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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * net/sched/cls_tcindex.c	Packet classifier for skb->tc_index
4  *
5  * Written 1998,1999 by Werner Almesberger, EPFL ICA
6  */
7 
8 #include <linux/module.h>
9 #include <linux/types.h>
10 #include <linux/kernel.h>
11 #include <linux/skbuff.h>
12 #include <linux/errno.h>
13 #include <linux/slab.h>
14 #include <net/act_api.h>
15 #include <net/netlink.h>
16 #include <net/pkt_cls.h>
17 #include <net/sch_generic.h>
18 
19 /*
20  * Passing parameters to the root seems to be done more awkwardly than really
21  * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
22  * verified. FIXME.
23  */
24 
25 #define PERFECT_HASH_THRESHOLD	64	/* use perfect hash if not bigger */
26 #define DEFAULT_HASH_SIZE	64	/* optimized for diffserv */
27 
28 
29 struct tcindex_filter_result {
30 	struct tcf_exts		exts;
31 	struct tcf_result	res;
32 	struct rcu_work		rwork;
33 };
34 
35 struct tcindex_filter {
36 	u16 key;
37 	struct tcindex_filter_result result;
38 	struct tcindex_filter __rcu *next;
39 	struct rcu_work rwork;
40 };
41 
42 
43 struct tcindex_data {
44 	struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
45 	struct tcindex_filter __rcu **h; /* imperfect hash; */
46 	struct tcf_proto *tp;
47 	u16 mask;		/* AND key with mask */
48 	u32 shift;		/* shift ANDed key to the right */
49 	u32 hash;		/* hash table size; 0 if undefined */
50 	u32 alloc_hash;		/* allocated size */
51 	u32 fall_through;	/* 0: only classify if explicit match */
52 	struct rcu_work rwork;
53 };
54 
tcindex_filter_is_set(struct tcindex_filter_result * r)55 static inline int tcindex_filter_is_set(struct tcindex_filter_result *r)
56 {
57 	return tcf_exts_has_actions(&r->exts) || r->res.classid;
58 }
59 
tcindex_lookup(struct tcindex_data * p,u16 key)60 static struct tcindex_filter_result *tcindex_lookup(struct tcindex_data *p,
61 						    u16 key)
62 {
63 	if (p->perfect) {
64 		struct tcindex_filter_result *f = p->perfect + key;
65 
66 		return tcindex_filter_is_set(f) ? f : NULL;
67 	} else if (p->h) {
68 		struct tcindex_filter __rcu **fp;
69 		struct tcindex_filter *f;
70 
71 		fp = &p->h[key % p->hash];
72 		for (f = rcu_dereference_bh_rtnl(*fp);
73 		     f;
74 		     fp = &f->next, f = rcu_dereference_bh_rtnl(*fp))
75 			if (f->key == key)
76 				return &f->result;
77 	}
78 
79 	return NULL;
80 }
81 
82 
tcindex_classify(struct sk_buff * skb,const struct tcf_proto * tp,struct tcf_result * res)83 static int tcindex_classify(struct sk_buff *skb, const struct tcf_proto *tp,
84 			    struct tcf_result *res)
85 {
86 	struct tcindex_data *p = rcu_dereference_bh(tp->root);
87 	struct tcindex_filter_result *f;
88 	int key = (skb->tc_index & p->mask) >> p->shift;
89 
90 	pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
91 		 skb, tp, res, p);
92 
93 	f = tcindex_lookup(p, key);
94 	if (!f) {
95 		struct Qdisc *q = tcf_block_q(tp->chain->block);
96 
97 		if (!p->fall_through)
98 			return -1;
99 		res->classid = TC_H_MAKE(TC_H_MAJ(q->handle), key);
100 		res->class = 0;
101 		pr_debug("alg 0x%x\n", res->classid);
102 		return 0;
103 	}
104 	*res = f->res;
105 	pr_debug("map 0x%x\n", res->classid);
106 
107 	return tcf_exts_exec(skb, &f->exts, res);
108 }
109 
110 
tcindex_get(struct tcf_proto * tp,u32 handle)111 static void *tcindex_get(struct tcf_proto *tp, u32 handle)
112 {
