Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Christophe Saout <christophe@saout.de> | |
3 | * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> | |
3f1e9070 | 4 | * Copyright (C) 2006-2008 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
5 | * |
6 | * This file is released under the GPL. | |
7 | */ | |
8 | ||
43d69034 | 9 | #include <linux/completion.h> |
d1806f6a | 10 | #include <linux/err.h> |
1da177e4 LT |
11 | #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> | |
3fcfab16 | 20 | #include <linux/backing-dev.h> |
1da177e4 | 21 | #include <asm/atomic.h> |
378f058c | 22 | #include <linux/scatterlist.h> |
1da177e4 | 23 | #include <asm/page.h> |
48527fa7 | 24 | #include <asm/unaligned.h> |
1da177e4 | 25 | |
586e80e6 | 26 | #include <linux/device-mapper.h> |
1da177e4 | 27 | |
72d94861 | 28 | #define DM_MSG_PREFIX "crypt" |
e48d4bbf | 29 | #define MESG_STR(x) x, sizeof(x) |
1da177e4 | 30 | |
1da177e4 LT |
31 | /* |
32 | * context holding the current state of a multi-part conversion | |
33 | */ | |
34 | struct convert_context { | |
43d69034 | 35 | struct completion restart; |
1da177e4 LT |
36 | 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; | |
43d69034 | 43 | atomic_t pending; |
1da177e4 LT |
44 | }; |
45 | ||
53017030 MB |
46 | /* |
47 | * per bio private data | |
48 | */ | |
49 | struct 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; | |
0c395b0f | 58 | sector_t sector; |
393b47ef | 59 | struct dm_crypt_io *base_io; |
53017030 MB |
60 | }; |
61 | ||
01482b76 | 62 | struct dm_crypt_request { |
b2174eeb | 63 | struct convert_context *ctx; |
01482b76 MB |
64 | struct scatterlist sg_in; |
65 | struct scatterlist sg_out; | |
66 | }; | |
67 | ||
1da177e4 LT |
68 | struct crypt_config; |
69 | ||
70 | struct crypt_iv_operations { | |
71 | int (*ctr)(struct crypt_config *cc, struct dm_target *ti, | |
d469f841 | 72 | const char *opts); |
1da177e4 | 73 | void (*dtr)(struct crypt_config *cc); |
1da177e4 LT |
74 | int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); |
75 | }; | |
76 | ||
60473592 MB |
77 | struct iv_essiv_private { |
78 | struct crypto_cipher *tfm; | |
79 | }; | |
80 | ||
81 | struct iv_benbi_private { | |
82 | int shift; | |
83 | }; | |
84 | ||
1da177e4 LT |
85 | /* |
86 | * Crypt: maps a linear range of a block device | |
87 | * and encrypts / decrypts at the same time. | |
88 | */ | |
e48d4bbf | 89 | enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; |
1da177e4 LT |
90 | struct crypt_config { |
91 | struct dm_dev *dev; | |
92 | sector_t start; | |
93 | ||
94 | /* | |
ddd42edf MB |
95 | * pool for per bio private data, crypto requests and |
96 | * encryption requeusts/buffer pages | |
1da177e4 LT |
97 | */ |
98 | mempool_t *io_pool; | |
ddd42edf | 99 | mempool_t *req_pool; |
1da177e4 | 100 | mempool_t *page_pool; |
6a24c718 | 101 | struct bio_set *bs; |
1da177e4 | 102 | |
cabf08e4 MB |
103 | struct workqueue_struct *io_queue; |
104 | struct workqueue_struct *crypt_queue; | |
3f1e9070 | 105 | |
1da177e4 LT |
106 | /* |
107 | * crypto related data | |
108 | */ | |
109 | struct crypt_iv_operations *iv_gen_ops; | |
110 | char *iv_mode; | |
79066ad3 | 111 | union { |
60473592 MB |
112 | struct iv_essiv_private essiv; |
113 | struct iv_benbi_private benbi; | |
79066ad3 | 114 | } iv_gen_private; |
1da177e4 LT |
115 | sector_t iv_offset; |
116 | unsigned int iv_size; | |
117 | ||
ddd42edf MB |
118 | /* |
119 | * Layout of each crypto request: | |
120 | * | |
121 | * struct ablkcipher_request | |
122 | * context | |
123 | * padding | |
124 | * struct dm_crypt_request | |
125 | * padding | |
126 | * IV | |
127 | * | |
128 | * The padding is added so that dm_crypt_request and the IV are | |
129 | * correctly aligned. | |
130 | */ | |
131 | unsigned int dmreq_start; | |
132 | struct ablkcipher_request *req; | |
133 | ||
d1806f6a HX |
134 | char cipher[CRYPTO_MAX_ALG_NAME]; |
135 | char chainmode[CRYPTO_MAX_ALG_NAME]; | |
3a7f6c99 | 136 | struct crypto_ablkcipher *tfm; |
e48d4bbf | 137 | unsigned long flags; |
1da177e4 LT |
138 | unsigned int key_size; |
139 | u8 key[0]; | |
140 | }; | |
141 | ||
6a24c718 | 142 | #define MIN_IOS 16 |
1da177e4 LT |
143 | #define MIN_POOL_PAGES 32 |
144 | #define MIN_BIO_PAGES 8 | |
145 | ||
e18b890b | 146 | static struct kmem_cache *_crypt_io_pool; |
1da177e4 | 147 | |
028867ac | 148 | static void clone_init(struct dm_crypt_io *, struct bio *); |
395b167c | 149 | static void kcryptd_queue_crypt(struct dm_crypt_io *io); |
027581f3 | 150 | |
1da177e4 LT |
151 | /* |
152 | * Different IV generation algorithms: | |
153 | * | |
3c164bd8 | 154 | * plain: the initial vector is the 32-bit little-endian version of the sector |
3a4fa0a2 | 155 | * number, padded with zeros if necessary. |
1da177e4 | 156 | * |
3c164bd8 RS |
157 | * essiv: "encrypted sector|salt initial vector", the sector number is |
158 | * encrypted with the bulk cipher using a salt as key. The salt | |
159 | * should be derived from the bulk cipher's key via hashing. | |
1da177e4 | 160 | * |
48527fa7 RS |
161 | * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 |
162 | * (needed for LRW-32-AES and possible other narrow block modes) | |
163 | * | |
46b47730 LN |
164 | * null: the initial vector is always zero. Provides compatibility with |
165 | * obsolete loop_fish2 devices. Do not use for new devices. | |
166 | * | |
1da177e4 LT |
167 | * plumb: unimplemented, see: |
168 | * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 | |
169 | */ | |
170 | ||
171 | static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) | |
172 | { | |
173 | memset(iv, 0, cc->iv_size); | |
174 | *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); | |
175 | ||
176 | return 0; | |
177 | } | |
178 | ||
60473592 MB |
179 | static void crypt_iv_essiv_dtr(struct crypt_config *cc) |
180 | { | |
181 | struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv; | |
182 | ||
183 | crypto_free_cipher(essiv->tfm); | |
184 | essiv->tfm = NULL; | |
185 | } | |
186 | ||
1da177e4 | 187 | static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, |
d469f841 | 188 | const char *opts) |
1da177e4 | 189 | { |
