crypto: api - Fix crypto_drop_spawn crash on blank spawns
[linux-2.6.git] / crypto / algapi.c
1 /*
2  * Cryptographic API for algorithms (i.e., low-level API).
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 <linux/err.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/list.h>
18 #include <linux/module.h>
19 #include <linux/rtnetlink.h>
20 #include <linux/string.h>
21
22 #include "internal.h"
23
24 static void crypto_remove_final(struct list_head *list);
25
26 static LIST_HEAD(crypto_template_list);
27
28 void crypto_larval_error(const char *name, u32 type, u32 mask)
29 {
30         struct crypto_alg *alg;
31
32         alg = crypto_alg_lookup(name, type, mask);
33
34         if (alg) {
35                 if (crypto_is_larval(alg)) {
36                         struct crypto_larval *larval = (void *)alg;
37                         complete_all(&larval->completion);
38                 }
39                 crypto_mod_put(alg);
40         }
41 }
42 EXPORT_SYMBOL_GPL(crypto_larval_error);
43
44 static inline int crypto_set_driver_name(struct crypto_alg *alg)
45 {
46         static const char suffix[] = "-generic";
47         char *driver_name = alg->cra_driver_name;
48         int len;
49
50         if (*driver_name)
51                 return 0;
52
53         len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
54         if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
55                 return -ENAMETOOLONG;
56
57         memcpy(driver_name + len, suffix, sizeof(suffix));
58         return 0;
59 }
60
61 static int crypto_check_alg(struct crypto_alg *alg)
62 {
63         if (alg->cra_alignmask & (alg->cra_alignmask + 1))
64                 return -EINVAL;
65
66         if (alg->cra_blocksize > PAGE_SIZE / 8)
67                 return -EINVAL;
68
69         if (alg->cra_priority < 0)
70                 return -EINVAL;
71
72         return crypto_set_driver_name(alg);
73 }
74
75 static void crypto_destroy_instance(struct crypto_alg *alg)
76 {
77         struct crypto_instance *inst = (void *)alg;
78         struct crypto_template *tmpl = inst->tmpl;
79
80         tmpl->free(inst);
81         crypto_tmpl_put(tmpl);
82 }
83
84 static void crypto_remove_spawn(struct crypto_spawn *spawn,
85                                 struct list_head *list,
86                                 struct list_head *secondary_spawns)
87 {
88         struct crypto_instance *inst = spawn->inst;
89         struct crypto_template *tmpl = inst->tmpl;
90
91         list_del_init(&spawn->list);
92         spawn->alg = NULL;
93
94         if (crypto_is_dead(&inst->alg))
95                 return;
96
97         inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
98         if (hlist_unhashed(&inst->list))
99                 return;
100
101         if (!tmpl || !crypto_tmpl_get(tmpl))
102                 return;
103
104         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
105         list_move(&inst->alg.cra_list, list);
106         hlist_del(&inst->list);
107         inst->alg.cra_destroy = crypto_destroy_instance;
108
109         list_splice(&inst->alg.cra_users, secondary_spawns);
110 }
111
112 static void crypto_remove_spawns(struct list_head *spawns,
113                                  struct list_head *list, u32 new_type)
114 {
115         struct crypto_spawn *spawn, *n;
116         LIST_HEAD(secondary_spawns);
117
118         list_for_each_entry_safe(spawn, n, spawns, list) {
119                 if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
120                         continue;
121
122                 crypto_remove_spawn(spawn, list, &secondary_spawns);
123         }
124
125         while (!list_empty(&secondary_spawns)) {
