blob: 35bda49796fbca493800a275360a6d443dac5cf2 [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 Broz3f1e9072008-03-28 14:16:07 -07004 * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07005 *
6 * This file is released under the GPL.
7 */
8
Milan Broz43d69032008-02-08 02:11:09 +00009#include <linux/completion.h>
Herbert Xud1806f62006-08-22 20:29:17 +100010#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070011#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>
Andrew Morton3fcfab12006-10-19 23:28:16 -070020#include <linux/backing-dev.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <asm/atomic.h>
David Hardeman378f0582005-09-17 17:55:31 +100022#include <linux/scatterlist.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070023#include <asm/page.h>
Rik Snel48527fa2006-09-03 08:56:39 +100024#include <asm/unaligned.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
Mikulas Patocka586e80e2008-10-21 17:44:59 +010026#include <linux/device-mapper.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Alasdair G Kergon72d94862006-06-26 00:27:35 -070028#define DM_MSG_PREFIX "crypt"
Milan Broze48d4bb2006-10-03 01:15:37 -070029#define MESG_STR(x) x, sizeof(x)
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
31/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070032 * context holding the current state of a multi-part conversion
33 */
34struct convert_context {
Milan Broz43d69032008-02-08 02:11:09 +000035 struct completion restart;
Linus Torvalds1da177e2005-04-16 15:20:36 -070036 struct bio *bio_in;
37 struct bio *bio_out;
38 unsigned int offset_in;
39 unsigned int offset_out;
40 unsigned int idx_in;
41 unsigned int idx_out;
42 sector_t sector;
Milan Broz43d69032008-02-08 02:11:09 +000043 atomic_t pending;
Linus Torvalds1da177e2005-04-16 15:20:36 -070044};
45
Milan Broz53017032008-02-08 02:10:38 +000046/*
47 * per bio private data
48 */
49struct dm_crypt_io {
50 struct dm_target *target;
51 struct bio *base_bio;
52 struct work_struct work;
53
54 struct convert_context ctx;
55
56 atomic_t pending;
57 int error;
Milan Broz0c395b02008-02-08 02:10:54 +000058 sector_t sector;
Milan Broz393b47e2008-10-21 17:45:02 +010059 struct dm_crypt_io *base_io;
Milan Broz53017032008-02-08 02:10:38 +000060};
61
Milan Broz01482b72008-02-08 02:11:04 +000062struct dm_crypt_request {
63 struct scatterlist sg_in;
64 struct scatterlist sg_out;
65};
66
Linus Torvalds1da177e2005-04-16 15:20:36 -070067struct crypt_config;
68
69struct crypt_iv_operations {
70 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
Milan Brozd469f842007-10-19 22:42:37 +010071 const char *opts);
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 void (*dtr)(struct crypt_config *cc);
73 const char *(*status)(struct crypt_config *cc);
74 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
75};
76
77/*
78 * Crypt: maps a linear range of a block device
79 * and encrypts / decrypts at the same time.
80 */
Milan Broze48d4bb2006-10-03 01:15:37 -070081enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
Linus Torvalds1da177e2005-04-16 15:20:36 -070082struct crypt_config {
83 struct dm_dev *dev;
84 sector_t start;
85
86 /*
Milan Brozddd42ed2008-02-08 02:11:07 +000087 * pool for per bio private data, crypto requests and
88 * encryption requeusts/buffer pages
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 */
90 mempool_t *io_pool;
Milan Brozddd42ed2008-02-08 02:11:07 +000091 mempool_t *req_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 mempool_t *page_pool;
Milan Broz6a24c712006-10-03 01:15:40 -070093 struct bio_set *bs;
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
Milan Brozcabf08e2007-10-19 22:38:58 +010095 struct workqueue_struct *io_queue;
96 struct workqueue_struct *crypt_queue;
Milan Broz3f1e9072008-03-28 14:16:07 -070097
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 /*
99 * crypto related data
100 */
101 struct crypt_iv_operations *iv_gen_ops;
102 char *iv_mode;
Herbert Xu79066ad2006-12-05 13:41:52 -0800103 union {
104 struct crypto_cipher *essiv_tfm;
105 int benbi_shift;
106 } iv_gen_private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 sector_t iv_offset;
108 unsigned int iv_size;
109
Milan Brozddd42ed2008-02-08 02:11:07 +0000110 /*
111 * Layout of each crypto request:
112 *
113 * struct ablkcipher_request
114 * context
115 * padding
116 * struct dm_crypt_request
117 * padding
118 * IV
119 *
120 * The padding is added so that dm_crypt_request and the IV are
121 * correctly aligned.
122 */
123 unsigned int dmreq_start;
124 struct ablkcipher_request *req;
125
Herbert Xud1806f62006-08-22 20:29:17 +1000126 char cipher[CRYPTO_MAX_ALG_NAME];
127 char chainmode[CRYPTO_MAX_ALG_NAME];
Milan Broz3a7f6c92008-02-08 02:11:14 +0000128 struct crypto_ablkcipher *tfm;
Milan Broze48d4bb2006-10-03 01:15:37 -0700129 unsigned long flags;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 unsigned int key_size;
131 u8 key[0];
132};
133
Milan Broz6a24c712006-10-03 01:15:40 -0700134#define MIN_IOS 16
Linus Torvalds1da177e2005-04-16 15:20:36 -0700135#define MIN_POOL_PAGES 32
136#define MIN_BIO_PAGES 8
137
Christoph Lametere18b8902006-12-06 20:33:20 -0800138static struct kmem_cache *_crypt_io_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100140static void clone_init(struct dm_crypt_io *, struct bio *);
Alasdair G Kergon395b1672008-02-08 02:10:52 +0000141static void kcryptd_queue_crypt(struct dm_crypt_io *io);
Olaf Kirch027581f2007-05-09 02:32:52 -0700142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 * Different IV generation algorithms:
145 *
Rik Snel3c164bd2006-09-02 18:17:33 +1000146 * plain: the initial vector is the 32-bit little-endian version of the sector
Robert P. J. Day3a4fa0a2007-10-19 23:10:43 +0200147 * number, padded with zeros if necessary.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 *
Rik Snel3c164bd2006-09-02 18:17:33 +1000149 * essiv: "encrypted sector|salt initial vector", the sector number is
150 * encrypted with the bulk cipher using a salt as key. The salt
151 * should be derived from the bulk cipher's key via hashing.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 *
Rik Snel48527fa2006-09-03 08:56:39 +1000153 * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
154 * (needed for LRW-32-AES and possible other narrow block modes)
155 *
Ludwig Nussel46b47732007-05-09 02:32:55 -0700156 * null: the initial vector is always zero. Provides compatibility with
157 * obsolete loop_fish2 devices. Do not use for new devices.
