xref: /linux/net/sched/cls_u32.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 <net/netlink.h>
42 #include <net/act_api.h>
43 #include <net/pkt_cls.h>
44 
45 struct tc_u_knode {
46 	struct tc_u_knode	*next;
47 	u32			handle;
48 	struct tc_u_hnode	*ht_up;
49 	struct tcf_exts		exts;
50 #ifdef CONFIG_NET_CLS_IND
51 	char                     indev[IFNAMSIZ];
52 #endif
53 	u8			fshift;
54 	struct tcf_result	res;
55 	struct tc_u_hnode	*ht_down;
56 #ifdef CONFIG_CLS_U32_PERF
57 	struct tc_u32_pcnt	*pf;
58 #endif
59 #ifdef CONFIG_CLS_U32_MARK
60 	struct tc_u32_mark	mark;
61 #endif
62 	struct tc_u32_sel	sel;
63 };
64 
65 struct tc_u_hnode {
66 	struct tc_u_hnode	*next;
67 	u32			handle;
68 	u32			prio;
69 	struct tc_u_common	*tp_c;
70 	int			refcnt;
71 	unsigned int		divisor;
72 	struct tc_u_knode	*ht[1];
73 };
74 
75 struct tc_u_common {
76 	struct tc_u_hnode	*hlist;
77 	struct Qdisc		*q;
78 	int			refcnt;
79 	u32			hgenerator;
80 };
81 
82 static const struct tcf_ext_map u32_ext_map = {
83 	.action = TCA_U32_ACT,
84 	.police = TCA_U32_POLICE
85 };
86 
87 static inline unsigned int u32_hash_fold(__be32 key,
88 					 const struct tc_u32_sel *sel,
89 					 u8 fshift)
90 {
91 	unsigned int h = ntohl(key & sel->hmask) >> fshift;
92 
93 	return h;
94 }
95 
96 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res)
97 {
98 	struct {
99 		struct tc_u_knode *knode;
100 		unsigned int	  off;
101 	} stack[TC_U32_MAXDEPTH];
102 
103 	struct tc_u_hnode *ht = (struct tc_u_hnode *)tp->root;
104 	unsigned int off = skb_network_offset(skb);
105 	struct tc_u_knode *n;
106 	int sdepth = 0;
107 	int off2 = 0;
108 	int sel = 0;
109 #ifdef CONFIG_CLS_U32_PERF
110 	int j;
111 #endif
112 	int i, r;
113 
114 next_ht:
115 	n = ht->ht[sel];
116 
117 next_knode:
118 	if (n) {
119 		struct tc_u32_key *key = n->sel.keys;
120 
121 #ifdef CONFIG_CLS_U32_PERF
122 		n->pf->rcnt += 1;
123 		j = 0;
124 #endif
125 
126 #ifdef CONFIG_CLS_U32_MARK
127 		if ((skb->mark & n->mark.mask) != n->mark.val) {
128 			n = n->next;
129 			goto next_knode;
130 		} else {
131 			n->mark.success++;
132 		}
133 #endif
134 
135 		for (i = n->sel.nkeys; i > 0; i--, key++) {
136 			int toff = off + key->off + (off2 & key->offmask);
137 			__be32 *data, hdata;
138 
139 			if (skb_headroom(skb) + toff > INT_MAX)
140 				goto out;
141 
142 			data = skb_header_pointer(skb, toff, 4, &hdata);
143 			if (!data)
144 				goto out;
145 			if ((*data ^ key->val) & key->mask) {
146 				n = n->next;
147 				goto next_knode;
148 			}
149 #ifdef CONFIG_CLS_U32_PERF
150 			n->pf->kcnts[j] += 1;
151 			j++;
152 #endif
153 		}
154 		if (n->ht_down == NULL) {
155 check_terminal:
156 			if (n->sel.flags & TC_U32_TERMINAL) {
157 
158 				*res = n->res;
159 #ifdef CONFIG_NET_CLS_IND
160 				if (!tcf_match_indev(skb, n->indev)) {
161 					n = n->next;
162 					goto next_knode;
163 				}
164 #endif
165 #ifdef CONFIG_CLS_U32_PERF
166 				n->pf->rhit += 1;
167 #endif
168 				r = tcf_exts_exec(skb, &n->exts, res);
169 				if (r < 0) {
170 					n = n->next;
171 					goto next_knode;
172 				}
173 
174 				return r;
175 			}
176 			n = n->next;
177 			goto next_knode;
178 		}
