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
25#include <net/pkt_cls.h>
26#include <net/ip.h>
27#include <net/route.h>
28#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
29#include <net/netfilter/nf_conntrack.h>
30#endif
31
32struct flow_head {
33	struct list_head	filters;
34};
35
36struct flow_filter {
37	struct list_head	list;
38	struct tcf_exts		exts;
39	struct tcf_ematch_tree	ematches;
40	struct timer_list	perturb_timer;
41	u32			perturb_period;
42	u32			handle;
43
44	u32			nkeys;
45	u32			keymask;
46	u32			mode;
47	u32			mask;
48	u32			xor;
49	u32			rshift;
50	u32			addend;
51	u32			divisor;
52	u32			baseclass;
53	u32			hashrnd;
54};
55
56static const struct tcf_ext_map flow_ext_map = {
57	.action	= TCA_FLOW_ACT,
58	.police	= TCA_FLOW_POLICE,
59};
60
61static inline u32 addr_fold(void *addr)
62{
63	unsigned long a = (unsigned long)addr;
64
65	return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
66}
67
68static u32 flow_get_src(struct sk_buff *skb)
69{
70	switch (skb->protocol) {
71	case htons(ETH_P_IP):
72		if (pskb_network_may_pull(skb, sizeof(struct iphdr)))
73			return ntohl(ip_hdr(skb)->saddr);
74		break;
75	case htons(ETH_P_IPV6):
76		if (pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
77			return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]);
78		break;
79	}
80
81	return addr_fold(skb->sk);
82}
83
84static u32 flow_get_dst(struct sk_buff *skb)
85{
86	switch (skb->protocol) {
87	case htons(ETH_P_IP):
88		if (pskb_network_may_pull(skb, sizeof(struct iphdr)))
89			return ntohl(ip_hdr(skb)->daddr);
90		break;
91	case htons(ETH_P_IPV6):
92		if (pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
93			return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
94		break;
95	}
96
97	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
98}
99
100static u32 flow_get_proto(struct sk_buff *skb)
101{
102	switch (skb->protocol) {
103	case htons(ETH_P_IP):
104		return pskb_network_may_pull(skb, sizeof(struct iphdr)) ?
105		       ip_hdr(skb)->protocol : 0;
106	case htons(ETH_P_IPV6):
107		return pskb_network_may_pull(skb, sizeof(struct ipv6hdr)) ?
108		       ipv6_hdr(skb)->nexthdr : 0;
109	default:
110		return 0;
111	}
112}
113
114static int has_ports(u8 protocol)
115{
116	switch (protocol) {
117	case IPPROTO_TCP:
118	case IPPROTO_UDP:
119	case IPPROTO_UDPLITE:
120	case IPPROTO_SCTP:
121	case IPPROTO_DCCP:
122	case IPPROTO_ESP:
123		return 1;
124	default:
125		return 0;
126	}
127}
128
129static u32 flow_get_proto_src(struct sk_buff *skb)
130{
131	switch (skb->protocol) {
132	case htons(ETH_P_IP): {
133		struct iphdr *iph;
134
135		if (!pskb_network_may_pull(skb, sizeof(*iph)))
136			break;
137		iph = ip_hdr(skb);
138		if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
139		    has_ports(iph->protocol) &&
140		    pskb_network_may_pull(skb, iph->ihl * 4 + 2))
141			return ntohs(*(__be16 *)((void *)iph + iph->ihl * 4));
142		break;
143	}
144	case htons(ETH_P_IPV6): {
145		struct ipv6hdr *iph;
146
147		if (!pskb_network_may_pull(skb, sizeof(*iph) + 2))
148			break;
149		iph = ipv6_hdr(skb);
150		if (has_ports(iph->nexthdr))
151			return ntohs(*(__be16 *)&iph[1]);
152		break;
153	}
154	}
155
156	return addr_fold(skb->sk);
157}
158
159static u32 flow_get_proto_dst(struct sk_buff *skb)
160{
161	switch (skb->protocol) {
162	case htons(ETH_P_IP): {
163		struct iphdr *iph;
164
165		if (!pskb_network_may_pull(skb, sizeof(*iph)))
166			break;
167		iph = ip_hdr(skb);
168		if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
169		    has_ports(iph->protocol) &&
