xref: /openbmc/linux/net/sched/act_api.c (revision 4e8ddd7f1758ca4ddd0c1f7cf3e66fce736241d2)
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 <linux/rhashtable.h>
25 #include <linux/list.h>
26 #include <net/net_namespace.h>
27 #include <net/sock.h>
28 #include <net/sch_generic.h>
29 #include <net/pkt_cls.h>
30 #include <net/act_api.h>
31 #include <net/netlink.h>
32 
33 static int tcf_action_goto_chain_init(struct tc_action *a, struct tcf_proto *tp)
34 {
35 	u32 chain_index = a->tcfa_action & TC_ACT_EXT_VAL_MASK;
36 
37 	if (!tp)
38 		return -EINVAL;
39 	a->goto_chain = tcf_chain_get(tp->chain->block, chain_index, true);
40 	if (!a->goto_chain)
41 		return -ENOMEM;
42 	return 0;
43 }
44 
45 static void tcf_action_goto_chain_fini(struct tc_action *a)
46 {
47 	tcf_chain_put(a->goto_chain);
48 }
49 
50 static void tcf_action_goto_chain_exec(const struct tc_action *a,
51 				       struct tcf_result *res)
52 {
53 	const struct tcf_chain *chain = a->goto_chain;
54 
55 	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
56 }
57 
58 static void tcf_free_cookie_rcu(struct rcu_head *p)
59 {
60 	struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
61 
62 	kfree(cookie->data);
63 	kfree(cookie);
64 }
65 
66 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
67 				  struct tc_cookie *new_cookie)
68 {
69 	struct tc_cookie *old;
70 
71 	old = xchg(old_cookie, new_cookie);
72 	if (old)
73 		call_rcu(&old->rcu, tcf_free_cookie_rcu);
74 }
75 
76 /* XXX: For standalone actions, we don't need a RCU grace period either, because
77  * actions are always connected to filters and filters are already destroyed in
78  * RCU callbacks, so after a RCU grace period actions are already disconnected
79  * from filters. Readers later can not find us.
80  */
81 static void free_tcf(struct tc_action *p)
82 {
83 	free_percpu(p->cpu_bstats);
84 	free_percpu(p->cpu_qstats);
85 
86 	tcf_set_action_cookie(&p->act_cookie, NULL);
87 	if (p->goto_chain)
88 		tcf_action_goto_chain_fini(p);
89 
90 	kfree(p);
91 }
92 
93 static void tcf_action_cleanup(struct tc_action *p)
94 {
95 	if (p->ops->cleanup)
96 		p->ops->cleanup(p);
97 
98 	gen_kill_estimator(&p->tcfa_rate_est);
99 	free_tcf(p);
100 }
101 
102 static int __tcf_action_put(struct tc_action *p, bool bind)
103 {
104 	struct tcf_idrinfo *idrinfo = p->idrinfo;
105 
106 	if (refcount_dec_and_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
107 		if (bind)
108 			atomic_dec(&p->tcfa_bindcnt);
109 		idr_remove(&idrinfo->action_idr, p->tcfa_index);
110 		spin_unlock(&idrinfo->lock);
111 
112 		tcf_action_cleanup(p);
113 		return 1;
114 	}
115 
116 	if (bind)
117 		atomic_dec(&p->tcfa_bindcnt);
118 
119 	return 0;
120 }
121 
122 int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
123 {
124 	int ret = 0;
125 
126 	/* Release with strict==1 and bind==0 is only called through act API
127 	 * interface (classifiers always bind). Only case when action with
128 	 * positive reference count and zero bind count can exist is when it was
129 	 * also created with act API (unbinding last classifier will destroy the
130 	 * action if it was created by classifier). So only case when bind count
131 	 * can be changed after initial check is when unbound action is
132 	 * destroyed by act API while classifier binds to action with same id
133 	 * concurrently. This result either creation of new action(same behavior
134 	 * as before), or reusing existing action if concurrent process
135 	 * increments reference count before action is deleted. Both scenarios
136 	 * are acceptable.
137 	 */
138 	if (p) {
139 		if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
140 			return -EPERM;
141 
142 		if (__tcf_action_put(p, bind))
143 			ret = ACT_P_DELETED;
144 	}
145 
146 	return ret;
147 }
148 EXPORT_SYMBOL(__tcf_idr_release);
149 
150 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
151 {
152 	u32 cookie_len = 0;
153 
154 	if (act->act_cookie)
155 		cookie_len = nla_total_size(act->act_cookie->len);
156 
157 	return  nla_total_size(0) /* action number nested */
158 		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
159 		+ cookie_len /* TCA_ACT_COOKIE */
160 		+ nla_total_size(0) /* TCA_ACT_STATS nested */
161 		/* TCA_STATS_BASIC */
162 		+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
163 		/* TCA_STATS_QUEUE */
164 		+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
165 		+ nla_total_size(0) /* TCA_OPTIONS nested */
166 		+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
167 }
168 
169 static size_t tcf_action_full_attrs_size(size_t sz)
170 {
171 	return NLMSG_HDRLEN                     /* struct nlmsghdr */
172 		+ sizeof(struct tcamsg)
173 		+ nla_total_size(0)             /* TCA_ACT_TAB nested */
174 		+ sz;
175 }
176 
177 static size_t tcf_action_fill_size(const struct tc_action *act)
178 {
179 	size_t sz = tcf_action_shared_attrs_size(act);
180 
181 	if (act->ops->get_fill_size)
182 		return act->ops->get_fill_size(act) + sz;
183 	return sz;
184 }
185 
186 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
187 			   struct netlink_callback *cb)
188 {
189 	int err = 0, index = -1, s_i = 0, n_i = 0;
190 	u32 act_flags = cb->args[2];
191 	unsigned long jiffy_since = cb->args[3];
192 	struct nlattr *nest;
193 	struct idr *idr = &idrinfo->action_idr;
194 	struct tc_action *p;
195 	unsigned long id = 1;
196 
197 	spin_lock(&idrinfo->lock);
198 
199 	s_i = cb->args[0];
200 
201 	idr_for_each_entry_ul(idr, p, id) {
202 		index++;
203 		if (index < s_i)
204 			continue;
205 
206 		if (jiffy_since &&
207 		    time_after(jiffy_since,
208 			       (unsigned long)p->tcfa_tm.lastuse))
209 			continue;
210 
211 		nest = nla_nest_start(skb, n_i);
212 		if (!nest) {
213 			index--;
214 			goto nla_put_failure;
215 		}
216 		err = tcf_action_dump_1(skb, p, 0, 0);
217 		if (err < 0) {
218 			index--;
219 			nlmsg_trim(skb, nest);
220 			goto done;
221 		}
222 		nla_nest_end(skb, nest);
223 		n_i++;
224 		if (!(act_flags & TCA_FLAG_LARGE_DUMP_ON) &&
225 		    n_i >= TCA_ACT_MAX_PRIO)
226 			goto done;
227 	}
228 done:
229 	if (index >= 0)
230 		cb->args[0] = index + 1;
231 
232 	spin_unlock(&idrinfo->lock);
233 	if (n_i) {
234 		if (act_flags & TCA_FLAG_LARGE_DUMP_ON)
235 			cb->args[1] = n_i;
236 	}
237 	return n_i;
238 
239 nla_put_failure:
240 	nla_nest_cancel(skb, nest);
241 	goto done;
242 }
243 