179 
180 		/* PUSH */
181 		if (sdepth >= TC_U32_MAXDEPTH)
182 			goto deadloop;
183 		stack[sdepth].knode = n;
184 		stack[sdepth].off = off;
185 		sdepth++;
186 
187 		ht = n->ht_down;
188 		sel = 0;
189 		if (ht->divisor) {
190 			__be32 *data, hdata;
191 
192 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
193 						  &hdata);
194 			if (!data)
195 				goto out;
196 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
197 							  n->fshift);
198 		}
199 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
200 			goto next_ht;
201 
202 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
203 			off2 = n->sel.off + 3;
204 			if (n->sel.flags & TC_U32_VAROFFSET) {
205 				__be16 *data, hdata;
206 
207 				data = skb_header_pointer(skb,
208 							  off + n->sel.offoff,
209 							  2, &hdata);
210 				if (!data)
211 					goto out;
212 				off2 += ntohs(n->sel.offmask & *data) >>
213 					n->sel.offshift;
214 			}
215 			off2 &= ~3;
216 		}
217 		if (n->sel.flags & TC_U32_EAT) {
218 			off += off2;
219 			off2 = 0;
220 		}
221 
222 		if (off < skb->len)
223 			goto next_ht;
224 	}
225 
226 	/* POP */
227 	if (sdepth--) {
228 		n = stack[sdepth].knode;
229 		ht = n->ht_up;
230 		off = stack[sdepth].off;
231 		goto check_terminal;
232 	}
233 out:
234 	return -1;
235 
236 deadloop:
237 	net_warn_ratelimited("cls_u32: dead loop\n");
238 	return -1;
239 }
240 
241 static struct tc_u_hnode *
242 u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
243 {
244 	struct tc_u_hnode *ht;
245 
246 	for (ht = tp_c->hlist; ht; ht = ht->next)
247 		if (ht->handle == handle)
248 			break;
249 
250 	return ht;
251 }
252 
253 static struct tc_u_knode *
254 u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
255 {
256 	unsigned int sel;
257 	struct tc_u_knode *n = NULL;
258 
259 	sel = TC_U32_HASH(handle);
260 	if (sel > ht->divisor)
261 		goto out;
262 
263 	for (n = ht->ht[sel]; n; n = n->next)
264 		if (n->handle == handle)
265 			break;
266 out:
267 	return n;
268 }
269 
270 
271 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
272 {
273 	struct tc_u_hnode *ht;
274 	struct tc_u_common *tp_c = tp->data;
275 
276 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
277 		ht = tp->root;
278 	else
279 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
280 
281 	if (!ht)
282 		return 0;
283 
284 	if (TC_U32_KEY(handle) == 0)
285 		return (unsigned long)ht;
286 
287 	return (unsigned long)u32_lookup_key(ht, handle);
288 }
289 
290 static void u32_put(struct tcf_proto *tp, unsigned long f)
291 {
292 }
293 
294 static u32 gen_new_htid(struct tc_u_common *tp_c)
295 {
296 	int i = 0x800;
297 
298 	do {
299 		if (++tp_c->hgenerator == 0x7FF)
300 			tp_c->hgenerator = 1;
301 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
302 
303 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
304 }
305 
306 static int u32_init(struct tcf_proto *tp)
307 {
308 	struct tc_u_hnode *root_ht;
309 	struct tc_u_common *tp_c;
310 
311 	tp_c = tp->q->u32_node;
312 
313 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
314 	if (root_ht == NULL)
315 		return -ENOBUFS;
316 
317 	root_ht->divisor = 0;
