blob: ab6a61db63ce2248b5553ec43678fab61642e9a7 [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
26#include "dm.h"
27
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 Broz53017032008-02-08 02:10:38 +000059};
60
Milan Broz01482b72008-02-08 02:11:04 +000061struct dm_crypt_request {
62 struct scatterlist sg_in;
63 struct scatterlist sg_out;
64};
65
Linus Torvalds1da177e2005-04-16 15:20:36 -070066struct crypt_config;
67
68struct crypt_iv_operations {
69 int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
Milan Brozd469f842007-10-19 22:42:37 +010070 const char *opts);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 void (*dtr)(struct crypt_config *cc);
72 const char *(*status)(struct crypt_config *cc);
73 int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
74};
75
76/*
77 * Crypt: maps a linear range of a block device
78 * and encrypts / decrypts at the same time.
79 */
Milan Broze48d4bb2006-10-03 01:15:37 -070080enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
Linus Torvalds1da177e2005-04-16 15:20:36 -070081struct crypt_config {
82 struct dm_dev *dev;
83 sector_t start;
84
85 /*
Milan Brozddd42ed2008-02-08 02:11:07 +000086 * pool for per bio private data, crypto requests and
87 * encryption requeusts/buffer pages
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 */
89 mempool_t *io_pool;
Milan Brozddd42ed2008-02-08 02:11:07 +000090 mempool_t *req_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 mempool_t *page_pool;
Milan Broz6a24c712006-10-03 01:15:40 -070092 struct bio_set *bs;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093
Milan Brozcabf08e2007-10-19 22:38:58 +010094 struct workqueue_struct *io_queue;
95 struct workqueue_struct *crypt_queue;
Milan Broz3f1e9072008-03-28 14:16:07 -070096 wait_queue_head_t writeq;
97
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);
Milan Broz3f1e9072008-03-28 14:16:07 -0700336 atomic_set(&ctx->pending, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337}
338
Milan Broz01482b72008-02-08 02:11:04 +0000339static int crypt_convert_block(struct crypt_config *cc,
Milan Broz3a7f6c92008-02-08 02:11:14 +0000340 struct convert_context *ctx,
341 struct ablkcipher_request *req)
Milan Broz01482b72008-02-08 02:11:04 +0000342{
343 struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
344 struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
Milan Broz3a7f6c92008-02-08 02:11:14 +0000345 struct dm_crypt_request *dmreq;
346 u8 *iv;
347 int r = 0;
Milan Broz01482b72008-02-08 02:11:04 +0000348
Milan Broz3a7f6c92008-02-08 02:11:14 +0000349 dmreq = (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
350 iv = (u8 *)ALIGN((unsigned long)(dmreq + 1),
351 crypto_ablkcipher_alignmask(cc->tfm) + 1);
352
353 sg_init_table(&dmreq->sg_in, 1);
354 sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
Milan Broz01482b72008-02-08 02:11:04 +0000355 bv_in->bv_offset + ctx->offset_in);
356
Milan Broz3a7f6c92008-02-08 02:11:14 +0000357 sg_init_table(&dmreq->sg_out, 1);
358 sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
Milan Broz01482b72008-02-08 02:11:04 +0000359 bv_out->bv_offset + ctx->offset_out);
360
361 ctx->offset_in += 1 << SECTOR_SHIFT;
362 if (ctx->offset_in >= bv_in->bv_len) {
363 ctx->offset_in = 0;
364 ctx->idx_in++;
365 }
366
367 ctx->offset_out += 1 << SECTOR_SHIFT;
368 if (ctx->offset_out >= bv_out->bv_len) {
369 ctx->offset_out = 0;
370 ctx->idx_out++;
371 }
372
Milan Broz3a7f6c92008-02-08 02:11:14 +0000373 if (cc->iv_gen_ops) {
374 r = cc->iv_gen_ops->generator(cc, iv, ctx->sector);
375 if (r < 0)
376 return r;
377 }
378
379 ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
380 1 << SECTOR_SHIFT, iv);
381
382 if (bio_data_dir(ctx->bio_in) == WRITE)
383 r = crypto_ablkcipher_encrypt(req);
384 else
385 r = crypto_ablkcipher_decrypt(req);
386
387 return r;
Milan Broz01482b72008-02-08 02:11:04 +0000388}
389
Milan Broz95497a92008-02-08 02:11:12 +0000390static void kcryptd_async_done(struct crypto_async_request *async_req,
391 int error);
Milan Brozddd42ed2008-02-08 02:11:07 +0000392static void crypt_alloc_req(struct crypt_config *cc,
393 struct convert_context *ctx)
394{
395 if (!cc->req)
396 cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
Milan Broz95497a92008-02-08 02:11:12 +0000397 ablkcipher_request_set_tfm(cc->req, cc->tfm);
398 ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG |
399 CRYPTO_TFM_REQ_MAY_SLEEP,
400 kcryptd_async_done, ctx);
Milan Brozddd42ed2008-02-08 02:11:07 +0000401}
402
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403/*
404 * Encrypt / decrypt data from one bio to another one (can be the same one)
405 */
406static int crypt_convert(struct crypt_config *cc,
Milan Brozd469f842007-10-19 22:42:37 +0100407 struct convert_context *ctx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408{
Milan Broz3f1e9072008-03-28 14:16:07 -0700409 int r;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700410
411 while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
412 ctx->idx_out < ctx->bio_out->bi_vcnt) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
Milan Broz3a7f6c92008-02-08 02:11:14 +0000414 crypt_alloc_req(cc, ctx);
415
Milan Broz3f1e9072008-03-28 14:16:07 -0700416 atomic_inc(&ctx->pending);
417
Milan Broz3a7f6c92008-02-08 02:11:14 +0000418 r = crypt_convert_block(cc, ctx, cc->req);
419
420 switch (r) {
