root/branches/follower/libw5100/src/libw5100/interface.cpp

/*

   Network Interface

   Generic wrapper around a specific network device.

   A Network Interface (representing the physical network device) returns a
   connecting or listening Network Connection (representing a socket in either
   client or server state).

   Author: 

      Philip Lindsay <follower@rancidbacon.com>

   License:

      Copyright 2007-2008 // LGPL

*/

#include "interface.h"

#define HANDLE_BAD_ERROR() while (1) {};

NetworkInterface::NetworkInterface(W5100Device& networkDevice) : device (networkDevice) {
  /*

     Initialise the physical device with default network details.

     Note: The "weirdness" in this function declaration is a "initalization list",
          i.e. this bit:
    
         ) : device (networkDevice) {
  
          it is needed to give the 'device' Reference a value supplied to the method
          rather than having a new 'W5100Device' instance created. 
   */
   
   // This may not be the best place to do all this, but it'll do for now:
  device.setMac(0x02,0xDE,0xAD,0xBE,0xEF,0x00);
   
  device.setIp(169,254,254,169); // A local-link IP -- NOTE: This is out of spec.
  device.setMask(255,255,0,0);   // Matches local-link IP /16
  
  device.setGateway(0,0,0,0);   // We can't even guess this, so just skip it.
   
};

NetworkConnection NetworkInterface::listen(uint16_t port) {
   /*
  
      Start to listen for a request from a client.

  
      NOTE: For reasons I don't understand, this FAILS TO WORK if port >255.
            The port that gets opened is ~(port mod 255) but if you limit
            port to be uint8_t for example you don't get an error until
            the port number is bigger than 'long'.
            
      TODO: Track and fix this for port numbers > 255.
      

      Returns a NetworkConnection listening on the specified TCP port.
  
    */
    NetworkConnection connection = NetworkConnection(port);
    
    // TODO: How to best handle errors?
    //       There's two major categories I can think of currently:
    //         1) A socket wasn't available to listen in the first place
    //         2) The listen attempt failed for some reason
    //       Using 'HANDLE_BAD_ERROR()' (currently an infinite loop) is
    //       not ideal but should prevent the above errors slipping by unnoticed.
    if (!connection.listen()) {
      HANDLE_BAD_ERROR(); 
    }
    
    return connection;
}


NetworkConnection NetworkInterface::connect(byte b0, byte b1, byte b2, byte b3, uint16 port) {
   /*

      Connect to a server.
   
    */
  NetworkConnection connection = NetworkConnection(4000);
    
  byte _scratchBuffer[4];   // TODO: Move this?

  // TODO: Better?
  _scratchBuffer[0] = b0;
  _scratchBuffer[1] = b1;
  _scratchBuffer[2] = b2;
  _scratchBuffer[3] = b3;
  
    if (!connection.connect(_scratchBuffer, port)) {
      HANDLE_BAD_ERROR(); 
    }
  
  return connection;
}

//#include "w5100_device.h"

//NetworkInterface Network = NetworkInterface(W5100);