318 	root_ht->refcnt++;
319 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
320 	root_ht->prio = tp->prio;
321 
322 	if (tp_c == NULL) {
323 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
324 		if (tp_c == NULL) {
325 			kfree(root_ht);
326 			return -ENOBUFS;
327 		}
328 		tp_c->q = tp->q;
329 		tp->q->u32_node = tp_c;
330 	}
331 
332 	tp_c->refcnt++;
333 	root_ht->next = tp_c->hlist;
334 	tp_c->hlist = root_ht;
335 	root_ht->tp_c = tp_c;
336 
337 	tp->root = root_ht;
338 	tp->data = tp_c;
339 	return 0;
340 }
341 
342 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n)
343 {
344 	tcf_unbind_filter(tp, &n->res);
345 	tcf_exts_destroy(tp, &n->exts);
346 	if (n->ht_down)
347 		n->ht_down->refcnt--;
348 #ifdef CONFIG_CLS_U32_PERF
349 	kfree(n->pf);
350 #endif
351 	kfree(n);
352 	return 0;
353 }
354 
355 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode* key)
356 {
357 	struct tc_u_knode **kp;
358 	struct tc_u_hnode *ht = key->ht_up;
359 
360 	if (ht) {
361 		for (kp = &ht->ht[TC_U32_HASH(key->handle)]; *kp; kp = &(*kp)->next) {
362 			if (*kp == key) {
363 				tcf_tree_lock(tp);
364 				*kp = key->next;
365 				tcf_tree_unlock(tp);
366 
367 				u32_destroy_key(tp, key);
368 				return 0;
369 			}
370 		}
371 	}
372 	WARN_ON(1);
373 	return 0;
374 }
375 
376 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
377 {
378 	struct tc_u_knode *n;
379 	unsigned int h;
380 
381 	for (h = 0; h <= ht->divisor; h++) {
382 		while ((n = ht->ht[h]) != NULL) {
383 			ht->ht[h] = n->next;
384 
385 			u32_destroy_key(tp, n);
386 		}
387 	}
388 }
389 
390 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
391 {
392 	struct tc_u_common *tp_c = tp->data;
393 	struct tc_u_hnode **hn;
394 
395 	WARN_ON(ht->refcnt);
396 
397 	u32_clear_hnode(tp, ht);
398 
399 	for (hn = &tp_c->hlist; *hn; hn = &(*hn)->next) {
400 		if (*hn == ht) {
401 			*hn = ht->next;
402 			kfree(ht);
403 			return 0;
404 		}
405 	}
406 
407 	WARN_ON(1);
408 	return -ENOENT;
409 }
410 
411 static void u32_destroy(struct tcf_proto *tp)
412 {
413 	struct tc_u_common *tp_c = tp->data;
414 	struct tc_u_hnode *root_ht = tp->root;
415 
416 	WARN_ON(root_ht == NULL);
417 
418 	if (root_ht && --root_ht->refcnt == 0)
419 		u32_destroy_hnode(tp, root_ht);
420 
421 	if (--tp_c->refcnt == 0) {
422 		struct tc_u_hnode *ht;
423 
424 		tp->q->u32_node = NULL;
425 
426 		for (ht = tp_c->hlist; ht; ht = ht->next) {
427 			ht->refcnt--;
428 			u32_clear_hnode(tp, ht);
429 		}
430 
431 		while ((ht = tp_c->hlist) != NULL) {
432 			tp_c->hlist = ht->next;
433 
434 			WARN_ON(ht->refcnt != 0);
435 
436 			kfree(ht);
437 		}
438 
439 		kfree(tp_c);
440 	}
441 
442 	tp->data = NULL;
443 }
444 
445 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
446 {
447 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
448 
449 	if (ht == NULL)
450 		return 0;
451 
452 	if (TC_U32_KEY(ht->handle))
453 		return u32_delete_key(tp, (struct tc_u_knode *)ht);
454 
455 	if (tp->root == ht)
456 		return -EINVAL;
457 
458 	if (ht->refcnt == 1) {
459 		ht->refcnt--;
460 		u32_destroy_hnode(tp, ht);
461 	} else {
462 		return -EBUSY;
463 	}
464 
465 	return 0;
466 }
