xref: /openbmc/linux/net/sched/cls_u32.c (revision e8f6f3b4)
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 u32 gen_new_htid(struct tc_u_common *tp_c)
303 {
304 	int i = 0x800;
305 
306 	/* hgenerator only used inside rtnl lock it is safe to increment
307 	 * without read _copy_ update semantics
308 	 */
309 	do {
310 		if (++tp_c->hgenerator == 0x7FF)
311 			tp_c->hgenerator = 1;
312 	} while (--i > 0 && u32_lookup_ht(tp_c, (tp_c->hgenerator|0x800)<<20));
313 
314 	return i > 0 ? (tp_c->hgenerator|0x800)<<20 : 0;
315 }
316 
317 static int u32_init(struct tcf_proto *tp)
318 {
319 	struct tc_u_hnode *root_ht;
320 	struct tc_u_common *tp_c;
321 
322 	tp_c = tp->q->u32_node;
323 
324 	root_ht = kzalloc(sizeof(*root_ht), GFP_KERNEL);
325 	if (root_ht == NULL)
326 		return -ENOBUFS;
327 
328 	root_ht->divisor = 0;
329 	root_ht->refcnt++;
330 	root_ht->handle = tp_c ? gen_new_htid(tp_c) : 0x80000000;
331 	root_ht->prio = tp->prio;
332 
333 	if (tp_c == NULL) {
334 		tp_c = kzalloc(sizeof(*tp_c), GFP_KERNEL);
335 		if (tp_c == NULL) {
336 			kfree(root_ht);
337 			return -ENOBUFS;
338 		}
339 		tp_c->q = tp->q;
340 		tp->q->u32_node = tp_c;
341 	}
342 
343 	tp_c->refcnt++;
344 	RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
345 	rcu_assign_pointer(tp_c->hlist, root_ht);
346 	root_ht->tp_c = tp_c;
347 
348 	rcu_assign_pointer(tp->root, root_ht);
349 	tp->data = tp_c;
350 	return 0;
351 }
352 
353 static int u32_destroy_key(struct tcf_proto *tp,
354 			   struct tc_u_knode *n,
355 			   bool free_pf)
356 {
357 	tcf_exts_destroy(&n->exts);
358 	if (n->ht_down)
359 		n->ht_down->refcnt--;
360 #ifdef CONFIG_CLS_U32_PERF
361 	if (free_pf)
362 		free_percpu(n->pf);
363 #endif
364 #ifdef CONFIG_CLS_U32_MARK
365 	if (free_pf)
366 		free_percpu(n->pcpu_success);
367 #endif
368 	kfree(n);
369 	return 0;
370 }
371 
372 /* u32_delete_key_rcu should be called when free'ing a copied
373  * version of a tc_u_knode obtained from u32_init_knode(). When
374  * copies are obtained from u32_init_knode() the statistics are
375  * shared between the old and new copies to allow readers to
376  * continue to update the statistics during the copy. To support
377  * this the u32_delete_key_rcu variant does not free the percpu
378  * statistics.
379  */
380 static void u32_delete_key_rcu(struct rcu_head *rcu)
381 {
382 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
383 
384 	u32_destroy_key(key->tp, key, false);
385 }
386 
387 /* u32_delete_key_freepf_rcu is the rcu callback variant
388  * that free's the entire structure including the statistics
389  * percpu variables. Only use this if the key is not a copy
390  * returned by u32_init_knode(). See u32_delete_key_rcu()
391  * for the variant that should be used with keys return from
392  * u32_init_knode()
393  */
394 static void u32_delete_key_freepf_rcu(struct rcu_head *rcu)
395 {
396 	struct tc_u_knode *key = container_of(rcu, struct tc_u_knode, rcu);
397 
398 	u32_destroy_key(key->tp, key, true);
399 }
400 
401 static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
402 {
403 	struct tc_u_knode __rcu **kp;
404 	struct tc_u_knode *pkp;
405 	struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);
406 
407 	if (ht) {
408 		kp = &ht->ht[TC_U32_HASH(key->handle)];
409 		for (pkp = rtnl_dereference(*kp); pkp;
410 		     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
411 			if (pkp == key) {
412 				RCU_INIT_POINTER(*kp, key->next);
