act_api.c revision 1f747c26c48bb290c79c34e155860c7e2ec3926a 
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
30void tcf_hash_destroy(struct tcf_common *p, struct tcf_hashinfo *hinfo)
31{
32	spin_lock_bh(&hinfo->lock);
33	hlist_del(&p->tcfc_head);
34	spin_unlock_bh(&hinfo->lock);
35	gen_kill_estimator(&p->tcfc_bstats,
36			   &p->tcfc_rate_est);
37	/*
38	 * gen_estimator est_timer() might access p->tcfc_lock
39	 * or bstats, wait a RCU grace period before freeing p
40	 */
41	kfree_rcu(p, tcfc_rcu);
42}
43EXPORT_SYMBOL(tcf_hash_destroy);
44
45int tcf_hash_release(struct tcf_common *p, int bind,
46		     struct tcf_hashinfo *hinfo)
47{
48	int ret = 0;
49
50	if (p) {
51		if (bind)
52			p->tcfc_bindcnt--;
53
54		p->tcfc_refcnt--;
55		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
56			tcf_hash_destroy(p, hinfo);
57			ret = 1;
58		}
59	}
60	return ret;
61}
62EXPORT_SYMBOL(tcf_hash_release);
63
64static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
65			   struct tc_action *a, struct tcf_hashinfo *hinfo)
66{
67	struct hlist_head *head;
68	struct tcf_common *p;
69	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
70	struct nlattr *nest;
71
72	spin_lock_bh(&hinfo->lock);
73
74	s_i = cb->args[0];
75
76	for (i = 0; i < (hinfo->hmask + 1); i++) {
77		head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
78
79		hlist_for_each_entry_rcu(p, head, tcfc_head) {
80			index++;
81			if (index < s_i)
82				continue;
83			a->priv = p;
84			a->order = n_i;
85
86			nest = nla_nest_start(skb, a->order);
87			if (nest == NULL)
88				goto nla_put_failure;
89			err = tcf_action_dump_1(skb, a, 0, 0);
90			if (err < 0) {
91				index--;
92				nlmsg_trim(skb, nest);
93				goto done;
94			}
95			nla_nest_end(skb, nest);
96			n_i++;
97			if (n_i >= TCA_ACT_MAX_PRIO)
98				goto done;
99		}
100	}
101done:
102	spin_unlock_bh(&hinfo->lock);
103	if (n_i)
104		cb->args[0] += n_i;
105	return n_i;
106
107nla_put_failure:
108	nla_nest_cancel(skb, nest);
109	goto done;
110}
111
112static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
113			  struct tcf_hashinfo *hinfo)
114{
115	struct hlist_head *head;
116	struct hlist_node *n;
117	struct tcf_common *p;
118	struct nlattr *nest;
119	int i = 0, n_i = 0;
120
121	nest = nla_nest_start(skb, a->order);
122	if (nest == NULL)
123		goto nla_put_failure;
124	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
125		goto nla_put_failure;
126	for (i = 0; i < (hinfo->hmask + 1); i++) {
127		head = &hinfo->htab[tcf_hash(i, hinfo->hmask)];
128		hlist_for_each_entry_safe(p, n, head, tcfc_head) {
129			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
130				module_put(a->ops->owner);
131			n_i++;
132		}
133	}
134	if (nla_put_u32(skb, TCA_FCNT, n_i))
135		goto nla_put_failure;
136	nla_nest_end(skb, nest);
137
138	return n_i;
139nla_put_failure:
140	nla_nest_cancel(skb, nest);
141	return -EINVAL;
142}
143
144int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
145		       int type, struct tc_action *a)
146{
147	struct tcf_hashinfo *hinfo = a->ops->hinfo;
148
149	if (type == RTM_DELACTION) {
150		return tcf_del_walker(skb, a, hinfo);
151	} else if (type == RTM_GETACTION) {
152		return tcf_dump_walker(skb, cb, a, hinfo);
153	} else {
154		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
155		return -EINVAL;
156	}
157}
158EXPORT_SYMBOL(tcf_generic_walker);
159
160struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
161{
162	struct tcf_common *p = NULL;
163	struct hlist_head *head;
164
165	spin_lock_bh(&hinfo->lock);
166	head = &hinfo->htab[tcf_hash(index, hinfo->hmask)];