244 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
245 			  const struct tc_action_ops *ops)
246 {
247 	struct nlattr *nest;
248 	int n_i = 0;
249 	int ret = -EINVAL;
250 	struct idr *idr = &idrinfo->action_idr;
251 	struct tc_action *p;
252 	unsigned long id = 1;
253 
254 	nest = nla_nest_start(skb, 0);
255 	if (nest == NULL)
256 		goto nla_put_failure;
257 	if (nla_put_string(skb, TCA_KIND, ops->kind))
258 		goto nla_put_failure;
259 
260 	idr_for_each_entry_ul(idr, p, id) {
261 		ret = __tcf_idr_release(p, false, true);
262 		if (ret == ACT_P_DELETED) {
263 			module_put(ops->owner);
264 			n_i++;
265 		} else if (ret < 0) {
266 			goto nla_put_failure;
267 		}
268 	}
269 	if (nla_put_u32(skb, TCA_FCNT, n_i))
270 		goto nla_put_failure;
271 	nla_nest_end(skb, nest);
272 
273 	return n_i;
274 nla_put_failure:
275 	nla_nest_cancel(skb, nest);
276 	return ret;
277 }
278 
279 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
280 		       struct netlink_callback *cb, int type,
281 		       const struct tc_action_ops *ops,
282 		       struct netlink_ext_ack *extack)
283 {
284 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
285 
286 	if (type == RTM_DELACTION) {
287 		return tcf_del_walker(idrinfo, skb, ops);
288 	} else if (type == RTM_GETACTION) {
289 		return tcf_dump_walker(idrinfo, skb, cb);
290 	} else {
291 		WARN(1, "tcf_generic_walker: unknown command %d\n", type);
292 		NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
293 		return -EINVAL;
294 	}
295 }
296 EXPORT_SYMBOL(tcf_generic_walker);
297 
298 static bool __tcf_idr_check(struct tc_action_net *tn, u32 index,
299 			    struct tc_action **a, int bind)
300 {
301 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
302 	struct tc_action *p;
303 
304 	spin_lock(&idrinfo->lock);
305 	p = idr_find(&idrinfo->action_idr, index);
306 	if (p) {
307 		refcount_inc(&p->tcfa_refcnt);
308 		if (bind)
309 			atomic_inc(&p->tcfa_bindcnt);
310 	}
311 	spin_unlock(&idrinfo->lock);
312 
313 	if (p) {
314 		*a = p;
315 		return true;
316 	}
317 	return false;
318 }
319 
320 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
321 {
322 	return __tcf_idr_check(tn, index, a, 0);
323 }
324 EXPORT_SYMBOL(tcf_idr_search);
325 
326 bool tcf_idr_check(struct tc_action_net *tn, u32 index, struct tc_action **a,
327 		   int bind)
328 {
329 	return __tcf_idr_check(tn, index, a, bind);
330 }
331 EXPORT_SYMBOL(tcf_idr_check);
332 
333 int tcf_idr_delete_index(struct tc_action_net *tn, u32 index)
334 {
335 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
336 	struct tc_action *p;
337 	int ret = 0;
338 
339 	spin_lock(&idrinfo->lock);
340 	p = idr_find(&idrinfo->action_idr, index);
341 	if (!p) {
342 		spin_unlock(&idrinfo->lock);
343 		return -ENOENT;
344 	}
345 
346 	if (!atomic_read(&p->tcfa_bindcnt)) {
347 		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
348 			struct module *owner = p->ops->owner;
349 
350 			WARN_ON(p != idr_remove(&idrinfo->action_idr,
351 						p->tcfa_index));
352 			spin_unlock(&idrinfo->lock);
353 
354 			tcf_action_cleanup(p);
355 			module_put(owner);
356 			return 0;
357 		}
358 		ret = 0;
359 	} else {
360 		ret = -EPERM;
361 	}
362 
363 	spin_unlock(&idrinfo->lock);
364 	return ret;
365 }
366 EXPORT_SYMBOL(tcf_idr_delete_index);
367 
368 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
369 		   struct tc_action **a, const struct tc_action_ops *ops,
370 		   int bind, bool cpustats)
371 {
372 	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
373 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
374 	struct idr *idr = &idrinfo->action_idr;
375 	int err = -ENOMEM;
376 
377 	if (unlikely(!p))
378 		return -ENOMEM;
379 	refcount_set(&p->tcfa_refcnt, 1);
380 	if (bind)
381 		atomic_set(&p->tcfa_bindcnt, 1);
382 
383 	if (cpustats) {
384 		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_cpu);
385 		if (!p->cpu_bstats)
386 			goto err1;
387 		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
388 		if (!p->cpu_qstats)
389 			goto err2;
390 	}
391 	spin_lock_init(&p->tcfa_lock);
392 	idr_preload(GFP_KERNEL);
393 	spin_lock(&idrinfo->lock);
394 	/* user doesn't specify an index */
395 	if (!index) {
396 		index = 1;
397 		err = idr_alloc_u32(idr, NULL, &index, UINT_MAX, GFP_ATOMIC);
398 	} else {
399 		err = idr_alloc_u32(idr, NULL, &index, index, GFP_ATOMIC);
400 	}
401 	spin_unlock(&idrinfo->lock);
402 	idr_preload_end();
403 	if (err)
404 		goto err3;
405 
406 	p->tcfa_index = index;
407 	p->tcfa_tm.install = jiffies;
408 	p->tcfa_tm.lastuse = jiffies;
409 	p->tcfa_tm.firstuse = 0;
410 	if (est) {
411 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
412 					&p->tcfa_rate_est,
413 					&p->tcfa_lock, NULL, est);
414 		if (err)
415 			goto err4;
416 	}
417 
418 	p->idrinfo = idrinfo;
419 	p->ops = ops;
420 	INIT_LIST_HEAD(&p->list);
421 	*a = p;
422 	return 0;
423 err4:
424 	idr_remove(idr, index);
425 err3:
426 	free_percpu(p->cpu_qstats);
427 err2:
428 	free_percpu(p->cpu_bstats);
429 err1:
430 	kfree(p);
431 	return err;
432 }
433 EXPORT_SYMBOL(tcf_idr_create);
434 
435 void tcf_idr_insert(struct tc_action_net *tn, struct tc_action *a)
436 {
437 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
438 
439 	spin_lock(&idrinfo->lock);
440 	idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
441 	spin_unlock(&idrinfo->lock);
442 }
443 EXPORT_SYMBOL(tcf_idr_insert);
444 
445 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
446 			 struct tcf_idrinfo *idrinfo)
447 {
448 	struct idr *idr = &idrinfo->action_idr;
449 	struct tc_action *p;
450 	int ret;
451 	unsigned long id = 1;
452 
453 	idr_for_each_entry_ul(idr, p, id) {
454 		ret = __tcf_idr_release(p, false, true);
455 		if (ret == ACT_P_DELETED)
456 			module_put(ops->owner);
457 		else if (ret < 0)
458 			return;
459 	}
460 	idr_destroy(&idrinfo->action_idr);
461 }
462 EXPORT_SYMBOL(tcf_idrinfo_destroy);
463 
464 static LIST_HEAD(act_base);
465 static DEFINE_RWLOCK(act_mod_lock);
466 
467 int tcf_register_action(struct tc_action_ops *act,
468 			struct pernet_operations *ops)
469 {
470 	struct tc_action_ops *a;
471 	int ret;
472 
473 	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
474 		return -EINVAL;
475 
476 	/* We have to register pernet ops before making the action ops visible,
477 	 * otherwise tcf_action_init_1() could get a partially initialized
478 	 * netns.
