BlueDataDistributor/firmware/tcp.h (fd252ce) - bluebox · BlinkenArea

tcp.h

/* BlueDataDistributor - data distribution module from ethernet to 32 serial ports
 * version 0.1.1 date 2006-10-07
 * Copyright (C) 2006 Stefan Schuermans <stefan@blinkenarea.org>
 * a BlinkenArea project - http://www.blinkenarea.org/
 */

#ifndef INC_tcp
#define INC_tcp

#include "ethernet.h"
#include "ip.h"

// header of a TCP packet
struct TcpHeader
{
  unsigned int SrcPort;
  unsigned int DestPort;
  unsigned long SeqNo;
  unsigned long AckNo;
  unsigned int Ofs_Flags;
  unsigned int WndSz;
  unsigned int Chk;
  unsigned int UrgentPtr;
};

// a TCP packet
struct TcpPacket
{
  struct EthernetHeader EthHdr;
  struct IpHeader IpHdr;
  struct TcpHeader TcpHdr;
};

// TCP notify functions
struct TcpNotify
{
  // called when connection is established
  void (*Connect)( unsigned char ConnNo );
  // called when connection is closed / reset
  // (after this, the connection number may not be used any more)
  void (*Close)( unsigned char ConnNo );
  // called when sending data is possible
  // (return length of available data, 0xFFFF to close connection)
  unsigned short (*Send)( unsigned char ConnNo, unsigned long Pos, unsigned char * pBuffer, unsigned short MaxLen );
  // called when data was sent and ACKed
  void (*Sent)( unsigned char ConnNo, unsigned long Pos );
  // called when data was received, must return new window size (not smaller than curWnd)
  unsigned short (*Received)( unsigned char ConnNo, unsigned long Pos, unsigned char * pBuffer, unsigned short Len, unsigned short curWnd );
};

// a TCP connection (member names according to RFC793)
// BUG: missing urgent pointers, which must be supported according to RFC793
//      but urgent data is not used in protocols we use, so leave this out here to save time and memory
#define TCP_CLOSED 0
#define TCP_LISTEN 1
#define TCP_SYN_SENT 2
#define TCP_SYN_RCVD 3
#define TCP_ESTAB 4
#define TCP_FIN_WAIT_1 5
#define TCP_FIN_WAIT_2 6
#define TCP_CLOSE_WAIT 7
#define TCP_LAST_ACK 8
#define TCP_CLOSING 9
#define TCP_TIME_WAIT 10
struct TcpConnection
{
  unsigned char RemoteIp[4];
  unsigned short LocalPort, RemotePort;
  unsigned char State; // one of TCP_*
  unsigned long SndUna; // send unacknowledged
  unsigned long SndNxt; // send next
  unsigned short SndWnd; // send window
  unsigned long SndWl1; // segment sequence number used for last window update
  unsigned long SndWl2; // segment acknowledgment number used for last window update
  unsigned long Iss; // initial send sequence number
  unsigned long RcvNxt; // receive next
  unsigned short RcvWnd; // receive window
  unsigned long Irs; // initial receive sequence number
  unsigned short Mss; // maximum segment size
  unsigned char Ticks; // retransmission and time-wait timer (time since last packet sent or received in 200ms steps)
  unsigned char Timeout; // timeout timer (time since last data was sent or received)
  unsigned char LifeTime; // lifetime timer (time since begin of connection)
  struct TcpNotify * Notify; // notification functions
};

// initialize
extern void TcpInit( void );

// tick procedure - call every 200ms
extern void TcpTick200( void );

// process a received TCP packet
extern void TcpRecv( unsigned char * pData, unsigned short Length );

// open a TCP connection
// must not be called from a TCP notification function
// returns the connection number of the new connection of 0xFF in case of error
extern unsigned char TcpOpen( unsigned char * remoteIp, unsigned short remotePort,
                              unsigned short initialWnd, struct TcpNotify * Notify );

// close a TCP connection
// must not be called from a TCP notification function
extern void TcpClose( unsigned char connNo );

// request sending on a TCP connection
// must not be called from a TCP notification function
// this makes the send notification to be called if possible
extern void TcpSend( unsigned char connNo );

#endif // #ifdef INC_tcp

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