1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 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/netfilter.h>
13 #include <linux/icmp.h>
16 #include <linux/netfilter_ipv4/ip_nat.h>
17 #include <linux/netfilter_ipv4/ip_nat_core.h>
18 #include <linux/netfilter_ipv4/ip_nat_rule.h>
19 #include <linux/netfilter_ipv4/ip_nat_protocol.h>
22 icmp_in_range(const struct ip_conntrack_tuple
*tuple
,
23 enum ip_nat_manip_type maniptype
,
24 const union ip_conntrack_manip_proto
*min
,
25 const union ip_conntrack_manip_proto
*max
)
27 return ntohs(tuple
->src
.u
.icmp
.id
) >= ntohs(min
->icmp
.id
) &&
28 ntohs(tuple
->src
.u
.icmp
.id
) <= ntohs(max
->icmp
.id
);
32 icmp_unique_tuple(struct ip_conntrack_tuple
*tuple
,
33 const struct ip_nat_range
*range
,
34 enum ip_nat_manip_type maniptype
,
35 const struct ip_conntrack
*conntrack
)
38 unsigned int range_size
;
41 range_size
= ntohs(range
->max
.icmp
.id
) - ntohs(range
->min
.icmp
.id
) + 1;
42 /* If no range specified... */
43 if (!(range
->flags
& IP_NAT_RANGE_PROTO_SPECIFIED
))
46 for (i
= 0; i
< range_size
; i
++, id
++) {
47 tuple
->src
.u
.icmp
.id
= htons(ntohs(range
->min
.icmp
.id
) +
49 if (!ip_nat_used_tuple(tuple
, conntrack
))
56 icmp_manip_pkt(struct sk_buff
**pskb
,
57 unsigned int iphdroff
,
58 const struct ip_conntrack_tuple
*tuple
,
59 enum ip_nat_manip_type maniptype
)
61 struct iphdr
*iph
= (struct iphdr
*)((*pskb
)->data
+ iphdroff
);
63 unsigned int hdroff
= iphdroff
+ iph
->ihl
*4;
65 if (!skb_make_writable(pskb
, hdroff
+ sizeof(*hdr
)))
68 hdr
= (struct icmphdr
*)((*pskb
)->data
+ hdroff
);
69 nf_proto_csum_replace2(&hdr
->checksum
, *pskb
,
70 hdr
->un
.echo
.id
, tuple
->src
.u
.icmp
.id
, 0);
71 hdr
->un
.echo
.id
= tuple
->src
.u
.icmp
.id
;
75 struct ip_nat_protocol ip_nat_protocol_icmp
= {
77 .protonum
= IPPROTO_ICMP
,
79 .manip_pkt
= icmp_manip_pkt
,
80 .in_range
= icmp_in_range
,
81 .unique_tuple
= icmp_unique_tuple
,
82 #if defined(CONFIG_IP_NF_CONNTRACK_NETLINK) || \
83 defined(CONFIG_IP_NF_CONNTRACK_NETLINK_MODULE)
84 .range_to_nfattr
= ip_nat_port_range_to_nfattr
,
85 .nfattr_to_range
= ip_nat_port_nfattr_to_range
,