linux-imx

/*

 * algif_rng: User-space interface for random number generators

 *

 * This file provides the user-space API for random number generators.

 *

 * Copyright (C) 2014, Stephan Mueller <smueller@chronox.de>

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, and the entire permission notice in its entirety,

 *    including the disclaimer of warranties.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. The name of the author may not be used to endorse or promote

 *    products derived from this software without specific prior

 *    written permission.

 *

 * ALTERNATIVELY, this product may be distributed under the terms of

 * the GNU General Public License, in which case the provisions of the GPL2

 * are required INSTEAD OF the above restrictions.  (This clause is

 * necessary due to a potential bad interaction between the GPL and

 * the restrictions contained in a BSD-style copyright.)

 *

 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED

 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE, ALL OF

 * WHICH ARE HEREBY DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE

 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT

 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR

 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF

 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE

 * USE OF THIS SOFTWARE, EVEN IF NOT ADVISED OF THE POSSIBILITY OF SUCH

 * DAMAGE.

 */

​

#include <linux/module.h>

#include <crypto/rng.h>

#include <linux/random.h>

#include <crypto/if_alg.h>

#include <linux/net.h>

#include <net/sock.h>

​

MODULE_LICENSE("GPL");

MODULE_AUTHOR("Stephan Mueller <smueller@chronox.de>");

MODULE_DESCRIPTION("User-space interface for random number generators");

​

struct rng_ctx {

#define MAXSIZE 128

    unsigned int len;

    struct crypto_rng *drng;

};

​

static int rng_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,

               int flags)

{

    struct sock *sk = sock->sk;

    struct alg_sock *ask = alg_sk(sk);

    struct rng_ctx *ctx = ask->private;