path: root/crypto/algapi.c

/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * 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/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/string.h>

#include "internal.h"

static void crypto_remove_final(struct list_head *list);

static LIST_HEAD(crypto_template_list);

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

	alg = crypto_alg_lookup(name, type, mask);

	if (alg) {
		if (crypto_is_larval(alg)) {
			struct crypto_larval *larval = (void *)alg;
			complete_all(&larval->completion);
		}
		crypto_mod_put(alg);
	}
}
EXPORT_SYMBOL_GPL(crypto_larval_error);

static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
	static const char suffix[] = "-generic";
	char *driver_name = alg->cra_driver_name;
	int len;

	if (*driver_name)
		return 0;

	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	memcpy(driver_name + len, suffix, sizeof(suffix));
	return 0;
}

static int crypto_check_alg(struct crypto_alg *alg)
{
	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
		return -EINVAL;

	if (alg->cra_blocksize > PAGE_SIZE / 8)
		return -EINVAL;

	if (alg->cra_priority < 0)
		return -EINVAL;

	return crypto_set_driver_name(alg);
}

static void crypto_destroy_instance(struct crypto_alg *alg)
{
	struct crypto_instance *inst = (void *)alg;
	struct crypto_template *tmpl = inst->tmpl;

	tmpl->free(inst);
	crypto_tmpl_put(tmpl);
}

static void crypto_remove_spawn(struct crypto_spawn *spawn,
				struct list_head *list,
				struct list_head *secondary_spawns)
{
	struct crypto_instance *inst = spawn->inst;
	struct crypto_template *tmpl = inst->tmpl;

	list_del_init(&spawn->list);
	spawn->alg = NULL;

	if (crypto_is_dead(&inst->alg))
		return;

	inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
	if (hlist_unhashed(&inst->list))
		return;

	if (!tmpl || !crypto_tmpl_get(tmpl))
		return;

	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
	list_move(&inst->alg.cra_list, list);
	hlist_del(&inst->list);
	inst->alg.cra_destroy = crypto_destroy_instance;

	list_splice(&inst->alg.cra_users, secondary_spawns);
}

static void crypto_remove_spawns(struct list_head *spawns,
				 struct list_head *list, u32 new_type)
{
	struct crypto_spawn *spawn, *n;
	LIST_HEAD(secondary_spawns);

	list_for_each_entry_safe(spawn, n, spawns, list) {
		if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
			continue;

		crypto_remove_spawn(spawn, list, &secondary_spawns);
	}

	while (!list_empty(&secondary_spawns)) {
		list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
			crypto_remove_spawn(spawn, list, &secondary_spawns);
	}
}

static struct crypto_larval *__crypto_register_alg(struct crypto_alg *alg)
{
	struct crypto_alg *q;
	struct crypto_larval *larval;
	int ret = -EAGAIN;

	if (crypto_is_dead(alg))
		goto err;

	INIT_LIST_HEAD(&alg->cra_users);

	/* No cheating! */
	alg->cra_flags &= ~CRYPTO_ALG_TESTED;

	ret = -EEXIST;

	atomic_set(&alg->cra_refcnt, 1);
	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		if (q == alg)
			goto err;

		if (crypto_is_moribund(q))
			continue;

		if (crypto_is_larval(q)) {
			if (!strcmp(alg->cra_driver_name, q->cra_driver_name))
				goto err;
			continue;
		}

		if (!strcmp(q->cra_driver_name, alg->cra_name) ||
		    !strcmp(q->cra_name, alg->cra_driver_name))
			goto err;
	}

	larval = crypto_larval_alloc(alg->cra_name,
				     alg->cra_flags | CRYPTO_ALG_TESTED, 0);
	if (IS_ERR(larval))
		goto out;

	ret = -ENOENT;
	larval->adult = crypto_mod_get(alg);
	if (!