167	hlist_for_each_entry_rcu(p, head, tcfc_head)
168		if (p->tcfc_index == index)
169			break;
170	spin_unlock_bh(&hinfo->lock);
171
172	return p;
173}
174EXPORT_SYMBOL(tcf_hash_lookup);
175
176u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
177{
178	u32 val = *idx_gen;
179
180	do {
181		if (++val == 0)
182			val = 1;
183	} while (tcf_hash_lookup(val, hinfo));
184
185	*idx_gen = val;
186	return val;
187}
188EXPORT_SYMBOL(tcf_hash_new_index);
189
190int tcf_hash_search(struct tc_action *a, u32 index)
191{
192	struct tcf_hashinfo *hinfo = a->ops->hinfo;
193	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
194
195	if (p) {
196		a->priv = p;
197		return 1;
198	}
199	return 0;
200}
201EXPORT_SYMBOL(tcf_hash_search);
202
203struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
204				  struct tcf_hashinfo *hinfo)
205{
206	struct tcf_common *p = NULL;
207	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
208		if (bind)
209			p->tcfc_bindcnt++;
210		p->tcfc_refcnt++;
211		a->priv = p;
212	}
213	return p;
214}
215EXPORT_SYMBOL(tcf_hash_check);
216
217struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
218				   struct tc_action *a, int size, int bind,
219				   u32 *idx_gen, struct tcf_hashinfo *hinfo)
220{
221	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
222
223	if (unlikely(!p))
224		return ERR_PTR(-ENOMEM);
225	p->tcfc_refcnt = 1;
226	if (bind)
227		p->tcfc_bindcnt = 1;
228
229	spin_lock_init(&p->tcfc_lock);
230	INIT_HLIST_NODE(&p->tcfc_head);
231	p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
232	p->tcfc_tm.install = jiffies;
233	p->tcfc_tm.lastuse = jiffies;
234	if (est) {
235		int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
236					    &p->tcfc_lock, est);
237		if (err) {
238			kfree(p);
239			return ERR_PTR(err);
240		}
241	}
242
243	a->priv = (void *) p;
244	return p;
245}
246EXPORT_SYMBOL(tcf_hash_create);
247
248void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
249{
250	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
251
252	spin_lock_bh(&hinfo->lock);
253	hlist_add_head(&p->tcfc_head, &hinfo->htab[h]);
254	spin_unlock_bh(&hinfo->lock);
255}
256EXPORT_SYMBOL(tcf_hash_insert);
257
258static LIST_HEAD(act_base);
259static DEFINE_RWLOCK(act_mod_lock);
260
261int tcf_register_action(struct tc_action_ops *act)
262{
263	struct tc_action_ops *a;
264
265	/* Must supply act, dump, cleanup and init */
266	if (!act->act || !act->dump || !act->cleanup || !act->init)
267		return -EINVAL;
268
269	/* Supply defaults */
270	if (!act->lookup)
271		act->lookup = tcf_hash_search;
272	if (!act->walk)
273		act->walk = tcf_generic_walker;
274
275	write_lock(&act_mod_lock);
276	list_for_each_entry(a, &act_base, head) {
277		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
278			write_unlock(&act_mod_lock);
279			return -EEXIST;
280		}
281	}
282	list_add_tail(&act->head, &act_base);
283	write_unlock(&act_mod_lock);
284	return 0;
285}
286EXPORT_SYMBOL(tcf_register_action);
287
288int tcf_unregister_action(struct tc_action_ops *act)
289{
290	struct tc_action_ops *a;
291	int err = -ENOENT;
292
293	write_lock(&act_mod_lock);
294	list_for_each_entry(a, &act_base, head)
295		if (a == act)
296			break;
297	if (a) {
298		list_del(&act->head);
299		err = 0;
300	}
301	write_unlock(&act_mod_lock);
302	return err;
303}
304EXPORT_SYMBOL(tcf_unregister_action);
305
306/* lookup by name */
307static struct tc_action_ops *tc_lookup_action_n(char *kind)
308{
309	struct tc_action_ops *a = NULL;
310
311	if (kind) {
312		read_lock(&act_mod_lock);
