 return NULL;
439 }
440
Milan Broz8b004452006-10-03 01:15:37 -0700441 return clone;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700442}
443
444static void crypt_free_buffer_pages(struct crypt_config *cc,
Milan Broz8b004452006-10-03 01:15:37 -0700445 struct bio *clone, unsigned int bytes)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446{
447 unsigned int i, start, end;
448 struct bio_vec *bv;
449
450 /*
451 * This is ugly, but Jens Axboe thinks that using bi_idx in the
452 * endio function is too dangerous at the moment, so I calculate the
453 * correct position using bi_vcnt and bi_size.
454 * The bv_offset and bv_len fields might already be modified but we
455 * know that we always allocated whole pages.
456 * A fix to the bi_idx issue in the kernel is in the works, so
457 * we will hopefully be able to revert to the cleaner solution soon.
458 */
Milan Broz8b004452006-10-03 01:15:37 -0700459 i = clone->bi_vcnt - 1;
460 bv = bio_iovec_idx(clone, i);
461 end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - clone->bi_size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 start = end - bytes;
463
464 start >>= PAGE_SHIFT;
Milan Broz8b004452006-10-03 01:15:37 -0700465 if (!clone->bi_size)
466 end = clone->bi_vcnt;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 else
468 end >>= PAGE_SHIFT;
469
Milan Broz8b004452006-10-03 01:15:37 -0700470 for (i = start; i < end; i++) {
471 bv = bio_iovec_idx(clone, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 BUG_ON(!bv->bv_page);
473 mempool_free(bv->bv_page, cc->page_pool);
474 bv->bv_page = NULL;
475 }
476}
477
478/*
479 * One of the bios was finished. Check for completion of
480 * the whole request and correctly clean up the buffer.
481 */
482static void dec_pending(struct crypt_io *io, int error)
483{
484 struct crypt_config *cc = (struct crypt_config *) io->target->private;
485
486 if (error < 0)
487 io->error = error;
488
489 if (!atomic_dec_and_test(&io->pending))
490 return;
491
Milan Broz8b004452006-10-03 01:15:37 -0700492 bio_endio(io->base_bio, io->base_bio->bi_size, io->error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
494 mempool_free(io, cc->io_pool);
495}
496
497/*
498 * kcryptd:
499 *
500 * Needed because it would be very unwise to do decryption in an
Milan Broz23541d22006-10-03 01:15:39 -0700501 * interrupt context.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700502 */
503static struct workqueue_struct *_kcryptd_workqueue;
David Howellsc4028952006-11-22 14:57:56 +0000504static void kcryptd_do_work(struct work_struct *work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
506static void kcryptd_queue_io(struct crypt_io *io)
507{
David Howellsc4028952006-11-22 14:57:56 +0000508 INIT_WORK(&io->work, kcryptd_do_work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700509 queue_work(_kcryptd_workqueue, &io->work);
510}
511
Milan Broz8b004452006-10-03 01:15:37 -0700512static int crypt_endio(struct bio *clone, unsigned int done, int error)
513{
514 struct crypt_io *io = clone->bi_private;
515 struct crypt_config *cc = io->target->private;
516 unsigned read_io = bio_data_dir(clone) == READ;
517
518 /*
519 * free the processed pages, even if
520 * it's only a partially completed write
521 */
522 if (!read_io)
523 crypt_free_buffer_pages(cc, clone, done);
524
Milan Broz23541d22006-10-03 01:15:39 -0700525 /* keep going - not finished yet */
Milan Broz8b004452006-10-03 01:15:37 -0700526 if (unlikely(clone->bi_size))
527 return 1;
528
Milan Broz8b004452006-10-03 01:15:37 -0700529 if (!read_io)
530 goto out;
531
532 if (unlikely(!bio_flagged(clone, BIO_UPTODATE))) {
533 error = -EIO;
534 goto out;
535 }
536
537 bio_put(clone);
Milan Broz23541d22006-10-03 01:15:39 -0700538 io->post_process = 1;
Milan Broz8b004452006-10-03 01:15:37 -0700539 kcryptd_queue_io(io);
540 return 0;
541
542out:
543 bio_put(clone);
544 dec_pending(io, error);
545 return error;
546}
547
548static void clone_init(struct crypt_io *io, struct bio *clone)
549{
550 struct crypt_config *cc = io->target->private;
551
552 clone->bi_private = io;
553 clone->bi_end_io = crypt_endio;
554 clone->bi_bdev = cc->dev->bdev;
555 clone->bi_rw = io->base_bio->bi_rw;
Olaf Kirch027581f2007-05-09 02:32:52 -0700556 clone->bi_destructor = dm_crypt_bio_destructor;
Milan Broz8b004452006-10-03 01:15:37 -0700557}
558
Milan Broz23541d22006-10-03 01:15:39 -0700559static void process_read(struct crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700560{
561 struct crypt_config *cc = io->target->private;
562 struct bio *base_bio = io->base_bio;
563 struct bio *clone;
Milan Broz93e605c2006-10-03 01:15:38 -0700564 sector_t sector = base_bio->bi_sector - io->target->begin;
565
566 atomic_inc(&io->pending);
Milan Broz8b004452006-10-03 01:15:37 -0700567
568 /*
569 * The block layer might modify the bvec array, so always
570 * copy the required bvecs because we need the original
571 * one in order to decrypt the whole bio data *afterwards*.
