1 /*
2 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
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 * Development of this code funded by Astaro AG (http://www.astaro.com/)
9 */
10
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/netlink.h>
15 #include <linux/netfilter.h>
16 #include <linux/netfilter/nf_tables.h>
17 #include <linux/in.h>
18 #include <linux/ip.h>
19 #include <linux/ipv6.h>
20 #include <linux/smp.h>
21 #include <linux/static_key.h>
22 #include <net/dst.h>
23 #include <net/sock.h>
24 #include <net/tcp_states.h> /* for TCP_TIME_WAIT */
25 #include <net/netfilter/nf_tables.h>
26 #include <net/netfilter/nf_tables_core.h>
27 #include <net/netfilter/nft_meta.h>
28
29 #include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */
30
31 static DEFINE_PER_CPU(struct rnd_state, nft_prandom_state);
32
33 void nft_meta_get_eval(const struct nft_expr *expr,
34 struct nft_regs *regs,
35 const struct nft_pktinfo *pkt)
36 {
37 const struct nft_meta *priv = nft_expr_priv(expr);
38 const struct sk_buff *skb = pkt->skb;
39 const struct net_device *in = nft_in(pkt), *out = nft_out(pkt);
40 struct sock *sk;
41 u32 *dest = ®s->data[priv->dreg];
42
43 switch (priv->key) {
44 case NFT_META_LEN:
45 *dest = skb->len;
46 break;
47 case NFT_META_PROTOCOL:
48 nft_reg_store16(dest, (__force u16)skb->protocol);
49 break;
50 case NFT_META_NFPROTO:
51 nft_reg_store8(dest, nft_pf(pkt));
52 break;
53 case NFT_META_L4PROTO:
54 if (!pkt->tprot_set)
55 goto err;
56 nft_reg_store8(dest, pkt->tprot);
57 break;
58 case NFT_META_PRIORITY:
59 *dest = skb->priority;
60 break;
61 case NFT_META_MARK:
62 *dest = skb->mark;
63 break;
64 case NFT_META_IIF:
65 if (in == NULL)
66 goto err;
67 *dest = in->ifindex;
68 break;
69 case NFT_META_OIF:
70 if (out == NULL)
71 goto err;
72 *dest = out->ifindex;
73 break;
74 case NFT_META_IIFNAME:
75 if (in == NULL)
76 goto err;
77 strncpy((char *)dest, in->name, IFNAMSIZ);
78 break;
79 case NFT_META_OIFNAME:
80 if (out == NULL)
81 goto err;
82 strncpy((char *)dest, out->name, IFNAMSIZ);
83 break;
84 case NFT_META_IIFTYPE:
85 if (in == NULL)
86 goto err;
87 nft_reg_store16(dest, in->type);
88 break;
89 case NFT_META_OIFTYPE:
90 if (out == NULL)
91 goto err;
92 nft_reg_store16(dest, out->type);
93 break;
94 case NFT_META_SKUID:
95 sk = skb_to_full_sk(skb);
96 if (!sk || !sk_fullsock(sk))
97 goto err;
98
99 read_lock_bh(&sk->sk_callback_lock);
100 if (sk->sk_socket == NULL ||
101 sk->sk_socket->file == NULL) {
102 read_unlock_bh(&sk->sk_callback_lock);
103 goto err;
104 }
105
106 *dest = from_kuid_munged(&init_user_ns,
107 sk->sk_socket->file->f_cred->fsuid);
108 read_unlock_bh(&sk->sk_callback_lock);
109 break;
110 case NFT_META_SKGID:
111 sk = skb_to_full_sk(skb);
112 if (!sk || !sk_fullsock(sk))
113 goto err;
114
115 read_lock_bh(&sk->sk_callback_lock);
116 if (sk->sk_socket == NULL ||
117 sk->sk_socket->file == NULL) {
118 read_unlock_bh(&sk->sk_callback_lock);
119 goto err;
120 }
121 *dest = from_kgid_munged(&init_user_ns,
122 sk->sk_socket->file->f_cred->fsgid);
123 read_unlock_bh(&sk->sk_callback_lock);
124 break;
125 #ifdef CONFIG_IP_ROUTE_CLASSID
126 case NFT_META_RTCLASSID: {
127 const struct dst_entry *dst = skb_dst(skb);
128
129 if (dst == NULL)
130 goto err;
131 *dest = dst->tclassid;
132 break;
133 }
134 #endif
