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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Christophe Saout <christophe@saout.de> | |
3 | * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> | |
e48d4bbf | 4 | * Copyright (C) 2006 Red Hat, Inc. All rights reserved. |
1da177e4 LT |
5 | * |
6 | * This file is released under the GPL. | |
7 | */ | |
8 | ||
d1806f6a | 9 | #include <linux/err.h> |
1da177e4 LT |
10 | #include <linux/module.h> |
11 | #include <linux/init.h> | |
12 | #include <linux/kernel.h> | |
13 | #include <linux/bio.h> | |
14 | #include <linux/blkdev.h> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/crypto.h> | |
18 | #include <linux/workqueue.h> | |
3fcfab16 | 19 | #include <linux/backing-dev.h> |
1da177e4 | 20 | #include <asm/atomic.h> |
378f058c | 21 | #include <linux/scatterlist.h> |
1da177e4 | 22 | #include <asm/page.h> |
48527fa7 | 23 | #include <asm/unaligned.h> |
1da177e4 LT |
24 | |
25 | #include "dm.h" | |
26 | ||
72d94861 | 27 | #define DM_MSG_PREFIX "crypt" |
e48d4bbf | 28 | #define MESG_STR(x) x, sizeof(x) |
1da177e4 LT |
29 | |
30 | /* | |
31 | * per bio private data | |
32 | */ | |
028867ac | 33 | struct dm_crypt_io { |
1da177e4 | 34 | struct dm_target *target; |
8b004457 | 35 | struct bio *base_bio; |
1da177e4 LT |
36 | struct work_struct work; |
37 | atomic_t pending; | |
38 | int error; | |
39 | }; | |
40 | ||
41 | /* | |
42 | * context holding the current state of a multi-part conversion | |
43 | */ | |
44 | struct convert_context { | |
45 | struct bio *bio_in; | |
46 | struct bio *bio_out; | |
47 | unsigned int offset_in; | |
48 | unsigned int offset_out; | |
49 | unsigned int idx_in; | |
50 | unsigned int idx_out; | |
51 | sector_t sector; | |
52 | int write; | |
53 | }; | |
54 | ||
55 | struct crypt_config; | |
56 | ||
57 | struct crypt_iv_operations { | |
58 | int (*ctr)(struct crypt_config *cc, struct dm_target *ti, | |
d469f841 | 59 | const char *opts); |
1da177e4 LT |
60 | void (*dtr)(struct crypt_config *cc); |
61 | const char *(*status)(struct crypt_config *cc); | |
62 | int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); | |
63 | }; | |
64 | ||
65 | /* | |
66 | * Crypt: maps a linear range of a block device | |
67 | * and encrypts / decrypts at the same time. | |
68 | */ | |
e48d4bbf | 69 | enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID }; |
1da177e4 LT |
70 | struct crypt_config { |
71 | struct dm_dev *dev; | |
72 | sector_t start; | |
73 | ||
74 | /* | |
75 | * pool for per bio private data and | |
76 | * for encryption buffer pages | |
77 | */ | |
78 | mempool_t *io_pool; | |
79 | mempool_t *page_pool; | |
6a24c718 | 80 | struct bio_set *bs; |
1da177e4 | 81 | |
cabf08e4 MB |
82 | struct workqueue_struct *io_queue; |
83 | struct workqueue_struct *crypt_queue; | |
1da177e4 LT |
84 | /* |
85 | * crypto related data | |
86 | */ | |
87 | struct crypt_iv_operations *iv_gen_ops; | |
88 | char *iv_mode; | |
79066ad3 HX |
89 | union { |
90 | struct crypto_cipher *essiv_tfm; | |
91 | int benbi_shift; | |
92 | } iv_gen_private; | |
1da177e4 LT |
93 | sector_t iv_offset; |
94 | unsigned int iv_size; | |
95 | ||
d1806f6a HX |
96 | char cipher[CRYPTO_MAX_ALG_NAME]; |
97 | char chainmode[CRYPTO_MAX_ALG_NAME]; | |
98 | struct crypto_blkcipher *tfm; | |
e48d4bbf | 99 | unsigned long flags; |
1da177e4 LT |
100 | unsigned int key_size; |
101 | u8 key[0]; | |
102 | }; | |
103 | ||
6a24c718 | 104 | #define MIN_IOS 16 |
1da177e4 LT |
105 | #define MIN_POOL_PAGES 32 |
106 | #define MIN_BIO_PAGES 8 | |
107 | ||
e18b890b | 108 | static struct kmem_cache *_crypt_io_pool; |
1da177e4 | 109 | |
028867ac | 110 | static void clone_init(struct dm_crypt_io *, struct bio *); |
027581f3 | 111 | |
1da177e4 LT |
112 | /* |
113 | * Different IV generation algorithms: | |
114 | * | |
3c164bd8 | 115 | * plain: the initial vector is the 32-bit little-endian version of the sector |
3a4fa0a2 | 116 | * number, padded with zeros if necessary. |
1da177e4 | 117 | * |
3c164bd8 RS |
118 | * essiv: "encrypted sector|salt initial vector", the sector number is |
119 | * encrypted with the bulk cipher using a salt as key. The salt | |
120 | * should be derived from the bulk cipher's key via hashing. | |
1da177e4 | 121 | * |
48527fa7 RS |
122 | * benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1 |
123 | * (needed for LRW-32-AES and possible other narrow block modes) | |
124 | * | |
46b47730 LN |
125 | * null: the initial vector is always zero. Provides compatibility with |
126 | * obsolete loop_fish2 devices. Do not use for new devices. | |
127 | * | |
1da177e4 LT |
128 | * plumb: unimplemented, see: |
129 | * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 | |
130 | */ | |
131 | ||
132 | static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) | |
133 | { | |
134 | memset(iv, 0, cc->iv_size); | |
135 | *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); | |
136 | ||
137 | return 0; | |
138 | } | |
139 | ||
140 | static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, | |
