xref: /linux/net/sched/act_api.c (revision ccab211af3c2b90ed792eb5f33707d2f0d59fe50)
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 #include <net/tc_wrapper.h>
27 
28 #ifdef CONFIG_INET
29 DEFINE_STATIC_KEY_FALSE(tcf_frag_xmit_count);
30 EXPORT_SYMBOL_GPL(tcf_frag_xmit_count);
31 #endif
32 
33 int tcf_dev_queue_xmit(struct sk_buff *skb, int (*xmit)(struct sk_buff *skb))
34 {
35 #ifdef CONFIG_INET
36 	if (static_branch_unlikely(&tcf_frag_xmit_count))
37 		return sch_frag_xmit_hook(skb, xmit);
38 #endif
39 
40 	return xmit(skb);
41 }
42 EXPORT_SYMBOL_GPL(tcf_dev_queue_xmit);
43 
44 static void tcf_action_goto_chain_exec(const struct tc_action *a,
45 				       struct tcf_result *res)
46 {
47 	const struct tcf_chain *chain = rcu_dereference_bh(a->goto_chain);
48 
49 	res->goto_tp = rcu_dereference_bh(chain->filter_chain);
50 }
51 
52 static void tcf_free_cookie_rcu(struct rcu_head *p)
53 {
54 	struct tc_cookie *cookie = container_of(p, struct tc_cookie, rcu);
55 
56 	kfree(cookie->data);
57 	kfree(cookie);
58 }
59 
60 static void tcf_set_action_cookie(struct tc_cookie __rcu **old_cookie,
61 				  struct tc_cookie *new_cookie)
62 {
63 	struct tc_cookie *old;
64 
65 	old = xchg((__force struct tc_cookie **)old_cookie, new_cookie);
66 	if (old)
67 		call_rcu(&old->rcu, tcf_free_cookie_rcu);
68 }
69 
70 int tcf_action_check_ctrlact(int action, struct tcf_proto *tp,
71 			     struct tcf_chain **newchain,
72 			     struct netlink_ext_ack *extack)
73 {
74 	int opcode = TC_ACT_EXT_OPCODE(action), ret = -EINVAL;
75 	u32 chain_index;
76 
77 	if (!opcode)
78 		ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0;
79 	else if (opcode <= TC_ACT_EXT_OPCODE_MAX || action == TC_ACT_UNSPEC)
80 		ret = 0;
81 	if (ret) {
82 		NL_SET_ERR_MSG(extack, "invalid control action");
83 		goto end;
84 	}
85 
86 	if (TC_ACT_EXT_CMP(action, TC_ACT_GOTO_CHAIN)) {
87 		chain_index = action & TC_ACT_EXT_VAL_MASK;
88 		if (!tp || !newchain) {
89 			ret = -EINVAL;
90 			NL_SET_ERR_MSG(extack,
91 				       "can't goto NULL proto/chain");
92 			goto end;
93 		}
94 		*newchain = tcf_chain_get_by_act(tp->chain->block, chain_index);
95 		if (!*newchain) {
96 			ret = -ENOMEM;
97 			NL_SET_ERR_MSG(extack,
98 				       "can't allocate goto_chain");
99 		}
100 	}
101 end:
102 	return ret;
103 }
104 EXPORT_SYMBOL(tcf_action_check_ctrlact);
105 
106 struct tcf_chain *tcf_action_set_ctrlact(struct tc_action *a, int action,
107 					 struct tcf_chain *goto_chain)
108 {
109 	a->tcfa_action = action;
110 	goto_chain = rcu_replace_pointer(a->goto_chain, goto_chain, 1);
111 	return goto_chain;
112 }
113 EXPORT_SYMBOL(tcf_action_set_ctrlact);
114 
115 /* XXX: For standalone actions, we don't need a RCU grace period either, because
116  * actions are always connected to filters and filters are already destroyed in
117  * RCU callbacks, so after a RCU grace period actions are already disconnected
118  * from filters. Readers later can not find us.
119  */
120 static void free_tcf(struct tc_action *p)
121 {
122 	struct tcf_chain *chain = rcu_dereference_protected(p->goto_chain, 1);
123 
124 	free_percpu(p->cpu_bstats);
125 	free_percpu(p->cpu_bstats_hw);
126 	free_percpu(p->cpu_qstats);
127 
128 	tcf_set_action_cookie(&p->user_cookie, NULL);
129 	if (chain)
130 		tcf_chain_put_by_act(chain);
131 
132 	kfree(p);
133 }
134 
135 static void offload_action_hw_count_set(struct tc_action *act,
136 					u32 hw_count)
137 {
138 	act->in_hw_count = hw_count;
139 }
140 
141 static void offload_action_hw_count_inc(struct tc_action *act,
142 					u32 hw_count)
143 {
144 	act->in_hw_count += hw_count;
145 }
146 
147 static void offload_action_hw_count_dec(struct tc_action *act,
148 					u32 hw_count)
149 {
150 	act->in_hw_count = act->in_hw_count > hw_count ?
151 			   act->in_hw_count - hw_count : 0;
152 }
153 
154 static unsigned int tcf_offload_act_num_actions_single(struct tc_action *act)
155 {
156 	if (is_tcf_pedit(act))
157 		return tcf_pedit_nkeys(act);
158 	else
159 		return 1;
160 }
161 
162 static bool tc_act_skip_hw(u32 flags)
163 {
164 	return (flags & TCA_ACT_FLAGS_SKIP_HW) ? true : false;
165 }
166 
167 static bool tc_act_skip_sw(u32 flags)
168 {
169 	return (flags & TCA_ACT_FLAGS_SKIP_SW) ? true : false;
170 }
171 
172 /* SKIP_HW and SKIP_SW are mutually exclusive flags. */
173 static bool tc_act_flags_valid(u32 flags)
174 {
175 	flags &= TCA_ACT_FLAGS_SKIP_HW | TCA_ACT_FLAGS_SKIP_SW;
176 
177 	return flags ^ (TCA_ACT_FLAGS_SKIP_HW | TCA_ACT_FLAGS_SKIP_SW);
178 }
179 
180 static int offload_action_init(struct flow_offload_action *fl_action,
181 			       struct tc_action *act,
182 			       enum offload_act_command  cmd,
183 			       struct netlink_ext_ack *extack)
184 {
185 	int err;
186 
187 	fl_action->extack = extack;
188 	fl_action->command = cmd;
189 	fl_action->index = act->tcfa_index;
190 	fl_action->cookie = (unsigned long)act;
191 
192 	if (act->ops->offload_act_setup) {
193 		spin_lock_bh(&act->tcfa_lock);
194 		err = act->ops->offload_act_setup(act, fl_action, NULL,
195 						  false, extack);
196 		spin_unlock_bh(&act->tcfa_lock);
197 		return err;
198 	}
199 
200 	return -EOPNOTSUPP;
201 }
202 
203 static int tcf_action_offload_cmd_ex(struct flow_offload_action *fl_act,
204 				     u32 *hw_count)
205 {
206 	int err;
207 
208 	err = flow_indr_dev_setup_offload(NULL, NULL, TC_SETUP_ACT,
209 					  fl_act, NULL, NULL);
210 	if (err < 0)
211 		return err;
212 
213 	if (hw_count)
214 		*hw_count = err;
215 
216 	return 0;
217 }
218 
219 static int tcf_action_offload_cmd_cb_ex(struct flow_offload_action *fl_act,
220 					u32 *hw_count,
221 					flow_indr_block_bind_cb_t *cb,
222 					void *cb_priv)
223 {
224 	int err;
225 
226 	err = cb(NULL, NULL, cb_priv, TC_SETUP_ACT, NULL, fl_act, NULL);
227 	if (err < 0)
228 		return err;
229 
230 	if (hw_count)
231 		*hw_count = 1;
232 
233 	return 0;
234 }
235 
236 static int tcf_action_offload_cmd(struct flow_offload_action *fl_act,
237 				  u32 *hw_count,
238 				  flow_indr_block_bind_cb_t *cb,
239 				  void *cb_priv)
240 {
241 	return cb ? tcf_action_offload_cmd_cb_ex(fl_act, hw_count,
242 						 cb, cb_priv) :
243 		    tcf_action_offload_cmd_ex(fl_act, hw_count);
244 }
245 
246 static int tcf_action_offload_add_ex(struct tc_action *action,
247 				     struct netlink_ext_ack *extack,
248 				     flow_indr_block_bind_cb_t *cb,
249 				     void *cb_priv)
250 {
251 	bool skip_sw = tc_act_skip_sw(action->tcfa_flags);
252 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {
253 		[0] = action,
254 	};
255 	struct flow_offload_action *fl_action;
256 	u32 in_hw_count = 0;
257 	int num, err = 0;
258 
259 	if (tc_act_skip_hw(action->tcfa_flags))
260 		return 0;
261 
262 	num = tcf_offload_act_num_actions_single(action);
263 	fl_action = offload_action_alloc(num);
264 	if (!fl_action)
265 		return -ENOMEM;
266 
267 	err = offload_action_init(fl_action, action, FLOW_ACT_REPLACE, extack);
268 	if (err)
269 		goto fl_err;
270 
271 	err = tc_setup_action(&fl_action->action, actions, 0, extack);
272 	if (err) {
273 		NL_SET_ERR_MSG_MOD(extack,
274 				   "Failed to setup tc actions for offload");
275 		goto fl_err;
276 	}
277 
278 	err = tcf_action_offload_cmd(fl_action, &in_hw_count, cb, cb_priv);
279 	if (!err)
280 		cb ? offload_action_hw_count_inc(action, in_hw_count) :
281 		     offload_action_hw_count_set(action, in_hw_count);
282 
283 	if (skip_sw && !tc_act_in_hw(action))
284 		err = -EINVAL;
