Linux Audio

Check our new training course

Loading...
v5.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * net/sched/cls_route.c	ROUTE4 classifier.
  4 *
 
 
 
 
 
  5 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
  6 */
  7
  8#include <linux/module.h>
  9#include <linux/slab.h>
 10#include <linux/types.h>
 11#include <linux/kernel.h>
 12#include <linux/string.h>
 13#include <linux/errno.h>
 14#include <linux/skbuff.h>
 15#include <net/dst.h>
 16#include <net/route.h>
 17#include <net/netlink.h>
 18#include <net/act_api.h>
 19#include <net/pkt_cls.h>
 20
 21/*
 22 * 1. For now we assume that route tags < 256.
 23 *    It allows to use direct table lookups, instead of hash tables.
 24 * 2. For now we assume that "from TAG" and "fromdev DEV" statements
 25 *    are mutually  exclusive.
 26 * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
 27 */
 28struct route4_fastmap {
 29	struct route4_filter		*filter;
 30	u32				id;
 31	int				iif;
 32};
 33
 34struct route4_head {
 35	struct route4_fastmap		fastmap[16];
 36	struct route4_bucket __rcu	*table[256 + 1];
 37	struct rcu_head			rcu;
 38};
 39
 40struct route4_bucket {
 41	/* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
 42	struct route4_filter __rcu	*ht[16 + 16 + 1];
 43	struct rcu_head			rcu;
 44};
 45
 46struct route4_filter {
 47	struct route4_filter __rcu	*next;
 48	u32			id;
 49	int			iif;
 50
 51	struct tcf_result	res;
 52	struct tcf_exts		exts;
 53	u32			handle;
 54	struct route4_bucket	*bkt;
 55	struct tcf_proto	*tp;
 56	struct rcu_work		rwork;
 
 
 
 57};
 58
 59#define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
 60
 61static inline int route4_fastmap_hash(u32 id, int iif)
 62{
 63	return id & 0xF;
 64}
 65
 66static DEFINE_SPINLOCK(fastmap_lock);
 67static void
 68route4_reset_fastmap(struct route4_head *head)
 69{
 70	spin_lock_bh(&fastmap_lock);
 71	memset(head->fastmap, 0, sizeof(head->fastmap));
 72	spin_unlock_bh(&fastmap_lock);
 73}
 74
 75static void
 76route4_set_fastmap(struct route4_head *head, u32 id, int iif,
 77		   struct route4_filter *f)
 78{
 79	int h = route4_fastmap_hash(id, iif);
 80
 81	/* fastmap updates must look atomic to aling id, iff, filter */
 82	spin_lock_bh(&fastmap_lock);
 83	head->fastmap[h].id = id;
 84	head->fastmap[h].iif = iif;
 85	head->fastmap[h].filter = f;
 86	spin_unlock_bh(&fastmap_lock);
 87}
 88
 89static inline int route4_hash_to(u32 id)
 90{
 91	return id & 0xFF;
 92}
 93
 94static inline int route4_hash_from(u32 id)
 95{
 96	return (id >> 16) & 0xF;
 97}
 98
 99static inline int route4_hash_iif(int iif)
100{
101	return 16 + ((iif >> 16) & 0xF);
102}
103
104static inline int route4_hash_wild(void)
105{
106	return 32;
107}
108
109#define ROUTE4_APPLY_RESULT()					\
110{								\
111	*res = f->res;						\
112	if (tcf_exts_has_actions(&f->exts)) {			\
113		int r = tcf_exts_exec(skb, &f->exts, res);	\
114		if (r < 0) {					\
115			dont_cache = 1;				\
116			continue;				\
117		}						\
118		return r;					\
119	} else if (!dont_cache)					\
120		route4_set_fastmap(head, id, iif, f);		\
121	return 0;						\
122}
123
124static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
125			   struct tcf_result *res)
126{
127	struct route4_head *head = rcu_dereference_bh(tp->root);
128	struct dst_entry *dst;
129	struct route4_bucket *b;
130	struct route4_filter *f;
131	u32 id, h;
132	int iif, dont_cache = 0;
133
134	dst = skb_dst(skb);
135	if (!dst)
136		goto failure;
137
138	id = dst->tclassid;
139
140	iif = inet_iif(skb);
141
142	h = route4_fastmap_hash(id, iif);
143
144	spin_lock(&fastmap_lock);
145	if (id == head->fastmap[h].id &&
146	    iif == head->fastmap[h].iif &&
147	    (f = head->fastmap[h].filter) != NULL) {
148		if (f == ROUTE4_FAILURE) {
149			spin_unlock(&fastmap_lock);
150			goto failure;
151		}
152
153		*res = f->res;
154		spin_unlock(&fastmap_lock);
155		return 0;
156	}
157	spin_unlock(&fastmap_lock);
158
159	h = route4_hash_to(id);
160
161restart:
162	b = rcu_dereference_bh(head->table[h]);
163	if (b) {
164		for (f = rcu_dereference_bh(b->ht[route4_hash_from(id)]);
165		     f;
166		     f = rcu_dereference_bh(f->next))
