xref: /openbmc/linux/net/sched/cls_u32.c (revision 28efb0046512e8a13ed9f9bdf0d68d10bbfbe9cf)
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 <linux/netdevice.h>
44 #include <linux/hash.h>
45 #include <net/netlink.h>
46 #include <net/act_api.h>
47 #include <net/pkt_cls.h>
48 #include <linux/netdevice.h>
49 #include <linux/idr.h>
50 
51 struct tc_u_knode {
52 	struct tc_u_knode __rcu	*next;
53 	u32			handle;
54 	struct tc_u_hnode __rcu	*ht_up;
55 	struct tcf_exts		exts;
56 #ifdef CONFIG_NET_CLS_IND
57 	int			ifindex;
58 #endif
59 	u8			fshift;
60 	struct tcf_result	res;
61 	struct tc_u_hnode __rcu	*ht_down;
62 #ifdef CONFIG_CLS_U32_PERF
63 	struct tc_u32_pcnt __percpu *pf;
64 #endif
65 	u32			flags;
66 #ifdef CONFIG_CLS_U32_MARK
67 	u32			val;
68 	u32			mask;
69 	u32 __percpu		*pcpu_success;
70 #endif
71 	struct tcf_proto	*tp;
72 	struct rcu_head		rcu;
73 	/* The 'sel' field MUST be the last field in structure to allow for
74 	 * tc_u32_keys allocated at end of structure.
75 	 */
76 	struct tc_u32_sel	sel;
77 };
78 
79 struct tc_u_hnode {
80 	struct tc_u_hnode __rcu	*next;
81 	u32			handle;
82 	u32			prio;
83 	struct tc_u_common	*tp_c;
84 	int			refcnt;
85 	unsigned int		divisor;
86 	struct idr		handle_idr;
87 	struct rcu_head		rcu;
88 	/* The 'ht' field MUST be the last field in structure to allow for
89 	 * more entries allocated at end of structure.
90 	 */
91 	struct tc_u_knode __rcu	*ht[1];
92 };
93 
94 struct tc_u_common {
95 	struct tc_u_hnode __rcu	*hlist;
96 	struct Qdisc		*q;
97 	int			refcnt;
98 	struct idr		handle_idr;
99 	struct hlist_node	hnode;
100 	struct rcu_head		rcu;
101 };
102 
103 static inline unsigned int u32_hash_fold(__be32 key,
104 					 const struct tc_u32_sel *sel,
105 					 u8 fshift)
106 {
107 	unsigned int h = ntohl(key & sel->hmask) >> fshift;
108 
109 	return h;
110 }
111 
112 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp,
113 			struct tcf_result *res)
114 {
115 	struct {
116 		struct tc_u_knode *knode;
117 		unsigned int	  off;
118 	} stack[TC_U32_MAXDEPTH];
119 
120 	struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
121 	unsigned int off = skb_network_offset(skb);
122 	struct tc_u_knode *n;
123 	int sdepth = 0;
124 	int off2 = 0;
125 	int sel = 0;
126 #ifdef CONFIG_CLS_U32_PERF
127 	int j;
128 #endif
129 	int i, r;
130 
131 next_ht:
132 	n = rcu_dereference_bh(ht->ht[sel]);
133 
134 next_knode:
135 	if (n) {
136 		struct tc_u32_key *key = n->sel.keys;
137 
138 #ifdef CONFIG_CLS_U32_PERF
139 		__this_cpu_inc(n->pf->rcnt);
140 		j = 0;
141 #endif
142 
143 		if (tc_skip_sw(n->flags)) {
144 			n = rcu_dereference_bh(n->next);
145 			goto next_knode;
146 		}
147 
148 #ifdef CONFIG_CLS_U32_MARK
149 		if ((skb->mark & n->mask) != n->val) {
150 			n = rcu_dereference_bh(n->next);
151 			goto next_knode;
152 		} else {
153 			__this_cpu_inc(*n->pcpu_success);
154 		}
155 #endif
156 
157 		for (i = n->sel.nkeys; i > 0; i--, key++) {
158 			int toff = off + key->off + (off2 & key->offmask);
159 			__be32 *data, hdata;
160 
161 			if (skb_headroom(skb) + toff > INT_MAX)
162 				goto out;
163 
164 			data = skb_header_pointer(skb, toff, 4, &hdata);
165 			if (!data)
166 				goto out;
167 			if ((*data ^ key->val) & key->mask) {
168 				n = rcu_dereference_bh(n->next);
169 				goto next_knode;
170 			}
171 #ifdef CONFIG_CLS_U32_PERF
172 			__this_cpu_inc(n->pf->kcnts[j]);
173 			j++;
174 #endif
175 		}
176 
177 		ht = rcu_dereference_bh(n->ht_down);
178 		if (!ht) {
179 check_terminal:
180 			if (n->sel.flags & TC_U32_TERMINAL) {
181 
182 				*res = n->res;
183 #ifdef CONFIG_NET_CLS_IND
184 				if (!tcf_match_indev(skb, n->ifindex)) {
185 					n = rcu_dereference_bh(n->next);
186 					goto next_knode;
187 				}
188 #endif
189 #ifdef CONFIG_CLS_U32_PERF
190 				__this_cpu_inc(n->pf->rhit);
191 #endif
192 				r = tcf_exts_exec(skb, &n->exts, res);
193 				if (r < 0) {
194 					n = rcu_dereference_bh(n->next);
195 					goto next_knode;
196 				}
197 
198 				return r;
199 			}
200 			n = rcu_dereference_bh(n->next);
201 			goto next_knode;
202 		}
203 
204 		/* PUSH */
205 		if (sdepth >= TC_U32_MAXDEPTH)
206 			goto deadloop;
207 		stack[sdepth].knode = n;
208 		stack[sdepth].off = off;
209 		sdepth++;
210 