126                 list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
127                         crypto_remove_spawn(spawn, list, &secondary_spawns);
128         }
129 }
130
131 static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
132 {
133         struct crypto_alg *q;
134         struct crypto_larval *larval;
135         int ret = -EAGAIN;
136
137         if (crypto_is_dead(alg))
138                 goto err;
139
140         INIT_LIST_HEAD(&alg->cra_users);
141
142         /* No cheating! */
143         alg->cra_flags &= ~CRYPTO_ALG_TESTED;
144
145         ret = -EEXIST;
146
147         atomic_set(&alg->cra_refcnt, 1);
148         list_for_each_entry(q, &crypto_alg_list, cra_list) {
149                 if (q == alg)
150                         goto err;
151
152                 if (crypto_is_moribund(q))
153                         continue;
154
155                 if (crypto_is_larval(q)) {
156                         if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
157                                 goto err;
158                         continue;
159                 }
160
161                 if (!strcmp(q->cra_driver_name, alg->cra_name) ||
162                     !strcmp(q->cra_name, alg->cra_driver_name))
163                         goto err;
164         }
165
166         larval = crypto_larval_alloc(alg->cra_name,
167                                      alg->cra_flags | CRYPTO_ALG_TESTED, 0);
168         if (IS_ERR(larval))
169                 goto out;
170
171         ret = -ENOENT;
172         larval->adult = crypto_mod_get(alg);
173         if (!larval->adult)
174                 goto free_larval;
175
176         atomic_set(&larval->alg.cra_refcnt, 1);
177         memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
178                CRYPTO_MAX_ALG_NAME);
179         larval->alg.cra_priority = alg->cra_priority;
180
181         list_add(&alg->cra_list, &crypto_alg_list);
182         list_add(&larval->alg.cra_list, &crypto_alg_list);
183
184 out:    
185         return larval;
186
187 free_larval:
188         kfree(larval);
189 err:
190         larval = ERR_PTR(ret);
191         goto out;
192 }
193
194 void crypto_alg_tested(const char *name, int err)
195 {
196         struct crypto_larval *test;
197         struct crypto_alg *alg;
198         struct crypto_alg *q;
199         LIST_HEAD(list);
200
201         down_write(&crypto_alg_sem);
202         list_for_each_entry(q, &crypto_alg_list, cra_list) {
203                 if (crypto_is_moribund(q) || !crypto_is_larval(q))
204                         continue;
205
206                 test = (struct crypto_larval *)q;
207
208                 if (!strcmp(q->cra_driver_name, name))
209                         goto found;
210         }
211
212         printk(KERN_ERR "alg: Unexpected test result for %s: %d\n", name, err);
213         goto unlock;
214
215 found:
216         q->cra_flags |= CRYPTO_ALG_DEAD;
217         alg = test->adult;
218         if (err || list_empty(&alg->cra_list))
219                 goto complete;
220
221         alg->cra_flags |= CRYPTO_ALG_TESTED;
222
223         list_for_each_entry(q, &crypto_alg_list, cra_list) {
224                 if (q == alg)
225                         continue;
226
227                 if (crypto_is_moribund(q))
228                         continue;
229
230                 if (crypto_is_larval(q)) {
231                         struct crypto_larval *larval = (void *)q;
232
233                         /*
234                          * Check to see if either our generic name or
235                          * specific name can satisfy the name requested
236                          * by the larval entry q.