d1806f6a | 190 | struct crypto_cipher *essiv_tfm; |
35058687 HX |
191 | struct crypto_hash *hash_tfm; |
192 | struct hash_desc desc; | |
1da177e4 LT |
193 | struct scatterlist sg; |
194 | unsigned int saltsize; | |
195 | u8 *salt; | |
d1806f6a | 196 | int err; |
1da177e4 LT |
197 | |
198 | if (opts == NULL) { | |
72d94861 | 199 | ti->error = "Digest algorithm missing for ESSIV mode"; |
1da177e4 LT |
200 | return -EINVAL; |
201 | } | |
202 | ||
203 | /* Hash the cipher key with the given hash algorithm */ | |
35058687 HX |
204 | hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); |
205 | if (IS_ERR(hash_tfm)) { | |
72d94861 | 206 | ti->error = "Error initializing ESSIV hash"; |
35058687 | 207 | return PTR_ERR(hash_tfm); |
1da177e4 LT |
208 | } |
209 | ||
35058687 | 210 | saltsize = crypto_hash_digestsize(hash_tfm); |
1da177e4 LT |
211 | salt = kmalloc(saltsize, GFP_KERNEL); |
212 | if (salt == NULL) { | |
72d94861 | 213 | ti->error = "Error kmallocing salt storage in ESSIV"; |
35058687 | 214 | crypto_free_hash(hash_tfm); |
1da177e4 LT |
215 | return -ENOMEM; |
216 | } | |
217 | ||
68e3f5dd | 218 | sg_init_one(&sg, cc->key, cc->key_size); |
35058687 HX |
219 | desc.tfm = hash_tfm; |
220 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
221 | err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); | |
222 | crypto_free_hash(hash_tfm); | |
223 | ||
224 | if (err) { | |
225 | ti->error = "Error calculating hash in ESSIV"; | |
815f9e32 | 226 | kfree(salt); |
35058687 HX |
227 | return err; |
228 | } | |
1da177e4 LT |
229 | |
230 | /* Setup the essiv_tfm with the given salt */ | |
d1806f6a HX |
231 | essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
232 | if (IS_ERR(essiv_tfm)) { | |
72d94861 | 233 | ti->error = "Error allocating crypto tfm for ESSIV"; |
1da177e4 | 234 | kfree(salt); |
d1806f6a | 235 | return PTR_ERR(essiv_tfm); |
1da177e4 | 236 | } |
d1806f6a | 237 | if (crypto_cipher_blocksize(essiv_tfm) != |
3a7f6c99 | 238 | crypto_ablkcipher_ivsize(cc->tfm)) { |
72d94861 | 239 | ti->error = "Block size of ESSIV cipher does " |
d469f841 | 240 | "not match IV size of block cipher"; |
d1806f6a | 241 | crypto_free_cipher(essiv_tfm); |
1da177e4 LT |
242 | kfree(salt); |
243 | return -EINVAL; | |
244 | } | |
d1806f6a HX |
245 | err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); |
246 | if (err) { | |
72d94861 | 247 | ti->error = "Failed to set key for ESSIV cipher"; |
d1806f6a | 248 | crypto_free_cipher(essiv_tfm); |
1da177e4 | 249 | kfree(salt); |
d1806f6a | 250 | return err; |
1da177e4 LT |
251 | } |
252 | kfree(salt); | |
253 | ||
60473592 | 254 | cc->iv_gen_private.essiv.tfm = essiv_tfm; |
1da177e4 LT |
255 | return 0; |
256 | } | |
257 | ||
1da177e4 LT |
258 | static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
259 | { | |
1da177e4 LT |
260 | memset(iv, 0, cc->iv_size); |
261 | *(u64 *)iv = cpu_to_le64(sector); | |
60473592 | 262 | crypto_cipher_encrypt_one(cc->iv_gen_private.essiv.tfm, iv, iv); |
1da177e4 LT |
263 | return 0; |
264 | } | |
265 | ||
48527fa7 RS |
266 | static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, |
267 | const char *opts) | |
268 | { | |
3a7f6c99 | 269 | unsigned bs = crypto_ablkcipher_blocksize(cc->tfm); |
f0d1b0b3 | 270 | int log = ilog2(bs); |
48527fa7 RS |
271 | |
272 | /* we need to calculate how far we must shift the sector count | |
273 | * to get the cipher block count, we use this shift in _gen */ | |
274 | ||
275 | if (1 << log != bs) { | |
276 | ti->error = "cypher blocksize is not a power of 2"; | |
277 | return -EINVAL; | |
278 | } | |
279 | ||
280 | if (log > 9) { | |
281 | ti->error = "cypher blocksize is > 512"; | |
282 | return -EINVAL; | |
283 | } | |
284 | ||
60473592 | 285 | cc->iv_gen_private.benbi.shift = 9 - log; |
48527fa7 RS |
286 | |
287 | return 0; | |
288 | } | |
289 | ||
290 | static void crypt_iv_benbi_dtr(struct crypt_config *cc) | |
291 | { | |
48527fa7 RS |
292 | } |
293 | ||
294 | static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector) | |
295 | { | |
79066ad3 HX |
296 | __be64 val; |
297 | ||
48527fa7 | 298 | memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ |
79066ad3 | 299 | |
60473592 | 300 | val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi.shift) + 1); |
79066ad3 | 301 | put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); |
48527fa7 | 302 | |
1da177e4 LT |
303 | return 0; |
304 | } | |
305 | ||
46b47730 LN |
306 | static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
307 | { | |
308 | memset(iv, 0, cc->iv_size); | |
309 | ||
310 | return 0; | |
311 | } | |
312 | ||
1da177e4 LT |
313 | static struct crypt_iv_operations crypt_iv_plain_ops = { |
314 | .generator = crypt_iv_plain_gen | |
315 | }; | |
316 | ||
317 | static struct crypt_iv_operations crypt_iv_essiv_ops = { | |
318 | .ctr = crypt_iv_essiv_ctr, | |
319 | .dtr = crypt_iv_essiv_dtr, | |
320 | .generator = crypt_iv_essiv_gen | |
321 | }; | |
322 | ||
48527fa7 RS |
323 | static struct crypt_iv_operations crypt_iv_benbi_ops = { |
324 | .ctr = crypt_iv_benbi_ctr, | |
325 | .dtr = crypt_iv_benbi_dtr, | |
326 | .generator = crypt_iv_benbi_gen | |
327 | }; | |
1da177e4 | 328 | |
46b47730 LN |
329 | static struct crypt_iv_operations crypt_iv_null_ops = { |
330 | .generator = crypt_iv_null_gen | |
331 | }; | |
332 | ||
d469f841 MB |
333 | static void crypt_convert_init(struct crypt_config *cc, |
334 | struct convert_context *ctx, | |
335 | struct bio *bio_out, struct bio *bio_in, | |
fcd369da | 336 | sector_t sector) |
1da177e4 LT |
337 | { |
338 | ctx->bio_in = bio_in; | |
339 | ctx->bio_out = bio_out; | |
340 | ctx->offset_in = 0; | |
341 | ctx->offset_out = 0; | |
342 | ctx->idx_in = bio_in ? bio_in->bi_idx : 0; | |
343 | ctx->idx_out = bio_out ? bio_out->bi_idx : 0; | |
344 | ctx->sector = sector + cc->iv_offset; | |
43d69034 | 345 | init_completion(&ctx->restart); |
1da177e4 LT |
346 | } |
347 | ||
b2174eeb HY |
348 | static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc, |
349 | struct ablkcipher_request *req) | |
350 | { | |
351 | return (struct dm_crypt_request *)((char *)req + cc->dmreq_start); | |
352 | } | |
353 | ||