211 		ht = rcu_dereference_bh(n->ht_down);
212 		sel = 0;
213 		if (ht->divisor) {
214 			__be32 *data, hdata;
215 
216 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
217 						  &hdata);
218 			if (!data)
219 				goto out;
220 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
221 							  n->fshift);
222 		}
223 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
224 			goto next_ht;
225 
226 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
227 			off2 = n->sel.off + 3;
228 			if (n->sel.flags & TC_U32_VAROFFSET) {
229 				__be16 *data, hdata;
230 
231 				data = skb_header_pointer(skb,
232 							  off + n->sel.offoff,
233 							  2, &hdata);
234 				if (!data)
235 					goto out;
236 				off2 += ntohs(n->sel.offmask & *data) >>
237 					n->sel.offshift;
238 			}
239 			off2 &= ~3;
240 		}
241 		if (n->sel.flags & TC_U32_EAT) {
242 			off += off2;
243 			off2 = 0;
244 		}
245 
246 		if (off < skb->len)
247 			goto next_ht;
248 	}
249 
250 	/* POP */
251 	if (sdepth--) {
252 		n = stack[sdepth].knode;
253 		ht = rcu_dereference_bh(n->ht_up);
254 		off = stack[sdepth].off;
255 		goto check_terminal;
256 	}
257 out:
258 	return -1;
259 
260 deadloop:
261 	net_warn_ratelimited("cls_u32: dead loop\n");
262 	return -1;
263 }
264 
265 static struct tc_u_hnode *u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
266 {
267 	struct tc_u_hnode *ht;
268 
269 	for (ht = rtnl_dereference(tp_c->hlist);
270 	     ht;
271 	     ht = rtnl_dereference(ht->next))
272 		if (ht->handle == handle)
273 			break;
274 
275 	return ht;
276 }
277 
278 static struct tc_u_knode *u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
279 {
280 	unsigned int sel;
281 	struct tc_u_knode *n = NULL;
282 
283 	sel = TC_U32_HASH(handle);
284 	if (sel > ht->divisor)
285 		goto out;
286 
287 	for (n = rtnl_dereference(ht->ht[sel]);
288 	     n;
289 	     n = rtnl_dereference(n->next))
290 		if (n->handle == handle)
291 			break;
292 out:
293 	return n;
294 }
295 
296 
297 static void *u32_get(struct tcf_proto *tp, u32 handle)
298 {
299 	struct tc_u_hnode *ht;
300 	struct tc_u_common *tp_c = tp->data;
301 
302 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
303 		ht = rtnl_dereference(tp->root);
304 	else
305 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
306 
307 	if (!ht)
308 		return NULL;
309 
310 	if (TC_U32_KEY(handle) == 0)
311 		return ht;
312 
313 	return u32_lookup_key(ht, handle);
314 }
315 
316 static u32 gen_new_htid(struct tc_u_common *tp_c, struct tc_u_hnode *ptr)
317 {
318 	unsigned long idr_index;
319 	int err;
320 
321 	/* This is only used inside rtnl lock it is safe to increment
322 	 * without read _copy_ update semantics
323 	 */
324 	err = idr_alloc_ext(&tp_c->handle_idr, ptr, &idr_index,
325 			    1, 0x7FF, GFP_KERNEL);
326 	if (err)
327 		return 0;
328 	return (u32)(idr_index | 0x800) << 20;
329 }
330 
331 static struct hlist_head *tc_u_common_hash;
332 
333 #define U32_HASH_SHIFT 10
334 #define U32_HASH_SIZE (1 << U32_HASH_SHIFT)
335 
336 static unsigned int tc_u_hash(const struct tcf_proto *tp)
337 {
338 	struct net_device *dev = tp->q->dev_queue->dev;
339 	u32 qhandle = tp->q->handle;
340 	int ifindex = dev->ifindex;
341 
342 	return hash_64((u64)ifindex << 32 | qhandle, U32_HASH_SHIFT);
343 }
344 
345 static struct tc_u_common *tc_u_common_find(const struct tcf_proto *tp)
346 {
347 	struct tc_u_common *tc;
348 	unsigned int h;
349 
350 	h = tc_u_hash(tp);
351 	hlist_for_each_entry(tc, &tc_u_common_hash[h], hnode) {
352 		if (tc->q == tp->q)
353 			return tc;
354 	}
355 	return NULL;
356 }
357 
358 static int u32_init(struct tcf_proto *tp)
359 {
360 	struct tc_u_hnode *root_ht;
361 	struct tc_u_common *tp_c;
362 	unsigned int h;
363 
364 	tp_c = tc_u_common_find(tp);
365 
366 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
367 	if (root_ht == NULL)
368 		return -ENOBUFS;
369 
370 	root_ht->refcnt++;
371 	root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : 0x80000000;
372 	root_ht->prio = tp->prio;
373 	idr_init(&root_ht->handle_idr);
374 
375 	if (tp_c == NULL) {
376 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
377 		if (tp_c == NULL) {
378 			kfree(root_ht);
379 			return -ENOBUFS;
380 		}
381 		tp_c->q = tp->q;
382 		INIT_HLIST_NODE(&tp_c->hnode);