237                          */
238                         if (strcmp(alg->cra_name, q->cra_name) &&
239                             strcmp(alg->cra_driver_name, q->cra_name))
240                                 continue;
241
242                         if (larval->adult)
243                                 continue;
244                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
245                                 continue;
246                         if (!crypto_mod_get(alg))
247                                 continue;
248
249                         larval->adult = alg;
250                         complete_all(&larval->completion);
251                         continue;
252                 }
253
254                 if (strcmp(alg->cra_name, q->cra_name))
255                         continue;
256
257                 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
258                     q->cra_priority > alg->cra_priority)
259                         continue;
260
261                 crypto_remove_spawns(&q->cra_users, &list, alg->cra_flags);
262         }
263
264 complete:
265         complete_all(&test->completion);
266
267 unlock:
268         up_write(&crypto_alg_sem);
269
270         crypto_remove_final(&list);
271 }
272 EXPORT_SYMBOL_GPL(crypto_alg_tested);
273
274 static void crypto_remove_final(struct list_head *list)
275 {
276         struct crypto_alg *alg;
277         struct crypto_alg *n;
278
279         list_for_each_entry_safe(alg, n, list, cra_list) {
280                 list_del_init(&alg->cra_list);
281                 crypto_alg_put(alg);
282         }
283 }
284
285 static void crypto_wait_for_test(struct crypto_larval *larval)
286 {
287         int err;
288
289         err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
290         if (err != NOTIFY_STOP) {
291                 if (WARN_ON(err != NOTIFY_DONE))
292                         goto out;
293                 crypto_alg_tested(larval->alg.cra_driver_name, 0);
294         }
295
296         err = wait_for_completion_interruptible(&larval->completion);
297         WARN_ON(err);
298
299 out:
300         crypto_larval_kill(&larval->alg);
301 }
302
303 int crypto_register_alg(struct crypto_alg *alg)
304 {
305         struct crypto_larval *larval;
306         int err;
307
308         err = crypto_check_alg(alg);
309         if (err)
310                 return err;
311
312         down_write(&crypto_alg_sem);
313         larval = __crypto_register_alg(alg);
314         up_write(&crypto_alg_sem);
315
316         if (IS_ERR(larval))
317                 return PTR_ERR(larval);
318
319         crypto_wait_for_test(larval);
320         return 0;
321 }
322 EXPORT_SYMBOL_GPL(crypto_register_alg);
323
324 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
325 {
326         if (unlikely(list_empty(&alg->cra_list)))
327                 return -ENOENT;
328
329         alg->cra_flags |= CRYPTO_ALG_DEAD;
330
331         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
332         list_del_init(&alg->cra_list);
333         crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
334
335         return 0;
336 }
337
338 int crypto_unregister_alg(struct crypto_alg *alg)
339 {
340         int ret;
341         LIST_HEAD(list);
342         
343         down_write(&crypto_alg_sem);
344         ret = crypto_remove_alg(alg, &list);
345         up_write(&crypto_alg_sem);
346
347         if (ret)
348                 return ret;
349
350         BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
351         if (alg->cra_destroy)
352                 alg->cra_destroy(alg);
353
354         crypto_remove_final(&list);
355         return 0;
356 }
357 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
358
359 int crypto_register_template(struct crypto_template *tmpl)
360 {
361         struct crypto_template *q;
362         int err = -EEXIST;
363
364         down_write(&crypto_alg_sem);
365
366         list_for_each_entry(q, &crypto_template_list, list) {
367                 if (q == tmpl)
368                         goto out;
369         }
370
371         list_add(&tmpl->list, &crypto_template_list);
372         crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
373         err = 0;
374 out:
375         up_write(&crypto_alg_sem);
376         return err;
377 }
378 EXPORT_SYMBOL_GPL(crypto_register_template);
379
380 void crypto_unregister_template(struct crypto_template *tmpl)
381 {
382         struct crypto_instance *inst;
383         struct hlist_node *p, *n;
384         struct hlist_head *list;
385         LIST_HEAD(users);
386
387         down_write(&crypto_alg_sem);
388
