aboutsummaryrefslogtreecommitdiffstats
path: root/net/sched/act_police.c
blob: 3af5759aac26a569bd0b6456be083aa4008c6037 (plain) (blame)
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
/*
 * net/sched/police.c	Input police filter.
 *
 *		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>
 * 		J Hadi Salim (action changes)
 */

#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 <linux/rtnetlink.h>
#include <linux/init.h>
#include <net/act_api.h>
#include <net/netlink.h>

#define L2T(p,L)   qdisc_l2t((p)->tcfp_R_tab, L)
#define L2T_P(p,L) qdisc_l2t((p)->tcfp_P_tab, L)

#define POL_TAB_MASK     15
static struct tcf_common *tcf_police_ht[POL_TAB_MASK + 1];
static u32 police_idx_gen;
static DEFINE_RWLOCK(police_lock);

static struct tcf_hashinfo police_hash_info = {
	.htab	=	tcf_police_ht,
	.hmask	=	POL_TAB_MASK,
	.lock	=	&police_lock,
};

/* old policer structure from before tc actions */
struct tc_police_compat
{
	u32			index;
	int			action;
	u32			limit;
	u32			burst;
	u32			mtu;
	struct tc_ratespec	rate;
	struct tc_ratespec	peakrate;
};

/* Each policer is serialized by its individual spinlock */

static int tcf_act_police_walker(struct sk_buff *skb, struct netlink_callback *cb,
			      int type, struct tc_action *a)
{
	struct tcf_common *p;
	int err = 0, index = -1, i = 0, s_i = 0, n_i = 0;
	struct nlattr *r;

	read_lock_bh(&police_lock);

	s_i = cb->args[0];

	for (i = 0; i < (POL_TAB_MASK + 1); i++) {
		p = tcf_police_ht[tcf_hash(i, POL_TAB_MASK)];

		for (; p; p = p->tcfc_next) {
			index++;
			if (index < s_i)
				continue;
			a->priv = p;
			a->order = index;
			r = (struct nlattr *)skb_tail_pointer(skb);
			NLA_PUT(skb, a->order, 0, NULL);
			if (type == RTM_DELACTION)
				err = tcf_action_dump_1(skb, a, 0, 1);
			else
				err = tcf_action_dump_1(skb, a, 0, 0);
			if (err < 0) {
				index--;
				nlmsg_trim(skb, r);
				goto done;
			}
			r->nla_len = skb_tail_pointer(skb) - (u8 *)r;
			n_i++;
		}
	}
done:
	read_unlock_bh(&police_lock);
	if (n_i)
		cb->args[0] += n_i;
	return n_i;

nla_put_failure:
	nlmsg_trim(skb, r);
	goto done;
}

static void tcf_police_destroy(struct tcf_police *p)
{
	unsigned int h = tcf_hash(p->tcf_index, POL_TAB_MASK);
	struct tcf_common **p1p;

	for (p1p = &tcf_police_ht[h]; *p1p; p1p = &(*p1p)->tcfc_next) {
		if (*p1p == &p->common) {
			write_lock_bh(&police_lock);
			*p1p = p->tcf_next;
			write_unlock_bh(&police_lock);
			gen_kill_estimator(&p->tcf_bstats,
					   &p->tcf_rate_est);
			if (p->tcfp_R_tab)
				qdisc_put_rtab(p->tcfp_R_tab);
			if (p->tcfp_P_tab)
				qdisc_put_rtab(p->tcfp_P_tab);
			kfree(p);
			return;
		}
	}
	BUG_TRAP(0);
}

static int tcf_act_police_locate(struct nlattr *nla, struct nlattr *est,
				 struct tc_action *a, int ovr, int bind)
{
	unsigned h;
	int ret = 0, err;
	struct nlattr *tb[TCA_POLICE_MAX + 1];
	struct tc_police *parm;
	struct tcf_police *police;
	struct qdisc_rate_table *R_tab = NULL, *P_tab = NULL;
	int size;

	if (nla == NULL || nla_parse_nested(tb, TCA_POLICE_MAX, nla, NULL) < 0)
		return -EINVAL;

