#!/bin/bash
# Copyright 2021 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

[[ -n ${gbmc_br_ula_lib-} ]] && return

# shellcheck source=meta-google/recipes-google/networking/network-sh/lib.sh
source /usr/share/network/lib.sh || exit

gbmc_br_ula_init=
gbmc_br_ula_mac=

gbmc_br_ula_update() {
  [[ -n $gbmc_br_ula_init ]] || return

  echo "gBMC Bridge ULA MAC: ${gbmc_br_ula_mac:-(deleted)}" >&2

  local addr=
  contents='[Network]'$'\n'
  if [[ -n $gbmc_br_ula_mac ]]; then
    local sfx
    if sfx="$(mac_to_eui64 "$gbmc_br_ula_mac")" &&
       addr="$(ip_pfx_concat "fdb5:0481:10ce::/64" "$sfx")"; then
      contents+="Address=$addr"$'\n'
    fi
  fi

  local netfile
  for netfile in /run/systemd/network/{00,}-bmc-gbmcbr.network.d/60-ula.conf; do
    mkdir -p "$(dirname "$netfile")"
    printf '%s' "$contents" >"$netfile"
  done

  # Ensure that systemd-networkd performs a reconfiguration as it doesn't
  # currently check the mtime of drop-in files.
  touch -c /lib/systemd/network/*-bmc-gbmcbr.network

  if [[ $(systemctl is-active systemd-networkd) != inactive ]]; then
    networkctl reload
    networkctl reconfigure gbmcbr
  fi
}

gbmc_br_ula_hook() {
  # shellcheck disable=SC2154
  if [[ $change == init ]]; then
    gbmc_br_ula_init=1
    gbmc_br_ula_update
  elif [[ $change == link && $intf == gbmcbr ]]; then
    if [[ $action == add && $mac != "$gbmc_br_ula_mac" ]]; then
      gbmc_br_ula_mac="$mac"
      gbmc_br_ula_update
    fi
    if [[ $action == del && $mac == "$gbmc_br_ula_mac" ]]; then
      gbmc_br_ula_mac=
      gbmc_br_ula_update
    fi
  fi
}

GBMC_IP_MONITOR_HOOKS+=(gbmc_br_ula_hook)

gbmc_br_ula_lib=1