354 | static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc, | |
355 | struct dm_crypt_request *dmreq) | |
356 | { | |
357 | return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start); | |
358 | } | |
359 | ||
01482b76 | 360 | static int crypt_convert_block(struct crypt_config *cc, |
3a7f6c99 MB |
361 | struct convert_context *ctx, |
362 | struct ablkcipher_request *req) | |
01482b76 MB |
363 | { |
364 | struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); | |
365 | struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); | |
3a7f6c99 MB |
366 | struct dm_crypt_request *dmreq; |
367 | u8 *iv; | |
368 | int r = 0; | |
369 | ||
b2174eeb | 370 | dmreq = dmreq_of_req(cc, req); |
3a7f6c99 MB |
371 | iv = (u8 *)ALIGN((unsigned long)(dmreq + 1), |
372 | crypto_ablkcipher_alignmask(cc->tfm) + 1); | |
01482b76 | 373 | |
b2174eeb | 374 | dmreq->ctx = ctx; |
3a7f6c99 MB |
375 | sg_init_table(&dmreq->sg_in, 1); |
376 | sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, | |
01482b76 MB |
377 | bv_in->bv_offset + ctx->offset_in); |
378 | ||
3a7f6c99 MB |
379 | sg_init_table(&dmreq->sg_out, 1); |
380 | sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, | |
01482b76 MB |
381 | bv_out->bv_offset + ctx->offset_out); |
382 | ||
383 | ctx->offset_in += 1 << SECTOR_SHIFT; | |
384 | if (ctx->offset_in >= bv_in->bv_len) { | |
385 | ctx->offset_in = 0; | |
386 | ctx->idx_in++; | |
387 | } | |
388 | ||
389 | ctx->offset_out += 1 << SECTOR_SHIFT; | |
390 | if (ctx->offset_out >= bv_out->bv_len) { | |
391 | ctx->offset_out = 0; | |
392 | ctx->idx_out++; | |
393 | } | |
394 | ||
3a7f6c99 MB |
395 | if (cc->iv_gen_ops) { |
396 | r = cc->iv_gen_ops->generator(cc, iv, ctx->sector); | |
397 | if (r < 0) | |
398 | return r; | |
399 | } | |
400 | ||
401 | ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out, | |
402 | 1 << SECTOR_SHIFT, iv); | |
403 | ||
404 | if (bio_data_dir(ctx->bio_in) == WRITE) | |
405 | r = crypto_ablkcipher_encrypt(req); | |
406 | else | |
407 | r = crypto_ablkcipher_decrypt(req); | |
408 | ||
409 | return r; | |
01482b76 MB |
410 | } |
411 | ||
95497a96 MB |
412 | static void kcryptd_async_done(struct crypto_async_request *async_req, |
413 | int error); | |
ddd42edf MB |
414 | static void crypt_alloc_req(struct crypt_config *cc, |
415 | struct convert_context *ctx) | |
416 | { | |
417 | if (!cc->req) | |
418 | cc->req = mempool_alloc(cc->req_pool, GFP_NOIO); | |
95497a96 MB |
419 | ablkcipher_request_set_tfm(cc->req, cc->tfm); |
420 | ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG | | |
b2174eeb HY |
421 | CRYPTO_TFM_REQ_MAY_SLEEP, |
422 | kcryptd_async_done, | |
423 | dmreq_of_req(cc, cc->req)); | |
ddd42edf MB |
424 | } |
425 | ||
1da177e4 LT |
426 | /* |
427 | * Encrypt / decrypt data from one bio to another one (can be the same one) | |
428 | */ | |
429 | static int crypt_convert(struct crypt_config *cc, | |
d469f841 | 430 | struct convert_context *ctx) |
1da177e4 | 431 | { |
3f1e9070 | 432 | int r; |
1da177e4 | 433 | |
c8081618 MB |
434 | atomic_set(&ctx->pending, 1); |
435 | ||
1da177e4 LT |
436 | while(ctx->idx_in < ctx->bio_in->bi_vcnt && |
437 | ctx->idx_out < ctx->bio_out->bi_vcnt) { | |
1da177e4 | 438 | |
3a7f6c99 MB |
439 | crypt_alloc_req(cc, ctx); |
440 | ||
3f1e9070 MB |
441 | atomic_inc(&ctx->pending); |
442 | ||
3a7f6c99 MB |
443 | r = crypt_convert_block(cc, ctx, cc->req); |
444 | ||
445 | switch (r) { | |
3f1e9070 | 446 | /* async */ |
3a7f6c99 MB |
447 | case -EBUSY: |
448 | wait_for_completion(&ctx->restart); | |
449 | INIT_COMPLETION(ctx->restart); | |
450 | /* fall through*/ | |
451 | case -EINPROGRESS: | |
3a7f6c99 | 452 | cc->req = NULL; |
3f1e9070 MB |
453 | ctx->sector++; |
454 | continue; | |
455 | ||
456 | /* sync */ | |
3a7f6c99 | 457 | case 0: |
3f1e9070 | 458 | atomic_dec(&ctx->pending); |
3a7f6c99 | 459 | ctx->sector++; |
c7f1b204 | 460 | cond_resched(); |
3a7f6c99 | 461 | continue; |
3a7f6c99 | 462 | |
3f1e9070 MB |
463 | /* error */ |
464 | default: | |
465 | atomic_dec(&ctx->pending); | |
466 | return r; | |
467 | } | |
1da177e4 LT |
468 | } |
469 | ||
3f1e9070 | 470 | return 0; |
1da177e4 LT |
471 | } |
472 | ||
d469f841 MB |
473 | static void dm_crypt_bio_destructor(struct bio *bio) |
474 | { | |
028867ac | 475 | struct dm_crypt_io *io = bio->bi_private; |
6a24c718 MB |
476 | struct crypt_config *cc = io->target->private; |
477 | ||
478 | bio_free(bio, cc->bs); | |
d469f841 | 479 | } |
6a24c718 | 480 | |
1da177e4 LT |
481 | /* |
482 | * Generate a new unfragmented bio with the given size | |
483 | * This should never violate the device limitations | |
933f01d4 MB |
484 | * May return a smaller bio when running out of pages, indicated by |
485 | * *out_of_pages set to 1. | |
1da177e4 | 486 | */ |
933f01d4 MB |
487 | static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size, |
488 | unsigned *out_of_pages) | |
1da177e4 | 489 | { |
027581f3 | 490 | struct crypt_config *cc = io->target->private; |
8b004457 | 491 | struct bio *clone; |
1da177e4 | 492 | unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
b4e3ca1a | 493 | gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; |
91e10625 MB |
494 | unsigned i, len; |
495 | struct page *page; | |
1da177e4 | 496 | |
2f9941b6 | 497 | clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); |
8b004457 | 498 | if (!clone) |
1da177e4 | 499 | return NULL; |
1da177e4 | 500 | |
027581f3 | 501 | clone_init(io, clone); |
933f01d4 | 502 | *out_of_pages = 0; |
6a24c718 | 503 | |
f97380bc | 504 | for (i = 0; i < nr_iovecs; i++) { |
91e10625 | 505 | page = mempool_alloc(cc->page_pool, gfp_mask); |
933f01d4 MB |
506 | if (!page) { |
507 | *out_of_pages = 1; | |
1da177e4 | 508 | break; |
933f01d4 | 509 | } |
1da177e4 LT |
510 | |
511 | /* | |
512 | * if additional pages cannot be allocated without waiting, | |
513 | * return a partially allocated bio, the caller will then try | |
514 | * to allocate additional bios while submitting this partial bio | |
515 | */ | |
f97380bc | 516 | if (i == (MIN_BIO_PAGES - 1)) |
1da177e4 LT |
517 | gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; |
518 | ||
91e10625 MB |
519 | len = (size > PAGE_SIZE) ? PAGE_SIZE : size; |
