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 
35 struct flow_head {
36 	struct list_head	filters;
37 };
38 
39 struct flow_filter {
40 	struct list_head	list;
41 	struct tcf_exts		exts;
42 	struct tcf_ematch_tree	ematches;
43 	struct timer_list	perturb_timer;
44 	u32			perturb_period;
45 	u32			handle;
46 
47 	u32			nkeys;
48 	u32			keymask;
49 	u32			mode;
50 	u32			mask;
51 	u32			xor;
52 	u32			rshift;
53 	u32			addend;
54 	u32			divisor;
55 	u32			baseclass;
56 	u32			hashrnd;
57 };
58 
59 static const struct tcf_ext_map flow_ext_map = {
60 	.action	= TCA_FLOW_ACT,
61 	.police	= TCA_FLOW_POLICE,
62 };
63 
addr_fold(void * addr)64 static inline u32 addr_fold(void *addr)
65 {
66 	unsigned long a = (unsigned long)addr;
67 
68 	return (a & 0xFFFFFFFF) ^ (BITS_PER_LONG > 32 ? a >> 32 : 0);
69 }
70 
flow_get_src(const struct sk_buff * skb,const struct flow_keys * flow)71 static u32 flow_get_src(const struct sk_buff *skb, const struct flow_keys *flow)
72 {
73 	if (flow->src)
74 		return ntohl(flow->src);
75 	return addr_fold(skb->sk);
76 }
77 
flow_get_dst(const struct sk_buff * skb,const struct flow_keys * flow)78 static u32 flow_get_dst(const struct sk_buff *skb, const struct flow_keys *flow)
79 {
80 	if (flow->dst)
81 		return ntohl(flow->dst);
82 	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
83 }
84 
flow_get_proto(const struct sk_buff * skb,const struct flow_keys * flow)85 static u32 flow_get_proto(const struct sk_buff *skb, const struct flow_keys *flow)
86 {
87 	return flow->ip_proto;
88 }
89 
flow_get_proto_src(const struct sk_buff * skb,const struct flow_keys * flow)90 static u32 flow_get_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
91 {
92 	if (flow->ports)
93 		return ntohs(flow->port16[0]);
94 
95 	return addr_fold(skb->sk);
96 }
97 
flow_get_proto_dst(const struct sk_buff * skb,const struct flow_keys * flow)98 static u32 flow_get_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
99 {
100 	if (flow->ports)
101 		return ntohs(flow->port16[1]);
102 
103 	return addr_fold(skb_dst(skb)) ^ (__force u16)skb->protocol;
104 }
105 
flow_get_iif(const struct sk_buff * skb)106 static u32 flow_get_iif(const struct sk_buff *skb)
107 {
108 	return skb->skb_iif;
109 }
110 
flow_get_priority(const struct sk_buff * skb)111 static u32 flow_get_priority(const struct sk_buff *skb)
112 {
113 	return skb->priority;
114 }
115 
flow_get_mark(const struct sk_buff * skb)116 static u32 flow_get_mark(const struct sk_buff *skb)
117 {
118 	return skb->mark;
119 }
120 
flow_get_nfct(const struct sk_buff * skb)121 static u32 flow_get_nfct(const struct sk_buff *skb)
122 {
123 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
124 	return addr_fold(skb->nfct);
125 #else
126 	return 0;
127 #endif
128 }
129 
130 #if defined(CONFIG_NF_CONNTRACK) || defined(CONFIG_NF_CONNTRACK_MODULE)
131 #define CTTUPLE(skb, member)						\
132 ({									\
133 	enum ip_conntrack_info ctinfo;					\
134 	const struct nf_conn *ct = nf_ct_get(skb, &ctinfo);		\
135 	if (ct == NULL)							\
136 		goto fallback;						\
137 	ct->tuplehash[CTINFO2DIR(ctinfo)].tuple.member;			\
