[rbldnsd] AAAA Queries?

[Victor Duchovni]

On Fri, Jul 28, 2006 at 09:25:35PM +0400, Michael Tokarev wrote:

> > True for getaddrinfo(), but RBL lookups are not usually made from the
> > C-library getaddrinfo() routine. Rather RBL aware software makes
> > explicit DNS "T_A" lookups. If somebody writes broken RBL lookup
> > software that uses getaddrinfo() they need to be sent off for
> > "re-education"...
> 
> Well.  This stuff isn't this simple.
> It's trivial to write
> 
>   if (getaddrinfo(sprintf(..., ipaddr, dnsbl))) {
>      ...
>   }

Yes, but it is wrong...

> but it's *far* more complex to write a DNS client, even
> this simple one (I know because I did ;)

Yes, but this is the only correct way to do it...

> So "re-education" isn't quite a right word here.

I strongly disagree, because seemingly correct simple code, is worse
than no code.

> More, that getaddrinfo() version works, works right away (yes,
> it's still not complete, because we don't have TXT records).

Incomplete code does not "work"... And of course does not get
one the TXT records.

> Ditto for perl code for the same task.

Actually, Net::DNS is quite usable.

> gethostbyname() is
> here in standard install, but DNS-related things are huge
> slow monsters with difficult-to-use interface.

DNS is not "slow", it is always faster than getaddrinfo() making via
the nsswitch unnecessary local lookups in /etc/hosts and perhaps NIS
(shudder), first checking the "search ..." domains, and finally calling
DNS anyway. Yes code that is a DNS client requires some skill, not every
programming problem is for newbies....

RBL clients MUST NOT use getaddrinfo().

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