389         BUG_ON(list_empty(&tmpl->list));
390         list_del_init(&tmpl->list);
391
392         list = &tmpl->instances;
393         hlist_for_each_entry(inst, p, list, list) {
394                 int err = crypto_remove_alg(&inst->alg, &users);
395                 BUG_ON(err);
396         }
397
398         crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
399
400         up_write(&crypto_alg_sem);
401
402         hlist_for_each_entry_safe(inst, p, n, list, list) {
403                 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
404                 tmpl->free(inst);
405         }
406         crypto_remove_final(&users);
407 }
408 EXPORT_SYMBOL_GPL(crypto_unregister_template);
409
410 static struct crypto_template *__crypto_lookup_template(const char *name)
411 {
412         struct crypto_template *q, *tmpl = NULL;
413
414         down_read(&crypto_alg_sem);
415         list_for_each_entry(q, &crypto_template_list, list) {
416                 if (strcmp(q->name, name))
417                         continue;
418                 if (unlikely(!crypto_tmpl_get(q)))
419                         continue;
420
421                 tmpl = q;
422                 break;
423         }
424         up_read(&crypto_alg_sem);
425
426         return tmpl;
427 }
428
429 struct crypto_template *crypto_lookup_template(const char *name)
430 {
431         return try_then_request_module(__crypto_lookup_template(name), name);
432 }
433 EXPORT_SYMBOL_GPL(crypto_lookup_template);
434
435 int crypto_register_instance(struct crypto_template *tmpl,
436                              struct crypto_instance *inst)
437 {
438         struct crypto_larval *larval;
439         int err;
440
441         err = crypto_check_alg(&inst->alg);
442         if (err)
443                 goto err;
444
445         inst->alg.cra_module = tmpl->module;
446
447         down_write(&crypto_alg_sem);
448
449         larval = __crypto_register_alg(&inst->alg);
450         if (IS_ERR(larval))
451                 goto unlock;
452
453         hlist_add_head(&inst->list, &tmpl->instances);
454         inst->tmpl = tmpl;
455
456 unlock:
457         up_write(&crypto_alg_sem);
458
459         err = PTR_ERR(larval);
460         if (IS_ERR(larval))
461                 goto err;
462
463         crypto_wait_for_test(larval);
464         err = 0;
465
466 err:
467         return err;
468 }
469 EXPORT_SYMBOL_GPL(crypto_register_instance);
470
471 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
472                       struct crypto_instance *inst, u32 mask)
473 {
474         int err = -EAGAIN;
475
476         spawn->inst = inst;
477         spawn->mask = mask;
478
479         down_write(&crypto_alg_sem);
480         if (!crypto_is_moribund(alg)) {
481                 list_add(&spawn->list, &alg->cra_users);
482                 spawn->alg = alg;
483                 err = 0;
484         }
485         up_write(&crypto_alg_sem);
486
487         return err;
488 }
489 EXPORT_SYMBOL_GPL(crypto_init_spawn);
490
491 int crypto_init_spawn2(struct crypto_spawn *spawn, struct crypto_alg *alg,
492                        struct crypto_instance *inst,
493                        const struct crypto_type *frontend)
494 {
495         int err = -EINVAL;
496
497         if (frontend && (alg->cra_flags ^ frontend->type) & frontend->maskset)
498                 goto out;
499
500         spawn->frontend = frontend;
501         err = crypto_init_spawn(spawn, alg, inst, frontend->maskset);
502
503 out:
504         return err;
505 }
506 EXPORT_SYMBOL_GPL(crypto_init_spawn2);
507
508 void crypto_drop_spawn(struct crypto_spawn *spawn)
509 {
510         if (!spawn->alg)
511                 return;
512
513         down_write(&crypto_alg_sem);
514         list_del(&spawn->list);
515         up_write(&crypto_alg_sem);
516 }
517 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
518
519 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
520 {
521         struct crypto_alg *alg;
522         struct crypto_alg *alg2;
523
524         down_read(&crypto_alg_sem);
525         alg = spawn->alg;
526         alg2 = alg;
527         if (alg2)
528                 alg2 = crypto_mod_get(alg2);
529         up_read(&crypto_alg_sem);
530
531         if (!alg2) {
532                 if (alg)
533                         crypto_shoot_alg(alg);
534                 return ERR_PTR(-EAGAIN);
535         }
536
537         return alg;
538 }
539
540 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
541                                     u32 mask)
542 {
543         struct crypto_alg *alg;
544         struct crypto_tfm *tfm;
545
546         alg = crypto_spawn_alg(spawn);
