1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org>
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/icmp.h>
14 #include <linux/netfilter.h>
15 #include <net/netfilter/nf_nat.h>
16 #include <net/netfilter/nf_nat_core.h>
17 #include <net/netfilter/nf_nat_rule.h>
18 #include <net/netfilter/nf_nat_protocol.h>
21 icmp_in_range(const struct nf_conntrack_tuple
*tuple
,
22 enum nf_nat_manip_type maniptype
,
23 const union nf_conntrack_man_proto
*min
,
24 const union nf_conntrack_man_proto
*max
)
26 return ntohs(tuple
->src
.u
.icmp
.id
) >= ntohs(min
->icmp
.id
) &&
27 ntohs(tuple
->src
.u
.icmp
.id
) <= ntohs(max
->icmp
.id
);
31 icmp_unique_tuple(struct nf_conntrack_tuple
*tuple
,
32 const struct nf_nat_range
*range
,
33 enum nf_nat_manip_type maniptype
,
34 const struct nf_conn
*ct
)
37 unsigned int range_size
;
40 range_size
= ntohs(range
->max
.icmp
.id
) - ntohs(range
->min
.icmp
.id
) + 1;
41 /* If no range specified... */
42 if (!(range
->flags
& IP_NAT_RANGE_PROTO_SPECIFIED
))
45 for (i
= 0; i
< range_size
; i
++, id
++) {
46 tuple
->src
.u
.icmp
.id
= htons(ntohs(range
->min
.icmp
.id
) +
48 if (!nf_nat_used_tuple(tuple
, ct
))
55 icmp_manip_pkt(struct sk_buff
*skb
,
56 unsigned int iphdroff
,
57 const struct nf_conntrack_tuple
*tuple
,
58 enum nf_nat_manip_type maniptype
)
60 const struct iphdr
*iph
= (struct iphdr
*)(skb
->data
+ iphdroff
);
62 unsigned int hdroff
= iphdroff
+ iph
->ihl
*4;
64 if (!skb_make_writable(skb
, hdroff
+ sizeof(*hdr
)))
67 hdr
= (struct icmphdr
*)(skb
->data
+ hdroff
);
68 inet_proto_csum_replace2(&hdr
->checksum
, skb
,
69 hdr
->un
.echo
.id
, tuple
->src
.u
.icmp
.id
, 0);
70 hdr
->un
.echo
.id
= tuple
->src
.u
.icmp
.id
;
74 const struct nf_nat_protocol nf_nat_protocol_icmp
= {
75 .protonum
= IPPROTO_ICMP
,
77 .manip_pkt
= icmp_manip_pkt
,
78 .in_range
= icmp_in_range
,
79 .unique_tuple
= icmp_unique_tuple
,
80 #if defined(CONFIG_NF_CT_NETLINK) || defined(CONFIG_NF_CT_NETLINK_MODULE)
81 .range_to_nlattr
= nf_nat_proto_range_to_nlattr
,
82 .nlattr_to_range
= nf_nat_proto_nlattr_to_range
,