On Mon, Jan 27, 2014 at 03:55:06PM +0000, Viktor Dukhovni wrote:
> Postfix supports fallback to "native" address resolution (essentially
> getaddrinfo() and such) when DNS lookups return "notfound". It is
> essential to not that this fallback does not and did not happen on
-----
> lookup failure, it only takes place when DNS indicates the answer
> does not exist. Results from "native" resolution are always marked
> not validated.
Please ignore the underlined stray "to not" text...
I should also mention that fallback to "native" address resolution
of SMTP client destinations is optional and off by default. The
SMTP server on the other hand does not use explicit DNS lookups
when determining the IP->name mappings of connecting SMTP clients,
those lookups are always "native".
Another thing I forgot to mention is that each element of the DNS_RR
linked list carries within it two DNS domain names separate from any
associated type-dependent RDATA.
* qname The query domain requested by the caller.
* rname The full CNAME expansion of qname (== qname when not an alias).
You'll need those (call them whatever you wish) later. You won't
need any intermediate names encountered during CNAME expansion,
those can be thrown away before the answer linked list is constructed.
--
Viktor.