170		    pskb_network_may_pull(skb, iph->ihl * 4 + 4))
171			return ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 + 2));
172		break;
173	}
174	case htons(ETH_P_IPV6): {
175		struct ipv6hdr *iph;
176
177		if (!pskb_network_may_pull(skb, sizeof(*iph) + 4))
178			break;
179		iph = ipv6_hdr(skb);
180		if (has_ports(iph->nexthdr))
181			return ntohs(*(__be16 *)((void *)&iph[1] + 2));
182		break;
183	}
184	}
185
186	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
187}
188
189static u32 flow_get_iif(const struct sk_buff *skb)
190{
191	return skb->skb_iif;
192}
193
194static u32 flow_get_priority(const struct sk_buff *skb)
195{
196	return skb->priority;
197}
198
199static u32 flow_get_mark(const struct sk_buff *skb)
200{
201	return skb->mark;
202}
203
204static u32 flow_get_nfct(const struct sk_buff *skb)
205{
206#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
207	return addr_fold(skb->nfct);
208#else
209	return 0;
210#endif
211}
212
213#if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
214#define CTTUPLE(skb, member)						\
215({									\
216	enum ip_conntrack_info ctinfo;					\
217	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);			\
218	if (ct == NULL)							\
219		goto fallback;						\
220	ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;			\
221})
222#else
223#define CTTUPLE(skb, member)						\
224({									\
225	goto fallback;							\
226	0;								\
227})
228#endif
229
230static u32 flow_get_nfct_src(struct sk_buff *skb)
231{
232	switch (skb->protocol) {
233	case htons(ETH_P_IP):
234		return ntohl(CTTUPLE(skb, src.u3.ip));
235	case htons(ETH_P_IPV6):
236		return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
237	}
238fallback:
239	return flow_get_src(skb);
240}
241
242static u32 flow_get_nfct_dst(struct sk_buff *skb)
243{
244	switch (skb->protocol) {
245	case htons(ETH_P_IP):
246		return ntohl(CTTUPLE(skb, dst.u3.ip));
247	case htons(ETH_P_IPV6):
248		return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
249	}
250fallback:
251	return flow_get_dst(skb);
252}
253
254static u32 flow_get_nfct_proto_src(struct sk_buff *skb)
255{
256	return ntohs(CTTUPLE(skb, src.u.all));
257fallback:
258	return flow_get_proto_src(skb);
259}
260
261static u32 flow_get_nfct_proto_dst(struct sk_buff *skb)
262{
263	return ntohs(CTTUPLE(skb, dst.u.all));
264fallback:
265	return flow_get_proto_dst(skb);
266}
267
268static u32 flow_get_rtclassid(const struct sk_buff *skb)
269{
270#ifdef CONFIG_NET_CLS_ROUTE
271	if (skb_dst(skb))
272		return skb_dst(skb)->tclassid;
273#endif
274	return 0;
275}
276
277static u32 flow_get_skuid(const struct sk_buff *skb)
278{
279	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
280		return skb->sk->sk_socket->file->f_cred->fsuid;
281	return 0;
282}
283
284static u32 flow_get_skgid(const struct sk_buff *skb)
285{
286	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
287		return skb->sk->sk_socket->file->f_cred->fsgid;
288	return 0;
289}
290
291static u32 flow_get_vlan_tag(const struct sk_buff *skb)
292{
293	u16 uninitialized_var(tag);
294
295	if (vlan_get_tag(skb, &tag) < 0)
296		return 0;
297	return tag & VLAN_VID_MASK;
298}
299
300static u32 flow_key_get(struct sk_buff *skb, int key)
301{
302	switch (key) {
303	case FLOW_KEY_SRC:
304		return flow_get_src(skb);
305	case FLOW_KEY_DST:
306		return flow_get_dst(skb);
307	case FLOW_KEY_PROTO:
308		return flow_get_proto(skb);
309	case FLOW_KEY_PROTO_SRC:
310		return flow_get_proto_src(skb);
311	case FLOW_KEY_PROTO_DST:
312		return flow_get_proto_dst(skb);
313	case FLOW_KEY_IIF:
314		return flow_get_iif(skb);
315	case FLOW_KEY_PRIORITY:
316		return flow_get_priority(skb);
317	case FLOW_KEY_MARK:
318		return flow_get_mark(skb);
319	case FLOW_KEY_NFCT:
320		return flow_get_nfct(skb);
321	case FLOW_KEY_NFCT_SRC:
322		return flow_get_nfct_src(skb);
323	case FLOW_KEY_NFCT_DST:
324		return flow_get_nfct_dst(skb);
325	case FLOW_KEY_NFCT_PROTO_SRC:
326		return flow_get_nfct_proto_src(skb);
327	case FLOW_KEY_NFCT_PROTO_DST:
328		return flow_get_nfct_proto_dst(skb);
329	case FLOW_KEY_RTCLASSID:
330		return flow_get_rtclassid(skb);
331	case FLOW_KEY_SKUID:
332		return flow_get_skuid(skb);
333	case FLOW_KEY_SKGID:
334		return flow_get_skgid(skb);
335	case FLOW_KEY_VLAN_TAG:
336		return flow_get_vlan_tag(skb);
337	default:
338		WARN_ON(1);
339		return 0;
340	}
341}
342
343static int flow_classify(struct sk_buff *skb, struct tcf_proto *tp,
344			 struct tcf_result *res)
345{
346	struct flow_head *head = tp->root;
347	struct flow_filter *f;
348	u32 keymask;
349	u32 classid;
350	unsigned int n, key;
351	int r;
352
353	list_for_each_entry(f, &head->filters, list) {
354		u32 keys[f->nkeys];
355
356		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
357			continue;
358
359		keymask = f->keymask;
360
361		for (n = 0; n < f->nkeys; n++) {
362			key = ffs(keymask) - 1;
363			keymask &= ~(1 << key);
364			keys[n] = flow_key_get(skb, key);
365		}
366
367		if (f->mode == FLOW_MODE_HASH)
368			classid = jhash2(keys, f->nkeys, f->hashrnd);
369		else {
370			classid = keys[0];
371			classid = (classid & f->mask) ^ f->xor;
372			classid = (classid >> f->rshift) + f->addend;
373		}
374
375		if (f->divisor)
376			classid %= f->divisor;
377
378		res->class   = 0;
379		res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
380
381		r = tcf_exts_exec(skb, &f->exts, res);
382		if (r < 0)
383			continue;
384		return r;
385	}
386	return -1;
387}
388
389static void flow_perturbation(unsigned long arg)
390{
391	struct flow_filter *f = (struct flow_filter *)arg;
392
393	get_random_bytes(&f->hashrnd, 4);
394	if (f->perturb_period)
395		mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
396}
397
398static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
399	[TCA_FLOW_KEYS]		= { .type = NLA_U32 },
400	[TCA_FLOW_MODE]		= { .type = NLA_U32 },
401	[TCA_FLOW_BASECLASS]	= { .type = NLA_U32 },
402	[TCA_FLOW_RSHIFT]	= { .type = NLA_U32 },
403	[TCA_FLOW_ADDEND]	= { .type = NLA_U32 },
404	[TCA_FLOW_MASK]		= { .type = NLA_U32 },
405	[TCA_FLOW_XOR]		= { .type = NLA_U32 },
406	[TCA_FLOW_DIVISOR]	= { .type = NLA_U32 },
407	[TCA_FLOW_ACT]		= { .type = NLA_NESTED },
408	[TCA_FLOW_POLICE]	= { .type = NLA_NESTED },
409	[TCA_FLOW_EMATCHES]	= { .type = NLA_NESTED },
410	[TCA_FLOW_PERTURB]	= { .type = NLA_U32 },
411};
412
413static int flow_change(struct tcf_proto *tp, unsigned long base,
414		       u32 handle, struct nlattr **tca,
415		       unsigned long *arg)
416{
417	struct flow_head *head = tp->root;
418	struct flow_filter *f;
419	struct nlattr *opt = tca[TCA_OPTIONS];
420	struct nlattr *tb[TCA_FLOW_MAX + 1];
421	struct tcf_exts e;
422	struct tcf_ematch_tree t;
423	unsigned int nkeys = 0;
424	unsigned int perturb_period = 0;
425	u32 baseclass = 0;
426	u32 keymask = 0;
427	u32 mode;
428	int err;
429
430	if (opt == NULL)
431		return -EINVAL;
432
433	err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
434	if (err < 0)
435		return err;
436
437	if (tb[TCA_FLOW_BASECLASS]) {
438		baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
439		if (TC_H_MIN(baseclass) == 0)
440			return -EINVAL;
441	}
442
443	if (tb[TCA_FLOW_KEYS]) {
