1/*
2 * net/sched/cls_flow.c		Generic flow classifier
3 *
4 * Copyright (c) 2007, 2008 Patrick McHardy <kaber@trash.net>
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
10 */
11
12#include <linux/kernel.h>
13#include <linux/init.h>
14#include <linux/list.h>
15#include <linux/jhash.h>
16#include <linux/random.h>
17#include <linux/pkt_cls.h>
18#include <linux/skbuff.h>
19#include <linux/in.h>
20#include <linux/ip.h>
21#include <linux/ipv6.h>
22#include <linux/if_vlan.h>
23#include <linux/slab.h>
24#include <linux/module.h>
25
26#include <net/pkt_cls.h>
27#include <net/ip.h>
28#include <net/route.h>
29#include <net/flow_keys.h>
30
31#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
32#include <net/netfilter/nf_conntrack.h>
33#endif
34
35struct flow_head {
36	struct list_head	filters;
37	struct rcu_head		rcu;
38};
39
40struct flow_filter {
41	struct list_head	list;
42	struct tcf_exts		exts;
43	struct tcf_ematch_tree	ematches;
44	struct tcf_proto	*tp;
45	struct timer_list	perturb_timer;
46	u32			perturb_period;
47	u32			handle;
48
49	u32			nkeys;
50	u32			keymask;
51	u32			mode;
52	u32			mask;
53	u32			xor;
54	u32			rshift;
55	u32			addend;
56	u32			divisor;
57	u32			baseclass;
58	u32			hashrnd;
59	struct rcu_head		rcu;
60};
61
62static inline u32 addr_fold(void *addr)
63{
64	unsigned long a = (unsigned long)addr;
65
66	return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
67}
68
69static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
70{
71	if (flow->src)
72		return ntohl(flow->src);
73	return addr_fold(skb->sk);
74}
75
76static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
77{
78	if (flow->dst)
79		return ntohl(flow->dst);
80	return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
81}
82
83static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
84{
85	return flow->ip_proto;
86}
87
88static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
89{
90	if (flow->ports)
91		return ntohs(flow->port16[0]);
92
93	return addr_fold(skb->sk);
94}
95
96static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
97{
98	if (flow->ports)
99		return ntohs(flow->port16[1]);
100
101	return addr_fold(skb_dst(skb)) ^ (__force u16) tc_skb_protocol(skb);
102}
103
104static u32 flow_get_iif(const struct sk_buff *skb)
105{
106	return skb->skb_iif;
107}
108
109static u32 flow_get_priority(const struct sk_buff *skb)
110{
111	return skb->priority;
112}
113
114static u32 flow_get_mark(const struct sk_buff *skb)
115{
116	return skb->mark;
117}
118
119static u32 flow_get_nfct(const struct sk_buff *skb)
120{
121#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
122	return addr_fold(skb->nfct);
123#else
124	return 0;
125#endif
126}
127
128#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
129#define CTTUPLE(skb, member)						\
130({									\
131	enum ip_conntrack_info ctinfo;					\
132	const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);		\
133	if (ct == NULL)							\
134		goto fallback;						\
135	ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;			\
136})
137#else
138#define CTTUPLE(skb, member)						\
139({									\
140	goto fallback;							\
141	0;								\
142})
143#endif
144
145static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
146{
147	switch (tc_skb_protocol(skb)) {
148	case htons(ETH_P_IP):
149		return ntohl(CTTUPLE(skb, src.u3.ip));
150	case htons(ETH_P_IPV6):
151		return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
152	}
153fallback:
154	return flow_get_src(skb, flow);
155}
156
157static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
158{
159	switch (tc_skb_protocol(skb)) {
160	case htons(ETH_P_IP):
