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Commit 937e0dfd authored by Patrick McHardy's avatar Patrick McHardy
Browse files

[NETFILTER]: nf_nat: add helpers for common NAT protocol operations 



Add generic ->in_range and ->unique_tuple ops to avoid duplicating them
again and again for future NAT modules and save a few bytes of text:

net/ipv4/netfilter/nf_nat_proto_tcp.c:
  tcp_in_range     |  -62 (removed)
  tcp_unique_tuple | -259 # 271 -> 12, # inlines: 1 -> 0, size inlines: 7 -> 0
 2 functions changed, 321 bytes removed

net/ipv4/netfilter/nf_nat_proto_udp.c:
  udp_in_range     |  -62 (removed)
  udp_unique_tuple | -259 # 271 -> 12, # inlines: 1 -> 0, size inlines: 7 -> 0
 2 functions changed, 321 bytes removed

net/ipv4/netfilter/nf_nat_proto_gre.c:
  gre_in_range |  -62 (removed)
 1 function changed, 62 bytes removed

vmlinux:
 5 functions changed, 704 bytes removed

Signed-off-by: default avatarPatrick McHardy <kaber@trash.net>
parent 544473c1

include/net/netfilter/nf_nat_protocol.h

+11 −0
Original line number Diff line number Diff line
@@ -62,6 +62,17 @@ extern int init_protocols(void) __init; 
extern void cleanup_protocols(void);

extern const struct nf_nat_protocol *find_nat_proto(u_int16_t protonum);



extern int nf_nat_proto_in_range(const struct nf_conntrack_tuple *tuple,

				 enum nf_nat_manip_type maniptype,

				 const union nf_conntrack_man_proto *min,

				 const union nf_conntrack_man_proto *max);



extern int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,

				     const struct nf_nat_range *range,

				     enum nf_nat_manip_type maniptype,

				     const struct nf_conn *ct,

				     u_int16_t *rover);



extern int nf_nat_port_range_to_nlattr(struct sk_buff *skb,

				       const struct nf_nat_range *range);

extern int nf_nat_port_nlattr_to_range(struct nlattr *tb[],

net/ipv4/netfilter/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -10,7 +10,7 @@ nf_conntrack_ipv4-objs += nf_conntrack_l3proto_ipv4_compat.o 
endif

endif



nf_nat-objs		:= nf_nat_core.o nf_nat_helper.o nf_nat_proto_unknown.o nf_nat_proto_tcp.o nf_nat_proto_udp.o nf_nat_proto_icmp.o

nf_nat-objs		:= nf_nat_core.o nf_nat_helper.o nf_nat_proto_unknown.o nf_nat_proto_common.o nf_nat_proto_tcp.o nf_nat_proto_udp.o nf_nat_proto_icmp.o

iptable_nat-objs	:= nf_nat_rule.o nf_nat_standalone.o



# connection tracking

net/ipv4/netfilter/nf_nat_proto_common.c

0 → 100644
+85 −0
Original line number Diff line number Diff line 
/* (C) 1999-2001 Paul `Rusty' Russell

 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>

 * (C) 2008 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.

 */



#include <linux/types.h>

#include <linux/random.h>

#include <linux/ip.h>



#include <linux/netfilter.h>

#include <net/netfilter/nf_nat.h>

#include <net/netfilter/nf_nat_core.h>

#include <net/netfilter/nf_nat_rule.h>

#include <net/netfilter/nf_nat_protocol.h>



int nf_nat_proto_in_range(const struct nf_conntrack_tuple *tuple,

			  enum nf_nat_manip_type maniptype,

			  const union nf_conntrack_man_proto *min,

			  const union nf_conntrack_man_proto *max)

{

	__be16 port;



	if (maniptype == IP_NAT_MANIP_SRC)

		port = tuple->src.u.all;

	else

		port = tuple->dst.u.all;



	return ntohs(port) >= ntohs(min->all) &&

	       ntohs(port) <= ntohs(max->all);

}

EXPORT_SYMBOL_GPL(nf_nat_proto_in_range);



int nf_nat_proto_unique_tuple(struct nf_conntrack_tuple *tuple,

			      const struct nf_nat_range *range,

			      enum nf_nat_manip_type maniptype,

			      const struct nf_conn *ct,

			      u_int16_t *rover)

{

	unsigned int range_size, min, i;

	__be16 *portptr;



	if (maniptype == IP_NAT_MANIP_SRC)

		portptr = &tuple->src.u.all;

	else

		portptr = &tuple->dst.u.all;



	/* If no range specified... */

	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {

		/* If it's dst rewrite, can't change port */

		if (maniptype == IP_NAT_MANIP_DST)

			return 0;



		if (ntohs(*portptr) < 1024) {

			/* Loose convention: >> 512 is credential passing */

			if (ntohs(*portptr) < 512) {

				min = 1;

				range_size = 511 - min + 1;

			} else {

				min = 600;

				range_size = 1023 - min + 1;

			}

		} else {

			min = 1024;

			range_size = 65535 - 1024 + 1;

		}

	} else {

		min = ntohs(range->min.all);

		range_size = ntohs(range->max.all) - min + 1;

