act_api.c revision 661d2967b3f1b34eeaa7e212e7b9bbe8ee072b59 
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	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
33	struct tcf_common **p1p;
34
35	for (p1p = &hinfo->htab[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
36		if (*p1p == p) {
37			write_lock_bh(hinfo->lock);
38			*p1p = p->tcfc_next;
39			write_unlock_bh(hinfo->lock);
40			gen_kill_estimator(&p->tcfc_bstats,
41					   &p->tcfc_rate_est);
42			/*
43			 * gen_estimator est_timer() might access p->tcfc_lock
44			 * or bstats, wait a RCU grace period before freeing p
45			 */
46			kfree_rcu(p, tcfc_rcu);
47			return;
48		}
49	}
50	WARN_ON(1);
51}
52EXPORT_SYMBOL(tcf_hash_destroy);
53
54int tcf_hash_release(struct tcf_common *p, int bind,
55		     struct tcf_hashinfo *hinfo)
56{
57	int ret = 0;
58
59	if (p) {
60		if (bind)
61			p->tcfc_bindcnt--;
62
63		p->tcfc_refcnt--;
64		if (p->tcfc_bindcnt <= 0 && p->tcfc_refcnt <= 0) {
65			tcf_hash_destroy(p, hinfo);
66			ret = 1;
67		}
68	}
69	return ret;
70}
71EXPORT_SYMBOL(tcf_hash_release);
72
73static int tcf_dump_walker(struct sk_buff *skb, struct netlink_callback *cb,
74			   struct tc_action *a, struct tcf_hashinfo *hinfo)
75{
76	struct tcf_common *p;
77	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
78	struct nlattr *nest;
79
80	read_lock_bh(hinfo->lock);
81
82	s_i = cb->args[0];
83
84	for (i = 0; i < (hinfo->hmask + 1); i++) {
85		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
86
87		for (; p; p = p->tcfc_next) {
88			index++;
89			if (index < s_i)
90				continue;
91			a->priv = p;
92			a->order = n_i;
93
94			nest = nla_nest_start(skb, a->order);
95			if (nest == NULL)
96				goto nla_put_failure;
97			err = tcf_action_dump_1(skb, a, 0, 0);
98			if (err < 0) {
99				index--;
100				nlmsg_trim(skb, nest);
101				goto done;
102			}
103			nla_nest_end(skb, nest);
104			n_i++;
105			if (n_i >= TCA_ACT_MAX_PRIO)
106				goto done;
107		}
108	}
109done:
110	read_unlock_bh(hinfo->lock);
111	if (n_i)
112		cb->args[0] += n_i;
113	return n_i;
114
115nla_put_failure:
116	nla_nest_cancel(skb, nest);
117	goto done;
118}
119
120static int tcf_del_walker(struct sk_buff *skb, struct tc_action *a,
121			  struct tcf_hashinfo *hinfo)
122{
123	struct tcf_common *p, *s_p;
124	struct nlattr *nest;
125	int i = 0, n_i = 0;
126
127	nest = nla_nest_start(skb, a->order);
128	if (nest == NULL)
129		goto nla_put_failure;
130	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
131		goto nla_put_failure;
132	for (i = 0; i < (hinfo->hmask + 1); i++) {
133		p = hinfo->htab[tcf_hash(i, hinfo->hmask)];
134
135		while (p != NULL) {
136			s_p = p->tcfc_next;
137			if (ACT_P_DELETED == tcf_hash_release(p, 0, hinfo))
138				module_put(a->ops->owner);
139			n_i++;
140			p = s_p;
141		}
142	}
143	if (nla_put_u32(skb, TCA_FCNT, n_i))
144		goto nla_put_failure;
145	nla_nest_end(skb, nest);
146
147	return n_i;
148nla_put_failure:
149	nla_nest_cancel(skb, nest);
150	return -EINVAL;
151}
152
153int tcf_generic_walker(struct sk_buff *skb, struct netlink_callback *cb,
154		       int type, struct tc_action *a)
155{
156	struct tcf_hashinfo *hinfo = a->ops->hinfo;
157
158	if (type == RTM_DELACTION) {
159		return tcf_del_walker(skb, a, hinfo);
160	} else if (type == RTM_GETACTION) {
161		return tcf_dump_walker(skb, cb, a, hinfo);
162	} else {
163		WARN(1, "tcf_generic_walker: unknown action %d\n", type);
164		return -EINVAL;
165	}
166}
167EXPORT_SYMBOL(tcf_generic_walker);
168
169struct tcf_common *tcf_hash_lookup(u32 index, struct tcf_hashinfo *hinfo)
170{
171	struct tcf_common *p;
172
173	read_lock_bh(hinfo->lock);
