feat: Add iptables configuration script for free5GC UPF

- Add shell script to configure UPF (User Plane Function) iptables rules
- Flush existing filter, nat, and mangle tables
- Configure NAT masquerading on eth0 interface
- Set up forwarding rules for uesimtun0 tunnel interface
- Enable bidirectional traffic flow between UE tunnel and external network

deployments/free5gc/upf-iptables.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+iptables -t filter -F
+iptables -t nat -F
+iptables -t mangle -F
+
+iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
+
+iptables -A FORWARD -i uesimtun0 -o eth0 -j ACCEPT
+iptables -A FORWARD -i eth0 -o uesimtun0 -m state --state RELATED,ESTABLISHED -j ACCEPT
+
+echo "UPF iptables rules configured"