[Twisted-Python] Handeling unresolved DNS queries?
jesper at taxboel.dk
Mon Oct 26 17:34:50 EDT 2009
First of all. Thanx for the help!!! The internet is just fantastic!!
I like the wrapper approach.
I had not thought of that approach myself. Sounds very reasonable. -So I
started wrapping Resolver, but got stuck pretty fast. I get a problem saying
'NoneType' object has no attribute 'addCallback'
"addCallback" seems to be implemented in defer.py, but im unsure on how to
handle that in the wrapper?
As a side question: In my old hack approach, which I have had almost
working, I have had problems constructing valid DNS answers. Wold you happen
to know what requirements there is to the returning package, to be accepted.
I made some attempts by using pickle to capture live packages, but have a
hard time tweaking other values than the address. Ideally I would like to
pass on a very short TTL, so the client would not be bothered by fake DNS
when I turn the system off.
As you might have guessed, Im building a gateway system for a small set of
apartments. Requirements are:
invalid domains should go to a shop
valid domains should be redirected to the shop if the client have not paid,
except if the query is for paypal.
2009/10/25 <exarkun at twistedmatrix.com>
> On 24 Oct, 08:04 pm, jesper at taxboel.dk wrote:
> >Im looking at the common.py and I feel a bit confused about how to wrap
> >Would'nt a subclass achieve the same thing. I would only need to
> >the changed functions in the subclass.
> >I guess my problem is that I dont exactly know how to write a wrapper
> There's nothing special to it. Just do the obvious thing:
> class SomeWrapper:
> def __init__(self, wrapee):
> self.wrapee = wrapee
> def someMethod(self, args):
> do something with self.wrapee.someMethod and args
> common.py will show you all the methods that a resolver is expected to
> have. Subclassing ResolverBase might help, though it's unfortunate that
> it works by demultiplexing everything to "_lookup", a private method
> that Twisted's compatibility policy doesn't guarantee will continue to
> operate as it presently does.
> Wrapping (ie "containment" or "has-a") is just an alternative
> implementation strategy to subclassing (ie "inheritance" or "is-a").
> Generally it's a better approach for various reasons, none of which are
> really specific to Twisted.
> Twisted-Python mailing list
> Twisted-Python at twistedmatrix.com
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the Twisted-Python