xref: /openbmc/linux/net/sched/cls_u32.c (revision 6774def6)
1 /*
2  * net/sched/cls_u32.c	Ugly (or Universal) 32bit key Packet Classifier.
3  *
4  *		This program is free software; you can redistribute it and/or
5  *		modify it under the terms of the GNU General Public License
6  *		as published by the Free Software Foundation; either version
7  *		2 of the License, or (at your option) any later version.
8  *
9  * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
10  *
11  *	The filters are packed to hash tables of key nodes
12  *	with a set of 32bit key/mask pairs at every node.
13  *	Nodes reference next level hash tables etc.
14  *
15  *	This scheme is the best universal classifier I managed to
16  *	invent; it is not super-fast, but it is not slow (provided you
17  *	program it correctly), and general enough.  And its relative
18  *	speed grows as the number of rules becomes larger.
19  *
20  *	It seems that it represents the best middle point between
21  *	speed and manageability both by human and by machine.
22  *
23  *	It is especially useful for link sharing combined with QoS;
24  *	pure RSVP doesn't need such a general approach and can use
25  *	much simpler (and faster) schemes, sort of cls_rsvp.c.
26  *
27  *	JHS: We should remove the CONFIG_NET_CLS_IND from here
28  *	eventually when the meta match extension is made available
29  *
30  *	nfmark match added by Catalin(ux aka Dino) BOIE <catab at umbrella.ro>
31  */
32 
33 #include <linux/module.h>
34 #include <linux/slab.h>
35 #include <linux/types.h>
36 #include <linux/kernel.h>
37 #include <linux/string.h>
38 #include <linux/errno.h>
39 #include <linux/percpu.h>
40 #include <linux/rtnetlink.h>
41 #include <linux/skbuff.h>
42 #include <linux/bitmap.h>
43 #include <net/netlink.h>
44 #include <net/act_api.h>
45 #include <net/pkt_cls.h>
46 
47 struct tc_u_knode {
48 	struct tc_u_knode __rcu	*next;
49 	u32			handle;
50 	struct tc_u_hnode __rcu	*ht_up;
51 	struct tcf_exts		exts;
52 #ifdef CONFIG_NET_CLS_IND
53 	int			ifindex;
54 #endif
55 	u8			fshift;
56 	struct tcf_result	res;
57 	struct tc_u_hnode __rcu	*ht_down;
58 #ifdef CONFIG_CLS_U32_PERF
59 	struct tc_u32_pcnt __percpu *pf;
60 #endif
61 #ifdef CONFIG_CLS_U32_MARK
62 	u32			val;
63 	u32			mask;
64 	u32 __percpu		*pcpu_success;
65 #endif
66 	struct tcf_proto	*tp;
67 	struct rcu_head		rcu;
68 	/* The 'sel' field MUST be the last field in structure to allow for
69 	 * tc_u32_keys allocated at end of structure.