Milan Broz3f1e9072008-03-28 14:16:07 -0700421 /* async */
Milan Broz3a7f6c92008-02-08 02:11:14 +0000422 case -EBUSY:
423 wait_for_completion(&ctx->restart);
424 INIT_COMPLETION(ctx->restart);
425 /* fall through*/
426 case -EINPROGRESS:
Milan Broz3a7f6c92008-02-08 02:11:14 +0000427 cc->req = NULL;
Milan Broz3a7f6c92008-02-08 02:11:14 +0000428 ctx->sector++;
429 continue;
Milan Broz3a7f6c92008-02-08 02:11:14 +0000430
Milan Broz3f1e9072008-03-28 14:16:07 -0700431 /* sync */
432 case 0:
433 atomic_dec(&ctx->pending);
434 ctx->sector++;
Milan Brozc7f1b202008-07-02 09:34:28 +0100435 cond_resched();
Milan Broz3f1e9072008-03-28 14:16:07 -0700436 continue;
437
438 /* error */
439 default:
440 atomic_dec(&ctx->pending);
441 return r;
442 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 }
444
Milan Broz3f1e9072008-03-28 14:16:07 -0700445 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446}
447
Milan Brozd469f842007-10-19 22:42:37 +0100448static void dm_crypt_bio_destructor(struct bio *bio)
449{
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100450 struct dm_crypt_io *io = bio->bi_private;
Milan Broz6a24c712006-10-03 01:15:40 -0700451 struct crypt_config *cc = io->target->private;
452
453 bio_free(bio, cc->bs);
Milan Brozd469f842007-10-19 22:42:37 +0100454}
Milan Broz6a24c712006-10-03 01:15:40 -0700455
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456/*
457 * Generate a new unfragmented bio with the given size
458 * This should never violate the device limitations
459 * May return a smaller bio when running out of pages
460 */
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100461static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462{
Olaf Kirch027581f2007-05-09 02:32:52 -0700463 struct crypt_config *cc = io->target->private;
Milan Broz8b004452006-10-03 01:15:37 -0700464 struct bio *clone;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465 unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
Al Virob4e3ca12005-10-21 03:22:34 -0400466 gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
Milan Broz91e10622007-12-13 14:16:10 +0000467 unsigned i, len;
468 struct page *page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469
Olaf Kirch2f9941b2007-05-09 02:32:53 -0700470 clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
Milan Broz8b004452006-10-03 01:15:37 -0700471 if (!clone)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473
Olaf Kirch027581f2007-05-09 02:32:52 -0700474 clone_init(io, clone);
Milan Broz6a24c712006-10-03 01:15:40 -0700475
Olaf Kirchf97380b2007-05-09 02:32:54 -0700476 for (i = 0; i < nr_iovecs; i++) {
Milan Broz91e10622007-12-13 14:16:10 +0000477 page = mempool_alloc(cc->page_pool, gfp_mask);
478 if (!page)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 break;
480
481 /*
482 * if additional pages cannot be allocated without waiting,
483 * return a partially allocated bio, the caller will then try
484 * to allocate additional bios while submitting this partial bio
485 */
Olaf Kirchf97380b2007-05-09 02:32:54 -0700486 if (i == (MIN_BIO_PAGES - 1))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
488
Milan Broz91e10622007-12-13 14:16:10 +0000489 len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490
Milan Broz91e10622007-12-13 14:16:10 +0000491 if (!bio_add_page(clone, page, len, 0)) {
492 mempool_free(page, cc->page_pool);
493 break;
494 }
495
496 size -= len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700497 }
498
Milan Broz8b004452006-10-03 01:15:37 -0700499 if (!clone->bi_size) {
500 bio_put(clone);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 return NULL;
502 }
503
Milan Broz8b004452006-10-03 01:15:37 -0700504 return clone;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505}
506
Neil Brown644bd2f2007-10-16 13:48:46 +0200507static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508{
Neil Brown644bd2f2007-10-16 13:48:46 +0200509 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 struct bio_vec *bv;
511
Neil Brown644bd2f2007-10-16 13:48:46 +0200512 for (i = 0; i < clone->bi_vcnt; i++) {
Milan Broz8b004452006-10-03 01:15:37 -0700513 bv = bio_iovec_idx(clone, i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 BUG_ON(!bv->bv_page);
515 mempool_free(bv->bv_page, cc->page_pool);
516 bv->bv_page = NULL;
517 }
518}
519
520/*
521 * One of the bios was finished. Check for completion of
522 * the whole request and correctly clean up the buffer.
523 */
Milan Broz5742fd72008-02-08 02:10:43 +0000524static void crypt_dec_pending(struct dm_crypt_io *io)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525{
Milan Broz5742fd72008-02-08 02:10:43 +0000526 struct crypt_config *cc = io->target->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
528 if (!atomic_dec_and_test(&io->pending))
529 return;
530
NeilBrown6712ecf2007-09-27 12:47:43 +0200531 bio_endio(io->base_bio, io->error);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700532 mempool_free(io, cc->io_pool);
533}
534
535/*
Milan Brozcabf08e2007-10-19 22:38:58 +0100536 * kcryptd/kcryptd_io:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 *
538 * Needed because it would be very unwise to do decryption in an
Milan Broz23541d22006-10-03 01:15:39 -0700539 * interrupt context.
Milan Brozcabf08e2007-10-19 22:38:58 +0100540 *
541 * kcryptd performs the actual encryption or decryption.
542 *
543 * kcryptd_io performs the IO submission.
