Re: [UPDATE] zerocopy.. While working on ip.h stuff

[David S. Miller]

Michael Peddemors writes:
 > A few things.. why is ip.h not part of the linux/include/net rather than 
 > linux/include/linux hierachy?

Exported to older userlands...

 > Defined items that are not used anywhere in the source..
 > Can any of them be deleted now?
 > <see below>

So what, userland makes use of them :-)

 > Also, I was looking into some RFC 1812 stuff. (Thanks for nothing Dave :) and 
 > was looking at 4.2.2.6 where it mentions that a router MUST implement the End 
 > of Option List option..  Havent' figured out where that is implememented yet..

egrep "IPOPT_END" net/ipv4/ip_options.c

You just aren't looking hard enough.

 > Also was trying to figure out some things. 
 > I want to create a new ip_option for use in some DOS protection experiments.
 > I have a whole 40 bytes (+/-) to share...  Now although I don't see anything 
 > explicitly prohibiting the use of unused IP Header option space, I know that 
 > it really was designed for use by the sending parties, and not routers in 
 > between.. Has anyone seen any RFC that explicitly says I MUST NOT?

Not to my knowledge.  Routers already change the time to live field,
so I see no reason why they can't do smart things with special IP
options either (besides efficiency concerns :-).

Later,
David S. Miller
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