xref: /openbmc/linux/net/sched/act_api.c (revision 23966841)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * net/sched/act_api.c	Packet action API.
4  *
5  * Author:	Jamal Hadi Salim
6  */
7 
8 #include <linux/types.h>
9 #include <linux/kernel.h>
10 #include <linux/string.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/skbuff.h>
14 #include <linux/init.h>
15 #include <linux/kmod.h>
16 #include <linux/err.h>
17 #include <linux/module.h>
18 #include <net/net_namespace.h>
19 #include <net/sock.h>
20 #include <net/sch_generic.h>
21 #include <net/pkt_cls.h>
22 #include <net/act_api.h>
23 #include <net/netlink.h>
24 
25 static void tcf_action_goto_chain_exec(const struct tc_action *a,
26 				       struct tcf_result *res)
27 {
28 	const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
29 
30 	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
31 }
32 
33 static void tcf_free_cookie_rcu(struct rcu_head *p)
34 {
35 	struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
36 
37 	kfree(cookie->data);
38 	kfree(cookie);
39 }
40 
41 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
42 				  struct tc_cookie *new_cookie)
43 {
44 	struct tc_cookie *old;
45 
46 	old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
47 	if (old)
48 		call_rcu(&old->rcu, tcf_free_cookie_rcu);
49 }
50 
51 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
52 			     struct tcf_chain **newchain,
53 			     struct netlink_ext_ack *extack)
54 {
55 	int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
56 	u32 chain_index;
57 
58 	if (!opcode)
59 		ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
60 	else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
61 		ret = 0;
62 	if (ret) {
63 		NL_SET_ERR_MSG(extack, "invalid control action");
64 		goto end;
65 	}
66 
67 	if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
68 		chain_index = action & TC_ACT_EXT_VAL_MASK;
69 		if (!tp || !newchain) {
70 			ret = -EINVAL;
71 			NL_SET_ERR_MSG(extack,
72 				       "can't goto NULL proto/chain");
73 			goto end;
74 		}
75 		*newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
76 		if (!*newchain) {
77 			ret = -ENOMEM;
78 			NL_SET_ERR_MSG(extack,
79 				       "can't allocate goto_chain");
80 		}
81 	}
82 end:
83 	return ret;
84 }
85 EXPORT_SYMBOL(tcf_action_check_ctrlact);
86 
87 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
88 					 struct tcf_chain *goto_chain)
89 {
90 	a->tcfa_action = action;
91 	rcu_swap_protected(a->goto_chain, goto_chain, 1);
92 	return goto_chain;
93 }
94 EXPORT_SYMBOL(tcf_action_set_ctrlact);
95 
96 /* XXX: For standalone actions, we don't need a RCU grace period either, because
97  * actions are always connected to filters and filters are already destroyed in
98  * RCU callbacks, so after a RCU grace period actions are already disconnected
99  * from filters. Readers later can not find us.
100  */
101 static void free_tcf(struct tc_action *p)
102 {
103 	struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
104 
105 	free_percpu(p->cpu_bstats);
106 	free_percpu(p->cpu_bstats_hw);
107 	free_percpu(p->cpu_qstats);
108 
109 	tcf_set_action_cookie(&p->act_cookie, NULL);
110 	if (chain)
111 		tcf_chain_put_by_act(chain);
112 
113 	kfree(p);
114 }
115 
116 static void tcf_action_cleanup(struct tc_action *p)
117 {
118 	if (p->ops->cleanup)
119 		p->ops->cleanup(p);
120 
121 	gen_kill_estimator(&p->tcfa_rate_est);
122 	free_tcf(p);
123 }
124 
125 static int __tcf_action_put(struct tc_action *p, bool bind)
126 {
127 	struct tcf_idrinfo *idrinfo = p->idrinfo;
128 
129 	if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
130 		if (bind)
131 			atomic_dec(&p->tcfa_bindcnt);
132 		idr_remove(&idrinfo->action_idr, p->tcfa_index);
133 		mutex_unlock(&idrinfo->lock);
134 
135 		tcf_action_cleanup(p);
136 		return 1;
137 	}
138 
139 	if (bind)
140 		atomic_dec(&p->tcfa_bindcnt);
141 
142 	return 0;
143 }
144 
145 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
146 {
147 	int ret = 0;
148 
149 	/* Release with strict==1 and bind==0 is only called through act API
150 	 * interface (classifiers always bind). Only case when action with
151 	 * positive reference count and zero bind count can exist is when it was
152 	 * also created with act API (unbinding last classifier will destroy the
153 	 * action if it was created by classifier). So only case when bind count
154 	 * can be changed after initial check is when unbound action is
155 	 * destroyed by act API while classifier binds to action with same id
156 	 * concurrently. This result either creation of new action(same behavior
157 	 * as before), or reusing existing action if concurrent process
158 	 * increments reference count before action is deleted. Both scenarios
159 	 * are acceptable.
