slsDetectorPackage/slsSupportLib/include/genericSocket.h

#pragma once
/**
 * 
 * @libdoc genericSocket provides some functions to open/close sockets both TCP and UDP
 *
 * @short some functions to open/close sockets both TCP and UDP
 * @author Anna Bergamaschi
 * @version 0.0
 */

#include "ansi.h"
#include "sls_detector_exceptions.h"

#ifdef __CINT__
//class  sockaddr_in;
class socklen_t;
class uint32_t;
class uint32_t_ss; 
// CINT view of types:
class sockaddr_in;
// {
//     unsigned short int sa_family;
//    unsigned char sa_data[14];
//   };
#else

#include <arpa/inet.h>
#include <netdb.h>
#include <netinet/in.h>
#include <sys/ioctl.h>
#include <net/if.h>
#include <ifaddrs.h>
#include <sys/prctl.h> // capabilities
#include <linux/capability.h>

#endif

#include <stdlib.h>  /******exit */
#include <unistd.h>
#include <string.h>
#include <iostream>
#include <math.h>
#include <errno.h>
#include <stdio.h>
#include "logger.h"

#define DEFAULT_PACKET_SIZE 1286
#define SOCKET_BUFFER_SIZE (100*1024*1024) //100 MB
#define DEFAULT_BACKLOG 5

using sls::SocketError;

class genericSocket{

public:

	/**  Communication protocol	 */
	enum communicationProtocol{
		TCP,  	/**< TCP/IP */
		UDP 	/**< UDP */
	};

	/**
	 * The constructor for a client
	 * throws an exception if the hostname/ip could not be converted to an internet address
	 * @param host_ip_or_name hostname or ip of the client
	 * @param port_number port number to connect to
	 * @param p TCP or UDP
	 * @param ps a single packet size
	 */
	genericSocket(const char* const host_ip_or_name,
			unsigned short int const port_number,
			communicationProtocol p, int ps = DEFAULT_PACKET_SIZE) :
				portno(port_number),
				protocol(p),
				is_a_server(0),
				packet_size(ps),
				nsending(0),
				nsent(0),
				total_sent(0),// sender (client): where to? ip
				header_packet_size(0),
				actual_udp_socket_buffer_size(0) {
		memset(&serverAddress, 0, sizeof(serverAddress));
		memset(&clientAddress, 0, sizeof(clientAddress));
		memset(lastClientIP,0,INET_ADDRSTRLEN);
		memset(thisClientIP,0,INET_ADDRSTRLEN);
		memset(dummyClientIP,0,INET_ADDRSTRLEN);
		differentClients = 0;

		struct addrinfo *result;
		if (ConvertHostnameToInternetAddress(host_ip_or_name, &result)) {
			sockfd.fd  = -1;
			throw SocketError("Could convert hostname to address");
		}

		sockfd.fd = 0;
		serverAddress.sin_family = result->ai_family;
		memcpy((char *) &serverAddress.sin_addr.s_addr,
				&((struct sockaddr_in *) result->ai_addr)->sin_addr, sizeof(in_addr_t));
		freeaddrinfo(result);
		serverAddress.sin_port = htons(port_number);
		clientAddress_length=sizeof(clientAddress);
	};

	/**
	 * The constructor for a server
	 * throws an exception if socket could not be created, closes descriptor before throwing
	 * @param port_number port number to connect to
	 * @param p TCP or UDP
	 * @param ps a single packet size
	 * @param eth interface name or IP address to listen to (if NULL, listen to all interfaces)
	 */
	genericSocket(unsigned short int const port_number, communicationProtocol p,
			int ps = DEFAULT_PACKET_SIZE, const char *eth=NULL, int hsize=0,
			uint64_t buf_size=SOCKET_BUFFER_SIZE):
				portno(port_number),
				protocol(p),
				is_a_server(1),
				packet_size(ps),
				nsending(0),
				nsent(0),
				total_sent(0),
				header_packet_size(hsize),
				actual_udp_socket_buffer_size(0) {


		memset(&serverAddress, 0, sizeof(serverAddress));
		memset(&clientAddress, 0, sizeof(clientAddress));
		memset(lastClientIP,0,INET_ADDRSTRLEN);
		memset(thisClientIP,0,INET_ADDRSTRLEN);
		memset(dummyClientIP,0,INET_ADDRSTRLEN);
		differentClients = 0;

