#! /usr/bin/perl
use Errno qw(EAGAIN);
use IO::Socket::UNIX;
use Carp;
use Net::IP::Route::Reject;

my $target_user ="dhudes";
my $ipv4octetregex = "([0-1]??(1,2)|2[0-4]|25[0-5])";
my $ipv4regex = "/^".$ipv4octetregex."\.".$ipv4octetregex."\.".$ipv4octetregex."\.".$ipv4octetregex."\$/o";
study $ipv4regex;
my $fifo = "/tmp/BlackList";
if (-e $fifo) {
  die "socket file present and I can't delete it" if((unlink $fifo) !=1);
}
my $message;
my @parts;

my $listen = IO::Socket::UNIX->new(Local=>$fifo, Listen=>0) || die "$!"; #per io_unix.t of IO::Socket::UNIX
my $rv = chown((getpwnam($target_user))[2,3],$fifo); #adapted from p691 of _Programming Perl_,3rd ed.
print "socket set blocking, was ".$listen->blocking(1);	#1 is TRUE
#my $oldtimeout = $listen->timeout(3600);
#print "\ntimeout set, was ".(defined $oldtimeout? $oldtimeout: "undefined\n");
my @ipaddr;
my $sock;
while (1) {
  $sock = $listen->accept();
  if (defined $sock) {
    $message= $sock->getline;
    if (!defined $message) {
      my $time=scalar localtime;
      print  "$time: socket problem $! no message\n";
      next;
    }
    @parts= split " ",$message;
    @ipaddr = grep $ipv4regex, $parts[1]; #strip out anything that doesn't belong in an ip addres
    if ($parts[0] eq 'B') {
      Net::IP::Route::Reject->add( $ipaddr[0]);
    } else {
      Net::IP::Route::Reject->del( $ipaddr[0]) if ($parts[0] eq 'U');
    }
  }
}