467 
468 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
469 {
470 	struct tc_u_knode *n;
471 	unsigned int i = 0x7FF;
472 
473 	for (n = ht->ht[TC_U32_HASH(handle)]; n; n = n->next)
474 		if (i < TC_U32_NODE(n->handle))
475 			i = TC_U32_NODE(n->handle);
476 	i++;
477 
478 	return handle | (i > 0xFFF ? 0xFFF : i);
479 }
480 
481 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
482 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
483 	[TCA_U32_HASH]		= { .type = NLA_U32 },
484 	[TCA_U32_LINK]		= { .type = NLA_U32 },
485 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
486 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
487 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
488 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
489 };
490 
491 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
492 			 unsigned long base, struct tc_u_hnode *ht,
493 			 struct tc_u_knode *n, struct nlattr **tb,
494 			 struct nlattr *est)
495 {
496 	int err;
497 	struct tcf_exts e;
498 
499 	err = tcf_exts_validate(net, tp, tb, est, &e, &u32_ext_map);
500 	if (err < 0)
501 		return err;
502 
503 	err = -EINVAL;
504 	if (tb[TCA_U32_LINK]) {
505 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
506 		struct tc_u_hnode *ht_down = NULL, *ht_old;
507 
508 		if (TC_U32_KEY(handle))
509 			goto errout;
510 
511 		if (handle) {
512 			ht_down = u32_lookup_ht(ht->tp_c, handle);
513 
514 			if (ht_down == NULL)
515 				goto errout;
516 			ht_down->refcnt++;
517 		}
518 
519 		tcf_tree_lock(tp);
520 		ht_old = n->ht_down;
521 		n->ht_down = ht_down;
522 		tcf_tree_unlock(tp);
523 
524 		if (ht_old)
525 			ht_old->refcnt--;
526 	}
527 	if (tb[TCA_U32_CLASSID]) {
528 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
529 		tcf_bind_filter(tp, &n->res, base);
530 	}
531 
532 #ifdef CONFIG_NET_CLS_IND
533 	if (tb[TCA_U32_INDEV]) {
534 		err = tcf_change_indev(tp, n->indev, tb[TCA_U32_INDEV]);
535 		if (err < 0)
536 			goto errout;
537 	}
538 #endif
539 	tcf_exts_change(tp, &n->exts, &e);
540 
541 	return 0;
542 errout:
543 	tcf_exts_destroy(tp, &e);
544 	return err;
545 }
546 
547 static int u32_change(struct net *net, struct sk_buff *in_skb,
548 		      struct tcf_proto *tp, unsigned long base, u32 handle,
549 		      struct nlattr **tca,
550 		      unsigned long *arg)
551 {
552 	struct tc_u_common *tp_c = tp->data;
553 	struct tc_u_hnode *ht;
554 	struct tc_u_knode *n;
555 	struct tc_u32_sel *s;
556 	struct nlattr *opt = tca[TCA_OPTIONS];
557 	struct nlattr *tb[TCA_U32_MAX + 1];
558 	u32 htid;
559 	int err;
560 
561 	if (opt == NULL)
562 		return handle ? -EINVAL : 0;
563 
564 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
565 	if (err < 0)
566 		return err;
567 
568 	n = (struct tc_u_knode *)*arg;
569 	if (n) {
570 		if (TC_U32_KEY(n->handle) == 0)
571 			return -EINVAL;
572 
573 		return u32_set_parms(net, tp, base, n->ht_up, n, tb,
574 				     tca[TCA_RATE]);
575 	}
576 
577 	if (tb[TCA_U32_DIVISOR]) {
578 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
579 
580 		if (--divisor > 0x100)
581 			return -EINVAL;
582 		if (TC_U32_KEY(handle))
583 			return -EINVAL;
