xref: /openbmc/linux/net/sched/cls_u32.c (revision ca55b2fe)
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/percpu.h>
40 #include <linux/rtnetlink.h>
41 #include <linux/skbuff.h>
42 #include <linux/bitmap.h>
43 #include <net/netlink.h>
44 #include <net/act_api.h>
45 #include <net/pkt_cls.h>
46 
47 struct tc_u_knode {
48 	struct tc_u_knode __rcu	*next;
49 	u32			handle;
50 	struct tc_u_hnode __rcu	*ht_up;
51 	struct tcf_exts		exts;
52 #ifdef CONFIG_NET_CLS_IND
53 	int			ifindex;
54 #endif
55 	u8			fshift;
56 	struct tcf_result	res;
57 	struct tc_u_hnode __rcu	*ht_down;
58 #ifdef CONFIG_CLS_U32_PERF
59 	struct tc_u32_pcnt __percpu *pf;
60 #endif
61 #ifdef CONFIG_CLS_U32_MARK
62 	u32			val;
63 	u32			mask;
64 	u32 __percpu		*pcpu_success;
65 #endif
66 	struct tcf_proto	*tp;
67 	struct rcu_head		rcu;
68 	/* The 'sel' field MUST be the last field in structure to allow for
69 	 * tc_u32_keys allocated at end of structure.
70 	 */
71 	struct tc_u32_sel	sel;
72 };
73 
74 struct tc_u_hnode {
75 	struct tc_u_hnode __rcu	*next;
76 	u32			handle;
77 	u32			prio;
78 	struct tc_u_common	*tp_c;
79 	int			refcnt;
80 	unsigned int		divisor;
81 	struct rcu_head		rcu;
82 	/* The 'ht' field MUST be the last field in structure to allow for
83 	 * more entries allocated at end of structure.
84 	 */
85 	struct tc_u_knode __rcu	*ht[1];
86 };
87 
88 struct tc_u_common {
89 	struct tc_u_hnode __rcu	*hlist;
90 	struct Qdisc		*q;
91 	int			refcnt;
92 	u32			hgenerator;
93 	struct rcu_head		rcu;
94 };
95 
96 static inline unsigned int u32_hash_fold(__be32 key,
97 					 const struct tc_u32_sel *sel,
98 					 u8 fshift)
99 {
100 	unsigned int h = ntohl(key & sel->hmask) >> fshift;
101 
102 	return h;
103 }
104 
105 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res)
106 {
107 	struct {
108 		struct tc_u_knode *knode;
109 		unsigned int	  off;
110 	} stack[TC_U32_MAXDEPTH];
111 
112 	struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
113 	unsigned int off = skb_network_offset(skb);
114 	struct tc_u_knode *n;
115 	int sdepth = 0;
116 	int off2 = 0;
117 	int sel = 0;
118 #ifdef CONFIG_CLS_U32_PERF
119 	int j;
120 #endif
121 	int i, r;
122 
123 next_ht:
124 	n = rcu_dereference_bh(ht->ht[sel]);
125 
126 next_knode:
127 	if (n) {
128 		struct tc_u32_key *key = n->sel.keys;
129 
130 #ifdef CONFIG_CLS_U32_PERF
131 		__this_cpu_inc(n->pf->rcnt);
132 		j = 0;
133 #endif
134 
135 #ifdef CONFIG_CLS_U32_MARK
136 		if ((skb->mark & n->mask) != n->val) {
137 			n = rcu_dereference_bh(n->next);
138 			goto next_knode;
139 		} else {
140 			__this_cpu_inc(*n->pcpu_success);
141 		}
142 #endif
143 
144 		for (i = n->sel.nkeys; i > 0; i--, key++) {
145 			int toff = off + key->off + (off2 & key->offmask);
146 			__be32 *data, hdata;
147 
148 			if (skb_headroom(skb) + toff > INT_MAX)
149 				goto out;
150 
151 			data = skb_header_pointer(skb, toff, 4, &hdata);
