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>");