479 	 */
480 	ret = register_pernet_subsys(ops);
481 	if (ret)
482 		return ret;
483 
484 	write_lock(&act_mod_lock);
485 	list_for_each_entry(a, &act_base, head) {
486 		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
487 			write_unlock(&act_mod_lock);
488 			unregister_pernet_subsys(ops);
489 			return -EEXIST;
490 		}
491 	}
492 	list_add_tail(&act->head, &act_base);
493 	write_unlock(&act_mod_lock);
494 
495 	return 0;
496 }
497 EXPORT_SYMBOL(tcf_register_action);
498 
499 int tcf_unregister_action(struct tc_action_ops *act,
500 			  struct pernet_operations *ops)
501 {
502 	struct tc_action_ops *a;
503 	int err = -ENOENT;
504 
505 	write_lock(&act_mod_lock);
506 	list_for_each_entry(a, &act_base, head) {
507 		if (a == act) {
508 			list_del(&act->head);
509 			err = 0;
510 			break;
511 		}
512 	}
513 	write_unlock(&act_mod_lock);
514 	if (!err)
515 		unregister_pernet_subsys(ops);
516 	return err;
517 }
518 EXPORT_SYMBOL(tcf_unregister_action);
519 
520 /* lookup by name */
521 static struct tc_action_ops *tc_lookup_action_n(char *kind)
522 {
523 	struct tc_action_ops *a, *res = NULL;
524 
525 	if (kind) {
526 		read_lock(&act_mod_lock);
527 		list_for_each_entry(a, &act_base, head) {
528 			if (strcmp(kind, a->kind) == 0) {
529 				if (try_module_get(a->owner))
530 					res = a;
531 				break;
532 			}
533 		}
534 		read_unlock(&act_mod_lock);
535 	}
536 	return res;
537 }
538 
539 /* lookup by nlattr */
540 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
541 {
542 	struct tc_action_ops *a, *res = NULL;
543 
544 	if (kind) {
545 		read_lock(&act_mod_lock);
546 		list_for_each_entry(a, &act_base, head) {
547 			if (nla_strcmp(kind, a->kind) == 0) {
548 				if (try_module_get(a->owner))
549 					res = a;
550 				break;
551 			}
552 		}
553 		read_unlock(&act_mod_lock);
554 	}
555 	return res;
556 }
557 
558 /*TCA_ACT_MAX_PRIO is 32, there count upto 32 */
559 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
560 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
561 		    int nr_actions, struct tcf_result *res)
562 {
563 	u32 jmp_prgcnt = 0;
564 	u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
565 	int i;
566 	int ret = TC_ACT_OK;
567 
568 	if (skb_skip_tc_classify(skb))
569 		return TC_ACT_OK;
570 
571 restart_act_graph:
572 	for (i = 0; i < nr_actions; i++) {
573 		const struct tc_action *a = actions[i];
574 
575 		if (jmp_prgcnt > 0) {
576 			jmp_prgcnt -= 1;
577 			continue;
578 		}
579 repeat:
580 		ret = a->ops->act(skb, a, res);
581 		if (ret == TC_ACT_REPEAT)
582 			goto repeat;	/* we need a ttl - JHS */
583 
584 		if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
585 			jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
586 			if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
587 				/* faulty opcode, stop pipeline */
588 				return TC_ACT_OK;
589 			} else {
590 				jmp_ttl -= 1;
591 				if (jmp_ttl > 0)
592 					goto restart_act_graph;
593 				else /* faulty graph, stop pipeline */
594 					return TC_ACT_OK;
595 			}
596 		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
597 			tcf_action_goto_chain_exec(a, res);
598 		}
599 
600 		if (ret != TC_ACT_PIPE)
601 			break;
602 	}
603 
604 	return ret;
605 }
606 EXPORT_SYMBOL(tcf_action_exec);
607 
608 int tcf_action_destroy(struct list_head *actions, int bind)
609 {
610 	const struct tc_action_ops *ops;
611 	struct tc_action *a, *tmp;
612 	int ret = 0;
613 
614 	list_for_each_entry_safe(a, tmp, actions, list) {
615 		ops = a->ops;
616 		ret = __tcf_idr_release(a, bind, true);
617 		if (ret == ACT_P_DELETED)
618 			module_put(ops->owner);
619 		else if (ret < 0)
620 			return ret;
621 	}
622 	return ret;
623 }
624 
625 static int tcf_action_put(struct tc_action *p)
626 {
627 	return __tcf_action_put(p, false);
628 }
629 
630 int
631 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
632 {
633 	return a->ops->dump(skb, a, bind, ref);
634 }
635 
636 int
637 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
638 {
639 	int err = -EINVAL;
640 	unsigned char *b = skb_tail_pointer(skb);
641 	struct nlattr *nest;
642 	struct tc_cookie *cookie;
643 
644 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
645 		goto nla_put_failure;
646 	if (tcf_action_copy_stats(skb, a, 0))
647 		goto nla_put_failure;
648 
649 	rcu_read_lock();
650 	cookie = rcu_dereference(a->act_cookie);
651 	if (cookie) {
652 		if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
653 			rcu_read_unlock();
654 			goto nla_put_failure;
655 		}
656 	}
657 	rcu_read_unlock();
658 
659 	nest = nla_nest_start(skb, TCA_OPTIONS);
660 	if (nest == NULL)
661 		goto nla_put_failure;
662 	err = tcf_action_dump_old(skb, a, bind, ref);
663 	if (err > 0) {
664 		nla_nest_end(skb, nest);
665 		return err;
666 	}
667 
668 nla_put_failure:
669 	nlmsg_trim(skb, b);
670 	return -1;
671 }
672 EXPORT_SYMBOL(tcf_action_dump_1);
673 
674 int tcf_action_dump(struct sk_buff *skb, struct list_head *actions,
675 		    int bind, int ref)
676 {
677 	struct tc_action *a;
678 	int err = -EINVAL;
679 	struct nlattr *nest;
680 
681 	list_for_each_entry(a, actions, list) {
682 		nest = nla_nest_start(skb, a->order);
683 		if (nest == NULL)
684 			goto nla_put_failure;
685 		err = tcf_action_dump_1(skb, a, bind, ref);
686 		if (err < 0)
687 			goto errout;
688 		nla_nest_end(skb, nest);
689 	}
690 
691 	return 0;
692 
693 nla_put_failure:
694 	err = -EINVAL;
695 errout:
696 	nla_nest_cancel(skb, nest);
697 	return err;