d469f841 | 141 | const char *opts) |
1da177e4 | 142 | { |
d1806f6a | 143 | struct crypto_cipher *essiv_tfm; |
35058687 HX |
144 | struct crypto_hash *hash_tfm; |
145 | struct hash_desc desc; | |
1da177e4 LT |
146 | struct scatterlist sg; |
147 | unsigned int saltsize; | |
148 | u8 *salt; | |
d1806f6a | 149 | int err; |
1da177e4 LT |
150 | |
151 | if (opts == NULL) { | |
72d94861 | 152 | ti->error = "Digest algorithm missing for ESSIV mode"; |
1da177e4 LT |
153 | return -EINVAL; |
154 | } | |
155 | ||
156 | /* Hash the cipher key with the given hash algorithm */ | |
35058687 HX |
157 | hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC); |
158 | if (IS_ERR(hash_tfm)) { | |
72d94861 | 159 | ti->error = "Error initializing ESSIV hash"; |
35058687 | 160 | return PTR_ERR(hash_tfm); |
1da177e4 LT |
161 | } |
162 | ||
35058687 | 163 | saltsize = crypto_hash_digestsize(hash_tfm); |
1da177e4 LT |
164 | salt = kmalloc(saltsize, GFP_KERNEL); |
165 | if (salt == NULL) { | |
72d94861 | 166 | ti->error = "Error kmallocing salt storage in ESSIV"; |
35058687 | 167 | crypto_free_hash(hash_tfm); |
1da177e4 LT |
168 | return -ENOMEM; |
169 | } | |
170 | ||
68e3f5dd | 171 | sg_init_one(&sg, cc->key, cc->key_size); |
35058687 HX |
172 | desc.tfm = hash_tfm; |
173 | desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP; | |
174 | err = crypto_hash_digest(&desc, &sg, cc->key_size, salt); | |
175 | crypto_free_hash(hash_tfm); | |
176 | ||
177 | if (err) { | |
178 | ti->error = "Error calculating hash in ESSIV"; | |
815f9e32 | 179 | kfree(salt); |
35058687 HX |
180 | return err; |
181 | } | |
1da177e4 LT |
182 | |
183 | /* Setup the essiv_tfm with the given salt */ | |
d1806f6a HX |
184 | essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
185 | if (IS_ERR(essiv_tfm)) { | |
72d94861 | 186 | ti->error = "Error allocating crypto tfm for ESSIV"; |
1da177e4 | 187 | kfree(salt); |
d1806f6a | 188 | return PTR_ERR(essiv_tfm); |
1da177e4 | 189 | } |
d1806f6a HX |
190 | if (crypto_cipher_blocksize(essiv_tfm) != |
191 | crypto_blkcipher_ivsize(cc->tfm)) { | |
72d94861 | 192 | ti->error = "Block size of ESSIV cipher does " |
d469f841 | 193 | "not match IV size of block cipher"; |
d1806f6a | 194 | crypto_free_cipher(essiv_tfm); |
1da177e4 LT |
195 | kfree(salt); |
196 | return -EINVAL; | |
197 | } | |
d1806f6a HX |
198 | err = crypto_cipher_setkey(essiv_tfm, salt, saltsize); |
199 | if (err) { | |
72d94861 | 200 | ti->error = "Failed to set key for ESSIV cipher"; |
d1806f6a | 201 | crypto_free_cipher(essiv_tfm); |
1da177e4 | 202 | kfree(salt); |
d1806f6a | 203 | return err; |
1da177e4 LT |
204 | } |
205 | kfree(salt); | |
206 | ||
79066ad3 | 207 | cc->iv_gen_private.essiv_tfm = essiv_tfm; |
1da177e4 LT |
208 | return 0; |
209 | } | |
210 | ||
211 | static void crypt_iv_essiv_dtr(struct crypt_config *cc) | |
212 | { | |
79066ad3 HX |
213 | crypto_free_cipher(cc->iv_gen_private.essiv_tfm); |
214 | cc->iv_gen_private.essiv_tfm = NULL; | |
1da177e4 LT |
215 | } |
216 | ||
217 | static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) | |
218 | { | |
1da177e4 LT |
219 | memset(iv, 0, cc->iv_size); |
220 | *(u64 *)iv = cpu_to_le64(sector); | |
79066ad3 | 221 | crypto_cipher_encrypt_one(cc->iv_gen_private.essiv_tfm, iv, iv); |
1da177e4 LT |
222 | return 0; |
223 | } | |
224 | ||
48527fa7 RS |
225 | static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti, |
226 | const char *opts) | |
227 | { | |
228 | unsigned int bs = crypto_blkcipher_blocksize(cc->tfm); | |
f0d1b0b3 | 229 | int log = ilog2(bs); |
48527fa7 RS |
230 | |
231 | /* we need to calculate how far we must shift the sector count | |
232 | * to get the cipher block count, we use this shift in _gen */ | |
233 | ||
234 | if (1 << log != bs) { | |
235 | ti->error = "cypher blocksize is not a power of 2"; | |
236 | return -EINVAL; | |
237 | } | |
238 | ||
239 | if (log > 9) { | |
240 | ti->error = "cypher blocksize is > 512"; | |
241 | return -EINVAL; | |
242 | } | |
243 | ||
79066ad3 | 244 | cc->iv_gen_private.benbi_shift = 9 - log; |
48527fa7 RS |
245 | |
246 | return 0; | |
247 | } | |
248 | ||
249 | static void crypt_iv_benbi_dtr(struct crypt_config *cc) | |
250 | { | |
48527fa7 RS |
251 | } |
252 | ||
253 | static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector) | |
254 | { | |
79066ad3 HX |
255 | __be64 val; |
256 | ||
48527fa7 | 257 | memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */ |
79066ad3 HX |
258 | |
259 | val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi_shift) + 1); | |
260 | put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64))); | |
48527fa7 | 261 | |
1da177e4 LT |
262 | return 0; |
263 | } | |
264 | ||
46b47730 LN |
265 | static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector) |
266 | { | |
267 | memset(iv, 0, cc->iv_size); | |
268 | ||
269 | return 0; | |
270 | } | |
271 | ||
1da177e4 LT |
272 | static struct crypt_iv_operations crypt_iv_plain_ops = { |
273 | .generator = crypt_iv_plain_gen | |
274 | }; | |
