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);
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);
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);
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);
153 break;
154 case NFPROTO_IPV6:
155 nft_set_pktinfo_ipv6(&pkt);
156 break;
157 default:
158 break;
159 }
160
161 return nft_do_chain(&pkt, priv);
162 }
163
nft_do_chain_inet_ingress(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)164 static unsigned int nft_do_chain_inet_ingress(void *priv, struct sk_buff *skb,
165 const struct nf_hook_state *state)
166 {
167 struct nf_hook_state ingress_state = *state;
168 struct nft_pktinfo pkt;
169
170 switch (skb->protocol) {
171 case htons(ETH_P_IP):
172 /* Original hook is NFPROTO_NETDEV and NF_NETDEV_INGRESS. */
173 ingress_state.pf = NFPROTO_IPV4;
174 ingress_state.hook = NF_INET_INGRESS;
175 nft_set_pktinfo(&pkt, skb, &ingress_state);
176
177 if (nft_set_pktinfo_ipv4_ingress(&pkt) < 0)
178 return NF_DROP;
179 break;
180 case htons(ETH_P_IPV6):
181 ingress_state.pf = NFPROTO_IPV6;
182 ingress_state.hook = NF_INET_INGRESS;
183 nft_set_pktinfo(&pkt, skb, &ingress_state);
184
185 if (nft_set_pktinfo_ipv6_ingress(&pkt) < 0)
186 return NF_DROP;
187 break;
188 default:
189 return NF_ACCEPT;
190 }
191
192 return nft_do_chain(&pkt, priv);
193 }
194
195 static const struct nft_chain_type nft_chain_filter_inet = {
196 .name = "filter",
197 .type = NFT_CHAIN_T_DEFAULT,
198 .family = NFPROTO_INET,
199 .hook_mask = (1 << NF_INET_INGRESS) |
200 (1 << NF_INET_LOCAL_IN) |
201 (1 << NF_INET_LOCAL_OUT) |
202 (1 << NF_INET_FORWARD) |
203 (1 << NF_INET_PRE_ROUTING) |
204 (1 << NF_INET_POST_ROUTING),
205 .hooks = {
206 [NF_INET_INGRESS] = nft_do_chain_inet_ingress,
207 [NF_INET_LOCAL_IN] = nft_do_chain_inet,
208 [NF_INET_LOCAL_OUT] = nft_do_chain_inet,
209 [NF_INET_FORWARD] = nft_do_chain_inet,
210 [NF_INET_PRE_ROUTING] = nft_do_chain_inet,
211 [NF_INET_POST_ROUTING] = nft_do_chain_inet,
212 },
213 };
214
nft_chain_filter_inet_init(void)215 static void nft_chain_filter_inet_init(void)
216 {
217 nft_register_chain_type(&nft_chain_filter_inet);
218 }
219
nft_chain_filter_inet_fini(void)220 static void nft_chain_filter_inet_fini(void)
221 {
222 nft_unregister_chain_type(&nft_chain_filter_inet);
223 }
224 #else
nft_chain_filter_inet_init(void)225 static inline void nft_chain_filter_inet_init(void) {}
nft_chain_filter_inet_fini(void)226 static inline void nft_chain_filter_inet_fini(void) {}
227 #endif /* CONFIG_NF_TABLES_IPV6 */
228
229 #if IS_ENABLED(CONFIG_NF_TABLES_BRIDGE)
230 static unsigned int
nft_do_chain_bridge(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)231 nft_do_chain_bridge(void *priv,
232 struct sk_buff *skb,
233 const struct nf_hook_state *state)
234 {
235 struct nft_pktinfo pkt;
236
237 nft_set_pktinfo(&pkt, skb, state);
238
239 switch (eth_hdr(skb)->h_proto) {
240 case htons(ETH_P_IP):
241 nft_set_pktinfo_ipv4_validate(&pkt);
242 break;
243 case htons(ETH_P_IPV6):
