xref: /openbmc/linux/net/sched/cls_u32.c (revision 9ee0034b8f49aaaa7e7c2da8db1038915db99c19)
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, struct tcf_result *res)
108 {
109 	struct {
110 		struct tc_u_knode *knode;
111 		unsigned int	  off;
112 	} stack[TC_U32_MAXDEPTH];
113 
114 	struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
115 	unsigned int off = skb_network_offset(skb);
116 	struct tc_u_knode *n;
117 	int sdepth = 0;
118 	int off2 = 0;
119 	int sel = 0;
120 #ifdef CONFIG_CLS_U32_PERF
121 	int j;
122 #endif
123 	int i, r;
124 
125 next_ht:
126 	n = rcu_dereference_bh(ht->ht[sel]);
127 
128 next_knode:
129 	if (n) {
130 		struct tc_u32_key *key = n->sel.keys;
131 
132 #ifdef CONFIG_CLS_U32_PERF
133 		__this_cpu_inc(n->pf->rcnt);
134 		j = 0;
135 #endif
136 
137 		if (tc_skip_sw(n->flags)) {
138 			n = rcu_dereference_bh(n->next);
139 			goto next_knode;
140 		}
141 
142 #ifdef CONFIG_CLS_U32_MARK
143 		if ((skb->mark & n->mask) != n->val) {
144 			n = rcu_dereference_bh(n->next);
145 			goto next_knode;
146 		} else {
147 			__this_cpu_inc(*n->pcpu_success);
148 		}
149 #endif
150 
151 		for (i = n->sel.nkeys; i > 0; i--, key++) {
152 			int toff = off + key->off + (off2 & key->offmask);
153 			__be32 *data, hdata;
154 
155 			if (skb_headroom(skb) + toff > INT_MAX)
156 				goto out;
157 
158 			data = skb_header_pointer(skb, toff, 4, &hdata);
159 			if (!data)
160 				goto out;
161 			if ((*data ^ key->val) & key->mask) {
162 				n = rcu_dereference_bh(n->next);
163 				goto next_knode;
164 			}
165 #ifdef CONFIG_CLS_U32_PERF
166 			__this_cpu_inc(n->pf->kcnts[j]);
167 			j++;
168 #endif
169 		}
170 
171 		ht = rcu_dereference_bh(n->ht_down);
172 		if (!ht) {
173 check_terminal:
174 			if (n->sel.flags & TC_U32_TERMINAL) {
175 
176 				*res = n->res;
177 #ifdef CONFIG_NET_CLS_IND
178 				if (!tcf_match_indev(skb, n->ifindex)) {
179 					n = rcu_dereference_bh(n->next);
180 					goto next_knode;
181 				}
182 #endif
183 #ifdef CONFIG_CLS_U32_PERF
184 				__this_cpu_inc(n->pf->rhit);
185 #endif
186 				r = tcf_exts_exec(skb, &n->exts, res);
187 				if (r < 0) {
188 					n = rcu_dereference_bh(n->next);
189 					goto next_knode;
190 				}
191 
192 				return r;
193 			}
194 			n = rcu_dereference_bh(n->next);
195 			goto next_knode;
196 		}
197 
198 		/* PUSH */
199 		if (sdepth >= TC_U32_MAXDEPTH)
200 			goto deadloop;
201 		stack[sdepth].knode = n;
202 		stack[sdepth].off = off;
203 		sdepth++;
204 
205 		ht = rcu_dereference_bh(n->ht_down);
206 		sel = 0;
207 		if (ht->divisor) {
208 			__be32 *data, hdata;
209 
210 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
211 						  &hdata);
212 			if (!data)
213 				goto out;
214 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
215 							  n->fshift);
216 		}
217 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
218 			goto next_ht;
219 
220 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
221 			off2 = n->sel.off + 3;
222 			if (n->sel.flags & TC_U32_VAROFFSET) {
223 				__be16 *data, hdata;
224 
225 				data = skb_header_pointer(skb,
226 							  off + n->sel.offoff,
227 							  2, &hdata);
228 				if (!data)
229 					goto out;
230 				off2 += ntohs(n->sel.offmask & *data) >>
231 					n->sel.offshift;
232 			}
233 			off2 &= ~3;
234 		}
235 		if (n->sel.flags & TC_U32_EAT) {
236 			off += off2;
237 			off2 = 0;
238 		}
239 
240 		if (off < skb->len)
241 			goto next_ht;
