summaryrefslogtreecommitdiff
path: root/net/sched/cls_route.c
blob: e70edd0f7bc80ad1aa7c424a28cec9a4e8444ddf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
/*
 * net/sched/cls_route.c	ROUTE4 classifier.
 *
 *		This program is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 * Authors:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 */

#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <net/dst.h>
#include <net/route.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>

/*
   1. For now we assume that route tags < 256.
      It allows to use direct table lookups, instead of hash tables.
   2. For now we assume that "from TAG" and "fromdev DEV" statements
      are mutually  exclusive.
   3. "to TAG from ANY" has higher priority, than "to ANY from XXX"
 */

struct route4_fastmap
{
	struct route4_filter	*filter;
	u32			id;
	int			iif;
};

struct route4_head
{
	struct route4_fastmap	fastmap[16];
	struct route4_bucket	*table[256+1];
};

struct route4_bucket
{
	/* 16 FROM buckets + 16 IIF buckets + 1 wildcard bucket */
	struct route4_filter	*ht[16+16+1];
};

struct route4_filter
{
	struct route4_filter	*next;
	u32			id;
	int			iif;

	struct tcf_result	res;
	struct tcf_exts		exts;
	u32			handle;
	struct route4_bucket	*bkt;
};

#define ROUTE4_FAILURE ((struct route4_filter*)(-1L))

static struct tcf_ext_map route_ext_map = {
	.police = TCA_ROUTE4_POLICE,
	.action = TCA_ROUTE4_ACT
};

static __inline__ int route4_fastmap_hash(u32 id, int iif)
{
	return id&0xF;
}

static inline
void route4_reset_fastmap(struct net_device *dev, struct route4_head *head, u32 id)
{
	qdisc_lock_tree(dev);
	memset(head->fastmap, 0, sizeof(head->fastmap));
	qdisc_unlock_tree(dev);
}

static inline void
route4_set_fastmap(struct route4_head *head, u32 id, int iif,
		   struct route4_filter *f)
{
	int h = route4_fastmap_hash(id, iif);
	head->fastmap[h].id = id;
	head->fastmap[h].iif = iif;
	head->fastmap[h].filter = f;
}

static __inline__ int route4_hash_to(u32 id)
{
	return id&0xFF;
}

static __inline__ int route4_hash_from(u32 id)
{
	return (id>>16)&0xF;
}

static __inline__ int route4_hash_iif(int iif)
{
	return 16 + ((iif>>16)&0xF);
}

static __inline__ int route4_hash_wild(void)
{
	return 32;
}

#define ROUTE4_APPLY_RESULT()					\
{								\
	*res = f->res;						\
	if (tcf_exts_is_available(&f->exts)) {			\
		int r = tcf_exts_exec(skb, &f->exts, res);	\
		if (r < 0) {					\
			dont_cache = 1;				\
			continue;				\
		}						\
		return r;					\
	} else if (!dont_cache)					\
		route4_set_fastmap(head, id, iif, f);		\
	return 0;						\
}

static int route4_classify(struct sk_buff *skb, struct tcf_proto *tp,
			   struct tcf_result *res)
{
	struct route4_head *head = (struct route4_head*)tp->root;
	struct dst_entry *dst;
	struct route4_bucket *b;
	struct route4_filter *f;
	u32 id, h;
	int iif, dont_cache = 0;

	if ((dst = skb->dst) == NULL)
		goto failure;

	id = dst->tclassid;
	if (head == NULL)
		goto old_method;

	iif = ((struct rtable*)dst)->fl.iif;

	h = route4_fastmap_hash(id, iif);
	if (id == head->fastmap[h].id &&
	    iif == head->fastmap[h].iif &&
	    (f = head->fastmap[h].filter) != NULL) {
		if (f == ROUTE4_FAILURE)
			goto failure;

		*res = f->res;
		return 0;
	}

	h = route4_hash_to(id);

restart:
	if ((b = head->table[h]) != NULL) {
		for (f = b->ht[route4_hash_from(id)]; f; f = f->next)
			if (f->id == id)
				ROUTE4_APPLY_RESULT();

		for (f = b->ht[route4_hash_iif(iif)]; f; f = f->next)
			if (f->iif == iif)
				ROUTE4_APPLY_RESULT();

		for (f = b->ht[route4_hash_wild()]; f; f = f->next)
			ROUTE4_APPLY_RESULT();

