openssh unix dev - Jun 2021 - [PATCH] Add an option for RFC5014 IPv6 source address preference

Another month, another ping.

I would love to see this upstream, so my long-term connections stop
breaking after a week.

-- 
Anton Khirnov

Hey,

this topic is indeed interesting.

I've read up on the bugreport: The patch does not seem to include the
preference flags to getaddinfo(3) as discussed here
https://bugzilla.redhat.com/show_bug.cgi?id=512032#c8. Is this
intentional?

https://biplane.com.au/blog/?p=30 lists the first three options to
globally control the ipv6 source address preference on linux. Technique
four and five can be used per socket (and by extension per process):

- Technique One: Deprecate the addresses you don't want selected
  via ip addr change $ip dev $dev preferred_lft 0
- Technique Two: Modify the label table
  via ip addrlabel
- Technique Three: Prefer privacy addresses
  via sysctl /proc/sys/net/ipv6/conf/$dev/use_tempaddr
- Technique Four: setsockopt(2) (may be set per socket)
- Technique Five: bind(2) (may be set per socket)

Is this assessment correct or did I miss some options?

BR

Maximilian Eschenbacher

Anton Khirnov:
> Another month, another ping.
> 
> I would love to see this upstream, so my long-term connections stop
> breaking after a week.
Well, OpenSSH is developed on OpenBSD and then portability goo is
added for the -portable version.

OpenBSD simply does not have such an address selection API, and I'm
skeptical that adding a whole feature falls into the purview of
-portable.

-- 
Christian "naddy" Weisgerber                          naddy at
mips.inka.de