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Commit 9ba1f726 authored by Arturo Borrero's avatar Arturo Borrero Committed by Pablo Neira Ayuso
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netfilter: nf_tables: add new nft_masq expression 



The nft_masq expression is intended to perform NAT in the masquerade flavour.

We decided to have the masquerade functionality in a separated expression other
than nft_nat.

Signed-off-by: default avatarArturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: default avatarPablo Neira Ayuso <pablo@netfilter.org>
parent be6b635c

include/net/netfilter/nft_masq.h

0 → 100644
+16 −0
Original line number Diff line number Diff line 
#ifndef _NFT_MASQ_H_

#define _NFT_MASQ_H_



struct nft_masq {

	u32	flags;

};



extern const struct nla_policy nft_masq_policy[];



int nft_masq_init(const struct nft_ctx *ctx,

		  const struct nft_expr *expr,

		  const struct nlattr * const tb[]);



int nft_masq_dump(struct sk_buff *skb, const struct nft_expr *expr);



#endif /* _NFT_MASQ_H_ */

include/uapi/linux/netfilter/nf_tables.h

+11 −0
Original line number Diff line number Diff line
@@ -800,4 +800,15 @@ enum nft_nat_attributes { 
};

#define NFTA_NAT_MAX		(__NFTA_NAT_MAX - 1)



/**

 * enum nft_masq_attributes - nf_tables masquerade expression attributes

 *

 * @NFTA_MASQ_FLAGS: NAT flags (see NF_NAT_RANGE_* in linux/netfilter/nf_nat.h) (NLA_U32)

 */

enum nft_masq_attributes {

	NFTA_MASQ_FLAGS,

	__NFTA_MASQ_MAX

};

#define NFTA_MASQ_MAX		(__NFTA_MASQ_MAX - 1)



#endif /* _LINUX_NF_TABLES_H */

net/ipv4/netfilter/Kconfig

+6 −0
Original line number Diff line number Diff line
@@ -190,6 +190,12 @@ config NF_NAT_MASQUERADE_IPV4 
	This is the kernel functionality to provide NAT in the masquerade

	flavour (automatic source address selection).



config NFT_MASQ_IPV4

	tristate "IPv4 masquerading support for nf_tables"

	depends on NF_TABLES_IPV4

	depends on NFT_MASQ

	select NF_NAT_MASQUERADE_IPV4



config IP_NF_TARGET_MASQUERADE

	tristate "MASQUERADE target support"

	select NF_NAT_MASQUERADE_IPV4

net/ipv4/netfilter/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -36,6 +36,7 @@ obj-$(CONFIG_NF_TABLES_IPV4) += nf_tables_ipv4.o 
obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV4) += nft_chain_route_ipv4.o

obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o

obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o

obj-$(CONFIG_NFT_MASQ_IPV4) += nft_masq_ipv4.o

obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o



# generic IP tables

net/ipv4/netfilter/nft_masq_ipv4.c

0 → 100644
+89 −0
Original line number Diff line number Diff line 
/*

 * Copyright (c) 2014 Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>

 *

 * 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.

 */



#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.h>

#include <net/netfilter/nft_masq.h>

#include <net/netfilter/ipv4/nf_nat_masquerade.h>



static void nft_masq_ipv4_eval(const struct nft_expr *expr,

			       struct nft_data data[NFT_REG_MAX + 1],

			       const struct nft_pktinfo *pkt)

{

	struct nft_masq *priv = nft_expr_priv(expr);

	struct nf_nat_range range;

	unsigned int verdict;



	range.flags = priv->flags;



	verdict = nf_nat_masquerade_ipv4(pkt->skb, pkt->ops->hooknum,

					 &range, pkt->out);



	data[NFT_REG_VERDICT].verdict = verdict;

}



static int nft_masq_ipv4_init(const struct nft_ctx *ctx,

			      const struct nft_expr *expr,

			      const struct nlattr * const tb[])

{

	int err;



	err = nft_masq_init(ctx, expr, tb);

	if (err < 0)

		return err;



	nf_nat_masquerade_ipv4_register_notifier();

	return 0;

}



static void nft_masq_ipv4_destroy(const struct nft_ctx *ctx,

				  const struct nft_expr *expr)

{

	nf_nat_masquerade_ipv4_unregister_notifier();

}



static struct nft_expr_type nft_masq_ipv4_type;

static const struct nft_expr_ops nft_masq_ipv4_ops = {

	.type		= &nft_masq_ipv4_type,

	.size		= NFT_EXPR_SIZE(sizeof(struct nft_masq)),

	.eval		= nft_masq_ipv4_eval,

	.init		= nft_masq_ipv4_init,

	.destroy	= nft_masq_ipv4_destroy,

	.dump		= nft_masq_dump,

};



static struct nft_expr_type nft_masq_ipv4_type __read_mostly = {

	.family		= NFPROTO_IPV4,

	.name		= "masq",

	.ops		= &nft_masq_ipv4_ops,

	.policy		= nft_masq_policy,

	.maxattr	= NFTA_MASQ_MAX,

	.owner		= THIS_MODULE,

};



static int __init nft_masq_ipv4_module_init(void)

{

	return nft_register_expr(&nft_masq_ipv4_type);

}



static void __exit nft_masq_ipv4_module_exit(void)

{

	nft_unregister_expr(&nft_masq_ipv4_type);

}



module_init(nft_masq_ipv4_module_init);

module_exit(nft_masq_ipv4_module_exit);



MODULE_LICENSE("GPL");

MODULE_AUTHOR("Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>");

MODULE_ALIAS_NFT_AF_EXPR(AF_INET, "masq");