544 *
545 * They must be separated as otherwise the final stages could be
546 * starved by new requests which can block in the first stages due
547 * to memory allocation.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700548 */
NeilBrown6712ecf2007-09-27 12:47:43 +0200549static void crypt_endio(struct bio *clone, int error)
Milan Broz8b004452006-10-03 01:15:37 -0700550{
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100551 struct dm_crypt_io *io = clone->bi_private;
Milan Broz8b004452006-10-03 01:15:37 -0700552 struct crypt_config *cc = io->target->private;
Milan Brozee7a4912008-02-08 02:10:46 +0000553 unsigned rw = bio_data_dir(clone);
Milan Broz8b004452006-10-03 01:15:37 -0700554
Milan Brozadfe4772007-12-13 14:15:51 +0000555 if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
556 error = -EIO;
557
Milan Broz8b004452006-10-03 01:15:37 -0700558 /*
NeilBrown6712ecf2007-09-27 12:47:43 +0200559 * free the processed pages
Milan Broz8b004452006-10-03 01:15:37 -0700560 */
Milan Brozee7a4912008-02-08 02:10:46 +0000561 if (rw == WRITE)
Neil Brown644bd2f2007-10-16 13:48:46 +0200562 crypt_free_buffer_pages(cc, clone);
Milan Brozee7a4912008-02-08 02:10:46 +0000563
564 bio_put(clone);
565
566 if (rw == READ && !error) {
567 kcryptd_queue_crypt(io);
568 return;
NeilBrown6712ecf2007-09-27 12:47:43 +0200569 }
Milan Broz8b004452006-10-03 01:15:37 -0700570
Milan Brozadfe4772007-12-13 14:15:51 +0000571 if (unlikely(error))
Milan Broz5742fd72008-02-08 02:10:43 +0000572 io->error = error;
573
574 crypt_dec_pending(io);
Milan Broz8b004452006-10-03 01:15:37 -0700575}
576
Alasdair G Kergon028867a2007-07-12 17:26:32 +0100577static void clone_init(struct dm_crypt_io *io, struct bio *clone)
Milan Broz8b004452006-10-03 01:15:37 -0700578{
579 struct crypt_config *cc = io->target->private;
580
581 clone->bi_private = io;
582 clone->bi_end_io = crypt_endio;
583 clone->bi_bdev = cc->dev->bdev;
584 clone->bi_rw = io->base_bio->bi_rw;
Olaf Kirch027581f2007-05-09 02:32:52 -0700585 clone->bi_destructor = dm_crypt_bio_destructor;
Milan Broz8b004452006-10-03 01:15:37 -0700586}
587
Milan Broz4e4eef62008-02-08 02:10:49 +0000588static void kcryptd_io_read(struct dm_crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700589{
590 struct crypt_config *cc = io->target->private;
591 struct bio *base_bio = io->base_bio;
592 struct bio *clone;
Milan Broz93e605c2006-10-03 01:15:38 -0700593
594 atomic_inc(&io->pending);
Milan Broz8b004452006-10-03 01:15:37 -0700595
596 /*
597 * The block layer might modify the bvec array, so always
598 * copy the required bvecs because we need the original
599 * one in order to decrypt the whole bio data *afterwards*.
600 */
Milan Broz6a24c712006-10-03 01:15:40 -0700601 clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
Milan Broz93e605c2006-10-03 01:15:38 -0700602 if (unlikely(!clone)) {
Milan Broz5742fd72008-02-08 02:10:43 +0000603 io->error = -ENOMEM;
604 crypt_dec_pending(io);
Milan Broz23541d22006-10-03 01:15:39 -0700605 return;
Milan Broz93e605c2006-10-03 01:15:38 -0700606 }
Milan Broz8b004452006-10-03 01:15:37 -0700607
608 clone_init(io, clone);
609 clone->bi_idx = 0;
610 clone->bi_vcnt = bio_segments(base_bio);
611 clone->bi_size = base_bio->bi_size;
Milan Broz0c395b02008-02-08 02:10:54 +0000612 clone->bi_sector = cc->start + io->sector;
Milan Broz8b004452006-10-03 01:15:37 -0700613 memcpy(clone->bi_io_vec, bio_iovec(base_bio),
614 sizeof(struct bio_vec) * clone->bi_vcnt);
Milan Broz8b004452006-10-03 01:15:37 -0700615
Milan Broz93e605c2006-10-03 01:15:38 -0700616 generic_make_request(clone);
Milan Broz8b004452006-10-03 01:15:37 -0700617}
618
Milan Broz4e4eef62008-02-08 02:10:49 +0000619static void kcryptd_io_write(struct dm_crypt_io *io)
620{
Milan Broz95497a92008-02-08 02:11:12 +0000621 struct bio *clone = io->ctx.bio_out;
Milan Broz3f1e9072008-03-28 14:16:07 -0700622 struct crypt_config *cc = io->target->private;
Milan Broz95497a92008-02-08 02:11:12 +0000623
624 generic_make_request(clone);