135 #ifdef CONFIG_NETWORK_SECMARK
136 case NFT_META_SECMARK:
137 *dest = skb->secmark;
138 break;
139 #endif
140 case NFT_META_PKTTYPE:
141 if (skb->pkt_type != PACKET_LOOPBACK) {
142 nft_reg_store8(dest, skb->pkt_type);
143 break;
144 }
145
146 switch (nft_pf(pkt)) {
147 case NFPROTO_IPV4:
148 if (ipv4_is_multicast(ip_hdr(skb)->daddr))
149 nft_reg_store8(dest, PACKET_MULTICAST);
150 else
151 nft_reg_store8(dest, PACKET_BROADCAST);
152 break;
153 case NFPROTO_IPV6:
154 nft_reg_store8(dest, PACKET_MULTICAST);
155 break;
156 case NFPROTO_NETDEV:
157 switch (skb->protocol) {
158 case htons(ETH_P_IP): {
159 int noff = skb_network_offset(skb);
160 struct iphdr *iph, _iph;
161
162 iph = skb_header_pointer(skb, noff,
163 sizeof(_iph), &_iph);
164 if (!iph)
165 goto err;
166
167 if (ipv4_is_multicast(iph->daddr))
168 nft_reg_store8(dest, PACKET_MULTICAST);
169 else
170 nft_reg_store8(dest, PACKET_BROADCAST);
171
172 break;
173 }
174 case htons(ETH_P_IPV6):
175 nft_reg_store8(dest, PACKET_MULTICAST);
176 break;
177 default:
178 WARN_ON_ONCE(1);
179 goto err;
180 }
181 break;
182 default:
183 WARN_ON_ONCE(1);
184 goto err;
185 }
186 break;
187 case NFT_META_CPU:
188 *dest = raw_smp_processor_id();
189 break;
190 case NFT_META_IIFGROUP:
191 if (in == NULL)
192 goto err;
193 *dest = in->group;
194 break;
195 case NFT_META_OIFGROUP:
196 if (out == NULL)
197 goto err;
198 *dest = out->group;
199 break;
200 #ifdef CONFIG_CGROUP_NET_CLASSID
201 case NFT_META_CGROUP:
202 sk = skb_to_full_sk(skb);
203 if (!sk || !sk_fullsock(sk))
204 goto err;
205 *dest = sock_cgroup_classid(&sk->sk_cgrp_data);
206 break;
207 #endif
208 case NFT_META_PRANDOM: {
209 struct rnd_state *state = this_cpu_ptr(&nft_prandom_state);
210 *dest = prandom_u32_state(state);
211 break;
212 }
213 #ifdef CONFIG_XFRM
214 case NFT_META_SECPATH:
215 nft_reg_store8(dest, !!skb->sp);
216 break;
217 #endif
218 default:
219 WARN_ON(1);
220 goto err;
221 }
222 return;
223
224 err:
225 regs->verdict.code = NFT_BREAK;
226 }
227 EXPORT_SYMBOL_GPL(nft_meta_get_eval);
228
229 void nft_meta_set_eval(const struct nft_expr *expr,
230 struct nft_regs *regs,
231 const struct nft_pktinfo *pkt)
232 {
233 const struct nft_meta *meta = nft_expr_priv(expr);
234 struct sk_buff *skb = pkt->skb;
235 u32 *sreg = ®s->data[meta->sreg];
236 u32 value = *sreg;
237 u8 value8;
238
239 switch (meta->key) {
240 case NFT_META_MARK:
241 skb->mark = value;
242 break;
243 case NFT_META_PRIORITY:
244 skb->priority = value;
245 break;
246 case NFT_META_PKTTYPE:
247 value8 = nft_reg_load8(sreg);
248
249 if (skb->pkt_type != value8 &&
250 skb_pkt_type_ok(value8) &&
251 skb_pkt_type_ok(skb->pkt_type))
252 skb->pkt_type = value8;
253 break;
254 case NFT_META_NFTRACE:
255 value8 = nft_reg_load8(sreg);
256
257 skb->nf_trace = !!value8;
258 break;
259 default:
260 WARN_ON(1);
261 }
262 }
263 EXPORT_SYMBOL_GPL(nft_meta_set_eval);
264
265 const struct nla_policy nft_meta_policy[NFTA_META_MAX + 1] = {
266 [NFTA_META_DREG] = { .type = NLA_U32 },
267 [NFTA_META_KEY] = { .type = NLA_U32 },
268 [NFTA_META_SREG] = { .type = NLA_U32 },
269 };
270 EXPORT_SYMBOL_GPL(nft_meta_policy);
271
272 int nft_meta_get_init(const struct nft_ctx *ctx,
273 const struct nft_expr *expr,
274 const struct nlattr * const tb[])
275 {
276 struct nft_meta *priv = nft_expr_priv(expr);