174	for (p = hinfo->htab[tcf_hash(index, hinfo->hmask)]; p;
175	     p = p->tcfc_next) {
176		if (p->tcfc_index == index)
177			break;
178	}
179	read_unlock_bh(hinfo->lock);
180
181	return p;
182}
183EXPORT_SYMBOL(tcf_hash_lookup);
184
185u32 tcf_hash_new_index(u32 *idx_gen, struct tcf_hashinfo *hinfo)
186{
187	u32 val = *idx_gen;
188
189	do {
190		if (++val == 0)
191			val = 1;
192	} while (tcf_hash_lookup(val, hinfo));
193
194	return (*idx_gen = val);
195}
196EXPORT_SYMBOL(tcf_hash_new_index);
197
198int tcf_hash_search(struct tc_action *a, u32 index)
199{
200	struct tcf_hashinfo *hinfo = a->ops->hinfo;
201	struct tcf_common *p = tcf_hash_lookup(index, hinfo);
202
203	if (p) {
204		a->priv = p;
205		return 1;
206	}
207	return 0;
208}
209EXPORT_SYMBOL(tcf_hash_search);
210
211struct tcf_common *tcf_hash_check(u32 index, struct tc_action *a, int bind,
212				  struct tcf_hashinfo *hinfo)
213{
214	struct tcf_common *p = NULL;
215	if (index && (p = tcf_hash_lookup(index, hinfo)) != NULL) {
216		if (bind)
217			p->tcfc_bindcnt++;
218		p->tcfc_refcnt++;
219		a->priv = p;
220	}
221	return p;
222}
223EXPORT_SYMBOL(tcf_hash_check);
224
225struct tcf_common *tcf_hash_create(u32 index, struct nlattr *est,
226				   struct tc_action *a, int size, int bind,
227				   u32 *idx_gen, struct tcf_hashinfo *hinfo)
228{
229	struct tcf_common *p = kzalloc(size, GFP_KERNEL);
230
231	if (unlikely(!p))
232		return ERR_PTR(-ENOMEM);
233	p->tcfc_refcnt = 1;
234	if (bind)
235		p->tcfc_bindcnt = 1;
236
237	spin_lock_init(&p->tcfc_lock);
238	p->tcfc_index = index ? index : tcf_hash_new_index(idx_gen, hinfo);
239	p->tcfc_tm.install = jiffies;
240	p->tcfc_tm.lastuse = jiffies;
241	if (est) {
242		int err = gen_new_estimator(&p->tcfc_bstats, &p->tcfc_rate_est,
243					    &p->tcfc_lock, est);
244		if (err) {
245			kfree(p);
246			return ERR_PTR(err);
247		}
248	}
249
250	a->priv = (void *) p;
251	return p;
252}
253EXPORT_SYMBOL(tcf_hash_create);
254
255void tcf_hash_insert(struct tcf_common *p, struct tcf_hashinfo *hinfo)
256{
257	unsigned int h = tcf_hash(p->tcfc_index, hinfo->hmask);
258
259	write_lock_bh(hinfo->lock);
260	p->tcfc_next = hinfo->htab[h];
261	hinfo->htab[h] = p;
262	write_unlock_bh(hinfo->lock);
263}
264EXPORT_SYMBOL(tcf_hash_insert);
265
266static struct tc_action_ops *act_base = NULL;
267static DEFINE_RWLOCK(act_mod_lock);
268
269int tcf_register_action(struct tc_action_ops *act)
270{
271	struct tc_action_ops *a, **ap;
272
273	write_lock(&act_mod_lock);
274	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next) {
275		if (act->type == a->type || (strcmp(act->kind, a->kind) == 0)) {
276			write_unlock(&act_mod_lock);
277			return -EEXIST;
278		}
279	}
280	act->next = NULL;
281	*ap = act;
282	write_unlock(&act_mod_lock);
283	return 0;
284}
285EXPORT_SYMBOL(tcf_register_action);
286
287int tcf_unregister_action(struct tc_action_ops *act)
288{
289	struct tc_action_ops *a, **ap;
290	int err = -ENOENT;
291
292	write_lock(&act_mod_lock);
293	for (ap = &act_base; (a = *ap) != NULL; ap = &a->next)
294		if (a == act)
295			break;
296	if (a) {
297		*ap = a->next;
298		a->next = NULL;
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		for (a = act_base; a; a = a->next) {
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		for (a = act_base; a; a = a->next) {
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 tc_action *act,
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	while ((a = act) != NULL) {
383repeat:
384		if (a->ops && a->ops->act) {
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		act = a->next;
397	}
398exec_done:
399	return ret;
400}
401EXPORT_SYMBOL(tcf_action_exec);
