path: root/crypto/af_alg.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * af_alg: User-space algorithm interface
 *
 * This file provides the user-space API for algorithms.
 *
 * Copyright (c) 2010 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <linux/atomic.h>
#include <crypto/if_alg.h>
#include <linux/crypto.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/key.h>
#include <linux/key-type.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/net.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/sched/signal.h>
#include <linux/security.h>
#include <linux/string.h>
#include <keys/user-type.h>
#include <keys/trusted-type.h>
#include <keys/encrypted-type.h>

struct alg_type_list {
	const struct af_alg_type *type;
	struct list_head list;
};

static struct proto alg_proto = {
	.name			= "ALG",
	.owner			= THIS_MODULE,
	.obj_size		= sizeof(struct alg_sock),
};

static LIST_HEAD(alg_types);
static DECLARE_RWSEM(alg_types_sem);

static const struct af_alg_type *alg_get_type(const char *name)
{
	const struct af_alg_type *type = ERR_PTR(-ENOENT);
	struct alg_type_list *node;

	down_read(&alg_types_sem);
	list_for_each_entry(node, &alg_types, list) {
		if (strcmp(node->type->name, name))
			continue;

		if (try_module_get(node->type->owner))
			type = node->type;
		break;
	}
	up_read(&alg_types_sem);

	return type;
}

int af_alg_register_type(const struct af_alg_type *type)
{
	struct alg_type_list *node;
	int err = -EEXIST;

	down_write(&alg_types_sem);
	list_for_each_entry(node, &alg_types, list) {
		if (!strcmp(node->type->name, type->name))
			goto unlock;
	}

	node = kmalloc(sizeof(*node), GFP_KERNEL);
	err = -ENOMEM;
	if (!node)
		goto unlock;

	type->ops->owner = THIS_MODULE;
	if (type->ops_nokey)
		type->ops_nokey->owner = THIS_MODULE;
	node->type = type;
	list_add(&node->list, &alg_types);
	err = 0;

unlock:
	up_write(&alg_types_sem);

	return err;
}
EXPORT_SYMBOL_GPL(af_alg_register_type);

int af_alg_unregister_type(const struct af_alg_type *type)
{
	struct alg_type_list *node;
	int err = -ENOENT;

	down_write(&alg_types_sem);
	list_for_each_entry(node, &alg_types, list) {
		if (strcmp(node->