xref: /openbmc/linux/net/sched/cls_api.c (revision 4f6cce39)
1 /*
2  * net/sched/cls_api.c	Packet classifier API.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  *
11  * Changes:
12  *
13  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
14  *
15  */
16 
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/string.h>
21 #include <linux/errno.h>
22 #include <linux/err.h>
23 #include <linux/skbuff.h>
24 #include <linux/init.h>
25 #include <linux/kmod.h>
26 #include <linux/err.h>
27 #include <linux/slab.h>
28 #include <net/net_namespace.h>
29 #include <net/sock.h>
30 #include <net/netlink.h>
31 #include <net/pkt_sched.h>
32 #include <net/pkt_cls.h>
33 
34 /* The list of all installed classifier types */
35 static LIST_HEAD(tcf_proto_base);
36 
37 /* Protects list of registered TC modules. It is pure SMP lock. */
38 static DEFINE_RWLOCK(cls_mod_lock);
39 
40 /* Find classifier type by string name */
41 
42 static const struct tcf_proto_ops *tcf_proto_lookup_ops(const char *kind)
43 {
44 	const struct tcf_proto_ops *t, *res = NULL;
45 
46 	if (kind) {
47 		read_lock(&cls_mod_lock);
48 		list_for_each_entry(t, &tcf_proto_base, head) {
49 			if (strcmp(kind, t->kind) == 0) {
50 				if (try_module_get(t->owner))
51 					res = t;
52 				break;
53 			}
54 		}
55 		read_unlock(&cls_mod_lock);
56 	}
57 	return res;
58 }
59 
60 /* Register(unregister) new classifier type */
61 
62 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
63 {
64 	struct tcf_proto_ops *t;
65 	int rc = -EEXIST;
66 
67 	write_lock(&cls_mod_lock);
68 	list_for_each_entry(t, &tcf_proto_base, head)
69 		if (!strcmp(ops->kind, t->kind))
70 			goto out;
71 
72 	list_add_tail(&ops->head, &tcf_proto_base);
73 	rc = 0;
74 out:
75 	write_unlock(&cls_mod_lock);
76 	return rc;
77 }
78 EXPORT_SYMBOL(register_tcf_proto_ops);
79 
80 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
81 {
82 	struct tcf_proto_ops *t;
83 	int rc = -ENOENT;
84 
85 	/* Wait for outstanding call_rcu()s, if any, from a
86 	 * tcf_proto_ops's destroy() handler.
87 	 */
88 	rcu_barrier();
89 
90 	write_lock(&cls_mod_lock);
91 	list_for_each_entry(t, &tcf_proto_base, head) {
92 		if (t == ops) {
93 			list_del(&t->head);
94 			rc = 0;
95 			break;
96 		}
97 	}
98 	write_unlock(&cls_mod_lock);
99 	return rc;
100 }
101 EXPORT_SYMBOL(unregister_tcf_proto_ops);
102 
103 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
104 			  struct nlmsghdr *n, struct tcf_proto *tp,
105 			  unsigned long fh, int event, bool unicast);
106 
107 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
108 				 struct nlmsghdr *n,
109 				 struct tcf_proto __rcu **chain, int event)
110 {
111 	struct tcf_proto __rcu **it_chain;
112 	struct tcf_proto *tp;
113 
114 	for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL;
115 	     it_chain = &tp->next)
116 		tfilter_notify(net, oskb, n, tp, 0, event, false);
117 }
118 
119 /* Select new prio value from the range, managed by kernel. */
120 
121 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
122 {
123 	u32 first = TC_H_MAKE(0xC0000000U, 0U);
124 
125 	if (tp)
126 		first = tp->prio - 1;
127 
128 	return first;
129 }
130 
131 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
132 					  u32 prio, u32 parent, struct Qdisc *q)
133 {
134 	struct tcf_proto *tp;
135 	int err;
136 
137 	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
138 	if (!tp)
139 		return ERR_PTR(-ENOBUFS);
140 
141 	err = -ENOENT;
142 	tp->ops = tcf_proto_lookup_ops(kind);
143 	if (!tp->ops) {
144 #ifdef CONFIG_MODULES
145 		rtnl_unlock();
146 		request_module("cls_%s", kind);
147 		rtnl_lock();
148 		tp->ops = tcf_proto_lookup_ops(kind);
149 		/* We dropped the RTNL semaphore in order to perform
150 		 * the module load. So, even if we succeeded in loading
151 		 * the module we have to replay the request. We indicate
152 		 * this using -EAGAIN.
