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/sctp.h>
11 #include <net/sctp/checksum.h>
13 #include <net/netfilter/nf_nat_l4proto.h>
15 static u_int16_t nf_sctp_port_rover
;
18 sctp_unique_tuple(const struct nf_nat_l3proto
*l3proto
,
19 struct nf_conntrack_tuple
*tuple
,
20 const struct nf_nat_range
*range
,
21 enum nf_nat_manip_type maniptype
,
22 const struct nf_conn
*ct
)
24 nf_nat_l4proto_unique_tuple(l3proto
, tuple
, range
, maniptype
, ct
,
29 sctp_manip_pkt(struct sk_buff
*skb
,
30 const struct nf_nat_l3proto
*l3proto
,
31 unsigned int iphdroff
, unsigned int hdroff
,
32 const struct nf_conntrack_tuple
*tuple
,
33 enum nf_nat_manip_type maniptype
)
38 /* This could be an inner header returned in imcp packet; in such
39 * cases we cannot update the checksum field since it is outside
40 * of the 8 bytes of transport layer headers we are guaranteed.
42 if (skb
->len
>= hdroff
+ sizeof(*hdr
))
43 hdrsize
= sizeof(*hdr
);
45 if (!skb_make_writable(skb
, hdroff
+ hdrsize
))
48 hdr
= (struct sctphdr
*)(skb
->data
+ hdroff
);
50 if (maniptype
== NF_NAT_MANIP_SRC
) {
51 /* Get rid of src port */
52 hdr
->source
= tuple
->src
.u
.sctp
.port
;
54 /* Get rid of dst port */
55 hdr
->dest
= tuple
->dst
.u
.sctp
.port
;
58 if (hdrsize
< sizeof(*hdr
))
61 if (skb
->ip_summed
!= CHECKSUM_PARTIAL
) {
62 hdr
->checksum
= sctp_compute_cksum(skb
, hdroff
);
63 skb
->ip_summed
= CHECKSUM_NONE
;
69 const struct nf_nat_l4proto nf_nat_l4proto_sctp
= {
70 .l4proto
= IPPROTO_SCTP
,
71 .manip_pkt
= sctp_manip_pkt
,
72 .in_range
= nf_nat_l4proto_in_range
,
73 .unique_tuple
= sctp_unique_tuple
,
74 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
75 .nlattr_to_range
= nf_nat_l4proto_nlattr_to_range
,