xref: /openbmc/linux/net/sched/act_api.c (revision 565d76cb) 
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 <net/net_namespace.h>
24 #include <net/sock.h>
25 #include <net/sch_generic.h>
26 #include <net/act_api.h>
27 #include <net/netlink.h>
28 
29 static void tcf_common_free_rcu(struct rcu_head *head)
30 {
31 	kfree(container_of(head, struct tcf_common, tcfc_rcu));
32 }
33 
34 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
35 {
36 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
37 	struct tcf_common **p1p;
38 
39 	for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
40 		if (*p1p == p) {
41 			write_lock_bh(hinfo->lock);
42 			*p1p = p->tcfc_next;
43 			write_unlock_bh(hinfo->lock);
44 			gen_kill_estimator(&p->tcfc_bstats,
45 					   &p->tcfc_rate_est);
46 			/*
47 			 * gen_estimator est_timer() might access p->tcfc_lock
48 			 * or bstats, wait a RCU grace period before freeing p
49 			 */
50 			call_rcu(&p->tcfc_rcu, tcf_common_free_rcu);
51 			return;
52 		}
53 	}
54 	WARN_ON(1);
55 }
56 EXPORT_SYMBOL(tcf_hash_destroy);
57 
58 int tcf_hash_release(struct tcf_common *p, int bind,
59 		     struct tcf_hashinfo *hinfo)
60 {
61 	int ret = 0;
62 
63 	if (p) {
64 		if (bind)
65 			p->tcfc_bindcnt--;
66 
67 		p->tcfc_refcnt--;
68 		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
69 			tcf_hash_destroy(p, hinfo);
70 			ret = 1;
71 		}
72 	}
73 	return ret;
74 }
75 EXPORT_SYMBOL(tcf_hash_release);
76 
77 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
78 			   struct tc_action *a, struct tcf_hashinfo *hinfo)
79 {
80 	struct tcf_common *p;
81 	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
82 	struct nlattr *nest;
83 
84 	read_lock_bh(hinfo->lock);
85 
86 	s_i = cb->args[0];
87 
88 	for (i = 0; i < (hinfo->hmask + 1); i++) {
89 		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
90 
91 		for (; p; p = p->tcfc_next) {
92 			index++;
93 			if (index < s_i)
94 				continue;
95 			a->priv = p;
96 			a->order = n_i;
97 
98 			nest = nla_nest_start(skb, a->order);
99 			if (nest == NULL)
100 				goto nla_put_failure;
101 			err = tcf_action_dump_1(skb, a, 0, 0);
102 			if (err < 0) {
103 				index--;
104 				nlmsg_trim(skb, nest);
105 				goto done;
106 			}
107 			nla_nest_end(skb, nest);
108 			n_i++;
109 			if (n_i >= TCA_ACT_MAX_PRIO)
110 				goto done;
111 		}
112 	}
113 done:
114 	read_unlock_bh(hinfo->lock);
115 	if (n_i)
116 		cb->args[0] += n_i;
117 	return n_i;
118 
119 nla_put_failure:
120 	nla_nest_cancel(skb, nest);
121 	goto done;
122 }
123 
124 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
125 			  struct tcf_hashinfo *hinfo)
126 {
127 	struct tcf_common *p, *s_p;
128 	struct nlattr *nest;
129 	int i = 0, n_i = 0;
130 
131 	nest = nla_nest_start(skb, a->order);
132 	if (nest == NULL)
133 		goto nla_put_failure;
134 	NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
135 	for (i = 0; i < (hinfo->hmask + 1); i++) {
136 		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
137 
138 		while (p != NULL) {
139 			s_p = p->tcfc_next;
140 			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
141 				module_put(a->ops->owner);
142 			n_i++;
143 			p = s_p;
144 		}
145 	}
146 	NLA_PUT_U32(skb, TCA_FCNT, n_i);
147 	nla_nest_end(skb, nest);
148 
149 	return n_i;
150 nla_put_failure:
151 	nla_nest_cancel(skb, nest);
152 	return -EINVAL;
153 }
154 