383 		idr_init(&tp_c->handle_idr);
384 
385 		h = tc_u_hash(tp);
386 		hlist_add_head(&tp_c->hnode, &tc_u_common_hash[h]);
387 	}
388 
389 	tp_c->refcnt++;
390 	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
391 	rcu_assign_pointer(tp_c->hlist, root_ht);
392 	root_ht->tp_c = tp_c;
393 
394 	rcu_assign_pointer(tp->root, root_ht);
395 	tp->data = tp_c;
396 	return 0;
397 }
398 
399 static int u32_destroy_key(struct tcf_proto *tp, struct tc_u_knode *n,
400 			   bool free_pf)
401 {
402 	tcf_exts_destroy(&n->exts);
403 	if (n->ht_down)
404 		n->ht_down->refcnt--;
405 #ifdef CONFIG_CLS_U32_PERF
406 	if (free_pf)
407 		free_percpu(n->pf);
408 #endif
409 #ifdef CONFIG_CLS_U32_MARK
410 	if (free_pf)
411 		free_percpu(n->pcpu_success);
412 #endif
413 	kfree(n);
414 	return 0;
415 }
416 
417 /* u32_delete_key_rcu should be called when free'ing a copied
418  * version of a tc_u_knode obtained from u32_init_knode(). When
419  * copies are obtained from u32_init_knode() the statistics are
420  * shared between the old and new copies to allow readers to
421  * continue to update the statistics during the copy. To support
422  * this the u32_delete_key_rcu variant does not free the percpu
423  * statistics.
424  */
425 static void u32_delete_key_rcu(struct rcu_head *rcu)
426 {
427 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
428 
429 	u32_destroy_key(key->tp, key, false);
430 }
431 
432 /* u32_delete_key_freepf_rcu is the rcu callback variant
433  * that free's the entire structure including the statistics
434  * percpu variables. Only use this if the key is not a copy
435  * returned by u32_init_knode(). See u32_delete_key_rcu()
436  * for the variant that should be used with keys return from
437  * u32_init_knode()
438  */
439 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
440 {
441 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
442 
443 	u32_destroy_key(key->tp, key, true);
444 }
445 
446 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
447 {
448 	struct tc_u_knode __rcu **kp;
449 	struct tc_u_knode *pkp;
450 	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
451 
452 	if (ht) {
453 		kp = &ht->ht[TC_U32_HASH(key->handle)];
454 		for (pkp = rtnl_dereference(*kp); pkp;
455 		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
456 			if (pkp == key) {
457 				RCU_INIT_POINTER(*kp, key->next);
458 
459 				tcf_unbind_filter(tp, &key->res);
460 				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
461 				return 0;
462 			}
463 		}
464 	}
465 	WARN_ON(1);
466 	return 0;
467 }
468 
469 static void u32_remove_hw_knode(struct tcf_proto *tp, u32 handle)
470 {
471 	struct net_device *dev = tp->q->dev_queue->dev;
472 	struct tc_cls_u32_offload cls_u32 = {};
473 
474 	if (!tc_should_offload(dev, 0))
475 		return;
476 
477 	tc_cls_common_offload_init(&cls_u32.common, tp);
478 	cls_u32.command = TC_CLSU32_DELETE_KNODE;
479 	cls_u32.knode.handle = handle;
480 
481 	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSU32, &cls_u32);
482 }
483 
484 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
485 				u32 flags)
486 {
487 	struct net_device *dev = tp->q->dev_queue->dev;
488 	struct tc_cls_u32_offload cls_u32 = {};
489 	int err;
490 
491 	if (!tc_should_offload(dev, flags))
492 		return tc_skip_sw(flags) ? -EINVAL : 0;
493 
494 	tc_cls_common_offload_init(&cls_u32.common, tp);
495 	cls_u32.command = TC_CLSU32_NEW_HNODE;
496 	cls_u32.hnode.divisor = h->divisor;
497 	cls_u32.hnode.handle = h->handle;
498 	cls_u32.hnode.prio = h->prio;
499 
500 	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSU32, &cls_u32);
501 	if (tc_skip_sw(flags))
502 		return err;
503 
504 	return 0;
505 }
506 
507 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
508 {
509 	struct net_device *dev = tp->q->dev_queue->dev;
510 	struct tc_cls_u32_offload cls_u32 = {};
511 
512 	if (!tc_should_offload(dev, 0))
513 		return;
514 
515 	tc_cls_common_offload_init(&cls_u32.common, tp);
516 	cls_u32.command = TC_CLSU32_DELETE_HNODE;
517 	cls_u32.hnode.divisor = h->divisor;
518 	cls_u32.hnode.handle = h->handle;
519 	cls_u32.hnode.prio = h->prio;
520 
521 	dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSU32, &cls_u32);
522 }
523 
