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Commit | Line | Data |
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62b77434 PM |
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>"); | |
b22b9004 PM |
14 | MODULE_ALIAS("ipt_quota"); |
15 | MODULE_ALIAS("ip6t_quota"); | |
62b77434 PM |
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("a_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("a_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, | |
efa74165 | 44 | unsigned int hook_mask) |
62b77434 PM |
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 | ||
4470bbc7 PM |
55 | static struct xt_match xt_quota_match[] = { |
56 | { | |
57 | .name = "quota", | |
58 | .family = AF_INET, | |
59 | .checkentry = checkentry, | |
60 | .match = match, | |
61 | .matchsize = sizeof(struct xt_quota_info), | |
62 | .me = THIS_MODULE | |
63 | }, | |
64 | { | |
65 | .name = "quota", | |
66 | .family = AF_INET6, | |
67 | .checkentry = checkentry, | |
68 | .match = match, | |
69 | .matchsize = sizeof(struct xt_quota_info), | |
70 | .me = THIS_MODULE | |
71 | }, | |
62b77434 PM |
72 | }; |
73 | ||
74 | static int __init xt_quota_init(void) | |
75 | { | |
4470bbc7 | 76 | return xt_register_matches(xt_quota_match, ARRAY_SIZE(xt_quota_match)); |
62b77434 PM |
77 | } |
78 | ||
79 | static void __exit xt_quota_fini(void) | |
80 | { | |
4470bbc7 | 81 | xt_unregister_matches(xt_quota_match, ARRAY_SIZE(xt_quota_match)); |
62b77434 PM |
82 | } |
83 | ||
84 | module_init(xt_quota_init); | |
85 | module_exit(xt_quota_fini); |