Milan Broz3f1e9072008-03-28 14:16:07 -0700625 wake_up(&cc->writeq);
Milan Broz4e4eef62008-02-08 02:10:49 +0000626}
627
Alasdair G Kergon395b1672008-02-08 02:10:52 +0000628static void kcryptd_io(struct work_struct *work)
629{
630 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
631
632 if (bio_data_dir(io->base_bio) == READ)
633 kcryptd_io_read(io);
634 else
635 kcryptd_io_write(io);
636}
637
638static void kcryptd_queue_io(struct dm_crypt_io *io)
639{
640 struct crypt_config *cc = io->target->private;
641
642 INIT_WORK(&io->work, kcryptd_io);
643 queue_work(cc->io_queue, &io->work);
644}
645
Milan Broz95497a92008-02-08 02:11:12 +0000646static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
647 int error, int async)
Milan Broz4e4eef62008-02-08 02:10:49 +0000648{
Milan Brozdec1ced2008-02-08 02:10:57 +0000649 struct bio *clone = io->ctx.bio_out;
650 struct crypt_config *cc = io->target->private;
651
652 if (unlikely(error < 0)) {
653 crypt_free_buffer_pages(cc, clone);
654 bio_put(clone);
655 io->error = -EIO;
Milan Brozdec1ced2008-02-08 02:10:57 +0000656 return;
657 }
658
659 /* crypt_convert should have filled the clone bio */
660 BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
661
662 clone->bi_sector = cc->start + io->sector;
663 io->sector += bio_sectors(clone);
Milan Broz899c95d2008-02-08 02:11:02 +0000664
Milan Broz95497a92008-02-08 02:11:12 +0000665 if (async)
666 kcryptd_queue_io(io);
667 else {
668 atomic_inc(&io->pending);
669 generic_make_request(clone);
670 }
Milan Broz4e4eef62008-02-08 02:10:49 +0000671}
672
Milan Broz84131db2008-02-08 02:10:59 +0000673static void kcryptd_crypt_write_convert_loop(struct dm_crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700674{
675 struct crypt_config *cc = io->target->private;
Milan Broz8b004452006-10-03 01:15:37 -0700676 struct bio *clone;
Milan Brozdec1ced2008-02-08 02:10:57 +0000677 unsigned remaining = io->base_bio->bi_size;
678 int r;
Milan Broz8b004452006-10-03 01:15:37 -0700679
Milan Broz93e605c2006-10-03 01:15:38 -0700680 /*
681 * The allocated buffers can be smaller than the whole bio,
682 * so repeat the whole process until all the data can be handled.
683 */
684 while (remaining) {
Olaf Kirchf97380b2007-05-09 02:32:54 -0700685 clone = crypt_alloc_buffer(io, remaining);
Milan Broz23541d22006-10-03 01:15:39 -0700686 if (unlikely(!clone)) {
Milan Broz5742fd72008-02-08 02:10:43 +0000687 io->error = -ENOMEM;
Milan Broz23541d22006-10-03 01:15:39 -0700688 return;
689 }
Milan Broz93e605c2006-10-03 01:15:38 -0700690
Milan Broz53017032008-02-08 02:10:38 +0000691 io->ctx.bio_out = clone;
692 io->ctx.idx_out = 0;
Milan Broz93e605c2006-10-03 01:15:38 -0700693
Milan Broz93e605c2006-10-03 01:15:38 -0700694 remaining -= clone->bi_size;
Milan Brozdec1ced2008-02-08 02:10:57 +0000695
696 r = crypt_convert(cc, &io->ctx);
697
Milan Broz3f1e9072008-03-28 14:16:07 -0700698 if (atomic_dec_and_test(&io->ctx.pending)) {
699 /* processed, no running async crypto */
Milan Broz3a7f6c92008-02-08 02:11:14 +0000700 kcryptd_crypt_write_io_submit(io, r, 0);
701 if (unlikely(r < 0))
702 return;
703 } else
704 atomic_inc(&io->pending);
Milan Broz93e605c2006-10-03 01:15:38 -0700705
Milan Broz93e605c2006-10-03 01:15:38 -0700706 /* out of memory -> run queues */
Milan Broz3f1e9072008-03-28 14:16:07 -0700707 if (unlikely(remaining)) {
708 /* wait for async crypto then reinitialize pending */
709 wait_event(cc->writeq, !atomic_read(&io->ctx.pending));
710 atomic_set(&io->ctx.pending, 1);
Olaf Kirch98221eb2007-05-09 02:32:52 -0700711 congestion_wait(WRITE, HZ/100);
Milan Broz3f1e9072008-03-28 14:16:07 -0700712 }
Milan Broz8b004452006-10-03 01:15:37 -0700713 }
Milan Broz8b004452006-10-03 01:15:37 -0700714}
715
Milan Broz84131db2008-02-08 02:10:59 +0000716static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
717{
718 struct crypt_config *cc = io->target->private;
719
Milan Broz899c95d2008-02-08 02:11:02 +0000720 /*
721 * Prevent io from disappearing until this function completes.