153 		 */
154 		if (tp->ops) {
155 			module_put(tp->ops->owner);
156 			err = -EAGAIN;
157 		} else {
158 			err = -ENOENT;
159 		}
160 		goto errout;
161 #endif
162 	}
163 	tp->classify = tp->ops->classify;
164 	tp->protocol = protocol;
165 	tp->prio = prio;
166 	tp->classid = parent;
167 	tp->q = q;
168 
169 	err = tp->ops->init(tp);
170 	if (err) {
171 		module_put(tp->ops->owner);
172 		goto errout;
173 	}
174 	return tp;
175 
176 errout:
177 	kfree(tp);
178 	return ERR_PTR(err);
179 }
180 
181 static bool tcf_proto_destroy(struct tcf_proto *tp, bool force)
182 {
183 	if (tp->ops->destroy(tp, force)) {
184 		module_put(tp->ops->owner);
185 		kfree_rcu(tp, rcu);
186 		return true;
187 	}
188 	return false;
189 }
190 
191 void tcf_destroy_chain(struct tcf_proto __rcu **fl)
192 {
193 	struct tcf_proto *tp;
194 
195 	while ((tp = rtnl_dereference(*fl)) != NULL) {
196 		RCU_INIT_POINTER(*fl, tp->next);
197 		tcf_proto_destroy(tp, true);
198 	}
199 }
200 EXPORT_SYMBOL(tcf_destroy_chain);
201 
202 /* Add/change/delete/get a filter node */
203 
204 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n)
205 {
206 	struct net *net = sock_net(skb->sk);
207 	struct nlattr *tca[TCA_MAX + 1];
208 	struct tcmsg *t;
209 	u32 protocol;
210 	u32 prio;
211 	u32 nprio;
212 	u32 parent;
213 	struct net_device *dev;
214 	struct Qdisc  *q;
215 	struct tcf_proto __rcu **back;
216 	struct tcf_proto __rcu **chain;
217 	struct tcf_proto *next;
218 	struct tcf_proto *tp;
219 	const struct Qdisc_class_ops *cops;
220 	unsigned long cl;
221 	unsigned long fh;
222 	int err;
223 	int tp_created;
224 
225 	if ((n->nlmsg_type != RTM_GETTFILTER) &&
226 	    !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
227 		return -EPERM;
228 
229 replay:
230 	tp_created = 0;
231 
232 	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
233 	if (err < 0)
234 		return err;
235 
236 	t = nlmsg_data(n);
237 	protocol = TC_H_MIN(t->tcm_info);
238 	prio = TC_H_MAJ(t->tcm_info);
239 	nprio = prio;
240 	parent = t->tcm_parent;
241 	cl = 0;
242 
243 	if (prio == 0) {
244 		switch (n->nlmsg_type) {
245 		case RTM_DELTFILTER:
246 			if (protocol || t->tcm_handle || tca[TCA_KIND])
247 				return -ENOENT;
248 			break;
249 		case RTM_NEWTFILTER:
250 			/* If no priority is provided by the user,
251 			 * we allocate one.
