1 #include <linux/init.h>
2 #include <linux/kernel.h>
3 #include <linux/netdevice.h>
4 #include <net/net_namespace.h>
5 #include <net/netfilter/nf_tables.h>
6 #include <linux/netfilter_ipv4.h>
7 #include <linux/netfilter_ipv6.h>
8 #include <linux/netfilter_bridge.h>
9 #include <linux/netfilter_arp.h>
10 #include <net/netfilter/nf_tables_ipv4.h>
11 #include <net/netfilter/nf_tables_ipv6.h>
12
13 #ifdef CONFIG_NF_TABLES_IPV4
nft_do_chain_ipv4(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)14 static unsigned int nft_do_chain_ipv4(void *priv,
15 struct sk_buff *skb,
16 const struct nf_hook_state *state)
17 {
18 struct nft_pktinfo pkt;
19
20 nft_set_pktinfo(&pkt, skb, state);
21 nft_set_pktinfo_ipv4(&pkt, skb);
22
23 return nft_do_chain(&pkt, priv);
24 }
25
26 static const struct nft_chain_type nft_chain_filter_ipv4 = {
27 .name = "filter",
28 .type = NFT_CHAIN_T_DEFAULT,
29 .family = NFPROTO_IPV4,
30 .hook_mask = (1 << NF_INET_LOCAL_IN) |
31 (1 << NF_INET_LOCAL_OUT) |
32 (1 << NF_INET_FORWARD) |
33 (1 << NF_INET_PRE_ROUTING) |
34 (1 << NF_INET_POST_ROUTING),
35 .hooks = {
36 [NF_INET_LOCAL_IN] = nft_do_chain_ipv4,
37 [NF_INET_LOCAL_OUT] = nft_do_chain_ipv4,
38 [NF_INET_FORWARD] = nft_do_chain_ipv4,
39 [NF_INET_PRE_ROUTING] = nft_do_chain_ipv4,
40 [NF_INET_POST_ROUTING] = nft_do_chain_ipv4,
41 },
42 };
43
nft_chain_filter_ipv4_init(void)44 static void nft_chain_filter_ipv4_init(void)
45 {
46 nft_register_chain_type(&nft_chain_filter_ipv4);
47 }
nft_chain_filter_ipv4_fini(void)48 static void nft_chain_filter_ipv4_fini(void)
49 {
50 nft_unregister_chain_type(&nft_chain_filter_ipv4);
51 }
52
53 #else
nft_chain_filter_ipv4_init(void)54 static inline void nft_chain_filter_ipv4_init(void) {}
nft_chain_filter_ipv4_fini(void)55 static inline void nft_chain_filter_ipv4_fini(void) {}
56 #endif /* CONFIG_NF_TABLES_IPV4 */
57
58 #ifdef CONFIG_NF_TABLES_ARP
nft_do_chain_arp(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)59 static unsigned int nft_do_chain_arp(void *priv, struct sk_buff *skb,
60 const struct nf_hook_state *state)
61 {
62 struct nft_pktinfo pkt;
63
64 nft_set_pktinfo(&pkt, skb, state);
65 nft_set_pktinfo_unspec(&pkt, skb);
66
67 return nft_do_chain(&pkt, priv);
68 }
69
70 static const struct nft_chain_type nft_chain_filter_arp = {
71 .name = "filter",
72 .type = NFT_CHAIN_T_DEFAULT,
73 .family = NFPROTO_ARP,
74 .owner = THIS_MODULE,
75 .hook_mask = (1 << NF_ARP_IN) |
76 (1 << NF_ARP_OUT),
77 .hooks = {
78 [NF_ARP_IN] = nft_do_chain_arp,
79 [NF_ARP_OUT] = nft_do_chain_arp,
80 },
81 };
82
nft_chain_filter_arp_init(void)83 static void nft_chain_filter_arp_init(void)
84 {
85 nft_register_chain_type(&nft_chain_filter_arp);
86 }
87
nft_chain_filter_arp_fini(void)88 static void nft_chain_filter_arp_fini(void)
89 {
90 nft_unregister_chain_type(&nft_chain_filter_arp);
91 }
92 #else
nft_chain_filter_arp_init(void)93 static inline void nft_chain_filter_arp_init(void) {}
nft_chain_filter_arp_fini(void)94 static inline void nft_chain_filter_arp_fini(void) {}
95 #endif /* CONFIG_NF_TABLES_ARP */
96
97 #ifdef CONFIG_NF_TABLES_IPV6
