1 /*
2 * net/sched/cls_route.c ROUTE4 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
12 #include <linux/module.h>
13 #include <linux/slab.h>
14 #include <linux/types.h>
15 #include <linux/kernel.h>
16 #include <linux/string.h>
17 #include <linux/errno.h>
18 #include <linux/skbuff.h>
19 #include <net/dst.h>
20 #include <net/route.h>
21 #include <net/netlink.h>
22 #include <net/act_api.h>
23 #include <net/pkt_cls.h>
24
25 /*
26 * 1. For now we assume that route tags < 256.
27 * It allows to use direct table lookups, instead of hash tables.
28 * 2. For now we assume that "from TAG" and "fromdev DEV" statements
29 * are mutually exclusive.
30 * 3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
31 */
32 struct route4_fastmap {
33 struct route4_filter *filter;
34 u32 id;
35 int iif;
36 };
37
38 struct route4_head {
39 struct route4_fastmap fastmap[16];
40 struct route4_bucket __rcu *table[256 + 1];
41 struct rcu_head rcu;
42 };
43
44 struct route4_bucket {
45 /* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
46 struct route4_filter __rcu *ht[16 + 16 + 1];
47 struct rcu_head rcu;
48 };
49
50 struct route4_filter {
51 struct route4_filter __rcu *next;
52 u32 id;
53 int iif;
54
55 struct tcf_result res;
56 struct tcf_exts exts;
57 u32 handle;
58 struct route4_bucket *bkt;
59 struct tcf_proto *tp;
60 struct rcu_head rcu;
61 };
62
63 #define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
64
route4_fastmap_hash(u32 id,int iif)65 static inline int route4_fastmap_hash(u32 id, int iif)
66 {
67 return id & 0xF;
68 }
69
70 static DEFINE_SPINLOCK(fastmap_lock);
71 static void
route4_reset_fastmap(struct route4_head * head)72 route4_reset_fastmap(struct route4_head *head)
73 {
74 spin_lock_bh(&fastmap_lock);
75 memset(head->fastmap, 0, sizeof(head->fastmap));
76 spin_unlock_bh(&fastmap_lock);
77 }
78
79 static void
route4_set_fastmap(struct route4_head * head,u32 id,int iif,struct route4_filter * f)80 route4_set_fastmap(struct route4_head *head, u32 id, int iif,
81 struct route4_filter *f)
82 {
83 int h = route4_fastmap_hash(id, iif);
84
85 /* fastmap updates must look atomic to aling id, iff, filter */
86 spin_lock_bh(&fastmap_lock);
87 head->fastmap[h].id = id;
88 head->fastmap[h].iif = iif;
89 head->fastmap[h].filter = f;
90 spin_unlock_bh(&fastmap_lock);
91 }
92
route4_hash_to(u32 id)93 static inline int route4_hash_to(u32 id)
94 {
95 return id & 0xFF;
96 }
97
route4_hash_from(u32 id)98 static inline int route4_hash_from(u32 id)
99 {
100 return (id >> 16) & 0xF;
101 }
102
route4_hash_iif(int iif)103 static inline int route4_hash_iif(int iif)
104 {
105 return 16 + ((iif >> 16) & 0xF);
106 }
107
route4_hash_wild(void)108 static inline int route4_hash_wild(void)
109 {
110 return 32;
111 }
112
113 #define ROUTE4_APPLY_RESULT() \
114 { \
115 *res = f->res; \
116 if (tcf_exts_is_available(&f->exts)) { \
117 int r = tcf_exts_exec(skb, &f->exts, res); \
118 if (r < 0) { \
119 dont_cache = 1; \
120 continue; \
121 } \
122 return r; \
123 } else if (!dont_cache) \
124 route4_set_fastmap(head, id, iif, f); \
125 return 0; \
126 }
127
route4_classify(struct sk_buff * skb,const struct tcf_proto * tp,struct tcf_result * res)128 static int route4_classify(struct sk_buff *skb, const struct tcf_proto *tp,
129 struct tcf_result *res)
130 {
131 struct route4_head *head = rcu_dereference_bh(tp->root);