158 *
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159 * plumb: unimplemented, see:
160 * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
161 */
162
163static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
164{
165 memset(iv, 0, cc->iv_size);
166 *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
167
168 return 0;
169}
170
171static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
Milan Brozd469f842007-10-19 22:42:37 +0100172 const char *opts)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173{
Herbert Xud1806f62006-08-22 20:29:17 +1000174 struct crypto_cipher *essiv_tfm;
Herbert Xu35058682006-08-24 19:10:20 +1000175 struct crypto_hash *hash_tfm;
176 struct hash_desc desc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 struct scatterlist sg;
178 unsigned int saltsize;
179 u8 *salt;
Herbert Xud1806f62006-08-22 20:29:17 +1000180 int err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181
182 if (opts == NULL) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700183 ti->error = "Digest algorithm missing for ESSIV mode";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 return -EINVAL;
185 }
186
187 /* Hash the cipher key with the given hash algorithm */
Herbert Xu35058682006-08-24 19:10:20 +1000188 hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
189 if (IS_ERR(hash_tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700190 ti->error = "Error initializing ESSIV hash";
Herbert Xu35058682006-08-24 19:10:20 +1000191 return PTR_ERR(hash_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 }
193
Herbert Xu35058682006-08-24 19:10:20 +1000194 saltsize = crypto_hash_digestsize(hash_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 salt = kmalloc(saltsize, GFP_KERNEL);
196 if (salt == NULL) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700197 ti->error = "Error kmallocing salt storage in ESSIV";
Herbert Xu35058682006-08-24 19:10:20 +1000198 crypto_free_hash(hash_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 return -ENOMEM;
200 }
201
Herbert Xu68e3f5d2007-10-27 00:52:07 -0700202 sg_init_one(&sg, cc->key, cc->key_size);
Herbert Xu35058682006-08-24 19:10:20 +1000203 desc.tfm = hash_tfm;
204 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
205 err = crypto_hash_digest(&desc, &sg, cc->key_size, salt);
206 crypto_free_hash(hash_tfm);
207
208 if (err) {
209 ti->error = "Error calculating hash in ESSIV";
Dmitry Monakhov815f9e32007-10-19 22:38:38 +0100210 kfree(salt);
Herbert Xu35058682006-08-24 19:10:20 +1000211 return err;
212 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213
214 /* Setup the essiv_tfm with the given salt */
Herbert Xud1806f62006-08-22 20:29:17 +1000215 essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
216 if (IS_ERR(essiv_tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700217 ti->error = "Error allocating crypto tfm for ESSIV";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 kfree(salt);
Herbert Xud1806f62006-08-22 20:29:17 +1000219 return PTR_ERR(essiv_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 }
Herbert Xud1806f62006-08-22 20:29:17 +1000221 if (crypto_cipher_blocksize(essiv_tfm) !=
Milan Broz3a7f6c92008-02-08 02:11:14 +0000222 crypto_ablkcipher_ivsize(cc->tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700223 ti->error = "Block size of ESSIV cipher does "
Milan Brozd469f842007-10-19 22:42:37 +0100224 "not match IV size of block cipher";
Herbert Xud1806f62006-08-22 20:29:17 +1000225 crypto_free_cipher(essiv_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 kfree(salt);
227 return -EINVAL;
228 }
Herbert Xud1806f62006-08-22 20:29:17 +1000229 err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
230 if (err) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700231 ti->error = "Failed to set key for ESSIV cipher";
Herbert Xud1806f62006-08-22 20:29:17 +1000232 crypto_free_cipher(essiv_tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 kfree(salt);
Herbert Xud1806f62006-08-22 20:29:17 +1000234 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 }
236 kfree(salt);
237
Herbert Xu79066ad2006-12-05 13:41:52 -0800238 cc->iv_gen_private.essiv_tfm = essiv_tfm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 return 0;
240}
241
242static void crypt_iv_essiv_dtr(struct crypt_config *cc)
243{
Herbert Xu79066ad2006-12-05 13:41:52 -0800244 crypto_free_cipher(cc->iv_gen_private.essiv_tfm);
245 cc->iv_gen_private.essiv_tfm = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
248static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
249{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 memset(iv, 0, cc->iv_size);
251 *(u64 *)iv = cpu_to_le64(sector);
Herbert Xu79066ad2006-12-05 13:41:52 -0800252 crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 return 0;
254}
255
Rik Snel48527fa2006-09-03 08:56:39 +1000256static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
257 const char *opts)
258{
Milan Broz3a7f6c92008-02-08 02:11:14 +0000259 unsigned bs = crypto_ablkcipher_blocksize(cc->tfm);
David Howellsf0d1b0b2006-12-08 02:37:49 -0800260 int log = ilog2(bs);
Rik Snel48527fa2006-09-03 08:56:39 +1000261
262 /* we need to calculate how far we must shift the sector count
263 * to get the cipher block count, we use this shift in _gen */
264
265 if (1 << log != bs) {
266 ti->error = "cypher blocksize is not a power of 2";
267 return -EINVAL;
268 }
269
270 if (log > 9) {
271 ti->error = "cypher blocksize is > 512";
272 return -EINVAL;
273 }
274
Herbert Xu79066ad2006-12-05 13:41:52 -0800275 cc->iv_gen_private.benbi_shift = 9 - log;
Rik Snel48527fa2006-09-03 08:56:39 +1000276
277 return 0;
278}
279
280static void crypt_iv_benbi_dtr(struct crypt_config *cc)
281{
Rik Snel48527fa2006-09-03 08:56:39 +1000282}
283
284static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
285{
Herbert Xu79066ad2006-12-05 13:41:52 -0800286 __be64 val;
287
Rik Snel48527fa2006-09-03 08:56:39 +1000288 memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
Herbert Xu79066ad2006-12-05 13:41:52 -0800289
290 val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1);
291 put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
Rik Snel48527fa2006-09-03 08:56:39 +1000292
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 return 0;
294}
295
Ludwig Nussel46b47732007-05-09 02:32:55 -0700296static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
297{
298 memset(iv, 0, cc->iv_size);
299
300 return 0;
301}
302
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303static struct crypt_iv_operations crypt_iv_plain_ops = {
304 .generator = crypt_iv_plain_gen
305};
306
307static struct crypt_iv_operations crypt_iv_essiv_ops = {
308 .ctr = crypt_iv_essiv_ctr,
309 .dtr = crypt_iv_essiv_dtr,
310 .generator = crypt_iv_essiv_gen
311};
312
Rik Snel48527fa2006-09-03 08:56:39 +1000313static struct crypt_iv_operations crypt_iv_benbi_ops = {
314 .ctr = crypt_iv_benbi_ctr,
315 .dtr = crypt_iv_benbi_dtr,
316 .generator = crypt_iv_benbi_gen
317};
Linus Torvalds1da177e2005-04-16 15:20:36 -0700318
Ludwig Nussel46b47732007-05-09 02:32:55 -0700319static struct crypt_iv_operations crypt_iv_null_ops = {
320 .generator = crypt_iv_null_gen
321};
322
Milan Brozd469f842007-10-19 22:42:37 +0100323static void crypt_convert_init(struct crypt_config *cc,
324 struct convert_context *ctx,
325 struct bio *bio_out, struct bio *bio_in,
Milan Brozfcd369d2008-02-08 02:10:41 +0000326 sector_t sector)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327{
328 ctx->bio_in = bio_in;
329 ctx->bio_out = bio_out;
330 ctx->offset_in = 0;
331 ctx->offset_out = 0;
332 ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
333 ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
334 ctx->sector = sector + cc->iv_offset;
Milan Broz43d69032008-02-08 02:11:09 +0000335 init_completion(&ctx->restart);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336}
337
Milan Broz01482b72008-02-08 02:11:04 +0000338static int crypt_convert_block(struct crypt_config *cc,
Milan Broz3a7f6c92008-02-08 02:11:14 +0000339 struct convert_context *ctx,
340 struct ablkcipher_request *req)
Milan Broz01482b72008-02-08 02:11:04 +0000341{
342 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
343 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
Milan Broz3a7f6c92008-02-08 02:11:14 +0000344 struct dm_crypt_request *dmreq;
345 u8 *iv;
346 int r = 0;
Milan Broz01482b72008-02-08 02:11:04 +0000347
