(usagi-users 03631) Re: IPv6 multicast socket specific binding bug

[Stig Venaas <stig.venaas@xxxxxxxxxx>]

hoerdt@xxxxxxxxxxxxxxxxxxxxx wrote:
[...]
> So, the key issue here is what is the default filter present on a socket
> after being created. If I follow you correctly, the current 
> implementation, to be compatible with previous IGMP/MLD interface 
> service and applications assume EXCLUDE{} for all groups showing 
> up on the socket, but it is not possible to setup the opposite 
> filter and the socket (INCLUDE{} for all groups), why ? 

RFC 3678 doesn't suggest a way to do this for all groups. Maybe you
could do it for a specific group, but I don't really think it says what
should happen with 0 sources. It seems reasonable that 0 sources means
no include filter.

> According to RFC3678, I could use the full state API to setup
> the socket filter to INADDR_ANY as a group argument, an empty
> source list, and INCLUDE mode isn't it ?

I don't think 3678 says what should happen in that case. Maybe it could
be thought of as blocking all, but the RFC says no such thing AFAICS.

It would be nice if source filtering also got into POSIX (defined by
Austin group) with maybe some stricter defintions. I don't remember
seeing source filtering in there at all,

Stig

> Thanks,
>
> Mickael