524 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
525 				u32 flags)
526 {
527 	struct net_device *dev = tp->q->dev_queue->dev;
528 	struct tc_cls_u32_offload cls_u32 = {};
529 	int err;
530 
531 	if (!tc_should_offload(dev, flags))
532 		return tc_skip_sw(flags) ? -EINVAL : 0;
533 
534 	tc_cls_common_offload_init(&cls_u32.common, tp);
535 	cls_u32.command = TC_CLSU32_REPLACE_KNODE;
536 	cls_u32.knode.handle = n->handle;
537 	cls_u32.knode.fshift = n->fshift;
538 #ifdef CONFIG_CLS_U32_MARK
539 	cls_u32.knode.val = n->val;
540 	cls_u32.knode.mask = n->mask;
541 #else
542 	cls_u32.knode.val = 0;
543 	cls_u32.knode.mask = 0;
544 #endif
545 	cls_u32.knode.sel = &n->sel;
546 	cls_u32.knode.exts = &n->exts;
547 	if (n->ht_down)
548 		cls_u32.knode.link_handle = n->ht_down->handle;
549 
550 	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_CLSU32, &cls_u32);
551 
552 	if (!err)
553 		n->flags |= TCA_CLS_FLAGS_IN_HW;
554 
555 	if (tc_skip_sw(flags))
556 		return err;
557 
558 	return 0;
559 }
560 
561 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
562 {
563 	struct tc_u_knode *n;
564 	unsigned int h;
565 
566 	for (h = 0; h <= ht->divisor; h++) {
567 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
568 			RCU_INIT_POINTER(ht->ht[h],
569 					 rtnl_dereference(n->next));
570 			tcf_unbind_filter(tp, &n->res);
571 			u32_remove_hw_knode(tp, n->handle);
572 			idr_remove_ext(&ht->handle_idr, n->handle);
573 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
574 		}
575 	}
576 }
577 
578 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
579 {
580 	struct tc_u_common *tp_c = tp->data;
581 	struct tc_u_hnode __rcu **hn;
582 	struct tc_u_hnode *phn;
583 
584 	WARN_ON(ht->refcnt);
585 
586 	u32_clear_hnode(tp, ht);
587 
588 	hn = &tp_c->hlist;
589 	for (phn = rtnl_dereference(*hn);
590 	     phn;
591 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
592 		if (phn == ht) {
593 			u32_clear_hw_hnode(tp, ht);
594 			idr_destroy(&ht->handle_idr);
595 			idr_remove_ext(&tp_c->handle_idr, ht->handle);
596 			RCU_INIT_POINTER(*hn, ht->next);
597 			kfree_rcu(ht, rcu);
598 			return 0;
599 		}
600 	}
601 
602 	return -ENOENT;
603 }
604 
605 static bool ht_empty(struct tc_u_hnode *ht)
606 {
607 	unsigned int h;
608 
609 	for (h = 0; h <= ht->divisor; h++)
610 		if (rcu_access_pointer(ht->ht[h]))
611 			return false;
612 
613 	return true;
614 }
615 
616 static void u32_destroy(struct tcf_proto *tp)
617 {
618 	struct tc_u_common *tp_c = tp->data;
619 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
620 
621 	WARN_ON(root_ht == NULL);
622 
623 	if (root_ht && --root_ht->refcnt == 0)
624 		u32_destroy_hnode(tp, root_ht);
625 
626 	if (--tp_c->refcnt == 0) {
627 		struct tc_u_hnode *ht;
628 
629 		hlist_del(&tp_c->hnode);
630 
631 		for (ht = rtnl_dereference(tp_c->hlist);
632 		     ht;
633 		     ht = rtnl_dereference(ht->next)) {
634 			ht->refcnt--;
635 			u32_clear_hnode(tp, ht);
636 		}
637 
638 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
639 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
640 			kfree_rcu(ht, rcu);
641 		}
642 
643 		idr_destroy(&tp_c->handle_idr);
644 		kfree(tp_c);
645 	}
646 
647 	tp->data = NULL;
648 }
649 
650 static int u32_delete(struct tcf_proto *tp, void *arg, bool *last)
651 {
652 	struct tc_u_hnode *ht = arg;
653 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
654 	struct tc_u_common *tp_c = tp->data;
655 	int ret = 0;
656 
657 	if (ht == NULL)
658 		goto out;
659 
660 	if (TC_U32_KEY(ht->handle)) {
661 		u32_remove_hw_knode(tp, ht->handle);
662 		ret = u32_delete_key(tp, (struct tc_u_knode *)ht);
663 		goto out;
664 	}
665 
666 	if (root_ht == ht)
667 		return -EINVAL;
668 
669 	if (ht->refcnt == 1) {
670 		ht->refcnt--;
671 		u32_destroy_hnode(tp, ht);
672 	} else {
673 		return -EBUSY;
674 	}
675 
676 out:
677 	*last = true;
678 	if (root_ht) {
679 		if (root_ht->refcnt > 1) {
680 			*last = false;
681 			goto ret;
682 		}
683 		if (root_ht->refcnt == 1) {
684 			if (!ht_empty(root_ht)) {
685 				*last = false;
686 				goto ret;
687 			}
688 		}
689 	}
690 
691 	if (tp_c->refcnt > 1) {
692 		*last = false;
693 		goto ret;
694 	}
695 
696 	if (tp_c->refcnt == 1) {
697 		struct tc_u_hnode *ht;
698 
699 		for (ht = rtnl_dereference(tp_c->hlist);
