xref: /linux/net/sched/act_api.c (revision 8f7e001e0325de63a42f23342ac3b8139150c5cf)
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/tc_act/tc_pedit.h>
23 #include <net/act_api.h>
24 #include <net/netlink.h>
25 #include <net/flow_offload.h>
26 
27 #ifdef CONFIG_INET
28 DEFINE_STATIC_KEY_FALSE(tcf_frag_xmit_count);
29 EXPORT_SYMBOL_GPL(tcf_frag_xmit_count);
30 #endif
31 
32 int tcf_dev_queue_xmit(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))
33 {
34 #ifdef CONFIG_INET
35 	if (static_branch_unlikely(&tcf_frag_xmit_count))
36 		return sch_frag_xmit_hook(skb, xmit);
37 #endif
38 
39 	return xmit(skb);
40 }
41 EXPORT_SYMBOL_GPL(tcf_dev_queue_xmit);
42 
43 static void tcf_action_goto_chain_exec(const struct tc_action *a,
44 				       struct tcf_result *res)
45 {
46 	const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
47 
48 	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
49 }
50 
51 static void tcf_free_cookie_rcu(struct rcu_head *p)
52 {
53 	struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
54 
55 	kfree(cookie->data);
56 	kfree(cookie);
57 }
58 
59 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
60 				  struct tc_cookie *new_cookie)
61 {
62 	struct tc_cookie *old;
63 
64 	old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
65 	if (old)
66 		call_rcu(&old->rcu, tcf_free_cookie_rcu);
67 }
68 
69 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
70 			     struct tcf_chain **newchain,
71 			     struct netlink_ext_ack *extack)
72 {
73 	int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
74 	u32 chain_index;
75 
76 	if (!opcode)
77 		ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
78 	else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
79 		ret = 0;
80 	if (ret) {
81 		NL_SET_ERR_MSG(extack, "invalid control action");
82 		goto end;
83 	}
84 
85 	if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
86 		chain_index = action & TC_ACT_EXT_VAL_MASK;
87 		if (!tp || !newchain) {
88 			ret = -EINVAL;
89 			NL_SET_ERR_MSG(extack,
90 				       "can't goto NULL proto/chain");
91 			goto end;
92 		}
93 		*newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
94 		if (!*newchain) {
95 			ret = -ENOMEM;
96 			NL_SET_ERR_MSG(extack,
97 				       "can't allocate goto_chain");
98 		}
99 	}
100 end:
101 	return ret;
102 }
103 EXPORT_SYMBOL(tcf_action_check_ctrlact);
104 
105 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
106 					 struct tcf_chain *goto_chain)
107 {
108 	a->tcfa_action = action;
109 	goto_chain = rcu_replace_pointer(a->goto_chain, goto_chain, 1);
110 	return goto_chain;
111 }
112 EXPORT_SYMBOL(tcf_action_set_ctrlact);
113 
114 /* XXX: For standalone actions, we don't need a RCU grace period either, because
115  * actions are always connected to filters and filters are already destroyed in
116  * RCU callbacks, so after a RCU grace period actions are already disconnected
117  * from filters. Readers later can not find us.
118  */
119 static void free_tcf(struct tc_action *p)
120 {
121 	struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
122 
123 	free_percpu(p->cpu_bstats);
124 	free_percpu(p->cpu_bstats_hw);
125 	free_percpu(p->cpu_qstats);
126 
127 	tcf_set_action_cookie(&p->act_cookie, NULL);
128 	if (chain)
129 		tcf_chain_put_by_act(chain);
130 
131 	kfree(p);
132 }
133 
134 static void offload_action_hw_count_set(struct tc_action *act,
135 					u32 hw_count)
136 {
137 	act->in_hw_count = hw_count;
138 }
139 
140 static void offload_action_hw_count_inc(struct tc_action *act,
141 					u32 hw_count)
142 {
143 	act->in_hw_count += hw_count;
144 }
145 
146 static void offload_action_hw_count_dec(struct tc_action *act,
147 					u32 hw_count)
148 {
149 	act->in_hw_count = act->in_hw_count > hw_count ?
150 			   act->in_hw_count - hw_count : 0;
151 }
152 
153 static unsigned int tcf_offload_act_num_actions_single(struct tc_action *act)
154 {
155 	if (is_tcf_pedit(act))
156 		return tcf_pedit_nkeys(act);
157 	else
158 		return 1;
159 }
160 
161 static bool tc_act_skip_hw(u32 flags)
162 {
163 	return (flags & TCA_ACT_FLAGS_SKIP_HW) ? true : false;
164 }
165 
166 static bool tc_act_skip_sw(u32 flags)
167 {
168 	return (flags & TCA_ACT_FLAGS_SKIP_SW) ? true : false;
169 }
170 
171 static bool tc_act_in_hw(struct tc_action *act)
172 {
173 	return !!act->in_hw_count;
174 }
175 
176 /* SKIP_HW and SKIP_SW are mutually exclusive flags. */
177 static bool tc_act_flags_valid(u32 flags)
178 {
179 	flags &= TCA_ACT_FLAGS_SKIP_HW | TCA_ACT_FLAGS_SKIP_SW;
180 
181 	return flags ^ (TCA_ACT_FLAGS_SKIP_HW | TCA_ACT_FLAGS_SKIP_SW);
182 }
183 
184 static int offload_action_init(struct flow_offload_action *fl_action,
185 			       struct tc_action *act,
186 			       enum offload_act_command  cmd,
187 			       struct netlink_ext_ack *extack)
188 {
189 	int err;
190 
191 	fl_action->extack = extack;
192 	fl_action->command = cmd;
193 	fl_action->index = act->tcfa_index;
194 
195 	if (act->ops->offload_act_setup) {
196 		spin_lock_bh(&act->tcfa_lock);
197 		err = act->ops->offload_act_setup(act, fl_action, NULL,
198 						  false, extack);
199 		spin_unlock_bh(&act->tcfa_lock);
200 		return err;
201 	}
202 
203 	return -EOPNOTSUPP;
204 }
205 
206 static int tcf_action_offload_cmd_ex(struct flow_offload_action *fl_act,
207 				     u32 *hw_count)
208 {
209 	int err;
210 
211 	err = flow_indr_dev_setup_offload(NULL, NULL, TC_SETUP_ACT,
212 					  fl_act, NULL, NULL);
213 	if (err < 0)
214 		return err;
215 
216 	if (hw_count)
217 		*hw_count = err;
218 
219 	return 0;
220 }
221 
222 static int tcf_action_offload_cmd_cb_ex(struct flow_offload_action *fl_act,
223 					u32 *hw_count,
224 					flow_indr_block_bind_cb_t *cb,
225 					void *cb_priv)
226 {
227 	int err;
228 
229 	err = cb(NULL, NULL, cb_priv, TC_SETUP_ACT, NULL, fl_act, NULL);
230 	if (err < 0)
231 		return err;
232 
233 	if (hw_count)
234 		*hw_count = 1;
235 
236 	return 0;
237 }
238 
239 static int tcf_action_offload_cmd(struct flow_offload_action *fl_act,
240 				  u32 *hw_count,
241 				  flow_indr_block_bind_cb_t *cb,
242 				  void *cb_priv)
243 {
244 	return cb ? tcf_action_offload_cmd_cb_ex(fl_act, hw_count,
245 						 cb, cb_priv) :
246 		    tcf_action_offload_cmd_ex(fl_act, hw_count);
247 }
248 
249 static int tcf_action_offload_add_ex(struct tc_action *action,
250 				     struct netlink_ext_ack *extack,
251 				     flow_indr_block_bind_cb_t *cb,
252 				     void *cb_priv)
253 {
254 	bool skip_sw = tc_act_skip_sw(action->tcfa_flags);
255 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {
256 		[0] = action,
257 	};
258 	struct flow_offload_action *fl_action;
259 	u32 in_hw_count = 0;
260 	int num, err = 0;
261 
262 	if (tc_act_skip_hw(action->tcfa_flags))
263 		return 0;
264 
265 	num = tcf_offload_act_num_actions_single(action);
266 	fl_action = offload_action_alloc(num);
267 	if (!fl_action)
268 		return -ENOMEM;
269 
270 	err = offload_action_init(fl_action, action, FLOW_ACT_REPLACE, extack);
271 	if (err)
272 		goto fl_err;
273 
274 	err = tc_setup_action(&fl_action->action, actions, extack);
275 	if (err) {
276 		NL_SET_ERR_MSG_MOD(extack,
277 				   "Failed to setup tc actions for offload");
278 		goto fl_err;
279 	}
280 
281 	err = tcf_action_offload_cmd(fl_action, &in_hw_count, cb, cb_priv);
282 	if (!err)
283 		cb ? offload_action_hw_count_inc(action, in_hw_count) :
284 		     offload_action_hw_count_set(action, in_hw_count);
285 
