#!/bin/sh

ETHTOOL_PATH=$(command -v ethtool)

if [ -z "$ETHTOOL_PATH" ]; then
    echo "Error: ethtool command not found. Please install ethtool."
    exit 1
fi

NETDEV=$(ip route show default | awk '{for (i=1; i<=NF; i++) {if ($i == "dev") {print $(i+1); exit;}}}')

if [ -z "$NETDEV" ]; then
    echo "Error: Could not determine default network device using 'ip route show default'."
    exit 1
fi

echo "Configuring network device $NETDEV using $ETHTOOL_PATH for Tailscale optimizations..."

"$ETHTOOL_PATH" -K "$NETDEV" rx-udp-gro-forwarding on rx-gro-list off

if [ "$?" -eq 0 ]; then
    echo "Configuration successful for $NETDEV."
    exit 0
else
    echo "Error: ethtool configuration failed. Check permissions or device status."
    exit 1
fi