		// same port
		if(serverAddress.sin_port == htons(port_number)){
			sockfd.fd = -10;
			throw SocketError("Cannot create socket on same port");
		}

		char ip[20];

		strcpy(ip,"0.0.0.0");
		clientAddress_length=sizeof(clientAddress);
		if (eth) {
			strcpy(ip,nameToIp(std::string(eth)).c_str());
			if (std::string(ip)==std::string("0.0.0.0"))
				strcpy(ip,eth);
		}

		sockfd.fd = socket(AF_INET, getProtocol(),0); //tcp

		if (sockfd.fd < 0) {
			FILE_LOG(logERROR) << "Can not create socket";
			sockfd.fd =-1;
			throw SocketError("Can not create socket");
		}

		// Set some fields in the serverAddress structure.
		serverAddress.sin_family = AF_INET;
		serverAddress.sin_port = htons(port_number);
		serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);


		if (std::string(ip)!=std::string("0.0.0.0")) {
			if (inet_pton(AF_INET, ip, &(serverAddress.sin_addr)));
			else
				serverAddress.sin_addr.s_addr = htonl(INADDR_ANY);
		}


		// reuse port
		{
			int val=1;
			if (setsockopt(sockfd.fd,SOL_SOCKET,SO_REUSEADDR,
					&val,sizeof(int)) == -1) {
			    FILE_LOG(logERROR) << "setsockopt REUSEADDR failed";
				sockfd.fd =-1;
				throw SocketError("setsockopt REUSEADDR failed");
			}
		}

		//increase socket buffer size if its udp
		if (p == UDP) {
			uint64_t desired_size = buf_size;
			uint64_t real_size = desired_size * 2; // kernel doubles this value for bookkeeping overhead
			uint64_t ret_size = 0;
			socklen_t optlen = sizeof(uint64_t);

			// confirm if sufficient
			if (getsockopt(sockfd.fd, SOL_SOCKET, SO_RCVBUF, &ret_size, &optlen) == -1) {
				FILE_LOG(logWARNING) << "[Port " << port_number << "] "
						"Could not get rx socket receive buffer size";
			} else if (ret_size >= real_size) {
				actual_udp_socket_buffer_size = ret_size;
				FILE_LOG(logINFO) << "[Port " << port_number << "] "
						"UDP rx socket real buffer size is sufficient (" << ret_size << ")";
			}

			// not sufficient, enhance size
			else {
				FILE_LOG(logINFO) << "[Port " << port_number << "] UDP rx socket real buffer size to be modified from " << ret_size << " to " << real_size;
				// set buffer size (could not set)
				if (setsockopt(sockfd.fd, SOL_SOCKET, SO_RCVBUF,
						&desired_size, optlen) == -1) {
					FILE_LOG(logWARNING) << "[Port " << port_number << "] "
							"Could not set rx socket buffer size to "
							<< desired_size << ". (No Root Privileges?)";
				}
				// confirm size
				else if (getsockopt(sockfd.fd, SOL_SOCKET, SO_RCVBUF,
						&ret_size, &optlen) == -1) {
					FILE_LOG(logWARNING) << "[Port " << port_number << "] "
							"Could not get rx socket buffer size";
				}
				else if (ret_size >= real_size) {
					actual_udp_socket_buffer_size = ret_size;
					FILE_LOG(logINFO) << "[Port " << port_number << "] "
							"UDP rx socket buffer size modified to " << ret_size;
				}
				// buffer size too large
				else {
					actual_udp_socket_buffer_size = ret_size;
					// force a value larger than system limit
					// (if run in a privileged context (capability CAP_NET_ADMIN set))
					int ret = setsockopt(sockfd.fd, SOL_SOCKET, SO_RCVBUFFORCE,
							&desired_size, optlen);
					getsockopt(sockfd.fd, SOL_SOCKET, SO_RCVBUF,
							&ret_size, &optlen);
					if (ret == -1) {
						FILE_LOG(logWARNING) << "[Port " << port_number << "] "
								"Could not force rx socket buffer size to "
								<< desired_size << ".\n  Real size: " << ret_size <<
								". (No Root Privileges?)\n"
								"  To remove this warning: set rx_udpsocksize from client to <= " <<
								(ret_size/2) << " (Real size:" << ret_size << ").";
					} else {
						FILE_LOG(logINFO) << "[Port " << port_number << "] "
								"UDP rx socket buffer size (force) modified to " << ret_size;
					}
				}
			}
		}


		if(bind(sockfd.fd,(struct sockaddr *) &serverAddress,sizeof(serverAddress))<0){
            FILE_LOG(logERROR) << "Can not bind socket. Please check if another process is running.";
			sockfd.fd =-1;
			throw SocketError("Can not bind socket. Please check if another process is running.");
		}


		if (getProtocol()==SOCK_STREAM)
			listen(sockfd.fd, DEFAULT_BACKLOG);