167			if (f->id == id)
168				ROUTE4_APPLY_RESULT();
169
170		for (f = rcu_dereference_bh(b->ht[route4_hash_iif(iif)]);
171		     f;
172		     f = rcu_dereference_bh(f->next))
173			if (f->iif == iif)
174				ROUTE4_APPLY_RESULT();
175
176		for (f = rcu_dereference_bh(b->ht[route4_hash_wild()]);
177		     f;
178		     f = rcu_dereference_bh(f->next))
179			ROUTE4_APPLY_RESULT();
180	}
181	if (h < 256) {
182		h = 256;
183		id &= ~0xFFFF;
184		goto restart;
185	}
186
187	if (!dont_cache)
188		route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
189failure:
190	return -1;
191}
192
193static inline u32 to_hash(u32 id)
194{
195	u32 h = id & 0xFF;
196
197	if (id & 0x8000)
198		h += 256;
199	return h;
200}
201
202static inline u32 from_hash(u32 id)
203{
204	id &= 0xFFFF;
205	if (id == 0xFFFF)
206		return 32;
207	if (!(id & 0x8000)) {
208		if (id > 255)
209			return 256;
210		return id & 0xF;
211	}
212	return 16 + (id & 0xF);
213}
214
215static void *route4_get(struct tcf_proto *tp, u32 handle)
216{
217	struct route4_head *head = rtnl_dereference(tp->root);
218	struct route4_bucket *b;
219	struct route4_filter *f;
220	unsigned int h1, h2;
221
222	h1 = to_hash(handle);
223	if (h1 > 256)
224		return NULL;
225
226	h2 = from_hash(handle >> 16);
227	if (h2 > 32)
228		return NULL;
229
230	b = rtnl_dereference(head->table[h1]);
231	if (b) {
232		for (f = rtnl_dereference(b->ht[h2]);
233		     f;
234		     f = rtnl_dereference(f->next))
235			if (f->handle == handle)
236				return f;
237	}
238	return NULL;
239}
240
241static int route4_init(struct tcf_proto *tp)
242{
243	struct route4_head *head;
244
245	head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
246	if (head == NULL)
247		return -ENOBUFS;
248
249	rcu_assign_pointer(tp->root, head);
250	return 0;
251}
252
253static void __route4_delete_filter(struct route4_filter *f)
254{
255	tcf_exts_destroy(&f->exts);
256	tcf_exts_put_net(&f->exts);
257	kfree(f);
258}
259
260static void route4_delete_filter_work(struct work_struct *work)
261{
262	struct route4_filter *f = container_of(to_rcu_work(work),
263					       struct route4_filter,
264					       rwork);
265	rtnl_lock();
266	__route4_delete_filter(f);
267	rtnl_unlock();
268}
269
270static void route4_queue_work(struct route4_filter *f)
271{
272	tcf_queue_work(&f->rwork, route4_delete_filter_work);
 
 
 
273}
274
275static void route4_destroy(struct tcf_proto *tp, bool rtnl_held,
276			   struct netlink_ext_ack *extack)
277{
278	struct route4_head *head = rtnl_dereference(tp->root);
279	int h1, h2;
280
281	if (head == NULL)
282		return;
283
284	for (h1 = 0; h1 <= 256; h1++) {
285		struct route4_bucket *b;
286
287		b = rtnl_dereference(head->table[h1]);
288		if (b) {
289			for (h2 = 0; h2 <= 32; h2++) {
290				struct route4_filter *f;
291
292				while ((f = rtnl_dereference(b->ht[h2])) != NULL) {
293					struct route4_filter *next;
294
295					next = rtnl_dereference(f->next);
296					RCU_INIT_POINTER(b->ht[h2], next);
297					tcf_unbind_filter(tp, &f->res);
298					if (tcf_exts_get_net(&f->exts))
299						route4_queue_work(f);
300					else
301						__route4_delete_filter(f);
302				}
303			}
304			RCU_INIT_POINTER(head->table[h1], NULL);
305			kfree_rcu(b, rcu);
306		}
307	}
308	kfree_rcu(head, rcu);
309}
310
311static int route4_delete(struct tcf_proto *tp, void *arg, bool *last,
312			 bool rtnl_held, struct netlink_ext_ack *extack)
313{
314	struct route4_head *head = rtnl_dereference(tp->root);
315	struct route4_filter *f = arg;
316	struct route4_filter __rcu **fp;
317	struct route4_filter *nf;
318	struct route4_bucket *b;
319	unsigned int h = 0;
320	int i, h1;
321
322	if (!head || !f)
323		return -EINVAL;
324
325	h = f->handle;
326	b = f->bkt;
327
328	fp = &b->ht[from_hash(h >> 16)];
329	for (nf = rtnl_dereference(*fp); nf;
330	     fp = &nf->next, nf = rtnl_dereference(*fp)) {
331		if (nf == f) {
332			/* unlink it */
333			RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
334
335			/* Remove any fastmap lookups that might ref filter
336			 * notice we unlink'd the filter so we can't get it
337			 * back in the fastmap.