155 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
156 		       int type, struct tc_action *a)
157 {
158 	struct tcf_hashinfo *hinfo = a->ops->hinfo;
159 
160 	if (type == RTM_DELACTION) {
161 		return tcf_del_walker(skb, a, hinfo);
162 	} else if (type == RTM_GETACTION) {
163 		return tcf_dump_walker(skb, cb, a, hinfo);
164 	} else {
165 		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
166 		return -EINVAL;
167 	}
168 }
169 EXPORT_SYMBOL(tcf_generic_walker);
170 
171 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
172 {
173 	struct tcf_common *p;
174 
175 	read_lock_bh(hinfo->lock);
176 	for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
177 	     p = p->tcfc_next) {
178 		if (p->tcfc_index == index)
179 			break;
180 	}
181 	read_unlock_bh(hinfo->lock);
182 
183 	return p;
184 }
185 EXPORT_SYMBOL(tcf_hash_lookup);
186 
187 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
188 {
189 	u32 val = *idx_gen;
190 
191 	do {
192 		if (++val == 0)
193 			val = 1;
194 	} while (tcf_hash_lookup(val, hinfo));
195 
196 	return (*idx_gen = val);
197 }
198 EXPORT_SYMBOL(tcf_hash_new_index);
199 
200 int tcf_hash_search(struct tc_action *a, u32 index)
201 {
202 	struct tcf_hashinfo *hinfo = a->ops->hinfo;
203 	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
204 
205 	if (p) {
206 		a->priv = p;
207 		return 1;
208 	}
209 	return 0;
210 }
211 EXPORT_SYMBOL(tcf_hash_search);
212 
213 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
214 				  struct tcf_hashinfo *hinfo)
215 {
216 	struct tcf_common *p = NULL;
217 	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
218 		if (bind)
219 			p->tcfc_bindcnt++;
220 		p->tcfc_refcnt++;
221 		a->priv = p;
222 	}
223 	return p;
224 }
225 EXPORT_SYMBOL(tcf_hash_check);
226 
227 struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
228 				   struct tc_action *a, int size, int bind,
229 				   u32 *idx_gen, struct tcf_hashinfo *hinfo)
230 {
231 	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
232 
233 	if (unlikely(!p))
234 		return ERR_PTR(-ENOMEM);
235 	p->tcfc_refcnt = 1;
236 	if (bind)
237 		p->tcfc_bindcnt = 1;
238 
239 	spin_lock_init(&p->tcfc_lock);
240 	p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
241 	p->tcfc_tm.install = jiffies;
242 	p->tcfc_tm.lastuse = jiffies;
243 	if (est) {
244 		int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
245 					    &p->tcfc_lock, est);
246 		if (err) {
247 			kfree(p);
248 			return ERR_PTR(err);
249 		}
250 	}
251 
252 	a->priv = (void *) p;
253 	return p;
254 }
255 EXPORT_SYMBOL(tcf_hash_create);
256 
257 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
258 {
259 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
260 
261 	write_lock_bh(hinfo->lock);
262 	p->tcfc_next = hinfo->htab[h];
263 	hinfo->htab[h] = p;
264 	write_unlock_bh(hinfo->lock);
265 }
266 EXPORT_SYMBOL(tcf_hash_insert);
267 
268 static struct tc_action_ops *act_base = NULL;
269 static DEFINE_RWLOCK(act_mod_lock);
270 
271 int tcf_register_action(struct tc_action_ops *act)
272 {
273 	struct tc_action_ops *a, **ap;
274 
275 	write_lock(&act_mod_lock);
276 	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
277 		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
278 			write_unlock(&act_mod_lock);
279 			return -EEXIST;
280 		}
281 	}
282 	act->next = NULL;
283 	*ap = act;