584 		if (handle == 0) {
585 			handle = gen_new_htid(tp->data);
586 			if (handle == 0)
587 				return -ENOMEM;
588 		}
589 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
590 		if (ht == NULL)
591 			return -ENOBUFS;
592 		ht->tp_c = tp_c;
593 		ht->refcnt = 1;
594 		ht->divisor = divisor;
595 		ht->handle = handle;
596 		ht->prio = tp->prio;
597 		ht->next = tp_c->hlist;
598 		tp_c->hlist = ht;
599 		*arg = (unsigned long)ht;
600 		return 0;
601 	}
602 
603 	if (tb[TCA_U32_HASH]) {
604 		htid = nla_get_u32(tb[TCA_U32_HASH]);
605 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
606 			ht = tp->root;
607 			htid = ht->handle;
608 		} else {
609 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
610 			if (ht == NULL)
611 				return -EINVAL;
612 		}
613 	} else {
614 		ht = tp->root;
615 		htid = ht->handle;
616 	}
617 
618 	if (ht->divisor < TC_U32_HASH(htid))
619 		return -EINVAL;
620 
621 	if (handle) {
622 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
623 			return -EINVAL;
624 		handle = htid | TC_U32_NODE(handle);
625 	} else
626 		handle = gen_new_kid(ht, htid);
627 
628 	if (tb[TCA_U32_SEL] == NULL)
629 		return -EINVAL;
630 
631 	s = nla_data(tb[TCA_U32_SEL]);
632 
633 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
634 	if (n == NULL)
635 		return -ENOBUFS;
636 
637 #ifdef CONFIG_CLS_U32_PERF
638 	n->pf = kzalloc(sizeof(struct tc_u32_pcnt) + s->nkeys*sizeof(u64), GFP_KERNEL);
639 	if (n->pf == NULL) {
640 		kfree(n);
641 		return -ENOBUFS;
642 	}
643 #endif
644 
645 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
646 	n->ht_up = ht;
647 	n->handle = handle;
648 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
649 
650 #ifdef CONFIG_CLS_U32_MARK
651 	if (tb[TCA_U32_MARK]) {
652 		struct tc_u32_mark *mark;
653 
654 		mark = nla_data(tb[TCA_U32_MARK]);
655 		memcpy(&n->mark, mark, sizeof(struct tc_u32_mark));
656 		n->mark.success = 0;
657 	}
658 #endif
659 
660 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE]);
661 	if (err == 0) {
662 		struct tc_u_knode **ins;
663 		for (ins = &ht->ht[TC_U32_HASH(handle)]; *ins; ins = &(*ins)->next)
664 			if (TC_U32_NODE(handle) < TC_U32_NODE((*ins)->handle))
665 				break;
666 
667 		n->next = *ins;
668 		tcf_tree_lock(tp);
669 		*ins = n;
670 		tcf_tree_unlock(tp);
671 
672 		*arg = (unsigned long)n;
673 		return 0;
674 	}
675 #ifdef CONFIG_CLS_U32_PERF
676 	kfree(n->pf);
677 #endif
678 	kfree(n);
679 	return err;
680 }
681 
682 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
683 {
684 	struct tc_u_common *tp_c = tp->data;
685 	struct tc_u_hnode *ht;
686 	struct tc_u_knode *n;
687 	unsigned int h;
688 
689 	if (arg->stop)
690 		return;
691 
692 	for (ht = tp_c->hlist; ht; ht = ht->next) {
693 		if (ht->prio != tp->prio)
694 			continue;
695 		if (arg->count >= arg->skip) {
696 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
697 				arg->stop = 1;
698 				return;
699 			}
700 		}
701 		arg->count++;
702 		for (h = 0; h <= ht->divisor; h++) {
703 			for (n = ht->ht[h]; n; n = n->next) {
704 				if (arg->count < arg->skip) {
705 					arg->count++;
706 					continue;
707 				}