402
403void tcf_action_destroy(struct tc_action *act, int bind)
404{
405	struct tc_action *a;
406
407	for (a = act; a; a = act) {
408		if (a->ops && a->ops->cleanup) {
409			if (a->ops->cleanup(a, bind) == ACT_P_DELETED)
410				module_put(a->ops->owner);
411			act = act->next;
412			kfree(a);
413		} else {
414			/*FIXME: Remove later - catch insertion bugs*/
415			WARN(1, "tcf_action_destroy: BUG? destroying NULL ops\n");
416			act = act->next;
417			kfree(a);
418		}
419	}
420}
421
422int
423tcf_action_dump_old(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
424{
425	int err = -EINVAL;
426
427	if (a->ops == NULL || a->ops->dump == NULL)
428		return err;
429	return a->ops->dump(skb, a, bind, ref);
430}
431
432int
433tcf_action_dump_1(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
434{
435	int err = -EINVAL;
436	unsigned char *b = skb_tail_pointer(skb);
437	struct nlattr *nest;
438
439	if (a->ops == NULL || a->ops->dump == NULL)
440		return err;
441
442	if (nla_put_string(skb, TCA_KIND, a->ops->kind))
443		goto nla_put_failure;
444	if (tcf_action_copy_stats(skb, a, 0))
445		goto nla_put_failure;
446	nest = nla_nest_start(skb, TCA_OPTIONS);
447	if (nest == NULL)
448		goto nla_put_failure;
449	err = tcf_action_dump_old(skb, a, bind, ref);
450	if (err > 0) {
451		nla_nest_end(skb, nest);
452		return err;
453	}
454
455nla_put_failure:
456	nlmsg_trim(skb, b);
457	return -1;
458}
459EXPORT_SYMBOL(tcf_action_dump_1);
460
461int
462tcf_action_dump(struct sk_buff *skb, struct tc_action *act, int bind, int ref)
463{
464	struct tc_action *a;
465	int err = -EINVAL;
466	struct nlattr *nest;
467
468	while ((a = act) != NULL) {
469		act = a->next;
470		nest = nla_nest_start(skb, a->order);
471		if (nest == NULL)
472			goto nla_put_failure;
473		err = tcf_action_dump_1(skb, a, bind, ref);
474		if (err < 0)
475			goto errout;
476		nla_nest_end(skb, nest);
477	}
478
479	return 0;
480
481nla_put_failure:
482	err = -EINVAL;
483errout:
484	nla_nest_cancel(skb, nest);
485	return err;
486}
487
488struct tc_action *tcf_action_init_1(struct net *net, struct nlattr *nla,
489				    struct nlattr *est, char *name, int ovr,
490				    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(net, tb[TCA_ACT_OPTIONS], est, a, ovr, bind);
547	else
548		err = a_o->init(net, 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
562err_free:
563	kfree(a);
564err_mod:
565	module_put(a_o->owner);
566err_out:
567	return ERR_PTR(err);
568}
569
570struct tc_action *tcf_action_init(struct net *net, struct nlattr *nla,
571				  struct nlattr *est, char *name, int ovr,
572				  int bind)
573{
574	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
575	struct tc_action *head = NULL, *act, *act_prev = NULL;
576	int err;
577	int i;
578
579	err = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
580	if (err < 0)
581		return ERR_PTR(err);
582
583	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
584		act = tcf_action_init_1(net, tb[i], est, name, ovr, bind);
585		if (IS_ERR(act))
586			goto err;
587		act->order = i;
588
589		if (head == NULL)
590			head = act;
591		else
592			act_prev->next = act;
593		act_prev = act;
594	}
595	return head;
596
597err:
598	if (head != NULL)
599		tcf_action_destroy(head, bind);
600	return act;
601}
602
603int tcf_action_copy_stats(struct sk_buff *skb, struct tc_action *a,
604			  int compat_mode)
605{
606	int err = 0;
607	struct gnet_dump d;
608	struct tcf_act_hdr *h = a->priv;
609
610	if (h == NULL)
611		goto errout;
612
613	/* compat_mode being true specifies a call that is supposed
614	 * to add additional backward compatibility statistic TLVs.
