xref: /openbmc/linux/net/sched/cls_u32.c (revision bb0eb050)
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 #include <linux/netdevice.h>
47 
48 struct tc_u_knode {
49 	struct tc_u_knode __rcu	*next;
50 	u32			handle;
51 	struct tc_u_hnode __rcu	*ht_up;
52 	struct tcf_exts		exts;
53 #ifdef CONFIG_NET_CLS_IND
54 	int			ifindex;
55 #endif
56 	u8			fshift;
57 	struct tcf_result	res;
58 	struct tc_u_hnode __rcu	*ht_down;
59 #ifdef CONFIG_CLS_U32_PERF
60 	struct tc_u32_pcnt __percpu *pf;
61 #endif
62 	u32			flags;
63 #ifdef CONFIG_CLS_U32_MARK
64 	u32			val;
65 	u32			mask;
66 	u32 __percpu		*pcpu_success;
67 #endif
68 	struct tcf_proto	*tp;
69 	struct rcu_head		rcu;
70 	/* The 'sel' field MUST be the last field in structure to allow for
71 	 * tc_u32_keys allocated at end of structure.
72 	 */
73 	struct tc_u32_sel	sel;
74 };
75 
76 struct tc_u_hnode {
77 	struct tc_u_hnode __rcu	*next;
78 	u32			handle;
79 	u32			prio;
80 	struct tc_u_common	*tp_c;
81 	int			refcnt;
82 	unsigned int		divisor;
83 	struct rcu_head		rcu;
84 	/* The 'ht' field MUST be the last field in structure to allow for
85 	 * more entries allocated at end of structure.
86 	 */
87 	struct tc_u_knode __rcu	*ht[1];
88 };
89 
90 struct tc_u_common {
91 	struct tc_u_hnode __rcu	*hlist;
92 	struct Qdisc		*q;
93 	int			refcnt;
94 	u32			hgenerator;
95 	struct rcu_head		rcu;
96 };
97 
98 static inline unsigned int u32_hash_fold(__be32 key,
99 					 const struct tc_u32_sel *sel,
100 					 u8 fshift)
101 {
102 	unsigned int h = ntohl(key & sel->hmask) >> fshift;
103 
104 	return h;
105 }
106 
107 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp,
108 			struct tcf_result *res)
109 {
110 	struct {
111 		struct tc_u_knode *knode;
112 		unsigned int	  off;
113 	} stack[TC_U32_MAXDEPTH];
114 
115 	struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
116 	unsigned int off = skb_network_offset(skb);
117 	struct tc_u_knode *n;
118 	int sdepth = 0;
119 	int off2 = 0;
120 	int sel = 0;
121 #ifdef CONFIG_CLS_U32_PERF
122 	int j;
123 #endif
124 	int i, r;
125 
126 next_ht:
127 	n = rcu_dereference_bh(ht->ht[sel]);
128 
129 next_knode:
130 	if (n) {
131 		struct tc_u32_key *key = n->sel.keys;
132 
133 #ifdef CONFIG_CLS_U32_PERF
134 		__this_cpu_inc(n->pf->rcnt);
135 		j = 0;
136 #endif
137 
138 		if (tc_skip_sw(n->flags)) {
139 			n = rcu_dereference_bh(n->next);
140 			goto next_knode;
141 		}
142 
143 #ifdef CONFIG_CLS_U32_MARK
144 		if ((skb->mark & n->mask) != n->val) {
145 			n = rcu_dereference_bh(n->next);
146 			goto next_knode;
147 		} else {
148 			__this_cpu_inc(*n->pcpu_success);
149 		}
150 #endif
151 
152 		for (i = n->sel.nkeys; i > 0; i--, key++) {
153 			int toff = off + key->off + (off2 & key->offmask);
154 			__be32 *data, hdata;
155 
156 			if (skb_headroom(skb) + toff > INT_MAX)
157 				goto out;
158 
159 			data = skb_header_pointer(skb, toff, 4, &hdata);
160 			if (!data)
161 				goto out;
162 			if ((*data ^ key->val) & key->mask) {
163 				n = rcu_dereference_bh(n->next);
164 				goto next_knode;
165 			}
166 #ifdef CONFIG_CLS_U32_PERF
167 			__this_cpu_inc(n->pf->kcnts[j]);
168 			j++;
169 #endif
170 		}
171 
172 		ht = rcu_dereference_bh(n->ht_down);
173 		if (!ht) {
174 check_terminal:
175 			if (n->sel.flags & TC_U32_TERMINAL) {
176 
177 				*res = n->res;
178 #ifdef CONFIG_NET_CLS_IND
179 				if (!tcf_match_indev(skb, n->ifindex)) {
180 					n = rcu_dereference_bh(n->next);
181 					goto next_knode;
182 				}
183 #endif
184 #ifdef CONFIG_CLS_U32_PERF
185 				__this_cpu_inc(n->pf->rhit);
186 #endif
187 				r = tcf_exts_exec(skb, &n->exts, res);
188 				if (r < 0) {
189 					n = rcu_dereference_bh(n->next);
190 					goto next_knode;
191 				}
192 
193 				return r;
194 			}
195 			n = rcu_dereference_bh(n->next);
196 			goto next_knode;
197 		}
198 
199 		/* PUSH */
200 		if (sdepth >= TC_U32_MAXDEPTH)
201 			goto deadloop;
202 		stack[sdepth].knode = n;
203 		stack[sdepth].off = off;
204 		sdepth++;
205 
206 		ht = rcu_dereference_bh(n->ht_down);
207 		sel = 0;
208 		if (ht->divisor) {
209 			__be32 *data, hdata;
210 
211 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
212 						  &hdata);
213 			if (!data)
214 				goto out;
215 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
