PoCo::Client::Keepalive and dotted quads

J.G.Konrad <[email protected]> Mon, 28 Jul 2008 17:13:17 -0700

Newsgroups	gmane.comp.lang.perl.poe
Message-ID	<[email protected]>

I have a need to override DNS lookup and to for a request to go to a
specific IP address.  I decided to try and create a HTTP::Request object
with a dotted quad and to manually specify the host in headers.
example:

--snip--

  my $request =
    HTTP::Request->new(GET => 'http://10.1.0.1' );
  $request->header('host' => 'vhost.behindfirewall.com');

  $kernel->post( 'ua', 'request', 'response', $request );

--snip--


This did not work. I kept getting DNS resolve errors

<html>
<HEAD><TITLE>Error: Internal Server Error</TITLE></HEAD>
<BODY>
<H1>Error: Internal Server Error</H1>
Cannot connect to 10.1.0.1:80 (resolve error ??: Host has no address.)
</BODY>
</HTML>


After some fun playing with the perl debugger I got down to a section of the
PoCo::Client::Keepalive code that I think is not correct with how it handles
dotted quads. In _ka_resolve_request() there is this code


  # Skip DNS resolution if it's already a dotted quad.
  # TODO - Not all dotted quads are good.
  if ($host !~ /^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$/) {
    DEBUG_DNS and warn "DNS: $host is a dotted quad; skipping lookup";
    $kernel->call("$self", ka_add_to_queue => $request);
    return;
  }

The comments say that if it is a dotted quad then skip resolution but that
is not happening.  I think the conditional needs to be inverted. Change the
'!~' into a '=~'.

After I made the change in my copy of PoCo::Client::Keepalive the dotted
quad worked as expected.