722 */
Milan Broz84131db2008-02-08 02:10:59 +0000723 atomic_inc(&io->pending);
724
725 crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, io->sector);
726 kcryptd_crypt_write_convert_loop(io);
Milan Broz899c95d2008-02-08 02:11:02 +0000727
728 crypt_dec_pending(io);
Milan Broz84131db2008-02-08 02:10:59 +0000729}
730
Milan Broz4e4eef62008-02-08 02:10:49 +0000731static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
Milan Broz5742fd72008-02-08 02:10:43 +0000732{
733 if (unlikely(error < 0))
734 io->error = -EIO;
735
736 crypt_dec_pending(io);
737}
738
Milan Broz4e4eef62008-02-08 02:10:49 +0000739static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
Milan Broz8b004452006-10-03 01:15:37 -0700740{
741 struct crypt_config *cc = io->target->private;
Milan Broz5742fd72008-02-08 02:10:43 +0000742 int r = 0;
Milan Broz8b004452006-10-03 01:15:37 -0700743
Milan Broz3a7f6c92008-02-08 02:11:14 +0000744 atomic_inc(&io->pending);
745
Milan Broz53017032008-02-08 02:10:38 +0000746 crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
Milan Broz0c395b02008-02-08 02:10:54 +0000747 io->sector);
Milan Broz8b004452006-10-03 01:15:37 -0700748
Milan Broz5742fd72008-02-08 02:10:43 +0000749 r = crypt_convert(cc, &io->ctx);
750
Milan Broz3f1e9072008-03-28 14:16:07 -0700751 if (atomic_dec_and_test(&io->ctx.pending))
Milan Broz3a7f6c92008-02-08 02:11:14 +0000752 kcryptd_crypt_read_done(io, r);
753
754 crypt_dec_pending(io);
Milan Broz8b004452006-10-03 01:15:37 -0700755}
756
Milan Broz95497a92008-02-08 02:11:12 +0000757static void kcryptd_async_done(struct crypto_async_request *async_req,
758 int error)
759{
760 struct convert_context *ctx = async_req->data;
761 struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
762 struct crypt_config *cc = io->target->private;
763
764 if (error == -EINPROGRESS) {
765 complete(&ctx->restart);
766 return;
767 }
768
769 mempool_free(ablkcipher_request_cast(async_req), cc->req_pool);
770
771 if (!atomic_dec_and_test(&ctx->pending))
772 return;
773
774 if (bio_data_dir(io->base_bio) == READ)
775 kcryptd_crypt_read_done(io, error);
776 else
777 kcryptd_crypt_write_io_submit(io, error, 1);
778}
779
Milan Broz4e4eef62008-02-08 02:10:49 +0000780static void kcryptd_crypt(struct work_struct *work)
781{
782 struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
783
784 if (bio_data_dir(io->base_bio) == READ)
785 kcryptd_crypt_read_convert(io);
786 else
787 kcryptd_crypt_write_convert(io);
Milan Broz8b004452006-10-03 01:15:37 -0700788}
789
Alasdair G Kergon395b1672008-02-08 02:10:52 +0000790static void kcryptd_queue_crypt(struct dm_crypt_io *io)
791{
792 struct crypt_config *cc = io->target->private;
793
794 INIT_WORK(&io->work, kcryptd_crypt);
795 queue_work(cc->crypt_queue, &io->work);
796}
797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798/*
799 * Decode key from its hex representation
800 */
801static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
802{
803 char buffer[3];
804 char *endp;
805 unsigned int i;
806
807 buffer[2] = '\0';
808
Milan Broz8b004452006-10-03 01:15:37 -0700809 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810 buffer[0] = *hex++;
811 buffer[1] = *hex++;
812
813 key[i] = (u8)simple_strtoul(buffer, &endp, 16);
814
815 if (endp != &buffer[2])
816 return -EINVAL;
817 }
818
819 if (*hex != '\0')
820 return -EINVAL;
821
822 return 0;
823}
824
825/*
826 * Encode key into its hex representation
827 */
828static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
829{
830 unsigned int i;
831
Milan Broz8b004452006-10-03 01:15:37 -0700832 for (i = 0; i < size; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700833 sprintf(hex, "%02x", *key);
834 hex += 2;
835 key++;
836 }
837}
838
Milan Broze48d4bb2006-10-03 01:15:37 -0700839static int crypt_set_key(struct crypt_config *cc, char *key)
840{
841 unsigned key_size = strlen(key) >> 1;
842
843 if (cc->key_size && cc->key_size != key_size)
844 return -EINVAL;
845
846 cc->key_size = key_size; /* initial settings */
847
848 if ((!key_size && strcmp(key, "-")) ||
Milan Brozd469f842007-10-19 22:42:37 +0100849 (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
Milan Broze48d4bb2006-10-03 01:15:37 -0700850 return -EINVAL;
851
852 set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
853
854 return 0;
855}
856
857static int crypt_wipe_key(struct crypt_config *cc)
858{
859 clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
860 memset(&cc->key, 0, cc->key_size * sizeof(u8));
861 return 0;
862}
863
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864/*
865 * Construct an encryption mapping:
866 * <cipher> <key> <iv_offset> <dev_path> <start>
867 */
868static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
869{
870 struct crypt_config *cc;
Milan Broz3a7f6c92008-02-08 02:11:14 +0000871 struct crypto_ablkcipher *tfm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700872 char *tmp;
873 char *cipher;
874 char *chainmode;
875 char *ivmode;
876 char *ivopts;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700877 unsigned int key_size;
Andrew Morton4ee218c2006-03-27 01:17:48 -0800878 unsigned long long tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879
880 if (argc != 5) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700881 ti->error = "Not enough arguments";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 return -EINVAL;
883 }
884
885 tmp = argv[0];
886 cipher = strsep(&tmp, "-");
887 chainmode = strsep(&tmp, "-");
888 ivopts = strsep(&tmp, "-");
889 ivmode = strsep(&ivopts, ":");
890
891 if (tmp)
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700892 DMWARN("Unexpected additional cipher options");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700893
894 key_size = strlen(argv[1]) >> 1;
895
Milan Broze48d4bb2006-10-03 01:15:37 -0700896 cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897 if (cc == NULL) {
898 ti->error =
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700899 "Cannot allocate transparent encryption context";
Linus Torvalds1da177e2005-04-16 15:20:36 -0700900 return -ENOMEM;
901 }
902
Milan Broze48d4bb2006-10-03 01:15:37 -0700903 if (crypt_set_key(cc, argv[1])) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700904 ti->error = "Error decoding key";
Milan Broz636d5782007-10-19 22:47:52 +0100905 goto bad_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906 }
907
908 /* Compatiblity mode for old dm-crypt cipher strings */
909 if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) {
910 chainmode = "cbc";
911 ivmode = "plain";
912 }
913
Herbert Xud1806f62006-08-22 20:29:17 +1000914 if (strcmp(chainmode, "ecb") && !ivmode) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700915 ti->error = "This chaining mode requires an IV mechanism";
Milan Broz636d5782007-10-19 22:47:52 +0100916 goto bad_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700917 }
918
Milan Brozd469f842007-10-19 22:42:37 +0100919 if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)",
920 chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) {
Herbert Xud1806f62006-08-22 20:29:17 +1000921 ti->error = "Chain mode + cipher name is too long";
Milan Broz636d5782007-10-19 22:47:52 +0100922 goto bad_cipher;
Herbert Xud1806f62006-08-22 20:29:17 +1000923 }
924
Milan Broz3a7f6c92008-02-08 02:11:14 +0000925 tfm = crypto_alloc_ablkcipher(cc->cipher, 0, 0);
Herbert Xud1806f62006-08-22 20:29:17 +1000926 if (IS_ERR(tfm)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700927 ti->error = "Error allocating crypto tfm";
Milan Broz636d5782007-10-19 22:47:52 +0100928 goto bad_cipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700930
Herbert Xud1806f62006-08-22 20:29:17 +1000931 strcpy(cc->cipher, cipher);
932 strcpy(cc->chainmode, chainmode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 cc->tfm = tfm;
934
935 /*
Rik Snel48527fa2006-09-03 08:56:39 +1000936 * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi".
