xref: /openbmc/linux/net/sched/act_api.c (revision 930beb5a) 
1 /*
2  * net/sched/act_api.c	Packet action API.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  * Author:	Jamal Hadi Salim
10  *
11  *
12  */
13 
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/skbuff.h>
20 #include <linux/init.h>
21 #include <linux/kmod.h>
22 #include <linux/err.h>
23 #include <linux/module.h>
24 #include <net/net_namespace.h>
25 #include <net/sock.h>
26 #include <net/sch_generic.h>
27 #include <net/act_api.h>
28 #include <net/netlink.h>
29 
30 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
31 {
32 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
33 	struct tcf_common **p1p;
34 
35 	for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
36 		if (*p1p == p) {
37 			write_lock_bh(hinfo->lock);
38 			*p1p = p->tcfc_next;
39 			write_unlock_bh(hinfo->lock);
40 			gen_kill_estimator(&p->tcfc_bstats,
41 					   &p->tcfc_rate_est);
42 			/*
43 			 * gen_estimator est_timer() might access p->tcfc_lock
44 			 * or bstats, wait a RCU grace period before freeing p
45 			 */
46 			kfree_rcu(p, tcfc_rcu);
47 			return;
48 		}
49 	}
50 	WARN_ON(1);
51 }
52 EXPORT_SYMBOL(tcf_hash_destroy);
53 
54 int tcf_hash_release(struct tcf_common *p, int bind,
55 		     struct tcf_hashinfo *hinfo)
56 {
57 	int ret = 0;
58 
59 	if (p) {
60 		if (bind)
61 			p->tcfc_bindcnt--;
62 
63 		p->tcfc_refcnt--;
64 		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
65 			tcf_hash_destroy(p, hinfo);
66 			ret = 1;
67 		}
68 	}
69 	return ret;
70 }
71 EXPORT_SYMBOL(tcf_hash_release);
72 
73 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
74 			   struct tc_action *a, struct tcf_hashinfo *hinfo)
75 {
76 	struct tcf_common *p;
77 	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
78 	struct nlattr *nest;
79 
80 	read_lock_bh(hinfo->lock);
81 
82 	s_i = cb->args[0];
83 
84 	for (i = 0; i < (hinfo->hmask + 1); i++) {
85 		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
86 
87 		for (; p; p = p->tcfc_next) {
88 			index++;
89 			if (index < s_i)
90 				continue;
91 			a->priv = p;
92 			a->order = n_i;
93 
94 			nest = nla_nest_start(skb, a->order);
95 			if (nest == NULL)
96 				goto nla_put_failure;
97 			err = tcf_action_dump_1(skb, a, 0, 0);
98 			if (err < 0) {
99 				index--;
100 				nlmsg_trim(skb, nest);
101 				goto done;
102 			}
103 			nla_nest_end(skb, nest);
104 			n_i++;
105 			if (n_i >= TCA_ACT_MAX_PRIO)
106 				goto done;
107 		}
108 	}
109 done:
110 	read_unlock_bh(hinfo->lock);
111 	if (n_i)
112 		cb->args[0] += n_i;
113 	return n_i;
114 
115 nla_put_failure:
116 	nla_nest_cancel(skb, nest);
117 	goto done;
118 }
119 
120 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
121 			  struct tcf_hashinfo *hinfo)
122 {
123 	struct tcf_common *p, *s_p;
124 	struct nlattr *nest;
125 	int i = 0, n_i = 0;
126 
127 	nest = nla_nest_start(skb, a->order);
128 	if (nest == NULL)
129 		goto nla_put_failure;
130 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
131 		goto nla_put_failure;
132 	for (i = 0; i < (hinfo->hmask + 1); i++) {
133 		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
134 
135 		while (p != NULL) {
136 			s_p = p->tcfc_next;
137 			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
138 				module_put(a->ops->owner);
139 			n_i++;
140 			p = s_p;
141 		}
142 	}
143 	if (nla_put_u32(skb, TCA_FCNT, n_i))
144 		goto nla_put_failure;
145 	nla_nest_end(skb, nest);
146 
147 	return n_i;
148 nla_put_failure:
