CIDRChecker.scala

import java.net.InetAddress

object CIDRChecker {
  def isInRange(cidrs: Array[String], address: String): Boolean = {
    cidrs.exists { cidr =>
      if (!cidr.contains("/")) {
        InetAddress.getByName(cidr).getHostAddress == InetAddress.getByName(address).getHostAddress
      } else {
        val Array(cidrAddress, cidrMask) = cidr.split("/")
        val cidrInt = InetAddress.getByName(cidrAddress).getAddress.zipWithIndex.map { case (b, i) => (b & 0xff) << (8 * (3 - i)) }.sum
        val mask = ~((1 << (32 - cidrMask.toInt)) - 1)
        val addressInt = InetAddress.getByName(address).getAddress.zipWithIndex.map { case (b, i) => (b & 0xff) << (8 * (3 - i)) }.sum

        (addressInt & mask) == cidrInt
      }
    }
  }
}