242 	}
243 
244 	/* POP */
245 	if (sdepth--) {
246 		n = stack[sdepth].knode;
247 		ht = rcu_dereference_bh(n->ht_up);
248 		off = stack[sdepth].off;
249 		goto check_terminal;
250 	}
251 out:
252 	return -1;
253 
254 deadloop:
255 	net_warn_ratelimited("cls_u32: dead loop\n");
256 	return -1;
257 }
258 
259 static struct tc_u_hnode *
260 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 *
274 u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
275 {
276 	unsigned int sel;
277 	struct tc_u_knode *n = NULL;
278 
279 	sel = TC_U32_HASH(handle);
280 	if (sel > ht->divisor)
281 		goto out;
282 
283 	for (n = rtnl_dereference(ht->ht[sel]);
284 	     n;
285 	     n = rtnl_dereference(n->next))
286 		if (n->handle == handle)
287 			break;
288 out:
289 	return n;
290 }
291 
292 
293 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
294 {
295 	struct tc_u_hnode *ht;
296 	struct tc_u_common *tp_c = tp->data;
297 
298 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
299 		ht = rtnl_dereference(tp->root);
300 	else
301 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
302 
303 	if (!ht)
304 		return 0;
305 
306 	if (TC_U32_KEY(handle) == 0)
307 		return (unsigned long)ht;
308 
309 	return (unsigned long)u32_lookup_key(ht, handle);
310 }
311 
312 static u32 gen_new_htid(struct tc_u_common *tp_c)
313 {
314 	int i = 0x800;
315 
316 	/* hgenerator only used inside rtnl lock it is safe to increment
317 	 * without read _copy_ update semantics
318 	 */
319 	do {
320 		if (++tp_c->hgenerator == 0x7FF)
321 			tp_c->hgenerator = 1;
322 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
323 
324 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
325 }
326 
327 static int u32_init(struct tcf_proto *tp)
328 {
329 	struct tc_u_hnode *root_ht;
330 	struct tc_u_common *tp_c;
331 
332 	tp_c = tp->q->u32_node;
333 
334 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
335 	if (root_ht == NULL)
336 		return -ENOBUFS;
337 
338 	root_ht->divisor = 0;
339 	root_ht->refcnt++;
340 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
341 	root_ht->prio = tp->prio;
342 
343 	if (tp_c == NULL) {
344 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
345 		if (tp_c == NULL) {
346 			kfree(root_ht);
347 			return -ENOBUFS;
348 		}
349 		tp_c->q = tp->q;
350 		tp->q->u32_node = tp_c;
351 	}
352 
353 	tp_c->refcnt++;
354 	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
355 	rcu_assign_pointer(tp_c->hlist, root_ht);
356 	root_ht->tp_c = tp_c;
357 
358 	rcu_assign_pointer(tp->root, root_ht);
359 	tp->data = tp_c;
360 	return 0;
361 }
362 
363 static int u32_destroy_key(struct tcf_proto *tp,
364 			   struct tc_u_knode *n,
365 			   bool free_pf)
366 {
367 	tcf_exts_destroy(&n->exts);
368 	if (n->ht_down)
369 		n->ht_down->refcnt--;
370 #ifdef CONFIG_CLS_U32_PERF
371 	if (free_pf)
372 		free_percpu(n->pf);
373 #endif
374 #ifdef CONFIG_CLS_U32_MARK
375 	if (free_pf)
376 		free_percpu(n->pcpu_success);
377 #endif
378 	kfree(n);
379 	return 0;
380 }
381 
382 /* u32_delete_key_rcu should be called when free'ing a copied
383  * version of a tc_u_knode obtained from u32_init_knode(). When
384  * copies are obtained from u32_init_knode() the statistics are
385  * shared between the old and new copies to allow readers to
386  * continue to update the statistics during the copy. To support
387  * this the u32_delete_key_rcu variant does not free the percpu
388  * statistics.
