xref: /linux/crypto/algapi.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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/slab.h>
21 #include <linux/string.h>
22 
23 #include "internal.h"
24 
25 static void crypto_remove_final(struct list_head *list);
26 
27 static LIST_HEAD(crypto_template_list);
28 
29 void crypto_larval_error(const char *name, u32 type, u32 mask)
30 {
31 	struct crypto_alg *alg;
32 
33 	alg = crypto_alg_lookup(name, type, mask);
34 
35 	if (alg) {
36 		if (crypto_is_larval(alg)) {
37 			struct crypto_larval *larval = (void *)alg;
38 			complete_all(&larval->completion);
39 		}
40 		crypto_mod_put(alg);
41 	}
42 }
43 EXPORT_SYMBOL_GPL(crypto_larval_error);
44 
45 static inline int crypto_set_driver_name(struct crypto_alg *alg)
46 {
47 	static const char suffix[] = "-generic";
48 	char *driver_name = alg->cra_driver_name;
49 	int len;
50 
51 	if (*driver_name)
52 		return 0;
53 
54 	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
55 	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
56 		return -ENAMETOOLONG;
57 
58 	memcpy(driver_name + len, suffix, sizeof(suffix));
59 	return 0;
60 }
61 
62 static int crypto_check_alg(struct crypto_alg *alg)
63 {
64 	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
65 		return -EINVAL;
66 
67 	if (alg->cra_blocksize > PAGE_SIZE / 8)
68 		return -EINVAL;
69 
70 	if (alg->cra_priority < 0)
71 		return -EINVAL;
72 
73 	return crypto_set_driver_name(alg);
74 }
75 
76 static void crypto_destroy_instance(struct crypto_alg *alg)
77 {
78 	struct crypto_instance *inst = (void *)alg;
79 	struct crypto_template *tmpl = inst->tmpl;
80 
81 	tmpl->free(inst);
82 	crypto_tmpl_put(tmpl);
83 }
84 
85 static struct list_head *crypto_more_spawns(struct crypto_alg *alg,
86 					    struct list_head *stack,
87 					    struct list_head *top,
88 					    struct list_head *secondary_spawns)
89 {
90 	struct crypto_spawn *spawn, *n;
91 
92 	if (list_empty(stack))
93 		return NULL;
94 
95 	spawn = list_first_entry(stack, struct crypto_spawn, list);
96 	n = list_entry(spawn->list.next, struct crypto_spawn, list);
97 
98 	if (spawn->alg && &n->list != stack && !n->alg)
99 		n->alg = (n->list.next == stack) ? alg :
100 			 &list_entry(n->list.next, struct crypto_spawn,
101 				     list)->inst->alg;
102 
103 	list_move(&spawn->list, secondary_spawns);
104 
105 	return &n->list == stack ? top : &n->inst->alg.cra_users;
106 }
107 
108 static void crypto_remove_spawn(struct crypto_spawn *spawn,
109 				struct list_head *list)
110 {
111 	struct crypto_instance *inst = spawn->inst;
112 	struct crypto_template *tmpl = inst->tmpl;
113 
114 	if (crypto_is_dead(&inst->alg))
115 		return;
116 
117 	inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
118 	if (hlist_unhashed(&inst->list))
119 		return;
120 
121 	if (!tmpl || !crypto_tmpl_get(tmpl))
122 		return;
123 
124 	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
125 	list_move(&inst->alg.cra_list, list);
126 	hlist_del(&inst->list);
127 	inst->alg.cra_destroy = crypto_destroy_instance;
128 
129 	BUG_ON(!list_empty(&inst->alg.cra_users));
130 }
131 
132 static void crypto_remove_spawns(struct crypto_alg *alg,
133 				 struct list_head *list,
134 				 struct crypto_alg *nalg)
135 {
136 	u32 new_type = (nalg ?: alg)->cra_flags;
137 	struct crypto_spawn *spawn, *n;
138 	LIST_HEAD(secondary_spawns);
139 	struct list_head *spawns;
140 	LIST_HEAD(stack);
141 	LIST_HEAD(top);
142 
143 	spawns = &alg->cra_users;
144 	list_for_each_entry_safe(spawn, n, spawns, list) {