285 
286 	tc_cleanup_offload_action(&fl_action->action);
287 
288 fl_err:
289 	kfree(fl_action);
290 
291 	return err;
292 }
293 
294 /* offload the tc action after it is inserted */
295 static int tcf_action_offload_add(struct tc_action *action,
296 				  struct netlink_ext_ack *extack)
297 {
298 	return tcf_action_offload_add_ex(action, extack, NULL, NULL);
299 }
300 
301 int tcf_action_update_hw_stats(struct tc_action *action)
302 {
303 	struct flow_offload_action fl_act = {};
304 	int err;
305 
306 	err = offload_action_init(&fl_act, action, FLOW_ACT_STATS, NULL);
307 	if (err)
308 		return err;
309 
310 	err = tcf_action_offload_cmd(&fl_act, NULL, NULL, NULL);
311 	if (!err) {
312 		preempt_disable();
313 		tcf_action_stats_update(action, fl_act.stats.bytes,
314 					fl_act.stats.pkts,
315 					fl_act.stats.drops,
316 					fl_act.stats.lastused,
317 					true);
318 		preempt_enable();
319 		action->used_hw_stats = fl_act.stats.used_hw_stats;
320 		action->used_hw_stats_valid = true;
321 	} else {
322 		return -EOPNOTSUPP;
323 	}
324 
325 	return 0;
326 }
327 EXPORT_SYMBOL(tcf_action_update_hw_stats);
328 
329 static int tcf_action_offload_del_ex(struct tc_action *action,
330 				     flow_indr_block_bind_cb_t *cb,
331 				     void *cb_priv)
332 {
333 	struct flow_offload_action fl_act = {};
334 	u32 in_hw_count = 0;
335 	int err = 0;
336 
337 	if (!tc_act_in_hw(action))
338 		return 0;
339 
340 	err = offload_action_init(&fl_act, action, FLOW_ACT_DESTROY, NULL);
341 	if (err)
342 		return err;
343 
344 	err = tcf_action_offload_cmd(&fl_act, &in_hw_count, cb, cb_priv);
345 	if (err < 0)
346 		return err;
347 
348 	if (!cb && action->in_hw_count != in_hw_count)
349 		return -EINVAL;
350 
351 	/* do not need to update hw state when deleting action */
352 	if (cb && in_hw_count)
353 		offload_action_hw_count_dec(action, in_hw_count);
354 
355 	return 0;
356 }
357 
358 static int tcf_action_offload_del(struct tc_action *action)
359 {
360 	return tcf_action_offload_del_ex(action, NULL, NULL);
361 }
362 
363 static void tcf_action_cleanup(struct tc_action *p)
364 {
365 	tcf_action_offload_del(p);
366 	if (p->ops->cleanup)
367 		p->ops->cleanup(p);
368 
369 	gen_kill_estimator(&p->tcfa_rate_est);
370 	free_tcf(p);
371 }
372 
373 static int __tcf_action_put(struct tc_action *p, bool bind)
374 {
375 	struct tcf_idrinfo *idrinfo = p->idrinfo;
376 
377 	if (refcount_dec_and_mutex_lock(&p->tcfa_refcnt, &idrinfo->lock)) {
378 		if (bind)
379 			atomic_dec(&p->tcfa_bindcnt);
380 		idr_remove(&idrinfo->action_idr, p->tcfa_index);
381 		mutex_unlock(&idrinfo->lock);
382 
383 		tcf_action_cleanup(p);
384 		return 1;
385 	}
386 
387 	if (bind)
388 		atomic_dec(&p->tcfa_bindcnt);
389 
390 	return 0;
391 }
392 
393 static int __tcf_idr_release(struct tc_action *p, bool bind, bool strict)
394 {
395 	int ret = 0;
396 
397 	/* Release with strict==1 and bind==0 is only called through act API
398 	 * interface (classifiers always bind). Only case when action with
399 	 * positive reference count and zero bind count can exist is when it was
400 	 * also created with act API (unbinding last classifier will destroy the
401 	 * action if it was created by classifier). So only case when bind count
402 	 * can be changed after initial check is when unbound action is
403 	 * destroyed by act API while classifier binds to action with same id
404 	 * concurrently. This result either creation of new action(same behavior
405 	 * as before), or reusing existing action if concurrent process
406 	 * increments reference count before action is deleted. Both scenarios
407 	 * are acceptable.
408 	 */
409 	if (p) {
410 		if (!bind && strict && atomic_read(&p->tcfa_bindcnt) > 0)
411 			return -EPERM;
412 
413 		if (__tcf_action_put(p, bind))
414 			ret = ACT_P_DELETED;
415 	}
416 
417 	return ret;
418 }
419 
420 int tcf_idr_release(struct tc_action *a, bool bind)
421 {
422 	const struct tc_action_ops *ops = a->ops;
423 	int ret;
424 
425 	ret = __tcf_idr_release(a, bind, false);
426 	if (ret == ACT_P_DELETED)
427 		module_put(ops->owner);
428 	return ret;
429 }
430 EXPORT_SYMBOL(tcf_idr_release);
431 
432 static size_t tcf_action_shared_attrs_size(const struct tc_action *act)
433 {
434 	struct tc_cookie *user_cookie;
435 	u32 cookie_len = 0;
436 
437 	rcu_read_lock();
438 	user_cookie = rcu_dereference(act->user_cookie);
439 
440 	if (user_cookie)
441 		cookie_len = nla_total_size(user_cookie->len);
442 	rcu_read_unlock();
443 
444 	return  nla_total_size(0) /* action number nested */
445 		+ nla_total_size(IFNAMSIZ) /* TCA_ACT_KIND */
446 		+ cookie_len /* TCA_ACT_COOKIE */
447 		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_HW_STATS */
448 		+ nla_total_size(0) /* TCA_ACT_STATS nested */
449 		+ nla_total_size(sizeof(struct nla_bitfield32)) /* TCA_ACT_FLAGS */
450 		/* TCA_STATS_BASIC */
451 		+ nla_total_size_64bit(sizeof(struct gnet_stats_basic))
452 		/* TCA_STATS_PKT64 */
453 		+ nla_total_size_64bit(sizeof(u64))
454 		/* TCA_STATS_QUEUE */
455 		+ nla_total_size_64bit(sizeof(struct gnet_stats_queue))
456 		+ nla_total_size(0) /* TCA_ACT_OPTIONS nested */
457 		+ nla_total_size(sizeof(struct tcf_t)); /* TCA_GACT_TM */
458 }
459 
460 static size_t tcf_action_full_attrs_size(size_t sz)
461 {
462 	return NLMSG_HDRLEN                     /* struct nlmsghdr */
463 		+ sizeof(struct tcamsg)
464 		+ nla_total_size(0)             /* TCA_ACT_TAB nested */
465 		+ sz;
466 }
467 
468 static size_t tcf_action_fill_size(const struct tc_action *act)
469 {
470 	size_t sz = tcf_action_shared_attrs_size(act);
471 
472 	if (act->ops->get_fill_size)
473 		return act->ops->get_fill_size(act) + sz;
474 	return sz;
475 }
476 
477 static int
478 tcf_action_dump_terse(struct sk_buff *skb, struct tc_action *a, bool from_act)
479 {
480 	unsigned char *b = skb_tail_pointer(skb);
481 	struct tc_cookie *cookie;
482 
483 	if (nla_put_string(skb, TCA_ACT_KIND, a->ops->kind))
484 		goto nla_put_failure;
485 	if (tcf_action_copy_stats(skb, a, 0))
486 		goto nla_put_failure;
487 	if (from_act && nla_put_u32(skb, TCA_ACT_INDEX, a->tcfa_index))
488 		goto nla_put_failure;
489 
490 	rcu_read_lock();
491 	cookie = rcu_dereference(a->user_cookie);
492 	if (cookie) {
493 		if (nla_put(skb, TCA_ACT_COOKIE, cookie->len, cookie->data)) {
494 			rcu_read_unlock();
495 			goto nla_put_failure;
496 		}
497 	}
498 	rcu_read_unlock();
499 
500 	return 0;
501 
502 nla_put_failure:
503 	nlmsg_trim(skb, b);
504 	return -1;
505 }
506 
507 static int tcf_dump_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
508 			   struct netlink_callback *cb)
509 {
510 	int err = 0, index = -1, s_i = 0, n_i = 0;
511 	u32 act_flags = cb->args[2];
512 	unsigned long jiffy_since = cb->args[3];
513 	struct nlattr *nest;
514 	struct idr *idr = &idrinfo->action_idr;
515 	struct tc_action *p;
516 	unsigned long id = 1;
517 	unsigned long tmp;
518 
519 	mutex_lock(&idrinfo->lock);
520 
521 	s_i = cb->args[0];
522 
523 	idr_for_each_entry_ul(idr, p, tmp, id) {
524 		index++;
525 		if (index < s_i)
526 			continue;
527 		if (IS_ERR(p))
528 			continue;
529 
530 		if (jiffy_since &&
531 		    time_after(jiffy_since,
532 			       (unsigned long)p->tcfa_tm.lastuse))
533 			continue;
534 
535 		tcf_action_update_hw_stats(p);
536 
537 		nest = nla_nest_start_noflag(skb, n_i);
538 		if (!nest) {
539 			index--;
540 			goto nla_put_failure;
541 		}
542 		err = (act_flags & TCA_ACT_FLAG_TERSE_DUMP) ?
