act_api.c revision f5c8593c107500979909bd51c85e74bb2eaffbaa 
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
29void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
30{
31	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
32	struct tcf_common **p1p;
33
34	for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
35		if (*p1p == p) {
36			write_lock_bh(hinfo->lock);
37			*p1p = p->tcfc_next;
38			write_unlock_bh(hinfo->lock);
39			gen_kill_estimator(&p->tcfc_bstats,
40					   &p->tcfc_rate_est);
41			/*
42			 * gen_estimator est_timer() might access p->tcfc_lock
43			 * or bstats, wait a RCU grace period before freeing p
44			 */
45			kfree_rcu(p, tcfc_rcu);
46			return;
47		}
48	}
49	WARN_ON(1);
50}
51EXPORT_SYMBOL(tcf_hash_destroy);
52
53int tcf_hash_release(struct tcf_common *p, int bind,
54		     struct tcf_hashinfo *hinfo)
55{
56	int ret = 0;
57
58	if (p) {
59		if (bind)
60			p->tcfc_bindcnt--;
61
62		p->tcfc_refcnt--;
63		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
64			tcf_hash_destroy(p, hinfo);
65			ret = 1;
66		}
67	}
68	return ret;
69}
70EXPORT_SYMBOL(tcf_hash_release);
71
72static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
73			   struct tc_action *a, struct tcf_hashinfo *hinfo)
74{
75	struct tcf_common *p;
76	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
77	struct nlattr *nest;
78
79	read_lock_bh(hinfo->lock);
80
81	s_i = cb->args[0];
82
83	for (i = 0; i < (hinfo->hmask + 1); i++) {
84		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
85
86		for (; p; p = p->tcfc_next) {
87			index++;
88			if (index < s_i)
89				continue;
90			a->priv = p;
91			a->order = n_i;
92
93			nest = nla_nest_start(skb, a->order);
94			if (nest == NULL)
95				goto nla_put_failure;
96			err = tcf_action_dump_1(skb, a, 0, 0);
97			if (err < 0) {
98				index--;
99				nlmsg_trim(skb, nest);
100				goto done;
101			}
102			nla_nest_end(skb, nest);
103			n_i++;
104			if (n_i >= TCA_ACT_MAX_PRIO)
105				goto done;
106		}
107	}
108done:
109	read_unlock_bh(hinfo->lock);
110	if (n_i)
111		cb->args[0] += n_i;
112	return n_i;
113
114nla_put_failure:
115	nla_nest_cancel(skb, nest);
116	goto done;
117}
118
119static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
120			  struct tcf_hashinfo *hinfo)
121{
122	struct tcf_common *p, *s_p;
123	struct nlattr *nest;
124	int i = 0, n_i = 0;
125
126	nest = nla_nest_start(skb, a->order);
127	if (nest == NULL)
128		goto nla_put_failure;
129	NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
130	for (i = 0; i < (hinfo->hmask + 1); i++) {
131		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
132
133		while (p != NULL) {
134			s_p = p->tcfc_next;
135			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
136				module_put(a->ops->owner);
137			n_i++;
138			p = s_p;
139		}
140	}
141	NLA_PUT_U32(skb, TCA_FCNT, n_i);
142	nla_nest_end(skb, nest);
143
144	return n_i;
145nla_put_failure:
146	nla_nest_cancel(skb, nest);
147	return -EINVAL;
148}
149
150int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
151		       int type, struct tc_action *a)
152{
153	struct tcf_hashinfo *hinfo = a->ops->hinfo;
154
155	if (type == RTM_DELACTION) {
156		return tcf_del_walker(skb, a, hinfo);
157	} else if (type == RTM_GETACTION) {
158		return tcf_dump_walker(skb, cb, a, hinfo);
159	} else {
160		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
161		return -EINVAL;
162	}
163}
164EXPORT_SYMBOL(tcf_generic_walker);
165
166struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
167{
168	struct tcf_common *p;
169
170	read_lock_bh(hinfo->lock);
171	for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
172	     p = p->tcfc_next) {
173		if (p->tcfc_index == index)
174			break;
175	}
176	read_unlock_bh(hinfo->lock);
177
178	return p;
179}
180EXPORT_SYMBOL(tcf_hash_lookup);
181
182u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
183{
184	u32 val = *idx_gen;
185
186	do {
187		if (++val == 0)
188			val = 1;
189	} while (tcf_hash_lookup(val, hinfo));
190
191	return (*idx_gen = val);
192}