389  */
390 static void u32_delete_key_rcu(struct rcu_head *rcu)
391 {
392 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
393 
394 	u32_destroy_key(key->tp, key, false);
395 }
396 
397 /* u32_delete_key_freepf_rcu is the rcu callback variant
398  * that free's the entire structure including the statistics
399  * percpu variables. Only use this if the key is not a copy
400  * returned by u32_init_knode(). See u32_delete_key_rcu()
401  * for the variant that should be used with keys return from
402  * u32_init_knode()
403  */
404 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
405 {
406 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
407 
408 	u32_destroy_key(key->tp, key, true);
409 }
410 
411 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
412 {
413 	struct tc_u_knode __rcu **kp;
414 	struct tc_u_knode *pkp;
415 	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
416 
417 	if (ht) {
418 		kp = &ht->ht[TC_U32_HASH(key->handle)];
419 		for (pkp = rtnl_dereference(*kp); pkp;
420 		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
421 			if (pkp == key) {
422 				RCU_INIT_POINTER(*kp, key->next);
423 
424 				tcf_unbind_filter(tp, &key->res);
425 				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
426 				return 0;
427 			}
428 		}
429 	}
430 	WARN_ON(1);
431 	return 0;
432 }
433 
434 static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
435 {
436 	struct net_device *dev = tp->q->dev_queue->dev;
437 	struct tc_cls_u32_offload u32_offload = {0};
438 	struct tc_to_netdev offload;
439 
440 	offload.type = TC_SETUP_CLSU32;
441 	offload.cls_u32 = &u32_offload;
442 
443 	if (tc_should_offload(dev, tp, 0)) {
444 		offload.cls_u32->command = TC_CLSU32_DELETE_KNODE;
445 		offload.cls_u32->knode.handle = handle;
446 		dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
447 					      tp->protocol, &offload);
448 	}
449 }
450 
451 static int u32_replace_hw_hnode(struct tcf_proto *tp,
452 				 struct tc_u_hnode *h,
453 				 u32 flags)
454 {
455 	struct net_device *dev = tp->q->dev_queue->dev;
456 	struct tc_cls_u32_offload u32_offload = {0};
457 	struct tc_to_netdev offload;
458 	int err;
459 
460 	if (!tc_should_offload(dev, tp, flags))
461 		return tc_skip_sw(flags) ? -EINVAL : 0;
462 
463 	offload.type = TC_SETUP_CLSU32;
464 	offload.cls_u32 = &u32_offload;
465 
466 	offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
467 	offload.cls_u32->hnode.divisor = h->divisor;
468 	offload.cls_u32->hnode.handle = h->handle;
469 	offload.cls_u32->hnode.prio = h->prio;
470 
471 	err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
472 					    tp->protocol, &offload);
473 	if (tc_skip_sw(flags))
474 		return err;
475 
476 	return 0;
477 }
478 
479 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
480 {
481 	struct net_device *dev = tp->q->dev_queue->dev;
482 	struct tc_cls_u32_offload u32_offload = {0};
483 	struct tc_to_netdev offload;
484 
485 	offload.type = TC_SETUP_CLSU32;
486 	offload.cls_u32 = &u32_offload;
487 
488 	if (tc_should_offload(dev, tp, 0)) {
489 		offload.cls_u32->command = TC_CLSU32_DELETE_HNODE;
490 		offload.cls_u32->hnode.divisor = h->divisor;
491 		offload.cls_u32->hnode.handle = h->handle;
492 		offload.cls_u32->hnode.prio = h->prio;
493 
494 		dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
495 					      tp->protocol, &offload);
496 	}
497 }
498 
499 static int u32_replace_hw_knode(struct tcf_proto *tp,
500 				 struct tc_u_knode *n,
501 				 u32 flags)
502 {
503 	struct net_device *dev = tp->q->dev_queue->dev;
504 	struct tc_cls_u32_offload u32_offload = {0};
505 	struct tc_to_netdev offload;
506 	int err;
507 
508 	offload.type = TC_SETUP_CLSU32;
509 	offload.cls_u32 = &u32_offload;
510 
511 	if (!tc_should_offload(dev, tp, flags))
512 		return tc_skip_sw(flags) ? -EINVAL : 0;
513 
514 	offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
515 	offload.cls_u32->knode.handle = n->handle;
516 	offload.cls_u32->knode.fshift = n->fshift;
517 #ifdef CONFIG_CLS_U32_MARK
518 	offload.cls_u32->knode.val = n->val;