70 	 */
71 	struct tc_u32_sel	sel;
72 };
73 
74 struct tc_u_hnode {
75 	struct tc_u_hnode __rcu	*next;
76 	u32			handle;
77 	u32			prio;
78 	struct tc_u_common	*tp_c;
79 	int			refcnt;
80 	unsigned int		divisor;
81 	struct tc_u_knode __rcu	*ht[1];
82 	struct rcu_head		rcu;
83 };
84 
85 struct tc_u_common {
86 	struct tc_u_hnode __rcu	*hlist;
87 	struct Qdisc		*q;
88 	int			refcnt;
89 	u32			hgenerator;
90 	struct rcu_head		rcu;
91 };
92 
93 static inline unsigned int u32_hash_fold(__be32 key,
94 					 const struct tc_u32_sel *sel,
95 					 u8 fshift)
96 {
97 	unsigned int h = ntohl(key & sel->hmask) >> fshift;
98 
99 	return h;
100 }
101 
102 static int u32_classify(struct sk_buff *skb, const struct tcf_proto *tp, struct tcf_result *res)
103 {
104 	struct {
105 		struct tc_u_knode *knode;
106 		unsigned int	  off;
107 	} stack[TC_U32_MAXDEPTH];
108 
109 	struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
110 	unsigned int off = skb_network_offset(skb);
111 	struct tc_u_knode *n;
112 	int sdepth = 0;
113 	int off2 = 0;
114 	int sel = 0;
115 #ifdef CONFIG_CLS_U32_PERF
116 	int j;
117 #endif
118 	int i, r;
119 
120 next_ht:
121 	n = rcu_dereference_bh(ht->ht[sel]);
122 
123 next_knode:
124 	if (n) {
125 		struct tc_u32_key *key = n->sel.keys;
126 
127 #ifdef CONFIG_CLS_U32_PERF
128 		__this_cpu_inc(n->pf->rcnt);
129 		j = 0;
130 #endif
131 
132 #ifdef CONFIG_CLS_U32_MARK
133 		if ((skb->mark & n->mask) != n->val) {
134 			n = rcu_dereference_bh(n->next);
135 			goto next_knode;
136 		} else {
137 			__this_cpu_inc(*n->pcpu_success);
138 		}
139 #endif
140 
141 		for (i = n->sel.nkeys; i > 0; i--, key++) {
142 			int toff = off + key->off + (off2 & key->offmask);
143 			__be32 *data, hdata;
144 
145 			if (skb_headroom(skb) + toff > INT_MAX)
146 				goto out;
147 
148 			data = skb_header_pointer(skb, toff, 4, &hdata);
149 			if (!data)
150 				goto out;
151 			if ((*data ^ key->val) & key->mask) {
152 				n = rcu_dereference_bh(n->next);
153 				goto next_knode;
154 			}
155 #ifdef CONFIG_CLS_U32_PERF
156 			__this_cpu_inc(n->pf->kcnts[j]);
157 			j++;
158 #endif
159 		}
160 
161 		ht = rcu_dereference_bh(n->ht_down);
162 		if (!ht) {
163 check_terminal:
164 			if (n->sel.flags & TC_U32_TERMINAL) {
165 
166 				*res = n->res;
167 #ifdef CONFIG_NET_CLS_IND
168 				if (!tcf_match_indev(skb, n->ifindex)) {
169 					n = rcu_dereference_bh(n->next);
170 					goto next_knode;
171 				}
172 #endif
173 #ifdef CONFIG_CLS_U32_PERF
174 				__this_cpu_inc(n->pf->rhit);
175 #endif
176 				r = tcf_exts_exec(skb, &n->exts, res);
177 				if (r < 0) {
178 					n = rcu_dereference_bh(n->next);
179 					goto next_knode;
180 				}
181 
182 				return r;
183 			}
184 			n = rcu_dereference_bh(n->next);
185 			goto next_knode;
186 		}
187 
188 		/* PUSH */
189 		if (sdepth >= TC_U32_MAXDEPTH)
190 			goto deadloop;
191 		stack[sdepth].knode = n;
192 		stack[sdepth].off = off;
193 		sdepth++;
194 
195 		ht = rcu_dereference_bh(n->ht_down);
196 		sel = 0;
197 		if (ht->divisor) {
198 			__be32 *data, hdata;
199 
200 			data = skb_header_pointer(skb, off + n->sel.hoff, 4,
201 						  &hdata);
202 			if (!data)
203 				goto out;
204 			sel = ht->divisor & u32_hash_fold(*data, &n->sel,
205 							  n->fshift);
206 		}
207 		if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
208 			goto next_ht;
209 
210 		if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
211 			off2 = n->sel.off + 3;
212 			if (n->sel.flags & TC_U32_VAROFFSET) {
213 				__be16 *data, hdata;
214 
215 				data = skb_header_pointer(skb,
216 							  off + n->sel.offoff,
217 							  2, &hdata);
218 				if (!data)
219 					goto out;
220 				off2 += ntohs(n->sel.offmask & *data) >>
221 					n->sel.offshift;
222 			}
223 			off2 &= ~3;
224 		}
225 		if (n->sel.flags & TC_U32_EAT) {
226 			off += off2;
