xref: /openbmc/linux/net/sched/act_api.c (revision e868d61272caa648214046a096e5a6bfc068dc8c)
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 <asm/uaccess.h>
15 #include <asm/system.h>
16 #include <linux/bitops.h>
17 #include <linux/types.h>
18 #include <linux/kernel.h>
19 #include <linux/string.h>
20 #include <linux/mm.h>
21 #include <linux/socket.h>
22 #include <linux/sockios.h>
23 #include <linux/in.h>
24 #include <linux/errno.h>
25 #include <linux/interrupt.h>
26 #include <linux/netdevice.h>
27 #include <linux/skbuff.h>
28 #include <linux/init.h>
29 #include <linux/kmod.h>
30 #include <net/sock.h>
31 #include <net/sch_generic.h>
32 #include <net/act_api.h>
33 #include <net/netlink.h>
34 
35 void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
36 {
37 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
38 	struct tcf_common **p1p;
39 
40 	for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
41 		if (*p1p == p) {
42 			write_lock_bh(hinfo->lock);
43 			*p1p = p->tcfc_next;
44 			write_unlock_bh(hinfo->lock);
45 #ifdef CONFIG_NET_ESTIMATOR
46 			gen_kill_estimator(&p->tcfc_bstats,
47 					   &p->tcfc_rate_est);
48 #endif
49 			kfree(p);
50 			return;
51 		}
52 	}
53 	BUG_TRAP(0);
54 }
55 EXPORT_SYMBOL(tcf_hash_destroy);
56 
57 int tcf_hash_release(struct tcf_common *p, int bind,
58 		     struct tcf_hashinfo *hinfo)
59 {
60 	int ret = 0;
61 
62 	if (p) {
63 		if (bind)
64 			p->tcfc_bindcnt--;
65 
66 		p->tcfc_refcnt--;
67 		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
68 			tcf_hash_destroy(p, hinfo);
69 			ret = 1;
70 		}
71 	}
72 	return ret;
73 }
74 EXPORT_SYMBOL(tcf_hash_release);
75 
76 static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
77 			   struct tc_action *a, struct tcf_hashinfo *hinfo)
78 {
79 	struct tcf_common *p;
80 	int err = 0, index = -1,i = 0, s_i = 0, n_i = 0;
81 	struct rtattr *r ;
82 
83 	read_lock(hinfo->lock);
84 
85 	s_i = cb->args[0];
86 
87 	for (i = 0; i < (hinfo->hmask + 1); i++) {
88 		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
89 
90 		for (; p; p = p->tcfc_next) {
91 			index++;
92 			if (index < s_i)
93 				continue;
94 			a->priv = p;
95 			a->order = n_i;
96 			r = (struct rtattr *)skb_tail_pointer(skb);
97 			RTA_PUT(skb, a->order, 0, NULL);
98 			err = tcf_action_dump_1(skb, a, 0, 0);
99 			if (err < 0) {
100 				index--;
101 				nlmsg_trim(skb, r);
102 				goto done;
103 			}
104 			r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
105 			n_i++;
106 			if (n_i >= TCA_ACT_MAX_PRIO)
107 				goto done;
108 		}
109 	}
110 done:
111 	read_unlock(hinfo->lock);
112 	if (n_i)
113 		cb->args[0] += n_i;
114 	return n_i;
115 
116 rtattr_failure:
117 	nlmsg_trim(skb, r);
118 	goto done;
119 }
120 
121 static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
122 			  struct tcf_hashinfo *hinfo)
123 {
124 	struct tcf_common *p, *s_p;
125 	struct rtattr *r ;
126 	int i= 0, n_i = 0;
127 
128 	r = (struct rtattr *)skb_tail_pointer(skb);
129 	RTA_PUT(skb, a->order, 0, NULL);
130 	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
131 	for (i = 0; i < (hinfo->hmask + 1); i++) {
132 		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
133 
134 		while (p != NULL) {
135 			s_p = p->tcfc_next;
136 			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
137 				 module_put(a->ops->owner);
138 			n_i++;
139 			p = s_p;
