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13#include <crypto/algapi.h>
14#include <linux/err.h>
15#include <linux/init.h>
16#include <linux/kernel.h>
17#include <linux/kthread.h>
18#include <linux/list.h>
19#include <linux/module.h>
20#include <linux/mutex.h>
21#include <linux/scatterlist.h>
22#include <linux/sched.h>
23#include <linux/slab.h>
24#include <linux/spinlock.h>
25
26#define CRYPTD_MAX_QLEN 100
27
28struct cryptd_state {
29 spinlock_t lock;
30 struct mutex mutex;
31 struct crypto_queue queue;
32 struct task_struct *task;
33};
34
35struct cryptd_instance_ctx {
36 struct crypto_spawn spawn;
37 struct cryptd_state *state;
38};
39
40struct cryptd_blkcipher_ctx {
41 struct crypto_blkcipher *child;
42};
43
44struct cryptd_blkcipher_request_ctx {
45 crypto_completion_t complete;
46};
47
48
49static inline struct cryptd_state *cryptd_get_state(struct crypto_tfm *tfm)
50{
51 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
52 struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
53 return ictx->state;
54}
55
56static int cryptd_blkcipher_setkey(struct crypto_ablkcipher *parent,
57 const u8 *key, unsigned int keylen)
58{
59 struct cryptd_blkcipher_ctx *ctx = crypto_ablkcipher_ctx(parent);
60 struct crypto_blkcipher *child = ctx->child;
61 int err;
62
63 crypto_blkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
64 crypto_blkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
65 CRYPTO_TFM_REQ_MASK);
66 err = crypto_blkcipher_setkey(child, key, keylen);
67 crypto_ablkcipher_set_flags(parent, crypto_blkcipher_get_flags(child) &
68 CRYPTO_TFM_RES_MASK);
69 return err;
70}
71
72static void cryptd_blkcipher_crypt(struct ablkcipher_request *req,
73 struct crypto_blkcipher *child,
74 int err,
75 int (*crypt)(struct blkcipher_desc *desc,
76 struct scatterlist *dst,
77 struct scatterlist *src,
78 unsigned int len))
79{
80 struct cryptd_blkcipher_request_ctx *rctx;
81 struct blkcipher_desc desc;
82
83 rctx = ablkcipher_request_ctx(req);
84
85 if (unlikely(err == -EINPROGRESS)) {
86 rctx->complete(&req->base, err);
87 return;
88 }
89
90 desc.tfm = child;
91 desc.info = req->info;
92 desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
93
94 err = crypt(&desc, req->dst, req->src, req->nbytes);
95
96 req->base.complete = rctx->complete;
97
98 local_bh_disable();
99 req->base.complete(&req->base, err);
100 local_bh_enable();
101}
102
103static void cryptd_blkcipher_encrypt(struct crypto_async_request *req, int err)
104{
105 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
106 struct crypto_blkcipher *child = ctx->child;
107
108 cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
109 crypto_blkcipher_crt(child)->encrypt);
110}
111
112static void cryptd_blkcipher_decrypt(struct crypto_async_request *req, int err)
113{
114 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(req->tfm);
115 struct crypto_blkcipher *child = ctx->child;
116
117 cryptd_blkcipher_crypt(ablkcipher_request_cast(req), child, err,
118 crypto_blkcipher_crt(child)->decrypt);
119}
120
121static int cryptd_blkcipher_enqueue(struct ablkcipher_request *req,
122 crypto_completion_t complete)
123{
124 struct cryptd_blkcipher_request_ctx *rctx = ablkcipher_request_ctx(req);
125 struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
126 struct cryptd_state *state =
127 cryptd_get_state(crypto_ablkcipher_tfm(tfm));
128 int err;
129
130 rctx->complete = req->base.complete;
131 req->base.complete = complete;
132
133 spin_lock_bh(&state->lock);
134 err = ablkcipher_enqueue_request(&state->queue, req);
135 spin_unlock_bh(&state->lock);
136
137 wake_up_process(state->task);
138 return err;
139}
140
141static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req)
142{
143 return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt);
144}
145
146static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req)
147{
148 return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt);
149}
150
151static int cryptd_blkcipher_init_tfm(struct crypto_tfm *tfm)
152{
153 struct crypto_instance *inst = crypto_tfm_alg_instance(tfm);
154 struct cryptd_instance_ctx *ictx = crypto_instance_ctx(inst);
155 struct crypto_spawn *spawn = &ictx->spawn;
156 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
157 struct crypto_blkcipher *cipher;
158
159 cipher = crypto_spawn_blkcipher(spawn);
160 if (IS_ERR(cipher))
161 return PTR_ERR(cipher);
162
163 ctx->child = cipher;
164 tfm->crt_ablkcipher.reqsize =
165 sizeof(struct cryptd_blkcipher_request_ctx);
166 return 0;
167}
168
169static void cryptd_blkcipher_exit_tfm(struct crypto_tfm *tfm)
170{
171 struct cryptd_blkcipher_ctx *ctx = crypto_tfm_ctx(tfm);
172 struct cryptd_state *state = cryptd_get_state(tfm);
173 int active;
174
175 mutex_lock(&state->mutex);
176 active = ablkcipher_tfm_in_queue(&state->queue,
177 __crypto_ablkcipher_cast(tfm));
178 mutex_unlock(&state->mutex);
179
180 BUG_ON(active);
181
182 crypto_free_blkcipher(ctx->child);