543 			tcf_action_dump_terse(skb, p, true) :
544 			tcf_action_dump_1(skb, p, 0, 0);
545 		if (err < 0) {
546 			index--;
547 			nlmsg_trim(skb, nest);
548 			goto done;
549 		}
550 		nla_nest_end(skb, nest);
551 		n_i++;
552 		if (!(act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON) &&
553 		    n_i >= TCA_ACT_MAX_PRIO)
554 			goto done;
555 	}
556 done:
557 	if (index >= 0)
558 		cb->args[0] = index + 1;
559 
560 	mutex_unlock(&idrinfo->lock);
561 	if (n_i) {
562 		if (act_flags & TCA_ACT_FLAG_LARGE_DUMP_ON)
563 			cb->args[1] = n_i;
564 	}
565 	return n_i;
566 
567 nla_put_failure:
568 	nla_nest_cancel(skb, nest);
569 	goto done;
570 }
571 
572 static int tcf_idr_release_unsafe(struct tc_action *p)
573 {
574 	if (atomic_read(&p->tcfa_bindcnt) > 0)
575 		return -EPERM;
576 
577 	if (refcount_dec_and_test(&p->tcfa_refcnt)) {
578 		idr_remove(&p->idrinfo->action_idr, p->tcfa_index);
579 		tcf_action_cleanup(p);
580 		return ACT_P_DELETED;
581 	}
582 
583 	return 0;
584 }
585 
586 static int tcf_del_walker(struct tcf_idrinfo *idrinfo, struct sk_buff *skb,
587 			  const struct tc_action_ops *ops,
588 			  struct netlink_ext_ack *extack)
589 {
590 	struct nlattr *nest;
591 	int n_i = 0;
592 	int ret = -EINVAL;
593 	struct idr *idr = &idrinfo->action_idr;
594 	struct tc_action *p;
595 	unsigned long id = 1;
596 	unsigned long tmp;
597 
598 	nest = nla_nest_start_noflag(skb, 0);
599 	if (nest == NULL)
600 		goto nla_put_failure;
601 	if (nla_put_string(skb, TCA_ACT_KIND, ops->kind))
602 		goto nla_put_failure;
603 
604 	ret = 0;
605 	mutex_lock(&idrinfo->lock);
606 	idr_for_each_entry_ul(idr, p, tmp, id) {
607 		if (IS_ERR(p))
608 			continue;
609 		ret = tcf_idr_release_unsafe(p);
610 		if (ret == ACT_P_DELETED)
611 			module_put(ops->owner);
612 		else if (ret < 0)
613 			break;
614 		n_i++;
615 	}
616 	mutex_unlock(&idrinfo->lock);
617 	if (ret < 0) {
618 		if (n_i)
619 			NL_SET_ERR_MSG(extack, "Unable to flush all TC actions");
620 		else
621 			goto nla_put_failure;
622 	}
623 
624 	ret = nla_put_u32(skb, TCA_FCNT, n_i);
625 	if (ret)
626 		goto nla_put_failure;
627 	nla_nest_end(skb, nest);
628 
629 	return n_i;
630 nla_put_failure:
631 	nla_nest_cancel(skb, nest);
632 	return ret;
633 }
634 
635 int tcf_generic_walker(struct tc_action_net *tn, struct sk_buff *skb,
636 		       struct netlink_callback *cb, int type,
637 		       const struct tc_action_ops *ops,
638 		       struct netlink_ext_ack *extack)
639 {
640 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
641 
642 	if (type == RTM_DELACTION) {
643 		return tcf_del_walker(idrinfo, skb, ops, extack);
644 	} else if (type == RTM_GETACTION) {
645 		return tcf_dump_walker(idrinfo, skb, cb);
646 	} else {
647 		WARN(1, "tcf_generic_walker: unknown command %d\n", type);
648 		NL_SET_ERR_MSG(extack, "tcf_generic_walker: unknown command");
649 		return -EINVAL;
650 	}
651 }
652 EXPORT_SYMBOL(tcf_generic_walker);
653 
654 int tcf_idr_search(struct tc_action_net *tn, struct tc_action **a, u32 index)
655 {
656 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
657 	struct tc_action *p;
658 
659 	mutex_lock(&idrinfo->lock);
660 	p = idr_find(&idrinfo->action_idr, index);
661 	if (IS_ERR(p))
662 		p = NULL;
663 	else if (p)
664 		refcount_inc(&p->tcfa_refcnt);
665 	mutex_unlock(&idrinfo->lock);
666 
667 	if (p) {
668 		*a = p;
669 		return true;
670 	}
671 	return false;
672 }
673 EXPORT_SYMBOL(tcf_idr_search);
674 
675 static int __tcf_generic_walker(struct net *net, struct sk_buff *skb,
676 				struct netlink_callback *cb, int type,
677 				const struct tc_action_ops *ops,
678 				struct netlink_ext_ack *extack)
679 {
680 	struct tc_action_net *tn = net_generic(net, ops->net_id);
681 
682 	if (unlikely(ops->walk))
683 		return ops->walk(net, skb, cb, type, ops, extack);
684 
685 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
686 }
687 
688 static int __tcf_idr_search(struct net *net,
689 			    const struct tc_action_ops *ops,
690 			    struct tc_action **a, u32 index)
691 {
692 	struct tc_action_net *tn = net_generic(net, ops->net_id);
693 
694 	if (unlikely(ops->lookup))
695 		return ops->lookup(net, a, index);
696 
697 	return tcf_idr_search(tn, a, index);
698 }
699 
700 static int tcf_idr_delete_index(struct tcf_idrinfo *idrinfo, u32 index)
701 {
702 	struct tc_action *p;
703 	int ret = 0;
704 
705 	mutex_lock(&idrinfo->lock);
706 	p = idr_find(&idrinfo->action_idr, index);
707 	if (!p) {
708 		mutex_unlock(&idrinfo->lock);
709 		return -ENOENT;
710 	}
711 
712 	if (!atomic_read(&p->tcfa_bindcnt)) {
713 		if (refcount_dec_and_test(&p->tcfa_refcnt)) {
714 			struct module *owner = p->ops->owner;
715 
716 			WARN_ON(p != idr_remove(&idrinfo->action_idr,
717 						p->tcfa_index));
718 			mutex_unlock(&idrinfo->lock);
719 
720 			tcf_action_cleanup(p);
721 			module_put(owner);
722 			return 0;
723 		}
724 		ret = 0;
725 	} else {
726 		ret = -EPERM;
727 	}
728 
729 	mutex_unlock(&idrinfo->lock);
730 	return ret;
731 }
732 
733 int tcf_idr_create(struct tc_action_net *tn, u32 index, struct nlattr *est,
734 		   struct tc_action **a, const struct tc_action_ops *ops,
735 		   int bind, bool cpustats, u32 flags)
736 {
737 	struct tc_action *p = kzalloc(ops->size, GFP_KERNEL);
738 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
739 	int err = -ENOMEM;
740 
741 	if (unlikely(!p))
742 		return -ENOMEM;
743 	refcount_set(&p->tcfa_refcnt, 1);
744 	if (bind)
745 		atomic_set(&p->tcfa_bindcnt, 1);
746 
747 	if (cpustats) {
748 		p->cpu_bstats = netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
749 		if (!p->cpu_bstats)
750 			goto err1;
751 		p->cpu_bstats_hw = netdev_alloc_pcpu_stats(struct gnet_stats_basic_sync);
752 		if (!p->cpu_bstats_hw)
753 			goto err2;
754 		p->cpu_qstats = alloc_percpu(struct gnet_stats_queue);
755 		if (!p->cpu_qstats)
756 			goto err3;
757 	}
758 	gnet_stats_basic_sync_init(&p->tcfa_bstats);
759 	gnet_stats_basic_sync_init(&p->tcfa_bstats_hw);
760 	spin_lock_init(&p->tcfa_lock);
761 	p->tcfa_index = index;
762 	p->tcfa_tm.install = jiffies;
763 	p->tcfa_tm.lastuse = jiffies;
764 	p->tcfa_tm.firstuse = 0;
765 	p->tcfa_flags = flags;
766 	if (est) {
767 		err = gen_new_estimator(&p->tcfa_bstats, p->cpu_bstats,
768 					&p->tcfa_rate_est,
769 					&p->tcfa_lock, false, est);
770 		if (err)
771 			goto err4;
772 	}
773 
774 	p->idrinfo = idrinfo;
775 	__module_get(ops->owner);
776 	p->ops = ops;
777 	*a = p;
778 	return 0;
779 err4:
780 	free_percpu(p->cpu_qstats);
781 err3:
782 	free_percpu(p->cpu_bstats_hw);
783 err2:
784 	free_percpu(p->cpu_bstats);
785 err1:
786 	kfree(p);
787 	return err;
788 }
789 EXPORT_SYMBOL(tcf_idr_create);
790 
791 int tcf_idr_create_from_flags(struct tc_action_net *tn, u32 index,
792 			      struct nlattr *est, struct tc_action **a,
793 			      const struct tc_action_ops *ops, int bind,
794 			      u32 flags)
795 {
796 	/* Set cpustats according to actions flags. */
797 	return tcf_idr_create(tn, index, est, a, ops, bind,
798 			      !(flags & TCA_ACT_FLAGS_NO_PERCPU_STATS), flags);
799 }
800 EXPORT_SYMBOL(tcf_idr_create_from_flags);
801 
802 /* Cleanup idr index that was allocated but not initialized. */
803 
804 void tcf_idr_cleanup(struct tc_action_net *tn, u32 index)
805 {
806 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
807 
808 	mutex_lock(&idrinfo->lock);
809 	/* Remove ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc */
810 	WARN_ON(!IS_ERR(idr_remove(&idrinfo->action_idr, index)));
811 	mutex_unlock(&idrinfo->lock);
812 }
813 EXPORT_SYMBOL(tcf_idr_cleanup);
814 
815 /* Check if action with specified index exists. If actions is found, increments
816  * its reference and bind counters, and return 1. Otherwise insert temporary
817  * error pointer (to prevent concurrent users from inserting actions with same
818  * index) and return 0.
819  */
820 
821 int tcf_idr_check_alloc(struct tc_action_net *tn, u32 *index,
822 			struct tc_action **a, int bind)
823 {
824 	struct tcf_idrinfo *idrinfo = tn->idrinfo;
825 	struct tc_action *p;
826 	int ret;
827 
828 again:
829 	mutex_lock(&idrinfo->lock);
830 	if (*index) {
831 		p = idr_find(&idrinfo->action_idr, *index);
832 		if (IS_ERR(p)) {
833 			/* This means that another process allocated
834 			 * index but did not assign the pointer yet.