149 	nla_nest_cancel(skb, nest);
150 	return -EINVAL;
151 }
152 
153 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
154 		       int type, struct tc_action *a)
155 {
156 	struct tcf_hashinfo *hinfo = a->ops->hinfo;
157 
158 	if (type == RTM_DELACTION) {
159 		return tcf_del_walker(skb, a, hinfo);
160 	} else if (type == RTM_GETACTION) {
161 		return tcf_dump_walker(skb, cb, a, hinfo);
162 	} else {
163 		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
164 		return -EINVAL;
165 	}
166 }
167 EXPORT_SYMBOL(tcf_generic_walker);
168 
169 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
170 {
171 	struct tcf_common *p;
172 
173 	read_lock_bh(hinfo->lock);
174 	for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
175 	     p = p->tcfc_next) {
176 		if (p->tcfc_index == index)
177 			break;
178 	}
179 	read_unlock_bh(hinfo->lock);
180 
181 	return p;
182 }
183 EXPORT_SYMBOL(tcf_hash_lookup);
184 
185 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
186 {
187 	u32 val = *idx_gen;
188 
189 	do {
190 		if (++val == 0)
191 			val = 1;
192 	} while (tcf_hash_lookup(val, hinfo));
193 
194 	return (*idx_gen = val);
195 }
196 EXPORT_SYMBOL(tcf_hash_new_index);
197 
198 int tcf_hash_search(struct tc_action *a, u32 index)
199 {
200 	struct tcf_hashinfo *hinfo = a->ops->hinfo;
201 	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
202 
203 	if (p) {
204 		a->priv = p;
205 		return 1;
206 	}
207 	return 0;
208 }
209 EXPORT_SYMBOL(tcf_hash_search);
210 
211 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
212 				  struct tcf_hashinfo *hinfo)
213 {
214 	struct tcf_common *p = NULL;
215 	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
216 		if (bind)
217 			p->tcfc_bindcnt++;
218 		p->tcfc_refcnt++;
219 		a->priv = p;
220 	}
221 	return p;
222 }
223 EXPORT_SYMBOL(tcf_hash_check);
224 
225 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
226 				   struct tc_action *a, int size, int bind,
227 				   u32 *idx_gen, struct tcf_hashinfo *hinfo)
228 {
229 	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
230 
231 	if (unlikely(!p))
232 		return ERR_PTR(-ENOMEM);
233 	p->tcfc_refcnt = 1;
234 	if (bind)
235 		p->tcfc_bindcnt = 1;
236 
237 	spin_lock_init(&p->tcfc_lock);
238 	p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
239 	p->tcfc_tm.install = jiffies;
240 	p->tcfc_tm.lastuse = jiffies;
241 	if (est) {
242 		int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
243 					    &p->tcfc_lock, est);
244 		if (err) {
245 			kfree(p);
246 			return ERR_PTR(err);
247 		}
248 	}
249 
250 	a->priv = (void *) p;
251 	return p;
252 }
253 EXPORT_SYMBOL(tcf_hash_create);
254 
255 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
256 {
257 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
258 
259 	write_lock_bh(hinfo->lock);
260 	p->tcfc_next = hinfo->htab[h];
261 	hinfo->htab[h] = p;
262 	write_unlock_bh(hinfo->lock);
263 }
264 EXPORT_SYMBOL(tcf_hash_insert);
265 
266 static struct tc_action_ops *act_base = NULL;
267 static DEFINE_RWLOCK(act_mod_lock);
268 
269 int tcf_register_action(struct tc_action_ops *act)
270 {
271 	struct tc_action_ops *a, **ap;
272 
273 	/* Must supply act, dump, cleanup and init */
274 	if (!act->act || !act->dump || !act->cleanup || !act->init)
275 		return -EINVAL;
276 
277 	/* Supply defaults */
278 	if (!act->lookup)
279 		act->lookup = tcf_hash_search;
280 	if (!act->walk)
281 		act->walk = tcf_generic_walker;
282 
283 	write_lock(&act_mod_lock);
