Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / net / netfilter / xt_quota.c

diff --git a/kernel/net/netfilter/xt_quota.c b/kernel/net/netfilter/xt_quota.c
new file mode 100644 (file)
index 0000000..44c8eb4
--- /dev/null
+++ b/kernel/net/netfilter/xt_quota.c
@@ -0,0 +1,90 @@
+/*
+ * netfilter module to enforce network quotas
+ *
+ * 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>
+#include <linux/module.h>
+
+struct xt_quota_priv {
+       spinlock_t      lock;
+       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 bool
+quota_mt(const struct sk_buff *skb, struct xt_action_param *par)
+{
+       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(&priv->lock);
+       if (priv->quota >= skb->len) {
+               priv->quota -= skb->len;
+               ret = !ret;
+       } else {
+               /* we do not allow even small packets from now on */
+               priv->quota = 0;
+       }
+       spin_unlock_bh(&priv->lock);
+
+       return ret;
+}
+
+static int quota_mt_check(const struct xt_mtchk_param *par)
+{
+       struct xt_quota_info *q = par->matchinfo;
+
+       if (q->flags & ~XT_QUOTA_MASK)
+               return -EINVAL;
+
+       q->master = kmalloc(sizeof(*q->master), GFP_KERNEL);
+       if (q->master == NULL)
+               return -ENOMEM;
+
+       spin_lock_init(&q->master->lock);
+       q->master->quota = q->quota;
+       return 0;
+}
+
+static void quota_mt_destroy(const struct xt_mtdtor_param *par)
+{
+       const struct xt_quota_info *q = par->matchinfo;
+
+       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 quota_mt_init(void)
+{
+       return xt_register_match(&quota_mt_reg);
+}
+
+static void __exit quota_mt_exit(void)
+{
+       xt_unregister_match(&quota_mt_reg);
+}
+
+module_init(quota_mt_init);
+module_exit(quota_mt_exit);