835 			 */
836 			mutex_unlock(&idrinfo->lock);
837 			goto again;
838 		}
839 
840 		if (p) {
841 			refcount_inc(&p->tcfa_refcnt);
842 			if (bind)
843 				atomic_inc(&p->tcfa_bindcnt);
844 			*a = p;
845 			ret = 1;
846 		} else {
847 			*a = NULL;
848 			ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
849 					    *index, GFP_KERNEL);
850 			if (!ret)
851 				idr_replace(&idrinfo->action_idr,
852 					    ERR_PTR(-EBUSY), *index);
853 		}
854 	} else {
855 		*index = 1;
856 		*a = NULL;
857 		ret = idr_alloc_u32(&idrinfo->action_idr, NULL, index,
858 				    UINT_MAX, GFP_KERNEL);
859 		if (!ret)
860 			idr_replace(&idrinfo->action_idr, ERR_PTR(-EBUSY),
861 				    *index);
862 	}
863 	mutex_unlock(&idrinfo->lock);
864 	return ret;
865 }
866 EXPORT_SYMBOL(tcf_idr_check_alloc);
867 
868 void tcf_idrinfo_destroy(const struct tc_action_ops *ops,
869 			 struct tcf_idrinfo *idrinfo)
870 {
871 	struct idr *idr = &idrinfo->action_idr;
872 	struct tc_action *p;
873 	int ret;
874 	unsigned long id = 1;
875 	unsigned long tmp;
876 
877 	idr_for_each_entry_ul(idr, p, tmp, id) {
878 		ret = __tcf_idr_release(p, false, true);
879 		if (ret == ACT_P_DELETED)
880 			module_put(ops->owner);
881 		else if (ret < 0)
882 			return;
883 	}
884 	idr_destroy(&idrinfo->action_idr);
885 }
886 EXPORT_SYMBOL(tcf_idrinfo_destroy);
887 
888 static LIST_HEAD(act_base);
889 static DEFINE_RWLOCK(act_mod_lock);
890 /* since act ops id is stored in pernet subsystem list,
891  * then there is no way to walk through only all the action
892  * subsystem, so we keep tc action pernet ops id for
893  * reoffload to walk through.
894  */
895 static LIST_HEAD(act_pernet_id_list);
896 static DEFINE_MUTEX(act_id_mutex);
897 struct tc_act_pernet_id {
898 	struct list_head list;
899 	unsigned int id;
900 };
901 
902 static int tcf_pernet_add_id_list(unsigned int id)
903 {
904 	struct tc_act_pernet_id *id_ptr;
905 	int ret = 0;
906 
907 	mutex_lock(&act_id_mutex);
908 	list_for_each_entry(id_ptr, &act_pernet_id_list, list) {
909 		if (id_ptr->id == id) {
910 			ret = -EEXIST;
911 			goto err_out;
912 		}
913 	}
914 
915 	id_ptr = kzalloc(sizeof(*id_ptr), GFP_KERNEL);
916 	if (!id_ptr) {
917 		ret = -ENOMEM;
918 		goto err_out;
919 	}
920 	id_ptr->id = id;
921 
922 	list_add_tail(&id_ptr->list, &act_pernet_id_list);
923 
924 err_out:
925 	mutex_unlock(&act_id_mutex);
926 	return ret;
927 }
928 
929 static void tcf_pernet_del_id_list(unsigned int id)
930 {
931 	struct tc_act_pernet_id *id_ptr;
932 
933 	mutex_lock(&act_id_mutex);
934 	list_for_each_entry(id_ptr, &act_pernet_id_list, list) {
935 		if (id_ptr->id == id) {
936 			list_del(&id_ptr->list);
937 			kfree(id_ptr);
938 			break;
939 		}
940 	}
941 	mutex_unlock(&act_id_mutex);
942 }
943 
944 int tcf_register_action(struct tc_action_ops *act,
945 			struct pernet_operations *ops)
946 {
947 	struct tc_action_ops *a;
948 	int ret;
949 
950 	if (!act->act || !act->dump || !act->init)
951 		return -EINVAL;
952 
953 	/* We have to register pernet ops before making the action ops visible,
954 	 * otherwise tcf_action_init_1() could get a partially initialized
955 	 * netns.
956 	 */
957 	ret = register_pernet_subsys(ops);
958 	if (ret)
959 		return ret;
960 
961 	if (ops->id) {
962 		ret = tcf_pernet_add_id_list(*ops->id);
963 		if (ret)
964 			goto err_id;
965 	}
966 
967 	write_lock(&act_mod_lock);
968 	list_for_each_entry(a, &act_base, head) {
969 		if (act->id == a->id || (strcmp(act->kind, a->kind) == 0)) {
970 			ret = -EEXIST;
971 			goto err_out;
972 		}
973 	}
974 	list_add_tail(&act->head, &act_base);
975 	write_unlock(&act_mod_lock);
976 
977 	return 0;
978 
979 err_out:
980 	write_unlock(&act_mod_lock);
981 	if (ops->id)
982 		tcf_pernet_del_id_list(*ops->id);
983 err_id:
984 	unregister_pernet_subsys(ops);
985 	return ret;
986 }
987 EXPORT_SYMBOL(tcf_register_action);
988 
989 int tcf_unregister_action(struct tc_action_ops *act,
990 			  struct pernet_operations *ops)
991 {
992 	struct tc_action_ops *a;
993 	int err = -ENOENT;
994 
995 	write_lock(&act_mod_lock);
996 	list_for_each_entry(a, &act_base, head) {
997 		if (a == act) {
998 			list_del(&act->head);
999 			err = 0;
1000 			break;
1001 		}
1002 	}
1003 	write_unlock(&act_mod_lock);
1004 	if (!err) {
1005 		unregister_pernet_subsys(ops);
1006 		if (ops->id)
1007 			tcf_pernet_del_id_list(*ops->id);
1008 	}
1009 	return err;
1010 }
1011 EXPORT_SYMBOL(tcf_unregister_action);
1012 
1013 /* lookup by name */
1014 static struct tc_action_ops *tc_lookup_action_n(char *kind)
1015 {
1016 	struct tc_action_ops *a, *res = NULL;
1017 
1018 	if (kind) {
1019 		read_lock(&act_mod_lock);
1020 		list_for_each_entry(a, &act_base, head) {
1021 			if (strcmp(kind, a->kind) == 0) {
1022 				if (try_module_get(a->owner))
1023 					res = a;
1024 				break;
1025 			}
1026 		}
1027 		read_unlock(&act_mod_lock);
1028 	}
1029 	return res;
1030 }
1031 
1032 /* lookup by nlattr */
1033 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
1034 {
1035 	struct tc_action_ops *a, *res = NULL;
1036 
1037 	if (kind) {
1038 		read_lock(&act_mod_lock);
1039 		list_for_each_entry(a, &act_base, head) {
1040 			if (nla_strcmp(kind, a->kind) == 0) {
1041 				if (try_module_get(a->owner))
1042 					res = a;
1043 				break;
1044 			}
1045 		}
1046 		read_unlock(&act_mod_lock);
1047 	}
1048 	return res;
1049 }
1050 
1051 /*TCA_ACT_MAX_PRIO is 32, there count up to 32 */
1052 #define TCA_ACT_MAX_PRIO_MASK 0x1FF
1053 int tcf_action_exec(struct sk_buff *skb, struct tc_action **actions,
1054 		    int nr_actions, struct tcf_result *res)
1055 {
1056 	u32 jmp_prgcnt = 0;
1057 	u32 jmp_ttl = TCA_ACT_MAX_PRIO; /*matches actions per filter */
1058 	int i;
1059 	int ret = TC_ACT_OK;
1060 
1061 	if (skb_skip_tc_classify(skb))
1062 		return TC_ACT_OK;
1063 
1064 restart_act_graph:
1065 	for (i = 0; i < nr_actions; i++) {
1066 		const struct tc_action *a = actions[i];
1067 		int repeat_ttl;
1068 
1069 		if (jmp_prgcnt > 0) {
1070 			jmp_prgcnt -= 1;
1071 			continue;
1072 		}
1073 
1074 		if (tc_act_skip_sw(a->tcfa_flags))
1075 			continue;
1076 
1077 		repeat_ttl = 32;
1078 repeat:
1079 		ret = tc_act(skb, a, res);
1080 		if (unlikely(ret == TC_ACT_REPEAT)) {
1081 			if (--repeat_ttl != 0)
1082 				goto repeat;
1083 			/* suspicious opcode, stop pipeline */
1084 			net_warn_ratelimited("TC_ACT_REPEAT abuse ?\n");
1085 			return TC_ACT_OK;
1086 		}
1087 		if (TC_ACT_EXT_CMP(ret, TC_ACT_JUMP)) {
1088 			jmp_prgcnt = ret & TCA_ACT_MAX_PRIO_MASK;
1089 			if (!jmp_prgcnt || (jmp_prgcnt > nr_actions)) {
1090 				/* faulty opcode, stop pipeline */
1091 				return TC_ACT_OK;
1092 			} else {
1093 				jmp_ttl -= 1;
1094 				if (jmp_ttl > 0)
1095 					goto restart_act_graph;
1096 				else /* faulty graph, stop pipeline */
1097 					return TC_ACT_OK;
1098 			}
1099 		} else if (TC_ACT_EXT_CMP(ret, TC_ACT_GOTO_CHAIN)) {
1100 			if (unlikely(!rcu_access_pointer(a->goto_chain))) {
1101 				net_warn_ratelimited("can't go to NULL chain!\n");