572 */
Milan Broz6a24c712006-10-03 01:15:40 -0700573 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
Milan Broz93e605c2006-10-03 01:15:38 -0700574 if (unlikely(!clone)) {
575 dec_pending(io, -ENOMEM);
Milan Broz23541d22006-10-03 01:15:39 -0700576 return;
Milan Broz93e605c2006-10-03 01:15:38 -0700577 }
Milan Broz8b004452006-10-03 01:15:37 -0700578
579 clone_init(io, clone);
580 clone->bi_idx = 0;
581 clone->bi_vcnt = bio_segments(base_bio);
582 clone->bi_size = base_bio->bi_size;
Milan Broz93e605c2006-10-03 01:15:38 -0700583 clone->bi_sector = cc->start + sector;
Milan Broz8b004452006-10-03 01:15:37 -0700584 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
585 sizeof(struct bio_vec) * clone->bi_vcnt);
Milan Broz8b004452006-10-03 01:15:37 -0700586
Milan Broz93e605c2006-10-03 01:15:38 -0700587 generic_make_request(clone);
Milan Broz8b004452006-10-03 01:15:37 -0700588}
589
Milan Broz23541d22006-10-03 01:15:39 -0700590static void process_write(struct crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700591{
592 struct crypt_config *cc = io->target->private;
593 struct bio *base_bio = io->base_bio;
594 struct bio *clone;
Milan Broz93e605c2006-10-03 01:15:38 -0700595 struct convert_context ctx;
596 unsigned remaining = base_bio->bi_size;
597 sector_t sector = base_bio->bi_sector - io->target->begin;
Milan Broz8b004452006-10-03 01:15:37 -0700598
Milan Broz93e605c2006-10-03 01:15:38 -0700599 atomic_inc(&io->pending);
Milan Broz8b004452006-10-03 01:15:37 -0700600
Milan Broz93e605c2006-10-03 01:15:38 -0700601 crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1);
Milan Broz8b004452006-10-03 01:15:37 -0700602
Milan Broz93e605c2006-10-03 01:15:38 -0700603 /*
604 * The allocated buffers can be smaller than the whole bio,
605 * so repeat the whole process until all the data can be handled.