160 	 */
161 	if (p) {
162 		if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
163 			return -EPERM;
164 
165 		if (__tcf_action_put(p, bind))
166 			ret = ACT_P_DELETED;
167 	}
168 
169 	return ret;
170 }
171 EXPORT_SYMBOL(__tcf_idr_release);
172 
173 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
174 {
175 	struct tc_cookie *act_cookie;
176 	u32 cookie_len = 0;
177 
178 	rcu_read_lock();
179 	act_cookie = rcu_dereference(act->act_cookie);
180 
181 	if (act_cookie)
182 		cookie_len = nla_total_size(act_cookie->len);
183 	rcu_read_unlock();
184 
185 	return  nla_total_size(0) /* action number nested */
186 		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
187 		+ cookie_len /* TCA_ACT_COOKIE */
188 		+ nla_total_size(0) /* TCA_ACT_STATS nested */
189 		/* TCA_STATS_BASIC */
190 		+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
191 		/* TCA_STATS_QUEUE */
192 		+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
193 		+ nla_total_size(0) /* TCA_OPTIONS nested */
194 		+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
195 }
196 
197 static size_t tcf_action_full_attrs_size(size_t sz)
198 {
199 	return NLMSG_HDRLEN                     /* struct nlmsghdr */
200 		+ sizeof(struct tcamsg)
201 		+ nla_total_size(0)             /* TCA_ACT_TAB nested */
202 		+ sz;
203 }
204 
205 static size_t tcf_action_fill_size(const struct tc_action *act)
206 {
207 	size_t sz = tcf_action_shared_attrs_size(act);
208 
209 	if (act->ops->get_fill_size)
210 		return act->ops->get_fill_size(act) + sz;
211 	return sz;
212 }
213 
214 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
215 			   struct netlink_callback *cb)
216 {
217 	int err = 0, index = -1, s_i = 0, n_i = 0;
218 	u32 act_flags = cb->args[2];
219 	unsigned long jiffy_since = cb->args[3];
220 	struct nlattr *nest;
221 	struct idr *idr = &idrinfo->action_idr;
222 	struct tc_action *p;
223 	unsigned long id = 1;
224 	unsigned long tmp;
225 
226 	mutex_lock(&idrinfo->lock);
227 
228 	s_i = cb->args[0];
229 
230 	idr_for_each_entry_ul(idr, p, tmp, id) {
231 		index++;
232 		if (index < s_i)
233 			continue;
234 
235 		if (jiffy_since &&
236 		    time_after(jiffy_since,
237 			       (unsigned long)p->tcfa_tm.lastuse))
238 			continue;
239 
240 		nest = nla_nest_start_noflag(skb, n_i);
241 		if (!nest) {
242 			index--;
243 			goto nla_put_failure;
244 		}
245 		err = tcf_action_dump_1(skb, p, 0, 0);
246 		if (err < 0) {
247 			index--;
248 			nlmsg_trim(skb, nest);
249 			goto done;
250 		}
251 		nla_nest_end(skb, nest);
252 		n_i++;
253 		if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
254 		    n_i >= TCA_ACT_MAX_PRIO)
255 			goto done;
256 	}
257 done:
258 	if (index >= 0)
259 		cb->args[0] = index + 1;
260 
261 	mutex_unlock(&idrinfo->lock);
262 	if (n_i) {
263 		if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
264 			cb->args[1] = n_i;
265 	}
266 	return n_i;
267 
268 nla_put_failure:
269 	nla_nest_cancel(skb, nest);
270 	goto done;
271 }
272 
273 static int tcf_idr_release_unsafe(struct tc_action *p)
274 {
275 	if (atomic_read(&p->tcfa_bindcnt) > 0)
276 		return -EPERM;
277 
278 	if (refcount_dec_and_test(&p->tcfa_refcnt)) {
279 		idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
280 		tcf_action_cleanup(p);
281 		return ACT_P_DELETED;
282 	}
283 
284 	return 0;
285 }
286 
287 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
288 			  const struct tc_action_ops *ops)
289 {
290 	struct nlattr *nest;
291 	int n_i = 0;
292 	int ret = -EINVAL;
293 	struct idr *idr = &idrinfo->action_idr;
294 	struct tc_action *p;
295 	unsigned long id = 1;
296 	unsigned long tmp;
297 
298 	nest = nla_nest_start_noflag(skb, 0);
299 	if (nest == NULL)
300 		goto nla_put_failure;
301 	if (nla_put_string(skb, TCA_KIND, ops->kind))
302 		goto nla_put_failure;
303 
304 	mutex_lock(&idrinfo->lock);
305 	idr_for_each_entry_ul(idr, p, tmp, id) {
306 		ret = tcf_idr_release_unsafe(p);
307 		if (ret == ACT_P_DELETED) {
308 			module_put(ops->owner);
309 			n_i++;
310 		} else if (ret < 0) {
311 			mutex_unlock(&idrinfo->lock);
312 			goto nla_put_failure;
313 		}
314 	}
315 	mutex_unlock(&idrinfo->lock);
316 
317 	if (nla_put_u32(skb, TCA_FCNT, n_i))
318 		goto nla_put_failure;
319 	nla_nest_end(skb, nest);
320 
321 	return n_i;
322 nla_put_failure:
323 	nla_nest_cancel(skb, nest);
324 	return ret;
325 }
326 
327 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
328 		       struct netlink_callback *cb, int type,
329 		       const struct tc_action_ops *ops,
330 		       struct netlink_ext_ack *extack)
331 {
332 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
333 
334 	if (type == RTM_DELACTION) {
335 		return tcf_del_walker(idrinfo, skb, ops);
336 	} else if (type == RTM_GETACTION) {
337 		return tcf_dump_walker(idrinfo, skb, cb);
338 	} else {
339 		WARN(1, "tcf_generic_walker: unknown command %d\n", type);
340 		NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
341 		return -EINVAL;
342 	}
343 }
344 EXPORT_SYMBOL(tcf_generic_walker);
345 
346 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
347 {
348 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
349 	struct tc_action *p;
350 
351 	mutex_lock(&idrinfo->lock);
352 	p = idr_find(&idrinfo->action_idr, index);
353 	if (IS_ERR(p))
354 		p = NULL;
355 	else if (p)
356 		refcount_inc(&p->tcfa_refcnt);
357 	mutex_unlock(&idrinfo->lock);
358 
359 	if (p) {
360 		*a = p;
361 		return true;
362 	}
363 	return false;
364 }
365 EXPORT_SYMBOL(tcf_idr_search);
366 