284 	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
285 		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
286 			write_unlock(&act_mod_lock);
287 			return -EEXIST;
288 		}
289 	}
290 	act->next = NULL;
291 	*ap = act;
292 	write_unlock(&act_mod_lock);
293 	return 0;
294 }
295 EXPORT_SYMBOL(tcf_register_action);
296 
297 int tcf_unregister_action(struct tc_action_ops *act)
298 {
299 	struct tc_action_ops *a, **ap;
300 	int err = -ENOENT;
301 
302 	write_lock(&act_mod_lock);
303 	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
304 		if (a == act)
305 			break;
306 	if (a) {
307 		*ap = a->next;
308 		a->next = NULL;
309 		err = 0;
310 	}
311 	write_unlock(&act_mod_lock);
312 	return err;
313 }
314 EXPORT_SYMBOL(tcf_unregister_action);
315 
316 /* lookup by name */
317 static struct tc_action_ops *tc_lookup_action_n(char *kind)
318 {
319 	struct tc_action_ops *a = NULL;
320 
321 	if (kind) {
322 		read_lock(&act_mod_lock);
323 		for (a = act_base; a; a = a->next) {
324 			if (strcmp(kind, a->kind) == 0) {
325 				if (!try_module_get(a->owner)) {
326 					read_unlock(&act_mod_lock);
327 					return NULL;
328 				}
329 				break;
330 			}
331 		}
332 		read_unlock(&act_mod_lock);
333 	}
334 	return a;
335 }
336 
337 /* lookup by nlattr */
338 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
339 {
340 	struct tc_action_ops *a = NULL;
341 
342 	if (kind) {
343 		read_lock(&act_mod_lock);
344 		for (a = act_base; a; a = a->next) {
345 			if (nla_strcmp(kind, a->kind) == 0) {
346 				if (!try_module_get(a->owner)) {
347 					read_unlock(&act_mod_lock);
348 					return NULL;
349 				}
350 				break;
351 			}
352 		}
353 		read_unlock(&act_mod_lock);
354 	}
355 	return a;
356 }
357 
358 #if 0
359 /* lookup by id */
360 static struct tc_action_ops *tc_lookup_action_id(u32 type)
361 {
362 	struct tc_action_ops *a = NULL;
363 
364 	if (type) {
365 		read_lock(&act_mod_lock);
366 		for (a = act_base; a; a = a->next) {
367 			if (a->type == type) {
368 				if (!try_module_get(a->owner)) {
369 					read_unlock(&act_mod_lock);
370 					return NULL;
371 				}
372 				break;
373 			}
374 		}
375 		read_unlock(&act_mod_lock);
376 	}
377 	return a;
378 }
379 #endif
380 
381 int tcf_action_exec(struct sk_buff *skb, const struct tc_action *act,
382 		    struct tcf_result *res)
383 {
384 	const struct tc_action *a;
385 	int ret = -1;
386 
387 	if (skb->tc_verd & TC_NCLS) {
388 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
389 		ret = TC_ACT_OK;
390 		goto exec_done;
391 	}
392 	while ((a = act) != NULL) {
393 repeat:
394 		if (a->ops) {
395 			ret = a->ops->act(skb, a, res);
396 			if (TC_MUNGED & skb->tc_verd) {
397 				/* copied already, allow trampling */
398 				skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
399 				skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
400 			}
401 			if (ret == TC_ACT_REPEAT)
402 				goto repeat;	/* we need a ttl - JHS */
403 			if (ret != TC_ACT_PIPE)
404 				goto exec_done;
405 		}
406 		act = a->next;
407 	}
408 exec_done:
409 	return ret;
410 }
411 EXPORT_SYMBOL(tcf_action_exec);
412 
413 void tcf_action_destroy(struct tc_action *act, int bind)
414 {
415 	struct tc_action *a;
416 
417 	for (a = act; a; a = act) {
418 		if (a->ops) {
419 			if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
420 				module_put(a->ops->owner);
421 			act = act->next;
422 			kfree(a);
423 		} else {
424 			/*FIXME: Remove later - catch insertion bugs*/