244 nft_set_pktinfo_ipv6_validate(&pkt);
245 break;
246 default:
247 nft_set_pktinfo_unspec(&pkt);
248 break;
249 }
250
251 return nft_do_chain(&pkt, priv);
252 }
253
254 static const struct nft_chain_type nft_chain_filter_bridge = {
255 .name = "filter",
256 .type = NFT_CHAIN_T_DEFAULT,
257 .family = NFPROTO_BRIDGE,
258 .hook_mask = (1 << NF_BR_PRE_ROUTING) |
259 (1 << NF_BR_LOCAL_IN) |
260 (1 << NF_BR_FORWARD) |
261 (1 << NF_BR_LOCAL_OUT) |
262 (1 << NF_BR_POST_ROUTING),
263 .hooks = {
264 [NF_BR_PRE_ROUTING] = nft_do_chain_bridge,
265 [NF_BR_LOCAL_IN] = nft_do_chain_bridge,
266 [NF_BR_FORWARD] = nft_do_chain_bridge,
267 [NF_BR_LOCAL_OUT] = nft_do_chain_bridge,
268 [NF_BR_POST_ROUTING] = nft_do_chain_bridge,
269 },
270 };
271
nft_chain_filter_bridge_init(void)272 static void nft_chain_filter_bridge_init(void)
273 {
274 nft_register_chain_type(&nft_chain_filter_bridge);
275 }
276
nft_chain_filter_bridge_fini(void)277 static void nft_chain_filter_bridge_fini(void)
278 {
279 nft_unregister_chain_type(&nft_chain_filter_bridge);
280 }
281 #else
nft_chain_filter_bridge_init(void)282 static inline void nft_chain_filter_bridge_init(void) {}
nft_chain_filter_bridge_fini(void)283 static inline void nft_chain_filter_bridge_fini(void) {}
284 #endif /* CONFIG_NF_TABLES_BRIDGE */
285
286 #ifdef CONFIG_NF_TABLES_NETDEV
nft_do_chain_netdev(void * priv,struct sk_buff * skb,const struct nf_hook_state * state)287 static unsigned int nft_do_chain_netdev(void *priv, struct sk_buff *skb,
288 const struct nf_hook_state *state)
289 {
290 struct nft_pktinfo pkt;
291
292 nft_set_pktinfo(&pkt, skb, state);
293
294 switch (skb->protocol) {
295 case htons(ETH_P_IP):
296 nft_set_pktinfo_ipv4_validate(&pkt);
297 break;
298 case htons(ETH_P_IPV6):
299 nft_set_pktinfo_ipv6_validate(&pkt);
300 break;
301 default:
302 nft_set_pktinfo_unspec(&pkt);
303 break;
304 }
305
306 return nft_do_chain(&pkt, priv);
307 }
308
309 static const struct nft_chain_type nft_chain_filter_netdev = {
310 .name = "filter",
311 .type = NFT_CHAIN_T_DEFAULT,
312 .family = NFPROTO_NETDEV,
313 .hook_mask = (1 << NF_NETDEV_INGRESS) |
314 (1 << NF_NETDEV_EGRESS),
315 .hooks = {
316 [NF_NETDEV_INGRESS] = nft_do_chain_netdev,
317 [NF_NETDEV_EGRESS] = nft_do_chain_netdev,
318 },
319 };
320
nft_netdev_event(unsigned long event,struct net_device * dev,struct nft_ctx * ctx)321 static void nft_netdev_event(unsigned long event, struct net_device *dev,
322 struct nft_ctx *ctx)
323 {
324 struct nft_base_chain *basechain = nft_base_chain(ctx->chain);
325 struct nft_hook *hook, *found = NULL;
326 int n = 0;
327
328 list_for_each_entry(hook, &basechain->hook_list, list) {
329 if (hook->ops.dev == dev)
330 found = hook;
331
332 n++;
333 }
334 if (!found)
335 return;
336
337 if (n > 1) {
338 if (!(ctx->chain->table->flags & NFT_TABLE_F_DORMANT))
339 nf_unregister_net_hook(ctx->net, &found->ops);
340
341 list_del_rcu(&found->list);
342 kfree_rcu(found, rcu);
343 return;
344 }
345
346 /* UNREGISTER events are also happening on netns exit.
