xref: /openbmc/linux/net/sched/cls_u32.c (revision a977d045)
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->chain->index, tp->protocol,
445 					      &offload);
446 	}
447 }
448 
449 static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
450 				u32 flags)
451 {
452 	struct net_device *dev = tp->q->dev_queue->dev;
453 	struct tc_cls_u32_offload u32_offload = {0};
454 	struct tc_to_netdev offload;
455 	int err;
456 
457 	if (!tc_should_offload(dev, tp, flags))
458 		return tc_skip_sw(flags) ? -EINVAL : 0;
459 
460 	offload.type = TC_SETUP_CLSU32;
461 	offload.cls_u32 = &u32_offload;
462 
463 	offload.cls_u32->command = TC_CLSU32_NEW_HNODE;
464 	offload.cls_u32->hnode.divisor = h->divisor;
465 	offload.cls_u32->hnode.handle = h->handle;
466 	offload.cls_u32->hnode.prio = h->prio;
467 
468 	err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
469 					    tp->chain->index, tp->protocol,
470 					    &offload);
471 	if (tc_skip_sw(flags))
472 		return err;
473 
474 	return 0;
475 }
476 
477 static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h)
478 {
479 	struct net_device *dev = tp->q->dev_queue->dev;
480 	struct tc_cls_u32_offload u32_offload = {0};
481 	struct tc_to_netdev offload;
482 
483 	offload.type = TC_SETUP_CLSU32;
484 	offload.cls_u32 = &u32_offload;
485 
486 	if (tc_should_offload(dev, tp, 0)) {
487 		offload.cls_u32->command = TC_CLSU32_DELETE_HNODE;
488 		offload.cls_u32->hnode.divisor = h->divisor;
489 		offload.cls_u32->hnode.handle = h->handle;
490 		offload.cls_u32->hnode.prio = h->prio;
491 
492 		dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
493 					      tp->chain->index, tp->protocol,
494 					      &offload);
495 	}
496 }
497 
498 static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
499 				u32 flags)
500 {
501 	struct net_device *dev = tp->q->dev_queue->dev;
502 	struct tc_cls_u32_offload u32_offload = {0};
503 	struct tc_to_netdev offload;
504 	int err;
505 
506 	offload.type = TC_SETUP_CLSU32;
507 	offload.cls_u32 = &u32_offload;
508 
509 	if (!tc_should_offload(dev, tp, flags))
510 		return tc_skip_sw(flags) ? -EINVAL : 0;
511 
512 	offload.cls_u32->command = TC_CLSU32_REPLACE_KNODE;
513 	offload.cls_u32->knode.handle = n->handle;
514 	offload.cls_u32->knode.fshift = n->fshift;
515 #ifdef CONFIG_CLS_U32_MARK
516 	offload.cls_u32->knode.val = n->val;
517 	offload.cls_u32->knode.mask = n->mask;
518 #else
519 	offload.cls_u32->knode.val = 0;
520 	offload.cls_u32->knode.mask = 0;
521 #endif
522 	offload.cls_u32->knode.sel = &n->sel;
523 	offload.cls_u32->knode.exts = &n->exts;
524 	if (n->ht_down)
525 		offload.cls_u32->knode.link_handle = n->ht_down->handle;
526 
527 	err = dev->netdev_ops->ndo_setup_tc(dev, tp->q->handle,
528 					    tp->chain->index, tp->protocol,
529 					    &offload);
530 
531 	if (!err)
532 		n->flags |= TCA_CLS_FLAGS_IN_HW;
533 
534 	if (tc_skip_sw(flags))
535 		return err;
536 
537 	return 0;
538 }
539 
540 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
541 {
542 	struct tc_u_knode *n;
543 	unsigned int h;
544 
545 	for (h = 0; h <= ht->divisor; h++) {
546 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
547 			RCU_INIT_POINTER(ht->ht[h],
548 					 rtnl_dereference(n->next));
549 			tcf_unbind_filter(tp, &n->res);
550 			u32_remove_hw_knode(tp, n->handle);
551 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
552 		}
553 	}
554 }
555 
556 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
557 {
558 	struct tc_u_common *tp_c = tp->data;
559 	struct tc_u_hnode __rcu **hn;
560 	struct tc_u_hnode *phn;