425 			WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
426 			act = act->next;
427 			kfree(a);
428 		}
429 	}
430 }
431 
432 int
433 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
434 {
435 	int err = -EINVAL;
436 
437 	if (a->ops == NULL)
438 		return err;
439 	return a->ops->dump(skb, a, bind, ref);
440 }
441 
442 int
443 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
444 {
445 	int err = -EINVAL;
446 	unsigned char *b = skb_tail_pointer(skb);
447 	struct nlattr *nest;
448 
449 	if (a->ops == NULL)
450 		return err;
451 
452 	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
453 		goto nla_put_failure;
454 	if (tcf_action_copy_stats(skb, a, 0))
455 		goto nla_put_failure;
456 	nest = nla_nest_start(skb, TCA_OPTIONS);
457 	if (nest == NULL)
458 		goto nla_put_failure;
459 	err = tcf_action_dump_old(skb, a, bind, ref);
460 	if (err > 0) {
461 		nla_nest_end(skb, nest);
462 		return err;
463 	}
464 
465 nla_put_failure:
466 	nlmsg_trim(skb, b);
467 	return -1;
468 }
469 EXPORT_SYMBOL(tcf_action_dump_1);
470 
471 int
472 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
473 {
474 	struct tc_action *a;
475 	int err = -EINVAL;
476 	struct nlattr *nest;
477 
478 	while ((a = act) != NULL) {
479 		act = a->next;
480 		nest = nla_nest_start(skb, a->order);
481 		if (nest == NULL)
482 			goto nla_put_failure;
483 		err = tcf_action_dump_1(skb, a, bind, ref);
484 		if (err < 0)
485 			goto errout;
486 		nla_nest_end(skb, nest);
487 	}
488 
489 	return 0;
490 
491 nla_put_failure:
492 	err = -EINVAL;
493 errout:
494 	nla_nest_cancel(skb, nest);
495 	return err;
496 }
497 
498 struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
499 				    struct nlattr *est, char *name, int ovr,
500 				    int bind)
501 {
502 	struct tc_action *a;
503 	struct tc_action_ops *a_o;
504 	char act_name[IFNAMSIZ];
505 	struct nlattr *tb[TCA_ACT_MAX + 1];
506 	struct nlattr *kind;
507 	int err;
508 
509 	if (name == NULL) {
510 		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
511 		if (err < 0)
512 			goto err_out;
513 		err = -EINVAL;
514 		kind = tb[TCA_ACT_KIND];
515 		if (kind == NULL)
516 			goto err_out;
517 		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
518 			goto err_out;
519 	} else {
520 		err = -EINVAL;
521 		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
522 			goto err_out;
523 	}
524 
525 	a_o = tc_lookup_action_n(act_name);
526 	if (a_o == NULL) {
527 #ifdef CONFIG_MODULES
528 		rtnl_unlock();
529 		request_module("act_%s", act_name);
530 		rtnl_lock();
531 
532 		a_o = tc_lookup_action_n(act_name);
533 
534 		/* We dropped the RTNL semaphore in order to
535 		 * perform the module load.  So, even if we
536 		 * succeeded in loading the module we have to
537 		 * tell the caller to replay the request.  We
538 		 * indicate this using -EAGAIN.
539 		 */
540 		if (a_o != NULL) {
541 			err = -EAGAIN;
542 			goto err_mod;
543 		}
544 #endif
545 		err = -ENOENT;
546 		goto err_out;
547 	}
548 
549 	err = -ENOMEM;
550 	a = kzalloc(sizeof(*a), GFP_KERNEL);
551 	if (a == NULL)
552 		goto err_mod;
553 
554 	/* backward compatibility for policer */
555 	if (name == NULL)
556 		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
557 	else
558 		err = a_o->init(net, nla, est, a, ovr, bind);
559 	if (err < 0)
560 		goto err_free;
561 
562 	/* module count goes up only when brand new policy is created
563 	 * if it exists and is only bound to in a_o->init() then
564 	 * ACT_P_CREATED is not returned (a zero is).