132 struct dst_entry *dst;
133 struct route4_bucket *b;
134 struct route4_filter *f;
135 u32 id, h;
136 int iif, dont_cache = 0;
137
138 dst = skb_dst(skb);
139 if (!dst)
140 goto failure;
141
142 id = dst->tclassid;
143 if (head == NULL)
144 goto old_method;
145
146 iif = inet_iif(skb);
147
148 h = route4_fastmap_hash(id, iif);
149
150 spin_lock(&fastmap_lock);
151 if (id == head->fastmap[h].id &&
152 iif == head->fastmap[h].iif &&
153 (f = head->fastmap[h].filter) != NULL) {
154 if (f == ROUTE4_FAILURE) {
155 spin_unlock(&fastmap_lock);
156 goto failure;
157 }
158
159 *res = f->res;
160 spin_unlock(&fastmap_lock);
161 return 0;
162 }
163 spin_unlock(&fastmap_lock);
164
165 h = route4_hash_to(id);
166
167 restart:
168 b = rcu_dereference_bh(head->table[h]);
169 if (b) {
170 for (f = rcu_dereference_bh(b->ht[route4_hash_from(id)]);
171 f;
172 f = rcu_dereference_bh(f->next))
173 if (f->id == id)
174 ROUTE4_APPLY_RESULT();
175
176 for (f = rcu_dereference_bh(b->ht[route4_hash_iif(iif)]);
177 f;
178 f = rcu_dereference_bh(f->next))
179 if (f->iif == iif)
180 ROUTE4_APPLY_RESULT();
181
182 for (f = rcu_dereference_bh(b->ht[route4_hash_wild()]);
183 f;
184 f = rcu_dereference_bh(f->next))
185 ROUTE4_APPLY_RESULT();
186 }
187 if (h < 256) {
188 h = 256;
189 id &= ~0xFFFF;
190 goto restart;
191 }
192
193 if (!dont_cache)
194 route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
195 failure:
196 return -1;
197
198 old_method:
199 if (id && (TC_H_MAJ(id) == 0 ||
200 !(TC_H_MAJ(id^tp->q->handle)))) {
201 res->classid = id;
202 res->class = 0;
203 return 0;
204 }
205 return -1;
206 }
207
to_hash(u32 id)208 static inline u32 to_hash(u32 id)
209 {
210 u32 h = id & 0xFF;
211
212 if (id & 0x8000)
213 h += 256;
214 return h;
215 }
216
from_hash(u32 id)217 static inline u32 from_hash(u32 id)
218 {
219 id &= 0xFFFF;
220 if (id == 0xFFFF)
221 return 32;
222 if (!(id & 0x8000)) {
223 if (id > 255)
224 return 256;
225 return id & 0xF;
226 }
227 return 16 + (id & 0xF);
228 }
229
route4_get(struct tcf_proto * tp,u32 handle)230 static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
231 {
232 struct route4_head *head = rtnl_dereference(tp->root);
233 struct route4_bucket *b;
234 struct route4_filter *f;
235 unsigned int h1, h2;
236
237 if (!head)
238 return 0;
239
240 h1 = to_hash(handle);
241 if (h1 > 256)
242 return 0;
243
244 h2 = from_hash(handle >> 16);
245 if (h2 > 32)
246 return 0;
247
248 b = rtnl_dereference(head->table[h1]);
249 if (b) {
250 for (f = rtnl_dereference(b->ht[h2]);
251 f;
252 f = rtnl_dereference(f->next))
253 if (f->handle == handle)
254 return (unsigned long)f;
255 }
256 return 0;
257 }
258
route4_init(struct tcf_proto * tp)259 static int route4_init(struct tcf_proto *tp)
260 {
261 struct route4_head *head;
262
263 head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
264 if (head == NULL)
265 return -ENOBUFS;
266
267 rcu_assign_pointer(tp->root, head);
268 return 0;
269 }
270
271 static void
route4_delete_filter(struct rcu_head * head)272 route4_delete_filter(struct rcu_head *head)
273 {
274 struct route4_filter *f = container_of(head, struct route4_filter, rcu);
275
276 tcf_exts_destroy(&f->exts);
277 kfree(f);
278 }
279
route4_destroy(struct tcf_proto * tp,bool force)280 static bool route4_destroy(struct tcf_proto *tp, bool force)
281 {