561 
562 	WARN_ON(ht->refcnt);
563 
564 	u32_clear_hnode(tp, ht);
565 
566 	hn = &tp_c->hlist;
567 	for (phn = rtnl_dereference(*hn);
568 	     phn;
569 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
570 		if (phn == ht) {
571 			u32_clear_hw_hnode(tp, ht);
572 			RCU_INIT_POINTER(*hn, ht->next);
573 			kfree_rcu(ht, rcu);
574 			return 0;
575 		}
576 	}
577 
578 	return -ENOENT;
579 }
580 
581 static bool ht_empty(struct tc_u_hnode *ht)
582 {
583 	unsigned int h;
584 
585 	for (h = 0; h <= ht->divisor; h++)
586 		if (rcu_access_pointer(ht->ht[h]))
587 			return false;
588 
589 	return true;
590 }
591 
592 static void u32_destroy(struct tcf_proto *tp)
593 {
594 	struct tc_u_common *tp_c = tp->data;
595 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
596 
597 	WARN_ON(root_ht == NULL);
598 
599 	if (root_ht && --root_ht->refcnt == 0)
600 		u32_destroy_hnode(tp, root_ht);
601 
602 	if (--tp_c->refcnt == 0) {
603 		struct tc_u_hnode *ht;
604 
605 		tp->q->u32_node = NULL;
606 
607 		for (ht = rtnl_dereference(tp_c->hlist);
608 		     ht;
609 		     ht = rtnl_dereference(ht->next)) {
610 			ht->refcnt--;
611 			u32_clear_hnode(tp, ht);
612 		}
613 
614 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
615 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
616 			kfree_rcu(ht, rcu);
617 		}
618 
619 		kfree(tp_c);
620 	}
621 
622 	tp->data = NULL;
623 }
624 
625 static int u32_delete(struct tcf_proto *tp, unsigned long arg, bool *last)
626 {
627 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
628 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
629 	struct tc_u_common *tp_c = tp->data;
630 	int ret = 0;
631 
632 	if (ht == NULL)
633 		goto out;
634 
635 	if (TC_U32_KEY(ht->handle)) {
636 		u32_remove_hw_knode(tp, ht->handle);
637 		ret = u32_delete_key(tp, (struct tc_u_knode *)ht);
638 		goto out;
639 	}
640 
641 	if (root_ht == ht)
642 		return -EINVAL;
643 
644 	if (ht->refcnt == 1) {
645 		ht->refcnt--;
646 		u32_destroy_hnode(tp, ht);
647 	} else {
648 		return -EBUSY;
649 	}
650 
651 out:
652 	*last = true;
653 	if (root_ht) {
654 		if (root_ht->refcnt > 1) {
655 			*last = false;
656 			goto ret;
657 		}
658 		if (root_ht->refcnt == 1) {
659 			if (!ht_empty(root_ht)) {
660 				*last = false;
661 				goto ret;
662 			}
663 		}
664 	}
665 
666 	if (tp_c->refcnt > 1) {
667 		*last = false;
668 		goto ret;
669 	}
670 
671 	if (tp_c->refcnt == 1) {
672 		struct tc_u_hnode *ht;
673 
674 		for (ht = rtnl_dereference(tp_c->hlist);
675 		     ht;
676 		     ht = rtnl_dereference(ht->next))
677 			if (!ht_empty(ht)) {
678 				*last = false;
679 				break;
680 			}
681 	}
682 
683 ret:
684 	return ret;
685 }
686 
687 #define NR_U32_NODE (1<<12)
688 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
689 {
690 	struct tc_u_knode *n;
691 	unsigned long i;
692 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
693 					GFP_KERNEL);
694 	if (!bitmap)
695 		return handle | 0xFFF;
696 
697 	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
698 	     n;
699 	     n = rtnl_dereference(n->next))
700 		set_bit(TC_U32_NODE(n->handle), bitmap);
701 
702 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
703 	if (i >= NR_U32_NODE)
704 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
705 
706 	kfree(bitmap);
707 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
708 }
709 
710 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
711 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
712 	[TCA_U32_HASH]		= { .type = NLA_U32 },
713 	[TCA_U32_LINK]		= { .type = NLA_U32 },
