xref: /openbmc/linux/net/sched/cls_u32.c (revision 62e7ca52)
1 /*
2  * net/sched/cls_u32.c	Ugly (or Universal) 32bit key Packet 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  *	The filters are packed to hash tables of key nodes
12  *	with a set of 32bit key/mask pairs at every node.
13  *	Nodes reference next level hash tables etc.
14  *
15  *	This scheme is the best universal classifier I managed to
16  *	invent; it is not super-fast, but it is not slow (provided you
17  *	program it correctly), and general enough.  And its relative
18  *	speed grows as the number of rules becomes larger.
19  *
20  *	It seems that it represents the best middle point between
21  *	speed and manageability both by human and by machine.
22  *
23  *	It is especially useful for link sharing combined with QoS;
24  *	pure RSVP doesn't need such a general approach and can use
25  *	much simpler (and faster) schemes, sort of cls_rsvp.c.
26  *
27  *	JHS: We should remove the CONFIG_NET_CLS_IND from here
28  *	eventually when the meta match extension is made available
29  *
30  *	nfmark match added by Catalin(ux aka Dino) BOIE <catab at umbrella.ro>
31  */
32 
33 #include <linux/module.h>
34 #include <linux/slab.h>
35 #include <linux/types.h>
36 #include <linux/kernel.h>
37 #include <linux/string.h>
38 #include <linux/errno.h>
39 #include <linux/rtnetlink.h>
40 #include <linux/skbuff.h>
41 #include <linux/bitmap.h>
42 #include <net/netlink.h>
43 #include <net/act_api.h>
44 #include <net/pkt_cls.h>
45 
46 struct tc_u_knode {
47 	struct tc_u_knode	*next;
48 	u32			handle;
49 	struct tc_u_hnode	*ht_up;
50 	struct tcf_exts		exts;
51 #ifdef CONFIG_NET_CLS_IND
52 	int			ifindex;
53 #endif
54 	u8			fshift;
55 	struct tcf_result	res;
56 	struct tc_u_hnode	*ht_down;
57 #ifdef CONFIG_CLS_U32_PERF
58 	struct tc_u32_pcnt	*pf;
59 #endif
60 #ifdef CONFIG_CLS_U32_MARK
61 	struct tc_u32_mark	mark;
62 #endif
63 	struct tc_u32_sel	sel;
64 };
65 
66 struct tc_u_hnode {
67 	struct tc_u_hnode	*next;
68 	u32			handle;
69 	u32			prio;
70 	struct tc_u_common	*tp_c;
71 	int			refcnt;
72 	unsigned int		divisor;
73 	struct tc_u_knode	*ht[1];
74 };
75 
76 struct tc_u_common {
77 	struct tc_u_hnode	*hlist;
78 	struct Qdisc		*q;
79 	int			refcnt;
80 	u32			hgenerator;
81 };
82 
83 static inline unsigned int u32_hash_fold(__be32 key,
84 					 const struct tc_u32_sel *sel,
85 					 u8 fshift)
86 {
87 	unsigned int h = ntohl(key & sel->hmask) >> fshift;
88 
89 	return h;
90 }
91 
92 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res)
93 {
94 	struct {
95 		struct tc_u_knode *knode;
96 		unsigned int	  off;
97 	} stack[TC_U32_MAXDEPTH];
98 
99 	struct tc_u_hnode *ht = tp->root;
100 	unsigned int off = skb_network_offset(skb);
101 	struct tc_u_knode *n;
102 	int sdepth = 0;
103 	int off2 = 0;
104 	int sel = 0;
105 #ifdef CONFIG_CLS_U32_PERF
106 	int j;
107 #endif
108 	int i, r;
109 
110 next_ht:
111 	n = ht->ht[sel];
112 
113 next_knode:
114 	if (n) {
115 		struct tc_u32_key *key = n->sel.keys;
116 
117 #ifdef CONFIG_CLS_U32_PERF
118 		n->pf->rcnt += 1;
119 		j = 0;
120 #endif
121 
122 #ifdef CONFIG_CLS_U32_MARK
123 		if ((skb->mark & n->mark.mask) != n->mark.val) {
124 			n = n->next;
125 			goto next_knode;
126 		} else {
127 			n->mark.success++;
128 		}
129 #endif
130 
131 		for (i = n->sel.nkeys; i > 0; i--, key++) {
132 			int toff = off + key->off + (off2 & key->offmask);
133 			__be32 *data, hdata;
134 
