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v3.15
  1/*
  2 * Scatterlist Cryptographic API.
  3 *
  4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  5 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
  6 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
  7 *
  8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
  9 * and Nettle, by Niels Möller.
 10 *
 11 * This program is free software; you can redistribute it and/or modify it
 12 * under the terms of the GNU General Public License as published by the Free
 13 * Software Foundation; either version 2 of the License, or (at your option)
 14 * any later version.
 15 *
 16 */
 17
 18#include <linux/err.h>
 19#include <linux/errno.h>
 20#include <linux/kernel.h>
 21#include <linux/kmod.h>
 22#include <linux/module.h>
 23#include <linux/param.h>
 24#include <linux/sched.h>
 25#include <linux/slab.h>
 26#include <linux/string.h>
 27#include "internal.h"
 28
 29LIST_HEAD(crypto_alg_list);
 30EXPORT_SYMBOL_GPL(crypto_alg_list);
 31DECLARE_RWSEM(crypto_alg_sem);
 32EXPORT_SYMBOL_GPL(crypto_alg_sem);
 33
 34BLOCKING_NOTIFIER_HEAD(crypto_chain);
 35EXPORT_SYMBOL_GPL(crypto_chain);
 36
 37static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
 38
 39struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
 40{
 41	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
 42}
 43EXPORT_SYMBOL_GPL(crypto_mod_get);
 44
 45void crypto_mod_put(struct crypto_alg *alg)
 46{
 47	struct module *module = alg->cra_module;
 48
 49	crypto_alg_put(alg);
 50	module_put(module);
 51}
 52EXPORT_SYMBOL_GPL(crypto_mod_put);
 53
 54static inline int crypto_is_test_larval(struct crypto_larval *larval)
 55{
 56	return larval->alg.cra_driver_name[0];
 57}
 58
 59static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
 60					      u32 mask)
 61{
 62	struct crypto_alg *q, *alg = NULL;
 63	int best = -2;
 64
 65	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 66		int exact, fuzzy;
 67
 68		if (crypto_is_moribund(q))
 69			continue;
 70
 71		if ((q->cra_flags ^ type) & mask)
 72			continue;
 73
 74		if (crypto_is_larval(q) &&
 75		    !crypto_is_test_larval((struct crypto_larval *)q) &&
 76		    ((struct crypto_larval *)q)->mask != mask)
 77			continue;
 78
 79		exact = !strcmp(q->cra_driver_name, name);
 80		fuzzy = !strcmp(q->cra_name, name);
 81		if (!exact && !(fuzzy && q->cra_priority > best))
 82			continue;
 83
 84		if (unlikely(!crypto_mod_get(q)))
 85			continue;
 86
 87		best = q->cra_priority;
 88		if (alg)
 89			crypto_mod_put(alg);
 90		alg = q;
 91
 92		if (exact)
 93			break;
 94	}
 95
 96	return alg;
 97}
 98
 99static void crypto_larval_destroy(struct crypto_alg *alg)
100{
101	struct crypto_larval *larval = (void *)alg;
102
103	BUG_ON(!crypto_is_larval(alg));
104	if (larval->adult)
105		crypto_mod_put(larval->adult);
106	kfree(larval);
107}
108
109struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
110{
111	struct crypto_larval *larval;
112
113	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114	if (!larval)
115		return ERR_PTR(-ENOMEM);
116
117	larval->mask = mask;
118	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
119	larval->alg.cra_priority = -1;
120	larval->alg.cra_destroy = crypto_larval_destroy;
121
122	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
123	init_completion(&larval->completion);
124
125	return larval;
126}
127EXPORT_SYMBOL_GPL(crypto_larval_alloc);
128
129static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
130					    u32 mask)
131{
132	struct crypto_alg *alg;
