Programming Jabber

Handling version requests

Now that we’ve seen the iq_register() function, the function to handle jabber:iq:version queries looks pretty straightforward:

sub iq_version {

  my $node = shift;
  debug("[iq_version]");

  return unless my $query = $node->getTag('', NS_VERSION)
            and $node->attr('type', IQ_GET);

  debug("--> version request");

  $node = toFrom($node);
  $node->attr('code', IQ_RESULT);
  $query->insertTag('name')->data($NAME);
  $query->insertTag('version')->data($VERSION);
  $query->insertTag('os')->data(`uname -sr`);
  $c->send($node);

  return r_HANDLED;
}

Just as we check for whether the element is appropriate to handle in iq_register(), we do here, too, this time looking for an IQ-get with a query child tag qualified by the NS_VERSION (jabber:iq:version) namespace, which we grab in $query.

Setting the <iq/>’s type to result and flipping the addresses, we then just have to add <name/>, <version/>, and <os/> tags to the query child with appropriate values, to end up with a response like the one shown in Example 9-16.

If we do this, we deem the IQ to have been handled and return the special r_HANDLED value, as before, to stop the dispatching going any further for this element.