252 			 */
253 			if (n->nlmsg_flags & NLM_F_CREATE) {
254 				prio = TC_H_MAKE(0x80000000U, 0U);
255 				break;
256 			}
257 			/* fall-through */
258 		default:
259 			return -ENOENT;
260 		}
261 	}
262 
263 	/* Find head of filter chain. */
264 
265 	/* Find link */
266 	dev = __dev_get_by_index(net, t->tcm_ifindex);
267 	if (dev == NULL)
268 		return -ENODEV;
269 
270 	/* Find qdisc */
271 	if (!parent) {
272 		q = dev->qdisc;
273 		parent = q->handle;
274 	} else {
275 		q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
276 		if (q == NULL)
277 			return -EINVAL;
278 	}
279 
280 	/* Is it classful? */
281 	cops = q->ops->cl_ops;
282 	if (!cops)
283 		return -EINVAL;
284 
285 	if (cops->tcf_chain == NULL)
286 		return -EOPNOTSUPP;
287 
288 	/* Do we search for filter, attached to class? */
289 	if (TC_H_MIN(parent)) {
290 		cl = cops->get(q, parent);
291 		if (cl == 0)
292 			return -ENOENT;
293 	}
294 
295 	/* And the last stroke */
296 	chain = cops->tcf_chain(q, cl);
297 	if (chain == NULL) {
298 		err = -EINVAL;
299 		goto errout;
300 	}
301 	if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
302 		tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
303 		tcf_destroy_chain(chain);
304 		err = 0;
305 		goto errout;
306 	}
307 
308 	/* Check the chain for existence of proto-tcf with this priority */
309 	for (back = chain;
310 	     (tp = rtnl_dereference(*back)) != NULL;
311 	     back = &tp->next) {
312 		if (tp->prio >= prio) {
313 			if (tp->prio == prio) {
314 				if (!nprio ||
315 				    (tp->protocol != protocol && protocol)) {
316 					err = -EINVAL;
317 					goto errout;
318 				}
319 			} else {
320 				tp = NULL;
321 			}
322 			break;
323 		}
324 	}
325 
326 	if (tp == NULL) {
327 		/* Proto-tcf does not exist, create new one */
328 
329 		if (tca[TCA_KIND] == NULL || !protocol) {
330 			err = -EINVAL;
331 			goto errout;
332 		}
333 
334 		if (n->nlmsg_type != RTM_NEWTFILTER ||
335 		    !(n->nlmsg_flags & NLM_F_CREATE)) {
336 			err = -ENOENT;
337 			goto errout;
338 		}
339 
340 		if (!nprio)
341 			nprio = TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back)));
342 
343 		tp = tcf_proto_create(nla_data(tca[TCA_KIND]),
344 				      protocol, nprio, parent, q);
345 		if (IS_ERR(tp)) {
346 			err = PTR_ERR(tp);
347 			goto errout;
348 		}
349 		tp_created = 1;
350 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
351 		err = -EINVAL;
352 		goto errout;
353 	}
354 
355 	fh = tp->ops->get(tp, t->tcm_handle);
356 
357 	if (fh == 0) {
358 		if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
359 			next = rtnl_dereference(tp->next);
360 			RCU_INIT_POINTER(*back, next);
361 			tfilter_notify(net, skb, n, tp, fh,
362 				       RTM_DELTFILTER, false);
363 			tcf_proto_destroy(tp, true);
364 			err = 0;
365 			goto errout;
366 		}
367 
368 		if (n->nlmsg_type != RTM_NEWTFILTER ||
369 		    !(n->nlmsg_flags & NLM_F_CREATE)) {
370 			err = -ENOENT;
371 			goto errout;
372 		}
373 	} else {
374 		switch (n->nlmsg_type) {
375 		case RTM_NEWTFILTER:
376 			if (n->nlmsg_flags & NLM_F_EXCL) {
377 				if (tp_created)
378 					tcf_proto_destroy(tp, true);
379 				err = -EEXIST;
380 				goto errout;
381 			}
382 			break;
383 		case RTM_DELTFILTER:
384 			err = tp->ops->delete(tp, fh);
385 			if (err)
386 				goto errout;
