xref: /openbmc/linux/net/sched/cls_api.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
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/skbuff.h>
23 #include <linux/init.h>
24 #include <linux/kmod.h>
25 #include <linux/err.h>
26 #include <linux/slab.h>
27 #include <net/net_namespace.h>
28 #include <net/sock.h>
29 #include <net/netlink.h>
30 #include <net/pkt_sched.h>
31 #include <net/pkt_cls.h>
32 
33 /* The list of all installed classifier types */
34 static LIST_HEAD(tcf_proto_base);
35 
36 /* Protects list of registered TC modules. It is pure SMP lock. */
37 static DEFINE_RWLOCK(cls_mod_lock);
38 
39 /* Find classifier type by string name */
40 
41 static const struct tcf_proto_ops *tcf_proto_lookup_ops(struct nlattr *kind)
42 {
43 	const struct tcf_proto_ops *t, *res = NULL;
44 
45 	if (kind) {
46 		read_lock(&cls_mod_lock);
47 		list_for_each_entry(t, &tcf_proto_base, head) {
48 			if (nla_strcmp(kind, t->kind) == 0) {
49 				if (try_module_get(t->owner))
50 					res = t;
51 				break;
52 			}
53 		}
54 		read_unlock(&cls_mod_lock);
55 	}
56 	return res;
57 }
58 
59 /* Register(unregister) new classifier type */
60 
61 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
62 {
63 	struct tcf_proto_ops *t;
64 	int rc = -EEXIST;
65 
66 	write_lock(&cls_mod_lock);
67 	list_for_each_entry(t, &tcf_proto_base, head)
68 		if (!strcmp(ops->kind, t->kind))
69 			goto out;
70 
71 	list_add_tail(&ops->head, &tcf_proto_base);
72 	rc = 0;
73 out:
74 	write_unlock(&cls_mod_lock);
75 	return rc;
76 }
77 EXPORT_SYMBOL(register_tcf_proto_ops);
78 
79 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
80 {
81 	struct tcf_proto_ops *t;
82 	int rc = -ENOENT;
83 
84 	/* Wait for outstanding call_rcu()s, if any, from a
85 	 * tcf_proto_ops's destroy() handler.
86 	 */
87 	rcu_barrier();
88 
89 	write_lock(&cls_mod_lock);
90 	list_for_each_entry(t, &tcf_proto_base, head) {
91 		if (t == ops) {
92 			list_del(&t->head);
93 			rc = 0;
94 			break;
95 		}
96 	}
97 	write_unlock(&cls_mod_lock);
98 	return rc;
99 }
100 EXPORT_SYMBOL(unregister_tcf_proto_ops);
101 
102 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
103 			  struct nlmsghdr *n, struct tcf_proto *tp,
104 			  unsigned long fh, int event, bool unicast);
105 
106 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
107 				 struct nlmsghdr *n,
108 				 struct tcf_proto __rcu **chain, int event)
109 {
110 	struct tcf_proto __rcu **it_chain;
111 	struct tcf_proto *tp;
112 
113 	for (it_chain = chain; (tp = rtnl_dereference(*it_chain)) != NULL;
114 	     it_chain = &tp->next)
115 		tfilter_notify(net, oskb, n, tp, 0, event, false);
116 }
117 
118 /* Select new prio value from the range, managed by kernel. */
119 
120 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
121 {
122 	u32 first = TC_H_MAKE(0xC0000000U, 0U);
123 
124 	if (tp)
125 		first = tp->prio - 1;
126 
127 	return first;
128 }
129 
130 /* Add/change/delete/get a filter node */
131 
132 static int tc_ctl_tfilter(struct sk_buff *skb, struct nlmsghdr *n)
133 {
134 	struct net *net = sock_net(skb->sk);