227 			off2 = 0;
228 		}
229 
230 		if (off < skb->len)
231 			goto next_ht;
232 	}
233 
234 	/* POP */
235 	if (sdepth--) {
236 		n = stack[sdepth].knode;
237 		ht = rcu_dereference_bh(n->ht_up);
238 		off = stack[sdepth].off;
239 		goto check_terminal;
240 	}
241 out:
242 	return -1;
243 
244 deadloop:
245 	net_warn_ratelimited("cls_u32: dead loop\n");
246 	return -1;
247 }
248 
249 static struct tc_u_hnode *
250 u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
251 {
252 	struct tc_u_hnode *ht;
253 
254 	for (ht = rtnl_dereference(tp_c->hlist);
255 	     ht;
256 	     ht = rtnl_dereference(ht->next))
257 		if (ht->handle == handle)
258 			break;
259 
260 	return ht;
261 }
262 
263 static struct tc_u_knode *
264 u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
265 {
266 	unsigned int sel;
267 	struct tc_u_knode *n = NULL;
268 
269 	sel = TC_U32_HASH(handle);
270 	if (sel > ht->divisor)
271 		goto out;
272 
273 	for (n = rtnl_dereference(ht->ht[sel]);
274 	     n;
275 	     n = rtnl_dereference(n->next))
276 		if (n->handle == handle)
277 			break;
278 out:
279 	return n;
280 }
281 
282 
283 static unsigned long u32_get(struct tcf_proto *tp, u32 handle)
284 {
285 	struct tc_u_hnode *ht;
286 	struct tc_u_common *tp_c = tp->data;
287 
288 	if (TC_U32_HTID(handle) == TC_U32_ROOT)
289 		ht = rtnl_dereference(tp->root);
290 	else
291 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));
292 
293 	if (!ht)
294 		return 0;
295 
296 	if (TC_U32_KEY(handle) == 0)
297 		return (unsigned long)ht;
298 
299 	return (unsigned long)u32_lookup_key(ht, handle);
300 }
301 
302 static void u32_put(struct tcf_proto *tp, unsigned long f)
303 {
304 }
305 
306 static u32 gen_new_htid(struct tc_u_common *tp_c)
307 {
308 	int i = 0x800;
309 
310 	/* hgenerator only used inside rtnl lock it is safe to increment
311 	 * without read _copy_ update semantics
312 	 */
313 	do {
314 		if (++tp_c->hgenerator == 0x7FF)
315 			tp_c->hgenerator = 1;
316 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
317 
318 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
319 }
320 
321 static int u32_init(struct tcf_proto *tp)
322 {
323 	struct tc_u_hnode *root_ht;
324 	struct tc_u_common *tp_c;
325 
326 	tp_c = tp->q->u32_node;
327 
328 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
329 	if (root_ht == NULL)
330 		return -ENOBUFS;
331 
332 	root_ht->divisor = 0;
333 	root_ht->refcnt++;
334 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
335 	root_ht->prio = tp->prio;
336 
337 	if (tp_c == NULL) {
338 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
339 		if (tp_c == NULL) {
340 			kfree(root_ht);
341 			return -ENOBUFS;
342 		}
343 		tp_c->q = tp->q;
344 		tp->q->u32_node = tp_c;
345 	}
346 
347 	tp_c->refcnt++;
348 	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
349 	rcu_assign_pointer(tp_c->hlist, root_ht);
350 	root_ht->tp_c = tp_c;
351 
352 	rcu_assign_pointer(tp->root, root_ht);
353 	tp->data = tp_c;
354 	return 0;
355 }
356 
357 static int u32_destroy_key(struct tcf_proto *tp,
358 			   struct tc_u_knode *n,
359 			   bool free_pf)
360 {
361 	tcf_exts_destroy(&n->exts);
362 	if (n->ht_down)
363 		n->ht_down->refcnt--;
364 #ifdef CONFIG_CLS_U32_PERF
365 	if (free_pf)
366 		free_percpu(n->pf);
367 #endif
368 #ifdef CONFIG_CLS_U32_MARK
369 	if (free_pf)
370 		free_percpu(n->pcpu_success);
371 #endif
372 	kfree(n);
373 	return 0;
374 }
375 
376 /* u32_delete_key_rcu should be called when free'ing a copied
377  * version of a tc_u_knode obtained from u32_init_knode(). When
378  * copies are obtained from u32_init_knode() the statistics are
379  * shared between the old and new copies to allow readers to
380  * continue to update the statistics during the copy. To support
381  * this the u32_delete_key_rcu variant does not free the percpu
382  * statistics.
