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
xt_rateest_mt(const struct sk_buff * skb,struct xt_action_param * par)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 
xt_rateest_mt_checkentry(const struct xt_mtchk_param * par)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 
xt_rateest_mt_destroy(const struct xt_mtdtor_param * par)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 
xt_rateest_mt_init(void)137 static int __init xt_rateest_mt_init(void)
138 {
139 	return xt_register_match(&xt_rateest_mt_reg);
140 }
141 
xt_rateest_mt_fini(void)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