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
33 struct route4_fastmap {
34 struct route4_filter *filter;
35 u32 id;
36 int iif;
37 };
38
39 struct route4_head {
40 struct route4_fastmap fastmap[16];
41 struct route4_bucket *table[256 + 1];
42 };
43
44 struct route4_bucket {
45 /* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
46 struct route4_filter *ht[16 + 16 + 1];
47 };
48
49 struct route4_filter {
50 struct route4_filter *next;
51 u32 id;
52 int iif;
53
54 struct tcf_result res;
55 struct tcf_exts exts;
56 u32 handle;
57 struct route4_bucket *bkt;
58 };
59
60 #define ROUTE4_FAILURE ((struct route4_filter *)(-1L))
61
62 static const struct tcf_ext_map route_ext_map = {
63 .police = TCA_ROUTE4_POLICE,
64 .action = TCA_ROUTE4_ACT
65 };
66
route4_fastmap_hash(u32 id,int iif)67 static inline int route4_fastmap_hash(u32 id, int iif)
68 {
69 return id & 0xF;
70 }
71
72 static void
route4_reset_fastmap(struct Qdisc * q,struct route4_head * head,u32 id)73 route4_reset_fastmap(struct Qdisc *q, struct route4_head *head, u32 id)
74 {
75 spinlock_t *root_lock = qdisc_root_sleeping_lock(q);
76
77 spin_lock_bh(root_lock);
78 memset(head->fastmap, 0, sizeof(head->fastmap));
79 spin_unlock_bh(root_lock);
80 }
81
82 static void
route4_set_fastmap(struct route4_head * head,u32 id,int iif,struct route4_filter * f)83 route4_set_fastmap(struct route4_head *head, u32 id, int iif,
84 struct route4_filter *f)
85 {
86 int h = route4_fastmap_hash(id, iif);
87
88 head->fastmap[h].id = id;
89 head->fastmap[h].iif = iif;
90 head->fastmap[h].filter = f;
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,struct tcf_proto * tp,struct tcf_result * res)128 static int route4_classify(struct sk_buff *skb, struct tcf_proto *tp,
129 struct tcf_result *res)
130 {
131 struct route4_head *head = (struct route4_head *)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 = ((struct rtable *)dst)->rt_iif;
147
148 h = route4_fastmap_hash(id, iif);
149 if (id == head->fastmap[h].id &&
150 iif == head->fastmap[h].iif &&
151 (f = head->fastmap[h].filter) != NULL) {
152 if (f == ROUTE4_FAILURE)
153 goto failure;
154
155 *res = f->res;
156 return 0;
157 }
158
159 h = route4_hash_to(id);
160
161 restart:
162 b = head->table[h];
163 if (b) {
164 for (f = b->ht[route4_hash_from(id)]; f; f = f->next)
165 if (f->id == id)
166 ROUTE4_APPLY_RESULT();
167
168 for (f = b->ht[route4_hash_iif(iif)]; f; f = f->next)
169 if (f->iif == iif)
170 ROUTE4_APPLY_RESULT();
171
172 for (f = b->ht[route4_hash_wild()]; f; f = f->next)
173 ROUTE4_APPLY_RESULT();
174
175 }
176 if (h < 256) {
177 h = 256;
178 id &= ~0xFFFF;
179 goto restart;
180 }
181
182 if (!dont_cache)
183 route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
184 failure:
185 return -1;
186
187 old_method:
188 if (id && (TC_H_MAJ(id) == 0 ||
189 !(TC_H_MAJ(id^tp->q->handle)))) {
190 res->classid = id;
191 res->class = 0;
192 return 0;
193 }
194 return -1;
195 }
196
to_hash(u32 id)197 static inline u32 to_hash(u32 id)
198 {
199 u32 h = id & 0xFF;
200
201 if (id & 0x8000)
202 h += 256;
203 return h;
204 }
205
from_hash(u32 id)206 static inline u32 from_hash(u32 id)
207 {
208 id &= 0xFFFF;
209 if (id == 0xFFFF)
210 return 32;
211 if (!(id & 0x8000)) {
212 if (id > 255)
213 return 256;