145 		if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
146 			continue;
147 
148 		list_move(&spawn->list, &top);
149 	}
150 
151 	spawns = &top;
152 	do {
153 		while (!list_empty(spawns)) {
154 			struct crypto_instance *inst;
155 
156 			spawn = list_first_entry(spawns, struct crypto_spawn,
157 						 list);
158 			inst = spawn->inst;
159 
160 			BUG_ON(&inst->alg == alg);
161 
162 			list_move(&spawn->list, &stack);
163 
164 			if (&inst->alg == nalg)
165 				break;
166 
167 			spawn->alg = NULL;
168 			spawns = &inst->alg.cra_users;
169 		}
170 	} while ((spawns = crypto_more_spawns(alg, &stack, &top,
171 					      &secondary_spawns)));
172 
173 	list_for_each_entry_safe(spawn, n, &secondary_spawns, list) {
174 		if (spawn->alg)
175 			list_move(&spawn->list, &spawn->alg->cra_users);
176 		else
177 			crypto_remove_spawn(spawn, list);
178 	}
179 }
180 
181 static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
182 {
183 	struct crypto_alg *q;
184 	struct crypto_larval *larval;
185 	int ret = -EAGAIN;
186 
187 	if (crypto_is_dead(alg))
188 		goto err;
189 
190 	INIT_LIST_HEAD(&alg->cra_users);
191 
192 	/* No cheating! */
193 	alg->cra_flags &= ~CRYPTO_ALG_TESTED;
194 
195 	ret = -EEXIST;
196 
197 	atomic_set(&alg->cra_refcnt, 1);
198 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
199 		if (q == alg)
200 			goto err;
201 
202 		if (crypto_is_moribund(q))
203 			continue;
204 
205 		if (crypto_is_larval(q)) {
206 			if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
207 				goto err;
208 			continue;
209 		}
210 
211 		if (!strcmp(q->cra_driver_name, alg->cra_name) ||
212 		    !strcmp(q->cra_name, alg->cra_driver_name))
213 			goto err;
214 	}
215 
216 	larval = crypto_larval_alloc(alg->cra_name,
217 				     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
218 	if (IS_ERR(larval))
219 		goto out;
220 
221 	ret = -ENOENT;
222 	larval->adult = crypto_mod_get(alg);
223 	if (!larval->adult)
224 		goto free_larval;
225 
226 	atomic_set(&larval->alg.cra_refcnt, 1);
227 	memcpy(larval->alg.cra_driver_name, alg->cra_driver_name,
228 	       CRYPTO_MAX_ALG_NAME);
229 	larval->alg.cra_priority = alg->cra_priority;
230 
231 	list_add(&alg->cra_list, &crypto_alg_list);
232 	list_add(&larval->alg.cra_list, &crypto_alg_list);
233 
234 out:
235 	return larval;
236 
237 free_larval:
238 	kfree(larval);
239 err:
240 	larval = ERR_PTR(ret);
241 	goto out;
242 }
243 
244 void crypto_alg_tested(const char *name, int err)
245 {
246 	struct crypto_larval *test;
247 	struct crypto_alg *alg;
248 	struct crypto_alg *q;
249 	LIST_HEAD(list);
250 
251 	down_write(&crypto_alg_sem);
252 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
253 		if (crypto_is_moribund(q) || !crypto_is_larval(q))
254 			continue;
255 
256 		test = (struct crypto_larval *)q;
257 
258 		if (!strcmp(q->cra_driver_name, name))
259 			goto found;
260 	}
261 
262 	printk(KERN_ERR "alg: Unexpected test result for %s: %d\n", name, err);
263 	goto unlock;
264 
265 found:
266 	q->cra_flags |= CRYPTO_ALG_DEAD;
267 	alg = test->adult;
268 	if (err || list_empty(&alg->cra_list))
269 		goto complete;
270 
271 	alg->cra_flags |= CRYPTO_ALG_TESTED;
272 
273 	list_for_each_entry(q, &crypto_alg_list, cra_list) {
274 		if (q == alg)
275 			continue;
276 
277 		if (crypto_is_moribund(q))
278 			continue;
279 
280 		if (crypto_is_larval(q)) {
281 			struct crypto_larval *larval = (void *)q;
282 
283 			/*
284 			 * Check to see if either our generic name or
285 			 * specific name can satisfy the name requested
286 			 * by the larval entry q.
