sub netsearch() {
    my($ip, $host_list) = @_;
    my(@list) = split(/\s*:\s*/, $host_list);
    my(@ip_packed) = split(/\./, $ip);
    while (@ip_packed < 4) {
	@ip_packed = (@ip_packed, '0');
    }
    my($ip1_packed) = ($ip_packed[$[] << 24) +
		    ($ip_packed[$[+1] << 16) +
		    ($ip_packed[$[+2] << 8) +
		    $ip_packed[$[+3];

    my(%nets);
    my($line, $result, $found, $ip_net);
    foreach $line (@list) {
        unless ($line =~ /^\s*[#\r\n]/) {
            my($net, $tmp2, $tmp3, $mask, $value) = ($line =~
    	        /^\s*(\d{0,3}(\.\d{0,3}){0,3})(\s*\/\s*(\d+))?\s*:?\s*(.*)?\s*$/);
	    my(@ip_packed) = split(/\./, $net);
	    while (@ip_packed < 4) {
	        @ip_packed = (@ip_packed, '0');
	    }
	    my($ip2_packed) = ($ip_packed[$[] << 24) +
				    ($ip_packed[$[+1] << 16) +
				    ($ip_packed[$[+2] << 8) +
				    $ip_packed[$[+3];
	    chomp($value);
	    $mask = 32 unless ($mask);
	    my $packed_mask = (0xffffffff << (32-$mask)) & 0xffffffff;
	    my $ip_net1 = $ip1_packed & $packed_mask;
	    my $ip_net2 = $ip2_packed & $packed_mask;

	    if ($ip_net1 eq $ip_net2) {
    	        $result = ($value ? $value : 'found');
	        $found = 1;
	    }
	}
    }
    return($result) if ($found);
    return('');
}