1 files changed, 70 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/ip_nat_tftp.c b/net/ipv4/netfilter/ip_nat_tftp.c
new file mode 100644
index 00000000000..0343e0d6467
--- /dev/null
+++ b/net/ipv4/netfilter/ip_nat_tftp.c
@@ -0,0 +1,70 @@
+/* (C) 2001-2002 Magnus Boden <mb@ozaba.mine.nu>
+ *
+ * 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.
+ *
+ * Version: 0.0.7
+ *
+ * Thu 21 Mar 2002 Harald Welte <laforge@gnumonks.org>
+ * 	- Port to newnat API
+ *
+ * This module currently supports DNAT:
+ * iptables -t nat -A PREROUTING -d x.x.x.x -j DNAT --to-dest x.x.x.y
+ *
+ * and SNAT:
+ * iptables -t nat -A POSTROUTING { -j MASQUERADE , -j SNAT --to-source x.x.x.x }
+ *
+ * It has not been tested with
+ * -j SNAT --to-source x.x.x.x-x.x.x.y since I only have one external ip
+ * If you do test this please let me know if it works or not.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/netfilter_ipv4.h>
+#include <linux/ip.h>
+#include <linux/udp.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv4/ip_tables.h>
+#include <linux/netfilter_ipv4/ip_conntrack_helper.h>
+#include <linux/netfilter_ipv4/ip_conntrack_tftp.h>
+#include <linux/netfilter_ipv4/ip_nat_helper.h>
+#include <linux/netfilter_ipv4/ip_nat_rule.h>
+#include <linux/moduleparam.h>
+
+MODULE_AUTHOR("Magnus Boden <mb@ozaba.mine.nu>");
+MODULE_DESCRIPTION("tftp NAT helper");
+MODULE_LICENSE("GPL");
+
+static unsigned int help(struct sk_buff **pskb,
+			 enum ip_conntrack_info ctinfo,
+			 struct ip_conntrack_expect *exp)
+{
+	exp->saved_proto.udp.port = exp->tuple.dst.u.tcp.port;
+	exp->dir = IP_CT_DIR_REPLY;
+	exp->expectfn = ip_nat_follow_master;
+	if (ip_conntrack_expect_related(exp) != 0) {
+		ip_conntrack_expect_free(exp);
+		return NF_DROP;
+	}
+	return NF_ACCEPT;
+}
+
+static void __exit fini(void)
+{
+	ip_nat_tftp_hook = NULL;
+	/* Make sure noone calls it, meanwhile. */
+	synchronize_net();
+}
+
+static int __init init(void)
+{
+	BUG_ON(ip_nat_tftp_hook);
+	ip_nat_tftp_hook = help;
+	return 0;
+}
+
+module_init(init);
+module_exit(fini);