383  */
384 static void u32_delete_key_rcu(struct rcu_head *rcu)
385 {
386 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
387 
388 	u32_destroy_key(key->tp, key, false);
389 }
390 
391 /* u32_delete_key_freepf_rcu is the rcu callback variant
392  * that free's the entire structure including the statistics
393  * percpu variables. Only use this if the key is not a copy
394  * returned by u32_init_knode(). See u32_delete_key_rcu()
395  * for the variant that should be used with keys return from
396  * u32_init_knode()
397  */
398 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
399 {
400 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
401 
402 	u32_destroy_key(key->tp, key, true);
403 }
404 
405 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
406 {
407 	struct tc_u_knode __rcu **kp;
408 	struct tc_u_knode *pkp;
409 	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
410 
411 	if (ht) {
412 		kp = &ht->ht[TC_U32_HASH(key->handle)];
413 		for (pkp = rtnl_dereference(*kp); pkp;
414 		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
415 			if (pkp == key) {
416 				RCU_INIT_POINTER(*kp, key->next);
417 
418 				tcf_unbind_filter(tp, &key->res);
419 				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
420 				return 0;
421 			}
422 		}
423 	}
424 	WARN_ON(1);
425 	return 0;
426 }
427 
428 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
429 {
430 	struct tc_u_knode *n;
431 	unsigned int h;
432 
433 	for (h = 0; h <= ht->divisor; h++) {
434 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
435 			RCU_INIT_POINTER(ht->ht[h],
436 					 rtnl_dereference(n->next));
437 			tcf_unbind_filter(tp, &n->res);
438 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
439 		}
440 	}
441 }
442 
443 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
444 {
445 	struct tc_u_common *tp_c = tp->data;
446 	struct tc_u_hnode __rcu **hn;
447 	struct tc_u_hnode *phn;
448 
449 	WARN_ON(ht->refcnt);
450 
451 	u32_clear_hnode(tp, ht);
452 
453 	hn = &tp_c->hlist;
454 	for (phn = rtnl_dereference(*hn);
455 	     phn;
456 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
457 		if (phn == ht) {
458 			RCU_INIT_POINTER(*hn, ht->next);
459 			kfree_rcu(ht, rcu);
460 			return 0;
461 		}
462 	}
463 
464 	return -ENOENT;
465 }
466 
467 static void u32_destroy(struct tcf_proto *tp)
468 {
469 	struct tc_u_common *tp_c = tp->data;
470 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
471 
472 	WARN_ON(root_ht == NULL);
473 
474 	if (root_ht && --root_ht->refcnt == 0)
475 		u32_destroy_hnode(tp, root_ht);
476 
477 	if (--tp_c->refcnt == 0) {
478 		struct tc_u_hnode *ht;
479 
480 		tp->q->u32_node = NULL;
481 
482 		for (ht = rtnl_dereference(tp_c->hlist);
483 		     ht;
484 		     ht = rtnl_dereference(ht->next)) {
485 			ht->refcnt--;
486 			u32_clear_hnode(tp, ht);
487 		}
488 
489 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
490 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
491 			kfree_rcu(ht, rcu);
492 		}
493 
494 		kfree(tp_c);
495 	}
496 
497 	tp->data = NULL;
498 }
499 
500 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
501 {
502 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
503 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
504 
505 	if (ht == NULL)
506 		return 0;
507 
508 	if (TC_U32_KEY(ht->handle))
509 		return u32_delete_key(tp, (struct tc_u_knode *)ht);
510 
511 	if (root_ht == ht)
512 		return -EINVAL;
513 
514 	if (ht->refcnt == 1) {
515 		ht->refcnt--;
516 		u32_destroy_hnode(tp, ht);
517 	} else {
518 		return -EBUSY;
519 	}
520 
521 	return 0;
522 }
523 
524 #define NR_U32_NODE (1<<12)
525 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
526 {
527 	struct tc_u_knode *n;
528 	unsigned long i;
529 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
530 					GFP_KERNEL);
531 	if (!bitmap)
532 		return handle | 0xFFF;
533 
534 	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
535 	     n;
536 	     n = rtnl_dereference(n->next))
