On 01/06 08:56, Ted Unangst wrote: > On Thu, Jan 6, 2011 at 7:19 PM, Jeremy Evans <jer...@openbsd.org> wrote: > > I believe that for unix stream sockets, you don't need to have a sending > > socket file created, while you do for datagram sockets, as otherwise you > > can't have a bidirectional connection. > > > > I have no problem with always using a random sending socket file, and > > ignoring -p in the unix datagram case, if you think that is best. > > Thinking more about it, -s would be more appropriate than -p anyway if > > you did want to specify the source socket. > > The part that's confusing me is, who is at the other end of this tmp > socket? How do they know about it?
With a stream socket where you are acting as a client, you don't need a temporary socket created, because a stream socket is bidirectional. If you send a datagram to a server listening on a unix datagram socket, there is no way for the server program to respond to you unless the sending program is also bound to a socket. So with this patch, if you are operating nc in client mode and sending a datagram to a unix datagram socket, nc binds a temporary unix datagram socket so that you can receive responses. guenther@ agreed back in 2008 that it was necessary to create a temporary socket if you want bidirectional communication, see http://marc.info/?l=openbsd-tech&m=120299257422367&w=2. He also mentioned that it might be beneficial to implement two modes, one providing bidirectional and one providing unidirectional, but I have not implemented that (yet). Jeremy