347 *
348 * Although nf_tables core releases all tables/chains, only this event
349 * handler provides guarantee that hook->ops.dev is still accessible,
350 * so we cannot skip exiting net namespaces.
351 */
352 __nft_release_basechain(ctx);
353 }
354
nf_tables_netdev_event(struct notifier_block * this,unsigned long event,void * ptr)355 static int nf_tables_netdev_event(struct notifier_block *this,
356 unsigned long event, void *ptr)
357 {
358 struct net_device *dev = netdev_notifier_info_to_dev(ptr);
359 struct nft_base_chain *basechain;
360 struct nftables_pernet *nft_net;
361 struct nft_chain *chain, *nr;
362 struct nft_table *table;
363 struct nft_ctx ctx = {
364 .net = dev_net(dev),
365 };
366
367 if (event != NETDEV_UNREGISTER)
368 return NOTIFY_DONE;
369
370 nft_net = nft_pernet(ctx.net);
371 mutex_lock(&nft_net->commit_mutex);
372 list_for_each_entry(table, &nft_net->tables, list) {
373 if (table->family != NFPROTO_NETDEV &&
374 table->family != NFPROTO_INET)
375 continue;
376
377 ctx.family = table->family;
378 ctx.table = table;
379 list_for_each_entry_safe(chain, nr, &table->chains, list) {
380 if (!nft_is_base_chain(chain))
381 continue;
382
383 basechain = nft_base_chain(chain);
384 if (table->family == NFPROTO_INET &&
385 basechain->ops.hooknum != NF_INET_INGRESS)
386 continue;
387
388 ctx.chain = chain;
389 nft_netdev_event(event, dev, &ctx);
390 }
391 }
392 mutex_unlock(&nft_net->commit_mutex);
393
394 return NOTIFY_DONE;
395 }
396
397 static struct notifier_block nf_tables_netdev_notifier = {
398 .notifier_call = nf_tables_netdev_event,
399 };
400
nft_chain_filter_netdev_init(void)401 static int nft_chain_filter_netdev_init(void)
402 {
403 int err;
404
405 nft_register_chain_type(&nft_chain_filter_netdev);
406
407 err = register_netdevice_notifier(&nf_tables_netdev_notifier);
408 if (err)
409 goto err_register_netdevice_notifier;
410
411 return 0;
412
413 err_register_netdevice_notifier:
414 nft_unregister_chain_type(&nft_chain_filter_netdev);
415
416 return err;
417 }
418
nft_chain_filter_netdev_fini(void)419 static void nft_chain_filter_netdev_fini(void)
420 {
421 nft_unregister_chain_type(&nft_chain_filter_netdev);
422 unregister_netdevice_notifier(&nf_tables_netdev_notifier);
423 }
424 #else
nft_chain_filter_netdev_init(void)425 static inline int nft_chain_filter_netdev_init(void) { return 0; }
nft_chain_filter_netdev_fini(void)426 static inline void nft_chain_filter_netdev_fini(void) {}
427 #endif /* CONFIG_NF_TABLES_NETDEV */
428
nft_chain_filter_init(void)429 int __init nft_chain_filter_init(void)
430 {
431 int err;
432
433 err = nft_chain_filter_netdev_init();
434 if (err < 0)
435 return err;
436
437 nft_chain_filter_ipv4_init();
438 nft_chain_filter_ipv6_init();
439 nft_chain_filter_arp_init();
440 nft_chain_filter_inet_init();
441 nft_chain_filter_bridge_init();
442
443 return 0;
444 }
445
nft_chain_filter_fini(void)446 void nft_chain_filter_fini(void)
447 {
448 nft_chain_filter_bridge_fini();
449 nft_chain_filter_inet_fini();
450 nft_chain_filter_arp_fini();
451 nft_chain_filter_ipv6_fini();
452 nft_chain_filter_ipv4_fini();
453 nft_chain_filter_netdev_fini();
454 }
455