Patrick McHardy | 62b7743 | 2006-05-29 18:20:32 -0700 | [diff] [blame] | 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>"); |
Patrick McHardy | b22b900 | 2006-09-19 13:00:57 -0700 | [diff] [blame] | 14 | MODULE_ALIAS("ipt_quota"); |
| 15 | MODULE_ALIAS("ip6t_quota"); |
Patrick McHardy | 62b7743 | 2006-05-29 18:20:32 -0700 | [diff] [blame] | 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, |
Patrick McHardy | efa7416 | 2006-08-22 00:36:37 -0700 | [diff] [blame] | 44 | unsigned int hook_mask) |
Patrick McHardy | 62b7743 | 2006-05-29 18:20:32 -0700 | [diff] [blame] | 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 | |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 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 | }, |
Patrick McHardy | 62b7743 | 2006-05-29 18:20:32 -0700 | [diff] [blame] | 72 | }; |
| 73 | |
| 74 | static int __init xt_quota_init(void) |
| 75 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 76 | return xt_register_matches(xt_quota_match, ARRAY_SIZE(xt_quota_match)); |
Patrick McHardy | 62b7743 | 2006-05-29 18:20:32 -0700 | [diff] [blame] | 77 | } |
| 78 | |
| 79 | static void __exit xt_quota_fini(void) |
| 80 | { |
Patrick McHardy | 4470bbc | 2006-08-22 00:34:04 -0700 | [diff] [blame] | 81 | xt_unregister_matches(xt_quota_match, ARRAY_SIZE(xt_quota_match)); |
Patrick McHardy | 62b7743 | 2006-05-29 18:20:32 -0700 | [diff] [blame] | 82 | } |
| 83 | |
| 84 | module_init(xt_quota_init); |
| 85 | module_exit(xt_quota_fini); |