413 
414 				tcf_unbind_filter(tp, &key->res);
415 				call_rcu(&key->rcu, u32_delete_key_freepf_rcu);
416 				return 0;
417 			}
418 		}
419 	}
420 	WARN_ON(1);
421 	return 0;
422 }
423 
424 static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
425 {
426 	struct tc_u_knode *n;
427 	unsigned int h;
428 
429 	for (h = 0; h <= ht->divisor; h++) {
430 		while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
431 			RCU_INIT_POINTER(ht->ht[h],
432 					 rtnl_dereference(n->next));
433 			tcf_unbind_filter(tp, &n->res);
434 			call_rcu(&n->rcu, u32_delete_key_freepf_rcu);
435 		}
436 	}
437 }
438 
439 static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht)
440 {
441 	struct tc_u_common *tp_c = tp->data;
442 	struct tc_u_hnode __rcu **hn;
443 	struct tc_u_hnode *phn;
444 
445 	WARN_ON(ht->refcnt);
446 
447 	u32_clear_hnode(tp, ht);
448 
449 	hn = &tp_c->hlist;
450 	for (phn = rtnl_dereference(*hn);
451 	     phn;
452 	     hn = &phn->next, phn = rtnl_dereference(*hn)) {
453 		if (phn == ht) {
454 			RCU_INIT_POINTER(*hn, ht->next);
455 			kfree_rcu(ht, rcu);
456 			return 0;
457 		}
458 	}
459 
460 	return -ENOENT;
461 }
462 
463 static void u32_destroy(struct tcf_proto *tp)
464 {
465 	struct tc_u_common *tp_c = tp->data;
466 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
467 
468 	WARN_ON(root_ht == NULL);
469 
470 	if (root_ht && --root_ht->refcnt == 0)
471 		u32_destroy_hnode(tp, root_ht);
472 
473 	if (--tp_c->refcnt == 0) {
474 		struct tc_u_hnode *ht;
475 
476 		tp->q->u32_node = NULL;
477 
478 		for (ht = rtnl_dereference(tp_c->hlist);
479 		     ht;
480 		     ht = rtnl_dereference(ht->next)) {
481 			ht->refcnt--;
482 			u32_clear_hnode(tp, ht);
483 		}
484 
485 		while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
486 			RCU_INIT_POINTER(tp_c->hlist, ht->next);
487 			kfree_rcu(ht, rcu);
488 		}
489 
490 		kfree(tp_c);
491 	}
492 
493 	tp->data = NULL;
494 }
495 
496 static int u32_delete(struct tcf_proto *tp, unsigned long arg)
497 {
498 	struct tc_u_hnode *ht = (struct tc_u_hnode *)arg;
499 	struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);
500 
501 	if (ht == NULL)
502 		return 0;
503 
504 	if (TC_U32_KEY(ht->handle))
505 		return u32_delete_key(tp, (struct tc_u_knode *)ht);
506 
507 	if (root_ht == ht)
508 		return -EINVAL;
509 
510 	if (ht->refcnt == 1) {
511 		ht->refcnt--;
512 		u32_destroy_hnode(tp, ht);
513 	} else {
514 		return -EBUSY;
515 	}
516 
517 	return 0;
518 }
519 
520 #define NR_U32_NODE (1<<12)
521 static u32 gen_new_kid(struct tc_u_hnode *ht, u32 handle)
522 {
523 	struct tc_u_knode *n;
524 	unsigned long i;
525 	unsigned long *bitmap = kzalloc(BITS_TO_LONGS(NR_U32_NODE) * sizeof(unsigned long),
526 					GFP_KERNEL);
527 	if (!bitmap)
528 		return handle | 0xFFF;
529 
530 	for (n = rtnl_dereference(ht->ht[TC_U32_HASH(handle)]);
531 	     n;
532 	     n = rtnl_dereference(n->next))
533 		set_bit(TC_U32_NODE(n->handle), bitmap);
534 
535 	i = find_next_zero_bit(bitmap, NR_U32_NODE, 0x800);
536 	if (i >= NR_U32_NODE)
537 		i = find_next_zero_bit(bitmap, NR_U32_NODE, 1);
538 
539 	kfree(bitmap);
540 	return handle | (i >= NR_U32_NODE ? 0xFFF : i);
541 }
542 
543 static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
544 	[TCA_U32_CLASSID]	= { .type = NLA_U32 },
545 	[TCA_U32_HASH]		= { .type = NLA_U32 },
546 	[TCA_U32_LINK]		= { .type = NLA_U32 },
547 	[TCA_U32_DIVISOR]	= { .type = NLA_U32 },