700 		     ht;
701 		     ht = rtnl_dereference(ht->next))
702 			if (!ht_empty(ht)) {
703 				*last = false;
704 				break;
705 			}
706 	}
707 
708 ret:
709 	return ret;
710 }
711 
712 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 htid)
713 {
714 	unsigned long idr_index;
715 	u32 start = htid | 0x800;
716 	u32 max = htid | 0xFFF;
717 	u32 min = htid;
718 
719 	if (idr_alloc_ext(&ht->handle_idr, NULL, &idr_index,
720 			  start, max + 1, GFP_KERNEL)) {
721 		if (idr_alloc_ext(&ht->handle_idr, NULL, &idr_index,
722 				  min + 1, max + 1, GFP_KERNEL))
723 			return max;
724 	}
725 
726 	return (u32)idr_index;
727 }
728 
729 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
730 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
731 	[TCA_U32_HASH]		= { .type = NLA_U32 },
732 	[TCA_U32_LINK]		= { .type = NLA_U32 },
733 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
734 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
735 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
736 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
737 	[TCA_U32_FLAGS]		= { .type = NLA_U32 },
738 };
739 
740 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
741 			 unsigned long base, struct tc_u_hnode *ht,
742 			 struct tc_u_knode *n, struct nlattr **tb,
743 			 struct nlattr *est, bool ovr)
744 {
745 	int err;
746 
747 	err = tcf_exts_validate(net, tp, tb, est, &n->exts, ovr);
748 	if (err < 0)
749 		return err;
750 
751 	if (tb[TCA_U32_LINK]) {
752 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
753 		struct tc_u_hnode *ht_down = NULL, *ht_old;
754 
755 		if (TC_U32_KEY(handle))
756 			return -EINVAL;
757 
758 		if (handle) {
759 			ht_down = u32_lookup_ht(ht->tp_c, handle);
760 
761 			if (ht_down == NULL)
762 				return -EINVAL;
763 			ht_down->refcnt++;
764 		}
765 
766 		ht_old = rtnl_dereference(n->ht_down);
767 		rcu_assign_pointer(n->ht_down, ht_down);
768 
769 		if (ht_old)
770 			ht_old->refcnt--;
771 	}
772 	if (tb[TCA_U32_CLASSID]) {
773 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
774 		tcf_bind_filter(tp, &n->res, base);
775 	}
776 
777 #ifdef CONFIG_NET_CLS_IND
778 	if (tb[TCA_U32_INDEV]) {
779 		int ret;
780 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
781 		if (ret < 0)
782 			return -EINVAL;
783 		n->ifindex = ret;
784 	}
785 #endif
786 	return 0;
787 }
788 
789 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
790 			      struct tc_u_knode *n)
791 {
792 	struct tc_u_knode __rcu **ins;
793 	struct tc_u_knode *pins;
794 	struct tc_u_hnode *ht;
795 
796 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
797 		ht = rtnl_dereference(tp->root);
798 	else
799 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
800 
801 	ins = &ht->ht[TC_U32_HASH(n->handle)];
802 
803 	/* The node must always exist for it to be replaced if this is not the
804 	 * case then something went very wrong elsewhere.
805 	 */
806 	for (pins = rtnl_dereference(*ins); ;
807 	     ins = &pins->next, pins = rtnl_dereference(*ins))
808 		if (pins->handle == n->handle)
809 			break;
810 
811 	idr_replace_ext(&ht->handle_idr, n, n->handle);
812 	RCU_INIT_POINTER(n->next, pins->next);
813 	rcu_assign_pointer(*ins, n);
814 }
815 
816 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
817 					 struct tc_u_knode *n)
818 {
819 	struct tc_u_knode *new;
820 	struct tc_u32_sel *s = &n->sel;
821 
822 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
823 		      GFP_KERNEL);
824 
825 	if (!new)
826 		return NULL;
827 
828 	RCU_INIT_POINTER(new->next, n->next);
829 	new->handle = n->handle;
830 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
831 
832 #ifdef CONFIG_NET_CLS_IND
833 	new->ifindex = n->ifindex;
834 #endif
835 	new->fshift = n->fshift;
836 	new->res = n->res;
837 	new->flags = n->flags;
838 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
839 
840 	/* bump reference count as long as we hold pointer to structure */
841 	if (new->ht_down)
842 		new->ht_down->refcnt++;
843 
844 #ifdef CONFIG_CLS_U32_PERF
845 	/* Statistics may be incremented by readers during update
846 	 * so we must keep them in tact. When the node is later destroyed
847 	 * a special destroy call must be made to not free the pf memory.