161		return ntohl(CTTUPLE(skb, dst.u3.ip));
162	case htons(ETH_P_IPV6):
163		return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
164	}
165fallback:
166	return flow_get_dst(skb, flow);
167}
168
169static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
170{
171	return ntohs(CTTUPLE(skb, src.u.all));
172fallback:
173	return flow_get_proto_src(skb, flow);
174}
175
176static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
177{
178	return ntohs(CTTUPLE(skb, dst.u.all));
179fallback:
180	return flow_get_proto_dst(skb, flow);
181}
182
183static u32 flow_get_rtclassid(const struct sk_buff *skb)
184{
185#ifdef CONFIG_IP_ROUTE_CLASSID
186	if (skb_dst(skb))
187		return skb_dst(skb)->tclassid;
188#endif
189	return 0;
190}
191
192static u32 flow_get_skuid(const struct sk_buff *skb)
193{
194	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
195		kuid_t skuid = skb->sk->sk_socket->file->f_cred->fsuid;
196		return from_kuid(&init_user_ns, skuid);
197	}
198	return 0;
199}
200
201static u32 flow_get_skgid(const struct sk_buff *skb)
202{
203	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file) {
204		kgid_t skgid = skb->sk->sk_socket->file->f_cred->fsgid;
205		return from_kgid(&init_user_ns, skgid);
206	}
207	return 0;
208}
209
210static u32 flow_get_vlan_tag(const struct sk_buff *skb)
211{
212	u16 uninitialized_var(tag);
213
214	if (vlan_get_tag(skb, &tag) < 0)
215		return 0;
216	return tag & VLAN_VID_MASK;
217}
218
219static u32 flow_get_rxhash(struct sk_buff *skb)
220{
221	return skb_get_hash(skb);
222}
223
224static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
225{
226	switch (key) {
227	case FLOW_KEY_SRC:
228		return flow_get_src(skb, flow);
229	case FLOW_KEY_DST:
230		return flow_get_dst(skb, flow);
231	case FLOW_KEY_PROTO:
232		return flow_get_proto(skb, flow);
233	case FLOW_KEY_PROTO_SRC:
234		return flow_get_proto_src(skb, flow);
235	case FLOW_KEY_PROTO_DST:
236		return flow_get_proto_dst(skb, flow);
237	case FLOW_KEY_IIF:
238		return flow_get_iif(skb);
239	case FLOW_KEY_PRIORITY:
240		return flow_get_priority(skb);
241	case FLOW_KEY_MARK:
242		return flow_get_mark(skb);
243	case FLOW_KEY_NFCT:
244		return flow_get_nfct(skb);
245	case FLOW_KEY_NFCT_SRC:
246		return flow_get_nfct_src(skb, flow);
247	case FLOW_KEY_NFCT_DST:
248		return flow_get_nfct_dst(skb, flow);
249	case FLOW_KEY_NFCT_PROTO_SRC:
250		return flow_get_nfct_proto_src(skb, flow);
251	case FLOW_KEY_NFCT_PROTO_DST:
252		return flow_get_nfct_proto_dst(skb, flow);
253	case FLOW_KEY_RTCLASSID:
254		return flow_get_rtclassid(skb);
255	case FLOW_KEY_SKUID:
256		return flow_get_skuid(skb);
257	case FLOW_KEY_SKGID:
258		return flow_get_skgid(skb);
259	case FLOW_KEY_VLAN_TAG:
260		return flow_get_vlan_tag(skb);
261	case FLOW_KEY_RXHASH:
262		return flow_get_rxhash(skb);
263	default:
264		WARN_ON(1);
265		return 0;
266	}
267}
268
269#define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | 		\
270			  (1 << FLOW_KEY_DST) |			\
271			  (1 << FLOW_KEY_PROTO) |		\
272			  (1 << FLOW_KEY_PROTO_SRC) |		\
273			  (1 << FLOW_KEY_PROTO_DST) | 		\
274			  (1 << FLOW_KEY_NFCT_SRC) |		\
275			  (1 << FLOW_KEY_NFCT_DST) |		\
276			  (1 << FLOW_KEY_NFCT_PROTO_SRC) |	\
277			  (1 << FLOW_KEY_NFCT_PROTO_DST))
278
279static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
280			 struct tcf_result *res)
281{
282	struct flow_head *head = rcu_dereference_bh(tp->root);
283	struct flow_filter *f;
284	u32 keymask;
285	u32 classid;
286	unsigned int n, key;
287	int r;
288
289	list_for_each_entry_rcu(f, &head->filters, list) {
290		u32 keys[FLOW_KEY_MAX + 1];
291		struct flow_keys flow_keys;
292
293		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