338			 */
339			route4_reset_fastmap(head);
340
341			/* Delete it */
342			tcf_unbind_filter(tp, &f->res);
343			tcf_exts_get_net(&f->exts);
344			tcf_queue_work(&f->rwork, route4_delete_filter_work);
345
346			/* Strip RTNL protected tree */
347			for (i = 0; i <= 32; i++) {
348				struct route4_filter *rt;
349
350				rt = rtnl_dereference(b->ht[i]);
351				if (rt)
352					goto out;
353			}
354
355			/* OK, session has no flows */
356			RCU_INIT_POINTER(head->table[to_hash(h)], NULL);
357			kfree_rcu(b, rcu);
358			break;
359		}
360	}
361
362out:
363	*last = true;
364	for (h1 = 0; h1 <= 256; h1++) {
365		if (rcu_access_pointer(head->table[h1])) {
366			*last = false;
367			break;
368		}
369	}
370
371	return 0;
372}
373
374static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = {
375	[TCA_ROUTE4_CLASSID]	= { .type = NLA_U32 },
376	[TCA_ROUTE4_TO]		= { .type = NLA_U32 },
377	[TCA_ROUTE4_FROM]	= { .type = NLA_U32 },
378	[TCA_ROUTE4_IIF]	= { .type = NLA_U32 },
379};
380
381static int route4_set_parms(struct net *net, struct tcf_proto *tp,
382			    unsigned long base, struct route4_filter *f,
383			    u32 handle, struct route4_head *head,
384			    struct nlattr **tb, struct nlattr *est, int new,
385			    bool ovr, struct netlink_ext_ack *extack)
386{
387	u32 id = 0, to = 0, nhandle = 0x8000;
388	struct route4_filter *fp;
389	unsigned int h1;
390	struct route4_bucket *b;
391	int err;
392
393	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, true, extack);
394	if (err < 0)
395		return err;
396
397	if (tb[TCA_ROUTE4_TO]) {
398		if (new && handle & 0x8000)
399			return -EINVAL;
400		to = nla_get_u32(tb[TCA_ROUTE4_TO]);
401		if (to > 0xFF)
402			return -EINVAL;
403		nhandle = to;
404	}
405
406	if (tb[TCA_ROUTE4_FROM]) {
407		if (tb[TCA_ROUTE4_IIF])
408			return -EINVAL;
409		id = nla_get_u32(tb[TCA_ROUTE4_FROM]);
410		if (id > 0xFF)
411			return -EINVAL;
412		nhandle |= id << 16;
413	} else if (tb[TCA_ROUTE4_IIF]) {
414		id = nla_get_u32(tb[TCA_ROUTE4_IIF]);
415		if (id > 0x7FFF)
416			return -EINVAL;
417		nhandle |= (id | 0x8000) << 16;
418	} else
419		nhandle |= 0xFFFF << 16;
420
421	if (handle && new) {
422		nhandle |= handle & 0x7F00;
423		if (nhandle != handle)
424			return -EINVAL;
425	}
426
427	h1 = to_hash(nhandle);
428	b = rtnl_dereference(head->table[h1]);
429	if (!b) {
430		b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
431		if (b == NULL)
432			return -ENOBUFS;
433
434		rcu_assign_pointer(head->table[h1], b);
435	} else {
436		unsigned int h2 = from_hash(nhandle >> 16);
437
438		for (fp = rtnl_dereference(b->ht[h2]);
439		     fp;
440		     fp = rtnl_dereference(fp->next))
441			if (fp->handle == f->handle)
442				return -EEXIST;
443	}
444
445	if (tb[TCA_ROUTE4_TO])
446		f->id = to;
447
448	if (tb[TCA_ROUTE4_FROM])
449		f->id = to | id<<16;
450	else if (tb[TCA_ROUTE4_IIF])
451		f->iif = id;
452
453	f->handle = nhandle;
454	f->bkt = b;
455	f->tp = tp;
456
457	if (tb[TCA_ROUTE4_CLASSID]) {
458		f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
459		tcf_bind_filter(tp, &f->res, base);
460	}
461
462	return 0;
463}
464
465static int route4_change(struct net *net, struct sk_buff *in_skb,
466			 struct tcf_proto *tp, unsigned long base, u32 handle,
467			 struct nlattr **tca, void **arg, bool ovr,
468			 bool rtnl_held, struct netlink_ext_ack *extack)
469{
470	struct route4_head *head = rtnl_dereference(tp->root);
471	struct route4_filter __rcu **fp;
472	struct route4_filter *fold, *f1, *pfp, *f = NULL;
473	struct route4_bucket *b;
474	struct nlattr *opt = tca[TCA_OPTIONS];
475	struct nlattr *tb[TCA_ROUTE4_MAX + 1];
476	unsigned int h, th;
477	int err;
478	bool new = true;
479
480	if (opt == NULL)
481		return handle ? -EINVAL : 0;
482
483	err = nla_parse_nested_deprecated(tb, TCA_ROUTE4_MAX, opt,
484					  route4_policy, NULL);
485	if (err < 0)
486		return err;
487
488	fold = *arg;
489	if (fold && handle && fold->handle != handle)
490			return -EINVAL;
491
492	err = -ENOBUFS;
493	f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
494	if (!f)
495		goto errout;
496
497	err = tcf_exts_init(&f->exts, net, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE);
498	if (err < 0)
499		goto errout;
500
501	if (fold) {
502		f->id = fold->id;
503		f->iif = fold->iif;
504		f->res = fold->res;