367 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
368 {
369 	struct tc_action *p;
370 	int ret = 0;
371 
372 	mutex_lock(&idrinfo->lock);
373 	p = idr_find(&idrinfo->action_idr, index);
374 	if (!p) {
375 		mutex_unlock(&idrinfo->lock);
376 		return -ENOENT;
377 	}
378 
379 	if (!atomic_read(&p->tcfa_bindcnt)) {
380 		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
381 			struct module *owner = p->ops->owner;
382 
383 			WARN_ON(p != idr_remove(&idrinfo->action_idr,
384 						p->tcfa_index));
385 			mutex_unlock(&idrinfo->lock);
386 
387 			tcf_action_cleanup(p);
388 			module_put(owner);
389 			return 0;
390 		}
391 		ret = 0;
392 	} else {
393 		ret = -EPERM;
394 	}
395 
396 	mutex_unlock(&idrinfo->lock);
397 	return ret;
398 }
399 
400 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
401 		   struct tc_action **a, const struct tc_action_ops *ops,
402 		   int bind, bool cpustats)
403 {
404 	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
405 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
406 	int err = -ENOMEM;
407 
408 	if (unlikely(!p))
409 		return -ENOMEM;
410 	refcount_set(&p->tcfa_refcnt, 1);
411 	if (bind)
412 		atomic_set(&p->tcfa_bindcnt, 1);
413 
414 	if (cpustats) {
415 		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
416 		if (!p->cpu_bstats)
417 			goto err1;
418 		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
419 		if (!p->cpu_bstats_hw)
420 			goto err2;
421 		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
422 		if (!p->cpu_qstats)
423 			goto err3;
424 	}
425 	spin_lock_init(&p->tcfa_lock);
426 	p->tcfa_index = index;
427 	p->tcfa_tm.install = jiffies;
428 	p->tcfa_tm.lastuse = jiffies;
429 	p->tcfa_tm.firstuse = 0;
430 	if (est) {
431 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
432 					&p->tcfa_rate_est,
433 					&p->tcfa_lock, NULL, est);
434 		if (err)
435 			goto err4;
436 	}
437 
438 	p->idrinfo = idrinfo;
439 	p->ops = ops;
440 	*a = p;
441 	return 0;
442 err4:
443 	free_percpu(p->cpu_qstats);
444 err3:
445 	free_percpu(p->cpu_bstats_hw);
446 err2:
447 	free_percpu(p->cpu_bstats);
448 err1:
449 	kfree(p);
450 	return err;
451 }
452 EXPORT_SYMBOL(tcf_idr_create);
453 
454 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
455 {
456 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
457 
458 	mutex_lock(&idrinfo->lock);
459 	/* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
460 	WARN_ON(!IS_ERR(idr_replace(&idrinfo->action_idr, a, a->tcfa_index)));
461 	mutex_unlock(&idrinfo->lock);
462 }
463 EXPORT_SYMBOL(tcf_idr_insert);
464 
465 /* Cleanup idr index that was allocated but not initialized. */
466 
467 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
468 {
469 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
470 
471 	mutex_lock(&idrinfo->lock);
472 	/* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
473 	WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
474 	mutex_unlock(&idrinfo->lock);
475 }
476 EXPORT_SYMBOL(tcf_idr_cleanup);
477 
478 /* Check if action with specified index exists. If actions is found, increments
479  * its reference and bind counters, and return 1. Otherwise insert temporary
480  * error pointer (to prevent concurrent users from inserting actions with same
481  * index) and return 0.
482  */
483 
484 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
485 			struct tc_action **a, int bind)
486 {
487 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
488 	struct tc_action *p;
489 	int ret;
490 
491 again:
492 	mutex_lock(&idrinfo->lock);
493 	if (*index) {
494 		p = idr_find(&idrinfo->action_idr, *index);
495 		if (IS_ERR(p)) {
496 			/* This means that another process allocated
497 			 * index but did not assign the pointer yet.
498 			 */
499 			mutex_unlock(&idrinfo->lock);
500 			goto again;
501 		}
502 
503 		if (p) {
504 			refcount_inc(&p->tcfa_refcnt);
505 			if (bind)
506 				atomic_inc(&p->tcfa_bindcnt);
507 			*a = p;
508 			ret = 1;
509 		} else {
510 			*a = NULL;
511 			ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
512 					    *index, GFP_KERNEL);
513 			if (!ret)
514 				idr_replace(&idrinfo->action_idr,
515 					    ERR_PTR(-EBUSY), *index);
516 		}
517 	} else {
518 		*index = 1;
519 		*a = NULL;
520 		ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
521 				    UINT_MAX, GFP_KERNEL);
522 		if (!ret)
523 			idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
524 				    *index);
525 	}
526 	mutex_unlock(&idrinfo->lock);
527 	return ret;
528 }
529 EXPORT_SYMBOL(tcf_idr_check_alloc);
530 
531 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
532 			 struct tcf_idrinfo *idrinfo)
533 {
534 	struct idr *idr = &idrinfo->action_idr;
535 	struct tc_action *p;
536 	int ret;
537 	unsigned long id = 1;
538 	unsigned long tmp;
539 
540 	idr_for_each_entry_ul(idr, p, tmp, id) {
541 		ret = __tcf_idr_release(p, false, true);
542 		if (ret == ACT_P_DELETED)
543 			module_put(ops->owner);
544 		else if (ret < 0)
545 			return;
546 	}
547 	idr_destroy(&idrinfo->action_idr);
548 }
549 EXPORT_SYMBOL(tcf_idrinfo_destroy);
550 
551 static LIST_HEAD(act_base);
552 static DEFINE_RWLOCK(act_mod_lock);
553 
554 int tcf_register_action(struct tc_action_ops *act,
555 			struct pernet_operations *ops)
556 {
557 	struct tc_action_ops *a;
558 	int ret;
559 
560 	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
561 		return -EINVAL;
562 
563 	/* We have to register pernet ops before making the action ops visible,
564 	 * otherwise tcf_action_init_1() could get a partially initialized
565 	 * netns.
