summaryrefslogtreecommitdiff
path: root/net/netfilter/xt_rateest.c
blob: 4fc6a917f6de5b30d55de8dba82531be03e67826 (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
/*
 * (C) 2007 Patrick McHardy <kaber@trash.net>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/gen_stats.h>

#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_rateest.h>
#include <net/netfilter/xt_rateest.h>


static bool
xt_rateest_mt(const struct sk_buff *skb, const struct xt_match_param *par)
{
	const struct xt_rateest_match_info *info = par->matchinfo;
	struct gnet_stats_rate_est *r;
	u_int32_t bps1, bps2, pps1, pps2;
	bool ret = true;

	spin_lock_bh(&info->est1->lock);
	r = &info->est1->rstats;
	if (info->flags & XT_RATEEST_MATCH_DELTA) {
		bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0;
		pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0;
	} else {
		bps1 = r->bps;
		pps1 = r->pps;
	}
	spin_unlock_bh(&info->est1->lock);

	if (info->flags & XT_RATEEST_MATCH_ABS) {
		bps2 = info->bps2;
		pps2 = info->pps2;
	} else {
		spin_lock_bh(&info->est2->lock);
		r = &info->est2->rstats;
		if (info->flags & XT_RATEEST_MATCH_DELTA) {
			bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0;
			pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0;
		} else {
			bps2 = r->bps;
			pps2 = r->pps;
		}
		spin_unlock_bh(&info->est2->lock);
	}

	switch (info->mode) {
	case XT_RATEEST_MATCH_LT:
		if (info->flags & XT_RATEEST_MATCH_BPS)
			ret &= bps1 < bps2;
		if (info->flags & XT_RATEEST_MATCH_PPS)
			ret &= pps1 < pps2;
		break;
	case XT_RATEEST_MATCH_GT:
		if (info->flags & XT_RATEEST_MATCH_BPS)
			ret &= bps1 > bps2;
		if (info->flags & XT_RATEEST_MATCH_PPS)
			ret &= pps1 > pps2;
		break;
	case XT_RATEEST_MATCH_EQ:
		if (info->flags & XT_RATEEST_MATCH_BPS)
			ret &= bps1 == bps2;
		if (info->flags & XT_RATEEST_MATCH_PPS)
			ret &= pps1 == pps2;
		break;
	}

	ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
	return ret;
}

static bool xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
{
	struct xt_rateest_match_info *info = par->matchinfo;
	struct xt_rateest *est1, *est2;

	if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
				     XT_RATEEST_MATCH_REL)) != 1)
		goto err1;

	if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
		goto err1;

	switch (info->mode) {
	case XT_RATEEST_MATCH_EQ:
	case XT_RATEEST_MATCH_LT:
	case XT_RATEEST_MATCH_GT:
		break;
	default:
		goto err1;
	}

	est1 = xt_rateest_lookup(info->name1);
	if (!est1)
		goto err1;

	if (info->flags & XT_RATEEST_MATCH_REL) {
		est2 = xt_rateest_lookup(info->name2);
		if (!est2)
			goto err2;
	} else
		est2 = NULL;


	info->est1 = est1;
	info->est2 = est2;
	return true;

err2:
	xt_rateest_put(est1);
err1:
	return false;
}

static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
{
	struct xt_rateest_match_info *info = par->matchinfo;

	xt_rateest_put(info->est1);
	if (info->est2)
		xt_rateest_put(info->est2);
}

static struct xt_match xt_rateest_mt_reg __read_mostly = {
	.name       = "rateest",
	.revision   = 0,
	.family     = NFPROTO_UNSPEC,
	.match      = xt_rateest_mt,
	.checkentry = xt_rateest_mt_checkentry,
	.destroy    = xt_rateest_mt_destroy,
	.matchsize  = sizeof(struct xt_rateest_match_info),
	.me         = THIS_MODULE,
};

static int __init xt_rateest_mt_init(void)
{
	return xt_register_match(&xt_rateest_mt_reg);
}

static void __exit xt_rateest_mt_fini(void)
{
	xt_unregister_match(&xt_rateest_mt_reg);
}

MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("xtables rate estimator match");
MODULE_ALIAS("ipt_rateest");
MODULE_ALIAS("ip6t_rateest");
module_init(xt_rateest_mt_init);
module_exit(xt_rateest_mt_fini);