193EXPORT_SYMBOL(tcf_hash_new_index);
194
195int tcf_hash_search(struct tc_action *a, u32 index)
196{
197	struct tcf_hashinfo *hinfo = a->ops->hinfo;
198	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
199
200	if (p) {
201		a->priv = p;
202		return 1;
203	}
204	return 0;
205}
206EXPORT_SYMBOL(tcf_hash_search);
207
208struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
209				  struct tcf_hashinfo *hinfo)
210{
211	struct tcf_common *p = NULL;
212	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
213		if (bind)
214			p->tcfc_bindcnt++;
215		p->tcfc_refcnt++;
216		a->priv = p;
217	}
218	return p;
219}
220EXPORT_SYMBOL(tcf_hash_check);
221
222struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
223				   struct tc_action *a, int size, int bind,
224				   u32 *idx_gen, struct tcf_hashinfo *hinfo)
225{
226	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
227
228	if (unlikely(!p))
229		return ERR_PTR(-ENOMEM);
230	p->tcfc_refcnt = 1;
231	if (bind)
232		p->tcfc_bindcnt = 1;
233
234	spin_lock_init(&p->tcfc_lock);
235	p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
236	p->tcfc_tm.install = jiffies;
237	p->tcfc_tm.lastuse = jiffies;
238	if (est) {
239		int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
240					    &p->tcfc_lock, est);
241		if (err) {
242			kfree(p);
243			return ERR_PTR(err);
244		}
245	}
246
247	a->priv = (void *) p;
248	return p;
249}
250EXPORT_SYMBOL(tcf_hash_create);
251
252void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
253{
254	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
255
256	write_lock_bh(hinfo->lock);
257	p->tcfc_next = hinfo->htab[h];
258	hinfo->htab[h] = p;
259	write_unlock_bh(hinfo->lock);
260}
261EXPORT_SYMBOL(tcf_hash_insert);
262
263static struct tc_action_ops *act_base = NULL;
264static DEFINE_RWLOCK(act_mod_lock);
265
266int tcf_register_action(struct tc_action_ops *act)
267{
268	struct tc_action_ops *a, **ap;
269
270	write_lock(&act_mod_lock);
271	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
272		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
273			write_unlock(&act_mod_lock);
274			return -EEXIST;
275		}
276	}
277	act->next = NULL;
278	*ap = act;
279	write_unlock(&act_mod_lock);
280	return 0;
281}
282EXPORT_SYMBOL(tcf_register_action);
283
284int tcf_unregister_action(struct tc_action_ops *act)
285{
286	struct tc_action_ops *a, **ap;
287	int err = -ENOENT;
288
289	write_lock(&act_mod_lock);
290	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
291		if (a == act)
292			break;
293	if (a) {
294		*ap = a->next;
295		a->next = NULL;
296		err = 0;
297	}
298	write_unlock(&act_mod_lock);
299	return err;
300}
301EXPORT_SYMBOL(tcf_unregister_action);
302
303/* lookup by name */
304static struct tc_action_ops *tc_lookup_action_n(char *kind)
305{
306	struct tc_action_ops *a = NULL;
307
308	if (kind) {
309		read_lock(&act_mod_lock);
310		for (a = act_base; a; a = a->next) {
311			if (strcmp(kind, a->kind) == 0) {
312				if (!try_module_get(a->owner)) {
313					read_unlock(&act_mod_lock);
314					return NULL;
315				}
316				break;
317			}
318		}
319		read_unlock(&act_mod_lock);
320	}
321	return a;
322}
323
324/* lookup by nlattr */
325static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
326{
327	struct tc_action_ops *a = NULL;
328
329	if (kind) {
330		read_lock(&act_mod_lock);
331		for (a = act_base; a; a = a->next) {
332			if (nla_strcmp(kind, a->kind) == 0) {
333				if (!try_module_get(a->owner)) {
334					read_unlock(&act_mod_lock);
335					return NULL;
336				}
337				break;
338			}
339		}
340		read_unlock(&act_mod_lock);
341	}
342	return a;
343}
344
345#if 0
346/* lookup by id */
347static struct tc_action_ops *tc_lookup_action_id(u32 type)
348{
349	struct tc_action_ops *a = NULL;
350
351	if (type) {
352		read_lock(&act_mod_lock);
353		for (a = act_base; a; a = a->next) {
354			if (a->type == type) {
355				if (!try_module_get(a->owner)) {
356					read_unlock(&act_mod_lock);
357					return NULL;
358				}
359				break;
360			}
361		}