286 	if (skip_sw && !tc_act_in_hw(action))
287 		err = -EINVAL;
288 
289 	tc_cleanup_offload_action(&fl_action->action);
290 
291 fl_err:
292 	kfree(fl_action);
293 
294 	return err;
295 }
296 
297 /* offload the tc action after it is inserted */
298 static int tcf_action_offload_add(struct tc_action *action,
299 				  struct netlink_ext_ack *extack)
300 {
301 	return tcf_action_offload_add_ex(action, extack, NULL, NULL);
302 }
303 
304 int tcf_action_update_hw_stats(struct tc_action *action)
305 {
306 	struct flow_offload_action fl_act = {};
307 	int err;
308 
309 	if (!tc_act_in_hw(action))
310 		return -EOPNOTSUPP;
311 
312 	err = offload_action_init(&fl_act, action, FLOW_ACT_STATS, NULL);
313 	if (err)
314 		return err;
315 
316 	err = tcf_action_offload_cmd(&fl_act, NULL, NULL, NULL);
317 	if (!err) {
318 		preempt_disable();
319 		tcf_action_stats_update(action, fl_act.stats.bytes,
320 					fl_act.stats.pkts,
321 					fl_act.stats.drops,
322 					fl_act.stats.lastused,
323 					true);
324 		preempt_enable();
325 		action->used_hw_stats = fl_act.stats.used_hw_stats;
326 		action->used_hw_stats_valid = true;
327 	} else {
328 		return -EOPNOTSUPP;
329 	}
330 
331 	return 0;
332 }
333 EXPORT_SYMBOL(tcf_action_update_hw_stats);
334 
335 static int tcf_action_offload_del_ex(struct tc_action *action,
336 				     flow_indr_block_bind_cb_t *cb,
337 				     void *cb_priv)
338 {
339 	struct flow_offload_action fl_act = {};
340 	u32 in_hw_count = 0;
341 	int err = 0;
342 
343 	if (!tc_act_in_hw(action))
344 		return 0;
345 
346 	err = offload_action_init(&fl_act, action, FLOW_ACT_DESTROY, NULL);
347 	if (err)
348 		return err;
349 
350 	err = tcf_action_offload_cmd(&fl_act, &in_hw_count, cb, cb_priv);
351 	if (err < 0)
352 		return err;
353 
354 	if (!cb && action->in_hw_count != in_hw_count)
355 		return -EINVAL;
356 
357 	/* do not need to update hw state when deleting action */
358 	if (cb && in_hw_count)
359 		offload_action_hw_count_dec(action, in_hw_count);
360 
361 	return 0;
362 }
363 
364 static int tcf_action_offload_del(struct tc_action *action)
365 {
366 	return tcf_action_offload_del_ex(action, NULL, NULL);
367 }
368 
369 static void tcf_action_cleanup(struct tc_action *p)
370 {
371 	tcf_action_offload_del(p);
372 	if (p->ops->cleanup)
373 		p->ops->cleanup(p);
374 
375 	gen_kill_estimator(&p->tcfa_rate_est);
376 	free_tcf(p);
377 }
378 
379 static int __tcf_action_put(struct tc_action *p, bool bind)
380 {
381 	struct tcf_idrinfo *idrinfo = p->idrinfo;
382 
383 	if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
384 		if (bind)
385 			atomic_dec(&p->tcfa_bindcnt);
386 		idr_remove(&idrinfo->action_idr, p->tcfa_index);
387 		mutex_unlock(&idrinfo->lock);
388 
389 		tcf_action_cleanup(p);
390 		return 1;
391 	}
392 
393 	if (bind)
394 		atomic_dec(&p->tcfa_bindcnt);
395 
396 	return 0;
397 }
398 
399 static int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
400 {
401 	int ret = 0;
402 
403 	/* Release with strict==1 and bind==0 is only called through act API
404 	 * interface (classifiers always bind). Only case when action with
405 	 * positive reference count and zero bind count can exist is when it was
406 	 * also created with act API (unbinding last classifier will destroy the
407 	 * action if it was created by classifier). So only case when bind count
408 	 * can be changed after initial check is when unbound action is
409 	 * destroyed by act API while classifier binds to action with same id
410 	 * concurrently. This result either creation of new action(same behavior
411 	 * as before), or reusing existing action if concurrent process
412 	 * increments reference count before action is deleted. Both scenarios
413 	 * are acceptable.
414 	 */
415 	if (p) {
416 		if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
417 			return -EPERM;
418 
419 		if (__tcf_action_put(p, bind))
420 			ret = ACT_P_DELETED;
421 	}
422 
423 	return ret;
424 }
425 
426 int tcf_idr_release(struct tc_action *a, bool bind)
427 {
428 	const struct tc_action_ops *ops = a->ops;
429 	int ret;
430 
431 	ret = __tcf_idr_release(a, bind, false);
432 	if (ret == ACT_P_DELETED)
433 		module_put(ops->owner);
434 	return ret;
435 }
436 EXPORT_SYMBOL(tcf_idr_release);
437 
438 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
439 {
440 	struct tc_cookie *act_cookie;
441 	u32 cookie_len = 0;
442 
443 	rcu_read_lock();
444 	act_cookie = rcu_dereference(act->act_cookie);
445 
446 	if (act_cookie)
447 		cookie_len = nla_total_size(act_cookie->len);
448 	rcu_read_unlock();
449 
450 	return  nla_total_size(0) /* action number nested */
451 		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
452 		+ cookie_len /* TCA_ACT_COOKIE */
453 		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS */
454 		+ nla_total_size(0) /* TCA_ACT_STATS nested */
455 		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
456 		/* TCA_STATS_BASIC */
457 		+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
458 		/* TCA_STATS_PKT64 */
459 		+ nla_total_size_64bit(sizeof(u64))
460 		/* TCA_STATS_QUEUE */
461 		+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
462 		+ nla_total_size(0) /* TCA_OPTIONS nested */
463 		+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
464 }
465 
466 static size_t tcf_action_full_attrs_size(size_t sz)
467 {
468 	return NLMSG_HDRLEN                     /* struct nlmsghdr */
469 		+ sizeof(struct tcamsg)
470 		+ nla_total_size(0)             /* TCA_ACT_TAB nested */
471 		+ sz;
472 }
473 
474 static size_t tcf_action_fill_size(const struct tc_action *act)
475 {
476 	size_t sz = tcf_action_shared_attrs_size(act);
477 
478 	if (act->ops->get_fill_size)
479 		return act->ops->get_fill_size(act) + sz;
480 	return sz;
481 }
482 
483 static int
484 tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a, bool from_act)
485 {
486 	unsigned char *b = skb_tail_pointer(skb);
487 	struct tc_cookie *cookie;
488 
489 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
490 		goto nla_put_failure;
491 	if (tcf_action_copy_stats(skb, a, 0))
492 		goto nla_put_failure;
493 	if (from_act && nla_put_u32(skb, TCA_ACT_INDEX, a->tcfa_index))
494 		goto nla_put_failure;
495 
496 	rcu_read_lock();
497 	cookie = rcu_dereference(a->act_cookie);
498 	if (cookie) {
499 		if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
500 			rcu_read_unlock();
501 			goto nla_put_failure;
502 		}
503 	}
504 	rcu_read_unlock();
505 
506 	return 0;
507 
508 nla_put_failure:
509 	nlmsg_trim(skb, b);
510 	return -1;
511 }
512 
513 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
514 			   struct netlink_callback *cb)
515 {
516 	int err = 0, index = -1, s_i = 0, n_i = 0;
517 	u32 act_flags = cb->args[2];
518 	unsigned long jiffy_since = cb->args[3];
519 	struct nlattr *nest;
520 	struct idr *idr = &idrinfo->action_idr;
521 	struct tc_action *p;
522 	unsigned long id = 1;
523 	unsigned long tmp;
524 
525 	mutex_lock(&idrinfo->lock);
526 
527 	s_i = cb->args[0];
528 
529 	idr_for_each_entry_ul(idr, p, tmp, id) {
530 		index++;
531 		if (index < s_i)
532 			continue;
533 		if (IS_ERR(p))
534 			continue;
535 
536 		if (jiffy_since &&
537 		    time_after(jiffy_since,
538 			       (unsigned long)p->tcfa_tm.lastuse))
539 			continue;
540 
541 		nest = nla_nest_start_noflag(skb, n_i);
542 		if (!nest) {
543 			index--;
544 			goto nla_put_failure;
545 		}
546 		err = (act_flags & TCA_ACT_FLAG_TERSE_DUMP) ?