	if (tb[TCA_POLICE_TBF] == NULL)
		return -EINVAL;
	size = nla_len(tb[TCA_POLICE_TBF]);
	if (size != sizeof(*parm) && size != sizeof(struct tc_police_compat))
		return -EINVAL;
	parm = nla_data(tb[TCA_POLICE_TBF]);

	if (tb[TCA_POLICE_RESULT] != NULL &&
	    nla_len(tb[TCA_POLICE_RESULT]) != sizeof(u32))
		return -EINVAL;
	if (tb[TCA_POLICE_RESULT] != NULL &&
	    nla_len(tb[TCA_POLICE_RESULT]) != sizeof(u32))
		return -EINVAL;

	if (parm->index) {
		struct tcf_common *pc;

		pc = tcf_hash_lookup(parm->index, &police_hash_info);
		if (pc != NULL) {
			a->priv = pc;
			police = to_police(pc);
			if (bind) {
				police->tcf_bindcnt += 1;
				police->tcf_refcnt += 1;
			}
			if (ovr)
				goto override;
			return ret;
		}
	}

	police = kzalloc(sizeof(*police), GFP_KERNEL);
	if (police == NULL)
		return -ENOMEM;
	ret = ACT_P_CREATED;
	police->tcf_refcnt = 1;
	spin_lock_init(&police->tcf_lock);
	if (bind)
		police->tcf_bindcnt = 1;
override:
	if (parm->rate.rate) {
		err = -ENOMEM;
		R_tab = qdisc_get_rtab(&parm->rate, tb[TCA_POLICE_RATE]);
		if (R_tab == NULL)
			goto failure;
		if (parm->peakrate.rate) {
			P_tab = qdisc_get_rtab(&parm->peakrate,
					       tb[TCA_POLICE_PEAKRATE]);
			if (P_tab == NULL) {
				qdisc_put_rtab(R_tab);
				goto failure;
			}
		}
	}
	/* No failure allowed after this point */
	spin_lock_bh(&police->tcf_lock);
	if (R_tab != NULL) {
		qdisc_put_rtab(police->tcfp_R_tab);
		police->tcfp_R_tab = R_tab;
	}
	if (P_tab != NULL) {
		qdisc_put_rtab(police->tcfp_P_tab);
		police->tcfp_P_tab = P_tab;
	}

	if (tb[TCA_POLICE_RESULT])
		police->tcfp_result = *(u32*)nla_data(tb[TCA_POLICE_RESULT]);
	police->tcfp_toks = police->tcfp_burst = parm->burst;
	police->tcfp_mtu = parm->mtu;
	if (police->tcfp_mtu == 0) {
		police->tcfp_mtu = ~0;
		if (police->tcfp_R_tab)
			police->tcfp_mtu = 255<<police->tcfp_R_tab->rate.cell_log;
	}
	if (police->tcfp_P_tab)
		police->tcfp_ptoks = L2T_P(police, police->tcfp_mtu);
	police->tcf_action = parm->action;

	if (tb[TCA_POLICE_AVRATE])
		police->tcfp_ewma_rate =
			*(u32*)nla_data(tb[TCA_POLICE_AVRATE]);
	if (est)
		gen_replace_estimator(&police->tcf_bstats,
				      &police->tcf_rate_est,
				      &police->tcf_lock, est);

	spin_unlock_bh(&police->tcf_lock);
	if (ret != ACT_P_CREATED)
		return ret;

	police->tcfp_t_c = psched_get_time();
	police->tcf_index = parm->index ? parm->index :
		tcf_hash_new_index(&police_idx_gen, &police_hash_info);
	h = tcf_hash(police->tcf_index, POL_TAB_MASK);
	write_lock_bh(&police_lock);
	police->tcf_next = tcf_police_ht[h];
	tcf_police_ht[h] = &police->common;
	write_unlock_bh(&police_lock);

	a->priv = police;
	return ret;

failure:
	if (ret == ACT_P_CREATED)
		kfree(police);
	return err;
}

static int tcf_act_police_cleanup(struct tc_action *a, int bind)
{
	struct tcf_police *p = a->priv;
	int ret = 0;

	if (p != NULL) {
		if (bind)
			p->tcf_bindcnt--;

		p->tcf_refcnt--;
		if (p->tcf_refcnt <= 0 && !p->tcf_bindcnt) {
			tcf_police_destroy(p);
			ret = 1;
		}
	}
	return ret;
}

