2 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
9 #include <linux/types.h>
10 #include <linux/init.h>
11 #include <linux/sctp.h>
12 #include <linux/module.h>
13 #include <net/sctp/checksum.h>
15 #include <net/netfilter/nf_nat_l4proto.h>
17 static u_int16_t nf_sctp_port_rover;
20 sctp_unique_tuple(const struct nf_nat_l3proto *l3proto,
21 struct nf_conntrack_tuple *tuple,
22 const struct nf_nat_range *range,
23 enum nf_nat_manip_type maniptype,
24 const struct nf_conn *ct)
26 nf_nat_l4proto_unique_tuple(l3proto, tuple, range, maniptype, ct,
31 sctp_manip_pkt(struct sk_buff *skb,
32 const struct nf_nat_l3proto *l3proto,
33 unsigned int iphdroff, unsigned int hdroff,
34 const struct nf_conntrack_tuple *tuple,
35 enum nf_nat_manip_type maniptype)
41 if (!skb_make_writable(skb, hdroff + sizeof(*hdr)))
44 hdr = (struct sctphdr *)(skb->data + hdroff);
46 if (maniptype == NF_NAT_MANIP_SRC) {
47 /* Get rid of src port */
48 hdr->source = tuple->src.u.sctp.port;
50 /* Get rid of dst port */
51 hdr->dest = tuple->dst.u.sctp.port;
54 crc32 = sctp_start_cksum((u8 *)hdr, skb_headlen(skb) - hdroff);
55 skb_walk_frags(skb, frag)
56 crc32 = sctp_update_cksum((u8 *)frag->data, skb_headlen(frag),
58 crc32 = sctp_end_cksum(crc32);
59 hdr->checksum = crc32;
64 static const struct nf_nat_l4proto nf_nat_l4proto_sctp = {
65 .l4proto = IPPROTO_SCTP,
66 .manip_pkt = sctp_manip_pkt,
67 .in_range = nf_nat_l4proto_in_range,
68 .unique_tuple = sctp_unique_tuple,
69 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
70 .nlattr_to_range = nf_nat_l4proto_nlattr_to_range,
74 static int __init nf_nat_proto_sctp_init(void)
78 err = nf_nat_l4proto_register(NFPROTO_IPV4, &nf_nat_l4proto_sctp);
81 err = nf_nat_l4proto_register(NFPROTO_IPV6, &nf_nat_l4proto_sctp);
87 nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_sctp);
92 static void __exit nf_nat_proto_sctp_exit(void)
94 nf_nat_l4proto_unregister(NFPROTO_IPV6, &nf_nat_l4proto_sctp);
95 nf_nat_l4proto_unregister(NFPROTO_IPV4, &nf_nat_l4proto_sctp);
98 module_init(nf_nat_proto_sctp_init);
99 module_exit(nf_nat_proto_sctp_exit);
101 MODULE_LICENSE("GPL");
102 MODULE_DESCRIPTION("SCTP NAT protocol helper");
103 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");