Milan Broz3a7f6c92008-02-08 02:11:14 +0000348 dmreq = (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
349 iv = (u8 *)ALIGN((unsigned long)(dmreq + 1),
350 crypto_ablkcipher_alignmask(cc->tfm) + 1);
351
352 sg_init_table(&dmreq->sg_in, 1);
353 sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
Milan Broz01482b72008-02-08 02:11:04 +0000354 bv_in->bv_offset + ctx->offset_in);
355
Milan Broz3a7f6c92008-02-08 02:11:14 +0000356 sg_init_table(&dmreq->sg_out, 1);
357 sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
Milan Broz01482b72008-02-08 02:11:04 +0000358 bv_out->bv_offset + ctx->offset_out);
359
360 ctx->offset_in += 1 << SECTOR_SHIFT;
361 if (ctx->offset_in >= bv_in->bv_len) {
362 ctx->offset_in = 0;
363 ctx->idx_in++;
364 }
365
366 ctx->offset_out += 1 << SECTOR_SHIFT;
367 if (ctx->offset_out >= bv_out->bv_len) {
368 ctx->offset_out = 0;
369 ctx->idx_out++;
370 }
371
Milan Broz3a7f6c92008-02-08 02:11:14 +0000372 if (cc->iv_gen_ops) {
373 r = cc->iv_gen_ops->generator(cc, iv, ctx->sector);
374 if (r < 0)
375 return r;
376 }
377
378 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
379 1 << SECTOR_SHIFT, iv);
380
381 if (bio_data_dir(ctx->bio_in) == WRITE)
382 r = crypto_ablkcipher_encrypt(req);
383 else
384 r = crypto_ablkcipher_decrypt(req);
385
386 return r;
Milan Broz01482b72008-02-08 02:11:04 +0000387}
388
Milan Broz95497a92008-02-08 02:11:12 +0000389static void kcryptd_async_done(struct crypto_async_request *async_req,
390 int error);
Milan Brozddd42ed2008-02-08 02:11:07 +0000391static void crypt_alloc_req(struct crypt_config *cc,
392 struct convert_context *ctx)
393{
394 if (!cc->req)
395 cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
Milan Broz95497a92008-02-08 02:11:12 +0000396 ablkcipher_request_set_tfm(cc->req, cc->tfm);
397 ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG |
398 CRYPTO_TFM_REQ_MAY_SLEEP,
399 kcryptd_async_done, ctx);
Milan Brozddd42ed2008-02-08 02:11:07 +0000400}
401
Linus Torvalds1da177e2005-04-16 15:20:36 -0700402/*
403 * Encrypt / decrypt data from one bio to another one (can be the same one)
404 */
405static int crypt_convert(struct crypt_config *cc,
Milan Brozd469f842007-10-19 22:42:37 +0100406 struct convert_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407{
Milan Broz3f1e9072008-03-28 14:16:07 -0700408 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409
Milan Brozc8081612008-10-10 13:37:08 +0100410 atomic_set(&ctx->pending, 1);
411
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
413 ctx->idx_out < ctx->bio_out->bi_vcnt) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414
Milan Broz3a7f6c92008-02-08 02:11:14 +0000415 crypt_alloc_req(cc, ctx);
416
Milan Broz3f1e9072008-03-28 14:16:07 -0700417 atomic_inc(&ctx->pending);
418
Milan Broz3a7f6c92008-02-08 02:11:14 +0000419 r = crypt_convert_block(cc, ctx, cc->req);
420
421 switch (r) {
Milan Broz3f1e9072008-03-28 14:16:07 -0700422 /* async */
Milan Broz3a7f6c92008-02-08 02:11:14 +0000423 case -EBUSY:
424 wait_for_completion(&ctx->restart);
425 INIT_COMPLETION(ctx->restart);
426 /* fall through*/
427 case -EINPROGRESS:
Milan Broz3a7f6c92008-02-08 02:11:14 +0000428 cc->req = NULL;
Milan Broz3a7f6c92008-02-08 02:11:14 +0000429 ctx->sector++;
430 continue;
Milan Broz3a7f6c92008-02-08 02:11:14 +0000431
Milan Broz3f1e9072008-03-28 14:16:07 -0700432 /* sync */
433 case 0:
434 atomic_dec(&ctx->pending);
435 ctx->sector++;
Milan Brozc7f1b202008-07-02 09:34:28 +0100436 cond_resched();
Milan Broz3f1e9072008-03-28 14:16:07 -0700437 continue;
438
439 /* error */
440 default:
441 atomic_dec(&ctx->pending);
442 return r;
443 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 }
445
Milan Broz3f1e9072008-03-28 14:16:07 -0700446 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447}
448
Milan Brozd469f842007-10-19 22:42:37 +0100449static void dm_crypt_bio_destructor(struct bio *bio)
450{
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100451 struct dm_crypt_io *io = bio->bi_private;
Milan Broz6a24c712006-10-03 01:15:40 -0700452 struct crypt_config *cc = io->target->private;
453
454 bio_free(bio, cc->bs);
Milan Brozd469f842007-10-19 22:42:37 +0100455}
Milan Broz6a24c712006-10-03 01:15:40 -0700456
Linus Torvalds1da177e2005-04-16 15:20:36 -0700457/*
458 * Generate a new unfragmented bio with the given size
459 * This should never violate the device limitations
Milan Broz933f01d2008-10-10 13:37:08 +0100460 * May return a smaller bio when running out of pages, indicated by
461 * *out_of_pages set to 1.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 */
Milan Broz933f01d2008-10-10 13:37:08 +0100463static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
464 unsigned *out_of_pages)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465{
Olaf Kirch027581f2007-05-09 02:32:52 -0700466 struct crypt_config *cc = io->target->private;
Milan Broz8b004452006-10-03 01:15:37 -0700467 struct bio *clone;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
Al Virob4e3ca12005-10-21 03:22:34 -0400469 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
Milan Broz91e10622007-12-13 14:16:10 +0000470 unsigned i, len;
471 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472
Olaf Kirch2f9941b2007-05-09 02:32:53 -0700473 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
Milan Broz8b004452006-10-03 01:15:37 -0700474 if (!clone)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476
Olaf Kirch027581f2007-05-09 02:32:52 -0700477 clone_init(io, clone);
Milan Broz933f01d2008-10-10 13:37:08 +0100478 *out_of_pages = 0;
Milan Broz6a24c712006-10-03 01:15:40 -0700479
Olaf Kirchf97380b2007-05-09 02:32:54 -0700480 for (i = 0; i < nr_iovecs; i++) {
Milan Broz91e10622007-12-13 14:16:10 +0000481 page = mempool_alloc(cc->page_pool, gfp_mask);
Milan Broz933f01d2008-10-10 13:37:08 +0100482 if (!page) {
483 *out_of_pages = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 break;
Milan Broz933f01d2008-10-10 13:37:08 +0100485 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486
487 /*
488 * if additional pages cannot be allocated without waiting,
489 * return a partially allocated bio, the caller will then try
490 * to allocate additional bios while submitting this partial bio
491 */
Olaf Kirchf97380b2007-05-09 02:32:54 -0700492 if (i == (MIN_BIO_PAGES - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
494
Milan Broz91e10622007-12-13 14:16:10 +0000495 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
Milan Broz91e10622007-12-13 14:16:10 +0000497 if (!bio_add_page(clone, page, len, 0)) {
498 mempool_free(page, cc->page_pool);
499 break;
500 }
501
502 size -= len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 }
504
Milan Broz8b004452006-10-03 01:15:37 -0700505 if (!clone->bi_size) {
506 bio_put(clone);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 return NULL;
508 }
509
Milan Broz8b004452006-10-03 01:15:37 -0700510 return clone;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511}
512
Neil Brown644bd2f2007-10-16 13:48:46 +0200513static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514{
Neil Brown644bd2f2007-10-16 13:48:46 +0200515 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 struct bio_vec *bv;
517
Neil Brown644bd2f2007-10-16 13:48:46 +0200518 for (i = 0; i < clone->bi_vcnt; i++) {
Milan Broz8b004452006-10-03 01:15:37 -0700519 bv = bio_iovec_idx(clone, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 BUG_ON(!bv->bv_page);
521 mempool_free(bv->bv_page, cc->page_pool);
522 bv->bv_page = NULL;
523 }
524}
525
Milan Brozdc440d1e2008-10-10 13:37:03 +0100526static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
527 struct bio *bio, sector_t sector)
528{
529 struct crypt_config *cc = ti->private;
530 struct dm_crypt_io *io;
531
532 io = mempool_alloc(cc->io_pool, GFP_NOIO);
533 io->target = ti;
534 io->base_bio = bio;
535 io->sector = sector;
536 io->error = 0;
Milan Broz393b47e2008-10-21 17:45:02 +0100537 io->base_io = NULL;
Milan Brozdc440d1e2008-10-10 13:37:03 +0100538 atomic_set(&io->pending, 0);
539
540 return io;
541}
542
Milan Broz3e1a8bd2008-10-10 13:37:02 +0100543static void crypt_inc_pending(struct dm_crypt_io *io)
544{
545 atomic_inc(&io->pending);
546}
547
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548/*
549 * One of the bios was finished. Check for completion of
550 * the whole request and correctly clean up the buffer.