547 			tcf_action_dump_terse(skb, p, true) :
548 			tcf_action_dump_1(skb, p, 0, 0);
549 		if (err < 0) {
550 			index--;
551 			nlmsg_trim(skb, nest);
552 			goto done;
553 		}
554 		nla_nest_end(skb, nest);
555 		n_i++;
556 		if (!(act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON) &&
557 		    n_i >= TCA_ACT_MAX_PRIO)
558 			goto done;
559 	}
560 done:
561 	if (index >= 0)
562 		cb->args[0] = index + 1;
563 
564 	mutex_unlock(&idrinfo->lock);
565 	if (n_i) {
566 		if (act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON)
567 			cb->args[1] = n_i;
568 	}
569 	return n_i;
570 
571 nla_put_failure:
572 	nla_nest_cancel(skb, nest);
573 	goto done;
574 }
575 
576 static int tcf_idr_release_unsafe(struct tc_action *p)
577 {
578 	if (atomic_read(&p->tcfa_bindcnt) > 0)
579 		return -EPERM;
580 
581 	if (refcount_dec_and_test(&p->tcfa_refcnt)) {
582 		idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
583 		tcf_action_cleanup(p);
584 		return ACT_P_DELETED;
585 	}
586 
587 	return 0;
588 }
589 
590 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
591 			  const struct tc_action_ops *ops,
592 			  struct netlink_ext_ack *extack)
593 {
594 	struct nlattr *nest;
595 	int n_i = 0;
596 	int ret = -EINVAL;
597 	struct idr *idr = &idrinfo->action_idr;
598 	struct tc_action *p;
599 	unsigned long id = 1;
600 	unsigned long tmp;
601 
602 	nest = nla_nest_start_noflag(skb, 0);
603 	if (nest == NULL)
604 		goto nla_put_failure;
605 	if (nla_put_string(skb, TCA_KIND, ops->kind))
606 		goto nla_put_failure;
607 
608 	ret = 0;
609 	mutex_lock(&idrinfo->lock);
610 	idr_for_each_entry_ul(idr, p, tmp, id) {
611 		if (IS_ERR(p))
612 			continue;
613 		ret = tcf_idr_release_unsafe(p);
614 		if (ret == ACT_P_DELETED)
615 			module_put(ops->owner);
616 		else if (ret < 0)
617 			break;
618 		n_i++;
619 	}
620 	mutex_unlock(&idrinfo->lock);
621 	if (ret < 0) {
622 		if (n_i)
623 			NL_SET_ERR_MSG(extack, "Unable to flush all TC actions");
624 		else
625 			goto nla_put_failure;
626 	}
627 
628 	ret = nla_put_u32(skb, TCA_FCNT, n_i);
629 	if (ret)
630 		goto nla_put_failure;
631 	nla_nest_end(skb, nest);
632 
633 	return n_i;
634 nla_put_failure:
635 	nla_nest_cancel(skb, nest);
636 	return ret;
637 }
638 
639 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
640 		       struct netlink_callback *cb, int type,
641 		       const struct tc_action_ops *ops,
642 		       struct netlink_ext_ack *extack)
643 {
644 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
645 
646 	if (type == RTM_DELACTION) {
647 		return tcf_del_walker(idrinfo, skb, ops, extack);
648 	} else if (type == RTM_GETACTION) {
649 		return tcf_dump_walker(idrinfo, skb, cb);
650 	} else {
651 		WARN(1, "tcf_generic_walker: unknown command %d\n", type);
652 		NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
653 		return -EINVAL;
654 	}
655 }
656 EXPORT_SYMBOL(tcf_generic_walker);
657 
658 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
659 {
660 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
661 	struct tc_action *p;
662 
663 	mutex_lock(&idrinfo->lock);
664 	p = idr_find(&idrinfo->action_idr, index);
665 	if (IS_ERR(p))
666 		p = NULL;
667 	else if (p)
668 		refcount_inc(&p->tcfa_refcnt);
669 	mutex_unlock(&idrinfo->lock);
670 
671 	if (p) {
672 		*a = p;
673 		return true;
674 	}
675 	return false;
676 }
677 EXPORT_SYMBOL(tcf_idr_search);
678 
679 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
680 {
681 	struct tc_action *p;
682 	int ret = 0;
683 
684 	mutex_lock(&idrinfo->lock);
685 	p = idr_find(&idrinfo->action_idr, index);
686 	if (!p) {
687 		mutex_unlock(&idrinfo->lock);
688 		return -ENOENT;
689 	}
690 
691 	if (!atomic_read(&p->tcfa_bindcnt)) {
692 		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
693 			struct module *owner = p->ops->owner;
694 
695 			WARN_ON(p != idr_remove(&idrinfo->action_idr,
696 						p->tcfa_index));
697 			mutex_unlock(&idrinfo->lock);
698 
699 			tcf_action_cleanup(p);
700 			module_put(owner);
701 			return 0;
702 		}
703 		ret = 0;
704 	} else {
705 		ret = -EPERM;
706 	}
707 
708 	mutex_unlock(&idrinfo->lock);
709 	return ret;
710 }
711 
712 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
713 		   struct tc_action **a, const struct tc_action_ops *ops,
714 		   int bind, bool cpustats, u32 flags)
715 {
716 	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
717 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
718 	int err = -ENOMEM;
719 
720 	if (unlikely(!p))
721 		return -ENOMEM;
722 	refcount_set(&p->tcfa_refcnt, 1);
723 	if (bind)
724 		atomic_set(&p->tcfa_bindcnt, 1);
725 
726 	if (cpustats) {
727 		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
728 		if (!p->cpu_bstats)
729 			goto err1;
730 		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
731 		if (!p->cpu_bstats_hw)
732 			goto err2;
733 		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
734 		if (!p->cpu_qstats)
735 			goto err3;
736 	}
737 	gnet_stats_basic_sync_init(&p->tcfa_bstats);
738 	gnet_stats_basic_sync_init(&p->tcfa_bstats_hw);
739 	spin_lock_init(&p->tcfa_lock);
740 	p->tcfa_index = index;
741 	p->tcfa_tm.install = jiffies;
742 	p->tcfa_tm.lastuse = jiffies;
743 	p->tcfa_tm.firstuse = 0;
744 	p->tcfa_flags = flags;
745 	if (est) {
746 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
747 					&p->tcfa_rate_est,
748 					&p->tcfa_lock, false, est);
749 		if (err)
750 			goto err4;
751 	}
752 
753 	p->idrinfo = idrinfo;
754 	__module_get(ops->owner);
755 	p->ops = ops;
756 	*a = p;
757 	return 0;
758 err4:
759 	free_percpu(p->cpu_qstats);
760 err3:
761 	free_percpu(p->cpu_bstats_hw);
762 err2:
763 	free_percpu(p->cpu_bstats);
764 err1:
765 	kfree(p);
766 	return err;
767 }
768 EXPORT_SYMBOL(tcf_idr_create);
769 
770 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
771 			      struct nlattr *est, struct tc_action **a,
772 			      const struct tc_action_ops *ops, int bind,
773 			      u32 flags)
774 {
775 	/* Set cpustats according to actions flags. */
776 	return tcf_idr_create(tn, index, est, a, ops, bind,
777 			      !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
778 }
779 EXPORT_SYMBOL(tcf_idr_create_from_flags);
780 
781 /* Cleanup idr index that was allocated but not initialized. */
782 
783 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
784 {
785 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
786 
787 	mutex_lock(&idrinfo->lock);
788 	/* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
789 	WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
790 	mutex_unlock(&idrinfo->lock);
791 }
792 EXPORT_SYMBOL(tcf_idr_cleanup);
793 
794 /* Check if action with specified index exists. If actions is found, increments
795  * its reference and bind counters, and return 1. Otherwise insert temporary
796  * error pointer (to prevent concurrent users from inserting actions with same
797  * index) and return 0.
798  */
799 
800 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
801 			struct tc_action **a, int bind)
802 {
803 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
804 	struct tc_action *p;
805 	int ret;
806 
807 again:
808 	mutex_lock(&idrinfo->lock);
809 	if (*index) {
810 		p = idr_find(&idrinfo->action_idr, *index);
811 		if (IS_ERR(p)) {
812 			/* This means that another process allocated
813 			 * index but did not assign the pointer yet.
