Re: potential ncat bug

[David Fifield <david () bamsoftware com>]

On Wed, Apr 28, 2010 at 08:18:45PM -0400, Ryan Giobbi wrote:
> In ncat is --keep-open supported with udp?
>
> I tried the below command but had to use the second to get the expected results.
>
> sudo ncat -l 8080 < foo.html -u -k
> while true; do sudo ncat -l 8080 < foo.html -u; done

No, --keep-open doesn't work with UDP. The reason for this is that UDP
doesn't know who is "connected," so it defaults to sending to and
receiving from the first client to send it data.

In this case there's a good solution though; use
        sudo ncat -l -u --sh-exec "cat foo.html"

This solves a problem with your first command that would even be a
problem in TCP mode. Since Ncat is reading from stdin, it can only send
the file once. Even if another client connects later, there's no more
input for Ncat to read or send. So you have to use a loop like you did,
or use --sh-exec which will start a new handler for each client.

David Fifield
_______________________________________________
Sent through the nmap-dev mailing list
http://cgi.insecure.org/mailman/listinfo/nmap-dev
Archived at http://seclists.org/nmap-dev/