848 	 */
849 	new->pf = n->pf;
850 #endif
851 
852 #ifdef CONFIG_CLS_U32_MARK
853 	new->val = n->val;
854 	new->mask = n->mask;
855 	/* Similarly success statistics must be moved as pointers */
856 	new->pcpu_success = n->pcpu_success;
857 #endif
858 	new->tp = tp;
859 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
860 
861 	if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
862 		kfree(new);
863 		return NULL;
864 	}
865 
866 	return new;
867 }
868 
869 static int u32_change(struct net *net, struct sk_buff *in_skb,
870 		      struct tcf_proto *tp, unsigned long base, u32 handle,
871 		      struct nlattr **tca, void **arg, bool ovr)
872 {
873 	struct tc_u_common *tp_c = tp->data;
874 	struct tc_u_hnode *ht;
875 	struct tc_u_knode *n;
876 	struct tc_u32_sel *s;
877 	struct nlattr *opt = tca[TCA_OPTIONS];
878 	struct nlattr *tb[TCA_U32_MAX + 1];
879 	u32 htid, flags = 0;
880 	int err;
881 #ifdef CONFIG_CLS_U32_PERF
882 	size_t size;
883 #endif
884 
885 	if (opt == NULL)
886 		return handle ? -EINVAL : 0;
887 
888 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, NULL);
889 	if (err < 0)
890 		return err;
891 
892 	if (tb[TCA_U32_FLAGS]) {
893 		flags = nla_get_u32(tb[TCA_U32_FLAGS]);
894 		if (!tc_flags_valid(flags))
895 			return -EINVAL;
896 	}
897 
898 	n = *arg;
899 	if (n) {
900 		struct tc_u_knode *new;
901 
902 		if (TC_U32_KEY(n->handle) == 0)
903 			return -EINVAL;
904 
905 		if (n->flags != flags)
906 			return -EINVAL;
907 
908 		new = u32_init_knode(tp, n);
909 		if (!new)
910 			return -ENOMEM;
911 
912 		err = u32_set_parms(net, tp, base,
913 				    rtnl_dereference(n->ht_up), new, tb,
914 				    tca[TCA_RATE], ovr);
915 
916 		if (err) {
917 			u32_destroy_key(tp, new, false);
918 			return err;
919 		}
920 
921 		err = u32_replace_hw_knode(tp, new, flags);
922 		if (err) {
923 			u32_destroy_key(tp, new, false);
924 			return err;
925 		}
926 
927 		if (!tc_in_hw(new->flags))
928 			new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
929 
930 		u32_replace_knode(tp, tp_c, new);
931 		tcf_unbind_filter(tp, &n->res);
932 		call_rcu(&n->rcu, u32_delete_key_rcu);
933 		return 0;
934 	}
935 
936 	if (tb[TCA_U32_DIVISOR]) {
937 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
938 
939 		if (--divisor > 0x100)
940 			return -EINVAL;
941 		if (TC_U32_KEY(handle))
942 			return -EINVAL;
943 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
944 		if (ht == NULL)
945 			return -ENOBUFS;
946 		if (handle == 0) {
947 			handle = gen_new_htid(tp->data, ht);
948 			if (handle == 0) {
949 				kfree(ht);
950 				return -ENOMEM;
951 			}
952 		} else {
953 			err = idr_alloc_ext(&tp_c->handle_idr, ht, NULL,
954 					    handle, handle + 1, GFP_KERNEL);
955 			if (err) {
956 				kfree(ht);
957 				return err;
958 			}
959 		}
960 		ht->tp_c = tp_c;
961 		ht->refcnt = 1;
962 		ht->divisor = divisor;
963 		ht->handle = handle;
964 		ht->prio = tp->prio;
965 		idr_init(&ht->handle_idr);
966 
967 		err = u32_replace_hw_hnode(tp, ht, flags);
968 		if (err) {
969 			idr_remove_ext(&tp_c->handle_idr, handle);
970 			kfree(ht);
971 			return err;
972 		}
973 
974 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
975 		rcu_assign_pointer(tp_c->hlist, ht);
976 		*arg = ht;
977 
978 		return 0;
979 	}
980 
981 	if (tb[TCA_U32_HASH]) {
982 		htid = nla_get_u32(tb[TCA_U32_HASH]);
983 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
984 			ht = rtnl_dereference(tp->root);
985 			htid = ht->handle;
986 		} else {
987 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
988 			if (ht == NULL)
989 				return -EINVAL;
990 		}
991 	} else {
992 		ht = rtnl_dereference(tp->root);
993 		htid = ht->handle;
994 	}
995 
996 	if (ht->divisor < TC_U32_HASH(htid))
997 		return -EINVAL;
998 
999 	if (handle) {
1000 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
1001 			return -EINVAL;
1002 		handle = htid | TC_U32_NODE(handle);
1003 		err = idr_alloc_ext(&ht->handle_idr, NULL, NULL,
1004 				    handle, handle + 1,
1005 				    GFP_KERNEL);
1006 		if (err)
1007 			return err;