814 			 */
815 			mutex_unlock(&idrinfo->lock);
816 			goto again;
817 		}
818 
819 		if (p) {
820 			refcount_inc(&p->tcfa_refcnt);
821 			if (bind)
822 				atomic_inc(&p->tcfa_bindcnt);
823 			*a = p;
824 			ret = 1;
825 		} else {
826 			*a = NULL;
827 			ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
828 					    *index, GFP_KERNEL);
829 			if (!ret)
830 				idr_replace(&idrinfo->action_idr,
831 					    ERR_PTR(-EBUSY), *index);
832 		}
833 	} else {
834 		*index = 1;
835 		*a = NULL;
836 		ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
837 				    UINT_MAX, GFP_KERNEL);
838 		if (!ret)
839 			idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
840 				    *index);
841 	}
842 	mutex_unlock(&idrinfo->lock);
843 	return ret;
844 }
845 EXPORT_SYMBOL(tcf_idr_check_alloc);
846 
847 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
848 			 struct tcf_idrinfo *idrinfo)
849 {
850 	struct idr *idr = &idrinfo->action_idr;
851 	struct tc_action *p;
852 	int ret;
853 	unsigned long id = 1;
854 	unsigned long tmp;
855 
856 	idr_for_each_entry_ul(idr, p, tmp, id) {
857 		ret = __tcf_idr_release(p, false, true);
858 		if (ret == ACT_P_DELETED)
859 			module_put(ops->owner);
860 		else if (ret < 0)
861 			return;
862 	}
863 	idr_destroy(&idrinfo->action_idr);
864 }
865 EXPORT_SYMBOL(tcf_idrinfo_destroy);
866 
867 static LIST_HEAD(act_base);
868 static DEFINE_RWLOCK(act_mod_lock);
869 /* since act ops id is stored in pernet subsystem list,
870  * then there is no way to walk through only all the action
871  * subsystem, so we keep tc action pernet ops id for
872  * reoffload to walk through.
873  */
874 static LIST_HEAD(act_pernet_id_list);
875 static DEFINE_MUTEX(act_id_mutex);
876 struct tc_act_pernet_id {
877 	struct list_head list;
878 	unsigned int id;
879 };
880 
881 static int tcf_pernet_add_id_list(unsigned int id)
882 {
883 	struct tc_act_pernet_id *id_ptr;
884 	int ret = 0;
885 
886 	mutex_lock(&act_id_mutex);
887 	list_for_each_entry(id_ptr, &act_pernet_id_list, list) {
888 		if (id_ptr->id == id) {
889 			ret = -EEXIST;
890 			goto err_out;
891 		}
892 	}
893 
894 	id_ptr = kzalloc(sizeof(*id_ptr), GFP_KERNEL);
895 	if (!id_ptr) {
896 		ret = -ENOMEM;
897 		goto err_out;
898 	}
899 	id_ptr->id = id;
900 
901 	list_add_tail(&id_ptr->list, &act_pernet_id_list);
902 
903 err_out:
904 	mutex_unlock(&act_id_mutex);
905 	return ret;
906 }
907 
908 static void tcf_pernet_del_id_list(unsigned int id)
909 {
910 	struct tc_act_pernet_id *id_ptr;
911 
912 	mutex_lock(&act_id_mutex);
913 	list_for_each_entry(id_ptr, &act_pernet_id_list, list) {
914 		if (id_ptr->id == id) {
915 			list_del(&id_ptr->list);
916 			kfree(id_ptr);
917 			break;
918 		}
919 	}
920 	mutex_unlock(&act_id_mutex);
921 }
922 
923 int tcf_register_action(struct tc_action_ops *act,
924 			struct pernet_operations *ops)
925 {
926 	struct tc_action_ops *a;
927 	int ret;
928 
929 	if (!act->act || !act->dump || !act->init || !act->walk || !act->lookup)
930 		return -EINVAL;
931 
932 	/* We have to register pernet ops before making the action ops visible,
933 	 * otherwise tcf_action_init_1() could get a partially initialized
934 	 * netns.
935 	 */
936 	ret = register_pernet_subsys(ops);
937 	if (ret)
938 		return ret;
939 
940 	if (ops->id) {
941 		ret = tcf_pernet_add_id_list(*ops->id);
942 		if (ret)
943 			goto err_id;
944 	}
945 
946 	write_lock(&act_mod_lock);
947 	list_for_each_entry(a, &act_base, head) {
948 		if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
949 			ret = -EEXIST;
950 			goto err_out;
951 		}
952 	}
953 	list_add_tail(&act->head, &act_base);
954 	write_unlock(&act_mod_lock);
955 
956 	return 0;
957 
958 err_out:
959 	write_unlock(&act_mod_lock);
960 	if (ops->id)
961 		tcf_pernet_del_id_list(*ops->id);
962 err_id:
963 	unregister_pernet_subsys(ops);
964 	return ret;
965 }
966 EXPORT_SYMBOL(tcf_register_action);
967 
968 int tcf_unregister_action(struct tc_action_ops *act,
969 			  struct pernet_operations *ops)
970 {
971 	struct tc_action_ops *a;
972 	int err = -ENOENT;
973 
974 	write_lock(&act_mod_lock);
975 	list_for_each_entry(a, &act_base, head) {
976 		if (a == act) {
977 			list_del(&act->head);
978 			err = 0;
979 			break;
980 		}
981 	}
982 	write_unlock(&act_mod_lock);
983 	if (!err) {
984 		unregister_pernet_subsys(ops);
985 		if (ops->id)
986 			tcf_pernet_del_id_list(*ops->id);
987 	}
988 	return err;
989 }
990 EXPORT_SYMBOL(tcf_unregister_action);
991 
992 /* lookup by name */
993 static struct tc_action_ops *tc_lookup_action_n(char *kind)
994 {
995 	struct tc_action_ops *a, *res = NULL;
996 
997 	if (kind) {
998 		read_lock(&act_mod_lock);
999 		list_for_each_entry(a, &act_base, head) {
1000 			if (strcmp(kind, a->kind) == 0) {
1001 				if (try_module_get(a->owner))
1002 					res = a;
1003 				break;
1004 			}
1005 		}
1006 		read_unlock(&act_mod_lock);
1007 	}
1008 	return res;
1009 }
1010 
1011 /* lookup by nlattr */
1012 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
1013 {
1014 	struct tc_action_ops *a, *res = NULL;
1015 
1016 	if (kind) {
1017 		read_lock(&act_mod_lock);
1018 		list_for_each_entry(a, &act_base, head) {
1019 			if (nla_strcmp(kind, a->kind) == 0) {
1020 				if (try_module_get(a->owner))
1021 					res = a;
1022 				break;
1023 			}
1024 		}
1025 		read_unlock(&act_mod_lock);
1026 	}
1027 	return res;
1028 }
1029 
1030 /*TCA_ACT_MAX_PRIO is 32, there count up to 32 */
1031 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
1032 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
1033 		    int nr_actions, struct tcf_result *res)
1034 {
1035 	u32 jmp_prgcnt = 0;
1036 	u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
1037 	int i;
1038 	int ret = TC_ACT_OK;
1039 
1040 	if (skb_skip_tc_classify(skb))
1041 		return TC_ACT_OK;
1042 
1043 restart_act_graph:
1044 	for (i = 0; i < nr_actions; i++) {
1045 		const struct tc_action *a = actions[i];
1046 		int repeat_ttl;
1047 
1048 		if (jmp_prgcnt > 0) {
1049 			jmp_prgcnt -= 1;
1050 			continue;
1051 		}
1052 
1053 		if (tc_act_skip_sw(a->tcfa_flags))
1054 			continue;
1055 
1056 		repeat_ttl = 32;
1057 repeat:
1058 		ret = a->ops->act(skb, a, res);
1059 		if (unlikely(ret == TC_ACT_REPEAT)) {
1060 			if (--repeat_ttl != 0)
1061 				goto repeat;
1062 			/* suspicious opcode, stop pipeline */
1063 			net_warn_ratelimited("TC_ACT_REPEAT abuse ?\n");
1064 			return TC_ACT_OK;
1065 		}
1066 		if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
1067 			jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
1068 			if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
1069 				/* faulty opcode, stop pipeline */
1070 				return TC_ACT_OK;
1071 			} else {
1072 				jmp_ttl -= 1;
1073 				if (jmp_ttl > 0)
1074 					goto restart_act_graph;
1075 				else /* faulty graph, stop pipeline */
1076 					return TC_ACT_OK;
1077 			}
1078 		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
1079 			if (unlikely(!rcu_access_pointer(a->goto_chain))) {