698 }
699 
700 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
701 {
702 	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
703 	if (!c)
704 		return NULL;
705 
706 	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
707 	if (!c->data) {
708 		kfree(c);
709 		return NULL;
710 	}
711 	c->len = nla_len(tb[TCA_ACT_COOKIE]);
712 
713 	return c;
714 }
715 
716 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
717 				    struct nlattr *nla, struct nlattr *est,
718 				    char *name, int ovr, int bind,
719 				    bool rtnl_held,
720 				    struct netlink_ext_ack *extack)
721 {
722 	struct tc_action *a;
723 	struct tc_action_ops *a_o;
724 	struct tc_cookie *cookie = NULL;
725 	char act_name[IFNAMSIZ];
726 	struct nlattr *tb[TCA_ACT_MAX + 1];
727 	struct nlattr *kind;
728 	int err;
729 
730 	if (name == NULL) {
731 		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
732 		if (err < 0)
733 			goto err_out;
734 		err = -EINVAL;
735 		kind = tb[TCA_ACT_KIND];
736 		if (!kind) {
737 			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
738 			goto err_out;
739 		}
740 		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ) {
741 			NL_SET_ERR_MSG(extack, "TC action name too long");
742 			goto err_out;
743 		}
744 		if (tb[TCA_ACT_COOKIE]) {
745 			int cklen = nla_len(tb[TCA_ACT_COOKIE]);
746 
747 			if (cklen > TC_COOKIE_MAX_SIZE) {
748 				NL_SET_ERR_MSG(extack, "TC cookie size above the maximum");
749 				goto err_out;
750 			}
751 
752 			cookie = nla_memdup_cookie(tb);
753 			if (!cookie) {
754 				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
755 				err = -ENOMEM;
756 				goto err_out;
757 			}
758 		}
759 	} else {
760 		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ) {
761 			NL_SET_ERR_MSG(extack, "TC action name too long");
762 			err = -EINVAL;
763 			goto err_out;
764 		}
765 	}
766 
767 	a_o = tc_lookup_action_n(act_name);
768 	if (a_o == NULL) {
769 #ifdef CONFIG_MODULES
770 		if (rtnl_held)
771 			rtnl_unlock();
772 		request_module("act_%s", act_name);
773 		if (rtnl_held)
774 			rtnl_lock();
775 
776 		a_o = tc_lookup_action_n(act_name);
777 
778 		/* We dropped the RTNL semaphore in order to
779 		 * perform the module load.  So, even if we
780 		 * succeeded in loading the module we have to
781 		 * tell the caller to replay the request.  We
782 		 * indicate this using -EAGAIN.
783 		 */
784 		if (a_o != NULL) {
785 			err = -EAGAIN;
786 			goto err_mod;
787 		}
788 #endif
789 		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
790 		err = -ENOENT;
791 		goto err_out;
792 	}
793 
794 	/* backward compatibility for policer */
795 	if (name == NULL)
796 		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, ovr, bind,
797 				rtnl_held, extack);
798 	else
799 		err = a_o->init(net, nla, est, &a, ovr, bind, rtnl_held,
800 				extack);
801 	if (err < 0)
802 		goto err_mod;
803 
804 	if (!name && tb[TCA_ACT_COOKIE])
805 		tcf_set_action_cookie(&a->act_cookie, cookie);
806 
807 	/* module count goes up only when brand new policy is created
808 	 * if it exists and is only bound to in a_o->init() then
809 	 * ACT_P_CREATED is not returned (a zero is).
810 	 */
811 	if (err != ACT_P_CREATED)
812 		module_put(a_o->owner);
813 
814 	if (TC_ACT_EXT_CMP(a->tcfa_action, TC_ACT_GOTO_CHAIN)) {
815 		err = tcf_action_goto_chain_init(a, tp);
816 		if (err) {
817 			LIST_HEAD(actions);
818 
819 			list_add_tail(&a->list, &actions);
820 			tcf_action_destroy(&actions, bind);
821 			NL_SET_ERR_MSG(extack, "Failed to init TC action chain");
822 			return ERR_PTR(err);
823 		}
824 	}
825 
826 	return a;
827 
828 err_mod:
829 	module_put(a_o->owner);
830 err_out:
831 	if (cookie) {
832 		kfree(cookie->data);
833 		kfree(cookie);
834 	}
835 	return ERR_PTR(err);
836 }
837 
838 static void cleanup_a(struct list_head *actions, int ovr)
839 {
840 	struct tc_action *a;
841 
842 	if (!ovr)
843 		return;
844 
845 	list_for_each_entry(a, actions, list)
846 		refcount_dec(&a->tcfa_refcnt);
847 }
848 
849 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
850 		    struct nlattr *est, char *name, int ovr, int bind,
851 		    struct list_head *actions, size_t *attr_size,
852 		    bool rtnl_held, struct netlink_ext_ack *extack)
853 {
854 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
855 	struct tc_action *act;
856 	size_t sz = 0;
857 	int err;
858 	int i;
859 
860 	err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
861 	if (err < 0)
862 		return err;
863 
864 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
865 		act = tcf_action_init_1(net, tp, tb[i], est, name, ovr, bind,
866 					rtnl_held, extack);
867 		if (IS_ERR(act)) {
868 			err = PTR_ERR(act);
869 			goto err;
870 		}
871 		act->order = i;
872 		sz += tcf_action_fill_size(act);
873 		list_add_tail(&act->list, actions);
874 	}
875 
876 	*attr_size = tcf_action_full_attrs_size(sz);
877 
878 	/* Remove the temp refcnt which was necessary to protect against
879 	 * destroying an existing action which was being replaced
880 	 */
881 	cleanup_a(actions, ovr);
882 	return 0;
883 
884 err:
885 	tcf_action_destroy(actions, bind);
886 	return err;
887 }
888 
889 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
890 			  int compat_mode)
891 {
892 	int err = 0;
893 	struct gnet_dump d;
894 
895 	if (p == NULL)
896 		goto errout;
897 
898 	/* compat_mode being true specifies a call that is supposed
899 	 * to add additional backward compatibility statistic TLVs.