	}

	/**
	 * The destructor: disconnects and close the socket
	 */
	~genericSocket() {
		//mySocketDescriptor destructor also gets called
		serverAddress.sin_port=-1;
	};

	/**
	 * Returns actual udp socket buffer size/2.
	 * Halving is because of kernel book keeping
	 * @returns actual udp socket buffer size/2
	 */
	uint64_t getActualUDPSocketBufferSize(){return actual_udp_socket_buffer_size;};

	/**
	 * Get protocol TCP or UDP
-    * @returns TCP or UDP
	 */
	int getCommunicationProtocol(){return protocol;};

	/**
	 * Get port number
	 * @retrns port number
	 */
	uint16_t getPortNumber(){return ntohs(serverAddress.sin_port);}

	/**
	 * Get TCP Server File Descriptor
	 * @returns TCP Server file descriptor
	 */
	int getFileDes(){return sockfd.newfd;};

	/**
	 * Get socket descriptor
	 * @returns socket descriptor
	 */
	int getsocketDescriptor(){return sockfd.fd;};

	/**
	 * Get total bytes sent/received
	 * Makes sense only for udp socket as there is only receive data
	 */
	int getCurrentTotalReceived(){return total_sent;};

	/**
	 * Get type of protocol based on protocol
	 * @param p TCP or UDP
	 * @returns SOCK_STREAM/SOCK_DGRAM or -1
	 */
	int getProtocol(communicationProtocol p) {
		switch (p) {
		case TCP:
			return SOCK_STREAM;
			break;
		case UDP:
			return SOCK_DGRAM;
		default:
		    FILE_LOG(logERROR) << "unknown protocol: " << p;
			return -1;
		}
	};

	/**
	 * Get current protocol type
	 * @returns SOCK_STREAM/SOCK_DGRAM or -1
	 */
	int getProtocol() {return getProtocol(protocol);};

	/**
	 * Close TCP Server socket descriptor
	 */
	void CloseServerTCPSocketDescriptor() {
		if (protocol == TCP && is_a_server) {
			if (sockfd.fd >= 0) {
				close(sockfd.fd);
				sockfd.fd = -1;
			}
		}
	};

	/**
	 * Disconnect
	 */
	void Disconnect(){
		if (protocol == TCP && is_a_server) {
			if (sockfd.newfd >= 0) {
				close(sockfd.newfd);
				sockfd.newfd = -1;
			}
			return;
		}
		if (sockfd.fd >= 0) {
			close(sockfd.fd);
			sockfd.fd = -1;
		}
	};

	/**
	 * Establishes connection
	 * @returns 1 if error
	 */
	int  Connect(){

		if(sockfd.newfd>0) return sockfd.newfd;
		if (protocol==UDP) return -1;