1080 				net_warn_ratelimited("can't go to NULL chain!\n");
1081 				return TC_ACT_SHOT;
1082 			}
1083 			tcf_action_goto_chain_exec(a, res);
1084 		}
1085 
1086 		if (ret != TC_ACT_PIPE)
1087 			break;
1088 	}
1089 
1090 	return ret;
1091 }
1092 EXPORT_SYMBOL(tcf_action_exec);
1093 
1094 int tcf_action_destroy(struct tc_action *actions[], int bind)
1095 {
1096 	const struct tc_action_ops *ops;
1097 	struct tc_action *a;
1098 	int ret = 0, i;
1099 
1100 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1101 		a = actions[i];
1102 		actions[i] = NULL;
1103 		ops = a->ops;
1104 		ret = __tcf_idr_release(a, bind, true);
1105 		if (ret == ACT_P_DELETED)
1106 			module_put(ops->owner);
1107 		else if (ret < 0)
1108 			return ret;
1109 	}
1110 	return ret;
1111 }
1112 
1113 static int tcf_action_put(struct tc_action *p)
1114 {
1115 	return __tcf_action_put(p, false);
1116 }
1117 
1118 /* Put all actions in this array, skip those NULL's. */
1119 static void tcf_action_put_many(struct tc_action *actions[])
1120 {
1121 	int i;
1122 
1123 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1124 		struct tc_action *a = actions[i];
1125 		const struct tc_action_ops *ops;
1126 
1127 		if (!a)
1128 			continue;
1129 		ops = a->ops;
1130 		if (tcf_action_put(a))
1131 			module_put(ops->owner);
1132 	}
1133 }
1134 
1135 int
1136 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
1137 {
1138 	return a->ops->dump(skb, a, bind, ref);
1139 }
1140 
1141 int
1142 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
1143 {
1144 	int err = -EINVAL;
1145 	unsigned char *b = skb_tail_pointer(skb);
1146 	struct nlattr *nest;
1147 	u32 flags;
1148 
1149 	if (tcf_action_dump_terse(skb, a, false))
1150 		goto nla_put_failure;
1151 
1152 	if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
1153 	    nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
1154 			       a->hw_stats, TCA_ACT_HW_STATS_ANY))
1155 		goto nla_put_failure;
1156 
1157 	if (a->used_hw_stats_valid &&
1158 	    nla_put_bitfield32(skb, TCA_ACT_USED_HW_STATS,
1159 			       a->used_hw_stats, TCA_ACT_HW_STATS_ANY))
1160 		goto nla_put_failure;
1161 
1162 	flags = a->tcfa_flags & TCA_ACT_FLAGS_USER_MASK;
1163 	if (flags &&
1164 	    nla_put_bitfield32(skb, TCA_ACT_FLAGS,
1165 			       flags, flags))
1166 		goto nla_put_failure;
1167 
1168 	if (nla_put_u32(skb, TCA_ACT_IN_HW_COUNT, a->in_hw_count))
1169 		goto nla_put_failure;
1170 
1171 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
1172 	if (nest == NULL)
1173 		goto nla_put_failure;
1174 	err = tcf_action_dump_old(skb, a, bind, ref);
1175 	if (err > 0) {
1176 		nla_nest_end(skb, nest);
1177 		return err;
1178 	}
1179 
1180 nla_put_failure:
1181 	nlmsg_trim(skb, b);
1182 	return -1;
1183 }
1184 EXPORT_SYMBOL(tcf_action_dump_1);
1185 
1186 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
1187 		    int bind, int ref, bool terse)
1188 {
1189 	struct tc_action *a;
1190 	int err = -EINVAL, i;
1191 	struct nlattr *nest;
1192 
1193 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1194 		a = actions[i];
1195 		nest = nla_nest_start_noflag(skb, i + 1);
1196 		if (nest == NULL)
1197 			goto nla_put_failure;
1198 		err = terse ? tcf_action_dump_terse(skb, a, false) :
1199 			tcf_action_dump_1(skb, a, bind, ref);
1200 		if (err < 0)
1201 			goto errout;
1202 		nla_nest_end(skb, nest);
1203 	}
1204 
1205 	return 0;
1206 
1207 nla_put_failure:
1208 	err = -EINVAL;
1209 errout:
1210 	nla_nest_cancel(skb, nest);
1211 	return err;
1212 }
1213 
1214 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
1215 {
1216 	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
1217 	if (!c)
1218 		return NULL;
1219 
1220 	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
1221 	if (!c->data) {
1222 		kfree(c);
1223 		return NULL;
1224 	}
1225 	c->len = nla_len(tb[TCA_ACT_COOKIE]);
1226 
1227 	return c;
1228 }
1229 
1230 static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr)
1231 {
1232 	struct nla_bitfield32 hw_stats_bf;
1233 
1234 	/* If the user did not pass the attr, that means he does
1235 	 * not care about the type. Return "any" in that case
1236 	 * which is setting on all supported types.
1237 	 */
1238 	if (!hw_stats_attr)
1239 		return TCA_ACT_HW_STATS_ANY;
1240 	hw_stats_bf = nla_get_bitfield32(hw_stats_attr);
1241 	return hw_stats_bf.value;
1242 }
1243 
1244 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
1245 	[TCA_ACT_KIND]		= { .type = NLA_STRING },
1246 	[TCA_ACT_INDEX]		= { .type = NLA_U32 },
1247 	[TCA_ACT_COOKIE]	= { .type = NLA_BINARY,
1248 				    .len = TC_COOKIE_MAX_SIZE },
1249 	[TCA_ACT_OPTIONS]	= { .type = NLA_NESTED },
1250 	[TCA_ACT_FLAGS]		= NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS |
1251 							TCA_ACT_FLAGS_SKIP_HW |
1252 							TCA_ACT_FLAGS_SKIP_SW),
1253 	[TCA_ACT_HW_STATS]	= NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY),
1254 };
1255 
1256 void tcf_idr_insert_many(struct tc_action *actions[])
1257 {
1258 	int i;
1259 
1260 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1261 		struct tc_action *a = actions[i];
1262 		struct tcf_idrinfo *idrinfo;
1263 
1264 		if (!a)
1265 			continue;
1266 		idrinfo = a->idrinfo;
1267 		mutex_lock(&idrinfo->lock);
1268 		/* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc if
1269 		 * it is just created, otherwise this is just a nop.
1270 		 */
1271 		idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
1272 		mutex_unlock(&idrinfo->lock);
1273 	}
1274 }
1275 
1276 struct tc_action_ops *tc_action_load_ops(struct nlattr *nla, bool police,
1277 					 bool rtnl_held,
1278 					 struct netlink_ext_ack *extack)
1279 {
1280 	struct nlattr *tb[TCA_ACT_MAX + 1];
1281 	struct tc_action_ops *a_o;
1282 	char act_name[IFNAMSIZ];
1283 	struct nlattr *kind;
1284 	int err;
1285 
1286 	if (!police) {
1287 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1288 						  tcf_action_policy, extack);
1289 		if (err < 0)
1290 			return ERR_PTR(err);
1291 		err = -EINVAL;
1292 		kind = tb[TCA_ACT_KIND];
1293 		if (!kind) {
1294 			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
1295 			return ERR_PTR(err);
1296 		}
1297 		if (nla_strscpy(act_name, kind, IFNAMSIZ) < 0) {
1298 			NL_SET_ERR_MSG(extack, "TC action name too long");
1299 			return ERR_PTR(err);
1300 		}
1301 	} else {
1302 		if (strlcpy(act_name, "police", IFNAMSIZ) >= IFNAMSIZ) {
1303 			NL_SET_ERR_MSG(extack, "TC action name too long");
1304 			return ERR_PTR(-EINVAL);
1305 		}
1306 	}
1307 
1308 	a_o = tc_lookup_action_n(act_name);
1309 	if (a_o == NULL) {
1310 #ifdef CONFIG_MODULES
1311 		if (rtnl_held)
1312 			rtnl_unlock();
1313 		request_module("act_%s", act_name);
1314 		if (rtnl_held)
1315 			rtnl_lock();
1316 
1317 		a_o = tc_lookup_action_n(act_name);
1318 
1319 		/* We dropped the RTNL semaphore in order to
1320 		 * perform the module load.  So, even if we
1321 		 * succeeded in loading the module we have to
1322 		 * tell the caller to replay the request.  We
1323 		 * indicate this using -EAGAIN.