615	 */
616	if (compat_mode) {
617		if (a->type == TCA_OLD_COMPAT)
618			err = gnet_stats_start_copy_compat(skb, 0,
619				TCA_STATS, TCA_XSTATS, &h->tcf_lock, &d);
620		else
621			return 0;
622	} else
623		err = gnet_stats_start_copy(skb, TCA_ACT_STATS,
624					    &h->tcf_lock, &d);
625
626	if (err < 0)
627		goto errout;
628
629	if (a->ops != NULL && a->ops->get_stats != NULL)
630		if (a->ops->get_stats(skb, a) < 0)
631			goto errout;
632
633	if (gnet_stats_copy_basic(&d, &h->tcf_bstats) < 0 ||
634	    gnet_stats_copy_rate_est(&d, &h->tcf_bstats,
635				     &h->tcf_rate_est) < 0 ||
636	    gnet_stats_copy_queue(&d, &h->tcf_qstats) < 0)
637		goto errout;
638
639	if (gnet_stats_finish_copy(&d) < 0)
640		goto errout;
641
642	return 0;
643
644errout:
645	return -1;
646}
647
648static int
649tca_get_fill(struct sk_buff *skb, struct tc_action *a, u32 portid, u32 seq,
650	     u16 flags, int event, int bind, int ref)
651{
652	struct tcamsg *t;
653	struct nlmsghdr *nlh;
654	unsigned char *b = skb_tail_pointer(skb);
655	struct nlattr *nest;
656
657	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
658	if (!nlh)
659		goto out_nlmsg_trim;
660	t = nlmsg_data(nlh);
661	t->tca_family = AF_UNSPEC;
662	t->tca__pad1 = 0;
663	t->tca__pad2 = 0;
664
665	nest = nla_nest_start(skb, TCA_ACT_TAB);
666	if (nest == NULL)
667		goto out_nlmsg_trim;
668
669	if (tcf_action_dump(skb, a, bind, ref) < 0)
670		goto out_nlmsg_trim;
671
672	nla_nest_end(skb, nest);
673
674	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
675	return skb->len;
676
677out_nlmsg_trim:
678	nlmsg_trim(skb, b);
679	return -1;
680}
681
682static int
683act_get_notify(struct net *net, u32 portid, struct nlmsghdr *n,
684	       struct tc_action *a, int event)
685{
686	struct sk_buff *skb;
687
688	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
689	if (!skb)
690		return -ENOBUFS;
691	if (tca_get_fill(skb, a, portid, n->nlmsg_seq, 0, event, 0, 0) <= 0) {
692		kfree_skb(skb);
693		return -EINVAL;
694	}
695
696	return rtnl_unicast(skb, net, portid);
697}
698
699static struct tc_action *
700tcf_action_get_1(struct nlattr *nla, struct nlmsghdr *n, u32 portid)
701{
702	struct nlattr *tb[TCA_ACT_MAX + 1];
703	struct tc_action *a;
704	int index;
705	int err;
706
707	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
708	if (err < 0)
709		goto err_out;
710
711	err = -EINVAL;
712	if (tb[TCA_ACT_INDEX] == NULL ||
713	    nla_len(tb[TCA_ACT_INDEX]) < sizeof(index))
714		goto err_out;
715	index = nla_get_u32(tb[TCA_ACT_INDEX]);
716
717	err = -ENOMEM;
718	a = kzalloc(sizeof(struct tc_action), GFP_KERNEL);
719	if (a == NULL)
720		goto err_out;
721
722	err = -EINVAL;
723	a->ops = tc_lookup_action(tb[TCA_ACT_KIND]);
724	if (a->ops == NULL)
725		goto err_free;
726	if (a->ops->lookup == NULL)
727		goto err_mod;
728	err = -ENOENT;
729	if (a->ops->lookup(a, index) == 0)
730		goto err_mod;
731
732	module_put(a->ops->owner);
733	return a;
734
735err_mod:
736	module_put(a->ops->owner);
737err_free:
738	kfree(a);
739err_out:
740	return ERR_PTR(err);
741}
742
743static void cleanup_a(struct tc_action *act)
744{
745	struct tc_action *a;
746
747	for (a = act; a; a = act) {
748		act = a->next;
749		kfree(a);
750	}
751}
752