362		read_unlock(&act_mod_lock);
363	}
364	return a;
365}
366#endif
367
368int tcf_action_exec(struct sk_buff *skb, struct tc_action *act,
369		    struct tcf_result *res)
370{
371	struct tc_action *a;
372	int ret = -1;
373
374	if (skb->tc_verd & TC_NCLS) {
375		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
376		ret = TC_ACT_OK;
377		goto exec_done;
378	}
379	while ((a = act) != NULL) {
380repeat:
381		if (a->ops && a->ops->act) {
382			ret = a->ops->act(skb, a, res);
383			if (TC_MUNGED & skb->tc_verd) {
384				/* copied already, allow trampling */
385				skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
386				skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
387			}
388			if (ret == TC_ACT_REPEAT)
389				goto repeat;	/* we need a ttl - JHS */
390			if (ret != TC_ACT_PIPE)
391				goto exec_done;
392		}
393		act = a->next;
394	}
395exec_done:
396	return ret;
397}
398EXPORT_SYMBOL(tcf_action_exec);
399
400void tcf_action_destroy(struct tc_action *act, int bind)
401{
402	struct tc_action *a;
403
404	for (a = act; a; a = act) {
405		if (a->ops && a->ops->cleanup) {
406			if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
407				module_put(a->ops->owner);
408			act = act->next;
409			kfree(a);
410		} else {
411			/*FIXME: Remove later - catch insertion bugs*/
412			WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
413			act = act->next;
414			kfree(a);
415		}
416	}
417}
418
419int
420tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
421{
422	int err = -EINVAL;
423
424	if (a->ops == NULL || a->ops->dump == NULL)
425		return err;
426	return a->ops->dump(skb, a, bind, ref);
427}
428
429int
430tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
431{
432	int err = -EINVAL;
433	unsigned char *b = skb_tail_pointer(skb);
434	struct nlattr *nest;
435
436	if (a->ops == NULL || a->ops->dump == NULL)
437		return err;
438
439	NLA_PUT_STRING(skb, TCA_KIND, a->ops->kind);
440	if (tcf_action_copy_stats(skb, a, 0))
441		goto nla_put_failure;
442	nest = nla_nest_start(skb, TCA_OPTIONS);
443	if (nest == NULL)
444		goto nla_put_failure;
445	err = tcf_action_dump_old(skb, a, bind, ref);
446	if (err > 0) {
447		nla_nest_end(skb, nest);
448		return err;
449	}
450
451nla_put_failure:
452	nlmsg_trim(skb, b);
453	return -1;
454}
455EXPORT_SYMBOL(tcf_action_dump_1);
456
457int
458tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
459{
460	struct tc_action *a;
461	int err = -EINVAL;
462	struct nlattr *nest;
463
464	while ((a = act) != NULL) {
465		act = a->next;
466		nest = nla_nest_start(skb, a->order);
467		if (nest == NULL)
468			goto nla_put_failure;
469		err = tcf_action_dump_1(skb, a, bind, ref);
470		if (err < 0)
471			goto errout;
472		nla_nest_end(skb, nest);
473	}
474
475	return 0;
476
477nla_put_failure:
478	err = -EINVAL;
479errout:
480	nla_nest_cancel(skb, nest);
481	return err;
482}
483
484struct tc_action *tcf_action_init_1(struct nlattr *nla, struct nlattr *est,
485				    char *name, int ovr, int bind)
486{
487	struct tc_action *a;
488	struct tc_action_ops *a_o;
489	char act_name[IFNAMSIZ];
490	struct nlattr *tb[TCA_ACT_MAX + 1];
491	struct nlattr *kind;
492	int err;
493
494	if (name == NULL) {
495		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
496		if (err < 0)
497			goto err_out;
498		err = -EINVAL;
499		kind = tb[TCA_ACT_KIND];
500		if (kind == NULL)
501			goto err_out;
502		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
503			goto err_out;
504	} else {
505		err = -EINVAL;
506		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
507			goto err_out;
508	}
509
510	a_o = tc_lookup_action_n(act_name);
511	if (a_o == NULL) {
512#ifdef CONFIG_MODULES
513		rtnl_unlock();
514		request_module("act_%s", act_name);
515		rtnl_lock();
516
517		a_o = tc_lookup_action_n(act_name);
518
519		/* We dropped the RTNL semaphore in order to
520		 * perform the module load.  So, even if we
521		 * succeeded in loading the module we have to
522		 * tell the caller to replay the request.  We
523		 * indicate this using -EAGAIN.