287 			 */
288 			if (strcmp(alg->cra_name, q->cra_name) &&
289 			    strcmp(alg->cra_driver_name, q->cra_name))
290 				continue;
291 
292 			if (larval->adult)
293 				continue;
294 			if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
295 				continue;
296 			if (!crypto_mod_get(alg))
297 				continue;
298 
299 			larval->adult = alg;
300 			complete_all(&larval->completion);
301 			continue;
302 		}
303 
304 		if (strcmp(alg->cra_name, q->cra_name))
305 			continue;
306 
307 		if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
308 		    q->cra_priority > alg->cra_priority)
309 			continue;
310 
311 		crypto_remove_spawns(q, &list, alg);
312 	}
313 
314 complete:
315 	complete_all(&test->completion);
316 
317 unlock:
318 	up_write(&crypto_alg_sem);
319 
320 	crypto_remove_final(&list);
321 }
322 EXPORT_SYMBOL_GPL(crypto_alg_tested);
323 
324 static void crypto_remove_final(struct list_head *list)
325 {
326 	struct crypto_alg *alg;
327 	struct crypto_alg *n;
328 
329 	list_for_each_entry_safe(alg, n, list, cra_list) {
330 		list_del_init(&alg->cra_list);
331 		crypto_alg_put(alg);
332 	}
333 }
334 
335 static void crypto_wait_for_test(struct crypto_larval *larval)
336 {
337 	int err;
338 
339 	err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
340 	if (err != NOTIFY_STOP) {
341 		if (WARN_ON(err != NOTIFY_DONE))
342 			goto out;
343 		crypto_alg_tested(larval->alg.cra_driver_name, 0);
344 	}
345 
346 	err = wait_for_completion_interruptible(&larval->completion);
347 	WARN_ON(err);
348 
349 out:
350 	crypto_larval_kill(&larval->alg);
351 }
352 
353 int crypto_register_alg(struct crypto_alg *alg)
354 {
355 	struct crypto_larval *larval;
356 	int err;
357 
358 	err = crypto_check_alg(alg);
359 	if (err)
360 		return err;
361 
362 	down_write(&crypto_alg_sem);
363 	larval = __crypto_register_alg(alg);
364 	up_write(&crypto_alg_sem);
365 
366 	if (IS_ERR(larval))
367 		return PTR_ERR(larval);
368 
369 	crypto_wait_for_test(larval);
370 	return 0;
371 }
372 EXPORT_SYMBOL_GPL(crypto_register_alg);
373 
374 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
375 {
376 	if (unlikely(list_empty(&alg->cra_list)))
377 		return -ENOENT;
378 
379 	alg->cra_flags |= CRYPTO_ALG_DEAD;
380 
381 	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
382 	list_del_init(&alg->cra_list);
383 	crypto_remove_spawns(alg, list, NULL);
384 
385 	return 0;
386 }
387 
388 int crypto_unregister_alg(struct crypto_alg *alg)
389 {
390 	int ret;
391 	LIST_HEAD(list);
392 
393 	down_write(&crypto_alg_sem);
394 	ret = crypto_remove_alg(alg, &list);
395 	up_write(&crypto_alg_sem);
396 
397 	if (ret)
398 		return ret;
399 
400 	BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
401 	if (alg->cra_destroy)
402 		alg->cra_destroy(alg);
403 
404 	crypto_remove_final(&list);
405 	return 0;
406 }
407 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
408 
409 int crypto_register_template(struct crypto_template *tmpl)
410 {
411 	struct crypto_template *q;
412 	int err = -EEXIST;
413 
414 	down_write(&crypto_alg_sem);
415 
416 	list_for_each_entry(q, &crypto_template_list, list) {
