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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
29struct tcindex_filter_result {
30 struct tcf_exts exts;
31 struct tcf_result res;
32 struct rcu_work rwork;
33};
34
35struct 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
43struct 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
55static 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
60static 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
83static 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
111static 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
123static 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
140static 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
146static 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
158static 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
165static 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
176static 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
201found:
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
225static 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
236static inline int
237valid_perfect_hash(struct tcindex_data *p)
238{
239 return p->hash > (p->mask >> p->shift);
240}
241
242static 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
250static 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
258static 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
268static 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
277static 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
295errout:
296 tcindex_free_perfect_hash(cp);
297 return err;
298}
299
300static int
301tcindex_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
482errout_alloc:
483 if (balloc == 1)
484 tcindex_free_perfect_hash(cp);
485 else if (balloc == 2)
486 kfree(cp->h);
487errout1:
488 tcf_exts_destroy(&new_filter_result.exts);
489errout:
490 kfree(cp);
491 tcf_exts_destroy(&e);
492 return err;
493}
494
495static int
496tcindex_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
523static 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
560static 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
595static 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
652nla_put_failure:
653 nla_nest_cancel(skb, nest);
654 return -1;
655}
656
657static void tcindex_bind_class(void *fh, u32 classid, unsigned long cl)
658{
659 struct tcindex_filter_result *r = fh;
660
661 if (r && r->res.classid == classid)
662 r->res.class = cl;
663}
664
665static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
666 .kind = "tcindex",
667 .classify = tcindex_classify,
668 .init = tcindex_init,
669 .destroy = tcindex_destroy,
670 .get = tcindex_get,
671 .change = tcindex_change,
672 .delete = tcindex_delete,
673 .walk = tcindex_walk,
674 .dump = tcindex_dump,
675 .bind_class = tcindex_bind_class,
676 .owner = THIS_MODULE,
677};
678
679static int __init init_tcindex(void)
680{
681 return register_tcf_proto_ops(&cls_tcindex_ops);
682}
683
684static void __exit exit_tcindex(void)
685{
686 unregister_tcf_proto_ops(&cls_tcindex_ops);
687}
688
689module_init(init_tcindex)
690module_exit(exit_tcindex)
691MODULE_LICENSE("GPL");
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 <linux/refcount.h>
15#include <linux/rcupdate.h>
16#include <net/act_api.h>
17#include <net/netlink.h>
18#include <net/pkt_cls.h>
19#include <net/sch_generic.h>
20#include <net/tc_wrapper.h>
21
22/*