524		 */
525		if (a_o != NULL) {
526			err = -EAGAIN;
527			goto err_mod;
528		}
529#endif
530		err = -ENOENT;
531		goto err_out;
532	}
533
534	err = -ENOMEM;
535	a = kzalloc(sizeof(*a), GFP_KERNEL);
536	if (a == NULL)
537		goto err_mod;
538
539	/* backward compatibility for policer */
540	if (name == NULL)
541		err = a_o->init(tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
542	else
543		err = a_o->init(nla, est, a, ovr, bind);
544	if (err < 0)
545		goto err_free;
546
547	/* module count goes up only when brand new policy is created
548	 * if it exists and is only bound to in a_o->init() then
549	 * ACT_P_CREATED is not returned (a zero is).
550	 */
551	if (err != ACT_P_CREATED)
552		module_put(a_o->owner);
553	a->ops = a_o;
554
555	return a;
556
557err_free:
558	kfree(a);
559err_mod:
560	module_put(a_o->owner);
561err_out:
562	return ERR_PTR(err);
563}
564
565struct tc_action *tcf_action_init(struct nlattr *nla, struct nlattr *est,
566				  char *name, int ovr, int bind)
567{
568	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
569	struct tc_action *head = NULL, *act, *act_prev = NULL;
570	int err;
571	int i;
572
573	err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
574	if (err < 0)
575		return ERR_PTR(err);
576
577	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
578		act = tcf_action_init_1(tb[i], est, name, ovr, bind);
579		if (IS_ERR(act))
580			goto err;
581		act->order = i;
582
583		if (head == NULL)
584			head = act;
585		else
586			act_prev->next = act;
587		act_prev = act;
588	}
589	return head;
590
591err:
592	if (head != NULL)
593		tcf_action_destroy(head, bind);
594	return act;
595}
596
597int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
598			  int compat_mode)
599{
600	int err = 0;
601	struct gnet_dump d;
602	struct tcf_act_hdr *h = a->priv;
603
604	if (h == NULL)
605		goto errout;
606
607	/* compat_mode being true specifies a call that is supposed
608	 * to add additional backward compatibility statistic TLVs.
609	 */
610	if (compat_mode) {
611		if (a->type == TCA_OLD_COMPAT)
612			err = gnet_stats_start_copy_compat(skb, 0,
613				TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
614		else
615			return 0;
616	} else
617		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
618					    &h->tcf_lock, &d);
619
620	if (err < 0)
621		goto errout;
622
623	if (a->ops != NULL && a->ops->get_stats != NULL)
624		if (a->ops->get_stats(skb, a) < 0)
625			goto errout;
626
627	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
628	    gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
629				     &h->tcf_rate_est) < 0 ||
630	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
631		goto errout;
632
633	if (gnet_stats_finish_copy(&d) < 0)
634		goto errout;
635
636	return 0;
637
638errout:
639	return -1;
640}
641
642static int
643tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 pid, u32 seq,
644	     u16 flags, int event, int bind, int ref)
645{
646	struct tcamsg *t;
647	struct nlmsghdr *nlh;
648	unsigned char *b = skb_tail_pointer(skb);
649	struct nlattr *nest;
650
651	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
652
653	t = NLMSG_DATA(nlh);
654	t->tca_family = AF_UNSPEC;
655	t->tca__pad1 = 0;
656	t->tca__pad2 = 0;
657
658	nest = nla_nest_start(skb, TCA_ACT_TAB);
659	if (nest == NULL)
660		goto nla_put_failure;
661
662	if (tcf_action_dump(skb, a, bind, ref) < 0)
663		goto nla_put_failure;
664
665	nla_nest_end(skb, nest);
666
667	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
668	return skb->len;
669
670nla_put_failure:
671nlmsg_failure:
672	nlmsg_trim(skb, b);
673	return -1;
674}
675
676static int
677act_get_notify(struct net *net, u32 pid, struct nlmsghdr *n,
