xref: /openbmc/linux/net/sched/cls_flow.c (revision 5d4a2e29) 
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 
32 struct flow_head {
33 	struct list_head	filters;
34 };
35 
36 struct 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 
56 static const struct tcf_ext_map flow_ext_map = {
57 	.action	= TCA_FLOW_ACT,
58 	.police	= TCA_FLOW_POLICE,
59 };
60 
61 static 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 
68 static u32 flow_get_src(const struct sk_buff *skb)
69 {
70 	switch (skb->protocol) {
71 	case htons(ETH_P_IP):
72 		return ntohl(ip_hdr(skb)->saddr);
73 	case htons(ETH_P_IPV6):
74 		return ntohl(ipv6_hdr(skb)->saddr.s6_addr32[3]);
75 	default:
76 		return addr_fold(skb->sk);
77 	}
78 }
79 
80 static u32 flow_get_dst(const struct sk_buff *skb)
81 {
82 	switch (skb->protocol) {
83 	case htons(ETH_P_IP):
84 		return ntohl(ip_hdr(skb)->daddr);
85 	case htons(ETH_P_IPV6):
86 		return ntohl(ipv6_hdr(skb)->daddr.s6_addr32[3]);
87 	default:
88 		return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
89 	}
90 }
91 
92 static u32 flow_get_proto(const struct sk_buff *skb)
93 {
94 	switch (skb->protocol) {
95 	case htons(ETH_P_IP):
96 		return ip_hdr(skb)->protocol;
97 	case htons(ETH_P_IPV6):
98 		return ipv6_hdr(skb)->nexthdr;
99 	default:
100 		return 0;
101 	}
102 }
103 
104 static int has_ports(u8 protocol)
105 {
106 	switch (protocol) {
107 	case IPPROTO_TCP:
108 	case IPPROTO_UDP:
109 	case IPPROTO_UDPLITE:
110 	case IPPROTO_SCTP:
111 	case IPPROTO_DCCP:
112 	case IPPROTO_ESP:
113 		return 1;
114 	default:
115 		return 0;
116 	}
117 }
118 
119 static u32 flow_get_proto_src(const struct sk_buff *skb)
120 {
121 	u32 res = 0;
122 
123 	switch (skb->protocol) {
124 	case htons(ETH_P_IP): {
125 		struct iphdr *iph = ip_hdr(skb);
126 
127 		if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
128 		    has_ports(iph->protocol))
129 			res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4));
130 		break;
131 	}
132 	case htons(ETH_P_IPV6): {
133 		struct ipv6hdr *iph = ipv6_hdr(skb);
134 
135 		if (has_ports(iph->nexthdr))
136 			res = ntohs(*(__be16 *)&iph[1]);
137 		break;
138 	}
139 	default:
140 		res = addr_fold(skb->sk);
141 	}
142 
143 	return res;
144 }
145 
146 static u32 flow_get_proto_dst(const struct sk_buff *skb)
147 {
148 	u32 res = 0;
149 
150 	switch (skb->protocol) {
151 	case htons(ETH_P_IP): {
152 		struct iphdr *iph = ip_hdr(skb);
153 
154 		if (!(iph->frag_off&htons(IP_MF|IP_OFFSET)) &&
155 		    has_ports(iph->protocol))
156 			res = ntohs(*(__be16 *)((void *)iph + iph->ihl * 4 + 2));
157 		break;
158 	}
159 	case htons(ETH_P_IPV6): {
160 		struct ipv6hdr *iph = ipv6_hdr(skb);
161 
162 		if (has_ports(iph->nexthdr))
163 			res = ntohs(*(__be16 *)((void *)&iph[1] + 2));
164 		break;
165 	}
166 	default:
167 		res = addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
168 	}
169 
170 	return res;
171 }
172 
173 static u32 flow_get_iif(const struct sk_buff *skb)
174 {
175 	return skb->skb_iif;
176 }
177 
178 static u32 flow_get_priority(const struct sk_buff *skb)
179 {
180 	return skb->priority;
181 }
182 
183 static u32 flow_get_mark(const struct sk_buff *skb)
184 {
185 	return skb->mark;
186 }
187 
188 static u32 flow_get_nfct(const struct sk_buff *skb)
189 {
190 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
191 	return addr_fold(skb->nfct);
192 #else
193 	return 0;
194 #endif
195 }
196 