900 	 */
901 	if (compat_mode) {
902 		if (p->type == TCA_OLD_COMPAT)
903 			err = gnet_stats_start_copy_compat(skb, 0,
904 							   TCA_STATS,
905 							   TCA_XSTATS,
906 							   &p->tcfa_lock, &d,
907 							   TCA_PAD);
908 		else
909 			return 0;
910 	} else
911 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
912 					    &p->tcfa_lock, &d, TCA_ACT_PAD);
913 
914 	if (err < 0)
915 		goto errout;
916 
917 	if (gnet_stats_copy_basic(NULL, &d, p->cpu_bstats, &p->tcfa_bstats) < 0 ||
918 	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
919 	    gnet_stats_copy_queue(&d, p->cpu_qstats,
920 				  &p->tcfa_qstats,
921 				  p->tcfa_qstats.qlen) < 0)
922 		goto errout;
923 
924 	if (gnet_stats_finish_copy(&d) < 0)
925 		goto errout;
926 
927 	return 0;
928 
929 errout:
930 	return -1;
931 }
932 
933 static int tca_get_fill(struct sk_buff *skb, struct list_head *actions,
934 			u32 portid, u32 seq, u16 flags, int event, int bind,
935 			int ref)
936 {
937 	struct tcamsg *t;
938 	struct nlmsghdr *nlh;
939 	unsigned char *b = skb_tail_pointer(skb);
940 	struct nlattr *nest;
941 
942 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
943 	if (!nlh)
944 		goto out_nlmsg_trim;
945 	t = nlmsg_data(nlh);
946 	t->tca_family = AF_UNSPEC;
947 	t->tca__pad1 = 0;
948 	t->tca__pad2 = 0;
949 
950 	nest = nla_nest_start(skb, TCA_ACT_TAB);
951 	if (!nest)
952 		goto out_nlmsg_trim;
953 
954 	if (tcf_action_dump(skb, actions, bind, ref) < 0)
955 		goto out_nlmsg_trim;
956 
957 	nla_nest_end(skb, nest);
958 
959 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
960 	return skb->len;
961 
962 out_nlmsg_trim:
963 	nlmsg_trim(skb, b);
964 	return -1;
965 }
966 
967 static int
968 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
969 	       struct list_head *actions, int event,
970 	       struct netlink_ext_ack *extack)
971 {
972 	struct sk_buff *skb;
973 
974 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
975 	if (!skb)
976 		return -ENOBUFS;
977 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
978 			 0, 1) <= 0) {
979 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
980 		kfree_skb(skb);
981 		return -EINVAL;
982 	}
983 
984 	return rtnl_unicast(skb, net, portid);
985 }
986 
987 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
988 					  struct nlmsghdr *n, u32 portid,
989 					  struct netlink_ext_ack *extack)
990 {
991 	struct nlattr *tb[TCA_ACT_MAX + 1];
992 	const struct tc_action_ops *ops;
993 	struct tc_action *a;
994 	int index;
995 	int err;
996 
997 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
998 	if (err < 0)
999 		goto err_out;
1000 
1001 	err = -EINVAL;
1002 	if (tb[TCA_ACT_INDEX] == NULL ||
1003 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1004 		NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1005 		goto err_out;
1006 	}
1007 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
1008 
1009 	err = -EINVAL;
1010 	ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1011 	if (!ops) { /* could happen in batch of actions */
1012 		NL_SET_ERR_MSG(extack, "Specified TC action not found");
1013 		goto err_out;
1014 	}
1015 	err = -ENOENT;
1016 	if (ops->lookup(net, &a, index, extack) == 0)
1017 		goto err_mod;
1018 
1019 	module_put(ops->owner);
1020 	return a;
1021 
1022 err_mod:
1023 	module_put(ops->owner);
1024 err_out:
1025 	return ERR_PTR(err);
1026 }
1027 
1028 static int tca_action_flush(struct net *net, struct nlattr *nla,
1029 			    struct nlmsghdr *n, u32 portid,
1030 			    struct netlink_ext_ack *extack)
1031 {
1032 	struct sk_buff *skb;
1033 	unsigned char *b;
1034 	struct nlmsghdr *nlh;
1035 	struct tcamsg *t;
1036 	struct netlink_callback dcb;
1037 	struct nlattr *nest;
1038 	struct nlattr *tb[TCA_ACT_MAX + 1];
1039 	const struct tc_action_ops *ops;
1040 	struct nlattr *kind;
1041 	int err = -ENOMEM;
1042 
1043 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1044 	if (!skb)
1045 		return err;
1046 
1047 	b = skb_tail_pointer(skb);
1048 
1049 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL, extack);
1050 	if (err < 0)
1051 		goto err_out;
1052 
1053 	err = -EINVAL;
1054 	kind = tb[TCA_ACT_KIND];
1055 	ops = tc_lookup_action(kind);
1056 	if (!ops) { /*some idjot trying to flush unknown action */
1057 		NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1058 		goto err_out;
1059 	}
1060 
1061 	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1062 			sizeof(*t), 0);
1063 	if (!nlh) {
1064 		NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1065 		goto out_module_put;
1066 	}
1067 	t = nlmsg_data(nlh);
1068 	t->tca_family = AF_UNSPEC;
1069 	t->tca__pad1 = 0;
1070 	t->tca__pad2 = 0;
1071 
1072 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1073 	if (!nest) {
1074 		NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1075 		goto out_module_put;
1076 	}
1077 
1078 	err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1079 	if (err <= 0) {
1080 		nla_nest_cancel(skb, nest);
1081 		goto out_module_put;
1082 	}
1083 
1084 	nla_nest_end(skb, nest);
1085 
1086 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1087 	nlh->nlmsg_flags |= NLM_F_ROOT;
1088 	module_put(ops->owner);
1089 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1090 			     n->nlmsg_flags & NLM_F_ECHO);
1091 	if (err > 0)
1092 		return 0;
1093 	if (err < 0)
1094 		NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1095 
1096 	return err;
1097 
1098 out_module_put:
1099 	module_put(ops->owner);
1100 err_out:
1101 	kfree_skb(skb);
1102 	return err;
1103 }
1104 
1105 static int tcf_action_delete(struct net *net, struct list_head *actions,
1106 			     struct netlink_ext_ack *extack)
1107 {
1108 	struct tc_action *a, *tmp;
1109 	u32 act_index;
1110 	int ret;
1111 
1112 	list_for_each_entry_safe(a, tmp, actions, list) {
1113 		const struct tc_action_ops *ops = a->ops;
1114 
1115 		/* Actions can be deleted concurrently so we must save their
1116 		 * type and id to search again after reference is released.
