. /usr/share/libubox/jshn.sh

handle_iface() {
  local val=$1  # unusable for non-scalar values
  local key=$2
  local protocol

  json_select "$key"
  json_get_vars protocol
  json_select ..

  echo "Proto of $key is $protocol"
}

json_load "$(cat /etc/board.json)"
json_for_each_item handle_iface network