284 	write_unlock(&act_mod_lock);
285 	return 0;
286 }
287 EXPORT_SYMBOL(tcf_register_action);
288 
289 int tcf_unregister_action(struct tc_action_ops *act)
290 {
291 	struct tc_action_ops *a, **ap;
292 	int err = -ENOENT;
293 
294 	write_lock(&act_mod_lock);
295 	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
296 		if (a == act)
297 			break;
298 	if (a) {
299 		*ap = a->next;
300 		a->next = NULL;
301 		err = 0;
302 	}
303 	write_unlock(&act_mod_lock);
304 	return err;
305 }
306 EXPORT_SYMBOL(tcf_unregister_action);
307 
308 /* lookup by name */
309 static struct tc_action_ops *tc_lookup_action_n(char *kind)
310 {
311 	struct tc_action_ops *a = NULL;
312 
313 	if (kind) {
314 		read_lock(&act_mod_lock);
315 		for (a = act_base; a; a = a->next) {
316 			if (strcmp(kind, a->kind) == 0) {
317 				if (!try_module_get(a->owner)) {
318 					read_unlock(&act_mod_lock);
319 					return NULL;
320 				}
321 				break;
322 			}
323 		}
324 		read_unlock(&act_mod_lock);
325 	}
326 	return a;
327 }
328 
329 /* lookup by nlattr */
330 static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
331 {
332 	struct tc_action_ops *a = NULL;
333 
334 	if (kind) {
335 		read_lock(&act_mod_lock);
336 		for (a = act_base; a; a = a->next) {
337 			if (nla_strcmp(kind, a->kind) == 0) {
338 				if (!try_module_get(a->owner)) {
339 					read_unlock(&act_mod_lock);
340 					return NULL;
341 				}
342 				break;
343 			}
344 		}
345 		read_unlock(&act_mod_lock);
346 	}
347 	return a;
348 }
349 
350 #if 0
351 /* lookup by id */
352 static struct tc_action_ops *tc_lookup_action_id(u32 type)
353 {
354 	struct tc_action_ops *a = NULL;
355 
356 	if (type) {
357 		read_lock(&act_mod_lock);
358 		for (a = act_base; a; a = a->next) {
359 			if (a->type == type) {
360 				if (!try_module_get(a->owner)) {
361 					read_unlock(&act_mod_lock);
362 					return NULL;
363 				}
364 				break;
365 			}
366 		}
367 		read_unlock(&act_mod_lock);
368 	}
369 	return a;
370 }
371 #endif
372 
373 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
374 		    struct tcf_result *res)
375 {
376 	struct tc_action *a;
377 	int ret = -1;
378 
379 	if (skb->tc_verd & TC_NCLS) {
380 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
381 		ret = TC_ACT_OK;
382 		goto exec_done;
383 	}
384 	while ((a = act) != NULL) {
385 repeat:
386 		if (a->ops && a->ops->act) {
387 			ret = a->ops->act(skb, a, res);
388 			if (TC_MUNGED & skb->tc_verd) {
389 				/* copied already, allow trampling */
390 				skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
391 				skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
392 			}
393 			if (ret == TC_ACT_REPEAT)
394 				goto repeat;	/* we need a ttl - JHS */
395 			if (ret != TC_ACT_PIPE)
396 				goto exec_done;
397 		}
398 		act = a->next;
399 	}
400 exec_done:
401 	return ret;
402 }
403 EXPORT_SYMBOL(tcf_action_exec);
404 
405 void tcf_action_destroy(struct tc_action *act, int bind)
406 {
407 	struct tc_action *a;
408 
409 	for (a = act; a; a = act) {
410 		if (a->ops && a->ops->cleanup) {
411 			if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
412 				module_put(a->ops->owner);
413 			act = act->next;
414 			kfree(a);
415 		} else {
416 			/*FIXME: Remove later - catch insertion bugs*/
417 			WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
418 			act = act->next;
419 			kfree(a);
420 		}
421 	}
422 }
423 