23 * Passing parameters to the root seems to be done more awkwardly than really
24 * necessary. At least, u32 doesn't seem to use such dirty hacks. To be
25 * verified. FIXME.
26 */
27
28#define PERFECT_HASH_THRESHOLD 64 /* use perfect hash if not bigger */
29#define DEFAULT_HASH_SIZE 64 /* optimized for diffserv */
30
31
32struct tcindex_data;
33
34struct tcindex_filter_result {
35 struct tcf_exts exts;
36 struct tcf_result res;
37 struct tcindex_data *p;
38 struct rcu_work rwork;
39};
40
41struct tcindex_filter {
42 u16 key;
43 struct tcindex_filter_result result;
44 struct tcindex_filter __rcu *next;
45 struct rcu_work rwork;
46};
47
48
49struct tcindex_data {
50 struct tcindex_filter_result *perfect; /* perfect hash; NULL if none */
51 struct tcindex_filter __rcu **h; /* imperfect hash; */
52 struct tcf_proto *tp;
53 u16 mask; /* AND key with mask */
54 u32 shift; /* shift ANDed key to the right */
55 u32 hash; /* hash table size; 0 if undefined */
56 u32 alloc_hash; /* allocated size */
57 u32 fall_through; /* 0: only classify if explicit match */
58 refcount_t refcnt; /* a temporary refcnt for perfect hash */
59 struct rcu_work rwork;
60};
61
62static inline int tcindex_filter_is_set(struct tcindex_filter_result *r)
63{
64 return tcf_exts_has_actions(&r->exts) || r->res.classid;
65}
66
67static void tcindex_data_get(struct tcindex_data *p)
68{
69 refcount_inc(&p->refcnt);
70}
71
72static void tcindex_data_put(struct tcindex_data *p)
73{
74 if (refcount_dec_and_test(&p->refcnt)) {
75 kfree(p->perfect);
76 kfree(p->h);
77 kfree(p);
78 }
79}
80
81static struct tcindex_filter_result *tcindex_lookup(struct tcindex_data *p,
82 u16 key)
83{
84 if (p->perfect) {
85 struct tcindex_filter_result *f = p->perfect + key;
86
87 return tcindex_filter_is_set(f) ? f : NULL;
88 } else if (p->h) {
89 struct tcindex_filter __rcu **fp;
90 struct tcindex_filter *f;
91
92 fp = &p->h[key % p->hash];
93 for (f = rcu_dereference_bh_rtnl(*fp);
94 f;
95 fp = &f->next, f = rcu_dereference_bh_rtnl(*fp))
96 if (f->key == key)
97 return &f->result;
98 }
99
100 return NULL;
101}
102
103TC_INDIRECT_SCOPE int tcindex_classify(struct sk_buff *skb,
104 const struct tcf_proto *tp,
105 struct tcf_result *res)
106{
107 struct tcindex_data *p = rcu_dereference_bh(tp->root);
108 struct tcindex_filter_result *f;
109 int key = (skb->tc_index & p->mask) >> p->shift;
110
111 pr_debug("tcindex_classify(skb %p,tp %p,res %p),p %p\n",
112 skb, tp, res, p);
113
114 f = tcindex_lookup(p, key);
115 if (!f) {
116 struct Qdisc *q = tcf_block_q(tp->chain->block);
117
118 if (!p->fall_through)
119 return -1;
120 res->classid = TC_H_MAKE(TC_H_MAJ(q->handle), key);
121 res->class = 0;
122 pr_debug("alg 0x%x\n", res->classid);
123 return 0;
124 }
125 *res = f->res;
126 pr_debug("map 0x%x\n", res->classid);
127
128 return tcf_exts_exec(skb, &f->exts, res);
129}
130
131
132static void *tcindex_get(struct tcf_proto *tp, u32 handle)
133{
134 struct tcindex_data *p = rtnl_dereference(tp->root);
135 struct tcindex_filter_result *r;
136
137 pr_debug("tcindex_get(tp %p,handle 0x%08x)\n", tp, handle);
138 if (p->perfect && handle >= p->alloc_hash)
139 return NULL;
140 r = tcindex_lookup(p, handle);
141 return r && tcindex_filter_is_set(r) ? r : NULL;
142}
143
144static int tcindex_init(struct tcf_proto *tp)
145{
146 struct tcindex_data *p;
147
148 pr_debug("tcindex_init(tp %p)\n", tp);
149 p = kzalloc(sizeof(struct tcindex_data), GFP_KERNEL);
150 if (!p)
151 return -ENOMEM;
152
