feat: add ethernet & TCP/IP stack

scripts/net-teardown.sh

@@ -0,0 +1,38 @@
+#!/bin/bash
+# Tears down the bridge + TAP setup and restores the physical interface.
+# Requires root.
+
+set -e
+
+BRIDGE=br0
+TAP=tap0
+PHYS=enp0s31f6
+
+if ! ip link show "$TAP" &>/dev/null; then
+    echo "TAP $TAP doesn't exist, nothing to tear down."
+    exit 0
+fi
+
+echo "Tearing down network bridge..."
+
+# Grab IP config from bridge before removing
+ADDR=$(ip -4 addr show dev "$BRIDGE" 2>/dev/null | grep -oP 'inet \K[\d.]+/\d+')
+GW=$(ip route show default dev "$BRIDGE" 2>/dev/null | grep -oP 'via \K[\d.]+' | head -1)
+
+# Remove TAP
+ip link set "$TAP" down 2>/dev/null || true
+ip link delete "$TAP" 2>/dev/null || true
+
+# Remove physical interface from bridge and restore its config
+ip link set "$PHYS" nomaster 2>/dev/null || true
+ip link delete "$BRIDGE" type bridge 2>/dev/null || true
+
+# Restore IP config to physical interface
+if [ -n "$ADDR" ]; then
+    ip addr add "$ADDR" dev "$PHYS" 2>/dev/null || true
+fi
+if [ -n "$GW" ]; then
+    ip route add default via "$GW" dev "$PHYS" 2>/dev/null || true
+fi
+
+echo "Network bridge torn down, $PHYS restored."