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,
33 err = ip_defrag(net, skb, user);
37 ip_send_check(ip_hdr(skb));
44 static enum ip_defrag_users nf_ct_defrag_user(unsigned int hooknum,
47 u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
48 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
50 enum ip_conntrack_info ctinfo;
51 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
53 zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
56 if (nf_bridge_in_prerouting(skb))
57 return IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;
59 if (hooknum == NF_INET_PRE_ROUTING)
60 return IP_DEFRAG_CONNTRACK_IN + zone_id;
62 return IP_DEFRAG_CONNTRACK_OUT + zone_id;
65 static unsigned int ipv4_conntrack_defrag(void *priv,
67 const struct nf_hook_state *state)
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 IS_ENABLED(CONFIG_NF_CONNTRACK)
77 #if !IS_ENABLED(CONFIG_NF_NAT)
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(state->hook, skb);
89 if (nf_ct_ipv4_gather_frags(state->net, skb, user))
95 static struct nf_hook_ops ipv4_defrag_ops[] = {
97 .hook = ipv4_conntrack_defrag,
99 .hooknum = NF_INET_PRE_ROUTING,
100 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
103 .hook = ipv4_conntrack_defrag,
105 .hooknum = NF_INET_LOCAL_OUT,
106 .priority = NF_IP_PRI_CONNTRACK_DEFRAG,
110 static int __init nf_defrag_init(void)
112 return nf_register_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
115 static void __exit nf_defrag_fini(void)
117 nf_unregister_hooks(ipv4_defrag_ops, ARRAY_SIZE(ipv4_defrag_ops));
120 void nf_defrag_ipv4_enable(void)
123 EXPORT_SYMBOL_GPL(nf_defrag_ipv4_enable);
125 module_init(nf_defrag_init);
126 module_exit(nf_defrag_fini);
128 MODULE_LICENSE("GPL");