nft_do_chain_ipv6(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)98 static unsigned int nft_do_chain_ipv6(void *priv,
99 struct sk_buff *skb,
100 const struct nf_hook_state *state)
101 {
102 struct nft_pktinfo pkt;
103
104 nft_set_pktinfo(&pkt, skb, state);
105 nft_set_pktinfo_ipv6(&pkt, skb);
106
107 return nft_do_chain(&pkt, priv);
108 }
109
110 static const struct nft_chain_type nft_chain_filter_ipv6 = {
111 .name = "filter",
112 .type = NFT_CHAIN_T_DEFAULT,
113 .family = NFPROTO_IPV6,
114 .hook_mask = (1 << NF_INET_LOCAL_IN) |
115 (1 << NF_INET_LOCAL_OUT) |
116 (1 << NF_INET_FORWARD) |
117 (1 << NF_INET_PRE_ROUTING) |
118 (1 << NF_INET_POST_ROUTING),
119 .hooks = {
120 [NF_INET_LOCAL_IN] = nft_do_chain_ipv6,
121 [NF_INET_LOCAL_OUT] = nft_do_chain_ipv6,
122 [NF_INET_FORWARD] = nft_do_chain_ipv6,
123 [NF_INET_PRE_ROUTING] = nft_do_chain_ipv6,
124 [NF_INET_POST_ROUTING] = nft_do_chain_ipv6,
125 },
126 };
127
nft_chain_filter_ipv6_init(void)128 static void nft_chain_filter_ipv6_init(void)
129 {
130 nft_register_chain_type(&nft_chain_filter_ipv6);
131 }
132
nft_chain_filter_ipv6_fini(void)133 static void nft_chain_filter_ipv6_fini(void)
134 {
135 nft_unregister_chain_type(&nft_chain_filter_ipv6);
136 }
137 #else
nft_chain_filter_ipv6_init(void)138 static inline void nft_chain_filter_ipv6_init(void) {}
nft_chain_filter_ipv6_fini(void)139 static inline void nft_chain_filter_ipv6_fini(void) {}
140 #endif /* CONFIG_NF_TABLES_IPV6 */
141
142 #ifdef CONFIG_NF_TABLES_INET
nft_do_chain_inet(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)143 static unsigned int nft_do_chain_inet(void *priv, struct sk_buff *skb,
144 const struct nf_hook_state *state)
145 {
146 struct nft_pktinfo pkt;
147
148 nft_set_pktinfo(&pkt, skb, state);
149
150 switch (state->pf) {
151 case NFPROTO_IPV4:
152 nft_set_pktinfo_ipv4(&pkt, skb);
153 break;
154 case NFPROTO_IPV6:
155 nft_set_pktinfo_ipv6(&pkt, skb);
156 break;
157 default:
158 break;
159 }
160
161 return nft_do_chain(&pkt, priv);
162 }
163
164 static const struct nft_chain_type nft_chain_filter_inet = {
165 .name = "filter",
166 .type = NFT_CHAIN_T_DEFAULT,
167 .family = NFPROTO_INET,
168 .hook_mask = (1 << NF_INET_LOCAL_IN) |
169 (1 << NF_INET_LOCAL_OUT) |
170 (1 << NF_INET_FORWARD) |
171 (1 << NF_INET_PRE_ROUTING) |
172 (1 << NF_INET_POST_ROUTING),
173 .hooks = {
174 [NF_INET_LOCAL_IN] = nft_do_chain_inet,
175 [NF_INET_LOCAL_OUT] = nft_do_chain_inet,
176 [NF_INET_FORWARD] = nft_do_chain_inet,
177 [NF_INET_PRE_ROUTING] = nft_do_chain_inet,
178 [NF_INET_POST_ROUTING] = nft_do_chain_inet,
179 },
180 };
181
nft_chain_filter_inet_init(void)182 static void nft_chain_filter_inet_init(void)
183 {
184 nft_register_chain_type(&nft_chain_filter_inet);
185 }
186
nft_chain_filter_inet_fini(void)187 static void nft_chain_filter_inet_fini(void)
188 {
189 nft_unregister_chain_type(&nft_chain_filter_inet);
190 }
191 #else
nft_chain_filter_inet_init(void)192 static inline void nft_chain_filter_inet_init(void) {}
nft_chain_filter_inet_fini(void)193 static inline void nft_chain_filter_inet_fini(void) {}
194 #endif /* CONFIG_NF_TABLES_IPV6 */
195
