add network interface specifications to iptables rules

diff --git a/hook_monitor_pid b/hook_monitor_pid
index 435251d..da958c9 100755 (executable)
--- a/hook_monitor_pid
+++ b/hook_monitor_pid
@@ -70,9 +70,9 @@ sudo iptables -t filter -F OUTPUT > /dev/null 2>&1
 # add iptables rule
 sudo iptables -t filter -N udp_out
 sudo iptables -t filter -N udp_in
-sudo iptables -t filter -A OUTPUT -p udp -j udp_out
+sudo iptables -t filter -A OUTPUT -p udp -o eth0 -j udp_out
 sudo iptables -t filter -A udp_out -j ACCEPT
-sudo iptables -t filter -A OUTPUT -p udp -j udp_in
+sudo iptables -t filter -A OUTPUT -p udp -i eth0 -j udp_in
 sudo iptables -t filter -A udp_in -j ACCEPT
 
 timer_callback &