FreeRTOS-Labs/Demo/FreeRTOS_Plus_TCP_and_FAT_Windows_Simulator/DemoTasks/SimpleTCPEchoServer.c

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    ***************************************************************************

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*/

/*
 * FreeRTOS tasks are used with FreeRTOS+TCP to create a TCP echo server.  Echo
 * clients are also created, but the echo clients use Windows threads (as
 * opposed to FreeRTOS tasks) and use the Windows TCP library (Winsocks).  This
 * creates a communication between the FreeRTOS+TCP TCP/IP stack and the Windows
 * TCP/IP stack.
 *
 * See the following web page for essential demo usage and configuration
 * details:
 * http://www.FreeRTOS.org/FreeRTOS-Plus/FreeRTOS_Plus_TCP/examples_FreeRTOS_simulator.html
 */

/* Standard includes. */
#include <stdint.h>
#include <stdio.h>
#include <WinSock2.h>
#include <Mswsock.h>

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"

/* FreeRTOS+TCP includes. */
#include "FreeRTOS_IP.h"
#include "FreeRTOS_Sockets.h"

/* Remove the whole file if FreeRTOSIPConfig.h is set to exclude TCP. */
#if( ipconfigUSE_TCP == 1 )

/* This example uses Winsocks clients to talk to a FreeRTOS+TCP server. */
#pragma comment( lib, "ws2_32.lib" )

/* The number of Winsock clients that communicate with the FreeRTOS+TCP
server. */
#define tcpechoNUMBER_OF_CLIENTS		1

/* Specifies the size of the data sent to the server in MSS units. */
#define tcpechoBUFFER_SIZE_MULTIPLIER	3

/* Delay between cycles so as not to flood the network. */
#define tcpechoLOOP_DELAY	( ( TickType_t ) 750 / portTICK_PERIOD_MS )

/* The maximum time to wait for a closing socket to close. */
#define tcpechoSHUTDOWN_DELAY	( pdMS_TO_TICKS( 5000 ) )

/* The time to wait between reads of a Winsock socket when shutting the socket
down. */
#define tcpechoWINSOCK_SHUTDOWN_DELAY	( 5 )

/* The standard echo port number. */
#define tcpechoPORT_NUMBER		7

/* The size of the Rx and Tx buffers. */
#define tcpechoBUFFER_SIZE ( ipconfigTCP_MSS * tcpechoBUFFER_SIZE_MULTIPLIER )

/*-----------------------------------------------------------*/

/*
 * Uses Winsocks from Windows threads to send data from the real IP and MAC
 * addresses to the IP and MAC addresses spoofed by FreeRTOS+TCP.  Multiple
 * instances of this task are created.
 */
DWORD WINAPI prvSimpleWinsockTCPClientTask( void *pvParameters );

/*
 * Uses FreeRTOS+TCP to listen for incoming echo connections, creating a task
 * to handle each connection.
 */
static void prvConnectionListeningTask( void *pvParameters );

/*
 * Created by the connection listening task to handle a single connection.
 */
static void prvServerConnectionInstance( void *pvParameters );

/*
 * Create a string to transmit of pseudo random length.
 */
static BaseType_t prvCreateTxData( char *cBuffer, uint32_t ulBufferLength );

/*
 * Create the Windows threads that use the Windows TCP/IP stack to talk to the
 * FreeRTOS task that is using the FreeRTOS+TCP TCP/IP stack.
 */
static void prvCreateWindowsThreadClients( void );

/*-----------------------------------------------------------*/

/* Stores the stack size passed into vStartSimpleTCPServerTasks() so it can be
reused when the server listening task creates tasks to handle connections. */
static uint16_t usUsedStackSize = 0;

/* Used for error reporting. */
static uint32_t ulConnectionCount = 0, ulClientCycles = 0, ulClientTransmitErrors = 0, ulIncorrectDataReceived;
static uint32_t ulClientSocketsClosedDuringReceive = 0, ulClientReceiveErrors = 0;

/* The buffers used to hold the string to Tx and the received string. */
static char cTxBuffers[ tcpechoNUMBER_OF_CLIENTS ][ tcpechoBUFFER_SIZE ], cRxBuffers[ tcpechoNUMBER_OF_CLIENTS ][ tcpechoBUFFER_SIZE ];

/*-----------------------------------------------------------*/

void vStartSimpleTCPServerTasks( uint16_t usStackSize, UBaseType_t uxPriority )
{
WORD wVersionRequested;
WSADATA xWSAData;