152 			if (!data)
153 				goto out;
154 			if ((*data ^ key->val) & key->mask) {
155 				n = rcu_dereference_bh(n->next);
156 				goto next_knode;
157 			}
158 #ifdef CONFIG_CLS_U32_PERF
159 			__this_cpu_inc(n->pf->kcnts[j]);
160 			j++;
161 #endif
162 		}
163 
164 		ht = rcu_dereference_bh(n->ht_down);
165 		if (!ht) {
166 check_terminal:
167 			if (n->sel.flags & TC_U32_TERMINAL) {
168 
169 				*res = n->res;
170 #ifdef CONFIG_NET_CLS_IND
171 				if (!tcf_match_indev(skb, n->ifindex)) {
172 					n = rcu_dereference_bh(n->next);
173 					goto next_knode;
174 				}
175 #endif
176 #ifdef CONFIG_CLS_U32_PERF
177 				__this_cpu_inc(n->pf->rhit);
178 #endif
179 				r = tcf_exts_exec(skb, &n->exts, res);
180 				if (r < 0) {
181 					n = rcu_dereference_bh(n->next);
182 					goto next_knode;
183 				}
184 
185 				return r;
186 			}
187 			n = rcu_dereference_bh(n->next);
188 			goto next_knode;
189 		}
190 
191 		/* PUSH */
192 		if (sdepth >= TC_U32_MAXDEPTH)
193 			goto deadloop;
194 		stack[sdepth].knode = n;
195 		stack[sdepth].off = off;
196 		sdepth++;
197 
198 		ht = rcu_dereference_bh(n->ht_down);
199 		sel = 0;
200 		if (ht->divisor) {
201 			__be32 *data, hdata;
202 
203 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
204 						  &hdata);
205 			if (!data)
206 				goto out;
207 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
208 							  n->fshift);
209 		}
210 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
211 			goto next_ht;
212 
213 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
214 			off2 = n->sel.off + 3;
215 			if (n->sel.flags & TC_U32_VAROFFSET) {
216 				__be16 *data, hdata;
217 
218 				data = skb_header_pointer(skb,
219 							  off + n->sel.offoff,
220 							  2, &hdata);
221 				if (!data)
222 					goto out;
223 				off2 += ntohs(n->sel.offmask & *data) >>
224 					n->sel.offshift;
225 			}
226 			off2 &= ~3;
227 		}
228 		if (n->sel.flags & TC_U32_EAT) {
229 			off += off2;
230 			off2 = 0;
231 		}
232 
233 		if (off < skb->len)
234 			goto next_ht;
235 	}
236 
237 	/* POP */
238 	if (sdepth--) {
239 		n = stack[sdepth].knode;
240 		ht = rcu_dereference_bh(n->ht_up);
241 		off = stack[sdepth].off;
242 		goto check_terminal;
243 	}
244 out:
245 	return -1;
246 
247 deadloop:
248 	net_warn_ratelimited("cls_u32: dead loop\n");
249 	return -1;
250 }
251 
252 static struct tc_u_hnode *
253 u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
254 {
255 	struct tc_u_hnode *ht;
256 
257 	for (ht = rtnl_dereference(tp_c->hlist);
258 	     ht;
259 	     ht = rtnl_dereference(ht->next))
260 		if (ht->handle == handle)
261 			break;
262 
263 	return ht;
264 }
265 
266 static struct tc_u_knode *
267 u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
268 {
269 	unsigned int sel;
270 	struct tc_u_knode *n = NULL;
271 
272 	sel = TC_U32_HASH(handle);