519 	offload.cls_u32->knode.mask = n->mask;
520 #else
521 	offload.cls_u32->knode.val = 0;
522 	offload.cls_u32->knode.mask = 0;
523 #endif
524 	offload.cls_u32->knode.sel = &n->sel;
525 	offload.cls_u32->knode.exts = &n->exts;
526 	if (n->ht_down)
527 		offload.cls_u32->knode.link_handle = n->ht_down->handle;
528 
529 	err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
530 					    tp->protocol, &offload);
531 	if (tc_skip_sw(flags))
532 		return err;
533 
534 	return 0;
535 }
536 
537 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
538 {
539 	struct tc_u_knode *n;
540 	unsigned int h;
541 
542 	for (h = 0; h <= ht->divisor; h++) {
543 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
544 			RCU_INIT_POINTER(ht->ht[h],
545 					 rtnl_dereference(n->next));
546 			tcf_unbind_filter(tp, &n->res);
547 			u32_remove_hw_knode(tp, n->handle);
548 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
549 		}
550 	}
551 }
552 
553 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
554 {
555 	struct tc_u_common *tp_c = tp->data;
556 	struct tc_u_hnode __rcu **hn;
557 	struct tc_u_hnode *phn;
558 
559 	WARN_ON(ht->refcnt);
560 
561 	u32_clear_hnode(tp, ht);
562 
563 	hn = &tp_c->hlist;
564 	for (phn = rtnl_dereference(*hn);
565 	     phn;
566 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
567 		if (phn == ht) {
568 			u32_clear_hw_hnode(tp, ht);
569 			RCU_INIT_POINTER(*hn, ht->next);
570 			kfree_rcu(ht, rcu);
571 			return 0;
572 		}
573 	}
574 
575 	return -ENOENT;
576 }
577 
578 static bool ht_empty(struct tc_u_hnode *ht)
579 {
580 	unsigned int h;
581 
582 	for (h = 0; h <= ht->divisor; h++)
583 		if (rcu_access_pointer(ht->ht[h]))
584 			return false;
585 
586 	return true;
587 }
588 
589 static bool u32_destroy(struct tcf_proto *tp, bool force)
590 {
591 	struct tc_u_common *tp_c = tp->data;
592 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
593 
594 	WARN_ON(root_ht == NULL);
595 
596 	if (!force) {
597 		if (root_ht) {
598 			if (root_ht->refcnt > 1)
599 				return false;
600 			if (root_ht->refcnt == 1) {
601 				if (!ht_empty(root_ht))
602 					return false;
603 			}
604 		}
605 
606 		if (tp_c->refcnt > 1)
607 			return false;
608 
609 		if (tp_c->refcnt == 1) {
610 			struct tc_u_hnode *ht;
611 
612 			for (ht = rtnl_dereference(tp_c->hlist);
613 			     ht;
614 			     ht = rtnl_dereference(ht->next))
615 				if (!ht_empty(ht))
616 					return false;
617 		}
618 	}
619 
620 	if (root_ht && --root_ht->refcnt == 0)
621 		u32_destroy_hnode(tp, root_ht);
622 
623 	if (--tp_c->refcnt == 0) {
624 		struct tc_u_hnode *ht;
625 
626 		tp->q->u32_node = NULL;
627 
628 		for (ht = rtnl_dereference(tp_c->hlist);
629 		     ht;
630 		     ht = rtnl_dereference(ht->next)) {
631 			ht->refcnt--;
632 			u32_clear_hnode(tp, ht);
633 		}
634 
635 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
636 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
637 			kfree_rcu(ht, rcu);
638 		}
639 
640 		kfree(tp_c);
641 	}
642 
643 	tp->data = NULL;
644 	return true;
645 }
646 
647 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
648 {
649 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
650 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
651 
652 	if (ht == NULL)
653 		return 0;
654 
655 	if (TC_U32_KEY(ht->handle)) {
656 		u32_remove_hw_knode(tp, ht->handle);
657 		return u32_delete_key(tp, (struct tc_u_knode *)ht);
658 	}
659 
660 	if (root_ht == ht)
661 		return -EINVAL;
662 
663 	if (ht->refcnt == 1) {
664 		ht->refcnt--;
665 		u32_destroy_hnode(tp, ht);
666 	} else {
667 		return -EBUSY;
668 	}
669 
670 	return 0;
671 }
672 
673 #define NR_U32_NODE (1<<12)
674 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
675 {
676 	struct tc_u_knode *n;
677 	unsigned long i;
678 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
679 					GFP_KERNEL);
680 	if (!bitmap)
681 		return handle | 0xFFF;
682 
683 	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
684 	     n;
685 	     n = rtnl_dereference(n->next))
686 		set_bit(TC_U32_NODE(n->handle), bitmap);
