1 files changed, 79 insertions, 0 deletions
diff --git a/net/netfilter/xt_state.c b/net/netfilter/xt_state.c
new file mode 100644
index 00000000..a507922d
--- /dev/null
+++ b/net/netfilter/xt_state.c
@@ -0,0 +1,79 @@
+/* Kernel module to match connection tracking information. */
+
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2005 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 <net/netfilter/nf_conntrack.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_state.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>");
+MODULE_DESCRIPTION("ip[6]_tables connection tracking state match module");
+MODULE_ALIAS("ipt_state");
+MODULE_ALIAS("ip6t_state");
+
+static bool
+state_mt(const struct sk_buff *skb, struct xt_action_param *par)
+{
+	const struct xt_state_info *sinfo = par->matchinfo;
+	enum ip_conntrack_info ctinfo;
+	unsigned int statebit;
+	struct nf_conn *ct = nf_ct_get(skb, &ctinfo);
+
+	if (!ct)
+		statebit = XT_STATE_INVALID;
+	else {
+		if (nf_ct_is_untracked(ct))
+			statebit = XT_STATE_UNTRACKED;
+		else
+			statebit = XT_STATE_BIT(ctinfo);
+	}
+	return (sinfo->statemask & statebit);
+}
+
+static int state_mt_check(const struct xt_mtchk_param *par)
+{
+	int ret;
+
+	ret = nf_ct_l3proto_try_module_get(par->family);
+	if (ret < 0)
+		pr_info("cannot load conntrack support for proto=%u\n",
+			par->family);
+	return ret;
+}
+
+static void state_mt_destroy(const struct xt_mtdtor_param *par)
+{
+	nf_ct_l3proto_module_put(par->family);
+}
+
+static struct xt_match state_mt_reg __read_mostly = {
+	.name       = "state",
+	.family     = NFPROTO_UNSPEC,
+	.checkentry = state_mt_check,
+	.match      = state_mt,
+	.destroy    = state_mt_destroy,
+	.matchsize  = sizeof(struct xt_state_info),
+	.me         = THIS_MODULE,
+};
+
+static int __init state_mt_init(void)
+{
+	return xt_register_match(&state_mt_reg);
+}
+
+static void __exit state_mt_exit(void)
+{
+	xt_unregister_match(&state_mt_reg);
+}
+
+module_init(state_mt_init);
+module_exit(state_mt_exit);