omfs: sparse annotations
[linux-2.6] / 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 xt_rateest_mt(const struct sk_buff *skb,
18                           const struct net_device *in,
19                           const struct net_device *out,
20                           const struct xt_match *match,
21                           const void *matchinfo,
22                           int offset,
23                           unsigned int protoff,
24                           bool *hotdrop)
25 {
26         const struct xt_rateest_match_info *info = matchinfo;
27         struct gnet_stats_rate_est *r;
28         u_int32_t bps1, bps2, pps1, pps2;
29         bool ret = true;
30
31         spin_lock_bh(&info->est1->lock);
32         r = &info->est1->rstats;
33         if (info->flags & XT_RATEEST_MATCH_DELTA) {
34                 bps1 = info->bps1 >= r->bps ? info->bps1 - r->bps : 0;
35                 pps1 = info->pps1 >= r->pps ? info->pps1 - r->pps : 0;
36         } else {
37                 bps1 = r->bps;
38                 pps1 = r->pps;
39         }
40         spin_unlock_bh(&info->est1->lock);
41
42         if (info->flags & XT_RATEEST_MATCH_ABS) {
43                 bps2 = info->bps2;
44                 pps2 = info->pps2;
45         } else {
46                 spin_lock_bh(&info->est2->lock);
47                 r = &info->est2->rstats;
48                 if (info->flags & XT_RATEEST_MATCH_DELTA) {
49                         bps2 = info->bps2 >= r->bps ? info->bps2 - r->bps : 0;
50                         pps2 = info->pps2 >= r->pps ? info->pps2 - r->pps : 0;
51                 } else {
52                         bps2 = r->bps;
53                         pps2 = r->pps;
54                 }
55                 spin_unlock_bh(&info->est2->lock);
56         }
57
58         switch (info->mode) {
59         case XT_RATEEST_MATCH_LT:
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_GT:
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         case XT_RATEEST_MATCH_EQ:
72                 if (info->flags & XT_RATEEST_MATCH_BPS)
73                         ret &= bps1 == bps2;
74                 if (info->flags & XT_RATEEST_MATCH_PPS)
75                         ret &= pps2 == pps2;
76                 break;
77         }
78
79         ret ^= info->flags & XT_RATEEST_MATCH_INVERT ? true : false;
80         return ret;
81 }
82
83 static bool xt_rateest_mt_checkentry(const char *tablename,
84                                      const void *ip,
85                                      const struct xt_match *match,
86                                      void *matchinfo,
87                                      unsigned int hook_mask)
88 {
89         struct xt_rateest_match_info *info = matchinfo;
90         struct xt_rateest *est1, *est2;
91
92         if (hweight32(info->flags & (XT_RATEEST_MATCH_ABS |
93                                      XT_RATEEST_MATCH_REL)) != 1)
94                 goto err1;
95
96         if (!(info->flags & (XT_RATEEST_MATCH_BPS | XT_RATEEST_MATCH_PPS)))
97                 goto err1;
98
99         switch (info->mode) {
100         case XT_RATEEST_MATCH_EQ:
101         case XT_RATEEST_MATCH_LT:
102         case XT_RATEEST_MATCH_GT:
103                 break;
104         default:
105                 goto err1;
106         }
107
108         est1 = xt_rateest_lookup(info->name1);
109         if (!est1)
110                 goto err1;
111
112         if (info->flags & XT_RATEEST_MATCH_REL) {
113                 est2 = xt_rateest_lookup(info->name2);
114                 if (!est2)
115                         goto err2;
116         } else
117                 est2 = NULL;
118
119
120         info->est1 = est1;
121         info->est2 = est2;
122         return true;
123
124 err2:
125         xt_rateest_put(est1);
126 err1:
127         return false;
128 }
129
130 static void xt_rateest_mt_destroy(const struct xt_match *match,
131                                   void *matchinfo)
132 {
133         struct xt_rateest_match_info *info = matchinfo;
134
135         xt_rateest_put(info->est1);
136         if (info->est2)
137                 xt_rateest_put(info->est2);
138 }
139
140 static struct xt_match xt_rateest_match[] __read_mostly = {
141         {
142                 .family         = AF_INET,
143                 .name           = "rateest",
144                 .match          = xt_rateest_mt,
145                 .checkentry     = xt_rateest_mt_checkentry,
146                 .destroy        = xt_rateest_mt_destroy,
147                 .matchsize      = sizeof(struct xt_rateest_match_info),
148                 .me             = THIS_MODULE,
149         },
150         {
151                 .family         = AF_INET6,
152                 .name           = "rateest",
153                 .match          = xt_rateest_mt,
154                 .checkentry     = xt_rateest_mt_checkentry,
155                 .destroy        = xt_rateest_mt_destroy,
156                 .matchsize      = sizeof(struct xt_rateest_match_info),
157                 .me             = THIS_MODULE,
158         },
159 };
160
161 static int __init xt_rateest_mt_init(void)
162 {
163         return xt_register_matches(xt_rateest_match,
164                                    ARRAY_SIZE(xt_rateest_match));
165 }
166
167 static void __exit xt_rateest_mt_fini(void)
168 {
169         xt_unregister_matches(xt_rateest_match, ARRAY_SIZE(xt_rateest_match));
170 }
171
172 MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
173 MODULE_LICENSE("GPL");
174 MODULE_DESCRIPTION("xtables rate estimator match");
175 MODULE_ALIAS("ipt_rateest");
176 MODULE_ALIAS("ip6t_rateest");
177 module_init(xt_rateest_mt_init);
178 module_exit(xt_rateest_mt_fini);