216 							  n->fshift);
217 		}
218 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
219 			goto next_ht;
220 
221 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
222 			off2 = n->sel.off + 3;
223 			if (n->sel.flags & TC_U32_VAROFFSET) {
224 				__be16 *data, hdata;
225 
226 				data = skb_header_pointer(skb,
227 							  off + n->sel.offoff,
228 							  2, &hdata);
229 				if (!data)
230 					goto out;
231 				off2 += ntohs(n->sel.offmask & *data) >>
232 					n->sel.offshift;
233 			}
234 			off2 &= ~3;
235 		}
236 		if (n->sel.flags & TC_U32_EAT) {
237 			off += off2;
238 			off2 = 0;
239 		}
240 
241 		if (off < skb->len)
242 			goto next_ht;
243 	}
244 
245 	/* POP */
246 	if (sdepth--) {
247 		n = stack[sdepth].knode;
248 		ht = rcu_dereference_bh(n->ht_up);
249 		off = stack[sdepth].off;
250 		goto check_terminal;
251 	}
252 out:
253 	return -1;
254 
255 deadloop:
256 	net_warn_ratelimited("cls_u32: dead loop\n");
257 	return -1;
258 }
259 
260 static struct tc_u_hnode *u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
261 {
262 	struct tc_u_hnode *ht;
263 
264 	for (ht = rtnl_dereference(tp_c->hlist);
265 	     ht;
266 	     ht = rtnl_dereference(ht->next))
267 		if (ht->handle == handle)
268 			break;
269 
270 	return ht;
271 }
272 
273 static struct tc_u_knode *u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
274 {
275 	unsigned int sel;
276 	struct tc_u_knode *n = NULL;
277 
278 	sel = TC_U32_HASH(handle);
279 	if (sel > ht->divisor)
280 		goto out;
281 
282 	for (n = rtnl_dereference(ht->ht[sel]);
283 	     n;
284 	     n = rtnl_dereference(n->next))
285 		if (n->handle == handle)
286 			break;
287 out:
288 	return n;
289 }
290 
291 
292 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
293 {
294 	struct tc_u_hnode *ht;
295 	struct tc_u_common *tp_c = tp->data;
296 
297 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
298 		ht = rtnl_dereference(tp->root);
299 	else
300 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
301 
302 	if (!ht)
303 		return 0;
304 
305 	if (TC_U32_KEY(handle) == 0)
306 		return (unsigned long)ht;
307 
308 	return (unsigned long)u32_lookup_key(ht, handle);
309 }
310 
311 static u32 gen_new_htid(struct tc_u_common *tp_c)
312 {
313 	int i = 0x800;
314 
315 	/* hgenerator only used inside rtnl lock it is safe to increment
316 	 * without read _copy_ update semantics
317 	 */
318 	do {
319 		if (++tp_c->hgenerator == 0x7FF)
320 			tp_c->hgenerator = 1;
321 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
322 
323 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
324 }
325 
326 static int u32_init(struct tcf_proto *tp)
327 {
328 	struct tc_u_hnode *root_ht;
329 	struct tc_u_common *tp_c;
330 
331 	tp_c = tp->q->u32_node;
332 
333 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
334 	if (root_ht == NULL)
335 		return -ENOBUFS;
336 
337 	root_ht->refcnt++;
338 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
339 	root_ht->prio = tp->prio;
340 
341 	if (tp_c == NULL) {
342 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
343 		if (tp_c == NULL) {
344 			kfree(root_ht);
345 			return -ENOBUFS;
346 		}
347 		tp_c->q = tp->q;
348 		tp->q->u32_node = tp_c;
349 	}
350 
351 	tp_c->refcnt++;
352 	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
353 	rcu_assign_pointer(tp_c->hlist, root_ht);
354 	root_ht->tp_c = tp_c;
355 
356 	rcu_assign_pointer(tp->root, root_ht);
357 	tp->data = tp_c;
358 	return 0;
359 }
360 
361 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
362 			   bool free_pf)
363 {
364 	tcf_exts_destroy(&n->exts);
365 	if (n->ht_down)
366 		n->ht_down->refcnt--;
367 #ifdef CONFIG_CLS_U32_PERF
368 	if (free_pf)
369 		free_percpu(n->pf);
370 #endif
371 #ifdef CONFIG_CLS_U32_MARK
372 	if (free_pf)
373 		free_percpu(n->pcpu_success);
374 #endif
375 	kfree(n);
376 	return 0;
377 }
378 
379 /* u32_delete_key_rcu should be called when free'ing a copied
380  * version of a tc_u_knode obtained from u32_init_knode(). When
381  * copies are obtained from u32_init_knode() the statistics are
382  * shared between the old and new copies to allow readers to
383  * continue to update the statistics during the copy. To support
384  * this the u32_delete_key_rcu variant does not free the percpu
385  * statistics.
