tcpip.c

Plasma IP Core 你可以利用这个组件在FPGA中设计MIPS结构的CPU

      //Wakeup sender thread
      message[0] = 2;
      OS_MQueueSend(IPMQueue, message);
   }
}


static void IPSendPacket(IPSocket *socket, IPFrame *frame, int length)
{
   int checksum, length2=length;
   unsigned char pseudo[12], *packet=frame->packet;

   frame->length = (uint16)length;

   //Calculate checksums
   if(packet[ETHERNET_FRAME_TYPE+1] == 0x00)  //IP
   {
      length2 = length - IP_VERSION_LENGTH;
      packet[IP_LENGTH] = (uint8)(length2 >> 8);
      packet[IP_LENGTH+1] = (uint8)length2;
      memset(packet+IP_CHECKSUM, 0, 2);
      checksum = IPChecksum(0xffff, packet+IP_VERSION_LENGTH, 20);
      packet[IP_CHECKSUM] = (unsigned char)(checksum >> 8);
      packet[IP_CHECKSUM+1] = (unsigned char)checksum;
      if(packet[IP_PROTOCOL] == 0x01)         //PING
      {
         memset(packet+PING_CHECKSUM, 0, 2);
         checksum = IPChecksum(0xffff, packet+PING_TYPE, length-PING_TYPE);
         packet[PING_CHECKSUM] = (unsigned char)(checksum >> 8);
         packet[PING_CHECKSUM+1] = (unsigned char)checksum;
      }
      else if(packet[IP_PROTOCOL] == 0x11)    //UDP
      {
         length2 = length - UDP_SOURCE_PORT;
         packet[UDP_LENGTH] = (uint8)(length2 >> 8);
         packet[UDP_LENGTH+1] = (uint8)length2;
         memcpy(pseudo+PSEUDO_IP_SOURCE, packet+IP_SOURCE, 4);
         memcpy(pseudo+PSEUDO_IP_DEST, packet+IP_DEST, 4);
         pseudo[PSEUDO_ZERO] = 0;
         pseudo[PSEUDO_IP_PROTOCOL] = packet[IP_PROTOCOL];
         memcpy(pseudo+PSEUDO_LENGTH, packet+UDP_LENGTH, 2);
         checksum = IPChecksum(0xffff, pseudo, 12);
         memset(packet+UDP_CHECKSUM, 0, 2);
         length2 = (packet[UDP_LENGTH] << 8) + packet[UDP_LENGTH+1];
         checksum = IPChecksum(checksum, packet+UDP_SOURCE_PORT, length2);
         packet[UDP_CHECKSUM] = (unsigned char)(checksum >> 8);
         packet[UDP_CHECKSUM+1] = (unsigned char)checksum;
      }
      else if(packet[IP_PROTOCOL] == 0x06)    //TCP
      {
         memcpy(pseudo+PSEUDO_IP_SOURCE, packet+IP_SOURCE, 4);
         memcpy(pseudo+PSEUDO_IP_DEST, packet+IP_DEST, 4);
         pseudo[PSEUDO_ZERO] = 0;
         pseudo[PSEUDO_IP_PROTOCOL] = packet[IP_PROTOCOL];
         length2 = (packet[IP_LENGTH] << 8) + packet[IP_LENGTH+1];
         length2 = length2 - 20;
         pseudo[PSEUDO_LENGTH] = (unsigned char)(length2 >> 8);
         pseudo[PSEUDO_LENGTH+1] = (unsigned char)length2;
         checksum = IPChecksum(0xffff, pseudo, 12);
         memset(packet+TCP_CHECKSUM, 0, 2);
         checksum = IPChecksum(checksum, packet+TCP_SOURCE_PORT, length2);
         packet[TCP_CHECKSUM] = (unsigned char)(checksum >> 8);
         packet[TCP_CHECKSUM+1] = (unsigned char)checksum;
      }
   }

   length2 = length - TCP_DATA;
   if(socket && (packet[TCP_FLAGS] & (TCP_FLAGS_FIN | TCP_FLAGS_SYN)))
      length2 = 1;
   frame->socket = socket;
   frame->timeout = 0;
   frame->retryCnt = 0;
   if(socket)
      frame->seqEnd = socket->seq + length2;
   IPSendFrame(frame);
}


static void TCPSendPacket(IPSocket *socket, IPFrame *frame, int length)
{
   uint8 *packet = frame->packet;
   int flags, count;

