[deliverable/linux.git] / crypto / api.c

/*
 * Scatterlist Cryptographic API.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
 * and Nettle, by Niels Möller.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */

#include <linux/err.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/module.h>
#include <linux/param.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include "internal.h"

LIST_HEAD(crypto_alg_list);
EXPORT_SYMBOL_GPL(crypto_alg_list);
DECLARE_RWSEM(crypto_alg_sem);
EXPORT_SYMBOL_GPL(crypto_alg_sem);

BLOCKING_NOTIFIER_HEAD(crypto_chain);
EXPORT_SYMBOL_GPL(crypto_chain);

static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
{
	atomic_inc(&alg->cra_refcnt);
	return alg;
}

struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
{
	return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
}
EXPORT_SYMBOL_GPL(crypto_mod_get);

void crypto_mod_put(struct crypto_alg *alg)
{
	struct module *module = alg->cra_module;

	crypto_alg_put(alg);
	module_put(module);
}
EXPORT_SYMBOL_GPL(crypto_mod_put);

static inline int crypto_is_test_larval(struct crypto_larval *larval)
{
	return larval->alg.cra_driver_name[0];
}

static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
					      u32 mask)
{
	struct crypto_alg *q, *alg = NULL;
	int best = -2;

	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		int exact, fuzzy;

		if (crypto_is_moribund(q))
			continue;

		if ((q->cra_flags ^ type) & mask)
			continue;

		if (crypto_is_larval(q) &&
		    !crypto_is_test_larval((struct crypto_larval *)q) &&
		    ((struct crypto_larval *)q)->mask != mask)
			continue;

		exact = !strcmp(q->cra_driver_name, name);
		fuzzy = !strcmp(q->cra_name, name);
		if (!exact && !(fuzzy && q->cra_priority > best))
			continue;

		if (unlikely(!crypto_mod_get(q)))
			continue;

		best = q->cra_priority;
		if (alg)
			crypto_mod_put(alg);
		alg = q;

		if (exact)
			break;
	}

	return alg;
}

static void crypto_larval_destroy(struct crypto_alg *alg)
{
	struct crypto_larval *larval = (void *)alg;

	BUG_ON(!crypto_is_larval(alg));
	if (larval->adult)
		crypto_mod_put(larval->adult);
	kfree(larval);
}

struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
{
	struct crypto_larval *larval;

	larval = kzalloc(sizeof(*larval), GFP_KERNEL);
	if (!larval)
		return ERR_PTR(-ENOMEM);

	larval->mask = mask;
	larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
	larval->alg.cra_priority = -1;
	larval->alg.cra_destroy = crypto_larval_destroy;

	strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
	init_completion(&larval->completion);

	return larval;
}
EXPORT_SYMBOL_GPL(crypto_larval_alloc);

static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
					    u32 mask)
{
	struct crypto_alg *alg;
	struct crypto_larval *larval;

	larval = crypto_larval_alloc(name, type, mask);
	if (IS_ERR(larval))
		return ERR_CAST(larval);

	atomic_set(&larval->alg.cra_refcnt, 2);

	down_write(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type, mask);
	if (!alg) {
		alg = &larval->alg;
		list_add(&alg->cra_list, &crypto_alg_list);
	}
	up_write(&crypto_alg_sem);

	if (alg != &larval->alg)
		kfree(larval);

	return alg;
}

void crypto_larval_kill(struct crypto_alg *alg)
{
	struct crypto_larval *larval = (void *)alg;

	down_write(&crypto_alg_sem);
	list_del(&alg->cra_list);
	up_write(&crypto_alg_sem);
	complete_all(&larval->completion);
	crypto_alg_put(alg);
}
EXPORT_SYMBOL_GPL(crypto_larval_kill);

static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
{
	struct crypto_larval *larval = (void *)alg;
	long timeout;

	timeout = wait_for_completion_interruptible_timeout(
		&larval->completion, 60 * HZ);

	alg = larval->adult;
	if (timeout < 0)
		alg = ERR_PTR(-EINTR);
	else if (!timeout)
		alg = ERR_PTR(-ETIMEDOUT);
	else if (!alg)
		alg = ERR_PTR(-ENOENT);
	else if (crypto_is_test_larval(larval) &&
		 !(alg->cra_flags & CRYPTO_ALG_TESTED))
		alg = ERR_PTR(-EAGAIN);
	else if (!crypto_mod_get(alg))
		alg = ERR_PTR(-EAGAIN);
	crypto_mod_put(&larval->alg);

	return alg;
}

struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;

	down_read(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type, mask);
	up_read(&crypto_alg_sem);

	return alg;
}
EXPORT_SYMBOL_GPL(crypto_alg_lookup);

struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;

	if (!name)
		return ERR_PTR(-ENOENT);

	mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
	type &= mask;

	alg = crypto_alg_lookup(name, type, mask);
	if (!alg) {
		request_module("%s", name);

		if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
		      CRYPTO_ALG_NEED_FALLBACK))
			request_module("%s-all", name);

		alg = crypto_alg_lookup(name, type, mask);
	}

	if (alg)
		return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;

	return crypto_larval_add(name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_larval_lookup);

int crypto_probing_notify(unsigned long val, void *v)
{
	int ok;

	ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	if (ok == NOTIFY_DONE) {
		request_module("cryptomgr");
		ok = blocking_notifier_call_chain(&crypto_chain, val, v);
	}

	return ok;
}
EXPORT_SYMBOL_GPL(crypto_probing_notify);

struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;
	struct crypto_alg *larval;
	int ok;

	if (!((type | mask) & CRYPTO_ALG_TESTED)) {
		type |= CRYPTO_ALG_TESTED;
		mask |= CRYPTO_ALG_TESTED;
	}

	larval = crypto_larval_lookup(name, type, mask);
	if (IS_ERR(larval) || !crypto_is_larval(larval))
		return larval;

	ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);

	if (ok == NOTIFY_STOP)
		alg = crypto_larval_wait(larval);
	else {
		crypto_mod_put(larval);
		alg = ERR_PTR(-ENOENT);
	}
	crypto_larval_kill(larval);
	return alg;
}
EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);

static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;

	if (type_obj)
		return type_obj->init(tfm, type, mask);

	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		return crypto_init_cipher_ops(tfm);

	case CRYPTO_ALG_TYPE_COMPRESS:
		return crypto_init_compress_ops(tfm);
	
	default:
		break;
	}
	
	BUG();
	return -EINVAL;
}

static void crypto_exit_ops(struct crypto_tfm *tfm)
{
	const struct crypto_type *type = tfm->__crt_alg->cra_type;

	if (type) {
		if (tfm->exit)
			tfm->exit(tfm);
		return;
	}

	switch (crypto_tfm_alg_type(tfm)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		crypto_exit_cipher_ops(tfm);
		break;

	case CRYPTO_ALG_TYPE_COMPRESS:
		crypto_exit_compress_ops(tfm);
		break;
	
	default:
		BUG();
		
	}
}

static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
{
	const struct crypto_type *type_obj = alg->cra_type;
	unsigned int len;

	len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	if (type_obj)
		return len + type_obj->ctxsize(alg, type, mask);

	switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
	default:
		BUG();

	case CRYPTO_ALG_TYPE_CIPHER:
		len += crypto_cipher_ctxsize(alg);
		break;

	case CRYPTO_ALG_TYPE_COMPRESS:
		len += crypto_compress_ctxsize(alg);
		break;
	}

	return len;
}

void crypto_shoot_alg(struct crypto_alg *alg)
{
	down_write(&crypto_alg_sem);
	alg->cra_flags |= CRYPTO_ALG_DYING;
	up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_shoot_alg);

struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
				      u32 mask)
{
	struct crypto_tfm *tfm = NULL;
	unsigned int tfm_size;
	int err = -ENOMEM;

	tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
	tfm = kzalloc(tfm_size, GFP_KERNEL);
	if (tfm == NULL)
		goto out_err;

	tfm->__crt_alg = alg;

	err = crypto_init_ops(tfm, type, mask);
	if (err)
		goto out_free_tfm;

	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
		goto cra_init_failed;

	goto out;

cra_init_failed:
	crypto_exit_ops(tfm);
out_free_tfm:
	if (err == -EAGAIN)
		crypto_shoot_alg(alg);
	kfree(tfm);
out_err:
	tfm = ERR_PTR(err);
out:
	return tfm;
}
EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);

/*
 *	crypto_alloc_base - Locate algorithm and allocate transform
 *	@alg_name: Name of algorithm
 *	@type: Type of algorithm
 *	@mask: Mask for type comparison
 *
 *	This function should not be used by new algorithm types.
 *	Plesae use crypto_alloc_tfm instead.
 *
 *	crypto_alloc_base() will first attempt to locate an already loaded
 *	algorithm.  If that fails and the kernel supports dynamically loadable
 *	modules, it will then attempt to load a module of the same name or
 *	alias.  If that fails it will send a query to any loaded crypto manager
 *	to construct an algorithm on the fly.  A refcount is grabbed on the
 *	algorithm which is then associated with the new transform.
 *
 *	The returned transform is of a non-determinate type.  Most people
 *	should use one of the more specific allocation functions such as
 *	crypto_alloc_blkcipher.
 *
 *	In case of error the return value is an error pointer.
 */
struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
{
	struct crypto_tfm *tfm;
	int err;