714 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
715 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
716 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
717 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
718 	[TCA_U32_FLAGS]		= { .type = NLA_U32 },
719 };
720 
721 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
722 			 unsigned long base, struct tc_u_hnode *ht,
723 			 struct tc_u_knode *n, struct nlattr **tb,
724 			 struct nlattr *est, bool ovr)
725 {
726 	struct tcf_exts e;
727 	int err;
728 
729 	err = tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
730 	if (err < 0)
731 		return err;
732 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
733 	if (err < 0)
734 		goto errout;
735 
736 	err = -EINVAL;
737 	if (tb[TCA_U32_LINK]) {
738 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
739 		struct tc_u_hnode *ht_down = NULL, *ht_old;
740 
741 		if (TC_U32_KEY(handle))
742 			goto errout;
743 
744 		if (handle) {
745 			ht_down = u32_lookup_ht(ht->tp_c, handle);
746 
747 			if (ht_down == NULL)
748 				goto errout;
749 			ht_down->refcnt++;
750 		}
751 
752 		ht_old = rtnl_dereference(n->ht_down);
753 		rcu_assign_pointer(n->ht_down, ht_down);
754 
755 		if (ht_old)
756 			ht_old->refcnt--;
757 	}
758 	if (tb[TCA_U32_CLASSID]) {
759 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
760 		tcf_bind_filter(tp, &n->res, base);
761 	}
762 
763 #ifdef CONFIG_NET_CLS_IND
764 	if (tb[TCA_U32_INDEV]) {
765 		int ret;
766 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
767 		if (ret < 0)
768 			goto errout;
769 		n->ifindex = ret;
770 	}
771 #endif
772 	tcf_exts_change(tp, &n->exts, &e);
773 
774 	return 0;
775 errout:
776 	tcf_exts_destroy(&e);
777 	return err;
778 }
779 
780 static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
781 			      struct tc_u_knode *n)
782 {
783 	struct tc_u_knode __rcu **ins;
784 	struct tc_u_knode *pins;
785 	struct tc_u_hnode *ht;
786 
787 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
788 		ht = rtnl_dereference(tp->root);
789 	else
790 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
791 
792 	ins = &ht->ht[TC_U32_HASH(n->handle)];
793 
794 	/* The node must always exist for it to be replaced if this is not the
795 	 * case then something went very wrong elsewhere.
796 	 */
797 	for (pins = rtnl_dereference(*ins); ;
798 	     ins = &pins->next, pins = rtnl_dereference(*ins))
799 		if (pins->handle == n->handle)
800 			break;
801 
802 	RCU_INIT_POINTER(n->next, pins->next);
803 	rcu_assign_pointer(*ins, n);
804 }
805 
806 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
807 					 struct tc_u_knode *n)
808 {
809 	struct tc_u_knode *new;
810 	struct tc_u32_sel *s = &n->sel;
811 
812 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
813 		      GFP_KERNEL);
814 
815 	if (!new)
816 		return NULL;
817 
818 	RCU_INIT_POINTER(new->next, n->next);
819 	new->handle = n->handle;
820 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
821 
822 #ifdef CONFIG_NET_CLS_IND
823 	new->ifindex = n->ifindex;
824 #endif
825 	new->fshift = n->fshift;
826 	new->res = n->res;
827 	new->flags = n->flags;
828 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
829 
830 	/* bump reference count as long as we hold pointer to structure */
831 	if (new->ht_down)
832 		new->ht_down->refcnt++;
833 
834 #ifdef CONFIG_CLS_U32_PERF
835 	/* Statistics may be incremented by readers during update
836 	 * so we must keep them in tact. When the node is later destroyed
837 	 * a special destroy call must be made to not free the pf memory.