273 	if (sel > ht->divisor)
274 		goto out;
275 
276 	for (n = rtnl_dereference(ht->ht[sel]);
277 	     n;
278 	     n = rtnl_dereference(n->next))
279 		if (n->handle == handle)
280 			break;
281 out:
282 	return n;
283 }
284 
285 
286 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
287 {
288 	struct tc_u_hnode *ht;
289 	struct tc_u_common *tp_c = tp->data;
290 
291 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
292 		ht = rtnl_dereference(tp->root);
293 	else
294 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
295 
296 	if (!ht)
297 		return 0;
298 
299 	if (TC_U32_KEY(handle) == 0)
300 		return (unsigned long)ht;
301 
302 	return (unsigned long)u32_lookup_key(ht, handle);
303 }
304 
305 static u32 gen_new_htid(struct tc_u_common *tp_c)
306 {
307 	int i = 0x800;
308 
309 	/* hgenerator only used inside rtnl lock it is safe to increment
310 	 * without read _copy_ update semantics
311 	 */
312 	do {
313 		if (++tp_c->hgenerator == 0x7FF)
314 			tp_c->hgenerator = 1;
315 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
316 
317 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
318 }
319 
320 static int u32_init(struct tcf_proto *tp)
321 {
322 	struct tc_u_hnode *root_ht;
323 	struct tc_u_common *tp_c;
324 
325 	tp_c = tp->q->u32_node;
326 
327 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
328 	if (root_ht == NULL)
329 		return -ENOBUFS;
330 
331 	root_ht->divisor = 0;
332 	root_ht->refcnt++;
333 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
334 	root_ht->prio = tp->prio;
335 
336 	if (tp_c == NULL) {
337 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
338 		if (tp_c == NULL) {
339 			kfree(root_ht);
340 			return -ENOBUFS;
341 		}
342 		tp_c->q = tp->q;
343 		tp->q->u32_node = tp_c;
344 	}
345 
346 	tp_c->refcnt++;
347 	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
348 	rcu_assign_pointer(tp_c->hlist, root_ht);
349 	root_ht->tp_c = tp_c;
350 
351 	rcu_assign_pointer(tp->root, root_ht);
352 	tp->data = tp_c;
353 	return 0;
354 }
355 
356 static int u32_destroy_key(struct tcf_proto *tp,
357 			   struct tc_u_knode *n,
358 			   bool free_pf)
359 {
360 	tcf_exts_destroy(&n->exts);
361 	if (n->ht_down)
362 		n->ht_down->refcnt--;
363 #ifdef CONFIG_CLS_U32_PERF
364 	if (free_pf)
365 		free_percpu(n->pf);
366 #endif
367 #ifdef CONFIG_CLS_U32_MARK
368 	if (free_pf)
369 		free_percpu(n->pcpu_success);
370 #endif
371 	kfree(n);
372 	return 0;
373 }
374 
375 /* u32_delete_key_rcu should be called when free'ing a copied
376  * version of a tc_u_knode obtained from u32_init_knode(). When
377  * copies are obtained from u32_init_knode() the statistics are
378  * shared between the old and new copies to allow readers to
379  * continue to update the statistics during the copy. To support
380  * this the u32_delete_key_rcu variant does not free the percpu
381  * statistics.