294			continue;
295
296		keymask = f->keymask;
297		if (keymask & FLOW_KEYS_NEEDED)
298			skb_flow_dissect(skb, &flow_keys);
299
300		for (n = 0; n < f->nkeys; n++) {
301			key = ffs(keymask) - 1;
302			keymask &= ~(1 << key);
303			keys[n] = flow_key_get(skb, key, &flow_keys);
304		}
305
306		if (f->mode == FLOW_MODE_HASH)
307			classid = jhash2(keys, f->nkeys, f->hashrnd);
308		else {
309			classid = keys[0];
310			classid = (classid & f->mask) ^ f->xor;
311			classid = (classid >> f->rshift) + f->addend;
312		}
313
314		if (f->divisor)
315			classid %= f->divisor;
316
317		res->class   = 0;
318		res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
319
320		r = tcf_exts_exec(skb, &f->exts, res);
321		if (r < 0)
322			continue;
323		return r;
324	}
325	return -1;
326}
327
328static void flow_perturbation(unsigned long arg)
329{
330	struct flow_filter *f = (struct flow_filter *)arg;
331
332	get_random_bytes(&f->hashrnd, 4);
333	if (f->perturb_period)
334		mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
335}
336
337static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
338	[TCA_FLOW_KEYS]		= { .type = NLA_U32 },
339	[TCA_FLOW_MODE]		= { .type = NLA_U32 },
340	[TCA_FLOW_BASECLASS]	= { .type = NLA_U32 },
341	[TCA_FLOW_RSHIFT]	= { .type = NLA_U32 },
342	[TCA_FLOW_ADDEND]	= { .type = NLA_U32 },
343	[TCA_FLOW_MASK]		= { .type = NLA_U32 },
344	[TCA_FLOW_XOR]		= { .type = NLA_U32 },
345	[TCA_FLOW_DIVISOR]	= { .type = NLA_U32 },
346	[TCA_FLOW_ACT]		= { .type = NLA_NESTED },
347	[TCA_FLOW_POLICE]	= { .type = NLA_NESTED },
348	[TCA_FLOW_EMATCHES]	= { .type = NLA_NESTED },
349	[TCA_FLOW_PERTURB]	= { .type = NLA_U32 },
350};
351
352static void flow_destroy_filter(struct rcu_head *head)
353{
354	struct flow_filter *f = container_of(head, struct flow_filter, rcu);
355
356	del_timer_sync(&f->perturb_timer);
357	tcf_exts_destroy(&f->exts);
358	tcf_em_tree_destroy(&f->ematches);
359	kfree(f);
360}
361
362static int flow_change(struct net *net, struct sk_buff *in_skb,
363		       struct tcf_proto *tp, unsigned long base,
364		       u32 handle, struct nlattr **tca,
365		       unsigned long *arg, bool ovr)
366{
367	struct flow_head *head = rtnl_dereference(tp->root);
368	struct flow_filter *fold, *fnew;
369	struct nlattr *opt = tca[TCA_OPTIONS];
370	struct nlattr *tb[TCA_FLOW_MAX + 1];
371	struct tcf_exts e;
372	struct tcf_ematch_tree t;
373	unsigned int nkeys = 0;
374	unsigned int perturb_period = 0;
375	u32 baseclass = 0;
376	u32 keymask = 0;
377	u32 mode;
378	int err;
379
380	if (opt == NULL)
381		return -EINVAL;
382
383	err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
384	if (err < 0)
385		return err;
386
387	if (tb[TCA_FLOW_BASECLASS]) {
388		baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
389		if (TC_H_MIN(baseclass) == 0)
390			return -EINVAL;
391	}
392
393	if (tb[TCA_FLOW_KEYS]) {
394		keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
395
396		nkeys = hweight32(keymask);
397		if (nkeys == 0)
398			return -EINVAL;
399
400		if (fls(keymask) - 1 > FLOW_KEY_MAX)
401			return -EOPNOTSUPP;
402
403		if ((keymask & (FLOW_KEY_SKUID|FLOW_KEY_SKGID)) &&
404		    sk_user_ns(NETLINK_CB(in_skb).sk) != &init_user_ns)
405			return -EOPNOTSUPP;
406	}
407
408	tcf_exts_init(&e, TCA_FLOW_ACT, TCA_FLOW_POLICE);
409	err = tcf_exts_validate(net, tp, tb, tca[TCA_RATE], &e, ovr);
410	if (err < 0)
411		return err;
412
413	err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
414	if (err < 0)
415		goto err1;
416
417	err = -ENOBUFS;
418	fnew = kzalloc(sizeof(*fnew), GFP_KERNEL);
419	if (!fnew)
420		goto err2;
421
422	tcf_exts_init(&fnew->exts, TCA_FLOW_ACT, TCA_FLOW_POLICE);