417 		if (q == tmpl)
418 			goto out;
419 	}
420 
421 	list_add(&tmpl->list, &crypto_template_list);
422 	crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
423 	err = 0;
424 out:
425 	up_write(&crypto_alg_sem);
426 	return err;
427 }
428 EXPORT_SYMBOL_GPL(crypto_register_template);
429 
430 void crypto_unregister_template(struct crypto_template *tmpl)
431 {
432 	struct crypto_instance *inst;
433 	struct hlist_node *p, *n;
434 	struct hlist_head *list;
435 	LIST_HEAD(users);
436 
437 	down_write(&crypto_alg_sem);
438 
439 	BUG_ON(list_empty(&tmpl->list));
440 	list_del_init(&tmpl->list);
441 
442 	list = &tmpl->instances;
443 	hlist_for_each_entry(inst, p, list, list) {
444 		int err = crypto_remove_alg(&inst->alg, &users);
445 		BUG_ON(err);
446 	}
447 
448 	crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
449 
450 	up_write(&crypto_alg_sem);
451 
452 	hlist_for_each_entry_safe(inst, p, n, list, list) {
453 		BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
454 		tmpl->free(inst);
455 	}
456 	crypto_remove_final(&users);
457 }
458 EXPORT_SYMBOL_GPL(crypto_unregister_template);
459 
460 static struct crypto_template *__crypto_lookup_template(const char *name)
461 {
462 	struct crypto_template *q, *tmpl = NULL;
463 
464 	down_read(&crypto_alg_sem);
465 	list_for_each_entry(q, &crypto_template_list, list) {
466 		if (strcmp(q->name, name))
467 			continue;
468 		if (unlikely(!crypto_tmpl_get(q)))
469 			continue;
470 
471 		tmpl = q;
472 		break;
473 	}
474 	up_read(&crypto_alg_sem);
475 
476 	return tmpl;
477 }
478 
479 struct crypto_template *crypto_lookup_template(const char *name)
480 {
481 	return try_then_request_module(__crypto_lookup_template(name), name);
482 }
483 EXPORT_SYMBOL_GPL(crypto_lookup_template);
484 
485 int crypto_register_instance(struct crypto_template *tmpl,
486 			     struct crypto_instance *inst)
487 {
488 	struct crypto_larval *larval;
489 	int err;
490 
491 	err = crypto_check_alg(&inst->alg);
492 	if (err)
493 		goto err;
494 
495 	inst->alg.cra_module = tmpl->module;
496 
497 	down_write(&crypto_alg_sem);
498 
499 	larval = __crypto_register_alg(&inst->alg);
500 	if (IS_ERR(larval))
501 		goto unlock;
502 
503 	hlist_add_head(&inst->list, &tmpl->instances);
504 	inst->tmpl = tmpl;
505 
506 unlock:
507 	up_write(&crypto_alg_sem);
508 
509 	err = PTR_ERR(larval);
510 	if (IS_ERR(larval))
511 		goto err;
512 
513 	crypto_wait_for_test(larval);
514 	err = 0;
515 
516 err:
517 	return err;
518 }
519 EXPORT_SYMBOL_GPL(crypto_register_instance);
520 
521 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
522 		      struct crypto_instance *inst, u32 mask)
523 {
524 	int err = -EAGAIN;
525 
526 	spawn->inst = inst;
527 	spawn->mask = mask;
528 
529 	down_write(&crypto_alg_sem);
530 	if (!crypto_is_moribund(alg)) {
531 		list_add(&spawn->list, &alg->cra_users);
532 		spawn->alg = alg;
533 		err = 0;
534 	}
535 	up_write(&crypto_alg_sem);
536 
537 	return err;
538 }
539 EXPORT_SYMBOL_GPL(crypto_init_spawn);
540 
541 int crypto_init_spawn2(struct crypto_spawn *spawn, struct crypto_alg *alg,