520 | ||
521 | if (!bio_add_page(clone, page, len, 0)) { | |
522 | mempool_free(page, cc->page_pool); | |
523 | break; | |
524 | } | |
1da177e4 | 525 | |
91e10625 | 526 | size -= len; |
1da177e4 LT |
527 | } |
528 | ||
8b004457 MB |
529 | if (!clone->bi_size) { |
530 | bio_put(clone); | |
1da177e4 LT |
531 | return NULL; |
532 | } | |
533 | ||
8b004457 | 534 | return clone; |
1da177e4 LT |
535 | } |
536 | ||
644bd2f0 | 537 | static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) |
1da177e4 | 538 | { |
644bd2f0 | 539 | unsigned int i; |
1da177e4 LT |
540 | struct bio_vec *bv; |
541 | ||
644bd2f0 | 542 | for (i = 0; i < clone->bi_vcnt; i++) { |
8b004457 | 543 | bv = bio_iovec_idx(clone, i); |
1da177e4 LT |
544 | BUG_ON(!bv->bv_page); |
545 | mempool_free(bv->bv_page, cc->page_pool); | |
546 | bv->bv_page = NULL; | |
547 | } | |
548 | } | |
549 | ||
dc440d1e MB |
550 | static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti, |
551 | struct bio *bio, sector_t sector) | |
552 | { | |
553 | struct crypt_config *cc = ti->private; | |
554 | struct dm_crypt_io *io; | |
555 | ||
556 | io = mempool_alloc(cc->io_pool, GFP_NOIO); | |
557 | io->target = ti; | |
558 | io->base_bio = bio; | |
559 | io->sector = sector; | |
560 | io->error = 0; | |
393b47ef | 561 | io->base_io = NULL; |
dc440d1e MB |
562 | atomic_set(&io->pending, 0); |
563 | ||
564 | return io; | |
565 | } | |
566 | ||
3e1a8bdd MB |
567 | static void crypt_inc_pending(struct dm_crypt_io *io) |
568 | { | |
569 | atomic_inc(&io->pending); | |
570 | } | |
571 | ||
1da177e4 LT |
572 | /* |
573 | * One of the bios was finished. Check for completion of | |
574 | * the whole request and correctly clean up the buffer. | |
393b47ef | 575 | * If base_io is set, wait for the last fragment to complete. |
1da177e4 | 576 | */ |
5742fd77 | 577 | static void crypt_dec_pending(struct dm_crypt_io *io) |
1da177e4 | 578 | { |
5742fd77 | 579 | struct crypt_config *cc = io->target->private; |
b35f8caa MB |
580 | struct bio *base_bio = io->base_bio; |
581 | struct dm_crypt_io *base_io = io->base_io; | |
582 | int error = io->error; | |
1da177e4 LT |
583 | |
584 | if (!atomic_dec_and_test(&io->pending)) | |
585 | return; | |
586 | ||
b35f8caa MB |
587 | mempool_free(io, cc->io_pool); |
588 | ||
589 | if (likely(!base_io)) | |
590 | bio_endio(base_bio, error); | |
393b47ef | 591 | else { |
b35f8caa MB |
592 | if (error && !base_io->error) |
593 | base_io->error = error; | |
594 | crypt_dec_pending(base_io); | |
393b47ef | 595 | } |
1da177e4 LT |
596 | } |
597 | ||
598 | /* | |
cabf08e4 | 599 | * kcryptd/kcryptd_io: |
1da177e4 LT |
600 | * |
601 | * Needed because it would be very unwise to do decryption in an | |
23541d2d | 602 | * interrupt context. |
cabf08e4 MB |
603 | * |
604 | * kcryptd performs the actual encryption or decryption. | |
605 | * | |
606 | * kcryptd_io performs the IO submission. | |
607 | * | |
608 | * They must be separated as otherwise the final stages could be | |
609 | * starved by new requests which can block in the first stages due | |
610 | * to memory allocation. | |
1da177e4 | 611 | */ |
6712ecf8 | 612 | static void crypt_endio(struct bio *clone, int error) |
8b004457 | 613 | { |
028867ac | 614 | struct dm_crypt_io *io = clone->bi_private; |
8b004457 | 615 | struct crypt_config *cc = io->target->private; |
ee7a491e | 616 | unsigned rw = bio_data_dir(clone); |
8b004457 | 617 | |
adfe4770 MB |
618 | if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) |
619 | error = -EIO; | |
620 | ||
8b004457 | 621 | /* |
6712ecf8 | 622 | * free the processed pages |
8b004457 | 623 | */ |
ee7a491e | 624 | if (rw == WRITE) |
644bd2f0 | 625 | crypt_free_buffer_pages(cc, clone); |
8b004457 MB |
626 | |
627 | bio_put(clone); | |
8b004457 | 628 | |
ee7a491e MB |
629 | if (rw == READ && !error) { |
630 | kcryptd_queue_crypt(io); | |
631 | return; | |
632 | } | |
5742fd77 MB |
633 | |
634 | if (unlikely(error)) | |
635 | io->error = error; | |
636 | ||
637 | crypt_dec_pending(io); | |
8b004457 MB |
638 | } |
639 | ||
028867ac | 640 | static void clone_init(struct dm_crypt_io *io, struct bio *clone) |
8b004457 MB |
641 | { |
642 | struct crypt_config *cc = io->target->private; | |
643 | ||
644 | clone->bi_private = io; | |
645 | clone->bi_end_io = crypt_endio; | |
646 | clone->bi_bdev = cc->dev->bdev; | |
647 | clone->bi_rw = io->base_bio->bi_rw; | |
027581f3 | 648 | clone->bi_destructor = dm_crypt_bio_destructor; |
8b004457 MB |
649 | } |
650 | ||
4e4eef64 | 651 | static void kcryptd_io_read(struct dm_crypt_io *io) |
8b004457 MB |
652 | { |
653 | struct crypt_config *cc = io->target->private; | |
654 | struct bio *base_bio = io->base_bio; | |
655 | struct bio *clone; | |
93e605c2 | 656 | |
3e1a8bdd | 657 | crypt_inc_pending(io); |
8b004457 MB |
658 | |
659 | /* | |
660 | * The block layer might modify the bvec array, so always | |
661 | * copy the required bvecs because we need the original | |
662 | * one in order to decrypt the whole bio data *afterwards*. | |
663 | */ | |
6a24c718 | 664 | clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); |
93e605c2 | 665 | if (unlikely(!clone)) { |
5742fd77 MB |
666 | io->error = -ENOMEM; |
667 | crypt_dec_pending(io); | |
23541d2d | 668 | return; |
93e605c2 | 669 | } |
8b004457 MB |
670 | |
671 | clone_init(io, clone); | |
672 | clone->bi_idx = 0; | |
673 | clone->bi_vcnt = bio_segments(base_bio); | |
674 | clone->bi_size = base_bio->bi_size; | |
0c395b0f | 675 | clone->bi_sector = cc->start + io->sector; |
8b004457 MB |
676 | memcpy(clone->bi_io_vec, bio_iovec(base_bio), |
677 | sizeof(struct bio_vec) * clone->bi_vcnt); | |
8b004457 | 678 | |
93e605c2 | 679 | generic_make_request(clone); |
8b004457 MB |
680 | } |
681 | ||
4e4eef64 MB |
682 | static void kcryptd_io_write(struct dm_crypt_io *io) |
683 | { | |
95497a96 | 684 | struct bio *clone = io->ctx.bio_out; |
95497a96 | 685 | generic_make_request(clone); |
4e4eef64 MB |
686 | } |
687 | ||
395b167c AK |
688 | static void kcryptd_io(struct work_struct *work) |
689 | { | |
690 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); | |
691 | ||
