Merge branch 'master' into upstream
[linux-2.6] / net / netfilter / xt_quota.c
1 /*
2  * netfilter module to enforce network quotas
3  *
4  * Sam Johnston <samj@samj.net>
5  */
6 #include <linux/skbuff.h>
7 #include <linux/spinlock.h>
8
9 #include <linux/netfilter/x_tables.h>
10 #include <linux/netfilter/xt_quota.h>
11
12 MODULE_LICENSE("GPL");
13 MODULE_AUTHOR("Sam Johnston <samj@samj.net>");
14 MODULE_ALIAS("ipt_quota");
15 MODULE_ALIAS("ip6t_quota");
16
17 static DEFINE_SPINLOCK(quota_lock);
18
19 static int
20 match(const struct sk_buff *skb,
21       const struct net_device *in, const struct net_device *out,
22       const struct xt_match *match, const void *matchinfo,
23       int offset, unsigned int protoff, int *hotdrop)
24 {
25         struct xt_quota_info *q = ((struct xt_quota_info *)matchinfo)->master;
26         int ret = q->flags & XT_QUOTA_INVERT ? 1 : 0;
27
28         spin_lock_bh(&quota_lock);
29         if (q->quota >= skb->len) {
30                 q->quota -= skb->len;
31                 ret ^= 1;
32         } else {
33                 /* we do not allow even small packets from now on */
34                 q->quota = 0;
35         }
36         spin_unlock_bh(&quota_lock);
37
38         return ret;
39 }
40
41 static int
42 checkentry(const char *tablename, const void *entry,
43            const struct xt_match *match, void *matchinfo,
44            unsigned int matchsize, unsigned int hook_mask)
45 {
46         struct xt_quota_info *q = (struct xt_quota_info *)matchinfo;
47
48         if (q->flags & ~XT_QUOTA_MASK)
49                 return 0;
50         /* For SMP, we only want to use one set of counters. */
51         q->master = q;
52         return 1;
53 }
54
55 static struct xt_match quota_match = {
56         .name           = "quota",
57         .family         = AF_INET,
58         .match          = match,
59         .matchsize      = sizeof(struct xt_quota_info),
60         .checkentry     = checkentry,
61         .me             = THIS_MODULE
62 };
63
64 static struct xt_match quota_match6 = {
65         .name           = "quota",
66         .family         = AF_INET6,
67         .match          = match,
68         .matchsize      = sizeof(struct xt_quota_info),
69         .checkentry     = checkentry,
70         .me             = THIS_MODULE
71 };
72
73 static int __init xt_quota_init(void)
74 {
75         int ret;
76
77         ret = xt_register_match(&quota_match);
78         if (ret)
79                 goto err1;
80         ret = xt_register_match(&quota_match6);
81         if (ret)
82                 goto err2;
83         return ret;
84
85 err2:
86         xt_unregister_match(&quota_match);
87 err1:
88         return ret;
89 }
90
91 static void __exit xt_quota_fini(void)
92 {
93         xt_unregister_match(&quota_match6);
94         xt_unregister_match(&quota_match);
95 }
96
97 module_init(xt_quota_init);
98 module_exit(xt_quota_fini);