Milan Broz393b47e2008-10-21 17:45:02 +0100551 * If base_io is set, wait for the last fragment to complete.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 */
Milan Broz5742fd72008-02-08 02:10:43 +0000553static void crypt_dec_pending(struct dm_crypt_io *io)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554{
Milan Broz5742fd72008-02-08 02:10:43 +0000555 struct crypt_config *cc = io->target->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700556
557 if (!atomic_dec_and_test(&io->pending))
558 return;
559
Milan Broz393b47e2008-10-21 17:45:02 +0100560 if (likely(!io->base_io))
561 bio_endio(io->base_bio, io->error);
562 else {
563 if (io->error && !io->base_io->error)
564 io->base_io->error = io->error;
565 crypt_dec_pending(io->base_io);
566 }
567
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 mempool_free(io, cc->io_pool);
569}
570
571/*
Milan Brozcabf08e2007-10-19 22:38:58 +0100572 * kcryptd/kcryptd_io:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573 *
574 * Needed because it would be very unwise to do decryption in an
Milan Broz23541d22006-10-03 01:15:39 -0700575 * interrupt context.
Milan Brozcabf08e2007-10-19 22:38:58 +0100576 *
577 * kcryptd performs the actual encryption or decryption.
578 *
579 * kcryptd_io performs the IO submission.
580 *
581 * They must be separated as otherwise the final stages could be
582 * starved by new requests which can block in the first stages due
583 * to memory allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584 */
NeilBrown6712ecf2007-09-27 12:47:43 +0200585static void crypt_endio(struct bio *clone, int error)
Milan Broz8b004452006-10-03 01:15:37 -0700586{
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100587 struct dm_crypt_io *io = clone->bi_private;
Milan Broz8b004452006-10-03 01:15:37 -0700588 struct crypt_config *cc = io->target->private;
Milan Brozee7a4912008-02-08 02:10:46 +0000589 unsigned rw = bio_data_dir(clone);
Milan Broz8b004452006-10-03 01:15:37 -0700590
Milan Brozadfe4772007-12-13 14:15:51 +0000591 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
592 error = -EIO;
593
Milan Broz8b004452006-10-03 01:15:37 -0700594 /*
NeilBrown6712ecf2007-09-27 12:47:43 +0200595 * free the processed pages
Milan Broz8b004452006-10-03 01:15:37 -0700596 */
Milan Brozee7a4912008-02-08 02:10:46 +0000597 if (rw == WRITE)
Neil Brown644bd2f2007-10-16 13:48:46 +0200598 crypt_free_buffer_pages(cc, clone);
Milan Brozee7a4912008-02-08 02:10:46 +0000599
600 bio_put(clone);
601
602 if (rw == READ && !error) {
603 kcryptd_queue_crypt(io);
604 return;
NeilBrown6712ecf2007-09-27 12:47:43 +0200605 }
Milan Broz8b004452006-10-03 01:15:37 -0700606
Milan Brozadfe4772007-12-13 14:15:51 +0000607 if (unlikely(error))
Milan Broz5742fd72008-02-08 02:10:43 +0000608 io->error = error;
609
610 crypt_dec_pending(io);
Milan Broz8b004452006-10-03 01:15:37 -0700611}
612
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100613static void clone_init(struct dm_crypt_io *io, struct bio *clone)
Milan Broz8b004452006-10-03 01:15:37 -0700614{
615 struct crypt_config *cc = io->target->private;
616
617 clone->bi_private = io;
618 clone->bi_end_io = crypt_endio;
619 clone->bi_bdev = cc->dev->bdev;
620 clone->bi_rw = io->base_bio->bi_rw;
Olaf Kirch027581f2007-05-09 02:32:52 -0700621 clone->bi_destructor = dm_crypt_bio_destructor;
Milan Broz8b004452006-10-03 01:15:37 -0700622}
623
Milan Broz4e4eef62008-02-08 02:10:49 +0000624static void kcryptd_io_read(struct dm_crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700625{
626 struct crypt_config *cc = io->target->private;
627 struct bio *base_bio = io->base_bio;
628 struct bio *clone;
Milan Broz93e605c2006-10-03 01:15:38 -0700629
Milan Broz3e1a8bd2008-10-10 13:37:02 +0100630 crypt_inc_pending(io);
Milan Broz8b004452006-10-03 01:15:37 -0700631
632 /*
633 * The block layer might modify the bvec array, so always
634 * copy the required bvecs because we need the original
635 * one in order to decrypt the whole bio data *afterwards*.
