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>
11 #include <linux/netfilter.h>
12 #include <linux/module.h>
13 #include <linux/skbuff.h>
14 #include <net/route.h>
17 #include <linux/netfilter_ipv4.h>
18 #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
20 /* Returns new sk_buff, or NULL */
21 static int nf_ct_ipv4_gather_frags(struct sk_buff
*skb
, u_int32_t user
)
28 err
= ip_defrag(skb
, user
);
32 ip_send_check(ip_hdr(skb
));
37 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum
,
39 const struct net_device
*in
,
40 const struct net_device
*out
,
41 int (*okfn
)(struct sk_buff
*))
43 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
44 #if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
45 /* Previously seen (loopback)? Ignore. Do this before
51 /* Gather fragments. */
52 if (ip_hdr(skb
)->frag_off
& htons(IP_MF
| IP_OFFSET
)) {
53 if (nf_ct_ipv4_gather_frags(skb
,
54 hooknum
== NF_INET_PRE_ROUTING
?
55 IP_DEFRAG_CONNTRACK_IN
:
56 IP_DEFRAG_CONNTRACK_OUT
))
62 static struct nf_hook_ops ipv4_defrag_ops
[] = {
64 .hook
= ipv4_conntrack_defrag
,
67 .hooknum
= NF_INET_PRE_ROUTING
,
68 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
71 .hook
= ipv4_conntrack_defrag
,
74 .hooknum
= NF_INET_LOCAL_OUT
,
75 .priority
= NF_IP_PRI_CONNTRACK_DEFRAG
,
79 static int __init
nf_defrag_init(void)
81 return nf_register_hooks(ipv4_defrag_ops
, ARRAY_SIZE(ipv4_defrag_ops
));
84 static void __exit
nf_defrag_fini(void)
86 nf_unregister_hooks(ipv4_defrag_ops
, ARRAY_SIZE(ipv4_defrag_ops
));
89 void nf_defrag_ipv4_enable(void)
92 EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable
);
94 module_init(nf_defrag_init
);
95 module_exit(nf_defrag_fini
);
97 MODULE_LICENSE("GPL");