1117 		 */
1118 		act_index = a->tcfa_index;
1119 
1120 		list_del(&a->list);
1121 		if (tcf_action_put(a)) {
1122 			/* last reference, action was deleted concurrently */
1123 			module_put(ops->owner);
1124 		} else  {
1125 			/* now do the delete */
1126 			ret = ops->delete(net, act_index);
1127 			if (ret < 0)
1128 				return ret;
1129 		}
1130 	}
1131 	return 0;
1132 }
1133 
1134 static int
1135 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
1136 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1137 {
1138 	int ret;
1139 	struct sk_buff *skb;
1140 
1141 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1142 			GFP_KERNEL);
1143 	if (!skb)
1144 		return -ENOBUFS;
1145 
1146 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1147 			 0, 2) <= 0) {
1148 		NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1149 		kfree_skb(skb);
1150 		return -EINVAL;
1151 	}
1152 
1153 	/* now do the delete */
1154 	ret = tcf_action_delete(net, actions, extack);
1155 	if (ret < 0) {
1156 		NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1157 		kfree_skb(skb);
1158 		return ret;
1159 	}
1160 
1161 	ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1162 			     n->nlmsg_flags & NLM_F_ECHO);
1163 	if (ret > 0)
1164 		return 0;
1165 	return ret;
1166 }
1167 
1168 static int
1169 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1170 	      u32 portid, int event, struct netlink_ext_ack *extack)
1171 {
1172 	int i, ret;
1173 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1174 	struct tc_action *act;
1175 	size_t attr_size = 0;
1176 	LIST_HEAD(actions);
1177 
1178 	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL, extack);
1179 	if (ret < 0)
1180 		return ret;
1181 
1182 	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1183 		if (tb[1])
1184 			return tca_action_flush(net, tb[1], n, portid, extack);
1185 
1186 		NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1187 		return -EINVAL;
1188 	}
1189 
1190 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1191 		act = tcf_action_get_1(net, tb[i], n, portid, extack);
1192 		if (IS_ERR(act)) {
1193 			ret = PTR_ERR(act);
1194 			goto err;
1195 		}
1196 		act->order = i;
1197 		attr_size += tcf_action_fill_size(act);
1198 		list_add_tail(&act->list, &actions);
1199 	}
1200 
1201 	attr_size = tcf_action_full_attrs_size(attr_size);
1202 
1203 	if (event == RTM_GETACTION)
1204 		ret = tcf_get_notify(net, portid, n, &actions, event, extack);
1205 	else { /* delete */
1206 		ret = tcf_del_notify(net, n, &actions, portid, attr_size, extack);
1207 		if (ret)
1208 			goto err;
1209 		return ret;
1210 	}
1211 err:
1212 	tcf_action_destroy(&actions, 0);
1213 	return ret;
1214 }
1215 
1216 static int
1217 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct list_head *actions,
1218 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1219 {
1220 	struct sk_buff *skb;
1221 	int err = 0;
1222 
1223 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1224 			GFP_KERNEL);
1225 	if (!skb)
1226 		return -ENOBUFS;
1227 
1228 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1229 			 RTM_NEWACTION, 0, 0) <= 0) {
1230 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1231 		kfree_skb(skb);
1232 		return -EINVAL;
1233 	}
1234 
1235 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1236 			     n->nlmsg_flags & NLM_F_ECHO);
1237 	if (err > 0)
1238 		err = 0;
1239 	return err;
1240 }
1241 
1242 static int tcf_action_add(struct net *net, struct nlattr *nla,
1243 			  struct nlmsghdr *n, u32 portid, int ovr,
1244 			  struct netlink_ext_ack *extack)
1245 {
1246 	size_t attr_size = 0;
1247 	int ret = 0;
1248 	LIST_HEAD(actions);
1249 
1250 	ret = tcf_action_init(net, NULL, nla, NULL, NULL, ovr, 0, &actions,
1251 			      &attr_size, true, extack);
1252 	if (ret)
1253 		return ret;
1254 
1255 	return tcf_add_notify(net, n, &actions, portid, attr_size, extack);
1256 }
1257 
1258 static u32 tcaa_root_flags_allowed = TCA_FLAG_LARGE_DUMP_ON;
1259 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1260 	[TCA_ROOT_FLAGS] = { .type = NLA_BITFIELD32,
1261 			     .validation_data = &tcaa_root_flags_allowed },
1262 	[TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1263 };
1264 
1265 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1266 			 struct netlink_ext_ack *extack)
1267 {
1268 	struct net *net = sock_net(skb->sk);
1269 	struct nlattr *tca[TCA_ROOT_MAX + 1];
1270 	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
1271 	int ret = 0, ovr = 0;
1272 
1273 	if ((n->nlmsg_type != RTM_GETACTION) &&
1274 	    !netlink_capable(skb, CAP_NET_ADMIN))
1275 		return -EPERM;
1276 
1277 	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ROOT_MAX, NULL,
1278 			  extack);
1279 	if (ret < 0)
1280 		return ret;
1281 
1282 	if (tca[TCA_ACT_TAB] == NULL) {
1283 		NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
1284 		return -EINVAL;
1285 	}
1286 
1287 	/* n->nlmsg_flags & NLM_F_CREATE */
1288 	switch (n->nlmsg_type) {
1289 	case RTM_NEWACTION:
1290 		/* we are going to assume all other flags
1291 		 * imply create only if it doesn't exist
1292 		 * Note that CREATE | EXCL implies that
1293 		 * but since we want avoid ambiguity (eg when flags
1294 		 * is zero) then just set this