113 	struct tcindex_data *p = rtnl_dereference(tp->root);
114 	struct tcindex_filter_result *r;
115 
116 	pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
117 	if (p->perfect && handle >= p->alloc_hash)
118 		return NULL;
119 	r = tcindex_lookup(p, handle);
120 	return r && tcindex_filter_is_set(r) ? r : NULL;
121 }
122 
tcindex_init(struct tcf_proto * tp)123 static int tcindex_init(struct tcf_proto *tp)
124 {
125 	struct tcindex_data *p;
126 
127 	pr_debug("tcindex_init(tp %p)\n", tp);
128 	p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
129 	if (!p)
130 		return -ENOMEM;
131 
132 	p->mask = 0xffff;
133 	p->hash = DEFAULT_HASH_SIZE;
134 	p->fall_through = 1;
135 
136 	rcu_assign_pointer(tp->root, p);
137 	return 0;
138 }
139 
__tcindex_destroy_rexts(struct tcindex_filter_result * r)140 static void __tcindex_destroy_rexts(struct tcindex_filter_result *r)
141 {
142 	tcf_exts_destroy(&r->exts);
143 	tcf_exts_put_net(&r->exts);
144 }
145 
tcindex_destroy_rexts_work(struct work_struct * work)146 static void tcindex_destroy_rexts_work(struct work_struct *work)
147 {
148 	struct tcindex_filter_result *r;
149 
150 	r = container_of(to_rcu_work(work),
151 			 struct tcindex_filter_result,
152 			 rwork);
153 	rtnl_lock();
154 	__tcindex_destroy_rexts(r);
155 	rtnl_unlock();
156 }
157 
__tcindex_destroy_fexts(struct tcindex_filter * f)158 static void __tcindex_destroy_fexts(struct tcindex_filter *f)
159 {
160 	tcf_exts_destroy(&f->result.exts);
161 	tcf_exts_put_net(&f->result.exts);
162 	kfree(f);
163 }
164 
tcindex_destroy_fexts_work(struct work_struct * work)165 static void tcindex_destroy_fexts_work(struct work_struct *work)
166 {
167 	struct tcindex_filter *f = container_of(to_rcu_work(work),
168 						struct tcindex_filter,
169 						rwork);
170 
171 	rtnl_lock();
172 	__tcindex_destroy_fexts(f);
173 	rtnl_unlock();
174 }
175 
tcindex_delete(struct tcf_proto * tp,void * arg,bool * last,bool rtnl_held,struct netlink_ext_ack * extack)176 static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
177 			  bool rtnl_held, struct netlink_ext_ack *extack)
178 {
179 	struct tcindex_data *p = rtnl_dereference(tp->root);
180 	struct tcindex_filter_result *r = arg;
181 	struct tcindex_filter __rcu **walk;
182 	struct tcindex_filter *f = NULL;
183 
184 	pr_debug("tcindex_delete(tp %p,arg %p),p %p\n", tp, arg, p);
185 	if (p->perfect) {
186 		if (!r->res.class)
187 			return -ENOENT;
188 	} else {
189 		int i;
190 
191 		for (i = 0; i < p->hash; i++) {
192 			walk = p->h + i;
193 			for (f = rtnl_dereference(*walk); f;
194 			     walk = &f->next, f = rtnl_dereference(*walk)) {
195 				if (&f->result == r)
196 					goto found;
197 			}
198 		}
199 		return -ENOENT;
200 
201 found:
202 		rcu_assign_pointer(*walk, rtnl_dereference(f->next));
203 	}
204 	tcf_unbind_filter(tp, &r->res);
205 	/* all classifiers are required to call tcf_exts_destroy() after rcu
206 	 * grace period, since converted-to-rcu actions are relying on that
207 	 * in cleanup() callback
208 	 */
209 	if (f) {
210 		if (tcf_exts_get_net(&f->result.exts))
211 			tcf_queue_work(&f->rwork, tcindex_destroy_fexts_work);
212 		else
213 			__tcindex_destroy_fexts(f);
214 	} else {
215 		if (tcf_exts_get_net(&r->exts))
216 			tcf_queue_work(&r->rwork, tcindex_destroy_rexts_work);
217 		else
218 			__tcindex_destroy_rexts(r);
219 	}
220 
221 	*last = false;
222 	return 0;
223 }
224 