687 
688 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
689 	if (i >= NR_U32_NODE)
690 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
691 
692 	kfree(bitmap);
693 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
694 }
695 
696 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
697 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
698 	[TCA_U32_HASH]		= { .type = NLA_U32 },
699 	[TCA_U32_LINK]		= { .type = NLA_U32 },
700 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
701 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
702 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
703 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
704 	[TCA_U32_FLAGS]		= { .type = NLA_U32 },
705 };
706 
707 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
708 			 unsigned long base, struct tc_u_hnode *ht,
709 			 struct tc_u_knode *n, struct nlattr **tb,
710 			 struct nlattr *est, bool ovr)
711 {
712 	struct tcf_exts e;
713 	int err;
714 
715 	err = tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
716 	if (err < 0)
717 		return err;
718 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
719 	if (err < 0)
720 		goto errout;
721 
722 	err = -EINVAL;
723 	if (tb[TCA_U32_LINK]) {
724 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
725 		struct tc_u_hnode *ht_down = NULL, *ht_old;
726 
727 		if (TC_U32_KEY(handle))
728 			goto errout;
729 
730 		if (handle) {
731 			ht_down = u32_lookup_ht(ht->tp_c, handle);
732 
733 			if (ht_down == NULL)
734 				goto errout;
735 			ht_down->refcnt++;
736 		}
737 
738 		ht_old = rtnl_dereference(n->ht_down);
739 		rcu_assign_pointer(n->ht_down, ht_down);
740 
741 		if (ht_old)
742 			ht_old->refcnt--;
743 	}
744 	if (tb[TCA_U32_CLASSID]) {
745 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
746 		tcf_bind_filter(tp, &n->res, base);
747 	}
748 
749 #ifdef CONFIG_NET_CLS_IND
750 	if (tb[TCA_U32_INDEV]) {
751 		int ret;
752 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
753 		if (ret < 0)
754 			goto errout;
755 		n->ifindex = ret;
756 	}
757 #endif
758 	tcf_exts_change(tp, &n->exts, &e);
759 
760 	return 0;
761 errout:
762 	tcf_exts_destroy(&e);
763 	return err;
764 }
765 
766 static void u32_replace_knode(struct tcf_proto *tp,
767 			      struct tc_u_common *tp_c,
768 			      struct tc_u_knode *n)
769 {
770 	struct tc_u_knode __rcu **ins;
771 	struct tc_u_knode *pins;
772 	struct tc_u_hnode *ht;
773 
774 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
775 		ht = rtnl_dereference(tp->root);
776 	else
777 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
778 
779 	ins = &ht->ht[TC_U32_HASH(n->handle)];
780 
781 	/* The node must always exist for it to be replaced if this is not the
782 	 * case then something went very wrong elsewhere.
783 	 */
784 	for (pins = rtnl_dereference(*ins); ;
785 	     ins = &pins->next, pins = rtnl_dereference(*ins))
786 		if (pins->handle == n->handle)
787 			break;
788 
789 	RCU_INIT_POINTER(n->next, pins->next);
790 	rcu_assign_pointer(*ins, n);
791 }
792 
793 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
794 					 struct tc_u_knode *n)
795 {
796 	struct tc_u_knode *new;
797 	struct tc_u32_sel *s = &n->sel;
798 
799 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
800 		      GFP_KERNEL);
801 
802 	if (!new)
803 		return NULL;
804 
805 	RCU_INIT_POINTER(new->next, n->next);
806 	new->handle = n->handle;
807 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
808 
809 #ifdef CONFIG_NET_CLS_IND
810 	new->ifindex = n->ifindex;
811 #endif
812 	new->fshift = n->fshift;
813 	new->res = n->res;
814 	new->flags = n->flags;
815 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
816 
817 	/* bump reference count as long as we hold pointer to structure */
818 	if (new->ht_down)
819 		new->ht_down->refcnt++;
820 
821 #ifdef CONFIG_CLS_U32_PERF
822 	/* Statistics may be incremented by readers during update
823 	 * so we must keep them in tact. When the node is later destroyed
824 	 * a special destroy call must be made to not free the pf memory.