196 #if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE)
197 static unsigned int
nft_do_chain_bridge(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)198 nft_do_chain_bridge(void *priv,
199 struct sk_buff *skb,
200 const struct nf_hook_state *state)
201 {
202 struct nft_pktinfo pkt;
203
204 nft_set_pktinfo(&pkt, skb, state);
205
206 switch (eth_hdr(skb)->h_proto) {
207 case htons(ETH_P_IP):
208 nft_set_pktinfo_ipv4_validate(&pkt, skb);
209 break;
210 case htons(ETH_P_IPV6):
211 nft_set_pktinfo_ipv6_validate(&pkt, skb);
212 break;
213 default:
214 nft_set_pktinfo_unspec(&pkt, skb);
215 break;
216 }
217
218 return nft_do_chain(&pkt, priv);
219 }
220
221 static const struct nft_chain_type nft_chain_filter_bridge = {
222 .name = "filter",
223 .type = NFT_CHAIN_T_DEFAULT,
224 .family = NFPROTO_BRIDGE,
225 .hook_mask = (1 << NF_BR_PRE_ROUTING) |
226 (1 << NF_BR_LOCAL_IN) |
227 (1 << NF_BR_FORWARD) |
228 (1 << NF_BR_LOCAL_OUT) |
229 (1 << NF_BR_POST_ROUTING),
230 .hooks = {
231 [NF_BR_PRE_ROUTING] = nft_do_chain_bridge,
232 [NF_BR_LOCAL_IN] = nft_do_chain_bridge,
233 [NF_BR_FORWARD] = nft_do_chain_bridge,
234 [NF_BR_LOCAL_OUT] = nft_do_chain_bridge,
235 [NF_BR_POST_ROUTING] = nft_do_chain_bridge,
236 },
237 };
238
nft_chain_filter_bridge_init(void)239 static void nft_chain_filter_bridge_init(void)
240 {
241 nft_register_chain_type(&nft_chain_filter_bridge);
242 }
243
nft_chain_filter_bridge_fini(void)244 static void nft_chain_filter_bridge_fini(void)
245 {
246 nft_unregister_chain_type(&nft_chain_filter_bridge);
247 }
248 #else
nft_chain_filter_bridge_init(void)249 static inline void nft_chain_filter_bridge_init(void) {}
nft_chain_filter_bridge_fini(void)250 static inline void nft_chain_filter_bridge_fini(void) {}
251 #endif /* CONFIG_NF_TABLES_BRIDGE */
252
253 #ifdef CONFIG_NF_TABLES_NETDEV
nft_do_chain_netdev(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)254 static unsigned int nft_do_chain_netdev(void *priv, struct sk_buff *skb,
255 const struct nf_hook_state *state)
256 {
257 struct nft_pktinfo pkt;
258
259 nft_set_pktinfo(&pkt, skb, state);
260
261 switch (skb->protocol) {
262 case htons(ETH_P_IP):
263 nft_set_pktinfo_ipv4_validate(&pkt, skb);
264 break;
265 case htons(ETH_P_IPV6):
266 nft_set_pktinfo_ipv6_validate(&pkt, skb);
267 break;
268 default:
269 nft_set_pktinfo_unspec(&pkt, skb);
270 break;
271 }
272
273 return nft_do_chain(&pkt, priv);
274 }
275
276 static const struct nft_chain_type nft_chain_filter_netdev = {
277 .name = "filter",
278 .type = NFT_CHAIN_T_DEFAULT,
279 .family = NFPROTO_NETDEV,
280 .hook_mask = (1 << NF_NETDEV_INGRESS),
281 .hooks = {
282 [NF_NETDEV_INGRESS] = nft_do_chain_netdev,
283 },
284 };
285
nft_netdev_event(unsigned long event,struct net_device * dev,struct nft_ctx * ctx)286 static void nft_netdev_event(unsigned long event, struct net_device *dev,
287 struct nft_ctx *ctx)
288 {
289 struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
290
291 switch (event) {
292 case NETDEV_UNREGISTER:
293 if (strcmp(basechain->dev_name, dev->name) != 0)
294 return;
295
296 /* UNREGISTER events are also happpening on netns exit.