1102 				return TC_ACT_SHOT;
1103 			}
1104 			tcf_action_goto_chain_exec(a, res);
1105 		}
1106 
1107 		if (ret != TC_ACT_PIPE)
1108 			break;
1109 	}
1110 
1111 	return ret;
1112 }
1113 EXPORT_SYMBOL(tcf_action_exec);
1114 
1115 int tcf_action_destroy(struct tc_action *actions[], int bind)
1116 {
1117 	const struct tc_action_ops *ops;
1118 	struct tc_action *a;
1119 	int ret = 0, i;
1120 
1121 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1122 		a = actions[i];
1123 		actions[i] = NULL;
1124 		ops = a->ops;
1125 		ret = __tcf_idr_release(a, bind, true);
1126 		if (ret == ACT_P_DELETED)
1127 			module_put(ops->owner);
1128 		else if (ret < 0)
1129 			return ret;
1130 	}
1131 	return ret;
1132 }
1133 
1134 static int tcf_action_put(struct tc_action *p)
1135 {
1136 	return __tcf_action_put(p, false);
1137 }
1138 
1139 /* Put all actions in this array, skip those NULL's. */
1140 static void tcf_action_put_many(struct tc_action *actions[])
1141 {
1142 	int i;
1143 
1144 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1145 		struct tc_action *a = actions[i];
1146 		const struct tc_action_ops *ops;
1147 
1148 		if (!a)
1149 			continue;
1150 		ops = a->ops;
1151 		if (tcf_action_put(a))
1152 			module_put(ops->owner);
1153 	}
1154 }
1155 
1156 int
1157 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
1158 {
1159 	return a->ops->dump(skb, a, bind, ref);
1160 }
1161 
1162 int
1163 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
1164 {
1165 	int err = -EINVAL;
1166 	unsigned char *b = skb_tail_pointer(skb);
1167 	struct nlattr *nest;
1168 	u32 flags;
1169 
1170 	if (tcf_action_dump_terse(skb, a, false))
1171 		goto nla_put_failure;
1172 
1173 	if (a->hw_stats != TCA_ACT_HW_STATS_ANY &&
1174 	    nla_put_bitfield32(skb, TCA_ACT_HW_STATS,
1175 			       a->hw_stats, TCA_ACT_HW_STATS_ANY))
1176 		goto nla_put_failure;
1177 
1178 	if (a->used_hw_stats_valid &&
1179 	    nla_put_bitfield32(skb, TCA_ACT_USED_HW_STATS,
1180 			       a->used_hw_stats, TCA_ACT_HW_STATS_ANY))
1181 		goto nla_put_failure;
1182 
1183 	flags = a->tcfa_flags & TCA_ACT_FLAGS_USER_MASK;
1184 	if (flags &&
1185 	    nla_put_bitfield32(skb, TCA_ACT_FLAGS,
1186 			       flags, flags))
1187 		goto nla_put_failure;
1188 
1189 	if (nla_put_u32(skb, TCA_ACT_IN_HW_COUNT, a->in_hw_count))
1190 		goto nla_put_failure;
1191 
1192 	nest = nla_nest_start_noflag(skb, TCA_ACT_OPTIONS);
1193 	if (nest == NULL)
1194 		goto nla_put_failure;
1195 	err = tcf_action_dump_old(skb, a, bind, ref);
1196 	if (err > 0) {
1197 		nla_nest_end(skb, nest);
1198 		return err;
1199 	}
1200 
1201 nla_put_failure:
1202 	nlmsg_trim(skb, b);
1203 	return -1;
1204 }
1205 EXPORT_SYMBOL(tcf_action_dump_1);
1206 
1207 int tcf_action_dump(struct sk_buff *skb, struct tc_action *actions[],
1208 		    int bind, int ref, bool terse)
1209 {
1210 	struct tc_action *a;
1211 	int err = -EINVAL, i;
1212 	struct nlattr *nest;
1213 
1214 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1215 		a = actions[i];
1216 		nest = nla_nest_start_noflag(skb, i + 1);
1217 		if (nest == NULL)
1218 			goto nla_put_failure;
1219 		err = terse ? tcf_action_dump_terse(skb, a, false) :
1220 			tcf_action_dump_1(skb, a, bind, ref);
1221 		if (err < 0)
1222 			goto errout;
1223 		nla_nest_end(skb, nest);
1224 	}
1225 
1226 	return 0;
1227 
1228 nla_put_failure:
1229 	err = -EINVAL;
1230 errout:
1231 	nla_nest_cancel(skb, nest);
1232 	return err;
1233 }
1234 
1235 static struct tc_cookie *nla_memdup_cookie(struct nlattr **tb)
1236 {
1237 	struct tc_cookie *c = kzalloc(sizeof(*c), GFP_KERNEL);
1238 	if (!c)
1239 		return NULL;
1240 
1241 	c->data = nla_memdup(tb[TCA_ACT_COOKIE], GFP_KERNEL);
1242 	if (!c->data) {
1243 		kfree(c);
1244 		return NULL;
1245 	}
1246 	c->len = nla_len(tb[TCA_ACT_COOKIE]);
1247 
1248 	return c;
1249 }
1250 
1251 static u8 tcf_action_hw_stats_get(struct nlattr *hw_stats_attr)
1252 {
1253 	struct nla_bitfield32 hw_stats_bf;
1254 
1255 	/* If the user did not pass the attr, that means he does
1256 	 * not care about the type. Return "any" in that case
1257 	 * which is setting on all supported types.
1258 	 */
1259 	if (!hw_stats_attr)
1260 		return TCA_ACT_HW_STATS_ANY;
1261 	hw_stats_bf = nla_get_bitfield32(hw_stats_attr);
1262 	return hw_stats_bf.value;
1263 }
1264 
1265 static const struct nla_policy tcf_action_policy[TCA_ACT_MAX + 1] = {
1266 	[TCA_ACT_KIND]		= { .type = NLA_STRING },
1267 	[TCA_ACT_INDEX]		= { .type = NLA_U32 },
1268 	[TCA_ACT_COOKIE]	= { .type = NLA_BINARY,
1269 				    .len = TC_COOKIE_MAX_SIZE },
1270 	[TCA_ACT_OPTIONS]	= { .type = NLA_NESTED },
1271 	[TCA_ACT_FLAGS]		= NLA_POLICY_BITFIELD32(TCA_ACT_FLAGS_NO_PERCPU_STATS |
1272 							TCA_ACT_FLAGS_SKIP_HW |
1273 							TCA_ACT_FLAGS_SKIP_SW),
1274 	[TCA_ACT_HW_STATS]	= NLA_POLICY_BITFIELD32(TCA_ACT_HW_STATS_ANY),
1275 };
1276 
1277 void tcf_idr_insert_many(struct tc_action *actions[])
1278 {
1279 	int i;
1280 
1281 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1282 		struct tc_action *a = actions[i];
1283 		struct tcf_idrinfo *idrinfo;
1284 
1285 		if (!a)
1286 			continue;
1287 		idrinfo = a->idrinfo;
1288 		mutex_lock(&idrinfo->lock);
1289 		/* Replace ERR_PTR(-EBUSY) allocated by tcf_idr_check_alloc if
1290 		 * it is just created, otherwise this is just a nop.
1291 		 */
1292 		idr_replace(&idrinfo->action_idr, a, a->tcfa_index);
1293 		mutex_unlock(&idrinfo->lock);
1294 	}
1295 }
1296 
1297 struct tc_action_ops *tc_action_load_ops(struct nlattr *nla, bool police,
1298 					 bool rtnl_held,
1299 					 struct netlink_ext_ack *extack)
1300 {
1301 	struct nlattr *tb[TCA_ACT_MAX + 1];
1302 	struct tc_action_ops *a_o;
1303 	char act_name[IFNAMSIZ];
1304 	struct nlattr *kind;
1305 	int err;
1306 
1307 	if (!police) {
1308 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1309 						  tcf_action_policy, extack);
1310 		if (err < 0)
1311 			return ERR_PTR(err);
1312 		err = -EINVAL;
1313 		kind = tb[TCA_ACT_KIND];
1314 		if (!kind) {
1315 			NL_SET_ERR_MSG(extack, "TC action kind must be specified");
1316 			return ERR_PTR(err);
1317 		}
1318 		if (nla_strscpy(act_name, kind, IFNAMSIZ) < 0) {
1319 			NL_SET_ERR_MSG(extack, "TC action name too long");
1320 			return ERR_PTR(err);
1321 		}
1322 	} else {
1323 		if (strscpy(act_name, "police", IFNAMSIZ) < 0) {
1324 			NL_SET_ERR_MSG(extack, "TC action name too long");
1325 			return ERR_PTR(-EINVAL);
1326 		}
1327 	}
1328 
1329 	a_o = tc_lookup_action_n(act_name);
1330 	if (a_o == NULL) {
1331 #ifdef CONFIG_MODULES
1332 		if (rtnl_held)
1333 			rtnl_unlock();
1334 		request_module("act_%s", act_name);
1335 		if (rtnl_held)
1336 			rtnl_lock();
1337 
1338 		a_o = tc_lookup_action_n(act_name);
1339 
1340 		/* We dropped the RTNL semaphore in order to
1341 		 * perform the module load.  So, even if we
1342 		 * succeeded in loading the module we have to
1343 		 * tell the caller to replay the request.  We
1344 		 * indicate this using -EAGAIN.