678	       struct tc_action *a, int event)
679{
680	struct sk_buff *skb;
681
682	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
683	if (!skb)
684		return -ENOBUFS;
685	if (tca_get_fill(skb, a, pid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
686		kfree_skb(skb);
687		return -EINVAL;
688	}
689
690	return rtnl_unicast(skb, net, pid);
691}
692
693static struct tc_action *
694tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 pid)
695{
696	struct nlattr *tb[TCA_ACT_MAX + 1];
697	struct tc_action *a;
698	int index;
699	int err;
700
701	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
702	if (err < 0)
703		goto err_out;
704
705	err = -EINVAL;
706	if (tb[TCA_ACT_INDEX] == NULL ||
707	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
708		goto err_out;
709	index = nla_get_u32(tb[TCA_ACT_INDEX]);
710
711	err = -ENOMEM;
712	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
713	if (a == NULL)
714		goto err_out;
715
716	err = -EINVAL;
717	a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
718	if (a->ops == NULL)
719		goto err_free;
720	if (a->ops->lookup == NULL)
721		goto err_mod;
722	err = -ENOENT;
723	if (a->ops->lookup(a, index) == 0)
724		goto err_mod;
725
726	module_put(a->ops->owner);
727	return a;
728
729err_mod:
730	module_put(a->ops->owner);
731err_free:
732	kfree(a);
733err_out:
734	return ERR_PTR(err);
735}
736
737static void cleanup_a(struct tc_action *act)
738{
739	struct tc_action *a;
740
741	for (a = act; a; a = act) {
742		act = a->next;
743		kfree(a);
744	}
745}
746
747static struct tc_action *create_a(int i)
748{
749	struct tc_action *act;
750
751	act = kzalloc(sizeof(*act), GFP_KERNEL);
752	if (act == NULL) {
753		pr_debug("create_a: failed to alloc!\n");
754		return NULL;
755	}
756	act->order = i;
757	return act;
758}
759
760static int tca_action_flush(struct net *net, struct nlattr *nla,
761			    struct nlmsghdr *n, u32 pid)
762{
763	struct sk_buff *skb;
764	unsigned char *b;
765	struct nlmsghdr *nlh;
766	struct tcamsg *t;
767	struct netlink_callback dcb;
768	struct nlattr *nest;
769	struct nlattr *tb[TCA_ACT_MAX + 1];
770	struct nlattr *kind;
771	struct tc_action *a = create_a(0);
772	int err = -ENOMEM;
773
774	if (a == NULL) {
775		pr_debug("tca_action_flush: couldnt create tc_action\n");
776		return err;
777	}
778
779	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
780	if (!skb) {
781		pr_debug("tca_action_flush: failed skb alloc\n");
782		kfree(a);
783		return err;
784	}
785
786	b = skb_tail_pointer(skb);
787
788	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
789	if (err < 0)
790		goto err_out;
791
792	err = -EINVAL;
793	kind = tb[TCA_ACT_KIND];
794	a->ops = tc_lookup_action(kind);
795	if (a->ops == NULL)
796		goto err_out;
797
798	nlh = NLMSG_PUT(skb, pid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t));
799	t = NLMSG_DATA(nlh);
800	t->tca_family = AF_UNSPEC;
801	t->tca__pad1 = 0;
802	t->tca__pad2 = 0;
803
804	nest = nla_nest_start(skb, TCA_ACT_TAB);
805	if (nest == NULL)
806		goto nla_put_failure;
807
808	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
809	if (err < 0)
810		goto nla_put_failure;
811	if (err == 0)
812		goto noflush_out;
813
814	nla_nest_end(skb, nest);
815
816	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
817	nlh->nlmsg_flags |= NLM_F_ROOT;
818	module_put(a->ops->owner);
819	kfree(a);
820	err = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
821			     n->nlmsg_flags & NLM_F_ECHO);
822	if (err > 0)
823		return 0;
824
825	return err;
826
827nla_put_failure:
828nlmsg_failure:
829	module_put(a->ops->owner);
830err_out:
831noflush_out:
832	kfree_skb(skb);
833	kfree(a);
834	return err;
835}