1008 	} else
1009 		handle = gen_new_kid(ht, htid);
1010 
1011 	if (tb[TCA_U32_SEL] == NULL) {
1012 		err = -EINVAL;
1013 		goto erridr;
1014 	}
1015 
1016 	s = nla_data(tb[TCA_U32_SEL]);
1017 
1018 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
1019 	if (n == NULL) {
1020 		err = -ENOBUFS;
1021 		goto erridr;
1022 	}
1023 
1024 #ifdef CONFIG_CLS_U32_PERF
1025 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
1026 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
1027 	if (!n->pf) {
1028 		err = -ENOBUFS;
1029 		goto errfree;
1030 	}
1031 #endif
1032 
1033 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
1034 	RCU_INIT_POINTER(n->ht_up, ht);
1035 	n->handle = handle;
1036 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
1037 	n->flags = flags;
1038 	n->tp = tp;
1039 
1040 	err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
1041 	if (err < 0)
1042 		goto errout;
1043 
1044 #ifdef CONFIG_CLS_U32_MARK
1045 	n->pcpu_success = alloc_percpu(u32);
1046 	if (!n->pcpu_success) {
1047 		err = -ENOMEM;
1048 		goto errout;
1049 	}
1050 
1051 	if (tb[TCA_U32_MARK]) {
1052 		struct tc_u32_mark *mark;
1053 
1054 		mark = nla_data(tb[TCA_U32_MARK]);
1055 		n->val = mark->val;
1056 		n->mask = mark->mask;
1057 	}
1058 #endif
1059 
1060 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1061 	if (err == 0) {
1062 		struct tc_u_knode __rcu **ins;
1063 		struct tc_u_knode *pins;
1064 
1065 		err = u32_replace_hw_knode(tp, n, flags);
1066 		if (err)
1067 			goto errhw;
1068 
1069 		if (!tc_in_hw(n->flags))
1070 			n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
1071 
1072 		ins = &ht->ht[TC_U32_HASH(handle)];
1073 		for (pins = rtnl_dereference(*ins); pins;
1074 		     ins = &pins->next, pins = rtnl_dereference(*ins))
1075 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1076 				break;
1077 
1078 		RCU_INIT_POINTER(n->next, pins);
1079 		rcu_assign_pointer(*ins, n);
1080 		*arg = n;
1081 		return 0;
1082 	}
1083 
1084 errhw:
1085 #ifdef CONFIG_CLS_U32_MARK
1086 	free_percpu(n->pcpu_success);
1087 #endif
1088 
1089 errout:
1090 	tcf_exts_destroy(&n->exts);
1091 #ifdef CONFIG_CLS_U32_PERF
1092 errfree:
1093 	free_percpu(n->pf);
1094 #endif
1095 	kfree(n);
1096 erridr:
1097 	idr_remove_ext(&ht->handle_idr, handle);
1098 	return err;
1099 }
1100 
1101 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1102 {
1103 	struct tc_u_common *tp_c = tp->data;
1104 	struct tc_u_hnode *ht;
1105 	struct tc_u_knode *n;
1106 	unsigned int h;
1107 
1108 	if (arg->stop)
1109 		return;
1110 
1111 	for (ht = rtnl_dereference(tp_c->hlist);
1112 	     ht;
1113 	     ht = rtnl_dereference(ht->next)) {
1114 		if (ht->prio != tp->prio)
1115 			continue;
1116 		if (arg->count >= arg->skip) {
1117 			if (arg->fn(tp, ht, arg) < 0) {
1118 				arg->stop = 1;
1119 				return;
1120 			}
1121 		}
1122 		arg->count++;
1123 		for (h = 0; h <= ht->divisor; h++) {
1124 			for (n = rtnl_dereference(ht->ht[h]);
1125 			     n;
1126 			     n = rtnl_dereference(n->next)) {
1127 				if (arg->count < arg->skip) {
1128 					arg->count++;
1129 					continue;
1130 				}
1131 				if (arg->fn(tp, n, arg) < 0) {
1132 					arg->stop = 1;
1133 					return;
1134 				}
1135 				arg->count++;
1136 			}
1137 		}
1138 	}
1139 }
1140 
1141 static void u32_bind_class(void *fh, u32 classid, unsigned long cl)
1142 {
1143 	struct tc_u_knode *n = fh;
1144 
1145 	if (n && n->res.classid == classid)
1146 		n->res.class = cl;
1147 }
1148 
1149 static int u32_dump(struct net *net, struct tcf_proto *tp, void *fh,
1150 		    struct sk_buff *skb, struct tcmsg *t)
1151 {
1152 	struct tc_u_knode *n = fh;
1153 	struct tc_u_hnode *ht_up, *ht_down;
1154 	struct nlattr *nest;
1155 
1156 	if (n == NULL)
1157 		return skb->len;
1158 
1159 	t->tcm_handle = n->handle;
1160 
1161 	nest = nla_nest_start(skb, TCA_OPTIONS);
1162 	if (nest == NULL)
1163 		goto nla_put_failure;
1164 
1165 	if (TC_U32_KEY(n->handle) == 0) {
1166 		struct tc_u_hnode *ht = fh;
1167 		u32 divisor = ht->divisor + 1;
1168 
1169 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1170 			goto nla_put_failure;
