On Sun, 29 Jul 2001, Brad Chapman wrote:
> I am currently completing a port of the Netfilter connection
> tracking subsystem from IPv4 to IPv6. Most of the features in this
> port are complete, except for fragment handling, which is non-
> existent. I am also not entirely sure about how to properly parse
> header chains and extract various extension and layer-4 headers
> for use by the connection tracking subsystem. Enclosed with this
> message are my current efforts regarding IPv6 fragmentation and
> IPv6 header chain parsing.
>
> I would appreciate any feedback at all regarding this.
A comment: it appears some code from IPv4 is not applicable; ip6_refrag
etc. look a little dubious, for example, as IPv6 fragmentation is always
end-to-end with fragmentation header (or just avoiding it with PMTU), and
no (de)fragmentation should happen in the routers. If you haven't
already, I recomment checking out RFC2460 chapters 4.5 and 5.
Hope this helps, I'll leave it to the others to comment on header chaining
issues. (This may be complex as the extension headers' order is not
fixed; if macros or functions do not exist for handling these, perhaps
they should be created.)
--
Pekka Savola "Tell me of difficulties surmounted,
Netcore Oy not those you stumble over and fall"
Systems. Networks. Security. -- Robert Jordan: A Crown of Swords
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