1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * (C) 2007 Patrick McHardy <kaber@trash.net>
4 */
5 #include <linux/module.h>
6 #include <linux/skbuff.h>
7 #include <linux/gen_stats.h>
8
9 #include <linux/netfilter/x_tables.h>
10 #include <linux/netfilter/xt_rateest.h>
11 #include <net/netfilter/xt_rateest.h>
12
13
14 static bool
15 xt_rateest_mt(const struct sk_buff *skb, struct xt_action_param *par)
16 {
17 const struct xt_rateest_match_info *info = par->matchinfo;
18 struct gnet_stats_rate_est64 sample = {0};
19 u_int32_t bps1, bps2, pps1, pps2;
20 bool ret = true;
21
22 gen_estimator_read(&info->est1->rate_est, &sample);
23
24 if (info->flags & XT_RATEEST_MATCH_DELTA) {
25 bps1 = info->bps1 >= sample.bps ? info->bps1 - sample.bps : 0;
26 pps1 = info->pps1 >= sample.pps ? info->pps1 - sample.pps : 0;
27 } else {
28 bps1 = sample.bps;
29 pps1 = sample.pps;
30 }
31
32 if (info->flags & XT_RATEEST_MATCH_ABS) {
33 bps2 = info->bps2;
34 pps2 = info->pps2;
35 } else {
36 gen_estimator_read(&info->est2->rate_est, &sample);
37
38 if (info->flags & XT_RATEEST_MATCH_DELTA) {
39 bps2 = info->bps2 >= sample.bps ? info->bps2 - sample.bps : 0;
40 pps2 = info->pps2 >= sample.pps ? info->pps2 - sample.pps : 0;
41 } else {
42 bps2 = sample.bps;
43 pps2 = sample.pps;
44 }
45 }
46
47 switch (info->mode) {
48 case XT_RATEEST_MATCH_LT:
49 if (info->flags & XT_RATEEST_MATCH_BPS)
50 ret &= bps1 < bps2;
51 if (info->flags & XT_RATEEST_MATCH_PPS)
52 ret &= pps1 < pps2;
53 break;
54 case XT_RATEEST_MATCH_GT:
55 if (info->flags & XT_RATEEST_MATCH_BPS)
56 ret &= bps1 > bps2;
57 if (info->flags & XT_RATEEST_MATCH_PPS)
58 ret &= pps1 > pps2;
59 break;
60 case XT_RATEEST_MATCH_EQ:
61 if (info->flags & XT_RATEEST_MATCH_BPS)
62 ret &= bps1 == bps2;
63 if (info->flags & XT_RATEEST_MATCH_PPS)
64 ret &= pps1 == pps2;
65 break;
66 }
67
68 ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
69 return ret;
70 }
71
72 static int xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
73 {
74 struct xt_rateest_match_info *info = par->matchinfo;
75 struct xt_rateest *est1, *est2;
76 int ret = -EINVAL;
77
78 if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
79 XT_RATEEST_MATCH_REL)) != 1)
80 goto err1;
81
82 if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
83 goto err1;
84
85 switch (info->mode) {
86 case XT_RATEEST_MATCH_EQ:
87 case XT_RATEEST_MATCH_LT:
88 case XT_RATEEST_MATCH_GT:
89 break;
90 default:
91 goto err1;
92 }
93
94 ret = -ENOENT;
95 est1 = xt_rateest_lookup(par->net, info->name1);
96 if (!est1)
97 goto err1;
98
99 est2 = NULL;
100 if (info->flags & XT_RATEEST_MATCH_REL) {
101 est2 = xt_rateest_lookup(par->net, info->name2);
102 if (!est2)
103 goto err2;
104 }
105
106 info->est1 = est1;
107 info->est2 = est2;
108 return 0;
109
110 err2:
111 xt_rateest_put(par->net, est1);
112 err1:
113 return ret;
114 }
115
116 static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
117 {
118 struct xt_rateest_match_info *info = par->matchinfo;
119
120 xt_rateest_put(par->net, info->est1);
121 if (info->est2)
122 xt_rateest_put(par->net, info->est2);
123 }
124
125 static struct xt_match xt_rateest_mt_reg __read_mostly = {
126 .name = "rateest",
127 .revision = 0,
128 .family = NFPROTO_UNSPEC,
129 .match = xt_rateest_mt,
130 .checkentry = xt_rateest_mt_checkentry,
131 .destroy = xt_rateest_mt_destroy,
132 .matchsize = sizeof(struct xt_rateest_match_info),
133 .usersize = offsetof(struct xt_rateest_match_info, est1),
134 .me = THIS_MODULE,
135 };
136
137 static int __init xt_rateest_mt_init(void)
138 {
139 return xt_register_match(&xt_rateest_mt_reg);
140 }
141
142 static void __exit xt_rateest_mt_fini(void)
143 {
144 xt_unregister_match(&xt_rateest_mt_reg);
145 }
146
147 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
148 MODULE_LICENSE("GPL");
149 MODULE_DESCRIPTION("xtables rate estimator match");
150 MODULE_ALIAS("ipt_rateest");
151 MODULE_ALIAS("ip6t_rateest");
152 module_init(xt_rateest_mt_init);
153 module_exit(xt_rateest_mt_fini);
154
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