547         if (IS_ERR(alg))
548                 return ERR_CAST(alg);
549
550         tfm = ERR_PTR(-EINVAL);
551         if (unlikely((alg->cra_flags ^ type) & mask))
552                 goto out_put_alg;
553
554         tfm = __crypto_alloc_tfm(alg, type, mask);
555         if (IS_ERR(tfm))
556                 goto out_put_alg;
557
558         return tfm;
559
560 out_put_alg:
561         crypto_mod_put(alg);
562         return tfm;
563 }
564 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
565
566 void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
567 {
568         struct crypto_alg *alg;
569         struct crypto_tfm *tfm;
570
571         alg = crypto_spawn_alg(spawn);
572         if (IS_ERR(alg))
573                 return ERR_CAST(alg);
574
575         tfm = crypto_create_tfm(alg, spawn->frontend);
576         if (IS_ERR(tfm))
577                 goto out_put_alg;
578
579         return tfm;
580
581 out_put_alg:
582         crypto_mod_put(alg);
583         return tfm;
584 }
585 EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);
586
587 int crypto_register_notifier(struct notifier_block *nb)
588 {
589         return blocking_notifier_chain_register(&crypto_chain, nb);
590 }
591 EXPORT_SYMBOL_GPL(crypto_register_notifier);
592
593 int crypto_unregister_notifier(struct notifier_block *nb)
594 {
595         return blocking_notifier_chain_unregister(&crypto_chain, nb);
596 }
597 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
598
599 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
600 {
601         struct rtattr *rta = tb[0];
602         struct crypto_attr_type *algt;
603
604         if (!rta)
605                 return ERR_PTR(-ENOENT);
606         if (RTA_PAYLOAD(rta) < sizeof(*algt))
607                 return ERR_PTR(-EINVAL);
608         if (rta->rta_type != CRYPTOA_TYPE)
609                 return ERR_PTR(-EINVAL);
610
611         algt = RTA_DATA(rta);
612
613         return algt;
614 }
615 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
616
617 int crypto_check_attr_type(struct rtattr **tb, u32 type)
618 {
619         struct crypto_attr_type *algt;
620
621         algt = crypto_get_attr_type(tb);
622         if (IS_ERR(algt))
623                 return PTR_ERR(algt);
624
625         if ((algt->type ^ type) & algt->mask)
626                 return -EINVAL;
627
628         return 0;
629 }
630 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
631
632 const char *crypto_attr_alg_name(struct rtattr *rta)
633 {
634         struct crypto_attr_alg *alga;
635
636         if (!rta)
637                 return ERR_PTR(-ENOENT);
638         if (RTA_PAYLOAD(rta) < sizeof(*alga))
639                 return ERR_PTR(-EINVAL);
640         if (rta->rta_type != CRYPTOA_ALG)
641                 return ERR_PTR(-EINVAL);
642
643         alga = RTA_DATA(rta);
644         alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
645
646         return alga->name;
647 }
648 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
649
650 struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
651                                     const struct crypto_type *frontend,
652                                     u32 type, u32 mask)
653 {
654         const char *name;
655         int err;
656
657         name = crypto_attr_alg_name(rta);
658         err = PTR_ERR(name);
659         if (IS_ERR(name))
660                 return ERR_PTR(err);
661
662         return crypto_find_alg(name, frontend, type, mask);
663 }
664 EXPORT_SYMBOL_GPL(crypto_attr_alg2);
665
666 int crypto_attr_u32(struct rtattr *rta, u32 *num)
667 {
668         struct crypto_attr_u32 *nu32;
669
670         if (!rta)
671                 return -ENOENT;
672         if (RTA_PAYLOAD(rta) < sizeof(*nu32))
673                 return -EINVAL;
674         if (rta->rta_type != CRYPTOA_U32)
675                 return -EINVAL;
676
677         nu32 = RTA_DATA(rta);
678         *num = nu32->num;
679
680         return 0;
681 }
682 EXPORT_SYMBOL_GPL(crypto_attr_u32);
683
684 void *crypto_alloc_instance2(const char *name, struct crypto_alg *alg,
685                              unsigned int head)
686 {
687         struct crypto_instance *inst;
688         char *p;
689         int err;
690
691         p = kzalloc(head + sizeof(*inst) + sizeof(struct crypto_spawn),
692                     GFP_KERNEL);
693         if (!p)
694                 return ERR_PTR(-ENOMEM);
695
696         inst = (void *)(p + head);
697
698         err = -ENAMETOOLONG;
699         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
700                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
