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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * Software async crypto daemon.
  3  *
  4  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License as published by the Free
  8  * Software Foundation; either version 2 of the License, or (at your option)
  9  * any later version.
 10  *
 11  */
 12 
 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 
 28 struct cryptd_state {
 29         spinlock_t lock;
 30         struct mutex mutex;
 31         struct crypto_queue queue;
 32         struct task_struct *task;
 33 };
 34 
 35 struct cryptd_instance_ctx {
 36         struct crypto_spawn spawn;
 37         struct cryptd_state *state;
 38 };
 39 
 40 struct cryptd_blkcipher_ctx {
 41         struct crypto_blkcipher *child;
 42 };
 43 
 44 struct cryptd_blkcipher_request_ctx {
 45         crypto_completion_t complete;
 46 };
 47 
 48 
 49 static 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 
 56 static 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 
 72 static 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 
103 static 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 
112 static 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 
121 static 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 
141 static int cryptd_blkcipher_encrypt_enqueue(struct ablkcipher_request *req)
142 {
143         return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_encrypt);
144 }
145 
146 static int cryptd_blkcipher_decrypt_enqueue(struct ablkcipher_request *req)
147 {
148         return cryptd_blkcipher_enqueue(req, cryptd_blkcipher_decrypt);
149 }
150 
151 static 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 
169 static 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 
185 static 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 (IS_ERR(inst))
194                 goto out;
195 
196         err = -ENAMETOOLONG;
197         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
198                      "cryptd(%s)", alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
199                 goto out_free_inst;
200 
201         ctx = crypto_instance_ctx(inst);
202         err = crypto_init_spawn(&ctx->spawn, alg, inst,
203                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
204         if (err)
205                 goto out_free_inst;
206 
207         ctx->state = state;
208 
209         memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
210 
211         inst->alg.cra_priority = alg->cra_priority + 50;
212         inst->alg.cra_blocksize = alg->cra_blocksize;
213         inst->alg.cra_alignmask = alg->cra_alignmask;
214 
215 out:
216         return inst;
217 
218 out_free_inst:
219         kfree(inst);
220         inst = ERR_PTR(err);
221         goto out;
222 }
223 
224 static struct crypto_instance *cryptd_alloc_blkcipher(
225         struct rtattr **tb, struct cryptd_state *state)
226 {
227         struct crypto_instance *inst;
228         struct crypto_alg *alg;
229 
230         alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_BLKCIPHER,
231                                   CRYPTO_ALG_TYPE_MASK);
232         if (IS_ERR(alg))
233                 return ERR_CAST(alg);
234 
235         inst = cryptd_alloc_instance(alg, state);
236         if (IS_ERR(inst))
237                 goto out_put_alg;
238 
239         inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC;
240         inst->alg.cra_type = &crypto_ablkcipher_type;
241 
242         inst->alg.cra_ablkcipher.ivsize = alg->cra_blkcipher.ivsize;
243         inst->alg.cra_ablkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
244         inst->alg.cra_ablkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
245 
246         inst->alg.cra_ablkcipher.geniv = alg->cra_blkcipher.geniv;
247 
248         inst->alg.cra_ctxsize = sizeof(struct cryptd_blkcipher_ctx);
249 
250         inst->alg.cra_init = cryptd_blkcipher_init_tfm;
251         inst->alg.cra_exit = cryptd_blkcipher_exit_tfm;
252 
253         inst->alg.cra_ablkcipher.setkey = cryptd_blkcipher_setkey;
254         inst->alg.cra_ablkcipher.encrypt = cryptd_blkcipher_encrypt_enqueue;
255         inst->alg.cra_ablkcipher.decrypt = cryptd_blkcipher_decrypt_enqueue;
256 
257 out_put_alg:
258         crypto_mod_put(alg);
259         return inst;
260 }
261 
262 static struct cryptd_state state;
263 
264 static struct crypto_instance *cryptd_alloc(struct rtattr **tb)
265 {
266         struct crypto_attr_type *algt;
267 
268         algt = crypto_get_attr_type(tb);
269         if (IS_ERR(algt))
270                 return ERR_CAST(algt);
271 
272         switch (algt->type & algt->mask & CRYPTO_ALG_TYPE_MASK) {
273         case CRYPTO_ALG_TYPE_BLKCIPHER:
274                 return cryptd_alloc_blkcipher(tb, &state);
275         }
276 
277         return ERR_PTR(-EINVAL);
278 }
279 
280 static void cryptd_free(struct crypto_instance *inst)
281 {
282         struct cryptd_instance_ctx *ctx = crypto_instance_ctx(inst);
283 
284         crypto_drop_spawn(&ctx->spawn);
285         kfree(inst);
286 }
287 
288 static struct crypto_template cryptd_tmpl = {
289         .name = "cryptd",
290         .alloc = cryptd_alloc,
291         .free = cryptd_free,
292         .module = THIS_MODULE,
293 };
294 
295 static inline int cryptd_create_thread(struct cryptd_state *state,
296                                        int (*fn)(void *data), const char *name)
297 {
298         spin_lock_init(&state->lock);
299         mutex_init(&state->mutex);
300         crypto_init_queue(&state->queue, CRYPTD_MAX_QLEN);
301 
302         state->task = kthread_run(fn, state, name);
303         if (IS_ERR(state->task))
304                 return PTR_ERR(state->task);
305 
306         return 0;
307 }
308 
309 static inline void cryptd_stop_thread(struct cryptd_state *state)
310 {
311         BUG_ON(state->queue.qlen);
312         kthread_stop(state->task);
313 }
314 
315 static int cryptd_thread(void *data)
316 {
317         struct cryptd_state *state = data;
318         int stop;
319 
320         current->flags |= PF_NOFREEZE;
321 
322         do {
323                 struct crypto_async_request *req, *backlog;
324 
325                 mutex_lock(&state->mutex);
326                 __set_current_state(TASK_INTERRUPTIBLE);
327 
328                 spin_lock_bh(&state->lock);
329                 backlog = crypto_get_backlog(&state->queue);
330                 req = crypto_dequeue_request(&state->queue);
331                 spin_unlock_bh(&state->lock);
332 
333                 stop = kthread_should_stop();
334 
335                 if (stop || req) {
336                         __set_current_state(TASK_RUNNING);
337                         if (req) {
338                                 if (backlog)
339                                         backlog->complete(backlog,
340                                                           -EINPROGRESS);
341                                 req->complete(req, 0);
342                         }
343                 }
344 
345                 mutex_unlock(&state->mutex);
346 
347                 schedule();
348         } while (!stop);
349 
350         return 0;
351 }
352 
353 static int __init cryptd_init(void)
354 {
355         int err;
356 
357         err = cryptd_create_thread(&state, cryptd_thread, "cryptd");
358         if (err)
359                 return err;
360 
361         err = crypto_register_template(&cryptd_tmpl);
362         if (err)
363                 kthread_stop(state.task);
364 
365         return err;
366 }
367 
368 static void __exit cryptd_exit(void)
369 {
370         cryptd_stop_thread(&state);
371         crypto_unregister_template(&cryptd_tmpl);
372 }
373 
374 module_init(cryptd_init);
375 module_exit(cryptd_exit);
376 
377 MODULE_LICENSE("GPL");
378 MODULE_DESCRIPTION("Software async crypto daemon");
379 
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