135 			if (skb_headroom(skb) + toff > INT_MAX)
136 				goto out;
137 
138 			data = skb_header_pointer(skb, toff, 4, &hdata);
139 			if (!data)
140 				goto out;
141 			if ((*data ^ key->val) & key->mask) {
142 				n = n->next;
143 				goto next_knode;
144 			}
145 #ifdef CONFIG_CLS_U32_PERF
146 			n->pf->kcnts[j] += 1;
147 			j++;
148 #endif
149 		}
150 		if (n->ht_down == NULL) {
151 check_terminal:
152 			if (n->sel.flags & TC_U32_TERMINAL) {
153 
154 				*res = n->res;
155 #ifdef CONFIG_NET_CLS_IND
156 				if (!tcf_match_indev(skb, n->ifindex)) {
157 					n = n->next;
158 					goto next_knode;
159 				}
160 #endif
161 #ifdef CONFIG_CLS_U32_PERF
162 				n->pf->rhit += 1;
163 #endif
164 				r = tcf_exts_exec(skb, &n->exts, res);
165 				if (r < 0) {
166 					n = n->next;
167 					goto next_knode;
168 				}
169 
170 				return r;
171 			}
172 			n = n->next;
173 			goto next_knode;
174 		}
175 
176 		/* PUSH */
177 		if (sdepth >= TC_U32_MAXDEPTH)
178 			goto deadloop;
179 		stack[sdepth].knode = n;
180 		stack[sdepth].off = off;
181 		sdepth++;
182 
183 		ht = n->ht_down;
184 		sel = 0;
185 		if (ht->divisor) {
186 			__be32 *data, hdata;
187 
188 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
189 						  &hdata);
190 			if (!data)
191 				goto out;
192 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
193 							  n->fshift);
194 		}
195 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
196 			goto next_ht;
197 
198 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
199 			off2 = n->sel.off + 3;
200 			if (n->sel.flags & TC_U32_VAROFFSET) {
201 				__be16 *data, hdata;
202 
203 				data = skb_header_pointer(skb,
204 							  off + n->sel.offoff,
205 							  2, &hdata);
206 				if (!data)
207 					goto out;
208 				off2 += ntohs(n->sel.offmask & *data) >>
209 					n->sel.offshift;
210 			}
211 			off2 &= ~3;
212 		}
213 		if (n->sel.flags & TC_U32_EAT) {
214 			off += off2;
215 			off2 = 0;
216 		}
217 
218 		if (off < skb->len)
219 			goto next_ht;
220 	}
221 
222 	/* POP */
223 	if (sdepth--) {
224 		n = stack[sdepth].knode;
225 		ht = n->ht_up;
226 		off = stack[sdepth].off;
227 		goto check_terminal;
228 	}
229 out:
230 	return -1;
231 
232 deadloop:
233 	net_warn_ratelimited("cls_u32: dead loop\n");
234 	return -1;
235 }
236 
237 static struct tc_u_hnode *
238 u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
239 {
240 	struct tc_u_hnode *ht;
241 
242 	for (ht = tp_c->hlist; ht; ht = ht->next)
243 		if (ht->handle == handle)
244 			break;
245 
246 	return ht;
247 }
248 
249 static struct tc_u_knode *
250 u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
251 {
252 	unsigned int sel;
253 	struct tc_u_knode *n = NULL;
254 
255 	sel = TC_U32_HASH(handle);
256 	if (sel > ht->divisor)
257 		goto out;
258 
259 	for (n = ht->ht[sel]; n; n = n->next)
260 		if (n->handle == handle)
261 			break;
262 out:
263 	return n;
264 }
265 
266 
267 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
268 {
269 	struct tc_u_hnode *ht;
270 	struct tc_u_common *tp_c = tp->data;
271 
272 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
273 		ht = tp->root;
274 	else
275 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
276 
277 	if (!ht)
278 		return 0;
279 
280 	if (TC_U32_KEY(handle) == 0)
281 		return (unsigned long)ht;
282 
283 	return (unsigned long)u32_lookup_key(ht, handle);
284 }
285 
286 static void u32_put(struct tcf_proto *tp, unsigned long f)