692 | if (bio_data_dir(io->base_bio) == READ) | |
693 | kcryptd_io_read(io); | |
694 | else | |
695 | kcryptd_io_write(io); | |
696 | } | |
697 | ||
698 | static void kcryptd_queue_io(struct dm_crypt_io *io) | |
699 | { | |
700 | struct crypt_config *cc = io->target->private; | |
701 | ||
702 | INIT_WORK(&io->work, kcryptd_io); | |
703 | queue_work(cc->io_queue, &io->work); | |
704 | } | |
705 | ||
95497a96 MB |
706 | static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, |
707 | int error, int async) | |
4e4eef64 | 708 | { |
dec1cedf MB |
709 | struct bio *clone = io->ctx.bio_out; |
710 | struct crypt_config *cc = io->target->private; | |
711 | ||
712 | if (unlikely(error < 0)) { | |
713 | crypt_free_buffer_pages(cc, clone); | |
714 | bio_put(clone); | |
715 | io->error = -EIO; | |
6c031f41 | 716 | crypt_dec_pending(io); |
dec1cedf MB |
717 | return; |
718 | } | |
719 | ||
720 | /* crypt_convert should have filled the clone bio */ | |
721 | BUG_ON(io->ctx.idx_out < clone->bi_vcnt); | |
722 | ||
723 | clone->bi_sector = cc->start + io->sector; | |
899c95d3 | 724 | |
95497a96 MB |
725 | if (async) |
726 | kcryptd_queue_io(io); | |
1e37bb8e | 727 | else |
95497a96 | 728 | generic_make_request(clone); |
4e4eef64 MB |
729 | } |
730 | ||
fc5a5e9a | 731 | static void kcryptd_crypt_write_convert(struct dm_crypt_io *io) |
8b004457 MB |
732 | { |
733 | struct crypt_config *cc = io->target->private; | |
8b004457 | 734 | struct bio *clone; |
393b47ef | 735 | struct dm_crypt_io *new_io; |
c8081618 | 736 | int crypt_finished; |
933f01d4 | 737 | unsigned out_of_pages = 0; |
dec1cedf | 738 | unsigned remaining = io->base_bio->bi_size; |
b635b00e | 739 | sector_t sector = io->sector; |
dec1cedf | 740 | int r; |
8b004457 | 741 | |
fc5a5e9a MB |
742 | /* |
743 | * Prevent io from disappearing until this function completes. | |
744 | */ | |
745 | crypt_inc_pending(io); | |
b635b00e | 746 | crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector); |
fc5a5e9a | 747 | |
93e605c2 MB |
748 | /* |
749 | * The allocated buffers can be smaller than the whole bio, | |
750 | * so repeat the whole process until all the data can be handled. | |
751 | */ | |
752 | while (remaining) { | |
933f01d4 | 753 | clone = crypt_alloc_buffer(io, remaining, &out_of_pages); |
23541d2d | 754 | if (unlikely(!clone)) { |
5742fd77 | 755 | io->error = -ENOMEM; |
fc5a5e9a | 756 | break; |
23541d2d | 757 | } |
93e605c2 | 758 | |
53017030 MB |
759 | io->ctx.bio_out = clone; |
760 | io->ctx.idx_out = 0; | |
93e605c2 | 761 | |
dec1cedf | 762 | remaining -= clone->bi_size; |
b635b00e | 763 | sector += bio_sectors(clone); |
93e605c2 | 764 | |
4e594098 | 765 | crypt_inc_pending(io); |
dec1cedf | 766 | r = crypt_convert(cc, &io->ctx); |
c8081618 | 767 | crypt_finished = atomic_dec_and_test(&io->ctx.pending); |
f97380bc | 768 | |
c8081618 MB |
769 | /* Encryption was already finished, submit io now */ |
770 | if (crypt_finished) { | |
3a7f6c99 | 771 | kcryptd_crypt_write_io_submit(io, r, 0); |
c8081618 MB |
772 | |
773 | /* | |
774 | * If there was an error, do not try next fragments. | |
775 | * For async, error is processed in async handler. | |
776 | */ | |
6c031f41 | 777 | if (unlikely(r < 0)) |
fc5a5e9a | 778 | break; |
b635b00e MB |
779 | |
780 | io->sector = sector; | |
4e594098 | 781 | } |
93e605c2 | 782 | |
933f01d4 MB |
783 | /* |
784 | * Out of memory -> run queues | |
785 | * But don't wait if split was due to the io size restriction | |
786 | */ | |
787 | if (unlikely(out_of_pages)) | |
8aa7e847 | 788 | congestion_wait(BLK_RW_ASYNC, HZ/100); |
933f01d4 | 789 | |
393b47ef MB |
790 | /* |
791 | * With async crypto it is unsafe to share the crypto context | |
792 | * between fragments, so switch to a new dm_crypt_io structure. | |
793 | */ | |
794 | if (unlikely(!crypt_finished && remaining)) { | |
795 | new_io = crypt_io_alloc(io->target, io->base_bio, | |
796 | sector); | |
797 | crypt_inc_pending(new_io); | |
798 | crypt_convert_init(cc, &new_io->ctx, NULL, | |
799 | io->base_bio, sector); | |
800 | new_io->ctx.idx_in = io->ctx.idx_in; | |
801 | new_io->ctx.offset_in = io->ctx.offset_in; | |
802 | ||
803 | /* | |
804 | * Fragments after the first use the base_io | |
805 | * pending count. | |
806 | */ | |
807 | if (!io->base_io) | |
808 | new_io->base_io = io; | |
809 | else { | |
810 | new_io->base_io = io->base_io; | |
811 | crypt_inc_pending(io->base_io); | |
812 | crypt_dec_pending(io); | |
813 | } | |
814 | ||
815 | io = new_io; | |
816 | } | |
93e605c2 | 817 | } |
899c95d3 MB |
818 | |
819 | crypt_dec_pending(io); | |
84131db6 MB |
820 | } |
821 | ||
4e4eef64 | 822 | static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error) |
5742fd77 MB |
823 | { |
824 | if (unlikely(error < 0)) | |
825 | io->error = -EIO; | |
826 | ||
827 | crypt_dec_pending(io); | |
828 | } | |
829 | ||
4e4eef64 | 830 | static void kcryptd_crypt_read_convert(struct dm_crypt_io *io) |
8b004457 MB |
831 | { |
832 | struct crypt_config *cc = io->target->private; | |
5742fd77 | 833 | int r = 0; |
1da177e4 | 834 | |
3e1a8bdd | 835 | crypt_inc_pending(io); |
3a7f6c99 | 836 | |
53017030 | 837 | crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio, |
0c395b0f | 838 | io->sector); |
1da177e4 | 839 | |
5742fd77 MB |
840 | r = crypt_convert(cc, &io->ctx); |
841 | ||
3f1e9070 | 842 | if (atomic_dec_and_test(&io->ctx.pending)) |
3a7f6c99 MB |
843 | kcryptd_crypt_read_done(io, r); |
844 | ||
845 | crypt_dec_pending(io); | |
1da177e4 LT |
846 | } |
847 | ||
95497a96 MB |
848 | static void kcryptd_async_done(struct crypto_async_request *async_req, |
849 | int error) | |
850 | { | |
b2174eeb HY |
851 | struct dm_crypt_request *dmreq = async_req->data; |
852 | struct convert_context *ctx = dmreq->ctx; | |
95497a96 MB |
853 | struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx); |
854 | struct crypt_config *cc = io->target->private; | |
855 | ||
856 | if (error == -EINPROGRESS) { | |
857 | complete(&ctx->restart); | |
858 | return; | |
859 | } | |
860 | ||
b2174eeb | 861 | mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool); |
95497a96 MB |
862 | |
863 | if (!atomic_dec_and_test(&ctx->pending)) | |