140 		}
141 	}
142 	RTA_PUT(skb, TCA_FCNT, 4, &n_i);
143 	r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
144 
145 	return n_i;
146 rtattr_failure:
147 	nlmsg_trim(skb, r);
148 	return -EINVAL;
149 }
150 
151 int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
152 		       int type, struct tc_action *a)
153 {
154 	struct tcf_hashinfo *hinfo = a->ops->hinfo;
155 
156 	if (type == RTM_DELACTION) {
157 		return tcf_del_walker(skb, a, hinfo);
158 	} else if (type == RTM_GETACTION) {
159 		return tcf_dump_walker(skb, cb, a, hinfo);
160 	} else {
161 		printk("tcf_generic_walker: unknown action %d\n", type);
162 		return -EINVAL;
163 	}
164 }
165 EXPORT_SYMBOL(tcf_generic_walker);
166 
167 struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
168 {
169 	struct tcf_common *p;
170 
171 	read_lock(hinfo->lock);
172 	for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
173 	     p = p->tcfc_next) {
174 		if (p->tcfc_index == index)
175 			break;
176 	}
177 	read_unlock(hinfo->lock);
178 
179 	return p;
180 }
181 EXPORT_SYMBOL(tcf_hash_lookup);
182 
183 u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
184 {
185 	u32 val = *idx_gen;
186 
187 	do {
188 		if (++val == 0)
189 			val = 1;
190 	} while (tcf_hash_lookup(val, hinfo));
191 
192 	return (*idx_gen = val);
193 }
194 EXPORT_SYMBOL(tcf_hash_new_index);
195 
196 int tcf_hash_search(struct tc_action *a, u32 index)
197 {
198 	struct tcf_hashinfo *hinfo = a->ops->hinfo;
199 	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
200 
201 	if (p) {
202 		a->priv = p;
203 		return 1;
204 	}
205 	return 0;
206 }
207 EXPORT_SYMBOL(tcf_hash_search);
208 
209 struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
210 				  struct tcf_hashinfo *hinfo)
211 {
212 	struct tcf_common *p = NULL;
213 	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
214 		if (bind) {
215 			p->tcfc_bindcnt++;
216 			p->tcfc_refcnt++;
217 		}
218 		a->priv = p;
219 	}
220 	return p;
221 }
222 EXPORT_SYMBOL(tcf_hash_check);
223 
224 struct tcf_common *tcf_hash_create(u32 index, struct rtattr *est, struct tc_action *a, int size, int bind, u32 *idx_gen, struct tcf_hashinfo *hinfo)
225 {
226 	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
227 
228 	if (unlikely(!p))
229 		return p;
230 	p->tcfc_refcnt = 1;
231 	if (bind)
232 		p->tcfc_bindcnt = 1;
233 
234 	spin_lock_init(&p->tcfc_lock);
235 	p->tcfc_stats_lock = &p->tcfc_lock;
236 	p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
237 	p->tcfc_tm.install = jiffies;
238 	p->tcfc_tm.lastuse = jiffies;
239 #ifdef CONFIG_NET_ESTIMATOR
240 	if (est)
241 		gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
242 				  p->tcfc_stats_lock, est);
243 #endif
244 	a->priv = (void *) p;
245 	return p;
246 }
247 EXPORT_SYMBOL(tcf_hash_create);
248 
249 void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
250 {
251 	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
252 
253 	write_lock_bh(hinfo->lock);
254 	p->tcfc_next = hinfo->htab[h];
255 	hinfo->htab[h] = p;
256 	write_unlock_bh(hinfo->lock);
257 }
258 EXPORT_SYMBOL(tcf_hash_insert);
259 
260 static struct tc_action_ops *act_base = NULL;
261 static DEFINE_RWLOCK(act_mod_lock);
262 
263 int tcf_register_action(struct tc_action_ops *act)
264 {
265 	struct tc_action_ops *a, **ap;
266 
267 	write_lock(&act_mod_lock);
