> For 3.3, it may be relevant that send/recvmsg are now available via 
> the socket API (see #6560)

I think sendfds/recvfds helper methods could be added to the socket type, so that programmers don't have to get the incantations right by themselves (note the plural, because passing several fds at once is more generic :-)).

That said, +1 on committing Petri's patch. Will do it in a hour or two if noone is faster.