565 	 */
566 	if (err != ACT_P_CREATED)
567 		module_put(a_o->owner);
568 	a->ops = a_o;
569 
570 	return a;
571 
572 err_free:
573 	kfree(a);
574 err_mod:
575 	module_put(a_o->owner);
576 err_out:
577 	return ERR_PTR(err);
578 }
579 
580 struct tc_action *tcf_action_init(struct net *net, struct nlattr *nla,
581 				  struct nlattr *est, char *name, int ovr,
582 				  int bind)
583 {
584 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
585 	struct tc_action *head = NULL, *act, *act_prev = NULL;
586 	int err;
587 	int i;
588 
589 	err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
590 	if (err < 0)
591 		return ERR_PTR(err);
592 
593 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
594 		act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
595 		if (IS_ERR(act))
596 			goto err;
597 		act->order = i;
598 
599 		if (head == NULL)
600 			head = act;
601 		else
602 			act_prev->next = act;
603 		act_prev = act;
604 	}
605 	return head;
606 
607 err:
608 	if (head != NULL)
609 		tcf_action_destroy(head, bind);
610 	return act;
611 }
612 
613 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
614 			  int compat_mode)
615 {
616 	int err = 0;
617 	struct gnet_dump d;
618 	struct tcf_act_hdr *h = a->priv;
619 
620 	if (h == NULL)
621 		goto errout;
622 
623 	/* compat_mode being true specifies a call that is supposed
624 	 * to add additional backward compatibility statistic TLVs.
625 	 */
626 	if (compat_mode) {
627 		if (a->type == TCA_OLD_COMPAT)
628 			err = gnet_stats_start_copy_compat(skb, 0,
629 				TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
630 		else
631 			return 0;
632 	} else
633 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
634 					    &h->tcf_lock, &d);
635 
636 	if (err < 0)
637 		goto errout;
638 
639 	if (a->ops != NULL && a->ops->get_stats != NULL)
640 		if (a->ops->get_stats(skb, a) < 0)
641 			goto errout;
642 
643 	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
644 	    gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
645 				     &h->tcf_rate_est) < 0 ||
646 	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
647 		goto errout;
648 
649 	if (gnet_stats_finish_copy(&d) < 0)
650 		goto errout;
651 
652 	return 0;
653 
654 errout:
655 	return -1;
656 }
657 
658 static int
659 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 portid, u32 seq,
660 	     u16 flags, int event, int bind, int ref)
661 {
662 	struct tcamsg *t;
663 	struct nlmsghdr *nlh;
664 	unsigned char *b = skb_tail_pointer(skb);
665 	struct nlattr *nest;
666 
667 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
668 	if (!nlh)
669 		goto out_nlmsg_trim;
670 	t = nlmsg_data(nlh);
671 	t->tca_family = AF_UNSPEC;
672 	t->tca__pad1 = 0;
673 	t->tca__pad2 = 0;
674 
675 	nest = nla_nest_start(skb, TCA_ACT_TAB);
676 	if (nest == NULL)
677 		goto out_nlmsg_trim;
678 
679 	if (tcf_action_dump(skb, a, bind, ref) < 0)
680 		goto out_nlmsg_trim;
681 
682 	nla_nest_end(skb, nest);
683 
684 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
685 	return skb->len;
686 
687 out_nlmsg_trim:
688 	nlmsg_trim(skb, b);
689 	return -1;
690 }
691 
692 static int
693 act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
694 	       struct tc_action *a, int event)
695 {
696 	struct sk_buff *skb;
697 
698 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
699 	if (!skb)
700 		return -ENOBUFS;
701 	if (tca_get_fill(skb, a, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
702 		kfree_skb(skb);
703 		return -EINVAL;
704 	}
705 
706 	return rtnl_unicast(skb, net, portid);
707 }
708 
709 static struct tc_action *
710 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
