From 8094fa46da2d35632617ca1498148f7ad7483748 Mon Sep 17 00:00:00 2001
From: Jo-Philipp Wich <jow@openwrt.org>
Date: Sun, 8 Jan 2012 15:29:24 +0000
Subject: [PATCH] firewall: add support for "local" port forwards which target
 an internal address on the router itself

SVN-Revision: 29687
---
 package/firewall/Makefile                   |  4 ++--
 package/firewall/files/lib/core_redirect.sh | 15 +++++++++++++--
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/package/firewall/Makefile b/package/firewall/Makefile
index 3c5e10fe9d..746cca4882 100644
--- a/package/firewall/Makefile
+++ b/package/firewall/Makefile
@@ -1,5 +1,5 @@
 #
-# Copyright (C) 2008-2011 OpenWrt.org
+# Copyright (C) 2008-2012 OpenWrt.org
 #
 # This is free software, licensed under the GNU General Public License v2.
 # See /LICENSE for more information.
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
 PKG_NAME:=firewall
 
 PKG_VERSION:=2
-PKG_RELEASE:=43
+PKG_RELEASE:=44
 
 include $(INCLUDE_DIR)/package.mk
 
diff --git a/package/firewall/files/lib/core_redirect.sh b/package/firewall/files/lib/core_redirect.sh
index a3e70d40d7..fe396c1c12 100644
--- a/package/firewall/files/lib/core_redirect.sh
+++ b/package/firewall/files/lib/core_redirect.sh
@@ -34,7 +34,17 @@ fw_load_redirect() {
 			return 0
 		}
 
-		fwdchain="zone_${redirect_src}${redirect_dest_ip:+_forward}"
+		fwdopt=""
+		fwdchain=""
+
+		# Check whether only ports are given or whether the given dest ip is local,
+		# in this case match only DNATed traffic and allow it on input, not forward
+		if [ -z "$redirect_dest_ip" ] || /sbin/ifconfig | grep -qE "addr:${redirect_dest_ip//./\\.}\b"; then
+			fwdopt="-m conntrack --ctstate DNAT"
+			fwdchain="zone_${redirect_src}"
+		else
+			fwdchain="zone_${redirect_src}_forward"
+		fi
 
 		natopt="--to-destination"
 		natchain="zone_${redirect_src}_prerouting"
@@ -106,10 +116,11 @@ fw_load_redirect() {
 
 			fw add $mode f ${fwdchain:-forward} ACCEPT + \
 				{ $redirect_src_ip $redirect_dest_ip } { \
-				$srcaddr ${destaddr:--m conntrack --ctstate DNAT} \
+				$srcaddr $destaddr \
 				$pr \
 				$srcports $destports \
 				${sm:+-m mac $sm} \
+				$fwdopt \
 				$redirect_extra \
 			}
 		done