214 return id & 0xF;
215 }
216 return 16 + (id & 0xF);
217 }
218
route4_get(struct tcf_proto * tp,u32 handle)219 static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
220 {
221 struct route4_head *head = (struct route4_head *)tp->root;
222 struct route4_bucket *b;
223 struct route4_filter *f;
224 unsigned int h1, h2;
225
226 if (!head)
227 return 0;
228
229 h1 = to_hash(handle);
230 if (h1 > 256)
231 return 0;
232
233 h2 = from_hash(handle >> 16);
234 if (h2 > 32)
235 return 0;
236
237 b = head->table[h1];
238 if (b) {
239 for (f = b->ht[h2]; f; f = f->next)
240 if (f->handle == handle)
241 return (unsigned long)f;
242 }
243 return 0;
244 }
245
route4_put(struct tcf_proto * tp,unsigned long f)246 static void route4_put(struct tcf_proto *tp, unsigned long f)
247 {
248 }
249
route4_init(struct tcf_proto * tp)250 static int route4_init(struct tcf_proto *tp)
251 {
252 return 0;
253 }
254
255 static void
route4_delete_filter(struct tcf_proto * tp,struct route4_filter * f)256 route4_delete_filter(struct tcf_proto *tp, struct route4_filter *f)
257 {
258 tcf_unbind_filter(tp, &f->res);
259 tcf_exts_destroy(tp, &f->exts);
260 kfree(f);
261 }
262
route4_destroy(struct tcf_proto * tp)263 static void route4_destroy(struct tcf_proto *tp)
264 {
265 struct route4_head *head = tp->root;
266 int h1, h2;
267
268 if (head == NULL)
269 return;
270
271 for (h1 = 0; h1 <= 256; h1++) {
272 struct route4_bucket *b;
273
274 b = head->table[h1];
275 if (b) {
276 for (h2 = 0; h2 <= 32; h2++) {
277 struct route4_filter *f;
278
279 while ((f = b->ht[h2]) != NULL) {
280 b->ht[h2] = f->next;
281 route4_delete_filter(tp, f);
282 }
283 }
284 kfree(b);
285 }
286 }
287 kfree(head);
288 }
289
route4_delete(struct tcf_proto * tp,unsigned long arg)290 static int route4_delete(struct tcf_proto *tp, unsigned long arg)
291 {
292 struct route4_head *head = (struct route4_head *)tp->root;
293 struct route4_filter **fp, *f = (struct route4_filter *)arg;
294 unsigned int h = 0;
295 struct route4_bucket *b;
296 int i;
297
298 if (!head || !f)
299 return -EINVAL;
300
301 h = f->handle;
302 b = f->bkt;
303
304 for (fp = &b->ht[from_hash(h >> 16)]; *fp; fp = &(*fp)->next) {
305 if (*fp == f) {
306 tcf_tree_lock(tp);
307 *fp = f->next;
308 tcf_tree_unlock(tp);
309
310 route4_reset_fastmap(tp->q, head, f->id);
311 route4_delete_filter(tp, f);
312
313 /* Strip tree */
314
315 for (i = 0; i <= 32; i++)
316 if (b->ht[i])
317 return 0;
318
319 /* OK, session has no flows */
320 tcf_tree_lock(tp);
321 head->table[to_hash(h)] = NULL;
322 tcf_tree_unlock(tp);
323
324 kfree(b);
325 return 0;
326 }
327 }
328 return 0;
329 }
330
331 static const struct nla_policy route4_policy[TCA_ROUTE4_MAX + 1] = {
332 [TCA_ROUTE4_CLASSID] = { .type = NLA_U32 },
333 [TCA_ROUTE4_TO] = { .type = NLA_U32 },
334 [TCA_ROUTE4_FROM] = { .type = NLA_U32 },
335 [TCA_ROUTE4_IIF] = { .type = NLA_U32 },
336 };
337
route4_set_parms(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)338 static int route4_set_parms(struct tcf_proto *tp, unsigned long base,
339 struct route4_filter *f, u32 handle, struct route4_head *head,
340 struct nlattr **tb, struct nlattr *est, int new)
341 {
342 int err;
343 u32 id = 0, to = 0, nhandle = 0x8000;
344 struct route4_filter *fp;
345 unsigned int h1;
