man(1) Manual page archive

     CON(4)                                                     CON(4)

          con, tcp, udp - Network connection boxes


          Boxes under /b/proto represent network connection end-points
          implemented by the proto protocol. Even datagram based ser-
          vices are represented by connection end-point boxes. The
          prefix /b/con is used to import different network protocols
          under the same set of names.

          Applications can use make(2) to create new end-points. A
          make under /b/tcp creates a TCP end-point; the same happens
          under /b/udp for UDP end-points. Applications that do not
          care of the particular protocol used are expected to make
          new end-points under /b/con.  In what follows, all names
          refer to boxes under these prefixes.

          Plan B connection boxes are intended to be used under a
          client-server model.  A client is an application that cre-
          ates an end-point to send data to a server. A server is an
          application that creates an end-point to receive data from a
          client. Clients create boxes named machine:port and then
          copy data to them. A copy(2) to machine:port sends data to
          that port at that machine. The connection is established on
          demand (when copying). If it breaks, Plan B tries to recon-
          nect on demand. Servers create boxes named local.N:port to
          listen at port for new connection requests, and then copy
          data from them. There is no connection acceptance/refusal
          mechanism, the system accepts all requests. To simultane-
          ously listen for different requests at port, a server can
          create multiple local.N:port boxes (with different values
          for N).

          On connection-oriented protocols, a local.N box can be used
          to send data back to the client by copying data into it.

          On protocols supporting broadcast the application can create
          boxes named any:port to perform a broadcast targetted to

          Since the interface does not provide all the set of opera-
          tions available for the protocols implemented, there can be
          boxes named raw.N:0 providing raw access to the protocol
          stack. When using these boxes the application is responsible
          for supplying appropriate headers in addition to user data.

     CON(4)                                                     CON(4)

          Special operations such like accepting/refussing connections
          are done by copying fake headers into/out of the end-point.

          /b/tcp as /con.


          There is no raw box implemented, since no application
          requires it yet.

          Automatic reconnection should raise an error after N
          unsucessful attempts.