548 	[TCA_U32_SEL]		= { .len = sizeof(struct tc_u32_sel) },
549 	[TCA_U32_INDEV]		= { .type = NLA_STRING, .len = IFNAMSIZ },
550 	[TCA_U32_MARK]		= { .len = sizeof(struct tc_u32_mark) },
551 };
552 
553 static int u32_set_parms(struct net *net, struct tcf_proto *tp,
554 			 unsigned long base, struct tc_u_hnode *ht,
555 			 struct tc_u_knode *n, struct nlattr **tb,
556 			 struct nlattr *est, bool ovr)
557 {
558 	int err;
559 	struct tcf_exts e;
560 
561 	tcf_exts_init(&e, TCA_U32_ACT, TCA_U32_POLICE);
562 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
563 	if (err < 0)
564 		return err;
565 
566 	err = -EINVAL;
567 	if (tb[TCA_U32_LINK]) {
568 		u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
569 		struct tc_u_hnode *ht_down = NULL, *ht_old;
570 
571 		if (TC_U32_KEY(handle))
572 			goto errout;
573 
574 		if (handle) {
575 			ht_down = u32_lookup_ht(ht->tp_c, handle);
576 
577 			if (ht_down == NULL)
578 				goto errout;
579 			ht_down->refcnt++;
580 		}
581 
582 		ht_old = rtnl_dereference(n->ht_down);
583 		rcu_assign_pointer(n->ht_down, ht_down);
584 
585 		if (ht_old)
586 			ht_old->refcnt--;
587 	}
588 	if (tb[TCA_U32_CLASSID]) {
589 		n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
590 		tcf_bind_filter(tp, &n->res, base);
591 	}
592 
593 #ifdef CONFIG_NET_CLS_IND
594 	if (tb[TCA_U32_INDEV]) {
595 		int ret;
596 		ret = tcf_change_indev(net, tb[TCA_U32_INDEV]);
597 		if (ret < 0)
598 			goto errout;
599 		n->ifindex = ret;
600 	}
601 #endif
602 	tcf_exts_change(tp, &n->exts, &e);
603 
604 	return 0;
605 errout:
606 	tcf_exts_destroy(&e);
607 	return err;
608 }
609 
610 static void u32_replace_knode(struct tcf_proto *tp,
611 			      struct tc_u_common *tp_c,
612 			      struct tc_u_knode *n)
613 {
614 	struct tc_u_knode __rcu **ins;
615 	struct tc_u_knode *pins;
616 	struct tc_u_hnode *ht;
617 
618 	if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
619 		ht = rtnl_dereference(tp->root);
620 	else
621 		ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));
622 
623 	ins = &ht->ht[TC_U32_HASH(n->handle)];
624 
625 	/* The node must always exist for it to be replaced if this is not the
626 	 * case then something went very wrong elsewhere.
627 	 */
628 	for (pins = rtnl_dereference(*ins); ;
629 	     ins = &pins->next, pins = rtnl_dereference(*ins))
630 		if (pins->handle == n->handle)
631 			break;
632 
633 	RCU_INIT_POINTER(n->next, pins->next);
634 	rcu_assign_pointer(*ins, n);
635 }
636 
637 static struct tc_u_knode *u32_init_knode(struct tcf_proto *tp,
638 					 struct tc_u_knode *n)
639 {
640 	struct tc_u_knode *new;
641 	struct tc_u32_sel *s = &n->sel;
642 
643 	new = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key),
644 		      GFP_KERNEL);
645 
646 	if (!new)
647 		return NULL;
648 
649 	RCU_INIT_POINTER(new->next, n->next);
650 	new->handle = n->handle;
651 	RCU_INIT_POINTER(new->ht_up, n->ht_up);
652 
653 #ifdef CONFIG_NET_CLS_IND
654 	new->ifindex = n->ifindex;
655 #endif
656 	new->fshift = n->fshift;
657 	new->res = n->res;
658 	RCU_INIT_POINTER(new->ht_down, n->ht_down);
659 
660 	/* bump reference count as long as we hold pointer to structure */
661 	if (new->ht_down)
662 		new->ht_down->refcnt++;
663 
664 #ifdef CONFIG_CLS_U32_PERF
665 	/* Statistics may be incremented by readers during update
666 	 * so we must keep them in tact. When the node is later destroyed
667 	 * a special destroy call must be made to not free the pf memory.