287 {
288 }
289 
290 static u32 gen_new_htid(struct tc_u_common *tp_c)
291 {
292 	int i = 0x800;
293 
294 	do {
295 		if (++tp_c->hgenerator == 0x7FF)
296 			tp_c->hgenerator = 1;
297 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
298 
299 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
300 }
301 
302 static int u32_init(struct tcf_proto *tp)
303 {
304 	struct tc_u_hnode *root_ht;
305 	struct tc_u_common *tp_c;
306 
307 	tp_c = tp->q->u32_node;
308 
309 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
310 	if (root_ht == NULL)
311 		return -ENOBUFS;
312 
313 	root_ht->divisor = 0;
314 	root_ht->refcnt++;
315 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
316 	root_ht->prio = tp->prio;
317 
318 	if (tp_c == NULL) {
319 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
320 		if (tp_c == NULL) {
321 			kfree(root_ht);
322 			return -ENOBUFS;
323 		}
324 		tp_c->q = tp->q;
325 		tp->q->u32_node = tp_c;
326 	}
327 
328 	tp_c->refcnt++;
329 	root_ht->next = tp_c->hlist;
330 	tp_c->hlist = root_ht;
331 	root_ht->tp_c = tp_c;
332 
333 	tp->root = root_ht;
334 	tp->data = tp_c;
335 	return 0;
336 }
337 
338 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n)
339 {
340 	tcf_unbind_filter(tp, &n->res);
341 	tcf_exts_destroy(tp, &n->exts);
342 	if (n->ht_down)
343 		n->ht_down->refcnt--;
344 #ifdef CONFIG_CLS_U32_PERF
345 	kfree(n->pf);
346 #endif
347 	kfree(n);
348 	return 0;
349 }
350 
351 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
352 {
353 	struct tc_u_knode **kp;
354 	struct tc_u_hnode *ht = key->ht_up;
355 
356 	if (ht) {
357 		for (kp = &ht->ht[TC_U32_HASH(key->handle)]; *kp; kp = &(*kp)->next) {
358 			if (*kp == key) {
359 				tcf_tree_lock(tp);
360 				*kp = key->next;
361 				tcf_tree_unlock(tp);
362 
363 				u32_destroy_key(tp, key);
364 				return 0;
365 			}
366 		}
367 	}
368 	WARN_ON(1);
369 	return 0;
370 }
371 
372 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
373 {
374 	struct tc_u_knode *n;
375 	unsigned int h;
376 
377 	for (h = 0; h <= ht->divisor; h++) {
378 		while ((n = ht->ht[h]) != NULL) {
379 			ht->ht[h] = n->next;
380 
381 			u32_destroy_key(tp, n);
382 		}
383 	}
384 }
385 
386 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
387 {
388 	struct tc_u_common *tp_c = tp->data;
389 	struct tc_u_hnode **hn;
390 
391 	WARN_ON(ht->refcnt);
392 
393 	u32_clear_hnode(tp, ht);
394 
395 	for (hn = &tp_c->hlist; *hn; hn = &(*hn)->next) {
396 		if (*hn == ht) {
397 			*hn = ht->next;
398 			kfree(ht);
399 			return 0;
400 		}
401 	}
402 
403 	WARN_ON(1);
404 	return -ENOENT;
405 }
406 
407 static void u32_destroy(struct tcf_proto *tp)
408 {
409 	struct tc_u_common *tp_c = tp->data;
410 	struct tc_u_hnode *root_ht = tp->root;
411 
412 	WARN_ON(root_ht == NULL);
413 
414 	if (root_ht && --root_ht->refcnt == 0)
415 		u32_destroy_hnode(tp, root_ht);
416 
417 	if (--tp_c->refcnt == 0) {
418 		struct tc_u_hnode *ht;
419 
420 		tp->q->u32_node = NULL;
421 
422 		for (ht = tp_c->hlist; ht; ht = ht->next) {
423 			ht->refcnt--;
424 			u32_clear_hnode(tp, ht);
425 		}
426 
427 		while ((ht = tp_c->hlist) != NULL) {
428 			tp_c->hlist = ht->next;
429 
430 			WARN_ON(ht->refcnt != 0);
431 
432 			kfree(ht);
433 		}
434 
435 		kfree(tp_c);
436 	}
437 
438 	tp->data = NULL;
439 }
440 
441 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
442 {
443 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
444 
445 	if (ht == NULL)