537 		set_bit(TC_U32_NODE(n->handle), bitmap);
538 
539 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
540 	if (i >= NR_U32_NODE)
541 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
542 
543 	kfree(bitmap);
544 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
545 }
546 
547 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
548 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
549 	[TCA_U32_HASH]		= { .type = NLA_U32 },
550 	[TCA_U32_LINK]		= { .type = NLA_U32 },
551 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
552 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
553 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
554 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
555 };
556 
557 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
558 			 unsigned long base, struct tc_u_hnode *ht,
559 			 struct tc_u_knode *n, struct nlattr **tb,
560 			 struct nlattr *est, bool ovr)
561 {
562 	int err;
563 	struct tcf_exts e;
564 
565 	tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
566 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
567 	if (err < 0)
568 		return err;
569 
570 	err = -EINVAL;
571 	if (tb[TCA_U32_LINK]) {
572 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
573 		struct tc_u_hnode *ht_down = NULL, *ht_old;
574 
575 		if (TC_U32_KEY(handle))
576 			goto errout;
577 
578 		if (handle) {
579 			ht_down = u32_lookup_ht(ht->tp_c, handle);
580 
581 			if (ht_down == NULL)
582 				goto errout;
583 			ht_down->refcnt++;
584 		}
585 
586 		ht_old = rtnl_dereference(n->ht_down);
587 		rcu_assign_pointer(n->ht_down, ht_down);
588 
589 		if (ht_old)
590 			ht_old->refcnt--;
591 	}
592 	if (tb[TCA_U32_CLASSID]) {
593 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
594 		tcf_bind_filter(tp, &n->res, base);
595 	}
596 
597 #ifdef CONFIG_NET_CLS_IND
598 	if (tb[TCA_U32_INDEV]) {
599 		int ret;
600 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
601 		if (ret < 0)
602 			goto errout;
603 		n->ifindex = ret;
604 	}
605 #endif
606 	tcf_exts_change(tp, &n->exts, &e);
607 
608 	return 0;
609 errout:
610 	tcf_exts_destroy(&e);
611 	return err;
612 }
613 
614 static void u32_replace_knode(struct tcf_proto *tp,
615 			      struct tc_u_common *tp_c,
616 			      struct tc_u_knode *n)
617 {
618 	struct tc_u_knode __rcu **ins;
619 	struct tc_u_knode *pins;
620 	struct tc_u_hnode *ht;
621 
622 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
623 		ht = rtnl_dereference(tp->root);
624 	else
625 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
626 
627 	ins = &ht->ht[TC_U32_HASH(n->handle)];
628 
629 	/* The node must always exist for it to be replaced if this is not the
630 	 * case then something went very wrong elsewhere.
631 	 */
632 	for (pins = rtnl_dereference(*ins); ;
633 	     ins = &pins->next, pins = rtnl_dereference(*ins))
634 		if (pins->handle == n->handle)
635 			break;
636 
637 	RCU_INIT_POINTER(n->next, pins->next);
638 	rcu_assign_pointer(*ins, n);
639 }
640 
641 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
642 					 struct tc_u_knode *n)
643 {
644 	struct tc_u_knode *new;
645 	struct tc_u32_sel *s = &n->sel;
646 
647 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
648 		      GFP_KERNEL);
649 
650 	if (!new)
651 		return NULL;
652 
653 	RCU_INIT_POINTER(new->next, n->next);
654 	new->handle = n->handle;
655 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
656 
657 #ifdef CONFIG_NET_CLS_IND
658 	new->ifindex = n->ifindex;
659 #endif
660 	new->fshift = n->fshift;
661 	new->res = n->res;
662 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
663 
664 	/* bump reference count as long as we hold pointer to structure */
665 	if (new->ht_down)
666 		new->ht_down->refcnt++;
667 
668 #ifdef CONFIG_CLS_U32_PERF
669 	/* Statistics may be incremented by readers during update
670 	 * so we must keep them in tact. When the node is later destroyed
671 	 * a special destroy call must be made to not free the pf memory.