838 	 */
839 	new->pf = n->pf;
840 #endif
841 
842 #ifdef CONFIG_CLS_U32_MARK
843 	new->val = n->val;
844 	new->mask = n->mask;
845 	/* Similarly success statistics must be moved as pointers */
846 	new->pcpu_success = n->pcpu_success;
847 #endif
848 	new->tp = tp;
849 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
850 
851 	if (tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE)) {
852 		kfree(new);
853 		return NULL;
854 	}
855 
856 	return new;
857 }
858 
859 static int u32_change(struct net *net, struct sk_buff *in_skb,
860 		      struct tcf_proto *tp, unsigned long base, u32 handle,
861 		      struct nlattr **tca, unsigned long *arg, bool ovr)
862 {
863 	struct tc_u_common *tp_c = tp->data;
864 	struct tc_u_hnode *ht;
865 	struct tc_u_knode *n;
866 	struct tc_u32_sel *s;
867 	struct nlattr *opt = tca[TCA_OPTIONS];
868 	struct nlattr *tb[TCA_U32_MAX + 1];
869 	u32 htid, flags = 0;
870 	int err;
871 #ifdef CONFIG_CLS_U32_PERF
872 	size_t size;
873 #endif
874 
875 	if (opt == NULL)
876 		return handle ? -EINVAL : 0;
877 
878 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy, NULL);
879 	if (err < 0)
880 		return err;
881 
882 	if (tb[TCA_U32_FLAGS]) {
883 		flags = nla_get_u32(tb[TCA_U32_FLAGS]);
884 		if (!tc_flags_valid(flags))
885 			return -EINVAL;
886 	}
887 
888 	n = (struct tc_u_knode *)*arg;
889 	if (n) {
890 		struct tc_u_knode *new;
891 
892 		if (TC_U32_KEY(n->handle) == 0)
893 			return -EINVAL;
894 
895 		if (n->flags != flags)
896 			return -EINVAL;
897 
898 		new = u32_init_knode(tp, n);
899 		if (!new)
900 			return -ENOMEM;
901 
902 		err = u32_set_parms(net, tp, base,
903 				    rtnl_dereference(n->ht_up), new, tb,
904 				    tca[TCA_RATE], ovr);
905 
906 		if (err) {
907 			u32_destroy_key(tp, new, false);
908 			return err;
909 		}
910 
911 		err = u32_replace_hw_knode(tp, new, flags);
912 		if (err) {
913 			u32_destroy_key(tp, new, false);
914 			return err;
915 		}
916 
917 		if (!tc_in_hw(new->flags))
918 			new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
919 
920 		u32_replace_knode(tp, tp_c, new);
921 		tcf_unbind_filter(tp, &n->res);
922 		call_rcu(&n->rcu, u32_delete_key_rcu);
923 		return 0;
924 	}
925 
926 	if (tb[TCA_U32_DIVISOR]) {
927 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
928 
929 		if (--divisor > 0x100)
930 			return -EINVAL;
931 		if (TC_U32_KEY(handle))
932 			return -EINVAL;
933 		if (handle == 0) {
934 			handle = gen_new_htid(tp->data);
935 			if (handle == 0)
936 				return -ENOMEM;
937 		}
938 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
939 		if (ht == NULL)
940 			return -ENOBUFS;
941 		ht->tp_c = tp_c;
942 		ht->refcnt = 1;
943 		ht->divisor = divisor;
944 		ht->handle = handle;
945 		ht->prio = tp->prio;
946 
947 		err = u32_replace_hw_hnode(tp, ht, flags);
948 		if (err) {
949 			kfree(ht);
950 			return err;
951 		}
952 
953 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
954 		rcu_assign_pointer(tp_c->hlist, ht);
955 		*arg = (unsigned long)ht;
956 
957 		return 0;
958 	}
959 
960 	if (tb[TCA_U32_HASH]) {
961 		htid = nla_get_u32(tb[TCA_U32_HASH]);
962 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
963 			ht = rtnl_dereference(tp->root);
964 			htid = ht->handle;
965 		} else {
966 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
967 			if (ht == NULL)
968 				return -EINVAL;
969 		}
970 	} else {
971 		ht = rtnl_dereference(tp->root);
972 		htid = ht->handle;
973 	}
974 
975 	if (ht->divisor < TC_U32_HASH(htid))
976 		return -EINVAL;
977 
978 	if (handle) {
979 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
980 			return -EINVAL;
981 		handle = htid | TC_U32_NODE(handle);
982 	} else
983 		handle = gen_new_kid(ht, htid);