864 | return; | |
865 | ||
866 | if (bio_data_dir(io->base_bio) == READ) | |
867 | kcryptd_crypt_read_done(io, error); | |
868 | else | |
869 | kcryptd_crypt_write_io_submit(io, error, 1); | |
870 | } | |
871 | ||
395b167c | 872 | static void kcryptd_crypt(struct work_struct *work) |
1da177e4 | 873 | { |
028867ac | 874 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
8b004457 | 875 | |
cabf08e4 | 876 | if (bio_data_dir(io->base_bio) == READ) |
395b167c | 877 | kcryptd_crypt_read_convert(io); |
4e4eef64 | 878 | else |
395b167c | 879 | kcryptd_crypt_write_convert(io); |
cabf08e4 MB |
880 | } |
881 | ||
395b167c | 882 | static void kcryptd_queue_crypt(struct dm_crypt_io *io) |
cabf08e4 | 883 | { |
395b167c | 884 | struct crypt_config *cc = io->target->private; |
cabf08e4 | 885 | |
395b167c AK |
886 | INIT_WORK(&io->work, kcryptd_crypt); |
887 | queue_work(cc->crypt_queue, &io->work); | |
1da177e4 LT |
888 | } |
889 | ||
890 | /* | |
891 | * Decode key from its hex representation | |
892 | */ | |
893 | static int crypt_decode_key(u8 *key, char *hex, unsigned int size) | |
894 | { | |
895 | char buffer[3]; | |
896 | char *endp; | |
897 | unsigned int i; | |
898 | ||
899 | buffer[2] = '\0'; | |
900 | ||
8b004457 | 901 | for (i = 0; i < size; i++) { |
1da177e4 LT |
902 | buffer[0] = *hex++; |
903 | buffer[1] = *hex++; | |
904 | ||
905 | key[i] = (u8)simple_strtoul(buffer, &endp, 16); | |
906 | ||
907 | if (endp != &buffer[2]) | |
908 | return -EINVAL; | |
909 | } | |
910 | ||
911 | if (*hex != '\0') | |
912 | return -EINVAL; | |
913 | ||
914 | return 0; | |
915 | } | |
916 | ||
917 | /* | |
918 | * Encode key into its hex representation | |
919 | */ | |
920 | static void crypt_encode_key(char *hex, u8 *key, unsigned int size) | |
921 | { | |
922 | unsigned int i; | |
923 | ||
8b004457 | 924 | for (i = 0; i < size; i++) { |
1da177e4 LT |
925 | sprintf(hex, "%02x", *key); |
926 | hex += 2; | |
927 | key++; | |
928 | } | |
929 | } | |
930 | ||
e48d4bbf MB |
931 | static int crypt_set_key(struct crypt_config *cc, char *key) |
932 | { | |
933 | unsigned key_size = strlen(key) >> 1; | |
934 | ||
935 | if (cc->key_size && cc->key_size != key_size) | |
936 | return -EINVAL; | |
937 | ||
938 | cc->key_size = key_size; /* initial settings */ | |
939 | ||
940 | if ((!key_size && strcmp(key, "-")) || | |
d469f841 | 941 | (key_size && crypt_decode_key(cc->key, key, key_size) < 0)) |
e48d4bbf MB |
942 | return -EINVAL; |
943 | ||
944 | set_bit(DM_CRYPT_KEY_VALID, &cc->flags); | |
945 | ||
0b430958 | 946 | return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size); |
e48d4bbf MB |
947 | } |
948 | ||
949 | static int crypt_wipe_key(struct crypt_config *cc) | |
950 | { | |
951 | clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); | |
952 | memset(&cc->key, 0, cc->key_size * sizeof(u8)); | |
0b430958 | 953 | return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size); |
e48d4bbf MB |
954 | } |
955 | ||
1da177e4 LT |
956 | /* |
957 | * Construct an encryption mapping: | |
958 | * <cipher> <key> <iv_offset> <dev_path> <start> | |
959 | */ | |
960 | static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
961 | { | |
962 | struct crypt_config *cc; | |
3a7f6c99 | 963 | struct crypto_ablkcipher *tfm; |
1da177e4 LT |
964 | char *tmp; |
965 | char *cipher; | |
966 | char *chainmode; | |
967 | char *ivmode; | |
968 | char *ivopts; | |
1da177e4 | 969 | unsigned int key_size; |
4ee218cd | 970 | unsigned long long tmpll; |
1da177e4 LT |
971 | |
972 | if (argc != 5) { | |
72d94861 | 973 | ti->error = "Not enough arguments"; |
1da177e4 LT |
974 | return -EINVAL; |
975 | } | |
976 | ||
977 | tmp = argv[0]; | |
978 | cipher = strsep(&tmp, "-"); | |
979 | chainmode = strsep(&tmp, "-"); | |
980 | ivopts = strsep(&tmp, "-"); | |
981 | ivmode = strsep(&ivopts, ":"); | |
982 | ||
983 | if (tmp) | |
72d94861 | 984 | DMWARN("Unexpected additional cipher options"); |
1da177e4 LT |
985 | |
986 | key_size = strlen(argv[1]) >> 1; | |
987 | ||
e48d4bbf | 988 | cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); |
1da177e4 LT |
989 | if (cc == NULL) { |
990 | ti->error = | |
72d94861 | 991 | "Cannot allocate transparent encryption context"; |
1da177e4 LT |
992 | return -ENOMEM; |
993 | } | |
994 | ||
06fe9fb4 | 995 | /* Compatibility mode for old dm-crypt cipher strings */ |
1da177e4 LT |
996 | if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { |
997 | chainmode = "cbc"; | |
998 | ivmode = "plain"; | |
999 | } | |
1000 | ||
d1806f6a HX |
1001 | if (strcmp(chainmode, "ecb") && !ivmode) { |
1002 | ti->error = "This chaining mode requires an IV mechanism"; | |
636d5786 | 1003 | goto bad_cipher; |
1da177e4 LT |
1004 | } |
1005 | ||
d469f841 MB |
1006 | if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", |
1007 | chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) { | |
d1806f6a | 1008 | ti->error = "Chain mode + cipher name is too long"; |
636d5786 | 1009 | goto bad_cipher; |
1da177e4 LT |
1010 | } |
1011 | ||
3a7f6c99 | 1012 | tfm = crypto_alloc_ablkcipher(cc->cipher, 0, 0); |
d1806f6a | 1013 | if (IS_ERR(tfm)) { |
72d94861 | 1014 | ti->error = "Error allocating crypto tfm"; |
636d5786 | 1015 | goto bad_cipher; |
1da177e4 | 1016 | } |
1da177e4 | 1017 | |
d1806f6a HX |
1018 | strcpy(cc->cipher, cipher); |
1019 | strcpy(cc->chainmode, chainmode); | |
1da177e4 LT |
1020 | cc->tfm = tfm; |
1021 | ||
0b430958 MB |
1022 | if (crypt_set_key(cc, argv[1]) < 0) { |
1023 | ti->error = "Error decoding and setting key"; | |
1024 | goto bad_ivmode; | |
1025 | } | |
1026 | ||
1da177e4 | 1027 | /* |
48527fa7 | 1028 | * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi". |
1da177e4 LT |
1029 | * See comments at iv code |
1030 | */ | |
1031 | ||
1032 | if (ivmode == NULL) | |
1033 | cc->iv_gen_ops = NULL; | |
1034 | else if (strcmp(ivmode, "plain") == 0) | |
1035 | cc->iv_gen_ops = &crypt_iv_plain_ops; | |
1036 | else if (strcmp(ivmode, "essiv") == 0) | |
1037 | cc->iv_gen_ops = &crypt_iv_essiv_ops; | |
48527fa7 RS |
1038 | else if (strcmp(ivmode, "benbi") == 0) |
1039 | cc->iv_gen_ops = &crypt_iv_benbi_ops; | |
46b47730 LN |
1040 | else if (strcmp(ivmode, "null") == 0) |