275 | ||
276 | static struct crypt_iv_operations crypt_iv_essiv_ops = { | |
277 | .ctr = crypt_iv_essiv_ctr, | |
278 | .dtr = crypt_iv_essiv_dtr, | |
279 | .generator = crypt_iv_essiv_gen | |
280 | }; | |
281 | ||
48527fa7 RS |
282 | static struct crypt_iv_operations crypt_iv_benbi_ops = { |
283 | .ctr = crypt_iv_benbi_ctr, | |
284 | .dtr = crypt_iv_benbi_dtr, | |
285 | .generator = crypt_iv_benbi_gen | |
286 | }; | |
1da177e4 | 287 | |
46b47730 LN |
288 | static struct crypt_iv_operations crypt_iv_null_ops = { |
289 | .generator = crypt_iv_null_gen | |
290 | }; | |
291 | ||
858119e1 | 292 | static int |
1da177e4 LT |
293 | crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out, |
294 | struct scatterlist *in, unsigned int length, | |
295 | int write, sector_t sector) | |
296 | { | |
45789328 | 297 | u8 iv[cc->iv_size] __attribute__ ((aligned(__alignof__(u64)))); |
d1806f6a HX |
298 | struct blkcipher_desc desc = { |
299 | .tfm = cc->tfm, | |
300 | .info = iv, | |
301 | .flags = CRYPTO_TFM_REQ_MAY_SLEEP, | |
302 | }; | |
1da177e4 LT |
303 | int r; |
304 | ||
305 | if (cc->iv_gen_ops) { | |
306 | r = cc->iv_gen_ops->generator(cc, iv, sector); | |
307 | if (r < 0) | |
308 | return r; | |
309 | ||
310 | if (write) | |
d1806f6a | 311 | r = crypto_blkcipher_encrypt_iv(&desc, out, in, length); |
1da177e4 | 312 | else |
d1806f6a | 313 | r = crypto_blkcipher_decrypt_iv(&desc, out, in, length); |
1da177e4 LT |
314 | } else { |
315 | if (write) | |
d1806f6a | 316 | r = crypto_blkcipher_encrypt(&desc, out, in, length); |
1da177e4 | 317 | else |
d1806f6a | 318 | r = crypto_blkcipher_decrypt(&desc, out, in, length); |
1da177e4 LT |
319 | } |
320 | ||
321 | return r; | |
322 | } | |
323 | ||
d469f841 MB |
324 | static void crypt_convert_init(struct crypt_config *cc, |
325 | struct convert_context *ctx, | |
326 | struct bio *bio_out, struct bio *bio_in, | |
327 | sector_t sector, int write) | |
1da177e4 LT |
328 | { |
329 | ctx->bio_in = bio_in; | |
330 | ctx->bio_out = bio_out; | |
331 | ctx->offset_in = 0; | |
332 | ctx->offset_out = 0; | |
333 | ctx->idx_in = bio_in ? bio_in->bi_idx : 0; | |
334 | ctx->idx_out = bio_out ? bio_out->bi_idx : 0; | |
335 | ctx->sector = sector + cc->iv_offset; | |
336 | ctx->write = write; | |
337 | } | |
338 | ||
339 | /* | |
340 | * Encrypt / decrypt data from one bio to another one (can be the same one) | |
341 | */ | |
342 | static int crypt_convert(struct crypt_config *cc, | |
d469f841 | 343 | struct convert_context *ctx) |
1da177e4 LT |
344 | { |
345 | int r = 0; | |
346 | ||
347 | while(ctx->idx_in < ctx->bio_in->bi_vcnt && | |
348 | ctx->idx_out < ctx->bio_out->bi_vcnt) { | |
349 | struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); | |
350 | struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); | |
45711f1a JA |
351 | struct scatterlist sg_in, sg_out; |
352 | ||
353 | sg_init_table(&sg_in, 1); | |
642f1490 | 354 | sg_set_page(&sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT, bv_in->bv_offset + ctx->offset_in); |
45711f1a JA |
355 | |
356 | sg_init_table(&sg_out, 1); | |
642f1490 | 357 | sg_set_page(&sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT, bv_out->bv_offset + ctx->offset_out); |
1da177e4 LT |
358 | |
359 | ctx->offset_in += sg_in.length; | |
360 | if (ctx->offset_in >= bv_in->bv_len) { | |
361 | ctx->offset_in = 0; | |
362 | ctx->idx_in++; | |
363 | } | |
364 | ||
365 | ctx->offset_out += sg_out.length; | |
366 | if (ctx->offset_out >= bv_out->bv_len) { | |
367 | ctx->offset_out = 0; | |
368 | ctx->idx_out++; | |
369 | } | |
370 | ||
371 | r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, | |
d469f841 | 372 | ctx->write, ctx->sector); |
1da177e4 LT |
373 | if (r < 0) |
374 | break; | |
375 | ||
376 | ctx->sector++; | |
377 | } | |
378 | ||
379 | return r; | |
380 | } | |
381 | ||
d469f841 MB |
382 | static void dm_crypt_bio_destructor(struct bio *bio) |
383 | { | |
028867ac | 384 | struct dm_crypt_io *io = bio->bi_private; |
6a24c718 MB |
385 | struct crypt_config *cc = io->target->private; |
386 | ||
387 | bio_free(bio, cc->bs); | |
d469f841 | 388 | } |
6a24c718 | 389 | |
1da177e4 LT |
390 | /* |
391 | * Generate a new unfragmented bio with the given size | |
392 | * This should never violate the device limitations | |
393 | * May return a smaller bio when running out of pages | |
394 | */ | |
028867ac | 395 | static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size) |
1da177e4 | 396 | { |
027581f3 | 397 | struct crypt_config *cc = io->target->private; |
8b004457 | 398 | struct bio *clone; |
1da177e4 | 399 | unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; |
b4e3ca1a | 400 | gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM; |
91e10625 MB |
401 | unsigned i, len; |
402 | struct page *page; | |
1da177e4 | 403 | |
2f9941b6 | 404 | clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs); |
8b004457 | 405 | if (!clone) |
1da177e4 | 406 | return NULL; |
1da177e4 | 407 | |
027581f3 | 408 | clone_init(io, clone); |
