* Sam Johnston <samj@samj.net>
*/
#include <linux/skbuff.h>
+#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/netfilter/x_tables.h>
#include <linux/netfilter/xt_quota.h>
+struct xt_quota_priv {
+ uint64_t quota;
+};
+
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sam Johnston <samj@samj.net>");
+MODULE_DESCRIPTION("Xtables: countdown quota match");
+MODULE_ALIAS("ipt_quota");
+MODULE_ALIAS("ip6t_quota");
static DEFINE_SPINLOCK(quota_lock);
-static int
-match(const struct sk_buff *skb,
- const struct net_device *in, const struct net_device *out,
- const struct xt_match *match, const void *matchinfo,
- int offset, unsigned int protoff, int *hotdrop)
+static bool
+quota_mt(const struct sk_buff *skb, struct xt_action_param *par)
{
- struct xt_quota_info *q = ((struct xt_quota_info *)matchinfo)->master;
- int ret = q->flags & XT_QUOTA_INVERT ? 1 : 0;
+ struct xt_quota_info *q = (void *)par->matchinfo;
+ struct xt_quota_priv *priv = q->master;
+ bool ret = q->flags & XT_QUOTA_INVERT;
spin_lock_bh("a_lock);
- if (q->quota >= skb->len) {
- q->quota -= skb->len;
- ret ^= 1;
+ if (priv->quota >= skb->len) {
+ priv->quota -= skb->len;
+ ret = !ret;
} else {
- /* we do not allow even small packets from now on */
- q->quota = 0;
+ /* we do not allow even small packets from now on */
+ priv->quota = 0;
}
+ /* Copy quota back to matchinfo so that iptables can display it */
+ q->quota = priv->quota;
spin_unlock_bh("a_lock);
return ret;
}
-static int
-checkentry(const char *tablename, const void *entry,
- const struct xt_match *match, void *matchinfo,
- unsigned int matchsize, unsigned int hook_mask)
+static int quota_mt_check(const struct xt_mtchk_param *par)
{
- struct xt_quota_info *q = (struct xt_quota_info *)matchinfo;
+ struct xt_quota_info *q = par->matchinfo;
if (q->flags & ~XT_QUOTA_MASK)
- return 0;
- /* For SMP, we only want to use one set of counters. */
- q->master = q;
- return 1;
+ return -EINVAL;
+
+ q->master = kmalloc(sizeof(*q->master), GFP_KERNEL);
+ if (q->master == NULL)
+ return -ENOMEM;
+
+ q->master->quota = q->quota;
+ return 0;
}
-static struct xt_match quota_match = {
- .name = "quota",
- .family = AF_INET,
- .match = match,
- .matchsize = sizeof(struct xt_quota_info),
- .checkentry = checkentry,
- .me = THIS_MODULE
-};
+static void quota_mt_destroy(const struct xt_mtdtor_param *par)
+{
+ const struct xt_quota_info *q = par->matchinfo;
-static struct xt_match quota_match6 = {
- .name = "quota",
- .family = AF_INET6,
- .match = match,
- .matchsize = sizeof(struct xt_quota_info),
- .checkentry = checkentry,
- .me = THIS_MODULE
+ kfree(q->master);
+}
+
+static struct xt_match quota_mt_reg __read_mostly = {
+ .name = "quota",
+ .revision = 0,
+ .family = NFPROTO_UNSPEC,
+ .match = quota_mt,
+ .checkentry = quota_mt_check,
+ .destroy = quota_mt_destroy,
+ .matchsize = sizeof(struct xt_quota_info),
+ .me = THIS_MODULE,
};
-static int __init xt_quota_init(void)
+static int __init quota_mt_init(void)
{
- int ret;
-
- ret = xt_register_match("a_match);
- if (ret)
- goto err1;
- ret = xt_register_match("a_match6);
- if (ret)
- goto err2;
- return ret;
-
-err2:
- xt_unregister_match("a_match);
-err1:
- return ret;
+ return xt_register_match("a_mt_reg);
}
-static void __exit xt_quota_fini(void)
+static void __exit quota_mt_exit(void)
{
- xt_unregister_match("a_match6);
- xt_unregister_match("a_match);
+ xt_unregister_match("a_mt_reg);
}
-module_init(xt_quota_init);
-module_exit(xt_quota_fini);
+module_init(quota_mt_init);
+module_exit(quota_mt_exit);