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 IS_ENABLED(CONFIG_NF_CONNTRACK)
21 #include <net/netfilter/nf_conntrack.h>
23 #include <net/netfilter/nf_conntrack_zones.h>
25 static int nf_ct_ipv4_gather_frags(struct net *net, struct sk_buff *skb,
31 err = ip_defrag(net, skb, user);
40 static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
43 u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
44 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
46 enum ip_conntrack_info ctinfo;
47 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
49 zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
52 if (nf_bridge_in_prerouting(skb))
53 return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;
55 if (hooknum == NF_INET_PRE_ROUTING)
56 return IP_DEFRAG_CONNTRACK_IN + zone_id;
58 return IP_DEFRAG_CONNTRACK_OUT + zone_id;
61 static unsigned int ipv4_conntrack_defrag(void *priv,
63 const struct nf_hook_state *state)
65 struct sock *sk = skb->sk;
67 if (sk && sk_fullsock(sk) && (sk->sk_family == PF_INET) &&
68 inet_sk(sk)->nodefrag)
71 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
72 #if !IS_ENABLED(CONFIG_NF_NAT)
73 /* Previously seen (loopback)? Ignore. Do this before
75 if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
79 /* Gather fragments. */
80 if (ip_is_fragment(ip_hdr(skb))) {
81 enum ip_defrag_users user =
82 nf_ct_defrag_user(state->hook, skb);
84 if (nf_ct_ipv4_gather_frags(state->net, skb, user))
90 static struct nf_hook_ops ipv4_defrag_ops[] = {
92 .hook = ipv4_conntrack_defrag,
94 .hooknum = NF_INET_PRE_ROUTING,
95 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
98 .hook = ipv4_conntrack_defrag,
100 .hooknum = NF_INET_LOCAL_OUT,
101 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
105 static int __init nf_defrag_init(void)
107 return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
110 static void __exit nf_defrag_fini(void)
112 nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
115 void nf_defrag_ipv4_enable(void)
118 EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
120 module_init(nf_defrag_init);
121 module_exit(nf_defrag_fini);
123 MODULE_LICENSE("GPL");