386  */
387 static void u32_delete_key_rcu(struct rcu_head *rcu)
388 {
389 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
390 
391 	u32_destroy_key(key->tp, key, false);
392 }
393 
394 /* u32_delete_key_freepf_rcu is the rcu callback variant
395  * that free's the entire structure including the statistics
396  * percpu variables. Only use this if the key is not a copy
397  * returned by u32_init_knode(). See u32_delete_key_rcu()
398  * for the variant that should be used with keys return from
399  * u32_init_knode()
400  */
401 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
402 {
403 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
404 
405 	u32_destroy_key(key->tp, key, true);
406 }
407 
408 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
409 {
410 	struct tc_u_knode __rcu **kp;
411 	struct tc_u_knode *pkp;
412 	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
413 
414 	if (ht) {
415 		kp = &ht->ht[TC_U32_HASH(key->handle)];
416 		for (pkp = rtnl_dereference(*kp); pkp;
417 		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
418 			if (pkp == key) {
419 				RCU_INIT_POINTER(*kp, key->next);
420 
421 				tcf_unbind_filter(tp, &key->res);
422 				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
423 				return 0;
424 			}
425 		}
426 	}
427 	WARN_ON(1);
428 	return 0;
429 }
430 
431 static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
432 {
433 	struct net_device *dev = tp->q->dev_queue->dev;
434 	struct tc_cls_u32_offload u32_offload = {0};
435 	struct tc_to_netdev offload;
436 
437 	offload.type = TC_SETUP_CLSU32;
438 	offload.cls_u32 = &u32_offload;
439 
440 	if (tc_should_offload(dev, tp, 0)) {
441 		offload.cls_u32->command = TC_CLSU32_DELETE_KNODE;
442 		offload.cls_u32->knode.handle = handle;
443 		dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
444 					      tp->protocol, &offload);
445 	}
446 }
447 
448 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
449 				u32 flags)
450 {
451 	struct net_device *dev = tp->q->dev_queue->dev;
452 	struct tc_cls_u32_offload u32_offload = {0};
453 	struct tc_to_netdev offload;
454 	int err;
455 
456 	if (!tc_should_offload(dev, tp, flags))
457 		return tc_skip_sw(flags) ? -EINVAL : 0;
458 
459 	offload.type = TC_SETUP_CLSU32;
460 	offload.cls_u32 = &u32_offload;
461 
462 	offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
463 	offload.cls_u32->hnode.divisor = h->divisor;
464 	offload.cls_u32->hnode.handle = h->handle;
465 	offload.cls_u32->hnode.prio = h->prio;
466 
467 	err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
468 					    tp->protocol, &offload);
469 	if (tc_skip_sw(flags))
470 		return err;
471 
472 	return 0;
473 }
474 
475 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
476 {
477 	struct net_device *dev = tp->q->dev_queue->dev;
478 	struct tc_cls_u32_offload u32_offload = {0};
479 	struct tc_to_netdev offload;
480 
481 	offload.type = TC_SETUP_CLSU32;
482 	offload.cls_u32 = &u32_offload;
483 
484 	if (tc_should_offload(dev, tp, 0)) {
485 		offload.cls_u32->command = TC_CLSU32_DELETE_HNODE;
486 		offload.cls_u32->hnode.divisor = h->divisor;
487 		offload.cls_u32->hnode.handle = h->handle;
488 		offload.cls_u32->hnode.prio = h->prio;
489 
490 		dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
491 					      tp->protocol, &offload);
492 	}
493 }
494 
495 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
496 				u32 flags)
497 {
498 	struct net_device *dev = tp->q->dev_queue->dev;
499 	struct tc_cls_u32_offload u32_offload = {0};
500 	struct tc_to_netdev offload;
501 	int err;
502 
503 	offload.type = TC_SETUP_CLSU32;
504 	offload.cls_u32 = &u32_offload;
505 
506 	if (!tc_should_offload(dev, tp, flags))
507 		return tc_skip_sw(flags) ? -EINVAL : 0;
508 
509 	offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
510 	offload.cls_u32->knode.handle = n->handle;
511 	offload.cls_u32->knode.fshift = n->fshift;
512 #ifdef CONFIG_CLS_U32_MARK
513 	offload.cls_u32->knode.val = n->val;
514 	offload.cls_u32->knode.mask = n->mask;
515 #else
516 	offload.cls_u32->knode.val = 0;
517 	offload.cls_u32->knode.mask = 0;