387 			next = rtnl_dereference(tp->next);
388 			tfilter_notify(net, skb, n, tp, t->tcm_handle,
389 				       RTM_DELTFILTER, false);
390 			if (tcf_proto_destroy(tp, false))
391 				RCU_INIT_POINTER(*back, next);
392 			goto errout;
393 		case RTM_GETTFILTER:
394 			err = tfilter_notify(net, skb, n, tp, fh,
395 					     RTM_NEWTFILTER, true);
396 			goto errout;
397 		default:
398 			err = -EINVAL;
399 			goto errout;
400 		}
401 	}
402 
403 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
404 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
405 	if (err == 0) {
406 		if (tp_created) {
407 			RCU_INIT_POINTER(tp->next, rtnl_dereference(*back));
408 			rcu_assign_pointer(*back, tp);
409 		}
410 		tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);
411 	} else {
412 		if (tp_created)
413 			tcf_proto_destroy(tp, true);
414 	}
415 
416 errout:
417 	if (cl)
418 		cops->put(q, cl);
419 	if (err == -EAGAIN)
420 		/* Replay the request. */
421 		goto replay;
422 	return err;
423 }
424 
425 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
426 			 struct tcf_proto *tp, unsigned long fh, u32 portid,
427 			 u32 seq, u16 flags, int event)
428 {
429 	struct tcmsg *tcm;
430 	struct nlmsghdr  *nlh;
431 	unsigned char *b = skb_tail_pointer(skb);
432 
433 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
434 	if (!nlh)
435 		goto out_nlmsg_trim;
436 	tcm = nlmsg_data(nlh);
437 	tcm->tcm_family = AF_UNSPEC;
438 	tcm->tcm__pad1 = 0;
439 	tcm->tcm__pad2 = 0;
440 	tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
441 	tcm->tcm_parent = tp->classid;
442 	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
443 	if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
444 		goto nla_put_failure;
445 	tcm->tcm_handle = fh;
446 	if (RTM_DELTFILTER != event) {
447 		tcm->tcm_handle = 0;
448 		if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
449 			goto nla_put_failure;
450 	}
451 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
452 	return skb->len;
453 
454 out_nlmsg_trim:
455 nla_put_failure:
456 	nlmsg_trim(skb, b);
457 	return -1;
458 }
459 
460 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
461 			  struct nlmsghdr *n, struct tcf_proto *tp,
462 			  unsigned long fh, int event, bool unicast)
463 {
464 	struct sk_buff *skb;
465 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
466 
467 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
468 	if (!skb)
469 		return -ENOBUFS;
470 
471 	if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
472 			  n->nlmsg_flags, event) <= 0) {
473 		kfree_skb(skb);
474 		return -EINVAL;
475 	}
476 
477 	if (unicast)
478 		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
479 
480 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
481 			      n->nlmsg_flags & NLM_F_ECHO);
482 }
483 
484 struct tcf_dump_args {
485 	struct tcf_walker w;
486 	struct sk_buff *skb;
487 	struct netlink_callback *cb;
488 };
489 
490 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
491 			 struct tcf_walker *arg)
492 {
493 	struct tcf_dump_args *a = (void *)arg;
494 	struct net *net = sock_net(a->skb->sk);
495 
496 	return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid,
497 			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
498 			     RTM_NEWTFILTER);
499 }
500 
501 /* called with RTNL */
