f43dc98b3b
The only user of unique_tuple() get_unique_tuple() doesn't care about the return value of unique_tuple(), so make unique_tuple() return void (nothing). Signed-off-by: Changli Gao <xiaosuo@gmail.com> Signed-off-by: Patrick McHardy <kaber@trash.net>
109 lines
2.8 KiB
C
109 lines
2.8 KiB
C
/*
|
|
* DCCP NAT protocol helper
|
|
*
|
|
* Copyright (c) 2005, 2006. 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/kernel.h>
|
|
#include <linux/module.h>
|
|
#include <linux/init.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/ip.h>
|
|
#include <linux/dccp.h>
|
|
|
|
#include <net/netfilter/nf_conntrack.h>
|
|
#include <net/netfilter/nf_nat.h>
|
|
#include <net/netfilter/nf_nat_protocol.h>
|
|
|
|
static u_int16_t dccp_port_rover;
|
|
|
|
static void
|
|
dccp_unique_tuple(struct nf_conntrack_tuple *tuple,
|
|
const struct nf_nat_range *range,
|
|
enum nf_nat_manip_type maniptype,
|
|
const struct nf_conn *ct)
|
|
{
|
|
nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
|
|
&dccp_port_rover);
|
|
}
|
|
|
|
static bool
|
|
dccp_manip_pkt(struct sk_buff *skb,
|
|
unsigned int iphdroff,
|
|
const struct nf_conntrack_tuple *tuple,
|
|
enum nf_nat_manip_type maniptype)
|
|
{
|
|
const struct iphdr *iph = (const void *)(skb->data + iphdroff);
|
|
struct dccp_hdr *hdr;
|
|
unsigned int hdroff = iphdroff + iph->ihl * 4;
|
|
__be32 oldip, newip;
|
|
__be16 *portptr, oldport, newport;
|
|
int hdrsize = 8; /* DCCP connection tracking guarantees this much */
|
|
|
|
if (skb->len >= hdroff + sizeof(struct dccp_hdr))
|
|
hdrsize = sizeof(struct dccp_hdr);
|
|
|
|
if (!skb_make_writable(skb, hdroff + hdrsize))
|
|
return false;
|
|
|
|
iph = (struct iphdr *)(skb->data + iphdroff);
|
|
hdr = (struct dccp_hdr *)(skb->data + hdroff);
|
|
|
|
if (maniptype == IP_NAT_MANIP_SRC) {
|
|
oldip = iph->saddr;
|
|
newip = tuple->src.u3.ip;
|
|
newport = tuple->src.u.dccp.port;
|
|
portptr = &hdr->dccph_sport;
|
|
} else {
|
|
oldip = iph->daddr;
|
|
newip = tuple->dst.u3.ip;
|
|
newport = tuple->dst.u.dccp.port;
|
|
portptr = &hdr->dccph_dport;
|
|
}
|
|
|
|
oldport = *portptr;
|
|
*portptr = newport;
|
|
|
|
if (hdrsize < sizeof(*hdr))
|
|
return true;
|
|
|
|
inet_proto_csum_replace4(&hdr->dccph_checksum, skb, oldip, newip, 1);
|
|
inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport,
|
|
0);
|
|
return true;
|
|
}
|
|
|
|
static const struct nf_nat_protocol nf_nat_protocol_dccp = {
|
|
.protonum = IPPROTO_DCCP,
|
|
.me = THIS_MODULE,
|
|
.manip_pkt = dccp_manip_pkt,
|
|
.in_range = nf_nat_proto_in_range,
|
|
.unique_tuple = dccp_unique_tuple,
|
|
#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
|
|
.range_to_nlattr = nf_nat_proto_range_to_nlattr,
|
|
.nlattr_to_range = nf_nat_proto_nlattr_to_range,
|
|
#endif
|
|
};
|
|
|
|
static int __init nf_nat_proto_dccp_init(void)
|
|
{
|
|
return nf_nat_protocol_register(&nf_nat_protocol_dccp);
|
|
}
|
|
|
|
static void __exit nf_nat_proto_dccp_fini(void)
|
|
{
|
|
nf_nat_protocol_unregister(&nf_nat_protocol_dccp);
|
|
}
|
|
|
|
module_init(nf_nat_proto_dccp_init);
|
|
module_exit(nf_nat_proto_dccp_fini);
|
|
|
|
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
|
|
MODULE_DESCRIPTION("DCCP NAT protocol helper");
|
|
MODULE_LICENSE("GPL");
|