518 #endif
519 	offload.cls_u32->knode.sel = &n->sel;
520 	offload.cls_u32->knode.exts = &n->exts;
521 	if (n->ht_down)
522 		offload.cls_u32->knode.link_handle = n->ht_down->handle;
523 
524 	err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
525 					    tp->protocol, &offload);
526 
527 	if (!err)
528 		n->flags |= TCA_CLS_FLAGS_IN_HW;
529 
530 	if (tc_skip_sw(flags))
531 		return err;
532 
533 	return 0;
534 }
535 
536 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
537 {
538 	struct tc_u_knode *n;
539 	unsigned int h;
540 
541 	for (h = 0; h <= ht->divisor; h++) {
542 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
543 			RCU_INIT_POINTER(ht->ht[h],
544 					 rtnl_dereference(n->next));
545 			tcf_unbind_filter(tp, &n->res);
546 			u32_remove_hw_knode(tp, n->handle);
547 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
548 		}
549 	}
550 }
551 
552 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
553 {
554 	struct tc_u_common *tp_c = tp->data;
555 	struct tc_u_hnode __rcu **hn;
556 	struct tc_u_hnode *phn;
557 
558 	WARN_ON(ht->refcnt);
559 
560 	u32_clear_hnode(tp, ht);
561 
562 	hn = &tp_c->hlist;
563 	for (phn = rtnl_dereference(*hn);
564 	     phn;
565 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
566 		if (phn == ht) {
567 			u32_clear_hw_hnode(tp, ht);
568 			RCU_INIT_POINTER(*hn, ht->next);
569 			kfree_rcu(ht, rcu);
570 			return 0;
571 		}
572 	}
573 
574 	return -ENOENT;
575 }
576 
577 static bool ht_empty(struct tc_u_hnode *ht)
578 {
579 	unsigned int h;
580 
581 	for (h = 0; h <= ht->divisor; h++)
582 		if (rcu_access_pointer(ht->ht[h]))
583 			return false;
584 
585 	return true;
586 }
587 
588 static void u32_destroy(struct tcf_proto *tp)
589 {
590 	struct tc_u_common *tp_c = tp->data;
591 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
592 
593 	WARN_ON(root_ht == NULL);
594 
595 	if (root_ht && --root_ht->refcnt == 0)
596 		u32_destroy_hnode(tp, root_ht);
597 
598 	if (--tp_c->refcnt == 0) {
599 		struct tc_u_hnode *ht;
600 
601 		tp->q->u32_node = NULL;
602 
603 		for (ht = rtnl_dereference(tp_c->hlist);
604 		     ht;
605 		     ht = rtnl_dereference(ht->next)) {
606 			ht->refcnt--;
607 			u32_clear_hnode(tp, ht);
608 		}
609 
610 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
611 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
612 			kfree_rcu(ht, rcu);
613 		}
614 
615 		kfree(tp_c);
616 	}
617 
618 	tp->data = NULL;
619 }
620 
621 static int u32_delete(struct tcf_proto *tp, unsigned long arg, bool *last)
622 {
623 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
624 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
625 	struct tc_u_common *tp_c = tp->data;
626 	int ret = 0;
627 
628 	if (ht == NULL)
629 		goto out;
630 
631 	if (TC_U32_KEY(ht->handle)) {
632 		u32_remove_hw_knode(tp, ht->handle);
633 		ret = u32_delete_key(tp, (struct tc_u_knode *)ht);
634 		goto out;
635 	}
636 
637 	if (root_ht == ht)
638 		return -EINVAL;
639 
640 	if (ht->refcnt == 1) {
641 		ht->refcnt--;
642 		u32_destroy_hnode(tp, ht);
643 	} else {
644 		return -EBUSY;
645 	}
646 
647 out:
648 	*last = true;
649 	if (root_ht) {
650 		if (root_ht->refcnt > 1) {
651 			*last = false;
652 			goto ret;
653 		}
654 		if (root_ht->refcnt == 1) {
655 			if (!ht_empty(root_ht)) {
656 				*last = false;
657 				goto ret;
658 			}
659 		}
660 	}
661 
662 	if (tp_c->refcnt > 1) {
663 		*last = false;
664 		goto ret;
665 	}
666 
667 	if (tp_c->refcnt == 1) {
668 		struct tc_u_hnode *ht;
669 
670 		for (ht = rtnl_dereference(tp_c->hlist);
671 		     ht;
672 		     ht = rtnl_dereference(ht->next))
673 			if (!ht_empty(ht)) {
674 				*last = false;
675 				break;
676 			}
677 	}
678 
679 ret:
680 	return ret;
681 }
682 
683 #define NR_U32_NODE (1<<12)
684 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
685 {
686 	struct tc_u_knode *n;
687 	unsigned long i;
688 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
689 					GFP_KERNEL);
690 	if (!bitmap)
691 		return handle | 0xFFF;
692 
693 	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
694 	     n;