711 {
712 	struct nlattr *tb[TCA_ACT_MAX + 1];
713 	struct tc_action *a;
714 	int index;
715 	int err;
716 
717 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
718 	if (err < 0)
719 		goto err_out;
720 
721 	err = -EINVAL;
722 	if (tb[TCA_ACT_INDEX] == NULL ||
723 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
724 		goto err_out;
725 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
726 
727 	err = -ENOMEM;
728 	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
729 	if (a == NULL)
730 		goto err_out;
731 
732 	err = -EINVAL;
733 	a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
734 	if (a->ops == NULL)
735 		goto err_free;
736 	err = -ENOENT;
737 	if (a->ops->lookup(a, index) == 0)
738 		goto err_mod;
739 
740 	module_put(a->ops->owner);
741 	return a;
742 
743 err_mod:
744 	module_put(a->ops->owner);
745 err_free:
746 	kfree(a);
747 err_out:
748 	return ERR_PTR(err);
749 }
750 
751 static void cleanup_a(struct tc_action *act)
752 {
753 	struct tc_action *a;
754 
755 	for (a = act; a; a = act) {
756 		act = a->next;
757 		kfree(a);
758 	}
759 }
760 
761 static struct tc_action *create_a(int i)
762 {
763 	struct tc_action *act;
764 
765 	act = kzalloc(sizeof(*act), GFP_KERNEL);
766 	if (act == NULL) {
767 		pr_debug("create_a: failed to alloc!\n");
768 		return NULL;
769 	}
770 	act->order = i;
771 	return act;
772 }
773 
774 static int tca_action_flush(struct net *net, struct nlattr *nla,
775 			    struct nlmsghdr *n, u32 portid)
776 {
777 	struct sk_buff *skb;
778 	unsigned char *b;
779 	struct nlmsghdr *nlh;
780 	struct tcamsg *t;
781 	struct netlink_callback dcb;
782 	struct nlattr *nest;
783 	struct nlattr *tb[TCA_ACT_MAX + 1];
784 	struct nlattr *kind;
785 	struct tc_action *a = create_a(0);
786 	int err = -ENOMEM;
787 
788 	if (a == NULL) {
789 		pr_debug("tca_action_flush: couldnt create tc_action\n");
790 		return err;
791 	}
792 
793 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
794 	if (!skb) {
795 		pr_debug("tca_action_flush: failed skb alloc\n");
796 		kfree(a);
797 		return err;
798 	}
799 
800 	b = skb_tail_pointer(skb);
801 
802 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
803 	if (err < 0)
804 		goto err_out;
805 
806 	err = -EINVAL;
807 	kind = tb[TCA_ACT_KIND];
808 	a->ops = tc_lookup_action(kind);
809 	if (a->ops == NULL)
810 		goto err_out;
811 
812 	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
813 	if (!nlh)
814 		goto out_module_put;
815 	t = nlmsg_data(nlh);
816 	t->tca_family = AF_UNSPEC;
817 	t->tca__pad1 = 0;
818 	t->tca__pad2 = 0;
819 
820 	nest = nla_nest_start(skb, TCA_ACT_TAB);
821 	if (nest == NULL)
822 		goto out_module_put;
823 
824 	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
825 	if (err < 0)
826 		goto out_module_put;
827 	if (err == 0)
828 		goto noflush_out;
829 
830 	nla_nest_end(skb, nest);
831 
832 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
833 	nlh->nlmsg_flags |= NLM_F_ROOT;
834 	module_put(a->ops->owner);
835 	kfree(a);
836 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
837 			     n->nlmsg_flags & NLM_F_ECHO);
838 	if (err > 0)
839 		return 0;
840 
841 	return err;
842 
843 out_module_put:
844 	module_put(a->ops->owner);
845 err_out:
846 noflush_out:
847 	kfree_skb(skb);
848 	kfree(a);
849 	return err;
850 }
851 
852 static int
853 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
854 	      u32 portid, int event)
855 {
856 	int i, ret;
857 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
858 	struct tc_action *head = NULL, *act, *act_prev = NULL;
859 
860 	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
861 	if (ret < 0)