424 int
425 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
426 {
427 	int err = -EINVAL;
428 
429 	if (a->ops == NULL || a->ops->dump == NULL)
430 		return err;
431 	return a->ops->dump(skb, a, bind, ref);
432 }
433 
434 int
435 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
436 {
437 	int err = -EINVAL;
438 	unsigned char *b = skb_tail_pointer(skb);
439 	struct nlattr *nest;
440 
441 	if (a->ops == NULL || a->ops->dump == NULL)
442 		return err;
443 
444 	NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
445 	if (tcf_action_copy_stats(skb, a, 0))
446 		goto nla_put_failure;
447 	nest = nla_nest_start(skb, TCA_OPTIONS);
448 	if (nest == NULL)
449 		goto nla_put_failure;
450 	err = tcf_action_dump_old(skb, a, bind, ref);
451 	if (err > 0) {
452 		nla_nest_end(skb, nest);
453 		return err;
454 	}
455 
456 nla_put_failure:
457 	nlmsg_trim(skb, b);
458 	return -1;
459 }
460 EXPORT_SYMBOL(tcf_action_dump_1);
461 
462 int
463 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
464 {
465 	struct tc_action *a;
466 	int err = -EINVAL;
467 	struct nlattr *nest;
468 
469 	while ((a = act) != NULL) {
470 		act = a->next;
471 		nest = nla_nest_start(skb, a->order);
472 		if (nest == NULL)
473 			goto nla_put_failure;
474 		err = tcf_action_dump_1(skb, a, bind, ref);
475 		if (err < 0)
476 			goto errout;
477 		nla_nest_end(skb, nest);
478 	}
479 
480 	return 0;
481 
482 nla_put_failure:
483 	err = -EINVAL;
484 errout:
485 	nla_nest_cancel(skb, nest);
486 	return err;
487 }
488 
489 struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
490 				    char *name, int ovr, int bind)
491 {
492 	struct tc_action *a;
493 	struct tc_action_ops *a_o;
494 	char act_name[IFNAMSIZ];
495 	struct nlattr *tb[TCA_ACT_MAX + 1];
496 	struct nlattr *kind;
497 	int err;
498 
499 	if (name == NULL) {
500 		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
501 		if (err < 0)
502 			goto err_out;
503 		err = -EINVAL;
504 		kind = tb[TCA_ACT_KIND];
505 		if (kind == NULL)
506 			goto err_out;
507 		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
508 			goto err_out;
509 	} else {
510 		err = -EINVAL;
511 		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
512 			goto err_out;
513 	}
514 
515 	a_o = tc_lookup_action_n(act_name);
516 	if (a_o == NULL) {
517 #ifdef CONFIG_MODULES
518 		rtnl_unlock();
519 		request_module("act_%s", act_name);
520 		rtnl_lock();
521 
522 		a_o = tc_lookup_action_n(act_name);
523 
524 		/* We dropped the RTNL semaphore in order to
525 		 * perform the module load.  So, even if we
526 		 * succeeded in loading the module we have to
527 		 * tell the caller to replay the request.  We
528 		 * indicate this using -EAGAIN.
529 		 */
530 		if (a_o != NULL) {
531 			err = -EAGAIN;
532 			goto err_mod;
533 		}
534 #endif
535 		err = -ENOENT;
536 		goto err_out;
537 	}
538 
539 	err = -ENOMEM;
540 	a = kzalloc(sizeof(*a), GFP_KERNEL);
541 	if (a == NULL)
542 		goto err_mod;
543 
544 	/* backward compatibility for policer */
545 	if (name == NULL)
546 		err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
547 	else
548 		err = a_o->init(nla, est, a, ovr, bind);
549 	if (err < 0)
550 		goto err_free;
551 
552 	/* module count goes up only when brand new policy is created
553 	 * if it exists and is only bound to in a_o->init() then
554 	 * ACT_P_CREATED is not returned (a zero is).