133	struct crypto_larval *larval;
134
135	larval = crypto_larval_alloc(name, type, mask);
136	if (IS_ERR(larval))
137		return ERR_CAST(larval);
138
139	atomic_set(&larval->alg.cra_refcnt, 2);
140
141	down_write(&crypto_alg_sem);
142	alg = __crypto_alg_lookup(name, type, mask);
143	if (!alg) {
144		alg = &larval->alg;
145		list_add(&alg->cra_list, &crypto_alg_list);
146	}
147	up_write(&crypto_alg_sem);
148
149	if (alg != &larval->alg) {
150		kfree(larval);
151		if (crypto_is_larval(alg))
152			alg = crypto_larval_wait(alg);
153	}
154
155	return alg;
156}
157
158void crypto_larval_kill(struct crypto_alg *alg)
159{
160	struct crypto_larval *larval = (void *)alg;
161
162	down_write(&crypto_alg_sem);
163	list_del(&alg->cra_list);
164	up_write(&crypto_alg_sem);
165	complete_all(&larval->completion);
166	crypto_alg_put(alg);
167}
168EXPORT_SYMBOL_GPL(crypto_larval_kill);
169
170static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
171{
172	struct crypto_larval *larval = (void *)alg;
173	long timeout;
174
175	timeout = wait_for_completion_interruptible_timeout(
176		&larval->completion, 60 * HZ);
177
178	alg = larval->adult;
179	if (timeout < 0)
180		alg = ERR_PTR(-EINTR);
181	else if (!timeout)
182		alg = ERR_PTR(-ETIMEDOUT);
183	else if (!alg)
184		alg = ERR_PTR(-ENOENT);
185	else if (crypto_is_test_larval(larval) &&
186		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
187		alg = ERR_PTR(-EAGAIN);
188	else if (!crypto_mod_get(alg))
189		alg = ERR_PTR(-EAGAIN);
190	crypto_mod_put(&larval->alg);
191
192	return alg;
193}
194
195struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
196{
197	struct crypto_alg *alg;
198
199	down_read(&crypto_alg_sem);
200	alg = __crypto_alg_lookup(name, type, mask);
201	up_read(&crypto_alg_sem);
202
203	return alg;
204}
205EXPORT_SYMBOL_GPL(crypto_alg_lookup);
206
207struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
208{
209	struct crypto_alg *alg;
210
211	if (!name)
212		return ERR_PTR(-ENOENT);
213
 
214	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
215	type &= mask;
216
217	alg = crypto_alg_lookup(name, type, mask);
218	if (!alg) {
219		request_module("%s", name);
220
221		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
222		      CRYPTO_ALG_NEED_FALLBACK))
223			request_module("%s-all", name);
224
225		alg = crypto_alg_lookup(name, type, mask);
226	}
227
228	if (alg)
229		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
230
231	return crypto_larval_add(name, type, mask);
232}
233EXPORT_SYMBOL_GPL(crypto_larval_lookup);
234
235int crypto_probing_notify(unsigned long val, void *v)
236{
237	int ok;
238
239	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
240	if (ok == NOTIFY_DONE) {
241		request_module("cryptomgr");
242		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
243	}
244
245	return ok;
246}
247EXPORT_SYMBOL_GPL(crypto_probing_notify);
248
249struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
250{
251	struct crypto_alg *alg;
252	struct crypto_alg *larval;
253	int ok;
254
255	if (!((type | mask) & CRYPTO_ALG_TESTED)) {
256		type |= CRYPTO_ALG_TESTED;
257		mask |= CRYPTO_ALG_TESTED;
258	}
259
 
 
 
 
 
 
 
 
 
 
260	larval = crypto_larval_lookup(name, type, mask);
261	if (IS_ERR(larval) || !crypto_is_larval(larval))
262		return larval;
263
264	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
265
266	if (ok == NOTIFY_STOP)
267		alg = crypto_larval_wait(larval);
268	else {
269		crypto_mod_put(larval);
270		alg = ERR_PTR(-ENOENT);
271	}
272	crypto_larval_kill(larval);
273	return alg;
274}
275EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
276
277static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
278{
279	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
280
281	if (type_obj)
282		return type_obj->init(tfm, type, mask);
283
284	switch (crypto_tfm_alg_type(tfm)) {
285	case CRYPTO_ALG_TYPE_CIPHER:
286		return crypto_init_cipher_ops(tfm);
287
288	case CRYPTO_ALG_TYPE_COMPRESS:
289		return crypto_init_compress_ops(tfm);
290
291	default:
292		break;
293	}
294
295	BUG();
296	return -EINVAL;
297}
298
299static void crypto_exit_ops(struct crypto_tfm *tfm)
300{
301	const struct crypto_type *type = tfm->__crt_alg->cra_type;
302
303	if (type) {
304		if (tfm->exit)
305			tfm->exit(tfm);
306		return;
307	}
308
309	switch (crypto_tfm_alg_type(tfm)) {
310	case CRYPTO_ALG_TYPE_CIPHER:
311		crypto_exit_cipher_ops(tfm);
312		break;
313
314	case CRYPTO_ALG_TYPE_COMPRESS:
315		crypto_exit_compress_ops(tfm);
316		break;
317
318	default:
319		BUG();
320	}
321}
322
323static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
324{
325	const struct crypto_type *type_obj = alg->cra_type;
326	unsigned int len;
327
328	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
329	if (type_obj)
330		return len + type_obj->ctxsize(alg, type, mask);
331
332	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
333	default:
334		BUG();
335
336	case CRYPTO_ALG_TYPE_CIPHER:
337		len += crypto_cipher_ctxsize(alg);
338		break;
339
340	case CRYPTO_ALG_TYPE_COMPRESS:
341		len += crypto_compress_ctxsize(alg);
342		break;
343	}
344
345	return len;
346}
347
348void crypto_shoot_alg(struct crypto_alg *alg)
349{
350	down_write(&crypto_alg_sem);
351	alg->cra_flags |= CRYPTO_ALG_DYING;
352	up_write(&crypto_alg_sem);
353}
354EXPORT_SYMBOL_GPL(crypto_shoot_alg);
355
356struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
357				      u32 mask)
358{
359	struct crypto_tfm *tfm = NULL;
360	unsigned int tfm_size;
361	int err = -ENOMEM;
362
363	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
364	tfm = kzalloc(tfm_size, GFP_KERNEL);
365	if (tfm == NULL)
366		goto out_err;
367
368	tfm->__crt_alg = alg;
369
370	err = crypto_init_ops(tfm, type, mask);
371	if (err)
372		goto out_free_tfm;
373
374	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
375		goto cra_init_failed;
376
377	goto out;
378
379cra_init_failed:
380	crypto_exit_ops(tfm);
381out_free_tfm:
382	if (err == -EAGAIN)
383		crypto_shoot_alg(alg);
384	kfree(tfm);
385out_err:
386	tfm = ERR_PTR(err);
387out:
388	return tfm;
389}
390EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
391
392/*
393 *	crypto_alloc_base - Locate algorithm and allocate transform
394 *	@alg_name: Name of algorithm
395 *	@type: Type of algorithm
396 *	@mask: Mask for type comparison
397 *
398 *	This function should not be used by new algorithm types.
399 *	Please use crypto_alloc_tfm instead.
400 *
401 *	crypto_alloc_base() will first attempt to locate an already loaded
402 *	algorithm.  If that fails and the kernel supports dynamically loadable
403 *	modules, it will then attempt to load a module of the same name or
404 *	alias.  If that fails it will send a query to any loaded crypto manager
405 *	to construct an algorithm on the fly.  A refcount is grabbed on the
406 *	algorithm which is then associated with the new transform.
407 *
408 *	The returned transform is of a non-determinate type.  Most people
409 *	should use one of the more specific allocation functions such as
410 *	crypto_alloc_blkcipher.
411 *
412 *	In case of error the return value is an error pointer.
