[NUT-devel] huge vs. damaged forward_ptrs in packets

[Michael Niedermayer]

Hi

On Wed, Mar 08, 2006 at 08:01:45PM -0500, Rich Felker wrote:
> On Thu, Mar 09, 2006 at 01:40:45AM +0100, Michael Niedermayer wrote:
> > > Also, can we have a field in the header instead of arbitrary 64k? I'm
> > > fine with a requirement that it MUST be <= 64k. Some users may want
> > > more intense checksum.. Also some muxers with very small output buffer
> > > may want to use a smaller checksum block..
> > 
> > iam somewhat against this, at least for the main header its not possible
> > so it would mean 2 different rules depending on header type
> 
> Well, mainheader is important enough that it might always be good to
> have a checksum on the first N bytes of it..
> 
> > OTOH ill immedeatly agree to a smaller threshold, 16kb or so maybe?
> 
> Yeah, or even smaller. The majority of file contents will be frames,
> not packets, anyway so IMO overhead doesn't really matter here. What
> if all packets (regardless of size) have such a checksum, but it only
> covers the 'critical' fields (i.e. forward_ptr, etc.)? The only
> possible problem I see is that syncpoints would be a special case or
> have nasty overhead.. Maybe it's a bad idea tho.

hmm maybe we can find a solution without a special case, though i
wouldnt mind putting the checksum always on every header ...

what about a checksum after every 4kb of a packet?
it would even allow to recover part of a large damaged packet
or combine the undamaged blocks of 2 damaged packets
not that i think that would be important in practice ...

[...]
-- 
Michael