Fix iptables filtering rules when externalTrafficPolicy is Local (#54)

* destination port needs to be DEST_PORT because after PREROUTING rule
* redundant exclusion rule

Signed-off-by: motoki317 <motoki317@gmail.com>

entry

@@ -41,22 +41,22 @@ set_legacy() {
 start_proxy() {
     for src_range in ${SRC_RANGES}; do
     if echo ${src_range} | grep -Eq ":"; then
-        ip6tables -t filter -I FORWARD -s ${src_range} -p ${DEST_PROTO} --dport ${SRC_PORT} -j ACCEPT
+        ip6tables -t filter -I FORWARD -s ${src_range} -p ${DEST_PROTO} --dport ${DEST_PORT} -j ACCEPT
     else
-        iptables -t filter -I FORWARD -s ${src_range} -p ${DEST_PROTO} --dport ${SRC_PORT} -j ACCEPT
+        iptables -t filter -I FORWARD -s ${src_range} -p ${DEST_PROTO} --dport ${DEST_PORT} -j ACCEPT
     fi
     done
 
     for dest_ip in ${DEST_IPS}; do
         if echo ${dest_ip} | grep -Eq ":"; then
             [ $(cat /proc/sys/net/ipv6/conf/all/forwarding) == 1 ] || exit 1
             ip6tables -t filter -A FORWARD -d ${dest_ip}/128 -p ${DEST_PROTO} --dport ${DEST_PORT} -j DROP
-            ip6tables -t nat -I PREROUTING ! -s ${dest_ip}/128 -p ${DEST_PROTO} --dport ${SRC_PORT} -j DNAT --to [${dest_ip}]:${DEST_PORT}
+            ip6tables -t nat -I PREROUTING -p ${DEST_PROTO} --dport ${SRC_PORT} -j DNAT --to [${dest_ip}]:${DEST_PORT}
             ip6tables -t nat -I POSTROUTING -d ${dest_ip}/128 -p ${DEST_PROTO} -j MASQUERADE
         else
             [ $(cat /proc/sys/net/ipv4/ip_forward) == 1 ] || exit 1
             iptables -t filter -A FORWARD -d ${dest_ip}/32 -p ${DEST_PROTO} --dport ${DEST_PORT} -j DROP
-            iptables -t nat -I PREROUTING ! -s ${dest_ip}/32 -p ${DEST_PROTO} --dport ${SRC_PORT} -j DNAT --to ${dest_ip}:${DEST_PORT}
+            iptables -t nat -I PREROUTING -p ${DEST_PROTO} --dport ${SRC_PORT} -j DNAT --to ${dest_ip}:${DEST_PORT}
             iptables -t nat -I POSTROUTING -d ${dest_ip}/32 -p ${DEST_PROTO} -j MASQUERADE
         fi
     done