1324 		 */
1325 		if (a_o != NULL) {
1326 			module_put(a_o->owner);
1327 			return ERR_PTR(-EAGAIN);
1328 		}
1329 #endif
1330 		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
1331 		return ERR_PTR(-ENOENT);
1332 	}
1333 
1334 	return a_o;
1335 }
1336 
1337 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
1338 				    struct nlattr *nla, struct nlattr *est,
1339 				    struct tc_action_ops *a_o, int *init_res,
1340 				    u32 flags, struct netlink_ext_ack *extack)
1341 {
1342 	bool police = flags & TCA_ACT_FLAGS_POLICE;
1343 	struct nla_bitfield32 userflags = { 0, 0 };
1344 	u8 hw_stats = TCA_ACT_HW_STATS_ANY;
1345 	struct nlattr *tb[TCA_ACT_MAX + 1];
1346 	struct tc_cookie *cookie = NULL;
1347 	struct tc_action *a;
1348 	int err;
1349 
1350 	/* backward compatibility for policer */
1351 	if (!police) {
1352 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1353 						  tcf_action_policy, extack);
1354 		if (err < 0)
1355 			return ERR_PTR(err);
1356 		if (tb[TCA_ACT_COOKIE]) {
1357 			cookie = nla_memdup_cookie(tb);
1358 			if (!cookie) {
1359 				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
1360 				err = -ENOMEM;
1361 				goto err_out;
1362 			}
1363 		}
1364 		hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
1365 		if (tb[TCA_ACT_FLAGS]) {
1366 			userflags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
1367 			if (!tc_act_flags_valid(userflags.value)) {
1368 				err = -EINVAL;
1369 				goto err_out;
1370 			}
1371 		}
1372 
1373 		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, tp,
1374 				userflags.value | flags, extack);
1375 	} else {
1376 		err = a_o->init(net, nla, est, &a, tp, userflags.value | flags,
1377 				extack);
1378 	}
1379 	if (err < 0)
1380 		goto err_out;
1381 	*init_res = err;
1382 
1383 	if (!police && tb[TCA_ACT_COOKIE])
1384 		tcf_set_action_cookie(&a->act_cookie, cookie);
1385 
1386 	if (!police)
1387 		a->hw_stats = hw_stats;
1388 
1389 	return a;
1390 
1391 err_out:
1392 	if (cookie) {
1393 		kfree(cookie->data);
1394 		kfree(cookie);
1395 	}
1396 	return ERR_PTR(err);
1397 }
1398 
1399 static bool tc_act_bind(u32 flags)
1400 {
1401 	return !!(flags & TCA_ACT_FLAGS_BIND);
1402 }
1403 
1404 /* Returns numbers of initialized actions or negative error. */
1405 
1406 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
1407 		    struct nlattr *est, struct tc_action *actions[],
1408 		    int init_res[], size_t *attr_size,
1409 		    u32 flags, u32 fl_flags,
1410 		    struct netlink_ext_ack *extack)
1411 {
1412 	struct tc_action_ops *ops[TCA_ACT_MAX_PRIO] = {};
1413 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1414 	struct tc_action *act;
1415 	size_t sz = 0;
1416 	int err;
1417 	int i;
1418 
1419 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1420 					  extack);
1421 	if (err < 0)
1422 		return err;
1423 
1424 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1425 		struct tc_action_ops *a_o;
1426 
1427 		a_o = tc_action_load_ops(tb[i], flags & TCA_ACT_FLAGS_POLICE,
1428 					 !(flags & TCA_ACT_FLAGS_NO_RTNL),
1429 					 extack);
1430 		if (IS_ERR(a_o)) {
1431 			err = PTR_ERR(a_o);
1432 			goto err_mod;
1433 		}
1434 		ops[i - 1] = a_o;
1435 	}
1436 
1437 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1438 		act = tcf_action_init_1(net, tp, tb[i], est, ops[i - 1],
1439 					&init_res[i - 1], flags, extack);
1440 		if (IS_ERR(act)) {
1441 			err = PTR_ERR(act);
1442 			goto err;
1443 		}
1444 		sz += tcf_action_fill_size(act);
1445 		/* Start from index 0 */
1446 		actions[i - 1] = act;
1447 		if (tc_act_bind(flags)) {
1448 			bool skip_sw = tc_skip_sw(fl_flags);
1449 			bool skip_hw = tc_skip_hw(fl_flags);
1450 
1451 			if (tc_act_bind(act->tcfa_flags))
1452 				continue;
1453 			if (skip_sw != tc_act_skip_sw(act->tcfa_flags) ||
1454 			    skip_hw != tc_act_skip_hw(act->tcfa_flags)) {
1455 				NL_SET_ERR_MSG(extack,
1456 					       "Mismatch between action and filter offload flags");
1457 				err = -EINVAL;
1458 				goto err;
1459 			}
1460 		} else {
1461 			err = tcf_action_offload_add(act, extack);
1462 			if (tc_act_skip_sw(act->tcfa_flags) && err)
1463 				goto err;
1464 		}
1465 	}
1466 
1467 	/* We have to commit them all together, because if any error happened in
1468 	 * between, we could not handle the failure gracefully.
1469 	 */
1470 	tcf_idr_insert_many(actions);
1471 
1472 	*attr_size = tcf_action_full_attrs_size(sz);
1473 	err = i - 1;
1474 	goto err_mod;
1475 
1476 err:
1477 	tcf_action_destroy(actions, flags & TCA_ACT_FLAGS_BIND);
1478 err_mod:
1479 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1480 		if (ops[i])
1481 			module_put(ops[i]->owner);
1482 	}
1483 	return err;
1484 }
1485 
1486 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u64 packets,
1487 			     u64 drops, bool hw)
1488 {
1489 	if (a->cpu_bstats) {
1490 		_bstats_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1491 
1492 		this_cpu_ptr(a->cpu_qstats)->drops += drops;
1493 
1494 		if (hw)
1495 			_bstats_update(this_cpu_ptr(a->cpu_bstats_hw),
1496 				       bytes, packets);
1497 		return;
1498 	}
1499 
1500 	_bstats_update(&a->tcfa_bstats, bytes, packets);
1501 	a->tcfa_qstats.drops += drops;
1502 	if (hw)
1503 		_bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1504 }
1505 EXPORT_SYMBOL(tcf_action_update_stats);
1506 
1507 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1508 			  int compat_mode)
1509 {
1510 	int err = 0;
1511 	struct gnet_dump d;
1512 
1513 	if (p == NULL)
1514 		goto errout;
1515 
1516 	/* update hw stats for this action */
1517 	tcf_action_update_hw_stats(p);
1518 
1519 	/* compat_mode being true specifies a call that is supposed
1520 	 * to add additional backward compatibility statistic TLVs.