268 	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
269 		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
270 			write_unlock(&act_mod_lock);
271 			return -EEXIST;
272 		}
273 	}
274 	act->next = NULL;
275 	*ap = act;
276 	write_unlock(&act_mod_lock);
277 	return 0;
278 }
279 
280 int tcf_unregister_action(struct tc_action_ops *act)
281 {
282 	struct tc_action_ops *a, **ap;
283 	int err = -ENOENT;
284 
285 	write_lock(&act_mod_lock);
286 	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
287 		if (a == act)
288 			break;
289 	if (a) {
290 		*ap = a->next;
291 		a->next = NULL;
292 		err = 0;
293 	}
294 	write_unlock(&act_mod_lock);
295 	return err;
296 }
297 
298 /* lookup by name */
299 static struct tc_action_ops *tc_lookup_action_n(char *kind)
300 {
301 	struct tc_action_ops *a = NULL;
302 
303 	if (kind) {
304 		read_lock(&act_mod_lock);
305 		for (a = act_base; a; a = a->next) {
306 			if (strcmp(kind, a->kind) == 0) {
307 				if (!try_module_get(a->owner)) {
308 					read_unlock(&act_mod_lock);
309 					return NULL;
310 				}
311 				break;
312 			}
313 		}
314 		read_unlock(&act_mod_lock);
315 	}
316 	return a;
317 }
318 
319 /* lookup by rtattr */
320 static struct tc_action_ops *tc_lookup_action(struct rtattr *kind)
321 {
322 	struct tc_action_ops *a = NULL;
323 
324 	if (kind) {
325 		read_lock(&act_mod_lock);
326 		for (a = act_base; a; a = a->next) {
327 			if (rtattr_strcmp(kind, a->kind) == 0) {
328 				if (!try_module_get(a->owner)) {
329 					read_unlock(&act_mod_lock);
330 					return NULL;
331 				}
332 				break;
333 			}
334 		}
335 		read_unlock(&act_mod_lock);
336 	}
337 	return a;
338 }
339 
340 #if 0
341 /* lookup by id */
342 static struct tc_action_ops *tc_lookup_action_id(u32 type)
343 {
344 	struct tc_action_ops *a = NULL;
345 
346 	if (type) {
347 		read_lock(&act_mod_lock);
348 		for (a = act_base; a; a = a->next) {
349 			if (a->type == type) {
350 				if (!try_module_get(a->owner)) {
351 					read_unlock(&act_mod_lock);
352 					return NULL;
353 				}
354 				break;
355 			}
356 		}
357 		read_unlock(&act_mod_lock);
358 	}
359 	return a;
360 }
361 #endif
362 
363 int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
364 		    struct tcf_result *res)
365 {
366 	struct tc_action *a;
367 	int ret = -1;
368 
369 	if (skb->tc_verd & TC_NCLS) {
370 		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
371 		ret = TC_ACT_OK;
372 		goto exec_done;
373 	}
374 	while ((a = act) != NULL) {
375 repeat:
376 		if (a->ops && a->ops->act) {
377 			ret = a->ops->act(skb, a, res);
378 			if (TC_MUNGED & skb->tc_verd) {
379 				/* copied already, allow trampling */
380 				skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
381 				skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
382 			}
383 			if (ret == TC_ACT_REPEAT)
384 				goto repeat;	/* we need a ttl - JHS */
385 			if (ret != TC_ACT_PIPE)
386 				goto exec_done;
387 		}
388 		act = a->next;
389 	}
390 exec_done:
391 	return ret;
392 }
393 
394 void tcf_action_destroy(struct tc_action *act, int bind)
395 {
396 	struct tc_action *a;
397 
398 	for (a = act; a; a = act) {
399 		if (a->ops && a->ops->cleanup) {
400 			if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
401 				module_put(a->ops->owner);
402 			act = act->next;
403 			kfree(a);
404 		} else { /*FIXME: Remove later - catch insertion bugs*/
