text: /*
   * FreeRTOS Kernel V10.0.1
   * Copyright (C) 2017 Amazon.com, Inc. or its affiliates.  All Rights Reserved.
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy of
   * this software and associated documentation files (the "Software"), to deal in
   * the Software without restriction, including without limitation the rights to
   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
   * the Software, and to permit persons to whom the Software is furnished to do so,
   * subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
   * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
   * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
   * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
   * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
   *
   * http://www.FreeRTOS.org
   * http://aws.amazon.com/freertos
   *
   * 1 tab == 4 spaces!
   */
  
  /* Standard includes. */
  #include <stdint.h>
  #include <stdio.h>
  
  /* FreeRTOS includes. */
  #include "FreeRTOS.h"
  #include "task.h"
  
  /* FreeRTOS+CLI includes. */
  #include "FreeRTOS_CLI.h"
  
  /* FreeRTOS+UDP includes. */
  #include "FreeRTOS_UDP_IP.h"
  #include "FreeRTOS_Sockets.h"
  
  /* Demo app includes. */
  #include "UDPCommandInterpreter.h"
  
  /* Dimensions the buffer into which input characters are placed. */
  #define cmdMAX_INPUT_SIZE	60
  
  /* Dimensions the buffer into which string outputs can be placed. */
  #define cmdMAX_OUTPUT_SIZE	1250
  
  /* Dimensions the buffer passed to the recvfrom() call. */
  #define cmdSOCKET_INPUT_BUFFER_SIZE 60
  
  /*
   * The task that runs FreeRTOS+CLI.
   */
  void vUDPCommandInterpreterTask( void *pvParameters );
  
  /*
   * Open and configure the UDP socket.
   */
  static xSocket_t prvOpenUDPServerSocket( uint16_t usPort );
  
  /*-----------------------------------------------------------*/
  
  void vStartUDPCommandInterpreterTask( uint16_t usStackSize, uint32_t ulPort, UBaseType_t uxPriority )
  {
  	xTaskCreate( vUDPCommandInterpreterTask, "CLI", usStackSize, ( void * ) ulPort, uxPriority, NULL );
  }
  /*-----------------------------------------------------------*/
  
  /*
   * Task that provides the input and output for the FreeRTOS+CLI command
   * interpreter.  In this case a UDP port is used.  See the URL in the comments
   * within main.c for the location of the online documentation.
   */
  void vUDPCommandInterpreterTask( void *pvParameters )
  {
  long lBytes, lByte;
  signed char cInChar, cInputIndex = 0;
  static char cInputString[ cmdMAX_INPUT_SIZE ], cOutputString[ cmdMAX_OUTPUT_SIZE ], cLocalBuffer[ cmdSOCKET_INPUT_BUFFER_SIZE ];
  BaseType_t xMoreDataToFollow;
  struct freertos_sockaddr xClient;
  socklen_t xClientAddressLength = 0; /* This is required as a parameter to maintain the sendto() Berkeley sockets API - but it is not actually used so can take any value. */
  xSocket_t xSocket;
  
  	/* Just to prevent compiler warnings. */
  	( void ) pvParameters;
  
  	/* Attempt to open the socket.  The port number is passed in the task
  	parameter.  The strange casting is to remove compiler warnings on 32-bit
  	machines. */
  	xSocket = prvOpenUDPServerSocket( ( uint16_t ) ( ( uint32_t ) pvParameters ) & 0xffffUL );
  
  	if( xSocket != FREERTOS_INVALID_SOCKET )
  	{
  		for( ;; )
  		{
  			/* Wait for incoming data on the opened socket. */
  			lBytes = FreeRTOS_recvfrom( xSocket, ( void * ) cLocalBuffer, sizeof( cLocalBuffer ), 0, &xClient, &xClientAddressLength );
  
  			if( lBytes != FREERTOS_SOCKET_ERROR )
  			{
  				/* Process each received byte in turn. */
  				lByte = 0;
  				while( lByte < lBytes )
  				{
  					/* The next character in the input buffer. */
  					cInChar = cLocalBuffer[ lByte ];
  					lByte++;
  
  					/* Newline characters are taken as the end of the command
  					string. */
  					if( cInChar == '\n' )
  					{
  						/* Process the input string received prior to the
  						newline. */
  						do
  						{
  							/* Pass the string to FreeRTOS+CLI. */
  							xMoreDataToFollow = FreeRTOS_CLIProcessCommand( cInputString, cOutputString, cmdMAX_OUTPUT_SIZE );
  
  							/* Send the output generated by the command's
  							implementation. */
  							FreeRTOS_sendto( xSocket, cOutputString,  strlen( cOutputString ), 0, &xClient, xClientAddressLength );
  
  						} while( xMoreDataToFollow != pdFALSE ); /* Until the command does not generate any more output. */
  
  						/* All the strings generated by the command processing
  						have been sent.  Clear the input string ready to receive
  						the next command. */
  						cInputIndex = 0;
  						memset( cInputString, 0x00, cmdMAX_INPUT_SIZE );
  
  						/* Transmit a spacer, just to make the command console
  						easier to read. */
  						FreeRTOS_sendto( xSocket, "\r\n",  strlen( "\r\n" ), 0, &xClient, xClientAddressLength );
  					}
  					else
  					{
  						if( cInChar == '\r' )
  						{
  							/* Ignore the character.  Newlines are used to
  							detect the end of the input string. */
  						}
  						else if( cInChar == '\b' )
  						{
  							/* Backspace was pressed.  Erase the last character
  							in the string - if any. */
  							if( cInputIndex > 0 )
  							{
  								cInputIndex--;
  								cInputString[ cInputIndex ] = '\0';
  							}
  						}
  						else
  						{
  							/* A character was entered.  Add it to the string
  							entered so far.  When a \n is entered the complete
  							string will be passed to the command interpreter. */
  							if( cInputIndex < cmdMAX_INPUT_SIZE )
  							{
  								cInputString[ cInputIndex ] = cInChar;
  								cInputIndex++;
  							}
  						}
  					}
  				}
  			}
  		}
  	}
  	else
  	{
  		/* The socket could not be opened. */
  		vTaskDelete( NULL );
  	}
  }
  /*-----------------------------------------------------------*/
  
  static xSocket_t prvOpenUDPServerSocket( uint16_t usPort )
  {
  struct freertos_sockaddr xServer;
  xSocket_t xSocket = FREERTOS_INVALID_SOCKET;
  
  	xSocket = FreeRTOS_socket( FREERTOS_AF_INET, FREERTOS_SOCK_DGRAM, FREERTOS_IPPROTO_UDP );
  	if( xSocket != FREERTOS_INVALID_SOCKET)
  	{
  		/* Zero out the server structure. */
  		memset( ( void * ) &xServer, 0x00, sizeof( xServer ) );
  
  		/* Set family and port. */
  		xServer.sin_port = FreeRTOS_htons( usPort );
  
  		/* Bind the address to the socket. */
  		if( FreeRTOS_bind( xSocket, &xServer, sizeof( xServer ) ) == -1 )
  		{
  			FreeRTOS_closesocket( xSocket );
  			xSocket = FREERTOS_INVALID_SOCKET;
  		}
  	}
  
  	return xSocket;
  }
  
  
  