1345 		 */
1346 		if (a_o != NULL) {
1347 			module_put(a_o->owner);
1348 			return ERR_PTR(-EAGAIN);
1349 		}
1350 #endif
1351 		NL_SET_ERR_MSG(extack, "Failed to load TC action module");
1352 		return ERR_PTR(-ENOENT);
1353 	}
1354 
1355 	return a_o;
1356 }
1357 
1358 struct tc_action *tcf_action_init_1(struct net *net, struct tcf_proto *tp,
1359 				    struct nlattr *nla, struct nlattr *est,
1360 				    struct tc_action_ops *a_o, int *init_res,
1361 				    u32 flags, struct netlink_ext_ack *extack)
1362 {
1363 	bool police = flags & TCA_ACT_FLAGS_POLICE;
1364 	struct nla_bitfield32 userflags = { 0, 0 };
1365 	struct tc_cookie *user_cookie = NULL;
1366 	u8 hw_stats = TCA_ACT_HW_STATS_ANY;
1367 	struct nlattr *tb[TCA_ACT_MAX + 1];
1368 	struct tc_action *a;
1369 	int err;
1370 
1371 	/* backward compatibility for policer */
1372 	if (!police) {
1373 		err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1374 						  tcf_action_policy, extack);
1375 		if (err < 0)
1376 			return ERR_PTR(err);
1377 		if (tb[TCA_ACT_COOKIE]) {
1378 			user_cookie = nla_memdup_cookie(tb);
1379 			if (!user_cookie) {
1380 				NL_SET_ERR_MSG(extack, "No memory to generate TC cookie");
1381 				err = -ENOMEM;
1382 				goto err_out;
1383 			}
1384 		}
1385 		hw_stats = tcf_action_hw_stats_get(tb[TCA_ACT_HW_STATS]);
1386 		if (tb[TCA_ACT_FLAGS]) {
1387 			userflags = nla_get_bitfield32(tb[TCA_ACT_FLAGS]);
1388 			if (!tc_act_flags_valid(userflags.value)) {
1389 				err = -EINVAL;
1390 				goto err_out;
1391 			}
1392 		}
1393 
1394 		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, &a, tp,
1395 				userflags.value | flags, extack);
1396 	} else {
1397 		err = a_o->init(net, nla, est, &a, tp, userflags.value | flags,
1398 				extack);
1399 	}
1400 	if (err < 0)
1401 		goto err_out;
1402 	*init_res = err;
1403 
1404 	if (!police && tb[TCA_ACT_COOKIE])
1405 		tcf_set_action_cookie(&a->user_cookie, user_cookie);
1406 
1407 	if (!police)
1408 		a->hw_stats = hw_stats;
1409 
1410 	return a;
1411 
1412 err_out:
1413 	if (user_cookie) {
1414 		kfree(user_cookie->data);
1415 		kfree(user_cookie);
1416 	}
1417 	return ERR_PTR(err);
1418 }
1419 
1420 static bool tc_act_bind(u32 flags)
1421 {
1422 	return !!(flags & TCA_ACT_FLAGS_BIND);
1423 }
1424 
1425 /* Returns numbers of initialized actions or negative error. */
1426 
1427 int tcf_action_init(struct net *net, struct tcf_proto *tp, struct nlattr *nla,
1428 		    struct nlattr *est, struct tc_action *actions[],
1429 		    int init_res[], size_t *attr_size,
1430 		    u32 flags, u32 fl_flags,
1431 		    struct netlink_ext_ack *extack)
1432 {
1433 	struct tc_action_ops *ops[TCA_ACT_MAX_PRIO] = {};
1434 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1435 	struct tc_action *act;
1436 	size_t sz = 0;
1437 	int err;
1438 	int i;
1439 
1440 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1441 					  extack);
1442 	if (err < 0)
1443 		return err;
1444 
1445 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1446 		struct tc_action_ops *a_o;
1447 
1448 		a_o = tc_action_load_ops(tb[i], flags & TCA_ACT_FLAGS_POLICE,
1449 					 !(flags & TCA_ACT_FLAGS_NO_RTNL),
1450 					 extack);
1451 		if (IS_ERR(a_o)) {
1452 			err = PTR_ERR(a_o);
1453 			goto err_mod;
1454 		}
1455 		ops[i - 1] = a_o;
1456 	}
1457 
1458 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1459 		act = tcf_action_init_1(net, tp, tb[i], est, ops[i - 1],
1460 					&init_res[i - 1], flags, extack);
1461 		if (IS_ERR(act)) {
1462 			err = PTR_ERR(act);
1463 			goto err;
1464 		}
1465 		sz += tcf_action_fill_size(act);
1466 		/* Start from index 0 */
1467 		actions[i - 1] = act;
1468 		if (tc_act_bind(flags)) {
1469 			bool skip_sw = tc_skip_sw(fl_flags);
1470 			bool skip_hw = tc_skip_hw(fl_flags);
1471 
1472 			if (tc_act_bind(act->tcfa_flags))
1473 				continue;
1474 			if (skip_sw != tc_act_skip_sw(act->tcfa_flags) ||
1475 			    skip_hw != tc_act_skip_hw(act->tcfa_flags)) {
1476 				NL_SET_ERR_MSG(extack,
1477 					       "Mismatch between action and filter offload flags");
1478 				err = -EINVAL;
1479 				goto err;
1480 			}
1481 		} else {
1482 			err = tcf_action_offload_add(act, extack);
1483 			if (tc_act_skip_sw(act->tcfa_flags) && err)
1484 				goto err;
1485 		}
1486 	}
1487 
1488 	/* We have to commit them all together, because if any error happened in
1489 	 * between, we could not handle the failure gracefully.
1490 	 */
1491 	tcf_idr_insert_many(actions);
1492 
1493 	*attr_size = tcf_action_full_attrs_size(sz);
1494 	err = i - 1;
1495 	goto err_mod;
1496 
1497 err:
1498 	tcf_action_destroy(actions, flags & TCA_ACT_FLAGS_BIND);
1499 err_mod:
1500 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++) {
1501 		if (ops[i])
1502 			module_put(ops[i]->owner);
1503 	}
1504 	return err;
1505 }
1506 
1507 void tcf_action_update_stats(struct tc_action *a, u64 bytes, u64 packets,
1508 			     u64 drops, bool hw)
1509 {
1510 	if (a->cpu_bstats) {
1511 		_bstats_update(this_cpu_ptr(a->cpu_bstats), bytes, packets);
1512 
1513 		this_cpu_ptr(a->cpu_qstats)->drops += drops;
1514 
1515 		if (hw)
1516 			_bstats_update(this_cpu_ptr(a->cpu_bstats_hw),
1517 				       bytes, packets);
1518 		return;
1519 	}
1520 
1521 	_bstats_update(&a->tcfa_bstats, bytes, packets);
1522 	a->tcfa_qstats.drops += drops;
1523 	if (hw)
1524 		_bstats_update(&a->tcfa_bstats_hw, bytes, packets);
1525 }
1526 EXPORT_SYMBOL(tcf_action_update_stats);
1527 
1528 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *p,
1529 			  int compat_mode)
1530 {
1531 	int err = 0;
1532 	struct gnet_dump d;
1533 
1534 	if (p == NULL)
1535 		goto errout;
1536 
1537 	/* compat_mode being true specifies a call that is supposed
1538 	 * to add additional backward compatibility statistic TLVs.
1539 	 */
1540 	if (compat_mode) {
1541 		if (p->type == TCA_OLD_COMPAT)
1542 			err = gnet_stats_start_copy_compat(skb, 0,
1543 							   TCA_STATS,
1544 							   TCA_XSTATS,
1545 							   &p->tcfa_lock, &d,
1546 							   TCA_PAD);
1547 		else
1548 			return 0;
1549 	} else
1550 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
1551 					    &p->tcfa_lock, &d, TCA_ACT_PAD);
1552 
1553 	if (err < 0)
1554 		goto errout;
1555 
1556 	if (gnet_stats_copy_basic(&d, p->cpu_bstats,
1557 				  &p->tcfa_bstats, false) < 0 ||
1558 	    gnet_stats_copy_basic_hw(&d, p->cpu_bstats_hw,
1559 				     &p->tcfa_bstats_hw, false) < 0 ||
1560 	    gnet_stats_copy_rate_est(&d, &p->tcfa_rate_est) < 0 ||
1561 	    gnet_stats_copy_queue(&d, p->cpu_qstats,
1562 				  &p->tcfa_qstats,
1563 				  p->tcfa_qstats.qlen) < 0)
1564 		goto errout;
1565 
1566 	if (gnet_stats_finish_copy(&d) < 0)
1567 		goto errout;
1568 
1569 	return 0;
1570 
1571 errout:
1572 	return -1;
1573 }
1574 
1575 static int tca_get_fill(struct sk_buff *skb, struct tc_action *actions[],
1576 			u32 portid, u32 seq, u16 flags, int event, int bind,
1577 			int ref, struct netlink_ext_ack *extack)
1578 {
1579 	struct tcamsg *t;
1580 	struct nlmsghdr *nlh;
1581 	unsigned char *b = skb_tail_pointer(skb);
1582 	struct nlattr *nest;
1583 
1584 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
1585 	if (!nlh)
1586 		goto out_nlmsg_trim;
1587 	t = nlmsg_data(nlh);
1588 	t->tca_family = AF_UNSPEC;
1589 	t->tca__pad1 = 0;
1590 	t->tca__pad2 = 0;
1591 
1592 	if (extack && extack->_msg &&
1593 	    nla_put_string(skb, TCA_ROOT_EXT_WARN_MSG, extack->_msg))
1594 		goto out_nlmsg_trim;
1595 
1596 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1597 	if (!nest)
1598 		goto out_nlmsg_trim;
1599 
1600 	if (tcf_action_dump(skb, actions, bind, ref, false) < 0)
1601 		goto out_nlmsg_trim;
1602 
1603 	nla_nest_end(skb, nest);
1604 
1605 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1606 
1607 	return skb->len;
1608 
1609 out_nlmsg_trim:
1610 	nlmsg_trim(skb, b);
1611 	return -1;
1612 }
1613 
1614 static int
1615 tcf_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
1616 	       struct tc_action *actions[], int event,
1617 	       struct netlink_ext_ack *extack)
1618 {
1619 	struct sk_buff *skb;
1620 
1621 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1622 	if (!skb)
1623 		return -ENOBUFS;
1624 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event,