346 struct route4_bucket *b;
347 struct tcf_exts e;
348
349 err = tcf_exts_validate(tp, tb, est, &e, &route_ext_map);
350 if (err < 0)
351 return err;
352
353 err = -EINVAL;
354 if (tb[TCA_ROUTE4_TO]) {
355 if (new && handle & 0x8000)
356 goto errout;
357 to = nla_get_u32(tb[TCA_ROUTE4_TO]);
358 if (to > 0xFF)
359 goto errout;
360 nhandle = to;
361 }
362
363 if (tb[TCA_ROUTE4_FROM]) {
364 if (tb[TCA_ROUTE4_IIF])
365 goto errout;
366 id = nla_get_u32(tb[TCA_ROUTE4_FROM]);
367 if (id > 0xFF)
368 goto errout;
369 nhandle |= id << 16;
370 } else if (tb[TCA_ROUTE4_IIF]) {
371 id = nla_get_u32(tb[TCA_ROUTE4_IIF]);
372 if (id > 0x7FFF)
373 goto errout;
374 nhandle |= (id | 0x8000) << 16;
375 } else
376 nhandle |= 0xFFFF << 16;
377
378 if (handle && new) {
379 nhandle |= handle & 0x7F00;
380 if (nhandle != handle)
381 goto errout;
382 }
383
384 h1 = to_hash(nhandle);
385 b = head->table[h1];
386 if (!b) {
387 err = -ENOBUFS;
388 b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
389 if (b == NULL)
390 goto errout;
391
392 tcf_tree_lock(tp);
393 head->table[h1] = b;
394 tcf_tree_unlock(tp);
395 } else {
396 unsigned int h2 = from_hash(nhandle >> 16);
397
398 err = -EEXIST;
399 for (fp = b->ht[h2]; fp; fp = fp->next)
400 if (fp->handle == f->handle)
401 goto errout;
402 }
403
404 tcf_tree_lock(tp);
405 if (tb[TCA_ROUTE4_TO])
406 f->id = to;
407
408 if (tb[TCA_ROUTE4_FROM])
409 f->id = to | id<<16;
410 else if (tb[TCA_ROUTE4_IIF])
411 f->iif = id;
412
413 f->handle = nhandle;
414 f->bkt = b;
415 tcf_tree_unlock(tp);
416
417 if (tb[TCA_ROUTE4_CLASSID]) {
418 f->res.classid = nla_get_u32(tb[TCA_ROUTE4_CLASSID]);
419 tcf_bind_filter(tp, &f->res, base);
420 }
421
422 tcf_exts_change(tp, &f->exts, &e);
423
424 return 0;
425 errout:
426 tcf_exts_destroy(tp, &e);
427 return err;
428 }
429
route4_change(struct tcf_proto * tp,unsigned long base,u32 handle,struct nlattr ** tca,unsigned long * arg)430 static int route4_change(struct tcf_proto *tp, unsigned long base,
431 u32 handle,
432 struct nlattr **tca,
433 unsigned long *arg)
434 {
435 struct route4_head *head = tp->root;
436 struct route4_filter *f, *f1, **fp;
437 struct route4_bucket *b;
438 struct nlattr *opt = tca[TCA_OPTIONS];
439 struct nlattr *tb[TCA_ROUTE4_MAX + 1];
440 unsigned int h, th;
441 u32 old_handle = 0;
442 int err;
443
444 if (opt == NULL)
445 return handle ? -EINVAL : 0;
446
447 err = nla_parse_nested(tb, TCA_ROUTE4_MAX, opt, route4_policy);
448 if (err < 0)
449 return err;
450
451 f = (struct route4_filter *)*arg;
452 if (f) {
453 if (f->handle != handle && handle)
454 return -EINVAL;
455
456 if (f->bkt)
457 old_handle = f->handle;
458
459 err = route4_set_parms(tp, base, f, handle, head, tb,
460 tca[TCA_RATE], 0);
461 if (err < 0)
462 return err;
463
464 goto reinsert;
465 }
466
467 err = -ENOBUFS;
468 if (head == NULL) {
469 head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
470 if (head == NULL)
471 goto errout;
472
473 tcf_tree_lock(tp);
474 tp->root = head;
475 tcf_tree_unlock(tp);
476 }
477
478 f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
479 if (f == NULL)
480 goto errout;
481
482 err = route4_set_parms(tp, base, f, handle, head, tb,
483 tca[TCA_RATE], 1);
484 if (err < 0)
485 goto errout;
486
487 reinsert:
488 h = from_hash(f->handle >> 16);
489 for (fp = &f->bkt->ht[h]; (f1 = *fp) != NULL; fp = &f1->next)
490 if (f->handle < f1->handle)
491 break;
492
493 f->next = f1;
494 tcf_tree_lock(tp);
495 *fp = f;
496
497 if (old_handle && f->handle != old_handle) {
498 th = to_hash(old_handle);
499 h = from_hash(old_handle >> 16);
500 b = head->table[th];
501 if (b) {
502 for (fp = &b->ht[h]; *fp; fp = &(*fp)->next) {
503 if (*fp == f) {
504 *fp = f->next;
505 break;
506 }
507 }
508 }
509 }
510 tcf_tree_unlock(tp);
511
512 route4_reset_fastmap(tp->q, head, f->id);
513 *arg = (unsigned long)f;
514 return 0;
515
516 errout:
517 kfree(f);
518 return err;
519 }
520
route4_walk(struct tcf_proto * tp,struct tcf_walker * arg)521 static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
522 {
523 struct route4_head *head = tp->root;
524 unsigned int h, h1;
525
526 if (head == NULL)
527 arg->stop = 1;
528
529 if (arg->stop)
530 return;
531
532 for (h = 0; h <= 256; h++) {
533 struct route4_bucket *b = head->table[h];
534
535 if (b) {
536 for (h1 = 0; h1 <= 32; h1++) {
537 struct route4_filter *f;
538
539 for (f = b->ht[h1]; f; f = f->next) {
540 if (arg->count < arg->skip) {
541 arg->count++;
542 continue;
543 }
544 if (arg->fn(tp, (unsigned long)f, arg) < 0) {
545 arg->stop = 1;
546 return;
547 }
548 arg->count++;
549 }
550 }
551 }
552 }
553 }
554
route4_dump(struct tcf_proto * tp,unsigned long fh,struct sk_buff * skb,struct tcmsg * t)555 static int route4_dump(struct tcf_proto *tp, unsigned long fh,
556 struct sk_buff *skb, struct tcmsg *t)
557 {
558 struct route4_filter *f = (struct route4_filter *)fh;
559 unsigned char *b = skb_tail_pointer(skb);
560 struct nlattr *nest;
561 u32 id;
562
563 if (f == NULL)
564 return skb->len;
565
566 t->tcm_handle = f->handle;
567
568 nest = nla_nest_start(skb, TCA_OPTIONS);
569 if (nest == NULL)
570 goto nla_put_failure;
571
572 if (!(f->handle & 0x8000)) {
573 id = f->id & 0xFF;
574 NLA_PUT_U32(skb, TCA_ROUTE4_TO, id);
575 }
576 if (f->handle & 0x80000000) {
577 if ((f->handle >> 16) != 0xFFFF)
578 NLA_PUT_U32(skb, TCA_ROUTE4_IIF, f->iif);
579 } else {
580 id = f->id >> 16;
581 NLA_PUT_U32(skb, TCA_ROUTE4_FROM, id);
582 }
583 if (f->res.classid)
584 NLA_PUT_U32(skb, TCA_ROUTE4_CLASSID, f->res.classid);
585
586 if (tcf_exts_dump(skb, &f->exts, &route_ext_map) < 0)
587 goto nla_put_failure;
588
589 nla_nest_end(skb, nest);
590
591 if (tcf_exts_dump_stats(skb, &f->exts, &route_ext_map) < 0)
592 goto nla_put_failure;
593
594 return skb->len;
595
596 nla_put_failure:
597 nlmsg_trim(skb, b);
598 return -1;
599 }
600
601 static struct tcf_proto_ops cls_route4_ops __read_mostly = {
602 .kind = "route",
603 .classify = route4_classify,
604 .init = route4_init,
605 .destroy = route4_destroy,
606 .get = route4_get,
607 .put = route4_put,
608 .change = route4_change,
609 .delete = route4_delete,
610 .walk = route4_walk,
611 .dump = route4_dump,
612 .owner = THIS_MODULE,
613 };
614
init_route4(void)615 static int __init init_route4(void)
616 {
617 return register_tcf_proto_ops(&cls_route4_ops);
618 }
619
exit_route4(void)620 static void __exit exit_route4(void)
621 {
622 unregister_tcf_proto_ops(&cls_route4_ops);
623 }
624
625 module_init(init_route4)
626 module_exit(exit_route4)
627 MODULE_LICENSE("GPL");
628