313		list_for_each_entry(a, &act_base, head) {
314			if (strcmp(kind, a->kind) == 0) {
315				if (!try_module_get(a->owner)) {
316					read_unlock(&act_mod_lock);
317					return NULL;
318				}
319				break;
320			}
321		}
322		read_unlock(&act_mod_lock);
323	}
324	return a;
325}
326
327/* lookup by nlattr */
328static struct tc_action_ops *tc_lookup_action(struct nlattr *kind)
329{
330	struct tc_action_ops *a = NULL;
331
332	if (kind) {
333		read_lock(&act_mod_lock);
334		list_for_each_entry(a, &act_base, head) {
335			if (nla_strcmp(kind, a->kind) == 0) {
336				if (!try_module_get(a->owner)) {
337					read_unlock(&act_mod_lock);
338					return NULL;
339				}
340				break;
341			}
342		}
343		read_unlock(&act_mod_lock);
344	}
345	return a;
346}
347
348#if 0
349/* lookup by id */
350static struct tc_action_ops *tc_lookup_action_id(u32 type)
351{
352	struct tc_action_ops *a = NULL;
353
354	if (type) {
355		read_lock(&act_mod_lock);
356		for (a = act_base; a; a = a->next) {
357			if (a->type == type) {
358				if (!try_module_get(a->owner)) {
359					read_unlock(&act_mod_lock);
360					return NULL;
361				}
362				break;
363			}
364		}
365		read_unlock(&act_mod_lock);
366	}
367	return a;
368}
369#endif
370
371int tcf_action_exec(struct sk_buff *skb, const struct list_head *actions,
372		    struct tcf_result *res)
373{
374	const struct tc_action *a;
375	int ret = -1;
376
377	if (skb->tc_verd & TC_NCLS) {
378		skb->tc_verd = CLR_TC_NCLS(skb->tc_verd);
379		ret = TC_ACT_OK;
380		goto exec_done;
381	}
382	list_for_each_entry(a, actions, list) {
383repeat:
384		if (a->ops) {
385			ret = a->ops->act(skb, a, res);
386			if (TC_MUNGED & skb->tc_verd) {
387				/* copied already, allow trampling */
388				skb->tc_verd = SET_TC_OK2MUNGE(skb->tc_verd);
389				skb->tc_verd = CLR_TC_MUNGED(skb->tc_verd);
390			}
391			if (ret == TC_ACT_REPEAT)
392				goto repeat;	/* we need a ttl - JHS */
393			if (ret != TC_ACT_PIPE)
394				goto exec_done;
395		}
396	}
397exec_done:
398	return ret;
399}
400EXPORT_SYMBOL(tcf_action_exec);
401
402void tcf_action_destroy(struct list_head *actions, int bind)
403{
404	struct tc_action *a, *tmp;
405
406	list_for_each_entry_safe(a, tmp, actions, list) {
407		if (a->ops) {
408			if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
409				module_put(a->ops->owner);
410			list_del(&a->list);
411			kfree(a);
412		} else {
413			/*FIXME: Remove later - catch insertion bugs*/
414			WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
415			list_del(&a->list);
416			kfree(a);
417		}
418	}
419}
420
421int
422tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
423{
424	int err = -EINVAL;
425
426	if (a->ops == NULL)
427		return err;
428	return a->ops->dump(skb, a, bind, ref);
429}
430
431int
432tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
433{
434	int err = -EINVAL;
435	unsigned char *b = skb_tail_pointer(skb);
436	struct nlattr *nest;
437
438	if (a->ops == NULL)
439		return err;
440
441	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
442		goto nla_put_failure;
443	if (tcf_action_copy_stats(skb, a, 0))
444		goto nla_put_failure;
445	nest = nla_nest_start(skb, TCA_OPTIONS);
446	if (nest == NULL)
447		goto nla_put_failure;
448	err = tcf_action_dump_old(skb, a, bind, ref);
449	if (err > 0) {
450		nla_nest_end(skb, nest);
451		return err;
452	}
453
454nla_put_failure:
455	nlmsg_trim(skb, b);
456	return -1;
457}
458EXPORT_SYMBOL(tcf_action_dump_1);
459
460int
461tcf_action_dump(struct sk_buff *skb, struct list_head *actions, int bind, int ref)
462{