tcindex_destroy_work(struct work_struct * work)225 static void tcindex_destroy_work(struct work_struct *work)
226 {
227 	struct tcindex_data *p = container_of(to_rcu_work(work),
228 					      struct tcindex_data,
229 					      rwork);
230 
231 	kfree(p->perfect);
232 	kfree(p->h);
233 	kfree(p);
234 }
235 
236 static inline int
valid_perfect_hash(struct tcindex_data * p)237 valid_perfect_hash(struct tcindex_data *p)
238 {
239 	return  p->hash > (p->mask >> p->shift);
240 }
241 
242 static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
243 	[TCA_TCINDEX_HASH]		= { .type = NLA_U32 },
244 	[TCA_TCINDEX_MASK]		= { .type = NLA_U16 },
245 	[TCA_TCINDEX_SHIFT]		= { .type = NLA_U32 },
246 	[TCA_TCINDEX_FALL_THROUGH]	= { .type = NLA_U32 },
247 	[TCA_TCINDEX_CLASSID]		= { .type = NLA_U32 },
248 };
249 
tcindex_filter_result_init(struct tcindex_filter_result * r,struct net * net)250 static int tcindex_filter_result_init(struct tcindex_filter_result *r,
251 				      struct net *net)
252 {
253 	memset(r, 0, sizeof(*r));
254 	return tcf_exts_init(&r->exts, net, TCA_TCINDEX_ACT,
255 			     TCA_TCINDEX_POLICE);
256 }
257 
tcindex_partial_destroy_work(struct work_struct * work)258 static void tcindex_partial_destroy_work(struct work_struct *work)
259 {
260 	struct tcindex_data *p = container_of(to_rcu_work(work),
261 					      struct tcindex_data,
262 					      rwork);
263 
264 	kfree(p->perfect);
265 	kfree(p);
266 }
267 
tcindex_free_perfect_hash(struct tcindex_data * cp)268 static void tcindex_free_perfect_hash(struct tcindex_data *cp)
269 {
270 	int i;
271 
272 	for (i = 0; i < cp->hash; i++)
273 		tcf_exts_destroy(&cp->perfect[i].exts);
274 	kfree(cp->perfect);
275 }
276 
tcindex_alloc_perfect_hash(struct net * net,struct tcindex_data * cp)277 static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)
278 {
279 	int i, err = 0;
280 
281 	cp->perfect = kcalloc(cp->hash, sizeof(struct tcindex_filter_result),
282 			      GFP_KERNEL);
283 	if (!cp->perfect)
284 		return -ENOMEM;
285 
286 	for (i = 0; i < cp->hash; i++) {
287 		err = tcf_exts_init(&cp->perfect[i].exts, net,
288 				    TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
289 		if (err < 0)
290 			goto errout;
291 	}
292 
293 	return 0;
294 
295 errout:
296 	tcindex_free_perfect_hash(cp);
297 	return err;
298 }
299 
300 static int
tcindex_set_parms(struct net * net,struct tcf_proto * tp,unsigned long base,u32 handle,struct tcindex_data * p,struct tcindex_filter_result * r,struct nlattr ** tb,struct nlattr * est,bool ovr,struct netlink_ext_ack * extack)301 tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
302 		  u32 handle, struct tcindex_data *p,
303 		  struct tcindex_filter_result *r, struct nlattr **tb,
304 		  struct nlattr *est, bool ovr, struct netlink_ext_ack *extack)
305 {
306 	struct tcindex_filter_result new_filter_result, *old_r = r;
307 	struct tcindex_data *cp = NULL, *oldp;
308 	struct tcindex_filter *f = NULL; /* make gcc behave */
309 	struct tcf_result cr = {};
310 	int err, balloc = 0;
311 	struct tcf_exts e;
312 
313 	err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
314 	if (err < 0)
315 		return err;
316 	err = tcf_exts_validate(net, tp, tb, est, &e, ovr, true, extack);
317 	if (err < 0)
318 		goto errout;
319 
320 	err = -ENOMEM;
321 	/* tcindex_data attributes must look atomic to classifier/lookup so
322 	 * allocate new tcindex data and RCU assign it onto root. Keeping
323 	 * perfect hash and hash pointers from old data.