825 	 */
826 	new->pf = n->pf;
827 #endif
828 
829 #ifdef CONFIG_CLS_U32_MARK
830 	new->val = n->val;
831 	new->mask = n->mask;
832 	/* Similarly success statistics must be moved as pointers */
833 	new->pcpu_success = n->pcpu_success;
834 #endif
835 	new->tp = tp;
836 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
837 
838 	if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
839 		kfree(new);
840 		return NULL;
841 	}
842 
843 	return new;
844 }
845 
846 static int u32_change(struct net *net, struct sk_buff *in_skb,
847 		      struct tcf_proto *tp, unsigned long base, u32 handle,
848 		      struct nlattr **tca,
849 		      unsigned long *arg, bool ovr)
850 {
851 	struct tc_u_common *tp_c = tp->data;
852 	struct tc_u_hnode *ht;
853 	struct tc_u_knode *n;
854 	struct tc_u32_sel *s;
855 	struct nlattr *opt = tca[TCA_OPTIONS];
856 	struct nlattr *tb[TCA_U32_MAX + 1];
857 	u32 htid, flags = 0;
858 	int err;
859 #ifdef CONFIG_CLS_U32_PERF
860 	size_t size;
861 #endif
862 
863 	if (opt == NULL)
864 		return handle ? -EINVAL : 0;
865 
866 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
867 	if (err < 0)
868 		return err;
869 
870 	if (tb[TCA_U32_FLAGS]) {
871 		flags = nla_get_u32(tb[TCA_U32_FLAGS]);
872 		if (!tc_flags_valid(flags))
873 			return -EINVAL;
874 	}
875 
876 	n = (struct tc_u_knode *)*arg;
877 	if (n) {
878 		struct tc_u_knode *new;
879 
880 		if (TC_U32_KEY(n->handle) == 0)
881 			return -EINVAL;
882 
883 		if (n->flags != flags)
884 			return -EINVAL;
885 
886 		new = u32_init_knode(tp, n);
887 		if (!new)
888 			return -ENOMEM;
889 
890 		err = u32_set_parms(net, tp, base,
891 				    rtnl_dereference(n->ht_up), new, tb,
892 				    tca[TCA_RATE], ovr);
893 
894 		if (err) {
895 			u32_destroy_key(tp, new, false);
896 			return err;
897 		}
898 
899 		err = u32_replace_hw_knode(tp, new, flags);
900 		if (err) {
901 			u32_destroy_key(tp, new, false);
902 			return err;
903 		}
904 
905 		u32_replace_knode(tp, tp_c, new);
906 		tcf_unbind_filter(tp, &n->res);
907 		call_rcu(&n->rcu, u32_delete_key_rcu);
908 		return 0;
909 	}
910 
911 	if (tb[TCA_U32_DIVISOR]) {
912 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
913 
914 		if (--divisor > 0x100)
915 			return -EINVAL;
916 		if (TC_U32_KEY(handle))
917 			return -EINVAL;
918 		if (handle == 0) {
919 			handle = gen_new_htid(tp->data);
920 			if (handle == 0)
921 				return -ENOMEM;
922 		}
923 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
924 		if (ht == NULL)
925 			return -ENOBUFS;
926 		ht->tp_c = tp_c;
927 		ht->refcnt = 1;
928 		ht->divisor = divisor;
929 		ht->handle = handle;
930 		ht->prio = tp->prio;
931 
932 		err = u32_replace_hw_hnode(tp, ht, flags);
933 		if (err) {
934 			kfree(ht);
935 			return err;
936 		}
937 
938 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
939 		rcu_assign_pointer(tp_c->hlist, ht);
940 		*arg = (unsigned long)ht;
941 
942 		return 0;
943 	}
944 
945 	if (tb[TCA_U32_HASH]) {
946 		htid = nla_get_u32(tb[TCA_U32_HASH]);
947 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
948 			ht = rtnl_dereference(tp->root);
949 			htid = ht->handle;
950 		} else {
951 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
952 			if (ht == NULL)
953 				return -EINVAL;
954 		}
955 	} else {
956 		ht = rtnl_dereference(tp->root);
957 		htid = ht->handle;
958 	}
959 
960 	if (ht->divisor < TC_U32_HASH(htid))
961 		return -EINVAL;
962 
963 	if (handle) {
964 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
965 			return -EINVAL;
966 		handle = htid | TC_U32_NODE(handle);
967 	} else
968 		handle = gen_new_kid(ht, htid);
969 
