Solved

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

Posted on 2008-10-01
2
695 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
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
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: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying 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

I've just discovered very important differences between Windows an Unix formats in Perl,at least 5.xx.. MOST IMPORTANT: Use Unix file format while saving Your script. otherwise it will have ^M s or smth likely weird in the EOL, Then DO NOT use m…
In the distant past (last year) I hacked together a little toy that would allow a couple of Manager types to query, preview, and extract data from a number of MongoDB instances, to their tool of choice: Excel (http://dilbert.com/strips/comic/2007-08…
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…

740 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