636 */
Milan Broz6a24c712006-10-03 01:15:40 -0700637 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
Milan Broz93e605c2006-10-03 01:15:38 -0700638 if (unlikely(!clone)) {
Milan Broz5742fd72008-02-08 02:10:43 +0000639 io->error = -ENOMEM;
640 crypt_dec_pending(io);
Milan Broz23541d22006-10-03 01:15:39 -0700641 return;
Milan Broz93e605c2006-10-03 01:15:38 -0700642 }
Milan Broz8b004452006-10-03 01:15:37 -0700643
644 clone_init(io, clone);
645 clone->bi_idx = 0;
646 clone->bi_vcnt = bio_segments(base_bio);
647 clone->bi_size = base_bio->bi_size;
Milan Broz0c395b02008-02-08 02:10:54 +0000648 clone->bi_sector = cc->start + io->sector;
Milan Broz8b004452006-10-03 01:15:37 -0700649 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
650 sizeof(struct bio_vec) * clone->bi_vcnt);
Milan Broz8b004452006-10-03 01:15:37 -0700651
Milan Broz93e605c2006-10-03 01:15:38 -0700652 generic_make_request(clone);
Milan Broz8b004452006-10-03 01:15:37 -0700653}
654
Milan Broz4e4eef62008-02-08 02:10:49 +0000655static void kcryptd_io_write(struct dm_crypt_io *io)
656{
Milan Broz95497a92008-02-08 02:11:12 +0000657 struct bio *clone = io->ctx.bio_out;
Milan Broz95497a92008-02-08 02:11:12 +0000658 generic_make_request(clone);
Milan Broz4e4eef62008-02-08 02:10:49 +0000659}
660
Alasdair G Kergon395b1672008-02-08 02:10:52 +0000661static void kcryptd_io(struct work_struct *work)
662{
663 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
664
665 if (bio_data_dir(io->base_bio) == READ)
666 kcryptd_io_read(io);
667 else
668 kcryptd_io_write(io);
669}
670
671static void kcryptd_queue_io(struct dm_crypt_io *io)
672{
673 struct crypt_config *cc = io->target->private;
674
675 INIT_WORK(&io->work, kcryptd_io);
676 queue_work(cc->io_queue, &io->work);
677}
678
Milan Broz95497a92008-02-08 02:11:12 +0000679static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
680 int error, int async)
Milan Broz4e4eef62008-02-08 02:10:49 +0000681{
Milan Brozdec1ced2008-02-08 02:10:57 +0000682 struct bio *clone = io->ctx.bio_out;
683 struct crypt_config *cc = io->target->private;
684
685 if (unlikely(error < 0)) {
686 crypt_free_buffer_pages(cc, clone);
687 bio_put(clone);
688 io->error = -EIO;
Milan Broz6c031f42008-10-10 13:37:06 +0100689 crypt_dec_pending(io);
Milan Brozdec1ced2008-02-08 02:10:57 +0000690 return;
691 }
692
693 /* crypt_convert should have filled the clone bio */
694 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
695
696 clone->bi_sector = cc->start + io->sector;
Milan Broz899c95d2008-02-08 02:11:02 +0000697
Milan Broz95497a92008-02-08 02:11:12 +0000698 if (async)
699 kcryptd_queue_io(io);
Alasdair G Kergon1e37bb82008-10-10 13:37:05 +0100700 else
Milan Broz95497a92008-02-08 02:11:12 +0000701 generic_make_request(clone);
Milan Broz4e4eef62008-02-08 02:10:49 +0000702}
703
Milan Brozfc5a5e92008-10-10 13:37:04 +0100704static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700705{
706 struct crypt_config *cc = io->target->private;
Milan Broz8b004452006-10-03 01:15:37 -0700707 struct bio *clone;
Milan Broz393b47e2008-10-21 17:45:02 +0100708 struct dm_crypt_io *new_io;
Milan Brozc8081612008-10-10 13:37:08 +0100709 int crypt_finished;
Milan Broz933f01d2008-10-10 13:37:08 +0100710 unsigned out_of_pages = 0;
Milan Brozdec1ced2008-02-08 02:10:57 +0000711 unsigned remaining = io->base_bio->bi_size;
Milan Brozb635b002008-10-21 17:45:00 +0100712 sector_t sector = io->sector;
Milan Brozdec1ced2008-02-08 02:10:57 +0000713 int r;
Milan Broz8b004452006-10-03 01:15:37 -0700714
Milan Broz93e605c2006-10-03 01:15:38 -0700715 /*
Milan Brozfc5a5e92008-10-10 13:37:04 +0100716 * Prevent io from disappearing until this function completes.
717 */
718 crypt_inc_pending(io);
Milan Brozb635b002008-10-21 17:45:00 +0100719 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
Milan Brozfc5a5e92008-10-10 13:37:04 +0100720
721 /*
Milan Broz93e605c2006-10-03 01:15:38 -0700722 * The allocated buffers can be smaller than the whole bio,
723 * so repeat the whole process until all the data can be handled.
724 */
725 while (remaining) {
Milan Broz933f01d2008-10-10 13:37:08 +0100726 clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
Milan Broz23541d22006-10-03 01:15:39 -0700727 if (unlikely(!clone)) {
Milan Broz5742fd72008-02-08 02:10:43 +0000728 io->error = -ENOMEM;
Milan Brozfc5a5e92008-10-10 13:37:04 +0100729 break;
Milan Broz23541d22006-10-03 01:15:39 -0700730 }
Milan Broz93e605c2006-10-03 01:15:38 -0700731
Milan Broz53017032008-02-08 02:10:38 +0000732 io->ctx.bio_out = clone;
733 io->ctx.idx_out = 0;
Milan Broz93e605c2006-10-03 01:15:38 -0700734
Milan Broz93e605c2006-10-03 01:15:38 -0700735 remaining -= clone->bi_size;
Milan Brozb635b002008-10-21 17:45:00 +0100736 sector += bio_sectors(clone);
Milan Brozdec1ced2008-02-08 02:10:57 +0000737
Milan Broz4e594092008-10-10 13:37:07 +0100738 crypt_inc_pending(io);
Milan Brozdec1ced2008-02-08 02:10:57 +0000739 r = crypt_convert(cc, &io->ctx);
Milan Brozc8081612008-10-10 13:37:08 +0100740 crypt_finished = atomic_dec_and_test(&io->ctx.pending);
Milan Brozdec1ced2008-02-08 02:10:57 +0000741
Milan Brozc8081612008-10-10 13:37:08 +0100742 /* Encryption was already finished, submit io now */
743 if (crypt_finished) {
Milan Broz3a7f6c92008-02-08 02:11:14 +0000744 kcryptd_crypt_write_io_submit(io, r, 0);
Milan Brozc8081612008-10-10 13:37:08 +0100745
746 /*
747 * If there was an error, do not try next fragments.
748 * For async, error is processed in async handler.
749 */
Milan Broz6c031f42008-10-10 13:37:06 +0100750 if (unlikely(r < 0))
Milan Brozfc5a5e92008-10-10 13:37:04 +0100751 break;
Milan Brozb635b002008-10-21 17:45:00 +0100752
753 io->sector = sector;
Milan Broz4e594092008-10-10 13:37:07 +0100754 }
Milan Broz93e605c2006-10-03 01:15:38 -0700755
Milan Broz933f01d2008-10-10 13:37:08 +0100756 /*
757 * Out of memory -> run queues
758 * But don't wait if split was due to the io size restriction
759 */
760 if (unlikely(out_of_pages))
Olaf Kirch98221eb2007-05-09 02:32:52 -0700761 congestion_wait(WRITE, HZ/100);
Milan Broz933f01d2008-10-10 13:37:08 +0100762
Milan Broz393b47e2008-10-21 17:45:02 +0100763 /*
764 * With async crypto it is unsafe to share the crypto context
765 * between fragments, so switch to a new dm_crypt_io structure.
766 */
767 if (unlikely(!crypt_finished && remaining)) {
768 new_io = crypt_io_alloc(io->target, io->base_bio,
769 sector);
770 crypt_inc_pending(new_io);
771 crypt_convert_init(cc, &new_io->ctx, NULL,
772 io->base_bio, sector);
773 new_io->ctx.idx_in = io->ctx.idx_in;
774 new_io->ctx.offset_in = io->ctx.offset_in;
775
776 /*
777 * Fragments after the first use the base_io
778 * pending count.