444		keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
445
446		nkeys = hweight32(keymask);
447		if (nkeys == 0)
448			return -EINVAL;
449
450		if (fls(keymask) - 1 > FLOW_KEY_MAX)
451			return -EOPNOTSUPP;
452	}
453
454	err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
455	if (err < 0)
456		return err;
457
458	err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
459	if (err < 0)
460		goto err1;
461
462	f = (struct flow_filter *)*arg;
463	if (f != NULL) {
464		err = -EINVAL;
465		if (f->handle != handle && handle)
466			goto err2;
467
468		mode = f->mode;
469		if (tb[TCA_FLOW_MODE])
470			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
471		if (mode != FLOW_MODE_HASH && nkeys > 1)
472			goto err2;
473
474		if (mode == FLOW_MODE_HASH)
475			perturb_period = f->perturb_period;
476		if (tb[TCA_FLOW_PERTURB]) {
477			if (mode != FLOW_MODE_HASH)
478				goto err2;
479			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
480		}
481	} else {
482		err = -EINVAL;
483		if (!handle)
484			goto err2;
485		if (!tb[TCA_FLOW_KEYS])
486			goto err2;
487
488		mode = FLOW_MODE_MAP;
489		if (tb[TCA_FLOW_MODE])
490			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
491		if (mode != FLOW_MODE_HASH && nkeys > 1)
492			goto err2;
493
494		if (tb[TCA_FLOW_PERTURB]) {
495			if (mode != FLOW_MODE_HASH)
496				goto err2;
497			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
498		}
499
500		if (TC_H_MAJ(baseclass) == 0)
501			baseclass = TC_H_MAKE(tp->q->handle, baseclass);
502		if (TC_H_MIN(baseclass) == 0)
503			baseclass = TC_H_MAKE(baseclass, 1);
504
505		err = -ENOBUFS;
506		f = kzalloc(sizeof(*f), GFP_KERNEL);
507		if (f == NULL)
508			goto err2;
509
510		f->handle = handle;
511		f->mask	  = ~0U;
512
513		get_random_bytes(&f->hashrnd, 4);
514		f->perturb_timer.function = flow_perturbation;
515		f->perturb_timer.data = (unsigned long)f;
516		init_timer_deferrable(&f->perturb_timer);
517	}
518
519	tcf_exts_change(tp, &f->exts, &e);
520	tcf_em_tree_change(tp, &f->ematches, &t);
521
522	tcf_tree_lock(tp);
523
524	if (tb[TCA_FLOW_KEYS]) {
525		f->keymask = keymask;
526		f->nkeys   = nkeys;
527	}
528
529	f->mode = mode;
530
531	if (tb[TCA_FLOW_MASK])
532		f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
533	if (tb[TCA_FLOW_XOR])
534		f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
535	if (tb[TCA_FLOW_RSHIFT])
536		f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
537	if (tb[TCA_FLOW_ADDEND])
538		f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
539
540	if (tb[TCA_FLOW_DIVISOR])
541		f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
542	if (baseclass)
543		f->baseclass = baseclass;
544
545	f->perturb_period = perturb_period;
546	del_timer(&f->perturb_timer);
547	if (perturb_period)
548		mod_timer(&f->perturb_timer, jiffies + perturb_period);
549
550	if (*arg == 0)
551		list_add_tail(&f->list, &head->filters);
552
553	tcf_tree_unlock(tp);
554
555	*arg = (unsigned long)f;
556	return 0;
557
558err2:
559	tcf_em_tree_destroy(tp, &t);
560err1:
561	tcf_exts_destroy(tp, &e);
562	return err;
563}
564
565static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
566{
567	del_timer_sync(&f->perturb_timer);
568	tcf_exts_destroy(tp, &f->exts);
569	tcf_em_tree_destroy(tp, &f->ematches);
570	kfree(f);
571}
572
573static int flow_delete(struct tcf_proto *tp, unsigned long arg)
574{
575	struct flow_filter *f = (struct flow_filter *)arg;
576
577	tcf_tree_lock(tp);
578	list_del(&f->list);
579	tcf_tree_unlock(tp);
580	flow_destroy_filter(tp, f);
581	return 0;
582}
583