505		f->handle = fold->handle;
506
507		f->tp = fold->tp;
508		f->bkt = fold->bkt;
509		new = false;
510	}
511
512	err = route4_set_parms(net, tp, base, f, handle, head, tb,
513			       tca[TCA_RATE], new, ovr, extack);
514	if (err < 0)
515		goto errout;
516
517	h = from_hash(f->handle >> 16);
518	fp = &f->bkt->ht[h];
519	for (pfp = rtnl_dereference(*fp);
520	     (f1 = rtnl_dereference(*fp)) != NULL;
521	     fp = &f1->next)
522		if (f->handle < f1->handle)
523			break;
524
525	tcf_block_netif_keep_dst(tp->chain->block);
526	rcu_assign_pointer(f->next, f1);
527	rcu_assign_pointer(*fp, f);
528
529	if (fold && fold->handle && f->handle != fold->handle) {
530		th = to_hash(fold->handle);
531		h = from_hash(fold->handle >> 16);
532		b = rtnl_dereference(head->table[th]);
533		if (b) {
534			fp = &b->ht[h];
535			for (pfp = rtnl_dereference(*fp); pfp;
536			     fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
537				if (pfp == f) {
538					*fp = f->next;
539					break;
540				}
541			}
542		}
543	}
544
545	route4_reset_fastmap(head);
546	*arg = f;
547	if (fold) {
548		tcf_unbind_filter(tp, &fold->res);
549		tcf_exts_get_net(&fold->exts);
550		tcf_queue_work(&fold->rwork, route4_delete_filter_work);
551	}
552	return 0;
553
554errout:
555	if (f)
556		tcf_exts_destroy(&f->exts);
557	kfree(f);
558	return err;
559}
560
561static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg,
562			bool rtnl_held)
563{
564	struct route4_head *head = rtnl_dereference(tp->root);
565	unsigned int h, h1;
566
567	if (head == NULL || arg->stop)
 
 
 
568		return;
569
570	for (h = 0; h <= 256; h++) {
571		struct route4_bucket *b = rtnl_dereference(head->table[h]);
572
573		if (b) {
574			for (h1 = 0; h1 <= 32; h1++) {
575				struct route4_filter *f;
576
577				for (f = rtnl_dereference(b->ht[h1]);
578				     f;
579				     f = rtnl_dereference(f->next)) {
580					if (arg->count < arg->skip) {
581						arg->count++;
582						continue;
583					}
584					if (arg->fn(tp, f, arg) < 0) {
585						arg->stop = 1;
586						return;
587					}
588					arg->count++;
589				}
590			}
591		}
592	}
593}
594
595static int route4_dump(struct net *net, struct tcf_proto *tp, void *fh,
596		       struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
597{
598	struct route4_filter *f = fh;
599	struct nlattr *nest;
600	u32 id;
601
602	if (f == NULL)
603		return skb->len;
604
605	t->tcm_handle = f->handle;
606
607	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
608	if (nest == NULL)
609		goto nla_put_failure;
610
611	if (!(f->handle & 0x8000)) {
612		id = f->id & 0xFF;
613		if (nla_put_u32(skb, TCA_ROUTE4_TO, id))
614			goto nla_put_failure;
615	}
616	if (f->handle & 0x80000000) {
617		if ((f->handle >> 16) != 0xFFFF &&
618		    nla_put_u32(skb, TCA_ROUTE4_IIF, f->iif))
619			goto nla_put_failure;
620	} else {
621		id = f->id >> 16;
622		if (nla_put_u32(skb, TCA_ROUTE4_FROM, id))
623			goto nla_put_failure;
624	}
625	if (f->res.classid &&
626	    nla_put_u32(skb, TCA_ROUTE4_CLASSID, f->res.classid))
627		goto nla_put_failure;
628
629	if (tcf_exts_dump(skb, &f->exts) < 0)
630		goto nla_put_failure;
631
632	nla_nest_end(skb, nest);
633
634	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
635		goto nla_put_failure;
636
637	return skb->len;
638
639nla_put_failure:
640	nla_nest_cancel(skb, nest);
641	return -1;
642}
643
644static void route4_bind_class(void *fh, u32 classid, unsigned long cl)
645{
646	struct route4_filter *f = fh;
647
648	if (f && f->res.classid == classid)
649		f->res.class = cl;
650}
651
652static struct tcf_proto_ops cls_route4_ops __read_mostly = {
653	.kind		=	"route",
654	.classify	=	route4_classify,
655	.init		=	route4_init,
656	.destroy	=	route4_destroy,
657	.get		=	route4_get,
658	.change		=	route4_change,
659	.delete		=	route4_delete,
660	.walk		=	route4_walk,
661	.dump		=	route4_dump,
662	.bind_class	=	route4_bind_class,
663	.owner		=	THIS_MODULE,
664};
665
666static int __init init_route4(void)
667{
668	return register_tcf_proto_ops(&cls_route4_ops);
669}
670
671static void __exit exit_route4(void)
672{
673	unregister_tcf_proto_ops(&cls_route4_ops);
674}
675
676module_init(init_route4)
677module_exit(exit_route4)
678MODULE_LICENSE("GPL");
v4.17
 
  1/*
  2 * net/sched/cls_route.c	ROUTE4 classifier.