672 	 */
673 	new->pf = n->pf;
674 #endif
675 
676 #ifdef CONFIG_CLS_U32_MARK
677 	new->val = n->val;
678 	new->mask = n->mask;
679 	/* Similarly success statistics must be moved as pointers */
680 	new->pcpu_success = n->pcpu_success;
681 #endif
682 	new->tp = tp;
683 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
684 
685 	tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE);
686 
687 	return new;
688 }
689 
690 static int u32_change(struct net *net, struct sk_buff *in_skb,
691 		      struct tcf_proto *tp, unsigned long base, u32 handle,
692 		      struct nlattr **tca,
693 		      unsigned long *arg, bool ovr)
694 {
695 	struct tc_u_common *tp_c = tp->data;
696 	struct tc_u_hnode *ht;
697 	struct tc_u_knode *n;
698 	struct tc_u32_sel *s;
699 	struct nlattr *opt = tca[TCA_OPTIONS];
700 	struct nlattr *tb[TCA_U32_MAX + 1];
701 	u32 htid;
702 	int err;
703 #ifdef CONFIG_CLS_U32_PERF
704 	size_t size;
705 #endif
706 
707 	if (opt == NULL)
708 		return handle ? -EINVAL : 0;
709 
710 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
711 	if (err < 0)
712 		return err;
713 
714 	n = (struct tc_u_knode *)*arg;
715 	if (n) {
716 		struct tc_u_knode *new;
717 
718 		if (TC_U32_KEY(n->handle) == 0)
719 			return -EINVAL;
720 
721 		new = u32_init_knode(tp, n);
722 		if (!new)
723 			return -ENOMEM;
724 
725 		err = u32_set_parms(net, tp, base,
726 				    rtnl_dereference(n->ht_up), new, tb,
727 				    tca[TCA_RATE], ovr);
728 
729 		if (err) {
730 			u32_destroy_key(tp, new, false);
731 			return err;
732 		}
733 
734 		u32_replace_knode(tp, tp_c, new);
735 		tcf_unbind_filter(tp, &n->res);
736 		call_rcu(&n->rcu, u32_delete_key_rcu);
737 		return 0;
738 	}
739 
740 	if (tb[TCA_U32_DIVISOR]) {
741 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
742 
743 		if (--divisor > 0x100)
744 			return -EINVAL;
745 		if (TC_U32_KEY(handle))
746 			return -EINVAL;
747 		if (handle == 0) {
748 			handle = gen_new_htid(tp->data);
749 			if (handle == 0)
750 				return -ENOMEM;
751 		}
752 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
753 		if (ht == NULL)
754 			return -ENOBUFS;
755 		ht->tp_c = tp_c;
756 		ht->refcnt = 1;
757 		ht->divisor = divisor;
758 		ht->handle = handle;
759 		ht->prio = tp->prio;
760 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
761 		rcu_assign_pointer(tp_c->hlist, ht);
762 		*arg = (unsigned long)ht;
763 		return 0;
764 	}
765 
766 	if (tb[TCA_U32_HASH]) {
767 		htid = nla_get_u32(tb[TCA_U32_HASH]);
768 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
769 			ht = rtnl_dereference(tp->root);
770 			htid = ht->handle;
771 		} else {
772 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
773 			if (ht == NULL)
774 				return -EINVAL;
775 		}
776 	} else {
777 		ht = rtnl_dereference(tp->root);
778 		htid = ht->handle;
779 	}
780 
781 	if (ht->divisor < TC_U32_HASH(htid))
782 		return -EINVAL;
783 
784 	if (handle) {
785 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
786 			return -EINVAL;
787 		handle = htid | TC_U32_NODE(handle);
788 	} else
789 		handle = gen_new_kid(ht, htid);
790 
791 	if (tb[TCA_U32_SEL] == NULL)
792 		return -EINVAL;
793 
794 	s = nla_data(tb[TCA_U32_SEL]);
795 
796 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
797 	if (n == NULL)
798 		return -ENOBUFS;