	}



	if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)

		*rover = net_random();



	for (i = 0; i < range_size; i++, (*rover)++) {

		*portptr = htons(min + *rover % range_size);

		if (!nf_nat_used_tuple(tuple, ct))

			return 1;

	}

	return 0;

}

EXPORT_SYMBOL_GPL(nf_nat_proto_unique_tuple);

net/ipv4/netfilter/nf_nat_proto_gre.c

+1 −19
Original line number Diff line number Diff line
@@ -36,24 +36,6 @@ MODULE_LICENSE("GPL"); 
MODULE_AUTHOR("Harald Welte <laforge@gnumonks.org>");

MODULE_DESCRIPTION("Netfilter NAT protocol helper module for GRE");



/* is key in given range between min and max */

static int

gre_in_range(const struct nf_conntrack_tuple *tuple,

	     enum nf_nat_manip_type maniptype,

	     const union nf_conntrack_man_proto *min,

	     const union nf_conntrack_man_proto *max)

{

	__be16 key;



	if (maniptype == IP_NAT_MANIP_SRC)

		key = tuple->src.u.gre.key;

	else

		key = tuple->dst.u.gre.key;



	return ntohs(key) >= ntohs(min->gre.key) &&

	       ntohs(key) <= ntohs(max->gre.key);

}



/* generate unique tuple ... */

static int

gre_unique_tuple(struct nf_conntrack_tuple *tuple,
@@ -140,7 +122,7 @@ static const struct nf_nat_protocol gre = { 
	.protonum		= IPPROTO_GRE,

	.me			= THIS_MODULE,

	.manip_pkt		= gre_manip_pkt,

	.in_range		= gre_in_range,

	.in_range		= nf_nat_proto_in_range,

	.unique_tuple		= gre_unique_tuple,

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

	.range_to_nlattr	= nf_nat_port_range_to_nlattr,

net/ipv4/netfilter/nf_nat_proto_tcp.c

+4 −61
Original line number Diff line number Diff line
@@ -8,7 +8,6 @@ 


#include <linux/types.h>

#include <linux/init.h>

#include <linux/random.h>

#include <linux/ip.h>

#include <linux/tcp.h>
@@ -19,22 +18,7 @@ 
#include <net/netfilter/nf_nat_protocol.h>

#include <net/netfilter/nf_nat_core.h>



static int

tcp_in_range(const struct nf_conntrack_tuple *tuple,

	     enum nf_nat_manip_type maniptype,

	     const union nf_conntrack_man_proto *min,

	     const union nf_conntrack_man_proto *max)

{

	__be16 port;



	if (maniptype == IP_NAT_MANIP_SRC)

		port = tuple->src.u.tcp.port;

	else

		port = tuple->dst.u.tcp.port;



	return ntohs(port) >= ntohs(min->tcp.port) &&

	       ntohs(port) <= ntohs(max->tcp.port);

}

static u_int16_t tcp_port_rover;



static int

tcp_unique_tuple(struct nf_conntrack_tuple *tuple,
@@ -42,49 +26,8 @@ tcp_unique_tuple(struct nf_conntrack_tuple *tuple, 
		 enum nf_nat_manip_type maniptype,

		 const struct nf_conn *ct)

{

	static u_int16_t port;

	__be16 *portptr;

	unsigned int range_size, min, i;



	if (maniptype == IP_NAT_MANIP_SRC)

		portptr = &tuple->src.u.tcp.port;

	else

		portptr = &tuple->dst.u.tcp.port;



	/* If no range specified... */

	if (!(range->flags & IP_NAT_RANGE_PROTO_SPECIFIED)) {

		/* If it's dst rewrite, can't change port */

		if (maniptype == IP_NAT_MANIP_DST)

			return 0;



		/* Map privileged onto privileged. */

		if (ntohs(*portptr) < 1024) {

			/* Loose convention: >> 512 is credential passing */

			if (ntohs(*portptr)<512) {

				min = 1;

				range_size = 511 - min + 1;

			} else {

				min = 600;

				range_size = 1023 - min + 1;

			}

		} else {

			min = 1024;

			range_size = 65535 - 1024 + 1;

		}

	} else {

		min = ntohs(range->min.tcp.port);

		range_size = ntohs(range->max.tcp.port) - min + 1;

	}



	if (range->flags & IP_NAT_RANGE_PROTO_RANDOM)

		port =  net_random();



	for (i = 0; i < range_size; i++, port++) {

		*portptr = htons(min + port % range_size);

		if (!nf_nat_used_tuple(tuple, ct))

			return 1;

	}

	return 0;

	return nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,

					 &tcp_port_rover);

}



static int
@@ -142,7 +85,7 @@ const struct nf_nat_protocol nf_nat_protocol_tcp = { 
	.protonum		= IPPROTO_TCP,

	.me			= THIS_MODULE,

	.manip_pkt		= tcp_manip_pkt,

	.in_range		= tcp_in_range,

	.in_range		= nf_nat_proto_in_range,

	.unique_tuple		= tcp_unique_tuple,

#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)

	.range_to_nlattr	= nf_nat_port_range_to_nlattr,