153 p->mask = 0xffff;
154 p->hash = DEFAULT_HASH_SIZE;
155 p->fall_through = 1;
156 refcount_set(&p->refcnt, 1); /* Paired with tcindex_destroy_work() */
157
158 rcu_assign_pointer(tp->root, p);
159 return 0;
160}
161
162static void __tcindex_destroy_rexts(struct tcindex_filter_result *r)
163{
164 tcf_exts_destroy(&r->exts);
165 tcf_exts_put_net(&r->exts);
166 tcindex_data_put(r->p);
167}
168
169static void tcindex_destroy_rexts_work(struct work_struct *work)
170{
171 struct tcindex_filter_result *r;
172
173 r = container_of(to_rcu_work(work),
174 struct tcindex_filter_result,
175 rwork);
176 rtnl_lock();
177 __tcindex_destroy_rexts(r);
178 rtnl_unlock();
179}
180
181static void __tcindex_destroy_fexts(struct tcindex_filter *f)
182{
183 tcf_exts_destroy(&f->result.exts);
184 tcf_exts_put_net(&f->result.exts);
185 kfree(f);
186}
187
188static void tcindex_destroy_fexts_work(struct work_struct *work)
189{
190 struct tcindex_filter *f = container_of(to_rcu_work(work),
191 struct tcindex_filter,
192 rwork);
193
194 rtnl_lock();
195 __tcindex_destroy_fexts(f);
196 rtnl_unlock();
197}
198
199static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
200 bool rtnl_held, struct netlink_ext_ack *extack)
201{
202 struct tcindex_data *p = rtnl_dereference(tp->root);
203 struct tcindex_filter_result *r = arg;
204 struct tcindex_filter __rcu **walk;
205 struct tcindex_filter *f = NULL;
206
207 pr_debug("tcindex_delete(tp %p,arg %p),p %p\n", tp, arg, p);
208 if (p->perfect) {
209 if (!r->res.class)
210 return -ENOENT;
211 } else {
212 int i;
213
214 for (i = 0; i < p->hash; i++) {
215 walk = p->h + i;
216 for (f = rtnl_dereference(*walk); f;
217 walk = &f->next, f = rtnl_dereference(*walk)) {
218 if (&f->result == r)
219 goto found;
220 }
221 }
222 return -ENOENT;
223
224found:
225 rcu_assign_pointer(*walk, rtnl_dereference(f->next));
226 }
227 tcf_unbind_filter(tp, &r->res);
228 /* all classifiers are required to call tcf_exts_destroy() after rcu
229 * grace period, since converted-to-rcu actions are relying on that
230 * in cleanup() callback
231 */
232 if (f) {
233 if (tcf_exts_get_net(&f->result.exts))
234 tcf_queue_work(&f->rwork, tcindex_destroy_fexts_work);
235 else
236 __tcindex_destroy_fexts(f);
237 } else {
238 tcindex_data_get(p);
239
240 if (tcf_exts_get_net(&r->exts))
241 tcf_queue_work(&r->rwork, tcindex_destroy_rexts_work);
242 else
243 __tcindex_destroy_rexts(r);
244 }
245
246 *last = false;
247 return 0;
248}
249
250static void tcindex_destroy_work(struct work_struct *work)
251{
252 struct tcindex_data *p = container_of(to_rcu_work(work),
253 struct tcindex_data,
254 rwork);
255
256 tcindex_data_put(p);
257}
258
259static inline int
260valid_perfect_hash(struct tcindex_data *p)
261{
262 return p->hash > (p->mask >> p->shift);
263}
264
265static const struct nla_policy tcindex_policy[TCA_TCINDEX_MAX + 1] = {
266 [TCA_TCINDEX_HASH] = { .type = NLA_U32 },
267 [TCA_TCINDEX_MASK] = { .type = NLA_U16 },
268 [TCA_TCINDEX_SHIFT] = { .type = NLA_U32 },
269 [TCA_TCINDEX_FALL_THROUGH] = { .type = NLA_U32 },
270 [TCA_TCINDEX_CLASSID] = { .type = NLA_U32 },
271};
272
273static int tcindex_filter_result_init(struct tcindex_filter_result *r,
274 struct tcindex_data *p,
275 struct net *net)
276{
277 memset(r, 0, sizeof(*r));
278 r->p = p;
279 return tcf_exts_init(&r->exts, net, TCA_TCINDEX_ACT,
280 TCA_TCINDEX_POLICE);
281}
282
283static void tcindex_free_perfect_hash(struct tcindex_data *cp);
284