799 
800 #ifdef CONFIG_CLS_U32_PERF
801 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
802 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
803 	if (!n->pf) {
804 		kfree(n);
805 		return -ENOBUFS;
806 	}
807 #endif
808 
809 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
810 	RCU_INIT_POINTER(n->ht_up, ht);
811 	n->handle = handle;
812 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
813 	tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
814 	n->tp = tp;
815 
816 #ifdef CONFIG_CLS_U32_MARK
817 	n->pcpu_success = alloc_percpu(u32);
818 	if (!n->pcpu_success) {
819 		err = -ENOMEM;
820 		goto errout;
821 	}
822 
823 	if (tb[TCA_U32_MARK]) {
824 		struct tc_u32_mark *mark;
825 
826 		mark = nla_data(tb[TCA_U32_MARK]);
827 		n->val = mark->val;
828 		n->mask = mark->mask;
829 	}
830 #endif
831 
832 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
833 	if (err == 0) {
834 		struct tc_u_knode __rcu **ins;
835 		struct tc_u_knode *pins;
836 
837 		ins = &ht->ht[TC_U32_HASH(handle)];
838 		for (pins = rtnl_dereference(*ins); pins;
839 		     ins = &pins->next, pins = rtnl_dereference(*ins))
840 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
841 				break;
842 
843 		RCU_INIT_POINTER(n->next, pins);
844 		rcu_assign_pointer(*ins, n);
845 
846 		*arg = (unsigned long)n;
847 		return 0;
848 	}
849 
850 #ifdef CONFIG_CLS_U32_MARK
851 	free_percpu(n->pcpu_success);
852 errout:
853 #endif
854 
855 #ifdef CONFIG_CLS_U32_PERF
856 	free_percpu(n->pf);
857 #endif
858 	kfree(n);
859 	return err;
860 }
861 
862 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
863 {
864 	struct tc_u_common *tp_c = tp->data;
865 	struct tc_u_hnode *ht;
866 	struct tc_u_knode *n;
867 	unsigned int h;
868 
869 	if (arg->stop)
870 		return;
871 
872 	for (ht = rtnl_dereference(tp_c->hlist);
873 	     ht;
874 	     ht = rtnl_dereference(ht->next)) {
875 		if (ht->prio != tp->prio)
876 			continue;
877 		if (arg->count >= arg->skip) {
878 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
879 				arg->stop = 1;
880 				return;
881 			}
882 		}
883 		arg->count++;
884 		for (h = 0; h <= ht->divisor; h++) {
885 			for (n = rtnl_dereference(ht->ht[h]);
886 			     n;
887 			     n = rtnl_dereference(n->next)) {
888 				if (arg->count < arg->skip) {
889 					arg->count++;
890 					continue;
891 				}
892 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
893 					arg->stop = 1;
894 					return;
895 				}
896 				arg->count++;
897 			}
898 		}
899 	}
900 }
901 
902 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
903 		     struct sk_buff *skb, struct tcmsg *t)
904 {
905 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
906 	struct tc_u_hnode *ht_up, *ht_down;
907 	struct nlattr *nest;
908 
909 	if (n == NULL)
910 		return skb->len;
911 
912 	t->tcm_handle = n->handle;
913 
914 	nest = nla_nest_start(skb, TCA_OPTIONS);
915 	if (nest == NULL)
916 		goto nla_put_failure;
917 
918 	if (TC_U32_KEY(n->handle) == 0) {
919 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
920 		u32 divisor = ht->divisor + 1;
921 
922 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
923 			goto nla_put_failure;
924 	} else {
925 #ifdef CONFIG_CLS_U32_PERF
926 		struct tc_u32_pcnt *gpf;
927 		int cpu;
928 #endif
929 
930 		if (nla_put(skb, TCA_U32_SEL,