297 *
298 * Altough nf_tables core releases all tables/chains, only
299 * this event handler provides guarantee that
300 * basechain.ops->dev is still accessible, so we cannot
301 * skip exiting net namespaces.
302 */
303 __nft_release_basechain(ctx);
304 break;
305 case NETDEV_CHANGENAME:
306 if (dev->ifindex != basechain->ops.dev->ifindex)
307 return;
308
309 strncpy(basechain->dev_name, dev->name, IFNAMSIZ);
310 break;
311 }
312 }
313
nf_tables_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)314 static int nf_tables_netdev_event(struct notifier_block *this,
315 unsigned long event, void *ptr)
316 {
317 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
318 struct nft_table *table;
319 struct nft_chain *chain, *nr;
320 struct nft_ctx ctx = {
321 .net = dev_net(dev),
322 };
323
324 if (event != NETDEV_UNREGISTER &&
325 event != NETDEV_CHANGENAME)
326 return NOTIFY_DONE;
327
328 mutex_lock(&ctx.net->nft.commit_mutex);
329 list_for_each_entry(table, &ctx.net->nft.tables, list) {
330 if (table->family != NFPROTO_NETDEV)
331 continue;
332
333 ctx.family = table->family;
334 ctx.table = table;
335 list_for_each_entry_safe(chain, nr, &table->chains, list) {
336 if (!nft_is_base_chain(chain))
337 continue;
338
339 ctx.chain = chain;
340 nft_netdev_event(event, dev, &ctx);
341 }
342 }
343 mutex_unlock(&ctx.net->nft.commit_mutex);
344
345 return NOTIFY_DONE;
346 }
347
348 static struct notifier_block nf_tables_netdev_notifier = {
349 .notifier_call = nf_tables_netdev_event,
350 };
351
nft_chain_filter_netdev_init(void)352 static int nft_chain_filter_netdev_init(void)
353 {
354 int err;
355
356 nft_register_chain_type(&nft_chain_filter_netdev);
357
358 err = register_netdevice_notifier(&nf_tables_netdev_notifier);
359 if (err)
360 goto err_register_netdevice_notifier;
361
362 return 0;
363
364 err_register_netdevice_notifier:
365 nft_unregister_chain_type(&nft_chain_filter_netdev);
366
367 return err;
368 }
369
nft_chain_filter_netdev_fini(void)370 static void nft_chain_filter_netdev_fini(void)
371 {
372 nft_unregister_chain_type(&nft_chain_filter_netdev);
373 unregister_netdevice_notifier(&nf_tables_netdev_notifier);
374 }
375 #else
nft_chain_filter_netdev_init(void)376 static inline int nft_chain_filter_netdev_init(void) { return 0; }
nft_chain_filter_netdev_fini(void)377 static inline void nft_chain_filter_netdev_fini(void) {}
378 #endif /* CONFIG_NF_TABLES_NETDEV */
379
nft_chain_filter_init(void)380 int __init nft_chain_filter_init(void)
381 {
382 int err;
383
384 err = nft_chain_filter_netdev_init();
385 if (err < 0)
386 return err;
387
388 nft_chain_filter_ipv4_init();
389 nft_chain_filter_ipv6_init();
390 nft_chain_filter_arp_init();
391 nft_chain_filter_inet_init();
392 nft_chain_filter_bridge_init();
393
394 return 0;
395 }
396
nft_chain_filter_fini(void)397 void nft_chain_filter_fini(void)
398 {
399 nft_chain_filter_bridge_fini();
400 nft_chain_filter_inet_fini();
401 nft_chain_filter_arp_fini();
402 nft_chain_filter_ipv6_fini();
403 nft_chain_filter_ipv4_fini();
404 nft_chain_filter_netdev_fini();
405 }
406