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 /* Previously seen (loopback)? Ignore. Do this before
50 /* Gather fragments. */
51 if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
52 if (nf_ct_ipv4_gather_frags(skb,
53 hooknum == NF_INET_PRE_ROUTING ?
54 IP_DEFRAG_CONNTRACK_IN :
55 IP_DEFRAG_CONNTRACK_OUT))
61 static struct nf_hook_ops ipv4_defrag_ops[] = {
63 .hook = ipv4_conntrack_defrag,
66 .hooknum = NF_INET_PRE_ROUTING,
67 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
70 .hook = ipv4_conntrack_defrag,
73 .hooknum = NF_INET_LOCAL_OUT,
74 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
78 static int __init nf_defrag_init(void)
80 return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
83 static void __exit nf_defrag_fini(void)
85 nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
88 void nf_defrag_ipv4_enable(void)
91 EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
93 module_init(nf_defrag_init);
94 module_exit(nf_defrag_fini);
96 MODULE_LICENSE("GPL");