#!/bin/bash
source "$(dirname "${BASH_SOURCE[0]}")"/ncsid_lib.sh

DetermineRouterMac() {
  # Attempt to find the neighbor once, in case our configuration is already
  # valid. Errors are silenced to make the logs more clear. The next call
  # will print any real errors.
  if DetermineNeighbor4 "$interface" "$router" 2>/dev/null; then
    return 0
  fi

  # arping might not have a valid source address, so we need to assign
  # the given address so arping has a source to write into the request
  # packet. We don't want a persistent configuration yet so we modify
  # the kernel directly.
  if ! ip -4 addr flush dev "$interface"; then
    echo "Failed to flush $interface" >&2
    return 1
  fi
  if ! ip addr add "$ip/$mask" dev "$interface"; then
    echo "Failed to assign $ip/$mask to $interface" >&2
    # Don't return, because we need to reset networkd
  fi

  local rc=0
  DetermineNeighbor4 "$interface" "$router" || rc=$?

  # We need to ensure that our old network configuration gets
  # restored, in case our early flushing breaks things.
  systemctl restart systemd-networkd || return $?
  return $rc
}

HandleDHCP4() {
  local op="$1"

  if [ "$op" = "bound" ]; then
    echo "INTF: $interface" >&2
    echo "IP: $ip/$mask" >&2
    echo "GW: $router" >&2

    local router_mac
    if ! router_mac="$(DetermineRouterMac "$interface" "$router")"; then
      echo "Failed to acquire gateway mac for $router" >&2
      return 1
    fi
    echo "GW_MAC: $router_mac" >&2

    SuppressTerm
    local service='xyz.openbmc_project.Network'
    local rc=0
    UpdateIP "$service" "$interface" "$ip" "$mask" && \
      UpdateGateway "$service" "$router" && \
      UpdateNeighbor "$service" "$interface" "$router" "$router_mac" || \
      rc=$?
    UnsuppressTerm
    touch /run/dhcp4.done
    return $rc
  fi
}

Main() {
  set -o nounset
  set -o errexit
  set -o pipefail

  InitTerm
  HandleDHCP4 "$@"
}

return 0 2>/dev/null
Main "$@"