1041 | cc->iv_gen_ops = &crypt_iv_null_ops; | |
1da177e4 | 1042 | else { |
72d94861 | 1043 | ti->error = "Invalid IV mode"; |
636d5786 | 1044 | goto bad_ivmode; |
1da177e4 LT |
1045 | } |
1046 | ||
1047 | if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && | |
1048 | cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) | |
636d5786 | 1049 | goto bad_ivmode; |
1da177e4 | 1050 | |
3a7f6c99 | 1051 | cc->iv_size = crypto_ablkcipher_ivsize(tfm); |
d1806f6a | 1052 | if (cc->iv_size) |
1da177e4 | 1053 | /* at least a 64 bit sector number should fit in our buffer */ |
d1806f6a | 1054 | cc->iv_size = max(cc->iv_size, |
d469f841 | 1055 | (unsigned int)(sizeof(u64) / sizeof(u8))); |
1da177e4 | 1056 | else { |
1da177e4 | 1057 | if (cc->iv_gen_ops) { |
72d94861 | 1058 | DMWARN("Selected cipher does not support IVs"); |
1da177e4 LT |
1059 | if (cc->iv_gen_ops->dtr) |
1060 | cc->iv_gen_ops->dtr(cc); | |
1061 | cc->iv_gen_ops = NULL; | |
1062 | } | |
1063 | } | |
1064 | ||
93d2341c | 1065 | cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); |
1da177e4 | 1066 | if (!cc->io_pool) { |
72d94861 | 1067 | ti->error = "Cannot allocate crypt io mempool"; |
636d5786 | 1068 | goto bad_slab_pool; |
1da177e4 LT |
1069 | } |
1070 | ||
ddd42edf | 1071 | cc->dmreq_start = sizeof(struct ablkcipher_request); |
3a7f6c99 | 1072 | cc->dmreq_start += crypto_ablkcipher_reqsize(tfm); |
ddd42edf | 1073 | cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment()); |
3a7f6c99 MB |
1074 | cc->dmreq_start += crypto_ablkcipher_alignmask(tfm) & |
1075 | ~(crypto_tfm_ctx_alignment() - 1); | |
ddd42edf MB |
1076 | |
1077 | cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start + | |
1078 | sizeof(struct dm_crypt_request) + cc->iv_size); | |
1079 | if (!cc->req_pool) { | |
1080 | ti->error = "Cannot allocate crypt request mempool"; | |
1081 | goto bad_req_pool; | |
1082 | } | |
1083 | cc->req = NULL; | |
1084 | ||
a19b27ce | 1085 | cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); |
1da177e4 | 1086 | if (!cc->page_pool) { |
72d94861 | 1087 | ti->error = "Cannot allocate page mempool"; |
636d5786 | 1088 | goto bad_page_pool; |
1da177e4 LT |
1089 | } |
1090 | ||
bb799ca0 | 1091 | cc->bs = bioset_create(MIN_IOS, 0); |
6a24c718 MB |
1092 | if (!cc->bs) { |
1093 | ti->error = "Cannot allocate crypt bioset"; | |
1094 | goto bad_bs; | |
1095 | } | |
1096 | ||
4ee218cd | 1097 | if (sscanf(argv[2], "%llu", &tmpll) != 1) { |
72d94861 | 1098 | ti->error = "Invalid iv_offset sector"; |
636d5786 | 1099 | goto bad_device; |
1da177e4 | 1100 | } |
4ee218cd | 1101 | cc->iv_offset = tmpll; |
1da177e4 | 1102 | |
4ee218cd | 1103 | if (sscanf(argv[4], "%llu", &tmpll) != 1) { |
72d94861 | 1104 | ti->error = "Invalid device sector"; |
636d5786 | 1105 | goto bad_device; |
1da177e4 | 1106 | } |
4ee218cd | 1107 | cc->start = tmpll; |
1da177e4 LT |
1108 | |
1109 | if (dm_get_device(ti, argv[3], cc->start, ti->len, | |
d469f841 | 1110 | dm_table_get_mode(ti->table), &cc->dev)) { |
72d94861 | 1111 | ti->error = "Device lookup failed"; |
636d5786 | 1112 | goto bad_device; |
1da177e4 LT |
1113 | } |
1114 | ||
1115 | if (ivmode && cc->iv_gen_ops) { | |
1116 | if (ivopts) | |
1117 | *(ivopts - 1) = ':'; | |
1118 | cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); | |
1119 | if (!cc->iv_mode) { | |
72d94861 | 1120 | ti->error = "Error kmallocing iv_mode string"; |
636d5786 | 1121 | goto bad_ivmode_string; |
1da177e4 LT |
1122 | } |
1123 | strcpy(cc->iv_mode, ivmode); | |
1124 | } else | |
1125 | cc->iv_mode = NULL; | |
1126 | ||
cabf08e4 MB |
1127 | cc->io_queue = create_singlethread_workqueue("kcryptd_io"); |
1128 | if (!cc->io_queue) { | |
1129 | ti->error = "Couldn't create kcryptd io queue"; | |
1130 | goto bad_io_queue; | |
1131 | } | |
1132 | ||
1133 | cc->crypt_queue = create_singlethread_workqueue("kcryptd"); | |
1134 | if (!cc->crypt_queue) { | |
9934a8be | 1135 | ti->error = "Couldn't create kcryptd queue"; |
cabf08e4 | 1136 | goto bad_crypt_queue; |
9934a8be MB |
1137 | } |
1138 | ||
647c7db1 | 1139 | ti->num_flush_requests = 1; |
1da177e4 LT |
1140 | ti->private = cc; |
1141 | return 0; | |
1142 | ||
cabf08e4 MB |
1143 | bad_crypt_queue: |
1144 | destroy_workqueue(cc->io_queue); | |
1145 | bad_io_queue: | |
9934a8be | 1146 | kfree(cc->iv_mode); |
636d5786 | 1147 | bad_ivmode_string: |
55b42c5a | 1148 | dm_put_device(ti, cc->dev); |
636d5786 | 1149 | bad_device: |
6a24c718 MB |
1150 | bioset_free(cc->bs); |
1151 | bad_bs: | |
1da177e4 | 1152 | mempool_destroy(cc->page_pool); |
636d5786 | 1153 | bad_page_pool: |
ddd42edf MB |
1154 | mempool_destroy(cc->req_pool); |
1155 | bad_req_pool: | |
1da177e4 | 1156 | mempool_destroy(cc->io_pool); |
636d5786 | 1157 | bad_slab_pool: |
1da177e4 LT |
1158 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
1159 | cc->iv_gen_ops->dtr(cc); | |
636d5786 | 1160 | bad_ivmode: |
3a7f6c99 | 1161 | crypto_free_ablkcipher(tfm); |
636d5786 | 1162 | bad_cipher: |
9d3520a3 | 1163 | /* Must zero key material before freeing */ |
b81d6cf7 | 1164 | kzfree(cc); |
1da177e4 LT |
1165 | return -EINVAL; |
1166 | } | |
1167 | ||
1168 | static void crypt_dtr(struct dm_target *ti) | |
1169 | { | |
1170 | struct crypt_config *cc = (struct crypt_config *) ti->private; | |
1171 | ||
cabf08e4 MB |
1172 | destroy_workqueue(cc->io_queue); |
1173 | destroy_workqueue(cc->crypt_queue); | |
80b16c19 | 1174 | |
ddd42edf MB |
1175 | if (cc->req) |
1176 | mempool_free(cc->req, cc->req_pool); | |
1177 | ||
6a24c718 | 1178 | bioset_free(cc->bs); |
1da177e4 | 1179 | mempool_destroy(cc->page_pool); |
ddd42edf | 1180 | mempool_destroy(cc->req_pool); |
1da177e4 LT |
1181 | mempool_destroy(cc->io_pool); |
1182 | ||
990a8baf | 1183 | kfree(cc->iv_mode); |
1da177e4 LT |
1184 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
1185 | cc->iv_gen_ops->dtr(cc); | |
3a7f6c99 | 1186 | crypto_free_ablkcipher(cc->tfm); |
1da177e4 | 1187 | dm_put_device(ti, cc->dev); |
9d3520a3 SR |
1188 | |
1189 | /* Must zero key material before freeing */ | |
b81d6cf7 | 1190 | kzfree(cc); |
1da177e4 LT |
1191 | } |
1192 | ||
1da177e4 LT |