984 
985 	if (tb[TCA_U32_SEL] == NULL)
986 		return -EINVAL;
987 
988 	s = nla_data(tb[TCA_U32_SEL]);
989 
990 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
991 	if (n == NULL)
992 		return -ENOBUFS;
993 
994 #ifdef CONFIG_CLS_U32_PERF
995 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
996 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
997 	if (!n->pf) {
998 		kfree(n);
999 		return -ENOBUFS;
1000 	}
1001 #endif
1002 
1003 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
1004 	RCU_INIT_POINTER(n->ht_up, ht);
1005 	n->handle = handle;
1006 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
1007 	n->flags = flags;
1008 	n->tp = tp;
1009 
1010 	err = tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
1011 	if (err < 0)
1012 		goto errout;
1013 
1014 #ifdef CONFIG_CLS_U32_MARK
1015 	n->pcpu_success = alloc_percpu(u32);
1016 	if (!n->pcpu_success) {
1017 		err = -ENOMEM;
1018 		goto errout;
1019 	}
1020 
1021 	if (tb[TCA_U32_MARK]) {
1022 		struct tc_u32_mark *mark;
1023 
1024 		mark = nla_data(tb[TCA_U32_MARK]);
1025 		n->val = mark->val;
1026 		n->mask = mark->mask;
1027 	}
1028 #endif
1029 
1030 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
1031 	if (err == 0) {
1032 		struct tc_u_knode __rcu **ins;
1033 		struct tc_u_knode *pins;
1034 
1035 		err = u32_replace_hw_knode(tp, n, flags);
1036 		if (err)
1037 			goto errhw;
1038 
1039 		if (!tc_in_hw(n->flags))
1040 			n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;
1041 
1042 		ins = &ht->ht[TC_U32_HASH(handle)];
1043 		for (pins = rtnl_dereference(*ins); pins;
1044 		     ins = &pins->next, pins = rtnl_dereference(*ins))
1045 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
1046 				break;
1047 
1048 		RCU_INIT_POINTER(n->next, pins);
1049 		rcu_assign_pointer(*ins, n);
1050 		*arg = (unsigned long)n;
1051 		return 0;
1052 	}
1053 
1054 errhw:
1055 #ifdef CONFIG_CLS_U32_MARK
1056 	free_percpu(n->pcpu_success);
1057 #endif
1058 
1059 errout:
1060 	tcf_exts_destroy(&n->exts);
1061 #ifdef CONFIG_CLS_U32_PERF
1062 	free_percpu(n->pf);
1063 #endif
1064 	kfree(n);
1065 	return err;
1066 }
1067 
1068 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
1069 {
1070 	struct tc_u_common *tp_c = tp->data;
1071 	struct tc_u_hnode *ht;
1072 	struct tc_u_knode *n;
1073 	unsigned int h;
1074 
1075 	if (arg->stop)
1076 		return;
1077 
1078 	for (ht = rtnl_dereference(tp_c->hlist);
1079 	     ht;
1080 	     ht = rtnl_dereference(ht->next)) {
1081 		if (ht->prio != tp->prio)
1082 			continue;
1083 		if (arg->count >= arg->skip) {
1084 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
1085 				arg->stop = 1;
1086 				return;
1087 			}
1088 		}
1089 		arg->count++;
1090 		for (h = 0; h <= ht->divisor; h++) {
1091 			for (n = rtnl_dereference(ht->ht[h]);
1092 			     n;
1093 			     n = rtnl_dereference(n->next)) {
1094 				if (arg->count < arg->skip) {
1095 					arg->count++;
1096 					continue;
1097 				}
1098 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
1099 					arg->stop = 1;
1100 					return;
1101 				}
1102 				arg->count++;
1103 			}
1104 		}
1105 	}
1106 }
1107 
1108 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
1109 		    struct sk_buff *skb, struct tcmsg *t)
1110 {
1111 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
1112 	struct tc_u_hnode *ht_up, *ht_down;
1113 	struct nlattr *nest;
1114 
1115 	if (n == NULL)
1116 		return skb->len;
1117 
1118 	t->tcm_handle = n->handle;
1119 
1120 	nest = nla_nest_start(skb, TCA_OPTIONS);
1121 	if (nest == NULL)
1122 		goto nla_put_failure;
1123 
1124 	if (TC_U32_KEY(n->handle) == 0) {
1125 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
1126 		u32 divisor = ht->divisor + 1;
