feat(netns): add netns

setup-netns.sh

@@ -0,0 +1,45 @@
+#!/bin/bash
+
+# Exit on error
+set -e
+
+NETNS_NAME="sdns"
+VETH_HOST="veth0"
+VETH_NS="veth1"
+HOST_IP="192.168.100.1"
+NS_IP="192.168.100.2"
+SUBNET="192.168.100.0/24"
+PHYSICAL_IF="en0"
+
+echo "Creating network namespace: $NETNS_NAME"
+sudo ip netns add $NETNS_NAME
+
+echo "Creating veth pair: $VETH_HOST <-> $VETH_NS"
+sudo ip link add $VETH_HOST type veth peer name $VETH_NS
+
+echo "Moving $VETH_NS into namespace"
+sudo ip link set $VETH_NS netns $NETNS_NAME
+
+echo "Configuring host side ($VETH_HOST)"
+sudo ip addr add $HOST_IP/24 dev $VETH_HOST
+sudo ip link set $VETH_HOST up
+
+echo "Configuring namespace side ($VETH_NS)"
+sudo ip netns exec $NETNS_NAME ip addr add $NS_IP/24 dev $VETH_NS
+sudo ip netns exec $NETNS_NAME ip link set $VETH_NS up
+sudo ip netns exec $NETNS_NAME ip link set lo up
+sudo ip netns exec $NETNS_NAME ip route add default via $HOST_IP
+
+echo "Enabling IP forwarding"
+sudo sysctl -w net.ipv4.ip_forward=1
+
+echo "Setting up NAT"
+sudo iptables -t nat -A POSTROUTING -s $SUBNET -o $PHYSICAL_IF -j MASQUERADE
+
+echo "Done! Network namespace '$NETNS_NAME' is ready."
+echo ""
+echo "To run your app in the namespace:"
+echo "  sudo ip netns exec $NETNS_NAME ./your_app"
+echo ""
+echo "To capture traffic:"
+echo "  sudo tshark -i $VETH_HOST -w app.pcap"