summaryrefslogtreecommitdiffstats
path: root/net/sched/sch_dsmark.c
blob: afedd92b7496658249ee6e5af1a6b982f8f10692 (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
/* net/sched/sch_dsmark.c - Differentiated Services field marker */

/* Written 1998-2000 by Werner Almesberger, EPFL ICA */


#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h> /* for pkt_sched */
#include <linux/rtnetlink.h>
#include <net/pkt_sched.h>
#include <net/dsfield.h>
#include <net/inet_ecn.h>
#include <asm/byteorder.h>


#if 0 /* control */
#define DPRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define DPRINTK(format,args...)
#endif

#if 0 /* data */
#define D2PRINTK(format,args...) printk(KERN_DEBUG format,##args)
#else
#define D2PRINTK(format,args...)
#endif


#define PRIV(sch) ((struct dsmark_qdisc_data *) qdisc_priv(sch))


/*
 * classid	class		marking
 * -------	-----		-------
 *   n/a	  0		n/a
 *   x:0	  1		use entry [0]
 *   ...	 ...		...
 *   x:y y>0	 y+1		use entry [y]
 *   ...	 ...		...
 * x:indices-1	indices		use entry [indices-1]
 *   ...	 ...		...
 *   x:y	 y+1		use entry [y & (indices-1)]
 *   ...	 ...		...
 * 0xffff	0x10000		use entry [indices-1]
 */


#define NO_DEFAULT_INDEX	(1 << 16)

struct dsmark_qdisc_data {
	struct Qdisc		*q;
	struct tcf_proto	*filter_list;
	u8			*mask;	/* "owns" the array */
	u8			*value;
	u16			indices;
	u32			default_index;	/* index range is 0...0xffff */
	int			set_tc_index;
};

static inline int dsmark_valid_indices(u16 indices)
{
	while (indices != 1) {
		if (indices & 1)
			return 0;
		indices >>= 1;
	}
 
	return 1;
}

static inline int dsmark_valid_index(struct dsmark_qdisc_data *p, u16 index)
{
	return (index <= p->indices && index > 0);
}

/* ------------------------- Class/flow operations ------------------------- */

static int dsmark_graft(struct Qdisc *sch, unsigned long arg,
			struct Qdisc *new, struct Qdisc **old)
{
	struct dsmark_qdisc_data *p = PRIV(sch);

	DPRINTK("dsmark_graft(sch %p,[qdisc %p],new %p,old %p)\n",
		sch, p, new, old);

	if (new == NULL) {
		new = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops,
					sch->handle);
		if (new == NULL)
			new = &noop_qdisc;
	}

	sch_tree_lock(sch);
	*old = xchg(&p->q, new);
	qdisc_reset(*old);
	sch->q.qlen = 0;
	sch_tree_unlock(sch);

        return 0;
}

static struct Qdisc *dsmark_leaf(struct Qdisc *sch, unsigned long arg)
{
	return PRIV(sch)->q;
}

static unsigned long dsmark_get(struct Qdisc *sch, u32 classid)
{
	DPRINTK("dsmark_get(sch %p,[qdisc %p],classid %x)\n",
		sch, PRIV(sch), classid);

	return TC_H_MIN(classid) + 1;
}

static unsigned long dsmark_bind_filter(struct Qdisc *sch,
					unsigned long parent, u32 classid)
{
	return dsmark_get(sch, classid);
}

static void dsmark_put(struct Qdisc *sch, unsigned long cl)
{
}

static int dsmark_change(struct Qdisc *sch, u32 classid, u32 parent,
			 struct rtattr **tca, unsigned long *arg)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	struct rtattr *opt = tca[TCA_OPTIONS-1];
	struct rtattr *tb[TCA_DSMARK_MAX];
	int err = -EINVAL;
	u8 mask = 0;

	DPRINTK("dsmark_change(sch %p,[qdisc %p],classid %x,parent %x),"
		"arg 0x%lx\n", sch, p, classid, parent, *arg);

	if (!dsmark_valid_index(p, *arg)) {
		err = -ENOENT;
		goto rtattr_failure;
	}

	if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt))
		goto rtattr_failure;

	if (tb[TCA_DSMARK_MASK-1])
		mask = RTA_GET_U8(tb[TCA_DSMARK_MASK-1]);

	if (tb[TCA_DSMARK_VALUE-1])
		p->value[*arg-1] = RTA_GET_U8(tb[TCA_DSMARK_VALUE-1]);
		
	if (tb[TCA_DSMARK_MASK-1])
		p->mask[*arg-1] = mask;

	err = 0;

rtattr_failure:
	return err;
}

static int dsmark_delete(struct Qdisc *sch, unsigned long arg)
{
	struct dsmark_qdisc_data *p = PRIV(sch);

	if (!dsmark_valid_index(p, arg))
		return -EINVAL;
	
	p->mask[arg-1] = 0xff;
	p->value[arg-1] = 0;

	return 0;
}

static void dsmark_walk(struct Qdisc *sch,struct qdisc_walker *walker)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	int i;