606 */
607 while (remaining) {
Olaf Kirchf97380b2007-05-09 02:32:54 -0700608 clone = crypt_alloc_buffer(io, remaining);
Milan Broz23541d22006-10-03 01:15:39 -0700609 if (unlikely(!clone)) {
610 dec_pending(io, -ENOMEM);
611 return;
612 }
Milan Broz93e605c2006-10-03 01:15:38 -0700613
614 ctx.bio_out = clone;
Olaf Kirchf97380b2007-05-09 02:32:54 -0700615 ctx.idx_out = 0;
Milan Broz93e605c2006-10-03 01:15:38 -0700616
617 if (unlikely(crypt_convert(cc, &ctx) < 0)) {
618 crypt_free_buffer_pages(cc, clone, clone->bi_size);
619 bio_put(clone);
Milan Broz23541d22006-10-03 01:15:39 -0700620 dec_pending(io, -EIO);
621 return;
Milan Broz93e605c2006-10-03 01:15:38 -0700622 }
623
Olaf Kirchf97380b2007-05-09 02:32:54 -0700624 /* crypt_convert should have filled the clone bio */
625 BUG_ON(ctx.idx_out < clone->bi_vcnt);
626
Milan Broz93e605c2006-10-03 01:15:38 -0700627 clone->bi_sector = cc->start + sector;
Milan Broz93e605c2006-10-03 01:15:38 -0700628 remaining -= clone->bi_size;
629 sector += bio_sectors(clone);
630
Olaf Kirch2f9941b2007-05-09 02:32:53 -0700631 /* Grab another reference to the io struct
632 * before we kick off the request */
Milan Broz23541d22006-10-03 01:15:39 -0700633 if (remaining)
634 atomic_inc(&io->pending);
635
Milan Broz93e605c2006-10-03 01:15:38 -0700636 generic_make_request(clone);
637
Olaf Kirch98221eb2007-05-09 02:32:52 -0700638 /* Do not reference clone after this - it
639 * may be gone already. */
640
Milan Broz93e605c2006-10-03 01:15:38 -0700641 /* out of memory -> run queues */
642 if (remaining)
Olaf Kirch98221eb2007-05-09 02:32:52 -0700643 congestion_wait(WRITE, HZ/100);
Milan Broz8b004452006-10-03 01:15:37 -0700644 }
Milan Broz8b004452006-10-03 01:15:37 -0700645}
646
647static void process_read_endio(struct crypt_io *io)
648{
649 struct crypt_config *cc = io->target->private;
650 struct convert_context ctx;
651
652 crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio,
653 io->base_bio->bi_sector - io->target->begin, 0);
654
655 dec_pending(io, crypt_convert(cc, &ctx));
656}
657
David Howellsc4028952006-11-22 14:57:56 +0000658static void kcryptd_do_work(struct work_struct *work)
Milan Broz8b004452006-10-03 01:15:37 -0700659{
David Howellsc4028952006-11-22 14:57:56 +0000660 struct crypt_io *io = container_of(work, struct crypt_io, work);
Milan Broz8b004452006-10-03 01:15:37 -0700661
Milan Broz23541d22006-10-03 01:15:39 -0700662 if (io->post_process)
663 process_read_endio(io);
664 else if (bio_data_dir(io->base_bio) == READ)
665 process_read(io);
666 else
667 process_write(io);
Milan Broz8b004452006-10-03 01:15:37 -0700668}
669
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670/*
671 * Decode key from its hex representation
672 */
673static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
674{
675 char buffer[3];
676 char *endp;
677 unsigned int i;
678
679 buffer[2] = '\0';
680
Milan Broz8b004452006-10-03 01:15:37 -0700681 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700682 buffer[0] = *hex++;
683 buffer[1] = *hex++;
684
685 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
686
687 if (endp != &buffer[2])
688 return -EINVAL;
689 }
690
691 if (*hex != '\0')
692 return -EINVAL;
693
694 return 0;
695}
696
697/*
698 * Encode key into its hex representation
699 */
700static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
701{
702 unsigned int i;
703
Milan Broz8b004452006-10-03 01:15:37 -0700704 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 sprintf(hex, "%02x", *key);
706 hex += 2;
707 key++;
708 }
709}
710
Milan Broze48d4bb2006-10-03 01:15:37 -0700711static int crypt_set_key(struct crypt_config *cc, char *key)
712{
713 unsigned key_size = strlen(key) >> 1;
714
715 if (cc->key_size && cc->key_size != key_size)
716 return -EINVAL;
717
718 cc->key_size = key_size; /* initial settings */
719
720 if ((!key_size && strcmp(key, "-")) ||
721 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
722 return -EINVAL;
723
724 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
725
726 return 0;
727}
728
729static int crypt_wipe_key(struct crypt_config *cc)
730{
731 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
732 memset(&cc->key, 0, cc->key_size * sizeof(u8));
733 return 0;
734}
735
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736/*
737 * Construct an encryption mapping:
738 * <cipher> <key> <iv_offset> <dev_path> <start>
739 */
740static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
741{
742 struct crypt_config *cc;
Herbert Xud1806f62006-08-22 20:29:17 +1000743 struct crypto_blkcipher *tfm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 char *tmp;
745 char *cipher;
746 char *chainmode;
747 char *ivmode;