197 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
198 #define CTTUPLE(skb, member)						\
199 ({									\
200 	enum ip_conntrack_info ctinfo;					\
201 	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);			\
202 	if (ct == NULL)							\
203 		goto fallback;						\
204 	ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;			\
205 })
206 #else
207 #define CTTUPLE(skb, member)						\
208 ({									\
209 	goto fallback;							\
210 	0;								\
211 })
212 #endif
213 
214 static u32 flow_get_nfct_src(const struct sk_buff *skb)
215 {
216 	switch (skb->protocol) {
217 	case htons(ETH_P_IP):
218 		return ntohl(CTTUPLE(skb, src.u3.ip));
219 	case htons(ETH_P_IPV6):
220 		return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
221 	}
222 fallback:
223 	return flow_get_src(skb);
224 }
225 
226 static u32 flow_get_nfct_dst(const struct sk_buff *skb)
227 {
228 	switch (skb->protocol) {
229 	case htons(ETH_P_IP):
230 		return ntohl(CTTUPLE(skb, dst.u3.ip));
231 	case htons(ETH_P_IPV6):
232 		return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
233 	}
234 fallback:
235 	return flow_get_dst(skb);
236 }
237 
238 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb)
239 {
240 	return ntohs(CTTUPLE(skb, src.u.all));
241 fallback:
242 	return flow_get_proto_src(skb);
243 }
244 
245 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb)
246 {
247 	return ntohs(CTTUPLE(skb, dst.u.all));
248 fallback:
249 	return flow_get_proto_dst(skb);
250 }
251 
252 static u32 flow_get_rtclassid(const struct sk_buff *skb)
253 {
254 #ifdef CONFIG_NET_CLS_ROUTE
255 	if (skb_dst(skb))
256 		return skb_dst(skb)->tclassid;
257 #endif
258 	return 0;
259 }
260 
261 static u32 flow_get_skuid(const struct sk_buff *skb)
262 {
263 	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
264 		return skb->sk->sk_socket->file->f_cred->fsuid;
265 	return 0;
266 }
267 
268 static u32 flow_get_skgid(const struct sk_buff *skb)
269 {
270 	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
271 		return skb->sk->sk_socket->file->f_cred->fsgid;
272 	return 0;
273 }
274 
275 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
276 {
277 	u16 uninitialized_var(tag);
278 
279 	if (vlan_get_tag(skb, &tag) < 0)
280 		return 0;
281 	return tag & VLAN_VID_MASK;
282 }
283 
284 static u32 flow_key_get(const struct sk_buff *skb, int key)
285 {
286 	switch (key) {
287 	case FLOW_KEY_SRC:
288 		return flow_get_src(skb);
289 	case FLOW_KEY_DST:
290 		return flow_get_dst(skb);
291 	case FLOW_KEY_PROTO:
292 		return flow_get_proto(skb);
293 	case FLOW_KEY_PROTO_SRC:
294 		return flow_get_proto_src(skb);
295 	case FLOW_KEY_PROTO_DST:
296 		return flow_get_proto_dst(skb);
297 	case FLOW_KEY_IIF:
298 		return flow_get_iif(skb);
299 	case FLOW_KEY_PRIORITY:
300 		return flow_get_priority(skb);
301 	case FLOW_KEY_MARK:
302 		return flow_get_mark(skb);
303 	case FLOW_KEY_NFCT:
304 		return flow_get_nfct(skb);
305 	case FLOW_KEY_NFCT_SRC:
306 		return flow_get_nfct_src(skb);
307 	case FLOW_KEY_NFCT_DST:
308 		return flow_get_nfct_dst(skb);
309 	case FLOW_KEY_NFCT_PROTO_SRC:
310 		return flow_get_nfct_proto_src(skb);
311 	case FLOW_KEY_NFCT_PROTO_DST:
312 		return flow_get_nfct_proto_dst(skb);
313 	case FLOW_KEY_RTCLASSID:
314 		return flow_get_rtclassid(skb);
315 	case FLOW_KEY_SKUID:
316 		return flow_get_skuid(skb);
317 	case FLOW_KEY_SKGID:
318 		return flow_get_skgid(skb);
319 	case FLOW_KEY_VLAN_TAG:
320 		return flow_get_vlan_tag(skb);