Linus Torvalds1da177e2005-04-16 15:20:36 -0700937 * See comments at iv code
938 */
939
940 if (ivmode == NULL)
941 cc->iv_gen_ops = NULL;
942 else if (strcmp(ivmode, "plain") == 0)
943 cc->iv_gen_ops = &crypt_iv_plain_ops;
944 else if (strcmp(ivmode, "essiv") == 0)
945 cc->iv_gen_ops = &crypt_iv_essiv_ops;
Rik Snel48527fa2006-09-03 08:56:39 +1000946 else if (strcmp(ivmode, "benbi") == 0)
947 cc->iv_gen_ops = &crypt_iv_benbi_ops;
Ludwig Nussel46b47732007-05-09 02:32:55 -0700948 else if (strcmp(ivmode, "null") == 0)
949 cc->iv_gen_ops = &crypt_iv_null_ops;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700950 else {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700951 ti->error = "Invalid IV mode";
Milan Broz636d5782007-10-19 22:47:52 +0100952 goto bad_ivmode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700953 }
954
955 if (cc->iv_gen_ops && cc->iv_gen_ops->ctr &&
956 cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0)
Milan Broz636d5782007-10-19 22:47:52 +0100957 goto bad_ivmode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958
Milan Broz3a7f6c92008-02-08 02:11:14 +0000959 cc->iv_size = crypto_ablkcipher_ivsize(tfm);
Herbert Xud1806f62006-08-22 20:29:17 +1000960 if (cc->iv_size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700961 /* at least a 64 bit sector number should fit in our buffer */
Herbert Xud1806f62006-08-22 20:29:17 +1000962 cc->iv_size = max(cc->iv_size,
Milan Brozd469f842007-10-19 22:42:37 +0100963 (unsigned int)(sizeof(u64) / sizeof(u8)));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700965 if (cc->iv_gen_ops) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700966 DMWARN("Selected cipher does not support IVs");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700967 if (cc->iv_gen_ops->dtr)
968 cc->iv_gen_ops->dtr(cc);
969 cc->iv_gen_ops = NULL;
970 }
971 }
972
Matthew Dobson93d23412006-03-26 01:37:50 -0800973 cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 if (!cc->io_pool) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700975 ti->error = "Cannot allocate crypt io mempool";
Milan Broz636d5782007-10-19 22:47:52 +0100976 goto bad_slab_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700977 }
978
Milan Brozddd42ed2008-02-08 02:11:07 +0000979 cc->dmreq_start = sizeof(struct ablkcipher_request);
Milan Broz3a7f6c92008-02-08 02:11:14 +0000980 cc->dmreq_start += crypto_ablkcipher_reqsize(tfm);
Milan Brozddd42ed2008-02-08 02:11:07 +0000981 cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
Milan Broz3a7f6c92008-02-08 02:11:14 +0000982 cc->dmreq_start += crypto_ablkcipher_alignmask(tfm) &
983 ~(crypto_tfm_ctx_alignment() - 1);
Milan Brozddd42ed2008-02-08 02:11:07 +0000984
985 cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
986 sizeof(struct dm_crypt_request) + cc->iv_size);
987 if (!cc->req_pool) {
988 ti->error = "Cannot allocate crypt request mempool";
989 goto bad_req_pool;
990 }
991 cc->req = NULL;
992
Matthew Dobsona19b27c2006-03-26 01:37:45 -0800993 cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700994 if (!cc->page_pool) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -0700995 ti->error = "Cannot allocate page mempool";
Milan Broz636d5782007-10-19 22:47:52 +0100996 goto bad_page_pool;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700997 }
998
Jens Axboe59725112007-04-02 10:06:42 +0200999 cc->bs = bioset_create(MIN_IOS, MIN_IOS);
Milan Broz6a24c712006-10-03 01:15:40 -07001000 if (!cc->bs) {
1001 ti->error = "Cannot allocate crypt bioset";
1002 goto bad_bs;
1003 }
1004
Milan Broz3a7f6c92008-02-08 02:11:14 +00001005 if (crypto_ablkcipher_setkey(tfm, cc->key, key_size) < 0) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001006 ti->error = "Error setting key";
Milan Broz636d5782007-10-19 22:47:52 +01001007 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001008 }
1009
Andrew Morton4ee218c2006-03-27 01:17:48 -08001010 if (sscanf(argv[2], "%llu", &tmpll) != 1) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001011 ti->error = "Invalid iv_offset sector";
Milan Broz636d5782007-10-19 22:47:52 +01001012 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001013 }
Andrew Morton4ee218c2006-03-27 01:17:48 -08001014 cc->iv_offset = tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015
Andrew Morton4ee218c2006-03-27 01:17:48 -08001016 if (sscanf(argv[4], "%llu", &tmpll) != 1) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001017 ti->error = "Invalid device sector";
Milan Broz636d5782007-10-19 22:47:52 +01001018 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019 }
Andrew Morton4ee218c2006-03-27 01:17:48 -08001020 cc->start = tmpll;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021
1022 if (dm_get_device(ti, argv[3], cc->start, ti->len,
Milan Brozd469f842007-10-19 22:42:37 +01001023 dm_table_get_mode(ti->table), &cc->dev)) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001024 ti->error = "Device lookup failed";
