aboutsummaryrefslogtreecommitdiffstats
path: root/crypto/cryptd.c
blob: 074298f2f8e392ef56391db7c2029fe07d1489c2 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
/*
 * Software async crypto daemon.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/algapi.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/kthread.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#define CRYPTD_MAX_QLEN 100

struct cryptd_state {
	spinlock_t lock;
	struct mutex mutex;
	struct crypto_queue queue;
	struct task_struct *task;
};

struct cryptd_instance_ctx {
	struct crypto_spawn spawn;
	struct cryptd_state *state;
};

struct cryptd_blkcipher_ctx {
	struct crypto_blkcipher *child;
};

struct cryptd_blkcipher_request_ctx {
	crypto_completion_t complete;
};


static inline struct cryptd_state *cryptd_get_state(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
	return ictx->state;
}

static int cryptd_blkcipher_setkey(struct crypto_ablkcipher *parent,
				   const u8 *key, unsigned int keylen)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(parent);
	struct crypto_blkcipher *child = ctx->child;
	int err;

	crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_blkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
					  CRYPTO_TFM_REQ_MASK);
	err = crypto_blkcipher_setkey(child, key, keylen);
	crypto_ablkcipher_set_flags(parent, crypto_blkcipher_get_flags(child) &
					    CRYPTO_TFM_RES_MASK);
	return err;
}

static void cryptd_blkcipher_crypt(struct ablkcipher_request *req,
				   struct crypto_blkcipher *child,
				   int err,
				   int (*crypt)(struct blkcipher_desc *desc,
						struct scatterlist *dst,
						struct scatterlist *src,
						unsigned int len))
{
	struct cryptd_blkcipher_request_ctx *rctx;
	struct blkcipher_desc desc;

	rctx = ablkcipher_request_ctx(req);

	if (unlikely(err == -EINPROGRESS)) {
		rctx->complete(&req->base, err);
		return;
	}

	desc.tfm = child;
	desc.info = req->info;
	desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;

	err = crypt(&desc, req->dst, req->src, req->nbytes);

	req->base.complete = rctx->complete;

	local_bh_disable();
	req->base.complete(&req->base, err);
	local_bh_enable();
}

static void cryptd_blkcipher_encrypt(struct crypto_async_request *req, int err)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
	struct crypto_blkcipher *child = ctx->child;

	cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
			       crypto_blkcipher_crt(child)->encrypt);
}

static void cryptd_blkcipher_decrypt(struct crypto_async_request *req, int err)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
	struct crypto_blkcipher *child = ctx->child;

	cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
			       crypto_blkcipher_crt(child)->decrypt);
}

static int cryptd_blkcipher_enqueue(struct ablkcipher_request *req,
				    crypto_completion_t complete)
{
	struct cryptd_blkcipher_request_ctx *rctx = ablkcipher_request_ctx(req);
	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
	struct cryptd_state *state =
		cryptd_get_state(crypto_ablkcipher_tfm(tfm));
	int err;

	rctx->complete = req->base.complete;
	req->base.complete = complete;

	spin_lock_bh(&state->lock);
	err = ablkcipher_enqueue_request(&state->queue, req);
	spin_unlock_bh(&state->lock);

	wake_up_process(state->task);
	return err;
}

static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req)
{
	return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt);
}

static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req)
{
	return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt);
}

static int cryptd_blkcipher_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
	struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
	struct crypto_spawn *spawn = &ictx->spawn;
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
	struct crypto_blkcipher *cipher;

	cipher = crypto_spawn_blkcipher(spawn);
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	ctx->child = cipher;
	tfm->crt_ablkcipher.reqsize =
		sizeof(struct cryptd_blkcipher_request_ctx);
	return 0;
}

static void cryptd_blkcipher_exit_tfm(struct crypto_tfm *tfm)
{
	struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
	struct cryptd_state *state = cryptd_get_state(tfm);
	int active;

	mutex_lock(&state->mutex);
	active = ablkcipher_tfm_in_queue(&state->queue,
					 __crypto_ablkcipher_cast(tfm));
	mutex_unlock(&state->mutex);