321 	default:
322 		WARN_ON(1);
323 		return 0;
324 	}
325 }
326 
327 static int flow_classify(struct sk_buff *skb, struct tcf_proto *tp,
328 			 struct tcf_result *res)
329 {
330 	struct flow_head *head = tp->root;
331 	struct flow_filter *f;
332 	u32 keymask;
333 	u32 classid;
334 	unsigned int n, key;
335 	int r;
336 
337 	list_for_each_entry(f, &head->filters, list) {
338 		u32 keys[f->nkeys];
339 
340 		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
341 			continue;
342 
343 		keymask = f->keymask;
344 
345 		for (n = 0; n < f->nkeys; n++) {
346 			key = ffs(keymask) - 1;
347 			keymask &= ~(1 << key);
348 			keys[n] = flow_key_get(skb, key);
349 		}
350 
351 		if (f->mode == FLOW_MODE_HASH)
352 			classid = jhash2(keys, f->nkeys, f->hashrnd);
353 		else {
354 			classid = keys[0];
355 			classid = (classid & f->mask) ^ f->xor;
356 			classid = (classid >> f->rshift) + f->addend;
357 		}
358 
359 		if (f->divisor)
360 			classid %= f->divisor;
361 
362 		res->class   = 0;
363 		res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
364 
365 		r = tcf_exts_exec(skb, &f->exts, res);
366 		if (r < 0)
367 			continue;
368 		return r;
369 	}
370 	return -1;
371 }
372 
373 static void flow_perturbation(unsigned long arg)
374 {
375 	struct flow_filter *f = (struct flow_filter *)arg;
376 
377 	get_random_bytes(&f->hashrnd, 4);
378 	if (f->perturb_period)
379 		mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
380 }
381 
382 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
383 	[TCA_FLOW_KEYS]		= { .type = NLA_U32 },
384 	[TCA_FLOW_MODE]		= { .type = NLA_U32 },
385 	[TCA_FLOW_BASECLASS]	= { .type = NLA_U32 },
386 	[TCA_FLOW_RSHIFT]	= { .type = NLA_U32 },
387 	[TCA_FLOW_ADDEND]	= { .type = NLA_U32 },
388 	[TCA_FLOW_MASK]		= { .type = NLA_U32 },
389 	[TCA_FLOW_XOR]		= { .type = NLA_U32 },
390 	[TCA_FLOW_DIVISOR]	= { .type = NLA_U32 },
391 	[TCA_FLOW_ACT]		= { .type = NLA_NESTED },
392 	[TCA_FLOW_POLICE]	= { .type = NLA_NESTED },
393 	[TCA_FLOW_EMATCHES]	= { .type = NLA_NESTED },
394 	[TCA_FLOW_PERTURB]	= { .type = NLA_U32 },
395 };
396 
397 static int flow_change(struct tcf_proto *tp, unsigned long base,
398 		       u32 handle, struct nlattr **tca,
399 		       unsigned long *arg)
400 {
401 	struct flow_head *head = tp->root;
402 	struct flow_filter *f;
403 	struct nlattr *opt = tca[TCA_OPTIONS];
404 	struct nlattr *tb[TCA_FLOW_MAX + 1];
405 	struct tcf_exts e;
406 	struct tcf_ematch_tree t;
407 	unsigned int nkeys = 0;
408 	unsigned int perturb_period = 0;
409 	u32 baseclass = 0;
410 	u32 keymask = 0;
411 	u32 mode;
412 	int err;
413 
414 	if (opt == NULL)
415 		return -EINVAL;
416 
417 	err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
418 	if (err < 0)
419 		return err;
420 
421 	if (tb[TCA_FLOW_BASECLASS]) {
422 		baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
423 		if (TC_H_MIN(baseclass) == 0)
424 			return -EINVAL;
425 	}
426 
427 	if (tb[TCA_FLOW_KEYS]) {
428 		keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
429 
430 		nkeys = hweight32(keymask);
431 		if (nkeys == 0)
432 			return -EINVAL;
433 
434 		if (fls(keymask) - 1 > FLOW_KEY_MAX)
435 			return -EOPNOTSUPP;
436 	}
437 
438 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
439 	if (err < 0)
440 		return err;
441 
442 	err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
443 	if (err < 0)
444 		goto err1;
445 
446 	f = (struct flow_filter *)*arg;
447 	if (f != NULL) {