708 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
709 					arg->stop = 1;
710 					return;
711 				}
712 				arg->count++;
713 			}
714 		}
715 	}
716 }
717 
718 static int u32_dump(struct tcf_proto *tp, unsigned long fh,
719 		     struct sk_buff *skb, struct tcmsg *t)
720 {
721 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
722 	struct nlattr *nest;
723 
724 	if (n == NULL)
725 		return skb->len;
726 
727 	t->tcm_handle = n->handle;
728 
729 	nest = nla_nest_start(skb, TCA_OPTIONS);
730 	if (nest == NULL)
731 		goto nla_put_failure;
732 
733 	if (TC_U32_KEY(n->handle) == 0) {
734 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
735 		u32 divisor = ht->divisor + 1;
736 
737 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
738 			goto nla_put_failure;
739 	} else {
740 		if (nla_put(skb, TCA_U32_SEL,
741 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
742 			    &n->sel))
743 			goto nla_put_failure;
744 		if (n->ht_up) {
745 			u32 htid = n->handle & 0xFFFFF000;
746 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
747 				goto nla_put_failure;
748 		}
749 		if (n->res.classid &&
750 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
751 			goto nla_put_failure;
752 		if (n->ht_down &&
753 		    nla_put_u32(skb, TCA_U32_LINK, n->ht_down->handle))
754 			goto nla_put_failure;
755 
756 #ifdef CONFIG_CLS_U32_MARK
757 		if ((n->mark.val || n->mark.mask) &&
758 		    nla_put(skb, TCA_U32_MARK, sizeof(n->mark), &n->mark))
759 			goto nla_put_failure;
760 #endif
761 
762 		if (tcf_exts_dump(skb, &n->exts, &u32_ext_map) < 0)
763 			goto nla_put_failure;
764 
765 #ifdef CONFIG_NET_CLS_IND
766 		if (strlen(n->indev) &&
767 		    nla_put_string(skb, TCA_U32_INDEV, n->indev))
768 			goto nla_put_failure;
769 #endif
770 #ifdef CONFIG_CLS_U32_PERF
771 		if (nla_put(skb, TCA_U32_PCNT,
772 			    sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
773 			    n->pf))
774 			goto nla_put_failure;
775 #endif
776 	}
777 
778 	nla_nest_end(skb, nest);
779 
780 	if (TC_U32_KEY(n->handle))
781 		if (tcf_exts_dump_stats(skb, &n->exts, &u32_ext_map) < 0)
782 			goto nla_put_failure;
783 	return skb->len;
784 
785 nla_put_failure:
786 	nla_nest_cancel(skb, nest);
787 	return -1;
788 }
789 
790 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
791 	.kind		=	"u32",
792 	.classify	=	u32_classify,
793 	.init		=	u32_init,
794 	.destroy	=	u32_destroy,
795 	.get		=	u32_get,
796 	.put		=	u32_put,
797 	.change		=	u32_change,
798 	.delete		=	u32_delete,
799 	.walk		=	u32_walk,
800 	.dump		=	u32_dump,
801 	.owner		=	THIS_MODULE,
802 };
803 
804 static int __init init_u32(void)
805 {
806 	pr_info("u32 classifier\n");
807 #ifdef CONFIG_CLS_U32_PERF
808 	pr_info("    Performance counters on\n");
809 #endif
810 #ifdef CONFIG_NET_CLS_IND
811 	pr_info("    input device check on\n");
812 #endif
813 #ifdef CONFIG_NET_CLS_ACT
814 	pr_info("    Actions configured\n");
815 #endif
816 	return register_tcf_proto_ops(&cls_u32_ops);
817 }
818 
819 static void __exit exit_u32(void)
820 {
821 	unregister_tcf_proto_ops(&cls_u32_ops);
822 }
823 
824 module_init(init_u32)
825 module_exit(exit_u32)
826 MODULE_LICENSE("GPL");
827