static int tcf_act_police(struct sk_buff *skb, struct tc_action *a,
			  struct tcf_result *res)
{
	struct tcf_police *police = a->priv;
	psched_time_t now;
	long toks;
	long ptoks = 0;

	spin_lock(&police->tcf_lock);

	police->tcf_bstats.bytes += skb->len;
	police->tcf_bstats.packets++;

	if (police->tcfp_ewma_rate &&
	    police->tcf_rate_est.bps >= police->tcfp_ewma_rate) {
		police->tcf_qstats.overlimits++;
		spin_unlock(&police->tcf_lock);
		return police->tcf_action;
	}

	if (skb->len <= police->tcfp_mtu) {
		if (police->tcfp_R_tab == NULL) {
			spin_unlock(&police->tcf_lock);
			return police->tcfp_result;
		}

		now = psched_get_time();
		toks = psched_tdiff_bounded(now, police->tcfp_t_c,
					    police->tcfp_burst);
		if (police->tcfp_P_tab) {
			ptoks = toks + police->tcfp_ptoks;
			if (ptoks > (long)L2T_P(police, police->tcfp_mtu))
				ptoks = (long)L2T_P(police, police->tcfp_mtu);
			ptoks -= L2T_P(police, skb->len);
		}
		toks += police->tcfp_toks;
		if (toks > (long)police->tcfp_burst)
			toks = police->tcfp_burst;
		toks -= L2T(police, skb->len);
		if ((toks|ptoks) >= 0) {
			police->tcfp_t_c = now;
			police->tcfp_toks = toks;
			police->tcfp_ptoks = ptoks;
			spin_unlock(&police->tcf_lock);
			return police->tcfp_result;
		}
	}

	police->tcf_qstats.overlimits++;
	spin_unlock(&police->tcf_lock);
	return police->tcf_action;
}

static int
tcf_act_police_dump(struct sk_buff *skb, struct tc_action *a, int bind, int ref)
{
	unsigned char *b = skb_tail_pointer(skb);
	struct tcf_police *police = a->priv;
	struct tc_police opt;

	opt.index = police->tcf_index;
	opt.action = police->tcf_action;
	opt.mtu = police->tcfp_mtu;
	opt.burst = police->tcfp_burst;
	opt.refcnt = police->tcf_refcnt - ref;
	opt.bindcnt = police->tcf_bindcnt - bind;
	if (police->tcfp_R_tab)
		opt.rate = police->tcfp_R_tab->rate;
	else
		memset(&opt.rate, 0, sizeof(opt.rate));
	if (police->tcfp_P_tab)
		opt.peakrate = police->tcfp_P_tab->rate;
	else
		memset(&opt.peakrate, 0, sizeof(opt.peakrate));
	NLA_PUT(skb, TCA_POLICE_TBF, sizeof(opt), &opt);
	if (police->tcfp_result)
		NLA_PUT(skb, TCA_POLICE_RESULT, sizeof(int),
			&police->tcfp_result);
	if (police->tcfp_ewma_rate)
		NLA_PUT(skb, TCA_POLICE_AVRATE, 4, &police->tcfp_ewma_rate);
	return skb->len;

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

MODULE_AUTHOR("Alexey Kuznetsov");
MODULE_DESCRIPTION("Policing actions");
MODULE_LICENSE("GPL");

static struct tc_action_ops act_police_ops = {
	.kind		=	"police",
	.hinfo		=	&police_hash_info,
	.type		=	TCA_ID_POLICE,
	.capab		=	TCA_CAP_NONE,
	.owner		=	THIS_MODULE,
	.act		=	tcf_act_police,
	.dump		=	tcf_act_police_dump,
	.cleanup	=	tcf_act_police_cleanup,
	.lookup		=	tcf_hash_search,
	.init		=	tcf_act_police_locate,
	.walk		=	tcf_act_police_walker
};

static int __init
police_init_module(void)
{
	return tcf_register_action(&act_police_ops);
}

static void __exit
police_cleanup_module(void)
{
	tcf_unregister_action(&act_police_ops);
}

module_init(police_init_module);
module_exit(police_cleanup_module);