error_t udpReceiveDatagram(Socket *socket, IpAddr *srcIpAddr, uint16_t *srcPort,
IpAddr *destIpAddr, void *data, size_t size, size_t *received, uint_t flags)
{
SocketQueueItem *queueItem;
//The receive queue is empty?
if(!socket->receiveQueue)
{
//Set the events the application is interested in
socket->eventMask = SOCKET_EVENT_RX_READY;
//Reset the event object
osResetEvent(&socket->event);
//Leave critical section
osReleaseMutex(&socketMutex);
//Wait until an event is triggered
osWaitForEvent(&socket->event, socket->timeout);
//Enter critical section
osAcquireMutex(&socketMutex);
}
//Check whether the read operation timed out
if(!socket->receiveQueue)
{
//No data can be read
*received = 0;
//Report a timeout error
return ERROR_TIMEOUT;
}
//Point to the first item in the receive queue
queueItem = socket->receiveQueue;
//Copy data to user buffer
*received = chunkedBufferRead(data, queueItem->buffer, queueItem->offset, size);
//Save the source IP address
if(srcIpAddr)
*srcIpAddr = queueItem->srcIpAddr;
//Save the source port number
if(srcPort)
*srcPort = queueItem->srcPort;
//Save the destination IP address
if(destIpAddr)
*destIpAddr = queueItem->destIpAddr;
//If the SOCKET_FLAG_PEEK flag is set, the data is copied
//into the buffer but is not removed from the input queue
if(!(flags & SOCKET_FLAG_PEEK))
{
//Remove the item from the receive queue
socket->receiveQueue = queueItem->next;
//Deallocate memory buffer
chunkedBufferFree(queueItem->buffer);
}
//Update the state of events
udpUpdateEvents(socket);
//Successful read operation
return NO_ERROR;
}
error_t rawSocketReceiveEthPacket(Socket *socket,
void *data, size_t size, size_t *received, uint_t flags)
{
SocketQueueItem *queueItem;
//The SOCKET_FLAG_DONT_WAIT enables non-blocking operation
if(!(flags & SOCKET_FLAG_DONT_WAIT))
{
//The receive queue is empty?
if(!socket->receiveQueue)
{
//Set the events the application is interested in
socket->eventMask = SOCKET_EVENT_RX_READY;
//Reset the event object
osResetEvent(&socket->event);
//Leave critical section
osReleaseMutex(&socketMutex);
//Wait until an event is triggered
osWaitForEvent(&socket->event, socket->timeout);
//Enter critical section
osAcquireMutex(&socketMutex);
}
}
//Check whether the read operation timed out
if(!socket->receiveQueue)
{
//No data can be read
*received = 0;
//Report a timeout error
return ERROR_TIMEOUT;
}
//Point to the first item in the receive queue
queueItem = socket->receiveQueue;
//Copy data to user buffer
*received = netBufferRead(data, queueItem->buffer, queueItem->offset, size);
//If the SOCKET_FLAG_PEEK flag is set, the data is copied
//into the buffer but is not removed from the input queue
if(!(flags & SOCKET_FLAG_PEEK))
{
//Remove the item from the receive queue
socket->receiveQueue = queueItem->next;
//Deallocate memory buffer
netBufferFree(queueItem->buffer);
}
//Update the state of events
rawSocketUpdateEvents(socket);
//Successful read operation
return NO_ERROR;
}
error_t socketPoll(SocketEventDesc *eventDesc, uint_t size, OsEvent *extEvent, systime_t timeout)
{
uint_t i;
bool_t status;
OsEvent *event;
OsEvent eventObject;
//Check parameters
if(!eventDesc || !size)
return ERROR_INVALID_PARAMETER;
//Try to use the supplied event object to receive notifications
if(!extEvent)
{
//Create an event object only if necessary
if(!osCreateEvent(&eventObject))
{
//Report an error
return ERROR_OUT_OF_RESOURCES;
}
//Reference to the newly created event
event = &eventObject;
}
else
{
//Reference to the external event
event = extEvent;
}
//Loop through descriptors
for(i = 0; i < size; i++)
{
//Clear event flags
eventDesc[i].eventFlags = 0;
//Subscribe to the requested events
socketRegisterEvents(eventDesc[i].socket, event, eventDesc[i].eventMask);
}
//Block the current task until an event occurs
status = osWaitForEvent(event, timeout);
//Any socket event is in the signaled state?
if(status)
{
//Loop through descriptors
for(i = 0; i < size; i++)
{
//Retrieve event flags for the current socket
socketGetEvents(eventDesc[i].socket, &eventDesc[i].eventFlags);
//Clear unnecessary flags
eventDesc[i].eventFlags &= eventDesc[i].eventMask;
}
}
//Unsubscribe previously registered events
for(i = 0; i < size; i++)
socketUnregisterEvents(eventDesc[i].socket);
//Reset event object before exiting...