701                 goto err_free_inst;
702
703         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
704                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
705                 goto err_free_inst;
706
707         return p;
708
709 err_free_inst:
710         kfree(p);
711         return ERR_PTR(err);
712 }
713 EXPORT_SYMBOL_GPL(crypto_alloc_instance2);
714
715 struct crypto_instance *crypto_alloc_instance(const char *name,
716                                               struct crypto_alg *alg)
717 {
718         struct crypto_instance *inst;
719         struct crypto_spawn *spawn;
720         int err;
721
722         inst = crypto_alloc_instance2(name, alg, 0);
723         if (IS_ERR(inst))
724                 goto out;
725
726         spawn = crypto_instance_ctx(inst);
727         err = crypto_init_spawn(spawn, alg, inst,
728                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
729
730         if (err)
731                 goto err_free_inst;
732
733         return inst;
734
735 err_free_inst:
736         kfree(inst);
737         inst = ERR_PTR(err);
738
739 out:
740         return inst;
741 }
742 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
743
744 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
745 {
746         INIT_LIST_HEAD(&queue->list);
747         queue->backlog = &queue->list;
748         queue->qlen = 0;
749         queue->max_qlen = max_qlen;
750 }
751 EXPORT_SYMBOL_GPL(crypto_init_queue);
752
753 int crypto_enqueue_request(struct crypto_queue *queue,
754                            struct crypto_async_request *request)
755 {
756         int err = -EINPROGRESS;
757
758         if (unlikely(queue->qlen >= queue->max_qlen)) {
759                 err = -EBUSY;
760                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
761                         goto out;
762                 if (queue->backlog == &queue->list)
763                         queue->backlog = &request->list;
764         }
765
766         queue->qlen++;
767         list_add_tail(&request->list, &queue->list);
768
769 out:
770         return err;
771 }
772 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
773
774 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
775 {
776         struct list_head *request;
777
778         if (unlikely(!queue->qlen))
779                 return NULL;
780
781         queue->qlen--;
782
783         if (queue->backlog != &queue->list)
784                 queue->backlog = queue->backlog->next;
785
786         request = queue->list.next;
787         list_del(request);
788
789         return list_entry(request, struct crypto_async_request, list);
790 }
791 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
792
793 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
794 {
795         struct crypto_async_request *req;
796
797         list_for_each_entry(req, &queue->list, list) {
798                 if (req->tfm == tfm)
799                         return 1;
800         }
801
802         return 0;
803 }
804 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
805
806 static inline void crypto_inc_byte(u8 *a, unsigned int size)
807 {
808         u8 *b = (a + size);
809         u8 c;
810
811         for (; size; size--) {
812                 c = *--b + 1;
813                 *b = c;
814                 if (c)
815                         break;
816         }
817 }
818
819 void crypto_inc(u8 *a, unsigned int size)
820 {
821         __be32 *b = (__be32 *)(a + size);
822         u32 c;
823
824         for (; size >= 4; size -= 4) {
825                 c = be32_to_cpu(*--b) + 1;
826                 *b = cpu_to_be32(c);
827                 if (c)
828                         return;
829         }
830
831         crypto_inc_byte(a, size);
832 }
833 EXPORT_SYMBOL_GPL(crypto_inc);
834
835 static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
836 {
837         for (; size; size--)
838                 *a++ ^= *b++;
839 }
840
841 void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
842 {
843         u32 *a = (u32 *)dst;
844         u32 *b = (u32 *)src;
845
846         for (; size >= 4; size -= 4)
847                 *a++ ^= *b++;
848
849         crypto_xor_byte((u8 *)a, (u8 *)b, size);
850 }
851 EXPORT_SYMBOL_GPL(crypto_xor);
852
853 static int __init crypto_algapi_init(void)
854 {
855         crypto_init_proc();
856         return 0;
857 }
858
859 static void __exit crypto_algapi_exit(void)
860 {
861         crypto_exit_proc();
862 }
863
864 module_init(crypto_algapi_init);
865 module_exit(crypto_algapi_exit);
866
867 MODULE_LICENSE("GPL");
868 MODULE_DESCRIPTION("Cryptographic algorithms API");