285static void tcindex_partial_destroy_work(struct work_struct *work)
286{
287 struct tcindex_data *p = container_of(to_rcu_work(work),
288 struct tcindex_data,
289 rwork);
290
291 rtnl_lock();
292 if (p->perfect)
293 tcindex_free_perfect_hash(p);
294 kfree(p);
295 rtnl_unlock();
296}
297
298static void tcindex_free_perfect_hash(struct tcindex_data *cp)
299{
300 int i;
301
302 for (i = 0; i < cp->hash; i++)
303 tcf_exts_destroy(&cp->perfect[i].exts);
304 kfree(cp->perfect);
305}
306
307static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)
308{
309 int i, err = 0;
310
311 cp->perfect = kcalloc(cp->hash, sizeof(struct tcindex_filter_result),
312 GFP_KERNEL | __GFP_NOWARN);
313 if (!cp->perfect)
314 return -ENOMEM;
315
316 for (i = 0; i < cp->hash; i++) {
317 err = tcf_exts_init(&cp->perfect[i].exts, net,
318 TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
319 if (err < 0)
320 goto errout;
321 cp->perfect[i].p = cp;
322 }
323
324 return 0;
325
326errout:
327 tcindex_free_perfect_hash(cp);
328 return err;
329}
330
331static int
332tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
333 u32 handle, struct tcindex_data *p,
334 struct tcindex_filter_result *r, struct nlattr **tb,
335 struct nlattr *est, u32 flags, struct netlink_ext_ack *extack)
336{
337 struct tcindex_filter_result new_filter_result;
338 struct tcindex_data *cp = NULL, *oldp;
339 struct tcindex_filter *f = NULL; /* make gcc behave */
340 struct tcf_result cr = {};
341 int err, balloc = 0;
342 struct tcf_exts e;
343 bool update_h = false;
344
345 err = tcf_exts_init(&e, net, TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
346 if (err < 0)
347 return err;
348 err = tcf_exts_validate(net, tp, tb, est, &e, flags, extack);
349 if (err < 0)
350 goto errout;
351
352 err = -ENOMEM;
353 /* tcindex_data attributes must look atomic to classifier/lookup so
354 * allocate new tcindex data and RCU assign it onto root. Keeping
355 * perfect hash and hash pointers from old data.
356 */
357 cp = kzalloc(sizeof(*cp), GFP_KERNEL);
358 if (!cp)
359 goto errout;
360
361 cp->mask = p->mask;
362 cp->shift = p->shift;
363 cp->hash = p->hash;
364 cp->alloc_hash = p->alloc_hash;
365 cp->fall_through = p->fall_through;
366 cp->tp = tp;
367 refcount_set(&cp->refcnt, 1); /* Paired with tcindex_destroy_work() */
368
369 if (tb[TCA_TCINDEX_HASH])
370 cp->hash = nla_get_u32(tb[TCA_TCINDEX_HASH]);
371
372 if (tb[TCA_TCINDEX_MASK])
373 cp->mask = nla_get_u16(tb[TCA_TCINDEX_MASK]);
374
375 if (tb[TCA_TCINDEX_SHIFT]) {
376 cp->shift = nla_get_u32(tb[TCA_TCINDEX_SHIFT]);
377 if (cp->shift > 16) {
378 err = -EINVAL;
379 goto errout;
380 }
381 }
382 if (!cp->hash) {
383 /* Hash not specified, use perfect hash if the upper limit
384 * of the hashing index is below the threshold.
385 */
386 if ((cp->mask >> cp->shift) < PERFECT_HASH_THRESHOLD)
387 cp->hash = (cp->mask >> cp->shift) + 1;
388 else
389 cp->hash = DEFAULT_HASH_SIZE;
390 }
391
392 if (p->perfect) {
393 int i;
394
395 if (tcindex_alloc_perfect_hash(net, cp) < 0)
396 goto errout;
397 cp->alloc_hash = cp->hash;
398 for (i = 0; i < min(cp->hash, p->hash); i++)
399 cp->perfect[i].res = p->perfect[i].res;
400 balloc = 1;
401 }
402 cp->h = p->h;
403
404 err = tcindex_filter_result_init(&new_filter_result, cp, net);
405 if (err < 0)
406 goto errout_alloc;
407 if (r)
408 cr = r->res;
409
410 err = -EBUSY;
411
412 /* Hash already allocated, make sure that we still meet the
413 * requirements for the allocated hash.