413 */
414struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
415{
416	struct crypto_tfm *tfm;
417	int err;
418
419	for (;;) {
420		struct crypto_alg *alg;
421
422		alg = crypto_alg_mod_lookup(alg_name, type, mask);
423		if (IS_ERR(alg)) {
424			err = PTR_ERR(alg);
425			goto err;
426		}
427
428		tfm = __crypto_alloc_tfm(alg, type, mask);
429		if (!IS_ERR(tfm))
430			return tfm;
431
432		crypto_mod_put(alg);
433		err = PTR_ERR(tfm);
434
435err:
436		if (err != -EAGAIN)
437			break;
438		if (signal_pending(current)) {
439			err = -EINTR;
440			break;
441		}
442	}
443
444	return ERR_PTR(err);
445}
446EXPORT_SYMBOL_GPL(crypto_alloc_base);
447
448void *crypto_create_tfm(struct crypto_alg *alg,
449			const struct crypto_type *frontend)
450{
451	char *mem;
452	struct crypto_tfm *tfm = NULL;
453	unsigned int tfmsize;
454	unsigned int total;
455	int err = -ENOMEM;
456
457	tfmsize = frontend->tfmsize;
458	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
459
460	mem = kzalloc(total, GFP_KERNEL);
461	if (mem == NULL)
462		goto out_err;
463
464	tfm = (struct crypto_tfm *)(mem + tfmsize);
465	tfm->__crt_alg = alg;
466
467	err = frontend->init_tfm(tfm);
468	if (err)
469		goto out_free_tfm;
470
471	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
472		goto cra_init_failed;
473
474	goto out;
475
476cra_init_failed:
477	crypto_exit_ops(tfm);
478out_free_tfm:
479	if (err == -EAGAIN)
480		crypto_shoot_alg(alg);
481	kfree(mem);
482out_err:
483	mem = ERR_PTR(err);
484out:
485	return mem;
486}
487EXPORT_SYMBOL_GPL(crypto_create_tfm);
488
489struct crypto_alg *crypto_find_alg(const char *alg_name,
490				   const struct crypto_type *frontend,
491				   u32 type, u32 mask)
492{
493	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
494		crypto_alg_mod_lookup;
495
496	if (frontend) {
497		type &= frontend->maskclear;
498		mask &= frontend->maskclear;
499		type |= frontend->type;
500		mask |= frontend->maskset;
501
502		if (frontend->lookup)
503			lookup = frontend->lookup;
504	}
505
506	return lookup(alg_name, type, mask);
507}
508EXPORT_SYMBOL_GPL(crypto_find_alg);
509
510/*
511 *	crypto_alloc_tfm - Locate algorithm and allocate transform
512 *	@alg_name: Name of algorithm
513 *	@frontend: Frontend algorithm type
514 *	@type: Type of algorithm
515 *	@mask: Mask for type comparison
516 *
517 *	crypto_alloc_tfm() will first attempt to locate an already loaded
518 *	algorithm.  If that fails and the kernel supports dynamically loadable
519 *	modules, it will then attempt to load a module of the same name or
520 *	alias.  If that fails it will send a query to any loaded crypto manager
521 *	to construct an algorithm on the fly.  A refcount is grabbed on the
522 *	algorithm which is then associated with the new transform.
523 *
524 *	The returned transform is of a non-determinate type.  Most people
525 *	should use one of the more specific allocation functions such as
526 *	crypto_alloc_blkcipher.
527 *
528 *	In case of error the return value is an error pointer.
529 */
530void *crypto_alloc_tfm(const char *alg_name,
531		       const struct crypto_type *frontend, u32 type, u32 mask)
532{
533	void *tfm;
534	int err;
535
536	for (;;) {
537		struct crypto_alg *alg;
538
539		alg = crypto_find_alg(alg_name, frontend, type, mask);
540		if (IS_ERR(alg)) {
541			err = PTR_ERR(alg);
542			goto err;
543		}
544
545		tfm = crypto_create_tfm(alg, frontend);
546		if (!IS_ERR(tfm))
547			return tfm;
548
549		crypto_mod_put(alg);
550		err = PTR_ERR(tfm);
551
552err:
553		if (err != -EAGAIN)
554			break;
555		if (signal_pending(current)) {
556			err = -EINTR;
557			break;
558		}
559	}
560
561	return ERR_PTR(err);
562}
563EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
564
565/*
566 *	crypto_destroy_tfm - Free crypto transform
567 *	@mem: Start of tfm slab
568 *	@tfm: Transform to free
569 *
570 *	This function frees up the transform and any associated resources,
571 *	then drops the refcount on the associated algorithm.
572 */
573void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
574{
575	struct crypto_alg *alg;
576
577	if (unlikely(!mem))
578		return;
579
580	alg = tfm->__crt_alg;
581
582	if (!tfm->exit && alg->cra_exit)
583		alg->cra_exit(tfm);
584	crypto_exit_ops(tfm);
585	crypto_mod_put(alg);
586	kzfree(mem);
587}
588EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
589
590int crypto_has_alg(const char *name, u32 type, u32 mask)
591{
592	int ret = 0;
593	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
594
595	if (!IS_ERR(alg)) {
596		crypto_mod_put(alg);
597		ret = 1;
598	}
599
600	return ret;
601}
602EXPORT_SYMBOL_GPL(crypto_has_alg);
603
604MODULE_DESCRIPTION("Cryptographic core API");
605MODULE_LICENSE("GPL");
v4.10.11
  1/*
  2 * Scatterlist Cryptographic API.
