Re: [dccp] Re: DCCP and draft-ietf-v6ops-v6onbydefault-01.txt

[Eddie Kohler <kohler@cs.ucla.edu>]

Long cc: list... :(

> As a status update, the TCP part has been put in a separate draft -- 
> draft-gont-tcpm-tcp-soft-errors-00.txt.  What is the status wrt. the 
> modification you propose in DCCP?

The DCCP specs do not talk about network layer interactions like ICMP.  That is 
probably a new draft we'll eventually have to work on.

> It would indeed be possible to provide an API for the application to
> act on the soft error information.  However, I think the application
> still cannot ignore the SYN-SENT/SYN-RECEIVED state issues due to
> security reasons (otherwise anyone could start aborting the ongoing
> connections for those who use the API).
>
> In other words, it would be possible to provide an API (e.g., a socket 
> option that could be set) which would abort the connection if it 
> receives a soft error in SYN-SENT/RECEIVED states.

This is trivial at the application level: simply turn off the "soft errors are 
hard" API once connect() has completed.  I think embedding SYN-SENT/RECEIVED 
knowledge in any kernel/user API is a bad idea.

> Another alternative is to make the change by default, but provide the
> identical API (e.g., a socket option) which would prevent the address
> cycling -- 

This assumes that all address cycling will happen below the application, which 
is doubtful.

Eddie