6a24c718 | 409 | |
f97380bc | 410 | for (i = 0; i < nr_iovecs; i++) { |
91e10625 MB |
411 | page = mempool_alloc(cc->page_pool, gfp_mask); |
412 | if (!page) | |
1da177e4 LT |
413 | break; |
414 | ||
415 | /* | |
416 | * if additional pages cannot be allocated without waiting, | |
417 | * return a partially allocated bio, the caller will then try | |
418 | * to allocate additional bios while submitting this partial bio | |
419 | */ | |
f97380bc | 420 | if (i == (MIN_BIO_PAGES - 1)) |
1da177e4 LT |
421 | gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; |
422 | ||
91e10625 MB |
423 | len = (size > PAGE_SIZE) ? PAGE_SIZE : size; |
424 | ||
425 | if (!bio_add_page(clone, page, len, 0)) { | |
426 | mempool_free(page, cc->page_pool); | |
427 | break; | |
428 | } | |
1da177e4 | 429 | |
91e10625 | 430 | size -= len; |
1da177e4 LT |
431 | } |
432 | ||
8b004457 MB |
433 | if (!clone->bi_size) { |
434 | bio_put(clone); | |
1da177e4 LT |
435 | return NULL; |
436 | } | |
437 | ||
8b004457 | 438 | return clone; |
1da177e4 LT |
439 | } |
440 | ||
644bd2f0 | 441 | static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone) |
1da177e4 | 442 | { |
644bd2f0 | 443 | unsigned int i; |
1da177e4 LT |
444 | struct bio_vec *bv; |
445 | ||
644bd2f0 | 446 | for (i = 0; i < clone->bi_vcnt; i++) { |
8b004457 | 447 | bv = bio_iovec_idx(clone, i); |
1da177e4 LT |
448 | BUG_ON(!bv->bv_page); |
449 | mempool_free(bv->bv_page, cc->page_pool); | |
450 | bv->bv_page = NULL; | |
451 | } | |
452 | } | |
453 | ||
454 | /* | |
455 | * One of the bios was finished. Check for completion of | |
456 | * the whole request and correctly clean up the buffer. | |
457 | */ | |
80fd6626 | 458 | static void crypt_dec_pending(struct dm_crypt_io *io, int error) |
1da177e4 LT |
459 | { |
460 | struct crypt_config *cc = (struct crypt_config *) io->target->private; | |
461 | ||
462 | if (error < 0) | |
463 | io->error = error; | |
464 | ||
465 | if (!atomic_dec_and_test(&io->pending)) | |
466 | return; | |
467 | ||
6712ecf8 | 468 | bio_endio(io->base_bio, io->error); |
1da177e4 LT |
469 | |
470 | mempool_free(io, cc->io_pool); | |
471 | } | |
472 | ||
473 | /* | |
cabf08e4 | 474 | * kcryptd/kcryptd_io: |
1da177e4 LT |
475 | * |
476 | * Needed because it would be very unwise to do decryption in an | |
23541d2d | 477 | * interrupt context. |
cabf08e4 MB |
478 | * |
479 | * kcryptd performs the actual encryption or decryption. | |
480 | * | |
481 | * kcryptd_io performs the IO submission. | |
482 | * | |
483 | * They must be separated as otherwise the final stages could be | |
484 | * starved by new requests which can block in the first stages due | |
485 | * to memory allocation. | |
1da177e4 | 486 | */ |
c4028958 | 487 | static void kcryptd_do_work(struct work_struct *work); |
cabf08e4 | 488 | static void kcryptd_do_crypt(struct work_struct *work); |
1da177e4 | 489 | |
028867ac | 490 | static void kcryptd_queue_io(struct dm_crypt_io *io) |
1da177e4 | 491 | { |
9934a8be MB |
492 | struct crypt_config *cc = io->target->private; |
493 | ||
c4028958 | 494 | INIT_WORK(&io->work, kcryptd_do_work); |
cabf08e4 MB |
495 | queue_work(cc->io_queue, &io->work); |
496 | } | |
497 | ||
498 | static void kcryptd_queue_crypt(struct dm_crypt_io *io) | |
499 | { | |
500 | struct crypt_config *cc = io->target->private; | |
501 | ||
502 | INIT_WORK(&io->work, kcryptd_do_crypt); | |
503 | queue_work(cc->crypt_queue, &io->work); | |
8b004457 MB |
504 | } |
505 | ||
6712ecf8 | 506 | static void crypt_endio(struct bio *clone, int error) |
8b004457 | 507 | { |
028867ac | 508 | struct dm_crypt_io *io = clone->bi_private; |
8b004457 MB |
509 | struct crypt_config *cc = io->target->private; |
510 | unsigned read_io = bio_data_dir(clone) == READ; | |
511 | ||
adfe4770 MB |
512 | if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error)) |
513 | error = -EIO; | |
514 | ||
8b004457 | 515 | /* |
6712ecf8 | 516 | * free the processed pages |
8b004457 | 517 | */ |
6712ecf8 | 518 | if (!read_io) { |
644bd2f0 | 519 | crypt_free_buffer_pages(cc, clone); |
8b004457 | 520 | goto out; |
6712ecf8 | 521 | } |
8b004457 | 522 | |
adfe4770 | 523 | if (unlikely(error)) |
8b004457 | 524 | goto out; |
8b004457 MB |
525 | |
526 | bio_put(clone); | |
cabf08e4 | 527 | kcryptd_queue_crypt(io); |
6712ecf8 | 528 | return; |
8b004457 MB |
529 | |
530 | out: | |
531 | bio_put(clone); | |
80fd6626 | 532 | crypt_dec_pending(io, error); |
8b004457 MB |
533 | } |
534 | ||
028867ac | 535 | static void clone_init(struct dm_crypt_io *io, struct bio *clone) |
8b004457 MB |
536 | { |
537 | struct crypt_config *cc = io->target->private; | |
538 | ||
539 | clone->bi_private = io; | |
540 | clone->bi_end_io = crypt_endio; | |
541 | clone->bi_bdev = cc->dev->bdev; | |
542 | clone->bi_rw = io->base_bio->bi_rw; | |
027581f3 | 543 | clone->bi_destructor = dm_crypt_bio_destructor; |
8b004457 MB |
544 | } |
545 | ||
028867ac | 546 | static void process_read(struct dm_crypt_io *io) |
8b004457 MB |
547 | { |