  3 *
  4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
  5 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
  6 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
  7 *
  8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
  9 * and Nettle, by Niels Möller.
 10 *
 11 * This program is free software; you can redistribute it and/or modify it
 12 * under the terms of the GNU General Public License as published by the Free
 13 * Software Foundation; either version 2 of the License, or (at your option)
 14 * any later version.
 15 *
 16 */
 17
 18#include <linux/err.h>
 19#include <linux/errno.h>
 20#include <linux/kernel.h>
 21#include <linux/kmod.h>
 22#include <linux/module.h>
 23#include <linux/param.h>
 24#include <linux/sched.h>
 25#include <linux/slab.h>
 26#include <linux/string.h>
 27#include "internal.h"
 28
 29LIST_HEAD(crypto_alg_list);
 30EXPORT_SYMBOL_GPL(crypto_alg_list);
 31DECLARE_RWSEM(crypto_alg_sem);
 32EXPORT_SYMBOL_GPL(crypto_alg_sem);
 33
 34BLOCKING_NOTIFIER_HEAD(crypto_chain);
 35EXPORT_SYMBOL_GPL(crypto_chain);
 36
 37static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
 38
 39struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
 40{
 41	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
 42}
 43EXPORT_SYMBOL_GPL(crypto_mod_get);
 44
 45void crypto_mod_put(struct crypto_alg *alg)
 46{
 47	struct module *module = alg->cra_module;
 48
 49	crypto_alg_put(alg);
 50	module_put(module);
 51}
 52EXPORT_SYMBOL_GPL(crypto_mod_put);
 53
 54static inline int crypto_is_test_larval(struct crypto_larval *larval)
 55{
 56	return larval->alg.cra_driver_name[0];
 57}
 58
 59static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
 60					      u32 mask)
 61{
 62	struct crypto_alg *q, *alg = NULL;
 63	int best = -2;
 64
 65	list_for_each_entry(q, &crypto_alg_list, cra_list) {
 66		int exact, fuzzy;
 67
 68		if (crypto_is_moribund(q))
 69			continue;
 70
 71		if ((q->cra_flags ^ type) & mask)
 72			continue;
 73
 74		if (crypto_is_larval(q) &&
 75		    !crypto_is_test_larval((struct crypto_larval *)q) &&
 76		    ((struct crypto_larval *)q)->mask != mask)
 77			continue;
 78
 79		exact = !strcmp(q->cra_driver_name, name);
 80		fuzzy = !strcmp(q->cra_name, name);
 81		if (!exact && !(fuzzy && q->cra_priority > best))
 82			continue;
 83
 84		if (unlikely(!crypto_mod_get(q)))
 85			continue;
 86
 87		best = q->cra_priority;
 88		if (alg)
 89			crypto_mod_put(alg);
 90		alg = q;
 91
 92		if (exact)
 93			break;
 94	}
 95
 96	return alg;
 97}
 98
 99static void crypto_larval_destroy(struct crypto_alg *alg)
100{
101	struct crypto_larval *larval = (void *)alg;
102
103	BUG_ON(!crypto_is_larval(alg));
104	if (larval->adult)
105		crypto_mod_put(larval->adult);
106	kfree(larval);
107}
108
109struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
110{
111	struct crypto_larval *larval;
112
113	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114	if (!larval)
115		return ERR_PTR(-ENOMEM);
116
117	larval->mask = mask;
118	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
119	larval->alg.cra_priority = -1;
120	larval->alg.cra_destroy = crypto_larval_destroy;
121
122	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
123	init_completion(&larval->completion);
124
125	return larval;
126}
127EXPORT_SYMBOL_GPL(crypto_larval_alloc);
128
129static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
130					    u32 mask)
131{
132	struct crypto_alg *alg;
133	struct crypto_larval *larval;