	/* The clients use Winsock sockets and must therefore run at the idle
	priority. */
	configASSERT( uxPriority == tskIDLE_PRIORITY );

	/* Create the TCP echo server.  The echo server uses FreeRTOS+TCP through
	the spoofed IP and MAC address.  The WinSock client tasks are created from
	inside the listening task. */
	xTaskCreate( prvConnectionListeningTask, "ServerListener", usStackSize, NULL, uxPriority + 1, NULL );

	/* Prepare to use WinSock library. */
	wVersionRequested = MAKEWORD( 2, 2 );
	configASSERT( WSAStartup( wVersionRequested, &xWSAData ) == ( WORD ) 0 );

	/* Remember the requested stack size so it can be re-used by the server
	listening task when it creates tasks to handle connections. */
	usUsedStackSize = usStackSize;
}
/*-----------------------------------------------------------*/

static void prvCreateWindowsThreadClients( void )
{
BaseType_t xClientTask;
HANDLE xWinHandle;

	/* Create a set of (Windows thread) clients, all of which talk to the same
	(FreeRTOS task) server.  The clients use Winsocks through the real IP and
	MAC address. */
	for( xClientTask = 0; xClientTask < tcpechoNUMBER_OF_CLIENTS; xClientTask++ )
	{
		xWinHandle = CreateThread(
			NULL,							/* Pointer to thread security attributes. */
			0,								/* Initial thread stack size, in bytes. */
			prvSimpleWinsockTCPClientTask,	/* Pointer to thread function. */
			( void * ) xClientTask,			/* Argument for new thread. */
			0,								/* Creation flags. */
			NULL );

		/* Set the priority and the cores used of the Windows threads such that
		they do no interfere with the FreeRTOS simulator. */
		SetThreadPriority( xWinHandle, THREAD_PRIORITY_IDLE );
		SetThreadPriorityBoost( xWinHandle, TRUE );
		SetThreadAffinityMask( xWinHandle, ~0x01u );
	}
}
/*-----------------------------------------------------------*/

static void prvConnectionListeningTask( void *pvParameters )
{
struct freertos_sockaddr xClient, xBindAddress;
Socket_t xListeningSocket, xConnectedSocket;
socklen_t xSize = sizeof( xClient );
static const TickType_t xReceiveTimeOut = portMAX_DELAY;
const BaseType_t xBacklog = 20;
WinProperties_t xWinProps;

	/* Just to prevent compiler warnings. */
	( void ) pvParameters;

	/* Attempt to open the socket. */
	xListeningSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_STREAM, FREERTOS_IPPROTO_TCP );
	configASSERT( xListeningSocket != FREERTOS_INVALID_SOCKET );

	/* Set a time out so accept() will just wait for a connection. */
	FreeRTOS_setsockopt( xListeningSocket, 0, FREERTOS_SO_RCVTIMEO, &xReceiveTimeOut, sizeof( xReceiveTimeOut ) );

	/* Fill in the buffer and window sizes that will be used by the socket. */
	xWinProps.lTxBufSize = 6 * ipconfigTCP_MSS;
	xWinProps.lTxWinSize = 3;
	xWinProps.lRxBufSize = 6 * ipconfigTCP_MSS;
	xWinProps.lRxWinSize = 3;

	/* Set the window and buffer sizes. */
	FreeRTOS_setsockopt( xListeningSocket, 0, FREERTOS_SO_WIN_PROPERTIES, ( void * ) &xWinProps, sizeof( xWinProps ) );

	/* Bind the socket to the port that the client task will send to, then
	listen for incoming connections. */
	xBindAddress.sin_port = tcpechoPORT_NUMBER;
	xBindAddress.sin_port = FreeRTOS_htons( xBindAddress.sin_port );
	FreeRTOS_bind( xListeningSocket, &xBindAddress, sizeof( xBindAddress ) );
	FreeRTOS_listen( xListeningSocket, xBacklog );

	/* Create the clients that will connect to the listening socket. */
	prvCreateWindowsThreadClients();

	for( ;; )
	{
		/* Wait for a client to connect. */
		xConnectedSocket = FreeRTOS_accept( xListeningSocket, &xClient, &xSize );
		configASSERT( xConnectedSocket != FREERTOS_INVALID_SOCKET );