502 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
503 {
504 	struct net *net = sock_net(skb->sk);
505 	int t;
506 	int s_t;
507 	struct net_device *dev;
508 	struct Qdisc *q;
509 	struct tcf_proto *tp, __rcu **chain;
510 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
511 	unsigned long cl = 0;
512 	const struct Qdisc_class_ops *cops;
513 	struct tcf_dump_args arg;
514 
515 	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
516 		return skb->len;
517 	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
518 	if (!dev)
519 		return skb->len;
520 
521 	if (!tcm->tcm_parent)
522 		q = dev->qdisc;
523 	else
524 		q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
525 	if (!q)
526 		goto out;
527 	cops = q->ops->cl_ops;
528 	if (!cops)
529 		goto errout;
530 	if (cops->tcf_chain == NULL)
531 		goto errout;
532 	if (TC_H_MIN(tcm->tcm_parent)) {
533 		cl = cops->get(q, tcm->tcm_parent);
534 		if (cl == 0)
535 			goto errout;
536 	}
537 	chain = cops->tcf_chain(q, cl);
538 	if (chain == NULL)
539 		goto errout;
540 
541 	s_t = cb->args[0];
542 
543 	for (tp = rtnl_dereference(*chain), t = 0;
544 	     tp; tp = rtnl_dereference(tp->next), t++) {
545 		if (t < s_t)
546 			continue;
547 		if (TC_H_MAJ(tcm->tcm_info) &&
548 		    TC_H_MAJ(tcm->tcm_info) != tp->prio)
549 			continue;
550 		if (TC_H_MIN(tcm->tcm_info) &&
551 		    TC_H_MIN(tcm->tcm_info) != tp->protocol)
552 			continue;
553 		if (t > s_t)
554 			memset(&cb->args[1], 0,
555 			       sizeof(cb->args)-sizeof(cb->args[0]));
556 		if (cb->args[1] == 0) {
557 			if (tcf_fill_node(net, skb, tp, 0,
558 					  NETLINK_CB(cb->skb).portid,
559 					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
560 					  RTM_NEWTFILTER) <= 0)
561 				break;
562 
563 			cb->args[1] = 1;
564 		}
565 		if (tp->ops->walk == NULL)
566 			continue;
567 		arg.w.fn = tcf_node_dump;
568 		arg.skb = skb;
569 		arg.cb = cb;
570 		arg.w.stop = 0;
571 		arg.w.skip = cb->args[1] - 1;
572 		arg.w.count = 0;
573 		tp->ops->walk(tp, &arg.w);
574 		cb->args[1] = arg.w.count + 1;
575 		if (arg.w.stop)
576 			break;
577 	}
578 
579 	cb->args[0] = t;
580 
581 errout:
582 	if (cl)
583 		cops->put(q, cl);
584 out:
585 	return skb->len;
586 }
587 
588 void tcf_exts_destroy(struct tcf_exts *exts)
589 {
590 #ifdef CONFIG_NET_CLS_ACT
591 	LIST_HEAD(actions);
592 
593 	tcf_exts_to_list(exts, &actions);
594 	tcf_action_destroy(&actions, TCA_ACT_UNBIND);
595 	kfree(exts->actions);
596 	exts->nr_actions = 0;
597 #endif
598 }
599 EXPORT_SYMBOL(tcf_exts_destroy);
600 
601 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
602 		      struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
603 {
604 #ifdef CONFIG_NET_CLS_ACT
605 	{
606 		struct tc_action *act;
607 
608 		if (exts->police && tb[exts->police]) {
609 			act = tcf_action_init_1(net, tb[exts->police], rate_tlv,
610 						"police", ovr, TCA_ACT_BIND);
611 			if (IS_ERR(act))
612 				return PTR_ERR(act);
613 
614 			act->type = exts->type = TCA_OLD_COMPAT;
615 			exts->actions[0] = act;
616 			exts->nr_actions = 1;
617 		} else if (exts->action && tb[exts->action]) {
618 			LIST_HEAD(actions);
619 			int err, i = 0;
620 
621 			err = tcf_action_init(net, tb[exts->action], rate_tlv,
622 					      NULL, ovr, TCA_ACT_BIND,
623 					      &actions);
624 			if (err)
625 				return err;
626 			list_for_each_entry(act, &actions, list)