779 */
780 if (!io->base_io)
781 new_io->base_io = io;
782 else {
783 new_io->base_io = io->base_io;
784 crypt_inc_pending(io->base_io);
785 crypt_dec_pending(io);
786 }
787
788 io = new_io;
789 }
Milan Broz8b004452006-10-03 01:15:37 -0700790 }
Milan Broz899c95d2008-02-08 02:11:02 +0000791
792 crypt_dec_pending(io);
Milan Broz84131db2008-02-08 02:10:59 +0000793}
794
Milan Broz4e4eef62008-02-08 02:10:49 +0000795static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
Milan Broz5742fd72008-02-08 02:10:43 +0000796{
797 if (unlikely(error < 0))
798 io->error = -EIO;
799
800 crypt_dec_pending(io);
801}
802
Milan Broz4e4eef62008-02-08 02:10:49 +0000803static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700804{
805 struct crypt_config *cc = io->target->private;
Milan Broz5742fd72008-02-08 02:10:43 +0000806 int r = 0;
Milan Broz8b004452006-10-03 01:15:37 -0700807
Milan Broz3e1a8bd2008-10-10 13:37:02 +0100808 crypt_inc_pending(io);
Milan Broz3a7f6c92008-02-08 02:11:14 +0000809
Milan Broz53017032008-02-08 02:10:38 +0000810 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
Milan Broz0c395b02008-02-08 02:10:54 +0000811 io->sector);
Milan Broz8b004452006-10-03 01:15:37 -0700812
Milan Broz5742fd72008-02-08 02:10:43 +0000813 r = crypt_convert(cc, &io->ctx);
814
Milan Broz3f1e9072008-03-28 14:16:07 -0700815 if (atomic_dec_and_test(&io->ctx.pending))
Milan Broz3a7f6c92008-02-08 02:11:14 +0000816 kcryptd_crypt_read_done(io, r);
817
818 crypt_dec_pending(io);
Milan Broz8b004452006-10-03 01:15:37 -0700819}
820
Milan Broz95497a92008-02-08 02:11:12 +0000821static void kcryptd_async_done(struct crypto_async_request *async_req,
822 int error)
823{
824 struct convert_context *ctx = async_req->data;
825 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
826 struct crypt_config *cc = io->target->private;
827
828 if (error == -EINPROGRESS) {
829 complete(&ctx->restart);
830 return;
831 }
832
833 mempool_free(ablkcipher_request_cast(async_req), cc->req_pool);
834
835 if (!atomic_dec_and_test(&ctx->pending))
836 return;
837
838 if (bio_data_dir(io->base_bio) == READ)
839 kcryptd_crypt_read_done(io, error);
840 else
841 kcryptd_crypt_write_io_submit(io, error, 1);
842}
843
Milan Broz4e4eef62008-02-08 02:10:49 +0000844static void kcryptd_crypt(struct work_struct *work)
845{
846 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
847
848 if (bio_data_dir(io->base_bio) == READ)
849 kcryptd_crypt_read_convert(io);
850 else
851 kcryptd_crypt_write_convert(io);
Milan Broz8b004452006-10-03 01:15:37 -0700852}
853
Alasdair G Kergon395b1672008-02-08 02:10:52 +0000854static void kcryptd_queue_crypt(struct dm_crypt_io *io)
855{
856 struct crypt_config *cc = io->target->private;
857
858 INIT_WORK(&io->work, kcryptd_crypt);
859 queue_work(cc->crypt_queue, &io->work);
860}
861
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862/*
863 * Decode key from its hex representation
864 */
865static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
866{
867 char buffer[3];
868 char *endp;
869 unsigned int i;
870
871 buffer[2] = '\0';
872
Milan Broz8b004452006-10-03 01:15:37 -0700873 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700874 buffer[0] = *hex++;
875 buffer[1] = *hex++;
876
877 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
878
879 if (endp != &buffer[2])
880 return -EINVAL;
881 }
882
883 if (*hex != '\0')
884 return -EINVAL;
885
886 return 0;
887}
888
889/*
890 * Encode key into its hex representation
891 */
892static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
893{
894 unsigned int i;
895
Milan Broz8b004452006-10-03 01:15:37 -0700896 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 sprintf(hex, "%02x", *key);
898 hex += 2;
899 key++;
900 }
901}
902
Milan Broze48d4bb2006-10-03 01:15:37 -0700903static int crypt_set_key(struct crypt_config *cc, char *key)
904{
905 unsigned key_size = strlen(key) >> 1;
906
907 if (cc->key_size && cc->key_size != key_size)
908 return -EINVAL;
909
910 cc->key_size = key_size; /* initial settings */
911
912 if ((!key_size && strcmp(key, "-")) ||
Milan Brozd469f842007-10-19 22:42:37 +0100913 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
Milan Broze48d4bb2006-10-03 01:15:37 -0700914 return -EINVAL;
915
916 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
917
918 return 0;
919}
920
921static int crypt_wipe_key(struct crypt_config *cc)
922{
923 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
924 memset(&cc->key, 0, cc->key_size * sizeof(u8));
925 return 0;
926}
927
Linus Torvalds1da177e2005-04-16 15:20:36 -0700928/*
929 * Construct an encryption mapping:
930 * <cipher> <key> <iv_offset> <dev_path> <start>
931 */
932static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
933{
934 struct crypt_config *cc;
Milan Broz3a7f6c92008-02-08 02:11:14 +0000935 struct crypto_ablkcipher *tfm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700936 char *tmp;
937 char *cipher;
938 char *chainmode;
939 char *ivmode;
940 char *ivopts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700941 unsigned int key_size;
Andrew Morton4ee218c2006-03-27 01:17:48 -0800942 unsigned long long tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700943
944 if (argc != 5) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700945 ti->error = "Not enough arguments";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 return -EINVAL;
947 }
948
949 tmp = argv[0];
950 cipher = strsep(&tmp, "-");
951 chainmode = strsep(&tmp, "-");
952 ivopts = strsep(&tmp, "-");
953 ivmode = strsep(&ivopts, ":");
954
955 if (tmp)
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700956 DMWARN("Unexpected additional cipher options");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700957
958 key_size = strlen(argv[1]) >> 1;
959
Milan Broze48d4bb2006-10-03 01:15:37 -0700960 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 if (cc == NULL) {
962 ti->error =
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700963 "Cannot allocate transparent encryption context";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 return -ENOMEM;
965 }
966
Milan Broze48d4bb2006-10-03 01:15:37 -0700967 if (crypt_set_key(cc, argv[1])) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700968 ti->error = "Error decoding key";
Milan Broz636d5782007-10-19 22:47:52 +0100969 goto bad_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700970 }
971
972 /* Compatiblity mode for old dm-crypt cipher strings */
973 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
974 chainmode = "cbc";
975 ivmode = "plain";
976 }
977
Herbert Xud1806f62006-08-22 20:29:17 +1000978 if (strcmp(chainmode, "ecb") && !ivmode) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700979 ti->error = "This chaining mode requires an IV mechanism";
Milan Broz636d5782007-10-19 22:47:52 +0100980 goto bad_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 }
982
Milan Brozd469f842007-10-19 22:42:37 +0100983 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
984 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
Herbert Xud1806f62006-08-22 20:29:17 +1000985 ti->error = "Chain mode + cipher name is too long";
Milan Broz636d5782007-10-19 22:47:52 +0100986 goto bad_cipher;
Herbert Xud1806f62006-08-22 20:29:17 +1000987 }
988
Milan Broz3a7f6c92008-02-08 02:11:14 +0000989 tfm = crypto_alloc_ablkcipher(cc->cipher, 0, 0);
Herbert Xud1806f62006-08-22 20:29:17 +1000990 if (IS_ERR(tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700991 ti->error = "Error allocating crypto tfm";