931 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
932 			    &n->sel))
933 			goto nla_put_failure;
934 
935 		ht_up = rtnl_dereference(n->ht_up);
936 		if (ht_up) {
937 			u32 htid = n->handle & 0xFFFFF000;
938 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
939 				goto nla_put_failure;
940 		}
941 		if (n->res.classid &&
942 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
943 			goto nla_put_failure;
944 
945 		ht_down = rtnl_dereference(n->ht_down);
946 		if (ht_down &&
947 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
948 			goto nla_put_failure;
949 
950 #ifdef CONFIG_CLS_U32_MARK
951 		if ((n->val || n->mask)) {
952 			struct tc_u32_mark mark = {.val = n->val,
953 						   .mask = n->mask,
954 						   .success = 0};
955 			int cpum;
956 
957 			for_each_possible_cpu(cpum) {
958 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
959 
960 				mark.success += cnt;
961 			}
962 
963 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
964 				goto nla_put_failure;
965 		}
966 #endif
967 
968 		if (tcf_exts_dump(skb, &n->exts) < 0)
969 			goto nla_put_failure;
970 
971 #ifdef CONFIG_NET_CLS_IND
972 		if (n->ifindex) {
973 			struct net_device *dev;
974 			dev = __dev_get_by_index(net, n->ifindex);
975 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
976 				goto nla_put_failure;
977 		}
978 #endif
979 #ifdef CONFIG_CLS_U32_PERF
980 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
981 			      n->sel.nkeys * sizeof(u64),
982 			      GFP_KERNEL);
983 		if (!gpf)
984 			goto nla_put_failure;
985 
986 		for_each_possible_cpu(cpu) {
987 			int i;
988 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
989 
990 			gpf->rcnt += pf->rcnt;
991 			gpf->rhit += pf->rhit;
992 			for (i = 0; i < n->sel.nkeys; i++)
993 				gpf->kcnts[i] += pf->kcnts[i];
994 		}
995 
996 		if (nla_put(skb, TCA_U32_PCNT,
997 			    sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
998 			    gpf)) {
999 			kfree(gpf);
1000 			goto nla_put_failure;
1001 		}
1002 		kfree(gpf);
1003 #endif
1004 	}
1005 
1006 	nla_nest_end(skb, nest);
1007 
1008 	if (TC_U32_KEY(n->handle))
1009 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1010 			goto nla_put_failure;
1011 	return skb->len;
1012 
1013 nla_put_failure:
1014 	nla_nest_cancel(skb, nest);
1015 	return -1;
1016 }
1017 
1018 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1019 	.kind		=	"u32",
1020 	.classify	=	u32_classify,
1021 	.init		=	u32_init,
1022 	.destroy	=	u32_destroy,
1023 	.get		=	u32_get,
1024 	.put		=	u32_put,
1025 	.change		=	u32_change,
1026 	.delete		=	u32_delete,
1027 	.walk		=	u32_walk,
1028 	.dump		=	u32_dump,
1029 	.owner		=	THIS_MODULE,
1030 };
1031 
1032 static int __init init_u32(void)
1033 {
1034 	pr_info("u32 classifier\n");
1035 #ifdef CONFIG_CLS_U32_PERF
1036 	pr_info("    Performance counters on\n");
1037 #endif
1038 #ifdef CONFIG_NET_CLS_IND
1039 	pr_info("    input device check on\n");
1040 #endif
1041 #ifdef CONFIG_NET_CLS_ACT
1042 	pr_info("    Actions configured\n");
1043 #endif
1044 	return register_tcf_proto_ops(&cls_u32_ops);
1045 }
1046 
1047 static void __exit exit_u32(void)
1048 {
1049 	unregister_tcf_proto_ops(&cls_u32_ops);
1050 }
1051 
1052 module_init(init_u32)
1053 module_exit(exit_u32)
1054 MODULE_LICENSE("GPL");
1055