382  */
383 static void u32_delete_key_rcu(struct rcu_head *rcu)
384 {
385 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
386 
387 	u32_destroy_key(key->tp, key, false);
388 }
389 
390 /* u32_delete_key_freepf_rcu is the rcu callback variant
391  * that free's the entire structure including the statistics
392  * percpu variables. Only use this if the key is not a copy
393  * returned by u32_init_knode(). See u32_delete_key_rcu()
394  * for the variant that should be used with keys return from
395  * u32_init_knode()
396  */
397 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
398 {
399 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
400 
401 	u32_destroy_key(key->tp, key, true);
402 }
403 
404 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
405 {
406 	struct tc_u_knode __rcu **kp;
407 	struct tc_u_knode *pkp;
408 	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
409 
410 	if (ht) {
411 		kp = &ht->ht[TC_U32_HASH(key->handle)];
412 		for (pkp = rtnl_dereference(*kp); pkp;
413 		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
414 			if (pkp == key) {
415 				RCU_INIT_POINTER(*kp, key->next);
416 
417 				tcf_unbind_filter(tp, &key->res);
418 				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
419 				return 0;
420 			}
421 		}
422 	}
423 	WARN_ON(1);
424 	return 0;
425 }
426 
427 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
428 {
429 	struct tc_u_knode *n;
430 	unsigned int h;
431 
432 	for (h = 0; h <= ht->divisor; h++) {
433 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
434 			RCU_INIT_POINTER(ht->ht[h],
435 					 rtnl_dereference(n->next));
436 			tcf_unbind_filter(tp, &n->res);
437 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
438 		}
439 	}
440 }
441 
442 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
443 {
444 	struct tc_u_common *tp_c = tp->data;
445 	struct tc_u_hnode __rcu **hn;
446 	struct tc_u_hnode *phn;
447 
448 	WARN_ON(ht->refcnt);
449 
450 	u32_clear_hnode(tp, ht);
451 
452 	hn = &tp_c->hlist;
453 	for (phn = rtnl_dereference(*hn);
454 	     phn;
455 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
456 		if (phn == ht) {
457 			RCU_INIT_POINTER(*hn, ht->next);
458 			kfree_rcu(ht, rcu);
459 			return 0;
460 		}
461 	}
462 
463 	return -ENOENT;
464 }
465 
466 static bool ht_empty(struct tc_u_hnode *ht)
467 {
468 	unsigned int h;
469 
470 	for (h = 0; h <= ht->divisor; h++)
471 		if (rcu_access_pointer(ht->ht[h]))
472 			return false;
473 
474 	return true;
475 }
476 
477 static bool u32_destroy(struct tcf_proto *tp, bool force)
478 {
479 	struct tc_u_common *tp_c = tp->data;
480 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
481 
482 	WARN_ON(root_ht == NULL);
483 
484 	if (!force) {
485 		if (root_ht) {
486 			if (root_ht->refcnt > 1)
487 				return false;
488 			if (root_ht->refcnt == 1) {
489 				if (!ht_empty(root_ht))
490 					return false;
491 			}
492 		}
493 
494 		if (tp_c->refcnt > 1)
495 			return false;
496 
497 		if (tp_c->refcnt == 1) {
498 			struct tc_u_hnode *ht;
499 
500 			for (ht = rtnl_dereference(tp_c->hlist);
501 			     ht;
502 			     ht = rtnl_dereference(ht->next))
503 				if (!ht_empty(ht))
504 					return false;
505 		}
506 	}
507 
508 	if (root_ht && --root_ht->refcnt == 0)
509 		u32_destroy_hnode(tp, root_ht);
510 
511 	if (--tp_c->refcnt == 0) {
512 		struct tc_u_hnode *ht;
513 
514 		tp->q->u32_node = NULL;
515 
516 		for (ht = rtnl_dereference(tp_c->hlist);
517 		     ht;
518 		     ht = rtnl_dereference(ht->next)) {
519 			ht->refcnt--;
520 			u32_clear_hnode(tp, ht);
521 		}
522 
523 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
524 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
525 			kfree_rcu(ht, rcu);
526 		}
527 
528 		kfree(tp_c);
529 	}
530 
531 	tp->data = NULL;
532 	return true;
533 }
534 
535 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
536 {
537 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
538 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
539 
540 	if (ht == NULL)
541 		return 0;
542 
543 	if (TC_U32_KEY(ht->handle))
544 		return u32_delete_key(tp, (struct tc_u_knode *)ht);
545 
546 	if (root_ht == ht)
547 		return -EINVAL;
548 
549 	if (ht->refcnt == 1) {
550 		ht->refcnt--;
551 		u32_destroy_hnode(tp, ht);
552 	} else {
553 		return -EBUSY;
554 	}
555 
556 	return 0;
557 }
558 