970 	if (tb[TCA_U32_SEL] == NULL)
971 		return -EINVAL;
972 
973 	s = nla_data(tb[TCA_U32_SEL]);
974 
975 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
976 	if (n == NULL)
977 		return -ENOBUFS;
978 
979 #ifdef CONFIG_CLS_U32_PERF
980 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
981 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
982 	if (!n->pf) {
983 		kfree(n);
984 		return -ENOBUFS;
985 	}
986 #endif
987 
988 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
989 	RCU_INIT_POINTER(n->ht_up, ht);
990 	n->handle = handle;
991 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
992 	n->flags = flags;
993 	n->tp = tp;
994 
995 	err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
996 	if (err < 0)
997 		goto errout;
998 
999 #ifdef CONFIG_CLS_U32_MARK
1000 	n->pcpu_success = alloc_percpu(u32);
1001 	if (!n->pcpu_success) {
1002 		err = -ENOMEM;
1003 		goto errout;
1004 	}
1005 
1006 	if (tb[TCA_U32_MARK]) {
1007 		struct tc_u32_mark *mark;
1008 
1009 		mark = nla_data(tb[TCA_U32_MARK]);
1010 		n->val = mark->val;
1011 		n->mask = mark->mask;
1012 	}
1013 #endif
1014 
1015 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1016 	if (err == 0) {
1017 		struct tc_u_knode __rcu **ins;
1018 		struct tc_u_knode *pins;
1019 
1020 		err = u32_replace_hw_knode(tp, n, flags);
1021 		if (err)
1022 			goto errhw;
1023 
1024 		ins = &ht->ht[TC_U32_HASH(handle)];
1025 		for (pins = rtnl_dereference(*ins); pins;
1026 		     ins = &pins->next, pins = rtnl_dereference(*ins))
1027 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1028 				break;
1029 
1030 		RCU_INIT_POINTER(n->next, pins);
1031 		rcu_assign_pointer(*ins, n);
1032 		*arg = (unsigned long)n;
1033 		return 0;
1034 	}
1035 
1036 errhw:
1037 #ifdef CONFIG_CLS_U32_MARK
1038 	free_percpu(n->pcpu_success);
1039 #endif
1040 
1041 errout:
1042 	tcf_exts_destroy(&n->exts);
1043 #ifdef CONFIG_CLS_U32_PERF
1044 	free_percpu(n->pf);
1045 #endif
1046 	kfree(n);
1047 	return err;
1048 }
1049 
1050 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1051 {
1052 	struct tc_u_common *tp_c = tp->data;
1053 	struct tc_u_hnode *ht;
1054 	struct tc_u_knode *n;
1055 	unsigned int h;
1056 
1057 	if (arg->stop)
1058 		return;
1059 
1060 	for (ht = rtnl_dereference(tp_c->hlist);
1061 	     ht;
1062 	     ht = rtnl_dereference(ht->next)) {
1063 		if (ht->prio != tp->prio)
1064 			continue;
1065 		if (arg->count >= arg->skip) {
1066 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
1067 				arg->stop = 1;
1068 				return;
1069 			}
1070 		}
1071 		arg->count++;
1072 		for (h = 0; h <= ht->divisor; h++) {
1073 			for (n = rtnl_dereference(ht->ht[h]);
1074 			     n;
1075 			     n = rtnl_dereference(n->next)) {
1076 				if (arg->count < arg->skip) {
1077 					arg->count++;
1078 					continue;
1079 				}
1080 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
1081 					arg->stop = 1;
1082 					return;
1083 				}
1084 				arg->count++;
1085 			}
1086 		}
1087 	}
1088 }
1089 
1090 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
1091 		     struct sk_buff *skb, struct tcmsg *t)
1092 {
1093 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
1094 	struct tc_u_hnode *ht_up, *ht_down;
1095 	struct nlattr *nest;
1096 
1097 	if (n == NULL)
1098 		return skb->len;
1099 
1100 	t->tcm_handle = n->handle;
1101 
1102 	nest = nla_nest_start(skb, TCA_OPTIONS);
1103 	if (nest == NULL)
1104 		goto nla_put_failure;
1105 
1106 	if (TC_U32_KEY(n->handle) == 0) {
1107 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
1108 		u32 divisor = ht->divisor + 1;
1109 
1110 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1111 			goto nla_put_failure;