  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 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 10 */
 11
 12#include <linux/module.h>
 13#include <linux/slab.h>
 14#include <linux/types.h>
 15#include <linux/kernel.h>
 16#include <linux/string.h>
 17#include <linux/errno.h>
 18#include <linux/skbuff.h>
 19#include <net/dst.h>
 20#include <net/route.h>
 21#include <net/netlink.h>
 22#include <net/act_api.h>
 23#include <net/pkt_cls.h>
 24
 25/*
 26 * 1. For now we assume that route tags < 256.
 27 *    It allows to use direct table lookups, instead of hash tables.
 28 * 2. For now we assume that "from TAG" and "fromdev DEV" statements
 29 *    are mutually  exclusive.
 30 * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
 31 */
 32struct route4_fastmap {
 33	struct route4_filter		*filter;
 34	u32				id;
 35	int				iif;
 36};
 37
 38struct route4_head {
 39	struct route4_fastmap		fastmap[16];
 40	struct route4_bucket __rcu	*table[256 + 1];
 41	struct rcu_head			rcu;
 42};
 43
 44struct route4_bucket {
 45	/* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
 46	struct route4_filter __rcu	*ht[16 + 16 + 1];
 47	struct rcu_head			rcu;
 48};
 49
 50struct route4_filter {
 51	struct route4_filter __rcu	*next;
 52	u32			id;
 53	int			iif;
 54
 55	struct tcf_result	res;
 56	struct tcf_exts		exts;
 57	u32			handle;
 58	struct route4_bucket	*bkt;
 59	struct tcf_proto	*tp;
 60	union {
 61		struct work_struct	work;
 62		struct rcu_head		rcu;
 63	};
 64};
 65
 66#define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
 67
 68static inline int route4_fastmap_hash(u32 id, int iif)
 69{
 70	return id & 0xF;
 71}
 72
 73static DEFINE_SPINLOCK(fastmap_lock);
 74static void
 75route4_reset_fastmap(struct route4_head *head)
 76{
 77	spin_lock_bh(&fastmap_lock);
 78	memset(head->fastmap, 0, sizeof(head->fastmap));
 79	spin_unlock_bh(&fastmap_lock);
 80}
 81
 82static void
 83route4_set_fastmap(struct route4_head *head, u32 id, int iif,
 84		   struct route4_filter *f)
 85{
 86	int h = route4_fastmap_hash(id, iif);
 87
 88	/* fastmap updates must look atomic to aling id, iff, filter */
 89	spin_lock_bh(&fastmap_lock);
 90	head->fastmap[h].id = id;
 91	head->fastmap[h].iif = iif;
 92	head->fastmap[h].filter = f;
 93	spin_unlock_bh(&fastmap_lock);
 94}
 95
 96static inline int route4_hash_to(u32 id)
 97{
 98	return id & 0xFF;
 99}
100
101static inline int route4_hash_from(u32 id)
102{
103	return (id >> 16) & 0xF;
104}
105
106static inline int route4_hash_iif(int iif)
107{
108	return 16 + ((iif >> 16) & 0xF);
109}
110
111static inline int route4_hash_wild(void)
112{
113	return 32;
114}
115
116#define ROUTE4_APPLY_RESULT()					\
117{								\
118	*res = f->res;						\
119	if (tcf_exts_has_actions(&f->exts)) {			\
120		int r = tcf_exts_exec(skb, &f->exts, res);	\
121		if (r < 0) {					\
122			dont_cache = 1;				\
123			continue;				\
124		}						\
125		return r;					\
126	} else if (!dont_cache)					\
127		route4_set_fastmap(head, id, iif, f);		\
128	return 0;						\
129}
130
131static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
132			   struct tcf_result *res)
133{
134	struct route4_head *head = rcu_dereference_bh(tp->root);
135	struct dst_entry *dst;
136	struct route4_bucket *b;
137	struct route4_filter *f;
138	u32 id, h;
139	int iif, dont_cache = 0;
140
141	dst = skb_dst(skb);
142	if (!dst)
143		goto failure;
144
145	id = dst->tclassid;
146
147	iif = inet_iif(skb);
148
149	h = route4_fastmap_hash(id, iif);
150
151	spin_lock(&fastmap_lock);
152	if (id == head->fastmap[h].id &&
153	    iif == head->fastmap[h].iif &&
154	    (f = head->fastmap[h].filter) != NULL) {
155		if (f == ROUTE4_FAILURE) {
156			spin_unlock(&fastmap_lock);
157			goto failure;
158		}
159
160		*res = f->res;
161		spin_unlock(&fastmap_lock);
162		return 0;
163	}
164	spin_unlock(&fastmap_lock);
165
166	h = route4_hash_to(id);
167
168restart:
169	b = rcu_dereference_bh(head->table[h]);
170	if (b) {
171		for (f = rcu_dereference_bh(b->ht[route4_hash_from(id)]);
172		     f;
173		     f = rcu_dereference_bh(f->next))
174			if (f->id == id)