695 	     n = rtnl_dereference(n->next))
696 		set_bit(TC_U32_NODE(n->handle), bitmap);
697 
698 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
699 	if (i >= NR_U32_NODE)
700 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
701 
702 	kfree(bitmap);
703 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
704 }
705 
706 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
707 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
708 	[TCA_U32_HASH]		= { .type = NLA_U32 },
709 	[TCA_U32_LINK]		= { .type = NLA_U32 },
710 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
711 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
712 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
713 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
714 	[TCA_U32_FLAGS]		= { .type = NLA_U32 },
715 };
716 
717 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
718 			 unsigned long base, struct tc_u_hnode *ht,
719 			 struct tc_u_knode *n, struct nlattr **tb,
720 			 struct nlattr *est, bool ovr)
721 {
722 	struct tcf_exts e;
723 	int err;
724 
725 	err = tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
726 	if (err < 0)
727 		return err;
728 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
729 	if (err < 0)
730 		goto errout;
731 
732 	err = -EINVAL;
733 	if (tb[TCA_U32_LINK]) {
734 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
735 		struct tc_u_hnode *ht_down = NULL, *ht_old;
736 
737 		if (TC_U32_KEY(handle))
738 			goto errout;
739 
740 		if (handle) {
741 			ht_down = u32_lookup_ht(ht->tp_c, handle);
742 
743 			if (ht_down == NULL)
744 				goto errout;
745 			ht_down->refcnt++;
746 		}
747 
748 		ht_old = rtnl_dereference(n->ht_down);
749 		rcu_assign_pointer(n->ht_down, ht_down);
750 
751 		if (ht_old)
752 			ht_old->refcnt--;
753 	}
754 	if (tb[TCA_U32_CLASSID]) {
755 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
756 		tcf_bind_filter(tp, &n->res, base);
757 	}
758 
759 #ifdef CONFIG_NET_CLS_IND
760 	if (tb[TCA_U32_INDEV]) {
761 		int ret;
762 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
763 		if (ret < 0)
764 			goto errout;
765 		n->ifindex = ret;
766 	}
767 #endif
768 	tcf_exts_change(tp, &n->exts, &e);
769 
770 	return 0;
771 errout:
772 	tcf_exts_destroy(&e);
773 	return err;
774 }
775 
776 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
777 			      struct tc_u_knode *n)
778 {
779 	struct tc_u_knode __rcu **ins;
780 	struct tc_u_knode *pins;
781 	struct tc_u_hnode *ht;
782 
783 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
784 		ht = rtnl_dereference(tp->root);
785 	else
786 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
787 
788 	ins = &ht->ht[TC_U32_HASH(n->handle)];
789 
790 	/* The node must always exist for it to be replaced if this is not the
791 	 * case then something went very wrong elsewhere.
792 	 */
793 	for (pins = rtnl_dereference(*ins); ;
794 	     ins = &pins->next, pins = rtnl_dereference(*ins))
795 		if (pins->handle == n->handle)
796 			break;
797 
798 	RCU_INIT_POINTER(n->next, pins->next);
799 	rcu_assign_pointer(*ins, n);
800 }
801 
802 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
803 					 struct tc_u_knode *n)
804 {
805 	struct tc_u_knode *new;
806 	struct tc_u32_sel *s = &n->sel;
807 
808 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
809 		      GFP_KERNEL);
810 
811 	if (!new)
812 		return NULL;
813 
814 	RCU_INIT_POINTER(new->next, n->next);
815 	new->handle = n->handle;
816 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
817 
818 #ifdef CONFIG_NET_CLS_IND
819 	new->ifindex = n->ifindex;
820 #endif
821 	new->fshift = n->fshift;
822 	new->res = n->res;
823 	new->flags = n->flags;
824 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
825 
826 	/* bump reference count as long as we hold pointer to structure */
827 	if (new->ht_down)
828 		new->ht_down->refcnt++;
829 
830 #ifdef CONFIG_CLS_U32_PERF
831 	/* Statistics may be incremented by readers during update
832 	 * so we must keep them in tact. When the node is later destroyed
833 	 * a special destroy call must be made to not free the pf memory.