463	struct tc_action *a;
464	int err = -EINVAL;
465	struct nlattr *nest;
466
467	list_for_each_entry(a, actions, list) {
468		nest = nla_nest_start(skb, a->order);
469		if (nest == NULL)
470			goto nla_put_failure;
471		err = tcf_action_dump_1(skb, a, bind, ref);
472		if (err < 0)
473			goto errout;
474		nla_nest_end(skb, nest);
475	}
476
477	return 0;
478
479nla_put_failure:
480	err = -EINVAL;
481errout:
482	nla_nest_cancel(skb, nest);
483	return err;
484}
485
486struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
487				    struct nlattr *est, char *name, int ovr,
488				    int bind)
489{
490	struct tc_action *a;
491	struct tc_action_ops *a_o;
492	char act_name[IFNAMSIZ];
493	struct nlattr *tb[TCA_ACT_MAX + 1];
494	struct nlattr *kind;
495	int err;
496
497	if (name == NULL) {
498		err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
499		if (err < 0)
500			goto err_out;
501		err = -EINVAL;
502		kind = tb[TCA_ACT_KIND];
503		if (kind == NULL)
504			goto err_out;
505		if (nla_strlcpy(act_name, kind, IFNAMSIZ) >= IFNAMSIZ)
506			goto err_out;
507	} else {
508		err = -EINVAL;
509		if (strlcpy(act_name, name, IFNAMSIZ) >= IFNAMSIZ)
510			goto err_out;
511	}
512
513	a_o = tc_lookup_action_n(act_name);
514	if (a_o == NULL) {
515#ifdef CONFIG_MODULES
516		rtnl_unlock();
517		request_module("act_%s", act_name);
518		rtnl_lock();
519
520		a_o = tc_lookup_action_n(act_name);
521
522		/* We dropped the RTNL semaphore in order to
523		 * perform the module load.  So, even if we
524		 * succeeded in loading the module we have to
525		 * tell the caller to replay the request.  We
526		 * indicate this using -EAGAIN.
527		 */
528		if (a_o != NULL) {
529			err = -EAGAIN;
530			goto err_mod;
531		}
532#endif
533		err = -ENOENT;
534		goto err_out;
535	}
536
537	err = -ENOMEM;
538	a = kzalloc(sizeof(*a), GFP_KERNEL);
539	if (a == NULL)
540		goto err_mod;
541
542	INIT_LIST_HEAD(&a->list);
543	/* backward compatibility for policer */
544	if (name == NULL)
545		err = a_o->init(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
546	else
547		err = a_o->init(net, nla, est, a, ovr, bind);
548	if (err < 0)
549		goto err_free;
550
551	/* module count goes up only when brand new policy is created
552	 * if it exists and is only bound to in a_o->init() then
553	 * ACT_P_CREATED is not returned (a zero is).
554	 */
555	if (err != ACT_P_CREATED)
556		module_put(a_o->owner);
557	a->ops = a_o;
558
559	return a;
560
561err_free:
562	kfree(a);
563err_mod:
564	module_put(a_o->owner);
565err_out:
566	return ERR_PTR(err);
567}
568
569int tcf_action_init(struct net *net, struct nlattr *nla,
570				  struct nlattr *est, char *name, int ovr,
571				  int bind, struct list_head *actions)
572{
573	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
574	struct tc_action *act;
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;
581
582	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
583		act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
584		if (IS_ERR(act)) {
585			err = PTR_ERR(act);
586			goto err;
587		}
588		act->order = i;
589		list_add_tail(&act->list, actions);
590	}
591	return 0;
592
593err:
594	tcf_action_destroy(actions, bind);
595	return err;
596}
597
598int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
599			  int compat_mode)
600{
601	int err = 0;
602	struct gnet_dump d;
603	struct tcf_act_hdr *h = a->priv;
604
605	if (h == NULL)
606		goto errout;
607
608	/* compat_mode being true specifies a call that is supposed
609	 * to add additional backward compatibility statistic TLVs.
