blob: 10d61a6eed712442c14cc1011341c2dff5890c2d [file] [log] [blame]
Patrick McHardy62b77432006-05-29 18:20:32 -07001/*
2 * netfilter module to enforce network quotas
3 *
4 * Sam Johnston <samj@samj.net>
5 */
6#include <linux/skbuff.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +09007#include <linux/slab.h>
Patrick McHardy62b77432006-05-29 18:20:32 -07008#include <linux/spinlock.h>
9
10#include <linux/netfilter/x_tables.h>
11#include <linux/netfilter/xt_quota.h>
Paul Gortmaker3a9a2312011-05-27 09:12:25 -040012#include <linux/module.h>
Patrick McHardy62b77432006-05-29 18:20:32 -070013
Jan Engelhardtacc738f2009-03-16 15:35:29 +010014struct xt_quota_priv {
Changli Gaob0c81aa2010-07-23 14:04:03 +020015 spinlock_t lock;
16 uint64_t quota;
Jan Engelhardtacc738f2009-03-16 15:35:29 +010017};
18
Patrick McHardy62b77432006-05-29 18:20:32 -070019MODULE_LICENSE("GPL");
20MODULE_AUTHOR("Sam Johnston <samj@samj.net>");
Jan Engelhardt2ae15b62008-01-14 23:42:28 -080021MODULE_DESCRIPTION("Xtables: countdown quota match");
Patrick McHardyb22b9002006-09-19 13:00:57 -070022MODULE_ALIAS("ipt_quota");
23MODULE_ALIAS("ip6t_quota");
Patrick McHardy62b77432006-05-29 18:20:32 -070024
Jan Engelhardt1d93a9c2007-07-07 22:15:35 -070025static bool
Jan Engelhardt62fc8052009-07-07 20:42:08 +020026quota_mt(const struct sk_buff *skb, struct xt_action_param *par)
Patrick McHardy62b77432006-05-29 18:20:32 -070027{
Jan Engelhardtacc738f2009-03-16 15:35:29 +010028 struct xt_quota_info *q = (void *)par->matchinfo;
29 struct xt_quota_priv *priv = q->master;
Jan Engelhardt1d93a9c2007-07-07 22:15:35 -070030 bool ret = q->flags & XT_QUOTA_INVERT;
Patrick McHardy62b77432006-05-29 18:20:32 -070031
Changli Gaob0c81aa2010-07-23 14:04:03 +020032 spin_lock_bh(&priv->lock);
Jan Engelhardtacc738f2009-03-16 15:35:29 +010033 if (priv->quota >= skb->len) {
34 priv->quota -= skb->len;
Jan Engelhardt1d93a9c2007-07-07 22:15:35 -070035 ret = !ret;
Patrick McHardy62b77432006-05-29 18:20:32 -070036 } else {
YOSHIFUJI Hideaki601e68e2007-02-12 11:15:49 -080037 /* we do not allow even small packets from now on */
Jan Engelhardtacc738f2009-03-16 15:35:29 +010038 priv->quota = 0;
Patrick McHardy62b77432006-05-29 18:20:32 -070039 }
Changli Gaob0c81aa2010-07-23 14:04:03 +020040 spin_unlock_bh(&priv->lock);
Patrick McHardy62b77432006-05-29 18:20:32 -070041
42 return ret;
43}
44
Jan Engelhardtb0f38452010-03-19 17:16:42 +010045static int quota_mt_check(const struct xt_mtchk_param *par)
Patrick McHardy62b77432006-05-29 18:20:32 -070046{
Jan Engelhardt9b4fce72008-10-08 11:35:18 +020047 struct xt_quota_info *q = par->matchinfo;
Patrick McHardy62b77432006-05-29 18:20:32 -070048
49 if (q->flags & ~XT_QUOTA_MASK)
Jan Engelhardtbd414ee2010-03-23 16:35:56 +010050 return -EINVAL;
Jan Engelhardtacc738f2009-03-16 15:35:29 +010051
52 q->master = kmalloc(sizeof(*q->master), GFP_KERNEL);
53 if (q->master == NULL)
Jan Engelhardt4a5a5c72010-03-19 17:32:59 +010054 return -ENOMEM;
Jan Engelhardtacc738f2009-03-16 15:35:29 +010055
Changli Gaob0c81aa2010-07-23 14:04:03 +020056 spin_lock_init(&q->master->lock);
Jan Engelhardt6d621822009-06-22 14:16:45 +020057 q->master->quota = q->quota;
Jan Engelhardtbd414ee2010-03-23 16:35:56 +010058 return 0;
Patrick McHardy62b77432006-05-29 18:20:32 -070059}
60
Jan Engelhardtacc738f2009-03-16 15:35:29 +010061static void quota_mt_destroy(const struct xt_mtdtor_param *par)
62{
63 const struct xt_quota_info *q = par->matchinfo;
64
65 kfree(q->master);
66}
67
Jan Engelhardt55b69e92008-10-08 11:35:01 +020068static struct xt_match quota_mt_reg __read_mostly = {
69 .name = "quota",
70 .revision = 0,
71 .family = NFPROTO_UNSPEC,
72 .match = quota_mt,
73 .checkentry = quota_mt_check,
Jan Engelhardtacc738f2009-03-16 15:35:29 +010074 .destroy = quota_mt_destroy,
Jan Engelhardt55b69e92008-10-08 11:35:01 +020075 .matchsize = sizeof(struct xt_quota_info),
Willem de Bruijnec231892017-01-02 17:19:46 -050076 .usersize = offsetof(struct xt_quota_info, master),
Jan Engelhardt55b69e92008-10-08 11:35:01 +020077 .me = THIS_MODULE,
Patrick McHardy62b77432006-05-29 18:20:32 -070078};
79
Jan Engelhardtd3c5ee62007-12-04 23:24:03 -080080static int __init quota_mt_init(void)
Patrick McHardy62b77432006-05-29 18:20:32 -070081{
Jan Engelhardt55b69e92008-10-08 11:35:01 +020082 return xt_register_match(&quota_mt_reg);
Patrick McHardy62b77432006-05-29 18:20:32 -070083}
84
Jan Engelhardtd3c5ee62007-12-04 23:24:03 -080085static void __exit quota_mt_exit(void)
Patrick McHardy62b77432006-05-29 18:20:32 -070086{
Jan Engelhardt55b69e92008-10-08 11:35:01 +020087 xt_unregister_match(&quota_mt_reg);
Patrick McHardy62b77432006-05-29 18:20:32 -070088}
89
Jan Engelhardtd3c5ee62007-12-04 23:24:03 -080090module_init(quota_mt_init);
91module_exit(quota_mt_exit);