		if(is_a_server && protocol==TCP){ //server tcp; the server will wait for the clients connection
			if (sockfd.fd>0) {
				if ((sockfd.newfd = accept(sockfd.fd,(struct sockaddr *) &clientAddress, &clientAddress_length)) < 0) {
				    FILE_LOG(logERROR) << "with server accept, connection refused";
					switch(errno) {
					case EWOULDBLOCK:
					    FILE_LOG(logERROR) << "ewouldblock eagain";
						break;
					case EBADF:
						FILE_LOG(logERROR) << "ebadf";
						break;
					case ECONNABORTED:
						FILE_LOG(logERROR) << "econnaborted";
						break;
					case EFAULT:
						FILE_LOG(logERROR) << "efault";
						break;
					case EINTR:
						FILE_LOG(logERROR) << "eintr";
						break;
					case EINVAL:
						FILE_LOG(logERROR) << "einval";
						break;
					case EMFILE:
						FILE_LOG(logERROR) << "emfile";
						break;
					case ENFILE:
						FILE_LOG(logERROR) << "enfile";
						break;
					case ENOTSOCK:
						FILE_LOG(logERROR) << "enotsock";
						break;
					case EOPNOTSUPP:
						FILE_LOG(logERROR) << "eOPNOTSUPP";
						break;
					case ENOBUFS:
						FILE_LOG(logERROR) << "ENOBUFS";
						break;
					case ENOMEM:
						FILE_LOG(logERROR) << "ENOMEM";
						break;
					case ENOSR:
						FILE_LOG(logERROR) << "ENOSR";
						break;
					case EPROTO:
						FILE_LOG(logERROR) << "EPROTO";
						break;
					default:
						FILE_LOG(logERROR) << "unknown error";
					}
				}
				else{
					inet_ntop(AF_INET, &(clientAddress.sin_addr), dummyClientIP, INET_ADDRSTRLEN);
					FILE_LOG(logDEBUG1) << "client connected " << sockfd.newfd;
				}
			}
			FILE_LOG(logDEBUG1) << "fd " << sockfd.newfd;
			return sockfd.newfd;
		} else {
			if (sockfd.fd<=0)
				sockfd.fd = socket(AF_INET, getProtocol(),0);
			//    SetTimeOut(10);
			if (sockfd.fd < 0){
			    FILE_LOG(logERROR) << "Can not create socket";
			} else {
				if(connect(sockfd.fd,(struct sockaddr *) &serverAddress,sizeof(serverAddress))<0){
				    FILE_LOG(logERROR) << "Can not connect to socket";
					return -1;
				}
			}
			return sockfd.fd;
		}
	};

	/**
	 * Exit server
	 */
	void exitServer(){
		Disconnect();
		CloseServerTCPSocketDescriptor();
	};

	/**
	 * Shut down socket
	 */
	void ShutDownSocket(){
		shutdown(sockfd.fd, SHUT_RDWR);
		Disconnect();
	};

	/**
	 * Set the socket timeout ts is in seconds
	 * @param ts time in seconds
	 * @returns 0 for success, else -1
	 */
	int SetTimeOut(int ts){
		if (ts<=0)
			return -1;

		struct timeval tout;
		tout.tv_sec  = 0;
		tout.tv_usec = 0;
		if(::setsockopt(sockfd.fd, SOL_SOCKET, SO_RCVTIMEO,
				&tout, sizeof(struct timeval)) <0) {
		    FILE_LOG(logERROR) << "setsockopt SO_RCVTIMEO " << 0;
		}
		tout.tv_sec  = ts;
		tout.tv_usec = 0;
		if(::setsockopt(sockfd.fd, SOL_SOCKET, SO_SNDTIMEO,
				&tout, sizeof(struct timeval)) < 0)	{
		    FILE_LOG(logERROR) << "setsockopt SO_SNDTIMEO " << ts;
		}
		return 0;
	};

	/**
	 * Set packet size
	 * @param i packet size
	 * @returns current packet size
	 */
	int setPacketSize(int i=-1) { if (i>=0) packet_size=i;return packet_size;};

	/**
	 * Convert IP to hostname
	 * @param ip IP
	 * @returns hostname
	 */
	static std::string ipToName(std::string ip) {
		struct ifaddrs *addrs, *iap;
		struct sockaddr_in *sa;

		char buf[32];
		const int buf_len = sizeof(buf);
		memset(buf,0,buf_len);
		strcpy(buf,"none");

		getifaddrs(&addrs);
		for (iap = addrs; iap != NULL; iap = iap->ifa_next) {
			if (iap->ifa_addr && (iap->ifa_flags & IFF_UP) && iap->ifa_addr->sa_family == AF_INET) {
				sa = (struct sockaddr_in *)(iap->ifa_addr);
				inet_ntop(iap->ifa_addr->sa_family, (void *)&(sa->sin_addr), buf, buf_len);
				if (ip==std::string(buf)) {
					strcpy(buf,iap->ifa_name);
					break;
				}
			}
		}
		freeifaddrs(addrs);
		return std::string(buf);
	};

	/**
	 * Convert interface to mac address
	 * @param inf interface
	 * @returns mac address
	 */
	static std::string nameToMac(std::string inf) {
		struct ifreq ifr;
		int sock, j, k;
		char mac[32];
		const int mac_len = sizeof(mac);
		memset(mac,0,mac_len);

		sock=getSock(inf,&ifr);

		if (-1==ioctl(sock, SIOCGIFHWADDR, &ifr)) {
			perror("ioctl(SIOCGIFHWADDR) ");
			return std::string("00:00:00:00:00:00");
		}
		for (j=0, k=0; j<6; j++) {
			k+=snprintf(mac+k, mac_len-k-1, j ? ":%02X" : "%02X",
					(int)(unsigned int)(unsigned char)ifr.ifr_hwaddr.sa_data[j]);
		}
		mac[mac_len-1]='\0';

		if(sock!=1){
			close(sock);
		}
		return std::string(mac);

