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
osEventReset(socket->event);
//Leave critical section
osMutexRelease(socketMutex);
//Wait until an event is triggered
osEventWait(socket->event, socket->timeout);
//Enter critical section
osMutexAcquire(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 dhcpv6RelayStop(Dhcpv6RelayCtx *context)
{
uint_t i;
//Debug message
TRACE_INFO("Stopping DHCPv6 relay agent...\r\n");
//Ensure the specified pointer is valid
if(!context)
return ERROR_INVALID_PARAMETER;
//Check DHCPv6 relay agent state
if(!context->running)
return ERROR_WRONG_STATE;
//Reset ACK event before sending the kill signal
osEventReset(context->ackEvent);
//Stop the DHCPv6 relay agent task
context->stopRequest = TRUE;
//Send a signal to the task in order to abort any blocking operation
osEventSet(context->event);
//Wait for the process to terminate...
osEventWait(context->ackEvent, INFINITE_DELAY);
//Leave the All_DHCP_Relay_Agents_and_Servers multicast group
//for each client-facing interface
dhcpv6RelayLeaveMulticastGroup(context);
//Close the socket that carries traffic towards the DHCPv6 server
socketClose(context->serverSocket);
//Properly dispose the sockets that carry traffic towards the DHCPv6 clients
for(i = 0; i < context->clientInterfaceCount; i++)
socketClose(context->clientSocket[i]);
//Close event objects
osEventClose(context->event);
osEventClose(context->ackEvent);
//Successful processing
return NO_ERROR;
}
Socket *tcpAccept(Socket *socket, IpAddr *clientIpAddr, uint16_t *clientPort)
{
error_t error;
TcpSynQueueItem *queueItem;
Socket *newSocket;
//Ensure the socket was previously placed in the listening state
if(tcpGetState(socket) != TCP_STATE_LISTEN)
return NULL;
//Enter critical section
osMutexAcquire(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
osEventReset(socket->event);
//Leave critical section
osMutexRelease(socketMutex);
//Wait until a SYN message is received from a client
osEventWait(socket->event, socket->timeout);
//Enter critical section
osMutexAcquire(socketMutex);
}
//Check whether the queue is still empty
if(!socket->synQueue)
{
//Leave critical section
osMutexRelease(socketMutex);
//Timeout error
return NULL;
}
//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
osMutexRelease(socketMutex);
//Create a new socket to handle the incoming connection request
newSocket = socketOpen(SOCKET_TYPE_STREAM, SOCKET_PROTOCOL_TCP);
//Failed to open socket?
if(!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
continue;
}
//Enter critical section
osMutexAcquire(socketMutex);
//The user owns the socket
newSocket->ownedFlag = TRUE;
//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 = chunkedBufferSetLength((ChunkedBuffer *) &newSocket->txBuffer, newSocket->txBufferSize);
//Allocate receive buffer
if(!error)
error = chunkedBufferSetLength((ChunkedBuffer *) &newSocket->rxBuffer, newSocket->rxBufferSize);
//Failed to allocate memory?
if(error)
{
//Debug message
TRACE_WARNING("Cannot accept TCP connection!\r\n");
//Properly close the socket
tcpAbort(newSocket);
//Remove the item from the SYN queue
socket->synQueue = queueItem->next;
//Deallocate memory buffer
memPoolFree(queueItem);
//Wait for the next connection attempt
continue;
}
//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 = rand();
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;
//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;
//Send a SYN ACK control segment
error = tcpSendSegment(newSocket, TCP_FLAG_SYN | TCP_FLAG_ACK,
newSocket->iss, newSocket->rcvNxt, 0, TRUE);
//Failed to send TCP segment?
if(error)
{
//Debug message
TRACE_WARNING("Cannot accept TCP connection!\r\n");
//Close previously created socket
tcpAbort(newSocket);
//Remove the item from the SYN queue
socket->synQueue = queueItem->next;
//Deallocate memory buffer
memPoolFree(queueItem);
//Wait for the next connection attempt
continue;
}
//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);
//Leave critical section
osMutexRelease(socketMutex);
//Return a handle to the newly created socket
return newSocket;
}
}