1625 			 0, 1, NULL) <= 0) {
1626 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1627 		kfree_skb(skb);
1628 		return -EINVAL;
1629 	}
1630 
1631 	return rtnl_unicast(skb, net, portid);
1632 }
1633 
1634 static struct tc_action *tcf_action_get_1(struct net *net, struct nlattr *nla,
1635 					  struct nlmsghdr *n, u32 portid,
1636 					  struct netlink_ext_ack *extack)
1637 {
1638 	struct nlattr *tb[TCA_ACT_MAX + 1];
1639 	const struct tc_action_ops *ops;
1640 	struct tc_action *a;
1641 	int index;
1642 	int err;
1643 
1644 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1645 					  tcf_action_policy, extack);
1646 	if (err < 0)
1647 		goto err_out;
1648 
1649 	err = -EINVAL;
1650 	if (tb[TCA_ACT_INDEX] == NULL ||
1651 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index)) {
1652 		NL_SET_ERR_MSG(extack, "Invalid TC action index value");
1653 		goto err_out;
1654 	}
1655 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
1656 
1657 	err = -EINVAL;
1658 	ops = tc_lookup_action(tb[TCA_ACT_KIND]);
1659 	if (!ops) { /* could happen in batch of actions */
1660 		NL_SET_ERR_MSG(extack, "Specified TC action kind not found");
1661 		goto err_out;
1662 	}
1663 	err = -ENOENT;
1664 	if (__tcf_idr_search(net, ops, &a, index) == 0) {
1665 		NL_SET_ERR_MSG(extack, "TC action with specified index not found");
1666 		goto err_mod;
1667 	}
1668 
1669 	module_put(ops->owner);
1670 	return a;
1671 
1672 err_mod:
1673 	module_put(ops->owner);
1674 err_out:
1675 	return ERR_PTR(err);
1676 }
1677 
1678 static int tca_action_flush(struct net *net, struct nlattr *nla,
1679 			    struct nlmsghdr *n, u32 portid,
1680 			    struct netlink_ext_ack *extack)
1681 {
1682 	struct sk_buff *skb;
1683 	unsigned char *b;
1684 	struct nlmsghdr *nlh;
1685 	struct tcamsg *t;
1686 	struct netlink_callback dcb;
1687 	struct nlattr *nest;
1688 	struct nlattr *tb[TCA_ACT_MAX + 1];
1689 	const struct tc_action_ops *ops;
1690 	struct nlattr *kind;
1691 	int err = -ENOMEM;
1692 
1693 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
1694 	if (!skb)
1695 		return err;
1696 
1697 	b = skb_tail_pointer(skb);
1698 
1699 	err = nla_parse_nested_deprecated(tb, TCA_ACT_MAX, nla,
1700 					  tcf_action_policy, extack);
1701 	if (err < 0)
1702 		goto err_out;
1703 
1704 	err = -EINVAL;
1705 	kind = tb[TCA_ACT_KIND];
1706 	ops = tc_lookup_action(kind);
1707 	if (!ops) { /*some idjot trying to flush unknown action */
1708 		NL_SET_ERR_MSG(extack, "Cannot flush unknown TC action");
1709 		goto err_out;
1710 	}
1711 
1712 	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION,
1713 			sizeof(*t), 0);
1714 	if (!nlh) {
1715 		NL_SET_ERR_MSG(extack, "Failed to create TC action flush notification");
1716 		goto out_module_put;
1717 	}
1718 	t = nlmsg_data(nlh);
1719 	t->tca_family = AF_UNSPEC;
1720 	t->tca__pad1 = 0;
1721 	t->tca__pad2 = 0;
1722 
1723 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
1724 	if (!nest) {
1725 		NL_SET_ERR_MSG(extack, "Failed to add new netlink message");
1726 		goto out_module_put;
1727 	}
1728 
1729 	err = __tcf_generic_walker(net, skb, &dcb, RTM_DELACTION, ops, extack);
1730 	if (err <= 0) {
1731 		nla_nest_cancel(skb, nest);
1732 		goto out_module_put;
1733 	}
1734 
1735 	nla_nest_end(skb, nest);
1736 
1737 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1738 	nlh->nlmsg_flags |= NLM_F_ROOT;
1739 	module_put(ops->owner);
1740 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1741 			     n->nlmsg_flags & NLM_F_ECHO);
1742 	if (err < 0)
1743 		NL_SET_ERR_MSG(extack, "Failed to send TC action flush notification");
1744 
1745 	return err;
1746 
1747 out_module_put:
1748 	module_put(ops->owner);
1749 err_out:
1750 	kfree_skb(skb);
1751 	return err;
1752 }
1753 
1754 static int tcf_action_delete(struct net *net, struct tc_action *actions[])
1755 {
1756 	int i;
1757 
1758 	for (i = 0; i < TCA_ACT_MAX_PRIO && actions[i]; i++) {
1759 		struct tc_action *a = actions[i];
1760 		const struct tc_action_ops *ops = a->ops;
1761 		/* Actions can be deleted concurrently so we must save their
1762 		 * type and id to search again after reference is released.
1763 		 */
1764 		struct tcf_idrinfo *idrinfo = a->idrinfo;
1765 		u32 act_index = a->tcfa_index;
1766 
1767 		actions[i] = NULL;
1768 		if (tcf_action_put(a)) {
1769 			/* last reference, action was deleted concurrently */
1770 			module_put(ops->owner);
1771 		} else  {
1772 			int ret;
1773 
1774 			/* now do the delete */
1775 			ret = tcf_idr_delete_index(idrinfo, act_index);
1776 			if (ret < 0)
1777 				return ret;
1778 		}
1779 	}
1780 	return 0;
1781 }
1782 
1783 static int
1784 tcf_reoffload_del_notify(struct net *net, struct tc_action *action)
1785 {
1786 	size_t attr_size = tcf_action_fill_size(action);
1787 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {
1788 		[0] = action,
1789 	};
1790 	const struct tc_action_ops *ops = action->ops;
1791 	struct sk_buff *skb;
1792 	int ret;
1793 
1794 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1795 			GFP_KERNEL);
1796 	if (!skb)
1797 		return -ENOBUFS;
1798 
1799 	if (tca_get_fill(skb, actions, 0, 0, 0, RTM_DELACTION, 0, 1, NULL) <= 0) {
1800 		kfree_skb(skb);
1801 		return -EINVAL;
1802 	}
1803 
1804 	ret = tcf_idr_release_unsafe(action);
1805 	if (ret == ACT_P_DELETED) {
1806 		module_put(ops->owner);
1807 		ret = rtnetlink_send(skb, net, 0, RTNLGRP_TC, 0);
1808 	} else {
1809 		kfree_skb(skb);
1810 	}
1811 
1812 	return ret;
1813 }
1814 
1815 int tcf_action_reoffload_cb(flow_indr_block_bind_cb_t *cb,
1816 			    void *cb_priv, bool add)
1817 {
1818 	struct tc_act_pernet_id *id_ptr;
1819 	struct tcf_idrinfo *idrinfo;
1820 	struct tc_action_net *tn;
1821 	struct tc_action *p;
1822 	unsigned int act_id;
1823 	unsigned long tmp;
1824 	unsigned long id;
1825 	struct idr *idr;
1826 	struct net *net;
1827 	int ret;
1828 
1829 	if (!cb)
1830 		return -EINVAL;
1831 
1832 	down_read(&net_rwsem);
1833 	mutex_lock(&act_id_mutex);
1834 
1835 	for_each_net(net) {
1836 		list_for_each_entry(id_ptr, &act_pernet_id_list, list) {
1837 			act_id = id_ptr->id;
1838 			tn = net_generic(net, act_id);
1839 			if (!tn)
1840 				continue;
1841 			idrinfo = tn->idrinfo;
1842 			if (!idrinfo)
1843 				continue;
1844 
1845 			mutex_lock(&idrinfo->lock);
1846 			idr = &idrinfo->action_idr;
1847 			idr_for_each_entry_ul(idr, p, tmp, id) {
1848 				if (IS_ERR(p) || tc_act_bind(p->tcfa_flags))
1849 					continue;
1850 				if (add) {
1851 					tcf_action_offload_add_ex(p, NULL, cb,
1852 								  cb_priv);
1853 					continue;
1854 				}
1855 
1856 				/* cb unregister to update hw count */
1857 				ret = tcf_action_offload_del_ex(p, cb, cb_priv);
1858 				if (ret < 0)
1859 					continue;
1860 				if (tc_act_skip_sw(p->tcfa_flags) &&
1861 				    !tc_act_in_hw(p))
1862 					tcf_reoffload_del_notify(net, p);
1863 			}
1864 			mutex_unlock(&idrinfo->lock);
1865 		}
1866 	}
1867 	mutex_unlock(&act_id_mutex);
1868 	up_read(&net_rwsem);
1869 
1870 	return 0;
1871 }
1872 
1873 static int
1874 tcf_del_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1875 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1876 {
1877 	int ret;
1878 	struct sk_buff *skb;
1879 
1880 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1881 			GFP_KERNEL);
1882 	if (!skb)
1883 		return -ENOBUFS;
1884 
1885 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, RTM_DELACTION,
1886 			 0, 2, extack) <= 0) {
1887 		NL_SET_ERR_MSG(extack, "Failed to fill netlink TC action attributes");
1888 		kfree_skb(skb);
1889 		return -EINVAL;
1890 	}
1891 
1892 	/* now do the delete */
1893 	ret = tcf_action_delete(net, actions);
1894 	if (ret < 0) {
1895 		NL_SET_ERR_MSG(extack, "Failed to delete TC action");
1896 		kfree_skb(skb);
1897 		return ret;
1898 	}
1899 
1900 	ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1901 			     n->nlmsg_flags & NLM_F_ECHO);
1902 	return ret;
1903 }
1904 
1905 static int
1906 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
1907 	      u32 portid, int event, struct netlink_ext_ack *extack)
1908 {
1909 	int i, ret;
1910 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1911 	struct tc_action *act;
1912 	size_t attr_size = 0;