542 		       struct crypto_instance *inst,
543 		       const struct crypto_type *frontend)
544 {
545 	int err = -EINVAL;
546 
547 	if ((alg->cra_flags ^ frontend->type) & frontend->maskset)
548 		goto out;
549 
550 	spawn->frontend = frontend;
551 	err = crypto_init_spawn(spawn, alg, inst, frontend->maskset);
552 
553 out:
554 	return err;
555 }
556 EXPORT_SYMBOL_GPL(crypto_init_spawn2);
557 
558 void crypto_drop_spawn(struct crypto_spawn *spawn)
559 {
560 	if (!spawn->alg)
561 		return;
562 
563 	down_write(&crypto_alg_sem);
564 	list_del(&spawn->list);
565 	up_write(&crypto_alg_sem);
566 }
567 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
568 
569 static struct crypto_alg *crypto_spawn_alg(struct crypto_spawn *spawn)
570 {
571 	struct crypto_alg *alg;
572 	struct crypto_alg *alg2;
573 
574 	down_read(&crypto_alg_sem);
575 	alg = spawn->alg;
576 	alg2 = alg;
577 	if (alg2)
578 		alg2 = crypto_mod_get(alg2);
579 	up_read(&crypto_alg_sem);
580 
581 	if (!alg2) {
582 		if (alg)
583 			crypto_shoot_alg(alg);
584 		return ERR_PTR(-EAGAIN);
585 	}
586 
587 	return alg;
588 }
589 
590 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
591 				    u32 mask)
592 {
593 	struct crypto_alg *alg;
594 	struct crypto_tfm *tfm;
595 
596 	alg = crypto_spawn_alg(spawn);
597 	if (IS_ERR(alg))
598 		return ERR_CAST(alg);
599 
600 	tfm = ERR_PTR(-EINVAL);
601 	if (unlikely((alg->cra_flags ^ type) & mask))
602 		goto out_put_alg;
603 
604 	tfm = __crypto_alloc_tfm(alg, type, mask);
605 	if (IS_ERR(tfm))
606 		goto out_put_alg;
607 
608 	return tfm;
609 
610 out_put_alg:
611 	crypto_mod_put(alg);
612 	return tfm;
613 }
614 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
615 
616 void *crypto_spawn_tfm2(struct crypto_spawn *spawn)
617 {
618 	struct crypto_alg *alg;
619 	struct crypto_tfm *tfm;
620 
621 	alg = crypto_spawn_alg(spawn);
622 	if (IS_ERR(alg))
623 		return ERR_CAST(alg);
624 
625 	tfm = crypto_create_tfm(alg, spawn->frontend);
626 	if (IS_ERR(tfm))
627 		goto out_put_alg;
628 
629 	return tfm;
630 
631 out_put_alg:
632 	crypto_mod_put(alg);
633 	return tfm;
634 }
635 EXPORT_SYMBOL_GPL(crypto_spawn_tfm2);
636 
637 int crypto_register_notifier(struct notifier_block *nb)
638 {
639 	return blocking_notifier_chain_register(&crypto_chain, nb);
640 }
641 EXPORT_SYMBOL_GPL(crypto_register_notifier);
642 
643 int crypto_unregister_notifier(struct notifier_block *nb)
644 {
645 	return blocking_notifier_chain_unregister(&crypto_chain, nb);
646 }
647 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
648 
649 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
650 {
651 	struct rtattr *rta = tb[0];
652 	struct crypto_attr_type *algt;
653 
654 	if (!rta)
655 		return ERR_PTR(-ENOENT);
656 	if (RTA_PAYLOAD(rta) < sizeof(*algt))
657 		return ERR_PTR(-EINVAL);
658 	if (rta->rta_type != CRYPTOA_TYPE)
659 		return ERR_PTR(-EINVAL);
660 
661 	algt = RTA_DATA(rta);
662 
663 	return algt;
664 }
665 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
666 
667 int crypto_check_attr_type(struct rtattr **tb, u32 type)
668 {
