/****************************************************************** *****                                                        ***** *****  Name: tcpip.c                                         ***** *****  Ver.: 1.0                                             ***** *****  Date: 07/05/2001                                      ***** *****  Auth: Andreas Dannenberg                              ***** *****        HTWK Leipzig                                    ***** *****        university of applied sciences                  ***** *****        Germany                                         ***** *****  Func: implements the TCP/IP-stack and provides a      ***** *****        simple API to the user                          ***** *****                                                        ***** ******************************************************************/#include "tcpip.h"#include "EMAC.h"         // Keil: Line added#include <string.h>       // Keil: Line added#include <LPC230x.h>      // Keil: Register definition file for LPC2378const unsigned char MyMAC[6] =   // "M1-M2-M3-M4-M5-M6"{  MYMAC_1, MYMAC_2, MYMAC_3,  MYMAC_4, MYMAC_5, MYMAC_6};// easyWEB-API function// initalizes the LAN-controller, reset flags, starts timer-ISRvoid TCPLowLevelInit(void){// Keil: Timer 0 is used for TCP retransmission control  T0MR0 = 3144000;                            // 262mSec
  T0MCR = 3;                                  // Interrupt and Reset on MR0
  T0TCR = 1;                                  // Timer0 Enable
  VICVectAddr4 = (unsigned int)TCPClockHandler;// set interrupt vector in 4
  VICIntEnable = 0x00000010;                  // Enable Timer0 Interrupt

  PCONP |= (1<<12);                           // Deliver clock to AD
  PINSEL1 = 0x00014000;                       // Enable AD0 and AD1 inputs

  Init_EMAC();  TransmitControl = 0;  TCPFlags = 0;  TCPStateMachine = CLOSED;  SocketStatus = 0;}// easyWEB-API function// does a passive open (listen on 'MyIP:TCPLocalPort' for an incoming// connection)void TCPPassiveOpen(void){  if (TCPStateMachine == CLOSED)  {    TCPFlags &= ~TCP_ACTIVE_OPEN;                // let's do a passive open!    TCPStateMachine = LISTENING;    SocketStatus = SOCK_ACTIVE;                  // reset, socket now active  }}// easyWEB-API function// does an active open (tries to establish a connection between// 'MyIP:TCPLocalPort' and 'RemoteIP:TCPRemotePort')void TCPActiveOpen(void){  if ((TCPStateMachine == CLOSED) || (TCPStateMachine == LISTENING))  {    TCPFlags |= TCP_ACTIVE_OPEN;                 // let's do an active open!    TCPFlags &= ~IP_ADDR_RESOLVED;               // we haven't opponents MAC yet      PrepareARP_REQUEST();                        // ask for MAC by sending a broadcast    LastFrameSent = ARP_REQUEST;    TCPStartRetryTimer();    SocketStatus = SOCK_ACTIVE;                  // reset, socket now active      }}// easyWEB-API function// closes an open connectionvoid TCPClose(void){  switch (TCPStateMachine)  {    case LISTENING :    case SYN_SENT :    {      TCPStateMachine = CLOSED;      TCPFlags = 0;      SocketStatus = 0;      break;    }    case SYN_RECD :    case ESTABLISHED :    {      TCPFlags |= TCP_CLOSE_REQUESTED;      break;    }  }}// easyWEB-API function// releases the receive-buffer and allows easyWEB to store new data// NOTE: rx-buffer MUST be released periodically, else the other TCP//       get no ACKs for the data it sentvoid TCPReleaseRxBuffer(void){  SocketStatus &= ~SOCK_DATA_AVAILABLE;}// easyWEB-API function// transmitts data stored in 'TCP_TX_BUF'// NOTE: * number of bytes to transmit must have been written to 'TCPTxDataCount'//       * data-count