	BUG_ON(active);

	crypto_free_blkcipher(ctx->child);
}

static struct crypto_instance *cryptd_alloc_instance(struct crypto_alg *alg,
						     struct cryptd_state *state)
{
	struct crypto_instance *inst;
	struct cryptd_instance_ctx *ctx;
	int err;

	inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
	if (IS_ERR(inst))
		goto out;

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
		     "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
		goto out_free_inst;

	ctx = crypto_instance_ctx(inst);
	err = crypto_init_spawn(&ctx->spawn, alg, inst,
				CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
	if (err)
		goto out_free_inst;

	ctx->state = state;

	memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);

	inst->alg.cra_priority = alg->cra_priority + 50;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;

out:
	return inst;

out_free_inst:
	kfree(inst);
	inst = ERR_PTR(err);
	goto out;
}

static struct crypto_instance *cryptd_alloc_blkcipher(
	struct rtattr **tb, struct cryptd_state *state)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;

	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
				  CRYPTO_ALG_TYPE_MASK);
	if (IS_ERR(alg))
		return ERR_PTR(PTR_ERR(alg));

	inst = cryptd_alloc_instance(alg, state);
	if (IS_ERR(inst))
		goto out_put_alg;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC;
	inst->alg.cra_type = &crypto_ablkcipher_type;

	inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize;
	inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
	inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize;

	inst->alg.cra_ablkcipher.geniv = alg->cra_blkcipher.geniv;

	inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx);

	inst->alg.cra_init = cryptd_blkcipher_init_tfm;
	inst->alg.cra_exit = cryptd_blkcipher_exit_tfm;

	inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey;
	inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue;
	inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue;

out_put_alg:
	crypto_mod_put(alg);
	return inst;
}

static struct cryptd_state state;

static struct crypto_instance *cryptd_alloc(struct rtattr **tb)
{
	struct crypto_attr_type *algt;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return ERR_PTR(PTR_ERR(algt));

	switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
	case CRYPTO_ALG_TYPE_BLKCIPHER:
		return cryptd_alloc_blkcipher(tb, &state);
	}

	return ERR_PTR(-EINVAL);
}

static void cryptd_free(struct crypto_instance *inst)
{
	struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);

	crypto_drop_spawn(&ctx->spawn);
	kfree(inst);
}

static struct crypto_template cryptd_tmpl = {
	.name = "cryptd",
	.alloc = cryptd_alloc,
	.free = cryptd_free,
	.module = THIS_MODULE,
};

static inline int cryptd_create_thread(struct cryptd_state *state,
				       int (*fn)(void *data), const char *name)
{
	spin_lock_init(&state->lock);
	mutex_init(&state->mutex);
	crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN);

	state->task = kthread_run(fn, state, name);
	if (IS_ERR(state->task))
		return PTR_ERR(state->task);

	return 0;
}

static inline void cryptd_stop_thread(struct cryptd_state *state)
{
	BUG_ON(state->queue.qlen);
	kthread_stop(state->task);
}

static int cryptd_thread(void *data)
{
	struct cryptd_state *state = data;
	int stop;

	current->flags |= PF_NOFREEZE;

	do {
		struct crypto_async_request *req, *backlog;

		mutex_lock(&state->mutex);
		__set_current_state(TASK_INTERRUPTIBLE);

		spin_lock_bh(&state->lock);
		backlog = crypto_get_backlog(&state->queue);
		req = crypto_dequeue_request(&state->queue);
		spin_unlock_bh(&state->lock);

		stop = kthread_should_stop();

		if (stop || req) {
			__set_current_state(TASK_RUNNING);
			if (req) {
				if (backlog)
					backlog->complete(backlog,
							  -EINPROGRESS);
				req->complete(req, 0);
			}
		}

		mutex_unlock(&state->mutex);

		schedule();
	} while (!stop);

	return 0;
}

static int __init cryptd_init(void)
{
	int err;

	err = cryptd_create_thread(&state, cryptd_thread, "cryptd");
	if (err)
		return err;

	err = crypto_register_template(&cryptd_tmpl);
	if (err)
		kthread_stop(state.task);

	return err;
}

static void __exit cryptd_exit(void)
{
	cryptd_stop_thread(&state);
	crypto_unregister_template(&cryptd_tmpl);
}

module_init(cryptd_init);
module_exit(cryptd_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Software async crypto daemon");