282 struct route4_head *head = rtnl_dereference(tp->root);
283 int h1, h2;
284
285 if (head == NULL)
286 return true;
287
288 if (!force) {
289 for (h1 = 0; h1 <= 256; h1++) {
290 if (rcu_access_pointer(head->table[h1]))
291 return false;
292 }
293 }
294
295 for (h1 = 0; h1 <= 256; h1++) {
296 struct route4_bucket *b;
297
298 b = rtnl_dereference(head->table[h1]);
299 if (b) {
300 for (h2 = 0; h2 <= 32; h2++) {
301 struct route4_filter *f;
302
303 while ((f = rtnl_dereference(b->ht[h2])) != NULL) {
304 struct route4_filter *next;
305
306 next = rtnl_dereference(f->next);
307 RCU_INIT_POINTER(b->ht[h2], next);
308 tcf_unbind_filter(tp, &f->res);
309 call_rcu(&f->rcu, route4_delete_filter);
310 }
311 }
312 RCU_INIT_POINTER(head->table[h1], NULL);
313 kfree_rcu(b, rcu);
314 }
315 }
316 RCU_INIT_POINTER(tp->root, NULL);
317 kfree_rcu(head, rcu);
318 return true;
319 }
320
route4_delete(struct tcf_proto * tp,unsigned long arg)321 static int route4_delete(struct tcf_proto *tp, unsigned long arg)
322 {
323 struct route4_head *head = rtnl_dereference(tp->root);
324 struct route4_filter *f = (struct route4_filter *)arg;
325 struct route4_filter __rcu **fp;
326 struct route4_filter *nf;
327 struct route4_bucket *b;
328 unsigned int h = 0;
329 int i;
330
331 if (!head || !f)
332 return -EINVAL;
333
334 h = f->handle;
335 b = f->bkt;
336
337 fp = &b->ht[from_hash(h >> 16)];
338 for (nf = rtnl_dereference(*fp); nf;
339 fp = &nf->next, nf = rtnl_dereference(*fp)) {
340 if (nf == f) {
341 /* unlink it */
342 RCU_INIT_POINTER(*fp, rtnl_dereference(f->next));
343
344 /* Remove any fastmap lookups that might ref filter
345 * notice we unlink'd the filter so we can't get it
346 * back in the fastmap.
347 */
348 route4_reset_fastmap(head);
349
350 /* Delete it */
351 tcf_unbind_filter(tp, &f->res);
352 call_rcu(&f->rcu, route4_delete_filter);
353
354 /* Strip RTNL protected tree */
355 for (i = 0; i <= 32; i++) {
356 struct route4_filter *rt;
357
358 rt = rtnl_dereference(b->ht[i]);
359 if (rt)
360 return 0;
361 }
362
363 /* OK, session has no flows */
364 RCU_INIT_POINTER(head->table[to_hash(h)], NULL);
365 kfree_rcu(b, rcu);
366
367 return 0;
368 }
369 }
370 return 0;
371 }
372
373 static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = {
374 [TCA_ROUTE4_CLASSID] = { .type = NLA_U32 },
375 [TCA_ROUTE4_TO] = { .type = NLA_U32 },
376 [TCA_ROUTE4_FROM] = { .type = NLA_U32 },
377 [TCA_ROUTE4_IIF] = { .type = NLA_U32 },
378 };
379
route4_set_parms(struct net * net,struct tcf_proto * tp,unsigned long base,struct route4_filter * f,u32 handle,struct route4_head * head,struct nlattr ** tb,struct nlattr * est,int new,bool ovr)380 static int route4_set_parms(struct net *net, struct tcf_proto *tp,
381 unsigned long base, struct route4_filter *f,
382 u32 handle, struct route4_head *head,
383 struct nlattr **tb, struct nlattr *est, int new,
384 bool ovr)
385 {
386 int err;
387 u32 id = 0, to = 0, nhandle = 0x8000;
388 struct route4_filter *fp;
389 unsigned int h1;
390 struct route4_bucket *b;
391 struct tcf_exts e;
392
393 tcf_exts_init(&e, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE);
394 err = tcf_exts_validate(net, tp, tb, est, &e, ovr);
395 if (err < 0)
396 return err;
397
398 err = -EINVAL;
399 if (tb[TCA_ROUTE4_TO]) {
400 if (new && handle & 0x8000)
401 goto errout;
402 to = nla_get_u32(tb[TCA_ROUTE4_TO]);