MUST NOT exceed 'MAX_TCP_TX_DATA_SIZE'void TCPTransmitTxBuffer(void){  if ((TCPStateMachine == ESTABLISHED) || (TCPStateMachine == CLOSE_WAIT))    if (SocketStatus & SOCK_TX_BUF_RELEASED)    {      SocketStatus &= ~SOCK_TX_BUF_RELEASED;               // occupy tx-buffer      TCPUNASeqNr += TCPTxDataCount;                       // advance UNA            TxFrame1Size = ETH_HEADER_SIZE + IP_HEADER_SIZE + TCP_HEADER_SIZE + TCPTxDataCount;      TransmitControl |= SEND_FRAME1;            LastFrameSent = TCP_DATA_FRAME;      TCPStartRetryTimer();    }}// Reads the length of the received ethernet frame and checks if the // destination address is a broadcast message or notunsigned int IsBroadcast(void) {  unsigned short RecdDestMAC[3];         // 48 bit MAC  RecdFrameLength = StartReadFrame();  CopyFromFrame_EMAC(&RecdDestMAC,  6);           // receive DA to see if it was a broadcast  CopyFromFrame_EMAC(&RecdFrameMAC, 6);           // store SA (for our answer)  if ((RecdDestMAC[0] == 0xFFFF) &&       (RecdDestMAC[1] == 0xFFFF) &&       (RecdDestMAC[2] == 0xFFFF)) {     return(1);  } else {    return (0);  }}// easyWEB's 'main()'-function// must be called from user program periodically (the often - the better)// handles network, TCP/IP-stack and user eventsvoid DoNetworkStuff(void){  if (CheckFrameReceived())                      // Packet received  {    if (IsBroadcast()) {      ProcessEthBroadcastFrame();    } else {      ProcessEthIAFrame();     }    EndReadFrame();                              // release buffer in ethernet controller  }  if (TCPFlags & TCP_TIMER_RUNNING)    if (TCPFlags & TIMER_TYPE_RETRY)    {      if (TCPTimer > RETRY_TIMEOUT)      {        TCPRestartTimer();                       // set a new timeout        if (RetryCounter)        {          TCPHandleRetransmission();             // resend last frame          RetryCounter--;        }        else        {          TCPStopTimer();          TCPHandleTimeout();        }      }    }    else if (TCPTimer > FIN_TIMEOUT)    {      TCPStateMachine = CLOSED;      TCPFlags = 0;                              // reset all flags, stop retransmission...      SocketStatus &= SOCK_DATA_AVAILABLE;       // clear all flags but data available    }  switch (TCPStateMachine)  {    case CLOSED :    case LISTENING :    {      if (TCPFlags & TCP_ACTIVE_OPEN)            // stack has to open a connection?        if (TCPFlags & IP_ADDR_RESOLVED)         // IP resolved?          if (!(TransmitControl & SEND_FRAME2))  // buffer free?          {            TCPSeqNr = ((unsigned long)ISNGenHigh << 16) | (T0TC & 0xFFFF);  // Keil: changed from TAR to T0TC; 
                                                                // set local ISN            TCPUNASeqNr = TCPSeqNr;            TCPAckNr = 0;                                       // we don't know what to ACK!            TCPUNASeqNr++;                                      // count SYN as a byte            PrepareTCP_FRAME(TCP_CODE_SYN);                     // send SYN frame            LastFrameSent = TCP_SYN_FRAME;            TCPStartRetryTimer();                               // we NEED a retry-timeout            TCPStateMachine = SYN_SENT;          }      break;    }    case SYN_RECD :    case ESTABLISHED :    {      if (TCPFlags & TCP_CLOSE_REQUESTED)                  // user has user initated a close?        if (!(TransmitControl & (SEND_FRAME2 | SEND_FRAME1)))   // buffers free?          if (TCPSeqNr == TCPUNASeqNr)                          // all data ACKed?          {            TCPUNASeqNr++;            PrepareTCP_FRAME(TCP_CODE_FIN | TCP_CODE_ACK);            LastFrameSent = TCP_FIN_FRAME;            TCPStartRetryTimer();            TCPStateMachine = FIN_WAIT_1;          }      break;    }    case CLOSE_WAIT :    {      if (!