446 		return 0;
447 
448 	if (TC_U32_KEY(ht->handle))
449 		return u32_delete_key(tp, (struct tc_u_knode *)ht);
450 
451 	if (tp->root == ht)
452 		return -EINVAL;
453 
454 	if (ht->refcnt == 1) {
455 		ht->refcnt--;
456 		u32_destroy_hnode(tp, ht);
457 	} else {
458 		return -EBUSY;
459 	}
460 
461 	return 0;
462 }
463 
464 #define NR_U32_NODE (1<<12)
465 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
466 {
467 	struct tc_u_knode *n;
468 	unsigned long i;
469 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
470 					GFP_KERNEL);
471 	if (!bitmap)
472 		return handle | 0xFFF;
473 
474 	for (n = ht->ht[TC_U32_HASH(handle)]; n; n = n->next)
475 		set_bit(TC_U32_NODE(n->handle), bitmap);
476 
477 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
478 	if (i >= NR_U32_NODE)
479 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
480 
481 	kfree(bitmap);
482 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
483 }
484 
485 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
486 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
487 	[TCA_U32_HASH]		= { .type = NLA_U32 },
488 	[TCA_U32_LINK]		= { .type = NLA_U32 },
489 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
490 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
491 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
492 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
493 };
494 
495 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
496 			 unsigned long base, struct tc_u_hnode *ht,
497 			 struct tc_u_knode *n, struct nlattr **tb,
498 			 struct nlattr *est, bool ovr)
499 {
500 	int err;
501 	struct tcf_exts e;
502 
503 	tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
504 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
505 	if (err < 0)
506 		return err;
507 
508 	err = -EINVAL;
509 	if (tb[TCA_U32_LINK]) {
510 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
511 		struct tc_u_hnode *ht_down = NULL, *ht_old;
512 
513 		if (TC_U32_KEY(handle))
514 			goto errout;
515 
516 		if (handle) {
517 			ht_down = u32_lookup_ht(ht->tp_c, handle);
518 
519 			if (ht_down == NULL)
520 				goto errout;
521 			ht_down->refcnt++;
522 		}
523 
524 		tcf_tree_lock(tp);
525 		ht_old = n->ht_down;
526 		n->ht_down = ht_down;
527 		tcf_tree_unlock(tp);
528 
529 		if (ht_old)
530 			ht_old->refcnt--;
531 	}
532 	if (tb[TCA_U32_CLASSID]) {
533 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
534 		tcf_bind_filter(tp, &n->res, base);
535 	}
536 
537 #ifdef CONFIG_NET_CLS_IND
538 	if (tb[TCA_U32_INDEV]) {
539 		int ret;
540 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
541 		if (ret < 0)
542 			goto errout;
543 		n->ifindex = ret;
544 	}
545 #endif
546 	tcf_exts_change(tp, &n->exts, &e);
547 
548 	return 0;
549 errout:
550 	tcf_exts_destroy(tp, &e);
551 	return err;
552 }
553 
554 static int u32_change(struct net *net, struct sk_buff *in_skb,
555 		      struct tcf_proto *tp, unsigned long base, u32 handle,
556 		      struct nlattr **tca,
557 		      unsigned long *arg, bool ovr)
558 {
559 	struct tc_u_common *tp_c = tp->data;
560 	struct tc_u_hnode *ht;
561 	struct tc_u_knode *n;
562 	struct tc_u32_sel *s;
563 	struct nlattr *opt = tca[TCA_OPTIONS];
564 	struct nlattr *tb[TCA_U32_MAX + 1];
565 	u32 htid;
566 	int err;
567 
568 	if (opt == NULL)
569 		return handle ? -EINVAL : 0;
570 
571 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
572 	if (err < 0)