559 #define NR_U32_NODE (1<<12)
560 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
561 {
562 	struct tc_u_knode *n;
563 	unsigned long i;
564 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
565 					GFP_KERNEL);
566 	if (!bitmap)
567 		return handle | 0xFFF;
568 
569 	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
570 	     n;
571 	     n = rtnl_dereference(n->next))
572 		set_bit(TC_U32_NODE(n->handle), bitmap);
573 
574 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
575 	if (i >= NR_U32_NODE)
576 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
577 
578 	kfree(bitmap);
579 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
580 }
581 
582 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
583 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
584 	[TCA_U32_HASH]		= { .type = NLA_U32 },
585 	[TCA_U32_LINK]		= { .type = NLA_U32 },
586 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
587 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
588 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
589 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
590 };
591 
592 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
593 			 unsigned long base, struct tc_u_hnode *ht,
594 			 struct tc_u_knode *n, struct nlattr **tb,
595 			 struct nlattr *est, bool ovr)
596 {
597 	int err;
598 	struct tcf_exts e;
599 
600 	tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
601 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
602 	if (err < 0)
603 		return err;
604 
605 	err = -EINVAL;
606 	if (tb[TCA_U32_LINK]) {
607 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
608 		struct tc_u_hnode *ht_down = NULL, *ht_old;
609 
610 		if (TC_U32_KEY(handle))
611 			goto errout;
612 
613 		if (handle) {
614 			ht_down = u32_lookup_ht(ht->tp_c, handle);
615 
616 			if (ht_down == NULL)
617 				goto errout;
618 			ht_down->refcnt++;
619 		}
620 
621 		ht_old = rtnl_dereference(n->ht_down);
622 		rcu_assign_pointer(n->ht_down, ht_down);
623 
624 		if (ht_old)
625 			ht_old->refcnt--;
626 	}
627 	if (tb[TCA_U32_CLASSID]) {
628 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
629 		tcf_bind_filter(tp, &n->res, base);
630 	}
631 
632 #ifdef CONFIG_NET_CLS_IND
633 	if (tb[TCA_U32_INDEV]) {
634 		int ret;
635 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
636 		if (ret < 0)
637 			goto errout;
638 		n->ifindex = ret;
639 	}
640 #endif
641 	tcf_exts_change(tp, &n->exts, &e);
642 
643 	return 0;
644 errout:
645 	tcf_exts_destroy(&e);
646 	return err;
647 }
648 
649 static void u32_replace_knode(struct tcf_proto *tp,
650 			      struct tc_u_common *tp_c,
651 			      struct tc_u_knode *n)
652 {
653 	struct tc_u_knode __rcu **ins;
654 	struct tc_u_knode *pins;
655 	struct tc_u_hnode *ht;
656 
657 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
658 		ht = rtnl_dereference(tp->root);
659 	else
660 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
661 
662 	ins = &ht->ht[TC_U32_HASH(n->handle)];
663 
664 	/* The node must always exist for it to be replaced if this is not the
665 	 * case then something went very wrong elsewhere.
666 	 */
667 	for (pins = rtnl_dereference(*ins); ;
668 	     ins = &pins->next, pins = rtnl_dereference(*ins))
669 		if (pins->handle == n->handle)
670 			break;
671 
672 	RCU_INIT_POINTER(n->next, pins->next);
673 	rcu_assign_pointer(*ins, n);
674 }
675 
676 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
677 					 struct tc_u_knode *n)
678 {
679 	struct tc_u_knode *new;
680 	struct tc_u32_sel *s = &n->sel;
681 
682 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
683 		      GFP_KERNEL);
684 
685 	if (!new)
686 		return NULL;
687 
688 	RCU_INIT_POINTER(new->next, n->next);
689 	new->handle = n->handle;
690 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
691 
692 #ifdef CONFIG_NET_CLS_IND
693 	new->ifindex = n->ifindex;
694 #endif
695 	new->fshift = n->fshift;
696 	new->res = n->res;
697 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
698 
699 	/* bump reference count as long as we hold pointer to structure */
700 	if (new->ht_down)
701 		new->ht_down->refcnt++;
702 
703 #ifdef CONFIG_CLS_U32_PERF
704 	/* Statistics may be incremented by readers during update
705 	 * so we must keep them in tact. When the node is later destroyed
706 	 * a special destroy call must be made to not free the pf memory.