584static int flow_init(struct tcf_proto *tp)
585{
586	struct flow_head *head;
587
588	head = kzalloc(sizeof(*head), GFP_KERNEL);
589	if (head == NULL)
590		return -ENOBUFS;
591	INIT_LIST_HEAD(&head->filters);
592	tp->root = head;
593	return 0;
594}
595
596static void flow_destroy(struct tcf_proto *tp)
597{
598	struct flow_head *head = tp->root;
599	struct flow_filter *f, *next;
600
601	list_for_each_entry_safe(f, next, &head->filters, list) {
602		list_del(&f->list);
603		flow_destroy_filter(tp, f);
604	}
605	kfree(head);
606}
607
608static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
609{
610	struct flow_head *head = tp->root;
611	struct flow_filter *f;
612
613	list_for_each_entry(f, &head->filters, list)
614		if (f->handle == handle)
615			return (unsigned long)f;
616	return 0;
617}
618
619static void flow_put(struct tcf_proto *tp, unsigned long f)
620{
621}
622
623static int flow_dump(struct tcf_proto *tp, unsigned long fh,
624		     struct sk_buff *skb, struct tcmsg *t)
625{
626	struct flow_filter *f = (struct flow_filter *)fh;
627	struct nlattr *nest;
628
629	if (f == NULL)
630		return skb->len;
631
632	t->tcm_handle = f->handle;
633
634	nest = nla_nest_start(skb, TCA_OPTIONS);
635	if (nest == NULL)
636		goto nla_put_failure;
637
638	NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
639	NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
640
641	if (f->mask != ~0 || f->xor != 0) {
642		NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
643		NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
644	}
645	if (f->rshift)
646		NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
647	if (f->addend)
648		NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
649
650	if (f->divisor)
651		NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
652	if (f->baseclass)
653		NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
654
655	if (f->perturb_period)
656		NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
657
658	if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
659		goto nla_put_failure;
660#ifdef CONFIG_NET_EMATCH
661	if (f->ematches.hdr.nmatches &&
662	    tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
663		goto nla_put_failure;
664#endif
665	nla_nest_end(skb, nest);
666
667	if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
668		goto nla_put_failure;
669
670	return skb->len;
671
672nla_put_failure:
673	nlmsg_trim(skb, nest);
674	return -1;
675}
676
677static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
678{
679	struct flow_head *head = tp->root;
680	struct flow_filter *f;
681
682	list_for_each_entry(f, &head->filters, list) {
683		if (arg->count < arg->skip)
684			goto skip;
685		if (arg->fn(tp, (unsigned long)f, arg) < 0) {
686			arg->stop = 1;
687			break;
688		}
689skip:
690		arg->count++;
691	}
692}
693
694static struct tcf_proto_ops cls_flow_ops __read_mostly = {
695	.kind		= "flow",
696	.classify	= flow_classify,
697	.init		= flow_init,
698	.destroy	= flow_destroy,
699	.change		= flow_change,
700	.delete		= flow_delete,
701	.get		= flow_get,
702	.put		= flow_put,
703	.dump		= flow_dump,
704	.walk		= flow_walk,
705	.owner		= THIS_MODULE,
706};
707
708static int __init cls_flow_init(void)
709{
710	return register_tcf_proto_ops(&cls_flow_ops);
711}
712
713static void __exit cls_flow_exit(void)
714{
715	unregister_tcf_proto_ops(&cls_flow_ops);
716}
717
718module_init(cls_flow_init);
719module_exit(cls_flow_exit);
720
721MODULE_LICENSE("GPL");
722MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
723MODULE_DESCRIPTION("TC flow classifier");
724