566 	 */
567 	ret = register_pernet_subsys(ops);
568 	if (ret)
569 		return ret;
570 
571 	write_lock(&act_mod_lock);
572 	list_for_each_entry(a, &act_base, head) {
573 		if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
574 			write_unlock(&act_mod_lock);
575 			unregister_pernet_subsys(ops);
576 			return -EEXIST;
577 		}
578 	}
579 	list_add_tail(&act->head, &act_base);
580 	write_unlock(&act_mod_lock);
581 
582 	return 0;
583 }
584 EXPORT_SYMBOL(tcf_register_action);
585 
586 int tcf_unregister_action(struct tc_action_ops *act,
587 			  struct pernet_operations *ops)
588 {
589 	struct tc_action_ops *a;
590 	int err = -ENOENT;
591 
592 	write_lock(&act_mod_lock);
593 	list_for_each_entry(a, &act_base, head) {
594 		if (a == act) {
595 			list_del(&act->head);
596 			err = 0;
597 			break;
598 		}
599 	}
600 	write_unlock(&act_mod_lock);
601 	if (!err)
602 		unregister_pernet_subsys(ops);
603 	return err;
604 }
605 EXPORT_SYMBOL(tcf_unregister_action);
606 
607 /* lookup by name */
608 static struct tc_action_ops *tc_lookup_action_n(char *kind)
609 {
610 	struct tc_action_ops *a, *res = NULL;
611 
612 	if (kind) {
613 		read_lock(&act_mod_lock);
614 		list_for_each_entry(a, &act_base, head) {
615 			if (strcmp(kind, a->kind) == 0) {
616 				if (try_module_get(a->owner))
617 					res = a;
618 				break;
619 			}
620 		}
621 		read_unlock(&act_mod_lock);
622 	}
623 	return res;
624 }
625 
626 /* lookup by nlattr */
627 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
628 {
629 	struct tc_action_ops *a, *res = NULL;
630 
631 	if (kind) {
632 		read_lock(&act_mod_lock);
633 		list_for_each_entry(a, &act_base, head) {
634 			if (nla_strcmp(kind, a->kind) == 0) {
635 				if (try_module_get(a->owner))
636 					res = a;
637 				break;
638 			}
639 		}
640 		read_unlock(&act_mod_lock);
641 	}
642 	return res;
643 }
644 
645 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
646 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
647 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
648 		    int nr_actions, struct tcf_result *res)
649 {
650 	u32 jmp_prgcnt = 0;
651 	u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
652 	int i;
653 	int ret = TC_ACT_OK;
654 
655 	if (skb_skip_tc_classify(skb))
656 		return TC_ACT_OK;
657 
658 restart_act_graph:
659 	for (i = 0; i < nr_actions; i++) {
660 		const struct tc_action *a = actions[i];
661 
662 		if (jmp_prgcnt > 0) {
663 			jmp_prgcnt -= 1;
664 			continue;
665 		}
666 repeat:
667 		ret = a->ops->act(skb, a, res);
668 		if (ret == TC_ACT_REPEAT)
669 			goto repeat;	/* we need a ttl - JHS */
670 
671 		if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
672 			jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
673 			if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
674 				/* faulty opcode, stop pipeline */
675 				return TC_ACT_OK;
676 			} else {
677 				jmp_ttl -= 1;
678 				if (jmp_ttl > 0)
679 					goto restart_act_graph;
680 				else /* faulty graph, stop pipeline */
681 					return TC_ACT_OK;
682 			}
683 		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
684 			if (unlikely(!rcu_access_pointer(a->goto_chain))) {
685 				net_warn_ratelimited("can't go to NULL chain!\n");
686 				return TC_ACT_SHOT;
687 			}
688 			tcf_action_goto_chain_exec(a, res);
689 		}
690 
691 		if (ret != TC_ACT_PIPE)
692 			break;
693 	}
694 
695 	return ret;
696 }
697 EXPORT_SYMBOL(tcf_action_exec);
698 
699 int tcf_action_destroy(struct tc_action *actions[], int bind)
700 {
701 	const struct tc_action_ops *ops;
702 	struct tc_action *a;
703 	int ret = 0, i;
704 
705 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
706 		a = actions[i];
707 		actions[i] = NULL;
708 		ops = a->ops;
709 		ret = __tcf_idr_release(a, bind, true);
710 		if (ret == ACT_P_DELETED)
711 			module_put(ops->owner);
712 		else if (ret < 0)
713 			return ret;
714 	}
715 	return ret;
716 }
717 
718 static int tcf_action_destroy_1(struct tc_action *a, int bind)
719 {
720 	struct tc_action *actions[] = { a, NULL };
721 
722 	return tcf_action_destroy(actions, bind);
723 }
724 
725 static int tcf_action_put(struct tc_action *p)
726 {
727 	return __tcf_action_put(p, false);
728 }
729 
730 /* Put all actions in this array, skip those NULL's. */
731 static void tcf_action_put_many(struct tc_action *actions[])
732 {
733 	int i;
734 
735 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
736 		struct tc_action *a = actions[i];
737 		const struct tc_action_ops *ops;
738 
739 		if (!a)
740 			continue;
741 		ops = a->ops;
742 		if (tcf_action_put(a))
743 			module_put(ops->owner);
744 	}
745 }
746 
747 int
748 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
749 {
750 	return a->ops->dump(skb, a, bind, ref);
751 }
752 