707 	 */
708 	new->pf = n->pf;
709 #endif
710 
711 #ifdef CONFIG_CLS_U32_MARK
712 	new->val = n->val;
713 	new->mask = n->mask;
714 	/* Similarly success statistics must be moved as pointers */
715 	new->pcpu_success = n->pcpu_success;
716 #endif
717 	new->tp = tp;
718 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
719 
720 	tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE);
721 
722 	return new;
723 }
724 
725 static int u32_change(struct net *net, struct sk_buff *in_skb,
726 		      struct tcf_proto *tp, unsigned long base, u32 handle,
727 		      struct nlattr **tca,
728 		      unsigned long *arg, bool ovr)
729 {
730 	struct tc_u_common *tp_c = tp->data;
731 	struct tc_u_hnode *ht;
732 	struct tc_u_knode *n;
733 	struct tc_u32_sel *s;
734 	struct nlattr *opt = tca[TCA_OPTIONS];
735 	struct nlattr *tb[TCA_U32_MAX + 1];
736 	u32 htid;
737 	int err;
738 #ifdef CONFIG_CLS_U32_PERF
739 	size_t size;
740 #endif
741 
742 	if (opt == NULL)
743 		return handle ? -EINVAL : 0;
744 
745 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
746 	if (err < 0)
747 		return err;
748 
749 	n = (struct tc_u_knode *)*arg;
750 	if (n) {
751 		struct tc_u_knode *new;
752 
753 		if (TC_U32_KEY(n->handle) == 0)
754 			return -EINVAL;
755 
756 		new = u32_init_knode(tp, n);
757 		if (!new)
758 			return -ENOMEM;
759 
760 		err = u32_set_parms(net, tp, base,
761 				    rtnl_dereference(n->ht_up), new, tb,
762 				    tca[TCA_RATE], ovr);
763 
764 		if (err) {
765 			u32_destroy_key(tp, new, false);
766 			return err;
767 		}
768 
769 		u32_replace_knode(tp, tp_c, new);
770 		tcf_unbind_filter(tp, &n->res);
771 		call_rcu(&n->rcu, u32_delete_key_rcu);
772 		return 0;
773 	}
774 
775 	if (tb[TCA_U32_DIVISOR]) {
776 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
777 
778 		if (--divisor > 0x100)
779 			return -EINVAL;
780 		if (TC_U32_KEY(handle))
781 			return -EINVAL;
782 		if (handle == 0) {
783 			handle = gen_new_htid(tp->data);
784 			if (handle == 0)
785 				return -ENOMEM;
786 		}
787 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
788 		if (ht == NULL)
789 			return -ENOBUFS;
790 		ht->tp_c = tp_c;
791 		ht->refcnt = 1;
792 		ht->divisor = divisor;
793 		ht->handle = handle;
794 		ht->prio = tp->prio;
795 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
796 		rcu_assign_pointer(tp_c->hlist, ht);
797 		*arg = (unsigned long)ht;
798 		return 0;
799 	}
800 
801 	if (tb[TCA_U32_HASH]) {
802 		htid = nla_get_u32(tb[TCA_U32_HASH]);
803 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
804 			ht = rtnl_dereference(tp->root);
805 			htid = ht->handle;
806 		} else {
807 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
808 			if (ht == NULL)
809 				return -EINVAL;
810 		}
811 	} else {
812 		ht = rtnl_dereference(tp->root);
813 		htid = ht->handle;
814 	}
815 
816 	if (ht->divisor < TC_U32_HASH(htid))
817 		return -EINVAL;
818 
819 	if (handle) {
820 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
821 			return -EINVAL;
822 		handle = htid | TC_U32_NODE(handle);
823 	} else
824 		handle = gen_new_kid(ht, htid);
825 
826 	if (tb[TCA_U32_SEL] == NULL)
827 		return -EINVAL;
828 
829 	s = nla_data(tb[TCA_U32_SEL]);
830 
831 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
832 	if (n == NULL)
833 		return -ENOBUFS;
834 