668 	 */
669 	new->pf = n->pf;
670 #endif
671 
672 #ifdef CONFIG_CLS_U32_MARK
673 	new->val = n->val;
674 	new->mask = n->mask;
675 	/* Similarly success statistics must be moved as pointers */
676 	new->pcpu_success = n->pcpu_success;
677 #endif
678 	new->tp = tp;
679 	memcpy(&new->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
680 
681 	tcf_exts_init(&new->exts, TCA_U32_ACT, TCA_U32_POLICE);
682 
683 	return new;
684 }
685 
686 static int u32_change(struct net *net, struct sk_buff *in_skb,
687 		      struct tcf_proto *tp, unsigned long base, u32 handle,
688 		      struct nlattr **tca,
689 		      unsigned long *arg, bool ovr)
690 {
691 	struct tc_u_common *tp_c = tp->data;
692 	struct tc_u_hnode *ht;
693 	struct tc_u_knode *n;
694 	struct tc_u32_sel *s;
695 	struct nlattr *opt = tca[TCA_OPTIONS];
696 	struct nlattr *tb[TCA_U32_MAX + 1];
697 	u32 htid;
698 	int err;
699 #ifdef CONFIG_CLS_U32_PERF
700 	size_t size;
701 #endif
702 
703 	if (opt == NULL)
704 		return handle ? -EINVAL : 0;
705 
706 	err = nla_parse_nested(tb, TCA_U32_MAX, opt, u32_policy);
707 	if (err < 0)
708 		return err;
709 
710 	n = (struct tc_u_knode *)*arg;
711 	if (n) {
712 		struct tc_u_knode *new;
713 
714 		if (TC_U32_KEY(n->handle) == 0)
715 			return -EINVAL;
716 
717 		new = u32_init_knode(tp, n);
718 		if (!new)
719 			return -ENOMEM;
720 
721 		err = u32_set_parms(net, tp, base,
722 				    rtnl_dereference(n->ht_up), new, tb,
723 				    tca[TCA_RATE], ovr);
724 
725 		if (err) {
726 			u32_destroy_key(tp, new, false);
727 			return err;
728 		}
729 
730 		u32_replace_knode(tp, tp_c, new);
731 		tcf_unbind_filter(tp, &n->res);
732 		call_rcu(&n->rcu, u32_delete_key_rcu);
733 		return 0;
734 	}
735 
736 	if (tb[TCA_U32_DIVISOR]) {
737 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
738 
739 		if (--divisor > 0x100)
740 			return -EINVAL;
741 		if (TC_U32_KEY(handle))
742 			return -EINVAL;
743 		if (handle == 0) {
744 			handle = gen_new_htid(tp->data);
745 			if (handle == 0)
746 				return -ENOMEM;
747 		}
748 		ht = kzalloc(sizeof(*ht) + divisor*sizeof(void *), GFP_KERNEL);
749 		if (ht == NULL)
750 			return -ENOBUFS;
751 		ht->tp_c = tp_c;
752 		ht->refcnt = 1;
753 		ht->divisor = divisor;
754 		ht->handle = handle;
755 		ht->prio = tp->prio;
756 		RCU_INIT_POINTER(ht->next, tp_c->hlist);
757 		rcu_assign_pointer(tp_c->hlist, ht);
758 		*arg = (unsigned long)ht;
759 		return 0;
760 	}
761 
762 	if (tb[TCA_U32_HASH]) {
763 		htid = nla_get_u32(tb[TCA_U32_HASH]);
764 		if (TC_U32_HTID(htid) == TC_U32_ROOT) {
765 			ht = rtnl_dereference(tp->root);
766 			htid = ht->handle;
767 		} else {
768 			ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
769 			if (ht == NULL)
770 				return -EINVAL;
771 		}
772 	} else {
773 		ht = rtnl_dereference(tp->root);
774 		htid = ht->handle;
775 	}
776 
777 	if (ht->divisor < TC_U32_HASH(htid))
778 		return -EINVAL;
779 
780 	if (handle) {
781 		if (TC_U32_HTID(handle) && TC_U32_HTID(handle^htid))
782 			return -EINVAL;
783 		handle = htid | TC_U32_NODE(handle);
784 	} else
785 		handle = gen_new_kid(ht, htid);
786 
787 	if (tb[TCA_U32_SEL] == NULL)
788 		return -EINVAL;
789 
790 	s = nla_data(tb[TCA_U32_SEL]);
791 
792 	n = kzalloc(sizeof(*n) + s->nkeys*sizeof(struct tc_u32_key), GFP_KERNEL);
793 	if (n == NULL)
794 		return -ENOBUFS;
795 