748 char *ivopts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 unsigned int key_size;
Andrew Morton4ee218c2006-03-27 01:17:48 -0800750 unsigned long long tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700751
752 if (argc != 5) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700753 ti->error = "Not enough arguments";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 return -EINVAL;
755 }
756
757 tmp = argv[0];
758 cipher = strsep(&tmp, "-");
759 chainmode = strsep(&tmp, "-");
760 ivopts = strsep(&tmp, "-");
761 ivmode = strsep(&ivopts, ":");
762
763 if (tmp)
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700764 DMWARN("Unexpected additional cipher options");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700765
766 key_size = strlen(argv[1]) >> 1;
767
Milan Broze48d4bb2006-10-03 01:15:37 -0700768 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 if (cc == NULL) {
770 ti->error =
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700771 "Cannot allocate transparent encryption context";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700772 return -ENOMEM;
773 }
774
Milan Broze48d4bb2006-10-03 01:15:37 -0700775 if (crypt_set_key(cc, argv[1])) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700776 ti->error = "Error decoding key";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777 goto bad1;
778 }
779
780 /* Compatiblity mode for old dm-crypt cipher strings */
781 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
782 chainmode = "cbc";
783 ivmode = "plain";
784 }
785
Herbert Xud1806f62006-08-22 20:29:17 +1000786 if (strcmp(chainmode, "ecb") && !ivmode) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700787 ti->error = "This chaining mode requires an IV mechanism";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 goto bad1;
789 }
790
Herbert Xud1806f62006-08-22 20:29:17 +1000791 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", chainmode,
792 cipher) >= CRYPTO_MAX_ALG_NAME) {
793 ti->error = "Chain mode + cipher name is too long";
794 goto bad1;
795 }
796
797 tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
798 if (IS_ERR(tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700799 ti->error = "Error allocating crypto tfm";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800 goto bad1;
801 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700802
Herbert Xud1806f62006-08-22 20:29:17 +1000803 strcpy(cc->cipher, cipher);
804 strcpy(cc->chainmode, chainmode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 cc->tfm = tfm;
806
807 /*
Rik Snel48527fa2006-09-03 08:56:39 +1000808 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700809 * See comments at iv code
810 */
811
812 if (ivmode == NULL)
813 cc->iv_gen_ops = NULL;
814 else if (strcmp(ivmode, "plain") == 0)
815 cc->iv_gen_ops = &crypt_iv_plain_ops;
816 else if (strcmp(ivmode, "essiv") == 0)
817 cc->iv_gen_ops = &crypt_iv_essiv_ops;
Rik Snel48527fa2006-09-03 08:56:39 +1000818 else if (strcmp(ivmode, "benbi") == 0)
819 cc->iv_gen_ops = &crypt_iv_benbi_ops;
Ludwig Nussel46b47732007-05-09 02:32:55 -0700820 else if (strcmp(ivmode, "null") == 0)
821 cc->iv_gen_ops = &crypt_iv_null_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700822 else {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700823 ti->error = "Invalid IV mode";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 goto bad2;
825 }
826
827 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
828 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
829 goto bad2;
830
Herbert Xud1806f62006-08-22 20:29:17 +1000831 cc->iv_size = crypto_blkcipher_ivsize(tfm);
832 if (cc->iv_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 /* at least a 64 bit sector number should fit in our buffer */
Herbert Xud1806f62006-08-22 20:29:17 +1000834 cc->iv_size = max(cc->iv_size,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700835 (unsigned int)(sizeof(u64) / sizeof(u8)));
836 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700837 if (cc->iv_gen_ops) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700838 DMWARN("Selected cipher does not support IVs");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700839 if (cc->iv_gen_ops->dtr)
840 cc->iv_gen_ops->dtr(cc);
841 cc->iv_gen_ops = NULL;
842 }
843 }
844
Matthew Dobson93d23412006-03-26 01:37:50 -0800845 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 if (!cc->io_pool) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700847 ti->error = "Cannot allocate crypt io mempool";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700848 goto bad3;
849 }
850
