/*********************************************************************
* Function: static void HTTPLoadConn(BYTE connID)
*
* PreCondition: None
*
* Input: connID the connection ID to load
*
* Output: curHTTP has a new connection loaded
*
* Side Effects: None
*
* Overview: Loads the current HTTP connection out of Ethernet
* buffer RAM and into local RAM for processing.
*
* Note: None
********************************************************************/
static void HTTPLoadConn(BYTE connID)
{
WORD oldPtr;
// Return if already loaded
if(connID == curHTTPID)
return;
// Save the old one
oldPtr = MACSetWritePtr(BASE_HTTPB_ADDR + curHTTPID*sizeof(HTTP_CONN));
MACPutArray((BYTE*)&curHTTP, sizeof(HTTP_CONN));
MACSetWritePtr(oldPtr);
// Load the new one
oldPtr = MACSetReadPtr(BASE_HTTPB_ADDR + connID*sizeof(HTTP_CONN));
MACGetArray((BYTE*)&curHTTP, sizeof(HTTP_CONN));
MACSetReadPtr(oldPtr);
// Remember which one is loaded
curHTTPID = connID;
}
/*****************************************************************************
Function:
void UDPFlush(void)
Summary:
Transmits all pending data in a UDP socket.
Description:
This function builds a UDP packet with the pending TX data and marks it
for transmission over the network interface. Since UDP is a frame-based
protocol, this function must be called before returning to the main
stack loop whenever any data is written.
Precondition:
UDPIsPutReady() was previously called to specify the current socket, and
data has been written to the socket using the UDPPut family of functions.
Parameters:
None
Returns:
None
Remarks:
Note that unlike TCPFlush, UDPFlush must be called before returning to
the main stack loop. There is no auto transmit for UDP segments.
***************************************************************************/
void UDPFlush(void)
{
UDP_HEADER h;
UDP_SOCKET_INFO *p;
WORD wUDPLength;
p = &UDPSocketInfo[activeUDPSocket];
wUDPLength = UDPTxCount + sizeof(UDP_HEADER);
// Generate the correct UDP header
h.SourcePort = swaps(p->localPort);
h.DestinationPort = swaps(p->remotePort);
h.Length = swaps(wUDPLength);
h.Checksum = 0x0000;
// Calculate IP pseudoheader checksum if we are going to enable
// the checksum field
#if defined(UDP_USE_TX_CHECKSUM)
{
PSEUDO_HEADER pseudoHeader;
pseudoHeader.SourceAddress = AppConfig.MyIPAddr;
pseudoHeader.DestAddress = p->remote.remoteNode.IPAddr;
pseudoHeader.Zero = 0x0;
pseudoHeader.Protocol = IP_PROT_UDP;
pseudoHeader.Length = wUDPLength;
SwapPseudoHeader(pseudoHeader);
h.Checksum = ~CalcIPChecksum((BYTE*)&pseudoHeader, sizeof(pseudoHeader));
}
#endif
// Position the hardware write pointer where we will need to
// begin writing the IP header
MACSetWritePtr(BASE_TX_ADDR + sizeof(ETHER_HEADER));
// Write IP header to packet
IPPutHeader(&p->remote.remoteNode, IP_PROT_UDP, wUDPLength);
// Write UDP header to packet
MACPutArray((BYTE*)&h, sizeof(h));
// Calculate the final UDP checksum and write it in, if enabled
#if defined(UDP_USE_TX_CHECKSUM)
{
PTR_BASE wReadPtrSave;
WORD wChecksum;
wReadPtrSave = MACSetReadPtr(BASE_TX_ADDR + sizeof(ETHER_HEADER) + sizeof(IP_HEADER));
wChecksum = CalcIPBufferChecksum(wUDPLength);
if(wChecksum == 0x0000u)
wChecksum = 0xFFFF;
MACSetReadPtr(wReadPtrSave);
MACSetWritePtr(BASE_TX_ADDR + sizeof(ETHER_HEADER) + sizeof(IP_HEADER) + 6); // 6 is the offset to the Checksum field in UDP_HEADER
MACPutArray((BYTE*)&wChecksum, sizeof(wChecksum));
}
#endif
// Transmit the packet
MACFlush();
// Reset packet size counter for the next TX operation
UDPTxCount = 0;
LastPutSocket = INVALID_UDP_SOCKET;
}