Milan Broz636d5782007-10-19 22:47:52 +0100992 goto bad_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700993 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994
Herbert Xud1806f62006-08-22 20:29:17 +1000995 strcpy(cc->cipher, cipher);
996 strcpy(cc->chainmode, chainmode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 cc->tfm = tfm;
998
999 /*
Rik Snel48527fa2006-09-03 08:56:39 +10001000 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
Linus Torvalds1da177e2005-04-16 15:20:36 -07001001 * See comments at iv code
1002 */
1003
1004 if (ivmode == NULL)
1005 cc->iv_gen_ops = NULL;
1006 else if (strcmp(ivmode, "plain") == 0)
1007 cc->iv_gen_ops = &crypt_iv_plain_ops;
1008 else if (strcmp(ivmode, "essiv") == 0)
1009 cc->iv_gen_ops = &crypt_iv_essiv_ops;
Rik Snel48527fa2006-09-03 08:56:39 +10001010 else if (strcmp(ivmode, "benbi") == 0)
1011 cc->iv_gen_ops = &crypt_iv_benbi_ops;
Ludwig Nussel46b47732007-05-09 02:32:55 -07001012 else if (strcmp(ivmode, "null") == 0)
1013 cc->iv_gen_ops = &crypt_iv_null_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014 else {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001015 ti->error = "Invalid IV mode";
Milan Broz636d5782007-10-19 22:47:52 +01001016 goto bad_ivmode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001017 }
1018
1019 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
1020 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
Milan Broz636d5782007-10-19 22:47:52 +01001021 goto bad_ivmode;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001022
Milan Broz3a7f6c92008-02-08 02:11:14 +00001023 cc->iv_size = crypto_ablkcipher_ivsize(tfm);
Herbert Xud1806f62006-08-22 20:29:17 +10001024 if (cc->iv_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025 /* at least a 64 bit sector number should fit in our buffer */
Herbert Xud1806f62006-08-22 20:29:17 +10001026 cc->iv_size = max(cc->iv_size,
Milan Brozd469f842007-10-19 22:42:37 +01001027 (unsigned int)(sizeof(u64) / sizeof(u8)));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001028 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029 if (cc->iv_gen_ops) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001030 DMWARN("Selected cipher does not support IVs");
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 if (cc->iv_gen_ops->dtr)
1032 cc->iv_gen_ops->dtr(cc);
1033 cc->iv_gen_ops = NULL;
1034 }
1035 }
1036
Matthew Dobson93d23412006-03-26 01:37:50 -08001037 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001038 if (!cc->io_pool) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001039 ti->error = "Cannot allocate crypt io mempool";
Milan Broz636d5782007-10-19 22:47:52 +01001040 goto bad_slab_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 }
1042
Milan Brozddd42ed2008-02-08 02:11:07 +00001043 cc->dmreq_start = sizeof(struct ablkcipher_request);
Milan Broz3a7f6c92008-02-08 02:11:14 +00001044 cc->dmreq_start += crypto_ablkcipher_reqsize(tfm);
Milan Brozddd42ed2008-02-08 02:11:07 +00001045 cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
Milan Broz3a7f6c92008-02-08 02:11:14 +00001046 cc->dmreq_start += crypto_ablkcipher_alignmask(tfm) &
1047 ~(crypto_tfm_ctx_alignment() - 1);
Milan Brozddd42ed2008-02-08 02:11:07 +00001048
1049 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1050 sizeof(struct dm_crypt_request) + cc->iv_size);
1051 if (!cc->req_pool) {
1052 ti->error = "Cannot allocate crypt request mempool";
1053 goto bad_req_pool;
1054 }
1055 cc->req = NULL;
1056
Matthew Dobsona19b27c2006-03-26 01:37:45 -08001057 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001058 if (!cc->page_pool) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001059 ti->error = "Cannot allocate page mempool";
Milan Broz636d5782007-10-19 22:47:52 +01001060 goto bad_page_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001061 }
1062
Jens Axboebb799ca2008-12-10 15:35:05 +01001063 cc->bs = bioset_create(MIN_IOS, 0);
Milan Broz6a24c712006-10-03 01:15:40 -07001064 if (!cc->bs) {
1065 ti->error = "Cannot allocate crypt bioset";
1066 goto bad_bs;
1067 }
1068
Milan Broz3a7f6c92008-02-08 02:11:14 +00001069 if (crypto_ablkcipher_setkey(tfm, cc->key, key_size) < 0) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001070 ti->error = "Error setting key";
Milan Broz636d5782007-10-19 22:47:52 +01001071 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 }
1073
Andrew Morton4ee218c2006-03-27 01:17:48 -08001074 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001075 ti->error = "Invalid iv_offset sector";
Milan Broz636d5782007-10-19 22:47:52 +01001076 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001077 }
Andrew Morton4ee218c2006-03-27 01:17:48 -08001078 cc->iv_offset = tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079
Andrew Morton4ee218c2006-03-27 01:17:48 -08001080 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001081 ti->error = "Invalid device sector";
Milan Broz636d5782007-10-19 22:47:52 +01001082 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083 }
Andrew Morton4ee218c2006-03-27 01:17:48 -08001084 cc->start = tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001085
1086 if (dm_get_device(ti, argv[3], cc->start, ti->len,
Milan Brozd469f842007-10-19 22:42:37 +01001087 dm_table_get_mode(ti->table), &cc->dev)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001088 ti->error = "Device lookup failed";
Milan Broz636d5782007-10-19 22:47:52 +01001089 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001090 }
1091
1092 if (ivmode && cc->iv_gen_ops) {
1093 if (ivopts)
1094 *(ivopts - 1) = ':';
1095 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
1096 if (!cc->iv_mode) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001097 ti->error = "Error kmallocing iv_mode string";
Milan Broz636d5782007-10-19 22:47:52 +01001098 goto bad_ivmode_string;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099 }
1100 strcpy(cc->iv_mode, ivmode);
1101 } else
1102 cc->iv_mode = NULL;
1103
Milan Brozcabf08e2007-10-19 22:38:58 +01001104 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
1105 if (!cc->io_queue) {
1106 ti->error = "Couldn't create kcryptd io queue";
1107 goto bad_io_queue;
1108 }
1109
1110 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
1111 if (!cc->crypt_queue) {
Milan Broz9934a8b2007-10-19 22:38:57 +01001112 ti->error = "Couldn't create kcryptd queue";
Milan Brozcabf08e2007-10-19 22:38:58 +01001113 goto bad_crypt_queue;
Milan Broz9934a8b2007-10-19 22:38:57 +01001114 }
1115
Linus Torvalds1da177e2005-04-16 15:20:36 -07001116 ti->private = cc;
1117 return 0;
1118
Milan Brozcabf08e2007-10-19 22:38:58 +01001119bad_crypt_queue:
1120 destroy_workqueue(cc->io_queue);
1121bad_io_queue:
Milan Broz9934a8b2007-10-19 22:38:57 +01001122 kfree(cc->iv_mode);
Milan Broz636d5782007-10-19 22:47:52 +01001123bad_ivmode_string:
Dmitry Monakhov55b42c52007-10-19 22:38:37 +01001124 dm_put_device(ti, cc->dev);
Milan Broz636d5782007-10-19 22:47:52 +01001125bad_device:
Milan Broz6a24c712006-10-03 01:15:40 -07001126 bioset_free(cc->bs);
1127bad_bs:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128 mempool_destroy(cc->page_pool);
Milan Broz636d5782007-10-19 22:47:52 +01001129bad_page_pool:
Milan Brozddd42ed2008-02-08 02:11:07 +00001130 mempool_destroy(cc->req_pool);
1131bad_req_pool:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001132 mempool_destroy(cc->io_pool);
