1 /*
2 * Copyright (c) 2015 Pablo Neira Ayuso <pablo@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/init.h>
10 #include <linux/module.h>
11 #include <linux/netdevice.h>
12 #include <net/netfilter/nf_tables.h>
13 #include <linux/ip.h>
14 #include <linux/ipv6.h>
15 #include <net/netfilter/nf_tables_ipv4.h>
16 #include <net/netfilter/nf_tables_ipv6.h>
17
18 static unsigned int
nft_do_chain_netdev(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)19 nft_do_chain_netdev(void *priv, struct sk_buff *skb,
20 const struct nf_hook_state *state)
21 {
22 struct nft_pktinfo pkt;
23
24 switch (skb->protocol) {
25 case htons(ETH_P_IP):
26 nft_set_pktinfo_ipv4_validate(&pkt, skb, state);
27 break;
28 case htons(ETH_P_IPV6):
29 nft_set_pktinfo_ipv6_validate(&pkt, skb, state);
30 break;
31 default:
32 nft_set_pktinfo_unspec(&pkt, skb, state);
33 break;
34 }
35
36 return nft_do_chain(&pkt, priv);
37 }
38
39 static struct nft_af_info nft_af_netdev __read_mostly = {
40 .family = NFPROTO_NETDEV,
41 .nhooks = NF_NETDEV_NUMHOOKS,
42 .owner = THIS_MODULE,
43 .flags = NFT_AF_NEEDS_DEV,
44 .nops = 1,
45 .hooks = {
46 [NF_NETDEV_INGRESS] = nft_do_chain_netdev,
47 },
48 };
49
nf_tables_netdev_init_net(struct net * net)50 static int nf_tables_netdev_init_net(struct net *net)
51 {
52 net->nft.netdev = kmalloc(sizeof(struct nft_af_info), GFP_KERNEL);
53 if (net->nft.netdev == NULL)
54 return -ENOMEM;
55
56 memcpy(net->nft.netdev, &nft_af_netdev, sizeof(nft_af_netdev));
57
58 if (nft_register_afinfo(net, net->nft.netdev) < 0)
59 goto err;
60
61 return 0;
62 err:
63 kfree(net->nft.netdev);
64 return -ENOMEM;
65 }
66
nf_tables_netdev_exit_net(struct net * net)67 static void nf_tables_netdev_exit_net(struct net *net)
68 {
69 nft_unregister_afinfo(net, net->nft.netdev);
70 kfree(net->nft.netdev);
71 }
72
73 static struct pernet_operations nf_tables_netdev_net_ops = {
74 .init = nf_tables_netdev_init_net,
75 .exit = nf_tables_netdev_exit_net,
76 };
77
78 static const struct nf_chain_type nft_filter_chain_netdev = {
79 .name = "filter",
80 .type = NFT_CHAIN_T_DEFAULT,
81 .family = NFPROTO_NETDEV,
82 .owner = THIS_MODULE,
83 .hook_mask = (1 << NF_NETDEV_INGRESS),
84 };
85
nft_netdev_event(unsigned long event,struct net_device * dev,struct nft_ctx * ctx)86 static void nft_netdev_event(unsigned long event, struct net_device *dev,
87 struct nft_ctx *ctx)
88 {
89 struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
90
91 switch (event) {
92 case NETDEV_UNREGISTER:
93 if (strcmp(basechain->dev_name, dev->name) != 0)
94 return;
95
96 __nft_release_basechain(ctx);
97 break;
98 case NETDEV_CHANGENAME:
99 if (dev->ifindex != basechain->ops[0].dev->ifindex)
100 return;
101
102 strncpy(basechain->dev_name, dev->name, IFNAMSIZ);
103 break;
104 }
105 }
106
nf_tables_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)107 static int nf_tables_netdev_event(struct notifier_block *this,
108 unsigned long event, void *ptr)
109 {
110 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
111 struct nft_af_info *afi;
112 struct nft_table *table;
113 struct nft_chain *chain, *nr;
114 struct nft_ctx ctx = {
115 .net = dev_net(dev),
116 };
117
118 if (event != NETDEV_UNREGISTER &&
119 event != NETDEV_CHANGENAME)
120 return NOTIFY_DONE;
121
122 nfnl_lock(NFNL_SUBSYS_NFTABLES);
123 list_for_each_entry(afi, &dev_net(dev)->nft.af_info, list) {
124 ctx.afi = afi;
125 if (afi->family != NFPROTO_NETDEV)
126 continue;
127
128 list_for_each_entry(table, &afi->tables, list) {
129 ctx.table = table;
130 list_for_each_entry_safe(chain, nr, &table->chains, list) {
131 if (!(chain->flags & NFT_BASE_CHAIN))
132 continue;
133
134 ctx.chain = chain;
135 nft_netdev_event(event, dev, &ctx);
136 }
137 }
138 }
139 nfnl_unlock(NFNL_SUBSYS_NFTABLES);
140
141 return NOTIFY_DONE;
142 }
143
144 static struct notifier_block nf_tables_netdev_notifier = {
145 .notifier_call = nf_tables_netdev_event,
146 };
147
nf_tables_netdev_init(void)148 static int __init nf_tables_netdev_init(void)
149 {
150 int ret;
151
152 ret = nft_register_chain_type(&nft_filter_chain_netdev);
153 if (ret)
154 return ret;
155
156 ret = register_pernet_subsys(&nf_tables_netdev_net_ops);
157 if (ret)
158 goto err1;
159
160 ret = register_netdevice_notifier(&nf_tables_netdev_notifier);
161 if (ret)
162 goto err2;
163
164 return 0;
165
166 err2:
167 unregister_pernet_subsys(&nf_tables_netdev_net_ops);
168 err1:
169 nft_unregister_chain_type(&nft_filter_chain_netdev);
170 return ret;
171 }
172
nf_tables_netdev_exit(void)173 static void __exit nf_tables_netdev_exit(void)
174 {
175 unregister_netdevice_notifier(&nf_tables_netdev_notifier);
176 unregister_pernet_subsys(&nf_tables_netdev_net_ops);
177 nft_unregister_chain_type(&nft_filter_chain_netdev);
178 }
179
180 module_init(nf_tables_netdev_init);
181 module_exit(nf_tables_netdev_exit);
182
183 MODULE_LICENSE("GPL");
184 MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>");
185 MODULE_ALIAS_NFT_FAMILY(5); /* NFPROTO_NETDEV */
186