405 			printk("tcf_action_destroy: BUG? destroying NULL ops\n");
406 			act = act->next;
407 			kfree(a);
408 		}
409 	}
410 }
411 
412 int
413 tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
414 {
415 	int err = -EINVAL;
416 
417 	if (a->ops == NULL || a->ops->dump == NULL)
418 		return err;
419 	return a->ops->dump(skb, a, bind, ref);
420 }
421 
422 int
423 tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
424 {
425 	int err = -EINVAL;
426 	unsigned char *b = skb_tail_pointer(skb);
427 	struct rtattr *r;
428 
429 	if (a->ops == NULL || a->ops->dump == NULL)
430 		return err;
431 
432 	RTA_PUT(skb, TCA_KIND, IFNAMSIZ, a->ops->kind);
433 	if (tcf_action_copy_stats(skb, a, 0))
434 		goto rtattr_failure;
435 	r = (struct rtattr *)skb_tail_pointer(skb);
436 	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);
437 	if ((err = tcf_action_dump_old(skb, a, bind, ref)) > 0) {
438 		r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
439 		return err;
440 	}
441 
442 rtattr_failure:
443 	nlmsg_trim(skb, b);
444 	return -1;
445 }
446 
447 int
448 tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
449 {
450 	struct tc_action *a;
451 	int err = -EINVAL;
452 	unsigned char *b = skb_tail_pointer(skb);
453 	struct rtattr *r ;
454 
455 	while ((a = act) != NULL) {
456 		r = (struct rtattr *)skb_tail_pointer(skb);
457 		act = a->next;
458 		RTA_PUT(skb, a->order, 0, NULL);
459 		err = tcf_action_dump_1(skb, a, bind, ref);
460 		if (err < 0)
461 			goto errout;
462 		r->rta_len = skb_tail_pointer(skb) - (u8 *)r;
463 	}
464 
465 	return 0;
466 
467 rtattr_failure:
468 	err = -EINVAL;
469 errout:
470 	nlmsg_trim(skb, b);
471 	return err;
472 }
473 
474 struct tc_action *tcf_action_init_1(struct rtattr *rta, struct rtattr *est,
475 				    char *name, int ovr, int bind, int *err)
476 {
477 	struct tc_action *a;
478 	struct tc_action_ops *a_o;
479 	char act_name[IFNAMSIZ];
480 	struct rtattr *tb[TCA_ACT_MAX+1];
481 	struct rtattr *kind;
482 
483 	*err = -EINVAL;
484 
485 	if (name == NULL) {
486 		if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
487 			goto err_out;
488 		kind = tb[TCA_ACT_KIND-1];
489 		if (kind == NULL)
490 			goto err_out;
491 		if (rtattr_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
492 			goto err_out;
493 	} else {
494 		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
495 			goto err_out;
496 	}
497 
498 	a_o = tc_lookup_action_n(act_name);
499 	if (a_o == NULL) {
500 #ifdef CONFIG_KMOD
501 		rtnl_unlock();
502 		request_module("act_%s", act_name);
503 		rtnl_lock();
504 
505 		a_o = tc_lookup_action_n(act_name);
506 
507 		/* We dropped the RTNL semaphore in order to
508 		 * perform the module load.  So, even if we
509 		 * succeeded in loading the module we have to
510 		 * tell the caller to replay the request.  We
511 		 * indicate this using -EAGAIN.
512 		 */
513 		if (a_o != NULL) {
514 			*err = -EAGAIN;
515 			goto err_mod;
516 		}
517 #endif
518 		*err = -ENOENT;
519 		goto err_out;
520 	}
521 
522 	*err = -ENOMEM;
523 	a = kzalloc(sizeof(*a), GFP_KERNEL);
524 	if (a == NULL)
525 		goto err_mod;
526 
527 	/* backward compatibility for policer */
528 	if (name == NULL)
529 		*err = a_o->init(tb[TCA_ACT_OPTIONS-1], est, a, ovr, bind);
530 	else
531 		*err = a_o->init(rta, est, a, ovr, bind);
532 	if (*err < 0)
533 		goto err_free;