(TransmitControl & (SEND_FRAME2 | SEND_FRAME1)))     // buffers free?        if (TCPSeqNr == TCPUNASeqNr)                            // all data ACKed?        {          TCPUNASeqNr++;                                        // count FIN as a byte          PrepareTCP_FRAME(TCP_CODE_FIN | TCP_CODE_ACK);        // we NEED a retry-timeout          LastFrameSent = TCP_FIN_FRAME;                        // time to say goodbye...          TCPStartRetryTimer();          TCPStateMachine = LAST_ACK;        }      break;    }  }  if (TransmitControl & SEND_FRAME2)  {    RequestSend(TxFrame2Size);    if (Rdy4Tx())                                // NOTE: when using a very fast MCU, maybe      SendFrame2();                              // the EMAC isn't ready yet, include    else {                                       // a kind of timer or counter here      TCPStateMachine = CLOSED;      SocketStatus = SOCK_ERR_ETHERNET;          // indicate an error to user      TCPFlags = 0;                              // clear all flags, stop timers etc.    }    TransmitControl &= ~SEND_FRAME2;             // clear tx-flag  }  if (TransmitControl & SEND_FRAME1)  {    PrepareTCP_DATA_FRAME();                     // build frame w/ actual SEQ, ACK....    RequestSend(TxFrame1Size);      if (Rdy4Tx())                                // EMAC ready to accept our frame?      SendFrame1();                              // (see note above)    else {      TCPStateMachine = CLOSED;      SocketStatus = SOCK_ERR_ETHERNET;          // indicate an error to user      TCPFlags = 0;                              // clear all flags, stop timers etc.    }    TransmitControl &= ~SEND_FRAME1;             // clear tx-flag  }}// easyWEB internal function// handles an incoming broadcast framevoid ProcessEthBroadcastFrame(void){  unsigned short TargetIP[2];  if (ReadFrameBE_EMAC() == FRAME_ARP)           // get frame type, check for ARP    if (ReadFrameBE_EMAC() == HARDW_ETH10)       // Ethernet frame      if (ReadFrameBE_EMAC() == FRAME_IP)        // check protocol        if (ReadFrameBE_EMAC() == IP_HLEN_PLEN)  // check HLEN, PLEN          if (ReadFrameBE_EMAC() == OP_ARP_REQUEST)          {            DummyReadFrame_EMAC(6);              // ignore sender's hardware address            CopyFromFrame_EMAC(&RecdFrameIP, 4); // read sender's protocol address            DummyReadFrame_EMAC(6);              // ignore target's hardware address            CopyFromFrame_EMAC(&TargetIP, 4);    // read target's protocol address            if (!memcmp(&MyIP, &TargetIP, 4))    // is it for us?              PrepareARP_ANSWER();               // yes->create ARP_ANSWER frame          }}// easyWEB internal function// handles an incoming frame that passed EMAC's address filter// (individual addressed = IA)void ProcessEthIAFrame(void){  unsigned short TargetIP[2];  unsigned char ProtocolType;  switch (ReadFrameBE_EMAC())                     // get frame type  {    case FRAME_ARP :                             // check for ARP    {      if ((TCPFlags & (TCP_ACTIVE_OPEN | IP_ADDR_RESOLVED)) == TCP_ACTIVE_OPEN)        if (ReadFrameBE_EMAC() == HARDW_ETH10)         // check for the right prot. etc.          if (ReadFrameBE_EMAC() == FRAME_IP)            if (ReadFrameBE_EMAC() == IP_HLEN_PLEN)              if (ReadFrameBE_EMAC() == OP_ARP_ANSWER)              {                TCPStopTimer();                       // OK, now we've the MAC we wanted ;-)                CopyFromFrame_EMAC(&RemoteMAC, 6);    // extract opponents MAC                TCPFlags |= IP_ADDR_RESOLVED;