138 })
139 #else
140 #define CTTUPLE(skb, member)						\
141 ({									\
142 	goto fallback;							\
143 	0;								\
144 })
145 #endif
146 
flow_get_nfct_src(const struct sk_buff * skb,const struct flow_keys * flow)147 static u32 flow_get_nfct_src(const struct sk_buff *skb, const struct flow_keys *flow)
148 {
149 	switch (skb->protocol) {
150 	case htons(ETH_P_IP):
151 		return ntohl(CTTUPLE(skb, src.u3.ip));
152 	case htons(ETH_P_IPV6):
153 		return ntohl(CTTUPLE(skb, src.u3.ip6[3]));
154 	}
155 fallback:
156 	return flow_get_src(skb, flow);
157 }
158 
flow_get_nfct_dst(const struct sk_buff * skb,const struct flow_keys * flow)159 static u32 flow_get_nfct_dst(const struct sk_buff *skb, const struct flow_keys *flow)
160 {
161 	switch (skb->protocol) {
162 	case htons(ETH_P_IP):
163 		return ntohl(CTTUPLE(skb, dst.u3.ip));
164 	case htons(ETH_P_IPV6):
165 		return ntohl(CTTUPLE(skb, dst.u3.ip6[3]));
166 	}
167 fallback:
168 	return flow_get_dst(skb, flow);
169 }
170 
flow_get_nfct_proto_src(const struct sk_buff * skb,const struct flow_keys * flow)171 static u32 flow_get_nfct_proto_src(const struct sk_buff *skb, const struct flow_keys *flow)
172 {
173 	return ntohs(CTTUPLE(skb, src.u.all));
174 fallback:
175 	return flow_get_proto_src(skb, flow);
176 }
177 
flow_get_nfct_proto_dst(const struct sk_buff * skb,const struct flow_keys * flow)178 static u32 flow_get_nfct_proto_dst(const struct sk_buff *skb, const struct flow_keys *flow)
179 {
180 	return ntohs(CTTUPLE(skb, dst.u.all));
181 fallback:
182 	return flow_get_proto_dst(skb, flow);
183 }
184 
flow_get_rtclassid(const struct sk_buff * skb)185 static u32 flow_get_rtclassid(const struct sk_buff *skb)
186 {
187 #ifdef CONFIG_IP_ROUTE_CLASSID
188 	if (skb_dst(skb))
189 		return skb_dst(skb)->tclassid;
190 #endif
191 	return 0;
192 }
193 
flow_get_skuid(const struct sk_buff * skb)194 static u32 flow_get_skuid(const struct sk_buff *skb)
195 {
196 	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
197 		return skb->sk->sk_socket->file->f_cred->fsuid;
198 	return 0;
199 }
200 
flow_get_skgid(const struct sk_buff * skb)201 static u32 flow_get_skgid(const struct sk_buff *skb)
202 {
203 	if (skb->sk && skb->sk->sk_socket && skb->sk->sk_socket->file)
204 		return skb->sk->sk_socket->file->f_cred->fsgid;
205 	return 0;
206 }
207 
flow_get_vlan_tag(const struct sk_buff * skb)208 static u32 flow_get_vlan_tag(const struct sk_buff *skb)
209 {
210 	u16 uninitialized_var(tag);
211 
212 	if (vlan_get_tag(skb, &tag) < 0)
213 		return 0;
214 	return tag & VLAN_VID_MASK;
215 }
216 
flow_get_rxhash(struct sk_buff * skb)217 static u32 flow_get_rxhash(struct sk_buff *skb)
218 {
219 	return skb_get_rxhash(skb);
220 }
221 
flow_key_get(struct sk_buff * skb,int key,struct flow_keys * flow)222 static u32 flow_key_get(struct sk_buff *skb, int key, struct flow_keys *flow)
223 {
224 	switch (key) {
225 	case FLOW_KEY_SRC:
226 		return flow_get_src(skb, flow);
227 	case FLOW_KEY_DST:
228 		return flow_get_dst(skb, flow);
229 	case FLOW_KEY_PROTO:
230 		return flow_get_proto(skb, flow);
231 	case FLOW_KEY_PROTO_SRC:
232 		return flow_get_proto_src(skb, flow);
233 	case FLOW_KEY_PROTO_DST:
234 		return flow_get_proto_dst(skb, flow);
235 	case FLOW_KEY_IIF:
236 		return flow_get_iif(skb);
237 	case FLOW_KEY_PRIORITY:
238 		return flow_get_priority(skb);
239 	case FLOW_KEY_MARK:
240 		return flow_get_mark(skb);
241 	case FLOW_KEY_NFCT:
242 		return flow_get_nfct(skb);
243 	case FLOW_KEY_NFCT_SRC:
244 		return flow_get_nfct_src(skb, flow);
245 	case FLOW_KEY_NFCT_DST:
246 		return flow_get_nfct_dst(skb, flow);
247 	case FLOW_KEY_NFCT_PROTO_SRC:
248 		return flow_get_nfct_proto_src(skb, flow);
249 	case FLOW_KEY_NFCT_PROTO_DST:
250 		return flow_get_nfct_proto_dst(skb, flow);
251 	case FLOW_KEY_RTCLASSID:
252 		return flow_get_rtclassid(skb);
253 	case FLOW_KEY_SKUID:
254 		return flow_get_skuid(skb);
255 	case FLOW_KEY_SKGID:
256 		return flow_get_skgid(skb);
257 	case FLOW_KEY_VLAN_TAG:
258 		return flow_get_vlan_tag(skb);
259 	case FLOW_KEY_RXHASH:
260 		return flow_get_rxhash(skb);
261 	default:
262 		WARN_ON(1);
263 		return 0;
264 	}
265 }
266 
267 #define FLOW_KEYS_NEEDED ((1 << FLOW_KEY_SRC) | 		\
268 			  (1 << FLOW_KEY_DST) |			\
269 			  (1 << FLOW_KEY_PROTO) |		\
270 			  (1 << FLOW_KEY_PROTO_SRC) |		\
271 			  (1 << FLOW_KEY_PROTO_DST) | 		\
272 			  (1 << FLOW_KEY_NFCT_SRC) |		\
273 			  (1 << FLOW_KEY_NFCT_DST) |		\
274 			  (1 << FLOW_KEY_NFCT_PROTO_SRC) |	\
275 			  (1 << FLOW_KEY_NFCT_PROTO_DST))
276 
flow_classify(struct sk_buff * skb,const struct tcf_proto * tp,struct tcf_result * res)277 static int flow_classify(struct sk_buff *skb, const struct tcf_proto *tp,
278 			 struct tcf_result *res)
279 {
280 	struct flow_head *head = tp->root;
281 	struct flow_filter *f;
282 	u32 keymask;
283 	u32 classid;
284 	unsigned int n, key;
285 	int r;
286 
287 	list_for_each_entry(f, &head->filters, list) {
288 		u32 keys[FLOW_KEY_MAX + 1];
289 		struct flow_keys flow_keys;
290 
291 		if (!tcf_em_tree_match(skb, &f->ematches, NULL))
292 			continue;
293 
294 		keymask = f->keymask;
295 		if (keymask & FLOW_KEYS_NEEDED)
296 			skb_flow_dissect(skb, &flow_keys);
297 
298 		for (n = 0; n < f->nkeys; n++) {
299 			key = ffs(keymask) - 1;
300 			keymask &= ~(1 << key);
301 			keys[n] = flow_key_get(skb, key, &flow_keys);
302 		}
303 
304 		if (f->mode == FLOW_MODE_HASH)
305 			classid = jhash2(keys, f->nkeys, f->hashrnd);
306 		else {
307 			classid = keys[0];
308 			classid = (classid & f->mask) ^ f->xor;
309 			classid = (classid >> f->rshift) + f->addend;
310 		}
311 
312 		if (f->divisor)
313 			classid %= f->divisor;
314 
315 		res->class   = 0;
316 		res->classid = TC_H_MAKE(f->baseclass, f->baseclass + classid);
317 
318 		r = tcf_exts_exec(skb, &f->exts, res);
319 		if (r < 0)
320 			continue;
321 		return r;
322 	}
323 	return -1;
324 }
325 
flow_perturbation(unsigned long arg)326 static void flow_perturbation(unsigned long arg)
327 {
328 	struct flow_filter *f = (struct flow_filter *)arg;
329 
330 	get_random_bytes(&f->hashrnd, 4);
331 	if (f->perturb_period)
332 		mod_timer(&f->perturb_timer, jiffies + f->perturb_period);
333 }
334 
