b9e61f0dff
The NAT range to nlattr conversation callbacks and helpers are entirely dead code and are also useless since there are no NAT ranges in conntrack context, they are only used for initially selecting a tuple. The final NAT information is contained in the selected tuples of the conntrack entry. Signed-off-by: Patrick McHardy <kaber@trash.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
107 lines
2.8 KiB
C
107 lines
2.8 KiB
C
/*
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* DCCP NAT protocol helper
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*
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* Copyright (c) 2005, 2006. 2008 Patrick McHardy <kaber@trash.net>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/skbuff.h>
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#include <linux/ip.h>
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#include <linux/dccp.h>
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#include <net/netfilter/nf_conntrack.h>
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#include <net/netfilter/nf_nat.h>
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#include <net/netfilter/nf_nat_protocol.h>
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static u_int16_t dccp_port_rover;
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static void
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dccp_unique_tuple(struct nf_conntrack_tuple *tuple,
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const struct nf_nat_ipv4_range *range,
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enum nf_nat_manip_type maniptype,
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const struct nf_conn *ct)
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{
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nf_nat_proto_unique_tuple(tuple, range, maniptype, ct,
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&dccp_port_rover);
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}
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static bool
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dccp_manip_pkt(struct sk_buff *skb,
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unsigned int iphdroff,
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const struct nf_conntrack_tuple *tuple,
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enum nf_nat_manip_type maniptype)
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{
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const struct iphdr *iph = (const void *)(skb->data + iphdroff);
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struct dccp_hdr *hdr;
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unsigned int hdroff = iphdroff + iph->ihl * 4;
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__be32 oldip, newip;
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__be16 *portptr, oldport, newport;
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int hdrsize = 8; /* DCCP connection tracking guarantees this much */
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if (skb->len >= hdroff + sizeof(struct dccp_hdr))
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hdrsize = sizeof(struct dccp_hdr);
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if (!skb_make_writable(skb, hdroff + hdrsize))
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return false;
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iph = (struct iphdr *)(skb->data + iphdroff);
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hdr = (struct dccp_hdr *)(skb->data + hdroff);
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if (maniptype == NF_NAT_MANIP_SRC) {
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oldip = iph->saddr;
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newip = tuple->src.u3.ip;
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newport = tuple->src.u.dccp.port;
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portptr = &hdr->dccph_sport;
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} else {
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oldip = iph->daddr;
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newip = tuple->dst.u3.ip;
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newport = tuple->dst.u.dccp.port;
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portptr = &hdr->dccph_dport;
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}
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oldport = *portptr;
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*portptr = newport;
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if (hdrsize < sizeof(*hdr))
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return true;
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inet_proto_csum_replace4(&hdr->dccph_checksum, skb, oldip, newip, 1);
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inet_proto_csum_replace2(&hdr->dccph_checksum, skb, oldport, newport,
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0);
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return true;
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}
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static const struct nf_nat_protocol nf_nat_protocol_dccp = {
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.protonum = IPPROTO_DCCP,
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.manip_pkt = dccp_manip_pkt,
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.in_range = nf_nat_proto_in_range,
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.unique_tuple = dccp_unique_tuple,
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#if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
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.nlattr_to_range = nf_nat_proto_nlattr_to_range,
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#endif
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};
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static int __init nf_nat_proto_dccp_init(void)
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{
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return nf_nat_protocol_register(&nf_nat_protocol_dccp);
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}
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static void __exit nf_nat_proto_dccp_fini(void)
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{
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nf_nat_protocol_unregister(&nf_nat_protocol_dccp);
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}
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module_init(nf_nat_proto_dccp_init);
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module_exit(nf_nat_proto_dccp_fini);
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MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
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MODULE_DESCRIPTION("DCCP NAT protocol helper");
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MODULE_LICENSE("GPL");
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