	for (;;) {
		struct crypto_alg *alg;

		alg = crypto_alg_mod_lookup(alg_name, type, mask);
		if (IS_ERR(alg)) {
			err = PTR_ERR(alg);
			goto err;
		}

		tfm = __crypto_alloc_tfm(alg, type, mask);
		if (!IS_ERR(tfm))
			return tfm;

		crypto_mod_put(alg);
		err = PTR_ERR(tfm);

err:
		if (err != -EAGAIN)
			break;
		if (signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_base);

void *crypto_create_tfm(struct crypto_alg *alg,
			const struct crypto_type *frontend)
{
	char *mem;
	struct crypto_tfm *tfm = NULL;
	unsigned int tfmsize;
	unsigned int total;
	int err = -ENOMEM;

	tfmsize = frontend->tfmsize;
	total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);

	mem = kzalloc(total, GFP_KERNEL);
	if (mem == NULL)
		goto out_err;

	tfm = (struct crypto_tfm *)(mem + tfmsize);
	tfm->__crt_alg = alg;

	err = frontend->init_tfm(tfm);
	if (err)
		goto out_free_tfm;

	if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
		goto cra_init_failed;

	goto out;

cra_init_failed:
	crypto_exit_ops(tfm);
out_free_tfm:
	if (err == -EAGAIN)
		crypto_shoot_alg(alg);
	kfree(mem);
out_err:
	mem = ERR_PTR(err);
out:
	return mem;
}
EXPORT_SYMBOL_GPL(crypto_create_tfm);

struct crypto_alg *crypto_find_alg(const char *alg_name,
				   const struct crypto_type *frontend,
				   u32 type, u32 mask)
{
	struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask) =
		crypto_alg_mod_lookup;

	if (frontend) {
		type &= frontend->maskclear;
		mask &= frontend->maskclear;
		type |= frontend->type;
		mask |= frontend->maskset;

		if (frontend->lookup)
			lookup = frontend->lookup;
	}

	return lookup(alg_name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_find_alg);

/*
 *	crypto_alloc_tfm - Locate algorithm and allocate transform
 *	@alg_name: Name of algorithm
 *	@frontend: Frontend algorithm type
 *	@type: Type of algorithm
 *	@mask: Mask for type comparison
 *
 *	crypto_alloc_tfm() will first attempt to locate an already loaded
 *	algorithm.  If that fails and the kernel supports dynamically loadable
 *	modules, it will then attempt to load a module of the same name or
 *	alias.  If that fails it will send a query to any loaded crypto manager
 *	to construct an algorithm on the fly.  A refcount is grabbed on the
 *	algorithm which is then associated with the new transform.
 *
 *	The returned transform is of a non-determinate type.  Most people
 *	should use one of the more specific allocation functions such as
 *	crypto_alloc_blkcipher.
 *
 *	In case of error the return value is an error pointer.
 */
void *crypto_alloc_tfm(const char *alg_name,
		       const struct crypto_type *frontend, u32 type, u32 mask)
{
	void *tfm;
	int err;

	for (;;) {
		struct crypto_alg *alg;

		alg = crypto_find_alg(alg_name, frontend, type, mask);
		if (IS_ERR(alg)) {
			err = PTR_ERR(alg);
			goto err;
		}

		tfm = crypto_create_tfm(alg, frontend);
		if (!IS_ERR(tfm))
			return tfm;

		crypto_mod_put(alg);
		err = PTR_ERR(tfm);

err:
		if (err != -EAGAIN)
			break;
		if (signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_tfm);

/*
 *	crypto_destroy_tfm - Free crypto transform
 *	@mem: Start of tfm slab
 *	@tfm: Transform to free
 *
 *	This function frees up the transform and any associated resources,
 *	then drops the refcount on the associated algorithm.
 */
void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
{
	struct crypto_alg *alg;

	if (unlikely(!mem))
		return;

	alg = tfm->__crt_alg;

	if (!tfm->exit && alg->cra_exit)
		alg->cra_exit(tfm);
	crypto_exit_ops(tfm);
	crypto_mod_put(alg);
	kzfree(mem);
}
EXPORT_SYMBOL_GPL(crypto_destroy_tfm);

int crypto_has_alg(const char *name, u32 type, u32 mask)
{
	int ret = 0;
	struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
	
	if (!IS_ERR(alg)) {
		crypto_mod_put(alg);
		ret = 1;
	}
	
	return ret;
}
EXPORT_SYMBOL_GPL(crypto_has_alg);

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