1295 		 */
1296 		if (n->nlmsg_flags & NLM_F_REPLACE)
1297 			ovr = 1;
1298 replay:
1299 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr,
1300 				     extack);
1301 		if (ret == -EAGAIN)
1302 			goto replay;
1303 		break;
1304 	case RTM_DELACTION:
1305 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1306 				    portid, RTM_DELACTION, extack);
1307 		break;
1308 	case RTM_GETACTION:
1309 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1310 				    portid, RTM_GETACTION, extack);
1311 		break;
1312 	default:
1313 		BUG();
1314 	}
1315 
1316 	return ret;
1317 }
1318 
1319 static struct nlattr *find_dump_kind(struct nlattr **nla)
1320 {
1321 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1322 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1323 	struct nlattr *kind;
1324 
1325 	tb1 = nla[TCA_ACT_TAB];
1326 	if (tb1 == NULL)
1327 		return NULL;
1328 
1329 	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1330 		      NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
1331 		return NULL;
1332 
1333 	if (tb[1] == NULL)
1334 		return NULL;
1335 	if (nla_parse_nested(tb2, TCA_ACT_MAX, tb[1], NULL, NULL) < 0)
1336 		return NULL;
1337 	kind = tb2[TCA_ACT_KIND];
1338 
1339 	return kind;
1340 }
1341 
1342 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1343 {
1344 	struct net *net = sock_net(skb->sk);
1345 	struct nlmsghdr *nlh;
1346 	unsigned char *b = skb_tail_pointer(skb);
1347 	struct nlattr *nest;
1348 	struct tc_action_ops *a_o;
1349 	int ret = 0;
1350 	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1351 	struct nlattr *tb[TCA_ROOT_MAX + 1];
1352 	struct nlattr *count_attr = NULL;
1353 	unsigned long jiffy_since = 0;
1354 	struct nlattr *kind = NULL;
1355 	struct nla_bitfield32 bf;
1356 	u32 msecs_since = 0;
1357 	u32 act_count = 0;
1358 
1359 	ret = nlmsg_parse(cb->nlh, sizeof(struct tcamsg), tb, TCA_ROOT_MAX,
1360 			  tcaa_policy, NULL);
1361 	if (ret < 0)
1362 		return ret;
1363 
1364 	kind = find_dump_kind(tb);
1365 	if (kind == NULL) {
1366 		pr_info("tc_dump_action: action bad kind\n");
1367 		return 0;
1368 	}
1369 
1370 	a_o = tc_lookup_action(kind);
1371 	if (a_o == NULL)
1372 		return 0;
1373 
1374 	cb->args[2] = 0;
1375 	if (tb[TCA_ROOT_FLAGS]) {
1376 		bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
1377 		cb->args[2] = bf.value;
1378 	}
1379 
1380 	if (tb[TCA_ROOT_TIME_DELTA]) {
1381 		msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
1382 	}
1383 
1384 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1385 			cb->nlh->nlmsg_type, sizeof(*t), 0);
1386 	if (!nlh)
1387 		goto out_module_put;
1388 
1389 	if (msecs_since)
1390 		jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
1391 
1392 	t = nlmsg_data(nlh);
1393 	t->tca_family = AF_UNSPEC;
1394 	t->tca__pad1 = 0;
1395 	t->tca__pad2 = 0;
1396 	cb->args[3] = jiffy_since;
1397 	count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
1398 	if (!count_attr)
1399 		goto out_module_put;
1400 
1401 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1402 	if (nest == NULL)
1403 		goto out_module_put;
1404 
1405 	ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
1406 	if (ret < 0)
1407 		goto out_module_put;
1408 
1409 	if (ret > 0) {
1410 		nla_nest_end(skb, nest);
1411 		ret = skb->len;
1412 		act_count = cb->args[1];
1413 		memcpy(nla_data(count_attr), &act_count, sizeof(u32));
1414 		cb->args[1] = 0;
1415 	} else
1416 		nlmsg_trim(skb, b);
1417 
1418 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1419 	if (NETLINK_CB(cb->skb).portid && ret)
1420 		nlh->nlmsg_flags |= NLM_F_MULTI;
1421 	module_put(a_o->owner);
1422 	return skb->len;
1423 
1424 out_module_put:
1425 	module_put(a_o->owner);
1426 	nlmsg_trim(skb, b);
1427 	return skb->len;
1428 }
1429 
1430 struct tcf_action_net {
1431 	struct rhashtable egdev_ht;
1432 };
1433 
1434 static unsigned int tcf_action_net_id;
1435 
1436 struct tcf_action_egdev_cb {
1437 	struct list_head list;
1438 	tc_setup_cb_t *cb;
1439 	void *cb_priv;
1440 };
1441 
1442 struct tcf_action_egdev {
1443 	struct rhash_head ht_node;
1444 	const struct net_device *dev;
1445 	unsigned int refcnt;
1446 	struct list_head cb_list;
1447 };
1448 
1449 static const struct rhashtable_params tcf_action_egdev_ht_params = {
1450 	.key_offset = offsetof(struct tcf_action_egdev, dev),
1451 	.head_offset = offsetof(struct tcf_action_egdev, ht_node),
1452 	.key_len = sizeof(const struct net_device *),
1453 };
1454 
1455 static struct tcf_action_egdev *
1456 tcf_action_egdev_lookup(const struct net_device *dev)
1457 {
1458 	struct net *net = dev_net(dev);
1459 	struct tcf_action_net *tan = net_generic(net, tcf_action_net_id);
1460 
1461 	return rhashtable_lookup_fast(&tan->egdev_ht, &dev,
1462 				      tcf_action_egdev_ht_params);
1463 }
1464 
1465 static struct tcf_action_egdev *
1466 tcf_action_egdev_get(const struct net_device *dev)
1467 {
1468 	struct tcf_action_egdev *egdev;
1469 	struct tcf_action_net *tan;
1470 
1471 	egdev = tcf_action_egdev_lookup(dev);
1472 	if (egdev)
1473 		goto inc_ref;
1474 
1475 	egdev = kzalloc(sizeof(*egdev), GFP_KERNEL);
1476 	if (!egdev)
1477 		return NULL;
1478 	INIT_LIST_HEAD(&egdev->cb_list);
1479 	egdev->dev = dev;
1480 	tan = net_generic(dev_net(dev), tcf_action_net_id);
