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>
11 #include <linux/export.h>
13 #include <linux/icmp.h>
15 #include <linux/netfilter.h>
16 #include <net/netfilter/nf_nat.h>
17 #include <net/netfilter/nf_nat_core.h>
18 #include <net/netfilter/nf_nat_l4proto.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(const struct nf_nat_l3proto
*l3proto
,
32 struct nf_conntrack_tuple
*tuple
,
33 const struct nf_nat_range
*range
,
34 enum nf_nat_manip_type maniptype
,
35 const struct nf_conn
*ct
)
38 unsigned int range_size
;
41 range_size
= ntohs(range
->max_proto
.icmp
.id
) -
42 ntohs(range
->min_proto
.icmp
.id
) + 1;
43 /* If no range specified... */
44 if (!(range
->flags
& NF_NAT_RANGE_PROTO_SPECIFIED
))
48 tuple
->src
.u
.icmp
.id
= htons(ntohs(range
->min_proto
.icmp
.id
) +
50 if (++i
== range_size
|| !nf_nat_used_tuple(tuple
, ct
))
57 icmp_manip_pkt(struct sk_buff
*skb
,
58 const struct nf_nat_l3proto
*l3proto
,
59 unsigned int iphdroff
, unsigned int hdroff
,
60 const struct nf_conntrack_tuple
*tuple
,
61 enum nf_nat_manip_type maniptype
)
65 if (!skb_make_writable(skb
, hdroff
+ sizeof(*hdr
)))
68 hdr
= (struct icmphdr
*)(skb
->data
+ hdroff
);
69 inet_proto_csum_replace2(&hdr
->checksum
, skb
,
70 hdr
->un
.echo
.id
, tuple
->src
.u
.icmp
.id
, false);
71 hdr
->un
.echo
.id
= tuple
->src
.u
.icmp
.id
;
75 const struct nf_nat_l4proto nf_nat_l4proto_icmp
= {
76 .l4proto
= IPPROTO_ICMP
,
77 .manip_pkt
= icmp_manip_pkt
,
78 .in_range
= icmp_in_range
,
79 .unique_tuple
= icmp_unique_tuple
,
80 #if IS_ENABLED(CONFIG_NF_CT_NETLINK)
81 .nlattr_to_range
= nf_nat_l4proto_nlattr_to_range
,