548 | struct crypt_config *cc = io->target->private; | |
549 | struct bio *base_bio = io->base_bio; | |
550 | struct bio *clone; | |
93e605c2 MB |
551 | sector_t sector = base_bio->bi_sector - io->target->begin; |
552 | ||
553 | atomic_inc(&io->pending); | |
8b004457 MB |
554 | |
555 | /* | |
556 | * The block layer might modify the bvec array, so always | |
557 | * copy the required bvecs because we need the original | |
558 | * one in order to decrypt the whole bio data *afterwards*. | |
559 | */ | |
6a24c718 | 560 | clone = bio_alloc_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs); |
93e605c2 | 561 | if (unlikely(!clone)) { |
80fd6626 | 562 | crypt_dec_pending(io, -ENOMEM); |
23541d2d | 563 | return; |
93e605c2 | 564 | } |
8b004457 MB |
565 | |
566 | clone_init(io, clone); | |
567 | clone->bi_idx = 0; | |
568 | clone->bi_vcnt = bio_segments(base_bio); | |
569 | clone->bi_size = base_bio->bi_size; | |
93e605c2 | 570 | clone->bi_sector = cc->start + sector; |
8b004457 MB |
571 | memcpy(clone->bi_io_vec, bio_iovec(base_bio), |
572 | sizeof(struct bio_vec) * clone->bi_vcnt); | |
8b004457 | 573 | |
93e605c2 | 574 | generic_make_request(clone); |
8b004457 MB |
575 | } |
576 | ||
028867ac | 577 | static void process_write(struct dm_crypt_io *io) |
8b004457 MB |
578 | { |
579 | struct crypt_config *cc = io->target->private; | |
580 | struct bio *base_bio = io->base_bio; | |
581 | struct bio *clone; | |
93e605c2 MB |
582 | struct convert_context ctx; |
583 | unsigned remaining = base_bio->bi_size; | |
584 | sector_t sector = base_bio->bi_sector - io->target->begin; | |
8b004457 | 585 | |
93e605c2 | 586 | atomic_inc(&io->pending); |
8b004457 | 587 | |
93e605c2 | 588 | crypt_convert_init(cc, &ctx, NULL, base_bio, sector, 1); |
8b004457 | 589 | |
93e605c2 MB |
590 | /* |
591 | * The allocated buffers can be smaller than the whole bio, | |
592 | * so repeat the whole process until all the data can be handled. | |
593 | */ | |
594 | while (remaining) { | |
f97380bc | 595 | clone = crypt_alloc_buffer(io, remaining); |
23541d2d | 596 | if (unlikely(!clone)) { |
80fd6626 | 597 | crypt_dec_pending(io, -ENOMEM); |
23541d2d MB |
598 | return; |
599 | } | |
93e605c2 MB |
600 | |
601 | ctx.bio_out = clone; | |
f97380bc | 602 | ctx.idx_out = 0; |
93e605c2 MB |
603 | |
604 | if (unlikely(crypt_convert(cc, &ctx) < 0)) { | |
644bd2f0 | 605 | crypt_free_buffer_pages(cc, clone); |
93e605c2 | 606 | bio_put(clone); |
80fd6626 | 607 | crypt_dec_pending(io, -EIO); |
23541d2d | 608 | return; |
93e605c2 MB |
609 | } |
610 | ||
f97380bc OK |
611 | /* crypt_convert should have filled the clone bio */ |
612 | BUG_ON(ctx.idx_out < clone->bi_vcnt); | |
613 | ||
93e605c2 | 614 | clone->bi_sector = cc->start + sector; |
93e605c2 MB |
615 | remaining -= clone->bi_size; |
616 | sector += bio_sectors(clone); | |
617 | ||
2f9941b6 OK |
618 | /* Grab another reference to the io struct |
619 | * before we kick off the request */ | |
23541d2d MB |
620 | if (remaining) |
621 | atomic_inc(&io->pending); | |
622 | ||
93e605c2 MB |
623 | generic_make_request(clone); |
624 | ||
98221eb7 OK |
625 | /* Do not reference clone after this - it |
626 | * may be gone already. */ | |
627 | ||
93e605c2 MB |
628 | /* out of memory -> run queues */ |
629 | if (remaining) | |
98221eb7 | 630 | congestion_wait(WRITE, HZ/100); |
93e605c2 | 631 | } |
8b004457 MB |
632 | } |
633 | ||
028867ac | 634 | static void process_read_endio(struct dm_crypt_io *io) |
8b004457 MB |
635 | { |
636 | struct crypt_config *cc = io->target->private; | |
1da177e4 | 637 | struct convert_context ctx; |
1da177e4 | 638 | |
8b004457 MB |
639 | crypt_convert_init(cc, &ctx, io->base_bio, io->base_bio, |
640 | io->base_bio->bi_sector - io->target->begin, 0); | |
1da177e4 | 641 | |
80fd6626 | 642 | crypt_dec_pending(io, crypt_convert(cc, &ctx)); |
1da177e4 LT |
643 | } |
644 | ||
c4028958 | 645 | static void kcryptd_do_work(struct work_struct *work) |
1da177e4 | 646 | { |
028867ac | 647 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); |
8b004457 | 648 | |
cabf08e4 | 649 | if (bio_data_dir(io->base_bio) == READ) |
23541d2d | 650 | process_read(io); |
cabf08e4 MB |
651 | } |
652 | ||
653 | static void kcryptd_do_crypt(struct work_struct *work) | |
654 | { | |
655 | struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work); | |
656 | ||
657 | if (bio_data_dir(io->base_bio) == READ) | |
658 | process_read_endio(io); | |
23541d2d MB |
659 | else |
660 | process_write(io); | |
1da177e4 LT |
661 | } |
662 | ||
663 | /* | |
664 | * Decode key from its hex representation | |
665 | */ | |
666 | static int crypt_decode_key(u8 *key, char *hex, unsigned int size) | |
667 | { | |
668 | char buffer[3]; | |
669 | char *endp; | |
670 | unsigned int i; | |
671 | ||
672 | buffer[2] = '\0'; | |
673 | ||
8b004457 | 674 | for (i = 0; i < size; i++) { |
1da177e4 LT |
675 | buffer[0] = *hex++; |
676 | buffer[1] = *hex++; | |
677 | ||
678 | key[i] = (u8)simple_strtoul(buffer, &endp, 16); | |
679 | ||
680 | if (endp != &buffer[2]) | |