573 		return err;
574 
575 	n = (struct tc_u_knode *)*arg;
576 	if (n) {
577 		if (TC_U32_KEY(n->handle) == 0)
578 			return -EINVAL;
579 
580 		return u32_set_parms(net, tp, base, n->ht_up, n, tb,
581 				     tca[TCA_RATE], ovr);
582 	}
583 
584 	if (tb[TCA_U32_DIVISOR]) {
585 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
586 
587 		if (--divisor > 0x100)
588 			return -EINVAL;
589 		if (TC_U32_KEY(handle))
590 			return -EINVAL;
591 		if (handle == 0) {
592 			handle = gen_new_htid(tp->data);
593 			if (handle == 0)
594 				return -ENOMEM;
595 		}
596 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
597 		if (ht == NULL)
598 			return -ENOBUFS;
599 		ht->tp_c = tp_c;
600 		ht->refcnt = 1;
601 		ht->divisor = divisor;
602 		ht->handle = handle;
603 		ht->prio = tp->prio;
604 		ht->next = tp_c->hlist;
605 		tp_c->hlist = ht;
606 		*arg = (unsigned long)ht;
607 		return 0;
608 	}
609 
610 	if (tb[TCA_U32_HASH]) {
611 		htid = nla_get_u32(tb[TCA_U32_HASH]);
612 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
613 			ht = tp->root;
614 			htid = ht->handle;
615 		} else {
616 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
617 			if (ht == NULL)
618 				return -EINVAL;
619 		}
620 	} else {
621 		ht = tp->root;
622 		htid = ht->handle;
623 	}
624 
625 	if (ht->divisor < TC_U32_HASH(htid))
626 		return -EINVAL;
627 
628 	if (handle) {
629 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
630 			return -EINVAL;
631 		handle = htid | TC_U32_NODE(handle);
632 	} else
633 		handle = gen_new_kid(ht, htid);
634 
635 	if (tb[TCA_U32_SEL] == NULL)
636 		return -EINVAL;
637 
638 	s = nla_data(tb[TCA_U32_SEL]);
639 
640 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
641 	if (n == NULL)
642 		return -ENOBUFS;
643 
644 #ifdef CONFIG_CLS_U32_PERF
645 	n->pf = kzalloc(sizeof(struct tc_u32_pcnt) + s->nkeys*sizeof(u64), GFP_KERNEL);
646 	if (n->pf == NULL) {
647 		kfree(n);
648 		return -ENOBUFS;
649 	}
650 #endif
651 
652 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
653 	n->ht_up = ht;
654 	n->handle = handle;
655 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
656 	tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
657 
658 #ifdef CONFIG_CLS_U32_MARK
659 	if (tb[TCA_U32_MARK]) {
660 		struct tc_u32_mark *mark;
661 
662 		mark = nla_data(tb[TCA_U32_MARK]);
663 		memcpy(&n->mark, mark, sizeof(struct tc_u32_mark));
664 		n->mark.success = 0;
665 	}
666 #endif
667 
668 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
669 	if (err == 0) {
670 		struct tc_u_knode **ins;
671 		for (ins = &ht->ht[TC_U32_HASH(handle)]; *ins; ins = &(*ins)->next)
672 			if (TC_U32_NODE(handle) < TC_U32_NODE((*ins)->handle))
673 				break;
674 
675 		n->next = *ins;
676 		tcf_tree_lock(tp);
677 		*ins = n;
678 		tcf_tree_unlock(tp);
679 
680 		*arg = (unsigned long)n;
681 		return 0;
682 	}
683 #ifdef CONFIG_CLS_U32_PERF
684 	kfree(n->pf);
685 #endif
686 	kfree(n);
687 	return err;
688 }
689 
690 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
691 {
692 	struct tc_u_common *tp_c = tp->data;
693 	struct tc_u_hnode *ht;
694 	struct tc_u_knode *n;
695 	unsigned int h;
696 
697 	if (arg->stop)
698 		return;
699 
700 	for (ht = tp_c->hlist; ht; ht = ht->next) {
701 		if (ht->prio != tp->prio)
702 			continue;
703 		if (arg->count >= arg->skip) {
704 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
705 				arg->stop = 1;
706 				return;
707 			}
708 		}