335 static const struct nla_policy flow_policy[TCA_FLOW_MAX + 1] = {
336 	[TCA_FLOW_KEYS]		= { .type = NLA_U32 },
337 	[TCA_FLOW_MODE]		= { .type = NLA_U32 },
338 	[TCA_FLOW_BASECLASS]	= { .type = NLA_U32 },
339 	[TCA_FLOW_RSHIFT]	= { .type = NLA_U32 },
340 	[TCA_FLOW_ADDEND]	= { .type = NLA_U32 },
341 	[TCA_FLOW_MASK]		= { .type = NLA_U32 },
342 	[TCA_FLOW_XOR]		= { .type = NLA_U32 },
343 	[TCA_FLOW_DIVISOR]	= { .type = NLA_U32 },
344 	[TCA_FLOW_ACT]		= { .type = NLA_NESTED },
345 	[TCA_FLOW_POLICE]	= { .type = NLA_NESTED },
346 	[TCA_FLOW_EMATCHES]	= { .type = NLA_NESTED },
347 	[TCA_FLOW_PERTURB]	= { .type = NLA_U32 },
348 };
349 
flow_change(struct tcf_proto * tp,unsigned long base,u32 handle,struct nlattr ** tca,unsigned long * arg)350 static int flow_change(struct tcf_proto *tp, unsigned long base,
351 		       u32 handle, struct nlattr **tca,
352 		       unsigned long *arg)
353 {
354 	struct flow_head *head = tp->root;
355 	struct flow_filter *f;
356 	struct nlattr *opt = tca[TCA_OPTIONS];
357 	struct nlattr *tb[TCA_FLOW_MAX + 1];
358 	struct tcf_exts e;
359 	struct tcf_ematch_tree t;
360 	unsigned int nkeys = 0;
361 	unsigned int perturb_period = 0;
362 	u32 baseclass = 0;
363 	u32 keymask = 0;
364 	u32 mode;
365 	int err;
366 
367 	if (opt == NULL)
368 		return -EINVAL;
369 
370 	err = nla_parse_nested(tb, TCA_FLOW_MAX, opt, flow_policy);
371 	if (err < 0)
372 		return err;
373 
374 	if (tb[TCA_FLOW_BASECLASS]) {
375 		baseclass = nla_get_u32(tb[TCA_FLOW_BASECLASS]);
376 		if (TC_H_MIN(baseclass) == 0)
377 			return -EINVAL;
378 	}
379 
380 	if (tb[TCA_FLOW_KEYS]) {
381 		keymask = nla_get_u32(tb[TCA_FLOW_KEYS]);
382 
383 		nkeys = hweight32(keymask);
384 		if (nkeys == 0)
385 			return -EINVAL;
386 
387 		if (fls(keymask) - 1 > FLOW_KEY_MAX)
388 			return -EOPNOTSUPP;
389 	}
390 
391 	err = tcf_exts_validate(tp, tb, tca[TCA_RATE], &e, &flow_ext_map);
392 	if (err < 0)
393 		return err;
394 
395 	err = tcf_em_tree_validate(tp, tb[TCA_FLOW_EMATCHES], &t);
396 	if (err < 0)
397 		goto err1;
398 
399 	f = (struct flow_filter *)*arg;
400 	if (f != NULL) {
401 		err = -EINVAL;
402 		if (f->handle != handle && handle)
403 			goto err2;
404 
405 		mode = f->mode;
406 		if (tb[TCA_FLOW_MODE])
407 			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
408 		if (mode != FLOW_MODE_HASH && nkeys > 1)
409 			goto err2;
410 
411 		if (mode == FLOW_MODE_HASH)
412 			perturb_period = f->perturb_period;
413 		if (tb[TCA_FLOW_PERTURB]) {
414 			if (mode != FLOW_MODE_HASH)
415 				goto err2;
416 			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
417 		}
418 	} else {
419 		err = -EINVAL;
420 		if (!handle)
421 			goto err2;
422 		if (!tb[TCA_FLOW_KEYS])
423 			goto err2;
424 
425 		mode = FLOW_MODE_MAP;
426 		if (tb[TCA_FLOW_MODE])
427 			mode = nla_get_u32(tb[TCA_FLOW_MODE]);
428 		if (mode != FLOW_MODE_HASH && nkeys > 1)
429 			goto err2;
430 
431 		if (tb[TCA_FLOW_PERTURB]) {
432 			if (mode != FLOW_MODE_HASH)
433 				goto err2;
434 			perturb_period = nla_get_u32(tb[TCA_FLOW_PERTURB]) * HZ;
435 		}
436 
437 		if (TC_H_MAJ(baseclass) == 0)
438 			baseclass = TC_H_MAKE(tp->q->handle, baseclass);