1521 	 */
1522 	if (compat_mode) {
1523 		if (p->type == TCA_OLD_COMPAT)
1524 			err = gnet_stats_start_copy_compat(skb, 0,
1525 							   TCA_STATS,
1526 							   TCA_XSTATS,
1527 							   &p->tcfa_lock, &d,
1528 							   TCA_PAD);
1529 		else
1530 			return 0;
1531 	} else
1532 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1533 					    &p->tcfa_lock, &d, TCA_ACT_PAD);
1534 
1535 	if (err < 0)
1536 		goto errout;
1537 
1538 	if (gnet_stats_copy_basic(&d, p->cpu_bstats,
1539 				  &p->tcfa_bstats, false) < 0 ||
1540 	    gnet_stats_copy_basic_hw(&d, p->cpu_bstats_hw,
1541 				     &p->tcfa_bstats_hw, false) < 0 ||
1542 	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1543 	    gnet_stats_copy_queue(&d, p->cpu_qstats,
1544 				  &p->tcfa_qstats,
1545 				  p->tcfa_qstats.qlen) < 0)
1546 		goto errout;
1547 
1548 	if (gnet_stats_finish_copy(&d) < 0)
1549 		goto errout;
1550 
1551 	return 0;
1552 
1553 errout:
1554 	return -1;
1555 }
1556 
1557 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1558 			u32 portid, u32 seq, u16 flags, int event, int bind,
1559 			int ref)
1560 {
1561 	struct tcamsg *t;
1562 	struct nlmsghdr *nlh;
1563 	unsigned char *b = skb_tail_pointer(skb);
1564 	struct nlattr *nest;
1565 
1566 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1567 	if (!nlh)
1568 		goto out_nlmsg_trim;
1569 	t = nlmsg_data(nlh);
1570 	t->tca_family = AF_UNSPEC;
1571 	t->tca__pad1 = 0;
1572 	t->tca__pad2 = 0;
1573 
1574 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1575 	if (!nest)
1576 		goto out_nlmsg_trim;
1577 
1578 	if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
1579 		goto out_nlmsg_trim;
1580 
1581 	nla_nest_end(skb, nest);
1582 
1583 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1584 	return skb->len;
1585 
1586 out_nlmsg_trim:
1587 	nlmsg_trim(skb, b);
1588 	return -1;
1589 }
1590 
1591 static int
1592 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1593 	       struct tc_action *actions[], int event,
1594 	       struct netlink_ext_ack *extack)
1595 {
1596 	struct sk_buff *skb;
1597 
1598 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1599 	if (!skb)
1600 		return -ENOBUFS;
1601 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1602 			 0, 1) <= 0) {
1603 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1604 		kfree_skb(skb);
1605 		return -EINVAL;
1606 	}
1607 
1608 	return rtnl_unicast(skb, net, portid);
1609 }
1610 
1611 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1612 					  struct nlmsghdr *n, u32 portid,
1613 					  struct netlink_ext_ack *extack)
1614 {
1615 	struct nlattr *tb[TCA_ACT_MAX + 1];
1616 	const struct tc_action_ops *ops;
1617 	struct tc_action *a;
1618 	int index;
1619 	int err;
1620 
1621 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1622 					  tcf_action_policy, extack);
1623 	if (err < 0)
1624 		goto err_out;
1625 
1626 	err = -EINVAL;
1627 	if (tb[TCA_ACT_INDEX] == NULL ||
1628 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1629 		NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1630 		goto err_out;
1631 	}
1632 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
1633 
1634 	err = -EINVAL;
1635 	ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1636 	if (!ops) { /* could happen in batch of actions */
1637 		NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1638 		goto err_out;
1639 	}
1640 	err = -ENOENT;
1641 	if (ops->lookup(net, &a, index) == 0) {
1642 		NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1643 		goto err_mod;
1644 	}
1645 
1646 	module_put(ops->owner);
1647 	return a;
1648 
1649 err_mod:
1650 	module_put(ops->owner);
1651 err_out:
1652 	return ERR_PTR(err);
1653 }
1654 
1655 static int tca_action_flush(struct net *net, struct nlattr *nla,
1656 			    struct nlmsghdr *n, u32 portid,
1657 			    struct netlink_ext_ack *extack)
1658 {
1659 	struct sk_buff *skb;
1660 	unsigned char *b;
1661 	struct nlmsghdr *nlh;
1662 	struct tcamsg *t;
1663 	struct netlink_callback dcb;
1664 	struct nlattr *nest;
1665 	struct nlattr *tb[TCA_ACT_MAX + 1];
1666 	const struct tc_action_ops *ops;
1667 	struct nlattr *kind;
1668 	int err = -ENOMEM;
1669 
1670 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1671 	if (!skb)
1672 		return err;
1673 
1674 	b = skb_tail_pointer(skb);
1675 
1676 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1677 					  tcf_action_policy, extack);
1678 	if (err < 0)
1679 		goto err_out;
1680 
1681 	err = -EINVAL;
1682 	kind = tb[TCA_ACT_KIND];
1683 	ops = tc_lookup_action(kind);
1684 	if (!ops) { /*some idjot trying to flush unknown action */
1685 		NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1686 		goto err_out;
1687 	}
1688 
1689 	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1690 			sizeof(*t), 0);
1691 	if (!nlh) {
1692 		NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1693 		goto out_module_put;
1694 	}
1695 	t = nlmsg_data(nlh);
1696 	t->tca_family = AF_UNSPEC;
1697 	t->tca__pad1 = 0;
1698 	t->tca__pad2 = 0;
1699 
1700 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1701 	if (!nest) {
1702 		NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1703 		goto out_module_put;
1704 	}
1705 
1706 	err = ops->walk(net, skb, &dcb, RTM_DELACTION, ops, extack);
1707 	if (err <= 0) {
1708 		nla_nest_cancel(skb, nest);
1709 		goto out_module_put;
1710 	}
1711 
1712 	nla_nest_end(skb, nest);
1713 
1714 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1715 	nlh->nlmsg_flags |= NLM_F_ROOT;
1716 	module_put(ops->owner);
1717 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1718 			     n->nlmsg_flags & NLM_F_ECHO);
1719 	if (err < 0)
1720 		NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1721 
1722 	return err;
1723 
1724 out_module_put:
1725 	module_put(ops->owner);
1726 err_out:
1727 	kfree_skb(skb);
1728 	return err;
1729 }
1730 
1731 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1732 {
1733 	int i;
1734 
1735 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1736 		struct tc_action *a = actions[i];
1737 		const struct tc_action_ops *ops = a->ops;
1738 		/* Actions can be deleted concurrently so we must save their
1739 		 * type and id to search again after reference is released.
1740 		 */
1741 		struct tcf_idrinfo *idrinfo = a->idrinfo;
1742 		u32 act_index = a->tcfa_index;
1743 
1744 		actions[i] = NULL;
1745 		if (tcf_action_put(a)) {
1746 			/* last reference, action was deleted concurrently */
1747 			module_put(ops->owner);
1748 		} else  {
1749 			int ret;
1750 
1751 			/* now do the delete */
1752 			ret = tcf_idr_delete_index(idrinfo, act_index);
1753 			if (ret < 0)
1754 				return ret;
1755 		}
1756 	}
1757 	return 0;
1758 }
1759 
1760 static int
1761 tcf_reoffload_del_notify(struct net *net, struct tc_action *action)
1762 {
1763 	size_t attr_size = tcf_action_fill_size(action);
1764 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {
1765 		[0] = action,
1766 	};
1767 	const struct tc_action_ops *ops = action->ops;
1768 	struct sk_buff *skb;
1769 	int ret;
1770 
1771 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1772 			GFP_KERNEL);
1773 	if (!skb)
1774 		return -ENOBUFS;
1775 
1776 	if (tca_get_fill(skb, actions, 0, 0, 0, RTM_DELACTION, 0, 1) <= 0) {
1777 		kfree_skb(skb);
1778 		return -EINVAL;
1779 	}
1780 
1781 	ret = tcf_idr_release_unsafe(action);
1782 	if (ret == ACT_P_DELETED) {
1783 		module_put(ops->owner);
1784 		ret = rtnetlink_send(skb, net, 0, RTNLGRP_TC, 0);
1785 	} else {
1786 		kfree_skb(skb);
1787 	}
1788 
1789 	return ret;
1790 }
1791 
1792 int tcf_action_reoffload_cb(flow_indr_block_bind_cb_t *cb,
1793 			    void *cb_priv, bool add)
1794 {
1795 	struct tc_act_pernet_id *id_ptr;
1796 	struct tcf_idrinfo *idrinfo;
1797 	struct tc_action_net *tn;
1798 	struct tc_action *p;
1799 	unsigned int act_id;
1800 	unsigned long tmp;
1801 	unsigned long id;
1802 	struct idr *idr;
1803 	struct net *net;
1804 	int ret;
1805 
1806 	if (!cb)
1807 		return -EINVAL;
1808 
1809 	down_read(&net_rwsem);
1810 	mutex_lock(&act_id_mutex);
1811 
1812 	for_each_net(net) {
1813 		list_for_each_entry(id_ptr, &act_pernet_id_list, list) {
1814 			act_id = id_ptr->id;
1815 			tn = net_generic(net, act_id);
1816 			if (!tn)
1817 				continue;
1818 			idrinfo = tn->idrinfo;
1819 			if (!idrinfo)
1820 				continue;
1821 
1822 			mutex_lock(&idrinfo->lock);
1823 			idr = &idrinfo->action_idr;
1824 			idr_for_each_entry_ul(idr, p, tmp, id) {
1825 				if (IS_ERR(p) || tc_act_bind(p->tcfa_flags))
1826 					continue;
1827 				if (add) {
1828 					tcf_action_offload_add_ex(p, NULL, cb,
1829 								  cb_priv);
1830 					continue;
1831 				}
1832 
1833 				/* cb unregister to update hw count */
1834 				ret = tcf_action_offload_del_ex(p, cb, cb_priv);
1835 				if (ret < 0)
1836 					continue;
1837 				if (tc_act_skip_sw(p->tcfa_flags) &&
1838 				    !tc_act_in_hw(p))
1839 					tcf_reoffload_del_notify(net, p);
1840 			}
1841 			mutex_unlock(&idrinfo->lock);
1842 		}
1843 	}
1844 	mutex_unlock(&act_id_mutex);
1845 	up_read(&net_rwsem);
1846 
1847 	return 0;
1848 }