1171 	} else {
1172 #ifdef CONFIG_CLS_U32_PERF
1173 		struct tc_u32_pcnt *gpf;
1174 		int cpu;
1175 #endif
1176 
1177 		if (nla_put(skb, TCA_U32_SEL,
1178 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1179 			    &n->sel))
1180 			goto nla_put_failure;
1181 
1182 		ht_up = rtnl_dereference(n->ht_up);
1183 		if (ht_up) {
1184 			u32 htid = n->handle & 0xFFFFF000;
1185 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
1186 				goto nla_put_failure;
1187 		}
1188 		if (n->res.classid &&
1189 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1190 			goto nla_put_failure;
1191 
1192 		ht_down = rtnl_dereference(n->ht_down);
1193 		if (ht_down &&
1194 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1195 			goto nla_put_failure;
1196 
1197 		if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1198 			goto nla_put_failure;
1199 
1200 #ifdef CONFIG_CLS_U32_MARK
1201 		if ((n->val || n->mask)) {
1202 			struct tc_u32_mark mark = {.val = n->val,
1203 						   .mask = n->mask,
1204 						   .success = 0};
1205 			int cpum;
1206 
1207 			for_each_possible_cpu(cpum) {
1208 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1209 
1210 				mark.success += cnt;
1211 			}
1212 
1213 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1214 				goto nla_put_failure;
1215 		}
1216 #endif
1217 
1218 		if (tcf_exts_dump(skb, &n->exts) < 0)
1219 			goto nla_put_failure;
1220 
1221 #ifdef CONFIG_NET_CLS_IND
1222 		if (n->ifindex) {
1223 			struct net_device *dev;
1224 			dev = __dev_get_by_index(net, n->ifindex);
1225 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1226 				goto nla_put_failure;
1227 		}
1228 #endif
1229 #ifdef CONFIG_CLS_U32_PERF
1230 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1231 			      n->sel.nkeys * sizeof(u64),
1232 			      GFP_KERNEL);
1233 		if (!gpf)
1234 			goto nla_put_failure;
1235 
1236 		for_each_possible_cpu(cpu) {
1237 			int i;
1238 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1239 
1240 			gpf->rcnt += pf->rcnt;
1241 			gpf->rhit += pf->rhit;
1242 			for (i = 0; i < n->sel.nkeys; i++)
1243 				gpf->kcnts[i] += pf->kcnts[i];
1244 		}
1245 
1246 		if (nla_put_64bit(skb, TCA_U32_PCNT,
1247 				  sizeof(struct tc_u32_pcnt) +
1248 				  n->sel.nkeys * sizeof(u64),
1249 				  gpf, TCA_U32_PAD)) {
1250 			kfree(gpf);
1251 			goto nla_put_failure;
1252 		}
1253 		kfree(gpf);
1254 #endif
1255 	}
1256 
1257 	nla_nest_end(skb, nest);
1258 
1259 	if (TC_U32_KEY(n->handle))
1260 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1261 			goto nla_put_failure;
1262 	return skb->len;
1263 
1264 nla_put_failure:
1265 	nla_nest_cancel(skb, nest);
1266 	return -1;
1267 }
1268 
1269 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1270 	.kind		=	"u32",
1271 	.classify	=	u32_classify,
1272 	.init		=	u32_init,
1273 	.destroy	=	u32_destroy,
1274 	.get		=	u32_get,
1275 	.change		=	u32_change,
1276 	.delete		=	u32_delete,
1277 	.walk		=	u32_walk,
1278 	.dump		=	u32_dump,
1279 	.bind_class	=	u32_bind_class,
1280 	.owner		=	THIS_MODULE,
1281 };
1282 
1283 static int __init init_u32(void)
1284 {
1285 	int i, ret;
1286 
1287 	pr_info("u32 classifier\n");
1288 #ifdef CONFIG_CLS_U32_PERF
1289 	pr_info("    Performance counters on\n");
1290 #endif
1291 #ifdef CONFIG_NET_CLS_IND
1292 	pr_info("    input device check on\n");
1293 #endif
1294 #ifdef CONFIG_NET_CLS_ACT
1295 	pr_info("    Actions configured\n");
1296 #endif
1297 	tc_u_common_hash = kvmalloc_array(U32_HASH_SIZE,
1298 					  sizeof(struct hlist_head),
1299 					  GFP_KERNEL);
1300 	if (!tc_u_common_hash)
1301 		return -ENOMEM;
1302 
1303 	for (i = 0; i < U32_HASH_SIZE; i++)
1304 		INIT_HLIST_HEAD(&tc_u_common_hash[i]);
1305 
1306 	ret = register_tcf_proto_ops(&cls_u32_ops);
1307 	if (ret)
1308 		kvfree(tc_u_common_hash);
1309 	return ret;
1310 }
1311 
1312 static void __exit exit_u32(void)
1313 {
1314 	unregister_tcf_proto_ops(&cls_u32_ops);
1315 	kvfree(tc_u_common_hash);
1316 }
1317 
1318 module_init(init_u32)
1319 module_exit(exit_u32)
1320 MODULE_LICENSE("GPL");
1321