324 	 */
325 	cp = kzalloc(sizeof(*cp), GFP_KERNEL);
326 	if (!cp)
327 		goto errout;
328 
329 	cp->mask = p->mask;
330 	cp->shift = p->shift;
331 	cp->hash = p->hash;
332 	cp->alloc_hash = p->alloc_hash;
333 	cp->fall_through = p->fall_through;
334 	cp->tp = tp;
335 
336 	if (p->perfect) {
337 		int i;
338 
339 		if (tcindex_alloc_perfect_hash(net, cp) < 0)
340 			goto errout;
341 		for (i = 0; i < cp->hash; i++)
342 			cp->perfect[i].res = p->perfect[i].res;
343 		balloc = 1;
344 	}
345 	cp->h = p->h;
346 
347 	err = tcindex_filter_result_init(&new_filter_result, net);
348 	if (err < 0)
349 		goto errout1;
350 	if (old_r)
351 		cr = r->res;
352 
353 	if (tb[TCA_TCINDEX_HASH])
354 		cp->hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
355 
356 	if (tb[TCA_TCINDEX_MASK])
357 		cp->mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
358 
359 	if (tb[TCA_TCINDEX_SHIFT])
360 		cp->shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
361 
362 	err = -EBUSY;
363 
364 	/* Hash already allocated, make sure that we still meet the
365 	 * requirements for the allocated hash.
366 	 */
367 	if (cp->perfect) {
368 		if (!valid_perfect_hash(cp) ||
369 		    cp->hash > cp->alloc_hash)
370 			goto errout_alloc;
371 	} else if (cp->h && cp->hash != cp->alloc_hash) {
372 		goto errout_alloc;
373 	}
374 
375 	err = -EINVAL;
376 	if (tb[TCA_TCINDEX_FALL_THROUGH])
377 		cp->fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
378 
379 	if (!cp->hash) {
380 		/* Hash not specified, use perfect hash if the upper limit
381 		 * of the hashing index is below the threshold.
382 		 */
383 		if ((cp->mask >> cp->shift) < PERFECT_HASH_THRESHOLD)
384 			cp->hash = (cp->mask >> cp->shift) + 1;
385 		else
386 			cp->hash = DEFAULT_HASH_SIZE;
387 	}
388 
389 	if (!cp->perfect && !cp->h)
390 		cp->alloc_hash = cp->hash;
391 
392 	/* Note: this could be as restrictive as if (handle & ~(mask >> shift))
393 	 * but then, we'd fail handles that may become valid after some future
394 	 * mask change. While this is extremely unlikely to ever matter,
395 	 * the check below is safer (and also more backwards-compatible).
396 	 */
397 	if (cp->perfect || valid_perfect_hash(cp))
398 		if (handle >= cp->alloc_hash)
399 			goto errout_alloc;
400 
401 
402 	err = -ENOMEM;
403 	if (!cp->perfect && !cp->h) {
404 		if (valid_perfect_hash(cp)) {
405 			if (tcindex_alloc_perfect_hash(net, cp) < 0)
406 				goto errout_alloc;
407 			balloc = 1;
408 		} else {
409 			struct tcindex_filter __rcu **hash;
410 
411 			hash = kcalloc(cp->hash,
412 				       sizeof(struct tcindex_filter *),
413 				       GFP_KERNEL);
414 
415 			if (!hash)
416 				goto errout_alloc;
417 
418 			cp->h = hash;
419 			balloc = 2;
420 		}
421 	}
422 
423 	if (cp->perfect)
424 		r = cp->perfect + handle;
425 	else
426 		r = tcindex_lookup(cp, handle) ? : &new_filter_result;
427 
428 	if (r == &new_filter_result) {
429 		f = kzalloc(sizeof(*f), GFP_KERNEL);
430 		if (!f)
431 			goto errout_alloc;
432 		f->key = handle;
433 		f->next = NULL;
434 		err = tcindex_filter_result_init(&f->result, net);
435 		if (err < 0) {
436 			kfree(f);
437 			goto errout_alloc;
438 		}
439 	}
440 
441 	if (tb[TCA_TCINDEX_CLASSID]) {
442 		cr.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
443 		tcf_bind_filter(tp, &cr, base);
444 	}
445 
446 	if (old_r && old_r != r) {
447 		err = tcindex_filter_result_init(old_r, net);
448 		if (err < 0) {
449 			kfree(f);
450 			goto errout_alloc;
451 		}
452 	}
453 
454 	oldp = p;
455 	r->res = cr;
456 	tcf_exts_change(&r->exts, &e);
457 
458 	rcu_assign_pointer(tp->root, cp);
459 
460 	if (r == &new_filter_result) {
