--- a/example.conf	Thu Aug 13 18:17:26 2009 +0300
+++ b/example.conf	Thu Aug 13 18:55:55 2009 +0300
@@ -49,8 +49,11 @@
 # Full path to iptables binary
 IPTABLES = "/sbin/iptables"
   
-# IP(s) NOT to be blocked under any circumstances, separated by pipes (|).
-# You should set this if you wish to have a surefire open channel from
-# somewhere, even in case someone tries to spoof IPs for denial of service.
+# IP addresses that should NOT be blocked under any circumstances. You should
+# set this if you wish to have a surefire open channel from some host, even in
+# the case someone tries to spoof IPs for denial of service.
+#
 # NOTICE! This setting supports only IPv4 addresses, no IPv6 or DNS names.
-NOBLOCK_HOSTS = "127.0.0.1|74.125.45.100"
+# You can have any number of NOBLOCK_IPS settings.
+NOBLOCK_IPS = "127.0.0.1"
+NOBLOCK_IPS = "74.125.45.100"

--- a/maltfilter	Thu Aug 13 18:17:26 2009 +0300
+++ b/maltfilter	Thu Aug 13 18:55:55 2009 +0300
@@ -26,7 +26,6 @@
   "ACTION" => "DROP",
   "LOGFILE" => "/var/log/maltfilter",
   "IPTABLES" => "/sbin/iptables",
-  "NOBLOCK_HOSTS" => "127.0.0.1",
 
   "CHK_SSHD"            => 1,
   "CHK_KNOWN_CGI"       => 1,
@@ -43,11 +42,15 @@
   "/var/log/httpd/access.log"
 );
 
+my @noblock_ips_def = (
+  "127.0.0.1",
+);
 
 #############################################################################
 ### Script code
 #############################################################################
 my @scanfiles = ();
+my @noblock_ips = ();
 my %filehandles = ();
 my %hitcount = ();
 my %iplist = ();
@@ -127,17 +130,19 @@
   }
 }
 
-sub check_hosts($$)
+
+sub check_hosts_array(@$)
 {
-  my $host = $_[1];
-  my $ip = new Net::IP($host);
-  foreach my $test (split(/\s*\|\s*/, $_[0])) {
-    my $test_ip = new Net::IP($test);
-    if ($host eq $test) {
+  my @hostlist = shift;
+  my $chk_host = shift;
+  my $chk_ip = new Net::IP($chk_host);
+  foreach my $host (@hostlist) {
+    my $ip = new Net::IP($host);
+    if ($chk_host eq $host) {
       return 1;
     }
-    if (defined($ip) && defined($test_ip)) {
-      if ($ip->binip() eq $test_ip->binip()) {
+    if (defined($chk_ip) && defined($ip)) {
+      if ($chk_ip->binip() eq $ip->binip()) {
         return 1;
       }
     }
@@ -145,6 +150,12 @@
   return 0;
 }
 
+sub check_hosts($$)
+{
+  return check_hosts_array(split(/\s*\|\s*/, $_[0]), $_[1]);
+}
+
+
 ### Execute iptables
 sub exec_iptables(@)
 {
@@ -219,7 +230,7 @@
       return;
     }
     if (!defined($iplist{$mip})) {
-      if (!check_hosts($settings{"NOBLOCK_HOSTS"}, $mip)) {
+      if (!check_hosts_array(@noblock_ips, $mip)) {
         # Add entry that has >= treshold hits and is not added yet
         mlog(1, "* Adding $mip ($mdate): $mreason\n");
         exec_iptables("-I", "INPUT", "1", "-s", $mip, "-j", $settings{"ACTION"});
@@ -371,6 +382,8 @@
       my $value = $2;
       if ($key eq "SCANFILE") {
         push(@scanfiles_def, $value);
+      elsif ($key eq "NOBLOCK_IPS") {
+        push(@noblock_ips_def, $value);
       } elsif (defined($settings{$key})) {
         $settings{$key} = $value;
       } else {
@@ -386,10 +399,12 @@
   die("Errors in configuration file '$config_file', bailing out.\n") unless ($errors == 0);
 }
 
-# Clean up scanfiles from duplicate entries
+# Clean up certain arrays duplicate entries
 my %saw = ();
 @scanfiles = grep(!$saw{$_}++, @scanfiles_def);
 
+undef(%saw);
+@noblock_ips = grep(!$saw{$_}++, @noblock_ips_def);
 
 # Open logfile
 if ($settings{"DRY_RUN"}) {
@@ -403,6 +418,12 @@
   mlog(-1, "Log started\n");
 }
 
+# Test existence of iptables
+if (! -e $settings{"IPTABLES"} || ! -x $settings{"IPTABLES"}) {
+  my $msg = "iptables binary does not exist or is not executable: ".$settings{"IPTABLES"}."\n";
+  mlog(-1, $msg);
+  die($msg);
+}
 
 # Initialize
 update_iplist(-1);