spam-champru.lisp

(require :sb-bsd-sockets)
(require :cl-ppcre)

(defpackage :dnsbl 
  (:use :cl)
  (:export :spam-champuru-p))

(in-package :dnsbl)

(defconstant +champuru-server+ "dnsbl.spam-champuru.livedoor.com")
(defconstant +black+ #(127 0 0 2))

(defun spam-champuru-p (address)
  (equalp +black+
          (handler-case (sb-bsd-sockets:host-ent-address 
                         (sb-bsd-sockets:get-host-by-name
                          (format nil "~{~A.~}~A"
                                  (nreverse (ppcre:split "\\." address))
                                  +champuru-server+)))
            (sb-bsd-sockets:host-not-found-error () nil))))

#|
 (spam-champuru-p "192.0.2.1") ;=> T
 (spam-champuru-p "yahoo.com") ;=> nil
 (spam-champuru-p "127.0.0.1") ;=> nil
|#