Milan Broz636d5782007-10-19 22:47:52 +01001025 goto bad_device;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001026 }
1027
1028 if (ivmode && cc->iv_gen_ops) {
1029 if (ivopts)
1030 *(ivopts - 1) = ':';
1031 cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL);
1032 if (!cc->iv_mode) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001033 ti->error = "Error kmallocing iv_mode string";
Milan Broz636d5782007-10-19 22:47:52 +01001034 goto bad_ivmode_string;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001035 }
1036 strcpy(cc->iv_mode, ivmode);
1037 } else
1038 cc->iv_mode = NULL;
1039
Milan Brozcabf08e2007-10-19 22:38:58 +01001040 cc->io_queue = create_singlethread_workqueue("kcryptd_io");
1041 if (!cc->io_queue) {
1042 ti->error = "Couldn't create kcryptd io queue";
1043 goto bad_io_queue;
1044 }
1045
1046 cc->crypt_queue = create_singlethread_workqueue("kcryptd");
1047 if (!cc->crypt_queue) {
Milan Broz9934a8b2007-10-19 22:38:57 +01001048 ti->error = "Couldn't create kcryptd queue";
Milan Brozcabf08e2007-10-19 22:38:58 +01001049 goto bad_crypt_queue;
Milan Broz9934a8b2007-10-19 22:38:57 +01001050 }
1051
Milan Broz3f1e9072008-03-28 14:16:07 -07001052 init_waitqueue_head(&cc->writeq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001053 ti->private = cc;
1054 return 0;
1055
Milan Brozcabf08e2007-10-19 22:38:58 +01001056bad_crypt_queue:
1057 destroy_workqueue(cc->io_queue);
1058bad_io_queue:
Milan Broz9934a8b2007-10-19 22:38:57 +01001059 kfree(cc->iv_mode);
Milan Broz636d5782007-10-19 22:47:52 +01001060bad_ivmode_string:
Dmitry Monakhov55b42c52007-10-19 22:38:37 +01001061 dm_put_device(ti, cc->dev);
Milan Broz636d5782007-10-19 22:47:52 +01001062bad_device:
Milan Broz6a24c712006-10-03 01:15:40 -07001063 bioset_free(cc->bs);
1064bad_bs:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001065 mempool_destroy(cc->page_pool);
Milan Broz636d5782007-10-19 22:47:52 +01001066bad_page_pool:
Milan Brozddd42ed2008-02-08 02:11:07 +00001067 mempool_destroy(cc->req_pool);
1068bad_req_pool:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 mempool_destroy(cc->io_pool);
Milan Broz636d5782007-10-19 22:47:52 +01001070bad_slab_pool:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001071 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1072 cc->iv_gen_ops->dtr(cc);
Milan Broz636d5782007-10-19 22:47:52 +01001073bad_ivmode:
Milan Broz3a7f6c92008-02-08 02:11:14 +00001074 crypto_free_ablkcipher(tfm);
Milan Broz636d5782007-10-19 22:47:52 +01001075bad_cipher:
Stefan Rompf9d3520a2006-01-06 00:20:08 -08001076 /* Must zero key material before freeing */
1077 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001078 kfree(cc);
1079 return -EINVAL;
1080}
1081
1082static void crypt_dtr(struct dm_target *ti)
1083{
1084 struct crypt_config *cc = (struct crypt_config *) ti->private;
1085
Milan Brozcabf08e2007-10-19 22:38:58 +01001086 destroy_workqueue(cc->io_queue);
1087 destroy_workqueue(cc->crypt_queue);
Milan Broz80b16c12007-07-21 04:37:27 -07001088
Milan Brozddd42ed2008-02-08 02:11:07 +00001089 if (cc->req)
1090 mempool_free(cc->req, cc->req_pool);
1091
Milan Broz6a24c712006-10-03 01:15:40 -07001092 bioset_free(cc->bs);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 mempool_destroy(cc->page_pool);
Milan Brozddd42ed2008-02-08 02:11:07 +00001094 mempool_destroy(cc->req_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 mempool_destroy(cc->io_pool);
1096
Jesper Juhl990a8ba2005-06-21 17:17:30 -07001097 kfree(cc->iv_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001098 if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1099 cc->iv_gen_ops->dtr(cc);
Milan Broz3a7f6c92008-02-08 02:11:14 +00001100 crypto_free_ablkcipher(cc->tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001101 dm_put_device(ti, cc->dev);
Stefan Rompf9d3520a2006-01-06 00:20:08 -08001102
1103 /* Must zero key material before freeing */
1104 memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001105 kfree(cc);
1106}
1107
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108static int crypt_map(struct dm_target *ti, struct bio *bio,
1109 union map_info *map_context)
1110{
Milan Broz8b004452006-10-03 01:15:37 -07001111 struct crypt_config *cc = ti->private;
Alasdair G Kergon028867a2007-07-12 17:26:32 +01001112 struct dm_crypt_io *io;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001113
Milan Broze48d4bb2006-10-03 01:15:37 -07001114 io = mempool_alloc(cc->io_pool, GFP_NOIO);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001115 io->target = ti;
Milan Broz8b004452006-10-03 01:15:37 -07001116 io->base_bio = bio;
Milan Broz0c395b02008-02-08 02:10:54 +00001117 io->sector = bio->bi_sector - ti->begin;
Milan Brozcabf08e2007-10-19 22:38:58 +01001118 io->error = 0;
Milan Broz93e605c2006-10-03 01:15:38 -07001119 atomic_set(&io->pending, 0);
Milan Brozcabf08e2007-10-19 22:38:58 +01001120
