Wireshark · Wireshark-users: Re: [Wireshark-users] ipv6 unknown extension header

[Martin d Anjou <point14@xxxxxxxx>]

> > Is wireshark able to "jump" over the unknwon extension header (using 
> > the Hdr Ext Len) and keep searching for next headers and eventually 
> > find L4 protocols like TCP?
>
> No - is anything *else* able to do so?
>
> [explanation deleted]
>
> This doesn't seem to suggest that skipping over unknown headers is
> necessarily the right thing to do.

I agree with your conclusion. An "unknown" ipv6 extension header could be 
a new layer 4 protocol, or a new ipv6 extension header whose second byte 
is not the Hdr Ext Len, which makes "jumping over it" the wrong thing to 
do.

And like you, I don't see any "correct" thing to do with unknown ipv6 
extension header, so it does not seem like Sake Blok's "fix" is the right 
thing to do either:

> I committed a patch in SVN 26722 that fixes this issue...

Sorry Sake... Although I can probably use your commit to patch my local 
copy for the time being, so thanks a lot for that!

Now, any advice for me? Write a dissector for my "unknown" extension 
header therefore making it a known one? I am just trying to put out an 
extension header whose length I can control easily, but the content does 
not matter.

Thanks,
Martin