175				ROUTE4_APPLY_RESULT();
176
177		for (f = rcu_dereference_bh(b->ht[route4_hash_iif(iif)]);
178		     f;
179		     f = rcu_dereference_bh(f->next))
180			if (f->iif == iif)
181				ROUTE4_APPLY_RESULT();
182
183		for (f = rcu_dereference_bh(b->ht[route4_hash_wild()]);
184		     f;
185		     f = rcu_dereference_bh(f->next))
186			ROUTE4_APPLY_RESULT();
187	}
188	if (h < 256) {
189		h = 256;
190		id &= ~0xFFFF;
191		goto restart;
192	}
193
194	if (!dont_cache)
195		route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
196failure:
197	return -1;
198}
199
200static inline u32 to_hash(u32 id)
201{
202	u32 h = id & 0xFF;
203
204	if (id & 0x8000)
205		h += 256;
206	return h;
207}
208
209static inline u32 from_hash(u32 id)
210{
211	id &= 0xFFFF;
212	if (id == 0xFFFF)
213		return 32;
214	if (!(id & 0x8000)) {
215		if (id > 255)
216			return 256;
217		return id & 0xF;
218	}
219	return 16 + (id & 0xF);
220}
221
222static void *route4_get(struct tcf_proto *tp, u32 handle)
223{
224	struct route4_head *head = rtnl_dereference(tp->root);
225	struct route4_bucket *b;
226	struct route4_filter *f;
227	unsigned int h1, h2;
228
229	h1 = to_hash(handle);
230	if (h1 > 256)
231		return NULL;
232
233	h2 = from_hash(handle >> 16);
234	if (h2 > 32)
235		return NULL;
236
237	b = rtnl_dereference(head->table[h1]);
238	if (b) {
239		for (f = rtnl_dereference(b->ht[h2]);
240		     f;
241		     f = rtnl_dereference(f->next))
242			if (f->handle == handle)
243				return f;
244	}
245	return NULL;
246}
247
248static int route4_init(struct tcf_proto *tp)
249{
250	struct route4_head *head;
251
252	head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
253	if (head == NULL)
254		return -ENOBUFS;
255
256	rcu_assign_pointer(tp->root, head);
257	return 0;
258}
259
260static void __route4_delete_filter(struct route4_filter *f)
261{
262	tcf_exts_destroy(&f->exts);
263	tcf_exts_put_net(&f->exts);
264	kfree(f);
265}
266
267static void route4_delete_filter_work(struct work_struct *work)
268{
269	struct route4_filter *f = container_of(work, struct route4_filter, work);
270
 
271	rtnl_lock();
272	__route4_delete_filter(f);
273	rtnl_unlock();
274}
275
276static void route4_delete_filter(struct rcu_head *head)
277{
278	struct route4_filter *f = container_of(head, struct route4_filter, rcu);
279
280	INIT_WORK(&f->work, route4_delete_filter_work);
281	tcf_queue_work(&f->work);
282}
283
284static void route4_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 
285{
286	struct route4_head *head = rtnl_dereference(tp->root);
287	int h1, h2;
288
289	if (head == NULL)
290		return;
291
292	for (h1 = 0; h1 <= 256; h1++) {
293		struct route4_bucket *b;
294
295		b = rtnl_dereference(head->table[h1]);
296		if (b) {
297			for (h2 = 0; h2 <= 32; h2++) {
298				struct route4_filter *f;
299
300				while ((f = rtnl_dereference(b->ht[h2])) != NULL) {
301					struct route4_filter *next;
302
303					next = rtnl_dereference(f->next);
304					RCU_INIT_POINTER(b->ht[h2], next);
305					tcf_unbind_filter(tp, &f->res);
306					if (tcf_exts_get_net(&f->exts))
307						call_rcu(&f->rcu, route4_delete_filter);
308					else
309						__route4_delete_filter(f);
310				}
311			}
312			RCU_INIT_POINTER(head->table[h1], NULL);
313			kfree_rcu(b, rcu);
314		}
315	}
316	kfree_rcu(head, rcu);
317}
318
319static int route4_delete(struct tcf_proto *tp, void *arg, bool *last,
320			 struct netlink_ext_ack *extack)
321{
322	struct route4_head *head = rtnl_dereference(tp->root);
323	struct route4_filter *f = arg;
324	struct route4_filter __rcu **fp;
325	struct route4_filter *nf;
326	struct route4_bucket *b;
327	unsigned int h = 0;
328	int i, h1;
329
330	if (!head || !f)
331		return -EINVAL;
332
333	h = f->handle;
334	b = f->bkt;
335
336	fp = &b->ht[from_hash(h >> 16)];
337	for (nf = rtnl_dereference(*fp); nf;
338	     fp = &nf->next, nf = rtnl_dereference(*fp)) {
339		if (nf == f) {
340			/* unlink it */
341			RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
342
343			/* Remove any fastmap lookups that might ref filter
344			 * notice we unlink'd the filter so we can't get it
345			 * back in the fastmap.