461 		struct tcindex_filter *nfp;
462 		struct tcindex_filter __rcu **fp;
463 
464 		f->result.res = r->res;
465 		tcf_exts_change(&f->result.exts, &r->exts);
466 
467 		fp = cp->h + (handle % cp->hash);
468 		for (nfp = rtnl_dereference(*fp);
469 		     nfp;
470 		     fp = &nfp->next, nfp = rtnl_dereference(*fp))
471 				; /* nothing */
472 
473 		rcu_assign_pointer(*fp, f);
474 	} else {
475 		tcf_exts_destroy(&new_filter_result.exts);
476 	}
477 
478 	if (oldp)
479 		tcf_queue_work(&oldp->rwork, tcindex_partial_destroy_work);
480 	return 0;
481 
482 errout_alloc:
483 	if (balloc == 1)
484 		tcindex_free_perfect_hash(cp);
485 	else if (balloc == 2)
486 		kfree(cp->h);
487 errout1:
488 	tcf_exts_destroy(&new_filter_result.exts);
489 errout:
490 	kfree(cp);
491 	tcf_exts_destroy(&e);
492 	return err;
493 }
494 
495 static int
tcindex_change(struct net * net,struct sk_buff * in_skb,struct tcf_proto * tp,unsigned long base,u32 handle,struct nlattr ** tca,void ** arg,bool ovr,bool rtnl_held,struct netlink_ext_ack * extack)496 tcindex_change(struct net *net, struct sk_buff *in_skb,
497 	       struct tcf_proto *tp, unsigned long base, u32 handle,
498 	       struct nlattr **tca, void **arg, bool ovr,
499 	       bool rtnl_held, struct netlink_ext_ack *extack)
500 {
501 	struct nlattr *opt = tca[TCA_OPTIONS];
502 	struct nlattr *tb[TCA_TCINDEX_MAX + 1];
503 	struct tcindex_data *p = rtnl_dereference(tp->root);
504 	struct tcindex_filter_result *r = *arg;
505 	int err;
506 
507 	pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
508 	    "p %p,r %p,*arg %p\n",
509 	    tp, handle, tca, arg, opt, p, r, arg ? *arg : NULL);
510 
511 	if (!opt)
512 		return 0;
513 
514 	err = nla_parse_nested_deprecated(tb, TCA_TCINDEX_MAX, opt,
515 					  tcindex_policy, NULL);
516 	if (err < 0)
517 		return err;
518 
519 	return tcindex_set_parms(net, tp, base, handle, p, r, tb,
520 				 tca[TCA_RATE], ovr, extack);
521 }
522 
tcindex_walk(struct tcf_proto * tp,struct tcf_walker * walker,bool rtnl_held)523 static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker,
524 			 bool rtnl_held)
525 {
526 	struct tcindex_data *p = rtnl_dereference(tp->root);
527 	struct tcindex_filter *f, *next;
528 	int i;
529 
530 	pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
531 	if (p->perfect) {
532 		for (i = 0; i < p->hash; i++) {
533 			if (!p->perfect[i].res.class)
534 				continue;
535 			if (walker->count >= walker->skip) {
536 				if (walker->fn(tp, p->perfect + i, walker) < 0) {
537 					walker->stop = 1;
538 					return;
539 				}
540 			}
541 			walker->count++;
542 		}
543 	}
544 	if (!p->h)
545 		return;
546 	for (i = 0; i < p->hash; i++) {
547 		for (f = rtnl_dereference(p->h[i]); f; f = next) {
548 			next = rtnl_dereference(f->next);
549 			if (walker->count >= walker->skip) {
550 				if (walker->fn(tp, &f->result, walker) < 0) {
551 					walker->stop = 1;
552 					return;
553 				}
554 			}
555 			walker->count++;
556 		}
557 	}
558 }
559 
tcindex_destroy(struct tcf_proto * tp,bool rtnl_held,struct netlink_ext_ack * extack)560 static void tcindex_destroy(struct tcf_proto *tp, bool rtnl_held,
561 			    struct netlink_ext_ack *extack)
562 {
563 	struct tcindex_data *p = rtnl_dereference(tp->root);
564 	int i;
565 
566 	pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
567 
568 	if (p->perfect) {
569 		for (i = 0; i < p->hash; i++) {
570 			struct tcindex_filter_result *r = p->perfect + i;
571 
572 			tcf_unbind_filter(tp, &r->res);
573 			if (tcf_exts_get_net(&r->exts))
574 				tcf_queue_work(&r->rwork,
575 					       tcindex_destroy_rexts_work);
576 			else
