1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * IPv6 raw table, a port of the IPv4 raw table to IPv6
4  *
5  * Copyright (C) 2003 Jozsef Kadlecsik <kadlec@netfilter.org>
6  */
7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8 #include <linux/module.h>
9 #include <linux/netfilter_ipv6/ip6_tables.h>
10 #include <linux/slab.h>
11 
12 #define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
13 
14 static int __net_init ip6table_raw_table_init(struct net *net);
15 
16 static bool raw_before_defrag __read_mostly;
17 MODULE_PARM_DESC(raw_before_defrag, "Enable raw table before defrag");
18 module_param(raw_before_defrag, bool, 0000);
19 
20 static const struct xt_table packet_raw = {
21 	.name = "raw",
22 	.valid_hooks = RAW_VALID_HOOKS,
23 	.me = THIS_MODULE,
24 	.af = NFPROTO_IPV6,
25 	.priority = NF_IP6_PRI_RAW,
26 	.table_init = ip6table_raw_table_init,
27 };
28 
29 static const struct xt_table packet_raw_before_defrag = {
30 	.name = "raw",
31 	.valid_hooks = RAW_VALID_HOOKS,
32 	.me = THIS_MODULE,
33 	.af = NFPROTO_IPV6,
34 	.priority = NF_IP6_PRI_RAW_BEFORE_DEFRAG,
35 	.table_init = ip6table_raw_table_init,
36 };
37 
38 /* The work comes in here from netfilter.c. */
39 static unsigned int
40 ip6table_raw_hook(void *priv, struct sk_buff *skb,
41 		  const struct nf_hook_state *state)
42 {
43 	return ip6t_do_table(skb, state, state->net->ipv6.ip6table_raw);
44 }
45 
46 static struct nf_hook_ops *rawtable_ops __read_mostly;
47 
48 static int __net_init ip6table_raw_table_init(struct net *net)
49 {
50 	struct ip6t_replace *repl;
51 	const struct xt_table *table = &packet_raw;
52 	int ret;
53 
54 	if (raw_before_defrag)
55 		table = &packet_raw_before_defrag;
56 
57 	if (net->ipv6.ip6table_raw)
58 		return 0;
59 
60 	repl = ip6t_alloc_initial_table(table);
61 	if (repl == NULL)
62 		return -ENOMEM;
63 	ret = ip6t_register_table(net, table, repl, rawtable_ops,
64 				  &net->ipv6.ip6table_raw);
65 	kfree(repl);
66 	return ret;
67 }
68 
69 static void __net_exit ip6table_raw_net_pre_exit(struct net *net)
70 {
71 	if (net->ipv6.ip6table_raw)
72 		ip6t_unregister_table_pre_exit(net, net->ipv6.ip6table_raw,
73 					       rawtable_ops);
74 }
75 
76 static void __net_exit ip6table_raw_net_exit(struct net *net)
77 {
78 	if (!net->ipv6.ip6table_raw)
79 		return;
80 	ip6t_unregister_table_exit(net, net->ipv6.ip6table_raw);
81 	net->ipv6.ip6table_raw = NULL;
82 }
83 
84 static struct pernet_operations ip6table_raw_net_ops = {
85 	.pre_exit = ip6table_raw_net_pre_exit,
86 	.exit = ip6table_raw_net_exit,
87 };
88 
89 static int __init ip6table_raw_init(void)
90 {
91 	int ret;
92 	const struct xt_table *table = &packet_raw;
93 
94 	if (raw_before_defrag) {
95 		table = &packet_raw_before_defrag;
96 
97 		pr_info("Enabling raw table before defrag\n");
98 	}
99 
100 	/* Register hooks */
101 	rawtable_ops = xt_hook_ops_alloc(table, ip6table_raw_hook);
102 	if (IS_ERR(rawtable_ops))
103 		return PTR_ERR(rawtable_ops);
104 
105 	ret = register_pernet_subsys(&ip6table_raw_net_ops);
106 	if (ret < 0) {
107 		kfree(rawtable_ops);
108 		return ret;
109 	}
110 
111 	ret = ip6table_raw_table_init(&init_net);
112 	if (ret) {
113 		unregister_pernet_subsys(&ip6table_raw_net_ops);
114 		kfree(rawtable_ops);
115 	}
116 	return ret;
117 }
118 
119 static void __exit ip6table_raw_fini(void)
120 {
121 	unregister_pernet_subsys(&ip6table_raw_net_ops);
122 	kfree(rawtable_ops);
123 }
124 
125 module_init(ip6table_raw_init);
126 module_exit(ip6table_raw_fini);
127 MODULE_LICENSE("GPL");
128