610	 */
611	if (compat_mode) {
612		if (a->type == TCA_OLD_COMPAT)
613			err = gnet_stats_start_copy_compat(skb, 0,
614				TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
615		else
616			return 0;
617	} else
618		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
619					    &h->tcf_lock, &d);
620
621	if (err < 0)
622		goto errout;
623
624	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
625	    gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
626				     &h->tcf_rate_est) < 0 ||
627	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
628		goto errout;
629
630	if (gnet_stats_finish_copy(&d) < 0)
631		goto errout;
632
633	return 0;
634
635errout:
636	return -1;
637}
638
639static int
640tca_get_fill(struct sk_buff *skb, struct list_head *actions, u32 portid, u32 seq,
641	     u16 flags, int event, int bind, int ref)
642{
643	struct tcamsg *t;
644	struct nlmsghdr *nlh;
645	unsigned char *b = skb_tail_pointer(skb);
646	struct nlattr *nest;
647
648	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
649	if (!nlh)
650		goto out_nlmsg_trim;
651	t = nlmsg_data(nlh);
652	t->tca_family = AF_UNSPEC;
653	t->tca__pad1 = 0;
654	t->tca__pad2 = 0;
655
656	nest = nla_nest_start(skb, TCA_ACT_TAB);
657	if (nest == NULL)
658		goto out_nlmsg_trim;
659
660	if (tcf_action_dump(skb, actions, bind, ref) < 0)
661		goto out_nlmsg_trim;
662
663	nla_nest_end(skb, nest);
664
665	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
666	return skb->len;
667
668out_nlmsg_trim:
669	nlmsg_trim(skb, b);
670	return -1;
671}
672
673static int
674act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
675	       struct list_head *actions, int event)
676{
677	struct sk_buff *skb;
678
679	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
680	if (!skb)
681		return -ENOBUFS;
682	if (tca_get_fill(skb, actions, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
683		kfree_skb(skb);
684		return -EINVAL;
685	}
686
687	return rtnl_unicast(skb, net, portid);
688}
689
690static struct tc_action *
691tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
692{
693	struct nlattr *tb[TCA_ACT_MAX + 1];
694	struct tc_action *a;
695	int index;
696	int err;
697
698	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
699	if (err < 0)
700		goto err_out;
701
702	err = -EINVAL;
703	if (tb[TCA_ACT_INDEX] == NULL ||
704	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
705		goto err_out;
706	index = nla_get_u32(tb[TCA_ACT_INDEX]);
707
708	err = -ENOMEM;
709	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
710	if (a == NULL)
711		goto err_out;
712
713	INIT_LIST_HEAD(&a->list);
714	err = -EINVAL;
715	a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
716	if (a->ops == NULL)
717		goto err_free;
718	err = -ENOENT;
719	if (a->ops->lookup(a, index) == 0)
720		goto err_mod;
721
722	module_put(a->ops->owner);
723	return a;
724
725err_mod:
726	module_put(a->ops->owner);
727err_free:
728	kfree(a);
729err_out:
730	return ERR_PTR(err);
731}
732
733static void cleanup_a(struct list_head *actions)
734{
735	struct tc_action *a, *tmp;
736
737	list_for_each_entry_safe(a, tmp, actions, list) {
738		list_del(&a->list);
739		kfree(a);
740	}
741}
742
743static struct tc_action *create_a(int i)
744{
745	struct tc_action *act;
746
747	act = kzalloc(sizeof(*act), GFP_KERNEL);
748	if (act == NULL) {
749		pr_debug("create_a: failed to alloc!\n");
750		return NULL;
751	}
752	act->order = i;
753	INIT_LIST_HEAD(&act->list);
754	return act;
755}
756
757static int tca_action_flush(struct net *net, struct nlattr *nla,
758			    struct nlmsghdr *n, u32 portid)
759{
760	struct sk_buff *skb;
761	unsigned char *b;
762	struct nlmsghdr *nlh;
763	struct tcamsg *t;
764	struct netlink_callback dcb;
765	struct nlattr *nest;
766	struct nlattr *tb[TCA_ACT_MAX + 1];
767	struct nlattr *kind;
768	struct tc_action *a = create_a(0);
769	int err = -ENOMEM;
770
771	if (a == NULL) {
772		pr_debug("tca_action_flush: couldnt create tc_action\n");
773		return err;
774	}
775
776	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
777	if (!skb) {
778		pr_debug("tca_action_flush: failed skb alloc\n");
779		kfree(a);
780		return err;
781	}
782