403 if (to > 0xFF)
404 goto errout;
405 nhandle = to;
406 }
407
408 if (tb[TCA_ROUTE4_FROM]) {
409 if (tb[TCA_ROUTE4_IIF])
410 goto errout;
411 id = nla_get_u32(tb[TCA_ROUTE4_FROM]);
412 if (id > 0xFF)
413 goto errout;
414 nhandle |= id << 16;
415 } else if (tb[TCA_ROUTE4_IIF]) {
416 id = nla_get_u32(tb[TCA_ROUTE4_IIF]);
417 if (id > 0x7FFF)
418 goto errout;
419 nhandle |= (id | 0x8000) << 16;
420 } else
421 nhandle |= 0xFFFF << 16;
422
423 if (handle && new) {
424 nhandle |= handle & 0x7F00;
425 if (nhandle != handle)
426 goto errout;
427 }
428
429 h1 = to_hash(nhandle);
430 b = rtnl_dereference(head->table[h1]);
431 if (!b) {
432 err = -ENOBUFS;
433 b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
434 if (b == NULL)
435 goto errout;
436
437 rcu_assign_pointer(head->table[h1], b);
438 } else {
439 unsigned int h2 = from_hash(nhandle >> 16);
440
441 err = -EEXIST;
442 for (fp = rtnl_dereference(b->ht[h2]);
443 fp;
444 fp = rtnl_dereference(fp->next))
445 if (fp->handle == f->handle)
446 goto errout;
447 }
448
449 if (tb[TCA_ROUTE4_TO])
450 f->id = to;
451
452 if (tb[TCA_ROUTE4_FROM])
453 f->id = to | id<<16;
454 else if (tb[TCA_ROUTE4_IIF])
455 f->iif = id;
456
457 f->handle = nhandle;
458 f->bkt = b;
459 f->tp = tp;
460
461 if (tb[TCA_ROUTE4_CLASSID]) {
462 f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
463 tcf_bind_filter(tp, &f->res, base);
464 }
465
466 tcf_exts_change(tp, &f->exts, &e);
467
468 return 0;
469 errout:
470 tcf_exts_destroy(&e);
471 return err;
472 }
473
route4_change(struct net * net,struct sk_buff * in_skb,struct tcf_proto * tp,unsigned long base,u32 handle,struct nlattr ** tca,unsigned long * arg,bool ovr)474 static int route4_change(struct net *net, struct sk_buff *in_skb,
475 struct tcf_proto *tp, unsigned long base,
476 u32 handle,
477 struct nlattr **tca,
478 unsigned long *arg, bool ovr)
479 {
480 struct route4_head *head = rtnl_dereference(tp->root);
481 struct route4_filter __rcu **fp;
482 struct route4_filter *fold, *f1, *pfp, *f = NULL;
483 struct route4_bucket *b;
484 struct nlattr *opt = tca[TCA_OPTIONS];
485 struct nlattr *tb[TCA_ROUTE4_MAX + 1];
486 unsigned int h, th;
487 int err;
488 bool new = true;
489
490 if (opt == NULL)
491 return handle ? -EINVAL : 0;
492
493 err = nla_parse_nested(tb, TCA_ROUTE4_MAX, opt, route4_policy);
494 if (err < 0)
495 return err;
496
497 fold = (struct route4_filter *)*arg;
498 if (fold && handle && fold->handle != handle)
499 return -EINVAL;
500
501 err = -ENOBUFS;
502 f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
503 if (!f)
504 goto errout;
505
506 tcf_exts_init(&f->exts, TCA_ROUTE4_ACT, TCA_ROUTE4_POLICE);
507 if (fold) {
508 f->id = fold->id;
509 f->iif = fold->iif;
510 f->res = fold->res;
511 f->handle = fold->handle;
512
513 f->tp = fold->tp;
514 f->bkt = fold->bkt;
515 new = false;
516 }
517
518 err = route4_set_parms(net, tp, base, f, handle, head, tb,
519 tca[TCA_RATE], new, ovr);
520 if (err < 0)
521 goto errout;
522
523 h = from_hash(f->handle >> 16);
524 fp = &f->bkt->ht[h];
525 for (pfp = rtnl_dereference(*fp);
526 (f1 = rtnl_dereference(*fp)) != NULL;
527 fp = &f1->next)
528 if (f->handle < f1->handle)
529 break;
530
531 netif_keep_dst(qdisc_dev(tp->q));
532 rcu_assign_pointer(f->next, f1);
533 rcu_assign_pointer(*fp, f);
534
535 if (fold && fold->handle && f->handle != fold->handle) {