836
837static int
838tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
839	      u32 pid, int event)
840{
841	int i, ret;
842	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
843	struct tc_action *head = NULL, *act, *act_prev = NULL;
844
845	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
846	if (ret < 0)
847		return ret;
848
849	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
850		if (tb[1] != NULL)
851			return tca_action_flush(net, tb[1], n, pid);
852		else
853			return -EINVAL;
854	}
855
856	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
857		act = tcf_action_get_1(tb[i], n, pid);
858		if (IS_ERR(act)) {
859			ret = PTR_ERR(act);
860			goto err;
861		}
862		act->order = i;
863
864		if (head == NULL)
865			head = act;
866		else
867			act_prev->next = act;
868		act_prev = act;
869	}
870
871	if (event == RTM_GETACTION)
872		ret = act_get_notify(net, pid, n, head, event);
873	else { /* delete */
874		struct sk_buff *skb;
875
876		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
877		if (!skb) {
878			ret = -ENOBUFS;
879			goto err;
880		}
881
882		if (tca_get_fill(skb, head, pid, n->nlmsg_seq, 0, event,
883				 0, 1) <= 0) {
884			kfree_skb(skb);
885			ret = -EINVAL;
886			goto err;
887		}
888
889		/* now do the delete */
890		tcf_action_destroy(head, 0);
891		ret = rtnetlink_send(skb, net, pid, RTNLGRP_TC,
892				     n->nlmsg_flags & NLM_F_ECHO);
893		if (ret > 0)
894			return 0;
895		return ret;
896	}
897err:
898	cleanup_a(head);
899	return ret;
900}
901
902static int tcf_add_notify(struct net *net, struct tc_action *a,
903			  u32 pid, u32 seq, int event, u16 flags)
904{
905	struct tcamsg *t;
906	struct nlmsghdr *nlh;
907	struct sk_buff *skb;
908	struct nlattr *nest;
909	unsigned char *b;
910	int err = 0;
911
912	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
913	if (!skb)
914		return -ENOBUFS;
915
916	b = skb_tail_pointer(skb);
917
918	nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*t), flags);
919	t = NLMSG_DATA(nlh);
920	t->tca_family = AF_UNSPEC;
921	t->tca__pad1 = 0;
922	t->tca__pad2 = 0;
923
924	nest = nla_nest_start(skb, TCA_ACT_TAB);
925	if (nest == NULL)
926		goto nla_put_failure;
927
928	if (tcf_action_dump(skb, a, 0, 0) < 0)
929		goto nla_put_failure;
930
931	nla_nest_end(skb, nest);
932
933	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
934	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
935
936	err = rtnetlink_send(skb, net, pid, RTNLGRP_TC, flags & NLM_F_ECHO);
937	if (err > 0)
938		err = 0;
939	return err;
940
941nla_put_failure:
942nlmsg_failure:
943	kfree_skb(skb);
944	return -1;
945}
946
947
948static int
949tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
950	       u32 pid, int ovr)
951{
952	int ret = 0;
953	struct tc_action *act;
954	struct tc_action *a;
955	u32 seq = n->nlmsg_seq;
956
957	act = tcf_action_init(nla, NULL, NULL, ovr, 0);
958	if (act == NULL)
959		goto done;
960	if (IS_ERR(act)) {
961		ret = PTR_ERR(act);
962		goto done;
963	}
964
965	/* dump then free all the actions after update; inserted policy
966	 * stays intact
967	 */
968	ret = tcf_add_notify(net, act, pid, seq, RTM_NEWACTION, n->nlmsg_flags);
969	for (a = act; a; a = act) {
970		act = a->next;
971		kfree(a);
972	}
973done:
974	return ret;
975}
976
977static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n, void *arg)
978{
979	struct net *net = sock_net(skb->sk);
980	struct nlattr *tca[TCA_ACT_MAX + 1];
981	u32 pid = skb ? NETLINK_CB(skb).pid : 0;
982	int ret = 0, ovr = 0;
983
984	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
985	if (ret < 0)
986		return ret;
987
988	if (tca[TCA_ACT_TAB] == NULL) {
989		pr_notice("tc_ctl_action: received NO action attribs\n");