	};

	/**
	 * Convert hostname to ip
	 * @param inf hostname
	 * @returns IP
	 */
	static std::string nameToIp(std::string inf){
		struct ifreq ifr;
		int sock;
		char *p, addr[32];
		const int addr_len = sizeof(addr);
		memset(addr,0,addr_len);

		sock=getSock(inf,&ifr);

		if (-1==ioctl(sock, SIOCGIFADDR, &ifr)) {
			perror("ioctl(SIOCGIFADDR) ");
			return std::string("0.0.0.0");
		}
		p=inet_ntoa(((struct sockaddr_in *)(&ifr.ifr_addr))->sin_addr);
		strncpy(addr,p,addr_len-1);
		addr[addr_len-1]='\0';

		if(sock!=1){
			close(sock);
		}
		return std::string(addr);

	};

	/**
	 * Get socket
	 * @param inf hostname
	 * @param ifr interface request structure
	 * @returns sock
	 */
	static int getSock(std::string inf, struct ifreq *ifr) {

		int sock;
		sock=socket(PF_INET, SOCK_STREAM, 0);
		if (-1==sock) {
			perror("socket() ");
			return 1;
		}
		strncpy(ifr->ifr_name,inf.c_str(),sizeof(ifr->ifr_name)-1);
		ifr->ifr_name[sizeof(ifr->ifr_name)-1]='\0';

		return sock;
	};

	/**
	 * Convert Hostname to Internet address info structure
	 * One must use freeaddrinfo(res) after using it
	 * @param hostname hostname
	 * @param res address of pointer to address info structure
	 * @return 1 for fail, 0 for success
	 */
	// Do not make this static (for multi threading environment)
	int ConvertHostnameToInternetAddress (const char* const hostname, struct addrinfo **res) {
		// criteria in selecting socket address structures returned by res
		struct addrinfo hints;
		memset (&hints, 0, sizeof (hints));
		hints.ai_family = AF_INET;
		hints.ai_socktype = SOCK_STREAM;
		// get host info into res
		int errcode = getaddrinfo (hostname, NULL, &hints, res);
		if (errcode != 0) {
		    FILE_LOG(logERROR) << "Could not convert hostname (" << hostname << ") to internet address (zmq):" <<
					gai_strerror(errcode);
		} else {
			if (*res == NULL) {
			    FILE_LOG(logERROR) << "Could not converthostname (" << hostname << ") to internet address (zmq):"
						"gettaddrinfo returned null";
			} else{
				return 0;
			}
		}
		 FILE_LOG(logERROR) << "Could not convert hostname to internet address";
		return 1;
	};

	/**
	 * Convert Internet Address structure pointer to ip string (char*)
	 * Clears the internet address structure as well
	 * @param res pointer to internet address structure
	 * @param ip pointer to char array to store result in
	 * @param ipsize size available in ip buffer
	 * @return 1 for fail, 0 for success
	 */
	// Do not make this static (for multi threading environment)
	int ConvertInternetAddresstoIpString (struct addrinfo *res, char* ip, const int ipsize) {
		if (inet_ntop (res->ai_family, &((struct sockaddr_in *) res->ai_addr)->sin_addr, ip, ipsize) != NULL) {
			freeaddrinfo(res);
			return 0;
		}
		 FILE_LOG(logERROR) << "Could not convert internet address to ip string";
		return 1;
	}

	/**
	 * Receive data only
	 * @param buf data
	 * @param length size of data expecting, 0 for a single packet
	 * @returns size of data received
	 */
	int ReceiveDataOnly(void* buf,int length=0){

		if (buf==NULL) return -1;

		total_sent=0;
		int tcpfd = sockfd.fd;

		switch(protocol) {
		case TCP:
			tcpfd = (is_a_server ? sockfd.newfd : sockfd.fd);
			if (tcpfd<0) return -1;
			while(length>0){
				nsending = (length>packet_size) ? packet_size:length;
				nsent = read(tcpfd,(char*)buf+total_sent,nsending);
				if(!nsent) {
					if(!total_sent) {
						return -1; //to handle it
					}
					break;
				}
				length-=nsent;
				total_sent+=nsent;
			}