1112 	} else {
1113 #ifdef CONFIG_CLS_U32_PERF
1114 		struct tc_u32_pcnt *gpf;
1115 		int cpu;
1116 #endif
1117 
1118 		if (nla_put(skb, TCA_U32_SEL,
1119 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1120 			    &n->sel))
1121 			goto nla_put_failure;
1122 
1123 		ht_up = rtnl_dereference(n->ht_up);
1124 		if (ht_up) {
1125 			u32 htid = n->handle & 0xFFFFF000;
1126 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
1127 				goto nla_put_failure;
1128 		}
1129 		if (n->res.classid &&
1130 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1131 			goto nla_put_failure;
1132 
1133 		ht_down = rtnl_dereference(n->ht_down);
1134 		if (ht_down &&
1135 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1136 			goto nla_put_failure;
1137 
1138 		if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1139 			goto nla_put_failure;
1140 
1141 #ifdef CONFIG_CLS_U32_MARK
1142 		if ((n->val || n->mask)) {
1143 			struct tc_u32_mark mark = {.val = n->val,
1144 						   .mask = n->mask,
1145 						   .success = 0};
1146 			int cpum;
1147 
1148 			for_each_possible_cpu(cpum) {
1149 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1150 
1151 				mark.success += cnt;
1152 			}
1153 
1154 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1155 				goto nla_put_failure;
1156 		}
1157 #endif
1158 
1159 		if (tcf_exts_dump(skb, &n->exts) < 0)
1160 			goto nla_put_failure;
1161 
1162 #ifdef CONFIG_NET_CLS_IND
1163 		if (n->ifindex) {
1164 			struct net_device *dev;
1165 			dev = __dev_get_by_index(net, n->ifindex);
1166 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1167 				goto nla_put_failure;
1168 		}
1169 #endif
1170 #ifdef CONFIG_CLS_U32_PERF
1171 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1172 			      n->sel.nkeys * sizeof(u64),
1173 			      GFP_KERNEL);
1174 		if (!gpf)
1175 			goto nla_put_failure;
1176 
1177 		for_each_possible_cpu(cpu) {
1178 			int i;
1179 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1180 
1181 			gpf->rcnt += pf->rcnt;
1182 			gpf->rhit += pf->rhit;
1183 			for (i = 0; i < n->sel.nkeys; i++)
1184 				gpf->kcnts[i] += pf->kcnts[i];
1185 		}
1186 
1187 		if (nla_put_64bit(skb, TCA_U32_PCNT,
1188 				  sizeof(struct tc_u32_pcnt) +
1189 				  n->sel.nkeys * sizeof(u64),
1190 				  gpf, TCA_U32_PAD)) {
1191 			kfree(gpf);
1192 			goto nla_put_failure;
1193 		}
1194 		kfree(gpf);
1195 #endif
1196 	}
1197 
1198 	nla_nest_end(skb, nest);
1199 
1200 	if (TC_U32_KEY(n->handle))
1201 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1202 			goto nla_put_failure;
1203 	return skb->len;
1204 
1205 nla_put_failure:
1206 	nla_nest_cancel(skb, nest);
1207 	return -1;
1208 }
1209 
1210 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1211 	.kind		=	"u32",
1212 	.classify	=	u32_classify,
1213 	.init		=	u32_init,
1214 	.destroy	=	u32_destroy,
1215 	.get		=	u32_get,
1216 	.change		=	u32_change,
1217 	.delete		=	u32_delete,
1218 	.walk		=	u32_walk,
1219 	.dump		=	u32_dump,
1220 	.owner		=	THIS_MODULE,
1221 };
1222 
1223 static int __init init_u32(void)
1224 {
1225 	pr_info("u32 classifier\n");
1226 #ifdef CONFIG_CLS_U32_PERF
1227 	pr_info("    Performance counters on\n");
1228 #endif
1229 #ifdef CONFIG_NET_CLS_IND
1230 	pr_info("    input device check on\n");
1231 #endif
1232 #ifdef CONFIG_NET_CLS_ACT
1233 	pr_info("    Actions configured\n");
1234 #endif
1235 	return register_tcf_proto_ops(&cls_u32_ops);
1236 }
1237 
1238 static void __exit exit_u32(void)
1239 {
1240 	unregister_tcf_proto_ops(&cls_u32_ops);
1241 }
1242 
1243 module_init(init_u32)
1244 module_exit(exit_u32)
1245 MODULE_LICENSE("GPL");
1246