681 | return -EINVAL; | |
682 | } | |
683 | ||
684 | if (*hex != '\0') | |
685 | return -EINVAL; | |
686 | ||
687 | return 0; | |
688 | } | |
689 | ||
690 | /* | |
691 | * Encode key into its hex representation | |
692 | */ | |
693 | static void crypt_encode_key(char *hex, u8 *key, unsigned int size) | |
694 | { | |
695 | unsigned int i; | |
696 | ||
8b004457 | 697 | for (i = 0; i < size; i++) { |
1da177e4 LT |
698 | sprintf(hex, "%02x", *key); |
699 | hex += 2; | |
700 | key++; | |
701 | } | |
702 | } | |
703 | ||
e48d4bbf MB |
704 | static int crypt_set_key(struct crypt_config *cc, char *key) |
705 | { | |
706 | unsigned key_size = strlen(key) >> 1; | |
707 | ||
708 | if (cc->key_size && cc->key_size != key_size) | |
709 | return -EINVAL; | |
710 | ||
711 | cc->key_size = key_size; /* initial settings */ | |
712 | ||
713 | if ((!key_size && strcmp(key, "-")) || | |
d469f841 | 714 | (key_size && crypt_decode_key(cc->key, key, key_size) < 0)) |
e48d4bbf MB |
715 | return -EINVAL; |
716 | ||
717 | set_bit(DM_CRYPT_KEY_VALID, &cc->flags); | |
718 | ||
719 | return 0; | |
720 | } | |
721 | ||
722 | static int crypt_wipe_key(struct crypt_config *cc) | |
723 | { | |
724 | clear_bit(DM_CRYPT_KEY_VALID, &cc->flags); | |
725 | memset(&cc->key, 0, cc->key_size * sizeof(u8)); | |
726 | return 0; | |
727 | } | |
728 | ||
1da177e4 LT |
729 | /* |
730 | * Construct an encryption mapping: | |
731 | * <cipher> <key> <iv_offset> <dev_path> <start> | |
732 | */ | |
733 | static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
734 | { | |
735 | struct crypt_config *cc; | |
d1806f6a | 736 | struct crypto_blkcipher *tfm; |
1da177e4 LT |
737 | char *tmp; |
738 | char *cipher; | |
739 | char *chainmode; | |
740 | char *ivmode; | |
741 | char *ivopts; | |
1da177e4 | 742 | unsigned int key_size; |
4ee218cd | 743 | unsigned long long tmpll; |
1da177e4 LT |
744 | |
745 | if (argc != 5) { | |
72d94861 | 746 | ti->error = "Not enough arguments"; |
1da177e4 LT |
747 | return -EINVAL; |
748 | } | |
749 | ||
750 | tmp = argv[0]; | |
751 | cipher = strsep(&tmp, "-"); | |
752 | chainmode = strsep(&tmp, "-"); | |
753 | ivopts = strsep(&tmp, "-"); | |
754 | ivmode = strsep(&ivopts, ":"); | |
755 | ||
756 | if (tmp) | |
72d94861 | 757 | DMWARN("Unexpected additional cipher options"); |
1da177e4 LT |
758 | |
759 | key_size = strlen(argv[1]) >> 1; | |
760 | ||
e48d4bbf | 761 | cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); |
1da177e4 LT |
762 | if (cc == NULL) { |
763 | ti->error = | |
72d94861 | 764 | "Cannot allocate transparent encryption context"; |
1da177e4 LT |
765 | return -ENOMEM; |
766 | } | |
767 | ||
e48d4bbf | 768 | if (crypt_set_key(cc, argv[1])) { |
72d94861 | 769 | ti->error = "Error decoding key"; |
636d5786 | 770 | goto bad_cipher; |
1da177e4 LT |
771 | } |
772 | ||
773 | /* Compatiblity mode for old dm-crypt cipher strings */ | |
774 | if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { | |
775 | chainmode = "cbc"; | |
776 | ivmode = "plain"; | |
777 | } | |
778 | ||
d1806f6a HX |
779 | if (strcmp(chainmode, "ecb") && !ivmode) { |
780 | ti->error = "This chaining mode requires an IV mechanism"; | |
636d5786 | 781 | goto bad_cipher; |
1da177e4 LT |
782 | } |
783 | ||
d469f841 MB |
784 | if (snprintf(cc->cipher, CRYPTO_MAX_ALG_NAME, "%s(%s)", |
785 | chainmode, cipher) >= CRYPTO_MAX_ALG_NAME) { | |
d1806f6a | 786 | ti->error = "Chain mode + cipher name is too long"; |
636d5786 | 787 | goto bad_cipher; |
1da177e4 LT |
788 | } |
789 | ||
d1806f6a HX |
790 | tfm = crypto_alloc_blkcipher(cc->cipher, 0, CRYPTO_ALG_ASYNC); |
791 | if (IS_ERR(tfm)) { | |
72d94861 | 792 | ti->error = "Error allocating crypto tfm"; |
636d5786 | 793 | goto bad_cipher; |
1da177e4 | 794 | } |
1da177e4 | 795 | |
d1806f6a HX |
796 | strcpy(cc->cipher, cipher); |
797 | strcpy(cc->chainmode, chainmode); | |
1da177e4 LT |
798 | cc->tfm = tfm; |
799 | ||
800 | /* | |
48527fa7 | 801 | * Choose ivmode. Valid modes: "plain", "essiv:<esshash>", "benbi". |
1da177e4 LT |
802 | * See comments at iv code |
803 | */ | |
804 | ||
805 | if (ivmode == NULL) | |
806 | cc->iv_gen_ops = NULL; | |
807 | else if (strcmp(ivmode, "plain") == 0) | |
808 | cc->iv_gen_ops = &crypt_iv_plain_ops; | |
809 | else if (strcmp(ivmode, "essiv") == 0) | |
810 | cc->iv_gen_ops = &crypt_iv_essiv_ops; | |
48527fa7 RS |
811 | else if (strcmp(ivmode, "benbi") == 0) |
812 | cc->iv_gen_ops = &crypt_iv_benbi_ops; | |
46b47730 LN |
813 | else if (strcmp(ivmode, "null") == 0) |
814 | cc->iv_gen_ops = &crypt_iv_null_ops; | |
1da177e4 | 815 | else { |
72d94861 | 816 | ti->error = "Invalid IV mode"; |
636d5786 | 817 | goto bad_ivmode; |
1da177e4 LT |
818 | } |
819 | ||
820 | if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && | |
821 | cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) | |
636d5786 | 822 | goto bad_ivmode; |
1da177e4 | 823 | |
d1806f6a HX |
824 | cc->iv_size = crypto_blkcipher_ivsize(tfm); |
825 | if (cc->iv_size) | |
1da177e4 | 826 | /* at least a 64 bit sector number should fit in our buffer */ |