990		return -EINVAL;
991	}
992
993	/* n->nlmsg_flags & NLM_F_CREATE */
994	switch (n->nlmsg_type) {
995	case RTM_NEWACTION:
996		/* we are going to assume all other flags
997		 * imply create only if it doesn't exist
998		 * Note that CREATE | EXCL implies that
999		 * but since we want avoid ambiguity (eg when flags
1000		 * is zero) then just set this
1001		 */
1002		if (n->nlmsg_flags & NLM_F_REPLACE)
1003			ovr = 1;
1004replay:
1005		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, pid, ovr);
1006		if (ret == -EAGAIN)
1007			goto replay;
1008		break;
1009	case RTM_DELACTION:
1010		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1011				    pid, RTM_DELACTION);
1012		break;
1013	case RTM_GETACTION:
1014		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1015				    pid, RTM_GETACTION);
1016		break;
1017	default:
1018		BUG();
1019	}
1020
1021	return ret;
1022}
1023
1024static struct nlattr *
1025find_dump_kind(const struct nlmsghdr *n)
1026{
1027	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1028	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1029	struct nlattr *nla[TCAA_MAX + 1];
1030	struct nlattr *kind;
1031
1032	if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1033		return NULL;
1034	tb1 = nla[TCA_ACT_TAB];
1035	if (tb1 == NULL)
1036		return NULL;
1037
1038	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1039		      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1040		return NULL;
1041
1042	if (tb[1] == NULL)
1043		return NULL;
1044	if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1045		      nla_len(tb[1]), NULL) < 0)
1046		return NULL;
1047	kind = tb2[TCA_ACT_KIND];
1048
1049	return kind;
1050}
1051
1052static int
1053tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1054{
1055	struct nlmsghdr *nlh;
1056	unsigned char *b = skb_tail_pointer(skb);
1057	struct nlattr *nest;
1058	struct tc_action_ops *a_o;
1059	struct tc_action a;
1060	int ret = 0;
1061	struct tcamsg *t = (struct tcamsg *) NLMSG_DATA(cb->nlh);
1062	struct nlattr *kind = find_dump_kind(cb->nlh);
1063
1064	if (kind == NULL) {
1065		pr_info("tc_dump_action: action bad kind\n");
1066		return 0;
1067	}
1068
1069	a_o = tc_lookup_action(kind);
1070	if (a_o == NULL)
1071		return 0;
1072
1073	memset(&a, 0, sizeof(struct tc_action));
1074	a.ops = a_o;
1075
1076	if (a_o->walk == NULL) {
1077		WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1078		     a_o->kind);
1079		goto nla_put_failure;
1080	}
1081
1082	nlh = NLMSG_PUT(skb, NETLINK_CB(cb->skb).pid, cb->nlh->nlmsg_seq,
1083			cb->nlh->nlmsg_type, sizeof(*t));
1084	t = NLMSG_DATA(nlh);
1085	t->tca_family = AF_UNSPEC;
1086	t->tca__pad1 = 0;
1087	t->tca__pad2 = 0;
1088
1089	nest = nla_nest_start(skb, TCA_ACT_TAB);
1090	if (nest == NULL)
1091		goto nla_put_failure;
1092
1093	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1094	if (ret < 0)
1095		goto nla_put_failure;
1096
1097	if (ret > 0) {
1098		nla_nest_end(skb, nest);
1099		ret = skb->len;
1100	} else
1101		nla_nest_cancel(skb, nest);
1102
1103	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1104	if (NETLINK_CB(cb->skb).pid && ret)
1105		nlh->nlmsg_flags |= NLM_F_MULTI;
1106	module_put(a_o->owner);
1107	return skb->len;
1108
1109nla_put_failure:
1110nlmsg_failure:
1111	module_put(a_o->owner);
1112	nlmsg_trim(skb, b);
1113	return skb->len;
1114}
1115
1116static int __init tc_action_init(void)
1117{
1118	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL);
1119	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL);
1120	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action);
1121
1122	return 0;
1123}
1124
1125subsys_initcall(tc_action_init);
1126