346			 */
347			route4_reset_fastmap(head);
348
349			/* Delete it */
350			tcf_unbind_filter(tp, &f->res);
351			tcf_exts_get_net(&f->exts);
352			call_rcu(&f->rcu, route4_delete_filter);
353
354			/* Strip RTNL protected tree */
355			for (i = 0; i <= 32; i++) {
356				struct route4_filter *rt;
357
358				rt = rtnl_dereference(b->ht[i]);
359				if (rt)
360					goto out;
361			}
362
363			/* OK, session has no flows */
364			RCU_INIT_POINTER(head->table[to_hash(h)], NULL);
365			kfree_rcu(b, rcu);
366			break;
367		}
368	}
369
370out:
371	*last = true;
372	for (h1 = 0; h1 <= 256; h1++) {
373		if (rcu_access_pointer(head->table[h1])) {
374			*last = false;
375			break;
376		}
377	}
378
379	return 0;
380}
381
382static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = {
383	[TCA_ROUTE4_CLASSID]	= { .type = NLA_U32 },
384	[TCA_ROUTE4_TO]		= { .type = NLA_U32 },
385	[TCA_ROUTE4_FROM]	= { .type = NLA_U32 },
386	[TCA_ROUTE4_IIF]	= { .type = NLA_U32 },
387};
388
389static int route4_set_parms(struct net *net, struct tcf_proto *tp,
390			    unsigned long base, struct route4_filter *f,
391			    u32 handle, struct route4_head *head,
392			    struct nlattr **tb, struct nlattr *est, int new,
393			    bool ovr, struct netlink_ext_ack *extack)
394{
395	u32 id = 0, to = 0, nhandle = 0x8000;
396	struct route4_filter *fp;
397	unsigned int h1;
398	struct route4_bucket *b;
399	int err;
400
401	err = tcf_exts_validate(net, tp, tb, est, &f->exts, ovr, extack);
402	if (err < 0)
403		return err;
404
405	if (tb[TCA_ROUTE4_TO]) {
406		if (new && handle & 0x8000)
407			return -EINVAL;
408		to = nla_get_u32(tb[TCA_ROUTE4_TO]);
409		if (to > 0xFF)
410			return -EINVAL;
411		nhandle = to;
412	}
413
414	if (tb[TCA_ROUTE4_FROM]) {
415		if (tb[TCA_ROUTE4_IIF])
416			return -EINVAL;
417		id = nla_get_u32(tb[TCA_ROUTE4_FROM]);
418		if (id > 0xFF)
419			return -EINVAL;
420		nhandle |= id << 16;
421	} else if (tb[TCA_ROUTE4_IIF]) {
422		id = nla_get_u32(tb[TCA_ROUTE4_IIF]);
423		if (id > 0x7FFF)
424			return -EINVAL;
425		nhandle |= (id | 0x8000) << 16;
426	} else
427		nhandle |= 0xFFFF << 16;
428
429	if (handle && new) {
430		nhandle |= handle & 0x7F00;
431		if (nhandle != handle)
432			return -EINVAL;
433	}
434
435	h1 = to_hash(nhandle);
436	b = rtnl_dereference(head->table[h1]);
437	if (!b) {
438		b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
439		if (b == NULL)
440			return -ENOBUFS;
441
442		rcu_assign_pointer(head->table[h1], b);
443	} else {
444		unsigned int h2 = from_hash(nhandle >> 16);
445
446		for (fp = rtnl_dereference(b->ht[h2]);
447		     fp;
448		     fp = rtnl_dereference(fp->next))
449			if (fp->handle == f->handle)
450				return -EEXIST;
451	}
452
453	if (tb[TCA_ROUTE4_TO])
454		f->id = to;
455
456	if (tb[TCA_ROUTE4_FROM])
457		f->id = to | id<<16;
458	else if (tb[TCA_ROUTE4_IIF])
459		f->iif = id;
460
461	f->handle = nhandle;
462	f->bkt = b;
463	f->tp = tp;
464
465	if (tb[TCA_ROUTE4_CLASSID]) {
466		f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
467		tcf_bind_filter(tp, &f->res, base);
468	}
469
470	return 0;
471}
472
473static int route4_change(struct net *net, struct sk_buff *in_skb,
474			 struct tcf_proto *tp, unsigned long base, u32 handle,
475			 struct nlattr **tca, void **arg, bool ovr,
476			 struct netlink_ext_ack *extack)
477{
478	struct route4_head *head = rtnl_dereference(tp->root);
479	struct route4_filter __rcu **fp;
480	struct route4_filter *fold, *f1, *pfp, *f = NULL;
481	struct route4_bucket *b;
482	struct nlattr *opt = tca[TCA_OPTIONS];
483	struct nlattr *tb[TCA_ROUTE4_MAX + 1];
484	unsigned int h, th;
485	int err;
486	bool new = true;
487
488	if (opt == NULL)
489		return handle ? -EINVAL : 0;
490
491	err = nla_parse_nested(tb, TCA_ROUTE4_MAX, opt, route4_policy, NULL);
 
492	if (err < 0)
493		return err;
494
495	fold = *arg;
496	if (fold && handle && fold->handle != handle)
497			return -EINVAL;
498
499	err = -ENOBUFS;
500	f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
501	if (!f)
502		goto errout;
503
504	err = tcf_exts_init(&f->exts, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE);
505	if (err < 0)
506		goto errout;
507
508	if (fold) {
509		f->id = fold->id;
510		f->iif = fold->iif;