796 #ifdef CONFIG_CLS_U32_PERF
797 	size = sizeof(struct tc_u32_pcnt) + s->nkeys * sizeof(u64);
798 	n->pf = __alloc_percpu(size, __alignof__(struct tc_u32_pcnt));
799 	if (!n->pf) {
800 		kfree(n);
801 		return -ENOBUFS;
802 	}
803 #endif
804 
805 	memcpy(&n->sel, s, sizeof(*s) + s->nkeys*sizeof(struct tc_u32_key));
806 	RCU_INIT_POINTER(n->ht_up, ht);
807 	n->handle = handle;
808 	n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
809 	tcf_exts_init(&n->exts, TCA_U32_ACT, TCA_U32_POLICE);
810 	n->tp = tp;
811 
812 #ifdef CONFIG_CLS_U32_MARK
813 	n->pcpu_success = alloc_percpu(u32);
814 	if (!n->pcpu_success) {
815 		err = -ENOMEM;
816 		goto errout;
817 	}
818 
819 	if (tb[TCA_U32_MARK]) {
820 		struct tc_u32_mark *mark;
821 
822 		mark = nla_data(tb[TCA_U32_MARK]);
823 		n->val = mark->val;
824 		n->mask = mark->mask;
825 	}
826 #endif
827 
828 	err = u32_set_parms(net, tp, base, ht, n, tb, tca[TCA_RATE], ovr);
829 	if (err == 0) {
830 		struct tc_u_knode __rcu **ins;
831 		struct tc_u_knode *pins;
832 
833 		ins = &ht->ht[TC_U32_HASH(handle)];
834 		for (pins = rtnl_dereference(*ins); pins;
835 		     ins = &pins->next, pins = rtnl_dereference(*ins))
836 			if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
837 				break;
838 
839 		RCU_INIT_POINTER(n->next, pins);
840 		rcu_assign_pointer(*ins, n);
841 
842 		*arg = (unsigned long)n;
843 		return 0;
844 	}
845 
846 #ifdef CONFIG_CLS_U32_MARK
847 	free_percpu(n->pcpu_success);
848 errout:
849 #endif
850 
851 #ifdef CONFIG_CLS_U32_PERF
852 	free_percpu(n->pf);
853 #endif
854 	kfree(n);
855 	return err;
856 }
857 
858 static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg)
859 {
860 	struct tc_u_common *tp_c = tp->data;
861 	struct tc_u_hnode *ht;
862 	struct tc_u_knode *n;
863 	unsigned int h;
864 
865 	if (arg->stop)
866 		return;
867 
868 	for (ht = rtnl_dereference(tp_c->hlist);
869 	     ht;
870 	     ht = rtnl_dereference(ht->next)) {
871 		if (ht->prio != tp->prio)
872 			continue;
873 		if (arg->count >= arg->skip) {
874 			if (arg->fn(tp, (unsigned long)ht, arg) < 0) {
875 				arg->stop = 1;
876 				return;
877 			}
878 		}
879 		arg->count++;
880 		for (h = 0; h <= ht->divisor; h++) {
881 			for (n = rtnl_dereference(ht->ht[h]);
882 			     n;
883 			     n = rtnl_dereference(n->next)) {
884 				if (arg->count < arg->skip) {
885 					arg->count++;
886 					continue;
887 				}
888 				if (arg->fn(tp, (unsigned long)n, arg) < 0) {
889 					arg->stop = 1;
890 					return;
891 				}
892 				arg->count++;
893 			}
894 		}
895 	}
896 }
897 
898 static int u32_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
899 		     struct sk_buff *skb, struct tcmsg *t)
900 {
901 	struct tc_u_knode *n = (struct tc_u_knode *)fh;
902 	struct tc_u_hnode *ht_up, *ht_down;
903 	struct nlattr *nest;
904 
905 	if (n == NULL)
906 		return skb->len;
907 
908 	t->tcm_handle = n->handle;
909 
910 	nest = nla_nest_start(skb, TCA_OPTIONS);
911 	if (nest == NULL)
912 		goto nla_put_failure;
913 
914 	if (TC_U32_KEY(n->handle) == 0) {
915 		struct tc_u_hnode *ht = (struct tc_u_hnode *)fh;
916 		u32 divisor = ht->divisor + 1;
917 
918 		if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
919 			goto nla_put_failure;
920 	} else {
921 #ifdef CONFIG_CLS_U32_PERF
922 		struct tc_u32_pcnt *gpf;
923 		int cpu;
924 #endif
925 
