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>
20 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
21 #include <net/netfilter/nf_conntrack.h>
23 #include <net/netfilter/nf_conntrack_zones.h>
25 /* Returns new sk_buff, or NULL */
26 static int nf_ct_ipv4_gather_frags(struct sk_buff *skb, u_int32_t user)
33 err = ip_defrag(skb, user);
37 ip_send_check(ip_hdr(skb));
42 static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
45 u16 zone = NF_CT_DEFAULT_ZONE;
47 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
49 zone = nf_ct_zone((struct nf_conn *)skb->nfct);
52 #ifdef CONFIG_BRIDGE_NETFILTER
54 skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
55 return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
57 if (hooknum == NF_INET_PRE_ROUTING)
58 return IP_DEFRAG_CONNTRACK_IN + zone;
60 return IP_DEFRAG_CONNTRACK_OUT + zone;
63 static unsigned int ipv4_conntrack_defrag(const struct nf_hook_ops *ops,
65 const struct net_device *in,
66 const struct net_device *out,
67 int (*okfn)(struct sk_buff *))
69 struct sock *sk = skb->sk;
70 struct inet_sock *inet = inet_sk(skb->sk);
72 if (sk && (sk->sk_family == PF_INET) &&
76 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
77 #if !defined(CONFIG_NF_NAT) && !defined(CONFIG_NF_NAT_MODULE)
78 /* Previously seen (loopback)? Ignore. Do this before
80 if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
84 /* Gather fragments. */
85 if (ip_is_fragment(ip_hdr(skb))) {
86 enum ip_defrag_users user =
87 nf_ct_defrag_user(ops->hooknum, skb);
89 if (nf_ct_ipv4_gather_frags(skb, user))
95 static struct nf_hook_ops ipv4_defrag_ops[] = {
97 .hook = ipv4_conntrack_defrag,
100 .hooknum = NF_INET_PRE_ROUTING,
101 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
104 .hook = ipv4_conntrack_defrag,
105 .owner = THIS_MODULE,
107 .hooknum = NF_INET_LOCAL_OUT,
108 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
112 static int __init nf_defrag_init(void)
114 return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
117 static void __exit nf_defrag_fini(void)
119 nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
122 void nf_defrag_ipv4_enable(void)
125 EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
127 module_init(nf_defrag_init);
128 module_exit(nf_defrag_fini);
130 MODULE_LICENSE("GPL");