[PATCH] Disable AF_UNIX handshake with setsockopt(..., SO_PEERCRED, ...)

[Christian Franke]

Corinna Vinschen wrote:
> I was just looking into applying your patch when I got thinking over the
> change in select.cc once more.  You're setting the connect_state from
> connect_pending to connected there when there's something to read on the
> socket.
>
> This puzzles me.  A completed connection attempt should set the
> write_selected flag (see function peek_socket).

No, peek_socket() does not change write_selected. It sets write_read if 
write_selected is set.


>    The AF_LOCAL handling
> in the
>
>    if (me->write_selected && me->write_ready)
>
> case in set_bits should cover this.  What situation is your special case
> covering which is not already covered by the write_selected case?

If only read status is requested via select()/poll(), write_selected is 
always false and the connect_pending=>connected transition is never done.

After a nonblocking connect(), postfix calls poll() with pollfd.events = 
POLLIN only. If poll() succeeds, it calls recv(). This fails with 
ENOTCONN because the state is still connect_pending.

Christian