277 unsigned int len;
278
279 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
280 switch (priv->key) {
281 case NFT_META_PROTOCOL:
282 case NFT_META_IIFTYPE:
283 case NFT_META_OIFTYPE:
284 len = sizeof(u16);
285 break;
286 case NFT_META_NFPROTO:
287 case NFT_META_L4PROTO:
288 case NFT_META_LEN:
289 case NFT_META_PRIORITY:
290 case NFT_META_MARK:
291 case NFT_META_IIF:
292 case NFT_META_OIF:
293 case NFT_META_SKUID:
294 case NFT_META_SKGID:
295 #ifdef CONFIG_IP_ROUTE_CLASSID
296 case NFT_META_RTCLASSID:
297 #endif
298 #ifdef CONFIG_NETWORK_SECMARK
299 case NFT_META_SECMARK:
300 #endif
301 case NFT_META_PKTTYPE:
302 case NFT_META_CPU:
303 case NFT_META_IIFGROUP:
304 case NFT_META_OIFGROUP:
305 #ifdef CONFIG_CGROUP_NET_CLASSID
306 case NFT_META_CGROUP:
307 #endif
308 len = sizeof(u32);
309 break;
310 case NFT_META_IIFNAME:
311 case NFT_META_OIFNAME:
312 len = IFNAMSIZ;
313 break;
314 case NFT_META_PRANDOM:
315 prandom_init_once(&nft_prandom_state);
316 len = sizeof(u32);
317 break;
318 #ifdef CONFIG_XFRM
319 case NFT_META_SECPATH:
320 len = sizeof(u8);
321 break;
322 #endif
323 default:
324 return -EOPNOTSUPP;
325 }
326
327 priv->dreg = nft_parse_register(tb[NFTA_META_DREG]);
328 return nft_validate_register_store(ctx, priv->dreg, NULL,
329 NFT_DATA_VALUE, len);
330 }
331 EXPORT_SYMBOL_GPL(nft_meta_get_init);
332
333 static int nft_meta_get_validate(const struct nft_ctx *ctx,
334 const struct nft_expr *expr,
335 const struct nft_data **data)
336 {
337 #ifdef CONFIG_XFRM
338 const struct nft_meta *priv = nft_expr_priv(expr);
339 unsigned int hooks;
340
341 if (priv->key != NFT_META_SECPATH)
342 return 0;
343
344 switch (ctx->family) {
345 case NFPROTO_NETDEV:
346 hooks = 1 << NF_NETDEV_INGRESS;
347 break;
348 case NFPROTO_IPV4:
349 case NFPROTO_IPV6:
350 case NFPROTO_INET:
351 hooks = (1 << NF_INET_PRE_ROUTING) |
352 (1 << NF_INET_LOCAL_IN) |
353 (1 << NF_INET_FORWARD);
354 break;
355 default:
356 return -EOPNOTSUPP;
357 }
358
359 return nft_chain_validate_hooks(ctx->chain, hooks);
360 #else
361 return 0;
362 #endif
363 }
364
365 int nft_meta_set_validate(const struct nft_ctx *ctx,
366 const struct nft_expr *expr,
367 const struct nft_data **data)
368 {
369 struct nft_meta *priv = nft_expr_priv(expr);
370 unsigned int hooks;
371
372 if (priv->key != NFT_META_PKTTYPE)
373 return 0;
374
375 switch (ctx->family) {
376 case NFPROTO_BRIDGE:
377 hooks = 1 << NF_BR_PRE_ROUTING;
378 break;
379 case NFPROTO_NETDEV:
380 hooks = 1 << NF_NETDEV_INGRESS;
381 break;
382 case NFPROTO_IPV4:
383 case NFPROTO_IPV6:
384 case NFPROTO_INET:
385 hooks = 1 << NF_INET_PRE_ROUTING;
386 break;
387 default:
388 return -EOPNOTSUPP;
389 }
390
391 return nft_chain_validate_hooks(ctx->chain, hooks);
392 }
393 EXPORT_SYMBOL_GPL(nft_meta_set_validate);
394
395 int nft_meta_set_init(const struct nft_ctx *ctx,
396 const struct nft_expr *expr,
397 const struct nlattr * const tb[])
398 {
399 struct nft_meta *priv = nft_expr_priv(expr);
400 unsigned int len;
401 int err;
402
403 priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY]));
404 switch (priv->key) {
405 case NFT_META_MARK:
406 case NFT_META_PRIORITY:
407 len = sizeof(u32);
408 break;
409 case NFT_META_NFTRACE:
410 len = sizeof(u8);
411 break;
412 case NFT_META_PKTTYPE:
413 len = sizeof(u8);
414 break;