511		f->res = fold->res;
512		f->handle = fold->handle;
513
514		f->tp = fold->tp;
515		f->bkt = fold->bkt;
516		new = false;
517	}
518
519	err = route4_set_parms(net, tp, base, f, handle, head, tb,
520			       tca[TCA_RATE], new, ovr, extack);
521	if (err < 0)
522		goto errout;
523
524	h = from_hash(f->handle >> 16);
525	fp = &f->bkt->ht[h];
526	for (pfp = rtnl_dereference(*fp);
527	     (f1 = rtnl_dereference(*fp)) != NULL;
528	     fp = &f1->next)
529		if (f->handle < f1->handle)
530			break;
531
532	tcf_block_netif_keep_dst(tp->chain->block);
533	rcu_assign_pointer(f->next, f1);
534	rcu_assign_pointer(*fp, f);
535
536	if (fold && fold->handle && f->handle != fold->handle) {
537		th = to_hash(fold->handle);
538		h = from_hash(fold->handle >> 16);
539		b = rtnl_dereference(head->table[th]);
540		if (b) {
541			fp = &b->ht[h];
542			for (pfp = rtnl_dereference(*fp); pfp;
543			     fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
544				if (pfp == f) {
545					*fp = f->next;
546					break;
547				}
548			}
549		}
550	}
551
552	route4_reset_fastmap(head);
553	*arg = f;
554	if (fold) {
555		tcf_unbind_filter(tp, &fold->res);
556		tcf_exts_get_net(&fold->exts);
557		call_rcu(&fold->rcu, route4_delete_filter);
558	}
559	return 0;
560
561errout:
562	if (f)
563		tcf_exts_destroy(&f->exts);
564	kfree(f);
565	return err;
566}
567
568static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 
569{
570	struct route4_head *head = rtnl_dereference(tp->root);
571	unsigned int h, h1;
572
573	if (head == NULL)
574		arg->stop = 1;
575
576	if (arg->stop)
577		return;
578
579	for (h = 0; h <= 256; h++) {
580		struct route4_bucket *b = rtnl_dereference(head->table[h]);
581
582		if (b) {
583			for (h1 = 0; h1 <= 32; h1++) {
584				struct route4_filter *f;
585
586				for (f = rtnl_dereference(b->ht[h1]);
587				     f;
588				     f = rtnl_dereference(f->next)) {
589					if (arg->count < arg->skip) {
590						arg->count++;
591						continue;
592					}
593					if (arg->fn(tp, f, arg) < 0) {
594						arg->stop = 1;
595						return;
596					}
597					arg->count++;
598				}
599			}
600		}
601	}
602}
603
604static int route4_dump(struct net *net, struct tcf_proto *tp, void *fh,
605		       struct sk_buff *skb, struct tcmsg *t)
606{
607	struct route4_filter *f = fh;
608	struct nlattr *nest;
609	u32 id;
610
611	if (f == NULL)
612		return skb->len;
613
614	t->tcm_handle = f->handle;
615
616	nest = nla_nest_start(skb, TCA_OPTIONS);
617	if (nest == NULL)
618		goto nla_put_failure;
619
620	if (!(f->handle & 0x8000)) {
621		id = f->id & 0xFF;
622		if (nla_put_u32(skb, TCA_ROUTE4_TO, id))
623			goto nla_put_failure;
624	}
625	if (f->handle & 0x80000000) {
626		if ((f->handle >> 16) != 0xFFFF &&
627		    nla_put_u32(skb, TCA_ROUTE4_IIF, f->iif))
628			goto nla_put_failure;
629	} else {
630		id = f->id >> 16;
631		if (nla_put_u32(skb, TCA_ROUTE4_FROM, id))
632			goto nla_put_failure;
633	}
634	if (f->res.classid &&
635	    nla_put_u32(skb, TCA_ROUTE4_CLASSID, f->res.classid))
636		goto nla_put_failure;
637
638	if (tcf_exts_dump(skb, &f->exts) < 0)
639		goto nla_put_failure;
640
641	nla_nest_end(skb, nest);
642
643	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
644		goto nla_put_failure;
645
646	return skb->len;
647
648nla_put_failure:
649	nla_nest_cancel(skb, nest);
650	return -1;
651}
652
653static void route4_bind_class(void *fh, u32 classid, unsigned long cl)
654{
655	struct route4_filter *f = fh;
656
657	if (f && f->res.classid == classid)
658		f->res.class = cl;
659}
660
661static struct tcf_proto_ops cls_route4_ops __read_mostly = {
662	.kind		=	"route",
663	.classify	=	route4_classify,
664	.init		=	route4_init,
665	.destroy	=	route4_destroy,
666	.get		=	route4_get,
667	.change		=	route4_change,
668	.delete		=	route4_delete,
669	.walk		=	route4_walk,
670	.dump		=	route4_dump,
671	.bind_class	=	route4_bind_class,
672	.owner		=	THIS_MODULE,
673};
674
675static int __init init_route4(void)
676{
677	return register_tcf_proto_ops(&cls_route4_ops);
678}
679
680static void __exit exit_route4(void)
681{
682	unregister_tcf_proto_ops(&cls_route4_ops);
683}
684
685module_init(init_route4)
686module_exit(exit_route4)
687MODULE_LICENSE("GPL");