		/* Spawn a task to handle the connection. */
		xTaskCreate( prvServerConnectionInstance, "EchoServer", usUsedStackSize, ( void * ) xConnectedSocket, tskIDLE_PRIORITY, NULL );
	}
}
/*-----------------------------------------------------------*/

static void prvServerConnectionInstance( void *pvParameters )
{
int32_t lBytes, lSent, lTotalSent;
uint8_t cReceivedString[ ipconfigTCP_MSS ];
Socket_t xConnectedSocket;
static const TickType_t xReceiveTimeOut = pdMS_TO_TICKS( 5000 );
static const TickType_t xSendTimeOut = pdMS_TO_TICKS( 5000 );
TickType_t xTimeOnShutdown;

	ulConnectionCount++;
	xConnectedSocket = ( Socket_t ) pvParameters;
	FreeRTOS_setsockopt( xConnectedSocket, 0, FREERTOS_SO_RCVTIMEO, &xReceiveTimeOut, sizeof( xReceiveTimeOut ) );
	FreeRTOS_setsockopt( xConnectedSocket, 0, FREERTOS_SO_SNDTIMEO, &xSendTimeOut, sizeof( xReceiveTimeOut ) );

	for( ;; )
	{
		/* Zero out the receive array so there is NULL at the end of the string
		when it is printed out. */
		memset( cReceivedString, 0x00, sizeof( cReceivedString ) );

		/* Receive data on the socket. */
		lBytes = FreeRTOS_recv( xConnectedSocket, cReceivedString, sizeof( cReceivedString ), 0 );

		/* If data was received, echo it back. */
		if( lBytes >= 0 )
		{
			lSent = 0;
			lTotalSent = 0;

			/* Call send() until all the data has been sent. */
			while( ( lSent >= 0 ) && ( lTotalSent < lBytes ) )
			{
				lSent = FreeRTOS_send( xConnectedSocket, cReceivedString, lBytes - lTotalSent, 0 );
				lTotalSent += lSent;
			}

			if( lSent < 0 )
			{
				/* Socket closed? */
				break;
			}
		}
		else
		{
			/* Socket closed? */
			break;
		}
	}

	/* Initiate a shutdown in case it has not already been initiated. */
	FreeRTOS_shutdown( xConnectedSocket, FREERTOS_SHUT_RDWR );

	/* Wait for the shutdown to take effect, indicated by FreeRTOS_recv()
	returning an error. */
	xTimeOnShutdown = xTaskGetTickCount();
	do
	{
		if( FreeRTOS_recv( xConnectedSocket, cReceivedString, ipconfigTCP_MSS, 0 ) < 0 )
		{
			break;
		}
	} while( ( xTaskGetTickCount() - xTimeOnShutdown ) < tcpechoSHUTDOWN_DELAY );

	/* Finished with the socket and the task. */
	FreeRTOS_closesocket( xConnectedSocket );
	vTaskDelete( NULL );
}
/*-----------------------------------------------------------*/

static BaseType_t prvCreateTxData( char *cBuffer, uint32_t ulBufferLength )
{
BaseType_t lCharactersToAdd, lCharacter;
char cChar = '0';

	/* Randomise the number of characters that will be sent. */
	do
	{
		lCharactersToAdd = ipconfigRAND32() % ( ulBufferLength - 20UL );
	} while ( lCharactersToAdd == 0 );

	/* Fill the buffer. */
	for( lCharacter = 0; lCharacter < lCharactersToAdd; lCharacter++ )
	{
		cBuffer[ lCharacter ] = cChar;
		cChar++;

		if( cChar > '~' )
		{
			cChar = '0';
		}
	}

	return lCharactersToAdd;
}
/*-----------------------------------------------------------*/

BaseType_t xAreTCPEchoServersStillRunning( void )
{
static uint32_t ulLastConnectionCount = 0, ulLastClientCycles = 0;
BaseType_t xReturn = pdPASS;

	if( ulConnectionCount == ulLastConnectionCount )
	{
		xReturn = pdFAIL;
	}
	else
	{
		ulLastConnectionCount = ulConnectionCount;
	}

	if( ulClientCycles == ulLastClientCycles )
	{
		xReturn = pdFAIL;
	}
	else
	{
		ulLastClientCycles = ulClientCycles;
	}

	return xReturn;
}
/*-----------------------------------------------------------*/