414 */
415 if (cp->perfect) {
416 if (!valid_perfect_hash(cp) ||
417 cp->hash > cp->alloc_hash)
418 goto errout_alloc;
419 } else if (cp->h && cp->hash != cp->alloc_hash) {
420 goto errout_alloc;
421 }
422
423 err = -EINVAL;
424 if (tb[TCA_TCINDEX_FALL_THROUGH])
425 cp->fall_through = nla_get_u32(tb[TCA_TCINDEX_FALL_THROUGH]);
426
427 if (!cp->perfect && !cp->h)
428 cp->alloc_hash = cp->hash;
429
430 /* Note: this could be as restrictive as if (handle & ~(mask >> shift))
431 * but then, we'd fail handles that may become valid after some future
432 * mask change. While this is extremely unlikely to ever matter,
433 * the check below is safer (and also more backwards-compatible).
434 */
435 if (cp->perfect || valid_perfect_hash(cp))
436 if (handle >= cp->alloc_hash)
437 goto errout_alloc;
438
439
440 err = -ENOMEM;
441 if (!cp->perfect && !cp->h) {
442 if (valid_perfect_hash(cp)) {
443 if (tcindex_alloc_perfect_hash(net, cp) < 0)
444 goto errout_alloc;
445 balloc = 1;
446 } else {
447 struct tcindex_filter __rcu **hash;
448
449 hash = kcalloc(cp->hash,
450 sizeof(struct tcindex_filter *),
451 GFP_KERNEL);
452
453 if (!hash)
454 goto errout_alloc;
455
456 cp->h = hash;
457 balloc = 2;
458 }
459 }
460
461 if (cp->perfect) {
462 r = cp->perfect + handle;
463 } else {
464 /* imperfect area is updated in-place using rcu */
465 update_h = !!tcindex_lookup(cp, handle);
466 r = &new_filter_result;
467 }
468
469 if (r == &new_filter_result) {
470 f = kzalloc(sizeof(*f), GFP_KERNEL);
471 if (!f)
472 goto errout_alloc;
473 f->key = handle;
474 f->next = NULL;
475 err = tcindex_filter_result_init(&f->result, cp, net);
476 if (err < 0) {
477 kfree(f);
478 goto errout_alloc;
479 }
480 }
481
482 if (tb[TCA_TCINDEX_CLASSID]) {
483 cr.classid = nla_get_u32(tb[TCA_TCINDEX_CLASSID]);
484 tcf_bind_filter(tp, &cr, base);
485 }
486
487 oldp = p;
488 r->res = cr;
489 tcf_exts_change(&r->exts, &e);
490
491 rcu_assign_pointer(tp->root, cp);
492
493 if (update_h) {
494 struct tcindex_filter __rcu **fp;
495 struct tcindex_filter *cf;
496
497 f->result.res = r->res;
498 tcf_exts_change(&f->result.exts, &r->exts);
499
500 /* imperfect area bucket */
501 fp = cp->h + (handle % cp->hash);
502
503 /* lookup the filter, guaranteed to exist */
504 for (cf = rcu_dereference_bh_rtnl(*fp); cf;
505 fp = &cf->next, cf = rcu_dereference_bh_rtnl(*fp))
506 if (cf->key == (u16)handle)
507 break;
508
509 f->next = cf->next;
510
511 cf = rcu_replace_pointer(*fp, f, 1);
512 tcf_exts_get_net(&cf->result.exts);
513 tcf_queue_work(&cf->rwork, tcindex_destroy_fexts_work);
514 } else if (r == &new_filter_result) {
515 struct tcindex_filter *nfp;
516 struct tcindex_filter __rcu **fp;
517
518 f->result.res = r->res;
519 tcf_exts_change(&f->result.exts, &r->exts);
520
