xref: /openbmc/linux/net/sched/cls_api.c (revision a6377d90)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * net/sched/cls_api.c	Packet classifier API.
4  *
5  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
6  *
7  * Changes:
8  *
9  * Eduardo J. Blanco <ejbs@netlabs.com.uy> :990222: kmod support
10  */
11 
12 #include <linux/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/string.h>
16 #include <linux/errno.h>
17 #include <linux/err.h>
18 #include <linux/skbuff.h>
19 #include <linux/init.h>
20 #include <linux/kmod.h>
21 #include <linux/slab.h>
22 #include <linux/idr.h>
23 #include <linux/rhashtable.h>
24 #include <net/net_namespace.h>
25 #include <net/sock.h>
26 #include <net/netlink.h>
27 #include <net/pkt_sched.h>
28 #include <net/pkt_cls.h>
29 #include <net/tc_act/tc_pedit.h>
30 #include <net/tc_act/tc_mirred.h>
31 #include <net/tc_act/tc_vlan.h>
32 #include <net/tc_act/tc_tunnel_key.h>
33 #include <net/tc_act/tc_csum.h>
34 #include <net/tc_act/tc_gact.h>
35 #include <net/tc_act/tc_police.h>
36 #include <net/tc_act/tc_sample.h>
37 #include <net/tc_act/tc_skbedit.h>
38 
39 extern const struct nla_policy rtm_tca_policy[TCA_MAX + 1];
40 
41 /* The list of all installed classifier types */
42 static LIST_HEAD(tcf_proto_base);
43 
44 /* Protects list of registered TC modules. It is pure SMP lock. */
45 static DEFINE_RWLOCK(cls_mod_lock);
46 
47 /* Find classifier type by string name */
48 
49 static const struct tcf_proto_ops *__tcf_proto_lookup_ops(const char *kind)
50 {
51 	const struct tcf_proto_ops *t, *res = NULL;
52 
53 	if (kind) {
54 		read_lock(&cls_mod_lock);
55 		list_for_each_entry(t, &tcf_proto_base, head) {
56 			if (strcmp(kind, t->kind) == 0) {
57 				if (try_module_get(t->owner))
58 					res = t;
59 				break;
60 			}
61 		}
62 		read_unlock(&cls_mod_lock);
63 	}
64 	return res;
65 }
66 
67 static const struct tcf_proto_ops *
68 tcf_proto_lookup_ops(const char *kind, bool rtnl_held,
69 		     struct netlink_ext_ack *extack)
70 {
71 	const struct tcf_proto_ops *ops;
72 
73 	ops = __tcf_proto_lookup_ops(kind);
74 	if (ops)
75 		return ops;
76 #ifdef CONFIG_MODULES
77 	if (rtnl_held)
78 		rtnl_unlock();
79 	request_module("cls_%s", kind);
80 	if (rtnl_held)
81 		rtnl_lock();
82 	ops = __tcf_proto_lookup_ops(kind);
83 	/* We dropped the RTNL semaphore in order to perform
84 	 * the module load. So, even if we succeeded in loading
85 	 * the module we have to replay the request. We indicate
86 	 * this using -EAGAIN.
87 	 */
88 	if (ops) {
89 		module_put(ops->owner);
90 		return ERR_PTR(-EAGAIN);
91 	}
92 #endif
93 	NL_SET_ERR_MSG(extack, "TC classifier not found");
94 	return ERR_PTR(-ENOENT);
95 }
96 
97 /* Register(unregister) new classifier type */
98 
99 int register_tcf_proto_ops(struct tcf_proto_ops *ops)
100 {
101 	struct tcf_proto_ops *t;
102 	int rc = -EEXIST;
103 
104 	write_lock(&cls_mod_lock);
105 	list_for_each_entry(t, &tcf_proto_base, head)
106 		if (!strcmp(ops->kind, t->kind))
107 			goto out;
108 
109 	list_add_tail(&ops->head, &tcf_proto_base);
110 	rc = 0;
111 out:
112 	write_unlock(&cls_mod_lock);
113 	return rc;
114 }
115 EXPORT_SYMBOL(register_tcf_proto_ops);
116 
117 static struct workqueue_struct *tc_filter_wq;
118 
119 int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
120 {
121 	struct tcf_proto_ops *t;
122 	int rc = -ENOENT;
123 
124 	/* Wait for outstanding call_rcu()s, if any, from a
125 	 * tcf_proto_ops's destroy() handler.
126 	 */
127 	rcu_barrier();
128 	flush_workqueue(tc_filter_wq);
129 
130 	write_lock(&cls_mod_lock);
131 	list_for_each_entry(t, &tcf_proto_base, head) {
132 		if (t == ops) {
133 			list_del(&t->head);
134 			rc = 0;
135 			break;
136 		}
137 	}
138 	write_unlock(&cls_mod_lock);
139 	return rc;
140 }
141 EXPORT_SYMBOL(unregister_tcf_proto_ops);
142 
143 bool tcf_queue_work(struct rcu_work *rwork, work_func_t func)
144 {
145 	INIT_RCU_WORK(rwork, func);
146 	return queue_rcu_work(tc_filter_wq, rwork);
147 }
148 EXPORT_SYMBOL(tcf_queue_work);
149 
150 /* Select new prio value from the range, managed by kernel. */
151 
152 static inline u32 tcf_auto_prio(struct tcf_proto *tp)
153 {
154 	u32 first = TC_H_MAKE(0xC0000000U, 0U);
155 
156 	if (tp)
157 		first = tp->prio - 1;
158 
159 	return TC_H_MAJ(first);
160 }
161 
162 static bool tcf_proto_is_unlocked(const char *kind)
163 {
164 	const struct tcf_proto_ops *ops;
165 	bool ret;
166 
167 	ops = tcf_proto_lookup_ops(kind, false, NULL);
168 	/* On error return false to take rtnl lock. Proto lookup/create
169 	 * functions will perform lookup again and properly handle errors.
170 	 */
171 	if (IS_ERR(ops))
172 		return false;
173 
174 	ret = !!(ops->flags & TCF_PROTO_OPS_DOIT_UNLOCKED);
175 	module_put(ops->owner);
176 	return ret;
177 }
178 
179 static struct tcf_proto *tcf_proto_create(const char *kind, u32 protocol,
180 					  u32 prio, struct tcf_chain *chain,
181 					  bool rtnl_held,
182 					  struct netlink_ext_ack *extack)
183 {
184 	struct tcf_proto *tp;
185 	int err;
186 
187 	tp = kzalloc(sizeof(*tp), GFP_KERNEL);
188 	if (!tp)
189 		return ERR_PTR(-ENOBUFS);
190 
191 	tp->ops = tcf_proto_lookup_ops(kind, rtnl_held, extack);
192 	if (IS_ERR(tp->ops)) {
193 		err = PTR_ERR(tp->ops);
194 		goto errout;
195 	}
196 	tp->classify = tp->ops->classify;
197 	tp->protocol = protocol;
198 	tp->prio = prio;
199 	tp->chain = chain;
200 	spin_lock_init(&tp->lock);
201 	refcount_set(&tp->refcnt, 1);
202 
203 	err = tp->ops->init(tp);
204 	if (err) {
205 		module_put(tp->ops->owner);
206 		goto errout;
207 	}
208 	return tp;
209 
210 errout:
211 	kfree(tp);
212 	return ERR_PTR(err);
213 }
214 
215 static void tcf_proto_get(struct tcf_proto *tp)
216 {
217 	refcount_inc(&tp->refcnt);
218 }
219 
220 static void tcf_chain_put(struct tcf_chain *chain);
221 
222 static void tcf_proto_destroy(struct tcf_proto *tp, bool rtnl_held,
223 			      struct netlink_ext_ack *extack)
224 {
225 	tp->ops->destroy(tp, rtnl_held, extack);
226 	tcf_chain_put(tp->chain);
227 	module_put(tp->ops->owner);
228 	kfree_rcu(tp, rcu);
229 }
230 
231 static void tcf_proto_put(struct tcf_proto *tp, bool rtnl_held,
232 			  struct netlink_ext_ack *extack)
233 {
234 	if (refcount_dec_and_test(&tp->refcnt))
235 		tcf_proto_destroy(tp, rtnl_held, extack);
236 }
237 
238 static int walker_check_empty(struct tcf_proto *tp, void *fh,
239 			      struct tcf_walker *arg)
240 {
241 	if (fh) {
242 		arg->nonempty = true;
243 		return -1;
244 	}
245 	return 0;
246 }
247 
248 static bool tcf_proto_is_empty(struct tcf_proto *tp, bool rtnl_held)
249 {
250 	struct tcf_walker walker = { .fn = walker_check_empty, };
251 
252 	if (tp->ops->walk) {
253 		tp->ops->walk(tp, &walker, rtnl_held);
254 		return !walker.nonempty;
255 	}
256 	return true;
257 }
258 
259 static bool tcf_proto_check_delete(struct tcf_proto *tp, bool rtnl_held)
260 {
261 	spin_lock(&tp->lock);
262 	if (tcf_proto_is_empty(tp, rtnl_held))
263 		tp->deleting = true;
264 	spin_unlock(&tp->lock);
265 	return tp->deleting;
266 }
267 
268 static void tcf_proto_mark_delete(struct tcf_proto *tp)
269 {
270 	spin_lock(&tp->lock);
271 	tp->deleting = true;
272 	spin_unlock(&tp->lock);
273 }
274 
275 static bool tcf_proto_is_deleting(struct tcf_proto *tp)
276 {
277 	bool deleting;
278 
279 	spin_lock(&tp->lock);
280 	deleting = tp->deleting;
281 	spin_unlock(&tp->lock);
282 
283 	return deleting;
284 }
285 
286 #define ASSERT_BLOCK_LOCKED(block)					\
287 	lockdep_assert_held(&(block)->lock)
288 
289 struct tcf_filter_chain_list_item {
290 	struct list_head list;
291 	tcf_chain_head_change_t *chain_head_change;
292 	void *chain_head_change_priv;
293 };
294 
295 static struct tcf_chain *tcf_chain_create(struct tcf_block *block,
296 					  u32 chain_index)
297 {
298 	struct tcf_chain *chain;
299 
300 	ASSERT_BLOCK_LOCKED(block);
301 
302 	chain = kzalloc(sizeof(*chain), GFP_KERNEL);
303 	if (!chain)
304 		return NULL;
305 	list_add_tail(&chain->list, &block->chain_list);
306 	mutex_init(&chain->filter_chain_lock);
307 	chain->block = block;
308 	chain->index = chain_index;
309 	chain->refcnt = 1;
310 	if (!chain->index)
311 		block->chain0.chain = chain;
312 	return chain;
313 }
314 
315 static void tcf_chain_head_change_item(struct tcf_filter_chain_list_item *item,
316 				       struct tcf_proto *tp_head)
317 {
318 	if (item->chain_head_change)
319 		item->chain_head_change(tp_head, item->chain_head_change_priv);
320 }
321 
322 static void tcf_chain0_head_change(struct tcf_chain *chain,
323 				   struct tcf_proto *tp_head)
324 {
325 	struct tcf_filter_chain_list_item *item;
326 	struct tcf_block *block = chain->block;
327 
328 	if (chain->index)
329 		return;
330 
331 	mutex_lock(&block->lock);
332 	list_for_each_entry(item, &block->chain0.filter_chain_list, list)
333 		tcf_chain_head_change_item(item, tp_head);
334 	mutex_unlock(&block->lock);
335 }
336 
337 /* Returns true if block can be safely freed. */
338 
339 static bool tcf_chain_detach(struct tcf_chain *chain)
340 {
341 	struct tcf_block *block = chain->block;
342 
343 	ASSERT_BLOCK_LOCKED(block);
344 
345 	list_del(&chain->list);
346 	if (!chain->index)
347 		block->chain0.chain = NULL;
348 
349 	if (list_empty(&block->chain_list) &&
350 	    refcount_read(&block->refcnt) == 0)
351 		return true;
352 
353 	return false;
354 }
355 
356 static void tcf_block_destroy(struct tcf_block *block)
357 {
358 	mutex_destroy(&block->lock);
359 	kfree_rcu(block, rcu);
360 }
361 
362 static void tcf_chain_destroy(struct tcf_chain *chain, bool free_block)
363 {
364 	struct tcf_block *block = chain->block;
365 
366 	mutex_destroy(&chain->filter_chain_lock);
367 	kfree_rcu(chain, rcu);
368 	if (free_block)
369 		tcf_block_destroy(block);
370 }
371 
372 static void tcf_chain_hold(struct tcf_chain *chain)
373 {
374 	ASSERT_BLOCK_LOCKED(chain->block);
375 
376 	++chain->refcnt;
377 }
378 
379 static bool tcf_chain_held_by_acts_only(struct tcf_chain *chain)
380 {
381 	ASSERT_BLOCK_LOCKED(chain->block);
382 
383 	/* In case all the references are action references, this
384 	 * chain should not be shown to the user.
385 	 */
386 	return chain->refcnt == chain->action_refcnt;
387 }
388 
389 static struct tcf_chain *tcf_chain_lookup(struct tcf_block *block,
390 					  u32 chain_index)
391 {
392 	struct tcf_chain *chain;
393 
394 	ASSERT_BLOCK_LOCKED(block);
395 
396 	list_for_each_entry(chain, &block->chain_list, list) {
397 		if (chain->index == chain_index)
398 			return chain;
399 	}
400 	return NULL;
401 }
402 
403 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
404 			   u32 seq, u16 flags, int event, bool unicast);
405 
406 static struct tcf_chain *__tcf_chain_get(struct tcf_block *block,
407 					 u32 chain_index, bool create,
408 					 bool by_act)
409 {
410 	struct tcf_chain *chain = NULL;
411 	bool is_first_reference;
412 
413 	mutex_lock(&block->lock);
414 	chain = tcf_chain_lookup(block, chain_index);
415 	if (chain) {
416 		tcf_chain_hold(chain);
417 	} else {
418 		if (!create)
419 			goto errout;
420 		chain = tcf_chain_create(block, chain_index);
421 		if (!chain)
422 			goto errout;
423 	}
424 
425 	if (by_act)
426 		++chain->action_refcnt;
427 	is_first_reference = chain->refcnt - chain->action_refcnt == 1;
428 	mutex_unlock(&block->lock);
429 
430 	/* Send notification only in case we got the first
431 	 * non-action reference. Until then, the chain acts only as
432 	 * a placeholder for actions pointing to it and user ought
433 	 * not know about them.
434 	 */
435 	if (is_first_reference && !by_act)
436 		tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
437 				RTM_NEWCHAIN, false);
438 
439 	return chain;
440 
441 errout:
442 	mutex_unlock(&block->lock);
443 	return chain;
444 }
445 
446 static struct tcf_chain *tcf_chain_get(struct tcf_block *block, u32 chain_index,
447 				       bool create)
448 {
449 	return __tcf_chain_get(block, chain_index, create, false);
450 }
451 
452 struct tcf_chain *tcf_chain_get_by_act(struct tcf_block *block, u32 chain_index)
453 {
454 	return __tcf_chain_get(block, chain_index, true, true);
455 }
456 EXPORT_SYMBOL(tcf_chain_get_by_act);
457 
458 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
459 			       void *tmplt_priv);
460 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
461 				  void *tmplt_priv, u32 chain_index,
462 				  struct tcf_block *block, struct sk_buff *oskb,
463 				  u32 seq, u16 flags, bool unicast);
464 
465 static void __tcf_chain_put(struct tcf_chain *chain, bool by_act,
466 			    bool explicitly_created)
467 {
468 	struct tcf_block *block = chain->block;
469 	const struct tcf_proto_ops *tmplt_ops;
470 	bool free_block = false;
471 	unsigned int refcnt;
472 	void *tmplt_priv;
473 
474 	mutex_lock(&block->lock);
475 	if (explicitly_created) {
476 		if (!chain->explicitly_created) {
477 			mutex_unlock(&block->lock);
478 			return;
479 		}
480 		chain->explicitly_created = false;
481 	}
482 
483 	if (by_act)
484 		chain->action_refcnt--;
485 
486 	/* tc_chain_notify_delete can't be called while holding block lock.