1849 
1850 static int
1851 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1852 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1853 {
1854 	int ret;
1855 	struct sk_buff *skb;
1856 
1857 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1858 			GFP_KERNEL);
1859 	if (!skb)
1860 		return -ENOBUFS;
1861 
1862 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1863 			 0, 2) <= 0) {
1864 		NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1865 		kfree_skb(skb);
1866 		return -EINVAL;
1867 	}
1868 
1869 	/* now do the delete */
1870 	ret = tcf_action_delete(net, actions);
1871 	if (ret < 0) {
1872 		NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1873 		kfree_skb(skb);
1874 		return ret;
1875 	}
1876 
1877 	ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1878 			     n->nlmsg_flags & NLM_F_ECHO);
1879 	return ret;
1880 }
1881 
1882 static int
1883 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1884 	      u32 portid, int event, struct netlink_ext_ack *extack)
1885 {
1886 	int i, ret;
1887 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1888 	struct tc_action *act;
1889 	size_t attr_size = 0;
1890 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1891 
1892 	ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1893 					  extack);
1894 	if (ret < 0)
1895 		return ret;
1896 
1897 	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1898 		if (tb[1])
1899 			return tca_action_flush(net, tb[1], n, portid, extack);
1900 
1901 		NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1902 		return -EINVAL;
1903 	}
1904 
1905 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1906 		act = tcf_action_get_1(net, tb[i], n, portid, extack);
1907 		if (IS_ERR(act)) {
1908 			ret = PTR_ERR(act);
1909 			goto err;
1910 		}
1911 		attr_size += tcf_action_fill_size(act);
1912 		actions[i - 1] = act;
1913 	}
1914 
1915 	attr_size = tcf_action_full_attrs_size(attr_size);
1916 
1917 	if (event == RTM_GETACTION)
1918 		ret = tcf_get_notify(net, portid, n, actions, event, extack);
1919 	else { /* delete */
1920 		ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1921 		if (ret)
1922 			goto err;
1923 		return 0;
1924 	}
1925 err:
1926 	tcf_action_put_many(actions);
1927 	return ret;
1928 }
1929 
1930 static int
1931 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1932 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1933 {
1934 	struct sk_buff *skb;
1935 
1936 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1937 			GFP_KERNEL);
1938 	if (!skb)
1939 		return -ENOBUFS;
1940 
1941 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1942 			 RTM_NEWACTION, 0, 0) <= 0) {
1943 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1944 		kfree_skb(skb);
1945 		return -EINVAL;
1946 	}
1947 
1948 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1949 			      n->nlmsg_flags & NLM_F_ECHO);
1950 }
1951 
1952 static int tcf_action_add(struct net *net, struct nlattr *nla,
1953 			  struct nlmsghdr *n, u32 portid, u32 flags,
1954 			  struct netlink_ext_ack *extack)
1955 {
1956 	size_t attr_size = 0;
1957 	int loop, ret, i;
1958 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1959 	int init_res[TCA_ACT_MAX_PRIO] = {};
1960 
1961 	for (loop = 0; loop < 10; loop++) {
1962 		ret = tcf_action_init(net, NULL, nla, NULL, actions, init_res,
1963 				      &attr_size, flags, 0, extack);
1964 		if (ret != -EAGAIN)
1965 			break;
1966 	}
1967 
1968 	if (ret < 0)
1969 		return ret;
1970 	ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1971 
1972 	/* only put existing actions */
1973 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++)
1974 		if (init_res[i] == ACT_P_CREATED)
1975 			actions[i] = NULL;
1976 	tcf_action_put_many(actions);
1977 
1978 	return ret;
1979 }
1980 
1981 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
1982 	[TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_ACT_FLAG_LARGE_DUMP_ON |
1983 						 TCA_ACT_FLAG_TERSE_DUMP),
1984 	[TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
1985 };
1986 
1987 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
1988 			 struct netlink_ext_ack *extack)
1989 {
1990 	struct net *net = sock_net(skb->sk);
1991 	struct nlattr *tca[TCA_ROOT_MAX + 1];
1992 	u32 portid = NETLINK_CB(skb).portid;
1993 	u32 flags = 0;
1994 	int ret = 0;
1995 
1996 	if ((n->nlmsg_type != RTM_GETACTION) &&
1997 	    !netlink_capable(skb, CAP_NET_ADMIN))
1998 		return -EPERM;
1999 
2000 	ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
2001 				     TCA_ROOT_MAX, NULL, extack);
2002 	if (ret < 0)
2003 		return ret;
2004 
2005 	if (tca[TCA_ACT_TAB] == NULL) {
2006 		NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
2007 		return -EINVAL;
2008 	}
2009 
2010 	/* n->nlmsg_flags & NLM_F_CREATE */
2011 	switch (n->nlmsg_type) {
2012 	case RTM_NEWACTION:
2013 		/* we are going to assume all other flags
2014 		 * imply create only if it doesn't exist
2015 		 * Note that CREATE | EXCL implies that
2016 		 * but since we want avoid ambiguity (eg when flags
2017 		 * is zero) then just set this
2018 		 */
2019 		if (n->nlmsg_flags & NLM_F_REPLACE)
2020 			flags = TCA_ACT_FLAGS_REPLACE;
2021 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, flags,
2022 				     extack);
2023 		break;
2024 	case RTM_DELACTION:
2025 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
2026 				    portid, RTM_DELACTION, extack);
2027 		break;
2028 	case RTM_GETACTION:
2029 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
2030 				    portid, RTM_GETACTION, extack);
2031 		break;
2032 	default:
2033 		BUG();
2034 	}
2035 
2036 	return ret;
2037 }
2038 
2039 static struct nlattr *find_dump_kind(struct nlattr **nla)
2040 {
2041 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
2042 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
2043 	struct nlattr *kind;
2044 
2045 	tb1 = nla[TCA_ACT_TAB];
2046 	if (tb1 == NULL)
2047 		return NULL;
2048 
2049 	if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
2050 		return NULL;
2051 
2052 	if (tb[1] == NULL)
2053 		return NULL;
2054 	if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
2055 		return NULL;
2056 	kind = tb2[TCA_ACT_KIND];
2057 
2058 	return kind;
2059 }
2060 
2061 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
2062 {
2063 	struct net *net = sock_net(skb->sk);
2064 	struct nlmsghdr *nlh;
2065 	unsigned char *b = skb_tail_pointer(skb);
2066 	struct nlattr *nest;
2067 	struct tc_action_ops *a_o;
2068 	int ret = 0;
2069 	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
2070 	struct nlattr *tb[TCA_ROOT_MAX + 1];
2071 	struct nlattr *count_attr = NULL;
2072 	unsigned long jiffy_since = 0;
2073 	struct nlattr *kind = NULL;
2074 	struct nla_bitfield32 bf;
2075 	u32 msecs_since = 0;
2076 	u32 act_count = 0;
2077 
2078 	ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
2079 				     TCA_ROOT_MAX, tcaa_policy, cb->extack);
2080 	if (ret < 0)
2081 		return ret;
2082 
2083 	kind = find_dump_kind(tb);
2084 	if (kind == NULL) {
2085 		pr_info("tc_dump_action: action bad kind\n");
2086 		return 0;
2087 	}
2088 
2089 	a_o = tc_lookup_action(kind);
2090 	if (a_o == NULL)
2091 		return 0;
2092 
2093 	cb->args[2] = 0;
2094 	if (tb[TCA_ROOT_FLAGS]) {
2095 		bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
2096 		cb->args[2] = bf.value;
2097 	}
2098 
2099 	if (tb[TCA_ROOT_TIME_DELTA]) {
2100 		msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
2101 	}
2102 
2103 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
2104 			cb->nlh->nlmsg_type, sizeof(*t), 0);
2105 	if (!nlh)
2106 		goto out_module_put;
2107 
2108 	if (msecs_since)
2109 		jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
2110 
2111 	t = nlmsg_data(nlh);
2112 	t->tca_family = AF_UNSPEC;
2113 	t->tca__pad1 = 0;
2114 	t->tca__pad2 = 0;
2115 	cb->args[3] = jiffy_since;
2116 	count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
2117 	if (!count_attr)
2118 		goto out_module_put;
2119 
2120 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
2121 	if (nest == NULL)
2122 		goto out_module_put;
2123 
2124 	ret = a_o->walk(net, skb, cb, RTM_GETACTION, a_o, NULL);
2125 	if (ret < 0)
2126 		goto out_module_put;
2127 
2128 	if (ret > 0) {
2129 		nla_nest_end(skb, nest);
2130 		ret = skb->len;
2131 		act_count = cb->args[1];
2132 		memcpy(nla_data(count_attr), &act_count, sizeof(u32));
2133 		cb->args[1] = 0;
2134 	} else
2135 		nlmsg_trim(skb, b);
2136 
2137 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2138 	if (NETLINK_CB(cb->skb).portid && ret)
2139 		nlh->nlmsg_flags |= NLM_F_MULTI;
2140 	module_put(a_o->owner);
2141 	return skb->len;
2142 
2143 out_module_put:
2144 	module_put(a_o->owner);
2145 	nlmsg_trim(skb, b);
2146 	return skb->len;
2147 }
2148 
2149 static int __init tc_action_init(void)
2150 {
2151 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
2152 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
2153 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
2154 		      0);
2155 
2156 	return 0;
2157 }
2158 
2159 subsys_initcall(tc_action_init);
2160