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 = NF_CT_DEFAULT_ZONE;
37
38 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
39 if (skb->nfct)
40 zone = nf_ct_zone((struct nf_conn *)skb->nfct);
41 #endif
42
43 #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER)
44 if (skb->nf_bridge &&
45 skb->nf_bridge->mask & BRNF_NF_BRIDGE_PREROUTING)
46 return IP6_DEFRAG_CONNTRACK_BRIDGE_IN + zone;
47 #endif
48 if (hooknum == NF_INET_PRE_ROUTING)
49 return IP6_DEFRAG_CONNTRACK_IN + zone;
50 else
51 return IP6_DEFRAG_CONNTRACK_OUT + zone;
52
53 }
54
ipv6_defrag(const struct nf_hook_ops * ops,struct sk_buff * skb,const struct nf_hook_state * state)55 static unsigned int ipv6_defrag(const struct nf_hook_ops *ops,
56 struct sk_buff *skb,
57 const struct nf_hook_state *state)
58 {
59 struct sk_buff *reasm;
60
61 #if IS_ENABLED(CONFIG_NF_CONNTRACK)
62 /* Previously seen (loopback)? */
63 if (skb->nfct && !nf_ct_is_template((struct nf_conn *)skb->nfct))
64 return NF_ACCEPT;
65 #endif
66
67 reasm = nf_ct_frag6_gather(skb, nf_ct6_defrag_user(ops->hooknum, 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, ops->hooknum, 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 .owner = THIS_MODULE,
89 .pf = NFPROTO_IPV6,
90 .hooknum = NF_INET_PRE_ROUTING,
91 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
92 },
93 {
94 .hook = ipv6_defrag,
95 .owner = THIS_MODULE,
96 .pf = NFPROTO_IPV6,
97 .hooknum = NF_INET_LOCAL_OUT,
98 .priority = NF_IP6_PRI_CONNTRACK_DEFRAG,
99 },
100 };
101
nf_defrag_init(void)102 static int __init nf_defrag_init(void)
103 {
104 int ret = 0;
105
106 ret = nf_ct_frag6_init();
107 if (ret < 0) {
108 pr_err("nf_defrag_ipv6: can't initialize frag6.\n");
109 return ret;
110 }
111 ret = nf_register_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
112 if (ret < 0) {
113 pr_err("nf_defrag_ipv6: can't register hooks\n");
114 goto cleanup_frag6;
115 }
116 return ret;
117
118 cleanup_frag6:
119 nf_ct_frag6_cleanup();
120 return ret;
121
122 }
123
nf_defrag_fini(void)124 static void __exit nf_defrag_fini(void)
125 {
126 nf_unregister_hooks(ipv6_defrag_ops, ARRAY_SIZE(ipv6_defrag_ops));
127 nf_ct_frag6_cleanup();
128 }
129
nf_defrag_ipv6_enable(void)130 void nf_defrag_ipv6_enable(void)
131 {
132 }
133 EXPORT_SYMBOL_GPL(nf_defrag_ipv6_enable);
134
135 module_init(nf_defrag_init);
136 module_exit(nf_defrag_fini);
137
138 MODULE_LICENSE("GPL");
139