753static struct tc_action *create_a(int i)
754{
755	struct tc_action *act;
756
757	act = kzalloc(sizeof(*act), GFP_KERNEL);
758	if (act == NULL) {
759		pr_debug("create_a: failed to alloc!\n");
760		return NULL;
761	}
762	act->order = i;
763	return act;
764}
765
766static int tca_action_flush(struct net *net, struct nlattr *nla,
767			    struct nlmsghdr *n, u32 portid)
768{
769	struct sk_buff *skb;
770	unsigned char *b;
771	struct nlmsghdr *nlh;
772	struct tcamsg *t;
773	struct netlink_callback dcb;
774	struct nlattr *nest;
775	struct nlattr *tb[TCA_ACT_MAX + 1];
776	struct nlattr *kind;
777	struct tc_action *a = create_a(0);
778	int err = -ENOMEM;
779
780	if (a == NULL) {
781		pr_debug("tca_action_flush: couldnt create tc_action\n");
782		return err;
783	}
784
785	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
786	if (!skb) {
787		pr_debug("tca_action_flush: failed skb alloc\n");
788		kfree(a);
789		return err;
790	}
791
792	b = skb_tail_pointer(skb);
793
794	err = nla_parse_nested(tb, TCA_ACT_MAX, nla, NULL);
795	if (err < 0)
796		goto err_out;
797
798	err = -EINVAL;
799	kind = tb[TCA_ACT_KIND];
800	a->ops = tc_lookup_action(kind);
801	if (a->ops == NULL)
802		goto err_out;
803
804	nlh = nlmsg_put(skb, portid, n->nlmsg_seq, RTM_DELACTION, sizeof(*t), 0);
805	if (!nlh)
806		goto out_module_put;
807	t = nlmsg_data(nlh);
808	t->tca_family = AF_UNSPEC;
809	t->tca__pad1 = 0;
810	t->tca__pad2 = 0;
811
812	nest = nla_nest_start(skb, TCA_ACT_TAB);
813	if (nest == NULL)
814		goto out_module_put;
815
816	err = a->ops->walk(skb, &dcb, RTM_DELACTION, a);
817	if (err < 0)
818		goto out_module_put;
819	if (err == 0)
820		goto noflush_out;
821
822	nla_nest_end(skb, nest);
823
824	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
825	nlh->nlmsg_flags |= NLM_F_ROOT;
826	module_put(a->ops->owner);
827	kfree(a);
828	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
829			     n->nlmsg_flags & NLM_F_ECHO);
830	if (err > 0)
831		return 0;
832
833	return err;
834
835out_module_put:
836	module_put(a->ops->owner);
837err_out:
838noflush_out:
839	kfree_skb(skb);
840	kfree(a);
841	return err;
842}
843
844static int
845tca_action_gd(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
846	      u32 portid, int event)
847{
848	int i, ret;
849	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
850	struct tc_action *head = NULL, *act, *act_prev = NULL;
851
852	ret = nla_parse_nested(tb, TCA_ACT_MAX_PRIO, nla, NULL);
853	if (ret < 0)
854		return ret;
855
856	if (event == RTM_DELACTION && n->nlmsg_flags & NLM_F_ROOT) {
857		if (tb[1] != NULL)
858			return tca_action_flush(net, tb[1], n, portid);
859		else
860			return -EINVAL;
861	}
862
863	for (i = 1; i <= TCA_ACT_MAX_PRIO && tb[i]; i++) {
864		act = tcf_action_get_1(tb[i], n, portid);
865		if (IS_ERR(act)) {
866			ret = PTR_ERR(act);
867			goto err;
868		}
869		act->order = i;
870
871		if (head == NULL)
872			head = act;
873		else
874			act_prev->next = act;
875		act_prev = act;
876	}
877
878	if (event == RTM_GETACTION)
879		ret = act_get_notify(net, portid, n, head, event);
880	else { /* delete */
881		struct sk_buff *skb;
882
883		skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
884		if (!skb) {
885			ret = -ENOBUFS;
886			goto err;