134
135	larval = crypto_larval_alloc(name, type, mask);
136	if (IS_ERR(larval))
137		return ERR_CAST(larval);
138
139	atomic_set(&larval->alg.cra_refcnt, 2);
140
141	down_write(&crypto_alg_sem);
142	alg = __crypto_alg_lookup(name, type, mask);
143	if (!alg) {
144		alg = &larval->alg;
145		list_add(&alg->cra_list, &crypto_alg_list);
146	}
147	up_write(&crypto_alg_sem);
148
149	if (alg != &larval->alg) {
150		kfree(larval);
151		if (crypto_is_larval(alg))
152			alg = crypto_larval_wait(alg);
153	}
154
155	return alg;
156}
157
158void crypto_larval_kill(struct crypto_alg *alg)
159{
160	struct crypto_larval *larval = (void *)alg;
161
162	down_write(&crypto_alg_sem);
163	list_del(&alg->cra_list);
164	up_write(&crypto_alg_sem);
165	complete_all(&larval->completion);
166	crypto_alg_put(alg);
167}
168EXPORT_SYMBOL_GPL(crypto_larval_kill);
169
170static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
171{
172	struct crypto_larval *larval = (void *)alg;
173	long timeout;
174
175	timeout = wait_for_completion_killable_timeout(
176		&larval->completion, 60 * HZ);
177
178	alg = larval->adult;
179	if (timeout < 0)
180		alg = ERR_PTR(-EINTR);
181	else if (!timeout)
182		alg = ERR_PTR(-ETIMEDOUT);
183	else if (!alg)
184		alg = ERR_PTR(-ENOENT);
185	else if (crypto_is_test_larval(larval) &&
186		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
187		alg = ERR_PTR(-EAGAIN);
188	else if (!crypto_mod_get(alg))
189		alg = ERR_PTR(-EAGAIN);
190	crypto_mod_put(&larval->alg);
191
192	return alg;
193}
194
195struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
196{
197	struct crypto_alg *alg;
198
199	down_read(&crypto_alg_sem);
200	alg = __crypto_alg_lookup(name, type, mask);
201	up_read(&crypto_alg_sem);
202
203	return alg;
204}
205EXPORT_SYMBOL_GPL(crypto_alg_lookup);
206
207struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
208{
209	struct crypto_alg *alg;
210
211	if (!name)
212		return ERR_PTR(-ENOENT);
213
214	type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
215	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
 
216
217	alg = crypto_alg_lookup(name, type, mask);
218	if (!alg) {
219		request_module("crypto-%s", name);
220
221		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
222		      CRYPTO_ALG_NEED_FALLBACK))
223			request_module("crypto-%s-all", name);
224
225		alg = crypto_alg_lookup(name, type, mask);
226	}
227
228	if (alg)
229		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
230
231	return crypto_larval_add(name, type, mask);
232}
233EXPORT_SYMBOL_GPL(crypto_larval_lookup);
234
235int crypto_probing_notify(unsigned long val, void *v)
236{
237	int ok;
238
239	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
240	if (ok == NOTIFY_DONE) {
241		request_module("cryptomgr");
242		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
243	}
244
245	return ok;
246}
247EXPORT_SYMBOL_GPL(crypto_probing_notify);
248
249struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
250{
251	struct crypto_alg *alg;
252	struct crypto_alg *larval;
253	int ok;
254
255	if (!((type | mask) & CRYPTO_ALG_TESTED)) {
256		type |= CRYPTO_ALG_TESTED;
257		mask |= CRYPTO_ALG_TESTED;
258	}
259
260	/*
261	 * If the internal flag is set for a cipher, require a caller to
262	 * to invoke the cipher with the internal flag to use that cipher.
263	 * Also, if a caller wants to allocate a cipher that may or may
264	 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
265	 * !(mask & CRYPTO_ALG_INTERNAL).