753 int
754 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
755 {
756 	int err = -EINVAL;
757 	unsigned char *b = skb_tail_pointer(skb);
758 	struct nlattr *nest;
759 	struct tc_cookie *cookie;
760 
761 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
762 		goto nla_put_failure;
763 	if (tcf_action_copy_stats(skb, a, 0))
764 		goto nla_put_failure;
765 
766 	rcu_read_lock();
767 	cookie = rcu_dereference(a->act_cookie);
768 	if (cookie) {
769 		if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
770 			rcu_read_unlock();
771 			goto nla_put_failure;
772 		}
773 	}
774 	rcu_read_unlock();
775 
776 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
777 	if (nest == NULL)
778 		goto nla_put_failure;
779 	err = tcf_action_dump_old(skb, a, bind, ref);
780 	if (err > 0) {
781 		nla_nest_end(skb, nest);
782 		return err;
783 	}
784 
785 nla_put_failure:
786 	nlmsg_trim(skb, b);
787 	return -1;
788 }
789 EXPORT_SYMBOL(tcf_action_dump_1);
790 
791 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
792 		    int bind, int ref)
793 {
794 	struct tc_action *a;
795 	int err = -EINVAL, i;
796 	struct nlattr *nest;
797 
798 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
799 		a = actions[i];
800 		nest = nla_nest_start_noflag(skb, i + 1);
801 		if (nest == NULL)
802 			goto nla_put_failure;
803 		err = tcf_action_dump_1(skb, a, bind, ref);
804 		if (err < 0)
805 			goto errout;
806 		nla_nest_end(skb, nest);
807 	}
808 
809 	return 0;
810 
811 nla_put_failure:
812 	err = -EINVAL;
813 errout:
814 	nla_nest_cancel(skb, nest);
815 	return err;
816 }
817 
818 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
819 {
820 	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
821 	if (!c)
822 		return NULL;
823 
824 	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
825 	if (!c->data) {
826 		kfree(c);
827 		return NULL;
828 	}
829 	c->len = nla_len(tb[TCA_ACT_COOKIE]);
830 
831 	return c;
832 }
833 
834 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
835 				    struct nlattr *nla, struct nlattr *est,
836 				    char *name, int ovr, int bind,
837 				    bool rtnl_held,
838 				    struct netlink_ext_ack *extack)
839 {
840 	struct tc_action *a;
841 	struct tc_action_ops *a_o;
842 	struct tc_cookie *cookie = NULL;
843 	char act_name[IFNAMSIZ];
844 	struct nlattr *tb[TCA_ACT_MAX + 1];
845 	struct nlattr *kind;
846 	int err;
847 
848 	if (name == NULL) {
849 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL,
850 						  extack);
851 		if (err < 0)
852 			goto err_out;
853 		err = -EINVAL;
854 		kind = tb[TCA_ACT_KIND];
855 		if (!kind) {
856 			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
857 			goto err_out;
858 		}
859 		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
860 			NL_SET_ERR_MSG(extack, "TC action name too long");
861 			goto err_out;
862 		}
863 		if (tb[TCA_ACT_COOKIE]) {
864 			int cklen = nla_len(tb[TCA_ACT_COOKIE]);
865 
866 			if (cklen > TC_COOKIE_MAX_SIZE) {
867 				NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
868 				goto err_out;
869 			}
870 
871 			cookie = nla_memdup_cookie(tb);
872 			if (!cookie) {
873 				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
874 				err = -ENOMEM;
875 				goto err_out;
876 			}
877 		}
878 	} else {
879 		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
880 			NL_SET_ERR_MSG(extack, "TC action name too long");
881 			err = -EINVAL;
882 			goto err_out;
883 		}
884 	}
885 
886 	a_o = tc_lookup_action_n(act_name);
887 	if (a_o == NULL) {
888 #ifdef CONFIG_MODULES
889 		if (rtnl_held)
890 			rtnl_unlock();
891 		request_module("act_%s", act_name);
892 		if (rtnl_held)
893 			rtnl_lock();
894 
895 		a_o = tc_lookup_action_n(act_name);
896 
897 		/* We dropped the RTNL semaphore in order to
898 		 * perform the module load.  So, even if we
899 		 * succeeded in loading the module we have to
900 		 * tell the caller to replay the request.  We
901 		 * indicate this using -EAGAIN.
902 		 */
903 		if (a_o != NULL) {
904 			err = -EAGAIN;
905 			goto err_mod;
906 		}
907 #endif
908 		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
909 		err = -ENOENT;
910 		goto err_out;
911 	}
912 
913 	/* backward compatibility for policer */
914 	if (name == NULL)
915 		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
916 				rtnl_held, tp, extack);
917 	else
918 		err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
919 				tp, extack);
920 	if (err < 0)
921 		goto err_mod;
922 
923 	if (!name && tb[TCA_ACT_COOKIE])
924 		tcf_set_action_cookie(&a->act_cookie, cookie);
925 
926 	/* module count goes up only when brand new policy is created
927 	 * if it exists and is only bound to in a_o->init() then
928 	 * ACT_P_CREATED is not returned (a zero is).