835 #ifdef CONFIG_CLS_U32_PERF
836 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
837 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
838 	if (!n->pf) {
839 		kfree(n);
840 		return -ENOBUFS;
841 	}
842 #endif
843 
844 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
845 	RCU_INIT_POINTER(n->ht_up, ht);
846 	n->handle = handle;
847 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
848 	tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
849 	n->tp = tp;
850 
851 #ifdef CONFIG_CLS_U32_MARK
852 	n->pcpu_success = alloc_percpu(u32);
853 	if (!n->pcpu_success) {
854 		err = -ENOMEM;
855 		goto errout;
856 	}
857 
858 	if (tb[TCA_U32_MARK]) {
859 		struct tc_u32_mark *mark;
860 
861 		mark = nla_data(tb[TCA_U32_MARK]);
862 		n->val = mark->val;
863 		n->mask = mark->mask;
864 	}
865 #endif
866 
867 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
868 	if (err == 0) {
869 		struct tc_u_knode __rcu **ins;
870 		struct tc_u_knode *pins;
871 
872 		ins = &ht->ht[TC_U32_HASH(handle)];
873 		for (pins = rtnl_dereference(*ins); pins;
874 		     ins = &pins->next, pins = rtnl_dereference(*ins))
875 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
876 				break;
877 
878 		RCU_INIT_POINTER(n->next, pins);
879 		rcu_assign_pointer(*ins, n);
880 
881 		*arg = (unsigned long)n;
882 		return 0;
883 	}
884 
885 #ifdef CONFIG_CLS_U32_MARK
886 	free_percpu(n->pcpu_success);
887 errout:
888 #endif
889 
890 #ifdef CONFIG_CLS_U32_PERF
891 	free_percpu(n->pf);
892 #endif
893 	kfree(n);
894 	return err;
895 }
896 
897 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
898 {
899 	struct tc_u_common *tp_c = tp->data;
900 	struct tc_u_hnode *ht;
901 	struct tc_u_knode *n;
902 	unsigned int h;
903 
904 	if (arg->stop)
905 		return;
906 
907 	for (ht = rtnl_dereference(tp_c->hlist);
908 	     ht;
909 	     ht = rtnl_dereference(ht->next)) {
910 		if (ht->prio != tp->prio)
911 			continue;
912 		if (arg->count >= arg->skip) {
913 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
914 				arg->stop = 1;
915 				return;
916 			}
917 		}
918 		arg->count++;
919 		for (h = 0; h <= ht->divisor; h++) {
920 			for (n = rtnl_dereference(ht->ht[h]);
921 			     n;
922 			     n = rtnl_dereference(n->next)) {
923 				if (arg->count < arg->skip) {
924 					arg->count++;
925 					continue;
926 				}
927 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
928 					arg->stop = 1;
929 					return;
930 				}
931 				arg->count++;
932 			}
933 		}
934 	}
935 }
936 
937 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
938 		     struct sk_buff *skb, struct tcmsg *t)
939 {
940 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
941 	struct tc_u_hnode *ht_up, *ht_down;
942 	struct nlattr *nest;
943 
944 	if (n == NULL)
945 		return skb->len;
946 
947 	t->tcm_handle = n->handle;
948 
949 	nest = nla_nest_start(skb, TCA_OPTIONS);
950 	if (nest == NULL)
951 		goto nla_put_failure;
952 
953 	if (TC_U32_KEY(n->handle) == 0) {
954 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
955 		u32 divisor = ht->divisor + 1;
956 
957 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
958 			goto nla_put_failure;
959 	} else {
960 #ifdef CONFIG_CLS_U32_PERF
961 		struct tc_u32_pcnt *gpf;
962 		int cpu;
963 #endif
964 
965 		if (nla_put(skb, TCA_U32_SEL,