DWORD WINAPI prvSimpleWinsockTCPClientTask( void *pvParameters )
{
char *pcTransmittedString, *pcReceivedString;
BaseType_t lReceived, lTransmitted = 0, lStringLength, lReturned = 0, lInstance;
uint32_t ulCount = 0UL, ulMaxCount, ulIPAddress;
const uint32_t ulMaxLoopsPerSocket = 100UL;
struct sockaddr_in xConnection;
SOCKET xClientSocket;
int iReturned;
TickType_t xTimeOnShutdown;

	/* Multiple instances of this task are created.  The instance is passed in
	as the parameter. */
	lInstance = ( BaseType_t ) pvParameters;

	/* Locate the buffers for this instance of this task. */
	pcTransmittedString = &( cTxBuffers[ lInstance ][ 0 ] );
	pcReceivedString = &( cRxBuffers[ lInstance ][ 0 ] );

	/* It is assumed that this task is not created until the network is up,
	so the IP address of the server (which is the FreeRTOS+TCP side of the
	connection) can be obtained immediately.  Store the IP address being
	used in ulIPAddress. */
	FreeRTOS_GetAddressConfiguration( &ulIPAddress, NULL, NULL, NULL );

	/* Set family and port for client socket. */
	memset( ( void * ) &xConnection, 0x00, sizeof( struct sockaddr_in ) );
	xConnection.sin_family = AF_INET;
	xConnection.sin_addr.s_addr = ulIPAddress;
	xConnection.sin_port = htons( tcpechoPORT_NUMBER );

	for( ;; )
	{
		/* Create the socket then connect it to the FreeRTOS+TCP server. */
		xClientSocket = socket( AF_INET, SOCK_STREAM, 0 );
		configASSERT( xClientSocket != INVALID_SOCKET );

		do
		{
			iReturned = connect( xClientSocket, (const struct sockaddr*) &xConnection, sizeof( xConnection ) );
		} while( iReturned != 0 );

		ulMaxCount = ipconfigRAND32() % ulMaxLoopsPerSocket;

		for( ulCount = 0; ulCount < ulMaxCount; ulCount++ )
		{
			/* Create a string then send it to the server. */
			lStringLength = prvCreateTxData( pcTransmittedString, tcpechoBUFFER_SIZE );
			lTransmitted = send( xClientSocket, pcTransmittedString, lStringLength, 0 );

			configASSERT( lTransmitted != SOCKET_ERROR );
			configASSERT( lTransmitted == lStringLength );

			if( lTransmitted == lStringLength )
			{
				memset( ( void * ) pcReceivedString, 0x00, tcpechoBUFFER_SIZE );
				lReceived = 0;

				/* Wait for the echoed string. */
				while( lReceived < lTransmitted )
				{
					lReturned = recv( xClientSocket, ( char * ) &( pcReceivedString[ lReceived ] ), lTransmitted - lReceived, 0 );

					if( lReturned >= 0 )
					{
						/* Data was received. */
						lReceived += lReturned;
					}
					else
					{
						/* Error was returned. */
						ulClientReceiveErrors++;
						break;
					}
				}

				/* If the socket was not closed, check the number of bytes
				received. */
				if( lReceived == lTransmitted )
				{
					/* Were the expected characters received? */
					configASSERT( memcmp( pcTransmittedString, pcReceivedString, lTransmitted ) == 0x00 );
					if( memcmp( pcTransmittedString, pcReceivedString, lReceived ) != 0x00 )
					{
						ulIncorrectDataReceived++;
						break;
					}
					else
					{
						/* Received expected string, increment the count of
						successful cycles. */
						ulClientCycles++;
					}
				}
				else
				{
					/* Socket is being closed or an error occurred.  Don't try
					using the same socket again. */
					break;
				}
			}
			else
			{
				ulClientTransmitErrors++;
				break;
			}
		}

		shutdown( xClientSocket, SD_BOTH );
		xTimeOnShutdown = xTaskGetTickCount();

		do
		{
			Sleep( tcpechoWINSOCK_SHUTDOWN_DELAY );
			lReturned = recv( xClientSocket, pcReceivedString, lTransmitted, 0 );

			if( lReturned < 0 )
			{
				break;
			}
		} while( ( xTaskGetTickCount() - xTimeOnShutdown ) < tcpechoSHUTDOWN_DELAY );

		configASSERT( closesocket( xClientSocket ) == 0 );

		Sleep( tcpechoLOOP_DELAY );
	}
}
/*-----------------------------------------------------------*/

/* The whole file is excluded if TCP is not compiled in. */
#endif /* ipconfigUSE_TCP */