929 	 */
930 	if (err != ACT_P_CREATED)
931 		module_put(a_o->owner);
932 
933 	if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN) &&
934 	    !rcu_access_pointer(a->goto_chain)) {
935 		tcf_action_destroy_1(a, bind);
936 		NL_SET_ERR_MSG(extack, "can't use goto chain with NULL chain");
937 		return ERR_PTR(-EINVAL);
938 	}
939 
940 	return a;
941 
942 err_mod:
943 	module_put(a_o->owner);
944 err_out:
945 	if (cookie) {
946 		kfree(cookie->data);
947 		kfree(cookie);
948 	}
949 	return ERR_PTR(err);
950 }
951 
952 /* Returns numbers of initialized actions or negative error. */
953 
954 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
955 		    struct nlattr *est, char *name, int ovr, int bind,
956 		    struct tc_action *actions[], size_t *attr_size,
957 		    bool rtnl_held, struct netlink_ext_ack *extack)
958 {
959 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
960 	struct tc_action *act;
961 	size_t sz = 0;
962 	int err;
963 	int i;
964 
965 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
966 					  extack);
967 	if (err < 0)
968 		return err;
969 
970 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
971 		act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
972 					rtnl_held, extack);
973 		if (IS_ERR(act)) {
974 			err = PTR_ERR(act);
975 			goto err;
976 		}
977 		act->order = i;
978 		sz += tcf_action_fill_size(act);
979 		/* Start from index 0 */
980 		actions[i - 1] = act;
981 	}
982 
983 	*attr_size = tcf_action_full_attrs_size(sz);
984 	return i - 1;
985 
986 err:
987 	tcf_action_destroy(actions, bind);
988 	return err;
989 }
990 
991 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
992 			  int compat_mode)
993 {
994 	int err = 0;
995 	struct gnet_dump d;
996 
997 	if (p == NULL)
998 		goto errout;
999 
1000 	/* compat_mode being true specifies a call that is supposed
1001 	 * to add additional backward compatibility statistic TLVs.
1002 	 */
1003 	if (compat_mode) {
1004 		if (p->type == TCA_OLD_COMPAT)
1005 			err = gnet_stats_start_copy_compat(skb, 0,
1006 							   TCA_STATS,
1007 							   TCA_XSTATS,
1008 							   &p->tcfa_lock, &d,
1009 							   TCA_PAD);
1010 		else
1011 			return 0;
1012 	} else
1013 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1014 					    &p->tcfa_lock, &d, TCA_ACT_PAD);
1015 
1016 	if (err < 0)
1017 		goto errout;
1018 
1019 	if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
1020 	    gnet_stats_copy_basic_hw(NULL, &d, p->cpu_bstats_hw,
1021 				     &p->tcfa_bstats_hw) < 0 ||
1022 	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1023 	    gnet_stats_copy_queue(&d, p->cpu_qstats,
1024 				  &p->tcfa_qstats,
1025 				  p->tcfa_qstats.qlen) < 0)
1026 		goto errout;
1027 
1028 	if (gnet_stats_finish_copy(&d) < 0)
1029 		goto errout;
1030 
1031 	return 0;
1032 
1033 errout:
1034 	return -1;
1035 }
1036 
1037 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1038 			u32 portid, u32 seq, u16 flags, int event, int bind,
1039 			int ref)
1040 {
1041 	struct tcamsg *t;
1042 	struct nlmsghdr *nlh;
1043 	unsigned char *b = skb_tail_pointer(skb);
1044 	struct nlattr *nest;
1045 
1046 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1047 	if (!nlh)
1048 		goto out_nlmsg_trim;
1049 	t = nlmsg_data(nlh);
1050 	t->tca_family = AF_UNSPEC;
1051 	t->tca__pad1 = 0;
1052 	t->tca__pad2 = 0;
1053 
1054 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1055 	if (!nest)
1056 		goto out_nlmsg_trim;
1057 
1058 	if (tcf_action_dump(skb, actions, bind, ref) < 0)
1059 		goto out_nlmsg_trim;
1060 
1061 	nla_nest_end(skb, nest);
1062 
1063 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1064 	return skb->len;
1065 
1066 out_nlmsg_trim:
1067 	nlmsg_trim(skb, b);
1068 	return -1;
1069 }
1070 
1071 static int
1072 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1073 	       struct tc_action *actions[], int event,
1074 	       struct netlink_ext_ack *extack)
1075 {
1076 	struct sk_buff *skb;
1077 
1078 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1079 	if (!skb)
1080 		return -ENOBUFS;
1081 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1082 			 0, 1) <= 0) {
1083 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1084 		kfree_skb(skb);
1085 		return -EINVAL;
1086 	}
1087 
1088 	return rtnl_unicast(skb, net, portid);
1089 }
1090 
1091 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1092 					  struct nlmsghdr *n, u32 portid,
1093 					  struct netlink_ext_ack *extack)
1094 {
1095 	struct nlattr *tb[TCA_ACT_MAX + 1];
1096 	const struct tc_action_ops *ops;
1097 	struct tc_action *a;
1098 	int index;
1099 	int err;
1100 
1101 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL, extack);
1102 	if (err < 0)
1103 		goto err_out;
1104 
1105 	err = -EINVAL;
1106 	if (tb[TCA_ACT_INDEX] == NULL ||
1107 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1108 		NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1109 		goto err_out;
1110 	}
1111 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
1112 
1113 	err = -EINVAL;
1114 	ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1115 	if (!ops) { /* could happen in batch of actions */
1116 		NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1117 		goto err_out;
1118 	}
1119 	err = -ENOENT;
1120 	if (ops->lookup(net, &a, index) == 0) {
1121 		NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1122 		goto err_mod;
1123 	}
1124 
1125 	module_put(ops->owner);
1126 	return a;
1127 
1128 err_mod:
1129 	module_put(ops->owner);
1130 err_out:
1131 	return ERR_PTR(err);
1132 }
1133 
1134 static int tca_action_flush(struct net *net, struct nlattr *nla,
1135 			    struct nlmsghdr *n, u32 portid,
