1 files changed, 74 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ipt_state.c b/net/ipv4/netfilter/ipt_state.c
new file mode 100644
index 00000000000..b1511b97ea5
--- /dev/null
+++ b/net/ipv4/netfilter/ipt_state.c
@@ -0,0 +1,74 @@
+/* Kernel module to match connection tracking information. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter_ipv4/ip_conntrack.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ipt_state.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
+MODULE_DESCRIPTION("iptables connection tracking state match module");
+
+static int
+match(const struct sk_buff *skb,
+      const struct net_device *in,
+      const struct net_device *out,
+      const void *matchinfo,
+      int offset,
+      int *hotdrop)
+{
+	const struct ipt_state_info *sinfo = matchinfo;
+	enum ip_conntrack_info ctinfo;
+	unsigned int statebit;
+
+	if (skb->nfct == &ip_conntrack_untracked.ct_general)
+		statebit = IPT_STATE_UNTRACKED;
+	else if (!ip_conntrack_get(skb, &ctinfo))
+		statebit = IPT_STATE_INVALID;
+	else
+		statebit = IPT_STATE_BIT(ctinfo);
+
+	return (sinfo->statemask & statebit);
+}
+
+static int check(const char *tablename,
+		 const struct ipt_ip *ip,
+		 void *matchinfo,
+		 unsigned int matchsize,
+		 unsigned int hook_mask)
+{
+	if (matchsize != IPT_ALIGN(sizeof(struct ipt_state_info)))
+		return 0;
+
+	return 1;
+}
+
+static struct ipt_match state_match = {
+	.name		= "state",
+	.match		= &match,
+	.checkentry	= &check,
+	.me		= THIS_MODULE,
+};
+
+static int __init init(void)
+{
+	need_ip_conntrack();
+	return ipt_register_match(&state_match);
+}
+
+static void __exit fini(void)
+{
+	ipt_unregister_match(&state_match);
+}
+
+module_init(init);
+module_exit(fini);