534 
535 	/* module count goes up only when brand new policy is created
536 	   if it exists and is only bound to in a_o->init() then
537 	   ACT_P_CREATED is not returned (a zero is).
538 	*/
539 	if (*err != ACT_P_CREATED)
540 		module_put(a_o->owner);
541 	a->ops = a_o;
542 
543 	*err = 0;
544 	return a;
545 
546 err_free:
547 	kfree(a);
548 err_mod:
549 	module_put(a_o->owner);
550 err_out:
551 	return NULL;
552 }
553 
554 struct tc_action *tcf_action_init(struct rtattr *rta, struct rtattr *est,
555 				  char *name, int ovr, int bind, int *err)
556 {
557 	struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
558 	struct tc_action *head = NULL, *act, *act_prev = NULL;
559 	int i;
560 
561 	if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0) {
562 		*err = -EINVAL;
563 		return head;
564 	}
565 
566 	for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
567 		act = tcf_action_init_1(tb[i], est, name, ovr, bind, err);
568 		if (act == NULL)
569 			goto err;
570 		act->order = i+1;
571 
572 		if (head == NULL)
573 			head = act;
574 		else
575 			act_prev->next = act;
576 		act_prev = act;
577 	}
578 	return head;
579 
580 err:
581 	if (head != NULL)
582 		tcf_action_destroy(head, bind);
583 	return NULL;
584 }
585 
586 int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
587 			  int compat_mode)
588 {
589 	int err = 0;
590 	struct gnet_dump d;
591 	struct tcf_act_hdr *h = a->priv;
592 
593 	if (h == NULL)
594 		goto errout;
595 
596 	/* compat_mode being true specifies a call that is supposed
597 	 * to add additional backward compatiblity statistic TLVs.
598 	 */
599 	if (compat_mode) {
600 		if (a->type == TCA_OLD_COMPAT)
601 			err = gnet_stats_start_copy_compat(skb, 0,
602 				TCA_STATS, TCA_XSTATS, h->tcf_stats_lock, &d);
603 		else
604 			return 0;
605 	} else
606 		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
607 			h->tcf_stats_lock, &d);
608 
609 	if (err < 0)
610 		goto errout;
611 
612 	if (a->ops != NULL && a->ops->get_stats != NULL)
613 		if (a->ops->get_stats(skb, a) < 0)
614 			goto errout;
615 
616 	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
617 #ifdef CONFIG_NET_ESTIMATOR
618 	    gnet_stats_copy_rate_est(&d, &h->tcf_rate_est) < 0 ||
619 #endif
620 	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
621 		goto errout;
622 
623 	if (gnet_stats_finish_copy(&d) < 0)
624 		goto errout;
625 
626 	return 0;
627 
628 errout:
629 	return -1;
630 }
631 
632 static int
633 tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
634 	     u16 flags, int event, int bind, int ref)
635 {
636 	struct tcamsg *t;
637 	struct nlmsghdr *nlh;
638 	unsigned char *b = skb_tail_pointer(skb);
639 	struct rtattr *x;
640 
641 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
642 
643 	t = NLMSG_DATA(nlh);
644 	t->tca_family = AF_UNSPEC;
645 	t->tca__pad1 = 0;
646 	t->tca__pad2 = 0;
647 
648 	x = (struct rtattr *)skb_tail_pointer(skb);
649 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
650 
651 	if (tcf_action_dump(skb, a, bind, ref) < 0)
652 		goto rtattr_failure;
653 
654 	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
655 
656 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
657 	return skb->len;
658 
659 rtattr_failure:
660 nlmsg_failure:
661 	nlmsg_trim(skb, b);
662 	return -1;
663 }
664 
665 static int
666 act_get_notify(u32 pid, struct nlmsghdr *n, struct tc_action *a, int event)
667 {
668 	struct sk_buff *skb;
669 
670 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
671 	if (!skb)
672 		return -ENOBUFS;
673 	if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
674 		kfree_skb(skb);