Matthew Dobsona19b27c2006-03-26 01:37:45 -0800851 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700852 if (!cc->page_pool) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700853 ti->error = "Cannot allocate page mempool";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700854 goto bad4;
855 }
856
Jens Axboe59725112007-04-02 10:06:42 +0200857 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
Milan Broz6a24c712006-10-03 01:15:40 -0700858 if (!cc->bs) {
859 ti->error = "Cannot allocate crypt bioset";
860 goto bad_bs;
861 }
862
Herbert Xud1806f62006-08-22 20:29:17 +1000863 if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700864 ti->error = "Error setting key";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700865 goto bad5;
866 }
867
Andrew Morton4ee218c2006-03-27 01:17:48 -0800868 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700869 ti->error = "Invalid iv_offset sector";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870 goto bad5;
871 }
Andrew Morton4ee218c2006-03-27 01:17:48 -0800872 cc->iv_offset = tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873
Andrew Morton4ee218c2006-03-27 01:17:48 -0800874 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700875 ti->error = "Invalid device sector";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 goto bad5;
877 }
Andrew Morton4ee218c2006-03-27 01:17:48 -0800878 cc->start = tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
880 if (dm_get_device(ti, argv[3], cc->start, ti->len,
881 dm_table_get_mode(ti->table), &cc->dev)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700882 ti->error = "Device lookup failed";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700883 goto bad5;
884 }
885
886 if (ivmode && cc->iv_gen_ops) {
887 if (ivopts)
888 *(ivopts - 1) = ':';
889 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
890 if (!cc->iv_mode) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700891 ti->error = "Error kmallocing iv_mode string";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700892 goto bad5;
893 }
894 strcpy(cc->iv_mode, ivmode);
895 } else
896 cc->iv_mode = NULL;
897
898 ti->private = cc;
899 return 0;
900
901bad5:
Milan Broz6a24c712006-10-03 01:15:40 -0700902 bioset_free(cc->bs);
903bad_bs:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700904 mempool_destroy(cc->page_pool);
905bad4:
906 mempool_destroy(cc->io_pool);
907bad3:
908 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
909 cc->iv_gen_ops->dtr(cc);
910bad2:
Herbert Xud1806f62006-08-22 20:29:17 +1000911 crypto_free_blkcipher(tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700912bad1:
Stefan Rompf9d3520a2006-01-06 00:20:08 -0800913 /* Must zero key material before freeing */
914 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700915 kfree(cc);
916 return -EINVAL;
917}
918
919static void crypt_dtr(struct dm_target *ti)
920{
921 struct crypt_config *cc = (struct crypt_config *) ti->private;
922
Milan Broz6a24c712006-10-03 01:15:40 -0700923 bioset_free(cc->bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700924 mempool_destroy(cc->page_pool);
925 mempool_destroy(cc->io_pool);
926
Jesper Juhl990a8ba2005-06-21 17:17:30 -0700927 kfree(cc->iv_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
929 cc->iv_gen_ops->dtr(cc);
Herbert Xud1806f62006-08-22 20:29:17 +1000930 crypto_free_blkcipher(cc->tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700931 dm_put_device(ti, cc->dev);
Stefan Rompf9d3520a2006-01-06 00:20:08 -0800932
933 /* Must zero key material before freeing */
934 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700935 kfree(cc);
936}
937
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938static int crypt_map(struct dm_target *ti, struct bio *bio,
939 union map_info *map_context)
940{
Milan Broz8b004452006-10-03 01:15:37 -0700941 struct crypt_config *cc = ti->private;
Milan Broze48d4bb2006-10-03 01:15:37 -0700942 struct crypt_io *io;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943
Milan Broz9c89f8b2007-05-09 02:32:51 -0700944 if (bio_barrier(bio))
945 return -EOPNOTSUPP;
946
Milan Broze48d4bb2006-10-03 01:15:37 -0700947 io = mempool_alloc(cc->io_pool, GFP_NOIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 io->target = ti;
Milan Broz8b004452006-10-03 01:15:37 -0700949 io->base_bio = bio;
Milan Broz23541d22006-10-03 01:15:39 -0700950 io->error = io->post_process = 0;
Milan Broz93e605c2006-10-03 01:15:38 -0700951 atomic_set(&io->pending, 0);
Milan Broz23541d22006-10-03 01:15:39 -0700952 kcryptd_queue_io(io);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953
Kiyoshi Uedad2a7ad22006-12-08 02:41:06 -0800954 return DM_MAPIO_SUBMITTED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955}
956
957static int crypt_status(struct dm_target *ti, status_type_t type,