d1806f6a | 827 | cc->iv_size = max(cc->iv_size, |
d469f841 | 828 | (unsigned int)(sizeof(u64) / sizeof(u8))); |
1da177e4 | 829 | else { |
1da177e4 | 830 | if (cc->iv_gen_ops) { |
72d94861 | 831 | DMWARN("Selected cipher does not support IVs"); |
1da177e4 LT |
832 | if (cc->iv_gen_ops->dtr) |
833 | cc->iv_gen_ops->dtr(cc); | |
834 | cc->iv_gen_ops = NULL; | |
835 | } | |
836 | } | |
837 | ||
93d2341c | 838 | cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool); |
1da177e4 | 839 | if (!cc->io_pool) { |
72d94861 | 840 | ti->error = "Cannot allocate crypt io mempool"; |
636d5786 | 841 | goto bad_slab_pool; |
1da177e4 LT |
842 | } |
843 | ||
a19b27ce | 844 | cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0); |
1da177e4 | 845 | if (!cc->page_pool) { |
72d94861 | 846 | ti->error = "Cannot allocate page mempool"; |
636d5786 | 847 | goto bad_page_pool; |
1da177e4 LT |
848 | } |
849 | ||
5972511b | 850 | cc->bs = bioset_create(MIN_IOS, MIN_IOS); |
6a24c718 MB |
851 | if (!cc->bs) { |
852 | ti->error = "Cannot allocate crypt bioset"; | |
853 | goto bad_bs; | |
854 | } | |
855 | ||
d1806f6a | 856 | if (crypto_blkcipher_setkey(tfm, cc->key, key_size) < 0) { |
72d94861 | 857 | ti->error = "Error setting key"; |
636d5786 | 858 | goto bad_device; |
1da177e4 LT |
859 | } |
860 | ||
4ee218cd | 861 | if (sscanf(argv[2], "%llu", &tmpll) != 1) { |
72d94861 | 862 | ti->error = "Invalid iv_offset sector"; |
636d5786 | 863 | goto bad_device; |
1da177e4 | 864 | } |
4ee218cd | 865 | cc->iv_offset = tmpll; |
1da177e4 | 866 | |
4ee218cd | 867 | if (sscanf(argv[4], "%llu", &tmpll) != 1) { |
72d94861 | 868 | ti->error = "Invalid device sector"; |
636d5786 | 869 | goto bad_device; |
1da177e4 | 870 | } |
4ee218cd | 871 | cc->start = tmpll; |
1da177e4 LT |
872 | |
873 | if (dm_get_device(ti, argv[3], cc->start, ti->len, | |
d469f841 | 874 | dm_table_get_mode(ti->table), &cc->dev)) { |
72d94861 | 875 | ti->error = "Device lookup failed"; |
636d5786 | 876 | goto bad_device; |
1da177e4 LT |
877 | } |
878 | ||
879 | if (ivmode && cc->iv_gen_ops) { | |
880 | if (ivopts) | |
881 | *(ivopts - 1) = ':'; | |
882 | cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); | |
883 | if (!cc->iv_mode) { | |
72d94861 | 884 | ti->error = "Error kmallocing iv_mode string"; |
636d5786 | 885 | goto bad_ivmode_string; |
1da177e4 LT |
886 | } |
887 | strcpy(cc->iv_mode, ivmode); | |
888 | } else | |
889 | cc->iv_mode = NULL; | |
890 | ||
cabf08e4 MB |
891 | cc->io_queue = create_singlethread_workqueue("kcryptd_io"); |
892 | if (!cc->io_queue) { | |
893 | ti->error = "Couldn't create kcryptd io queue"; | |
894 | goto bad_io_queue; | |
895 | } | |
896 | ||
897 | cc->crypt_queue = create_singlethread_workqueue("kcryptd"); | |
898 | if (!cc->crypt_queue) { | |
9934a8be | 899 | ti->error = "Couldn't create kcryptd queue"; |
cabf08e4 | 900 | goto bad_crypt_queue; |
9934a8be MB |
901 | } |
902 | ||
1da177e4 LT |
903 | ti->private = cc; |
904 | return 0; | |
905 | ||
cabf08e4 MB |
906 | bad_crypt_queue: |
907 | destroy_workqueue(cc->io_queue); | |
908 | bad_io_queue: | |
9934a8be | 909 | kfree(cc->iv_mode); |
636d5786 | 910 | bad_ivmode_string: |
55b42c5a | 911 | dm_put_device(ti, cc->dev); |
636d5786 | 912 | bad_device: |
6a24c718 MB |
913 | bioset_free(cc->bs); |
914 | bad_bs: | |
1da177e4 | 915 | mempool_destroy(cc->page_pool); |
636d5786 | 916 | bad_page_pool: |
1da177e4 | 917 | mempool_destroy(cc->io_pool); |
636d5786 | 918 | bad_slab_pool: |
1da177e4 LT |
919 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
920 | cc->iv_gen_ops->dtr(cc); | |
636d5786 | 921 | bad_ivmode: |
d1806f6a | 922 | crypto_free_blkcipher(tfm); |
636d5786 | 923 | bad_cipher: |
9d3520a3 SR |
924 | /* Must zero key material before freeing */ |
925 | memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); | |
1da177e4 LT |
926 | kfree(cc); |
927 | return -EINVAL; | |
928 | } | |
929 | ||
930 | static void crypt_dtr(struct dm_target *ti) | |
931 | { | |
932 | struct crypt_config *cc = (struct crypt_config *) ti->private; | |
933 | ||
cabf08e4 MB |
934 | destroy_workqueue(cc->io_queue); |
935 | destroy_workqueue(cc->crypt_queue); | |
80b16c19 | 936 | |
6a24c718 | 937 | bioset_free(cc->bs); |
1da177e4 LT |
938 | mempool_destroy(cc->page_pool); |
939 | mempool_destroy(cc->io_pool); | |
940 | ||
990a8baf | 941 | kfree(cc->iv_mode); |
1da177e4 LT |
942 | if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) |
943 | cc->iv_gen_ops->dtr(cc); | |
d1806f6a | 944 | crypto_free_blkcipher(cc->tfm); |
1da177e4 | 945 | dm_put_device(ti, cc->dev); |
9d3520a3 SR |
946 | |
947 | /* Must zero key material before freeing */ | |
948 | memset(cc, 0, sizeof(*cc) + cc->key_size * sizeof(u8)); | |
1da177e4 LT |
949 | kfree(cc); |
950 | } | |
951 | ||
1da177e4 LT |
952 | static int crypt_map(struct dm_target *ti, struct bio *bio, |
953 | union map_info *map_context) | |
954 | { | |
8b004457 | 955 | struct crypt_config *cc = ti->private; |
028867ac | 956 | struct dm_crypt_io *io; |
