On Apr 2, 2009, at 9:22 PM, Scott McMurray wrote:
I'm writing an application that makes use of the source port in the UDP header. The only way I've found that sets it is by setting the endpoint on construction of the udp::socket. The problem with that, however, is that I have 3 different components that want to use that port, one listening and two sending. Understandably, I cannot bind the same port for all three. (Incidentally, while binding with the udp::socket constructor works, the bind call gives a bad file descriptor exception. I'm using 1.35, though, so that may have been fixed.)
Is there some way to set the source port without binding? Since there's no session state, it seems like I should be able to send packets from any number of sockets. (I can't just share a socket, as they're not shared-objects thread-safe, according to the documentation.)
I think your only option here is to multiplex all over a single socket because your describing a UDP transponder/multiplexor if I am reading correctly and that is how they operate at the application level. Another problem here is that if you place a NAT between these hosts then the UDP src port will be mapped(by NAT device) to a sequenced port, thus the other end will see the wrong port. STUN takes care of this last part to get the reflexive/srv addr for you to insert into headers using an XOR. If this is a LAN protocol then you can forget the last part. -s7
Thanks, ~ Scott McMurray _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users