1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * 'raw' table, which is the very first hooked in at PRE_ROUTING and LOCAL_OUT .
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_ipv4/ip_tables.h>
10 #include <linux/slab.h>
11 #include <net/ip.h>
12
13 #define RAW_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT))
14
15 static bool raw_before_defrag __read_mostly;
16 MODULE_PARM_DESC(raw_before_defrag, "Enable raw table before defrag");
17 module_param(raw_before_defrag, bool, 0000);
18
19 static const struct xt_table packet_raw = {
20 .name = "raw",
21 .valid_hooks = RAW_VALID_HOOKS,
22 .me = THIS_MODULE,
23 .af = NFPROTO_IPV4,
24 .priority = NF_IP_PRI_RAW,
25 };
26
27 static const struct xt_table packet_raw_before_defrag = {
28 .name = "raw",
29 .valid_hooks = RAW_VALID_HOOKS,
30 .me = THIS_MODULE,
31 .af = NFPROTO_IPV4,
32 .priority = NF_IP_PRI_RAW_BEFORE_DEFRAG,
33 };
34
35 /* The work comes in here from netfilter.c. */
36 static unsigned int
iptable_raw_hook(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)37 iptable_raw_hook(void *priv, struct sk_buff *skb,
38 const struct nf_hook_state *state)
39 {
40 return ipt_do_table(skb, state, priv);
41 }
42
43 static struct nf_hook_ops *rawtable_ops __read_mostly;
44
iptable_raw_table_init(struct net * net)45 static int iptable_raw_table_init(struct net *net)
46 {
47 struct ipt_replace *repl;
48 const struct xt_table *table = &packet_raw;
49 int ret;
50
51 if (raw_before_defrag)
52 table = &packet_raw_before_defrag;
53
54 repl = ipt_alloc_initial_table(table);
55 if (repl == NULL)
56 return -ENOMEM;
57 ret = ipt_register_table(net, table, repl, rawtable_ops);
58 kfree(repl);
59 return ret;
60 }
61
iptable_raw_net_pre_exit(struct net * net)62 static void __net_exit iptable_raw_net_pre_exit(struct net *net)
63 {
64 ipt_unregister_table_pre_exit(net, "raw");
65 }
66
iptable_raw_net_exit(struct net * net)67 static void __net_exit iptable_raw_net_exit(struct net *net)
68 {
69 ipt_unregister_table_exit(net, "raw");
70 }
71
72 static struct pernet_operations iptable_raw_net_ops = {
73 .pre_exit = iptable_raw_net_pre_exit,
74 .exit = iptable_raw_net_exit,
75 };
76
iptable_raw_init(void)77 static int __init iptable_raw_init(void)
78 {
79 int ret;
80 const struct xt_table *table = &packet_raw;
81
82 if (raw_before_defrag) {
83 table = &packet_raw_before_defrag;
84
85 pr_info("Enabling raw table before defrag\n");
86 }
87
88 ret = xt_register_template(table,
89 iptable_raw_table_init);
90 if (ret < 0)
91 return ret;
92
93 rawtable_ops = xt_hook_ops_alloc(table, iptable_raw_hook);
94 if (IS_ERR(rawtable_ops)) {
95 xt_unregister_template(table);
96 return PTR_ERR(rawtable_ops);
97 }
98
99 ret = register_pernet_subsys(&iptable_raw_net_ops);
100 if (ret < 0) {
101 xt_unregister_template(table);
102 kfree(rawtable_ops);
103 return ret;
104 }
105
106 return ret;
107 }
108
iptable_raw_fini(void)109 static void __exit iptable_raw_fini(void)
110 {
111 unregister_pernet_subsys(&iptable_raw_net_ops);
112 kfree(rawtable_ops);
113 xt_unregister_template(&packet_raw);
114 }
115
116 module_init(iptable_raw_init);
117 module_exit(iptable_raw_fini);
118 MODULE_LICENSE("GPL");
119