669 	struct crypto_attr_type *algt;
670 
671 	algt = crypto_get_attr_type(tb);
672 	if (IS_ERR(algt))
673 		return PTR_ERR(algt);
674 
675 	if ((algt->type ^ type) & algt->mask)
676 		return -EINVAL;
677 
678 	return 0;
679 }
680 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
681 
682 const char *crypto_attr_alg_name(struct rtattr *rta)
683 {
684 	struct crypto_attr_alg *alga;
685 
686 	if (!rta)
687 		return ERR_PTR(-ENOENT);
688 	if (RTA_PAYLOAD(rta) < sizeof(*alga))
689 		return ERR_PTR(-EINVAL);
690 	if (rta->rta_type != CRYPTOA_ALG)
691 		return ERR_PTR(-EINVAL);
692 
693 	alga = RTA_DATA(rta);
694 	alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
695 
696 	return alga->name;
697 }
698 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
699 
700 struct crypto_alg *crypto_attr_alg2(struct rtattr *rta,
701 				    const struct crypto_type *frontend,
702 				    u32 type, u32 mask)
703 {
704 	const char *name;
705 	int err;
706 
707 	name = crypto_attr_alg_name(rta);
708 	err = PTR_ERR(name);
709 	if (IS_ERR(name))
710 		return ERR_PTR(err);
711 
712 	return crypto_find_alg(name, frontend, type, mask);
713 }
714 EXPORT_SYMBOL_GPL(crypto_attr_alg2);
715 
716 int crypto_attr_u32(struct rtattr *rta, u32 *num)
717 {
718 	struct crypto_attr_u32 *nu32;
719 
720 	if (!rta)
721 		return -ENOENT;
722 	if (RTA_PAYLOAD(rta) < sizeof(*nu32))
723 		return -EINVAL;
724 	if (rta->rta_type != CRYPTOA_U32)
725 		return -EINVAL;
726 
727 	nu32 = RTA_DATA(rta);
728 	*num = nu32->num;
729 
730 	return 0;
731 }
732 EXPORT_SYMBOL_GPL(crypto_attr_u32);
733 
734 void *crypto_alloc_instance2(const char *name, struct crypto_alg *alg,
735 			     unsigned int head)
736 {
737 	struct crypto_instance *inst;
738 	char *p;
739 	int err;
740 
741 	p = kzalloc(head + sizeof(*inst) + sizeof(struct crypto_spawn),
742 		    GFP_KERNEL);
743 	if (!p)
744 		return ERR_PTR(-ENOMEM);
745 
746 	inst = (void *)(p + head);
747 
748 	err = -ENAMETOOLONG;
749 	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
750 		     alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
751 		goto err_free_inst;
752 
753 	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
754 		     name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
755 		goto err_free_inst;
756 
757 	return p;
758 
759 err_free_inst:
760 	kfree(p);
761 	return ERR_PTR(err);
762 }
763 EXPORT_SYMBOL_GPL(crypto_alloc_instance2);
764 
765 struct crypto_instance *crypto_alloc_instance(const char *name,
766 					      struct crypto_alg *alg)
767 {
768 	struct crypto_instance *inst;
769 	struct crypto_spawn *spawn;
770 	int err;
771 
772 	inst = crypto_alloc_instance2(name, alg, 0);
773 	if (IS_ERR(inst))
774 		goto out;
775 
776 	spawn = crypto_instance_ctx(inst);
777 	err = crypto_init_spawn(spawn, alg, inst,
778 				CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
779 
780 	if (err)
781 		goto err_free_inst;
782 
783 	return inst;
784 
785 err_free_inst:
786 	kfree(inst);
787 	inst = ERR_PTR(err);
788 
789 out:
790 	return inst;
791 }
792 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
793 