183}
184
185static struct crypto_instance *cryptd_alloc_instance(struct crypto_alg *alg,
186 struct cryptd_state *state)
187{
188 struct crypto_instance *inst;
189 struct cryptd_instance_ctx *ctx;
190 int err;
191
192 inst = kzalloc(sizeof(*inst) + sizeof(*ctx), GFP_KERNEL);
193 if (!inst) {
194 inst = ERR_PTR(-ENOMEM);
195 goto out;
196 }
197
198 err = -ENAMETOOLONG;
199 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
200 "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
201 goto out_free_inst;
202
203 ctx = crypto_instance_ctx(inst);
204 err = crypto_init_spawn(&ctx->spawn, alg, inst,
205 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
206 if (err)
207 goto out_free_inst;
208
209 ctx->state = state;
210
211 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
212
213 inst->alg.cra_priority = alg->cra_priority + 50;
214 inst->alg.cra_blocksize = alg->cra_blocksize;
215 inst->alg.cra_alignmask = alg->cra_alignmask;
216
217out:
218 return inst;
219
220out_free_inst:
221 kfree(inst);
222 inst = ERR_PTR(err);
223 goto out;
224}
225
226static struct crypto_instance *cryptd_alloc_blkcipher(
227 struct rtattr **tb, struct cryptd_state *state)
228{
229 struct crypto_instance *inst;
230 struct crypto_alg *alg;
231
232 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
233 CRYPTO_ALG_TYPE_MASK);
234 if (IS_ERR(alg))
235 return ERR_CAST(alg);
236
237 inst = cryptd_alloc_instance(alg, state);
238 if (IS_ERR(inst))
239 goto out_put_alg;
240
241 inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC;
242 inst->alg.cra_type = &crypto_ablkcipher_type;
243
244 inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize;
245 inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
246 inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
247
248 inst->alg.cra_ablkcipher.geniv = alg->cra_blkcipher.geniv;
249
250 inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx);
251
252 inst->alg.cra_init = cryptd_blkcipher_init_tfm;
253 inst->alg.cra_exit = cryptd_blkcipher_exit_tfm;
254
255 inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey;
256 inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue;
257 inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue;
258
259out_put_alg:
260 crypto_mod_put(alg);
261 return inst;
262}
263
264static struct cryptd_state state;
265
266static struct crypto_instance *cryptd_alloc(struct rtattr **tb)
267{
268 struct crypto_attr_type *algt;
269
270 algt = crypto_get_attr_type(tb);
271 if (IS_ERR(algt))
272 return ERR_CAST(algt);
273
274 switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
275 case CRYPTO_ALG_TYPE_BLKCIPHER:
276 return cryptd_alloc_blkcipher(tb, &state);
277 }
278
279 return ERR_PTR(-EINVAL);
280}
281
282static void cryptd_free(struct crypto_instance *inst)
283{
284 struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
285
286 crypto_drop_spawn(&ctx->spawn);
287 kfree(inst);
288}
289
290static struct crypto_template cryptd_tmpl = {
291 .name = "cryptd",
292 .alloc = cryptd_alloc,
293 .free = cryptd_free,
294 .module = THIS_MODULE,
295};
296
297static inline int cryptd_create_thread(struct cryptd_state *state,
298 int (*fn)(void *data), const char *name)
299{
300 spin_lock_init(&state->lock);
301 mutex_init(&state->mutex);
302 crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN);
303
304 state->task = kthread_run(fn, state, name);
305 if (IS_ERR(state->task))
306 return PTR_ERR(state->task);
307
308 return 0;
309}
310
311static inline void cryptd_stop_thread(struct cryptd_state *state)
312{
313 BUG_ON(state->queue.qlen);
314 kthread_stop(state->task);
315}
316
317static int cryptd_thread(void *data)
318{
319 struct cryptd_state *state = data;
320 int stop;
321
322 current->flags |= PF_NOFREEZE;
323
324 do {
325 struct crypto_async_request *req, *backlog;
326
327 mutex_lock(&state->mutex);
328 __set_current_state(TASK_INTERRUPTIBLE);
329
330 spin_lock_bh(&state->lock);
331 backlog = crypto_get_backlog(&state->queue);
332 req = crypto_dequeue_request(&state->queue);
333 spin_unlock_bh(&state->lock);
334
335 stop = kthread_should_stop();
336
337 if (stop || req) {
338 __set_current_state(TASK_RUNNING);
339 if (req) {
340 if (backlog)
341 backlog->complete(backlog,
342 -EINPROGRESS);
343 req->complete(req, 0);
344 }
345 }
346
347 mutex_unlock(&state->mutex);
348
349 schedule();
350 } while (!stop);
351
352 return 0;
353}
354
355static int __init cryptd_init(void)
356{
357 int err;
358
359 err = cryptd_create_thread(&state, cryptd_thread, "cryptd");
360 if (err)
361 return err;
362
363 err = crypto_register_template(&cryptd_tmpl);
364 if (err)
365 kthread_stop(state.task);
366
367 return err;
368}
369
370static void __exit cryptd_exit(void)
371{
372 cryptd_stop_thread(&state);
373 crypto_unregister_template(&cryptd_tmpl);
374}
375
376module_init(cryptd_init);
377module_exit(cryptd_exit);
378
379MODULE_LICENSE("GPL");
380MODULE_DESCRIPTION("Software async crypto daemon");
381
