Comment 3 for bug 306955

There is a slight risk that some invalid data is floating into the application (see http://www.unixguide.net/network/socketfaq/4.5.shtml), but I don't know how common it is. I don't consider this anymore a security measure at all anymore as those daemons actively try to get rid of it and they have to agree upon it being deactivated. And it really slows down restarting on busy machines if you still have lots of connections up.

Actually this is only possible directly at the net6 level if we want to prevent an API change here, at least if you're dealing with a IPv6 socket and bindv6only set to 0 (so it is actually in use to listen on both IPv4 and IPv6). I wonder if get_socket should return the IPv6 socket in this case, but it looks very unclean to me somehow to have access only to one of the two sockets through get_socket.

Armin, do you have any objection to just set that for every server socket in net6?