	}
	if (h < 256) {
		h = 256;
		id &= ~0xFFFF;
		goto restart;
	}

	if (!dont_cache)
		route4_set_fastmap(head, id, iif, ROUTE4_FAILURE);
failure:
	return -1;

old_method:
	if (id && (TC_H_MAJ(id) == 0 ||
		   !(TC_H_MAJ(id^tp->q->handle)))) {
		res->classid = id;
		res->class = 0;
		return 0;
	}
	return -1;
}

static inline u32 to_hash(u32 id)
{
	u32 h = id&0xFF;
	if (id&0x8000)
		h += 256;
	return h;
}

static inline u32 from_hash(u32 id)
{
	id &= 0xFFFF;
	if (id == 0xFFFF)
		return 32;
	if (!(id & 0x8000)) {
		if (id > 255)
			return 256;
		return id&0xF;
	}
	return 16 + (id&0xF);
}

static unsigned long route4_get(struct tcf_proto *tp, u32 handle)
{
	struct route4_head *head = (struct route4_head*)tp->root;
	struct route4_bucket *b;
	struct route4_filter *f;
	unsigned h1, h2;

	if (!head)
		return 0;

	h1 = to_hash(handle);
	if (h1 > 256)
		return 0;

	h2 = from_hash(handle>>16);
	if (h2 > 32)
		return 0;

	if ((b = head->table[h1]) != NULL) {
		for (f = b->ht[h2]; f; f = f->next)
			if (f->handle == handle)
				return (unsigned long)f;
	}
	return 0;
}

static void route4_put(struct tcf_proto *tp, unsigned long f)
{
}

static int route4_init(struct tcf_proto *tp)
{
	return 0;
}

static inline void
route4_delete_filter(struct tcf_proto *tp, struct route4_filter *f)
{
	tcf_unbind_filter(tp, &f->res);
	tcf_exts_destroy(tp, &f->exts);
	kfree(f);
}

static void route4_destroy(struct tcf_proto *tp)
{
	struct route4_head *head = xchg(&tp->root, NULL);
	int h1, h2;

	if (head == NULL)
		return;

	for (h1=0; h1<=256; h1++) {
		struct route4_bucket *b;

		if ((b = head->table[h1]) != NULL) {
			for (h2=0; h2<=32; h2++) {
				struct route4_filter *f;

				while ((f = b->ht[h2]) != NULL) {
					b->ht[h2] = f->next;
					route4_delete_filter(tp, f);
				}
			}
			kfree(b);
		}
	}
	kfree(head);
}

static int route4_delete(struct tcf_proto *tp, unsigned long arg)
{
	struct route4_head *head = (struct route4_head*)tp->root;
	struct route4_filter **fp, *f = (struct route4_filter*)arg;
	unsigned h = 0;
	struct route4_bucket *b;
	int i;

	if (!head || !f)
		return -EINVAL;

	h = f->handle;
	b = f->bkt;

	for (fp = &b->ht[from_hash(h>>16)]; *fp; fp = &(*fp)->next) {
		if (*fp == f) {
			tcf_tree_lock(tp);
			*fp = f->next;
			tcf_tree_unlock(tp);

			route4_reset_fastmap(tp->q->dev, head, f->id);
			route4_delete_filter(tp, f);

			/* Strip tree */

			for (i=0; i<=32; i++)
				if (b->ht[i])
					return 0;

			/* OK, session has no flows */
			tcf_tree_lock(tp);
			head->table[to_hash(h)] = NULL;
			tcf_tree_unlock(tp);

			kfree(b);
			return 0;
		}
	}
	return 0;
}

static int route4_set_parms(struct tcf_proto *tp, unsigned long base,
	struct route4_filter *f, u32 handle, struct route4_head *head,
	struct rtattr **tb, struct rtattr *est, int new)
{
	int err;
	u32 id = 0, to = 0, nhandle = 0x8000;
	struct route4_filter *fp;
	unsigned int h1;
	struct route4_bucket *b;
	struct tcf_exts e;

	err = tcf_exts_validate(tp, tb, est, &e, &route_ext_map);
	if (err < 0)
		return err;