887		}
888
889		if (tca_get_fill(skb, head, portid, n->nlmsg_seq, 0, event,
890				 0, 1) <= 0) {
891			kfree_skb(skb);
892			ret = -EINVAL;
893			goto err;
894		}
895
896		/* now do the delete */
897		tcf_action_destroy(head, 0);
898		ret = rtnetlink_send(skb, net, portid, RTNLGRP_TC,
899				     n->nlmsg_flags & NLM_F_ECHO);
900		if (ret > 0)
901			return 0;
902		return ret;
903	}
904err:
905	cleanup_a(head);
906	return ret;
907}
908
909static int tcf_add_notify(struct net *net, struct tc_action *a,
910			  u32 portid, u32 seq, int event, u16 flags)
911{
912	struct tcamsg *t;
913	struct nlmsghdr *nlh;
914	struct sk_buff *skb;
915	struct nlattr *nest;
916	unsigned char *b;
917	int err = 0;
918
919	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
920	if (!skb)
921		return -ENOBUFS;
922
923	b = skb_tail_pointer(skb);
924
925	nlh = nlmsg_put(skb, portid, seq, event, sizeof(*t), flags);
926	if (!nlh)
927		goto out_kfree_skb;
928	t = nlmsg_data(nlh);
929	t->tca_family = AF_UNSPEC;
930	t->tca__pad1 = 0;
931	t->tca__pad2 = 0;
932
933	nest = nla_nest_start(skb, TCA_ACT_TAB);
934	if (nest == NULL)
935		goto out_kfree_skb;
936
937	if (tcf_action_dump(skb, a, 0, 0) < 0)
938		goto out_kfree_skb;
939
940	nla_nest_end(skb, nest);
941
942	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
943	NETLINK_CB(skb).dst_group = RTNLGRP_TC;
944
945	err = rtnetlink_send(skb, net, portid, RTNLGRP_TC, flags & NLM_F_ECHO);
946	if (err > 0)
947		err = 0;
948	return err;
949
950out_kfree_skb:
951	kfree_skb(skb);
952	return -1;
953}
954
955
956static int
957tcf_action_add(struct net *net, struct nlattr *nla, struct nlmsghdr *n,
958	       u32 portid, int ovr)
959{
960	int ret = 0;
961	struct tc_action *act;
962	struct tc_action *a;
963	u32 seq = n->nlmsg_seq;
964
965	act = tcf_action_init(net, nla, NULL, NULL, ovr, 0);
966	if (act == NULL)
967		goto done;
968	if (IS_ERR(act)) {
969		ret = PTR_ERR(act);
970		goto done;
971	}
972
973	/* dump then free all the actions after update; inserted policy
974	 * stays intact
975	 */
976	ret = tcf_add_notify(net, act, portid, seq, RTM_NEWACTION, n->nlmsg_flags);
977	for (a = act; a; a = act) {
978		act = a->next;
979		kfree(a);
980	}
981done:
982	return ret;
983}
984
985static int tc_ctl_action(struct sk_buff *skb, struct nlmsghdr *n)
986{
987	struct net *net = sock_net(skb->sk);
988	struct nlattr *tca[TCA_ACT_MAX + 1];
989	u32 portid = skb ? NETLINK_CB(skb).portid : 0;
990	int ret = 0, ovr = 0;
991
992	if ((n->nlmsg_type != RTM_GETACTION) && !capable(CAP_NET_ADMIN))
993		return -EPERM;
994
995	ret = nlmsg_parse(n, sizeof(struct tcamsg), tca, TCA_ACT_MAX, NULL);
996	if (ret < 0)
997		return ret;
998
999	if (tca[TCA_ACT_TAB] == NULL) {
1000		pr_notice("tc_ctl_action: received NO action attribs\n");
1001		return -EINVAL;
1002	}
1003
1004	/* n->nlmsg_flags & NLM_F_CREATE */
1005	switch (n->nlmsg_type) {
1006	case RTM_NEWACTION:
1007		/* we are going to assume all other flags
1008		 * imply create only if it doesn't exist
1009		 * Note that CREATE | EXCL implies that
1010		 * but since we want avoid ambiguity (eg when flags
1011		 * is zero) then just set this
1012		 */
1013		if (n->nlmsg_flags & NLM_F_REPLACE)
1014			ovr = 1;
1015replay:
1016		ret = tcf_action_add(net, tca[TCA_ACT_TAB], n, portid, ovr);
1017		if (ret == -EAGAIN)
1018			goto replay;
1019		break;
1020	case RTM_DELACTION:
1021		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1022				    portid, RTM_DELACTION);
1023		break;
1024	case RTM_GETACTION:
1025		ret = tca_action_gd(net, tca[TCA_ACT_TAB], n,
1026				    portid, RTM_GETACTION);
1027		break;
1028	default:
1029		BUG();
1030	}
1031
1032	return ret;
1033}
1034
1035static struct nlattr *
1036find_dump_kind(const struct nlmsghdr *n)
1037{
1038	struct nlattr *tb1, *tb2[TCA_ACT_MAX + 1];
1039	struct nlattr *tb[TCA_ACT_MAX_PRIO + 1];
1040	struct nlattr *nla[TCAA_MAX + 1];
1041	struct nlattr *kind;
1042
1043	if (nlmsg_parse(n, sizeof(struct tcamsg), nla, TCAA_MAX, NULL) < 0)
1044		return NULL;
1045	tb1 = nla[TCA_ACT_TAB];
1046	if (tb1 == NULL)
1047		return NULL;
1048
1049	if (nla_parse(tb, TCA_ACT_MAX_PRIO, nla_data(tb1),
1050		      NLMSG_ALIGN(nla_len(tb1)), NULL) < 0)
1051		return NULL;
1052
1053	if (tb[1] == NULL)
1054		return NULL;
1055	if (nla_parse(tb2, TCA_ACT_MAX, nla_data(tb[1]),
1056		      nla_len(tb[1]), NULL) < 0)
1057		return NULL;
1058	kind = tb2[TCA_ACT_KIND];
1059
1060	return kind;
1061}
1062
1063static int
1064tc_dump_action(struct sk_buff *skb, struct netlink_callback *cb)
1065{
1066	struct nlmsghdr *nlh;
1067	unsigned char *b = skb_tail_pointer(skb);
1068	struct nlattr *nest;
1069	struct tc_action_ops *a_o;
1070	struct tc_action a;
1071	int ret = 0;
1072	struct tcamsg *t = (struct tcamsg *) nlmsg_data(cb->nlh);
1073	struct nlattr *kind = find_dump_kind(cb->nlh);
1074
1075	if (kind == NULL) {
1076		pr_info("tc_dump_action: action bad kind\n");
1077		return 0;
1078	}
1079
1080	a_o = tc_lookup_action(kind);
1081	if (a_o == NULL)
1082		return 0;
1083
1084	memset(&a, 0, sizeof(struct tc_action));
1085	a.ops = a_o;
1086
1087	if (a_o->walk == NULL) {
1088		WARN(1, "tc_dump_action: %s !capable of dumping table\n",
1089		     a_o->kind);
1090		goto out_module_put;
1091	}
1092
1093	nlh = nlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
1094			cb->nlh->nlmsg_type, sizeof(*t), 0);
1095	if (!nlh)
1096		goto out_module_put;
1097	t = nlmsg_data(nlh);
1098	t->tca_family = AF_UNSPEC;
1099	t->tca__pad1 = 0;
1100	t->tca__pad2 = 0;
1101
1102	nest = nla_nest_start(skb, TCA_ACT_TAB);
1103	if (nest == NULL)
1104		goto out_module_put;
1105
1106	ret = a_o->walk(skb, cb, RTM_GETACTION, &a);
1107	if (ret < 0)
1108		goto out_module_put;
1109
1110	if (ret > 0) {
1111		nla_nest_end(skb, nest);
1112		ret = skb->len;
1113	} else
1114		nla_nest_cancel(skb, nest);
1115
1116	nlh->nlmsg_len = skb_tail_pointer(skb) - b;
1117	if (NETLINK_CB(cb->skb).portid && ret)
1118		nlh->nlmsg_flags |= NLM_F_MULTI;
1119	module_put(a_o->owner);
1120	return skb->len;
1121
1122out_module_put:
1123	module_put(a_o->owner);
1124	nlmsg_trim(skb, b);
1125	return skb->len;
1126}
1127
1128static int __init tc_action_init(void)
1129{
1130	rtnl_register(PF_UNSPEC, RTM_NEWACTION, tc_ctl_action, NULL, NULL);
1131	rtnl_register(PF_UNSPEC, RTM_DELACTION, tc_ctl_action, NULL, NULL);
1132	rtnl_register(PF_UNSPEC, RTM_GETACTION, tc_ctl_action, tc_dump_action,
1133		      NULL);
1134
1135	return 0;
1136}
1137
1138subsys_initcall(tc_action_init);
1139