555 	 */
556 	if (err != ACT_P_CREATED)
557 		module_put(a_o->owner);
558 	a->ops = a_o;
559 
560 	return a;
561 
562 err_free:
563 	kfree(a);
564 err_mod:
565 	module_put(a_o->owner);
566 err_out:
567 	return ERR_PTR(err);
568 }
569 
570 struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
571 				  char *name, int ovr, int bind)
572 {
573 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
574 	struct tc_action *head = NULL, *act, *act_prev = NULL;
575 	int err;
576 	int i;
577 
578 	err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
579 	if (err < 0)
580 		return ERR_PTR(err);
581 
582 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
583 		act = tcf_action_init_1(tb[i], est, name, ovr, bind);
584 		if (IS_ERR(act))
585 			goto err;
586 		act->order = i;
587 
588 		if (head == NULL)
589 			head = act;
590 		else
591 			act_prev->next = act;
592 		act_prev = act;
593 	}
594 	return head;
595 
596 err:
597 	if (head != NULL)
598 		tcf_action_destroy(head, bind);
599 	return act;
600 }
601 
602 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
603 			  int compat_mode)
604 {
605 	int err = 0;
606 	struct gnet_dump d;
607 	struct tcf_act_hdr *h = a->priv;
608 
609 	if (h == NULL)
610 		goto errout;
611 
612 	/* compat_mode being true specifies a call that is supposed
613 	 * to add additional backward compatibility statistic TLVs.
614 	 */
615 	if (compat_mode) {
616 		if (a->type == TCA_OLD_COMPAT)
617 			err = gnet_stats_start_copy_compat(skb, 0,
618 				TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
619 		else
620 			return 0;
621 	} else
622 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
623 					    &h->tcf_lock, &d);
624 
625 	if (err < 0)
626 		goto errout;
627 
628 	if (a->ops != NULL && a->ops->get_stats != NULL)
629 		if (a->ops->get_stats(skb, a) < 0)
630 			goto errout;
631 
632 	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
633 	    gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
634 				     &h->tcf_rate_est) < 0 ||
635 	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
636 		goto errout;
637 
638 	if (gnet_stats_finish_copy(&d) < 0)
639 		goto errout;
640 
641 	return 0;
642 
643 errout:
644 	return -1;
645 }
646 
647 static int
648 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
649 	     u16 flags, int event, int bind, int ref)
650 {
651 	struct tcamsg *t;
652 	struct nlmsghdr *nlh;
653 	unsigned char *b = skb_tail_pointer(skb);
654 	struct nlattr *nest;
655 
656 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
657 
658 	t = NLMSG_DATA(nlh);
659 	t->tca_family = AF_UNSPEC;
660 	t->tca__pad1 = 0;
661 	t->tca__pad2 = 0;
662 
663 	nest = nla_nest_start(skb, TCA_ACT_TAB);
664 	if (nest == NULL)
665 		goto nla_put_failure;
666 
667 	if (tcf_action_dump(skb, a, bind, ref) < 0)
668 		goto nla_put_failure;
669 
670 	nla_nest_end(skb, nest);
671 
672 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
673 	return skb->len;
674 
675 nla_put_failure:
676 nlmsg_failure:
677 	nlmsg_trim(skb, b);
678 	return -1;
679 }
680 
681 static int
682 act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
683 	       struct tc_action *a, int event)
684 {
685 	struct sk_buff *skb;
686 
687 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
688 	if (!skb)
689 		return -ENOBUFS;
690 	if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
691 		kfree_skb(skb);
692 		return -EINVAL;
693 	}
694 
695 	return rtnl_unicast(skb, net, pid);
696 }
697 
698 static struct tc_action *
699 tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
700 {
701 	struct nlattr *tb[TCA_ACT_MAX + 1];