862 		return ret;
863 
864 	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
865 		if (tb[1] != NULL)
866 			return tca_action_flush(net, tb[1], n, portid);
867 		else
868 			return -EINVAL;
869 	}
870 
871 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
872 		act = tcf_action_get_1(tb[i], n, portid);
873 		if (IS_ERR(act)) {
874 			ret = PTR_ERR(act);
875 			goto err;
876 		}
877 		act->order = i;
878 
879 		if (head == NULL)
880 			head = act;
881 		else
882 			act_prev->next = act;
883 		act_prev = act;
884 	}
885 
886 	if (event == RTM_GETACTION)
887 		ret = act_get_notify(net, portid, n, head, event);
888 	else { /* delete */
889 		struct sk_buff *skb;
890 
891 		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
892 		if (!skb) {
893 			ret = -ENOBUFS;
894 			goto err;
895 		}
896 
897 		if (tca_get_fill(skb, head, portid, n->nlmsg_seq, 0, event,
898 				 0, 1) <= 0) {
899 			kfree_skb(skb);
900 			ret = -EINVAL;
901 			goto err;
902 		}
903 
904 		/* now do the delete */
905 		tcf_action_destroy(head, 0);
906 		ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
907 				     n->nlmsg_flags & NLM_F_ECHO);
908 		if (ret > 0)
909 			return 0;
910 		return ret;
911 	}
912 err:
913 	cleanup_a(head);
914 	return ret;
915 }
916 
917 static int tcf_add_notify(struct net *net, struct tc_action *a,
918 			  u32 portid, u32 seq, int event, u16 flags)
919 {
920 	struct tcamsg *t;
921 	struct nlmsghdr *nlh;
922 	struct sk_buff *skb;
923 	struct nlattr *nest;
924 	unsigned char *b;
925 	int err = 0;
926 
927 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
928 	if (!skb)
929 		return -ENOBUFS;
930 
931 	b = skb_tail_pointer(skb);
932 
933 	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
934 	if (!nlh)
935 		goto out_kfree_skb;
936 	t = nlmsg_data(nlh);
937 	t->tca_family = AF_UNSPEC;
938 	t->tca__pad1 = 0;
939 	t->tca__pad2 = 0;
940 
941 	nest = nla_nest_start(skb, TCA_ACT_TAB);
942 	if (nest == NULL)
943 		goto out_kfree_skb;
944 
945 	if (tcf_action_dump(skb, a, 0, 0) < 0)
946 		goto out_kfree_skb;
947 
948 	nla_nest_end(skb, nest);
949 
950 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
951 	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
952 
953 	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
954 	if (err > 0)
955 		err = 0;
956 	return err;
957 
958 out_kfree_skb:
959 	kfree_skb(skb);
960 	return -1;
961 }
962 
963 
964 static int
965 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
966 	       u32 portid, int ovr)
967 {
968 	int ret = 0;
969 	struct tc_action *act;
970 	struct tc_action *a;
971 	u32 seq = n->nlmsg_seq;
972 
973 	act = tcf_action_init(net, nla, NULL, NULL, ovr, 0);
974 	if (act == NULL)
975 		goto done;
976 	if (IS_ERR(act)) {
977 		ret = PTR_ERR(act);
978 		goto done;
979 	}
980 
981 	/* dump then free all the actions after update; inserted policy
982 	 * stays intact
983 	 */
984 	ret = tcf_add_notify(net, act, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
985 	for (a = act; a; a = act) {
986 		act = a->next;
987 		kfree(a);
988 	}
989 done:
990 	return ret;
991 }
992 
993 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
994 {
995 	struct net *net = sock_net(skb->sk);
996 	struct nlattr *tca[TCA_ACT_MAX + 1];
997 	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
998 	int ret = 0, ovr = 0;
999 
1000 	if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
1001 		return -EPERM;
1002 
1003 	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
1004 	if (ret < 0)
1005 		return ret;
1006 
1007 	if (tca[TCA_ACT_TAB] == NULL) {
1008 		pr_notice("tc_ctl_action: received NO action attribs\n");