487 	 * However, when block is unlocked chain can be changed concurrently, so
488 	 * save these to temporary variables.
489 	 */
490 	refcnt = --chain->refcnt;
491 	tmplt_ops = chain->tmplt_ops;
492 	tmplt_priv = chain->tmplt_priv;
493 
494 	/* The last dropped non-action reference will trigger notification. */
495 	if (refcnt - chain->action_refcnt == 0 && !by_act) {
496 		tc_chain_notify_delete(tmplt_ops, tmplt_priv, chain->index,
497 				       block, NULL, 0, 0, false);
498 		/* Last reference to chain, no need to lock. */
499 		chain->flushing = false;
500 	}
501 
502 	if (refcnt == 0)
503 		free_block = tcf_chain_detach(chain);
504 	mutex_unlock(&block->lock);
505 
506 	if (refcnt == 0) {
507 		tc_chain_tmplt_del(tmplt_ops, tmplt_priv);
508 		tcf_chain_destroy(chain, free_block);
509 	}
510 }
511 
512 static void tcf_chain_put(struct tcf_chain *chain)
513 {
514 	__tcf_chain_put(chain, false, false);
515 }
516 
517 void tcf_chain_put_by_act(struct tcf_chain *chain)
518 {
519 	__tcf_chain_put(chain, true, false);
520 }
521 EXPORT_SYMBOL(tcf_chain_put_by_act);
522 
523 static void tcf_chain_put_explicitly_created(struct tcf_chain *chain)
524 {
525 	__tcf_chain_put(chain, false, true);
526 }
527 
528 static void tcf_chain_flush(struct tcf_chain *chain, bool rtnl_held)
529 {
530 	struct tcf_proto *tp, *tp_next;
531 
532 	mutex_lock(&chain->filter_chain_lock);
533 	tp = tcf_chain_dereference(chain->filter_chain, chain);
534 	RCU_INIT_POINTER(chain->filter_chain, NULL);
535 	tcf_chain0_head_change(chain, NULL);
536 	chain->flushing = true;
537 	mutex_unlock(&chain->filter_chain_lock);
538 
539 	while (tp) {
540 		tp_next = rcu_dereference_protected(tp->next, 1);
541 		tcf_proto_put(tp, rtnl_held, NULL);
542 		tp = tp_next;
543 	}
544 }
545 
546 static struct tcf_block *tc_dev_ingress_block(struct net_device *dev)
547 {
548 	const struct Qdisc_class_ops *cops;
549 	struct Qdisc *qdisc;
550 
551 	if (!dev_ingress_queue(dev))
552 		return NULL;
553 
554 	qdisc = dev_ingress_queue(dev)->qdisc_sleeping;
555 	if (!qdisc)
556 		return NULL;
557 
558 	cops = qdisc->ops->cl_ops;
559 	if (!cops)
560 		return NULL;
561 
562 	if (!cops->tcf_block)
563 		return NULL;
564 
565 	return cops->tcf_block(qdisc, TC_H_MIN_INGRESS, NULL);
566 }
567 
568 static struct rhashtable indr_setup_block_ht;
569 
570 struct tc_indr_block_dev {
571 	struct rhash_head ht_node;
572 	struct net_device *dev;
573 	unsigned int refcnt;
574 	struct list_head cb_list;
575 	struct tcf_block *block;
576 };
577 
578 struct tc_indr_block_cb {
579 	struct list_head list;
580 	void *cb_priv;
581 	tc_indr_block_bind_cb_t *cb;
582 	void *cb_ident;
583 };
584 
585 static const struct rhashtable_params tc_indr_setup_block_ht_params = {
586 	.key_offset	= offsetof(struct tc_indr_block_dev, dev),
587 	.head_offset	= offsetof(struct tc_indr_block_dev, ht_node),
588 	.key_len	= sizeof(struct net_device *),
589 };
590 
591 static struct tc_indr_block_dev *
592 tc_indr_block_dev_lookup(struct net_device *dev)
593 {
594 	return rhashtable_lookup_fast(&indr_setup_block_ht, &dev,
595 				      tc_indr_setup_block_ht_params);
596 }
597 
598 static struct tc_indr_block_dev *tc_indr_block_dev_get(struct net_device *dev)
599 {
600 	struct tc_indr_block_dev *indr_dev;
601 
602 	indr_dev = tc_indr_block_dev_lookup(dev);
603 	if (indr_dev)
604 		goto inc_ref;
605 
606 	indr_dev = kzalloc(sizeof(*indr_dev), GFP_KERNEL);
607 	if (!indr_dev)
608 		return NULL;
609 
610 	INIT_LIST_HEAD(&indr_dev->cb_list);
611 	indr_dev->dev = dev;
612 	indr_dev->block = tc_dev_ingress_block(dev);
613 	if (rhashtable_insert_fast(&indr_setup_block_ht, &indr_dev->ht_node,
614 				   tc_indr_setup_block_ht_params)) {
615 		kfree(indr_dev);
616 		return NULL;
617 	}
618 
619 inc_ref:
620 	indr_dev->refcnt++;
621 	return indr_dev;
622 }
623 
624 static void tc_indr_block_dev_put(struct tc_indr_block_dev *indr_dev)
625 {
626 	if (--indr_dev->refcnt)
627 		return;
628 
629 	rhashtable_remove_fast(&indr_setup_block_ht, &indr_dev->ht_node,
630 			       tc_indr_setup_block_ht_params);
631 	kfree(indr_dev);
632 }
633 
634 static struct tc_indr_block_cb *
635 tc_indr_block_cb_lookup(struct tc_indr_block_dev *indr_dev,
636 			tc_indr_block_bind_cb_t *cb, void *cb_ident)
637 {
638 	struct tc_indr_block_cb *indr_block_cb;
639 
640 	list_for_each_entry(indr_block_cb, &indr_dev->cb_list, list)
641 		if (indr_block_cb->cb == cb &&
642 		    indr_block_cb->cb_ident == cb_ident)
643 			return indr_block_cb;
644 	return NULL;
645 }
646 
647 static struct tc_indr_block_cb *
648 tc_indr_block_cb_add(struct tc_indr_block_dev *indr_dev, void *cb_priv,
649 		     tc_indr_block_bind_cb_t *cb, void *cb_ident)
650 {
651 	struct tc_indr_block_cb *indr_block_cb;
652 
653 	indr_block_cb = tc_indr_block_cb_lookup(indr_dev, cb, cb_ident);
654 	if (indr_block_cb)
655 		return ERR_PTR(-EEXIST);
656 
657 	indr_block_cb = kzalloc(sizeof(*indr_block_cb), GFP_KERNEL);
658 	if (!indr_block_cb)
659 		return ERR_PTR(-ENOMEM);
660 
661 	indr_block_cb->cb_priv = cb_priv;
662 	indr_block_cb->cb = cb;
663 	indr_block_cb->cb_ident = cb_ident;
664 	list_add(&indr_block_cb->list, &indr_dev->cb_list);
665 
666 	return indr_block_cb;
667 }
668 
669 static void tc_indr_block_cb_del(struct tc_indr_block_cb *indr_block_cb)
670 {
671 	list_del(&indr_block_cb->list);
672 	kfree(indr_block_cb);
673 }
674 
675 static void tc_indr_block_ing_cmd(struct tc_indr_block_dev *indr_dev,
676 				  struct tc_indr_block_cb *indr_block_cb,
677 				  enum tc_block_command command)
678 {
679 	struct tc_block_offload bo = {
680 		.command	= command,
681 		.binder_type	= TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS,
682 		.block		= indr_dev->block,
683 	};
684 
685 	if (!indr_dev->block)
686 		return;
687 
688 	indr_block_cb->cb(indr_dev->dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK,
689 			  &bo);
690 }
691 
692 int __tc_indr_block_cb_register(struct net_device *dev, void *cb_priv,
693 				tc_indr_block_bind_cb_t *cb, void *cb_ident)
694 {
695 	struct tc_indr_block_cb *indr_block_cb;
696 	struct tc_indr_block_dev *indr_dev;
697 	int err;
698 
699 	indr_dev = tc_indr_block_dev_get(dev);
700 	if (!indr_dev)
701 		return -ENOMEM;
702 
703 	indr_block_cb = tc_indr_block_cb_add(indr_dev, cb_priv, cb, cb_ident);
704 	err = PTR_ERR_OR_ZERO(indr_block_cb);
705 	if (err)
706 		goto err_dev_put;
707 
708 	tc_indr_block_ing_cmd(indr_dev, indr_block_cb, TC_BLOCK_BIND);
709 	return 0;
710 
711 err_dev_put:
712 	tc_indr_block_dev_put(indr_dev);
713 	return err;
714 }
715 EXPORT_SYMBOL_GPL(__tc_indr_block_cb_register);
716 
717 int tc_indr_block_cb_register(struct net_device *dev, void *cb_priv,
718 			      tc_indr_block_bind_cb_t *cb, void *cb_ident)
719 {
720 	int err;
721 
722 	rtnl_lock();
723 	err = __tc_indr_block_cb_register(dev, cb_priv, cb, cb_ident);
724 	rtnl_unlock();
725 
726 	return err;
727 }
728 EXPORT_SYMBOL_GPL(tc_indr_block_cb_register);
729 
730 void __tc_indr_block_cb_unregister(struct net_device *dev,
731 				   tc_indr_block_bind_cb_t *cb, void *cb_ident)
732 {
733 	struct tc_indr_block_cb *indr_block_cb;
734 	struct tc_indr_block_dev *indr_dev;
735 
736 	indr_dev = tc_indr_block_dev_lookup(dev);
737 	if (!indr_dev)
738 		return;
739 
740 	indr_block_cb = tc_indr_block_cb_lookup(indr_dev, cb, cb_ident);
741 	if (!indr_block_cb)
742 		return;
743 
744 	/* Send unbind message if required to free any block cbs. */
745 	tc_indr_block_ing_cmd(indr_dev, indr_block_cb, TC_BLOCK_UNBIND);
746 	tc_indr_block_cb_del(indr_block_cb);
747 	tc_indr_block_dev_put(indr_dev);
748 }
749 EXPORT_SYMBOL_GPL(__tc_indr_block_cb_unregister);
750 
751 void tc_indr_block_cb_unregister(struct net_device *dev,
752 				 tc_indr_block_bind_cb_t *cb, void *cb_ident)
753 {
754 	rtnl_lock();
755 	__tc_indr_block_cb_unregister(dev, cb, cb_ident);
756 	rtnl_unlock();
757 }
758 EXPORT_SYMBOL_GPL(tc_indr_block_cb_unregister);
759 
760 static void tc_indr_block_call(struct tcf_block *block, struct net_device *dev,
761 			       struct tcf_block_ext_info *ei,
762 			       enum tc_block_command command,
763 			       struct netlink_ext_ack *extack)
764 {
765 	struct tc_indr_block_cb *indr_block_cb;
766 	struct tc_indr_block_dev *indr_dev;
767 	struct tc_block_offload bo = {
768 		.command	= command,
769 		.binder_type	= ei->binder_type,
770 		.block		= block,
771 		.extack		= extack,
772 	};
773 
774 	indr_dev = tc_indr_block_dev_lookup(dev);
775 	if (!indr_dev)
776 		return;
777 
778 	indr_dev->block = command == TC_BLOCK_BIND ? block : NULL;
779 
780 	list_for_each_entry(indr_block_cb, &indr_dev->cb_list, list)
781 		indr_block_cb->cb(dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK,
782 				  &bo);
783 }
784 
785 static bool tcf_block_offload_in_use(struct tcf_block *block)
786 {
787 	return block->offloadcnt;
788 }
789 
790 static int tcf_block_offload_cmd(struct tcf_block *block,
791 				 struct net_device *dev,
792 				 struct tcf_block_ext_info *ei,
793 				 enum tc_block_command command,
794 				 struct netlink_ext_ack *extack)
795 {
796 	struct tc_block_offload bo = {};
797 
798 	bo.command = command;
799 	bo.binder_type = ei->binder_type;
800 	bo.block = block;
801 	bo.extack = extack;
802 	return dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_BLOCK, &bo);
803 }
804 
805 static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
806 				  struct tcf_block_ext_info *ei,
807 				  struct netlink_ext_ack *extack)
808 {
809 	struct net_device *dev = q->dev_queue->dev;
810 	int err;
811 
812 	if (!dev->netdev_ops->ndo_setup_tc)
813 		goto no_offload_dev_inc;
814 
815 	/* If tc offload feature is disabled and the block we try to bind
816 	 * to already has some offloaded filters, forbid to bind.
817 	 */
818 	if (!tc_can_offload(dev) && tcf_block_offload_in_use(block)) {
819 		NL_SET_ERR_MSG(extack, "Bind to offloaded block failed as dev has offload disabled");
820 		return -EOPNOTSUPP;
821 	}
822 
823 	err = tcf_block_offload_cmd(block, dev, ei, TC_BLOCK_BIND, extack);
824 	if (err == -EOPNOTSUPP)
825 		goto no_offload_dev_inc;
826 	if (err)
827 		return err;
828 
829 	tc_indr_block_call(block, dev, ei, TC_BLOCK_BIND, extack);
830 	return 0;
831 
832 no_offload_dev_inc:
833 	if (tcf_block_offload_in_use(block))
834 		return -EOPNOTSUPP;
835 	block->nooffloaddevcnt++;
836 	tc_indr_block_call(block, dev, ei, TC_BLOCK_BIND, extack);
837 	return 0;
838 }
839 
840 static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
841 				     struct tcf_block_ext_info *ei)
842 {
843 	struct net_device *dev = q->dev_queue->dev;
844 	int err;
845 
846 	tc_indr_block_call(block, dev, ei, TC_BLOCK_UNBIND, NULL);
847 
848 	if (!dev->netdev_ops->ndo_setup_tc)
849 		goto no_offload_dev_dec;
850 	err = tcf_block_offload_cmd(block, dev, ei, TC_BLOCK_UNBIND, NULL);
851 	if (err == -EOPNOTSUPP)
852 		goto no_offload_dev_dec;
853 	return;
854 
855 no_offload_dev_dec:
856 	WARN_ON(block->nooffloaddevcnt-- == 0);
857 }
858 
859 static int
860 tcf_chain0_head_change_cb_add(struct tcf_block *block,
861 			      struct tcf_block_ext_info *ei,
862 			      struct netlink_ext_ack *extack)
863 {
864 	struct tcf_filter_chain_list_item *item;
865 	struct tcf_chain *chain0;
866 
867 	item = kmalloc(sizeof(*item), GFP_KERNEL);
868 	if (!item) {
869 		NL_SET_ERR_MSG(extack, "Memory allocation for head change callback item failed");
870 		return -ENOMEM;
871 	}
872 	item->chain_head_change = ei->chain_head_change;
873 	item->chain_head_change_priv = ei->chain_head_change_priv;
874 
875 	mutex_lock(&block->lock);
876 	chain0 = block->chain0.chain;
877 	if (chain0)
878 		tcf_chain_hold(chain0);
879 	else
880 		list_add(&item->list, &block->chain0.filter_chain_list);
881 	mutex_unlock(&block->lock);
882 
883 	if (chain0) {
884 		struct tcf_proto *tp_head;
885 
886 		mutex_lock(&chain0->filter_chain_lock);
887 
888 		tp_head = tcf_chain_dereference(chain0->filter_chain, chain0);
889 		if (tp_head)
890 			tcf_chain_head_change_item(item, tp_head);
891 
892 		mutex_lock(&block->lock);
893 		list_add(&item->list, &block->chain0.filter_chain_list);
894 		mutex_unlock(&block->lock);
895 
896 		mutex_unlock(&chain0->filter_chain_lock);
897 		tcf_chain_put(chain0);
898 	}
899 
900 	return 0;
901 }
902 
903 static void
904 tcf_chain0_head_change_cb_del(struct tcf_block *block,
905 			      struct tcf_block_ext_info *ei)
906 {
907 	struct tcf_filter_chain_list_item *item;
908 
909 	mutex_lock(&block->lock);
910 	list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
911 		if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
912 		    (item->chain_head_change == ei->chain_head_change &&
913 		     item->chain_head_change_priv == ei->chain_head_change_priv)) {
914 			if (block->chain0.chain)
915 				tcf_chain_head_change_item(item, NULL);
916 			list_del(&item->list);
917 			mutex_unlock(&block->lock);
918 
919 			kfree(item);
920 			return;
921 		}
922 	}
923 	mutex_unlock(&block->lock);
924 	WARN_ON(1);
925 }
926 
927 struct tcf_net {
928 	spinlock_t idr_lock; /* Protects idr */
929 	struct idr idr;
930 };
931 
932 static unsigned int tcf_net_id;
933 
934 static int tcf_block_insert(struct tcf_block *block, struct net *net,
935 			    struct netlink_ext_ack *extack)
936 {
937 	struct tcf_net *tn = net_generic(net, tcf_net_id);
938 	int err;
939 
940 	idr_preload(GFP_KERNEL);
941 	spin_lock(&tn->idr_lock);
942 	err = idr_alloc_u32(&tn->idr, block, &block->index, block->index,
943 			    GFP_NOWAIT);
944 	spin_unlock(&tn->idr_lock);
945 	idr_preload_end();
946 
947 	return err;
948 }
949 
950 static void tcf_block_remove(struct tcf_block *block, struct net *net)
951 {
952 	struct tcf_net *tn = net_generic(net, tcf_net_id);
953 
954 	spin_lock(&tn->idr_lock);
955 	idr_remove(&tn->idr, block->index);
956 	spin_unlock(&tn->idr_lock);
957 }
958 
959 static struct tcf_block *tcf_block_create(struct net *net, struct Qdisc *q,
960 					  u32 block_index,
961 					  struct netlink_ext_ack *extack)
962 {
963 	struct tcf_block *block;
964 
965 	block = kzalloc(sizeof(*block), GFP_KERNEL);
966 	if (!block) {
967 		NL_SET_ERR_MSG(extack, "Memory allocation for block failed");
968 		return ERR_PTR(-ENOMEM);
969 	}
970 	mutex_init(&block->lock);
971 	INIT_LIST_HEAD(&block->chain_list);
972 	INIT_LIST_HEAD(&block->cb_list);
973 	INIT_LIST_HEAD(&block->owner_list);
974 	INIT_LIST_HEAD(&block->chain0.filter_chain_list);
975 
976 	refcount_set(&block->refcnt, 1);
977 	block->net = net;
978 	block->index = block_index;
979 
980 	/* Don't store q pointer for blocks which are shared */
981 	if (!tcf_block_shared(block))
982 		block->q = q;
983 	return block;
984 }
985 
986 static struct tcf_block *tcf_block_lookup(struct net *net, u32 block_index)
987 {
988 	struct tcf_net *tn = net_generic(net, tcf_net_id);
989 
990 	return idr_find(&tn->idr, block_index);
991 }
992 
993 static struct tcf_block *tcf_block_refcnt_get(struct net *net, u32 block_index)
994 {
995 	struct tcf_block *block;
996 
997 	rcu_read_lock();
998 	block = tcf_block_lookup(net, block_index);
999 	if (block && !refcount_inc_not_zero(&block->refcnt))
1000 		block = NULL;
1001 	rcu_read_unlock();
1002 
1003 	return block;
1004 }
1005 
1006 static struct tcf_chain *
1007 __tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1008 {
1009 	mutex_lock(&block->lock);
1010 	if (chain)
1011 		chain = list_is_last(&chain->list, &block->chain_list) ?
1012 			NULL : list_next_entry(chain, list);
1013 	else
1014 		chain = list_first_entry_or_null(&block->chain_list,
1015 						 struct tcf_chain, list);
1016 
1017 	/* skip all action-only chains */
1018 	while (chain && tcf_chain_held_by_acts_only(chain))
1019 		chain = list_is_last(&chain->list, &block->chain_list) ?
1020 			NULL : list_next_entry(chain, list);
1021 
1022 	if (chain)
1023 		tcf_chain_hold(chain);
1024 	mutex_unlock(&block->lock);
1025 
1026 	return chain;
1027 }
1028 
1029 /* Function to be used by all clients that want to iterate over all chains on
1030  * block. It properly obtains block->lock and takes reference to chain before
1031  * returning it. Users of this function must be tolerant to concurrent chain
1032  * insertion/deletion or ensure that no concurrent chain modification is
1033  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1034  * consistent dump because rtnl lock is released each time skb is filled with
1035  * data and sent to user-space.
1036  */
1037 
1038 struct tcf_chain *
1039 tcf_get_next_chain(struct tcf_block *block, struct tcf_chain *chain)
1040 {
1041 	struct tcf_chain *chain_next = __tcf_get_next_chain(block, chain);
1042 
1043 	if (chain)
1044 		tcf_chain_put(chain);
1045 
1046 	return chain_next;
1047 }
1048 EXPORT_SYMBOL(tcf_get_next_chain);
1049 
1050 static struct tcf_proto *
1051 __tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp)
1052 {
1053 	u32 prio = 0;
1054 
1055 	ASSERT_RTNL();
1056 	mutex_lock(&chain->filter_chain_lock);
1057 
1058 	if (!tp) {
1059 		tp = tcf_chain_dereference(chain->filter_chain, chain);
1060 	} else if (tcf_proto_is_deleting(tp)) {
1061 		/* 'deleting' flag is set and chain->filter_chain_lock was
1062 		 * unlocked, which means next pointer could be invalid. Restart
1063 		 * search.
1064 		 */
1065 		prio = tp->prio + 1;
1066 		tp = tcf_chain_dereference(chain->filter_chain, chain);
1067 
1068 		for (; tp; tp = tcf_chain_dereference(tp->next, chain))
1069 			if (!tp->deleting && tp->prio >= prio)
1070 				break;
1071 	} else {
1072 		tp = tcf_chain_dereference(tp->next, chain);
1073 	}
1074 
1075 	if (tp)
1076 		tcf_proto_get(tp);
1077 
1078 	mutex_unlock(&chain->filter_chain_lock);
1079 
1080 	return tp;
1081 }
1082 
1083 /* Function to be used by all clients that want to iterate over all tp's on
1084  * chain. Users of this function must be tolerant to concurrent tp
1085  * insertion/deletion or ensure that no concurrent chain modification is
1086  * possible. Note that all netlink dump callbacks cannot guarantee to provide
1087  * consistent dump because rtnl lock is released each time skb is filled with
1088  * data and sent to user-space.
1089  */
1090 
1091 struct tcf_proto *
1092 tcf_get_next_proto(struct tcf_chain *chain, struct tcf_proto *tp,
1093 		   bool rtnl_held)
1094 {
1095 	struct tcf_proto *tp_next = __tcf_get_next_proto(chain, tp);
1096 
1097 	if (tp)
1098 		tcf_proto_put(tp, rtnl_held, NULL);
1099 
1100 	return tp_next;
1101 }
1102 EXPORT_SYMBOL(tcf_get_next_proto);
1103 
1104 static void tcf_block_flush_all_chains(struct tcf_block *block, bool rtnl_held)
1105 {
1106 	struct tcf_chain *chain;
1107 
1108 	/* Last reference to block. At this point chains cannot be added or
1109 	 * removed concurrently.
1110 	 */
1111 	for (chain = tcf_get_next_chain(block, NULL);
1112 	     chain;
1113 	     chain = tcf_get_next_chain(block, chain)) {
1114 		tcf_chain_put_explicitly_created(chain);
1115 		tcf_chain_flush(chain, rtnl_held);
1116 	}
1117 }
1118 
1119 /* Lookup Qdisc and increments its reference counter.
1120  * Set parent, if necessary.
1121  */
1122 
1123 static int __tcf_qdisc_find(struct net *net, struct Qdisc **q,
1124 			    u32 *parent, int ifindex, bool rtnl_held,
1125 			    struct netlink_ext_ack *extack)
1126 {
1127 	const struct Qdisc_class_ops *cops;
1128 	struct net_device *dev;
1129 	int err = 0;
1130 
1131 	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1132 		return 0;
1133 
1134 	rcu_read_lock();
1135 
1136 	/* Find link */
1137 	dev = dev_get_by_index_rcu(net, ifindex);
1138 	if (!dev) {
1139 		rcu_read_unlock();
1140 		return -ENODEV;
1141 	}
1142 
1143 	/* Find qdisc */
1144 	if (!*parent) {
1145 		*q = dev->qdisc;
1146 		*parent = (*q)->handle;
1147 	} else {
1148 		*q = qdisc_lookup_rcu(dev, TC_H_MAJ(*parent));
1149 		if (!*q) {
1150 			NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1151 			err = -EINVAL;
1152 			goto errout_rcu;
1153 		}
1154 	}
1155 
1156 	*q = qdisc_refcount_inc_nz(*q);
1157 	if (!*q) {
1158 		NL_SET_ERR_MSG(extack, "Parent Qdisc doesn't exists");
1159 		err = -EINVAL;
1160 		goto errout_rcu;
1161 	}
1162 
1163 	/* Is it classful? */
1164 	cops = (*q)->ops->cl_ops;
1165 	if (!cops) {
1166 		NL_SET_ERR_MSG(extack, "Qdisc not classful");
1167 		err = -EINVAL;
1168 		goto errout_qdisc;
1169 	}
1170 
1171 	if (!cops->tcf_block) {
1172 		NL_SET_ERR_MSG(extack, "Class doesn't support blocks");
1173 		err = -EOPNOTSUPP;
1174 		goto errout_qdisc;
1175 	}
1176 
1177 errout_rcu:
1178 	/* At this point we know that qdisc is not noop_qdisc,
1179 	 * which means that qdisc holds a reference to net_device
1180 	 * and we hold a reference to qdisc, so it is safe to release
1181 	 * rcu read lock.
1182 	 */
1183 	rcu_read_unlock();
1184 	return err;
1185 
1186 errout_qdisc:
1187 	rcu_read_unlock();
1188 
1189 	if (rtnl_held)
1190 		qdisc_put(*q);
1191 	else
1192 		qdisc_put_unlocked(*q);
1193 	*q = NULL;
1194 
1195 	return err;
1196 }
1197 
1198 static int __tcf_qdisc_cl_find(struct Qdisc *q, u32 parent, unsigned long *cl,
1199 			       int ifindex, struct netlink_ext_ack *extack)
1200 {
1201 	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK)
1202 		return 0;
1203 
1204 	/* Do we search for filter, attached to class? */
1205 	if (TC_H_MIN(parent)) {
1206 		const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1207 
1208 		*cl = cops->find(q, parent);
1209 		if (*cl == 0) {
1210 			NL_SET_ERR_MSG(extack, "Specified class doesn't exist");
1211 			return -ENOENT;
1212 		}
1213 	}
1214 
1215 	return 0;
1216 }
1217 
1218 static struct tcf_block *__tcf_block_find(struct net *net, struct Qdisc *q,
1219 					  unsigned long cl, int ifindex,
1220 					  u32 block_index,
1221 					  struct netlink_ext_ack *extack)
1222 {
1223 	struct tcf_block *block;
1224 
1225 	if (ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
1226 		block = tcf_block_refcnt_get(net, block_index);
1227 		if (!block) {
1228 			NL_SET_ERR_MSG(extack, "Block of given index was not found");
1229 			return ERR_PTR(-EINVAL);
1230 		}
1231 	} else {
1232 		const struct Qdisc_class_ops *cops = q->ops->cl_ops;
1233 
1234 		block = cops->tcf_block(q, cl, extack);
1235 		if (!block)
1236 			return ERR_PTR(-EINVAL);
1237 
1238 		if (tcf_block_shared(block)) {
1239 			NL_SET_ERR_MSG(extack, "This filter block is shared. Please use the block index to manipulate the filters");
1240 			return ERR_PTR(-EOPNOTSUPP);
1241 		}
1242 
1243 		/* Always take reference to block in order to support execution
1244 		 * of rules update path of cls API without rtnl lock. Caller
1245 		 * must release block when it is finished using it. 'if' block
1246 		 * of this conditional obtain reference to block by calling
1247 		 * tcf_block_refcnt_get().
1248 		 */
1249 		refcount_inc(&block->refcnt);
1250 	}
1251 
1252 	return block;
1253 }
1254 
1255 static void __tcf_block_put(struct tcf_block *block, struct Qdisc *q,
1256 			    struct tcf_block_ext_info *ei, bool rtnl_held)
1257 {
1258 	if (refcount_dec_and_mutex_lock(&block->refcnt, &block->lock)) {
1259 		/* Flushing/putting all chains will cause the block to be
1260 		 * deallocated when last chain is freed. However, if chain_list
1261 		 * is empty, block has to be manually deallocated. After block
1262 		 * reference counter reached 0, it is no longer possible to
1263 		 * increment it or add new chains to block.
1264 		 */
1265 		bool free_block = list_empty(&block->chain_list);
1266 
1267 		mutex_unlock(&block->lock);
1268 		if (tcf_block_shared(block))
1269 			tcf_block_remove(block, block->net);
1270 
1271 		if (q)
1272 			tcf_block_offload_unbind(block, q, ei);
1273 
1274 		if (free_block)
1275 			tcf_block_destroy(block);
1276 		else
1277 			tcf_block_flush_all_chains(block, rtnl_held);
1278 	} else if (q) {
1279 		tcf_block_offload_unbind(block, q, ei);
1280 	}
1281 }
1282 
1283 static void tcf_block_refcnt_put(struct tcf_block *block, bool rtnl_held)
1284 {
1285 	__tcf_block_put(block, NULL, NULL, rtnl_held);
1286 }
1287 
1288 /* Find tcf block.
1289  * Set q, parent, cl when appropriate.
1290  */
1291 
1292 static struct tcf_block *tcf_block_find(struct net *net, struct Qdisc **q,
1293 					u32 *parent, unsigned long *cl,
1294 					int ifindex, u32 block_index,
1295 					struct netlink_ext_ack *extack)
1296 {
1297 	struct tcf_block *block;
1298 	int err = 0;
1299 
1300 	ASSERT_RTNL();
1301 
1302 	err = __tcf_qdisc_find(net, q, parent, ifindex, true, extack);
1303 	if (err)
1304 		goto errout;
1305 
1306 	err = __tcf_qdisc_cl_find(*q, *parent, cl, ifindex, extack);
1307 	if (err)
1308 		goto errout_qdisc;
1309 
1310 	block = __tcf_block_find(net, *q, *cl, ifindex, block_index, extack);
1311 	if (IS_ERR(block)) {
1312 		err = PTR_ERR(block);
1313 		goto errout_qdisc;
1314 	}
1315 
1316 	return block;
1317 
1318 errout_qdisc:
1319 	if (*q)
1320 		qdisc_put(*q);
1321 errout:
1322 	*q = NULL;
1323 	return ERR_PTR(err);
1324 }
1325 
1326 static void tcf_block_release(struct Qdisc *q, struct tcf_block *block,
1327 			      bool rtnl_held)
1328 {
1329 	if (!IS_ERR_OR_NULL(block))
1330 		tcf_block_refcnt_put(block, rtnl_held);
1331 
1332 	if (q) {
1333 		if (rtnl_held)
1334 			qdisc_put(q);
1335 		else
1336 			qdisc_put_unlocked(q);
1337 	}
1338 }
1339 
1340 struct tcf_block_owner_item {
1341 	struct list_head list;
1342 	struct Qdisc *q;
1343 	enum tcf_block_binder_type binder_type;
1344 };
1345 
1346 static void
1347 tcf_block_owner_netif_keep_dst(struct tcf_block *block,
1348 			       struct Qdisc *q,
1349 			       enum tcf_block_binder_type binder_type)
1350 {
1351 	if (block->keep_dst &&
1352 	    binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_INGRESS &&
1353 	    binder_type != TCF_BLOCK_BINDER_TYPE_CLSACT_EGRESS)
1354 		netif_keep_dst(qdisc_dev(q));
1355 }
1356 
1357 void tcf_block_netif_keep_dst(struct tcf_block *block)
1358 {
1359 	struct tcf_block_owner_item *item;
1360 
1361 	block->keep_dst = true;
1362 	list_for_each_entry(item, &block->owner_list, list)
1363 		tcf_block_owner_netif_keep_dst(block, item->q,
1364 					       item->binder_type);
1365 }
1366 EXPORT_SYMBOL(tcf_block_netif_keep_dst);
1367 
1368 static int tcf_block_owner_add(struct tcf_block *block,
1369 			       struct Qdisc *q,
1370 			       enum tcf_block_binder_type binder_type)
1371 {
1372 	struct tcf_block_owner_item *item;
1373 
1374 	item = kmalloc(sizeof(*item), GFP_KERNEL);
1375 	if (!item)
1376 		return -ENOMEM;
1377 	item->q = q;
1378 	item->binder_type = binder_type;
1379 	list_add(&item->list, &block->owner_list);
1380 	return 0;
1381 }
1382 
1383 static void tcf_block_owner_del(struct tcf_block *block,
1384 				struct Qdisc *q,
1385 				enum tcf_block_binder_type binder_type)
1386 {
1387 	struct tcf_block_owner_item *item;
1388 
1389 	list_for_each_entry(item, &block->owner_list, list) {
1390 		if (item->q == q && item->binder_type == binder_type) {
1391 			list_del(&item->list);
1392 			kfree(item);
1393 			return;
1394 		}
1395 	}
1396 	WARN_ON(1);
1397 }
1398 
1399 int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
1400 		      struct tcf_block_ext_info *ei,
1401 		      struct netlink_ext_ack *extack)
1402 {
1403 	struct net *net = qdisc_net(q);
1404 	struct tcf_block *block = NULL;
1405 	int err;
1406 
1407 	if (ei->block_index)
1408 		/* block_index not 0 means the shared block is requested */
1409 		block = tcf_block_refcnt_get(net, ei->block_index);
1410 
1411 	if (!block) {
1412 		block = tcf_block_create(net, q, ei->block_index, extack);
1413 		if (IS_ERR(block))
1414 			return PTR_ERR(block);
1415 		if (tcf_block_shared(block)) {
1416 			err = tcf_block_insert(block, net, extack);
1417 			if (err)
1418 				goto err_block_insert;
1419 		}
1420 	}
1421 
1422 	err = tcf_block_owner_add(block, q, ei->binder_type);
1423 	if (err)
1424 		goto err_block_owner_add;
1425 
1426 	tcf_block_owner_netif_keep_dst(block, q, ei->binder_type);
1427 
1428 	err = tcf_chain0_head_change_cb_add(block, ei, extack);
1429 	if (err)
1430 		goto err_chain0_head_change_cb_add;
1431 
1432 	err = tcf_block_offload_bind(block, q, ei, extack);
1433 	if (err)
1434 		goto err_block_offload_bind;
1435 
1436 	*p_block = block;
1437 	return 0;
1438 
1439 err_block_offload_bind:
1440 	tcf_chain0_head_change_cb_del(block, ei);
1441 err_chain0_head_change_cb_add:
1442 	tcf_block_owner_del(block, q, ei->binder_type);
1443 err_block_owner_add:
1444 err_block_insert:
1445 	tcf_block_refcnt_put(block, true);
1446 	return err;
1447 }
1448 EXPORT_SYMBOL(tcf_block_get_ext);
1449 
1450 static void tcf_chain_head_change_dflt(struct tcf_proto *tp_head, void *priv)
1451 {
1452 	struct tcf_proto __rcu **p_filter_chain = priv;
1453 
1454 	rcu_assign_pointer(*p_filter_chain, tp_head);
1455 }
1456 
1457 int tcf_block_get(struct tcf_block **p_block,
1458 		  struct tcf_proto __rcu **p_filter_chain, struct Qdisc *q,
1459 		  struct netlink_ext_ack *extack)
1460 {
1461 	struct tcf_block_ext_info ei = {
1462 		.chain_head_change = tcf_chain_head_change_dflt,
1463 		.chain_head_change_priv = p_filter_chain,
1464 	};
1465 
1466 	WARN_ON(!p_filter_chain);
1467 	return tcf_block_get_ext(p_block, q, &ei, extack);
1468 }
1469 EXPORT_SYMBOL(tcf_block_get);
1470 
1471 /* XXX: Standalone actions are not allowed to jump to any chain, and bound
1472  * actions should be all removed after flushing.
1473  */
1474 void tcf_block_put_ext(struct tcf_block *block, struct Qdisc *q,
1475 		       struct tcf_block_ext_info *ei)
1476 {
1477 	if (!block)
1478 		return;
1479 	tcf_chain0_head_change_cb_del(block, ei);
1480 	tcf_block_owner_del(block, q, ei->binder_type);
1481 
1482 	__tcf_block_put(block, q, ei, true);
1483 }
1484 EXPORT_SYMBOL(tcf_block_put_ext);
1485 
1486 void tcf_block_put(struct tcf_block *block)
1487 {
1488 	struct tcf_block_ext_info ei = {0, };
1489 
1490 	if (!block)
1491 		return;
1492 	tcf_block_put_ext(block, block->q, &ei);
1493 }
1494 
1495 EXPORT_SYMBOL(tcf_block_put);
1496 
1497 struct tcf_block_cb {
1498 	struct list_head list;
1499 	tc_setup_cb_t *cb;
1500 	void *cb_ident;
1501 	void *cb_priv;
1502 	unsigned int refcnt;
1503 };
1504 
1505 void *tcf_block_cb_priv(struct tcf_block_cb *block_cb)
1506 {
1507 	return block_cb->cb_priv;
1508 }
1509 EXPORT_SYMBOL(tcf_block_cb_priv);
1510 
1511 struct tcf_block_cb *tcf_block_cb_lookup(struct tcf_block *block,
1512 					 tc_setup_cb_t *cb, void *cb_ident)
1513 {	struct tcf_block_cb *block_cb;
1514 
1515 	list_for_each_entry(block_cb, &block->cb_list, list)
1516 		if (block_cb->cb == cb && block_cb->cb_ident == cb_ident)
1517 			return block_cb;
1518 	return NULL;
1519 }
1520 EXPORT_SYMBOL(tcf_block_cb_lookup);
1521 
1522 void tcf_block_cb_incref(struct tcf_block_cb *block_cb)
1523 {
1524 	block_cb->refcnt++;
1525 }
1526 EXPORT_SYMBOL(tcf_block_cb_incref);
1527 
1528 unsigned int tcf_block_cb_decref(struct tcf_block_cb *block_cb)
1529 {
1530 	return --block_cb->refcnt;
1531 }
1532 EXPORT_SYMBOL(tcf_block_cb_decref);
1533 
1534 static int
1535 tcf_block_playback_offloads(struct tcf_block *block, tc_setup_cb_t *cb,
1536 			    void *cb_priv, bool add, bool offload_in_use,
1537 			    struct netlink_ext_ack *extack)
1538 {
1539 	struct tcf_chain *chain, *chain_prev;
1540 	struct tcf_proto *tp, *tp_prev;
1541 	int err;
1542 
1543 	for (chain = __tcf_get_next_chain(block, NULL);
1544 	     chain;
1545 	     chain_prev = chain,
1546 		     chain = __tcf_get_next_chain(block, chain),
1547 		     tcf_chain_put(chain_prev)) {
1548 		for (tp = __tcf_get_next_proto(chain, NULL); tp;
1549 		     tp_prev = tp,
1550 			     tp = __tcf_get_next_proto(chain, tp),
1551 			     tcf_proto_put(tp_prev, true, NULL)) {
1552 			if (tp->ops->reoffload) {
1553 				err = tp->ops->reoffload(tp, add, cb, cb_priv,
1554 							 extack);
1555 				if (err && add)
1556 					goto err_playback_remove;
1557 			} else if (add && offload_in_use) {
1558 				err = -EOPNOTSUPP;
1559 				NL_SET_ERR_MSG(extack, "Filter HW offload failed - classifier without re-offloading support");
1560 				goto err_playback_remove;
1561 			}
1562 		}
1563 	}
1564 
1565 	return 0;
1566 
1567 err_playback_remove:
1568 	tcf_proto_put(tp, true, NULL);
1569 	tcf_chain_put(chain);
1570 	tcf_block_playback_offloads(block, cb, cb_priv, false, offload_in_use,
1571 				    extack);
1572 	return err;
1573 }
1574 
1575 struct tcf_block_cb *__tcf_block_cb_register(struct tcf_block *block,
1576 					     tc_setup_cb_t *cb, void *cb_ident,
1577 					     void *cb_priv,
1578 					     struct netlink_ext_ack *extack)
1579 {
1580 	struct tcf_block_cb *block_cb;
1581 	int err;
1582 
1583 	/* Replay any already present rules */
1584 	err = tcf_block_playback_offloads(block, cb, cb_priv, true,
1585 					  tcf_block_offload_in_use(block),
1586 					  extack);
1587 	if (err)
1588 		return ERR_PTR(err);
1589 
1590 	block_cb = kzalloc(sizeof(*block_cb), GFP_KERNEL);
1591 	if (!block_cb)
1592 		return ERR_PTR(-ENOMEM);
1593 	block_cb->cb = cb;
1594 	block_cb->cb_ident = cb_ident;
1595 	block_cb->cb_priv = cb_priv;
1596 	list_add(&block_cb->list, &block->cb_list);
1597 	return block_cb;
1598 }
1599 EXPORT_SYMBOL(__tcf_block_cb_register);
1600 
1601 int tcf_block_cb_register(struct tcf_block *block,
1602 			  tc_setup_cb_t *cb, void *cb_ident,
1603 			  void *cb_priv, struct netlink_ext_ack *extack)
1604 {
1605 	struct tcf_block_cb *block_cb;
1606 
1607 	block_cb = __tcf_block_cb_register(block, cb, cb_ident, cb_priv,
1608 					   extack);
1609 	return PTR_ERR_OR_ZERO(block_cb);
1610 }
1611 EXPORT_SYMBOL(tcf_block_cb_register);
1612 
1613 void __tcf_block_cb_unregister(struct tcf_block *block,
1614 			       struct tcf_block_cb *block_cb)
1615 {
1616 	tcf_block_playback_offloads(block, block_cb->cb, block_cb->cb_priv,
1617 				    false, tcf_block_offload_in_use(block),
1618 				    NULL);
1619 	list_del(&block_cb->list);
1620 	kfree(block_cb);
1621 }
1622 EXPORT_SYMBOL(__tcf_block_cb_unregister);
1623 
1624 void tcf_block_cb_unregister(struct tcf_block *block,
1625 			     tc_setup_cb_t *cb, void *cb_ident)
1626 {
1627 	struct tcf_block_cb *block_cb;
1628 
1629 	block_cb = tcf_block_cb_lookup(block, cb, cb_ident);
1630 	if (!block_cb)
1631 		return;
1632 	__tcf_block_cb_unregister(block, block_cb);
1633 }
1634 EXPORT_SYMBOL(tcf_block_cb_unregister);
1635 
1636 /* Main classifier routine: scans classifier chain attached
1637  * to this qdisc, (optionally) tests for protocol and asks
1638  * specific classifiers.
1639  */
1640 int tcf_classify(struct sk_buff *skb, const struct tcf_proto *tp,
1641 		 struct tcf_result *res, bool compat_mode)
1642 {
1643 #ifdef CONFIG_NET_CLS_ACT
1644 	const int max_reclassify_loop = 4;
1645 	const struct tcf_proto *orig_tp = tp;
1646 	const struct tcf_proto *first_tp;
1647 	int limit = 0;
1648 
1649 reclassify:
1650 #endif
1651 	for (; tp; tp = rcu_dereference_bh(tp->next)) {
1652 		__be16 protocol = tc_skb_protocol(skb);
1653 		int err;
1654 
1655 		if (tp->protocol != protocol &&
1656 		    tp->protocol != htons(ETH_P_ALL))
1657 			continue;
1658 
1659 		err = tp->classify(skb, tp, res);
1660 #ifdef CONFIG_NET_CLS_ACT
1661 		if (unlikely(err == TC_ACT_RECLASSIFY && !compat_mode)) {
1662 			first_tp = orig_tp;
1663 			goto reset;
1664 		} else if (unlikely(TC_ACT_EXT_CMP(err, TC_ACT_GOTO_CHAIN))) {
1665 			first_tp = res->goto_tp;
1666 			goto reset;
1667 		}
1668 #endif
1669 		if (err >= 0)
1670 			return err;
1671 	}
1672 
1673 	return TC_ACT_UNSPEC; /* signal: continue lookup */
1674 #ifdef CONFIG_NET_CLS_ACT
1675 reset:
1676 	if (unlikely(limit++ >= max_reclassify_loop)) {
1677 		net_notice_ratelimited("%u: reclassify loop, rule prio %u, protocol %02x\n",
1678 				       tp->chain->block->index,
1679 				       tp->prio & 0xffff,
1680 				       ntohs(tp->protocol));
1681 		return TC_ACT_SHOT;
1682 	}
1683 
1684 	tp = first_tp;
1685 	goto reclassify;
1686 #endif
1687 }
1688 EXPORT_SYMBOL(tcf_classify);
1689 
1690 struct tcf_chain_info {
1691 	struct tcf_proto __rcu **pprev;
1692 	struct tcf_proto __rcu *next;
1693 };
1694 
1695 static struct tcf_proto *tcf_chain_tp_prev(struct tcf_chain *chain,
1696 					   struct tcf_chain_info *chain_info)
1697 {
1698 	return tcf_chain_dereference(*chain_info->pprev, chain);
1699 }
1700 
1701 static int tcf_chain_tp_insert(struct tcf_chain *chain,
1702 			       struct tcf_chain_info *chain_info,
1703 			       struct tcf_proto *tp)
1704 {
1705 	if (chain->flushing)
1706 		return -EAGAIN;
1707 
1708 	if (*chain_info->pprev == chain->filter_chain)
1709 		tcf_chain0_head_change(chain, tp);
1710 	tcf_proto_get(tp);
1711 	RCU_INIT_POINTER(tp->next, tcf_chain_tp_prev(chain, chain_info));
1712 	rcu_assign_pointer(*chain_info->pprev, tp);
1713 
1714 	return 0;
1715 }
1716 
1717 static void tcf_chain_tp_remove(struct tcf_chain *chain,
1718 				struct tcf_chain_info *chain_info,
1719 				struct tcf_proto *tp)
1720 {
1721 	struct tcf_proto *next = tcf_chain_dereference(chain_info->next, chain);
1722 
1723 	tcf_proto_mark_delete(tp);
1724 	if (tp == chain->filter_chain)
1725 		tcf_chain0_head_change(chain, next);
1726 	RCU_INIT_POINTER(*chain_info->pprev, next);
1727 }
1728 
1729 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1730 					   struct tcf_chain_info *chain_info,
1731 					   u32 protocol, u32 prio,
1732 					   bool prio_allocate);
1733 
1734 /* Try to insert new proto.
1735  * If proto with specified priority already exists, free new proto
1736  * and return existing one.
1737  */
1738 
1739 static struct tcf_proto *tcf_chain_tp_insert_unique(struct tcf_chain *chain,
1740 						    struct tcf_proto *tp_new,
1741 						    u32 protocol, u32 prio,
1742 						    bool rtnl_held)
1743 {
1744 	struct tcf_chain_info chain_info;
1745 	struct tcf_proto *tp;
1746 	int err = 0;
1747 
1748 	mutex_lock(&chain->filter_chain_lock);
1749 
1750 	tp = tcf_chain_tp_find(chain, &chain_info,
1751 			       protocol, prio, false);
1752 	if (!tp)
1753 		err = tcf_chain_tp_insert(chain, &chain_info, tp_new);
1754 	mutex_unlock(&chain->filter_chain_lock);
1755 
1756 	if (tp) {
1757 		tcf_proto_destroy(tp_new, rtnl_held, NULL);
1758 		tp_new = tp;
1759 	} else if (err) {
1760 		tcf_proto_destroy(tp_new, rtnl_held, NULL);
1761 		tp_new = ERR_PTR(err);
1762 	}
1763 
1764 	return tp_new;
1765 }
1766 
1767 static void tcf_chain_tp_delete_empty(struct tcf_chain *chain,
1768 				      struct tcf_proto *tp, bool rtnl_held,
1769 				      struct netlink_ext_ack *extack)
1770 {
1771 	struct tcf_chain_info chain_info;
1772 	struct tcf_proto *tp_iter;
1773 	struct tcf_proto **pprev;
1774 	struct tcf_proto *next;
1775 
1776 	mutex_lock(&chain->filter_chain_lock);
1777 
1778 	/* Atomically find and remove tp from chain. */
1779 	for (pprev = &chain->filter_chain;
1780 	     (tp_iter = tcf_chain_dereference(*pprev, chain));
1781 	     pprev = &tp_iter->next) {
1782 		if (tp_iter == tp) {
1783 			chain_info.pprev = pprev;
1784 			chain_info.next = tp_iter->next;
1785 			WARN_ON(tp_iter->deleting);
1786 			break;
1787 		}
1788 	}
1789 	/* Verify that tp still exists and no new filters were inserted
1790 	 * concurrently.
1791 	 * Mark tp for deletion if it is empty.
1792 	 */
1793 	if (!tp_iter || !tcf_proto_check_delete(tp, rtnl_held)) {
1794 		mutex_unlock(&chain->filter_chain_lock);
1795 		return;
1796 	}
1797 
1798 	next = tcf_chain_dereference(chain_info.next, chain);
1799 	if (tp == chain->filter_chain)
1800 		tcf_chain0_head_change(chain, next);
1801 	RCU_INIT_POINTER(*chain_info.pprev, next);
1802 	mutex_unlock(&chain->filter_chain_lock);
1803 
1804 	tcf_proto_put(tp, rtnl_held, extack);
1805 }
1806 
1807 static struct tcf_proto *tcf_chain_tp_find(struct tcf_chain *chain,
1808 					   struct tcf_chain_info *chain_info,
1809 					   u32 protocol, u32 prio,
1810 					   bool prio_allocate)
1811 {
1812 	struct tcf_proto **pprev;
1813 	struct tcf_proto *tp;
1814 
1815 	/* Check the chain for existence of proto-tcf with this priority */
1816 	for (pprev = &chain->filter_chain;
1817 	     (tp = tcf_chain_dereference(*pprev, chain));
1818 	     pprev = &tp->next) {
1819 		if (tp->prio >= prio) {
1820 			if (tp->prio == prio) {
1821 				if (prio_allocate ||
1822 				    (tp->protocol != protocol && protocol))
1823 					return ERR_PTR(-EINVAL);
1824 			} else {
1825 				tp = NULL;
1826 			}
1827 			break;
1828 		}
1829 	}
1830 	chain_info->pprev = pprev;
1831 	if (tp) {
1832 		chain_info->next = tp->next;
1833 		tcf_proto_get(tp);
1834 	} else {
1835 		chain_info->next = NULL;
1836 	}
1837 	return tp;
1838 }
1839 
1840 static int tcf_fill_node(struct net *net, struct sk_buff *skb,
1841 			 struct tcf_proto *tp, struct tcf_block *block,
1842 			 struct Qdisc *q, u32 parent, void *fh,
1843 			 u32 portid, u32 seq, u16 flags, int event,
1844 			 bool rtnl_held)
1845 {
1846 	struct tcmsg *tcm;
1847 	struct nlmsghdr  *nlh;
1848 	unsigned char *b = skb_tail_pointer(skb);
1849 
1850 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
1851 	if (!nlh)
1852 		goto out_nlmsg_trim;
1853 	tcm = nlmsg_data(nlh);
1854 	tcm->tcm_family = AF_UNSPEC;
1855 	tcm->tcm__pad1 = 0;
1856 	tcm->tcm__pad2 = 0;
1857 	if (q) {
1858 		tcm->tcm_ifindex = qdisc_dev(q)->ifindex;
1859 		tcm->tcm_parent = parent;
1860 	} else {
1861 		tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
1862 		tcm->tcm_block_index = block->index;
1863 	}
1864 	tcm->tcm_info = TC_H_MAKE(tp->prio, tp->protocol);
1865 	if (nla_put_string(skb, TCA_KIND, tp->ops->kind))
1866 		goto nla_put_failure;
1867 	if (nla_put_u32(skb, TCA_CHAIN, tp->chain->index))
1868 		goto nla_put_failure;
1869 	if (!fh) {
1870 		tcm->tcm_handle = 0;
1871 	} else {
1872 		if (tp->ops->dump &&
1873 		    tp->ops->dump(net, tp, fh, skb, tcm, rtnl_held) < 0)
1874 			goto nla_put_failure;
1875 	}
1876 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1877 	return skb->len;
1878 
1879 out_nlmsg_trim:
1880 nla_put_failure:
1881 	nlmsg_trim(skb, b);
1882 	return -1;
1883 }
1884 
1885 static int tfilter_notify(struct net *net, struct sk_buff *oskb,
1886 			  struct nlmsghdr *n, struct tcf_proto *tp,
1887 			  struct tcf_block *block, struct Qdisc *q,
1888 			  u32 parent, void *fh, int event, bool unicast,
1889 			  bool rtnl_held)
1890 {
1891 	struct sk_buff *skb;
1892 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1893 	int err = 0;
1894 
1895 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1896 	if (!skb)
1897 		return -ENOBUFS;
1898 
1899 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1900 			  n->nlmsg_seq, n->nlmsg_flags, event,
1901 			  rtnl_held) <= 0) {
1902 		kfree_skb(skb);
1903 		return -EINVAL;
1904 	}
1905 
1906 	if (unicast)
1907 		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1908 	else
1909 		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1910 				     n->nlmsg_flags & NLM_F_ECHO);
1911 
1912 	if (err > 0)
1913 		err = 0;
1914 	return err;
1915 }
1916 
1917 static int tfilter_del_notify(struct net *net, struct sk_buff *oskb,
1918 			      struct nlmsghdr *n, struct tcf_proto *tp,
1919 			      struct tcf_block *block, struct Qdisc *q,
1920 			      u32 parent, void *fh, bool unicast, bool *last,
1921 			      bool rtnl_held, struct netlink_ext_ack *extack)
1922 {
1923 	struct sk_buff *skb;
1924 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
1925 	int err;
1926 
1927 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1928 	if (!skb)
1929 		return -ENOBUFS;
1930 
1931 	if (tcf_fill_node(net, skb, tp, block, q, parent, fh, portid,
1932 			  n->nlmsg_seq, n->nlmsg_flags, RTM_DELTFILTER,
1933 			  rtnl_held) <= 0) {
1934 		NL_SET_ERR_MSG(extack, "Failed to build del event notification");
1935 		kfree_skb(skb);
1936 		return -EINVAL;
1937 	}
1938 
1939 	err = tp->ops->delete(tp, fh, last, rtnl_held, extack);
1940 	if (err) {
1941 		kfree_skb(skb);
1942 		return err;
1943 	}
1944 
1945 	if (unicast)
1946 		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
1947 	else
1948 		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1949 				     n->nlmsg_flags & NLM_F_ECHO);
1950 	if (err < 0)
1951 		NL_SET_ERR_MSG(extack, "Failed to send filter delete notification");
1952 
1953 	if (err > 0)
1954 		err = 0;
1955 	return err;
1956 }
1957 
1958 static void tfilter_notify_chain(struct net *net, struct sk_buff *oskb,
1959 				 struct tcf_block *block, struct Qdisc *q,
1960 				 u32 parent, struct nlmsghdr *n,
1961 				 struct tcf_chain *chain, int event,
1962 				 bool rtnl_held)
1963 {
1964 	struct tcf_proto *tp;
1965 
1966 	for (tp = tcf_get_next_proto(chain, NULL, rtnl_held);
1967 	     tp; tp = tcf_get_next_proto(chain, tp, rtnl_held))
1968 		tfilter_notify(net, oskb, n, tp, block,
1969 			       q, parent, NULL, event, false, rtnl_held);
1970 }
1971 
1972 static void tfilter_put(struct tcf_proto *tp, void *fh)
1973 {
1974 	if (tp->ops->put && fh)
1975 		tp->ops->put(tp, fh);
1976 }
1977 
1978 static int tc_new_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
1979 			  struct netlink_ext_ack *extack)
1980 {
1981 	struct net *net = sock_net(skb->sk);
1982 	struct nlattr *tca[TCA_MAX + 1];
1983 	struct tcmsg *t;
1984 	u32 protocol;
1985 	u32 prio;
1986 	bool prio_allocate;
1987 	u32 parent;
1988 	u32 chain_index;
1989 	struct Qdisc *q = NULL;
1990 	struct tcf_chain_info chain_info;
1991 	struct tcf_chain *chain = NULL;
1992 	struct tcf_block *block;
1993 	struct tcf_proto *tp;
1994 	unsigned long cl;
1995 	void *fh;
1996 	int err;
1997 	int tp_created;
1998 	bool rtnl_held = false;
1999 
2000 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2001 		return -EPERM;
2002 
2003 replay:
2004 	tp_created = 0;
2005 
2006 	err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2007 				     rtm_tca_policy, extack);
2008 	if (err < 0)
2009 		return err;
2010 
2011 	t = nlmsg_data(n);
2012 	protocol = TC_H_MIN(t->tcm_info);
2013 	prio = TC_H_MAJ(t->tcm_info);
2014 	prio_allocate = false;
2015 	parent = t->tcm_parent;
2016 	tp = NULL;
2017 	cl = 0;
2018 	block = NULL;
2019 
2020 	if (prio == 0) {
2021 		/* If no priority is provided by the user,
2022 		 * we allocate one.
2023 		 */
2024 		if (n->nlmsg_flags & NLM_F_CREATE) {
2025 			prio = TC_H_MAKE(0x80000000U, 0U);
2026 			prio_allocate = true;
2027 		} else {
2028 			NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2029 			return -ENOENT;
2030 		}
2031 	}
2032 
2033 	/* Find head of filter chain. */
2034 
2035 	err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2036 	if (err)
2037 		return err;
2038 
2039 	/* Take rtnl mutex if rtnl_held was set to true on previous iteration,
2040 	 * block is shared (no qdisc found), qdisc is not unlocked, classifier
2041 	 * type is not specified, classifier is not unlocked.
2042 	 */
2043 	if (rtnl_held ||
2044 	    (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2045 	    !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
2046 		rtnl_held = true;
2047 		rtnl_lock();
2048 	}
2049 
2050 	err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2051 	if (err)
2052 		goto errout;
2053 
2054 	block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2055 				 extack);
2056 	if (IS_ERR(block)) {
2057 		err = PTR_ERR(block);
2058 		goto errout;
2059 	}
2060 
2061 	chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2062 	if (chain_index > TC_ACT_EXT_VAL_MASK) {
2063 		NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2064 		err = -EINVAL;
2065 		goto errout;
2066 	}
2067 	chain = tcf_chain_get(block, chain_index, true);
2068 	if (!chain) {
2069 		NL_SET_ERR_MSG(extack, "Cannot create specified filter chain");
2070 		err = -ENOMEM;
2071 		goto errout;
2072 	}
2073 
2074 	mutex_lock(&chain->filter_chain_lock);
2075 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2076 			       prio, prio_allocate);
2077 	if (IS_ERR(tp)) {
2078 		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2079 		err = PTR_ERR(tp);
2080 		goto errout_locked;
2081 	}
2082 
2083 	if (tp == NULL) {
2084 		struct tcf_proto *tp_new = NULL;
2085 
2086 		if (chain->flushing) {
2087 			err = -EAGAIN;
2088 			goto errout_locked;
2089 		}
2090 
2091 		/* Proto-tcf does not exist, create new one */
2092 
2093 		if (tca[TCA_KIND] == NULL || !protocol) {
2094 			NL_SET_ERR_MSG(extack, "Filter kind and protocol must be specified");
2095 			err = -EINVAL;
2096 			goto errout_locked;
2097 		}
2098 
2099 		if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2100 			NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2101 			err = -ENOENT;
2102 			goto errout_locked;
2103 		}
2104 
2105 		if (prio_allocate)
2106 			prio = tcf_auto_prio(tcf_chain_tp_prev(chain,
2107 							       &chain_info));
2108 
2109 		mutex_unlock(&chain->filter_chain_lock);
2110 		tp_new = tcf_proto_create(nla_data(tca[TCA_KIND]),
2111 					  protocol, prio, chain, rtnl_held,
2112 					  extack);
2113 		if (IS_ERR(tp_new)) {
2114 			err = PTR_ERR(tp_new);
2115 			goto errout_tp;
2116 		}
2117 
2118 		tp_created = 1;
2119 		tp = tcf_chain_tp_insert_unique(chain, tp_new, protocol, prio,
2120 						rtnl_held);
2121 		if (IS_ERR(tp)) {
2122 			err = PTR_ERR(tp);
2123 			goto errout_tp;
2124 		}
2125 	} else {
2126 		mutex_unlock(&chain->filter_chain_lock);
2127 	}
2128 
2129 	if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2130 		NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2131 		err = -EINVAL;
2132 		goto errout;
2133 	}
2134 
2135 	fh = tp->ops->get(tp, t->tcm_handle);
2136 
2137 	if (!fh) {
2138 		if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2139 			NL_SET_ERR_MSG(extack, "Need both RTM_NEWTFILTER and NLM_F_CREATE to create a new filter");
2140 			err = -ENOENT;
2141 			goto errout;
2142 		}
2143 	} else if (n->nlmsg_flags & NLM_F_EXCL) {
2144 		tfilter_put(tp, fh);
2145 		NL_SET_ERR_MSG(extack, "Filter already exists");
2146 		err = -EEXIST;
2147 		goto errout;
2148 	}
2149 
2150 	if (chain->tmplt_ops && chain->tmplt_ops != tp->ops) {
2151 		NL_SET_ERR_MSG(extack, "Chain template is set to a different filter kind");
2152 		err = -EINVAL;
2153 		goto errout;
2154 	}
2155 
2156 	err = tp->ops->change(net, skb, tp, cl, t->tcm_handle, tca, &fh,
2157 			      n->nlmsg_flags & NLM_F_CREATE ? TCA_ACT_NOREPLACE : TCA_ACT_REPLACE,
2158 			      rtnl_held, extack);
2159 	if (err == 0) {
2160 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2161 			       RTM_NEWTFILTER, false, rtnl_held);
2162 		tfilter_put(tp, fh);
2163 	}
2164 
2165 errout:
2166 	if (err && tp_created)
2167 		tcf_chain_tp_delete_empty(chain, tp, rtnl_held, NULL);
2168 errout_tp:
2169 	if (chain) {
2170 		if (tp && !IS_ERR(tp))
2171 			tcf_proto_put(tp, rtnl_held, NULL);
2172 		if (!tp_created)
2173 			tcf_chain_put(chain);
2174 	}
2175 	tcf_block_release(q, block, rtnl_held);
2176 
2177 	if (rtnl_held)
2178 		rtnl_unlock();
2179 
2180 	if (err == -EAGAIN) {
2181 		/* Take rtnl lock in case EAGAIN is caused by concurrent flush
2182 		 * of target chain.
2183 		 */
2184 		rtnl_held = true;
2185 		/* Replay the request. */
2186 		goto replay;
2187 	}
2188 	return err;
2189 
2190 errout_locked:
2191 	mutex_unlock(&chain->filter_chain_lock);
2192 	goto errout;
2193 }
2194 
2195 static int tc_del_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2196 			  struct netlink_ext_ack *extack)
2197 {
2198 	struct net *net = sock_net(skb->sk);
2199 	struct nlattr *tca[TCA_MAX + 1];
2200 	struct tcmsg *t;
2201 	u32 protocol;
2202 	u32 prio;
2203 	u32 parent;
2204 	u32 chain_index;
2205 	struct Qdisc *q = NULL;
2206 	struct tcf_chain_info chain_info;
2207 	struct tcf_chain *chain = NULL;
2208 	struct tcf_block *block = NULL;
2209 	struct tcf_proto *tp = NULL;
2210 	unsigned long cl = 0;
2211 	void *fh = NULL;
2212 	int err;
2213 	bool rtnl_held = false;
2214 
2215 	if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2216 		return -EPERM;
2217 
2218 	err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2219 				     rtm_tca_policy, extack);
2220 	if (err < 0)
2221 		return err;
2222 
2223 	t = nlmsg_data(n);
2224 	protocol = TC_H_MIN(t->tcm_info);
2225 	prio = TC_H_MAJ(t->tcm_info);
2226 	parent = t->tcm_parent;
2227 
2228 	if (prio == 0 && (protocol || t->tcm_handle || tca[TCA_KIND])) {
2229 		NL_SET_ERR_MSG(extack, "Cannot flush filters with protocol, handle or kind set");
2230 		return -ENOENT;
2231 	}
2232 
2233 	/* Find head of filter chain. */
2234 
2235 	err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2236 	if (err)
2237 		return err;
2238 
2239 	/* Take rtnl mutex if flushing whole chain, block is shared (no qdisc
2240 	 * found), qdisc is not unlocked, classifier type is not specified,
2241 	 * classifier is not unlocked.
2242 	 */
2243 	if (!prio ||
2244 	    (q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2245 	    !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
2246 		rtnl_held = true;
2247 		rtnl_lock();
2248 	}
2249 
2250 	err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2251 	if (err)
2252 		goto errout;
2253 
2254 	block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2255 				 extack);
2256 	if (IS_ERR(block)) {
2257 		err = PTR_ERR(block);
2258 		goto errout;
2259 	}
2260 
2261 	chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2262 	if (chain_index > TC_ACT_EXT_VAL_MASK) {
2263 		NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2264 		err = -EINVAL;
2265 		goto errout;
2266 	}
2267 	chain = tcf_chain_get(block, chain_index, false);
2268 	if (!chain) {
2269 		/* User requested flush on non-existent chain. Nothing to do,
2270 		 * so just return success.
2271 		 */
2272 		if (prio == 0) {
2273 			err = 0;
2274 			goto errout;
2275 		}
2276 		NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2277 		err = -ENOENT;
2278 		goto errout;
2279 	}
2280 
2281 	if (prio == 0) {
2282 		tfilter_notify_chain(net, skb, block, q, parent, n,
2283 				     chain, RTM_DELTFILTER, rtnl_held);
2284 		tcf_chain_flush(chain, rtnl_held);
2285 		err = 0;
2286 		goto errout;
2287 	}
2288 
2289 	mutex_lock(&chain->filter_chain_lock);
2290 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2291 			       prio, false);
2292 	if (!tp || IS_ERR(tp)) {
2293 		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2294 		err = tp ? PTR_ERR(tp) : -ENOENT;
2295 		goto errout_locked;
2296 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2297 		NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2298 		err = -EINVAL;
2299 		goto errout_locked;
2300 	} else if (t->tcm_handle == 0) {
2301 		tcf_chain_tp_remove(chain, &chain_info, tp);
2302 		mutex_unlock(&chain->filter_chain_lock);
2303 
2304 		tcf_proto_put(tp, rtnl_held, NULL);
2305 		tfilter_notify(net, skb, n, tp, block, q, parent, fh,
2306 			       RTM_DELTFILTER, false, rtnl_held);
2307 		err = 0;
2308 		goto errout;
2309 	}
2310 	mutex_unlock(&chain->filter_chain_lock);
2311 
2312 	fh = tp->ops->get(tp, t->tcm_handle);
2313 
2314 	if (!fh) {
2315 		NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2316 		err = -ENOENT;
2317 	} else {
2318 		bool last;
2319 
2320 		err = tfilter_del_notify(net, skb, n, tp, block,
2321 					 q, parent, fh, false, &last,
2322 					 rtnl_held, extack);
2323 
2324 		if (err)
2325 			goto errout;
2326 		if (last)
2327 			tcf_chain_tp_delete_empty(chain, tp, rtnl_held, extack);
2328 	}
2329 
2330 errout:
2331 	if (chain) {
2332 		if (tp && !IS_ERR(tp))
2333 			tcf_proto_put(tp, rtnl_held, NULL);
2334 		tcf_chain_put(chain);
2335 	}
2336 	tcf_block_release(q, block, rtnl_held);
2337 
2338 	if (rtnl_held)
2339 		rtnl_unlock();
2340 
2341 	return err;
2342 
2343 errout_locked:
2344 	mutex_unlock(&chain->filter_chain_lock);
2345 	goto errout;
2346 }
2347 
2348 static int tc_get_tfilter(struct sk_buff *skb, struct nlmsghdr *n,
2349 			  struct netlink_ext_ack *extack)
2350 {
2351 	struct net *net = sock_net(skb->sk);
2352 	struct nlattr *tca[TCA_MAX + 1];
2353 	struct tcmsg *t;
2354 	u32 protocol;
2355 	u32 prio;
2356 	u32 parent;
2357 	u32 chain_index;
2358 	struct Qdisc *q = NULL;
2359 	struct tcf_chain_info chain_info;
2360 	struct tcf_chain *chain = NULL;
2361 	struct tcf_block *block = NULL;
2362 	struct tcf_proto *tp = NULL;
2363 	unsigned long cl = 0;
2364 	void *fh = NULL;
2365 	int err;
2366 	bool rtnl_held = false;
2367 
2368 	err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2369 				     rtm_tca_policy, extack);
2370 	if (err < 0)
2371 		return err;
2372 
2373 	t = nlmsg_data(n);
2374 	protocol = TC_H_MIN(t->tcm_info);
2375 	prio = TC_H_MAJ(t->tcm_info);
2376 	parent = t->tcm_parent;
2377 
2378 	if (prio == 0) {
2379 		NL_SET_ERR_MSG(extack, "Invalid filter command with priority of zero");
2380 		return -ENOENT;
2381 	}
2382 
2383 	/* Find head of filter chain. */
2384 
2385 	err = __tcf_qdisc_find(net, &q, &parent, t->tcm_ifindex, false, extack);
2386 	if (err)
2387 		return err;
2388 
2389 	/* Take rtnl mutex if block is shared (no qdisc found), qdisc is not
2390 	 * unlocked, classifier type is not specified, classifier is not
2391 	 * unlocked.
2392 	 */
2393 	if ((q && !(q->ops->cl_ops->flags & QDISC_CLASS_OPS_DOIT_UNLOCKED)) ||
2394 	    !tca[TCA_KIND] || !tcf_proto_is_unlocked(nla_data(tca[TCA_KIND]))) {
2395 		rtnl_held = true;
2396 		rtnl_lock();
2397 	}
2398 
2399 	err = __tcf_qdisc_cl_find(q, parent, &cl, t->tcm_ifindex, extack);
2400 	if (err)
2401 		goto errout;
2402 
2403 	block = __tcf_block_find(net, q, cl, t->tcm_ifindex, t->tcm_block_index,
2404 				 extack);
2405 	if (IS_ERR(block)) {
2406 		err = PTR_ERR(block);
2407 		goto errout;
2408 	}
2409 
2410 	chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2411 	if (chain_index > TC_ACT_EXT_VAL_MASK) {
2412 		NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2413 		err = -EINVAL;
2414 		goto errout;
2415 	}
2416 	chain = tcf_chain_get(block, chain_index, false);
2417 	if (!chain) {
2418 		NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2419 		err = -EINVAL;
2420 		goto errout;
2421 	}
2422 
2423 	mutex_lock(&chain->filter_chain_lock);
2424 	tp = tcf_chain_tp_find(chain, &chain_info, protocol,
2425 			       prio, false);
2426 	mutex_unlock(&chain->filter_chain_lock);
2427 	if (!tp || IS_ERR(tp)) {
2428 		NL_SET_ERR_MSG(extack, "Filter with specified priority/protocol not found");
2429 		err = tp ? PTR_ERR(tp) : -ENOENT;
2430 		goto errout;
2431 	} else if (tca[TCA_KIND] && nla_strcmp(tca[TCA_KIND], tp->ops->kind)) {
2432 		NL_SET_ERR_MSG(extack, "Specified filter kind does not match existing one");
2433 		err = -EINVAL;
2434 		goto errout;
2435 	}
2436 
2437 	fh = tp->ops->get(tp, t->tcm_handle);
2438 
2439 	if (!fh) {
2440 		NL_SET_ERR_MSG(extack, "Specified filter handle not found");
2441 		err = -ENOENT;
2442 	} else {
2443 		err = tfilter_notify(net, skb, n, tp, block, q, parent,
2444 				     fh, RTM_NEWTFILTER, true, rtnl_held);
2445 		if (err < 0)
2446 			NL_SET_ERR_MSG(extack, "Failed to send filter notify message");
2447 	}
2448 
2449 	tfilter_put(tp, fh);
2450 errout:
2451 	if (chain) {
2452 		if (tp && !IS_ERR(tp))
2453 			tcf_proto_put(tp, rtnl_held, NULL);
2454 		tcf_chain_put(chain);
2455 	}
2456 	tcf_block_release(q, block, rtnl_held);
2457 
2458 	if (rtnl_held)
2459 		rtnl_unlock();
2460 
2461 	return err;
2462 }
2463 
2464 struct tcf_dump_args {
2465 	struct tcf_walker w;
2466 	struct sk_buff *skb;
2467 	struct netlink_callback *cb;
2468 	struct tcf_block *block;
2469 	struct Qdisc *q;
2470 	u32 parent;
2471 };
2472 
2473 static int tcf_node_dump(struct tcf_proto *tp, void *n, struct tcf_walker *arg)
2474 {
2475 	struct tcf_dump_args *a = (void *)arg;
2476 	struct net *net = sock_net(a->skb->sk);
2477 
2478 	return tcf_fill_node(net, a->skb, tp, a->block, a->q, a->parent,
2479 			     n, NETLINK_CB(a->cb->skb).portid,
2480 			     a->cb->nlh->nlmsg_seq, NLM_F_MULTI,
2481 			     RTM_NEWTFILTER, true);
2482 }
2483 
2484 static bool tcf_chain_dump(struct tcf_chain *chain, struct Qdisc *q, u32 parent,
2485 			   struct sk_buff *skb, struct netlink_callback *cb,
2486 			   long index_start, long *p_index)
2487 {
2488 	struct net *net = sock_net(skb->sk);
2489 	struct tcf_block *block = chain->block;
2490 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
2491 	struct tcf_proto *tp, *tp_prev;
2492 	struct tcf_dump_args arg;
2493 
2494 	for (tp = __tcf_get_next_proto(chain, NULL);
2495 	     tp;
2496 	     tp_prev = tp,
2497 		     tp = __tcf_get_next_proto(chain, tp),
2498 		     tcf_proto_put(tp_prev, true, NULL),
2499 		     (*p_index)++) {
2500 		if (*p_index < index_start)
2501 			continue;
2502 		if (TC_H_MAJ(tcm->tcm_info) &&
2503 		    TC_H_MAJ(tcm->tcm_info) != tp->prio)
2504 			continue;
2505 		if (TC_H_MIN(tcm->tcm_info) &&
2506 		    TC_H_MIN(tcm->tcm_info) != tp->protocol)
2507 			continue;
2508 		if (*p_index > index_start)
2509 			memset(&cb->args[1], 0,
2510 			       sizeof(cb->args) - sizeof(cb->args[0]));
2511 		if (cb->args[1] == 0) {
2512 			if (tcf_fill_node(net, skb, tp, block, q, parent, NULL,
2513 					  NETLINK_CB(cb->skb).portid,
2514 					  cb->nlh->nlmsg_seq, NLM_F_MULTI,
2515 					  RTM_NEWTFILTER, true) <= 0)
2516 				goto errout;
2517 			cb->args[1] = 1;
2518 		}
2519 		if (!tp->ops->walk)
2520 			continue;
2521 		arg.w.fn = tcf_node_dump;
2522 		arg.skb = skb;
2523 		arg.cb = cb;
2524 		arg.block = block;
2525 		arg.q = q;
2526 		arg.parent = parent;
2527 		arg.w.stop = 0;
2528 		arg.w.skip = cb->args[1] - 1;
2529 		arg.w.count = 0;
2530 		arg.w.cookie = cb->args[2];
2531 		tp->ops->walk(tp, &arg.w, true);
2532 		cb->args[2] = arg.w.cookie;
2533 		cb->args[1] = arg.w.count + 1;
2534 		if (arg.w.stop)
2535 			goto errout;
2536 	}
2537 	return true;
2538 
2539 errout:
2540 	tcf_proto_put(tp, true, NULL);
2541 	return false;
2542 }
2543 
2544 /* called with RTNL */
2545 static int tc_dump_tfilter(struct sk_buff *skb, struct netlink_callback *cb)
2546 {
2547 	struct tcf_chain *chain, *chain_prev;
2548 	struct net *net = sock_net(skb->sk);
2549 	struct nlattr *tca[TCA_MAX + 1];
2550 	struct Qdisc *q = NULL;
2551 	struct tcf_block *block;
2552 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
2553 	long index_start;
2554 	long index;
2555 	u32 parent;
2556 	int err;
2557 
2558 	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2559 		return skb->len;
2560 
2561 	err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2562 				     NULL, cb->extack);
2563 	if (err)
2564 		return err;
2565 
2566 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2567 		block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2568 		if (!block)
2569 			goto out;
2570 		/* If we work with block index, q is NULL and parent value
2571 		 * will never be used in the following code. The check
2572 		 * in tcf_fill_node prevents it. However, compiler does not
2573 		 * see that far, so set parent to zero to silence the warning
2574 		 * about parent being uninitialized.
2575 		 */
2576 		parent = 0;
2577 	} else {
2578 		const struct Qdisc_class_ops *cops;
2579 		struct net_device *dev;
2580 		unsigned long cl = 0;
2581 
2582 		dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2583 		if (!dev)
2584 			return skb->len;
2585 
2586 		parent = tcm->tcm_parent;
2587 		if (!parent) {
2588 			q = dev->qdisc;
2589 			parent = q->handle;
2590 		} else {
2591 			q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2592 		}
2593 		if (!q)
2594 			goto out;
2595 		cops = q->ops->cl_ops;
2596 		if (!cops)
2597 			goto out;
2598 		if (!cops->tcf_block)
2599 			goto out;
2600 		if (TC_H_MIN(tcm->tcm_parent)) {
2601 			cl = cops->find(q, tcm->tcm_parent);
2602 			if (cl == 0)
2603 				goto out;
2604 		}
2605 		block = cops->tcf_block(q, cl, NULL);
2606 		if (!block)
2607 			goto out;
2608 		if (tcf_block_shared(block))
2609 			q = NULL;
2610 	}
2611 
2612 	index_start = cb->args[0];
2613 	index = 0;
2614 
2615 	for (chain = __tcf_get_next_chain(block, NULL);
2616 	     chain;
2617 	     chain_prev = chain,
2618 		     chain = __tcf_get_next_chain(block, chain),
2619 		     tcf_chain_put(chain_prev)) {
2620 		if (tca[TCA_CHAIN] &&
2621 		    nla_get_u32(tca[TCA_CHAIN]) != chain->index)
2622 			continue;
2623 		if (!tcf_chain_dump(chain, q, parent, skb, cb,
2624 				    index_start, &index)) {
2625 			tcf_chain_put(chain);
2626 			err = -EMSGSIZE;
2627 			break;
2628 		}
2629 	}
2630 
2631 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
2632 		tcf_block_refcnt_put(block, true);
2633 	cb->args[0] = index;
2634 
2635 out:
2636 	/* If we did no progress, the error (EMSGSIZE) is real */
2637 	if (skb->len == 0 && err)
2638 		return err;
2639 	return skb->len;
2640 }
2641 
2642 static int tc_chain_fill_node(const struct tcf_proto_ops *tmplt_ops,
2643 			      void *tmplt_priv, u32 chain_index,
2644 			      struct net *net, struct sk_buff *skb,
2645 			      struct tcf_block *block,
2646 			      u32 portid, u32 seq, u16 flags, int event)
2647 {
2648 	unsigned char *b = skb_tail_pointer(skb);
2649 	const struct tcf_proto_ops *ops;
2650 	struct nlmsghdr *nlh;
2651 	struct tcmsg *tcm;
2652 	void *priv;
2653 
2654 	ops = tmplt_ops;
2655 	priv = tmplt_priv;
2656 
2657 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*tcm), flags);
2658 	if (!nlh)
2659 		goto out_nlmsg_trim;
2660 	tcm = nlmsg_data(nlh);
2661 	tcm->tcm_family = AF_UNSPEC;
2662 	tcm->tcm__pad1 = 0;
2663 	tcm->tcm__pad2 = 0;
2664 	tcm->tcm_handle = 0;
2665 	if (block->q) {
2666 		tcm->tcm_ifindex = qdisc_dev(block->q)->ifindex;
2667 		tcm->tcm_parent = block->q->handle;
2668 	} else {
2669 		tcm->tcm_ifindex = TCM_IFINDEX_MAGIC_BLOCK;
2670 		tcm->tcm_block_index = block->index;
2671 	}
2672 
2673 	if (nla_put_u32(skb, TCA_CHAIN, chain_index))
2674 		goto nla_put_failure;
2675 
2676 	if (ops) {
2677 		if (nla_put_string(skb, TCA_KIND, ops->kind))
2678 			goto nla_put_failure;
2679 		if (ops->tmplt_dump(skb, net, priv) < 0)
2680 			goto nla_put_failure;
2681 	}
2682 
2683 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2684 	return skb->len;
2685 
2686 out_nlmsg_trim:
2687 nla_put_failure:
2688 	nlmsg_trim(skb, b);
2689 	return -EMSGSIZE;
2690 }
2691 
2692 static int tc_chain_notify(struct tcf_chain *chain, struct sk_buff *oskb,
2693 			   u32 seq, u16 flags, int event, bool unicast)
2694 {
2695 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2696 	struct tcf_block *block = chain->block;
2697 	struct net *net = block->net;
2698 	struct sk_buff *skb;
2699 	int err = 0;
2700 
2701 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2702 	if (!skb)
2703 		return -ENOBUFS;
2704 
2705 	if (tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
2706 			       chain->index, net, skb, block, portid,
2707 			       seq, flags, event) <= 0) {
2708 		kfree_skb(skb);
2709 		return -EINVAL;
2710 	}
2711 
2712 	if (unicast)
2713 		err = netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2714 	else
2715 		err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
2716 				     flags & NLM_F_ECHO);
2717 
2718 	if (err > 0)
2719 		err = 0;
2720 	return err;
2721 }
2722 
2723 static int tc_chain_notify_delete(const struct tcf_proto_ops *tmplt_ops,
2724 				  void *tmplt_priv, u32 chain_index,
2725 				  struct tcf_block *block, struct sk_buff *oskb,
2726 				  u32 seq, u16 flags, bool unicast)
2727 {
2728 	u32 portid = oskb ? NETLINK_CB(oskb).portid : 0;
2729 	struct net *net = block->net;
2730 	struct sk_buff *skb;
2731 
2732 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
2733 	if (!skb)
2734 		return -ENOBUFS;
2735 
2736 	if (tc_chain_fill_node(tmplt_ops, tmplt_priv, chain_index, net, skb,
2737 			       block, portid, seq, flags, RTM_DELCHAIN) <= 0) {
2738 		kfree_skb(skb);
2739 		return -EINVAL;
2740 	}
2741 
2742 	if (unicast)
2743 		return netlink_unicast(net->rtnl, skb, portid, MSG_DONTWAIT);
2744 
2745 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
2746 }
2747 
2748 static int tc_chain_tmplt_add(struct tcf_chain *chain, struct net *net,
2749 			      struct nlattr **tca,
2750 			      struct netlink_ext_ack *extack)
2751 {
2752 	const struct tcf_proto_ops *ops;
2753 	void *tmplt_priv;
2754 
2755 	/* If kind is not set, user did not specify template. */
2756 	if (!tca[TCA_KIND])
2757 		return 0;
2758 
2759 	ops = tcf_proto_lookup_ops(nla_data(tca[TCA_KIND]), true, extack);
2760 	if (IS_ERR(ops))
2761 		return PTR_ERR(ops);
2762 	if (!ops->tmplt_create || !ops->tmplt_destroy || !ops->tmplt_dump) {
2763 		NL_SET_ERR_MSG(extack, "Chain templates are not supported with specified classifier");
2764 		return -EOPNOTSUPP;
2765 	}
2766 
2767 	tmplt_priv = ops->tmplt_create(net, chain, tca, extack);
2768 	if (IS_ERR(tmplt_priv)) {
2769 		module_put(ops->owner);
2770 		return PTR_ERR(tmplt_priv);
2771 	}
2772 	chain->tmplt_ops = ops;
2773 	chain->tmplt_priv = tmplt_priv;
2774 	return 0;
2775 }
2776 
2777 static void tc_chain_tmplt_del(const struct tcf_proto_ops *tmplt_ops,
2778 			       void *tmplt_priv)
2779 {
2780 	/* If template ops are set, no work to do for us. */
2781 	if (!tmplt_ops)
2782 		return;
2783 
2784 	tmplt_ops->tmplt_destroy(tmplt_priv);
2785 	module_put(tmplt_ops->owner);
2786 }
2787 
2788 /* Add/delete/get a chain */
2789 
2790 static int tc_ctl_chain(struct sk_buff *skb, struct nlmsghdr *n,
2791 			struct netlink_ext_ack *extack)
2792 {
2793 	struct net *net = sock_net(skb->sk);
2794 	struct nlattr *tca[TCA_MAX + 1];
2795 	struct tcmsg *t;
2796 	u32 parent;
2797 	u32 chain_index;
2798 	struct Qdisc *q = NULL;
2799 	struct tcf_chain *chain = NULL;
2800 	struct tcf_block *block;
2801 	unsigned long cl;
2802 	int err;
2803 
2804 	if (n->nlmsg_type != RTM_GETCHAIN &&
2805 	    !netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN))
2806 		return -EPERM;
2807 
2808 replay:
2809 	err = nlmsg_parse_deprecated(n, sizeof(*t), tca, TCA_MAX,
2810 				     rtm_tca_policy, extack);
2811 	if (err < 0)
2812 		return err;
2813 
2814 	t = nlmsg_data(n);
2815 	parent = t->tcm_parent;
2816 	cl = 0;
2817 
2818 	block = tcf_block_find(net, &q, &parent, &cl,
2819 			       t->tcm_ifindex, t->tcm_block_index, extack);
2820 	if (IS_ERR(block))
2821 		return PTR_ERR(block);
2822 
2823 	chain_index = tca[TCA_CHAIN] ? nla_get_u32(tca[TCA_CHAIN]) : 0;
2824 	if (chain_index > TC_ACT_EXT_VAL_MASK) {
2825 		NL_SET_ERR_MSG(extack, "Specified chain index exceeds upper limit");
2826 		err = -EINVAL;
2827 		goto errout_block;
2828 	}
2829 
2830 	mutex_lock(&block->lock);
2831 	chain = tcf_chain_lookup(block, chain_index);
2832 	if (n->nlmsg_type == RTM_NEWCHAIN) {
2833 		if (chain) {
2834 			if (tcf_chain_held_by_acts_only(chain)) {
2835 				/* The chain exists only because there is
2836 				 * some action referencing it.
2837 				 */
2838 				tcf_chain_hold(chain);
2839 			} else {
2840 				NL_SET_ERR_MSG(extack, "Filter chain already exists");
2841 				err = -EEXIST;
2842 				goto errout_block_locked;
2843 			}
2844 		} else {
2845 			if (!(n->nlmsg_flags & NLM_F_CREATE)) {
2846 				NL_SET_ERR_MSG(extack, "Need both RTM_NEWCHAIN and NLM_F_CREATE to create a new chain");
2847 				err = -ENOENT;
2848 				goto errout_block_locked;
2849 			}
2850 			chain = tcf_chain_create(block, chain_index);
2851 			if (!chain) {
2852 				NL_SET_ERR_MSG(extack, "Failed to create filter chain");
2853 				err = -ENOMEM;
2854 				goto errout_block_locked;
2855 			}
2856 		}
2857 	} else {
2858 		if (!chain || tcf_chain_held_by_acts_only(chain)) {
2859 			NL_SET_ERR_MSG(extack, "Cannot find specified filter chain");
2860 			err = -EINVAL;
2861 			goto errout_block_locked;
2862 		}
2863 		tcf_chain_hold(chain);
2864 	}
2865 
2866 	if (n->nlmsg_type == RTM_NEWCHAIN) {
2867 		/* Modifying chain requires holding parent block lock. In case
2868 		 * the chain was successfully added, take a reference to the
2869 		 * chain. This ensures that an empty chain does not disappear at
2870 		 * the end of this function.
2871 		 */
2872 		tcf_chain_hold(chain);
2873 		chain->explicitly_created = true;
2874 	}
2875 	mutex_unlock(&block->lock);
2876 
2877 	switch (n->nlmsg_type) {
2878 	case RTM_NEWCHAIN:
2879 		err = tc_chain_tmplt_add(chain, net, tca, extack);
2880 		if (err) {
2881 			tcf_chain_put_explicitly_created(chain);
2882 			goto errout;
2883 		}
2884 
2885 		tc_chain_notify(chain, NULL, 0, NLM_F_CREATE | NLM_F_EXCL,
2886 				RTM_NEWCHAIN, false);
2887 		break;
2888 	case RTM_DELCHAIN:
2889 		tfilter_notify_chain(net, skb, block, q, parent, n,
2890 				     chain, RTM_DELTFILTER, true);
2891 		/* Flush the chain first as the user requested chain removal. */
2892 		tcf_chain_flush(chain, true);
2893 		/* In case the chain was successfully deleted, put a reference
2894 		 * to the chain previously taken during addition.
2895 		 */
2896 		tcf_chain_put_explicitly_created(chain);
2897 		break;
2898 	case RTM_GETCHAIN:
2899 		err = tc_chain_notify(chain, skb, n->nlmsg_seq,
2900 				      n->nlmsg_seq, n->nlmsg_type, true);
2901 		if (err < 0)
2902 			NL_SET_ERR_MSG(extack, "Failed to send chain notify message");
2903 		break;
2904 	default:
2905 		err = -EOPNOTSUPP;
2906 		NL_SET_ERR_MSG(extack, "Unsupported message type");
2907 		goto errout;
2908 	}
2909 
2910 errout:
2911 	tcf_chain_put(chain);
2912 errout_block:
2913 	tcf_block_release(q, block, true);
2914 	if (err == -EAGAIN)
2915 		/* Replay the request. */
2916 		goto replay;
2917 	return err;
2918 
2919 errout_block_locked:
2920 	mutex_unlock(&block->lock);
2921 	goto errout_block;
2922 }
2923 
2924 /* called with RTNL */
2925 static int tc_dump_chain(struct sk_buff *skb, struct netlink_callback *cb)
2926 {
2927 	struct net *net = sock_net(skb->sk);
2928 	struct nlattr *tca[TCA_MAX + 1];
2929 	struct Qdisc *q = NULL;
2930 	struct tcf_block *block;
2931 	struct tcmsg *tcm = nlmsg_data(cb->nlh);
2932 	struct tcf_chain *chain;
2933 	long index_start;
2934 	long index;
2935 	u32 parent;
2936 	int err;
2937 
2938 	if (nlmsg_len(cb->nlh) < sizeof(*tcm))
2939 		return skb->len;
2940 
2941 	err = nlmsg_parse_deprecated(cb->nlh, sizeof(*tcm), tca, TCA_MAX,
2942 				     rtm_tca_policy, cb->extack);
2943 	if (err)
2944 		return err;
2945 
2946 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK) {
2947 		block = tcf_block_refcnt_get(net, tcm->tcm_block_index);
2948 		if (!block)
2949 			goto out;
2950 		/* If we work with block index, q is NULL and parent value
2951 		 * will never be used in the following code. The check
2952 		 * in tcf_fill_node prevents it. However, compiler does not
2953 		 * see that far, so set parent to zero to silence the warning
2954 		 * about parent being uninitialized.
2955 		 */
2956 		parent = 0;
2957 	} else {
2958 		const struct Qdisc_class_ops *cops;
2959 		struct net_device *dev;
2960 		unsigned long cl = 0;
2961 
2962 		dev = __dev_get_by_index(net, tcm->tcm_ifindex);
2963 		if (!dev)
2964 			return skb->len;
2965 
2966 		parent = tcm->tcm_parent;
2967 		if (!parent) {
2968 			q = dev->qdisc;
2969 			parent = q->handle;
2970 		} else {
2971 			q = qdisc_lookup(dev, TC_H_MAJ(tcm->tcm_parent));
2972 		}
2973 		if (!q)
2974 			goto out;
2975 		cops = q->ops->cl_ops;
2976 		if (!cops)
2977 			goto out;
2978 		if (!cops->tcf_block)
2979 			goto out;
2980 		if (TC_H_MIN(tcm->tcm_parent)) {
2981 			cl = cops->find(q, tcm->tcm_parent);
2982 			if (cl == 0)
2983 				goto out;
2984 		}
2985 		block = cops->tcf_block(q, cl, NULL);
2986 		if (!block)
2987 			goto out;
2988 		if (tcf_block_shared(block))
2989 			q = NULL;
2990 	}
2991 
2992 	index_start = cb->args[0];
2993 	index = 0;
2994 
2995 	mutex_lock(&block->lock);
2996 	list_for_each_entry(chain, &block->chain_list, list) {
2997 		if ((tca[TCA_CHAIN] &&
2998 		     nla_get_u32(tca[TCA_CHAIN]) != chain->index))
2999 			continue;
3000 		if (index < index_start) {
3001 			index++;
3002 			continue;
3003 		}
3004 		if (tcf_chain_held_by_acts_only(chain))
3005 			continue;
3006 		err = tc_chain_fill_node(chain->tmplt_ops, chain->tmplt_priv,
3007 					 chain->index, net, skb, block,
3008 					 NETLINK_CB(cb->skb).portid,
3009 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
3010 					 RTM_NEWCHAIN);
3011 		if (err <= 0)
3012 			break;
3013 		index++;
3014 	}
3015 	mutex_unlock(&block->lock);
3016 
3017 	if (tcm->tcm_ifindex == TCM_IFINDEX_MAGIC_BLOCK)
3018 		tcf_block_refcnt_put(block, true);
3019 	cb->args[0] = index;
3020 
3021 out:
3022 	/* If we did no progress, the error (EMSGSIZE) is real */
3023 	if (skb->len == 0 && err)
3024 		return err;
3025 	return skb->len;
3026 }
3027 
3028 void tcf_exts_destroy(struct tcf_exts *exts)
3029 {
3030 #ifdef CONFIG_NET_CLS_ACT
3031 	tcf_action_destroy(exts->actions, TCA_ACT_UNBIND);
3032 	kfree(exts->actions);
3033 	exts->nr_actions = 0;
3034 #endif
3035 }
3036 EXPORT_SYMBOL(tcf_exts_destroy);
3037 
3038 int tcf_exts_validate(struct net *net, struct tcf_proto *tp, struct nlattr **tb,
3039 		      struct nlattr *rate_tlv, struct tcf_exts *exts, bool ovr,
3040 		      bool rtnl_held, struct netlink_ext_ack *extack)
3041 {
3042 #ifdef CONFIG_NET_CLS_ACT
3043 	{
3044 		struct tc_action *act;
3045 		size_t attr_size = 0;
3046 
3047 		if (exts->police && tb[exts->police]) {
3048 			act = tcf_action_init_1(net, tp, tb[exts->police],
3049 						rate_tlv, "police", ovr,
3050 						TCA_ACT_BIND, rtnl_held,
3051 						extack);
3052 			if (IS_ERR(act))
3053 				return PTR_ERR(act);
3054 
3055 			act->type = exts->type = TCA_OLD_COMPAT;
3056 			exts->actions[0] = act;
3057 			exts->nr_actions = 1;
3058 		} else if (exts->action && tb[exts->action]) {
3059 			int err;
3060 
3061 			err = tcf_action_init(net, tp, tb[exts->action],
3062 					      rate_tlv, NULL, ovr, TCA_ACT_BIND,
3063 					      exts->actions, &attr_size,
3064 					      rtnl_held, extack);
3065 			if (err < 0)
3066 				return err;
3067 			exts->nr_actions = err;
3068 		}
3069 	}
3070 #else
3071 	if ((exts->action && tb[exts->action]) ||
3072 	    (exts->police && tb[exts->police])) {
3073 		NL_SET_ERR_MSG(extack, "Classifier actions are not supported per compile options (CONFIG_NET_CLS_ACT)");
3074 		return -EOPNOTSUPP;
3075 	}
3076 #endif
3077 
3078 	return 0;
3079 }
3080 EXPORT_SYMBOL(tcf_exts_validate);
3081 
3082 void tcf_exts_change(struct tcf_exts *dst, struct tcf_exts *src)
3083 {
3084 #ifdef CONFIG_NET_CLS_ACT
3085 	struct tcf_exts old = *dst;
3086 
3087 	*dst = *src;
3088 	tcf_exts_destroy(&old);
3089 #endif
3090 }
3091 EXPORT_SYMBOL(tcf_exts_change);
3092 
3093 #ifdef CONFIG_NET_CLS_ACT
3094 static struct tc_action *tcf_exts_first_act(struct tcf_exts *exts)
3095 {
3096 	if (exts->nr_actions == 0)
3097 		return NULL;
3098 	else
3099 		return exts->actions[0];
3100 }
3101 #endif
3102 
3103 int tcf_exts_dump(struct sk_buff *skb, struct tcf_exts *exts)
3104 {
3105 #ifdef CONFIG_NET_CLS_ACT
3106 	struct nlattr *nest;
3107 
3108 	if (exts->action && tcf_exts_has_actions(exts)) {
3109 		/*
3110 		 * again for backward compatible mode - we want
3111 		 * to work with both old and new modes of entering
3112 		 * tc data even if iproute2  was newer - jhs
3113 		 */
3114 		if (exts->type != TCA_OLD_COMPAT) {
3115 			nest = nla_nest_start_noflag(skb, exts->action);
3116 			if (nest == NULL)
3117 				goto nla_put_failure;
3118 
3119 			if (tcf_action_dump(skb, exts->actions, 0, 0) < 0)
3120 				goto nla_put_failure;
3121 			nla_nest_end(skb, nest);
3122 		} else if (exts->police) {
3123 			struct tc_action *act = tcf_exts_first_act(exts);
3124 			nest = nla_nest_start_noflag(skb, exts->police);
3125 			if (nest == NULL || !act)
3126 				goto nla_put_failure;
3127 			if (tcf_action_dump_old(skb, act, 0, 0) < 0)
3128 				goto nla_put_failure;
3129 			nla_nest_end(skb, nest);
3130 		}
3131 	}
3132 	return 0;
3133 
3134 nla_put_failure:
3135 	nla_nest_cancel(skb, nest);
3136 	return -1;
3137 #else
3138 	return 0;
3139 #endif
3140 }
3141 EXPORT_SYMBOL(tcf_exts_dump);
3142 
3143 
3144 int tcf_exts_dump_stats(struct sk_buff *skb, struct tcf_exts *exts)
3145 {
3146 #ifdef CONFIG_NET_CLS_ACT
3147 	struct tc_action *a = tcf_exts_first_act(exts);
3148 	if (a != NULL && tcf_action_copy_stats(skb, a, 1) < 0)
3149 		return -1;
3150 #endif
3151 	return 0;
3152 }
3153 EXPORT_SYMBOL(tcf_exts_dump_stats);
3154 
3155 int tc_setup_cb_call(struct tcf_block *block, enum tc_setup_type type,
3156 		     void *type_data, bool err_stop)
3157 {
3158 	struct tcf_block_cb *block_cb;
3159 	int ok_count = 0;
3160 	int err;
3161 
3162 	/* Make sure all netdevs sharing this block are offload-capable. */
3163 	if (block->nooffloaddevcnt && err_stop)
3164 		return -EOPNOTSUPP;
3165 
3166 	list_for_each_entry(block_cb, &block->cb_list, list) {
3167 		err = block_cb->cb(type, type_data, block_cb->cb_priv);
3168 		if (err) {
3169 			if (err_stop)
3170 				return err;
3171 		} else {
3172 			ok_count++;
3173 		}
3174 	}
3175 	return ok_count;
3176 }
3177 EXPORT_SYMBOL(tc_setup_cb_call);
3178 
3179 int tc_setup_flow_action(struct flow_action *flow_action,
3180 			 const struct tcf_exts *exts)
3181 {
3182 	const struct tc_action *act;
3183 	int i, j, k;
3184 
3185 	if (!exts)
3186 		return 0;
3187 
3188 	j = 0;
3189 	tcf_exts_for_each_action(i, act, exts) {
3190 		struct flow_action_entry *entry;
3191 
3192 		entry = &flow_action->entries[j];
3193 		if (is_tcf_gact_ok(act)) {
3194 			entry->id = FLOW_ACTION_ACCEPT;
3195 		} else if (is_tcf_gact_shot(act)) {
3196 			entry->id = FLOW_ACTION_DROP;
3197 		} else if (is_tcf_gact_trap(act)) {
3198 			entry->id = FLOW_ACTION_TRAP;
3199 		} else if (is_tcf_gact_goto_chain(act)) {
3200 			entry->id = FLOW_ACTION_GOTO;
3201 			entry->chain_index = tcf_gact_goto_chain_index(act);
3202 		} else if (is_tcf_mirred_egress_redirect(act)) {
3203 			entry->id = FLOW_ACTION_REDIRECT;
3204 			entry->dev = tcf_mirred_dev(act);
3205 		} else if (is_tcf_mirred_egress_mirror(act)) {
3206 			entry->id = FLOW_ACTION_MIRRED;
3207 			entry->dev = tcf_mirred_dev(act);
3208 		} else if (is_tcf_vlan(act)) {
3209 			switch (tcf_vlan_action(act)) {
3210 			case TCA_VLAN_ACT_PUSH:
3211 				entry->id = FLOW_ACTION_VLAN_PUSH;
3212 				entry->vlan.vid = tcf_vlan_push_vid(act);
3213 				entry->vlan.proto = tcf_vlan_push_proto(act);
3214 				entry->vlan.prio = tcf_vlan_push_prio(act);
3215 				break;
3216 			case TCA_VLAN_ACT_POP:
3217 				entry->id = FLOW_ACTION_VLAN_POP;
3218 				break;
3219 			case TCA_VLAN_ACT_MODIFY:
3220 				entry->id = FLOW_ACTION_VLAN_MANGLE;
3221 				entry->vlan.vid = tcf_vlan_push_vid(act);
3222 				entry->vlan.proto = tcf_vlan_push_proto(act);
3223 				entry->vlan.prio = tcf_vlan_push_prio(act);
3224 				break;
3225 			default:
3226 				goto err_out;
3227 			}
3228 		} else if (is_tcf_tunnel_set(act)) {
3229 			entry->id = FLOW_ACTION_TUNNEL_ENCAP;
3230 			entry->tunnel = tcf_tunnel_info(act);
3231 		} else if (is_tcf_tunnel_release(act)) {
3232 			entry->id = FLOW_ACTION_TUNNEL_DECAP;
3233 		} else if (is_tcf_pedit(act)) {
3234 			for (k = 0; k < tcf_pedit_nkeys(act); k++) {
3235 				switch (tcf_pedit_cmd(act, k)) {
3236 				case TCA_PEDIT_KEY_EX_CMD_SET:
3237 					entry->id = FLOW_ACTION_MANGLE;
3238 					break;
3239 				case TCA_PEDIT_KEY_EX_CMD_ADD:
3240 					entry->id = FLOW_ACTION_ADD;
3241 					break;
3242 				default:
3243 					goto err_out;
3244 				}
3245 				entry->mangle.htype = tcf_pedit_htype(act, k);
3246 				entry->mangle.mask = tcf_pedit_mask(act, k);
3247 				entry->mangle.val = tcf_pedit_val(act, k);
3248 				entry->mangle.offset = tcf_pedit_offset(act, k);
3249 				entry = &flow_action->entries[++j];
3250 			}
3251 		} else if (is_tcf_csum(act)) {
3252 			entry->id = FLOW_ACTION_CSUM;
3253 			entry->csum_flags = tcf_csum_update_flags(act);
3254 		} else if (is_tcf_skbedit_mark(act)) {
3255 			entry->id = FLOW_ACTION_MARK;
3256 			entry->mark = tcf_skbedit_mark(act);
3257 		} else if (is_tcf_sample(act)) {
3258 			entry->id = FLOW_ACTION_SAMPLE;
3259 			entry->sample.psample_group =
3260 				tcf_sample_psample_group(act);
3261 			entry->sample.trunc_size = tcf_sample_trunc_size(act);
3262 			entry->sample.truncate = tcf_sample_truncate(act);
3263 			entry->sample.rate = tcf_sample_rate(act);
3264 		} else if (is_tcf_police(act)) {
3265 			entry->id = FLOW_ACTION_POLICE;
3266 			entry->police.burst = tcf_police_tcfp_burst(act);
3267 			entry->police.rate_bytes_ps =
3268 				tcf_police_rate_bytes_ps(act);
3269 		} else {
3270 			goto err_out;
3271 		}
3272 
3273 		if (!is_tcf_pedit(act))
3274 			j++;
3275 	}
3276 	return 0;
3277 err_out:
3278 	return -EOPNOTSUPP;
3279 }
3280 EXPORT_SYMBOL(tc_setup_flow_action);
3281 
3282 unsigned int tcf_exts_num_actions(struct tcf_exts *exts)
3283 {
3284 	unsigned int num_acts = 0;
3285 	struct tc_action *act;
3286 	int i;
3287 
3288 	tcf_exts_for_each_action(i, act, exts) {
3289 		if (is_tcf_pedit(act))
3290 			num_acts += tcf_pedit_nkeys(act);
3291 		else
3292 			num_acts++;
3293 	}
3294 	return num_acts;
3295 }
3296 EXPORT_SYMBOL(tcf_exts_num_actions);
3297 
3298 static __net_init int tcf_net_init(struct net *net)
3299 {
3300 	struct tcf_net *tn = net_generic(net, tcf_net_id);
3301 
3302 	spin_lock_init(&tn->idr_lock);
3303 	idr_init(&tn->idr);
3304 	return 0;
3305 }
3306 
3307 static void __net_exit tcf_net_exit(struct net *net)
3308 {
3309 	struct tcf_net *tn = net_generic(net, tcf_net_id);
3310 
3311 	idr_destroy(&tn->idr);
3312 }
3313 
3314 static struct pernet_operations tcf_net_ops = {
3315 	.init = tcf_net_init,
3316 	.exit = tcf_net_exit,
3317 	.id   = &tcf_net_id,
3318 	.size = sizeof(struct tcf_net),
3319 };
3320 
3321 static int __init tc_filter_init(void)
3322 {
3323 	int err;
3324 
3325 	tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
3326 	if (!tc_filter_wq)
3327 		return -ENOMEM;
3328 
3329 	err = register_pernet_subsys(&tcf_net_ops);
3330 	if (err)
3331 		goto err_register_pernet_subsys;
3332 
3333 	err = rhashtable_init(&indr_setup_block_ht,
3334 			      &tc_indr_setup_block_ht_params);
3335 	if (err)
3336 		goto err_rhash_setup_block_ht;
3337 
3338 	rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_new_tfilter, NULL,
3339 		      RTNL_FLAG_DOIT_UNLOCKED);
3340 	rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_del_tfilter, NULL,
3341 		      RTNL_FLAG_DOIT_UNLOCKED);
3342 	rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_get_tfilter,
3343 		      tc_dump_tfilter, RTNL_FLAG_DOIT_UNLOCKED);
3344 	rtnl_register(PF_UNSPEC, RTM_NEWCHAIN, tc_ctl_chain, NULL, 0);
3345 	rtnl_register(PF_UNSPEC, RTM_DELCHAIN, tc_ctl_chain, NULL, 0);
3346 	rtnl_register(PF_UNSPEC, RTM_GETCHAIN, tc_ctl_chain,
3347 		      tc_dump_chain, 0);
3348 
3349 	return 0;
3350 
3351 err_rhash_setup_block_ht:
3352 	unregister_pernet_subsys(&tcf_net_ops);
3353 err_register_pernet_subsys:
3354 	destroy_workqueue(tc_filter_wq);
3355 	return err;
3356 }
3357 
3358 subsys_initcall(tc_filter_init);
3359