783	b = skb_tail_pointer(skb);
784
785	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
786	if (err < 0)
787		goto err_out;
788
789	err = -EINVAL;
790	kind = tb[TCA_ACT_KIND];
791	a->ops = tc_lookup_action(kind);
792	if (a->ops == NULL)
793		goto err_out;
794
795	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
796	if (!nlh)
797		goto out_module_put;
798	t = nlmsg_data(nlh);
799	t->tca_family = AF_UNSPEC;
800	t->tca__pad1 = 0;
801	t->tca__pad2 = 0;
802
803	nest = nla_nest_start(skb, TCA_ACT_TAB);
804	if (nest == NULL)
805		goto out_module_put;
806
807	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
808	if (err < 0)
809		goto out_module_put;
810	if (err == 0)
811		goto noflush_out;
812
813	nla_nest_end(skb, nest);
814
815	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
816	nlh->nlmsg_flags |= NLM_F_ROOT;
817	module_put(a->ops->owner);
818	kfree(a);
819	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
820			     n->nlmsg_flags & NLM_F_ECHO);
821	if (err > 0)
822		return 0;
823
824	return err;
825
826out_module_put:
827	module_put(a->ops->owner);
828err_out:
829noflush_out:
830	kfree_skb(skb);
831	kfree(a);
832	return err;
833}
834
835static int
836tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
837	      u32 portid, int event)
838{
839	int i, ret;
840	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
841	struct tc_action *act;
842	LIST_HEAD(actions);
843
844	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
845	if (ret < 0)
846		return ret;
847
848	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
849		if (tb[1] != NULL)
850			return tca_action_flush(net, tb[1], n, portid);
851		else
852			return -EINVAL;
853	}
854
855	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
856		act = tcf_action_get_1(tb[i], n, portid);
857		if (IS_ERR(act)) {
858			ret = PTR_ERR(act);
859			goto err;
860		}
861		act->order = i;
862		list_add_tail(&act->list, &actions);
863	}
864
865	if (event == RTM_GETACTION)
866		ret = act_get_notify(net, portid, n, &actions, event);
867	else { /* delete */
868		struct sk_buff *skb;
869
870		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
871		if (!skb) {
872			ret = -ENOBUFS;
873			goto err;
874		}
875
876		if (tca_get_fill(skb, &actions, portid, n->nlmsg_seq, 0, event,
877				 0, 1) <= 0) {
878			kfree_skb(skb);
879			ret = -EINVAL;
880			goto err;
881		}
882
883		/* now do the delete */
884		tcf_action_destroy(&actions, 0);
885		ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
886				     n->nlmsg_flags & NLM_F_ECHO);
887		if (ret > 0)
888			return 0;
889		return ret;
890	}
891err:
892	cleanup_a(&actions);
893	return ret;
894}
895
896static int tcf_add_notify(struct net *net, struct list_head *actions,
897			  u32 portid, u32 seq, int event, u16 flags)
898{
899	struct tcamsg *t;
900	struct nlmsghdr *nlh;
901	struct sk_buff *skb;
902	struct nlattr *nest;
903	unsigned char *b;
904	int err = 0;
905
906	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
907	if (!skb)
908		return -ENOBUFS;
909
910	b = skb_tail_pointer(skb);
911
912	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
913	if (!nlh)
914		goto out_kfree_skb;
915	t = nlmsg_data(nlh);
916	t->tca_family = AF_UNSPEC;
917	t->tca__pad1 = 0;
918	t->tca__pad2 = 0;
919
920	nest = nla_nest_start(skb, TCA_ACT_TAB);
921	if (nest == NULL)
922		goto out_kfree_skb;
923
924	if (tcf_action_dump(skb, actions, 0, 0) < 0)
925		goto out_kfree_skb;
926
927	nla_nest_end(skb, nest);
928
929	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
930	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
931
932	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
933	if (err > 0)
934		err = 0;
935	return err;
936
937out_kfree_skb:
938	kfree_skb(skb);
939	return -1;
940}
941
942
943static int
944tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
945	       u32 portid, int ovr)
946{
947	int ret = 0;
948	LIST_HEAD(actions);
949	u32 seq = n->nlmsg_seq;
950
951	ret = tcf_action_init(net, nla, NULL, NULL, ovr, 0, &actions);
952	if (ret)
953		goto done;
954
955	/* dump then free all the actions after update; inserted policy
956	 * stays intact
957	 */