135 	struct nlattr *tca[TCA_MAX + 1];
136 	struct tcmsg *t;
137 	u32 protocol;
138 	u32 prio;
139 	u32 nprio;
140 	u32 parent;
141 	struct net_device *dev;
142 	struct Qdisc  *q;
143 	struct tcf_proto __rcu **back;
144 	struct tcf_proto __rcu **chain;
145 	struct tcf_proto *tp;
146 	const struct tcf_proto_ops *tp_ops;
147 	const struct Qdisc_class_ops *cops;
148 	unsigned long cl;
149 	unsigned long fh;
150 	int err;
151 	int tp_created = 0;
152 
153 	if ((n->nlmsg_type != RTM_GETTFILTER) &&
154 	    !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
155 		return -EPERM;
156 
157 replay:
158 	err = nlmsg_parse(n, sizeof(*t), tca, TCA_MAX, NULL);
159 	if (err < 0)
160 		return err;
161 
162 	t = nlmsg_data(n);
163 	protocol = TC_H_MIN(t->tcm_info);
164 	prio = TC_H_MAJ(t->tcm_info);
165 	nprio = prio;
166 	parent = t->tcm_parent;
167 	cl = 0;
168 
169 	if (prio == 0) {
170 		switch (n->nlmsg_type) {
171 		case RTM_DELTFILTER:
172 			if (protocol || t->tcm_handle || tca[TCA_KIND])
173 				return -ENOENT;
174 			break;
175 		case RTM_NEWTFILTER:
176 			/* If no priority is provided by the user,
177 			 * we allocate one.
178 			 */
179 			if (n->nlmsg_flags & NLM_F_CREATE) {
180 				prio = TC_H_MAKE(0x80000000U, 0U);
181 				break;
182 			}
183 			/* fall-through */
184 		default:
185 			return -ENOENT;
186 		}
187 	}
188 
189 	/* Find head of filter chain. */
190 
191 	/* Find link */
192 	dev = __dev_get_by_index(net, t->tcm_ifindex);
193 	if (dev == NULL)
194 		return -ENODEV;
195 
196 	/* Find qdisc */
197 	if (!parent) {
198 		q = dev->qdisc;
199 		parent = q->handle;
200 	} else {
201 		q = qdisc_lookup(dev, TC_H_MAJ(t->tcm_parent));
202 		if (q == NULL)
203 			return -EINVAL;
204 	}
205 
206 	/* Is it classful? */
207 	cops = q->ops->cl_ops;
208 	if (!cops)
209 		return -EINVAL;
210 
211 	if (cops->tcf_chain == NULL)
212 		return -EOPNOTSUPP;
213 
214 	/* Do we search for filter, attached to class? */
215 	if (TC_H_MIN(parent)) {
216 		cl = cops->get(q, parent);
217 		if (cl == 0)
218 			return -ENOENT;
219 	}
220 
221 	/* And the last stroke */
222 	chain = cops->tcf_chain(q, cl);
223 	err = -EINVAL;
224 	if (chain == NULL)
225 		goto errout;
226 	if (n->nlmsg_type == RTM_DELTFILTER && prio == 0) {
227 		tfilter_notify_chain(net, skb, n, chain, RTM_DELTFILTER);
228 		tcf_destroy_chain(chain);
229 		err = 0;
230 		goto errout;
231 	}
232 
233 	/* Check the chain for existence of proto-tcf with this priority */
234 	for (back = chain;
235 	     (tp = rtnl_dereference(*back)) != NULL;
236 	     back = &tp->next) {
237 		if (tp->prio >= prio) {
238 			if (tp->prio == prio) {
239 				if (!nprio ||
240 				    (tp->protocol != protocol && protocol))
241 					goto errout;
242 			} else
243 				tp = NULL;
244 			break;
245 		}
246 	}
247 
248 	if (tp == NULL) {
249 		/* Proto-tcf does not exist, create new one */
250 
251 		if (tca[TCA_KIND] == NULL || !protocol)
252 			goto errout;
253 
254 		err = -ENOENT;
255 		if (n->nlmsg_type != RTM_NEWTFILTER ||
256 		    !(n->nlmsg_flags & NLM_F_CREATE))
257 			goto errout;
258 
259 
260 		/* Create new proto tcf */