			if (total_sent>0)
				strcpy(thisClientIP,dummyClientIP);

			if (strcmp(lastClientIP,thisClientIP))
				differentClients=1;
			else
				differentClients=0;

			break;
		case UDP:
			if (sockfd.fd<0) return -1;
			//if length given, listens to length, else listens for packetsize till length is reached
			if(length){
				while(length>0){
					nsending = (length>packet_size) ? packet_size:length;
					nsent = recvfrom(sockfd.fd,(char*)buf+total_sent,nsending, 0, (struct sockaddr *) &clientAddress, &clientAddress_length);
					if(nsent == header_packet_size)
						continue;
					if(nsent != nsending){
						if(nsent && (nsent != -1)) {
						    FILE_LOG(logERROR) << "Incomplete Packet size " << nsent;
						}
						break;
					}
					length-=nsent;
					total_sent+=nsent;
				}
			}
			//listens to only 1 packet
			else{
				//normal
				nsending=packet_size;
				while(1){
					nsent = recvfrom(sockfd.fd,(char*)buf+total_sent,nsending, 0, (struct sockaddr *) &clientAddress, &clientAddress_length);
					//break out of loop only if read one packets size or read didnt work (cuz of shutdown)
					if(nsent<=0 || nsent == packet_size)
						break;
					//incomplete packets or header packets ignored and read buffer again
					if(nsent != packet_size && nsent != header_packet_size) {
					    FILE_LOG(logERROR) << portno << ": Incomplete Packet size " << nsent;
					}
				}
				//nsent = 1040;
				if(nsent > 0)total_sent+=nsent;
			}
			break;
		default:
			;
		}
		FILE_LOG(logDEBUG1) << "sent " << total_sent << " Bytes";
		return total_sent;
	}

	/**
	 * Send data only
	 * @param buf data
	 * @param length size of data expecting
	 * @returns size of data sent
	 */
	int SendDataOnly(void *buf, int length) {
	    FILE_LOG(logDEBUG1) << "want to send " << length << " Bytes";
		if (buf==NULL) return -1;

		total_sent=0;

		int tcpfd = sockfd.fd;

		switch(protocol) {
		case TCP:
			tcpfd = (is_a_server ? sockfd.newfd : sockfd.fd);
			if (tcpfd<0) return -1;
			while(length>0){
				nsending = (length>packet_size) ? packet_size:length;
				nsent = write(tcpfd,(char*)buf+total_sent,nsending);
				if(is_a_server && nsent < 0) {
				    FILE_LOG(logERROR) << "Could not write to socket. Possible client socket crash";
					break;
				}
				if(!nsent) break;
				length-=nsent;
				total_sent+=nsent;
			}
			break;
		case UDP:
			if (sockfd.fd<0) return -1;
			while(length>0){
				nsending = (length>packet_size) ? packet_size:length;
				nsent = sendto(sockfd.fd,(char*)buf+total_sent,nsending, 0, (struct sockaddr *) &clientAddress, clientAddress_length);
				if(!nsent) break;
				length-=nsent;
				total_sent+=nsent;
			}

			break;
		default:
			;
		}
		FILE_LOG(logDEBUG1) << "sent "<< total_sent << " Bytes";
		return total_sent;
	}

	char lastClientIP[INET_ADDRSTRLEN];
	char thisClientIP[INET_ADDRSTRLEN];
	int differentClients;

private:
	/**
	 * Class to close socket descriptors automatically
	 * upon encountering exceptions in the genericSocket constructor
	 */
	class mySocketDescriptors {
	public:

		/** Constructor */
		mySocketDescriptors():fd(-1), newfd(-1){};
		/** Destructor */
		~mySocketDescriptors() {
			// close TCP server new socket descriptor from accept
			if (newfd >= 0) {
				close(newfd);
			}
			// close socket descriptor
			if (fd >= 0) {
				close(fd);
			}
		}
		/** socket descriptor */
		int fd;
		/** new socket descriptor in TCP server from accept */
		int newfd;
	};

protected:
	int portno;
	communicationProtocol protocol;
	int is_a_server;
	mySocketDescriptors sockfd;
	int packet_size;
	struct sockaddr_in clientAddress, serverAddress;
	socklen_t clientAddress_length;
	char dummyClientIP[INET_ADDRSTRLEN];

private:
	int nsending;
	int nsent;
	int total_sent;
	int header_packet_size;
	uint64_t actual_udp_socket_buffer_size;
};