xref: /openbmc/linux/net/sched/act_api.c (revision 1804569d)
1 /*
2  * net/sched/act_api.c	Packet action API.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  * Author:	Jamal Hadi Salim
10  *
11  *
12  */
13 
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/skbuff.h>
20 #include <linux/init.h>
21 #include <linux/kmod.h>
22 #include <linux/err.h>
23 #include <linux/module.h>
24 #include <net/net_namespace.h>
25 #include <net/sock.h>
26 #include <net/sch_generic.h>
27 #include <net/pkt_cls.h>
28 #include <net/act_api.h>
29 #include <net/netlink.h>
30 
31 static void tcf_action_goto_chain_exec(const struct tc_action *a,
32 				       struct tcf_result *res)
33 {
34 	const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
35 
36 	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
37 }
38 
39 static void tcf_free_cookie_rcu(struct rcu_head *p)
40 {
41 	struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
42 
43 	kfree(cookie->data);
44 	kfree(cookie);
45 }
46 
47 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
48 				  struct tc_cookie *new_cookie)
49 {
50 	struct tc_cookie *old;
51 
52 	old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
53 	if (old)
54 		call_rcu(&old->rcu, tcf_free_cookie_rcu);
55 }
56 
57 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
58 			     struct tcf_chain **newchain,
59 			     struct netlink_ext_ack *extack)
60 {
61 	int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
62 	u32 chain_index;
63 
64 	if (!opcode)
65 		ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
66 	else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
67 		ret = 0;
68 	if (ret) {
69 		NL_SET_ERR_MSG(extack, "invalid control action");
70 		goto end;
71 	}
72 
73 	if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
74 		chain_index = action & TC_ACT_EXT_VAL_MASK;
75 		if (!tp || !newchain) {
76 			ret = -EINVAL;
77 			NL_SET_ERR_MSG(extack,
78 				       "can't goto NULL proto/chain");
79 			goto end;
80 		}
81 		*newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
82 		if (!*newchain) {
83 			ret = -ENOMEM;
84 			NL_SET_ERR_MSG(extack,
85 				       "can't allocate goto_chain");
86 		}
87 	}
88 end:
89 	return ret;
90 }
91 EXPORT_SYMBOL(tcf_action_check_ctrlact);
92 
93 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
94 					 struct tcf_chain *goto_chain)
95 {
96 	a->tcfa_action = action;
97 	rcu_swap_protected(a->goto_chain, goto_chain, 1);
98 	return goto_chain;
99 }
100 EXPORT_SYMBOL(tcf_action_set_ctrlact);
101 
102 /* XXX: For standalone actions, we don't need a RCU grace period either, because
103  * actions are always connected to filters and filters are already destroyed in
104  * RCU callbacks, so after a RCU grace period actions are already disconnected
105  * from filters. Readers later can not find us.
106  */
107 static void free_tcf(struct tc_action *p)
108 {
109 	struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
110 
111 	free_percpu(p->cpu_bstats);
112 	free_percpu(p->cpu_bstats_hw);
113 	free_percpu(p->cpu_qstats);
114 
115 	tcf_set_action_cookie(&p->act_cookie, NULL);
116 	if (chain)
117 		tcf_chain_put_by_act(chain);
118 
119 	kfree(p);
120 }
121 
122 static void tcf_action_cleanup(struct tc_action *p)
123 {
124 	if (p->ops->cleanup)
125 		p->ops->cleanup(p);
126 
127 	gen_kill_estimator(&p->tcfa_rate_est);
128 	free_tcf(p);
129 }
130 
131 static int __tcf_action_put(struct tc_action *p, bool bind)
132 {
133 	struct tcf_idrinfo *idrinfo = p->idrinfo;
134 
135 	if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
136 		if (bind)
137 			atomic_dec(&p->tcfa_bindcnt);
138 		idr_remove(&idrinfo->action_idr, p->tcfa_index);
139 		mutex_unlock(&idrinfo->lock);
140 
141 		tcf_action_cleanup(p);
142 		return 1;
143 	}
144 
145 	if (bind)
146 		atomic_dec(&p->tcfa_bindcnt);
147 
148 	return 0;
149 }
150 
151 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
152 {
153 	int ret = 0;
154 
155 	/* Release with strict==1 and bind==0 is only called through act API
156 	 * interface (classifiers always bind). Only case when action with
157 	 * positive reference count and zero bind count can exist is when it was
158 	 * also created with act API (unbinding last classifier will destroy the
159 	 * action if it was created by classifier). So only case when bind count
160 	 * can be changed after initial check is when unbound action is
161 	 * destroyed by act API while classifier binds to action with same id
162 	 * concurrently. This result either creation of new action(same behavior
163 	 * as before), or reusing existing action if concurrent process
164 	 * increments reference count before action is deleted. Both scenarios
165 	 * are acceptable.
166 	 */
167 	if (p) {
168 		if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
169 			return -EPERM;
170 
171 		if (__tcf_action_put(p, bind))
172 			ret = ACT_P_DELETED;
173 	}
174 
175 	return ret;
176 }
177 EXPORT_SYMBOL(__tcf_idr_release);
178 
179 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
180 {
181 	struct tc_cookie *act_cookie;
182 	u32 cookie_len = 0;
183 
184 	rcu_read_lock();
185 	act_cookie = rcu_dereference(act->act_cookie);
186 
187 	if (act_cookie)
188 		cookie_len = nla_total_size(act_cookie->len);
189 	rcu_read_unlock();
190 
191 	return  nla_total_size(0) /* action number nested */
192 		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
193 		+ cookie_len /* TCA_ACT_COOKIE */
194 		+ nla_total_size(0) /* TCA_ACT_STATS nested */
195 		/* TCA_STATS_BASIC */
196 		+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
197 		/* TCA_STATS_QUEUE */
198 		+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
199 		+ nla_total_size(0) /* TCA_OPTIONS nested */
200 		+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
201 }
202 
203 static size_t tcf_action_full_attrs_size(size_t sz)
204 {
205 	return NLMSG_HDRLEN                     /* struct nlmsghdr */
206 		+ sizeof(struct tcamsg)
207 		+ nla_total_size(0)             /* TCA_ACT_TAB nested */
208 		+ sz;
209 }
210 
211 static size_t tcf_action_fill_size(const struct tc_action *act)
212 {
213 	size_t sz = tcf_action_shared_attrs_size(act);
214 
215 	if (act->ops->get_fill_size)
216 		return act->ops->get_fill_size(act) + sz;
217 	return sz;
218 }
219 
220 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
221 			   struct netlink_callback *cb)
222 {
223 	int err = 0, index = -1, s_i = 0, n_i = 0;
224 	u32 act_flags = cb->args[2];
225 	unsigned long jiffy_since = cb->args[3];
226 	struct nlattr *nest;
227 	struct idr *idr = &idrinfo->action_idr;
228 	struct tc_action *p;
229 	unsigned long id = 1;
230 
231 	mutex_lock(&idrinfo->lock);
232 
233 	s_i = cb->args[0];
234 
235 	idr_for_each_entry_ul(idr, p, id) {
236 		index++;
237 		if (index < s_i)
238 			continue;
239 
240 		if (jiffy_since &&
241 		    time_after(jiffy_since,
242 			       (unsigned long)p->tcfa_tm.lastuse))
243 			continue;
244 
245 		nest = nla_nest_start(skb, n_i);
246 		if (!nest) {
247 			index--;
248 			goto nla_put_failure;
249 		}
250 		err = tcf_action_dump_1(skb, p, 0, 0);
251 		if (err < 0) {
252 			index--;
253 			nlmsg_trim(skb, nest);
254 			goto done;
255 		}
256 		nla_nest_end(skb, nest);
257 		n_i++;
258 		if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
259 		    n_i >= TCA_ACT_MAX_PRIO)
260 			goto done;
261 	}
262 done:
263 	if (index >= 0)
264 		cb->args[0] = index + 1;
265 
266 	mutex_unlock(&idrinfo->lock);
267 	if (n_i) {
268 		if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
269 			cb->args[1] = n_i;
270 	}
271 	return n_i;
272 
273 nla_put_failure:
274 	nla_nest_cancel(skb, nest);
275 	goto done;
276 }
277 
278 static int tcf_idr_release_unsafe(struct tc_action *p)
279 {
280 	if (atomic_read(&p->tcfa_bindcnt) > 0)
281 		return -EPERM;
282 
283 	if (refcount_dec_and_test(&p->tcfa_refcnt)) {
284 		idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
285 		tcf_action_cleanup(p);
286 		return ACT_P_DELETED;
287 	}
288 
289 	return 0;
290 }
291 
292 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
293 			  const struct tc_action_ops *ops)
294 {
295 	struct nlattr *nest;
296 	int n_i = 0;
297 	int ret = -EINVAL;
298 	struct idr *idr = &idrinfo->action_idr;
299 	struct tc_action *p;
300 	unsigned long id = 1;
301 
302 	nest = nla_nest_start(skb, 0);
303 	if (nest == NULL)
304 		goto nla_put_failure;
305 	if (nla_put_string(skb, TCA_KIND, ops->kind))
306 		goto nla_put_failure;
307 
308 	mutex_lock(&idrinfo->lock);
309 	idr_for_each_entry_ul(idr, p, id) {
310 		ret = tcf_idr_release_unsafe(p);
311 		if (ret == ACT_P_DELETED) {
312 			module_put(ops->owner);
313 			n_i++;
314 		} else if (ret < 0) {
315 			mutex_unlock(&idrinfo->lock);
316 			goto nla_put_failure;
317 		}
318 	}
319 	mutex_unlock(&idrinfo->lock);
320 
321 	if (nla_put_u32(skb, TCA_FCNT, n_i))
322 		goto nla_put_failure;
323 	nla_nest_end(skb, nest);
324 
325 	return n_i;
326 nla_put_failure:
327 	nla_nest_cancel(skb, nest);
328 	return ret;
329 }
330 
331 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
332 		       struct netlink_callback *cb, int type,
333 		       const struct tc_action_ops *ops,
334 		       struct netlink_ext_ack *extack)
335 {
336 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
337 
338 	if (type == RTM_DELACTION) {
339 		return tcf_del_walker(idrinfo, skb, ops);
340 	} else if (type == RTM_GETACTION) {
341 		return tcf_dump_walker(idrinfo, skb, cb);
342 	} else {
343 		WARN(1, "tcf_generic_walker: unknown command %d\n", type);
344 		NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
345 		return -EINVAL;
346 	}
347 }
348 EXPORT_SYMBOL(tcf_generic_walker);
349 
350 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
351 {
352 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
353 	struct tc_action *p;
354 
355 	mutex_lock(&idrinfo->lock);
356 	p = idr_find(&idrinfo->action_idr, index);
357 	if (IS_ERR(p))
358 		p = NULL;
359 	else if (p)
360 		refcount_inc(&p->tcfa_refcnt);
361 	mutex_unlock(&idrinfo->lock);
362 
363 	if (p) {
364 		*a = p;
365 		return true;
366 	}
367 	return false;
368 }
369 EXPORT_SYMBOL(tcf_idr_search);
370 
371 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
372 {
373 	struct tc_action *p;
374 	int ret = 0;
375 
376 	mutex_lock(&idrinfo->lock);
377 	p = idr_find(&idrinfo->action_idr, index);
378 	if (!p) {
379 		mutex_unlock(&idrinfo->lock);
380 		return -ENOENT;
381 	}
382 
383 	if (!atomic_read(&p->tcfa_bindcnt)) {
384 		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
385 			struct module *owner = p->ops->owner;
386 
387 			WARN_ON(p != idr_remove(&idrinfo->action_idr,
388 						p->tcfa_index));
389 			mutex_unlock(&idrinfo->lock);
390 
391 			tcf_action_cleanup(p);
392 			module_put(owner);
393 			return 0;
394 		}
395 		ret = 0;
396 	} else {
397 		ret = -EPERM;
398 	}
399 
400 	mutex_unlock(&idrinfo->lock);
401 	return ret;
402 }
403 
404 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
405 		   struct tc_action **a, const struct tc_action_ops *ops,
406 		   int bind, bool cpustats)
407 {
408 	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
409 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
410 	int err = -ENOMEM;
411 
412 	if (unlikely(!p))
413 		return -ENOMEM;
414 	refcount_set(&p->tcfa_refcnt, 1);
415 	if (bind)
416 		atomic_set(&p->tcfa_bindcnt, 1);
417 
418 	if (cpustats) {
419 		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
420 		if (!p->cpu_bstats)
421 			goto err1;
422 		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
423 		if (!p->cpu_bstats_hw)
424 			goto err2;
425 		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
426 		if (!p->cpu_qstats)
427 			goto err3;
428 	}
429 	spin_lock_init(&p->tcfa_lock);
430 	p->tcfa_index = index;
431 	p->tcfa_tm.install = jiffies;
432 	p->tcfa_tm.lastuse = jiffies;
433 	p->tcfa_tm.firstuse = 0;
434 	if (est) {
435 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
436 					&p->tcfa_rate_est,
437 					&p->tcfa_lock, NULL, est);
438 		if (err)
439 			goto err4;
440 	}
441 
442 	p->idrinfo = idrinfo;
443 	p->ops = ops;
444 	*a = p;
445 	return 0;
446 err4:
447 	free_percpu(p->cpu_qstats);
448 err3:
449 	free_percpu(p->cpu_bstats_hw);
450 err2:
451 	free_percpu(p->cpu_bstats);
452 err1:
453 	kfree(p);
454 	return err;
455 }
456 EXPORT_SYMBOL(tcf_idr_create);
457 
458 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
459 {
460 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
461 
462 	mutex_lock(&idrinfo->lock);
463 	/* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
464 	WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
465 	mutex_unlock(&idrinfo->lock);
466 }
467 EXPORT_SYMBOL(tcf_idr_insert);
468 
469 /* Cleanup idr index that was allocated but not initialized. */
470 
471 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
472 {
473 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
474 
475 	mutex_lock(&idrinfo->lock);
476 	/* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
477 	WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
478 	mutex_unlock(&idrinfo->lock);
479 }
480 EXPORT_SYMBOL(tcf_idr_cleanup);
481 
482 /* Check if action with specified index exists. If actions is found, increments
483  * its reference and bind counters, and return 1. Otherwise insert temporary
484  * error pointer (to prevent concurrent users from inserting actions with same
485  * index) and return 0.
486  */
487 
488 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
489 			struct tc_action **a, int bind)
490 {
491 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
492 	struct tc_action *p;
493 	int ret;
494 
495 again:
496 	mutex_lock(&idrinfo->lock);
497 	if (*index) {
498 		p = idr_find(&idrinfo->action_idr, *index);
499 		if (IS_ERR(p)) {
500 			/* This means that another process allocated
501 			 * index but did not assign the pointer yet.
502 			 */
503 			mutex_unlock(&idrinfo->lock);
504 			goto again;
505 		}
506 
507 		if (p) {
508 			refcount_inc(&p->tcfa_refcnt);
509 			if (bind)
510 				atomic_inc(&p->tcfa_bindcnt);
511 			*a = p;
512 			ret = 1;
513 		} else {
514 			*a = NULL;
515 			ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
516 					    *index, GFP_KERNEL);
517 			if (!ret)
518 				idr_replace(&idrinfo->action_idr,
519 					    ERR_PTR(-EBUSY), *index);
520 		}
521 	} else {
522 		*index = 1;
523 		*a = NULL;
524 		ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
525 				    UINT_MAX, GFP_KERNEL);
526 		if (!ret)
527 			idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
528 				    *index);
529 	}
530 	mutex_unlock(&idrinfo->lock);
531 	return ret;
532 }
533 EXPORT_SYMBOL(tcf_idr_check_alloc);
534 
535 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
536 			 struct tcf_idrinfo *idrinfo)
537 {
538 	struct idr *idr = &idrinfo->action_idr;
539 	struct tc_action *p;
540 	int ret;
541 	unsigned long id = 1;
542 
543 	idr_for_each_entry_ul(idr, p, id) {
544 		ret = __tcf_idr_release(p, false, true);
545 		if (ret == ACT_P_DELETED)
546 			module_put(ops->owner);
547 		else if (ret < 0)
548 			return;
549 	}
550 	idr_destroy(&idrinfo->action_idr);
551 }
552 EXPORT_SYMBOL(tcf_idrinfo_destroy);
553 
554 static LIST_HEAD(act_base);
555 static DEFINE_RWLOCK(act_mod_lock);
556 
557 int tcf_register_action(struct tc_action_ops *act,
558 			struct pernet_operations *ops)
559 {
560 	struct tc_action_ops *a;
561 	int ret;
562 
563 	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
564 		return -EINVAL;
565 
566 	/* We have to register pernet ops before making the action ops visible,
567 	 * otherwise tcf_action_init_1() could get a partially initialized
568 	 * netns.
569 	 */
570 	ret = register_pernet_subsys(ops);
571 	if (ret)
572 		return ret;
573 
574 	write_lock(&act_mod_lock);
575 	list_for_each_entry(a, &act_base, head) {
576 		if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
577 			write_unlock(&act_mod_lock);
578 			unregister_pernet_subsys(ops);
579 			return -EEXIST;
580 		}
581 	}
582 	list_add_tail(&act->head, &act_base);
583 	write_unlock(&act_mod_lock);
584 
585 	return 0;
586 }
587 EXPORT_SYMBOL(tcf_register_action);
588 
589 int tcf_unregister_action(struct tc_action_ops *act,
590 			  struct pernet_operations *ops)
591 {
592 	struct tc_action_ops *a;
593 	int err = -ENOENT;
594 
595 	write_lock(&act_mod_lock);
596 	list_for_each_entry(a, &act_base, head) {
597 		if (a == act) {
598 			list_del(&act->head);
599 			err = 0;
600 			break;
601 		}
602 	}
603 	write_unlock(&act_mod_lock);
604 	if (!err)
605 		unregister_pernet_subsys(ops);
606 	return err;
607 }
608 EXPORT_SYMBOL(tcf_unregister_action);
609 
610 /* lookup by name */
611 static struct tc_action_ops *tc_lookup_action_n(char *kind)
612 {
613 	struct tc_action_ops *a, *res = NULL;
614 
615 	if (kind) {
616 		read_lock(&act_mod_lock);
617 		list_for_each_entry(a, &act_base, head) {
618 			if (strcmp(kind, a->kind) == 0) {
619 				if (try_module_get(a->owner))
620 					res = a;
621 				break;
622 			}
623 		}
624 		read_unlock(&act_mod_lock);
625 	}
626 	return res;
627 }
628 
629 /* lookup by nlattr */
630 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
631 {
632 	struct tc_action_ops *a, *res = NULL;
633 
634 	if (kind) {
635 		read_lock(&act_mod_lock);
636 		list_for_each_entry(a, &act_base, head) {
637 			if (nla_strcmp(kind, a->kind) == 0) {
638 				if (try_module_get(a->owner))
639 					res = a;
640 				break;
641 			}
642 		}
643 		read_unlock(&act_mod_lock);
644 	}
645 	return res;
646 }
647 
648 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
649 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
650 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
651 		    int nr_actions, struct tcf_result *res)
652 {
653 	u32 jmp_prgcnt = 0;
654 	u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
655 	int i;
656 	int ret = TC_ACT_OK;
657 
658 	if (skb_skip_tc_classify(skb))
659 		return TC_ACT_OK;
660 
661 restart_act_graph:
662 	for (i = 0; i < nr_actions; i++) {
663 		const struct tc_action *a = actions[i];
664 
665 		if (jmp_prgcnt > 0) {
666 			jmp_prgcnt -= 1;
667 			continue;
668 		}
669 repeat:
670 		ret = a->ops->act(skb, a, res);
671 		if (ret == TC_ACT_REPEAT)
672 			goto repeat;	/* we need a ttl - JHS */
673 
674 		if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
675 			jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
676 			if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
677 				/* faulty opcode, stop pipeline */
678 				return TC_ACT_OK;
679 			} else {
680 				jmp_ttl -= 1;
681 				if (jmp_ttl > 0)
682 					goto restart_act_graph;
683 				else /* faulty graph, stop pipeline */
684 					return TC_ACT_OK;
685 			}
686 		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
687 			if (unlikely(!rcu_access_pointer(a->goto_chain))) {
688 				net_warn_ratelimited("can't go to NULL chain!\n");
689 				return TC_ACT_SHOT;
690 			}
691 			tcf_action_goto_chain_exec(a, res);
692 		}
693 
694 		if (ret != TC_ACT_PIPE)
695 			break;
696 	}
697 
698 	return ret;
699 }
700 EXPORT_SYMBOL(tcf_action_exec);
701 
702 int tcf_action_destroy(struct tc_action *actions[], int bind)
703 {
704 	const struct tc_action_ops *ops;
705 	struct tc_action *a;
706 	int ret = 0, i;
707 
708 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
709 		a = actions[i];
710 		actions[i] = NULL;
711 		ops = a->ops;
712 		ret = __tcf_idr_release(a, bind, true);
713 		if (ret == ACT_P_DELETED)
714 			module_put(ops->owner);
715 		else if (ret < 0)
716 			return ret;
717 	}
718 	return ret;
719 }
720 
721 static int tcf_action_destroy_1(struct tc_action *a, int bind)
722 {
723 	struct tc_action *actions[] = { a, NULL };
724 
725 	return tcf_action_destroy(actions, bind);
726 }
727 
728 static int tcf_action_put(struct tc_action *p)
729 {
730 	return __tcf_action_put(p, false);
731 }
732 
733 /* Put all actions in this array, skip those NULL's. */
734 static void tcf_action_put_many(struct tc_action *actions[])
735 {
736 	int i;
737 
738 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
739 		struct tc_action *a = actions[i];
740 		const struct tc_action_ops *ops;
741 
742 		if (!a)
743 			continue;
744 		ops = a->ops;
745 		if (tcf_action_put(a))
746 			module_put(ops->owner);
747 	}
748 }
749 
750 int
751 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
752 {
753 	return a->ops->dump(skb, a, bind, ref);
754 }
755 
756 int
757 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
758 {
759 	int err = -EINVAL;
760 	unsigned char *b = skb_tail_pointer(skb);
761 	struct nlattr *nest;
762 	struct tc_cookie *cookie;
763 
764 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
765 		goto nla_put_failure;
766 	if (tcf_action_copy_stats(skb, a, 0))
767 		goto nla_put_failure;
768 
769 	rcu_read_lock();
770 	cookie = rcu_dereference(a->act_cookie);
771 	if (cookie) {
772 		if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
773 			rcu_read_unlock();
774 			goto nla_put_failure;
775 		}
776 	}
777 	rcu_read_unlock();
778 
779 	nest = nla_nest_start(skb, TCA_OPTIONS);
780 	if (nest == NULL)
781 		goto nla_put_failure;
782 	err = tcf_action_dump_old(skb, a, bind, ref);
783 	if (err > 0) {
784 		nla_nest_end(skb, nest);
785 		return err;
786 	}
787 
788 nla_put_failure:
789 	nlmsg_trim(skb, b);
790 	return -1;
791 }
792 EXPORT_SYMBOL(tcf_action_dump_1);
793 
794 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
795 		    int bind, int ref)
796 {
797 	struct tc_action *a;
798 	int err = -EINVAL, i;
799 	struct nlattr *nest;
800 
801 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
802 		a = actions[i];
803 		nest = nla_nest_start(skb, a->order);
804 		if (nest == NULL)
805 			goto nla_put_failure;
806 		err = tcf_action_dump_1(skb, a, bind, ref);
807 		if (err < 0)
808 			goto errout;
809 		nla_nest_end(skb, nest);
810 	}
811 
812 	return 0;
813 
814 nla_put_failure:
815 	err = -EINVAL;
816 errout:
817 	nla_nest_cancel(skb, nest);
818 	return err;
819 }
820 
821 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
822 {
823 	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
824 	if (!c)
825 		return NULL;
826 
827 	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
828 	if (!c->data) {
829 		kfree(c);
830 		return NULL;
831 	}
832 	c->len = nla_len(tb[TCA_ACT_COOKIE]);
833 
834 	return c;
835 }
836 
837 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
838 				    struct nlattr *nla, struct nlattr *est,
839 				    char *name, int ovr, int bind,
840 				    bool rtnl_held,
841 				    struct netlink_ext_ack *extack)
842 {
843 	struct tc_action *a;
844 	struct tc_action_ops *a_o;
845 	struct tc_cookie *cookie = NULL;
846 	char act_name[IFNAMSIZ];
847 	struct nlattr *tb[TCA_ACT_MAX + 1];
848 	struct nlattr *kind;
849 	int err;
850 
851 	if (name == NULL) {
852 		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
853 		if (err < 0)
854 			goto err_out;
855 		err = -EINVAL;
856 		kind = tb[TCA_ACT_KIND];
857 		if (!kind) {
858 			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
859 			goto err_out;
860 		}
861 		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
862 			NL_SET_ERR_MSG(extack, "TC action name too long");
863 			goto err_out;
864 		}
865 		if (tb[TCA_ACT_COOKIE]) {
866 			int cklen = nla_len(tb[TCA_ACT_COOKIE]);
867 
868 			if (cklen > TC_COOKIE_MAX_SIZE) {
869 				NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
870 				goto err_out;
871 			}
872 
873 			cookie = nla_memdup_cookie(tb);
874 			if (!cookie) {
875 				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
876 				err = -ENOMEM;
877 				goto err_out;
878 			}
879 		}
880 	} else {
881 		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
882 			NL_SET_ERR_MSG(extack, "TC action name too long");
883 			err = -EINVAL;
884 			goto err_out;
885 		}
886 	}
887 
888 	a_o = tc_lookup_action_n(act_name);
889 	if (a_o == NULL) {
890 #ifdef CONFIG_MODULES
891 		if (rtnl_held)
892 			rtnl_unlock();
893 		request_module("act_%s", act_name);
894 		if (rtnl_held)
895 			rtnl_lock();
896 
897 		a_o = tc_lookup_action_n(act_name);
898 
899 		/* We dropped the RTNL semaphore in order to
900 		 * perform the module load.  So, even if we
901 		 * succeeded in loading the module we have to
902 		 * tell the caller to replay the request.  We
903 		 * indicate this using -EAGAIN.
904 		 */
905 		if (a_o != NULL) {
906 			err = -EAGAIN;
907 			goto err_mod;
908 		}
909 #endif
910 		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
911 		err = -ENOENT;
912 		goto err_out;
913 	}
914 
915 	/* backward compatibility for policer */
916 	if (name == NULL)
917 		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
918 				rtnl_held, tp, extack);
919 	else
920 		err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
921 				tp, extack);
922 	if (err < 0)
923 		goto err_mod;
924 
925 	if (!name && tb[TCA_ACT_COOKIE])
926 		tcf_set_action_cookie(&a->act_cookie, cookie);
927 
928 	/* module count goes up only when brand new policy is created
929 	 * if it exists and is only bound to in a_o->init() then
930 	 * ACT_P_CREATED is not returned (a zero is).
931 	 */
932 	if (err != ACT_P_CREATED)
933 		module_put(a_o->owner);
934 
935 	if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
936 	    !rcu_access_pointer(a->goto_chain)) {
937 		tcf_action_destroy_1(a, bind);
938 		NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
939 		return ERR_PTR(-EINVAL);
940 	}
941 
942 	return a;
943 
944 err_mod:
945 	module_put(a_o->owner);
946 err_out:
947 	if (cookie) {
948 		kfree(cookie->data);
949 		kfree(cookie);
950 	}
951 	return ERR_PTR(err);
952 }
953 
954 /* Returns numbers of initialized actions or negative error. */
955 
956 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
957 		    struct nlattr *est, char *name, int ovr, int bind,
958 		    struct tc_action *actions[], size_t *attr_size,
959 		    bool rtnl_held, struct netlink_ext_ack *extack)
960 {
961 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
962 	struct tc_action *act;
963 	size_t sz = 0;
964 	int err;
965 	int i;
966 
967 	err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
968 	if (err < 0)
969 		return err;
970 
971 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
972 		act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
973 					rtnl_held, extack);
974 		if (IS_ERR(act)) {
975 			err = PTR_ERR(act);
976 			goto err;
977 		}
978 		act->order = i;
979 		sz += tcf_action_fill_size(act);
980 		/* Start from index 0 */
981 		actions[i - 1] = act;
982 	}
983 
984 	*attr_size = tcf_action_full_attrs_size(sz);
985 	return i - 1;
986 
987 err:
988 	tcf_action_destroy(actions, bind);
989 	return err;
990 }
991 
992 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
993 			  int compat_mode)
994 {
995 	int err = 0;
996 	struct gnet_dump d;
997 
998 	if (p == NULL)
999 		goto errout;
1000 
1001 	/* compat_mode being true specifies a call that is supposed
1002 	 * to add additional backward compatibility statistic TLVs.
1003 	 */
1004 	if (compat_mode) {
1005 		if (p->type == TCA_OLD_COMPAT)
1006 			err = gnet_stats_start_copy_compat(skb, 0,
1007 							   TCA_STATS,
1008 							   TCA_XSTATS,
1009 							   &p->tcfa_lock, &d,
1010 							   TCA_PAD);
1011 		else
1012 			return 0;
1013 	} else
1014 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1015 					    &p->tcfa_lock, &d, TCA_ACT_PAD);
1016 
1017 	if (err < 0)
1018 		goto errout;
1019 
1020 	if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1021 	    gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1022 				     &p->tcfa_bstats_hw) < 0 ||
1023 	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1024 	    gnet_stats_copy_queue(&d, p->cpu_qstats,
1025 				  &p->tcfa_qstats,
1026 				  p->tcfa_qstats.qlen) < 0)
1027 		goto errout;
1028 
1029 	if (gnet_stats_finish_copy(&d) < 0)
1030 		goto errout;
1031 
1032 	return 0;
1033 
1034 errout:
1035 	return -1;
1036 }
1037 
1038 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1039 			u32 portid, u32 seq, u16 flags, int event, int bind,
1040 			int ref)
1041 {
1042 	struct tcamsg *t;
1043 	struct nlmsghdr *nlh;
1044 	unsigned char *b = skb_tail_pointer(skb);
1045 	struct nlattr *nest;
1046 
1047 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1048 	if (!nlh)
1049 		goto out_nlmsg_trim;
1050 	t = nlmsg_data(nlh);
1051 	t->tca_family = AF_UNSPEC;
1052 	t->tca__pad1 = 0;
1053 	t->tca__pad2 = 0;
1054 
1055 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1056 	if (!nest)
1057 		goto out_nlmsg_trim;
1058 
1059 	if (tcf_action_dump(skb, actions, bind, ref) < 0)
1060 		goto out_nlmsg_trim;
1061 
1062 	nla_nest_end(skb, nest);
1063 
1064 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1065 	return skb->len;
1066 
1067 out_nlmsg_trim:
1068 	nlmsg_trim(skb, b);
1069 	return -1;
1070 }
1071 
1072 static int
1073 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1074 	       struct tc_action *actions[], int event,
1075 	       struct netlink_ext_ack *extack)
1076 {
1077 	struct sk_buff *skb;
1078 
1079 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1080 	if (!skb)
1081 		return -ENOBUFS;
1082 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1083 			 0, 1) <= 0) {
1084 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1085 		kfree_skb(skb);
1086 		return -EINVAL;
1087 	}
1088 
1089 	return rtnl_unicast(skb, net, portid);
1090 }
1091 
1092 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1093 					  struct nlmsghdr *n, u32 portid,
1094 					  struct netlink_ext_ack *extack)
1095 {
1096 	struct nlattr *tb[TCA_ACT_MAX + 1];
1097 	const struct tc_action_ops *ops;
1098 	struct tc_action *a;
1099 	int index;
1100 	int err;
1101 
1102 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1103 	if (err < 0)
1104 		goto err_out;
1105 
1106 	err = -EINVAL;
1107 	if (tb[TCA_ACT_INDEX] == NULL ||
1108 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1109 		NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1110 		goto err_out;
1111 	}
1112 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
1113 
1114 	err = -EINVAL;
1115 	ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1116 	if (!ops) { /* could happen in batch of actions */
1117 		NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1118 		goto err_out;
1119 	}
1120 	err = -ENOENT;
1121 	if (ops->lookup(net, &a, index) == 0) {
1122 		NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1123 		goto err_mod;
1124 	}
1125 
1126 	module_put(ops->owner);
1127 	return a;
1128 
1129 err_mod:
1130 	module_put(ops->owner);
1131 err_out:
1132 	return ERR_PTR(err);
1133 }
1134 
1135 static int tca_action_flush(struct net *net, struct nlattr *nla,
1136 			    struct nlmsghdr *n, u32 portid,
1137 			    struct netlink_ext_ack *extack)
1138 {
1139 	struct sk_buff *skb;
1140 	unsigned char *b;
1141 	struct nlmsghdr *nlh;
1142 	struct tcamsg *t;
1143 	struct netlink_callback dcb;
1144 	struct nlattr *nest;
1145 	struct nlattr *tb[TCA_ACT_MAX + 1];
1146 	const struct tc_action_ops *ops;
1147 	struct nlattr *kind;
1148 	int err = -ENOMEM;
1149 
1150 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1151 	if (!skb)
1152 		return err;
1153 
1154 	b = skb_tail_pointer(skb);
1155 
1156 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1157 	if (err < 0)
1158 		goto err_out;
1159 
1160 	err = -EINVAL;
1161 	kind = tb[TCA_ACT_KIND];
1162 	ops = tc_lookup_action(kind);
1163 	if (!ops) { /*some idjot trying to flush unknown action */
1164 		NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1165 		goto err_out;
1166 	}
1167 
1168 	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1169 			sizeof(*t), 0);
1170 	if (!nlh) {
1171 		NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1172 		goto out_module_put;
1173 	}
1174 	t = nlmsg_data(nlh);
1175 	t->tca_family = AF_UNSPEC;
1176 	t->tca__pad1 = 0;
1177 	t->tca__pad2 = 0;
1178 
1179 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1180 	if (!nest) {
1181 		NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1182 		goto out_module_put;
1183 	}
1184 
1185 	err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1186 	if (err <= 0) {
1187 		nla_nest_cancel(skb, nest);
1188 		goto out_module_put;
1189 	}
1190 
1191 	nla_nest_end(skb, nest);
1192 
1193 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1194 	nlh->nlmsg_flags |= NLM_F_ROOT;
1195 	module_put(ops->owner);
1196 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1197 			     n->nlmsg_flags & NLM_F_ECHO);
1198 	if (err > 0)
1199 		return 0;
1200 	if (err < 0)
1201 		NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1202 
1203 	return err;
1204 
1205 out_module_put:
1206 	module_put(ops->owner);
1207 err_out:
1208 	kfree_skb(skb);
1209 	return err;
1210 }
1211 
1212 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1213 {
1214 	int i;
1215 
1216 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1217 		struct tc_action *a = actions[i];
1218 		const struct tc_action_ops *ops = a->ops;
1219 		/* Actions can be deleted concurrently so we must save their
1220 		 * type and id to search again after reference is released.
1221 		 */
1222 		struct tcf_idrinfo *idrinfo = a->idrinfo;
1223 		u32 act_index = a->tcfa_index;
1224 
1225 		actions[i] = NULL;
1226 		if (tcf_action_put(a)) {
1227 			/* last reference, action was deleted concurrently */
1228 			module_put(ops->owner);
1229 		} else  {
1230 			int ret;
1231 
1232 			/* now do the delete */
1233 			ret = tcf_idr_delete_index(idrinfo, act_index);
1234 			if (ret < 0)
1235 				return ret;
1236 		}
1237 	}
1238 	return 0;
1239 }
1240 
1241 static int
1242 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1243 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1244 {
1245 	int ret;
1246 	struct sk_buff *skb;
1247 
1248 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1249 			GFP_KERNEL);
1250 	if (!skb)
1251 		return -ENOBUFS;
1252 
1253 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1254 			 0, 2) <= 0) {
1255 		NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1256 		kfree_skb(skb);
1257 		return -EINVAL;
1258 	}
1259 
1260 	/* now do the delete */
1261 	ret = tcf_action_delete(net, actions);
1262 	if (ret < 0) {
1263 		NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1264 		kfree_skb(skb);
1265 		return ret;
1266 	}
1267 
1268 	ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1269 			     n->nlmsg_flags & NLM_F_ECHO);
1270 	if (ret > 0)
1271 		return 0;
1272 	return ret;
1273 }
1274 
1275 static int
1276 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1277 	      u32 portid, int event, struct netlink_ext_ack *extack)
1278 {
1279 	int i, ret;
1280 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1281 	struct tc_action *act;
1282 	size_t attr_size = 0;
1283 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1284 
1285 	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
1286 	if (ret < 0)
1287 		return ret;
1288 
1289 	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1290 		if (tb[1])
1291 			return tca_action_flush(net, tb[1], n, portid, extack);
1292 
1293 		NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1294 		return -EINVAL;
1295 	}
1296 
1297 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1298 		act = tcf_action_get_1(net, tb[i], n, portid, extack);
1299 		if (IS_ERR(act)) {
1300 			ret = PTR_ERR(act);
1301 			goto err;
1302 		}
1303 		act->order = i;
1304 		attr_size += tcf_action_fill_size(act);
1305 		actions[i - 1] = act;
1306 	}
1307 
1308 	attr_size = tcf_action_full_attrs_size(attr_size);
1309 
1310 	if (event == RTM_GETACTION)
1311 		ret = tcf_get_notify(net, portid, n, actions, event, extack);
1312 	else { /* delete */
1313 		ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1314 		if (ret)
1315 			goto err;
1316 		return 0;
1317 	}
1318 err:
1319 	tcf_action_put_many(actions);
1320 	return ret;
1321 }
1322 
1323 static int
1324 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1325 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1326 {
1327 	struct sk_buff *skb;
1328 	int err = 0;
1329 
1330 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1331 			GFP_KERNEL);
1332 	if (!skb)
1333 		return -ENOBUFS;
1334 
1335 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1336 			 RTM_NEWACTION, 0, 0) <= 0) {
1337 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1338 		kfree_skb(skb);
1339 		return -EINVAL;
1340 	}
1341 
1342 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1343 			     n->nlmsg_flags & NLM_F_ECHO);
1344 	if (err > 0)
1345 		err = 0;
1346 	return err;
1347 }
1348 
1349 static int tcf_action_add(struct net *net, struct nlattr *nla,
1350 			  struct nlmsghdr *n, u32 portid, int ovr,
1351 			  struct netlink_ext_ack *extack)
1352 {
1353 	size_t attr_size = 0;
1354 	int ret = 0;
1355 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1356 
1357 	ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
1358 			      &attr_size, true, extack);
1359 	if (ret < 0)
1360 		return ret;
1361 	ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1362 	if (ovr)
1363 		tcf_action_put_many(actions);
1364 
1365 	return ret;
1366 }
1367 
1368 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1369 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1370 	[TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1371 			     .validation_data = &tcaa_root_flags_allowed },
1372 	[TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1373 };
1374 
1375 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1376 			 struct netlink_ext_ack *extack)
1377 {
1378 	struct net *net = sock_net(skb->sk);
1379 	struct nlattr *tca[TCA_ROOT_MAX + 1];
1380 	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1381 	int ret = 0, ovr = 0;
1382 
1383 	if ((n->nlmsg_type != RTM_GETACTION) &&
1384 	    !netlink_capable(skb, CAP_NET_ADMIN))
1385 		return -EPERM;
1386 
1387 	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
1388 			  extack);
1389 	if (ret < 0)
1390 		return ret;
1391 
1392 	if (tca[TCA_ACT_TAB] == NULL) {
1393 		NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1394 		return -EINVAL;
1395 	}
1396 
1397 	/* n->nlmsg_flags & NLM_F_CREATE */
1398 	switch (n->nlmsg_type) {
1399 	case RTM_NEWACTION:
1400 		/* we are going to assume all other flags
1401 		 * imply create only if it doesn't exist
1402 		 * Note that CREATE | EXCL implies that
1403 		 * but since we want avoid ambiguity (eg when flags
1404 		 * is zero) then just set this
1405 		 */
1406 		if (n->nlmsg_flags & NLM_F_REPLACE)
1407 			ovr = 1;
1408 replay:
1409 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1410 				     extack);
1411 		if (ret == -EAGAIN)
1412 			goto replay;
1413 		break;
1414 	case RTM_DELACTION:
1415 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1416 				    portid, RTM_DELACTION, extack);
1417 		break;
1418 	case RTM_GETACTION:
1419 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1420 				    portid, RTM_GETACTION, extack);
1421 		break;
1422 	default:
1423 		BUG();
1424 	}
1425 
1426 	return ret;
1427 }
1428 
1429 static struct nlattr *find_dump_kind(struct nlattr **nla)
1430 {
1431 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1432 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1433 	struct nlattr *kind;
1434 
1435 	tb1 = nla[TCA_ACT_TAB];
1436 	if (tb1 == NULL)
1437 		return NULL;
1438 
1439 	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1440 		      NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1441 		return NULL;
1442 
1443 	if (tb[1] == NULL)
1444 		return NULL;
1445 	if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1446 		return NULL;
1447 	kind = tb2[TCA_ACT_KIND];
1448 
1449 	return kind;
1450 }
1451 
1452 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1453 {
1454 	struct net *net = sock_net(skb->sk);
1455 	struct nlmsghdr *nlh;
1456 	unsigned char *b = skb_tail_pointer(skb);
1457 	struct nlattr *nest;
1458 	struct tc_action_ops *a_o;
1459 	int ret = 0;
1460 	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1461 	struct nlattr *tb[TCA_ROOT_MAX + 1];
1462 	struct nlattr *count_attr = NULL;
1463 	unsigned long jiffy_since = 0;
1464 	struct nlattr *kind = NULL;
1465 	struct nla_bitfield32 bf;
1466 	u32 msecs_since = 0;
1467 	u32 act_count = 0;
1468 
1469 	ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
1470 			  tcaa_policy, cb->extack);
1471 	if (ret < 0)
1472 		return ret;
1473 
1474 	kind = find_dump_kind(tb);
1475 	if (kind == NULL) {
1476 		pr_info("tc_dump_action: action bad kind\n");
1477 		return 0;
1478 	}
1479 
1480 	a_o = tc_lookup_action(kind);
1481 	if (a_o == NULL)
1482 		return 0;
1483 
1484 	cb->args[2] = 0;
1485 	if (tb[TCA_ROOT_FLAGS]) {
1486 		bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1487 		cb->args[2] = bf.value;
1488 	}
1489 
1490 	if (tb[TCA_ROOT_TIME_DELTA]) {
1491 		msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1492 	}
1493 
1494 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1495 			cb->nlh->nlmsg_type, sizeof(*t), 0);
1496 	if (!nlh)
1497 		goto out_module_put;
1498 
1499 	if (msecs_since)
1500 		jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1501 
1502 	t = nlmsg_data(nlh);
1503 	t->tca_family = AF_UNSPEC;
1504 	t->tca__pad1 = 0;
1505 	t->tca__pad2 = 0;
1506 	cb->args[3] = jiffy_since;
1507 	count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1508 	if (!count_attr)
1509 		goto out_module_put;
1510 
1511 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1512 	if (nest == NULL)
1513 		goto out_module_put;
1514 
1515 	ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1516 	if (ret < 0)
1517 		goto out_module_put;
1518 
1519 	if (ret > 0) {
1520 		nla_nest_end(skb, nest);
1521 		ret = skb->len;
1522 		act_count = cb->args[1];
1523 		memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1524 		cb->args[1] = 0;
1525 	} else
1526 		nlmsg_trim(skb, b);
1527 
1528 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1529 	if (NETLINK_CB(cb->skb).portid && ret)
1530 		nlh->nlmsg_flags |= NLM_F_MULTI;
1531 	module_put(a_o->owner);
1532 	return skb->len;
1533 
1534 out_module_put:
1535 	module_put(a_o->owner);
1536 	nlmsg_trim(skb, b);
1537 	return skb->len;
1538 }
1539 
1540 static int __init tc_action_init(void)
1541 {
1542 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1543 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1544 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1545 		      0);
1546 
1547 	return 0;
1548 }
1549 
1550 subsys_initcall(tc_action_init);
1551