Re: [DNSOP] Clarification question: compression pointers always to names earlier in the packet?

Tony Finch <dot@dotat.at> Wed, 24 October 2018 15:46 UTC

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Date: Wed, 24 Oct 2018 16:46:37 +0100
From: Tony Finch <dot@dotat.at>
To: Ray Bellis <ray@bellis.me.uk>
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Subject: Re: [DNSOP] Clarification question: compression pointers always to names earlier in the packet?
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Ray Bellis <ray@bellis.me.uk> wrote:
> On 24/10/2018 11:45, Tony Finch wrote:
> >
> > * Keep a high-water-mark separate from the current location, and require
> >   pointers to be strictly less than the HWM. (I prefer this way.)
>
> Right, but to be safe the HWM should be initialised with the position of
> the _start_ of the label sequence that's being parsed.
>
> Any time you follow a pointer you reset the HWM to the target of that
> pointer (which per the rule above must be lower than the current value).

Exactly, yes :-)

Tony.
-- 
f.anthony.n.finch  <dot@dotat.at>  http://dotat.at/
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