709 		arg->count++;
710 		for (h = 0; h <= ht->divisor; h++) {
711 			for (n = ht->ht[h]; n; n = n->next) {
712 				if (arg->count < arg->skip) {
713 					arg->count++;
714 					continue;
715 				}
716 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
717 					arg->stop = 1;
718 					return;
719 				}
720 				arg->count++;
721 			}
722 		}
723 	}
724 }
725 
726 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
727 		     struct sk_buff *skb, struct tcmsg *t)
728 {
729 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
730 	struct nlattr *nest;
731 
732 	if (n == NULL)
733 		return skb->len;
734 
735 	t->tcm_handle = n->handle;
736 
737 	nest = nla_nest_start(skb, TCA_OPTIONS);
738 	if (nest == NULL)
739 		goto nla_put_failure;
740 
741 	if (TC_U32_KEY(n->handle) == 0) {
742 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
743 		u32 divisor = ht->divisor + 1;
744 
745 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
746 			goto nla_put_failure;
747 	} else {
748 		if (nla_put(skb, TCA_U32_SEL,
749 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
750 			    &n->sel))
751 			goto nla_put_failure;
752 		if (n->ht_up) {
753 			u32 htid = n->handle & 0xFFFFF000;
754 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
755 				goto nla_put_failure;
756 		}
757 		if (n->res.classid &&
758 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
759 			goto nla_put_failure;
760 		if (n->ht_down &&
761 		    nla_put_u32(skb, TCA_U32_LINK, n->ht_down->handle))
762 			goto nla_put_failure;
763 
764 #ifdef CONFIG_CLS_U32_MARK
765 		if ((n->mark.val || n->mark.mask) &&
766 		    nla_put(skb, TCA_U32_MARK, sizeof(n->mark), &n->mark))
767 			goto nla_put_failure;
768 #endif
769 
770 		if (tcf_exts_dump(skb, &n->exts) < 0)
771 			goto nla_put_failure;
772 
773 #ifdef CONFIG_NET_CLS_IND
774 		if (n->ifindex) {
775 			struct net_device *dev;
776 			dev = __dev_get_by_index(net, n->ifindex);
777 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
778 				goto nla_put_failure;
779 		}
780 #endif
781 #ifdef CONFIG_CLS_U32_PERF
782 		if (nla_put(skb, TCA_U32_PCNT,
783 			    sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
784 			    n->pf))
785 			goto nla_put_failure;
786 #endif
787 	}
788 
789 	nla_nest_end(skb, nest);
790 
791 	if (TC_U32_KEY(n->handle))
792 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
793 			goto nla_put_failure;
794 	return skb->len;
795 
796 nla_put_failure:
797 	nla_nest_cancel(skb, nest);
798 	return -1;
799 }
800 
801 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
802 	.kind		=	"u32",
803 	.classify	=	u32_classify,
804 	.init		=	u32_init,
805 	.destroy	=	u32_destroy,
806 	.get		=	u32_get,
807 	.put		=	u32_put,
808 	.change		=	u32_change,
809 	.delete		=	u32_delete,
810 	.walk		=	u32_walk,
811 	.dump		=	u32_dump,
812 	.owner		=	THIS_MODULE,
813 };
814 
815 static int __init init_u32(void)
816 {
817 	pr_info("u32 classifier\n");
818 #ifdef CONFIG_CLS_U32_PERF
819 	pr_info("    Performance counters on\n");
820 #endif
821 #ifdef CONFIG_NET_CLS_IND
822 	pr_info("    input device check on\n");
823 #endif
824 #ifdef CONFIG_NET_CLS_ACT
825 	pr_info("    Actions configured\n");
826 #endif
827 	return register_tcf_proto_ops(&cls_u32_ops);
828 }
829 
830 static void __exit exit_u32(void)
831 {
832 	unregister_tcf_proto_ops(&cls_u32_ops);
833 }
834 
835 module_init(init_u32)
836 module_exit(exit_u32)
837 MODULE_LICENSE("GPL");
838