439 		if (TC_H_MIN(baseclass) == 0)
440 			baseclass = TC_H_MAKE(baseclass, 1);
441 
442 		err = -ENOBUFS;
443 		f = kzalloc(sizeof(*f), GFP_KERNEL);
444 		if (f == NULL)
445 			goto err2;
446 
447 		f->handle = handle;
448 		f->mask	  = ~0U;
449 
450 		get_random_bytes(&f->hashrnd, 4);
451 		f->perturb_timer.function = flow_perturbation;
452 		f->perturb_timer.data = (unsigned long)f;
453 		init_timer_deferrable(&f->perturb_timer);
454 	}
455 
456 	tcf_exts_change(tp, &f->exts, &e);
457 	tcf_em_tree_change(tp, &f->ematches, &t);
458 
459 	tcf_tree_lock(tp);
460 
461 	if (tb[TCA_FLOW_KEYS]) {
462 		f->keymask = keymask;
463 		f->nkeys   = nkeys;
464 	}
465 
466 	f->mode = mode;
467 
468 	if (tb[TCA_FLOW_MASK])
469 		f->mask = nla_get_u32(tb[TCA_FLOW_MASK]);
470 	if (tb[TCA_FLOW_XOR])
471 		f->xor = nla_get_u32(tb[TCA_FLOW_XOR]);
472 	if (tb[TCA_FLOW_RSHIFT])
473 		f->rshift = nla_get_u32(tb[TCA_FLOW_RSHIFT]);
474 	if (tb[TCA_FLOW_ADDEND])
475 		f->addend = nla_get_u32(tb[TCA_FLOW_ADDEND]);
476 
477 	if (tb[TCA_FLOW_DIVISOR])
478 		f->divisor = nla_get_u32(tb[TCA_FLOW_DIVISOR]);
479 	if (baseclass)
480 		f->baseclass = baseclass;
481 
482 	f->perturb_period = perturb_period;
483 	del_timer(&f->perturb_timer);
484 	if (perturb_period)
485 		mod_timer(&f->perturb_timer, jiffies + perturb_period);
486 
487 	if (*arg == 0)
488 		list_add_tail(&f->list, &head->filters);
489 
490 	tcf_tree_unlock(tp);
491 
492 	*arg = (unsigned long)f;
493 	return 0;
494 
495 err2:
496 	tcf_em_tree_destroy(tp, &t);
497 err1:
498 	tcf_exts_destroy(tp, &e);
499 	return err;
500 }
501 
flow_destroy_filter(struct tcf_proto * tp,struct flow_filter * f)502 static void flow_destroy_filter(struct tcf_proto *tp, struct flow_filter *f)
503 {
504 	del_timer_sync(&f->perturb_timer);
505 	tcf_exts_destroy(tp, &f->exts);
506 	tcf_em_tree_destroy(tp, &f->ematches);
507 	kfree(f);
508 }
509 
flow_delete(struct tcf_proto * tp,unsigned long arg)510 static int flow_delete(struct tcf_proto *tp, unsigned long arg)
511 {
512 	struct flow_filter *f = (struct flow_filter *)arg;
513 
514 	tcf_tree_lock(tp);
515 	list_del(&f->list);
516 	tcf_tree_unlock(tp);
517 	flow_destroy_filter(tp, f);
518 	return 0;
519 }
520 
flow_init(struct tcf_proto * tp)521 static int flow_init(struct tcf_proto *tp)
522 {
523 	struct flow_head *head;
524 
525 	head = kzalloc(sizeof(*head), GFP_KERNEL);
526 	if (head == NULL)
527 		return -ENOBUFS;
528 	INIT_LIST_HEAD(&head->filters);
529 	tp->root = head;
530 	return 0;
531 }
532 
flow_destroy(struct tcf_proto * tp)533 static void flow_destroy(struct tcf_proto *tp)
534 {
535 	struct flow_head *head = tp->root;
536 	struct flow_filter *f, *next;
537 
538 	list_for_each_entry_safe(f, next, &head->filters, list) {
539 		list_del(&f->list);
540 		flow_destroy_filter(tp, f);
541 	}
542 	kfree(head);
543 }
544 
flow_get(struct tcf_proto * tp,u32 handle)545 static unsigned long flow_get(struct tcf_proto *tp, u32 handle)
546 {
547 	struct flow_head *head = tp->root;
548 	struct flow_filter *f;
549 
550 	list_for_each_entry(f, &head->filters, list)
551 		if (f->handle == handle)
