diff -aurN pukiwiki-1.4.6_rc/lib/auth.php.orig pukiwiki-1.4.6_rc/lib/auth.php
--- pukiwiki-1.4.6_rc/lib/auth.php.orig	2005-06-13 23:02:07.000000000 +0900
+++ pukiwiki-1.4.6_rc/lib/auth.php	2005-10-05 20:06:47.000000000 +0900
@@ -116,6 +116,24 @@
 	return $hash;
 }
 
+// { check for blacklist
+// http://xoopscube.jp/modules/newbb/viewtopic.php?topic_id=10694&forum=14
+function is_blacklisted($dnsbl_target) {
+   $dnsbl_check=array("list.dsbl.org",
+                      "niku.2ch.net");
+   if ($dnsbl_target) {
+       $quads=explode(".",$dnsbl_target);
+       $rip=$quads[3].".".$quads[2].".".$quads[1].".".$quads[0];
+       for ($i=0; $i<count($dnsbl_check); $i++) {
+           if (checkdnsrr($rip.".".$dnsbl_check[$i] . '.',"A")) {
+               $listed.=$dnsbl_check[$i]." ";
+           }
+	   }
+       if ($listed) { return $listed; } else { return FALSE; }
+   }
+}
+// check for blacklist }
+
 
 // Basic-auth related ----
 
@@ -124,6 +142,21 @@
 {
 	global $script, $_title_cannotedit, $_msg_unfreeze;
 
+	// { check for blacklist
+	$blacklisted = "Your host is blacklisted.";
+	if (is_blacklisted($_SERVER['REMOTE_ADDR'])) {
+		// With exit
+		$body = $title = str_replace('$1',
+			htmlspecialchars(strip_bracket($page)), $_title_cannotedit);
+		if (is_freeze($page))
+			$body .= '(<a href="' . $script . '?cmd=unfreeze&amp;page=' .
+				rawurlencode($page) . '">' . $_msg_unfreeze . '</a>)';
+		$page = str_replace('$1', make_search($page), $blacklisted);
+		catbody($title, $page, $body);
+		exit;
+	}
+	// check for blacklist }
+
 	if (edit_auth($page, $auth_flag, $exit_flag) && is_editable($page)) {
 		// Editable
 		return TRUE;