266	 */
267	if (!((type | mask) & CRYPTO_ALG_INTERNAL))
268		mask |= CRYPTO_ALG_INTERNAL;
269
270	larval = crypto_larval_lookup(name, type, mask);
271	if (IS_ERR(larval) || !crypto_is_larval(larval))
272		return larval;
273
274	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
275
276	if (ok == NOTIFY_STOP)
277		alg = crypto_larval_wait(larval);
278	else {
279		crypto_mod_put(larval);
280		alg = ERR_PTR(-ENOENT);
281	}
282	crypto_larval_kill(larval);
283	return alg;
284}
285EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
286
287static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
288{
289	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
290
291	if (type_obj)
292		return type_obj->init(tfm, type, mask);
293
294	switch (crypto_tfm_alg_type(tfm)) {
295	case CRYPTO_ALG_TYPE_CIPHER:
296		return crypto_init_cipher_ops(tfm);
297
298	case CRYPTO_ALG_TYPE_COMPRESS:
299		return crypto_init_compress_ops(tfm);
300
301	default:
302		break;
303	}
304
305	BUG();
306	return -EINVAL;
307}
308
309static void crypto_exit_ops(struct crypto_tfm *tfm)
310{
311	const struct crypto_type *type = tfm->__crt_alg->cra_type;
312
313	if (type && tfm->exit)
314		tfm->exit(tfm);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
315}
316
317static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
318{
319	const struct crypto_type *type_obj = alg->cra_type;
320	unsigned int len;
321
322	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
323	if (type_obj)
324		return len + type_obj->ctxsize(alg, type, mask);
325
326	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
327	default:
328		BUG();
329
330	case CRYPTO_ALG_TYPE_CIPHER:
331		len += crypto_cipher_ctxsize(alg);
332		break;
333
334	case CRYPTO_ALG_TYPE_COMPRESS:
335		len += crypto_compress_ctxsize(alg);
336		break;
337	}
338
339	return len;
340}
341
342void crypto_shoot_alg(struct crypto_alg *alg)
343{
344	down_write(&crypto_alg_sem);
345	alg->cra_flags |= CRYPTO_ALG_DYING;
346	up_write(&crypto_alg_sem);
347}
348EXPORT_SYMBOL_GPL(crypto_shoot_alg);
349
350struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
351				      u32 mask)
352{
353	struct crypto_tfm *tfm = NULL;
354	unsigned int tfm_size;
355	int err = -ENOMEM;
356
357	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
358	tfm = kzalloc(tfm_size, GFP_KERNEL);
359	if (tfm == NULL)
360		goto out_err;
361
362	tfm->__crt_alg = alg;
363
364	err = crypto_init_ops(tfm, type, mask);
365	if (err)
366		goto out_free_tfm;
367
368	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
369		goto cra_init_failed;
370
371	goto out;
372
373cra_init_failed:
374	crypto_exit_ops(tfm);
375out_free_tfm:
376	if (err == -EAGAIN)
377		crypto_shoot_alg(alg);
378	kfree(tfm);
379out_err:
380	tfm = ERR_PTR(err);
381out:
382	return tfm;
383}
384EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
385
386/*
387 *	crypto_alloc_base - Locate algorithm and allocate transform
388 *	@alg_name: Name of algorithm
389 *	@type: Type of algorithm
390 *	@mask: Mask for type comparison
391 *
392 *	This function should not be used by new algorithm types.
393 *	Please use crypto_alloc_tfm instead.
394 *
395 *	crypto_alloc_base() will first attempt to locate an already loaded
396 *	algorithm.  If that fails and the kernel supports dynamically loadable
397 *	modules, it will then attempt to load a module of the same name or
398 *	alias.  If that fails it will send a query to any loaded crypto manager
399 *	to construct an algorithm on the fly.  A refcount is grabbed on the
400 *	algorithm which is then associated with the new transform.
401 *
402 *	The returned transform is of a non-determinate type.  Most people
403 *	should use one of the more specific allocation functions such as
404 *	crypto_alloc_blkcipher.
405 *
406 *	In case of error the return value is an error pointer.