834 	 */
835 	new->pf = n->pf;
836 #endif
837 
838 #ifdef CONFIG_CLS_U32_MARK
839 	new->val = n->val;
840 	new->mask = n->mask;
841 	/* Similarly success statistics must be moved as pointers */
842 	new->pcpu_success = n->pcpu_success;
843 #endif
844 	new->tp = tp;
845 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
846 
847 	if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
848 		kfree(new);
849 		return NULL;
850 	}
851 
852 	return new;
853 }
854 
855 static int u32_change(struct net *net, struct sk_buff *in_skb,
856 		      struct tcf_proto *tp, unsigned long base, u32 handle,
857 		      struct nlattr **tca, unsigned long *arg, bool ovr)
858 {
859 	struct tc_u_common *tp_c = tp->data;
860 	struct tc_u_hnode *ht;
861 	struct tc_u_knode *n;
862 	struct tc_u32_sel *s;
863 	struct nlattr *opt = tca[TCA_OPTIONS];
864 	struct nlattr *tb[TCA_U32_MAX + 1];
865 	u32 htid, flags = 0;
866 	int err;
867 #ifdef CONFIG_CLS_U32_PERF
868 	size_t size;
869 #endif
870 
871 	if (opt == NULL)
872 		return handle ? -EINVAL : 0;
873 
874 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, NULL);
875 	if (err < 0)
876 		return err;
877 
878 	if (tb[TCA_U32_FLAGS]) {
879 		flags = nla_get_u32(tb[TCA_U32_FLAGS]);
880 		if (!tc_flags_valid(flags))
881 			return -EINVAL;
882 	}
883 
884 	n = (struct tc_u_knode *)*arg;
885 	if (n) {
886 		struct tc_u_knode *new;
887 
888 		if (TC_U32_KEY(n->handle) == 0)
889 			return -EINVAL;
890 
891 		if (n->flags != flags)
892 			return -EINVAL;
893 
894 		new = u32_init_knode(tp, n);
895 		if (!new)
896 			return -ENOMEM;
897 
898 		err = u32_set_parms(net, tp, base,
899 				    rtnl_dereference(n->ht_up), new, tb,
900 				    tca[TCA_RATE], ovr);
901 
902 		if (err) {
903 			u32_destroy_key(tp, new, false);
904 			return err;
905 		}
906 
907 		err = u32_replace_hw_knode(tp, new, flags);
908 		if (err) {
909 			u32_destroy_key(tp, new, false);
910 			return err;
911 		}
912 
913 		if (!tc_in_hw(new->flags))
914 			new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
915 
916 		u32_replace_knode(tp, tp_c, new);
917 		tcf_unbind_filter(tp, &n->res);
918 		call_rcu(&n->rcu, u32_delete_key_rcu);
919 		return 0;
920 	}
921 
922 	if (tb[TCA_U32_DIVISOR]) {
923 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
924 
925 		if (--divisor > 0x100)
926 			return -EINVAL;
927 		if (TC_U32_KEY(handle))
928 			return -EINVAL;
929 		if (handle == 0) {
930 			handle = gen_new_htid(tp->data);
931 			if (handle == 0)
932 				return -ENOMEM;
933 		}
934 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
935 		if (ht == NULL)
936 			return -ENOBUFS;
937 		ht->tp_c = tp_c;
938 		ht->refcnt = 1;
939 		ht->divisor = divisor;
940 		ht->handle = handle;
941 		ht->prio = tp->prio;
942 
943 		err = u32_replace_hw_hnode(tp, ht, flags);
944 		if (err) {
945 			kfree(ht);
946 			return err;
947 		}
948 
949 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
950 		rcu_assign_pointer(tp_c->hlist, ht);
951 		*arg = (unsigned long)ht;
952 
953 		return 0;
954 	}
955 
956 	if (tb[TCA_U32_HASH]) {
957 		htid = nla_get_u32(tb[TCA_U32_HASH]);
958 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
959 			ht = rtnl_dereference(tp->root);
960 			htid = ht->handle;
961 		} else {
962 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
963 			if (ht == NULL)
964 				return -EINVAL;
965 		}
966 	} else {
967 		ht = rtnl_dereference(tp->root);
968 		htid = ht->handle;
969 	}
970 
971 	if (ht->divisor < TC_U32_HASH(htid))
972 		return -EINVAL;
973 
974 	if (handle) {
975 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
976 			return -EINVAL;
977 		handle = htid | TC_U32_NODE(handle);
978 	} else
979 		handle = gen_new_kid(ht, htid);