577 				__tcindex_destroy_rexts(r);
578 		}
579 	}
580 
581 	for (i = 0; p->h && i < p->hash; i++) {
582 		struct tcindex_filter *f, *next;
583 		bool last;
584 
585 		for (f = rtnl_dereference(p->h[i]); f; f = next) {
586 			next = rtnl_dereference(f->next);
587 			tcindex_delete(tp, &f->result, &last, rtnl_held, NULL);
588 		}
589 	}
590 
591 	tcf_queue_work(&p->rwork, tcindex_destroy_work);
592 }
593 
594 
tcindex_dump(struct net * net,struct tcf_proto * tp,void * fh,struct sk_buff * skb,struct tcmsg * t,bool rtnl_held)595 static int tcindex_dump(struct net *net, struct tcf_proto *tp, void *fh,
596 			struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
597 {
598 	struct tcindex_data *p = rtnl_dereference(tp->root);
599 	struct tcindex_filter_result *r = fh;
600 	struct nlattr *nest;
601 
602 	pr_debug("tcindex_dump(tp %p,fh %p,skb %p,t %p),p %p,r %p\n",
603 		 tp, fh, skb, t, p, r);
604 	pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
605 
606 	nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
607 	if (nest == NULL)
608 		goto nla_put_failure;
609 
610 	if (!fh) {
611 		t->tcm_handle = ~0; /* whatever ... */
612 		if (nla_put_u32(skb, TCA_TCINDEX_HASH, p->hash) ||
613 		    nla_put_u16(skb, TCA_TCINDEX_MASK, p->mask) ||
614 		    nla_put_u32(skb, TCA_TCINDEX_SHIFT, p->shift) ||
615 		    nla_put_u32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through))
616 			goto nla_put_failure;
617 		nla_nest_end(skb, nest);
618 	} else {
619 		if (p->perfect) {
620 			t->tcm_handle = r - p->perfect;
621 		} else {
622 			struct tcindex_filter *f;
623 			struct tcindex_filter __rcu **fp;
624 			int i;
625 
626 			t->tcm_handle = 0;
627 			for (i = 0; !t->tcm_handle && i < p->hash; i++) {
628 				fp = &p->h[i];
629 				for (f = rtnl_dereference(*fp);
630 				     !t->tcm_handle && f;
631 				     fp = &f->next, f = rtnl_dereference(*fp)) {
632 					if (&f->result == r)
633 						t->tcm_handle = f->key;
634 				}
635 			}
636 		}
637 		pr_debug("handle = %d\n", t->tcm_handle);
638 		if (r->res.class &&
639 		    nla_put_u32(skb, TCA_TCINDEX_CLASSID, r->res.classid))
640 			goto nla_put_failure;
641 
642 		if (tcf_exts_dump(skb, &r->exts) < 0)
643 			goto nla_put_failure;
644 		nla_nest_end(skb, nest);
645 
646 		if (tcf_exts_dump_stats(skb, &r->exts) < 0)
647 			goto nla_put_failure;
648 	}
649 
650 	return skb->len;
651 
652 nla_put_failure:
653 	nla_nest_cancel(skb, nest);
654 	return -1;
655 }
656 
tcindex_bind_class(void * fh,u32 classid,unsigned long cl,void * q,unsigned long base)657 static void tcindex_bind_class(void *fh, u32 classid, unsigned long cl,
658 			       void *q, unsigned long base)
659 {
660 	struct tcindex_filter_result *r = fh;
661 
662 	if (r && r->res.classid == classid) {
663 		if (cl)
664 			__tcf_bind_filter(q, &r->res, base);
665 		else
666 			__tcf_unbind_filter(q, &r->res);
667 	}
668 }
669 
670 static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
671 	.kind		=	"tcindex",
672 	.classify	=	tcindex_classify,
673 	.init		=	tcindex_init,
674 	.destroy	=	tcindex_destroy,
675 	.get		=	tcindex_get,
676 	.change		=	tcindex_change,
677 	.delete		=	tcindex_delete,
678 	.walk		=	tcindex_walk,
679 	.dump		=	tcindex_dump,
680 	.bind_class	=	tcindex_bind_class,
681 	.owner		=	THIS_MODULE,
682 };
683 
init_tcindex(void)684 static int __init init_tcindex(void)
685 {
686 	return register_tcf_proto_ops(&cls_tcindex_ops);
687 }
688 
exit_tcindex(void)689 static void __exit exit_tcindex(void)
690 {
691 	unregister_tcf_proto_ops(&cls_tcindex_ops);
692 }
693 
694 module_init(init_tcindex)
695 module_exit(exit_tcindex)
696 MODULE_LICENSE("GPL");
697