#!/bin/execlineb -P
# SPDX-License-Identifier: EUPL-1.2+
# SPDX-FileCopyrightText: 2020-2022, 2025 Alyssa Ross <hi@alyssa.is>

background {
  importas -Si INTERFACE

  # Our IP is encoded in the NIC-specific portion of the interface's MAC
  # address.
  backtick -E LOCAL_IP {
    awk -PF: "
      BEGIN { ex = 1 }
      $1 == \"02\" && $2 == \"00\" {
        printf \"100.64.%d.%d\\n\", \"0x\" $5, \"0x\" $6
        ex = 0
      }
      END { exit ex }
    " /sys/class/net/${INTERFACE}/address
  }

  if { ip address add ${LOCAL_IP}/32 dev $INTERFACE }
  if { ip link set $INTERFACE up }
  if { ip route add 169.254.0.1 dev $INTERFACE }
  ip route add default via 169.254.0.1 dev $INTERFACE
}