980 
981 	if (tb[TCA_U32_SEL] == NULL)
982 		return -EINVAL;
983 
984 	s = nla_data(tb[TCA_U32_SEL]);
985 
986 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
987 	if (n == NULL)
988 		return -ENOBUFS;
989 
990 #ifdef CONFIG_CLS_U32_PERF
991 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
992 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
993 	if (!n->pf) {
994 		kfree(n);
995 		return -ENOBUFS;
996 	}
997 #endif
998 
999 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
1000 	RCU_INIT_POINTER(n->ht_up, ht);
1001 	n->handle = handle;
1002 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
1003 	n->flags = flags;
1004 	n->tp = tp;
1005 
1006 	err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
1007 	if (err < 0)
1008 		goto errout;
1009 
1010 #ifdef CONFIG_CLS_U32_MARK
1011 	n->pcpu_success = alloc_percpu(u32);
1012 	if (!n->pcpu_success) {
1013 		err = -ENOMEM;
1014 		goto errout;
1015 	}
1016 
1017 	if (tb[TCA_U32_MARK]) {
1018 		struct tc_u32_mark *mark;
1019 
1020 		mark = nla_data(tb[TCA_U32_MARK]);
1021 		n->val = mark->val;
1022 		n->mask = mark->mask;
1023 	}
1024 #endif
1025 
1026 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1027 	if (err == 0) {
1028 		struct tc_u_knode __rcu **ins;
1029 		struct tc_u_knode *pins;
1030 
1031 		err = u32_replace_hw_knode(tp, n, flags);
1032 		if (err)
1033 			goto errhw;
1034 
1035 		if (!tc_in_hw(n->flags))
1036 			n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
1037 
1038 		ins = &ht->ht[TC_U32_HASH(handle)];
1039 		for (pins = rtnl_dereference(*ins); pins;
1040 		     ins = &pins->next, pins = rtnl_dereference(*ins))
1041 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1042 				break;
1043 
1044 		RCU_INIT_POINTER(n->next, pins);
1045 		rcu_assign_pointer(*ins, n);
1046 		*arg = (unsigned long)n;
1047 		return 0;
1048 	}
1049 
1050 errhw:
1051 #ifdef CONFIG_CLS_U32_MARK
1052 	free_percpu(n->pcpu_success);
1053 #endif
1054 
1055 errout:
1056 	tcf_exts_destroy(&n->exts);
1057 #ifdef CONFIG_CLS_U32_PERF
1058 	free_percpu(n->pf);
1059 #endif
1060 	kfree(n);
1061 	return err;
1062 }
1063 
1064 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1065 {
1066 	struct tc_u_common *tp_c = tp->data;
1067 	struct tc_u_hnode *ht;
1068 	struct tc_u_knode *n;
1069 	unsigned int h;
1070 
1071 	if (arg->stop)
1072 		return;
1073 
1074 	for (ht = rtnl_dereference(tp_c->hlist);
1075 	     ht;
1076 	     ht = rtnl_dereference(ht->next)) {
1077 		if (ht->prio != tp->prio)
1078 			continue;
1079 		if (arg->count >= arg->skip) {
1080 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
1081 				arg->stop = 1;
1082 				return;
1083 			}
1084 		}
1085 		arg->count++;
1086 		for (h = 0; h <= ht->divisor; h++) {
1087 			for (n = rtnl_dereference(ht->ht[h]);
1088 			     n;
1089 			     n = rtnl_dereference(n->next)) {
1090 				if (arg->count < arg->skip) {
1091 					arg->count++;
1092 					continue;
1093 				}
1094 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
1095 					arg->stop = 1;
1096 					return;
1097 				}
1098 				arg->count++;
1099 			}
1100 		}
1101 	}
1102 }
1103 
1104 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
1105 		    struct sk_buff *skb, struct tcmsg *t)
1106 {
1107 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
1108 	struct tc_u_hnode *ht_up, *ht_down;
1109 	struct nlattr *nest;
1110 
1111 	if (n == NULL)
1112 		return skb->len;
1113 
1114 	t->tcm_handle = n->handle;
1115 
1116 	nest = nla_nest_start(skb, TCA_OPTIONS);
1117 	if (nest == NULL)
1118 		goto nla_put_failure;
1119 
1120 	if (TC_U32_KEY(n->handle) == 0) {
1121 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
1122 		u32 divisor = ht->divisor + 1;
