1 /*
2 * Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
3 * Copyright (c) 2012-2013 Pablo Neira Ayuso <pablo@netfilter.org>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Development of this code funded by Astaro AG (http://www.astaro.com/)
10 */
11
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/ip.h>
15 #include <linux/netfilter_ipv4.h>
16 #include <net/netfilter/nf_tables.h>
17 #include <net/net_namespace.h>
18 #include <net/ip.h>
19 #include <net/netfilter/nf_tables_ipv4.h>
20
nft_do_chain_ipv4(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)21 static unsigned int nft_do_chain_ipv4(void *priv,
22 struct sk_buff *skb,
23 const struct nf_hook_state *state)
24 {
25 struct nft_pktinfo pkt;
26
27 nft_set_pktinfo_ipv4(&pkt, skb, state);
28
29 return nft_do_chain(&pkt, priv);
30 }
31
nft_ipv4_output(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)32 static unsigned int nft_ipv4_output(void *priv,
33 struct sk_buff *skb,
34 const struct nf_hook_state *state)
35 {
36 if (unlikely(skb->len < sizeof(struct iphdr) ||
37 ip_hdr(skb)->ihl < sizeof(struct iphdr) / 4)) {
38 if (net_ratelimit())
39 pr_info("nf_tables_ipv4: ignoring short SOCK_RAW "
40 "packet\n");
41 return NF_ACCEPT;
42 }
43
44 return nft_do_chain_ipv4(priv, skb, state);
45 }
46
47 struct nft_af_info nft_af_ipv4 __read_mostly = {
48 .family = NFPROTO_IPV4,
49 .nhooks = NF_INET_NUMHOOKS,
50 .owner = THIS_MODULE,
51 .nops = 1,
52 .hooks = {
53 [NF_INET_LOCAL_IN] = nft_do_chain_ipv4,
54 [NF_INET_LOCAL_OUT] = nft_ipv4_output,
55 [NF_INET_FORWARD] = nft_do_chain_ipv4,
56 [NF_INET_PRE_ROUTING] = nft_do_chain_ipv4,
57 [NF_INET_POST_ROUTING] = nft_do_chain_ipv4,
58 },
59 };
60 EXPORT_SYMBOL_GPL(nft_af_ipv4);
61
nf_tables_ipv4_init_net(struct net * net)62 static int nf_tables_ipv4_init_net(struct net *net)
63 {
64 net->nft.ipv4 = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
65 if (net->nft.ipv4 == NULL)
66 return -ENOMEM;
67
68 memcpy(net->nft.ipv4, &nft_af_ipv4, sizeof(nft_af_ipv4));
69
70 if (nft_register_afinfo(net, net->nft.ipv4) < 0)
71 goto err;
72
73 return 0;
74 err:
75 kfree(net->nft.ipv4);
76 return -ENOMEM;
77 }
78
nf_tables_ipv4_exit_net(struct net * net)79 static void nf_tables_ipv4_exit_net(struct net *net)
80 {
81 nft_unregister_afinfo(net, net->nft.ipv4);
82 kfree(net->nft.ipv4);
83 }
84
85 static struct pernet_operations nf_tables_ipv4_net_ops = {
86 .init = nf_tables_ipv4_init_net,
87 .exit = nf_tables_ipv4_exit_net,
88 };
89
90 static const struct nf_chain_type filter_ipv4 = {
91 .name = "filter",
92 .type = NFT_CHAIN_T_DEFAULT,
93 .family = NFPROTO_IPV4,
94 .owner = THIS_MODULE,
95 .hook_mask = (1 << NF_INET_LOCAL_IN) |
96 (1 << NF_INET_LOCAL_OUT) |
97 (1 << NF_INET_FORWARD) |
98 (1 << NF_INET_PRE_ROUTING) |
99 (1 << NF_INET_POST_ROUTING),
100 };
101
nf_tables_ipv4_init(void)102 static int __init nf_tables_ipv4_init(void)
103 {
104 int ret;
105
106 ret = nft_register_chain_type(&filter_ipv4);
107 if (ret < 0)
108 return ret;
109
110 ret = register_pernet_subsys(&nf_tables_ipv4_net_ops);
111 if (ret < 0)
112 nft_unregister_chain_type(&filter_ipv4);
113
114 return ret;
115 }
116
nf_tables_ipv4_exit(void)117 static void __exit nf_tables_ipv4_exit(void)
118 {
119 unregister_pernet_subsys(&nf_tables_ipv4_net_ops);
120 nft_unregister_chain_type(&filter_ipv4);
121 }
122
123 module_init(nf_tables_ipv4_init);
124 module_exit(nf_tables_ipv4_exit);
125
126 MODULE_LICENSE("GPL");
127 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
128 MODULE_ALIAS_NFT_FAMILY(AF_INET);
129