	DPRINTK("dsmark_walk(sch %p,[qdisc %p],walker %p)\n", sch, p, walker);

	if (walker->stop)
		return;

	for (i = 0; i < p->indices; i++) {
		if (p->mask[i] == 0xff && !p->value[i])
			goto ignore;
		if (walker->count >= walker->skip) {
			if (walker->fn(sch, i+1, walker) < 0) {
				walker->stop = 1;
				break;
			}
		}
ignore:		
		walker->count++;
        }
}

static struct tcf_proto **dsmark_find_tcf(struct Qdisc *sch,unsigned long cl)
{
	return &PRIV(sch)->filter_list;
}

/* --------------------------- Qdisc operations ---------------------------- */

static int dsmark_enqueue(struct sk_buff *skb,struct Qdisc *sch)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	int err;

	D2PRINTK("dsmark_enqueue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);

	if (p->set_tc_index) {
		/* FIXME: Safe with non-linear skbs? --RR */
		switch (skb->protocol) {
			case __constant_htons(ETH_P_IP):
				skb->tc_index = ipv4_get_dsfield(skb->nh.iph)
					& ~INET_ECN_MASK;
				break;
			case __constant_htons(ETH_P_IPV6):
				skb->tc_index = ipv6_get_dsfield(skb->nh.ipv6h)
					& ~INET_ECN_MASK;
				break;
			default:
				skb->tc_index = 0;
				break;
		};
	}

	if (TC_H_MAJ(skb->priority) == sch->handle)
		skb->tc_index = TC_H_MIN(skb->priority);
	else {
		struct tcf_result res;
		int result = tc_classify(skb, p->filter_list, &res);

		D2PRINTK("result %d class 0x%04x\n", result, res.classid);

		switch (result) {
#ifdef CONFIG_NET_CLS_POLICE
			case TC_POLICE_SHOT:
				kfree_skb(skb);
				sch->qstats.drops++;
				return NET_XMIT_POLICED;
#if 0
			case TC_POLICE_RECLASSIFY:
				/* FIXME: what to do here ??? */
#endif
#endif
			case TC_POLICE_OK:
				skb->tc_index = TC_H_MIN(res.classid);
				break;
			case TC_POLICE_UNSPEC:
				/* fall through */
			default:
				if (p->default_index != NO_DEFAULT_INDEX)
					skb->tc_index = p->default_index;
				break;
		};
	}

	err = p->q->enqueue(skb,p->q);
	if (err != NET_XMIT_SUCCESS) {
		sch->qstats.drops++;
		return err;
	}

	sch->bstats.bytes += skb->len;
	sch->bstats.packets++;
	sch->q.qlen++;

	return NET_XMIT_SUCCESS;
}

static struct sk_buff *dsmark_dequeue(struct Qdisc *sch)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	struct sk_buff *skb;
	u32 index;

	D2PRINTK("dsmark_dequeue(sch %p,[qdisc %p])\n", sch, p);

	skb = p->q->ops->dequeue(p->q);
	if (skb == NULL)
		return NULL;

	sch->q.qlen--;

	index = skb->tc_index & (p->indices - 1);
	D2PRINTK("index %d->%d\n", skb->tc_index, index);

	switch (skb->protocol) {
		case __constant_htons(ETH_P_IP):
			ipv4_change_dsfield(skb->nh.iph, p->mask[index],
					    p->value[index]);
			break;
		case __constant_htons(ETH_P_IPV6):
			ipv6_change_dsfield(skb->nh.ipv6h, p->mask[index],
					    p->value[index]);
			break;
		default:
			/*
			 * Only complain if a change was actually attempted.
			 * This way, we can send non-IP traffic through dsmark
			 * and don't need yet another qdisc as a bypass.
			 */
			if (p->mask[index] != 0xff || p->value[index])
				printk(KERN_WARNING "dsmark_dequeue: "
				       "unsupported protocol %d\n",
				       ntohs(skb->protocol));
			break;
	};

	return skb;
}

static int dsmark_requeue(struct sk_buff *skb,struct Qdisc *sch)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	int err;

	D2PRINTK("dsmark_requeue(skb %p,sch %p,[qdisc %p])\n", skb, sch, p);

	err = p->q->ops->requeue(skb, p->q);
	if (err != NET_XMIT_SUCCESS) {
		sch->qstats.drops++;
		return err;
	}

	sch->q.qlen++;
	sch->qstats.requeues++;

	return NET_XMIT_SUCCESS;
}

static unsigned int dsmark_drop(struct Qdisc *sch)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	unsigned int len;
	
	DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);

	if (p->q->ops->drop == NULL)
		return 0;

	len = p->q->ops->drop(p->q);
	if (len)
		sch->q.qlen--;

	return len;
}

static int dsmark_init(struct Qdisc *sch, struct rtattr *opt)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	struct rtattr *tb[TCA_DSMARK_MAX];
	int err = -EINVAL;
	u32 default_index = NO_DEFAULT_INDEX;
	u16 indices;
	u8 *mask;

