Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/kaber/nf-next-2.6
[linux-2.6.git] / net / netfilter / xt_rateest.c
1 /*
2  * (C) 2007 Patrick McHardy <kaber@trash.net>
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 #include <linux/module.h>
9 #include <linux/skbuff.h>
10 #include <linux/gen_stats.h>
11
12 #include <linux/netfilter/x_tables.h>
13 #include <linux/netfilter/xt_rateest.h>
14 #include <net/netfilter/xt_rateest.h>
15
16
17 static bool
18 xt_rateest_mt(const struct sk_buff *skb, const struct xt_match_param *par)
19 {
20         const struct xt_rateest_match_info *info = par->matchinfo;
21         struct gnet_stats_rate_est *r;
22         u_int32_t bps1, bps2, pps1, pps2;
23         bool ret = true;
24
25         spin_lock_bh(&info->est1->lock);
26         r = &info->est1->rstats;
27         if (info->flags & XT_RATEEST_MATCH_DELTA) {
28                 bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0;
29                 pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0;
30         } else {
31                 bps1 = r->bps;
32                 pps1 = r->pps;
33         }
34         spin_unlock_bh(&info->est1->lock);
35
36         if (info->flags & XT_RATEEST_MATCH_ABS) {
37                 bps2 = info->bps2;
38                 pps2 = info->pps2;
39         } else {
40                 spin_lock_bh(&info->est2->lock);
41                 r = &info->est2->rstats;
42                 if (info->flags & XT_RATEEST_MATCH_DELTA) {
43                         bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0;
44                         pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0;
45                 } else {
46                         bps2 = r->bps;
47                         pps2 = r->pps;
48                 }
49                 spin_unlock_bh(&info->est2->lock);
50         }
51
52         switch (info->mode) {
53         case XT_RATEEST_MATCH_LT:
54                 if (info->flags & XT_RATEEST_MATCH_BPS)
55                         ret &= bps1 < bps2;
56                 if (info->flags & XT_RATEEST_MATCH_PPS)
57                         ret &= pps1 < pps2;
58                 break;
59         case XT_RATEEST_MATCH_GT:
60                 if (info->flags & XT_RATEEST_MATCH_BPS)
61                         ret &= bps1 > bps2;
62                 if (info->flags & XT_RATEEST_MATCH_PPS)
63                         ret &= pps1 > pps2;
64                 break;
65         case XT_RATEEST_MATCH_EQ:
66                 if (info->flags & XT_RATEEST_MATCH_BPS)
67                         ret &= bps1 == bps2;
68                 if (info->flags & XT_RATEEST_MATCH_PPS)
69                         ret &= pps1 == pps2;
70                 break;
71         }
72
73         ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
74         return ret;
75 }
76
77 static bool xt_rateest_mt_checkentry(const struct xt_mtchk_param *par)
78 {
79         struct xt_rateest_match_info *info = par->matchinfo;
80         struct xt_rateest *est1, *est2;
81
82         if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
83                                      XT_RATEEST_MATCH_REL)) != 1)
84                 goto err1;
85
86         if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
87                 goto err1;
88
89         switch (info->mode) {
90         case XT_RATEEST_MATCH_EQ:
91         case XT_RATEEST_MATCH_LT:
92         case XT_RATEEST_MATCH_GT:
93                 break;
94         default:
95                 goto err1;
96         }
97
98         est1 = xt_rateest_lookup(info->name1);
99         if (!est1)
100                 goto err1;
101
102         if (info->flags & XT_RATEEST_MATCH_REL) {
103                 est2 = xt_rateest_lookup(info->name2);
104                 if (!est2)
105                         goto err2;
106         } else
107                 est2 = NULL;
108
109
110         info->est1 = est1;
111         info->est2 = est2;
112         return true;
113
114 err2:
115         xt_rateest_put(est1);
116 err1:
117         return false;
118 }
119
120 static void xt_rateest_mt_destroy(const struct xt_mtdtor_param *par)
121 {
122         struct xt_rateest_match_info *info = par->matchinfo;
123
124         xt_rateest_put(info->est1);
125         if (info->est2)
126                 xt_rateest_put(info->est2);
127 }
128
129 static struct xt_match xt_rateest_mt_reg __read_mostly = {
130         .name       = "rateest",
131         .revision   = 0,
132         .family     = NFPROTO_UNSPEC,
133         .match      = xt_rateest_mt,
134         .checkentry = xt_rateest_mt_checkentry,
135         .destroy    = xt_rateest_mt_destroy,
136         .matchsize  = sizeof(struct xt_rateest_match_info),
137         .me         = THIS_MODULE,
138 };
139
140 static int __init xt_rateest_mt_init(void)
141 {
142         return xt_register_match(&xt_rateest_mt_reg);
143 }
144
145 static void __exit xt_rateest_mt_fini(void)
146 {
147         xt_unregister_match(&xt_rateest_mt_reg);
148 }
149
150 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
151 MODULE_LICENSE("GPL");
152 MODULE_DESCRIPTION("xtables rate estimator match");
153 MODULE_ALIAS("ipt_rateest");
154 MODULE_ALIAS("ip6t_rateest");
155 module_init(xt_rateest_mt_init);
156 module_exit(xt_rateest_mt_fini);