Milan Broz636d5782007-10-19 22:47:52 +01001133bad_slab_pool:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1135 cc->iv_gen_ops->dtr(cc);
Milan Broz636d5782007-10-19 22:47:52 +01001136bad_ivmode:
Milan Broz3a7f6c92008-02-08 02:11:14 +00001137 crypto_free_ablkcipher(tfm);
Milan Broz636d5782007-10-19 22:47:52 +01001138bad_cipher:
Stefan Rompf9d3520a2006-01-06 00:20:08 -08001139 /* Must zero key material before freeing */
1140 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 kfree(cc);
1142 return -EINVAL;
1143}
1144
1145static void crypt_dtr(struct dm_target *ti)
1146{
1147 struct crypt_config *cc = (struct crypt_config *) ti->private;
1148
Milan Brozcabf08e2007-10-19 22:38:58 +01001149 destroy_workqueue(cc->io_queue);
1150 destroy_workqueue(cc->crypt_queue);
Milan Broz80b16c12007-07-21 04:37:27 -07001151
Milan Brozddd42ed2008-02-08 02:11:07 +00001152 if (cc->req)
1153 mempool_free(cc->req, cc->req_pool);
1154
Milan Broz6a24c712006-10-03 01:15:40 -07001155 bioset_free(cc->bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001156 mempool_destroy(cc->page_pool);
Milan Brozddd42ed2008-02-08 02:11:07 +00001157 mempool_destroy(cc->req_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001158 mempool_destroy(cc->io_pool);
1159
Jesper Juhl990a8ba2005-06-21 17:17:30 -07001160 kfree(cc->iv_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1162 cc->iv_gen_ops->dtr(cc);
Milan Broz3a7f6c92008-02-08 02:11:14 +00001163 crypto_free_ablkcipher(cc->tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 dm_put_device(ti, cc->dev);
Stefan Rompf9d3520a2006-01-06 00:20:08 -08001165
1166 /* Must zero key material before freeing */
1167 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001168 kfree(cc);
1169}
1170
Linus Torvalds1da177e2005-04-16 15:20:36 -07001171static int crypt_map(struct dm_target *ti, struct bio *bio,
1172 union map_info *map_context)
1173{
Alasdair G Kergon028867a2007-07-12 17:26:32 +01001174 struct dm_crypt_io *io;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175
Milan Brozdc440d1e2008-10-10 13:37:03 +01001176 io = crypt_io_alloc(ti, bio, bio->bi_sector - ti->begin);
Milan Brozcabf08e2007-10-19 22:38:58 +01001177
1178 if (bio_data_dir(io->base_bio) == READ)
1179 kcryptd_queue_io(io);
1180 else
1181 kcryptd_queue_crypt(io);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001182
Kiyoshi Uedad2a7ad22006-12-08 02:41:06 -08001183 return DM_MAPIO_SUBMITTED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001184}
1185
1186static int crypt_status(struct dm_target *ti, status_type_t type,
1187 char *result, unsigned int maxlen)
1188{
1189 struct crypt_config *cc = (struct crypt_config *) ti->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001190 unsigned int sz = 0;
1191
1192 switch (type) {
1193 case STATUSTYPE_INFO:
1194 result[0] = '\0';
1195 break;
1196
1197 case STATUSTYPE_TABLE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001198 if (cc->iv_mode)
Christophe Saout37af6562006-10-30 20:39:08 +01001199 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1200 cc->iv_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001201 else
Christophe Saout37af6562006-10-30 20:39:08 +01001202 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001203
1204 if (cc->key_size > 0) {
1205 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1206 return -ENOMEM;
1207
1208 crypt_encode_key(result + sz, cc->key, cc->key_size);
1209 sz += cc->key_size << 1;
1210 } else {
1211 if (sz >= maxlen)
1212 return -ENOMEM;
1213 result[sz++] = '-';
1214 }
1215
Andrew Morton4ee218c2006-03-27 01:17:48 -08001216 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1217 cc->dev->name, (unsigned long long)cc->start);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218 break;
1219 }
1220 return 0;
1221}
1222
Milan Broze48d4bb2006-10-03 01:15:37 -07001223static void crypt_postsuspend(struct dm_target *ti)
1224{
1225 struct crypt_config *cc = ti->private;
1226
1227 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1228}
1229
1230static int crypt_preresume(struct dm_target *ti)
1231{
1232 struct crypt_config *cc = ti->private;
1233
1234 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1235 DMERR("aborting resume - crypt key is not set.");
1236 return -EAGAIN;
1237 }
1238
1239 return 0;
1240}
1241
1242static void crypt_resume(struct dm_target *ti)
1243{
1244 struct crypt_config *cc = ti->private;
1245
1246 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1247}
1248
1249/* Message interface
1250 * key set <key>
1251 * key wipe
1252 */
1253static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1254{
1255 struct crypt_config *cc = ti->private;
1256
1257 if (argc < 2)
1258 goto error;
1259
1260 if (!strnicmp(argv[0], MESG_STR("key"))) {
1261 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1262 DMWARN("not suspended during key manipulation.");
1263 return -EINVAL;
1264 }
1265 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1266 return crypt_set_key(cc, argv[2]);
1267 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1268 return crypt_wipe_key(cc);
1269 }
1270
1271error:
1272 DMWARN("unrecognised message received.");
1273 return -EINVAL;
1274}
1275
Milan Brozd41e26b2008-07-21 12:00:40 +01001276static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1277 struct bio_vec *biovec, int max_size)
1278{
1279 struct crypt_config *cc = ti->private;
1280 struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1281
1282 if (!q->merge_bvec_fn)
1283 return max_size;
1284
1285 bvm->bi_bdev = cc->dev->bdev;
1286 bvm->bi_sector = cc->start + bvm->bi_sector - ti->begin;
1287
1288 return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
1289}
1290
Linus Torvalds1da177e2005-04-16 15:20:36 -07001291static struct target_type crypt_target = {
1292 .name = "crypt",
Milan Brozd41e26b2008-07-21 12:00:40 +01001293 .version= {1, 6, 0},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001294 .module = THIS_MODULE,
1295 .ctr = crypt_ctr,
1296 .dtr = crypt_dtr,
1297 .map = crypt_map,
1298 .status = crypt_status,
Milan Broze48d4bb2006-10-03 01:15:37 -07001299 .postsuspend = crypt_postsuspend,
1300 .preresume = crypt_preresume,
1301 .resume = crypt_resume,
1302 .message = crypt_message,
Milan Brozd41e26b2008-07-21 12:00:40 +01001303 .merge = crypt_merge,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001304};
1305
1306static int __init dm_crypt_init(void)
1307{
1308 int r;
1309
Alasdair G Kergon028867a2007-07-12 17:26:32 +01001310 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001311 if (!_crypt_io_pool)
1312 return -ENOMEM;
1313
Linus Torvalds1da177e2005-04-16 15:20:36 -07001314 r = dm_register_target(&crypt_target);
1315 if (r < 0) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001316 DMERR("register failed %d", r);
Milan Broz9934a8b2007-10-19 22:38:57 +01001317 kmem_cache_destroy(_crypt_io_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001318 }
1319
Linus Torvalds1da177e2005-04-16 15:20:36 -07001320 return r;
1321}
1322
1323static void __exit dm_crypt_exit(void)
1324{
Mikulas Patocka10d3bd02009-01-06 03:04:58 +00001325 dm_unregister_target(&crypt_target);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001326 kmem_cache_destroy(_crypt_io_pool);
1327}
1328
1329module_init(dm_crypt_init);
1330module_exit(dm_crypt_exit);
1331
1332MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1333MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1334MODULE_LICENSE("GPL");