   flags = packet[TCP_FLAGS];
   memcpy(packet, socket->headerSend, TCP_SEQ);
   packet[TCP_FLAGS] = (uint8)flags | (socket->headerSend[TCP_FLAGS] & TCP_FLAGS_PSH);
   if(flags & TCP_FLAGS_SYN)
      packet[TCP_HEADER_LENGTH] = 0x60;  //set maximum segment size
   else
      packet[TCP_HEADER_LENGTH] = 0x50;
   packet[TCP_SEQ]   = (uint8)(socket->seq >> 24);
   packet[TCP_SEQ+1] = (uint8)(socket->seq >> 16);
   packet[TCP_SEQ+2] = (uint8)(socket->seq >> 8);
   packet[TCP_SEQ+3] = (uint8)socket->seq;
   packet[TCP_ACK]   = (uint8)(socket->ack >> 24);
   packet[TCP_ACK+1] = (uint8)(socket->ack >> 16);
   packet[TCP_ACK+2] = (uint8)(socket->ack >> 8);
   packet[TCP_ACK+3] = (uint8)socket->ack;
   count = FrameFreeCount - FRAME_COUNT_WINDOW;
   if(count < 1)
      count = 1;
   if(count > 4)
      count = 4;
   count *= 512;
   packet[TCP_WINDOW_SIZE] = (uint8)(count >> 8);
   packet[TCP_WINDOW_SIZE+1] = (uint8)count;
   packet[TCP_URGENT_POINTER] = 0;
   packet[TCP_URGENT_POINTER+1] = 0;
   IPSendPacket(socket, frame, length);
}


static void EthernetCreateResponse(unsigned char *packetOut,
                                   const unsigned char *packet,
                                   int length)
{
   //Swap destination and source fields
   memcpy(packetOut, packet, length);
   memcpy(packetOut+ETHERNET_DEST, packet+ETHERNET_SOURCE, 6);
   memcpy(packetOut+ETHERNET_SOURCE, packet+ETHERNET_DEST, 6);
   if(packet[ETHERNET_FRAME_TYPE+1] == 0x00)  //IP
   {
      memcpy(packetOut+IP_SOURCE, packet+IP_DEST, 4);
      memcpy(packetOut+IP_DEST, packet+IP_SOURCE, 4);
      if(packet[IP_PROTOCOL] == 0x06 || packet[IP_PROTOCOL] == 0x11)   //TCP/UDP
      {
         memcpy(packetOut+TCP_SOURCE_PORT, packet+TCP_DEST_PORT, 2);
         memcpy(packetOut+TCP_DEST_PORT, packet+TCP_SOURCE_PORT, 2);
      }
   }
}


static void IPDhcp(const unsigned char *packet, int length, int state)
{
   uint8 *packetOut, *ptr;
   const uint8 *ptr2;
   IPFrame *frame;
   static int request=0;

   if(state == 1)
   {
      //Create DHCP Discover
      frame = IPFrameGet(0);
      if(frame == NULL)
         return;
      packetOut = frame->packet;
      memset(packetOut, 0, 512);
      memcpy(packetOut, dhcpDiscover, sizeof(dhcpDiscover));
      memcpy(packetOut+ETHERNET_SOURCE, ethernetAddressPlasma, 6);
      memcpy(packetOut+DHCP_CLIENT_ETHERNET, ethernetAddressPlasma, 6);
      memcpy(packetOut+DHCP_MAGIC_COOKIE, dhcpOptions, sizeof(dhcpOptions));
      memcpy(packetOut+DHCP_MAGIC_COOKIE+10, ethernetAddressPlasma, 6);
      IPSendPacket(NULL, frame, 400);
      request = DHCP_DISCOVER;
      DhcpRetrySeconds = RETRANSMIT_TIME;
   }
   else if(state == 2 && memcmp(packet+DHCP_CLIENT_ETHERNET, ethernetAddressPlasma, 6) == 0)
   {
      if(packet[DHCP_MAGIC_COOKIE+6] == DHCP_OFFER && request == DHCP_DISCOVER)
      {
         //Process DHCP Offer and send DHCP Request
         frame = IPFrameGet(0);
         if(frame == NULL)
            return;
         packetOut = frame->packet;
         memset(packetOut, 0, 512);
         memcpy(packetOut, dhcpDiscover, sizeof(dhcpDiscover));
         memcpy(packetOut+ETHERNET_SOURCE, ethernetAddressPlasma, 6);
         memcpy(packetOut+DHCP_CLIENT_ETHERNET, ethernetAddressPlasma, 6);
         memcpy(packetOut+DHCP_MAGIC_COOKIE, dhcpOptions, sizeof(dhcpOptions));
         memcpy(packetOut+DHCP_MAGIC_COOKIE+10, ethernetAddressPlasma, 6);
         request = DHCP_REQUEST;
         packetOut[DHCP_MAGIC_COOKIE+6] = DHCP_REQUEST;
         ptr = packetOut+DHCP_MAGIC_COOKIE+sizeof(dhcpOptions)-1;
         ptr[0] = DHCP_REQUEST_IP;
         ptr[1] = 4;
         memcpy(ptr+2, packet+DHCP_YOUR_IP, 4);
         ptr[6] = DHCP_REQUEST_SERV_IP;
         ptr[7] = 4;
         memcpy(ptr+8, packet+DHCP_SERVER_IP, 4);
         ptr[12] = DHCP_END_OPTION;
         IPSendPacket(NULL, frame, 400);
      }
      else if(packet[DHCP_MAGIC_COOKIE+6] == DHCP_ACK && request == DHCP_REQUEST)
      {
         //Process DHCP Ack
         request = 0;
         DhcpRetrySeconds = 3600*4;
         memcpy(ipAddressPlasma, packet+DHCP_YOUR_IP, 4);
         printf("IP=%d.%d.%d.%d ", ipAddressPlasma[0], ipAddressPlasma[1],
            ipAddressPlasma[2], ipAddressPlasma[3]);
         memcpy(ipAddressGateway, packet+DHCP_GATEWAY_IP, 4);
         if(ipAddressGateway[0] == 0 && ipAddressGateway[1] == 0 &&
            ipAddressGateway[2] == 0 && ipAddressGateway[3] == 0)
            memcpy(ipAddressGateway, packet+DHCP_SERVER_IP, 4);
         printf("GW=%d.%d.%d.%d ", ipAddressGateway[0], ipAddressGateway[1],
            ipAddressGateway[2], ipAddressGateway[3]);
         memcpy(ethernetAddressGateway, packet+ETHERNET_SOURCE, 6);
         ptr2 = packet+DHCP_MAGIC_COOKIE+4;
         while(ptr2[0] != DHCP_END_OPTION && (int)(ptr2 - packet) < length)
         {
            if(ptr2[0] == DHCP_PARAM_DNS)
            {
               ipAddressDns = (ptr2[2] << 24) | (ptr2[3] << 16) | (ptr2[4] << 8) | ptr2[5];
               printf("DNS=%d.%d.%d.%d ", ptr2[2], ptr2[3], ptr2[4], ptr2[5]);
            }
            ptr2 += ptr2[1] + 2;
         }