521 fp = cp->h + (handle % cp->hash);
522 for (nfp = rtnl_dereference(*fp);
523 nfp;
524 fp = &nfp->next, nfp = rtnl_dereference(*fp))
525 ; /* nothing */
526
527 rcu_assign_pointer(*fp, f);
528 } else {
529 tcf_exts_destroy(&new_filter_result.exts);
530 }
531
532 if (oldp)
533 tcf_queue_work(&oldp->rwork, tcindex_partial_destroy_work);
534 return 0;
535
536errout_alloc:
537 if (balloc == 1)
538 tcindex_free_perfect_hash(cp);
539 else if (balloc == 2)
540 kfree(cp->h);
541 tcf_exts_destroy(&new_filter_result.exts);
542errout:
543 kfree(cp);
544 tcf_exts_destroy(&e);
545 return err;
546}
547
548static int
549tcindex_change(struct net *net, struct sk_buff *in_skb,
550 struct tcf_proto *tp, unsigned long base, u32 handle,
551 struct nlattr **tca, void **arg, u32 flags,
552 struct netlink_ext_ack *extack)
553{
554 struct nlattr *opt = tca[TCA_OPTIONS];
555 struct nlattr *tb[TCA_TCINDEX_MAX + 1];
556 struct tcindex_data *p = rtnl_dereference(tp->root);
557 struct tcindex_filter_result *r = *arg;
558 int err;
559
560 pr_debug("tcindex_change(tp %p,handle 0x%08x,tca %p,arg %p),opt %p,"
561 "p %p,r %p,*arg %p\n",
562 tp, handle, tca, arg, opt, p, r, *arg);
563
564 if (!opt)
565 return 0;
566
567 err = nla_parse_nested_deprecated(tb, TCA_TCINDEX_MAX, opt,
568 tcindex_policy, NULL);
569 if (err < 0)
570 return err;
571
572 return tcindex_set_parms(net, tp, base, handle, p, r, tb,
573 tca[TCA_RATE], flags, extack);
574}
575
576static void tcindex_walk(struct tcf_proto *tp, struct tcf_walker *walker,
577 bool rtnl_held)
578{
579 struct tcindex_data *p = rtnl_dereference(tp->root);
580 struct tcindex_filter *f, *next;
581 int i;
582
583 pr_debug("tcindex_walk(tp %p,walker %p),p %p\n", tp, walker, p);
584 if (p->perfect) {
585 for (i = 0; i < p->hash; i++) {
586 if (!p->perfect[i].res.class)
587 continue;
588 if (!tc_cls_stats_dump(tp, walker, p->perfect + i))
589 return;
590 }
591 }
592 if (!p->h)
593 return;
594 for (i = 0; i < p->hash; i++) {
595 for (f = rtnl_dereference(p->h[i]); f; f = next) {
596 next = rtnl_dereference(f->next);
597 if (!tc_cls_stats_dump(tp, walker, &f->result))
598 return;
599 }
600 }
601}
602
603static void tcindex_destroy(struct tcf_proto *tp, bool rtnl_held,
604 struct netlink_ext_ack *extack)
605{
606 struct tcindex_data *p = rtnl_dereference(tp->root);
607 int i;
608
609 pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
610
611 if (p->perfect) {
612 for (i = 0; i < p->hash; i++) {
613 struct tcindex_filter_result *r = p->perfect + i;
614
615 /* tcf_queue_work() does not guarantee the ordering we
616 * want, so we have to take this refcnt temporarily to
617 * ensure 'p' is freed after all tcindex_filter_result
618 * here. Imperfect hash does not need this, because it
619 * uses linked lists rather than an array.
