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_bridge.h>
18 #include <linux/netfilter_ipv4.h>
19 #include <net/netfilter/ipv4/nf_defrag_ipv4.h>
21 /* Returns new sk_buff, or NULL */
22 static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
29 err = ip_defrag(skb, user);
33 ip_send_check(ip_hdr(skb));
38 static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
41 #ifdef CONFIG_BRIDGE_NETFILTER
43 skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
44 return IP_DEFRAG_CONNTRACK_BRIDGE_IN;
46 if (hooknum == NF_INET_PRE_ROUTING)
47 return IP_DEFRAG_CONNTRACK_IN;
49 return IP_DEFRAG_CONNTRACK_OUT;
52 static unsigned int ipv4_conntrack_defrag(unsigned int hooknum,
54 const struct net_device *in,
55 const struct net_device *out,
56 int (*okfn)(struct sk_buff *))
58 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
59 #if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
60 /* Previously seen (loopback)? Ignore. Do this before
62 if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
66 /* Gather fragments. */
67 if (ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET)) {
68 enum ip_defrag_users user = nf_ct_defrag_user(hooknum, skb);
69 if (nf_ct_ipv4_gather_frags(skb, user))
75 static struct nf_hook_ops ipv4_defrag_ops[] = {
77 .hook = ipv4_conntrack_defrag,
80 .hooknum = NF_INET_PRE_ROUTING,
81 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
84 .hook = ipv4_conntrack_defrag,
87 .hooknum = NF_INET_LOCAL_OUT,
88 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
92 static int __init nf_defrag_init(void)
94 return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
97 static void __exit nf_defrag_fini(void)
99 nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
102 void nf_defrag_ipv4_enable(void)
105 EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
107 module_init(nf_defrag_init);
108 module_exit(nf_defrag_fini);
110 MODULE_LICENSE("GPL");