         //Check if DHCP reply came from gateway
         if(memcmp(packet+IP_SOURCE, ipAddressGateway, 4))
         {
            //Send ARP to gateway
            frame = IPFrameGet(0);
            if(frame == NULL)
               return;
            packetOut = frame->packet;
            memset(packetOut, 0, 512);
            memset(packetOut+ETHERNET_DEST, 0xff, 6);
            memcpy(packetOut+ETHERNET_SOURCE, ethernetAddressPlasma, 6);
            packetOut[ETHERNET_FRAME_TYPE] = 0x08;
            packetOut[ETHERNET_FRAME_TYPE+1] = 0x06;
            packetOut[ARP_HARD_TYPE+1] = 0x01;
            packetOut[ARP_PROT_TYPE] = 0x08;
            packetOut[ARP_HARD_SIZE] = 0x06;
            packetOut[ARP_PROT_SIZE] = 0x04;
            packetOut[ARP_OP+1] = 1;
            memcpy(packetOut+ARP_ETHERNET_SENDER, ethernetAddressPlasma, 6);
            memcpy(packetOut+ARP_IP_SENDER, ipAddressPlasma, 4);
            memcpy(packetOut+ARP_IP_TARGET, ipAddressGateway, 4);
            IPSendPacket(NULL, frame, 60);
         }
      }
   }
}


uint32 IPAddressSelf(void)
{
   return (ipAddressPlasma[0] << 24) | (ipAddressPlasma[1] << 16) |
          (ipAddressPlasma[2] << 8) | ipAddressPlasma[3];
}


static int IPProcessTCPPacket(IPFrame *frameIn)
{
   uint32 seq, ack;
   int length, ip_length, bytes;
   IPSocket *socket, *socketNew;
   IPFrame *frameOut, *frame2, *framePrev;
   uint8 *packet, *packetOut;

   packet = frameIn->packet;
   length = frameIn->length;

   ip_length = (packet[IP_LENGTH] << 8) | packet[IP_LENGTH+1];
   seq = (packet[TCP_SEQ] << 24) | (packet[TCP_SEQ+1] << 16) | 
         (packet[TCP_SEQ+2] << 8) | packet[TCP_SEQ+3];
   ack = (packet[TCP_ACK] << 24) | (packet[TCP_ACK+1] << 16) | 
         (packet[TCP_ACK+2] << 8) | packet[TCP_ACK+3];