620 */
621 tcindex_data_get(p);
622
623 tcf_unbind_filter(tp, &r->res);
624 if (tcf_exts_get_net(&r->exts))
625 tcf_queue_work(&r->rwork,
626 tcindex_destroy_rexts_work);
627 else
628 __tcindex_destroy_rexts(r);
629 }
630 }
631
632 for (i = 0; p->h && i < p->hash; i++) {
633 struct tcindex_filter *f, *next;
634 bool last;
635
636 for (f = rtnl_dereference(p->h[i]); f; f = next) {
637 next = rtnl_dereference(f->next);
638 tcindex_delete(tp, &f->result, &last, rtnl_held, NULL);
639 }
640 }
641
642 tcf_queue_work(&p->rwork, tcindex_destroy_work);
643}
644
645
646static int tcindex_dump(struct net *net, struct tcf_proto *tp, void *fh,
647 struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
648{
649 struct tcindex_data *p = rtnl_dereference(tp->root);
650 struct tcindex_filter_result *r = fh;
651 struct nlattr *nest;
652
653 pr_debug("tcindex_dump(tp %p,fh %p,skb %p,t %p),p %p,r %p\n",
654 tp, fh, skb, t, p, r);
655 pr_debug("p->perfect %p p->h %p\n", p->perfect, p->h);
656
657 nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
658 if (nest == NULL)
659 goto nla_put_failure;
660
661 if (!fh) {
662 t->tcm_handle = ~0; /* whatever ... */
663 if (nla_put_u32(skb, TCA_TCINDEX_HASH, p->hash) ||
664 nla_put_u16(skb, TCA_TCINDEX_MASK, p->mask) ||
665 nla_put_u32(skb, TCA_TCINDEX_SHIFT, p->shift) ||
666 nla_put_u32(skb, TCA_TCINDEX_FALL_THROUGH, p->fall_through))
667 goto nla_put_failure;
668 nla_nest_end(skb, nest);
669 } else {
670 if (p->perfect) {
671 t->tcm_handle = r - p->perfect;
672 } else {
673 struct tcindex_filter *f;
674 struct tcindex_filter __rcu **fp;
675 int i;
676
677 t->tcm_handle = 0;
678 for (i = 0; !t->tcm_handle && i < p->hash; i++) {
679 fp = &p->h[i];
680 for (f = rtnl_dereference(*fp);
681 !t->tcm_handle && f;
682 fp = &f->next, f = rtnl_dereference(*fp)) {
683 if (&f->result == r)
684 t->tcm_handle = f->key;
685 }
686 }
687 }
688 pr_debug("handle = %d\n", t->tcm_handle);
689 if (r->res.class &&
690 nla_put_u32(skb, TCA_TCINDEX_CLASSID, r->res.classid))
691 goto nla_put_failure;
692
693 if (tcf_exts_dump(skb, &r->exts) < 0)
694 goto nla_put_failure;
695 nla_nest_end(skb, nest);
696
697 if (tcf_exts_dump_stats(skb, &r->exts) < 0)
698 goto nla_put_failure;
699 }
700
701 return skb->len;
702
703nla_put_failure:
704 nla_nest_cancel(skb, nest);
705 return -1;
706}
707
708static void tcindex_bind_class(void *fh, u32 classid, unsigned long cl,
709 void *q, unsigned long base)
710{
711 struct tcindex_filter_result *r = fh;
712
713 tc_cls_bind_class(classid, cl, q, &r->res, base);
714}
715
716static struct tcf_proto_ops cls_tcindex_ops __read_mostly = {
717 .kind = "tcindex",
718 .classify = tcindex_classify,
719 .init = tcindex_init,
720 .destroy = tcindex_destroy,
721 .get = tcindex_get,
722 .change = tcindex_change,
723 .delete = tcindex_delete,
724 .walk = tcindex_walk,
725 .dump = tcindex_dump,
726 .bind_class = tcindex_bind_class,
727 .owner = THIS_MODULE,
728};
729
730static int __init init_tcindex(void)
731{
732 return register_tcf_proto_ops(&cls_tcindex_ops);
733}
734
735static void __exit exit_tcindex(void)
736{
737 unregister_tcf_proto_ops(&cls_tcindex_ops);
738}
739
740module_init(init_tcindex)
741module_exit(exit_tcindex)
742MODULE_LICENSE("GPL");