675 		return -EINVAL;
676 	}
677 
678 	return rtnl_unicast(skb, pid);
679 }
680 
681 static struct tc_action *
682 tcf_action_get_1(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int *err)
683 {
684 	struct rtattr *tb[TCA_ACT_MAX+1];
685 	struct tc_action *a;
686 	int index;
687 
688 	*err = -EINVAL;
689 	if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
690 		return NULL;
691 
692 	if (tb[TCA_ACT_INDEX - 1] == NULL ||
693 	    RTA_PAYLOAD(tb[TCA_ACT_INDEX - 1]) < sizeof(index))
694 		return NULL;
695 	index = *(int *)RTA_DATA(tb[TCA_ACT_INDEX - 1]);
696 
697 	*err = -ENOMEM;
698 	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
699 	if (a == NULL)
700 		return NULL;
701 
702 	*err = -EINVAL;
703 	a->ops = tc_lookup_action(tb[TCA_ACT_KIND - 1]);
704 	if (a->ops == NULL)
705 		goto err_free;
706 	if (a->ops->lookup == NULL)
707 		goto err_mod;
708 	*err = -ENOENT;
709 	if (a->ops->lookup(a, index) == 0)
710 		goto err_mod;
711 
712 	module_put(a->ops->owner);
713 	*err = 0;
714 	return a;
715 err_mod:
716 	module_put(a->ops->owner);
717 err_free:
718 	kfree(a);
719 	return NULL;
720 }
721 
722 static void cleanup_a(struct tc_action *act)
723 {
724 	struct tc_action *a;
725 
726 	for (a = act; a; a = act) {
727 		act = a->next;
728 		kfree(a);
729 	}
730 }
731 
732 static struct tc_action *create_a(int i)
733 {
734 	struct tc_action *act;
735 
736 	act = kzalloc(sizeof(*act), GFP_KERNEL);
737 	if (act == NULL) {
738 		printk("create_a: failed to alloc!\n");
739 		return NULL;
740 	}
741 	act->order = i;
742 	return act;
743 }
744 
745 static int tca_action_flush(struct rtattr *rta, struct nlmsghdr *n, u32 pid)
746 {
747 	struct sk_buff *skb;
748 	unsigned char *b;
749 	struct nlmsghdr *nlh;
750 	struct tcamsg *t;
751 	struct netlink_callback dcb;
752 	struct rtattr *x;
753 	struct rtattr *tb[TCA_ACT_MAX+1];
754 	struct rtattr *kind;
755 	struct tc_action *a = create_a(0);
756 	int err = -EINVAL;
757 
758 	if (a == NULL) {
759 		printk("tca_action_flush: couldnt create tc_action\n");
760 		return err;
761 	}
762 
763 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
764 	if (!skb) {
765 		printk("tca_action_flush: failed skb alloc\n");
766 		kfree(a);
767 		return -ENOBUFS;
768 	}
769 
770 	b = skb_tail_pointer(skb);
771 
772 	if (rtattr_parse_nested(tb, TCA_ACT_MAX, rta) < 0)
773 		goto err_out;
774 
775 	kind = tb[TCA_ACT_KIND-1];
776 	a->ops = tc_lookup_action(kind);
777 	if (a->ops == NULL)
778 		goto err_out;
779 
780 	nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
781 	t = NLMSG_DATA(nlh);
782 	t->tca_family = AF_UNSPEC;
783 	t->tca__pad1 = 0;
784 	t->tca__pad2 = 0;
785 
786 	x = (struct rtattr *)skb_tail_pointer(skb);
787 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
788 
789 	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
790 	if (err < 0)
791 		goto rtattr_failure;
792 
793 	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
794 
795 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
796 	nlh->nlmsg_flags |= NLM_F_ROOT;
797 	module_put(a->ops->owner);
798 	kfree(a);
799 	err = rtnetlink_send(skb, pid, RTNLGRP_TC, n->nlmsg_flags&NLM_F_ECHO);
800 	if (err > 0)
801 		return 0;
802 
803 	return err;
804 
805 rtattr_failure:
806 nlmsg_failure:
807 	module_put(a->ops->owner);
808 err_out:
809 	kfree_skb(skb);
810 	kfree(a);
811 	return err;
812 }
813 
814 static int
815 tca_action_gd(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int event)
816 {
817 	int i, ret = 0;
818 	struct rtattr *tb[TCA_ACT_MAX_PRIO+1];
819 	struct tc_action *head = NULL, *act, *act_prev = NULL;
820 