261 
262 		err = -ENOBUFS;
263 		tp = kzalloc(sizeof(*tp), GFP_KERNEL);
264 		if (tp == NULL)
265 			goto errout;
266 		err = -ENOENT;
267 		tp_ops = tcf_proto_lookup_ops(tca[TCA_KIND]);
268 		if (tp_ops == NULL) {
269 #ifdef CONFIG_MODULES
270 			struct nlattr *kind = tca[TCA_KIND];
271 			char name[IFNAMSIZ];
272 
273 			if (kind != NULL &&
274 			    nla_strlcpy(name, kind, IFNAMSIZ) < IFNAMSIZ) {
275 				rtnl_unlock();
276 				request_module("cls_%s", name);
277 				rtnl_lock();
278 				tp_ops = tcf_proto_lookup_ops(kind);
279 				/* We dropped the RTNL semaphore in order to
280 				 * perform the module load.  So, even if we
281 				 * succeeded in loading the module we have to
282 				 * replay the request.  We indicate this using
283 				 * -EAGAIN.
284 				 */
285 				if (tp_ops != NULL) {
286 					module_put(tp_ops->owner);
287 					err = -EAGAIN;
288 				}
289 			}
290 #endif
291 			kfree(tp);
292 			goto errout;
293 		}
294 		tp->ops = tp_ops;
295 		tp->protocol = protocol;
296 		tp->prio = nprio ? :
297 			       TC_H_MAJ(tcf_auto_prio(rtnl_dereference(*back)));
298 		tp->q = q;
299 		tp->classify = tp_ops->classify;
300 		tp->classid = parent;
301 
302 		err = tp_ops->init(tp);
303 		if (err != 0) {
304 			module_put(tp_ops->owner);
305 			kfree(tp);
306 			goto errout;
307 		}
308 
309 		tp_created = 1;
310 
311 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind))
312 		goto errout;
313 
314 	fh = tp->ops->get(tp, t->tcm_handle);
315 
316 	if (fh == 0) {
317 		if (n->nlmsg_type == RTM_DELTFILTER && t->tcm_handle == 0) {
318 			struct tcf_proto *next = rtnl_dereference(tp->next);
319 
320 			RCU_INIT_POINTER(*back, next);
321 
322 			tfilter_notify(net, skb, n, tp, fh,
323 				       RTM_DELTFILTER, false);
324 			tcf_destroy(tp, true);
325 			err = 0;
326 			goto errout;
327 		}
328 
329 		err = -ENOENT;
330 		if (n->nlmsg_type != RTM_NEWTFILTER ||
331 		    !(n->nlmsg_flags & NLM_F_CREATE))
332 			goto errout;
333 	} else {
334 		switch (n->nlmsg_type) {
335 		case RTM_NEWTFILTER:
336 			err = -EEXIST;
337 			if (n->nlmsg_flags & NLM_F_EXCL) {
338 				if (tp_created)
339 					tcf_destroy(tp, true);
340 				goto errout;
341 			}
342 			break;
343 		case RTM_DELTFILTER:
344 			err = tp->ops->delete(tp, fh);
345 			if (err == 0) {
346 				struct tcf_proto *next = rtnl_dereference(tp->next);
347 
348 				tfilter_notify(net, skb, n, tp,
349 					       t->tcm_handle,
350 					       RTM_DELTFILTER, false);
351 				if (tcf_destroy(tp, false))
352 					RCU_INIT_POINTER(*back, next);
353 			}
354 			goto errout;
355 		case RTM_GETTFILTER:
356 			err = tfilter_notify(net, skb, n, tp, fh,
357 					     RTM_NEWTFILTER, true);
358 			goto errout;
359 		default:
360 			err = -EINVAL;
361 			goto errout;
362 		}
363 	}
364 
365 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
366 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE);
367 	if (err == 0) {
368 		if (tp_created) {
369 			RCU_INIT_POINTER(tp->next, rtnl_dereference(*back));
370 			rcu_assign_pointer(*back, tp);
371 		}
372 		tfilter_notify(net, skb, n, tp, fh, RTM_NEWTFILTER, false);