osResetEvent(event);
//Release previously allocated resources
if(!extEvent)
osDeleteEvent(&eventObject);
//Return status code
return status ? NO_ERROR : ERROR_TIMEOUT;
}
Socket *tcpAccept(Socket *socket, IpAddr *clientIpAddr, uint16_t *clientPort)
{
error_t error;
Socket *newSocket;
TcpSynQueueItem *queueItem;
//Ensure the socket was previously placed in the listening state
if(tcpGetState(socket) != TCP_STATE_LISTEN)
return NULL;
//Enter critical section
osAcquireMutex(&socketMutex);
//Wait for an connection attempt
while(1)
{
//The SYN queue is empty?
if(!socket->synQueue)
{
//Set the events the application is interested in
socket->eventMask = SOCKET_EVENT_RX_READY;
//Reset the event object
osResetEvent(&socket->event);
//Leave critical section
osReleaseMutex(&socketMutex);
//Wait until a SYN message is received from a client
osWaitForEvent(&socket->event, socket->timeout);
//Enter critical section
osAcquireMutex(&socketMutex);
}
//Check whether the queue is still empty
if(!socket->synQueue)
{
//Timeout error
newSocket = NULL;
//Exit immediately
break;
}
//Point to the first item in the receive queue
queueItem = socket->synQueue;
//Return the client IP address and port number
if(clientIpAddr)
*clientIpAddr = queueItem->srcAddr;
if(clientPort)
*clientPort = queueItem->srcPort;
//Leave critical section
osReleaseMutex(&socketMutex);
//Create a new socket to handle the incoming connection request
newSocket = socketOpen(SOCKET_TYPE_STREAM, SOCKET_IP_PROTO_TCP);
//Enter critical section
osAcquireMutex(&socketMutex);
//Socket successfully created?
if(newSocket != NULL)
{
//The user owns the socket
newSocket->ownedFlag = TRUE;
//Inherit settings from the listening socket
newSocket->txBufferSize = socket->txBufferSize;
newSocket->rxBufferSize = socket->rxBufferSize;
//Number of chunks that comprise the TX and the RX buffers
newSocket->txBuffer.maxChunkCount = arraysize(newSocket->txBuffer.chunk);
newSocket->rxBuffer.maxChunkCount = arraysize(newSocket->rxBuffer.chunk);
//Allocate transmit buffer
error = netBufferSetLength((NetBuffer *) &newSocket->txBuffer, newSocket->txBufferSize);
//Check status code
if(!error)
{
//Allocate receive buffer
error = netBufferSetLength((NetBuffer *) &newSocket->rxBuffer, newSocket->rxBufferSize);
}
//Transmit and receive buffers successfully allocated?
if(!error)
{
//Bind the newly created socket to the appropriate interface
newSocket->interface = queueItem->interface;
//Bind the socket to the specified address
newSocket->localIpAddr = queueItem->destAddr;
newSocket->localPort = socket->localPort;
//Save the port number and the IP address of the remote host
newSocket->remoteIpAddr = queueItem->srcAddr;
newSocket->remotePort = queueItem->srcPort;
//Save the maximum segment size
newSocket->mss = queueItem->mss;
//Initialize TCP control block
newSocket->iss = netGetRand();
newSocket->irs = queueItem->isn;
newSocket->sndUna = newSocket->iss;
newSocket->sndNxt = newSocket->iss + 1;
newSocket->rcvNxt = newSocket->irs + 1;
newSocket->rcvUser = 0;
newSocket->rcvWnd = newSocket->rxBufferSize;
//Default retransmission timeout
newSocket->rto = TCP_INITIAL_RTO;
#if (TCP_CONGESTION_CONTROL_SUPPORT == ENABLED)
//Initial congestion window
newSocket->cwnd = MIN(TCP_INITIAL_WINDOW * newSocket->mss, newSocket->txBufferSize);
//Slow start threshold should be set arbitrarily high
newSocket->ssthresh = UINT16_MAX;
#endif
//Send a SYN ACK control segment
error = tcpSendSegment(newSocket, TCP_FLAG_SYN | TCP_FLAG_ACK,
newSocket->iss, newSocket->rcvNxt, 0, TRUE);
//TCP segment successfully sent?
if(!error)
{
//Remove the item from the SYN queue
socket->synQueue = queueItem->next;
//Deallocate memory buffer
memPoolFree(queueItem);
//Update the state of events
tcpUpdateEvents(socket);
//The connection state should be changed to SYN-RECEIVED
tcpChangeState(newSocket, TCP_STATE_SYN_RECEIVED);
//We are done...
break;
}
}
//Dispose the socket
tcpAbort(newSocket);
}
//Debug message
TRACE_WARNING("Cannot accept TCP connection!\r\n");
//Remove the item from the SYN queue
socket->synQueue = queueItem->next;
//Deallocate memory buffer
memPoolFree(queueItem);
//Wait for the next connection attempt
}
//Leave critical section
osReleaseMutex(&socketMutex);
//Return a handle to the newly created socket
return newSocket;
}
