On Fri, 2016-08-19 at 23:41 +0300, Cristian Morales Vega wrote: > I would like a socket option that let's me share a source port as long > as the 4-tuples are unique in a UDP socket *and* specify which source > port that is. > It would be similar to IP_BIND_ADDRESS_NO_PORT. It would do exactly > the same when you bind to port 0, but when you bind to a different > port it would say "don't do anything with this port yet, but when I > connect() please use the port as source port instead of a random > ephemeral port". > > The reason is the following. I would like to have a server receiving > and sending UDP datagrams from multiple clients using a single port. I > would like to use multiple sockets for sending, so I can use different > SO_MAX_PACING_RATEs for each one. One socket per client/session. > So there is a single "main socket" bind to the relevant port > (equivalent to the one that accept()s in TCP), and when it receives a > new session request it creates a new socket specific for that season > (as accept() does). When creating that new socket I first need to > bind() it to select the port, and then connect() it to make it receive > only datagrams from the relevant session. > The problem is that between the bind() and the connect() there is a > small time in which the new socket can receive data that should go to > the "main socket". It's not an unsolvable problem but makes the server > code more complicated than it needs to be.
Yes, this is something I had on my plate for a while. This is indeed something we can solve easily.