702 	struct tc_action *a;
703 	int index;
704 	int err;
705 
706 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
707 	if (err < 0)
708 		goto err_out;
709 
710 	err = -EINVAL;
711 	if (tb[TCA_ACT_INDEX] == NULL ||
712 	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
713 		goto err_out;
714 	index = nla_get_u32(tb[TCA_ACT_INDEX]);
715 
716 	err = -ENOMEM;
717 	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
718 	if (a == NULL)
719 		goto err_out;
720 
721 	err = -EINVAL;
722 	a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
723 	if (a->ops == NULL)
724 		goto err_free;
725 	if (a->ops->lookup == NULL)
726 		goto err_mod;
727 	err = -ENOENT;
728 	if (a->ops->lookup(a, index) == 0)
729 		goto err_mod;
730 
731 	module_put(a->ops->owner);
732 	return a;
733 
734 err_mod:
735 	module_put(a->ops->owner);
736 err_free:
737 	kfree(a);
738 err_out:
739 	return ERR_PTR(err);
740 }
741 
742 static void cleanup_a(struct tc_action *act)
743 {
744 	struct tc_action *a;
745 
746 	for (a = act; a; a = act) {
747 		act = a->next;
748 		kfree(a);
749 	}
750 }
751 
752 static struct tc_action *create_a(int i)
753 {
754 	struct tc_action *act;
755 
756 	act = kzalloc(sizeof(*act), GFP_KERNEL);
757 	if (act == NULL) {
758 		pr_debug("create_a: failed to alloc!\n");
759 		return NULL;
760 	}
761 	act->order = i;
762 	return act;
763 }
764 
765 static int tca_action_flush(struct net *net, struct nlattr *nla,
766 			    struct nlmsghdr *n, u32 pid)
767 {
768 	struct sk_buff *skb;
769 	unsigned char *b;
770 	struct nlmsghdr *nlh;
771 	struct tcamsg *t;
772 	struct netlink_callback dcb;
773 	struct nlattr *nest;
774 	struct nlattr *tb[TCA_ACT_MAX + 1];
775 	struct nlattr *kind;
776 	struct tc_action *a = create_a(0);
777 	int err = -ENOMEM;
778 
779 	if (a == NULL) {
780 		pr_debug("tca_action_flush: couldnt create tc_action\n");
781 		return err;
782 	}
783 
784 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
785 	if (!skb) {
786 		pr_debug("tca_action_flush: failed skb alloc\n");
787 		kfree(a);
788 		return err;
789 	}
790 
791 	b = skb_tail_pointer(skb);
792 
793 	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
794 	if (err < 0)
795 		goto err_out;
796 
797 	err = -EINVAL;
798 	kind = tb[TCA_ACT_KIND];
799 	a->ops = tc_lookup_action(kind);
800 	if (a->ops == NULL)
801 		goto err_out;
802 
803 	nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
804 	t = NLMSG_DATA(nlh);
805 	t->tca_family = AF_UNSPEC;
806 	t->tca__pad1 = 0;
807 	t->tca__pad2 = 0;
808 
809 	nest = nla_nest_start(skb, TCA_ACT_TAB);
810 	if (nest == NULL)
811 		goto nla_put_failure;
812 
813 	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
814 	if (err < 0)
815 		goto nla_put_failure;
816 	if (err == 0)
817 		goto noflush_out;
818 
819 	nla_nest_end(skb, nest);
820 
821 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
822 	nlh->nlmsg_flags |= NLM_F_ROOT;
823 	module_put(a->ops->owner);
824 	kfree(a);
825 	err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
826 			     n->nlmsg_flags & NLM_F_ECHO);
827 	if (err > 0)
828 		return 0;
829 
830 	return err;
831 
832 nla_put_failure:
833 nlmsg_failure:
834 	module_put(a->ops->owner);
835 err_out:
836 noflush_out:
837 	kfree_skb(skb);
838 	kfree(a);
839 	return err;
840 }
841 
842 static int
843 tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
844 	      u32 pid, int event)
845 {
846 	int i, ret;
847 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
848 	struct tc_action *head = NULL, *act, *act_prev = NULL;
849 
850 	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
851 	if (ret < 0)