1123 
1124 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1125 			goto nla_put_failure;
1126 	} else {
1127 #ifdef CONFIG_CLS_U32_PERF
1128 		struct tc_u32_pcnt *gpf;
1129 		int cpu;
1130 #endif
1131 
1132 		if (nla_put(skb, TCA_U32_SEL,
1133 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1134 			    &n->sel))
1135 			goto nla_put_failure;
1136 
1137 		ht_up = rtnl_dereference(n->ht_up);
1138 		if (ht_up) {
1139 			u32 htid = n->handle & 0xFFFFF000;
1140 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
1141 				goto nla_put_failure;
1142 		}
1143 		if (n->res.classid &&
1144 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1145 			goto nla_put_failure;
1146 
1147 		ht_down = rtnl_dereference(n->ht_down);
1148 		if (ht_down &&
1149 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1150 			goto nla_put_failure;
1151 
1152 		if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1153 			goto nla_put_failure;
1154 
1155 #ifdef CONFIG_CLS_U32_MARK
1156 		if ((n->val || n->mask)) {
1157 			struct tc_u32_mark mark = {.val = n->val,
1158 						   .mask = n->mask,
1159 						   .success = 0};
1160 			int cpum;
1161 
1162 			for_each_possible_cpu(cpum) {
1163 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1164 
1165 				mark.success += cnt;
1166 			}
1167 
1168 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1169 				goto nla_put_failure;
1170 		}
1171 #endif
1172 
1173 		if (tcf_exts_dump(skb, &n->exts) < 0)
1174 			goto nla_put_failure;
1175 
1176 #ifdef CONFIG_NET_CLS_IND
1177 		if (n->ifindex) {
1178 			struct net_device *dev;
1179 			dev = __dev_get_by_index(net, n->ifindex);
1180 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1181 				goto nla_put_failure;
1182 		}
1183 #endif
1184 #ifdef CONFIG_CLS_U32_PERF
1185 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1186 			      n->sel.nkeys * sizeof(u64),
1187 			      GFP_KERNEL);
1188 		if (!gpf)
1189 			goto nla_put_failure;
1190 
1191 		for_each_possible_cpu(cpu) {
1192 			int i;
1193 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1194 
1195 			gpf->rcnt += pf->rcnt;
1196 			gpf->rhit += pf->rhit;
1197 			for (i = 0; i < n->sel.nkeys; i++)
1198 				gpf->kcnts[i] += pf->kcnts[i];
1199 		}
1200 
1201 		if (nla_put_64bit(skb, TCA_U32_PCNT,
1202 				  sizeof(struct tc_u32_pcnt) +
1203 				  n->sel.nkeys * sizeof(u64),
1204 				  gpf, TCA_U32_PAD)) {
1205 			kfree(gpf);
1206 			goto nla_put_failure;
1207 		}
1208 		kfree(gpf);
1209 #endif
1210 	}
1211 
1212 	nla_nest_end(skb, nest);
1213 
1214 	if (TC_U32_KEY(n->handle))
1215 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1216 			goto nla_put_failure;
1217 	return skb->len;
1218 
1219 nla_put_failure:
1220 	nla_nest_cancel(skb, nest);
1221 	return -1;
1222 }
1223 
1224 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1225 	.kind		=	"u32",
1226 	.classify	=	u32_classify,
1227 	.init		=	u32_init,
1228 	.destroy	=	u32_destroy,
1229 	.get		=	u32_get,
1230 	.change		=	u32_change,
1231 	.delete		=	u32_delete,
1232 	.walk		=	u32_walk,
1233 	.dump		=	u32_dump,
1234 	.owner		=	THIS_MODULE,
1235 };
1236 
1237 static int __init init_u32(void)
1238 {
1239 	pr_info("u32 classifier\n");
1240 #ifdef CONFIG_CLS_U32_PERF
1241 	pr_info("    Performance counters on\n");
1242 #endif
1243 #ifdef CONFIG_NET_CLS_IND
1244 	pr_info("    input device check on\n");
1245 #endif
1246 #ifdef CONFIG_NET_CLS_ACT
1247 	pr_info("    Actions configured\n");
1248 #endif
1249 	return register_tcf_proto_ops(&cls_u32_ops);
1250 }
1251 
1252 static void __exit exit_u32(void)
1253 {
1254 	unregister_tcf_proto_ops(&cls_u32_ops);
1255 }
1256 
1257 module_init(init_u32)
1258 module_exit(exit_u32)
1259 MODULE_LICENSE("GPL");
1260