407 */
408struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
409{
410	struct crypto_tfm *tfm;
411	int err;
412
413	for (;;) {
414		struct crypto_alg *alg;
415
416		alg = crypto_alg_mod_lookup(alg_name, type, mask);
417		if (IS_ERR(alg)) {
418			err = PTR_ERR(alg);
419			goto err;
420		}
421
422		tfm = __crypto_alloc_tfm(alg, type, mask);
423		if (!IS_ERR(tfm))
424			return tfm;
425
426		crypto_mod_put(alg);
427		err = PTR_ERR(tfm);
428
429err:
430		if (err != -EAGAIN)
431			break;
432		if (fatal_signal_pending(current)) {
433			err = -EINTR;
434			break;
435		}
436	}
437
438	return ERR_PTR(err);
439}
440EXPORT_SYMBOL_GPL(crypto_alloc_base);
441
442void *crypto_create_tfm(struct crypto_alg *alg,
443			const struct crypto_type *frontend)
444{
445	char *mem;
446	struct crypto_tfm *tfm = NULL;
447	unsigned int tfmsize;
448	unsigned int total;
449	int err = -ENOMEM;
450
451	tfmsize = frontend->tfmsize;
452	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
453
454	mem = kzalloc(total, GFP_KERNEL);
455	if (mem == NULL)
456		goto out_err;
457
458	tfm = (struct crypto_tfm *)(mem + tfmsize);
459	tfm->__crt_alg = alg;
460
461	err = frontend->init_tfm(tfm);
462	if (err)
463		goto out_free_tfm;
464
465	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
466		goto cra_init_failed;
467
468	goto out;
469
470cra_init_failed:
471	crypto_exit_ops(tfm);
472out_free_tfm:
473	if (err == -EAGAIN)
474		crypto_shoot_alg(alg);
475	kfree(mem);
476out_err:
477	mem = ERR_PTR(err);
478out:
479	return mem;
480}
481EXPORT_SYMBOL_GPL(crypto_create_tfm);
482
483struct crypto_alg *crypto_find_alg(const char *alg_name,
484				   const struct crypto_type *frontend,
485				   u32 type, u32 mask)
486{
487	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
488		crypto_alg_mod_lookup;
489
490	if (frontend) {
491		type &= frontend->maskclear;
492		mask &= frontend->maskclear;
493		type |= frontend->type;
494		mask |= frontend->maskset;
495
496		if (frontend->lookup)
497			lookup = frontend->lookup;
498	}
499
500	return lookup(alg_name, type, mask);
501}
502EXPORT_SYMBOL_GPL(crypto_find_alg);
503
504/*
505 *	crypto_alloc_tfm - Locate algorithm and allocate transform
506 *	@alg_name: Name of algorithm
507 *	@frontend: Frontend algorithm type
508 *	@type: Type of algorithm
509 *	@mask: Mask for type comparison
510 *
511 *	crypto_alloc_tfm() will first attempt to locate an already loaded
512 *	algorithm.  If that fails and the kernel supports dynamically loadable
513 *	modules, it will then attempt to load a module of the same name or
514 *	alias.  If that fails it will send a query to any loaded crypto manager
515 *	to construct an algorithm on the fly.  A refcount is grabbed on the
516 *	algorithm which is then associated with the new transform.
517 *
518 *	The returned transform is of a non-determinate type.  Most people
519 *	should use one of the more specific allocation functions such as
520 *	crypto_alloc_blkcipher.
521 *
522 *	In case of error the return value is an error pointer.
523 */
524void *crypto_alloc_tfm(const char *alg_name,
525		       const struct crypto_type *frontend, u32 type, u32 mask)
526{
527	void *tfm;
528	int err;
529
530	for (;;) {
531		struct crypto_alg *alg;
532
533		alg = crypto_find_alg(alg_name, frontend, type, mask);
534		if (IS_ERR(alg)) {
535			err = PTR_ERR(alg);
536			goto err;
537		}
538
539		tfm = crypto_create_tfm(alg, frontend);
540		if (!IS_ERR(tfm))
541			return tfm;
542
543		crypto_mod_put(alg);
544		err = PTR_ERR(tfm);
545
546err:
547		if (err != -EAGAIN)
548			break;
549		if (fatal_signal_pending(current)) {
550			err = -EINTR;
551			break;
552		}
553	}
554
555	return ERR_PTR(err);
556}
557EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
558
559/*
560 *	crypto_destroy_tfm - Free crypto transform
561 *	@mem: Start of tfm slab
562 *	@tfm: Transform to free
563 *
564 *	This function frees up the transform and any associated resources,
565 *	then drops the refcount on the associated algorithm.
566 */
567void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
568{
569	struct crypto_alg *alg;
570
571	if (unlikely(!mem))
572		return;
573
574	alg = tfm->__crt_alg;
575
576	if (!tfm->exit && alg->cra_exit)
577		alg->cra_exit(tfm);
578	crypto_exit_ops(tfm);
579	crypto_mod_put(alg);
580	kzfree(mem);
581}
582EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
583
584int crypto_has_alg(const char *name, u32 type, u32 mask)
585{
586	int ret = 0;
587	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
588
589	if (!IS_ERR(alg)) {
590		crypto_mod_put(alg);
591		ret = 1;
592	}
593
594	return ret;
595}
596EXPORT_SYMBOL_GPL(crypto_has_alg);
597
598MODULE_DESCRIPTION("Cryptographic core API");
599MODULE_LICENSE("GPL");