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/*
* Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* Development of this code funded by Astaro AG (http://www.astaro.com/)
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables_core.h>
#include <net/netfilter/nf_tables.h>
struct nft_bitwise {
enum nft_registers sreg:8;
enum nft_registers dreg:8;
u8 len;
struct nft_data mask;
struct nft_data xor;
};
static void nft_bitwise_eval(const struct nft_expr *expr,
struct nft_data data[NFT_REG_MAX + 1],
const struct nft_pktinfo *pkt)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
const struct nft_data *src = &data[priv->sreg];
struct nft_data *dst = &data[priv->dreg];
unsigned int i;
for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++) {
dst->data[i] = (src->data[i] & priv->mask.data[i]) ^
priv->xor.data[i];
}
}
static const struct nla_policy nft_bitwise_policy[NFTA_BITWISE_MAX + 1] = {
[NFTA_BITWISE_SREG] = { .type = NLA_U32 },
[NFTA_BITWISE_DREG] = { .type = NLA_U32 },
[NFTA_BITWISE_LEN] = { .type = NLA_U32 },
[NFTA_BITWISE_MASK] = { .type = NLA_NESTED },
[NFTA_BITWISE_XOR] = { .type = NLA_NESTED },
};
static int nft_bitwise_init(const struct nft_ctx *ctx,
const struct nft_expr *expr,
const struct nlattr * const tb[])
{
struct nft_bitwise *priv = nft_expr_priv(expr);
struct nft_data_desc d1, d2;
int err;
if (tb[NFTA_BITWISE_SREG] == NULL ||
tb[NFTA_BITWISE_DREG] == NULL ||
tb[NFTA_BITWISE_LEN] == NULL ||
tb[NFTA_BITWISE_MASK] == NULL ||
tb[NFTA_BITWISE_XOR] == NULL)
return -EINVAL;
priv->sreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_SREG]));
err = nft_validate_input_register(priv->sreg);
if (err < 0)
return err;
priv->dreg = ntohl(nla_get_be32(tb[NFTA_BITWISE_DREG]));
err = nft_validate_output_register(priv->dreg);
if (err < 0)
return err;
err = nft_validate_data_load(ctx, priv->dreg, NULL, NFT_DATA_VALUE);
if (err < 0)
return err;
priv->len = ntohl(nla_get_be32(tb[NFTA_BITWISE_LEN]));
err = nft_data_init(NULL, &priv->mask, &d1, tb[NFTA_BITWISE_MASK]);
if (err < 0)
return err;
if (d1.len != priv->len)
return -EINVAL;
err = nft_data_init(NULL, &priv->xor, &d2, tb[NFTA_BITWISE_XOR]);
if (err < 0)
return err;
if (d2.len != priv->len)
return -EINVAL;
return 0;
}
static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
const struct nft_bitwise *priv = nft_expr_priv(expr);
if (nla_put_be32(skb, NFTA_BITWISE_SREG, htonl(priv->sreg)))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_BITWISE_DREG, htonl(priv->dreg)))
goto nla_put_failure;
if (nla_put_be32(skb, NFTA_BITWISE_LEN, htonl(priv->len)))
goto nla_put_failure;
if (nft_data_dump(skb, NFTA_BITWISE_MASK, &priv->mask,
NFT_DATA_VALUE, priv->len) < 0)
goto nla_put_failure;
if (nft_data_dump(skb, NFTA_BITWISE_XOR, &priv->xor,
NFT_DATA_VALUE, priv->len) < 0)
goto nla_put_failure;
return 0;
nla_put_failure:
return -1;
}
static struct nft_expr_type nft_bitwise_type;
static const struct nft_expr_ops nft_bitwise_ops = {
.type = &nft_bitwise_type,
.size = NFT_EXPR_SIZE(sizeof(struct nft_bitwise)),
.eval = nft_bitwise_eval,
.init = nft_bitwise_init,
.dump = nft_bitwise_dump,
};
static struct nft_expr_type nft_bitwise_type __read_mostly = {
.name = "bitwise",
.ops = &nft_bitwise_ops,
.policy = nft_bitwise_policy,
.maxattr = NFTA_BITWISE_MAX,
.owner = THIS_MODULE,
};
int __init nft_bitwise_module_init(void)
{
return nft_register_expr(&nft_bitwise_type);
}
void nft_bitwise_module_exit(void)
{
nft_unregister_expr(&nft_bitwise_type);
}
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