448 		err = -EINVAL;
449 		if (f->handle != handle && handle)
450 			goto err2;
451 
452 		mode = f->mode;
453 		if (tb[TCA_FLOW_MODE])
454 			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
455 		if (mode != FLOW_MODE_HASH && nkeys > 1)
456 			goto err2;
457 
458 		if (mode == FLOW_MODE_HASH)
459 			perturb_period = f->perturb_period;
460 		if (tb[TCA_FLOW_PERTURB]) {
461 			if (mode != FLOW_MODE_HASH)
462 				goto err2;
463 			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
464 		}
465 	} else {
466 		err = -EINVAL;
467 		if (!handle)
468 			goto err2;
469 		if (!tb[TCA_FLOW_KEYS])
470 			goto err2;
471 
472 		mode = FLOW_MODE_MAP;
473 		if (tb[TCA_FLOW_MODE])
474 			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
475 		if (mode != FLOW_MODE_HASH && nkeys > 1)
476 			goto err2;
477 
478 		if (tb[TCA_FLOW_PERTURB]) {
479 			if (mode != FLOW_MODE_HASH)
480 				goto err2;
481 			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
482 		}
483 
484 		if (TC_H_MAJ(baseclass) == 0)
485 			baseclass = TC_H_MAKE(tp->q->handle, baseclass);
486 		if (TC_H_MIN(baseclass) == 0)
487 			baseclass = TC_H_MAKE(baseclass, 1);
488 
489 		err = -ENOBUFS;
490 		f = kzalloc(sizeof(*f), GFP_KERNEL);
491 		if (f == NULL)
492 			goto err2;
493 
494 		f->handle = handle;
495 		f->mask	  = ~0U;
496 
497 		get_random_bytes(&f->hashrnd, 4);
498 		f->perturb_timer.function = flow_perturbation;
499 		f->perturb_timer.data = (unsigned long)f;
500 		init_timer_deferrable(&f->perturb_timer);
501 	}
502 
503 	tcf_exts_change(tp, &f->exts, &e);
504 	tcf_em_tree_change(tp, &f->ematches, &t);
505 
506 	tcf_tree_lock(tp);
507 
508 	if (tb[TCA_FLOW_KEYS]) {
509 		f->keymask = keymask;
510 		f->nkeys   = nkeys;
511 	}
512 
513 	f->mode = mode;
514 
515 	if (tb[TCA_FLOW_MASK])
516 		f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
517 	if (tb[TCA_FLOW_XOR])
518 		f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
519 	if (tb[TCA_FLOW_RSHIFT])
520 		f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
521 	if (tb[TCA_FLOW_ADDEND])
522 		f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
523 
524 	if (tb[TCA_FLOW_DIVISOR])
525 		f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
526 	if (baseclass)
527 		f->baseclass = baseclass;
528 
529 	f->perturb_period = perturb_period;
530 	del_timer(&f->perturb_timer);
531 	if (perturb_period)
532 		mod_timer(&f->perturb_timer, jiffies + perturb_period);
533 
534 	if (*arg == 0)
535 		list_add_tail(&f->list, &head->filters);
536 
537 	tcf_tree_unlock(tp);
538 
539 	*arg = (unsigned long)f;
540 	return 0;
541 
542 err2:
543 	tcf_em_tree_destroy(tp, &t);
544 err1:
545 	tcf_exts_destroy(tp, &e);
546 	return err;
547 }
548 
549 static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
550 {
551 	del_timer_sync(&f->perturb_timer);
552 	tcf_exts_destroy(tp, &f->exts);
553 	tcf_em_tree_destroy(tp, &f->ematches);
554 	kfree(f);
555 }
556 
557 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
558 {
559 	struct flow_filter *f = (struct flow_filter *)arg;
560 
561 	tcf_tree_lock(tp);
562 	list_del(&f->list);
563 	tcf_tree_unlock(tp);
564 	flow_destroy_filter(tp, f);
565 	return 0;
566 }
567 
568 static int flow_init(struct tcf_proto *tp)
569 {
570 	struct flow_head *head;
571 
572 	head = kzalloc(sizeof(*head), GFP_KERNEL);
573 	if (head == NULL)
574 		return -ENOBUFS;
575 	INIT_LIST_HEAD(&head->filters);
576 	tp->root = head;
577 	return 0;