552 			return (unsigned long)f;
553 	return 0;
554 }
555 
flow_put(struct tcf_proto * tp,unsigned long f)556 static void flow_put(struct tcf_proto *tp, unsigned long f)
557 {
558 }
559 
flow_dump(struct tcf_proto * tp,unsigned long fh,struct sk_buff * skb,struct tcmsg * t)560 static int flow_dump(struct tcf_proto *tp, unsigned long fh,
561 		     struct sk_buff *skb, struct tcmsg *t)
562 {
563 	struct flow_filter *f = (struct flow_filter *)fh;
564 	struct nlattr *nest;
565 
566 	if (f == NULL)
567 		return skb->len;
568 
569 	t->tcm_handle = f->handle;
570 
571 	nest = nla_nest_start(skb, TCA_OPTIONS);
572 	if (nest == NULL)
573 		goto nla_put_failure;
574 
575 	NLA_PUT_U32(skb, TCA_FLOW_KEYS, f->keymask);
576 	NLA_PUT_U32(skb, TCA_FLOW_MODE, f->mode);
577 
578 	if (f->mask != ~0 || f->xor != 0) {
579 		NLA_PUT_U32(skb, TCA_FLOW_MASK, f->mask);
580 		NLA_PUT_U32(skb, TCA_FLOW_XOR, f->xor);
581 	}
582 	if (f->rshift)
583 		NLA_PUT_U32(skb, TCA_FLOW_RSHIFT, f->rshift);
584 	if (f->addend)
585 		NLA_PUT_U32(skb, TCA_FLOW_ADDEND, f->addend);
586 
587 	if (f->divisor)
588 		NLA_PUT_U32(skb, TCA_FLOW_DIVISOR, f->divisor);
589 	if (f->baseclass)
590 		NLA_PUT_U32(skb, TCA_FLOW_BASECLASS, f->baseclass);
591 
592 	if (f->perturb_period)
593 		NLA_PUT_U32(skb, TCA_FLOW_PERTURB, f->perturb_period / HZ);
594 
595 	if (tcf_exts_dump(skb, &f->exts, &flow_ext_map) < 0)
596 		goto nla_put_failure;
597 #ifdef CONFIG_NET_EMATCH
598 	if (f->ematches.hdr.nmatches &&
599 	    tcf_em_tree_dump(skb, &f->ematches, TCA_FLOW_EMATCHES) < 0)
600 		goto nla_put_failure;
601 #endif
602 	nla_nest_end(skb, nest);
603 
604 	if (tcf_exts_dump_stats(skb, &f->exts, &flow_ext_map) < 0)
605 		goto nla_put_failure;
606 
607 	return skb->len;
608 
609 nla_put_failure:
610 	nlmsg_trim(skb, nest);
611 	return -1;
612 }
613 
flow_walk(struct tcf_proto * tp,struct tcf_walker * arg)614 static void flow_walk(struct tcf_proto *tp, struct tcf_walker *arg)
615 {
616 	struct flow_head *head = tp->root;
617 	struct flow_filter *f;
618 
619 	list_for_each_entry(f, &head->filters, list) {
620 		if (arg->count < arg->skip)
621 			goto skip;
622 		if (arg->fn(tp, (unsigned long)f, arg) < 0) {
623 			arg->stop = 1;
624 			break;
625 		}
626 skip:
627 		arg->count++;
628 	}
629 }
630 
631 static struct tcf_proto_ops cls_flow_ops __read_mostly = {
632 	.kind		= "flow",
633 	.classify	= flow_classify,
634 	.init		= flow_init,
635 	.destroy	= flow_destroy,
636 	.change		= flow_change,
637 	.delete		= flow_delete,
638 	.get		= flow_get,
639 	.put		= flow_put,
640 	.dump		= flow_dump,
641 	.walk		= flow_walk,
642 	.owner		= THIS_MODULE,
643 };
644 
cls_flow_init(void)645 static int __init cls_flow_init(void)
646 {
647 	return register_tcf_proto_ops(&cls_flow_ops);
648 }
649 
cls_flow_exit(void)650 static void __exit cls_flow_exit(void)
651 {
652 	unregister_tcf_proto_ops(&cls_flow_ops);
653 }
654 
655 module_init(cls_flow_init);
656 module_exit(cls_flow_exit);
657 
658 MODULE_LICENSE("GPL");
659 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
660 MODULE_DESCRIPTION("TC flow classifier");
661