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>
12 #include <linux/sctp.h>
13 #include <net/sctp/checksum.h>
15 #include <net/netfilter/nf_nat_protocol.h>
17 static u_int16_t nf_sctp_port_rover
;
20 sctp_unique_tuple(struct nf_conntrack_tuple
*tuple
,
21 const struct nf_nat_range
*range
,
22 enum nf_nat_manip_type maniptype
,
23 const struct nf_conn
*ct
)
25 return nf_nat_proto_unique_tuple(tuple
, range
, maniptype
, ct
,
30 sctp_manip_pkt(struct sk_buff
*skb
,
31 unsigned int iphdroff
,
32 const struct nf_conntrack_tuple
*tuple
,
33 enum nf_nat_manip_type maniptype
)
35 const struct iphdr
*iph
= (struct iphdr
*)(skb
->data
+ iphdroff
);
37 unsigned int hdroff
= iphdroff
+ iph
->ihl
*4;
41 if (!skb_make_writable(skb
, hdroff
+ sizeof(*hdr
)))
44 iph
= (struct iphdr
*)(skb
->data
+ iphdroff
);
45 hdr
= (struct sctphdr
*)(skb
->data
+ hdroff
);
47 if (maniptype
== IP_NAT_MANIP_SRC
) {
48 /* Get rid of src ip and src pt */
50 newip
= tuple
->src
.u3
.ip
;
51 hdr
->source
= tuple
->src
.u
.sctp
.port
;
53 /* Get rid of dst ip and dst pt */
55 newip
= tuple
->dst
.u3
.ip
;
56 hdr
->dest
= tuple
->dst
.u
.sctp
.port
;
59 crc32
= sctp_start_cksum((u8
*)hdr
, skb_headlen(skb
) - hdroff
);
60 for (skb
= skb_shinfo(skb
)->frag_list
; skb
; skb
= skb
->next
)
61 crc32
= sctp_update_cksum((u8
*)skb
->data
, skb_headlen(skb
),
63 crc32
= sctp_end_cksum(crc32
);
64 hdr
->checksum
= crc32
;
69 static const struct nf_nat_protocol nf_nat_protocol_sctp
= {
70 .protonum
= IPPROTO_SCTP
,
72 .manip_pkt
= sctp_manip_pkt
,
73 .in_range
= nf_nat_proto_in_range
,
74 .unique_tuple
= sctp_unique_tuple
,
75 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
76 .range_to_nlattr
= nf_nat_proto_range_to_nlattr
,
77 .nlattr_to_range
= nf_nat_proto_nlattr_to_range
,
81 static int __init
nf_nat_proto_sctp_init(void)
83 return nf_nat_protocol_register(&nf_nat_protocol_sctp
);
86 static void __exit
nf_nat_proto_sctp_exit(void)
88 nf_nat_protocol_unregister(&nf_nat_protocol_sctp
);
91 module_init(nf_nat_proto_sctp_init
);
92 module_exit(nf_nat_proto_sctp_exit
);
94 MODULE_LICENSE("GPL");
95 MODULE_DESCRIPTION("SCTP NAT protocol helper");
96 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");