373 	} else {
374 		if (tp_created)
375 			tcf_destroy(tp, true);
376 	}
377 
378 errout:
379 	if (cl)
380 		cops->put(q, cl);
381 	if (err == -EAGAIN)
382 		/* Replay the request. */
383 		goto replay;
384 	return err;
385 }
386 
387 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
388 			 struct tcf_proto *tp, unsigned long fh, u32 portid,
389 			 u32 seq, u16 flags, int event)
390 {
391 	struct tcmsg *tcm;
392 	struct nlmsghdr  *nlh;
393 	unsigned char *b = skb_tail_pointer(skb);
394 
395 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
396 	if (!nlh)
397 		goto out_nlmsg_trim;
398 	tcm = nlmsg_data(nlh);
399 	tcm->tcm_family = AF_UNSPEC;
400 	tcm->tcm__pad1 = 0;
401 	tcm->tcm__pad2 = 0;
402 	tcm->tcm_ifindex = qdisc_dev(tp->q)->ifindex;
403 	tcm->tcm_parent = tp->classid;
404 	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
405 	if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
406 		goto nla_put_failure;
407 	tcm->tcm_handle = fh;
408 	if (RTM_DELTFILTER != event) {
409 		tcm->tcm_handle = 0;
410 		if (tp->ops->dump && tp->ops->dump(net, tp, fh, skb, tcm) < 0)
411 			goto nla_put_failure;
412 	}
413 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
414 	return skb->len;
415 
416 out_nlmsg_trim:
417 nla_put_failure:
418 	nlmsg_trim(skb, b);
419 	return -1;
420 }
421 
422 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
423 			  struct nlmsghdr *n, struct tcf_proto *tp,
424 			  unsigned long fh, int event, bool unicast)
425 {
426 	struct sk_buff *skb;
427 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
428 
429 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
430 	if (!skb)
431 		return -ENOBUFS;
432 
433 	if (tcf_fill_node(net, skb, tp, fh, portid, n->nlmsg_seq,
434 			  n->nlmsg_flags, event) <= 0) {
435 		kfree_skb(skb);
436 		return -EINVAL;
437 	}
438 
439 	if (unicast)
440 		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
441 
442 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
443 			      n->nlmsg_flags & NLM_F_ECHO);
444 }
445 
446 struct tcf_dump_args {
447 	struct tcf_walker w;
448 	struct sk_buff *skb;
449 	struct netlink_callback *cb;
450 };
451 
452 static int tcf_node_dump(struct tcf_proto *tp, unsigned long n,
453 			 struct tcf_walker *arg)
454 {
455 	struct tcf_dump_args *a = (void *)arg;
456 	struct net *net = sock_net(a->skb->sk);
457 
458 	return tcf_fill_node(net, a->skb, tp, n, NETLINK_CB(a->cb->skb).portid,
459 			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
460 			     RTM_NEWTFILTER);
461 }
462 
463 /* called with RTNL */
464 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
465 {
466 	struct net *net = sock_net(skb->sk);
467 	int t;
468 	int s_t;
469 	struct net_device *dev;
470 	struct Qdisc *q;
471 	struct tcf_proto *tp, __rcu **chain;
472 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
473 	unsigned long cl = 0;
474 	const struct Qdisc_class_ops *cops;
475 	struct tcf_dump_args arg;
476 
477 	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
478 		return skb->len;
479 	dev = __dev_get_by_index(net, tcm->tcm_ifindex);
