1 /* (C) 1999-2001 Paul `Rusty' Russell
2 * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
3 *
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.
7 */
8
9 #include <linux/types.h>
10 #include <linux/ipv6.h>
11 #include <linux/in6.h>
12 #include <linux/netfilter.h>
13 #include <linux/module.h>
14 #include <linux/skbuff.h>
15 #include <linux/icmp.h>
16 #include <linux/sysctl.h>
17 #include <net/ipv6.h>
18 #include <net/inet_frag.h>
19
20 #include <linux/netfilter_ipv6.h>
21 #include <linux/netfilter_bridge.h>
22 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
23 #include <net/netfilter/nf_conntrack.h>
24 #include <net/netfilter/nf_conntrack_helper.h>
25 #include <net/netfilter/nf_conntrack_l4proto.h>
26 #include <net/netfilter/nf_conntrack_l3proto.h>
27 #include <net/netfilter/nf_conntrack_core.h>
28 #include <net/netfilter/ipv6/nf_conntrack_ipv6.h>
29 #endif
30 #include <net/netfilter/nf_conntrack_zones.h>
31 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
32
nf_ct6_defrag_user(unsigned int hooknum,struct sk_buff * skb)33 static enum ip6_defrag_users nf_ct6_defrag_user(unsigned int hooknum,
34 struct sk_buff *skb)
35 {
36 u16 zone_id = NF_CT_DEFAULT_ZONE_ID;
37 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
38 if (skb->nfct) {
39 enum ip_conntrack_info ctinfo;
40 const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
41
42 zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo));
43 }
44 #endif
45 if (nf_bridge_in_prerouting(skb))
46 return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id;
47
48 if (hooknum == NF_INET_PRE_ROUTING)
49 return IP6_DEFRAG_CONNTRACK_IN + zone_id;
50 else
51 return IP6_DEFRAG_CONNTRACK_OUT + zone_id;
52 }
53
ipv6_defrag(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)54 static unsigned int ipv6_defrag(void *priv,
55 struct sk_buff *skb,
56 const struct nf_hook_state *state)
57 {
58 struct sk_buff *reasm;
59
60 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
61 /* Previously seen (loopback)? */
62 if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
63 return NF_ACCEPT;
64 #endif
65
66 reasm = nf_ct_frag6_gather(state->net, skb,
67 nf_ct6_defrag_user(state->hook, skb));
68 /* queued */
69 if (reasm == NULL)
70 return NF_STOLEN;
71
72 /* error occurred or not fragmented */
73 if (reasm == skb)
74 return NF_ACCEPT;
75
76 nf_ct_frag6_consume_orig(reasm);
77
78 NF_HOOK_THRESH(NFPROTO_IPV6, state->hook, state->net, state->sk, reasm,
79 state->in, state->out,
80 state->okfn, NF_IP6_PRI_CONNTRACK_DEFRAG + 1);
81
82 return NF_STOLEN;
83 }
84
85 static struct nf_hook_ops ipv6_defrag_ops[] = {
86 {
87 .hook = ipv6_defrag,
88 .pf = NFPROTO_IPV6,
89 .hooknum = NF_INET_PRE_ROUTING,
90 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
91 },
92 {
93 .hook = ipv6_defrag,
94 .pf = NFPROTO_IPV6,
95 .hooknum = NF_INET_LOCAL_OUT,
96 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
97 },
98 };
99
nf_defrag_init(void)100 static int __init nf_defrag_init(void)
101 {
102 int ret = 0;
103
104 ret = nf_ct_frag6_init();
105 if (ret < 0) {
106 pr_err("nf_defrag_ipv6: can't initialize frag6.\n");
107 return ret;
108 }
109 ret = nf_register_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
110 if (ret < 0) {
111 pr_err("nf_defrag_ipv6: can't register hooks\n");
112 goto cleanup_frag6;
113 }
114 return ret;
115
116 cleanup_frag6:
117 nf_ct_frag6_cleanup();
118 return ret;
119
120 }
121
nf_defrag_fini(void)122 static void __exit nf_defrag_fini(void)
123 {
124 nf_unregister_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
125 nf_ct_frag6_cleanup();
126 }
127
nf_defrag_ipv6_enable(void)128 void nf_defrag_ipv6_enable(void)
129 {
130 }
131 EXPORT_SYMBOL_GPL(nf_defrag_ipv6_enable);
132
133 module_init(nf_defrag_init);
134 module_exit(nf_defrag_fini);
135
136 MODULE_LICENSE("GPL");
137