1193 | static int crypt_map(struct dm_target *ti, struct bio *bio, |
1194 | union map_info *map_context) | |
1195 | { | |
028867ac | 1196 | struct dm_crypt_io *io; |
647c7db1 MP |
1197 | struct crypt_config *cc; |
1198 | ||
1199 | if (unlikely(bio_empty_barrier(bio))) { | |
1200 | cc = ti->private; | |
1201 | bio->bi_bdev = cc->dev->bdev; | |
1202 | return DM_MAPIO_REMAPPED; | |
1203 | } | |
1da177e4 | 1204 | |
dc440d1e | 1205 | io = crypt_io_alloc(ti, bio, bio->bi_sector - ti->begin); |
cabf08e4 MB |
1206 | |
1207 | if (bio_data_dir(io->base_bio) == READ) | |
1208 | kcryptd_queue_io(io); | |
1209 | else | |
1210 | kcryptd_queue_crypt(io); | |
1da177e4 | 1211 | |
d2a7ad29 | 1212 | return DM_MAPIO_SUBMITTED; |
1da177e4 LT |
1213 | } |
1214 | ||
1215 | static int crypt_status(struct dm_target *ti, status_type_t type, | |
1216 | char *result, unsigned int maxlen) | |
1217 | { | |
1218 | struct crypt_config *cc = (struct crypt_config *) ti->private; | |
1da177e4 LT |
1219 | unsigned int sz = 0; |
1220 | ||
1221 | switch (type) { | |
1222 | case STATUSTYPE_INFO: | |
1223 | result[0] = '\0'; | |
1224 | break; | |
1225 | ||
1226 | case STATUSTYPE_TABLE: | |
1da177e4 | 1227 | if (cc->iv_mode) |
37af6560 CS |
1228 | DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode, |
1229 | cc->iv_mode); | |
1da177e4 | 1230 | else |
37af6560 | 1231 | DMEMIT("%s-%s ", cc->cipher, cc->chainmode); |
1da177e4 LT |
1232 | |
1233 | if (cc->key_size > 0) { | |
1234 | if ((maxlen - sz) < ((cc->key_size << 1) + 1)) | |
1235 | return -ENOMEM; | |
1236 | ||
1237 | crypt_encode_key(result + sz, cc->key, cc->key_size); | |
1238 | sz += cc->key_size << 1; | |
1239 | } else { | |
1240 | if (sz >= maxlen) | |
1241 | return -ENOMEM; | |
1242 | result[sz++] = '-'; | |
1243 | } | |
1244 | ||
4ee218cd AM |
1245 | DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, |
1246 | cc->dev->name, (unsigned long long)cc->start); | |
1da177e4 LT |
1247 | break; |
1248 | } | |
1249 | return 0; | |
1250 | } | |
1251 | ||
e48d4bbf MB |
1252 | static void crypt_postsuspend(struct dm_target *ti) |
1253 | { | |
1254 | struct crypt_config *cc = ti->private; | |
1255 | ||
1256 | set_bit(DM_CRYPT_SUSPENDED, &cc->flags); | |
1257 | } | |
1258 | ||
1259 | static int crypt_preresume(struct dm_target *ti) | |
1260 | { | |
1261 | struct crypt_config *cc = ti->private; | |
1262 | ||
1263 | if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { | |
1264 | DMERR("aborting resume - crypt key is not set."); | |
1265 | return -EAGAIN; | |
1266 | } | |
1267 | ||
1268 | return 0; | |
1269 | } | |
1270 | ||
1271 | static void crypt_resume(struct dm_target *ti) | |
1272 | { | |
1273 | struct crypt_config *cc = ti->private; | |
1274 | ||
1275 | clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); | |
1276 | } | |
1277 | ||
1278 | /* Message interface | |
1279 | * key set <key> | |
1280 | * key wipe | |
1281 | */ | |
1282 | static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) | |
1283 | { | |
1284 | struct crypt_config *cc = ti->private; | |
1285 | ||
1286 | if (argc < 2) | |
1287 | goto error; | |
1288 | ||
1289 | if (!strnicmp(argv[0], MESG_STR("key"))) { | |
1290 | if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { | |
1291 | DMWARN("not suspended during key manipulation."); | |
1292 | return -EINVAL; | |
1293 | } | |
1294 | if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) | |
1295 | return crypt_set_key(cc, argv[2]); | |
1296 | if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) | |
1297 | return crypt_wipe_key(cc); | |
1298 | } | |
1299 | ||
1300 | error: | |
1301 | DMWARN("unrecognised message received."); | |
1302 | return -EINVAL; | |
1303 | } | |
1304 | ||
d41e26b9 MB |
1305 | static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm, |
1306 | struct bio_vec *biovec, int max_size) | |
1307 | { | |
1308 | struct crypt_config *cc = ti->private; | |
1309 | struct request_queue *q = bdev_get_queue(cc->dev->bdev); | |
1310 | ||
1311 | if (!q->merge_bvec_fn) | |
1312 | return max_size; | |
1313 | ||
1314 | bvm->bi_bdev = cc->dev->bdev; | |
1315 | bvm->bi_sector = cc->start + bvm->bi_sector - ti->begin; | |
1316 | ||
1317 | return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); | |
1318 | } | |
1319 | ||
af4874e0 MS |
1320 | static int crypt_iterate_devices(struct dm_target *ti, |
1321 | iterate_devices_callout_fn fn, void *data) | |
1322 | { | |
1323 | struct crypt_config *cc = ti->private; | |
1324 | ||
5dea271b | 1325 | return fn(ti, cc->dev, cc->start, ti->len, data); |
af4874e0 MS |
1326 | } |
1327 | ||
1da177e4 LT |
1328 | static struct target_type crypt_target = { |
1329 | .name = "crypt", | |
af4874e0 | 1330 | .version = {1, 7, 0}, |
1da177e4 LT |
1331 | .module = THIS_MODULE, |
1332 | .ctr = crypt_ctr, | |
1333 | .dtr = crypt_dtr, | |
1334 | .map = crypt_map, | |
1335 | .status = crypt_status, | |
e48d4bbf MB |
1336 | .postsuspend = crypt_postsuspend, |
1337 | .preresume = crypt_preresume, | |
1338 | .resume = crypt_resume, | |
1339 | .message = crypt_message, | |
d41e26b9 | 1340 | .merge = crypt_merge, |
af4874e0 | 1341 | .iterate_devices = crypt_iterate_devices, |
1da177e4 LT |
1342 | }; |
1343 | ||
1344 | static int __init dm_crypt_init(void) | |
1345 | { | |
1346 | int r; | |
1347 | ||
028867ac | 1348 | _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0); |
1da177e4 LT |
1349 | if (!_crypt_io_pool) |
1350 | return -ENOMEM; | |
1351 | ||
1da177e4 LT |
1352 | r = dm_register_target(&crypt_target); |
1353 | if (r < 0) { | |
72d94861 | 1354 | DMERR("register failed %d", r); |
9934a8be | 1355 | kmem_cache_destroy(_crypt_io_pool); |
1da177e4 LT |
1356 | } |
1357 | ||
1da177e4 LT |
1358 | return r; |
1359 | } | |
1360 | ||
1361 | static void __exit dm_crypt_exit(void) | |
1362 | { | |
10d3bd09 | 1363 | dm_unregister_target(&crypt_target); |
1da177e4 LT |
1364 | kmem_cache_destroy(_crypt_io_pool); |
1365 | } | |
1366 | ||
1367 | module_init(dm_crypt_init); | |
1368 | module_exit(dm_crypt_exit); | |
1369 | ||
1370 | MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); | |
1371 | MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); | |
1372 | MODULE_LICENSE("GPL"); |