1913 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1914 
1915 	ret = nla_parse_nested_deprecated(tb, TCA_ACT_MAX_PRIO, nla, NULL,
1916 					  extack);
1917 	if (ret < 0)
1918 		return ret;
1919 
1920 	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
1921 		if (tb[1])
1922 			return tca_action_flush(net, tb[1], n, portid, extack);
1923 
1924 		NL_SET_ERR_MSG(extack, "Invalid netlink attributes while flushing TC action");
1925 		return -EINVAL;
1926 	}
1927 
1928 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
1929 		act = tcf_action_get_1(net, tb[i], n, portid, extack);
1930 		if (IS_ERR(act)) {
1931 			ret = PTR_ERR(act);
1932 			goto err;
1933 		}
1934 		attr_size += tcf_action_fill_size(act);
1935 		actions[i - 1] = act;
1936 	}
1937 
1938 	attr_size = tcf_action_full_attrs_size(attr_size);
1939 
1940 	if (event == RTM_GETACTION)
1941 		ret = tcf_get_notify(net, portid, n, actions, event, extack);
1942 	else { /* delete */
1943 		ret = tcf_del_notify(net, n, actions, portid, attr_size, extack);
1944 		if (ret)
1945 			goto err;
1946 		return 0;
1947 	}
1948 err:
1949 	tcf_action_put_many(actions);
1950 	return ret;
1951 }
1952 
1953 static int
1954 tcf_add_notify(struct net *net, struct nlmsghdr *n, struct tc_action *actions[],
1955 	       u32 portid, size_t attr_size, struct netlink_ext_ack *extack)
1956 {
1957 	struct sk_buff *skb;
1958 
1959 	skb = alloc_skb(attr_size <= NLMSG_GOODSIZE ? NLMSG_GOODSIZE : attr_size,
1960 			GFP_KERNEL);
1961 	if (!skb)
1962 		return -ENOBUFS;
1963 
1964 	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, n->nlmsg_flags,
1965 			 RTM_NEWACTION, 0, 0, extack) <= 0) {
1966 		NL_SET_ERR_MSG(extack, "Failed to fill netlink attributes while adding TC action");
1967 		kfree_skb(skb);
1968 		return -EINVAL;
1969 	}
1970 
1971 	return rtnetlink_send(skb, net, portid, RTNLGRP_TC,
1972 			      n->nlmsg_flags & NLM_F_ECHO);
1973 }
1974 
1975 static int tcf_action_add(struct net *net, struct nlattr *nla,
1976 			  struct nlmsghdr *n, u32 portid, u32 flags,
1977 			  struct netlink_ext_ack *extack)
1978 {
1979 	size_t attr_size = 0;
1980 	int loop, ret, i;
1981 	struct tc_action *actions[TCA_ACT_MAX_PRIO] = {};
1982 	int init_res[TCA_ACT_MAX_PRIO] = {};
1983 
1984 	for (loop = 0; loop < 10; loop++) {
1985 		ret = tcf_action_init(net, NULL, nla, NULL, actions, init_res,
1986 				      &attr_size, flags, 0, extack);
1987 		if (ret != -EAGAIN)
1988 			break;
1989 	}
1990 
1991 	if (ret < 0)
1992 		return ret;
1993 	ret = tcf_add_notify(net, n, actions, portid, attr_size, extack);
1994 
1995 	/* only put existing actions */
1996 	for (i = 0; i < TCA_ACT_MAX_PRIO; i++)
1997 		if (init_res[i] == ACT_P_CREATED)
1998 			actions[i] = NULL;
1999 	tcf_action_put_many(actions);
2000 
2001 	return ret;
2002 }
2003 
2004 static const struct nla_policy tcaa_policy[TCA_ROOT_MAX + 1] = {
2005 	[TCA_ROOT_FLAGS] = NLA_POLICY_BITFIELD32(TCA_ACT_FLAG_LARGE_DUMP_ON |
2006 						 TCA_ACT_FLAG_TERSE_DUMP),
2007 	[TCA_ROOT_TIME_DELTA]      = { .type = NLA_U32 },
2008 };
2009 
2010 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n,
2011 			 struct netlink_ext_ack *extack)
2012 {
2013 	struct net *net = sock_net(skb->sk);
2014 	struct nlattr *tca[TCA_ROOT_MAX + 1];
2015 	u32 portid = NETLINK_CB(skb).portid;
2016 	u32 flags = 0;
2017 	int ret = 0;
2018 
2019 	if ((n->nlmsg_type != RTM_GETACTION) &&
2020 	    !netlink_capable(skb, CAP_NET_ADMIN))
2021 		return -EPERM;
2022 
2023 	ret = nlmsg_parse_deprecated(n, sizeof(struct tcamsg), tca,
2024 				     TCA_ROOT_MAX, NULL, extack);
2025 	if (ret < 0)
2026 		return ret;
2027 
2028 	if (tca[TCA_ACT_TAB] == NULL) {
2029 		NL_SET_ERR_MSG(extack, "Netlink action attributes missing");
2030 		return -EINVAL;
2031 	}
2032 
2033 	/* n->nlmsg_flags & NLM_F_CREATE */
2034 	switch (n->nlmsg_type) {
2035 	case RTM_NEWACTION:
2036 		/* we are going to assume all other flags
2037 		 * imply create only if it doesn't exist
2038 		 * Note that CREATE | EXCL implies that
2039 		 * but since we want avoid ambiguity (eg when flags
2040 		 * is zero) then just set this
2041 		 */
2042 		if (n->nlmsg_flags & NLM_F_REPLACE)
2043 			flags = TCA_ACT_FLAGS_REPLACE;
2044 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, flags,
2045 				     extack);
2046 		break;
2047 	case RTM_DELACTION:
2048 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
2049 				    portid, RTM_DELACTION, extack);
2050 		break;
2051 	case RTM_GETACTION:
2052 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
2053 				    portid, RTM_GETACTION, extack);
2054 		break;
2055 	default:
2056 		BUG();
2057 	}
2058 
2059 	return ret;
2060 }
2061 
2062 static struct nlattr *find_dump_kind(struct nlattr **nla)
2063 {
2064 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
2065 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
2066 	struct nlattr *kind;
2067 
2068 	tb1 = nla[TCA_ACT_TAB];
2069 	if (tb1 == NULL)
2070 		return NULL;
2071 
2072 	if (nla_parse_deprecated(tb, TCA_ACT_MAX_PRIO, nla_data(tb1), NLMSG_ALIGN(nla_len(tb1)), NULL, NULL) < 0)
2073 		return NULL;
2074 
2075 	if (tb[1] == NULL)
2076 		return NULL;
2077 	if (nla_parse_nested_deprecated(tb2, TCA_ACT_MAX, tb[1], tcf_action_policy, NULL) < 0)
2078 		return NULL;
2079 	kind = tb2[TCA_ACT_KIND];
2080 
2081 	return kind;
2082 }
2083 
2084 static int tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
2085 {
2086 	struct net *net = sock_net(skb->sk);
2087 	struct nlmsghdr *nlh;
2088 	unsigned char *b = skb_tail_pointer(skb);
2089 	struct nlattr *nest;
2090 	struct tc_action_ops *a_o;
2091 	int ret = 0;
2092 	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
2093 	struct nlattr *tb[TCA_ROOT_MAX + 1];
2094 	struct nlattr *count_attr = NULL;
2095 	unsigned long jiffy_since = 0;
2096 	struct nlattr *kind = NULL;
2097 	struct nla_bitfield32 bf;
2098 	u32 msecs_since = 0;
2099 	u32 act_count = 0;
2100 
2101 	ret = nlmsg_parse_deprecated(cb->nlh, sizeof(struct tcamsg), tb,
2102 				     TCA_ROOT_MAX, tcaa_policy, cb->extack);
2103 	if (ret < 0)
2104 		return ret;
2105 
2106 	kind = find_dump_kind(tb);
2107 	if (kind == NULL) {
2108 		pr_info("tc_dump_action: action bad kind\n");
2109 		return 0;
2110 	}
2111 
2112 	a_o = tc_lookup_action(kind);
2113 	if (a_o == NULL)
2114 		return 0;
2115 
2116 	cb->args[2] = 0;
2117 	if (tb[TCA_ROOT_FLAGS]) {
2118 		bf = nla_get_bitfield32(tb[TCA_ROOT_FLAGS]);
2119 		cb->args[2] = bf.value;
2120 	}
2121 
2122 	if (tb[TCA_ROOT_TIME_DELTA]) {
2123 		msecs_since = nla_get_u32(tb[TCA_ROOT_TIME_DELTA]);
2124 	}
2125 
2126 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
2127 			cb->nlh->nlmsg_type, sizeof(*t), 0);
2128 	if (!nlh)
2129 		goto out_module_put;
2130 
2131 	if (msecs_since)
2132 		jiffy_since = jiffies - msecs_to_jiffies(msecs_since);
2133 
2134 	t = nlmsg_data(nlh);
2135 	t->tca_family = AF_UNSPEC;
2136 	t->tca__pad1 = 0;
2137 	t->tca__pad2 = 0;
2138 	cb->args[3] = jiffy_since;
2139 	count_attr = nla_reserve(skb, TCA_ROOT_COUNT, sizeof(u32));
2140 	if (!count_attr)
2141 		goto out_module_put;
2142 
2143 	nest = nla_nest_start_noflag(skb, TCA_ACT_TAB);
2144 	if (nest == NULL)
2145 		goto out_module_put;
2146 
2147 	ret = __tcf_generic_walker(net, skb, cb, RTM_GETACTION, a_o, NULL);
2148 	if (ret < 0)
2149 		goto out_module_put;
2150 
2151 	if (ret > 0) {
2152 		nla_nest_end(skb, nest);
2153 		ret = skb->len;
2154 		act_count = cb->args[1];
2155 		memcpy(nla_data(count_attr), &act_count, sizeof(u32));
2156 		cb->args[1] = 0;
2157 	} else
2158 		nlmsg_trim(skb, b);
2159 
2160 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
2161 	if (NETLINK_CB(cb->skb).portid && ret)
2162 		nlh->nlmsg_flags |= NLM_F_MULTI;
2163 	module_put(a_o->owner);
2164 	return skb->len;
2165 
2166 out_module_put:
2167 	module_put(a_o->owner);
2168 	nlmsg_trim(skb, b);
2169 	return skb->len;
2170 }
2171 
2172 static int __init tc_action_init(void)
2173 {
2174 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, 0);
2175 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, 0);
2176 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
2177 		      0);
2178 
2179 	return 0;
2180 }
2181 
2182 subsys_initcall(tc_action_init);
2183