966 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
967 			    &n->sel))
968 			goto nla_put_failure;
969 
970 		ht_up = rtnl_dereference(n->ht_up);
971 		if (ht_up) {
972 			u32 htid = n->handle & 0xFFFFF000;
973 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
974 				goto nla_put_failure;
975 		}
976 		if (n->res.classid &&
977 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
978 			goto nla_put_failure;
979 
980 		ht_down = rtnl_dereference(n->ht_down);
981 		if (ht_down &&
982 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
983 			goto nla_put_failure;
984 
985 #ifdef CONFIG_CLS_U32_MARK
986 		if ((n->val || n->mask)) {
987 			struct tc_u32_mark mark = {.val = n->val,
988 						   .mask = n->mask,
989 						   .success = 0};
990 			int cpum;
991 
992 			for_each_possible_cpu(cpum) {
993 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
994 
995 				mark.success += cnt;
996 			}
997 
998 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
999 				goto nla_put_failure;
1000 		}
1001 #endif
1002 
1003 		if (tcf_exts_dump(skb, &n->exts) < 0)
1004 			goto nla_put_failure;
1005 
1006 #ifdef CONFIG_NET_CLS_IND
1007 		if (n->ifindex) {
1008 			struct net_device *dev;
1009 			dev = __dev_get_by_index(net, n->ifindex);
1010 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1011 				goto nla_put_failure;
1012 		}
1013 #endif
1014 #ifdef CONFIG_CLS_U32_PERF
1015 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1016 			      n->sel.nkeys * sizeof(u64),
1017 			      GFP_KERNEL);
1018 		if (!gpf)
1019 			goto nla_put_failure;
1020 
1021 		for_each_possible_cpu(cpu) {
1022 			int i;
1023 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1024 
1025 			gpf->rcnt += pf->rcnt;
1026 			gpf->rhit += pf->rhit;
1027 			for (i = 0; i < n->sel.nkeys; i++)
1028 				gpf->kcnts[i] += pf->kcnts[i];
1029 		}
1030 
1031 		if (nla_put(skb, TCA_U32_PCNT,
1032 			    sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
1033 			    gpf)) {
1034 			kfree(gpf);
1035 			goto nla_put_failure;
1036 		}
1037 		kfree(gpf);
1038 #endif
1039 	}
1040 
1041 	nla_nest_end(skb, nest);
1042 
1043 	if (TC_U32_KEY(n->handle))
1044 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1045 			goto nla_put_failure;
1046 	return skb->len;
1047 
1048 nla_put_failure:
1049 	nla_nest_cancel(skb, nest);
1050 	return -1;
1051 }
1052 
1053 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1054 	.kind		=	"u32",
1055 	.classify	=	u32_classify,
1056 	.init		=	u32_init,
1057 	.destroy	=	u32_destroy,
1058 	.get		=	u32_get,
1059 	.change		=	u32_change,
1060 	.delete		=	u32_delete,
1061 	.walk		=	u32_walk,
1062 	.dump		=	u32_dump,
1063 	.owner		=	THIS_MODULE,
1064 };
1065 
1066 static int __init init_u32(void)
1067 {
1068 	pr_info("u32 classifier\n");
1069 #ifdef CONFIG_CLS_U32_PERF
1070 	pr_info("    Performance counters on\n");
1071 #endif
1072 #ifdef CONFIG_NET_CLS_IND
1073 	pr_info("    input device check on\n");
1074 #endif
1075 #ifdef CONFIG_NET_CLS_ACT
1076 	pr_info("    Actions configured\n");
1077 #endif
1078 	return register_tcf_proto_ops(&cls_u32_ops);
1079 }
1080 
1081 static void __exit exit_u32(void)
1082 {
1083 	unregister_tcf_proto_ops(&cls_u32_ops);
1084 }
1085 
1086 module_init(init_u32)
1087 module_exit(exit_u32)
1088 MODULE_LICENSE("GPL");
1089