	err = -EINVAL;
	if (tb[TCA_ROUTE4_CLASSID-1])
		if (RTA_PAYLOAD(tb[TCA_ROUTE4_CLASSID-1]) < sizeof(u32))
			goto errout;

	if (tb[TCA_ROUTE4_TO-1]) {
		if (new && handle & 0x8000)
			goto errout;
		if (RTA_PAYLOAD(tb[TCA_ROUTE4_TO-1]) < sizeof(u32))
			goto errout;
		to = *(u32*)RTA_DATA(tb[TCA_ROUTE4_TO-1]);
		if (to > 0xFF)
			goto errout;
		nhandle = to;
	}

	if (tb[TCA_ROUTE4_FROM-1]) {
		if (tb[TCA_ROUTE4_IIF-1])
			goto errout;
		if (RTA_PAYLOAD(tb[TCA_ROUTE4_FROM-1]) < sizeof(u32))
			goto errout;
		id = *(u32*)RTA_DATA(tb[TCA_ROUTE4_FROM-1]);
		if (id > 0xFF)
			goto errout;
		nhandle |= id << 16;
	} else if (tb[TCA_ROUTE4_IIF-1]) {
		if (RTA_PAYLOAD(tb[TCA_ROUTE4_IIF-1]) < sizeof(u32))
			goto errout;
		id = *(u32*)RTA_DATA(tb[TCA_ROUTE4_IIF-1]);
		if (id > 0x7FFF)
			goto errout;
		nhandle |= (id | 0x8000) << 16;
	} else
		nhandle |= 0xFFFF << 16;

	if (handle && new) {
		nhandle |= handle & 0x7F00;
		if (nhandle != handle)
			goto errout;
	}

	h1 = to_hash(nhandle);
	if ((b = head->table[h1]) == NULL) {
		err = -ENOBUFS;
		b = kzalloc(sizeof(struct route4_bucket), GFP_KERNEL);
		if (b == NULL)
			goto errout;

		tcf_tree_lock(tp);
		head->table[h1] = b;
		tcf_tree_unlock(tp);
	} else {
		unsigned int h2 = from_hash(nhandle >> 16);
		err = -EEXIST;
		for (fp = b->ht[h2]; fp; fp = fp->next)
			if (fp->handle == f->handle)
				goto errout;
	}

	tcf_tree_lock(tp);
	if (tb[TCA_ROUTE4_TO-1])
		f->id = to;

	if (tb[TCA_ROUTE4_FROM-1])
		f->id = to | id<<16;
	else if (tb[TCA_ROUTE4_IIF-1])
		f->iif = id;

	f->handle = nhandle;
	f->bkt = b;
	tcf_tree_unlock(tp);

	if (tb[TCA_ROUTE4_CLASSID-1]) {
		f->res.classid = *(u32*)RTA_DATA(tb[TCA_ROUTE4_CLASSID-1]);
		tcf_bind_filter(tp, &f->res, base);
	}

	tcf_exts_change(tp, &f->exts, &e);

	return 0;
errout:
	tcf_exts_destroy(tp, &e);
	return err;
}

static int route4_change(struct tcf_proto *tp, unsigned long base,
		       u32 handle,
		       struct rtattr **tca,
		       unsigned long *arg)
{
	struct route4_head *head = tp->root;
	struct route4_filter *f, *f1, **fp;
	struct route4_bucket *b;
	struct rtattr *opt = tca[TCA_OPTIONS-1];
	struct rtattr *tb[TCA_ROUTE4_MAX];
	unsigned int h, th;
	u32 old_handle = 0;
	int err;

	if (opt == NULL)
		return handle ? -EINVAL : 0;

	if (rtattr_parse_nested(tb, TCA_ROUTE4_MAX, opt) < 0)
		return -EINVAL;

	if ((f = (struct route4_filter*)*arg) != NULL) {
		if (f->handle != handle && handle)
			return -EINVAL;

		if (f->bkt)
			old_handle = f->handle;

		err = route4_set_parms(tp, base, f, handle, head, tb,
			tca[TCA_RATE-1], 0);
		if (err < 0)
			return err;

		goto reinsert;
	}

	err = -ENOBUFS;
	if (head == NULL) {
		head = kzalloc(sizeof(struct route4_head), GFP_KERNEL);
		if (head == NULL)
			goto errout;