794 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
795 {
796 	INIT_LIST_HEAD(&queue->list);
797 	queue->backlog = &queue->list;
798 	queue->qlen = 0;
799 	queue->max_qlen = max_qlen;
800 }
801 EXPORT_SYMBOL_GPL(crypto_init_queue);
802 
803 int crypto_enqueue_request(struct crypto_queue *queue,
804 			   struct crypto_async_request *request)
805 {
806 	int err = -EINPROGRESS;
807 
808 	if (unlikely(queue->qlen >= queue->max_qlen)) {
809 		err = -EBUSY;
810 		if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
811 			goto out;
812 		if (queue->backlog == &queue->list)
813 			queue->backlog = &request->list;
814 	}
815 
816 	queue->qlen++;
817 	list_add_tail(&request->list, &queue->list);
818 
819 out:
820 	return err;
821 }
822 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
823 
824 void *__crypto_dequeue_request(struct crypto_queue *queue, unsigned int offset)
825 {
826 	struct list_head *request;
827 
828 	if (unlikely(!queue->qlen))
829 		return NULL;
830 
831 	queue->qlen--;
832 
833 	if (queue->backlog != &queue->list)
834 		queue->backlog = queue->backlog->next;
835 
836 	request = queue->list.next;
837 	list_del(request);
838 
839 	return (char *)list_entry(request, struct crypto_async_request, list) -
840 	       offset;
841 }
842 EXPORT_SYMBOL_GPL(__crypto_dequeue_request);
843 
844 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
845 {
846 	return __crypto_dequeue_request(queue, 0);
847 }
848 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
849 
850 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
851 {
852 	struct crypto_async_request *req;
853 
854 	list_for_each_entry(req, &queue->list, list) {
855 		if (req->tfm == tfm)
856 			return 1;
857 	}
858 
859 	return 0;
860 }
861 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
862 
863 static inline void crypto_inc_byte(u8 *a, unsigned int size)
864 {
865 	u8 *b = (a + size);
866 	u8 c;
867 
868 	for (; size; size--) {
869 		c = *--b + 1;
870 		*b = c;
871 		if (c)
872 			break;
873 	}
874 }
875 
876 void crypto_inc(u8 *a, unsigned int size)
877 {
878 	__be32 *b = (__be32 *)(a + size);
879 	u32 c;
880 
881 	for (; size >= 4; size -= 4) {
882 		c = be32_to_cpu(*--b) + 1;
883 		*b = cpu_to_be32(c);
884 		if (c)
885 			return;
886 	}
887 
888 	crypto_inc_byte(a, size);
889 }
890 EXPORT_SYMBOL_GPL(crypto_inc);
891 
892 static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
893 {
894 	for (; size; size--)
895 		*a++ ^= *b++;
896 }
897 
898 void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
899 {
900 	u32 *a = (u32 *)dst;
901 	u32 *b = (u32 *)src;
902 
903 	for (; size >= 4; size -= 4)
904 		*a++ ^= *b++;
905 
906 	crypto_xor_byte((u8 *)a, (u8 *)b, size);
907 }
908 EXPORT_SYMBOL_GPL(crypto_xor);
909 
910 static int __init crypto_algapi_init(void)
911 {
912 	crypto_init_proc();
913 	return 0;
914 }
915 
916 static void __exit crypto_algapi_exit(void)
917 {
918 	crypto_exit_proc();
919 }
920 
921 module_init(crypto_algapi_init);
922 module_exit(crypto_algapi_exit);
923 
924 MODULE_LICENSE("GPL");
925 MODULE_DESCRIPTION("Cryptographic algorithms API");
926