821 	if (rtattr_parse_nested(tb, TCA_ACT_MAX_PRIO, rta) < 0)
822 		return -EINVAL;
823 
824 	if (event == RTM_DELACTION && n->nlmsg_flags&NLM_F_ROOT) {
825 		if (tb[0] != NULL && tb[1] == NULL)
826 			return tca_action_flush(tb[0], n, pid);
827 	}
828 
829 	for (i=0; i < TCA_ACT_MAX_PRIO && tb[i]; i++) {
830 		act = tcf_action_get_1(tb[i], n, pid, &ret);
831 		if (act == NULL)
832 			goto err;
833 		act->order = i+1;
834 
835 		if (head == NULL)
836 			head = act;
837 		else
838 			act_prev->next = act;
839 		act_prev = act;
840 	}
841 
842 	if (event == RTM_GETACTION)
843 		ret = act_get_notify(pid, n, head, event);
844 	else { /* delete */
845 		struct sk_buff *skb;
846 
847 		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
848 		if (!skb) {
849 			ret = -ENOBUFS;
850 			goto err;
851 		}
852 
853 		if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
854 				 0, 1) <= 0) {
855 			kfree_skb(skb);
856 			ret = -EINVAL;
857 			goto err;
858 		}
859 
860 		/* now do the delete */
861 		tcf_action_destroy(head, 0);
862 		ret = rtnetlink_send(skb, pid, RTNLGRP_TC,
863 				     n->nlmsg_flags&NLM_F_ECHO);
864 		if (ret > 0)
865 			return 0;
866 		return ret;
867 	}
868 err:
869 	cleanup_a(head);
870 	return ret;
871 }
872 
873 static int tcf_add_notify(struct tc_action *a, u32 pid, u32 seq, int event,
874 			  u16 flags)
875 {
876 	struct tcamsg *t;
877 	struct nlmsghdr *nlh;
878 	struct sk_buff *skb;
879 	struct rtattr *x;
880 	unsigned char *b;
881 	int err = 0;
882 
883 	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
884 	if (!skb)
885 		return -ENOBUFS;
886 
887 	b = skb_tail_pointer(skb);
888 
889 	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
890 	t = NLMSG_DATA(nlh);
891 	t->tca_family = AF_UNSPEC;
892 	t->tca__pad1 = 0;
893 	t->tca__pad2 = 0;
894 
895 	x = (struct rtattr *)skb_tail_pointer(skb);
896 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
897 
898 	if (tcf_action_dump(skb, a, 0, 0) < 0)
899 		goto rtattr_failure;
900 
901 	x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
902 
903 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
904 	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
905 
906 	err = rtnetlink_send(skb, pid, RTNLGRP_TC, flags&NLM_F_ECHO);
907 	if (err > 0)
908 		err = 0;
909 	return err;
910 
911 rtattr_failure:
912 nlmsg_failure:
913 	kfree_skb(skb);
914 	return -1;
915 }
916 
917 
918 static int
919 tcf_action_add(struct rtattr *rta, struct nlmsghdr *n, u32 pid, int ovr)
920 {
921 	int ret = 0;
922 	struct tc_action *act;
923 	struct tc_action *a;
924 	u32 seq = n->nlmsg_seq;
925 
926 	act = tcf_action_init(rta, NULL, NULL, ovr, 0, &ret);
927 	if (act == NULL)
928 		goto done;
929 
930 	/* dump then free all the actions after update; inserted policy
931 	 * stays intact
932 	 * */
933 	ret = tcf_add_notify(act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
934 	for (a = act; a; a = act) {
935 		act = a->next;
936 		kfree(a);
937 	}
938 done:
939 	return ret;
940 }
941 
942 static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
943 {
944 	struct rtattr **tca = arg;
945 	u32 pid = skb ? NETLINK_CB(skb).pid : 0;
946 	int ret = 0, ovr = 0;
947 
948 	if (tca[TCA_ACT_TAB-1] == NULL) {
949 		printk("tc_ctl_action: received NO action attribs\n");
950 		return -EINVAL;
951 	}
952 
953 	/* n->nlmsg_flags&NLM_F_CREATE
954 	 * */
955 	switch (n->nlmsg_type) {
956 	case RTM_NEWACTION:
957 		/* we are going to assume all other flags
958 		 * imply create only if it doesnt exist
959 		 * Note that CREATE | EXCL implies that
960 		 * but since we want avoid ambiguity (eg when flags