		tcf_tree_lock(tp);
		tp->root = head;
		tcf_tree_unlock(tp);
	}

	f = kzalloc(sizeof(struct route4_filter), GFP_KERNEL);
	if (f == NULL)
		goto errout;

	err = route4_set_parms(tp, base, f, handle, head, tb,
		tca[TCA_RATE-1], 1);
	if (err < 0)
		goto errout;

reinsert:
	h = from_hash(f->handle >> 16);
	for (fp = &f->bkt->ht[h]; (f1=*fp) != NULL; fp = &f1->next)
		if (f->handle < f1->handle)
			break;

	f->next = f1;
	tcf_tree_lock(tp);
	*fp = f;

	if (old_handle && f->handle != old_handle) {
		th = to_hash(old_handle);
		h = from_hash(old_handle >> 16);
		if ((b = head->table[th]) != NULL) {
			for (fp = &b->ht[h]; *fp; fp = &(*fp)->next) {
				if (*fp == f) {
					*fp = f->next;
					break;
				}
			}
		}
	}
	tcf_tree_unlock(tp);

	route4_reset_fastmap(tp->q->dev, head, f->id);
	*arg = (unsigned long)f;
	return 0;

errout:
	kfree(f);
	return err;
}

static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
{
	struct route4_head *head = tp->root;
	unsigned h, h1;

	if (head == NULL)
		arg->stop = 1;

	if (arg->stop)
		return;

	for (h = 0; h <= 256; h++) {
		struct route4_bucket *b = head->table[h];

		if (b) {
			for (h1 = 0; h1 <= 32; h1++) {
				struct route4_filter *f;

				for (f = b->ht[h1]; f; f = f->next) {
					if (arg->count < arg->skip) {
						arg->count++;
						continue;
					}
					if (arg->fn(tp, (unsigned long)f, arg) < 0) {
						arg->stop = 1;
						return;
					}
					arg->count++;
				}
			}
		}
	}
}

static int route4_dump(struct tcf_proto *tp, unsigned long fh,
		       struct sk_buff *skb, struct tcmsg *t)
{
	struct route4_filter *f = (struct route4_filter*)fh;
	unsigned char *b = skb_tail_pointer(skb);
	struct rtattr *rta;
	u32 id;

	if (f == NULL)
		return skb->len;

	t->tcm_handle = f->handle;

	rta = (struct rtattr*)b;
	RTA_PUT(skb, TCA_OPTIONS, 0, NULL);

	if (!(f->handle&0x8000)) {
		id = f->id&0xFF;
		RTA_PUT(skb, TCA_ROUTE4_TO, sizeof(id), &id);
	}
	if (f->handle&0x80000000) {
		if ((f->handle>>16) != 0xFFFF)
			RTA_PUT(skb, TCA_ROUTE4_IIF, sizeof(f->iif), &f->iif);
	} else {
		id = f->id>>16;
		RTA_PUT(skb, TCA_ROUTE4_FROM, sizeof(id), &id);
	}
	if (f->res.classid)
		RTA_PUT(skb, TCA_ROUTE4_CLASSID, 4, &f->res.classid);

	if (tcf_exts_dump(skb, &f->exts, &route_ext_map) < 0)
		goto rtattr_failure;

	rta->rta_len = skb_tail_pointer(skb) - b;

	if (tcf_exts_dump_stats(skb, &f->exts, &route_ext_map) < 0)
		goto rtattr_failure;

	return skb->len;

rtattr_failure:
	nlmsg_trim(skb, b);
	return -1;
}

static struct tcf_proto_ops cls_route4_ops __read_mostly = {
	.kind		=	"route",
	.classify	=	route4_classify,
	.init		=	route4_init,
	.destroy	=	route4_destroy,
	.get		=	route4_get,
	.put		=	route4_put,
	.change		=	route4_change,
	.delete		=	route4_delete,
	.walk		=	route4_walk,
	.dump		=	route4_dump,
	.owner		=	THIS_MODULE,
};

static int __init init_route4(void)
{
	return register_tcf_proto_ops(&cls_route4_ops);
}

static void __exit exit_route4(void)
{
	unregister_tcf_proto_ops(&cls_route4_ops);
}

module_init(init_route4)
module_exit(exit_route4)
MODULE_LICENSE("GPL");