578 }
579 
580 static void flow_destroy(struct tcf_proto *tp)
581 {
582 	struct flow_head *head = tp->root;
583 	struct flow_filter *f, *next;
584 
585 	list_for_each_entry_safe(f, next, &head->filters, list) {
586 		list_del(&f->list);
587 		flow_destroy_filter(tp, f);
588 	}
589 	kfree(head);
590 }
591 
592 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
593 {
594 	struct flow_head *head = tp->root;
595 	struct flow_filter *f;
596 
597 	list_for_each_entry(f, &head->filters, list)
598 		if (f->handle == handle)
599 			return (unsigned long)f;
600 	return 0;
601 }
602 
603 static void flow_put(struct tcf_proto *tp, unsigned long f)
604 {
605 }
606 
607 static int flow_dump(struct tcf_proto *tp, unsigned long fh,
608 		     struct sk_buff *skb, struct tcmsg *t)
609 {
610 	struct flow_filter *f = (struct flow_filter *)fh;
611 	struct nlattr *nest;
612 
613 	if (f == NULL)
614 		return skb->len;
615 
616 	t->tcm_handle = f->handle;
617 
618 	nest = nla_nest_start(skb, TCA_OPTIONS);
619 	if (nest == NULL)
620 		goto nla_put_failure;
621 
622 	NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
623 	NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
624 
625 	if (f->mask != ~0 || f->xor != 0) {
626 		NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
627 		NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
628 	}
629 	if (f->rshift)
630 		NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
631 	if (f->addend)
632 		NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
633 
634 	if (f->divisor)
635 		NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
636 	if (f->baseclass)
637 		NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
638 
639 	if (f->perturb_period)
640 		NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
641 
642 	if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
643 		goto nla_put_failure;
644 #ifdef CONFIG_NET_EMATCH
645 	if (f->ematches.hdr.nmatches &&
646 	    tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
647 		goto nla_put_failure;
648 #endif
649 	nla_nest_end(skb, nest);
650 
651 	if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
652 		goto nla_put_failure;
653 
654 	return skb->len;
655 
656 nla_put_failure:
657 	nlmsg_trim(skb, nest);
658 	return -1;
659 }
660 
661 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
662 {
663 	struct flow_head *head = tp->root;
664 	struct flow_filter *f;
665 
666 	list_for_each_entry(f, &head->filters, list) {
667 		if (arg->count < arg->skip)
668 			goto skip;
669 		if (arg->fn(tp, (unsigned long)f, arg) < 0) {
670 			arg->stop = 1;
671 			break;
672 		}
673 skip:
674 		arg->count++;
675 	}
676 }
677 
678 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
679 	.kind		= "flow",
680 	.classify	= flow_classify,
681 	.init		= flow_init,
682 	.destroy	= flow_destroy,
683 	.change		= flow_change,
684 	.delete		= flow_delete,
685 	.get		= flow_get,
686 	.put		= flow_put,
687 	.dump		= flow_dump,
688 	.walk		= flow_walk,
689 	.owner		= THIS_MODULE,
690 };
691 
692 static int __init cls_flow_init(void)
693 {
694 	return register_tcf_proto_ops(&cls_flow_ops);
695 }
696 
697 static void __exit cls_flow_exit(void)
698 {
699 	unregister_tcf_proto_ops(&cls_flow_ops);
700 }
701 
702 module_init(cls_flow_init);
703 module_exit(cls_flow_exit);
704 
705 MODULE_LICENSE("GPL");
706 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
707 MODULE_DESCRIPTION("TC flow classifier");
708