627 				exts->actions[i++] = act;
628 			exts->nr_actions = i;
629 		}
630 	}
631 #else
632 	if ((exts->action && tb[exts->action]) ||
633 	    (exts->police && tb[exts->police]))
634 		return -EOPNOTSUPP;
635 #endif
636 
637 	return 0;
638 }
639 EXPORT_SYMBOL(tcf_exts_validate);
640 
641 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
642 		     struct tcf_exts *src)
643 {
644 #ifdef CONFIG_NET_CLS_ACT
645 	struct tcf_exts old = *dst;
646 
647 	tcf_tree_lock(tp);
648 	dst->nr_actions = src->nr_actions;
649 	dst->actions = src->actions;
650 	dst->type = src->type;
651 	tcf_tree_unlock(tp);
652 
653 	tcf_exts_destroy(&old);
654 #endif
655 }
656 EXPORT_SYMBOL(tcf_exts_change);
657 
658 #ifdef CONFIG_NET_CLS_ACT
659 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
660 {
661 	if (exts->nr_actions == 0)
662 		return NULL;
663 	else
664 		return exts->actions[0];
665 }
666 #endif
667 
668 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
669 {
670 #ifdef CONFIG_NET_CLS_ACT
671 	struct nlattr *nest;
672 
673 	if (exts->action && exts->nr_actions) {
674 		/*
675 		 * again for backward compatible mode - we want
676 		 * to work with both old and new modes of entering
677 		 * tc data even if iproute2  was newer - jhs
678 		 */
679 		if (exts->type != TCA_OLD_COMPAT) {
680 			LIST_HEAD(actions);
681 
682 			nest = nla_nest_start(skb, exts->action);
683 			if (nest == NULL)
684 				goto nla_put_failure;
685 
686 			tcf_exts_to_list(exts, &actions);
687 			if (tcf_action_dump(skb, &actions, 0, 0) < 0)
688 				goto nla_put_failure;
689 			nla_nest_end(skb, nest);
690 		} else if (exts->police) {
691 			struct tc_action *act = tcf_exts_first_act(exts);
692 			nest = nla_nest_start(skb, exts->police);
693 			if (nest == NULL || !act)
694 				goto nla_put_failure;
695 			if (tcf_action_dump_old(skb, act, 0, 0) < 0)
696 				goto nla_put_failure;
697 			nla_nest_end(skb, nest);
698 		}
699 	}
700 	return 0;
701 
702 nla_put_failure:
703 	nla_nest_cancel(skb, nest);
704 	return -1;
705 #else
706 	return 0;
707 #endif
708 }
709 EXPORT_SYMBOL(tcf_exts_dump);
710 
711 
712 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
713 {
714 #ifdef CONFIG_NET_CLS_ACT
715 	struct tc_action *a = tcf_exts_first_act(exts);
716 	if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
717 		return -1;
718 #endif
719 	return 0;
720 }
721 EXPORT_SYMBOL(tcf_exts_dump_stats);
722 
723 int tcf_exts_get_dev(struct net_device *dev, struct tcf_exts *exts,
724 		     struct net_device **hw_dev)
725 {
726 #ifdef CONFIG_NET_CLS_ACT
727 	const struct tc_action *a;
728 	LIST_HEAD(actions);
729 
730 	if (tc_no_actions(exts))
731 		return -EINVAL;
732 
733 	tcf_exts_to_list(exts, &actions);
734 	list_for_each_entry(a, &actions, list) {
735 		if (a->ops->get_dev) {
736 			a->ops->get_dev(a, dev_net(dev), hw_dev);
737 			break;
738 		}
739 	}
740 	if (*hw_dev)
741 		return 0;
742 #endif
743 	return -EOPNOTSUPP;
744 }
745 EXPORT_SYMBOL(tcf_exts_get_dev);
746 
747 static int __init tc_filter_init(void)
748 {
749 	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
750 	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
751 	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
752 		      tc_dump_tfilter, NULL);
753 
754 	return 0;
755 }
756 
757 subsys_initcall(tc_filter_init);
758