423
424	fold = (struct flow_filter *)*arg;
425	if (fold) {
426		err = -EINVAL;
427		if (fold->handle != handle && handle)
428			goto err2;
429
430		/* Copy fold into fnew */
431		fnew->tp = fold->tp;
432		fnew->handle = fold->handle;
433		fnew->nkeys = fold->nkeys;
434		fnew->keymask = fold->keymask;
435		fnew->mode = fold->mode;
436		fnew->mask = fold->mask;
437		fnew->xor = fold->xor;
438		fnew->rshift = fold->rshift;
439		fnew->addend = fold->addend;
440		fnew->divisor = fold->divisor;
441		fnew->baseclass = fold->baseclass;
442		fnew->hashrnd = fold->hashrnd;
443
444		mode = fold->mode;
445		if (tb[TCA_FLOW_MODE])
446			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
447		if (mode != FLOW_MODE_HASH && nkeys > 1)
448			goto err2;
449
450		if (mode == FLOW_MODE_HASH)
451			perturb_period = fold->perturb_period;
452		if (tb[TCA_FLOW_PERTURB]) {
453			if (mode != FLOW_MODE_HASH)
454				goto err2;
455			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
456		}
457	} else {
458		err = -EINVAL;
459		if (!handle)
460			goto err2;
461		if (!tb[TCA_FLOW_KEYS])
462			goto err2;
463
464		mode = FLOW_MODE_MAP;
465		if (tb[TCA_FLOW_MODE])
466			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
467		if (mode != FLOW_MODE_HASH && nkeys > 1)
468			goto err2;
469
470		if (tb[TCA_FLOW_PERTURB]) {
471			if (mode != FLOW_MODE_HASH)
472				goto err2;
473			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
474		}
475
476		if (TC_H_MAJ(baseclass) == 0)
477			baseclass = TC_H_MAKE(tp->q->handle, baseclass);
478		if (TC_H_MIN(baseclass) == 0)
479			baseclass = TC_H_MAKE(baseclass, 1);
480
481		fnew->handle = handle;
482		fnew->mask  = ~0U;
483		fnew->tp = tp;
484		get_random_bytes(&fnew->hashrnd, 4);
485	}
486
487	fnew->perturb_timer.function = flow_perturbation;
488	fnew->perturb_timer.data = (unsigned long)fnew;
489	init_timer_deferrable(&fnew->perturb_timer);
490
491	tcf_exts_change(tp, &fnew->exts, &e);
492	tcf_em_tree_change(tp, &fnew->ematches, &t);
493
494	netif_keep_dst(qdisc_dev(tp->q));
495
496	if (tb[TCA_FLOW_KEYS]) {
497		fnew->keymask = keymask;
498		fnew->nkeys   = nkeys;
499	}
500
501	fnew->mode = mode;
502
503	if (tb[TCA_FLOW_MASK])
504		fnew->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
505	if (tb[TCA_FLOW_XOR])
506		fnew->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
507	if (tb[TCA_FLOW_RSHIFT])
508		fnew->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
509	if (tb[TCA_FLOW_ADDEND])
510		fnew->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
511
512	if (tb[TCA_FLOW_DIVISOR])
513		fnew->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
514	if (baseclass)
515		fnew->baseclass = baseclass;
516
517	fnew->perturb_period = perturb_period;
518	if (perturb_period)
519		mod_timer(&fnew->perturb_timer, jiffies + perturb_period);
520
521	if (*arg == 0)
522		list_add_tail_rcu(&fnew->list, &head->filters);
523	else
524		list_replace_rcu(&fold->list, &fnew->list);
525
526	*arg = (unsigned long)fnew;
527
528	if (fold)
529		call_rcu(&fold->rcu, flow_destroy_filter);
530	return 0;
531
532err2:
533	tcf_em_tree_destroy(&t);
534	kfree(fnew);
535err1:
536	tcf_exts_destroy(&e);
537	return err;
538}
539
540static int flow_delete(struct tcf_proto *tp, unsigned long arg)
541{
542	struct flow_filter *f = (struct flow_filter *)arg;
543
544	list_del_rcu(&f->list);
545	call_rcu(&f->rcu, flow_destroy_filter);
546	return 0;
547}
548
549static int flow_init(struct tcf_proto *tp)
550{
551	struct flow_head *head;
552
553	head = kzalloc(sizeof(*head), GFP_KERNEL);
554	if (head == NULL)
555		return -ENOBUFS;
556	INIT_LIST_HEAD(&head->filters);