1127 
1128 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
1129 			goto nla_put_failure;
1130 	} else {
1131 #ifdef CONFIG_CLS_U32_PERF
1132 		struct tc_u32_pcnt *gpf;
1133 		int cpu;
1134 #endif
1135 
1136 		if (nla_put(skb, TCA_U32_SEL,
1137 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
1138 			    &n->sel))
1139 			goto nla_put_failure;
1140 
1141 		ht_up = rtnl_dereference(n->ht_up);
1142 		if (ht_up) {
1143 			u32 htid = n->handle & 0xFFFFF000;
1144 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
1145 				goto nla_put_failure;
1146 		}
1147 		if (n->res.classid &&
1148 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
1149 			goto nla_put_failure;
1150 
1151 		ht_down = rtnl_dereference(n->ht_down);
1152 		if (ht_down &&
1153 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
1154 			goto nla_put_failure;
1155 
1156 		if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
1157 			goto nla_put_failure;
1158 
1159 #ifdef CONFIG_CLS_U32_MARK
1160 		if ((n->val || n->mask)) {
1161 			struct tc_u32_mark mark = {.val = n->val,
1162 						   .mask = n->mask,
1163 						   .success = 0};
1164 			int cpum;
1165 
1166 			for_each_possible_cpu(cpum) {
1167 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
1168 
1169 				mark.success += cnt;
1170 			}
1171 
1172 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
1173 				goto nla_put_failure;
1174 		}
1175 #endif
1176 
1177 		if (tcf_exts_dump(skb, &n->exts) < 0)
1178 			goto nla_put_failure;
1179 
1180 #ifdef CONFIG_NET_CLS_IND
1181 		if (n->ifindex) {
1182 			struct net_device *dev;
1183 			dev = __dev_get_by_index(net, n->ifindex);
1184 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
1185 				goto nla_put_failure;
1186 		}
1187 #endif
1188 #ifdef CONFIG_CLS_U32_PERF
1189 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
1190 			      n->sel.nkeys * sizeof(u64),
1191 			      GFP_KERNEL);
1192 		if (!gpf)
1193 			goto nla_put_failure;
1194 
1195 		for_each_possible_cpu(cpu) {
1196 			int i;
1197 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
1198 
1199 			gpf->rcnt += pf->rcnt;
1200 			gpf->rhit += pf->rhit;
1201 			for (i = 0; i < n->sel.nkeys; i++)
1202 				gpf->kcnts[i] += pf->kcnts[i];
1203 		}
1204 
1205 		if (nla_put_64bit(skb, TCA_U32_PCNT,
1206 				  sizeof(struct tc_u32_pcnt) +
1207 				  n->sel.nkeys * sizeof(u64),
1208 				  gpf, TCA_U32_PAD)) {
1209 			kfree(gpf);
1210 			goto nla_put_failure;
1211 		}
1212 		kfree(gpf);
1213 #endif
1214 	}
1215 
1216 	nla_nest_end(skb, nest);
1217 
1218 	if (TC_U32_KEY(n->handle))
1219 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1220 			goto nla_put_failure;
1221 	return skb->len;
1222 
1223 nla_put_failure:
1224 	nla_nest_cancel(skb, nest);
1225 	return -1;
1226 }
1227 
1228 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1229 	.kind		=	"u32",
1230 	.classify	=	u32_classify,
1231 	.init		=	u32_init,
1232 	.destroy	=	u32_destroy,
1233 	.get		=	u32_get,
1234 	.change		=	u32_change,
1235 	.delete		=	u32_delete,
1236 	.walk		=	u32_walk,
1237 	.dump		=	u32_dump,
1238 	.owner		=	THIS_MODULE,
1239 };
1240 
1241 static int __init init_u32(void)
1242 {
1243 	pr_info("u32 classifier\n");
1244 #ifdef CONFIG_CLS_U32_PERF
1245 	pr_info("    Performance counters on\n");
1246 #endif
1247 #ifdef CONFIG_NET_CLS_IND
1248 	pr_info("    input device check on\n");
1249 #endif
1250 #ifdef CONFIG_NET_CLS_ACT
1251 	pr_info("    Actions configured\n");
1252 #endif
1253 	return register_tcf_proto_ops(&cls_u32_ops);
1254 }
1255 
1256 static void __exit exit_u32(void)
1257 {
1258 	unregister_tcf_proto_ops(&cls_u32_ops);
1259 }
1260 
1261 module_init(init_u32)
1262 module_exit(exit_u32)
1263 MODULE_LICENSE("GPL");
1264