	DPRINTK("dsmark_init(sch %p,[qdisc %p],opt %p)\n", sch, p, opt);

	if (!opt || rtattr_parse_nested(tb, TCA_DSMARK_MAX, opt) < 0)
		goto errout;

	indices = RTA_GET_U16(tb[TCA_DSMARK_INDICES-1]);
	if (!indices || !dsmark_valid_indices(indices))
		goto errout;

	if (tb[TCA_DSMARK_DEFAULT_INDEX-1])
		default_index = RTA_GET_U16(tb[TCA_DSMARK_DEFAULT_INDEX-1]);

	mask = kmalloc(indices * 2, GFP_KERNEL);
	if (mask == NULL) {
		err = -ENOMEM;
		goto errout;
	}

	p->mask = mask;
	memset(p->mask, 0xff, indices);

	p->value = p->mask + indices;
	memset(p->value, 0, indices);

	p->indices = indices;
	p->default_index = default_index;
	p->set_tc_index = RTA_GET_FLAG(tb[TCA_DSMARK_SET_TC_INDEX-1]);

	p->q = qdisc_create_dflt(sch->dev, &pfifo_qdisc_ops, sch->handle);
	if (p->q == NULL)
		p->q = &noop_qdisc;

	DPRINTK("dsmark_init: qdisc %p\n", p->q);

	err = 0;
errout:
rtattr_failure:
	return err;
}

static void dsmark_reset(struct Qdisc *sch)
{
	struct dsmark_qdisc_data *p = PRIV(sch);

	DPRINTK("dsmark_reset(sch %p,[qdisc %p])\n", sch, p);
	qdisc_reset(p->q);
	sch->q.qlen = 0;
}

static void dsmark_destroy(struct Qdisc *sch)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	struct tcf_proto *tp;

	DPRINTK("dsmark_destroy(sch %p,[qdisc %p])\n", sch, p);

	while (p->filter_list) {
		tp = p->filter_list;
		p->filter_list = tp->next;
		tcf_destroy(tp);
	}

	qdisc_destroy(p->q);
	kfree(p->mask);
}

static int dsmark_dump_class(struct Qdisc *sch, unsigned long cl,
			     struct sk_buff *skb, struct tcmsg *tcm)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	struct rtattr *opts = NULL;

	DPRINTK("dsmark_dump_class(sch %p,[qdisc %p],class %ld\n", sch, p, cl);

	if (!dsmark_valid_index(p, cl))
		return -EINVAL;

	tcm->tcm_handle = TC_H_MAKE(TC_H_MAJ(sch->handle), cl-1);
	tcm->tcm_info = p->q->handle;

	opts = RTA_NEST(skb, TCA_OPTIONS);
	RTA_PUT_U8(skb,TCA_DSMARK_MASK, p->mask[cl-1]);
	RTA_PUT_U8(skb,TCA_DSMARK_VALUE, p->value[cl-1]);

	return RTA_NEST_END(skb, opts);

rtattr_failure:
	return RTA_NEST_CANCEL(skb, opts);
}

static int dsmark_dump(struct Qdisc *sch, struct sk_buff *skb)
{
	struct dsmark_qdisc_data *p = PRIV(sch);
	struct rtattr *opts = NULL;

	opts = RTA_NEST(skb, TCA_OPTIONS);
	RTA_PUT_U16(skb, TCA_DSMARK_INDICES, p->indices);

	if (p->default_index != NO_DEFAULT_INDEX)
		RTA_PUT_U16(skb, TCA_DSMARK_DEFAULT_INDEX, p->default_index);

	if (p->set_tc_index)
		RTA_PUT_FLAG(skb, TCA_DSMARK_SET_TC_INDEX);

	return RTA_NEST_END(skb, opts);

rtattr_failure:
	return RTA_NEST_CANCEL(skb, opts);
}

static struct Qdisc_class_ops dsmark_class_ops = {
	.graft		=	dsmark_graft,
	.leaf		=	dsmark_leaf,
	.get		=	dsmark_get,
	.put		=	dsmark_put,
	.change		=	dsmark_change,
	.delete		=	dsmark_delete,
	.walk		=	dsmark_walk,
	.tcf_chain	=	dsmark_find_tcf,
	.bind_tcf	=	dsmark_bind_filter,
	.unbind_tcf	=	dsmark_put,
	.dump		=	dsmark_dump_class,
};

static struct Qdisc_ops dsmark_qdisc_ops = {
	.next		=	NULL,
	.cl_ops		=	&dsmark_class_ops,
	.id		=	"dsmark",
	.priv_size	=	sizeof(struct dsmark_qdisc_data),
	.enqueue	=	dsmark_enqueue,
	.dequeue	=	dsmark_dequeue,
	.requeue	=	dsmark_requeue,
	.drop		=	dsmark_drop,
	.init		=	dsmark_init,
	.reset		=	dsmark_reset,
	.destroy	=	dsmark_destroy,
	.change		=	NULL,
	.dump		=	dsmark_dump,
	.owner		=	THIS_MODULE,
};

static int __init dsmark_module_init(void)
{
	return register_qdisc(&dsmark_qdisc_ops);
}

static void __exit dsmark_module_exit(void) 
{
	unregister_qdisc(&dsmark_qdisc_ops);
}

module_init(dsmark_module_init)
module_exit(dsmark_module_exit)

MODULE_LICENSE("GPL");