926 		if (nla_put(skb, TCA_U32_SEL,
927 			    sizeof(n->sel) + n->sel.nkeys*sizeof(struct tc_u32_key),
928 			    &n->sel))
929 			goto nla_put_failure;
930 
931 		ht_up = rtnl_dereference(n->ht_up);
932 		if (ht_up) {
933 			u32 htid = n->handle & 0xFFFFF000;
934 			if (nla_put_u32(skb, TCA_U32_HASH, htid))
935 				goto nla_put_failure;
936 		}
937 		if (n->res.classid &&
938 		    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
939 			goto nla_put_failure;
940 
941 		ht_down = rtnl_dereference(n->ht_down);
942 		if (ht_down &&
943 		    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
944 			goto nla_put_failure;
945 
946 #ifdef CONFIG_CLS_U32_MARK
947 		if ((n->val || n->mask)) {
948 			struct tc_u32_mark mark = {.val = n->val,
949 						   .mask = n->mask,
950 						   .success = 0};
951 			int cpum;
952 
953 			for_each_possible_cpu(cpum) {
954 				__u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);
955 
956 				mark.success += cnt;
957 			}
958 
959 			if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
960 				goto nla_put_failure;
961 		}
962 #endif
963 
964 		if (tcf_exts_dump(skb, &n->exts) < 0)
965 			goto nla_put_failure;
966 
967 #ifdef CONFIG_NET_CLS_IND
968 		if (n->ifindex) {
969 			struct net_device *dev;
970 			dev = __dev_get_by_index(net, n->ifindex);
971 			if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
972 				goto nla_put_failure;
973 		}
974 #endif
975 #ifdef CONFIG_CLS_U32_PERF
976 		gpf = kzalloc(sizeof(struct tc_u32_pcnt) +
977 			      n->sel.nkeys * sizeof(u64),
978 			      GFP_KERNEL);
979 		if (!gpf)
980 			goto nla_put_failure;
981 
982 		for_each_possible_cpu(cpu) {
983 			int i;
984 			struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);
985 
986 			gpf->rcnt += pf->rcnt;
987 			gpf->rhit += pf->rhit;
988 			for (i = 0; i < n->sel.nkeys; i++)
989 				gpf->kcnts[i] += pf->kcnts[i];
990 		}
991 
992 		if (nla_put(skb, TCA_U32_PCNT,
993 			    sizeof(struct tc_u32_pcnt) + n->sel.nkeys*sizeof(u64),
994 			    gpf)) {
995 			kfree(gpf);
996 			goto nla_put_failure;
997 		}
998 		kfree(gpf);
999 #endif
1000 	}
1001 
1002 	nla_nest_end(skb, nest);
1003 
1004 	if (TC_U32_KEY(n->handle))
1005 		if (tcf_exts_dump_stats(skb, &n->exts) < 0)
1006 			goto nla_put_failure;
1007 	return skb->len;
1008 
1009 nla_put_failure:
1010 	nla_nest_cancel(skb, nest);
1011 	return -1;
1012 }
1013 
1014 static struct tcf_proto_ops cls_u32_ops __read_mostly = {
1015 	.kind		=	"u32",
1016 	.classify	=	u32_classify,
1017 	.init		=	u32_init,
1018 	.destroy	=	u32_destroy,
1019 	.get		=	u32_get,
1020 	.change		=	u32_change,
1021 	.delete		=	u32_delete,
1022 	.walk		=	u32_walk,
1023 	.dump		=	u32_dump,
1024 	.owner		=	THIS_MODULE,
1025 };
1026 
1027 static int __init init_u32(void)
1028 {
1029 	pr_info("u32 classifier\n");
1030 #ifdef CONFIG_CLS_U32_PERF
1031 	pr_info("    Performance counters on\n");
1032 #endif
1033 #ifdef CONFIG_NET_CLS_IND
1034 	pr_info("    input device check on\n");
1035 #endif
1036 #ifdef CONFIG_NET_CLS_ACT
1037 	pr_info("    Actions configured\n");
1038 #endif
1039 	return register_tcf_proto_ops(&cls_u32_ops);
1040 }
1041 
1042 static void __exit exit_u32(void)
1043 {
1044 	unregister_tcf_proto_ops(&cls_u32_ops);
1045 }
1046 
1047 module_init(init_u32)
1048 module_exit(exit_u32)
1049 MODULE_LICENSE("GPL");
1050