1009 		return -EINVAL;
1010 	}
1011 
1012 	/* n->nlmsg_flags & NLM_F_CREATE */
1013 	switch (n->nlmsg_type) {
1014 	case RTM_NEWACTION:
1015 		/* we are going to assume all other flags
1016 		 * imply create only if it doesn't exist
1017 		 * Note that CREATE | EXCL implies that
1018 		 * but since we want avoid ambiguity (eg when flags
1019 		 * is zero) then just set this
1020 		 */
1021 		if (n->nlmsg_flags & NLM_F_REPLACE)
1022 			ovr = 1;
1023 replay:
1024 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1025 		if (ret == -EAGAIN)
1026 			goto replay;
1027 		break;
1028 	case RTM_DELACTION:
1029 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1030 				    portid, RTM_DELACTION);
1031 		break;
1032 	case RTM_GETACTION:
1033 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1034 				    portid, RTM_GETACTION);
1035 		break;
1036 	default:
1037 		BUG();
1038 	}
1039 
1040 	return ret;
1041 }
1042 
1043 static struct nlattr *
1044 find_dump_kind(const struct nlmsghdr *n)
1045 {
1046 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1047 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1048 	struct nlattr *nla[TCAA_MAX + 1];
1049 	struct nlattr *kind;
1050 
1051 	if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1052 		return NULL;
1053 	tb1 = nla[TCA_ACT_TAB];
1054 	if (tb1 == NULL)
1055 		return NULL;
1056 
1057 	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1058 		      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1059 		return NULL;
1060 
1061 	if (tb[1] == NULL)
1062 		return NULL;
1063 	if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1064 		      nla_len(tb[1]), NULL) < 0)
1065 		return NULL;
1066 	kind = tb2[TCA_ACT_KIND];
1067 
1068 	return kind;
1069 }
1070 
1071 static int
1072 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1073 {
1074 	struct nlmsghdr *nlh;
1075 	unsigned char *b = skb_tail_pointer(skb);
1076 	struct nlattr *nest;
1077 	struct tc_action_ops *a_o;
1078 	struct tc_action a;
1079 	int ret = 0;
1080 	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1081 	struct nlattr *kind = find_dump_kind(cb->nlh);
1082 
1083 	if (kind == NULL) {
1084 		pr_info("tc_dump_action: action bad kind\n");
1085 		return 0;
1086 	}
1087 
1088 	a_o = tc_lookup_action(kind);
1089 	if (a_o == NULL)
1090 		return 0;
1091 
1092 	memset(&a, 0, sizeof(struct tc_action));
1093 	a.ops = a_o;
1094 
1095 	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1096 			cb->nlh->nlmsg_type, sizeof(*t), 0);
1097 	if (!nlh)
1098 		goto out_module_put;
1099 	t = nlmsg_data(nlh);
1100 	t->tca_family = AF_UNSPEC;
1101 	t->tca__pad1 = 0;
1102 	t->tca__pad2 = 0;
1103 
1104 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1105 	if (nest == NULL)
1106 		goto out_module_put;
1107 
1108 	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1109 	if (ret < 0)
1110 		goto out_module_put;
1111 
1112 	if (ret > 0) {
1113 		nla_nest_end(skb, nest);
1114 		ret = skb->len;
1115 	} else
1116 		nla_nest_cancel(skb, nest);
1117 
1118 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1119 	if (NETLINK_CB(cb->skb).portid && ret)
1120 		nlh->nlmsg_flags |= NLM_F_MULTI;
1121 	module_put(a_o->owner);
1122 	return skb->len;
1123 
1124 out_module_put:
1125 	module_put(a_o->owner);
1126 	nlmsg_trim(skb, b);
1127 	return skb->len;
1128 }
1129 
1130 static int __init tc_action_init(void)
1131 {
1132 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1133 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1134 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1135 		      NULL);
1136 
1137 	return 0;
1138 }
1139 
1140 subsys_initcall(tc_action_init);
1141