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

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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: Patrick McHardy <kaber@trash.net>
This commit is contained in:
Patrick McHardy 2008-03-20 15:15:47 +01:00
parent 544473c166
commit 937e0dfd87
6 changed files with 106 additions and 141 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
include/net/netfilter/nf_nat_protocol.h
View File

@ -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[],

2
net/ipv4/netfilter/Makefile
View File

@ -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

85
net/ipv4/netfilter/nf_nat_proto_common.c Normal file
View File

@ -0,0 +1,85 @@
/* (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);

20
net/ipv4/netfilter/nf_nat_proto_gre.c
View File

@ -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,

65
net/ipv4/netfilter/nf_nat_proto_tcp.c
View File

@ -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,

64
net/ipv4/netfilter/nf_nat_proto_udp.c
View File

@ -8,7 +8,6 @@
#include <linux/types.h>
#include <linux/init.h>
#include <linux/random.h>
#include <linux/ip.h>
#include <linux/udp.h>
@ -18,22 +17,7 @@
#include <net/netfilter/nf_nat_rule.h>
#include <net/netfilter/nf_nat_protocol.h>
static int
udp_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.udp.port;
else
port = tuple->dst.u.udp.port;
return ntohs(port) >= ntohs(min->udp.port) &&
ntohs(port) <= ntohs(max->udp.port);
}
static u_int16_t udp_port_rover;
static int
udp_unique_tuple(struct nf_conntrack_tuple *tuple,
@ -41,48 +25,8 @@ udp_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.udp.port;
else
portptr = &tuple->dst.u.udp.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;
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.udp.port);
range_size = ntohs(range->max.udp.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,
&udp_port_rover);
}
static int
@ -132,7 +76,7 @@ const struct nf_nat_protocol nf_nat_protocol_udp = {
.protonum = IPPROTO_UDP,
.me = THIS_MODULE,
.manip_pkt = udp_manip_pkt,
.in_range = udp_in_range,
.in_range = nf_nat_proto_in_range,
.unique_tuple = udp_unique_tuple,
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
.range_to_nlattr = nf_nat_port_range_to_nlattr,