1136 			    struct netlink_ext_ack *extack)
1137 {
1138 	struct sk_buff *skb;
1139 	unsigned char *b;
1140 	struct nlmsghdr *nlh;
1141 	struct tcamsg *t;
1142 	struct netlink_callback dcb;
1143 	struct nlattr *nest;
1144 	struct nlattr *tb[TCA_ACT_MAX + 1];
1145 	const struct tc_action_ops *ops;
1146 	struct nlattr *kind;
1147 	int err = -ENOMEM;
1148 
1149 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1150 	if (!skb)
1151 		return err;
1152 
1153 	b = skb_tail_pointer(skb);
1154 
1155 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla, NULL, extack);
1156 	if (err < 0)
1157 		goto err_out;
1158 
1159 	err = -EINVAL;
1160 	kind = tb[TCA_ACT_KIND];
1161 	ops = tc_lookup_action(kind);
1162 	if (!ops) { /*some idjot trying to flush unknown action */
1163 		NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1164 		goto err_out;
1165 	}
1166 
1167 	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1168 			sizeof(*t), 0);
1169 	if (!nlh) {
1170 		NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1171 		goto out_module_put;
1172 	}
1173 	t = nlmsg_data(nlh);
1174 	t->tca_family = AF_UNSPEC;
1175 	t->tca__pad1 = 0;
1176 	t->tca__pad2 = 0;
1177 
1178 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1179 	if (!nest) {
1180 		NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1181 		goto out_module_put;
1182 	}
1183 
1184 	err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1185 	if (err <= 0) {
1186 		nla_nest_cancel(skb, nest);
1187 		goto out_module_put;
1188 	}
1189 
1190 	nla_nest_end(skb, nest);
1191 
1192 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1193 	nlh->nlmsg_flags |= NLM_F_ROOT;
1194 	module_put(ops->owner);
1195 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1196 			     n->nlmsg_flags & NLM_F_ECHO);
1197 	if (err > 0)
1198 		return 0;
1199 	if (err < 0)
1200 		NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1201 
1202 	return err;
1203 
1204 out_module_put:
1205 	module_put(ops->owner);
1206 err_out:
1207 	kfree_skb(skb);
1208 	return err;
1209 }
1210 
1211 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1212 {
1213 	int i;
1214 
1215 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1216 		struct tc_action *a = actions[i];
1217 		const struct tc_action_ops *ops = a->ops;
1218 		/* Actions can be deleted concurrently so we must save their
1219 		 * type and id to search again after reference is released.
1220 		 */
1221 		struct tcf_idrinfo *idrinfo = a->idrinfo;
1222 		u32 act_index = a->tcfa_index;
1223 
1224 		actions[i] = NULL;
1225 		if (tcf_action_put(a)) {
1226 			/* last reference, action was deleted concurrently */
1227 			module_put(ops->owner);
1228 		} else  {
1229 			int ret;
1230 
1231 			/* now do the delete */
1232 			ret = tcf_idr_delete_index(idrinfo, act_index);
1233 			if (ret < 0)
1234 				return ret;
1235 		}
1236 	}
1237 	return 0;
1238 }
1239 
1240 static int
1241 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1242 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1243 {
1244 	int ret;
1245 	struct sk_buff *skb;
1246 
1247 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1248 			GFP_KERNEL);
1249 	if (!skb)
1250 		return -ENOBUFS;
1251 
1252 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1253 			 0, 2) <= 0) {
1254 		NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1255 		kfree_skb(skb);
1256 		return -EINVAL;
1257 	}
1258 
1259 	/* now do the delete */
1260 	ret = tcf_action_delete(net, actions);
1261 	if (ret < 0) {
1262 		NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1263 		kfree_skb(skb);
1264 		return ret;
1265 	}
1266 
1267 	ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1268 			     n->nlmsg_flags & NLM_F_ECHO);
1269 	if (ret > 0)
1270 		return 0;
1271 	return ret;
1272 }
1273 
1274 static int
1275 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1276 	      u32 portid, int event, struct netlink_ext_ack *extack)
1277 {
1278 	int i, ret;
1279 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1280 	struct tc_action *act;
1281 	size_t attr_size = 0;
1282 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1283 
1284 	ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1285 					  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 		attr_size += tcf_action_fill_size(act);
1304 		actions[i - 1] = act;
1305 	}
1306 
1307 	attr_size = tcf_action_full_attrs_size(attr_size);
1308 
1309 	if (event == RTM_GETACTION)
1310 		ret = tcf_get_notify(net, portid, n, actions, event, extack);
1311 	else { /* delete */
1312 		ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1313 		if (ret)
1314 			goto err;
1315 		return 0;
1316 	}
1317 err:
1318 	tcf_action_put_many(actions);
1319 	return ret;
1320 }
1321 
1322 static int
1323 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1324 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1325 {
1326 	struct sk_buff *skb;
1327 	int err = 0;
1328 
1329 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1330 			GFP_KERNEL);
1331 	if (!skb)
1332 		return -ENOBUFS;
1333 
1334 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1335 			 RTM_NEWACTION, 0, 0) <= 0) {
1336 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1337 		kfree_skb(skb);
1338 		return -EINVAL;
1339 	}
1340 
1341 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1342 			     n->nlmsg_flags & NLM_F_ECHO);
1343 	if (err > 0)
1344 		err = 0;
1345 	return err;
1346 }
1347 
1348 static int tcf_action_add(struct net *net, struct nlattr *nla,
1349 			  struct nlmsghdr *n, u32 portid, int ovr,
1350 			  struct netlink_ext_ack *extack)
1351 {
1352 	size_t attr_size = 0;
1353 	int ret = 0;
1354 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1355 