961 		 * is zero) then just set this
962 		 */
963 		if (n->nlmsg_flags&NLM_F_REPLACE)
964 			ovr = 1;
965 replay:
966 		ret = tcf_action_add(tca[TCA_ACT_TAB-1], n, pid, ovr);
967 		if (ret == -EAGAIN)
968 			goto replay;
969 		break;
970 	case RTM_DELACTION:
971 		ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_DELACTION);
972 		break;
973 	case RTM_GETACTION:
974 		ret = tca_action_gd(tca[TCA_ACT_TAB-1], n, pid, RTM_GETACTION);
975 		break;
976 	default:
977 		BUG();
978 	}
979 
980 	return ret;
981 }
982 
983 static struct rtattr *
984 find_dump_kind(struct nlmsghdr *n)
985 {
986 	struct rtattr *tb1, *tb2[TCA_ACT_MAX+1];
987 	struct rtattr *tb[TCA_ACT_MAX_PRIO + 1];
988 	struct rtattr *rta[TCAA_MAX + 1];
989 	struct rtattr *kind;
990 	int min_len = NLMSG_LENGTH(sizeof(struct tcamsg));
991 	int attrlen = n->nlmsg_len - NLMSG_ALIGN(min_len);
992 	struct rtattr *attr = (void *) n + NLMSG_ALIGN(min_len);
993 
994 	if (rtattr_parse(rta, TCAA_MAX, attr, attrlen) < 0)
995 		return NULL;
996 	tb1 = rta[TCA_ACT_TAB - 1];
997 	if (tb1 == NULL)
998 		return NULL;
999 
1000 	if (rtattr_parse(tb, TCA_ACT_MAX_PRIO, RTA_DATA(tb1),
1001 			 NLMSG_ALIGN(RTA_PAYLOAD(tb1))) < 0)
1002 		return NULL;
1003 	if (tb[0] == NULL)
1004 		return NULL;
1005 
1006 	if (rtattr_parse(tb2, TCA_ACT_MAX, RTA_DATA(tb[0]),
1007 			 RTA_PAYLOAD(tb[0])) < 0)
1008 		return NULL;
1009 	kind = tb2[TCA_ACT_KIND-1];
1010 
1011 	return kind;
1012 }
1013 
1014 static int
1015 tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1016 {
1017 	struct nlmsghdr *nlh;
1018 	unsigned char *b = skb_tail_pointer(skb);
1019 	struct rtattr *x;
1020 	struct tc_action_ops *a_o;
1021 	struct tc_action a;
1022 	int ret = 0;
1023 	struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1024 	struct rtattr *kind = find_dump_kind(cb->nlh);
1025 
1026 	if (kind == NULL) {
1027 		printk("tc_dump_action: action bad kind\n");
1028 		return 0;
1029 	}
1030 
1031 	a_o = tc_lookup_action(kind);
1032 	if (a_o == NULL) {
1033 		return 0;
1034 	}
1035 
1036 	memset(&a, 0, sizeof(struct tc_action));
1037 	a.ops = a_o;
1038 
1039 	if (a_o->walk == NULL) {
1040 		printk("tc_dump_action: %s !capable of dumping table\n", a_o->kind);
1041 		goto rtattr_failure;
1042 	}
1043 
1044 	nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1045 			cb->nlh->nlmsg_type, sizeof(*t));
1046 	t = NLMSG_DATA(nlh);
1047 	t->tca_family = AF_UNSPEC;
1048 	t->tca__pad1 = 0;
1049 	t->tca__pad2 = 0;
1050 
1051 	x = (struct rtattr *)skb_tail_pointer(skb);
1052 	RTA_PUT(skb, TCA_ACT_TAB, 0, NULL);
1053 
1054 	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1055 	if (ret < 0)
1056 		goto rtattr_failure;
1057 
1058 	if (ret > 0) {
1059 		x->rta_len = skb_tail_pointer(skb) - (u8 *)x;
1060 		ret = skb->len;
1061 	} else
1062 		nlmsg_trim(skb, x);
1063 
1064 	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1065 	if (NETLINK_CB(cb->skb).pid && ret)
1066 		nlh->nlmsg_flags |= NLM_F_MULTI;
1067 	module_put(a_o->owner);
1068 	return skb->len;
1069 
1070 rtattr_failure:
1071 nlmsg_failure:
1072 	module_put(a_o->owner);
1073 	nlmsg_trim(skb, b);
1074 	return skb->len;
1075 }
1076 
1077 static int __init tc_action_init(void)
1078 {
1079 	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1080 	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1081 	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1082 
1083 	return 0;
1084 }
1085 
1086 subsys_initcall(tc_action_init);
1087 
1088 EXPORT_SYMBOL(tcf_register_action);
1089 EXPORT_SYMBOL(tcf_unregister_action);
1090 EXPORT_SYMBOL(tcf_action_exec);
1091 EXPORT_SYMBOL(tcf_action_dump_1);
1092