/*
|
* 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_regs *regs,
|
const struct nft_pktinfo *pkt)
|
{
|
const struct nft_bitwise *priv = nft_expr_priv(expr);
|
const u32 *src = ®s->data[priv->sreg];
|
u32 *dst = ®s->data[priv->dreg];
|
unsigned int i;
|
|
for (i = 0; i < DIV_ROUND_UP(priv->len, 4); i++)
|
dst[i] = (src[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;
|
u32 len;
|
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;
|
|
err = nft_parse_u32_check(tb[NFTA_BITWISE_LEN], U8_MAX, &len);
|
if (err < 0)
|
return err;
|
|
priv->len = len;
|
|
priv->sreg = nft_parse_register(tb[NFTA_BITWISE_SREG]);
|
err = nft_validate_register_load(priv->sreg, priv->len);
|
if (err < 0)
|
return err;
|
|
priv->dreg = nft_parse_register(tb[NFTA_BITWISE_DREG]);
|
err = nft_validate_register_store(ctx, priv->dreg, NULL,
|
NFT_DATA_VALUE, priv->len);
|
if (err < 0)
|
return err;
|
|
err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
|
tb[NFTA_BITWISE_MASK]);
|
if (err < 0)
|
return err;
|
if (d1.type != NFT_DATA_VALUE || d1.len != priv->len) {
|
err = -EINVAL;
|
goto err1;
|
}
|
|
err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
|
tb[NFTA_BITWISE_XOR]);
|
if (err < 0)
|
goto err1;
|
if (d2.type != NFT_DATA_VALUE || d2.len != priv->len) {
|
err = -EINVAL;
|
goto err2;
|
}
|
|
return 0;
|
err2:
|
nft_data_release(&priv->xor, d2.type);
|
err1:
|
nft_data_release(&priv->mask, d1.type);
|
return err;
|
}
|
|
static int nft_bitwise_dump(struct sk_buff *skb, const struct nft_expr *expr)
|
{
|
const struct nft_bitwise *priv = nft_expr_priv(expr);
|
|
if (nft_dump_register(skb, NFTA_BITWISE_SREG, priv->sreg))
|
goto nla_put_failure;
|
if (nft_dump_register(skb, NFTA_BITWISE_DREG, 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 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,
|
};
|
|
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,
|
};
|