536 th = to_hash(fold->handle);
537 h = from_hash(fold->handle >> 16);
538 b = rtnl_dereference(head->table[th]);
539 if (b) {
540 fp = &b->ht[h];
541 for (pfp = rtnl_dereference(*fp); pfp;
542 fp = &pfp->next, pfp = rtnl_dereference(*fp)) {
543 if (pfp == fold) {
544 rcu_assign_pointer(*fp, fold->next);
545 break;
546 }
547 }
548 }
549 }
550
551 route4_reset_fastmap(head);
552 *arg = (unsigned long)f;
553 if (fold) {
554 tcf_unbind_filter(tp, &fold->res);
555 call_rcu(&fold->rcu, route4_delete_filter);
556 }
557 return 0;
558
559 errout:
560 kfree(f);
561 return err;
562 }
563
route4_walk(struct tcf_proto * tp,struct tcf_walker * arg)564 static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
565 {
566 struct route4_head *head = rtnl_dereference(tp->root);
567 unsigned int h, h1;
568
569 if (head == NULL)
570 arg->stop = 1;
571
572 if (arg->stop)
573 return;
574
575 for (h = 0; h <= 256; h++) {
576 struct route4_bucket *b = rtnl_dereference(head->table[h]);
577
578 if (b) {
579 for (h1 = 0; h1 <= 32; h1++) {
580 struct route4_filter *f;
581
582 for (f = rtnl_dereference(b->ht[h1]);
583 f;
584 f = rtnl_dereference(f->next)) {
585 if (arg->count < arg->skip) {
586 arg->count++;
587 continue;
588 }
589 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
590 arg->stop = 1;
591 return;
592 }
593 arg->count++;
594 }
595 }
596 }
597 }
598 }
599
route4_dump(struct net * net,struct tcf_proto * tp,unsigned long fh,struct sk_buff * skb,struct tcmsg * t)600 static int route4_dump(struct net *net, struct tcf_proto *tp, unsigned long fh,
601 struct sk_buff *skb, struct tcmsg *t)
602 {
603 struct route4_filter *f = (struct route4_filter *)fh;
604 struct nlattr *nest;
605 u32 id;
606
607 if (f == NULL)
608 return skb->len;
609
610 t->tcm_handle = f->handle;
611
612 nest = nla_nest_start(skb, TCA_OPTIONS);
613 if (nest == NULL)
614 goto nla_put_failure;
615
616 if (!(f->handle & 0x8000)) {
617 id = f->id & 0xFF;
618 if (nla_put_u32(skb, TCA_ROUTE4_TO, id))
619 goto nla_put_failure;
620 }
621 if (f->handle & 0x80000000) {
622 if ((f->handle >> 16) != 0xFFFF &&
623 nla_put_u32(skb, TCA_ROUTE4_IIF, f->iif))
624 goto nla_put_failure;
625 } else {
626 id = f->id >> 16;
627 if (nla_put_u32(skb, TCA_ROUTE4_FROM, id))
628 goto nla_put_failure;
629 }
630 if (f->res.classid &&
631 nla_put_u32(skb, TCA_ROUTE4_CLASSID, f->res.classid))
632 goto nla_put_failure;
633
634 if (tcf_exts_dump(skb, &f->exts) < 0)
635 goto nla_put_failure;
636
637 nla_nest_end(skb, nest);
638
639 if (tcf_exts_dump_stats(skb, &f->exts) < 0)
640 goto nla_put_failure;
641
642 return skb->len;
643
644 nla_put_failure:
645 nla_nest_cancel(skb, nest);
646 return -1;
647 }
648
649 static struct tcf_proto_ops cls_route4_ops __read_mostly = {
650 .kind = "route",
651 .classify = route4_classify,
652 .init = route4_init,
653 .destroy = route4_destroy,
654 .get = route4_get,
655 .change = route4_change,
656 .delete = route4_delete,
657 .walk = route4_walk,
658 .dump = route4_dump,
659 .owner = THIS_MODULE,
660 };
661
init_route4(void)662 static int __init init_route4(void)
663 {
664 return register_tcf_proto_ops(&cls_route4_ops);
665 }
666
exit_route4(void)667 static void __exit exit_route4(void)
668 {
669 unregister_tcf_proto_ops(&cls_route4_ops);
670 }
671
672 module_init(init_route4)
673 module_exit(exit_route4)
674 MODULE_LICENSE("GPL");
675