1481 	rhashtable_insert_fast(&tan->egdev_ht, &egdev->ht_node,
1482 			       tcf_action_egdev_ht_params);
1483 
1484 inc_ref:
1485 	egdev->refcnt++;
1486 	return egdev;
1487 }
1488 
1489 static void tcf_action_egdev_put(struct tcf_action_egdev *egdev)
1490 {
1491 	struct tcf_action_net *tan;
1492 
1493 	if (--egdev->refcnt)
1494 		return;
1495 	tan = net_generic(dev_net(egdev->dev), tcf_action_net_id);
1496 	rhashtable_remove_fast(&tan->egdev_ht, &egdev->ht_node,
1497 			       tcf_action_egdev_ht_params);
1498 	kfree(egdev);
1499 }
1500 
1501 static struct tcf_action_egdev_cb *
1502 tcf_action_egdev_cb_lookup(struct tcf_action_egdev *egdev,
1503 			   tc_setup_cb_t *cb, void *cb_priv)
1504 {
1505 	struct tcf_action_egdev_cb *egdev_cb;
1506 
1507 	list_for_each_entry(egdev_cb, &egdev->cb_list, list)
1508 		if (egdev_cb->cb == cb && egdev_cb->cb_priv == cb_priv)
1509 			return egdev_cb;
1510 	return NULL;
1511 }
1512 
1513 static int tcf_action_egdev_cb_call(struct tcf_action_egdev *egdev,
1514 				    enum tc_setup_type type,
1515 				    void *type_data, bool err_stop)
1516 {
1517 	struct tcf_action_egdev_cb *egdev_cb;
1518 	int ok_count = 0;
1519 	int err;
1520 
1521 	list_for_each_entry(egdev_cb, &egdev->cb_list, list) {
1522 		err = egdev_cb->cb(type, type_data, egdev_cb->cb_priv);
1523 		if (err) {
1524 			if (err_stop)
1525 				return err;
1526 		} else {
1527 			ok_count++;
1528 		}
1529 	}
1530 	return ok_count;
1531 }
1532 
1533 static int tcf_action_egdev_cb_add(struct tcf_action_egdev *egdev,
1534 				   tc_setup_cb_t *cb, void *cb_priv)
1535 {
1536 	struct tcf_action_egdev_cb *egdev_cb;
1537 
1538 	egdev_cb = tcf_action_egdev_cb_lookup(egdev, cb, cb_priv);
1539 	if (WARN_ON(egdev_cb))
1540 		return -EEXIST;
1541 	egdev_cb = kzalloc(sizeof(*egdev_cb), GFP_KERNEL);
1542 	if (!egdev_cb)
1543 		return -ENOMEM;
1544 	egdev_cb->cb = cb;
1545 	egdev_cb->cb_priv = cb_priv;
1546 	list_add(&egdev_cb->list, &egdev->cb_list);
1547 	return 0;
1548 }
1549 
1550 static void tcf_action_egdev_cb_del(struct tcf_action_egdev *egdev,
1551 				    tc_setup_cb_t *cb, void *cb_priv)
1552 {
1553 	struct tcf_action_egdev_cb *egdev_cb;
1554 
1555 	egdev_cb = tcf_action_egdev_cb_lookup(egdev, cb, cb_priv);
1556 	if (WARN_ON(!egdev_cb))
1557 		return;
1558 	list_del(&egdev_cb->list);
1559 	kfree(egdev_cb);
1560 }
1561 
1562 static int __tc_setup_cb_egdev_register(const struct net_device *dev,
1563 					tc_setup_cb_t *cb, void *cb_priv)
1564 {
1565 	struct tcf_action_egdev *egdev = tcf_action_egdev_get(dev);
1566 	int err;
1567 
1568 	if (!egdev)
1569 		return -ENOMEM;
1570 	err = tcf_action_egdev_cb_add(egdev, cb, cb_priv);
1571 	if (err)
1572 		goto err_cb_add;
1573 	return 0;
1574 
1575 err_cb_add:
1576 	tcf_action_egdev_put(egdev);
1577 	return err;
1578 }
1579 int tc_setup_cb_egdev_register(const struct net_device *dev,
1580 			       tc_setup_cb_t *cb, void *cb_priv)
1581 {
1582 	int err;
1583 
1584 	rtnl_lock();
1585 	err = __tc_setup_cb_egdev_register(dev, cb, cb_priv);
1586 	rtnl_unlock();
1587 	return err;
1588 }
1589 EXPORT_SYMBOL_GPL(tc_setup_cb_egdev_register);
1590 
1591 static void __tc_setup_cb_egdev_unregister(const struct net_device *dev,
1592 					   tc_setup_cb_t *cb, void *cb_priv)
1593 {
1594 	struct tcf_action_egdev *egdev = tcf_action_egdev_lookup(dev);
1595 
1596 	if (WARN_ON(!egdev))
1597 		return;
1598 	tcf_action_egdev_cb_del(egdev, cb, cb_priv);
1599 	tcf_action_egdev_put(egdev);
1600 }
1601 void tc_setup_cb_egdev_unregister(const struct net_device *dev,
1602 				  tc_setup_cb_t *cb, void *cb_priv)
1603 {
1604 	rtnl_lock();
1605 	__tc_setup_cb_egdev_unregister(dev, cb, cb_priv);
1606 	rtnl_unlock();
1607 }
1608 EXPORT_SYMBOL_GPL(tc_setup_cb_egdev_unregister);
1609 
1610 int tc_setup_cb_egdev_call(const struct net_device *dev,
1611 			   enum tc_setup_type type, void *type_data,
1612 			   bool err_stop)
1613 {
1614 	struct tcf_action_egdev *egdev = tcf_action_egdev_lookup(dev);
1615 
1616 	if (!egdev)
1617 		return 0;
1618 	return tcf_action_egdev_cb_call(egdev, type, type_data, err_stop);
1619 }
1620 EXPORT_SYMBOL_GPL(tc_setup_cb_egdev_call);
1621 
1622 static __net_init int tcf_action_net_init(struct net *net)
1623 {
1624 	struct tcf_action_net *tan = net_generic(net, tcf_action_net_id);
1625 
1626 	return rhashtable_init(&tan->egdev_ht, &tcf_action_egdev_ht_params);
1627 }
1628 
1629 static void __net_exit tcf_action_net_exit(struct net *net)
1630 {
1631 	struct tcf_action_net *tan = net_generic(net, tcf_action_net_id);
1632 
1633 	rhashtable_destroy(&tan->egdev_ht);
1634 }
1635 
1636 static struct pernet_operations tcf_action_net_ops = {
1637 	.init = tcf_action_net_init,
1638 	.exit = tcf_action_net_exit,
1639 	.id = &tcf_action_net_id,
1640 	.size = sizeof(struct tcf_action_net),
1641 };
1642 
1643 static int __init tc_action_init(void)
1644 {
1645 	int err;
1646 
1647 	err = register_pernet_subsys(&tcf_action_net_ops);
1648 	if (err)
1649 		return err;
1650 
1651 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
1652 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
1653 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1654 		      0);
1655 
1656 	return 0;
1657 }
1658 
1659 subsys_initcall(tc_action_init);
1660