480 	if (!dev)
481 		return skb->len;
482 
483 	if (!tcm->tcm_parent)
484 		q = dev->qdisc;
485 	else
486 		q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
487 	if (!q)
488 		goto out;
489 	cops = q->ops->cl_ops;
490 	if (!cops)
491 		goto errout;
492 	if (cops->tcf_chain == NULL)
493 		goto errout;
494 	if (TC_H_MIN(tcm->tcm_parent)) {
495 		cl = cops->get(q, tcm->tcm_parent);
496 		if (cl == 0)
497 			goto errout;
498 	}
499 	chain = cops->tcf_chain(q, cl);
500 	if (chain == NULL)
501 		goto errout;
502 
503 	s_t = cb->args[0];
504 
505 	for (tp = rtnl_dereference(*chain), t = 0;
506 	     tp; tp = rtnl_dereference(tp->next), t++) {
507 		if (t < s_t)
508 			continue;
509 		if (TC_H_MAJ(tcm->tcm_info) &&
510 		    TC_H_MAJ(tcm->tcm_info) != tp->prio)
511 			continue;
512 		if (TC_H_MIN(tcm->tcm_info) &&
513 		    TC_H_MIN(tcm->tcm_info) != tp->protocol)
514 			continue;
515 		if (t > s_t)
516 			memset(&cb->args[1], 0,
517 			       sizeof(cb->args)-sizeof(cb->args[0]));
518 		if (cb->args[1] == 0) {
519 			if (tcf_fill_node(net, skb, tp, 0,
520 					  NETLINK_CB(cb->skb).portid,
521 					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
522 					  RTM_NEWTFILTER) <= 0)
523 				break;
524 
525 			cb->args[1] = 1;
526 		}
527 		if (tp->ops->walk == NULL)
528 			continue;
529 		arg.w.fn = tcf_node_dump;
530 		arg.skb = skb;
531 		arg.cb = cb;
532 		arg.w.stop = 0;
533 		arg.w.skip = cb->args[1] - 1;
534 		arg.w.count = 0;
535 		tp->ops->walk(tp, &arg.w);
536 		cb->args[1] = arg.w.count + 1;
537 		if (arg.w.stop)
538 			break;
539 	}
540 
541 	cb->args[0] = t;
542 
543 errout:
544 	if (cl)
545 		cops->put(q, cl);
546 out:
547 	return skb->len;
548 }
549 
550 void tcf_exts_destroy(struct tcf_exts *exts)
551 {
552 #ifdef CONFIG_NET_CLS_ACT
553 	LIST_HEAD(actions);
554 
555 	tcf_exts_to_list(exts, &actions);
556 	tcf_action_destroy(&actions, TCA_ACT_UNBIND);
557 	kfree(exts->actions);
558 	exts->nr_actions = 0;
559 #endif
560 }
561 EXPORT_SYMBOL(tcf_exts_destroy);
562 
563 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
564 		      struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr)
565 {
566 #ifdef CONFIG_NET_CLS_ACT
567 	{
568 		struct tc_action *act;
569 
570 		if (exts->police && tb[exts->police]) {
571 			act = tcf_action_init_1(net, tb[exts->police], rate_tlv,
572 						"police", ovr, TCA_ACT_BIND);
573 			if (IS_ERR(act))
574 				return PTR_ERR(act);
575 
576 			act->type = exts->type = TCA_OLD_COMPAT;
577 			exts->actions[0] = act;
578 			exts->nr_actions = 1;
579 		} else if (exts->action && tb[exts->action]) {
580 			LIST_HEAD(actions);
581 			int err, i = 0;
582 
583 			err = tcf_action_init(net, tb[exts->action], rate_tlv,
584 					      NULL, ovr, TCA_ACT_BIND,
585 					      &actions);
586 			if (err)
587 				return err;
588 			list_for_each_entry(act, &actions, list)
589 				exts->actions[i++] = act;
590 			exts->nr_actions = i;
591 		}
592 	}
593 #else
594 	if ((exts->action && tb[exts->action]) ||
595 	    (exts->police && tb[exts->police]))
596 		return -EOPNOTSUPP;
597 #endif
598 
599 	return 0;
600 }
