> new ext_header_len. As a second step, I do my modifications in ip6_xmit/
> A general interface for this work would be ugly, but at least there would
> be an interface ;-)
> Any comments?
Comment is that it is right direction.
Only it is not so straightforward. Such adjustments violate existing
locking hierarchy, so that you have to design thing, which does not exist
now. Namely, message queue for relaible feedback from lower layers
to upper ones. It is for mobile IPv6.
And it still will not work with IPsec, because you cannot send anything
not-encrypted, while the information trips back to sender. So, direct
surgery inside TCP is required in any case.
Reserving space is much simpler and seems not to hurt anyone.
Surgeons wait, while terapeutics helps. 8)