   //Check if start of connection
   if((packet[TCP_FLAGS] & (TCP_FLAGS_SYN | TCP_FLAGS_ACK)) == TCP_FLAGS_SYN)
   {
      if(IPVerbose)
         printf("S");
      //Check if duplicate SYN
      for(socket = SocketHead; socket; socket = socket->next)
      {
         if(socket->state != IP_LISTEN &&
            packet[IP_PROTOCOL] == socket->headerRcv[IP_PROTOCOL] &&
            memcmp(packet+IP_SOURCE, socket->headerRcv+IP_SOURCE, 8) == 0 &&
            memcmp(packet+TCP_SOURCE_PORT, socket->headerRcv+TCP_SOURCE_PORT, 4) == 0)
         {
            if(IPVerbose)
               printf("s");
            return 0;
         }
      }

      //Find an open port
      for(socket = SocketHead; socket; socket = socket->next)
      {
         if(socket->state == IP_LISTEN &&
            packet[IP_PROTOCOL] == socket->headerRcv[IP_PROTOCOL] &&
            memcmp(packet+TCP_DEST_PORT, socket->headerRcv+TCP_DEST_PORT, 2) == 0)
         {
            //Create a new socket
            frameOut = IPFrameGet(FRAME_COUNT_SYNC);
            if(frameOut == NULL)
               return 0;
            socketNew = (IPSocket*)malloc(sizeof(IPSocket));
            if(socketNew == NULL)
               return 0;
            memcpy(socketNew, socket, sizeof(IPSocket));
            socketNew->state = IP_TCP;
            socketNew->timeout = RETRANSMIT_TIME * 3;
            socketNew->ack = seq;
            socketNew->seq = socketNew->ack + 0x12345678;
            socketNew->seqReceived = socketNew->seq;

            //Send ACK
            packetOut = frameOut->packet;
            EthernetCreateResponse(packetOut, packet, length);
            memcpy(socketNew->headerRcv, packet, TCP_SEQ);
            memcpy(socketNew->headerSend, packetOut, TCP_SEQ);
            packetOut[TCP_FLAGS] = TCP_FLAGS_SYN | TCP_FLAGS_ACK;
            ++socketNew->ack;
            packetOut[TCP_DATA] = 2;    //maximum segment size = 536
            packetOut[TCP_DATA+1] = 4;
            packetOut[TCP_DATA+2] = 2;
            packetOut[TCP_DATA+3] = 24;
            TCPSendPacket(socketNew, frameOut, TCP_DATA+4);
            ++socketNew->seq;

            //Add socket to linked list
            OS_MutexPend(IPMutex);
            socketNew->next = SocketHead;
            socketNew->prev = NULL;
            if(SocketHead)
               SocketHead->prev = socketNew;
            SocketHead = socketNew;
            OS_MutexPost(IPMutex);
            return 0;
         }
      }
      return 0;
   }

   //Find an open socket
   for(socket = SocketHead; socket; socket = socket->next)
   {
      if(packet[IP_PROTOCOL] == socket->headerRcv[IP_PROTOCOL] &&
         memcmp(packet+IP_SOURCE, socket->headerRcv+IP_SOURCE, 8) == 0 &&
         memcmp(packet+TCP_SOURCE_PORT, socket->headerRcv+TCP_SOURCE_PORT, 4) == 0)
      {
         break;
      }
   }
   if(socket == NULL)
      return 0;

   //Check if FIN flag set
   if(packet[TCP_FLAGS] & TCP_FLAGS_FIN)
   {
      socket->timeout = SOCKET_TIMEOUT;
      if(IPVerbose)
         printf("F");
      frameOut = IPFrameGet(0);
      if(frameOut == NULL)
         return 0;
      packetOut = frameOut->packet;
      packetOut[TCP_FLAGS] = TCP_FLAGS_ACK;
      ++socket->ack;
      TCPSendPacket(socket, frameOut, TCP_DATA);
      if(socket->state == IP_FIN_SERVER)
         IPClose2(socket);
      else
      {
         socket->state = IP_FIN_CLIENT;
         if(socket->funcPtr)
            socket->funcPtr(socket);
      }
   }
   else if(packet[TCP_FLAGS] & TCP_FLAGS_RST)
   {
      if(socket->state == IP_FIN_SERVER)
         IPClose2(socket);
      else
      {
         socket->state = IP_FIN_CLIENT;
         if(socket->funcPtr)
            socket->funcPtr(socket);
      }
   }
   else
   {
      //Check if packets can be removed from retransmition list
      if(ack != socket->seqReceived)
      {
         OS_MutexPend(IPMutex);
         for(frame2 = FrameResendHead; frame2; )
         {
            framePrev = frame2;
            frame2 = frame2->next;
            if(framePrev->socket == socket && (int)(ack - framePrev->seqEnd) >= 0)
            {
               //Remove packet from retransmition queue
               if(socket->timeout)
                  socket->timeout = SOCKET_TIMEOUT;
               FrameRemove(&FrameResendHead, &FrameResendTail, framePrev);
               FrameFree(framePrev);
            }
         }
         OS_MutexPost(IPMutex);
         socket->seqReceived = ack;