958	ret = tcf_add_notify(net, &actions, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
959	cleanup_a(&actions);
960done:
961	return ret;
962}
963
964static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
965{
966	struct net *net = sock_net(skb->sk);
967	struct nlattr *tca[TCA_ACT_MAX + 1];
968	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
969	int ret = 0, ovr = 0;
970
971	if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
972		return -EPERM;
973
974	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
975	if (ret < 0)
976		return ret;
977
978	if (tca[TCA_ACT_TAB] == NULL) {
979		pr_notice("tc_ctl_action: received NO action attribs\n");
980		return -EINVAL;
981	}
982
983	/* n->nlmsg_flags & NLM_F_CREATE */
984	switch (n->nlmsg_type) {
985	case RTM_NEWACTION:
986		/* we are going to assume all other flags
987		 * imply create only if it doesn't exist
988		 * Note that CREATE | EXCL implies that
989		 * but since we want avoid ambiguity (eg when flags
990		 * is zero) then just set this
991		 */
992		if (n->nlmsg_flags & NLM_F_REPLACE)
993			ovr = 1;
994replay:
995		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
996		if (ret == -EAGAIN)
997			goto replay;
998		break;
999	case RTM_DELACTION:
1000		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1001				    portid, RTM_DELACTION);
1002		break;
1003	case RTM_GETACTION:
1004		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1005				    portid, RTM_GETACTION);
1006		break;
1007	default:
1008		BUG();
1009	}
1010
1011	return ret;
1012}
1013
1014static struct nlattr *
1015find_dump_kind(const struct nlmsghdr *n)
1016{
1017	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1018	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1019	struct nlattr *nla[TCAA_MAX + 1];
1020	struct nlattr *kind;
1021
1022	if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1023		return NULL;
1024	tb1 = nla[TCA_ACT_TAB];
1025	if (tb1 == NULL)
1026		return NULL;
1027
1028	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1029		      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1030		return NULL;
1031
1032	if (tb[1] == NULL)
1033		return NULL;
1034	if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1035		      nla_len(tb[1]), NULL) < 0)
1036		return NULL;
1037	kind = tb2[TCA_ACT_KIND];
1038
1039	return kind;
1040}
1041
1042static int
1043tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1044{
1045	struct nlmsghdr *nlh;
1046	unsigned char *b = skb_tail_pointer(skb);
1047	struct nlattr *nest;
1048	struct tc_action_ops *a_o;
1049	struct tc_action a;
1050	int ret = 0;
1051	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1052	struct nlattr *kind = find_dump_kind(cb->nlh);
1053
1054	if (kind == NULL) {
1055		pr_info("tc_dump_action: action bad kind\n");
1056		return 0;
1057	}
1058
1059	a_o = tc_lookup_action(kind);
1060	if (a_o == NULL)
1061		return 0;
1062
1063	memset(&a, 0, sizeof(struct tc_action));
1064	a.ops = a_o;
1065
1066	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1067			cb->nlh->nlmsg_type, sizeof(*t), 0);
1068	if (!nlh)
1069		goto out_module_put;
1070	t = nlmsg_data(nlh);
1071	t->tca_family = AF_UNSPEC;
1072	t->tca__pad1 = 0;
1073	t->tca__pad2 = 0;
1074
1075	nest = nla_nest_start(skb, TCA_ACT_TAB);
1076	if (nest == NULL)
1077		goto out_module_put;
1078
1079	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1080	if (ret < 0)
1081		goto out_module_put;
1082
1083	if (ret > 0) {
1084		nla_nest_end(skb, nest);
1085		ret = skb->len;
1086	} else
1087		nla_nest_cancel(skb, nest);
1088
1089	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1090	if (NETLINK_CB(cb->skb).portid && ret)
1091		nlh->nlmsg_flags |= NLM_F_MULTI;
1092	module_put(a_o->owner);
1093	return skb->len;
1094
1095out_module_put:
1096	module_put(a_o->owner);
1097	nlmsg_trim(skb, b);
1098	return skb->len;
1099}
1100
1101static int __init tc_action_init(void)
1102{
1103	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1104	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1105	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1106		      NULL);
1107
1108	return 0;
1109}
1110
1111subsys_initcall(tc_action_init);
1112