linux-imx

/*

 * algif_hash: User-space interface for hash algorithms

 *

 * This file provides the user-space API for hash algorithms.

 *

 * Copyright (c) 2010 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 <crypto/hash.h>

#include <crypto/if_alg.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/mm.h>

#include <linux/module.h>

#include <linux/net.h>

#include <net/sock.h>

​

struct hash_ctx {

    struct af_alg_sgl sgl;

​

    u8 *result;

​

    struct crypto_wait wait;

​

    unsigned int len;

    bool more;

​

    struct ahash_request req;

};

​

static int hash_alloc_result(struct sock *sk, struct hash_ctx *ctx)

{

    unsigned ds;

​

    if (ctx->result)

        return 0;

​

    ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));

​

    ctx->result = sock_kmalloc(sk, ds, GFP_KERNEL);

    if (!ctx->result)

        return -ENOMEM;

​

    memset(ctx->result, 0, ds);

​

    return 0;

}

​

static void hash_free_result(struct sock *sk, struct hash_ctx *ctx)

{

    unsigned ds;

​

    if (!ctx->result)

        return;

​

    ds = crypto_ahash_digestsize(crypto_ahash_reqtfm(&ctx->req));

​

    sock_kzfree_s(sk, ctx->result, ds);

    ctx->result = NULL;

}

​

static int hash_sendmsg(struct socket *sock, struct msghdr *msg,

            size_t ignored)

{

    int limit = ALG_MAX_PAGES * PAGE_SIZE;

    struct sock *sk = sock->sk;

    struct alg_sock *ask = alg_sk(sk);

    struct hash_ctx *ctx = ask->private;

    long copied = 0;

    int err;

​

    if (limit > sk->sk_sndbuf)

        limit = sk->sk_sndbuf;

​

    lock_sock(sk);

    if (!ctx->more) {

        if ((msg->msg_flags & MSG_MORE))

            hash_free_result(sk, ctx);

​

        err = crypto_wait_req(crypto_ahash_init(&ctx->req), &ctx->wait);

        if (err)

            goto unlock;

    }

​

    ctx->more = 0;

​