958 char *result, unsigned int maxlen)
959{
960 struct crypt_config *cc = (struct crypt_config *) ti->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 unsigned int sz = 0;
962
963 switch (type) {
964 case STATUSTYPE_INFO:
965 result[0] = '\0';
966 break;
967
968 case STATUSTYPE_TABLE:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 if (cc->iv_mode)
Christophe Saout37af6562006-10-30 20:39:08 +0100970 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
971 cc->iv_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700972 else
Christophe Saout37af6562006-10-30 20:39:08 +0100973 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974
975 if (cc->key_size > 0) {
976 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
977 return -ENOMEM;
978
979 crypt_encode_key(result + sz, cc->key, cc->key_size);
980 sz += cc->key_size << 1;
981 } else {
982 if (sz >= maxlen)
983 return -ENOMEM;
984 result[sz++] = '-';
985 }
986
Andrew Morton4ee218c2006-03-27 01:17:48 -0800987 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
988 cc->dev->name, (unsigned long long)cc->start);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700989 break;
990 }
991 return 0;
992}
993
Milan Broze48d4bb2006-10-03 01:15:37 -0700994static void crypt_postsuspend(struct dm_target *ti)
995{
996 struct crypt_config *cc = ti->private;
997
998 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
999}
1000
1001static int crypt_preresume(struct dm_target *ti)
1002{
1003 struct crypt_config *cc = ti->private;
1004
1005 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1006 DMERR("aborting resume - crypt key is not set.");
1007 return -EAGAIN;
1008 }
1009
1010 return 0;
1011}
1012
1013static void crypt_resume(struct dm_target *ti)
1014{
1015 struct crypt_config *cc = ti->private;
1016
1017 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1018}
1019
1020/* Message interface
1021 * key set <key>
1022 * key wipe
1023 */
1024static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1025{
1026 struct crypt_config *cc = ti->private;
1027
1028 if (argc < 2)
1029 goto error;
1030
1031 if (!strnicmp(argv[0], MESG_STR("key"))) {
1032 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1033 DMWARN("not suspended during key manipulation.");
1034 return -EINVAL;
1035 }
1036 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1037 return crypt_set_key(cc, argv[2]);
1038 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1039 return crypt_wipe_key(cc);
1040 }
1041
1042error:
1043 DMWARN("unrecognised message received.");
1044 return -EINVAL;
1045}
1046
Linus Torvalds1da177e2005-04-16 15:20:36 -07001047static struct target_type crypt_target = {
1048 .name = "crypt",
Ludwig Nussel46b47732007-05-09 02:32:55 -07001049 .version= {1, 5, 0},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001050 .module = THIS_MODULE,
1051 .ctr = crypt_ctr,
1052 .dtr = crypt_dtr,
1053 .map = crypt_map,
1054 .status = crypt_status,
Milan Broze48d4bb2006-10-03 01:15:37 -07001055 .postsuspend = crypt_postsuspend,
1056 .preresume = crypt_preresume,
1057 .resume = crypt_resume,
1058 .message = crypt_message,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001059};
1060
1061static int __init dm_crypt_init(void)
1062{
1063 int r;
1064
1065 _crypt_io_pool = kmem_cache_create("dm-crypt_io",
1066 sizeof(struct crypt_io),
1067 0, 0, NULL, NULL);
1068 if (!_crypt_io_pool)
1069 return -ENOMEM;
1070
1071 _kcryptd_workqueue = create_workqueue("kcryptd");
1072 if (!_kcryptd_workqueue) {
1073 r = -ENOMEM;
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001074 DMERR("couldn't create kcryptd");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001075 goto bad1;
1076 }
1077
1078 r = dm_register_target(&crypt_target);
1079 if (r < 0) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001080 DMERR("register failed %d", r);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081 goto bad2;
1082 }
1083
1084 return 0;
1085
1086bad2:
1087 destroy_workqueue(_kcryptd_workqueue);
1088bad1:
1089 kmem_cache_destroy(_crypt_io_pool);
1090 return r;
1091}
1092
1093static void __exit dm_crypt_exit(void)
1094{
1095 int r = dm_unregister_target(&crypt_target);
1096
1097 if (r < 0)
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001098 DMERR("unregister failed %d", r);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099
1100 destroy_workqueue(_kcryptd_workqueue);
1101 kmem_cache_destroy(_crypt_io_pool);
1102}
1103
1104module_init(dm_crypt_init);
1105module_exit(dm_crypt_exit);
1106
1107MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1108MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1109MODULE_LICENSE("GPL");