852 		return ret;
853 
854 	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
855 		if (tb[1] != NULL)
856 			return tca_action_flush(net, tb[1], n, pid);
857 		else
858 			return -EINVAL;
859 	}
860 
861 	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
862 		act = tcf_action_get_1(tb[i], n, pid);
863 		if (IS_ERR(act)) {
864 			ret = PTR_ERR(act);
865 			goto err;
866 		}
867 		act->order = i;
868 
869 		if (head == NULL)
870 			head = act;
871 		else
872 			act_prev->next = act;
873 		act_prev = act;
874 	}
875 
876 	if (event == RTM_GETACTION)
877 		ret = act_get_notify(net, pid, n, head, event);
878 	else { /* delete */
879 		struct sk_buff *skb;
880 
881 		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
882 		if (!skb) {
883 			ret = -ENOBUFS;
884 			goto err;
885 		}
886 
887 		if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
888 				 0, 1) <= 0) {
889 			kfree_skb(skb);
890 			ret = -EINVAL;
891 			goto err;
892 		}
893 
894 		/* now do the delete */
895 		tcf_action_destroy(head, 0);
896 		ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
897 				     n->nlmsg_flags & NLM_F_ECHO);
898 		if (ret > 0)
899 			return 0;
900 		return ret;
901 	}
902 err:
903 	cleanup_a(head);
904 	return ret;
905 }
906 
907 static int tcf_add_notify(struct net *net, struct tc_action *a,
908 			  u32 pid, u32 seq, int event, u16 flags)
909 {
910 	struct tcamsg *t;
911 	struct nlmsghdr *nlh;
912 	struct sk_buff *skb;
913 	struct nlattr *nest;
914 	unsigned char *b;
915 	int err = 0;
916 
917 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
918 	if (!skb)
919 		return -ENOBUFS;
920 
921 	b = skb_tail_pointer(skb);
922 
923 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
924 	t = NLMSG_DATA(nlh);
925 	t->tca_family = AF_UNSPEC;
926 	t->tca__pad1 = 0;
927 	t->tca__pad2 = 0;
928 
929 	nest = nla_nest_start(skb, TCA_ACT_TAB);
930 	if (nest == NULL)
931 		goto nla_put_failure;
932 
933 	if (tcf_action_dump(skb, a, 0, 0) < 0)
934 		goto nla_put_failure;
935 
936 	nla_nest_end(skb, nest);
937 
938 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
939 	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
940 
941 	err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
942 	if (err > 0)
943 		err = 0;
944 	return err;
945 
946 nla_put_failure:
947 nlmsg_failure:
948 	kfree_skb(skb);
949 	return -1;
950 }
951 
952 
953 static int
954 tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
955 	       u32 pid, int ovr)
956 {
957 	int ret = 0;
958 	struct tc_action *act;
959 	struct tc_action *a;
960 	u32 seq = n->nlmsg_seq;
961 
962 	act = tcf_action_init(nla, NULL, NULL, ovr, 0);
963 	if (act == NULL)
964 		goto done;
965 	if (IS_ERR(act)) {
966 		ret = PTR_ERR(act);
967 		goto done;
968 	}
969 
970 	/* dump then free all the actions after update; inserted policy
971 	 * stays intact
972 	 */
973 	ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
974 	for (a = act; a; a = act) {
975 		act = a->next;
976 		kfree(a);
977 	}
978 done:
979 	return ret;
980 }
981 
982 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
983 {
984 	struct net *net = sock_net(skb->sk);
985 	struct nlattr *tca[TCA_ACT_MAX + 1];
986 	u32 pid = skb ? NETLINK_CB(skb).pid : 0;
987 	int ret = 0, ovr = 0;
988 
989 	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
990 	if (ret < 0)
991 		return ret;
992 
993 	if (tca[TCA_ACT_TAB] == NULL) {
994 		pr_notice("tc_ctl_action: received NO action attribs\n");
995 		return -EINVAL;
996 	}
997 
998 	/* n->nlmsg_flags & NLM_F_CREATE */
999 	switch (n->nlmsg_type) {
1000 	case RTM_NEWACTION:
1001 		/* we are going to assume all other flags
1002 		 * imply create only if it doesnt exist
1003 		 * Note that CREATE | EXCL implies that
1004 		 * but since we want avoid ambiguity (eg when flags
1005 		 * is zero) then just set this
1006 		 */
1007 		if (n->nlmsg_flags & NLM_F_REPLACE)
1008 			ovr = 1;
1009 replay:
1010 		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1011 		if (ret == -EAGAIN)
1012 			goto replay;
1013 		break;
1014 	case RTM_DELACTION:
1015 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1016 				    pid, RTM_DELACTION);
1017 		break;
1018 	case RTM_GETACTION:
1019 		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1020 				    pid, RTM_GETACTION);
1021 		break;
1022 	default:
1023 		BUG();
1024 	}
1025 
1026 	return ret;
1027 }
1028 
1029 static struct nlattr *
1030 find_dump_kind(const struct nlmsghdr *n)
1031 {
1032 	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1033 	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1034 	struct nlattr *nla[TCAA_MAX + 1];
1035 	struct nlattr *kind;
1036 
1037 	if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1038 		return NULL;
1039 	tb1 = nla[TCA_ACT_TAB];
1040 	if (tb1 == NULL)
1041 		return NULL;
1042 
1043 	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1044 		      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1045 		return NULL;
1046 
1047 	if (tb[1] == NULL)
1048 		return NULL;
1049 	if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1050 		      nla_len(tb[1]), NULL) < 0)
1051 		return NULL;
1052 	kind = tb2[TCA_ACT_KIND];
1053 
1054 	return kind;
1055 }
1056 
1057 static int
1058 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1059 {
1060 	struct nlmsghdr *nlh;
1061 	unsigned char *b = skb_tail_pointer(skb);
1062 	struct nlattr *nest;
1063 	struct tc_action_ops *a_o;
1064 	struct tc_action a;
1065 	int ret = 0;
1066 	struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1067 	struct nlattr *kind = find_dump_kind(cb->nlh);
1068 
1069 	if (kind == NULL) {
1070 		pr_info("tc_dump_action: action bad kind\n");
1071 		return 0;
1072 	}
1073 
1074 	a_o = tc_lookup_action(kind);
1075 	if (a_o == NULL)
1076 		return 0;
1077 
1078 	memset(&a, 0, sizeof(struct tc_action));
1079 	a.ops = a_o;
1080 
1081 	if (a_o->walk == NULL) {
1082 		WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1083 		     a_o->kind);
1084 		goto nla_put_failure;
1085 	}
1086 
1087 	nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1088 			cb->nlh->nlmsg_type, sizeof(*t));
1089 	t = NLMSG_DATA(nlh);
1090 	t->tca_family = AF_UNSPEC;
1091 	t->tca__pad1 = 0;
1092 	t->tca__pad2 = 0;
1093 
1094 	nest = nla_nest_start(skb, TCA_ACT_TAB);
1095 	if (nest == NULL)
1096 		goto nla_put_failure;
1097 
1098 	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1099 	if (ret < 0)
1100 		goto nla_put_failure;
1101 
1102 	if (ret > 0) {
1103 		nla_nest_end(skb, nest);
1104 		ret = skb->len;
1105 	} else
1106 		nla_nest_cancel(skb, nest);
1107 
1108 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1109 	if (NETLINK_CB(cb->skb).pid && ret)
1110 		nlh->nlmsg_flags |= NLM_F_MULTI;
1111 	module_put(a_o->owner);
1112 	return skb->len;
1113 
1114 nla_put_failure:
1115 nlmsg_failure:
1116 	module_put(a_o->owner);
1117 	nlmsg_trim(skb, b);
1118 	return skb->len;
1119 }
1120 
1121 static int __init tc_action_init(void)
1122 {
1123 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1124 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1125 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1126 
1127 	return 0;
1128 }
1129 
1130 subsys_initcall(tc_action_init);
1131