1121 if (bio_data_dir(io->base_bio) == READ)
1122 kcryptd_queue_io(io);
1123 else
1124 kcryptd_queue_crypt(io);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001125
Kiyoshi Uedad2a7ad22006-12-08 02:41:06 -08001126 return DM_MAPIO_SUBMITTED;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001127}
1128
1129static int crypt_status(struct dm_target *ti, status_type_t type,
1130 char *result, unsigned int maxlen)
1131{
1132 struct crypt_config *cc = (struct crypt_config *) ti->private;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001133 unsigned int sz = 0;
1134
1135 switch (type) {
1136 case STATUSTYPE_INFO:
1137 result[0] = '\0';
1138 break;
1139
1140 case STATUSTYPE_TABLE:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001141 if (cc->iv_mode)
Christophe Saout37af6562006-10-30 20:39:08 +01001142 DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode,
1143 cc->iv_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001144 else
Christophe Saout37af6562006-10-30 20:39:08 +01001145 DMEMIT("%s-%s ", cc->cipher, cc->chainmode);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001146
1147 if (cc->key_size > 0) {
1148 if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1149 return -ENOMEM;
1150
1151 crypt_encode_key(result + sz, cc->key, cc->key_size);
1152 sz += cc->key_size << 1;
1153 } else {
1154 if (sz >= maxlen)
1155 return -ENOMEM;
1156 result[sz++] = '-';
1157 }
1158
Andrew Morton4ee218c2006-03-27 01:17:48 -08001159 DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1160 cc->dev->name, (unsigned long long)cc->start);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001161 break;
1162 }
1163 return 0;
1164}
1165
Milan Broze48d4bb2006-10-03 01:15:37 -07001166static void crypt_postsuspend(struct dm_target *ti)
1167{
1168 struct crypt_config *cc = ti->private;
1169
1170 set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1171}
1172
1173static int crypt_preresume(struct dm_target *ti)
1174{
1175 struct crypt_config *cc = ti->private;
1176
1177 if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1178 DMERR("aborting resume - crypt key is not set.");
1179 return -EAGAIN;
1180 }
1181
1182 return 0;
1183}
1184
1185static void crypt_resume(struct dm_target *ti)
1186{
1187 struct crypt_config *cc = ti->private;
1188
1189 clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1190}
1191
1192/* Message interface
1193 * key set <key>
1194 * key wipe
1195 */
1196static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1197{
1198 struct crypt_config *cc = ti->private;
1199
1200 if (argc < 2)
1201 goto error;
1202
1203 if (!strnicmp(argv[0], MESG_STR("key"))) {
1204 if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1205 DMWARN("not suspended during key manipulation.");
1206 return -EINVAL;
1207 }
1208 if (argc == 3 && !strnicmp(argv[1], MESG_STR("set")))
1209 return crypt_set_key(cc, argv[2]);
1210 if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe")))
1211 return crypt_wipe_key(cc);
1212 }
1213
1214error:
1215 DMWARN("unrecognised message received.");
1216 return -EINVAL;
1217}
1218
Linus Torvalds1da177e2005-04-16 15:20:36 -07001219static struct target_type crypt_target = {
1220 .name = "crypt",
Ludwig Nussel46b47732007-05-09 02:32:55 -07001221 .version= {1, 5, 0},
Linus Torvalds1da177e2005-04-16 15:20:36 -07001222 .module = THIS_MODULE,
1223 .ctr = crypt_ctr,
1224 .dtr = crypt_dtr,
1225 .map = crypt_map,
1226 .status = crypt_status,
Milan Broze48d4bb2006-10-03 01:15:37 -07001227 .postsuspend = crypt_postsuspend,
1228 .preresume = crypt_preresume,
1229 .resume = crypt_resume,
1230 .message = crypt_message,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001231};
1232
1233static int __init dm_crypt_init(void)
1234{
1235 int r;
1236
Alasdair G Kergon028867a2007-07-12 17:26:32 +01001237 _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 if (!_crypt_io_pool)
1239 return -ENOMEM;
1240
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241 r = dm_register_target(&crypt_target);
1242 if (r < 0) {
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001243 DMERR("register failed %d", r);
Milan Broz9934a8b2007-10-19 22:38:57 +01001244 kmem_cache_destroy(_crypt_io_pool);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001245 }
1246
Linus Torvalds1da177e2005-04-16 15:20:36 -07001247 return r;
1248}
1249
1250static void __exit dm_crypt_exit(void)
1251{
1252 int r = dm_unregister_target(&crypt_target);
1253
1254 if (r < 0)
Alasdair G Kergon72d94862006-06-26 00:27:35 -07001255 DMERR("unregister failed %d", r);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001256
Linus Torvalds1da177e2005-04-16 15:20:36 -07001257 kmem_cache_destroy(_crypt_io_pool);
1258}
1259
1260module_init(dm_crypt_init);
1261module_exit(dm_crypt_exit);
1262
1263MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1264MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1265MODULE_LICENSE("GPL");