1da177e4 | 957 | |
e48d4bbf | 958 | io = mempool_alloc(cc->io_pool, GFP_NOIO); |
1da177e4 | 959 | io->target = ti; |
8b004457 | 960 | io->base_bio = bio; |
cabf08e4 | 961 | io->error = 0; |
93e605c2 | 962 | atomic_set(&io->pending, 0); |
cabf08e4 MB |
963 | |
964 | if (bio_data_dir(io->base_bio) == READ) | |
965 | kcryptd_queue_io(io); | |
966 | else | |
967 | kcryptd_queue_crypt(io); | |
1da177e4 | 968 | |
d2a7ad29 | 969 | return DM_MAPIO_SUBMITTED; |
1da177e4 LT |
970 | } |
971 | ||
972 | static int crypt_status(struct dm_target *ti, status_type_t type, | |
973 | char *result, unsigned int maxlen) | |
974 | { | |
975 | struct crypt_config *cc = (struct crypt_config *) ti->private; | |
1da177e4 LT |
976 | unsigned int sz = 0; |
977 | ||
978 | switch (type) { | |
979 | case STATUSTYPE_INFO: | |
980 | result[0] = '\0'; | |
981 | break; | |
982 | ||
983 | case STATUSTYPE_TABLE: | |
1da177e4 | 984 | if (cc->iv_mode) |
37af6560 CS |
985 | DMEMIT("%s-%s-%s ", cc->cipher, cc->chainmode, |
986 | cc->iv_mode); | |
1da177e4 | 987 | else |
37af6560 | 988 | DMEMIT("%s-%s ", cc->cipher, cc->chainmode); |
1da177e4 LT |
989 | |
990 | if (cc->key_size > 0) { | |
991 | if ((maxlen - sz) < ((cc->key_size << 1) + 1)) | |
992 | return -ENOMEM; | |
993 | ||
994 | crypt_encode_key(result + sz, cc->key, cc->key_size); | |
995 | sz += cc->key_size << 1; | |
996 | } else { | |
997 | if (sz >= maxlen) | |
998 | return -ENOMEM; | |
999 | result[sz++] = '-'; | |
1000 | } | |
1001 | ||
4ee218cd AM |
1002 | DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset, |
1003 | cc->dev->name, (unsigned long long)cc->start); | |
1da177e4 LT |
1004 | break; |
1005 | } | |
1006 | return 0; | |
1007 | } | |
1008 | ||
e48d4bbf MB |
1009 | static void crypt_postsuspend(struct dm_target *ti) |
1010 | { | |
1011 | struct crypt_config *cc = ti->private; | |
1012 | ||
1013 | set_bit(DM_CRYPT_SUSPENDED, &cc->flags); | |
1014 | } | |
1015 | ||
1016 | static int crypt_preresume(struct dm_target *ti) | |
1017 | { | |
1018 | struct crypt_config *cc = ti->private; | |
1019 | ||
1020 | if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) { | |
1021 | DMERR("aborting resume - crypt key is not set."); | |
1022 | return -EAGAIN; | |
1023 | } | |
1024 | ||
1025 | return 0; | |
1026 | } | |
1027 | ||
1028 | static void crypt_resume(struct dm_target *ti) | |
1029 | { | |
1030 | struct crypt_config *cc = ti->private; | |
1031 | ||
1032 | clear_bit(DM_CRYPT_SUSPENDED, &cc->flags); | |
1033 | } | |
1034 | ||
1035 | /* Message interface | |
1036 | * key set <key> | |
1037 | * key wipe | |
1038 | */ | |
1039 | static int crypt_message(struct dm_target *ti, unsigned argc, char **argv) | |
1040 | { | |
1041 | struct crypt_config *cc = ti->private; | |
1042 | ||
1043 | if (argc < 2) | |
1044 | goto error; | |
1045 | ||
1046 | if (!strnicmp(argv[0], MESG_STR("key"))) { | |
1047 | if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) { | |
1048 | DMWARN("not suspended during key manipulation."); | |
1049 | return -EINVAL; | |
1050 | } | |
1051 | if (argc == 3 && !strnicmp(argv[1], MESG_STR("set"))) | |
1052 | return crypt_set_key(cc, argv[2]); | |
1053 | if (argc == 2 && !strnicmp(argv[1], MESG_STR("wipe"))) | |
1054 | return crypt_wipe_key(cc); | |
1055 | } | |
1056 | ||
1057 | error: | |
1058 | DMWARN("unrecognised message received."); | |
1059 | return -EINVAL; | |
1060 | } | |
1061 | ||
1da177e4 LT |
1062 | static struct target_type crypt_target = { |
1063 | .name = "crypt", | |
46b47730 | 1064 | .version= {1, 5, 0}, |
1da177e4 LT |
1065 | .module = THIS_MODULE, |
1066 | .ctr = crypt_ctr, | |
1067 | .dtr = crypt_dtr, | |
1068 | .map = crypt_map, | |
1069 | .status = crypt_status, | |
e48d4bbf MB |
1070 | .postsuspend = crypt_postsuspend, |
1071 | .preresume = crypt_preresume, | |
1072 | .resume = crypt_resume, | |
1073 | .message = crypt_message, | |
1da177e4 LT |
1074 | }; |
1075 | ||
1076 | static int __init dm_crypt_init(void) | |
1077 | { | |
1078 | int r; | |
1079 | ||
028867ac | 1080 | _crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0); |
1da177e4 LT |
1081 | if (!_crypt_io_pool) |
1082 | return -ENOMEM; | |
1083 | ||
1da177e4 LT |
1084 | r = dm_register_target(&crypt_target); |
1085 | if (r < 0) { | |
72d94861 | 1086 | DMERR("register failed %d", r); |
9934a8be | 1087 | kmem_cache_destroy(_crypt_io_pool); |
1da177e4 LT |
1088 | } |
1089 | ||
1da177e4 LT |
1090 | return r; |
1091 | } | |
1092 | ||
1093 | static void __exit dm_crypt_exit(void) | |
1094 | { | |
1095 | int r = dm_unregister_target(&crypt_target); | |
1096 | ||
1097 | if (r < 0) | |
72d94861 | 1098 | DMERR("unregister failed %d", r); |
1da177e4 | 1099 | |
1da177e4 LT |
1100 | kmem_cache_destroy(_crypt_io_pool); |
1101 | } | |
1102 | ||
1103 | module_init(dm_crypt_init); | |
1104 | module_exit(dm_crypt_exit); | |
1105 | ||
1106 | MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); | |
1107 | MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); | |
1108 | MODULE_LICENSE("GPL"); |