601 EXPORT_SYMBOL(tcf_exts_validate);
602 
603 void tcf_exts_change(struct tcf_proto *tp, struct tcf_exts *dst,
604 		     struct tcf_exts *src)
605 {
606 #ifdef CONFIG_NET_CLS_ACT
607 	struct tcf_exts old = *dst;
608 
609 	tcf_tree_lock(tp);
610 	dst->nr_actions = src->nr_actions;
611 	dst->actions = src->actions;
612 	dst->type = src->type;
613 	tcf_tree_unlock(tp);
614 
615 	tcf_exts_destroy(&old);
616 #endif
617 }
618 EXPORT_SYMBOL(tcf_exts_change);
619 
620 #ifdef CONFIG_NET_CLS_ACT
621 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
622 {
623 	if (exts->nr_actions == 0)
624 		return NULL;
625 	else
626 		return exts->actions[0];
627 }
628 #endif
629 
630 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
631 {
632 #ifdef CONFIG_NET_CLS_ACT
633 	struct nlattr *nest;
634 
635 	if (exts->action && exts->nr_actions) {
636 		/*
637 		 * again for backward compatible mode - we want
638 		 * to work with both old and new modes of entering
639 		 * tc data even if iproute2  was newer - jhs
640 		 */
641 		if (exts->type != TCA_OLD_COMPAT) {
642 			LIST_HEAD(actions);
643 
644 			nest = nla_nest_start(skb, exts->action);
645 			if (nest == NULL)
646 				goto nla_put_failure;
647 
648 			tcf_exts_to_list(exts, &actions);
649 			if (tcf_action_dump(skb, &actions, 0, 0) < 0)
650 				goto nla_put_failure;
651 			nla_nest_end(skb, nest);
652 		} else if (exts->police) {
653 			struct tc_action *act = tcf_exts_first_act(exts);
654 			nest = nla_nest_start(skb, exts->police);
655 			if (nest == NULL || !act)
656 				goto nla_put_failure;
657 			if (tcf_action_dump_old(skb, act, 0, 0) < 0)
658 				goto nla_put_failure;
659 			nla_nest_end(skb, nest);
660 		}
661 	}
662 	return 0;
663 
664 nla_put_failure:
665 	nla_nest_cancel(skb, nest);
666 	return -1;
667 #else
668 	return 0;
669 #endif
670 }
671 EXPORT_SYMBOL(tcf_exts_dump);
672 
673 
674 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
675 {
676 #ifdef CONFIG_NET_CLS_ACT
677 	struct tc_action *a = tcf_exts_first_act(exts);
678 	if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
679 		return -1;
680 #endif
681 	return 0;
682 }
683 EXPORT_SYMBOL(tcf_exts_dump_stats);
684 
685 int tcf_exts_get_dev(struct net_device *dev, struct tcf_exts *exts,
686 		     struct net_device **hw_dev)
687 {
688 #ifdef CONFIG_NET_CLS_ACT
689 	const struct tc_action *a;
690 	LIST_HEAD(actions);
691 
692 	if (tc_no_actions(exts))
693 		return -EINVAL;
694 
695 	tcf_exts_to_list(exts, &actions);
696 	list_for_each_entry(a, &actions, list) {
697 		if (a->ops->get_dev) {
698 			a->ops->get_dev(a, dev_net(dev), hw_dev);
699 			break;
700 		}
701 	}
702 	if (*hw_dev)
703 		return 0;
704 #endif
705 	return -EOPNOTSUPP;
706 }
707 EXPORT_SYMBOL(tcf_exts_get_dev);
708 
709 static int __init tc_filter_init(void)
710 {
711 	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, NULL);
712 	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, NULL);
713 	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
714 		      tc_dump_tfilter, NULL);
715 
716 	return 0;
717 }
718 
719 subsys_initcall(tc_filter_init);
720