557	rcu_assign_pointer(tp->root, head);
558	return 0;
559}
560
561static bool flow_destroy(struct tcf_proto *tp, bool force)
562{
563	struct flow_head *head = rtnl_dereference(tp->root);
564	struct flow_filter *f, *next;
565
566	if (!force && !list_empty(&head->filters))
567		return false;
568
569	list_for_each_entry_safe(f, next, &head->filters, list) {
570		list_del_rcu(&f->list);
571		call_rcu(&f->rcu, flow_destroy_filter);
572	}
573	RCU_INIT_POINTER(tp->root, NULL);
574	kfree_rcu(head, rcu);
575	return true;
576}
577
578static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
579{
580	struct flow_head *head = rtnl_dereference(tp->root);
581	struct flow_filter *f;
582
583	list_for_each_entry(f, &head->filters, list)
584		if (f->handle == handle)
585			return (unsigned long)f;
586	return 0;
587}
588
589static int flow_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
590		     struct sk_buff *skb, struct tcmsg *t)
591{
592	struct flow_filter *f = (struct flow_filter *)fh;
593	struct nlattr *nest;
594
595	if (f == NULL)
596		return skb->len;
597
598	t->tcm_handle = f->handle;
599
600	nest = nla_nest_start(skb, TCA_OPTIONS);
601	if (nest == NULL)
602		goto nla_put_failure;
603
604	if (nla_put_u32(skb, TCA_FLOW_KEYS, f->keymask) ||
605	    nla_put_u32(skb, TCA_FLOW_MODE, f->mode))
606		goto nla_put_failure;
607
608	if (f->mask != ~0 || f->xor != 0) {
609		if (nla_put_u32(skb, TCA_FLOW_MASK, f->mask) ||
610		    nla_put_u32(skb, TCA_FLOW_XOR, f->xor))
611			goto nla_put_failure;
612	}
613	if (f->rshift &&
614	    nla_put_u32(skb, TCA_FLOW_RSHIFT, f->rshift))
615		goto nla_put_failure;
616	if (f->addend &&
617	    nla_put_u32(skb, TCA_FLOW_ADDEND, f->addend))
618		goto nla_put_failure;
619
620	if (f->divisor &&
621	    nla_put_u32(skb, TCA_FLOW_DIVISOR, f->divisor))
622		goto nla_put_failure;
623	if (f->baseclass &&
624	    nla_put_u32(skb, TCA_FLOW_BASECLASS, f->baseclass))
625		goto nla_put_failure;
626
627	if (f->perturb_period &&
628	    nla_put_u32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ))
629		goto nla_put_failure;
630
631	if (tcf_exts_dump(skb, &f->exts) < 0)
632		goto nla_put_failure;
633#ifdef CONFIG_NET_EMATCH
634	if (f->ematches.hdr.nmatches &&
635	    tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
636		goto nla_put_failure;
637#endif
638	nla_nest_end(skb, nest);
639
640	if (tcf_exts_dump_stats(skb, &f->exts) < 0)
641		goto nla_put_failure;
642
643	return skb->len;
644
645nla_put_failure:
646	nla_nest_cancel(skb, nest);
647	return -1;
648}
649
650static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
651{
652	struct flow_head *head = rtnl_dereference(tp->root);
653	struct flow_filter *f;
654
655	list_for_each_entry(f, &head->filters, list) {
656		if (arg->count < arg->skip)
657			goto skip;
658		if (arg->fn(tp, (unsigned long)f, arg) < 0) {
659			arg->stop = 1;
660			break;
661		}
662skip:
663		arg->count++;
664	}
665}
666
667static struct tcf_proto_ops cls_flow_ops __read_mostly = {
668	.kind		= "flow",
669	.classify	= flow_classify,
670	.init		= flow_init,
671	.destroy	= flow_destroy,
672	.change		= flow_change,
673	.delete		= flow_delete,
674	.get		= flow_get,
675	.dump		= flow_dump,
676	.walk		= flow_walk,
677	.owner		= THIS_MODULE,
678};
679
680static int __init cls_flow_init(void)
681{
682	return register_tcf_proto_ops(&cls_flow_ops);
683}
684
685static void __exit cls_flow_exit(void)
686{
687	unregister_tcf_proto_ops(&cls_flow_ops);
688}
689
690module_init(cls_flow_init);
691module_exit(cls_flow_exit);
692
693MODULE_LICENSE("GPL");
694MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
695MODULE_DESCRIPTION("TC flow classifier");
696