Solved

Perl - Problem writing script to get status of open ports.

Posted on 2008-10-01
2
693 Views
Last Modified: 2013-11-05
Hi,
Some background - I do a lot of vulnerability scanning, and as part of the remediation, when the server admins which reports they have closed, I usually have to manually 'telnet <ip_address> <port>' to see if the port has been closed. Most of these are prod servers, so I cannot just rescan them, but would need to go through a much longer process.

To get around this, I am trying to write a perl script that will do this for me. Basically, I read in the address and port info from an Excel report, and then have tried various methods to try to duplicate the manual telnet process to determine if a port is open or not.

I have tried Net::Telnet, IO::Socket::INET, and a few others that are basically versions of these. I have found that neither produce consistent results, which most often means it's a "me" problem. If someone could point out how I could make this work, or propose an alternate method, I would greatly appreciate it.

I have included a couple snippets to show what I have been trying.

Thanks,
Jeff
.....
use Net::Telnet();
...........
...........
foreach (@hosts)
{
    my $host = $_;
    $telnet = new Net::Telnet();
    $telnet->open(Host => $host,
                  Port => $port);
    $telnet->errmode('return');
    if (($telnet->errmsg eq "") || ( "$telnet->errmsg\n" =~ /^Net::Telnet=GLOB\(0x([0-9a-fA-F]+)\)->errmsg$/ ))
    {
        printf "%s: %s\n", $host, ${\$telnet->errmsg};       #"open";
    }
    else
    {
        printf "%s: %s\n", $host, ${\$telnet->errmsg};
    }
    $telnet->close;
}
***********************************************************************
 
************************************************************************
....
use IO::Socket::INET;
......
.....
            foreach (@hosts)
            {
              my $host = $_;
              $socket = new IO::Socket::INET (
                                              PeerAddr => $host,
                                              PeerPort => $port
                                              );
              if ($socket)
              {
                printf ("%s:%s -- %s\n", $host, $port, "open");
              }
              else
              {
                 printf ("%s:%s -- %s\n", $host, $port, "closed");               
              }
              if ($socket)
              {
                close($socket);
              }
            }

Open in new window

0
Comment
Question by:jpetter
2 Comments
 
LVL 39

Accepted Solution

by:
Adam314 earned 500 total points
ID: 22617042
I think for this (just testing if a port is open), the IO::Socket::INET module is probably what you want, not the Net::Telnet module.

What is wrong with the code you are using?  It should work just fine.  You might want to also use the Timeout option.  Also, if you care about the protocol, should specify the Proto option, otherwise IO::Socket::INET will make a guess based on the port.  
0
 

Author Comment

by:jpetter
ID: 22617426
Adam314,

Thanks again for the speedy response. I've added the proto and timeout options, and it seems to be working as expected now....and using the IO::Socket::INET as you recommended.

Thanks,
Jeff
0

Featured Post

Free Tool: ZipGrep

ZipGrep is a utility that can list and search zip (.war, .ear, .jar, etc) archives for text patterns, without the need to extract the archive's contents.

One of a set of tools we're offering as a way to say thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Many time we need to work with multiple files all together. If its windows system then we can use some GUI based editor to accomplish our task. But what if you are on putty or have only CLI(Command Line Interface) as an option to  edit your files. I…
There are many situations when we need to display the data in sorted order. For example: Student details by name or by rank or by total marks etc. If you are working on data driven based projects then you will use sorting techniques very frequently.…
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…

839 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question