1356 	ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, actions,
1357 			      &attr_size, true, extack);
1358 	if (ret < 0)
1359 		return ret;
1360 	ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1361 	if (ovr)
1362 		tcf_action_put_many(actions);
1363 
1364 	return ret;
1365 }
1366 
1367 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1368 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1369 	[TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1370 			     .validation_data = &tcaa_root_flags_allowed },
1371 	[TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1372 };
1373 
1374 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1375 			 struct netlink_ext_ack *extack)
1376 {
1377 	struct net *net = sock_net(skb->sk);
1378 	struct nlattr *tca[TCA_ROOT_MAX + 1];
1379 	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1380 	int ret = 0, ovr = 0;
1381 
1382 	if ((n->nlmsg_type != RTM_GETACTION) &&
1383 	    !netlink_capable(skb, CAP_NET_ADMIN))
1384 		return -EPERM;
1385 
1386 	ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
1387 				     TCA_ROOT_MAX, NULL, extack);
1388 	if (ret < 0)
1389 		return ret;
1390 
1391 	if (tca[TCA_ACT_TAB] == NULL) {
1392 		NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1393 		return -EINVAL;
1394 	}
1395 
1396 	/* n->nlmsg_flags & NLM_F_CREATE */
1397 	switch (n->nlmsg_type) {
1398 	case RTM_NEWACTION:
1399 		/* we are going to assume all other flags
1400 		 * imply create only if it doesn't exist
1401 		 * Note that CREATE | EXCL implies that
1402 		 * but since we want avoid ambiguity (eg when flags
1403 		 * is zero) then just set this
1404 		 */
1405 		if (n->nlmsg_flags & NLM_F_REPLACE)
1406 			ovr = 1;
1407 replay:
1408 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1409 				     extack);
1410 		if (ret == -EAGAIN)
1411 			goto replay;
1412 		break;
1413 	case RTM_DELACTION:
1414 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1415 				    portid, RTM_DELACTION, extack);
1416 		break;
1417 	case RTM_GETACTION:
1418 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1419 				    portid, RTM_GETACTION, extack);
1420 		break;
1421 	default:
1422 		BUG();
1423 	}
1424 
1425 	return ret;
1426 }
1427 
1428 static struct nlattr *find_dump_kind(struct nlattr **nla)
1429 {
1430 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1431 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1432 	struct nlattr *kind;
1433 
1434 	tb1 = nla[TCA_ACT_TAB];
1435 	if (tb1 == NULL)
1436 		return NULL;
1437 
1438 	if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1439 		return NULL;
1440 
1441 	if (tb[1] == NULL)
1442 		return NULL;
1443 	if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1444 		return NULL;
1445 	kind = tb2[TCA_ACT_KIND];
1446 
1447 	return kind;
1448 }
1449 
1450 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1451 {
1452 	struct net *net = sock_net(skb->sk);
1453 	struct nlmsghdr *nlh;
1454 	unsigned char *b = skb_tail_pointer(skb);
1455 	struct nlattr *nest;
1456 	struct tc_action_ops *a_o;
1457 	int ret = 0;
1458 	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1459 	struct nlattr *tb[TCA_ROOT_MAX + 1];
1460 	struct nlattr *count_attr = NULL;
1461 	unsigned long jiffy_since = 0;
1462 	struct nlattr *kind = NULL;
1463 	struct nla_bitfield32 bf;
1464 	u32 msecs_since = 0;
1465 	u32 act_count = 0;
1466 
1467 	ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
1468 				     TCA_ROOT_MAX, tcaa_policy, cb->extack);
1469 	if (ret < 0)
1470 		return ret;
1471 
1472 	kind = find_dump_kind(tb);
1473 	if (kind == NULL) {
1474 		pr_info("tc_dump_action: action bad kind\n");
1475 		return 0;
1476 	}
1477 
1478 	a_o = tc_lookup_action(kind);
1479 	if (a_o == NULL)
1480 		return 0;
1481 
1482 	cb->args[2] = 0;
1483 	if (tb[TCA_ROOT_FLAGS]) {
1484 		bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1485 		cb->args[2] = bf.value;
1486 	}
1487 
1488 	if (tb[TCA_ROOT_TIME_DELTA]) {
1489 		msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1490 	}
1491 
1492 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1493 			cb->nlh->nlmsg_type, sizeof(*t), 0);
1494 	if (!nlh)
1495 		goto out_module_put;
1496 
1497 	if (msecs_since)
1498 		jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1499 
1500 	t = nlmsg_data(nlh);
1501 	t->tca_family = AF_UNSPEC;
1502 	t->tca__pad1 = 0;
1503 	t->tca__pad2 = 0;
1504 	cb->args[3] = jiffy_since;
1505 	count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1506 	if (!count_attr)
1507 		goto out_module_put;
1508 
1509 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1510 	if (nest == NULL)
1511 		goto out_module_put;
1512 
1513 	ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1514 	if (ret < 0)
1515 		goto out_module_put;
1516 
1517 	if (ret > 0) {
1518 		nla_nest_end(skb, nest);
1519 		ret = skb->len;
1520 		act_count = cb->args[1];
1521 		memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1522 		cb->args[1] = 0;
1523 	} else
1524 		nlmsg_trim(skb, b);
1525 
1526 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1527 	if (NETLINK_CB(cb->skb).portid && ret)
1528 		nlh->nlmsg_flags |= NLM_F_MULTI;
1529 	module_put(a_o->owner);
1530 	return skb->len;
1531 
1532 out_module_put:
1533 	module_put(a_o->owner);
1534 	nlmsg_trim(skb, b);
1535 	return skb->len;
1536 }
1537 
1538 static int __init tc_action_init(void)
1539 {
1540 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1541 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1542 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1543 		      0);
1544 
1545 	return 0;
1546 }
1547 
1548 subsys_initcall(tc_action_init);
1549