415 default:
416 return -EOPNOTSUPP;
417 }
418
419 priv->sreg = nft_parse_register(tb[NFTA_META_SREG]);
420 err = nft_validate_register_load(priv->sreg, len);
421 if (err < 0)
422 return err;
423
424 if (priv->key == NFT_META_NFTRACE)
425 static_branch_inc(&nft_trace_enabled);
426
427 return 0;
428 }
429 EXPORT_SYMBOL_GPL(nft_meta_set_init);
430
431 int nft_meta_get_dump(struct sk_buff *skb,
432 const struct nft_expr *expr)
433 {
434 const struct nft_meta *priv = nft_expr_priv(expr);
435
436 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
437 goto nla_put_failure;
438 if (nft_dump_register(skb, NFTA_META_DREG, priv->dreg))
439 goto nla_put_failure;
440 return 0;
441
442 nla_put_failure:
443 return -1;
444 }
445 EXPORT_SYMBOL_GPL(nft_meta_get_dump);
446
447 int nft_meta_set_dump(struct sk_buff *skb,
448 const struct nft_expr *expr)
449 {
450 const struct nft_meta *priv = nft_expr_priv(expr);
451
452 if (nla_put_be32(skb, NFTA_META_KEY, htonl(priv->key)))
453 goto nla_put_failure;
454 if (nft_dump_register(skb, NFTA_META_SREG, priv->sreg))
455 goto nla_put_failure;
456
457 return 0;
458
459 nla_put_failure:
460 return -1;
461 }
462 EXPORT_SYMBOL_GPL(nft_meta_set_dump);
463
464 void nft_meta_set_destroy(const struct nft_ctx *ctx,
465 const struct nft_expr *expr)
466 {
467 const struct nft_meta *priv = nft_expr_priv(expr);
468
469 if (priv->key == NFT_META_NFTRACE)
470 static_branch_dec(&nft_trace_enabled);
471 }
472 EXPORT_SYMBOL_GPL(nft_meta_set_destroy);
473
474 static struct nft_expr_type nft_meta_type;
475 static const struct nft_expr_ops nft_meta_get_ops = {
476 .type = &nft_meta_type,
477 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
478 .eval = nft_meta_get_eval,
479 .init = nft_meta_get_init,
480 .dump = nft_meta_get_dump,
481 .validate = nft_meta_get_validate,
482 };
483
484 static const struct nft_expr_ops nft_meta_set_ops = {
485 .type = &nft_meta_type,
486 .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)),
487 .eval = nft_meta_set_eval,
488 .init = nft_meta_set_init,
489 .destroy = nft_meta_set_destroy,
490 .dump = nft_meta_set_dump,
491 .validate = nft_meta_set_validate,
492 };
493
494 static const struct nft_expr_ops *
495 nft_meta_select_ops(const struct nft_ctx *ctx,
496 const struct nlattr * const tb[])
497 {
498 if (tb[NFTA_META_KEY] == NULL)
499 return ERR_PTR(-EINVAL);
500
501 if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG])
502 return ERR_PTR(-EINVAL);
503
504 if (tb[NFTA_META_DREG])
505 return &nft_meta_get_ops;
506
507 if (tb[NFTA_META_SREG])
508 return &nft_meta_set_ops;
509
510 return ERR_PTR(-EINVAL);
511 }
512
513 static struct nft_expr_type nft_meta_type __read_mostly = {
514 .name = "meta",
515 .select_ops = nft_meta_select_ops,
516 .policy = nft_meta_policy,
517 .maxattr = NFTA_META_MAX,
518 .owner = THIS_MODULE,
519 };
520
521 static int __init nft_meta_module_init(void)
522 {
523 return nft_register_expr(&nft_meta_type);
524 }
525
526 static void __exit nft_meta_module_exit(void)
527 {
528 nft_unregister_expr(&nft_meta_type);
529 }
530
531 module_init(nft_meta_module_init);
532 module_exit(nft_meta_module_exit);
533
534 MODULE_LICENSE("GPL");
535 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
536 MODULE_ALIAS_NFT_EXPR("meta");
537
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