giuliomoro@44: /*
giuliomoro@44:  * udpServer.cpp
giuliomoro@44:  *
giuliomoro@44:  *  Created on: 19 May 2015
giuliomoro@44:  *      Author: giulio moro
giuliomoro@44:  */
giuliomoro@44: #include "../include/UdpServer.h"
giuliomoro@44: 
giuliomoro@44: UdpServer::UdpServer(int aPort){
giuliomoro@44: 	init(aPort);
giuliomoro@44: };
giuliomoro@44: UdpServer::UdpServer(){
giuliomoro@44: 	init(0);
giuliomoro@44: }
giuliomoro@44: UdpServer::~UdpServer(){
giuliomoro@54: 	//TODO: unbind from port. AFAIK, this involves closing the socket, therefore creating the socket should become part of bindToPort
giuliomoro@44: };
giuliomoro@44: bool UdpServer::init(int aPort){
giuliomoro@44: 	enabled=true;
giuliomoro@121: 	stZeroTimeOut.tv_sec = 0; //set timeout to 0
giuliomoro@121: 	stZeroTimeOut.tv_usec = 0;
giuliomoro@44: 	inSocket=socket(AF_INET, SOCK_DGRAM, 0);
giuliomoro@44: 	if (inSocket < 0){
giuliomoro@44: 		enabled=false;
giuliomoro@44: 	}
giuliomoro@44: 	length = sizeof(server);
giuliomoro@44: 	server.sin_family=AF_INET;
giuliomoro@44: 	server.sin_addr.s_addr=INADDR_ANY;
giuliomoro@44: 	enabled=bindToPort(aPort);
giuliomoro@44: 	wasteBufferSize=2048;
giuliomoro@44: 	wasteBuffer=malloc(wasteBufferSize);
giuliomoro@44: 	return enabled;
giuliomoro@44: }
giuliomoro@44: 
giuliomoro@44: bool UdpServer::bindToPort(int aPort){
giuliomoro@44: 	port=aPort;
giuliomoro@53: 	if(port<1){
giuliomoro@53: 		enabled=false;
giuliomoro@53: 		return false;
giuliomoro@53: 	}
giuliomoro@44: 	server.sin_port=htons(port);
giuliomoro@44: 	if (bind(inSocket,(struct sockaddr *)&server,length)<0){
giuliomoro@44: 		enabled=false;
giuliomoro@44: 		return false;
giuliomoro@44: 	}
giuliomoro@53: 	enabled=true;
giuliomoro@44: 	return true;
giuliomoro@44: };
giuliomoro@121: int UdpServer::waitUntilReady(bool readyForReading, int timeoutMsecs){
giuliomoro@121: //	If the socket is ready on return, this returns 1. If it times-out before the socket becomes ready, it returns 0. If an error occurs, it returns -1.
giuliomoro@121: 	if(enabled==false)
giuliomoro@121: 		return -1;
giuliomoro@121: 	if(timeoutMsecs<0)
giuliomoro@121: 		return select(inSocket+1, &stReadFDS, NULL, NULL, NULL); //calling this with a NULL timeout will block indefinitely
giuliomoro@121: 	FD_ZERO(&stReadFDS);
giuliomoro@121: 	FD_SET(inSocket, &stReadFDS);
giuliomoro@121: 	if(timeoutMsecs>=1000){
giuliomoro@121: 		float timeOutSecs=timeoutMsecs*0.001;
giuliomoro@121: 		stTimeOut.tv_sec=(long int)timeOutSecs;
giuliomoro@121: 		timeOutSecs-=(int)timeOutSecs;
giuliomoro@121: 		stTimeOut.tv_usec=(long int)(timeOutSecs*1000000);
giuliomoro@121: 	} else //faster!
giuliomoro@121: 		stTimeOut.tv_usec=(long int)timeoutMsecs*1000;
giuliomoro@121: 	int descriptorReady= select(inSocket+1, &stReadFDS, NULL, NULL, &stTimeOut);
giuliomoro@121: 	return descriptorReady>0? 1 : descriptorReady;
giuliomoro@121: }
giuliomoro@121: 
giuliomoro@44: int UdpServer::read(//Returns the number of bytes read, or -1 if there was an error.
giuliomoro@44: 					void *destBuffer,
giuliomoro@121: 					int maxBytesToRead,
giuliomoro@121: 					bool blockUntilSpecifiedAmountHasArrived)
giuliomoro@121: {
giuliomoro@44: 	if(enabled==false)
giuliomoro@44: 		return -1;
giuliomoro@44: 	FD_ZERO(&stReadFDS);
giuliomoro@44: 	FD_SET(inSocket, &stReadFDS);
giuliomoro@121: 	int descriptorReady= select(inSocket+1, &stReadFDS, NULL, NULL, &stZeroTimeOut);
giuliomoro@44: 	if(descriptorReady<0){ //an error occurred
giuliomoro@44: 		return -1;
giuliomoro@44: 	}
giuliomoro@44: 	int numberOfBytes=0;
giuliomoro@121: //	do
giuliomoro@121: 	{
giuliomoro@121: 		if (FD_ISSET(inSocket, &stReadFDS))
giuliomoro@121: 		{
giuliomoro@121: 	//		numberOfBytes=recvfrom(inSocket,destBuffer,maxBytesToRead,0,(struct sockaddr *)&from,&fromLength);
giuliomoro@121: 			numberOfBytes+=recv(inSocket,destBuffer,maxBytesToRead-numberOfBytes,0);
giuliomoro@121: 			if(numberOfBytes<0)
giuliomoro@121: 				return -1;
giuliomoro@121: 		}
giuliomoro@44: 	}
giuliomoro@121: //	while (blockUntilSpecifiedAmountHasArrived && numberOfBytes==maxBytesToRead);
giuliomoro@44: 	return numberOfBytes;
giuliomoro@121: }
giuliomoro@44: int UdpServer::emptySocket(){
giuliomoro@44: 	return emptySocket(0);
giuliomoro@44: }
giuliomoro@44: int UdpServer::emptySocket(int maxBytes){//discards up to maxBytes from the socket. Returns the number of bytes discarded.
giuliomoro@44: 	if(wasteBuffer==NULL)
giuliomoro@44: 		return -1;
giuliomoro@44: 	int numberOfBytes=0;
giuliomoro@121: 	while(int n=read(wasteBuffer, wasteBufferSize, false)){// calls the read function until it does not return any more bytes (i.e.: socket is empty)
giuliomoro@44: 		if(n>0)
giuliomoro@44: 			numberOfBytes+=n;
giuliomoro@44: 		if(n<0)
giuliomoro@44: 			return -1;
giuliomoro@44: 		if(maxBytes>0 && numberOfBytes>=maxBytes)
giuliomoro@44: 			break;
giuliomoro@44: 	};
giuliomoro@44: 	return numberOfBytes;
giuliomoro@44: }
giuliomoro@44: void* UdpServer::getWaste(){ //returns the last datagram retrieved by emptySocket()
giuliomoro@44: 	return wasteBuffer;
giuliomoro@44: }
giuliomoro@44: